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Trichoderma asperellum (NVTA2) as a potential antagonist for the management of stem rot in carnation under protected cultivation
Abstract
In the present investigative study, fifty Trichoderma spp. (Persoon) were isolated from the rhizosphere of various crop plants. Their potential, as an antagonist was assessed against S. sclerotiorum (Lib.) de Bary, causing stem rot of carnation (Dianthus caryophyllus L.). T. asperellum (NVTA2) was superior in inhibiting the growth and development of stem rot pathogen up to 53.7 per cent in vitro. Seven Trichoderma species with greatest antagonistic potential were identified up to species level through molecular characterization. They were identified as T. asperellum (NVTA1, NVTA2), T. harzianum (NVTH1, NVTH2), T. citrinoviride (NVTC1, NVTC2), and T. erinaceum (NVTE1). Effective strains were screened for the presence of cellobiohydrolase (cbh1) and endochitinase (ech42) genes through PCR. Among the seven strains, T. asperellum (NVTA2) alone had both genes. Crude metabolite extracted from T. asperellum (NVTA2), effectively inhibited the mycelial growth of S. sclerotiorum up to 374.4 mm². GC/MS profiling of crude extract revealed the presence of antifungal compounds including aliphatic hydrocarbons, terpenes and fatty acids. Root dipping and soil application of talc formulations of the seven Trichoderma spp. revealed that T. asperellum (NVTA2) effectively suppressed disease incidence up to 11.8 (PDI-Percent Disease Incidence) compared to the control (37.9 PDI), resulting in approximately 69% reduction. More over NVTA2 also promoted plant growth that resulted in increase in shoot numbers (6.60/plant), stalk length (72.7 cm) and flower yield (205.9 numbers/m²), which was comparatively greater than control.
... The eluted NVOC compounds from hyperparasitized region, antagonist control and pathogen control were analysed through GC/MS (GC Clarus 500 Perkin Elmer analysis). The compounds were identified through NIST MS Search version 2.2, 2005 (Vinodkumar et al. 2017). The mode of action and the metabolic pathway of compounds were identified from MetaCyc database collection. ...
... Three replications were maintained for each treatment. The samples were analysed through GC/MS (GC Clarus 500 Perkin Elmer analysis, US) and identified with NIST Ver.2005 MS data library (Vinodkumar et al. 2017). ...
... Emergence of conidiogenous cells with conidia of the antagonist along the hyphae of the pathogen was also observed. Vinodkumar et al. (2017) reported that T. asperellum-NVTA2 colonized sclerotial bodies and the entire surface of the sclerotia was covered up with abundant sporulation under SEM. Further, the conidia of T. asperellum (NVTA2) was observed to be lodged over the hyphae S. sclerotiorum. ...
Trichoderma spp. effectively inhibited mycelial growth of Fusarium oxysporum f. sp. cucumerinum F1, egg hatchability and juvenile mobility of M. incognita. Field emission scanning electron microscope (FESEM) studies revealed that Trichoderma koningiopsis TRI 41 effectively hyperparasitized and lysed the mycelium of F. oxysporum f. sp. cucumerinum F1, egg mass and individual eggs of root-knot nematode. Further, GC–MS profiling of the agar plugs, excised from the point of hyperparasitism by TRI 41, from the dual plate assay revealed a shift in the non-volatile organic compounds (NVOC) profile. In vitro, TRI 41 produced maximum indole acetic acid (IAA) (15.25 µg/ml) and gibberellic acid (GA) (10.40 µg/ml) in PDB. T. koningiopsis TRI 41 increased the root length (28.74 cm), shoot length (14.64 cm) and stem girth (1.76 cm) of cucumber seedlings to the maximum in vermicompost:soil:sand medium. Furthermore, TRI 41 influenced the root architecture of cucumber plants and altered the root exudate pattern in the rhizosphere of 35-day-old cucumber seedlings. Various non-volatile organic compounds with antifungal and antibacterial activity were detected in the rhizosphere. Under field conditions, seed treatment with the consortia of the isolates, including T. koningiopsis TRI 41, Trichoderma asperellum TRI 15 and Trichoderma asperelloides TNAU Tad 1 @ 1 ml/kg of seed (0.1%) applied as soil drenching (100 ml of gel formulation in 100 L of water over 1000 m² area of polyhouse), indicated that the incidence of fungal nematode complex was reduced to 13.45% with 80.0 fruits/plant with a mean yield of 15.01 t/1000m². For instance, the untreated control was reported with 41.32 percent disease incidence, 52.0 fruits/plant with a mean yield of 10.20 t/1000m².
... Trichoderma species are widely considered potential biological control agents (BCAs) against several plant diseases due to their unique characteristics. For instance, they can produce bioactive secondary metabolites [1], compete for nutrients and space [2,3], induce plant defensive mechanisms [2,4,5], and promote plant growth [6]. They also feature mechanisms such as antibiosis by producing extracellular cell wall-degrading enzymes [3,7] and mycoparasitism [8]. ...
... Such ability to produce VOCs is found in plants [14] and in microorganisms [15]. Recent publications have shown that the VOCs released by Trichoderma display antifungal activities [1,4,6] and promote plant growth [16]. ...
... In this study we found T. asperelloides also produces 6-PP ( Figure 8). 6-PP and its analogs have shown antifungal activity against plant pathogens [6,35]. However, herein, the antifungal ability of each commercial compound was lower than of the VOCs emitted by T. asperelloides PSU-P1. ...
Fungal volatile organic compounds (VOCs) emitted by Trichoderma species interact with a plant host and display multifaceted mechanisms. In this study, we investigated the antifungal activity of VOCs emitted by Trichoderma asperelloides PSU-P1 against fungal pathogens, as well as the ability of VOCs to activate defense responses and to promote plant growth in Arabidopsis thaliana. The strain’s VOCs had remarkable antifungal activity against fungal pathogens, with an inhibition range of 15.92–84.95% in a volatile antifungal bioassay. The VOCs of T. asperelloides PSU-P1 promoted the plant growth of A. thaliana, thereby increasing the fresh weight, root length, and chlorophyll content in the VOC-treated A. thaliana relative to those of the control. High expression levels of the chitinase (CHI) and β-1,3-glucanase (GLU) genes were found in the VOC-treated A. thaliana by quantitative reverse transcription polymerase chain reaction (RT-PCR). The VOC-treated A. thaliana had higher defense-related enzyme (peroxidase (POD)) and cell wall-degrading enzyme (chitinase and β-1,3-glucanase) activity than in the control. The headspace VOCs produced by PSU-P1, trapped with solid phase microextraction, and tentatively identified by gas chromatography–mass spectrometry, included 2-methyl-1-butanol, 2-pentylfuran, acetic acid, and 6-pentyl-2H-pyran-2-one (6-PP). The results suggest that T. asperelloides PSU-P1 emits VOCs responsible for antifungal activity, for promoting plant growth, and for inducing defense responses in A. thaliana.
... Trichoderma species are generally known as biological control agents (BCAs) against several plant diseases. Several Trichoderma species have multifaceted actions including parasitism (Matroudi et al., 2009;Monteiro et al., 2010), antibiosis (Howell, 1998), emission of volatile antifungal compounds (Dennis and Webster, 1971;Vinodkumar et al., 2017;Sunpapao et al., 2018), production of defense-related enzymes (Matroudi et al., 2009;Ting and Chai, 2015;Asad et al., 2015), induction of defense response (Singh et al., 2013;Sunpapao et al., 2018) and systemic resistance in plants (Hoitink et al., 2006;Mathys et al., 2012), as well as promoting plant growth (Conteras-Conrnejo et al., 2009;Vinodkumar et al., 2017). In agriculture, Trichoderma species are often added to soil or to hydroponic systems to increase biomass and control some soil-borne pathogens. ...
... Trichoderma species are generally known as biological control agents (BCAs) against several plant diseases. Several Trichoderma species have multifaceted actions including parasitism (Matroudi et al., 2009;Monteiro et al., 2010), antibiosis (Howell, 1998), emission of volatile antifungal compounds (Dennis and Webster, 1971;Vinodkumar et al., 2017;Sunpapao et al., 2018), production of defense-related enzymes (Matroudi et al., 2009;Ting and Chai, 2015;Asad et al., 2015), induction of defense response (Singh et al., 2013;Sunpapao et al., 2018) and systemic resistance in plants (Hoitink et al., 2006;Mathys et al., 2012), as well as promoting plant growth (Conteras-Conrnejo et al., 2009;Vinodkumar et al., 2017). In agriculture, Trichoderma species are often added to soil or to hydroponic systems to increase biomass and control some soil-borne pathogens. ...
... They are produced by plants (Dudareva et al., 2006) and microorganisms (Campos et al., 2010). They are chemically diverse and include aliphatic hydrocarbons, terpenes and fatty acids (Vinodkumar et al., 2017). It has been reported that the VOCs released by Trichoderma play an important role in its antifungal activity (Vinodkumar et al., 2017;Sunpapao et al., 2018); they can induce systemic resistance (Kishimoto et al., 2005;Yi et al., 2009) and promote plant growth (Vinale et al., 2008). ...
Trichoderma species are applied as biological control agents and biofertilizers to control plant diseases and enhance crop yields. The ability to inhibit pathogens, induce defense responses, and promote plant growth can result from the production of volatile organic compounds (VOCs). In this study, we evaluated the effects of VOCs from Trichoderma asperellum T1 on those multifaceted actions in lettuce. The VOCs released by T. asperellum T1 inhibited fungal growth of two leaf spot fungal pathogens, Corynespora cassiicola and Curvularia aeria. Lettuces responded to VOCs by increasing activities of the cell-wall degrading enzymes chitinase and β-1,3-glucanase to 1.26 U mL⁻¹ and 4.45 U mL⁻¹, respectively, above those in the control. Accumulation of cell-wall degrading enzymes in lettuce that had been treated with VOCs resulted in morphological changes to fungal cell-walls. Exposure to the VOCs emitted by T. asperellum T1 significantly increased numbers of leaves and roots, plant biomass and total chlorophyll content in lettuce. Furthermore, GC/MS analysis revealed that T. asperellum T1 emitted 22 volatile compounds, which are involved in antifungal activity, inducing defense responses, and promoting growth in lettuce.
... Trichoderma species are known as biological control agents (BCAs) that control several plant diseases by capacity to produce antibiosis, compete for nutrients and space, release enzymes, and promote plant growth and plant defense mechanisms [4][5][6]. Some studies have shown that Trichoderma spp. ...
... Application of spore suspension as foliar spray directly reduced disease severity index on lettuce leaves (Table 2). Several studies have shown that direct application of antagonistic microorganisms reduces and delays disease symptoms [6,31,39]. For instance, the application of Paenibacillus lentimorbus B-30488r as foliar spray reduced disease incidence and induced plant resistance [39]. ...
... For instance, the application of Paenibacillus lentimorbus B-30488r as foliar spray reduced disease incidence and induced plant resistance [39]. Application of T. asperellum (NVTA2) suppressed incidence of stem rot in carnation [6]. Furthermore, Sunpapao et al. [31] demonstrated that foliar spray of Trichoderma spore suspension reduced disease severity in oil palm seedlings as well as activated defense related enzymes, such as phenylalanine ammonia lyase, peroxidase, and polyphenol oxidase. ...
Leaf spot, caused by Corynespora cassiicola and Curvularia aeria, is a major disease of lettuce that results in the reduction of the quality and the quantity of lettuce production. Primary in vitro examination revealed that Trichoderma sp. T1 inhibited the mycelial growth of C. cassiicola and C. aeria by 83.79% and 85.71%, respectively, in dual culture assays. Gel diffusion showed cell-free culture filtrate of Trichoderma sp. T1 inhibited C. cassiicola and C. aeria by 50.38% and 53.97%, respectively. Based on the ITS gene sequence, an effective T1 isolate was identified as Trichoderma asperellum. Treatments of lettuce plants with spore suspension of T. asperellum T1 induced defense-related enzymes such as peroxidase and polyphenol oxidase, and the cell wall degrading enzymes β-1,3-glucanase and chitinase in the plants. The activities of β-1,3-glucanase, chitinase, peroxidase and polyphenol oxidase were higher at 24 and 48 h after treatment with spore suspension of T. asperellum T1 than in the control group. Crude extract from inoculated lettuce caused morphology changes in fungal mycelia. In addition, reduction of disease severity was observed in lettuce pretreated with T. asperellum T1. The obtained results suggest that T. asperellum T1 efficiently controlled leaf spot and induced defense responses in lettuce.
... Cell wall lysis and coiling of host hyphae by antagonist T. harzianum were observed by Inbar et al. (1994). Similar findings were reported by Vinodkumar et al. (2017) who observed the colonization of T. asperellum-NVTA2 on sclerotial bodies of S. sclerotiorum through SEM. Choudary et al. (2007) observed the metabolite produced from T. harzianum, which completely inhibited the mycelial growths of F. oxysporum, S. rolfsii and R. solani, respectively. ...
... ciceri by non-volatile organic metabolites of Trichoderma isolates. Vinodkumar et al. (2017) found a good inhibitory effect of cell-free crude extract from T. asperellum NVTA2 on the mycelial growth of S. sclerotiorum. Maddila et al. (2016) reported the antibacterial and antifungal activity of Benzothiazole compounds. ...
Abstract
Background: Sclerotinia sclerotiorumis the causal agent of white mould, stem and head rot diseases on a wide variety, including cabbage in the feld and storage. Control of this pathogen by using commercial disease management
methods is extremely difcult. Therefore, this study was performed to identify the potential biological control agent.
Results: The antagonist fungal isolates, a mycoparasite of S. sclerotiorum, were isolated and described as KET Cm1,
PAL Cm 2 and TDK Cm 3. They were subjected to morphological and microscopic observation. The growth of antagonist fungal isolates on diferent media revealed that PDA and half-strength Czapek dox agar medium showed the
maximum mycelial growth (28.67 and 28.33 mm) and pycnidial production in the PDA medium. The studies on
pH and temperature found that growth and sporulation of the antagonist fungal isolates were optimum at pH 5.5
(34 mm) and 20 °C. The molecular confrmation of antagonist fungal isolates was carried out using ITS 1 and ITS 4
primers, which target 18S-28S rRNA gene fragment. The isolates were partially sequenced and showed that more
than 99% identity with Coniothyrium minitansalready exist in the NCBI database. The accession numbers (MW093134,
MW111282 and MW136938) were obtained for all the three isolates and also confrmed using specifc primers Cm sp
1F and Cm sp 1R. Among the tested isolates, the antagonistic activity of C. minitansTDK Cm 3 showed the maximum
mycelial growth inhibition of 48.8% S. sclerotiorumand was used for further studies. Penetration and formation of
appressoria on the hyphae of S. sclerotiorumby C. minitansisolate TDK Cm 3 were observed through the scanning
electron microscope. The ethyl acetate fractions of TDK CM 3 isolate were evaluated against S. sclerotiorumby agar
well difusion assay, paper disc assay and poison food technique in vitro. Through GC–MS analysis, the efective antifungal compounds were identifed.
Conclusion: The present study focused on the identifcation and characterization of efective Coniothyriumisolates
as eco-friendly, integrated disease management strategies against cabbage head rot disease.
Keywords: Sclerotinia sclerotiorum, Media, pH, Temperature, Dual plate technique, SEM, GC–MS
... which depicts them as potential competitors among other biocontrol agents in the soil Mukherjee et al., 2012). Trichoderma VOCs can aid various signaling in plants by priming them against future pathogen attack (Boots et al., 2014;Vinodkumar et al., 2017;Sunpapao et al., 2018). Recently, few research groups made effort to study the diversity and biological roles of Trichoderma VOCs in root development, physiological alterations, hormonal pathways, plant growth promotion and inhibition the growth of plant pathogens including fungal, insect and aphids (Chen et al., 2016;Li et al., 2018;Guo et al., 2019;Coppola et al., 2019). ...
... Several other studies also reported production of different functional group compounds such as alcohols, pyrans, aldehydes, ketones, fatty acids, etc. from Trichoderma spp. (Vinodkumar et al., 2017;Sunpapao et al., 2018;Nagamani et al., 2017;Kumari et al., 2019). The production of a wide array of volatile compounds are depend on species, strain, substrate concentration, presence of pathogen and various other abiotic factors (Wheatley, 2002;Insam and Seewald, 2010). ...
Microbial volatile organic compounds (mVOCs) have great potential in plant ecophysiology, yet the role of belowground VOCs in plant stress management remains largely obscure. Analysis of biocontrol producing VOCs into the soil allow detailed insight into their interaction with soil borne pathogens for plant disease management. A root interaction trial was set up to evaluate the effects of VOCs released from Trichoderma viride BHU-V2 on soil-inhabiting fungal pathogen and okra plant growth. VOCs released into soil by T. viride BHU-V2 inhibited the growth of collar rot pathogen, Sclerotium rolfsii. Okra plants responded to VOCs by increasing the root growth (lateral roots) and total biomass content. VOCs exposure increased defense mechanism in okra plants by inducing different enzyme activities i.e. chitinase (0.89 fold), β-1,3-glucanase (0.42 fold), peroxidase (0.29 fold), polyphenol oxidase (0.33 fold) and phenylalanine lyase (0.7 fold) when inoculated with S. rolfsii. In addition, T. viride BHU-V2 secreted VOCs reduced lipid peroxidation and cell death in okra plants under pathogen inoculated condition. GC/MS analysis of VOCs blend revealed that T. viride BHU-V2 produced more number of antifungal compounds in soil medium as compared to standard medium. Based on the above observations it is concluded that okra plant roots perceive VOCs secreted by T. viride BHU-V2 into soil that involved in induction of plant defense system against S. rolfsii. In an ecological context, the findings reveal that belowground microbial VOCs may play an important role in stress signaling mechanism to interact with plants.
... Elad (2000) considered that induced resistance was the main mode of action of T. harzianum against powdery mildew fungi. Another species, T. asperellum, has been used as a biocontrol agent to control Pythium myriotylum, which causes root rot in cocoyam (Mbarga et al. 2012), and Sclerotium sclerotiorum, which causes stem rot in carnation (Vinodkumar et al. 2017). Trichoderma asperellum reduced conidial germination of Leveillula taurica, causing powdery mildew on pepper (López et al. 2019). ...
... It has been reported that the VOCs released by Trichoderma spp. play an important role in its antifungal activity (Vinodkumar et al. 2017;Sunpapao et al. 2018); they can induce systemic resistance (Yi et al. 2009) or promote plant growth (Vinale et al. 2006). The Trichoderma genus employs several modes of action contributing to biocontrol activity, and these modes vary much depending on the strain and environmental conditions. ...
The protective effects of Trichoderma asperellum IZR D-11 as a biocontrol agent against the powdery mildew Erysiphe alphitoides infecting leaves of Quercus robur were evaluated for the first time. A strain of Trichoderma had earlier been isolated in Belarus, and was identified in this study as T. asperellum by sequencing of three genomic markers: internal transcribed spacer, translation elongation factor 1 alpha and RNA polymerase II subunit 2, with over 99.2% identity to corresponding genomic sequences in GenBank. When applied once in the first year just after onset of powdery mildew disease, T asperellum IZR D-11 reduced disease progression and continued to reduce powdery mildew levels during the following three years. Photosynthetic activity as represented by chlorophyll fluorescence measured in oak seedlings was increased in treated plants, and greater assimilate production was also found. The use of this antagonistic fungus increased the total water content in oak leaves suggesting that T. asperellum IZR D-11 can serve as a preventive measure to reduce energy losses in the process of water transpiration. GC-MS analysis detected 49 volatile compounds in the headspace of pure cultures of T. asperellum . Sesquiterpenes represented mainly by daucene, dauca-4(11),8-diene and isodaucene were the largest group of compounds emitted. We speculate that these volatiles from T. asperellum IZR D-11 may be involved in induced resistance in the plant, but further research is needed. The above results suggest that T. asperellum strain IZR D-11 has potential as a biocontrol agent of oak powdery mildew in forest nurseries.
... Thus, Trichoderma spp. can inhibit the successful colonization and growth of plant pathogens in rhizosphere soil (Vinodkumar et al. 2017). In addition, regardless of the presence or absence of pathogens, Trichoderma spp. ...
... T. asperellum NVTA2 effectively inhibited mycelial growth of Sclerotinia sclerotiorum as well as arrested sclerotial production (Vinodkumar et al. 2017). Similarly, in our study, T. asperellum strain GDFS1009 effectively inhibited mycelial growth and mycoparasitized the hyphae of F. graminearum, but little is known regarding its value in the control of stalk rot in maize. ...
Of diseases affecting maize (Zea mays), Fusarium graminearum is one of the most common pathogenic fungi that cause stalk rot. In the present study, the Trichoderma asperellum GDFS1009 strain was shown to be an effective biocontrol agent against stalk rot. In a confrontation culture test, Trichoderma strain displayed an approximately 60% inhibition rate on the mycelial growth of F. graminearum. In pot trials, the application of 2 g/pot of T. asperellum GDFS1009 granules had the best control effect on stalk rot at the seedling stage (up to 53.7%), while the average plant height and fresh weight were also significantly improved. Additionally when fertilizer was added at 8 g/pot, the application of 3 g/pot of Trichoderma granules had the best control effect on maize stalk rot (40.95%). In field trials, when inoculating F. graminearum alone, the disease index for inoculating was 62.45, but only 31.43 after treatment with T. asperellum GDFS1009 granules, suggesting a control efficiency of 49.67%. Furthermore, in a naturally F. graminearum-infected field, Trichoderma granules, when applied for 3 consecutive years, showed significant control of stalk rot and increased yields.
... Furthermore, their physical properties allow them to diffuse and vaporize through the outer environment, thereby facilitating distant biological functions (Peñuelas et al. 2014). They are chemically diverse and include terpenes, acetoin, aliphatic hydrocarbons, and fatty acids (Vinodkumar et al. 2017). Trichoderma species have been shown to release VOCs and play an important role in plant growth promotion (Vinale et al. 2008), antifungal activity, and systemic resistance induction (Sunpapao et al. 2018;Yi et al. 2009). ...
Backgrounds and aims
Fungi produce an extensive variety of volatile organic compounds (VOCs) that play crucial roles in promoting plant growth and suppressing soil-borne fungal pathogens; however, our knowledge in this area is still limited.
Methods
In this study, we aimed to isolate novel fungal strains from green manure-incorporated soils by serial dilution plating on Martin agar plates and to analyse the functions of VOCs produced by them. We examined whether VOCs emitted by the novel fungal strains affect the growth and development of Lactuca sativa and mediate antifungal activity against Fusarium oxysporum.
Results
In vitro study, the fungal strains released a variety of volatile compounds. Four strains (H1 Penicillium spp., H2 Clonostachys spp., H19 Didymella spp., H21 Talaromyces spp.) from leguminous and four strains (B3 Purpureocillium spp., B4 Stachybotrys spp., B8 Trichoderma spp., and B13 Aspergillus spp.) from non-leguminous green manure-incorporated soils showed plant growth-promoting ability in terms of fresh shoot biomass and the number of roots by releasing VOCs in the shared atmosphere. Exposure to VOCs emitted by only B7 (Mucor circinelloides) suppressed the growth of F. oxysporum compared to that from exposure to the remaining strains and the control. A two-compartment plate assay was conducted to screen plant growth-promoting and suppression of plant pathogenic fungus by fungal strains based on VOC emission. Furthermore, gas chromatography-mass spectrometry analysis revealed that the fungal strains released 12 volatile compounds, including 1-butanol, 2-pentanone, and nonanal.
Conclusions
The fungal strains isolated from different green manures emitted several different VOCs that stimulated plant growth and inhibit the growth of pathogenic fungus.
... Only a few fungi can directly parasitize untreated sclerotia [53,54] and as a result, untreated sclerotia can become infected with mycoparasitic fungi. Similar findings were reported by Vinodkumar et al., (2017) [55] who observed the colonization of T. asperellum NVTA2 on sclerotial bodies of S. sclerotiorum through scanning electron microscopy. ...
Clonostachys rosea, an ascomycetous, omnipresent, cellulose-decaying soil fungus, has been reported to be a well-known mycoparasitic biological control agent. In this study, we isolated C. rosea, a mycoparasitic fungus for the first time in India from sclerotia of the notorious plant pathogen Sclerotinia sclerotiorum, causing head rot disease in cabbage. A total of five mycoparasitic fungi were isolated from the sclerotial bodies of S. sclerotiorum (TNAU-CR 01, 02, 03, 04 and 05). All the isolates were tested under morpho-molecular characterization. Among them, TNAU-CR 02 showed the greatest mycelial inhibition of 79.63% over the control. Similarly, the SEM imaging of effective C. rosea isolates indicated the presence of numerous conidia destroying the outer cortex layers of sclerotia. Metabolite fingerprinting of C. rosea TNAU-CR 02 identified 18 chemical compounds using GC-MS analysis. The crude antibiotics of C. rosea TNAU-CR 02 were verified for their antifungal activity against S. sclerotiorum and the results revealed 97.17% mycelial inhibition compared with the control. Similarly, foliar application of TNAU-CR 02 at 5 mL/litre on 30, 45 and 60 days after transplanting showed the lowest disease incidence of 15.1 PDI compared to the control. This discovery expands our understanding of the biology and the dissemination of C. rosea, providing a way for the exploitation of C. rosea against cabbage head rot pathogens.
... show potential for plant growth promotion [6,7] and are the main species used for biological control of phytopathogens. Trichoderma can interact with phytopathogens through different mechanisms, such as parasitism, antibiosis, and competition, and have a resistance-inducing effect on plants against diseases [8,9,10]. ...
Microencapsulation of microorganisms has been studied to increase product shelf life and stability to enable the application in sustainable agriculture. In this study, the microencapsulation of Trichoderma asperellum conidia by spray drying (SD) was evaluated. The objective was to assess the effect of drying air temperature and wall material (maltodextrin DE20, MD20) concentration on the microencapsulation and to identify the optimum conditions to produce, in high yield, microparticles with low moisture, high conidial viability and conidial survival. Microparticles were characterized in terms of morphology, particle size, and shelf life. A central composite rotatable design (CCRD) was used to evaluate the effect of operating parameters on drying yield (DY), moisture content, conidial viability (CV), and conidial survival (SP). Microencapsulation experiments were carried out under optimum conditions to validate the obtained model. The optimum temperature and MD20/conidia dry weight ratios were 80 °C and 1:4.5, respectively, which afforded a drying yield of 63.85 ± 0.86%, moisture content of 4.92 ± 0.07%, conidial viability of 87.10 ± 1.16%, and conidial survival of 85.78 ± 2.88%. Microencapsulation by spray drying using MD20 as wall material extended the viability of conidia stored at 29 °C compared with the control. The mathematical models accurately predicted all the variables studied, and the association of the microencapsulation technique using DE20 maltodextrin was able to optimize the process and increase the product’s shelf life. It was also concluded that high inlet air temperatures negatively affected conidia survival, especially above 100 °C.Graphical abstract
... Fusarium oxysporum f. melongenaeCherkupally et al., (2017) T. asperellum,T. harzianum, T. citrinoviride, and T. erinaceum Carnation Sclerotinia sclerotiorumVinodkumar et al., (2017) T. aureoviride, T. harzianumCassava Fusarium solani, Scytalidium lignicola Da Silva et al., (2016); Silva et al., (2017) T. asperellum, T. viride, T. harzianum, T. reesei, T. virens Chilli Fusarium oxysporum, Phytophthora capsici, Rhizoctonia solani Jiang et al., (2016); Vinodkumar et al., (2017) T. virens, T. koningii, T. viride, T. harzianum Groundnut Athelia rolfsii (as Sclerotium rolfsii) Hirpara et al., (2016); Hirpara et al., (2017) T. asperellum, T. harzianum, T. gamsii Maize Fusarium graminearum, Fusarium verticillioides Li et al., (2016); Saravanakumar et al., (2017); He et al., (2019); Galletti et al., (2020); Lu et al., (2020) T. harzianum Onion Stromatinia cepivora, Sclerotium rolfsii (as Sclerotium rolfsii) Zúñiga-Mendoza & Ceja-Torres (2017) T. harzianum Pea Fusarium oxysporum f. pisi Checa et al., (2017) T. atroviride, T. harzianum Rice Rhizoctonia solani, Sarocladium oryzae Bora, (2019); Chaudhary et al., (2020) T. asperelloides, T. koningiopsis, T. atroviride, T. virens, T. harzianum Soybean. Fusarium virguliforme, Macrophomina phaseolina, Sclerotinia sclerotiorum Khaled & Taheri, (2016); Zhang et al., (2016); Haddad et al., (2017); Sumida et al., (2018); Pimentel et al., (2020) T. harzianum Sugarcane Colletotrichum falcatum Elamathi et al., (2018) T. asperellum, T. harzianum, T. viride Tomato Botrytis cinérea, Fusarium oxysporum f. lycopersici Moosa eta al., (2017); Kuzmanovska et al., (2018) Trichoderma sp., T. harzianum, T. koningii Wheat Bipolaris sorokiniana, Fusarium sudanense, F. culmorum, F. graminearum and F. verticillioides, Zymoseptoria tritici, Cochliobolus sativus, Alternaria alternata Dendouga et al., (2016); Stocco et al., (2016); El-Gremi et al., (2017); Bhandari et al., (2017); Larran et al., (2020)T. ...
A better understanding of the use of biochar with Trichoderma spp. (TRI), considered the most studied tool for biological control, would increase our ability to set priorities. However, no studies exist using the two inputs on plant disease management. Here, we hypothesized that biochar and TRI would be used for the management of soilborne plant pathogens, mainly due to changes in soil properties and its interactions. To test this hypothesis, this review assesses papers that used biochar and TRI against plant diseases and we summarize the handling mechanisms for each input. Biochar acts by mechanisms: induction to plant resistance, sorption of allelopathic and fungitoxic compounds, increase of beneficial microorganisms, changes the soil properties that promote health and nutrient availability. Trichoderma as biocontrol agents by different mechanisms: mycoparasitism, enzyme and secondary metabolic production, plant promoter agent, natural decomposition agent, and biological agent of bioremediation. Overall, our findings expand our knowledge about the reuse of wastes transformed in biochar combined with Trichoderma has potential perspective to formulate products as alternative management tool of plant disease caused by soilborne fungal pathogen and add important information that can be suitable for development of strategy for use in the global health concept.
... However, in our study, chit42 was not detected. This finding was also reported by Vinodkumar et al. (2017). Despite this, the absence of this gene is not determinant to chitin degradation during a mycoparasitic event due to the fact that to break down the cell wall of fungi, the combination of a set of chitinases is required (Carsolio et al., 1999). ...
Peanut brown root rot is a rhizoplane disease caused by the soil-borne pathogen Fusarium solani. The objective of this study was to determine the genetic and physiological mechanisms of T. harzianum ITEM 3636 involved in the antagonism against the phytopathogenic fungi F. solani, and to evaluate its biocontrol effect on peanut brown root rot in greenhouse assays. The in vitro tests showed that T. harzianum ITEM 3636 exert its antagonistic activity against F. solani RC386 through the synthesis of secondary metabolites, high enzymatic activity (chitinases 0.054 U ml⁻¹, N-Acetyl-β-D-glucosaminidases 0.21 U ml⁻¹, proteases 0.063 U ml⁻¹ and glucanases 0.139 U ml⁻¹) and important modifications in the pathogen hyphae. In the gene expression analysis of biocontrol-associated genes (prb1, chit33, bgn13.1) an upregulation was detected when T. harzianum ITEM 3636 interacted with F. solani RC386 mycelia. The greenhouse assays showed that the previous application of T. harzianum ITEM 3636 on peanut seeds generated a protective effect in peanut plants which were then affected by F. solani, since it reduced both the incidence and the severity of peanut brown root rot, by 3.8% and 63.98% respectively. In conclusion, T. harzianum ITEM 3636 strain could be considered as a biofungicide against F. solani in microbial formulations intended for peanut plants.
... Trichoderma sp. is one type of saprophytic soil fungus that has the ability to suppress through the activity of extracellular compounds it produces and is mycoparasitic by directly attacking and inhibiting pathogenic fungi that cause plant disease [2][3][4] so that this fungus provides great benefits for plants. and able to produce growth-stimulating compounds for plants [5][6][7]. ...
This study aims to determine the effect of Trichoderma asperellum Tc-Clkt-01 and shallot extract and their interaction on the success of grafting mango seedlings. The factorial experiments in this study were arranged in a completely randomized design (CRD). The first factor is Trichoderma consisting of without and with Trichoderma . The second factor was the concentration of shallot extract above: 0, 15, and 30 ml.l ⁻¹ . With three replications, 18 experimental units were obtained. The variables observed were: shoot appearance time (days) and shoot growth length (mm) one to four weeks after grafting. All data from the observations were analyzed using ANOVA at the 5% level; the average of each treatment was compared with controls (without Trichoderma and without red onion extract). Trichoderma sp. isolate Tc-Clkt-01 accelerated the emergence time of shoots by 26.87% and increased shoot length growth by 41.76-43.71% compared to the control. Onion extract at a concentration of 15 ml.L ⁻¹ accelerated the emergence of shoots by 10.45% and increased shoot length increase by 20.59% compared to the control. The combination of Trichoderma and shallot extract at a concentration of 30 ml.l ⁻¹ accelerated the emergence of shoots by 23.17% and increased shoot length by 32.94% compared to the control.
... Research and isolation of MO with antifungal properties has become a trend in the development of new methods to substitute the use of synthetic origin compounds [2]. In the bibliography, this antifungal activity has been reported with many MO, just as Brevibacillus laterosporus [13], Trichoderma asperellum [14], Pseudomonas sp. [15], and many acid lactic bacteria (LAB) like Lactobacillus plantarum [16,17], Lactobacillus coryniformis [18], or Leuconostoc mesenteroides [4]. ...
Fungal spoilage is one of the main reasons of economic losses in the food industry, especially in the wine sector. Consequently, the search for safer and new preservation techniques has gained importance in recent years. The objective of this study was to investigate the antifungal and anti-mycotoxigenic activity from 28 microorganisms (MO) isolated from red grape. The antifungal activity of a cell free supernatant of fermented medium by the isolated MO (CFS) was tested with the agar diffusion method and the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) assay. Additionally, different antifungal compounds from the CFS were identified and quantified (organic acids, phenolic compounds, and volatile organic compounds). Finally, the most active CFS were tested as red grape bio-preservative agents. Results evidenced that CFS fermented by the strain UTA 6 had the highest antifungal activity, above all isolates, and produced a wide pool of antifungal compounds. The use of UTA 6 CFS as bio-preservative agent showed a reduction of 0.4 and 0.6 log10 spores per gram of fruit in grapes contaminated by A. flavus and B. cinerea, respectively. Moreover, UTA 6 CFS treatment reduced the occurrence of aflatoxin B1 and fumonisin (B2, B3, and B4) production in grapes contaminated by 28–100%.
... Tc-Jjr-02 was able to increase the biomass of tobacco seedlings, also similar to T. asperellum isolate RM-28 which increases sorghum-sudangrass seedling biomass (Anam et al., 2019). The characteristics of Tc-Jjr-02 in enhancing plant growth and resilience were represented by the suppression of a similar symptom index shown by T. asperellum TI which induces plant resilience to leaf spot fungi in lettuce (Baiyee et al., 2019) and T. asperellum TC01 on Camellia sinensis seedlings (Shang et al., 2020), and as a control for stem rot in carnation (Vinodkumar et al., 2017). ...
Characterizations of Trichoderma sp. and its effect on Ralstonia solanacearum of tobacco seedlings. This study aims todetermine the molecular-based characteristics of Trichoderma sp. Tc-Jjr-02 and its effect as a biocontrol agent in protecting tobaccoseedlings against bacterial wilt caused by R. solanacearum. The characterization of biocontrol agents was based on morphologicaland molecular data’s observation using microscope and the key of determination. The in vivo experiments was consist of fivetreatments: (1) inoculation of Trichoderma isolates at six hours before R. solanacearum inoculation, (2) inoculation of Trichodermaisolates at six hours after R. solanacearum inoculation (3) simultaneous inoculation of Trichoderma isolates and R. solanacearum,(4) inoculated only with R. solanacearum, and (5) without any inoculation. The experiment was repeated six times. Based onBLAST’s analysis, the Tc-Jjr-02 sequence is in accordance with T. asperellum with 100% Query Cover. Inoculation of T. asperellumTc-Jjr-02 at six hours before and after and simultaneously with pathogens providing protection for young tobacco plants by slowingdown the time for the onset of blight by 100–162%, reducing the symptom index by 56–63%, and increasing the dry weight of plantbiomass by 39–53% compared to tobacco seeds which were only inoculated with R. solanacearum.
... Trichoderma species are widely used to control numerous plant pathogens and reduce disease severity [3,4], due to their capacity for nutrient and space competition [5,6], parasitism [7], secretion of antimicrobial metabolites [7][8][9][10], activation of defense responses [11,12], and promotion of plant growth [8,9,13]. Moreover, metabolites, such as volatile organic compounds (VOCs), secreted from the Trichoderma species have been applied to promote plant growth [8,9,14]. Application of the Trichoderma species has been used to reduce the disease severity of leaf spots on lettuce [12] and sugar beet [15], as well as brown spots on rice [16]. ...
Several mechanisms are involved in the biological control of plant pathogens by the soil-borne Trichoderma spp. fungi. The aim of this study was to characterize a new strain of Trichoderma as a potential biological control agent to control the postharvest anthracnose of chili pepper caused by Colletotrichumgloeosporioides. A total of nine strains of Trichoderma spp. were screened for their antifungal activity using a dual culture assay against C.gloeosporioides. Trichoderma koningiopsis PSU3-2 was shown to be the most effective strain, with a percentage inhibition of 79.57%, which was significantly higher than that of other strains (p < 0.05). In the sealed plate method, T. koningiopsis PSU3-2 suppressed the growth of C.gloeosporioides by 38.33%. Solid-phase microextraction (SPME) was applied to trap volatiles emitted by T. koningiopsis PSU3-2, and the GC/MS profiling revealed the presence of antifungal compounds including azetidine, 2-phenylethanol, and ethyl hexadecanoate. The production of cell-wall-degrading enzymes (CWDEs) was assayed through cell-free culture filtrate (CF) of PSU3-2, and the enzyme activity of chitinase and β-1,3-glucanase was 0.06 and 0.23 U/mL, respectively, significantly higher than that in the control (p < 0.05). Scanning electron microscopy of the mycelium incubated in cell-free CF of T. koningiopsis PSU3-2 showed the abnormal shape of C.gloeosporioides hyphae. Application of T. koningiopsis PSU3-2 by the dipping method significantly reduced the lesion size (p < 0.05) after inoculation with C.gloeosporioides compared to the control, and there was no disease symptom development in T. koningiopsis PSU3-2-treated chili pepper. This study demonstrates that T. koningiopsis PSU3-2 is an effective antagonistic microorganism and a promising biocontrol agent against postharvest anthracnose of chili pepper, acting with multiple mechanisms.
... Tc-Jjr-02 was able to increase the biomass of tobacco seedlings, also similar to T. asperellum isolate RM-28 which increases sorghum-sudangrass seedling biomass (Anam et al., 2019). The characteristics of Tc-Jjr-02 in enhancing plant growth and resilience were represented by the suppression of a similar symptom index shown by T. asperellum TI which induces plant resilience to leaf spot fungi in lettuce (Baiyee et al., 2019) and T. asperellum TC01 on Camellia sinensis seedlings (Shang et al., 2020), and as a control for stem rot in carnation (Vinodkumar et al., 2017). ...
Characterizations of Trichoderma sp. and its effect on Ralstonia solanacearum of tobacco seedlings. This study aims to determine the molecular-based characteristics of Trichoderma sp. Tc-Jjr-02 and its effect as a biocontrol agent in protecting tobacco seedlings against bacterial wilt caused by R. solanacearum. The characterization of biocontrol agents was based on morphological and molecular data's observation using microscope and the key of determination. The in vivo experiments was consist of five treatments: (1) inoculation of Trichoderma isolates at six hours before R. solanacearum inoculation, (2) inoculation of Trichoderma isolates at six hours after R. solanacearum inoculation (3) simultaneous inoculation of Trichoderma isolates and R. solanacearum, (4) inoculated only with R. solanacearum, and (5) without any inoculation. The experiment was repeated six times. Based on BLAST's analysis, the Tc-Jjr-02 sequence is in accordance with T. asperellum with 100% Query Cover. Inoculation of T. asperellum Tc-Jjr-02 at six hours before and after and simultaneously with pathogens providing protection for young tobacco plants by slowing down the time for the onset of blight by 100-162%, reducing the symptom index by 56-63%, and increasing the dry weight of plant biomass by 39-53% compared to tobacco seeds which were only inoculated with R. solanacearum.
... Similarly, bulb treatment with T. harzianum enhanced the plant growth of tuberose and resulted in increased flower production and quality (Nosir 2016). Root dipping and soil application of T. asperellum-based talc formulation effectively suppressed carnation wilt by increasing plant growth, number of shoots, stalk length, and flower yield (Vinodkumar et al. 2017). ...
Fungi being the fifth kingdom of the eukaryotic heterotrophic organism, only 120,000 species have been identified among 1.6 million species distributed worldwide. Despite the huge diversity, the biogeography of fungi is still a neglected area. Among several fungi, the hymenomycetous genus Trichoderma is a predominant cosmopolitan fungus distributed in different soils in different agroclimatic zones. Trichoderma can grow on diversified substrates and has rapid growth with resistance to heavy metals and noxious chemicals. The fungi with their well-developed enzyme system play a vital role in improving both plant and soil health apart from their industrial applications. Besides, the antibiotics and lytic enzymes are used for the management of various plant pathogenic microbes infecting plants. Based on the efficacy of Trichoderma, several products of Trichoderma have been registered both at National and International level. Apart from the beneficial effect, certain species of Trichoderma also act as opportunistic human and plant pathogens. With the increased imports of foreign microbes either as commercial biocontrol products or for the research purpose, there is an increased threat to indigenous microflora.
... Earlier studies showed that Trichoderma spp. were very beneficial fungi and had the ability to control many pathogens by various biological means (Vinodkumar et al. 2017). The modes of action of Trichoderma were competition, antagonism and production of some compounds in the soil against fungal pathogens (Jorge 2014). ...
Sclerotium rolfsii is a soil-borne plant pathogen that causes root diseases in hundreds of plant species. It also causes collar rot disease in chickpea (Cicer arietinum L.). The present pot study was carried out to investigate the effect of soil amendment with dry biomass of a weed Chenopodium album L. and 2 antagonistic fungi namely; Trichoderma harzianum and T. viride on growth and yield of chickpea variety Noor 2009 in soil infected with S. rolfsii. The pathogen contaminated soil was amended either with 1, 2 and 3% C. album dry biomass, T. harzianum and T. viride alone, or combinations of either of the 2 Trichoderma species and plant dry biomass. The lowest shoot and root dry biomass and grain yield of chickpea were recorded in S. rolfsii inoculation alone without any soil amendment (positive control). Plant growth and yield were significantly and gradually increased over positive control with an increase in C. album dry biomass application in the soil. Likewise, soil application of either of the 2 Trichoderma species significantly enhanced plant growth and yield over positive control under biotic stress of S. rolfsii. Combined application of either T. harzianum or T. viride with 3% dry biomass of C. album also proved highly effective in alleviating biotic stress of S. rolfsii on growth and yield of chickpea.
... Similarly, bulb treatment with T. harzianum enhanced the plant growth of tuberose and resulted in increased flower production and quality (Nosir 2016). Root dipping and soil application of T. asperellum-based talc formulation effectively suppressed carnation wilt by increasing plant growth, number of shoots, stalk length, and flower yield (Vinodkumar et al. 2017). ...
... are well known producers of antifungal compounds, such as 6-pentyl-α-pyrone and trichodermaketones, it was expected that Trichoderma species could exhibit antagonistic ability against A. cruciatus and L. thalassiae, which are regarded as pathogenic fungi to algae [25,26]. Similarly, T. asperellum has already been investigated for its antagonistic ability against pathogenic fungi in several previous studies [57][58][59]. In addition, the synergistic effects of antifungal secondary metabolites and enzymes from Trichoderma could provide support to the plant rhizosphere attacked by other pathogenic fungi [21,27]. ...
Microorganisms are regarded as a sustainable source of biologically active molecules. Among them, Trichoderma spp. have been an attractive source of biological compounds. However, the study of marine-derived Trichoderma has developed slowly because of the difficulty in isolating the fungi. In our study, 30 strains of marine-derived Trichoderma were identified through the translation elongation factor 1-alpha (EF1α) sequences, and their biological activities, such as antioxidant activity by ABTS and DPPH assays, antifungal activity against Asteromyces cruciatus and Lindra thalassiae, and tyrosinase inhibition activity, were investigated. As a result, the 30 marine Trichoderma species were classified into 21 taxa, including three new species candidates. Three strains of T. asperellum showed the highest ABTS radical scavenging activity and antifungal activity. T. bissettii SFC20170821-M05 and T. guizhouense SFC20180619-M23 showed notable DPPH radical scavenging activity and tyrosinase inhibition activity, respectively. This study showed the potential of marine-derived Trichoderma as a source of bioactive compounds.
... For instance, several Trichoderma species could produce volatile antibiotics against Rhizoctonia solani (Dennis and Webster, 1971). Furthermore, T. asperellum (NVTA2) produced antifungal compounds including aliphatic hydrocarbons, terpenes and fatty acids that inhibit the mycelial growth of Sclerotinia sclerotiorum causing stem rot on carnation (Vinodkumar et al., 2017). ...
Leaf spot disease causes devastating damage to oil palm seedlings and reduces both quality and quantity of the produced seedlings. This study aimed to apply the selected microorganisms Streptomyces hygroscopicus subsp. angustmyceticus NR8-2, Trichoderma harzianum TM2/1, and endophytic Trichoderma V76-12, to the control of leaf spot disease caused by Curvularia oryzae on oil palm leaves, in vitro, in vivo and in field conditions. The isolate V76-12 inhibited the growth of C. oryzae the most at 85.71% inhibition, followed by the isolates TM2/1 (75.71%) and NR8-2 (72.50%) in dual culture tests. Volatile antifungal effects were observed for V76-12 with 68% inhibition, followed by the isolates TM2/1 (45%) and NR8-2 (10%) in a bioassay. Crude metabolites of the isolates inhibited the mycelial growth of C. oryzae in agar diffusion tests. In pot experiments, the V76-12 gave disease severity index (DSI) of about 21%, similar to that with a reference chemical (20%), whereas TM2/1 and NR8-2 gave 66% and 75%, respectively. In naturally infested cases, oil palm seedlings treated with V76-12 showed 35.33% DSI, which is statistically significantly below those obtained with TM2/1, NR8-2 and the chemical (48.67%, 53.33% and 49.33%, respectively). The control treatment without antagonistic microorganisms gave the most severe DSI at 75.33%. The results also show that treatment with the selected isolates enhanced the activities of phenylalanine ammonia-lyase (PAL), peroxidase (POD), and polyphenol oxidase (PPO) enzymes in the oil palm. The V76-12 isolate was the most effective treatment tested in reducing leaf spot disease of oil palm seedlings, due to its ability to inhibit mycelial growth in vitro, to reduce disease symptoms in vivo and in natural fields, as well as to enhance PAL, POD and PPO activities in the oil palm leaves.
The increase in population and food demand has led to the excessive utilization of chemical fertilizers. These fertilizers, in turn, affected the soil properties and decreased the fertility of the soil. The side effects of these chemicals have forced scientists to focus on plant growth-promoting rhizobacteria (PGPR) for sustainable farming. Some microbes and plants have a mutual relationship, and they use to help each other in various ways Rhi-zobacteria that promote plant growth enhance health of the plant and growth by increasing nutrient accessibility and assisting plants during abiotic and biotic stress. By direct or indirect mechanisms, the bacterial releases of volatile organic compounds (VOCs) are crucial in boosting plant development and disease resistance. The release of a range of low-molecular weight hydrocarbons, including the growth-promoting volatile organic compounds, 3-hydroxy-2-butanone (acetone), 2,3-butanediol, 2-pentylfuran, or dimethylhexadecyl-amine, was found by chemical analysis of bacterial volatile emissions. The plants provide nutrients and shelter to the microbes. Therefore, PGPRs play a vital role in sustainable agriculture In this review, the mechanism of action of VOCs for growth promotion and how they trigger the plant defense mechanism during biotic and abi-otic stress will be addressed.This review will addressthe mechanism of action of VOCs for growth promotion and how they trigger the plant defense mechanism during biotic and abiotic stress.
Two independent experiments were conducted on the effect of various factors, such as cultivars, growth activity of the rootstock and its treatment, with Trichoderma atroviride on graft success and growth of annual beech plants. The first experiment concerned the effect of propagation of five beech cultivars on rootstocks that are active (with growth activity), grown before the treatment in multi-cell plant trays (plastic seedling trays) or bare-root in the dormancy period. The highest success rate of the treatment was observed for dormant (without growth activity) and bare-root rootstocks. However, the best plant growth parameters during the first year of cultivation were observed when grafting active rootstocks obtained from multi-cell plant trays, while the worst results were observed for dormant, bare-root rootstocks. The individual cultivars varied significantly in terms of graft success and continued plant growth. The second experiment concerned the effect of rootstock growth activity and soaking of the rootstock root system in Trichoderma atroviride on graft success, growth parameters, and the intensity of some physiological processes in beech plants. The simultaneous use of both above-mentioned treatments resulted in the most intensive growth and accelerated physiological processes of the plants tested. Inoculation of rootstocks with Trichoderma atroviride did not affect the graft success. On the other hand, the growth activity of rootstocks at the time of grafting increased the success rate of the treatment. The treatments similarly differentiated the results obtained for two beech cultivars tested.
Microencapsulation of biological control agents by spray drying (SD) has been studied as a method for increasing product shelf life and stability to enable the application of microencapsulated agents in sustainable agriculture. In this study, the microencapsulation of Trichoderma asperellum conidia by spray drying was evaluated. The objective was to assess the influence of drying air temperature and wall material (maltodextrin DE20, MD20) concentration on the microencapsulation of Trichoderma asperellum conidia and to identify the optimum conditions to produce. Microparticles were characterized in terms of morphology, particle size, and shelf life. A central composite rotatable design (CCRD) was used to investigate the effect of operating parameters on drying yield (DY), moisture content, conidial viability (CV), and percentage of conidial survival (SP). Microencapsulation experiments were carried out under optimum conditions to validate the obtained model. The optimum temperature and MD20/conidia dry weight ratio were 80°C and 1:4.5, respectively, which afforded a drying yield of 63.85 ± 0.86%, a moisture content of 4.92 ± 0.07%, a conidial viability of 87.10 ± 1.16%, and a conidial survival of 85.78 ± 2.88%. Microencapsulation by spray drying using MD20 as wall material extended the viability of conidia stored at 29°C compared with the control.
The exploitation of antagonistic potential and plant-growth-promoting factors in microorganism is a well-investigated area in modern agriculture for plant protection. Trichoderma spp. is one of the highly potential biocontrol agents exploited for plant disease management and can be easily cultured by producing a rapid growth in the medium with natural conditions. Trichoderma is mostly associated with the plant root system thereby triggering systemic resistance and improving plant nutrient uptake. Several mechanisms have been proposed to explain the biocontrol potential of Trichoderma on the plant host. One factor that provides the beneficial biological activities of Trichoderma spp. is the wide range of metabolites that they produce. These metabolites have been found not only to directly inhibit the growth of the pathogen but also to trigger the defense system in the host plant to increase the disease resistance. Trichoderma spp. produces secondary metabolites in the form of antibiotic compounds, enzymes, toxins, and hormones. This review describes the important secondary metabolites produced by Trichoderma spp. and their ecological functions in the host plant. Many secondary metabolites of Trichoderma may also have antibiotic properties, which enable them to inhibit and/or kill other microorganisms. In addition to direct toxic activity against plant pathogens, biocontrol-related metabolites may increase disease resistance by triggering systemic plant defense activity and/or enhance root and shoot growth. The large-scale application of selected secondary metabolites to induce host resistance and/or to promote crop yield may be an effective alternative to chemicals. We discuss the bioactivity of selected Trichoderma-derived secondary metabolites with a focus on their roles in the interactions of Trichoderma between plants and fungal prey.
A major threat to agriculture is soilborne diseases which extensively decline the crop yield. Control of soilborne phytopathogens is challenging because these pathogens persist for numerous years as sclerotia in soil or in organic matter under numerous environmental conditions. Pathogen management with the application of chemical pesticides imposes environmental threats and is potentially dangerous to humans and other living forms. The employment of biological control agents for disease reduction and improved yield provides an alternative for the chemical pesticides and this is a key aspect of disease management of plant pathogens. Various control agents such as fungi and bacteria are involved in biocontrol activity among control agents, the fungal genus Trichoderma shows a major role in the control of phytopathogens. Trichoderma spp. are extensively applied as biocontrol agents for the management of soilborne phytopathogens in agriculture. The control effects of Trichoderma on soilborne pathogens are higher in comparison to synthetic fertilizers and they exhibit prolonged persistence in soil post application. The mechanisms of biocontrol exerted by Trichoderma are generally antibiosis, mycoparasitism, and competition for nutrients, induced defense responses, or systemic resistance responses in the plants. Trichoderma spp. are well known for the secretion of cell wall degrading enzymes (CWDEs) and these enzymes play key roles in the degradation of the cell wall of the pathogens and the biocontrol mechanism. Several genes and their products govern the biocontrol activity and are called biocontrol genes which are crucial for Trichoderma as a potent biological control agent.
In the fungal kingdom, Trichoderma is the most exploited biocontrol agent. It is known for its ability to colonize plant root, suppress many plant pathogens, and act as inducer of systemic resistance in plant and is also involved in growth promotional activities. The knowledge on rhizosphere signalling between plant root–Trichoderma interaction is highly essential to trigger the immune response and to improve plant health. There is a bidirectional perception of signal molecules for the successful establishment of its association. The interaction of Trichoderma starts with contact to the root surface, followed by attachment, penetration, and colonization. The signal molecules from root exudates and secretomes of Trichoderma are essential for successful accomplishment of a symbiotic relationship. Among the complex composition of root exudates, sucrose plays a vital role in the attraction of Trichoderma to the plant root system. The hydrophobin and swollenins and cysteine-rich proteins secreted by Trichoderma plays a role in each step towards successful plant root interaction. This review enlightens our knowledge on root–Trichoderma interaction and its ability to overcome plant’s defense mechanism to prove itself as a “true friend” to the plant system and for improvement of soil and plant health.
The Trichoderma genus is an inhabited the soil and rhizosphere of the host plant. Trichoderma has many useful mechanisms that possible utilize in introducing the best microbe to the plants. The mechanisms comprise parasitism and non parasitism which are affecting the plant enemies. The mechanisms comprise (I) parasitism, (II) producing the secondary metabolites, antibiosis, and enzymes, (III) inducing the defence and resistance of plant, (IV) enhancing the plant growth. These, the capabilities of Trichoderma control the plant pathogens in the soil, seeds, roots, stem, leaf, fruits, postharvest, insect and weeds. Hence are explored as possible be entomopathogen, nematophagous, herbicidal, and biofertilizer. The usage of Trichoderma can be helpful into two formulations such as conidia suspension, and culture filter. Finally, Trichoderma is useful for protection and inhibition all infections of a plant and saving a chance for the ecosystem from reducing any the residue of chemical synthetic pesticides and fertilizer.
Trichoderma asperellum ZZY has good tolerance to Pb²⁺, but the tolerance mechanism is not clear. The manuscript aimed to clarify the tolerance mechanism from the perspective of the response changes of related active ingredients. The synthesis of polysaccharides, proteins and thiol compounds in Trichoderma asperellum can be accelerated with Pb²⁺ stress. Under Pb²⁺ stress, Trichoderma asperellum can synthesize oxalic acid and secrete it extracellularly. In addition, high concentration of Pb²⁺ can inhibit the synthesis and extracellular secretion of formic acid and malic acid. The tolerance of Trichoderma asperellum to Pb²⁺ is the results of multiple reactions. The Pb²⁺ can promote the synthesis of polysaccharides, proteins, thiol compounds and oxalic acid. In the early stage of Pb²⁺ stress, Trichoderma asperellum can rapidly initiate an extracellular emergency mechanism, synthesize oxalic acid in mycelia and secrete it extracellularly to remove free Pb²⁺ and alleviate the toxicity of Pb²⁺ to cells. With the transport of Pb²⁺ into cells, it can promote the synthesis of polysaccharides, proteins, thiol compounds to adsorb and transform the Pb²⁺ and ease the damage to the cells. The manuscript provides theoretical support and scientific explanation for the application of Trichoderma asperellum.
Fusarium oxysporum is an important soilborne destructive plant pathogen that has an effect on several plant species worldwide. The suggested practice for their effective control was the integration of several management practices, but it remains elusive till now. Since it is important to develop disease-resistant and high-yielding crops due to the increase in food demand with minimum utilization of natural resources, it is necessary that the prerequisite employment methodology be of biological origin and that the candidature for the role of biological control agents implies antagonists in various plant–microbe interactions such as arbuscular mycorrhizal fungi and Trichoderma spp. This review proposes a framework that might be helpful in the use of AM fungi and Trichoderma spp. for their effective biocontrol of several plant pathogens and insights into the mechanisms involved. Also, a relationship between arbuscular mycorrhizal fungi or Trichoderma spp. and the host plant is being emphasized upon for improved health and growth for production in present agricultural systems. Therefore, this review focuses on some approaches aimed at the biocontrol of F. oxysporum and biotechnological advancement involved in it for paving insights for future research.
Diseases of carnation and integrated management practices.
We present the latest version of the Molecular Evolutionary Genetics Analysis (MEGA) software, which contains many sophisticated
methods and tools for phylogenomics and phylomedicine. In this major upgrade, MEGA has been optimized for use on 64-bit computing
systems for analyzing bigger datasets. Researchers can now explore and analyze tens of thousands of sequences in MEGA. The
new version also provides an advanced wizard for building timetrees and includes a new functionality to automatically predict
gene duplication events in gene family trees. The 64-bit MEGA is made available in two interfaces: graphical and command line.
The graphical user interface (GUI) is a native Microsoft Windows application that can also be used on Mac OSX. The command
line MEGA is available as native applications for Windows, Linux, and Mac OSX. They are intended for use in high-throughput
and scripted analysis. Both versions are available from www.megasoftware.net free of charge.
Bacillus species are widely exploited as biocontrol agents because of their efficiency in impeding various plant pathogens with multifaceted approach. In this study, Bacillus species were isolated from rhizosphere of various plants viz., carnations, cotton, turmeric, and bananas in Tamil Nadu state of India. Their potential to control the mycelial growth of Sclerotinia sclerotiorum was assessed in vitro by dual plate and partition plate techniques. B. amyloliquefaciens strain VB7 was much effective in inhibiting mycelial growth (45% inhibition of over control) and sclerotial production (100%). PCR detection of AMP genes revealed that B. amyloliquefaciens (VB7) had a maximum of 10 diverse antibiotic biosynthesis genes, namely, ituD, ipa14, bacA, bacD, bamC, sfP, spaC, spaS, alba, and albF, that resulted in production of the antibiotics iturin, bacilysin, bacillomycin, surfactin, subtilin, and subtilosin. Further, metabolites from B. amyloliquefaciens strains VB2 and VB7, associated with inhibition of S. sclerotiorum, were identified as phenols and fatty acids by gas chromatography mass spectrometry (GC-MS). Delivery of bacterial suspension of the effective strains of Bacillus spp. as root dip was found promising for the management of stem rot of cultivated carnations. Minimal percent disease incidence (4.6%) and maximum plant growth promotion was observed in the plants treated with B. amyloliquefaciens (VB7).
Background
Colletotrichum and Fusarium species are among pathogenic fungi widely affecting Coffea arabica L., resulting in major yield loss. In the present study, we aimed to isolate bacteria from root rhizosphere of the same plant that is capable of antagonizing Colletotrichum gloeosporioides and Fusarium oxysporum as well as promotes plant growth. ResultsA total of 42 Bacillus species were isolated, one of the isolates named BT42 showed maximum radial mycelial growth inhibition against Colletotrichum gloeosporioides (78%) and Fusarium oxysporum (86%). BT42 increased germination of Coffee arabica L. seeds by 38.89%, decreased disease incidence due to infection of Colletotrichum gloeosporioides to 2.77% and due to infection of Fusarium oxysporum to 0 (p < 0.001). The isolate BT42 showed multiple growth-promoting traits. The isolate showed maximum similarity with Bacillus amyloliquefaciens. Conclusion
Bacillus species (BT42), isolated in the present work was found to be capable of antagonizing the pathogenic effects of Colletotrichum gloeosporioides and Fusarium oxysporum. The mechanism of action of inhibition of the pathogenic fungi found to be synergistic effects of secondary metabolites, lytic enzymes, and siderophores. The major inhibitory secondary metabolite identified as harmine (β-carboline alkaloids).
Trichoderma harzianum is well known to exhibit induced systemic resistance (ISR) to Curvularia leaf spot. We previously reported that a C6 zinc finger protein (Thc6) is responsible for a major contribution to the ISR to the leaf disease, but the types of effectors and the signals mediated by Thc6 from Trichoderma are unclear. In this work, we demonstrated that two hydrolases, Thph1 and Thph2, from T. harzianum were regulated by Thc6. Furthermore, an electrophoretic mobility shift assay (EMSA) study revealed that Thc6 regulated mRNA expression by binding to GGCTAA and GGCTAAA in the promoters of the Thph1 and Thph2 genes, respectively. Moreover, the Thph1 and Thph2 proteins triggered the transient production of reactive oxygen species (ROS) and elevated the free cytosolic calcium levels in maize leaf. Furthermore, the genes related to the jasmonate/ethylene signaling pathway were up-regulated in the wild-type maize strain. However, the ΔThph1- or ΔThph2-deletion mutants could not activate the immune defense-related genes in maize to protect against leaf disease. Therefore, we conclude that functional Thph1 and Thph2 may be required in T. harzianum to activate ISR in maize.
Background: In Egypt, chocolate spot disease caused by Botrytis fabae Sard. and Botrytis sinerea Pers. is the most serious disease affecting bean. Trichoderma harzianum Rifai is one of the most potent bioagents used for the control of many plant pathogens. This biocontrol agent has not harmful effects on humans, wild life and other beneficial organisms, safe and effective biocontrol agent in both natural and controlled environments that doesn’t accumulate in the food chain. Materials and Methods: The antagonistic effect of T. harzianum against B. fabae was investigated on Potato Dextrose Agar (PDA) medium using dual culture technique. Also the antifungal activity of T. harzianum metabolites was also tested on the linear growth of B. fabae using cellophane method. Scanning electron microscopy was also used to investigate the mycoparasitic nature of T. harzianum on B. fabae. Results: An overgrowth of T. harzianum on B. fabae was observed, indicating the antagonistic behavior of T. harzianum against B. fabae. A complete reduction in the linear growth of B. fabae was observed indicating the antifungal activity of T. harzianum metabolites. By using the slide culture method, light microscopy observations showed an evidence about the mycoparasitic nature of the tested isolate of T. harzianum on B. fabae. Scanning electron microscopic observations confirmed the mycoparasitic nature of T. harzianum on B. fabae. Conclusion: The above results confirmed the mycoparasitic and aggressive nature of T. harzianum on B. fabae.
The antagonistic potential of Trichoderma strains was assayed by studying the effect of their culture filtrate on the radial growth of Sclerotium rolfsii, the causal agent of chickpea collar rot. Trichoderma harzianum-1432 (42.2%) and Trichoderma atroviride (40.3%) were found to be strong antagonists. To enhance their antagonistic potential, mutagenesis of these two selected strains was performed. Two mutants, Th-m1 and T. atroviride m1, were found to be more effective than their parent strains. The enzymatic activities of the selected parent and mutant strains were assayed, and although both mutants were found to have enhanced enzymatic activities compared to their respective parent strains, Th-m1 possessed the maximum cellulase (5.69U/mL) and β-1,3-glucanase activity (61.9U/mL). Th-m1 also showed high competitive saprophytic ability (CSA) among all of the selected parent and mutant strains, and during field experiments, Th-m1 was found to successfully possess enhanced disease control (82.9%).
Carnation (Dianthus caryophyllus L.) is a cut flower with greater stipulation in the world cut flower
market. In India, carnations are cultivated under polyhouses in Nilgiris and Kodaikanal districts in the
state of Tamil Nadu. Carnations cultivation is impeded by various diseases, among them stem rot
caused by Sclerotinia sclerotiorum (Lib.) de Bary was found to be predominant in all varieties. Survey
among commercially cultivated varieties of carnation during 2013, revealed the occurrence of stem rot
incited by Sclerotinia sclerotiorum, for the first time in India. The pathogen was identified as Sclerotinia
sclerotiorum on the basis of phenotypic and genotypic characteristics. Carpogenic germination was
induced artificially, and life cycle of the fungi was studied. Microscopic studies of the apothecium
revealed the presence of spermatia, croziers, paraphyses as well as monomorphic ascospores specific
to S. sclerotiorum.
This study investigated lytic enzyme activities in three indigenous Trichoderma strains namely, Trichoderma asperellum, Trichoderma harzianum and Trichoderma sp. Native Trichoderma strains and a virulent strain of Rhizoctonia solani isolated from infected bean plants were also included in the study. Enzyme activities were determined by measuring sugar reduction by dinitrosalicylic acid (DNS) method using suitable substrates. The antagonists were cultured in minimal salt medium with the following modifications: medium A (1 g of glucose), medium B (0.5 g of glucose + 0.5 g of deactivated R. solani mycelia), medium C (1.0 g of deactivated respective antagonist mycelium) and medium D (1 g of deactivated R. solani mycelia). T asperellum showed presence of higher amounts of chitinases, β-1, 3-glucanases and xylanases in extracellular protein extracts from medium D as compared to medium A. While, the higher activities of glucosidases and endoglucanses were shown in medium D extracts by T. harzianum. β-glucosidase activities were lower compared with other enzymes; however, activities of the extracts of medium D were significantly different. T. asperellum exhibited maximum inhibition (97.7%). On the other hand, Trichoderma sp. did not show any effect on mycelia growth of R. solani on crude extract.
The application of Trichoderma strains with biocontrol and plant growth-promoting capacities to plant substrates can help reduce the input of chemical pesticides and fertilizers in agriculture. Some Trichoderma isolates can directly affect plant pathogens, but they also are known to influence the phytohormonal network of their host plant, thus leading to an improvement of plant growth and stress tolerance. In this study, we tested whether alterations in the phytohormone signature induced by different Trichoderma isolates correspond with their ability for biocontrol and growth promotion. Four Trichoderma isolates were collected from agricultural soils and were identified as the species Trichoderma harzianum (two isolates), Trichoderma ghanense, and Trichoderma hamatum. Their antagonistic activity against the plant pathogen Fusarium oxysporum f. sp. melonis was tested in vitro, and their plant growth-promoting and biocontrol activity against Fusarium wilt on melon plants was examined in vivo, and compared to that of the commercial strain T. harzianum T-22. Several growth- and defense-related phytohormones were analyzed in the shoots of plants that were root-colonized by the different Trichoderma isolates. An increase in auxin and a decrease in cytokinins and abscisic acid content were induced by the isolates that promoted the plant growth. Principal component analysis (PCA) was used to evaluate the relationship between the plant phenotypic and hormonal variables. PCA pointed to a strong association of auxin induction with plant growth stimulation by Trichoderma. Furthermore, the disease-protectant ability of the Trichoderma strains against F. oxysporum infection seems to be more related to their induced alterations in the content of the hormones abscisic acid, ethylene, and the cytokinin trans-zeatin riboside than to the in vitro antagonism activity against F. oxysporum.
Role of endochitinase (ech42) gene in Trichoderma was worked out to prove the efficacy against most dreaded red rot disease of sugarcane caused by Colletotrichum
falcatum Went. Trichoderma spp. along with Trichoderma harzianum strain and Aspergillus
awamori were tested against the virulent pathotypes of C. falcatum (Cf08, Cf09 and Cf401) under in vitro and in vivo conditions. T. harzianum was significantly able to control the incidence of red rot disease in highly susceptible sugarcane cultivar. PCR-Random amplified polymorphic DNA amplification results clearly separated T. harzianum 1, 2 and 3 from rest of the biological agents. T. harzianum 1 strain was highly diverse and making distant relationship with rest of the T. harzianum bioagents. Wide genetic distance was observed among the red rot pathogens and biological agents. The ech42 specific primers pair amplified a corresponding fragment of 1.5 kb in all Trichoderma spp. Thus, the presence of the ech42 gene was found to be correlated with the biocontrol activity of Trichoderma species. These findings clearly supported that ech42 gene is more specifically responsible for controlling the red rot incidence in sugarcane.
Fusarium oxysporum f. sp. gladioli represent one of the problems of
greater importance in the culture of gladiolus. The resistance of
this fungus to the fungicides has stimulated the search of new alternatives
control measures. The natural plant extracts used in the study were
safer to the environment and effective in the control of the plant
pathogen tested. The present paper describes the in vitro fungicidal
or fungistatic effect of powders (20 mg mL-1) and of aqueou, methanol
and hexane extracts (5%) of 15 plant species on the development of
F. oxysporum f. sp. gladioli on artificial growth media and volatile
compound identification. Twelve plant species showed antifungal activity.
The hexane extract of Chenopodium ambrosioides (by its fungicidal
activity), the methanol extract with Spondias purpurea and Psidium
guajava, as well as the aqueous extract of L. esculenta and Guazuma
ulmifolia inhibited the mycelia growth with a percentage superior
to 50%. Also, the powders of Byrsonima crassifolia diminished the
percentage germination and sporulation of the pathogen. All the species
presented antifungal activity in form of methanol extract. The 80%
of the plant powders increased the rate of mycelial growth of the
fungus. By chromatography of gases and spectrometry of masses, 90
volatile compounds in the powders and extracts were identified that
showed activity on the fungus. The majority of the compounds were
fatty acids (18.8%), monoterpenes (4.2%), sesquiterpenes (23.6%)
and phenolic compound (6.3%). The high chemical diversity of the
analyzed plant species, differentially affected the development of
the fungus, either for the individual compounds or for synergism
of some of them. -�2010 Asian network for scientific information
The biocontrol strain P1 of Trichoderma harzianum was genetically modified by targeted disruption of the single-copy ech42 gene encoding for the secreted 42-kDa endochitinase (CHIT42). Stable mutants in which ech42 was interrupted, and unable to produce CHIT42, were obtained and characterized. These mutants lacked the ech42 transcript, the protein, and endochitinase activity in culture filtrates, and they were unable to clear a medium containing colloidal chitin. Other chitinolytic and glucanolytic enzymes expressed during mycoparasitism were not affected by the disruption of ech42. The disrupted mutant D11 grew and sporulated similarly to the wild type. In vitro antifungal activity of the ech42 disruptant culture filtrates against Botrytis cinerea and Rhizoctonia solani was reduced about 40%, compared with wild type; antifungal activity was fully restored by adding an equivalent amount of CHIT42 as secreted by P1. The mutant exhibited the same biocontrol effect against Pythium ultimum as strain P1, but the antagonism against B. cinerea on bean leaves by the mutant was significantly reduced (33% less biocontrol), compared with strain P1. Conversely, the endochitinase-deficient mutant performed better than the wild type (16% improvement of survival) in biocontrol experiments in soil infested with the soilborne fungus R. solani. These results indicate that the antagonistic interaction between the T. harzianum strain and various fungal hosts is based on different mechanisms.
Single-parameter optimization was carried out for the production of chitinase using a soil isolate belonging to Trichoderma harzianum in solid-state fermentation. Maximum chitinase activity (3.18 U/gds) was obtained after 96 h of incubation at 30 °C when wheat bran moistened (65.7%) with salt solution was supplemented with colloidal chitin (1%, w/w) and yeast extract (2%, w/w) used as the substrate. The inoculum contains 4×107 spores of T. harzianum (TUBF 781). The growth of the fungus on wheat bran particle was visualized by a scanning electron microscope. Chitinase activity was measured as the amount of N-acetyl glucosamine (NAG) liberated in μmol/min under reaction conditions. The crude extract showed antifungal activity against a wide range of fungal strains belonging to Aspergillus, Rhizopus and Mucor sp., and was found significant against Aspergillus niger (NCIM 563).
The efficacy of the essential oil and various organic extracts from flowers of Cestrum nocturnum L. was evaluated for controlling the growth of some important phytopathogenic fungi. The oil (1000 ppm) and the organic extracts (1500 μg/disc) revealed antifungal effects against Botrytis cinerea, Colletotrichum capsici, Fusarium oxysporum, Fusarium solani, Phytophthora capsici, Rhizoctonia solani and Sclerotinia sclerotiorum in the growth inhibition range of 59.2–80.6% and 46.6–78.9%, respectively, and their MIC values were ranged from 62.5 to 500 and 125 to 1000 μg/mL. The essential oil had a remarkable effect on spore germination of all the plant pathogens with concentration and time-dependent kinetic inhibition of P. capsici. Further, the oil displayed remarkable in vivo antifungal effect up to 82.4–100% disease suppression efficacy on greenhouse-grown pepper plants. The results obtained from this study may contribute to the development of new antifungal agents to protect the crops from fungal diseases.
Mycoparasitism, a lifestyle where one fungus is parasitic on another fungus, has special relevance when the prey is a plant pathogen, providing a strategy for biological control of pests for plant protection. Probably, the most studied biocontrol agents are species of the genus Hypocrea/Trichoderma.
Here we report an analysis of the genome sequences of the two biocontrol species Trichoderma atroviride (teleomorph Hypocrea atroviridis) and Trichoderma virens (formerly Gliocladium virens, teleomorph Hypocrea virens), and a comparison with Trichoderma reesei (teleomorph Hypocrea jecorina). These three Trichoderma species display a remarkable conservation of gene order (78 to 96%), and a lack of active mobile elements probably due to repeat-induced point mutation. Several gene families are expanded in the two mycoparasitic species relative to T. reesei or other ascomycetes, and are overrepresented in non-syntenic genome regions. A phylogenetic analysis shows that T. reesei and T. virens are derived relative to T. atroviride. The mycoparasitism-specific genes thus arose in a common Trichoderma ancestor but were subsequently lost in T. reesei.
The data offer a better understanding of mycoparasitism, and thus enforce the development of improved biocontrol strains for efficient and environmentally friendly protection of plants.
Trichoderma harzianum ALL42 were capable of overgrowing and degrading Rhizoctonia solani and Macrophomina phaseolina mycelia, coiling around the hyphae with formation of apressoria and hook-like structures. Hyphae of T. harzianum ALL42 did not show any coiling around Fusarium sp. hyphae suggesting that mycoparasitism may be different among the plant pathogens. In this study, a secretome analysis was used to identify some extracellular proteins secreted by T. harzianum ALL42 after growth on cell wall of M. phaseolina, Fusarium sp., and R. solani. The secreted proteins were analyzed by two-dimensional electrophoresis and MALDI-TOF mass spectrometry. A total of 60 T. harzianum ALL42 secreted proteins excised from the gel were analyzed from the three growth conditions. While seven cell wall-induced proteins were identified, more than 53 proteins spots remain unidentified, indicating that these proteins are either novel proteins or proteins that have not yet been sequenced. Endochitinase, β-glucosidase, α-mannosidase, acid phosphatase, α-1,3-glucanase, and proteases were identified in the gel and also detected in the supernatant of culture.
Trichoderma species belong to a class of free-living fungi beneficial to plants that are common in the rhizosphere. We investigated the role of auxin in regulating the growth and development of Arabidopsis (Arabidopsis thaliana) seedlings in response to inoculation with Trichoderma virens and Trichoderma atroviride by developing a plant-fungus interaction system. Wild-type Arabidopsis seedlings inoculated with either T. virens or T. atroviride showed characteristic auxin-related phenotypes, including increased biomass production and stimulated lateral root development. Mutations in genes involved in auxin transport or signaling, AUX1, BIG, EIR1, and AXR1, were found to reduce the growth-promoting and root developmental effects of T. virens inoculation. When grown under axenic conditions, T. virens produced the auxin-related compounds indole-3-acetic acid, indole-3-acetaldehyde, and indole-3-ethanol. A comparative analysis of all three indolic compounds provided detailed information about the structure-activity relationship based on their efficacy at modulating root system architecture, activation of auxin-regulated gene expression, and rescue of the root hair-defective phenotype of the rhd6 auxin response Arabidopsis mutant. Our results highlight the important role of auxin signaling for plant growth promotion by T. virens.
Chitinase, beta-1,3-glucanase, and protease activities were formed when Trichoderma harzianum mycelia, grown on glucose as the sole carbon source, were transferred to fresh medium containing cell walls of Botrytis cinerea. Chitobiohydrolase, endochitinase, and beta-1,3-glucanase activities were immunologically detected in culture supernatants by Western blotting (immunoblotting), and the first two were quantified by enzyme-linked immunosorbent assay. Under the same conditions, exogenously added [U-14C]valine was incorporated in acetone-soluble compounds with an apparent M(r) of < 2,000. These compounds comigrated with the peptaibols trichorzianines A1 and B1 in thin-layer chromatography and released [U-14C]valine after incubation in 6N HCl. Incorporation of radioactive valine into this material was stimulated by the exogenous supply of alpha-aminoisobutyric acid, a rare amino acid which is a major constituent of peptaibols. The obtained culture supernatants inhibited spore germination as well as hyphal elongation of B. cinerea. Culture supernatants from mycelia placed in fresh medium without cell walls of B. cinerea did not show hydrolase activities, incorporation of [U-14C]valine into peptaibol-like compounds, and inhibition of fungal growth. Purified trichorzianines A1 and B1 as well as purified chitobiohydrolase, endochitinase, or beta-1,3-glucanase inhibited spore germination and hyphal elongation, but at concentrations higher than those observed in the culture supernatants. However, when the enzymes and the peptaibols were tested together, an antifungal synergistic interaction was observed and the 50% effective dose values obtained were in the range of those determined in the culture supernatants. Therefore, the parallel formation and synergism of hydrolytic enzymes and antibiotics may have an important role in the antagonistic action of T. harzianum against fungal phytopathogens.
A gene (ech-42; previously named ThEn-42) coding for one of the endochitinases produced by the biocontrol agent Trichoderma harzianum IMI206040 was cloned and characterized. Expression of the cDNA clone in Escherichia coli resulted in bacteria with chitinase activity. This chitinase has been shown to have lytic activity on Botrytis cinerea cell walls in vitro. The ech-42 gene was assigned to a double chromosomal band (chromosome V or VI) upon electrophoretic separation and Southern analysis of the chromosomes. Primer extension analysis indicated that transcription of the gene begins preferentially 109 bp upstream of the translation initiation codon. Expression of ech-42 was strongly enhanced during direct interaction of the mycoparasite with a phytopathogenic fungus when confronted in vitro and by growing it in minimal medium containing chitin as sole carbon source. Similarly, light-induced sporulation resulted in high levels of transcript, suggesting developmental regulation of the gene. The implications of these findings are discussed.
The role of the Trichoderma harzianum endochitinase (Ech42) in mycoparasitism was studied by genetically manipulating the gene that encodes Ech42, ech42. We constructed several transgenic T. harzianum strains carrying multiple copies of ech42 and the corresponding gene disruptants. The level of extracellular endochitinase activity when T. harzianum was grown under inducing conditions increased up to 42-fold in multicopy strains as compared with the wild type, whereas gene disruptants exhibited practically no activity. The densities of chitin labeling of Rhizoctonia solani cell walls, after interactions with gene disruptants were not statistically significantly different than the density of chitin labeling after interactions with the wild type. Finally, no major differences in the efficacies of the strains generated as biocontrol agents against R. solani or Sclerotium rolfsii were observed in greenhouse experiments.
Problem statement: Sclerotinia sclerotiorum and Sclerotium cepivorum are soil pathogens which have generated resistance to synthetic fungicides. One biological alternative to this problem is to select novel strains of Trichoderma with different mechanisms of action against these plant pathogens to ensure efficient control. Approach: In the present research was determined the antagonism effect of Mexicans Trichoderma strains on S. sclerotiorum and S. cepivorum in vitro. It was used dual culture technique by determining the percentage of mycelia growth inhibition, days to contact and antagonism levels proposed by Bell. It was also determined the effect of volatile compounds and metabolites compound from Trichoderma produced in solutions. Results: The mycelia growth inhibition of S. sclerotiorum and S. cepivorum were 45-63.8 and 50.9-81.5% respectively by
the effect of Trichoderma strains. The T. ghanense and T. longibrachiatum (T15 and T10) inhibited in higher proportion to S. sclerotiorum. On the other hand T. inhamatum and T. asperellum (T32 and T11) inhibited in higher proportion to S. cepivorum. The days to contact between the Trichoderma and phytopathogen species were between two to three days. The levels of antagonism according to the Bell’s scale were different between the two species of phytopathogen and for Trichoderma strains were grouped into I and II class. The maximum inhibition effect by volatiles compound was occasioned by T. longibrachiatum with 31.5 (T3) and 59.2% (T10) on S. sclerotiorum and S. cepivorum respectively. Respect to metabolites, these shown high effects on phytopathogen growth, where T. asperellum is the more outstanding specie which produce totals mycelia growth inhibition of two phytopathogen species. Conclusion: T. longibrachiatum (T3 and T10) and T. asperellum (T1 and T11) were the most efficient species with the highest antagonist effects against S. sclerotiorum and S.
cepivorum.
Problem statement: Sclerotinia sclerotiorum and Sclerotium cepivorum are soil pathogens which have generated resistance to synthetic fungicides. One biological alternative to this problem is to select novel strains of Trichoderma with different mechanisms of action against these plant pathogens to ensure efficient control. Approach: In the present research was determined the antagonism effect of Mexicans Trichoderma strains on S. sclerotiorum and S. cepivorum in vitro. It was used dual culture technique by determining the percentage of mycelia growth inhibition, days to contact and antagonism levels proposed by Bell. It was also determined the effect of volatile compounds and metabolites compound from Trichoderma produced in solutions. Results: The mycelia growth inhibition of S. sclerotiorum and S. cepivorum were 45-63.8 and 50.9-81.5% respectively by the effect of Trichoderma strains. The T. ghanense and T. longibrachiatum (T15 and T10) inhibited in higher proportion to S. sclerotiorum. On the other hand T. inhamatum and T. asperellum (T32 and T11) inhibited in higher proportion to S. cepivorum. The days to contact between the Trichoderma and phytopathogen species were between two to three days. The levels of antagonism according to the Bell’s scale were different between the two species of phytopathogen and for Trichoderma strains were grouped into I and II class. The maximum inhibition effect by volatiles compound was occasioned by T. longibrachiatum with 31.5 (T3) and 59.2% (T10) on S. sclerotiorum and S. cepivorum respectively. Respect to metabolites, these shown high effects on fhytopathogen growth, where T. asperellum is the more outstanding specie which produce totals mycelia growth inhibition of two phytopathogen species. Conclusion: T. longibrachiatum (T3 and T10) and T. asperellum (T1 and T11) were the most efficient species with the highest antagonist effects against S. sclerotiorum and S.
cepivorum.
Botrytis cinerea is a widespread parasitic fungus that infects many crops and reduces their productivity. Trichoderma harzianum, also a fungus, has been commercially used as a biofungicide to control B. cinerea. The spores of T. harzianum, currently used in the application, have some drawbacks such as efficacy affected by the environmental condition and sensitivity to chemical fungicides. Instead of using the living microbe, the extract from T. harzianum fermented broth may be applied to control B. cinerea. It was found that the extract could inhibit mycelial growth (EC50 = 13.6 mg/L), conidia germination (EC50 = 17.5 mg/L) and conidia production (EC50 = 23.6 mg/L) of B. cinerea. In vitro, the extract showed excellent control effects on tomato grey mould caused by B. cinerea and the protective effect (EC50 = 99.6 mg/L) was better than the therapeutic effect (EC50 = 135.8 mg/L). In pot experiments, the extract also showed persistent protective (EC50 = 99.0 mg/L at day 7 and EC50 = 142.7 mg/L at day 15) and therapeutic (EC50 = 195.0 mg/L at day 7 and EC50 = 393.7 mg/L at day 15) effects over 15 days. This study showed that the extract was equivalent or superior to the commercial dicarboximide fungicide, procymidone. In conclusion, the ethyl acetate extract of T. harzianum fermented broth is effective in the treatment of tomato grey mould caused by B. cinerea.
Trichoderma hamatum (Bonord.) Bainier was evaluated for its antagonistic potential against Fusarium oxysporum Schlecht. emend. Snyder and Hansen sp. lentis, the causal agent of vascular wilt disease of lentil (Lens culinaris Medikus). Hyphal interactions on Petri plates resulted in an increase in the number of conidial spores and an increase in the vegetative growth of T. hamatum, and a decrease in the hyphal formation and sporulation of F. oxysporum f. sp. lentis. Electron and light microscopical observations suggested that hyphae of T. hamatum established aggressive contact and attachment with the hyphae of the pathogen. Growing in parallel, coiled densely and tightly, T. hamatum may penetrate those of the pathogen hyphae causing collapse due to the loss of turgor pressure. The cellulolytic enzymes produced by T. hamatum presented sufficient characteristics for its antifungal activity in the hyphae hydrolysis and competition process. In growth room and glasshouse experiments, the addition of the conidial suspension of T. hamatum or its culture filtrate to soil, significantly (p ≤ 0.05) reduced development and spore germination of F. oxysporum. In the rhizosphere, T. hamatum occupied the same ecological niches (rhizosphere, roots, and stems) parasitizing F. oxysporum f. sp. lentis. Treatments using T. hamatum delayed the time of infection by F. oxysporum, promoted the growth, and increased the dry weight of a susceptible variety of lentil (cv. Precoz). The percent of mortality was reduced to 33 and 40% when using T. hamatum and its filtrate, respectively, compared to 93% in the control treatment during the 65 days of growing in loam/sand (2:1 vol/vol) under glasshouse conditions. Plant colonization results indicate that T. hamatum and its filtrate significantly (p ≤ 0.05) reduced development of the pathogen in the vascular tissue of lentil to < 30 and < 40% stem colonization, respectively, compared to 100% in the plant pathogen control. Our results suggest that potential biocontrol mechanisms of T. hamatum towards F. oxysporum f. sp. lentis were antibiosis by production of antifungal enzymes, complex mechanisms of mycoparasitism, competition for key nutrients and/or ecological niches, growth promotion, and a combination of these effects. This study results hold important suggestions for further development of effective strategies of the biological control of Fusarium vascular wilt of lentil.
Stem rot of canola (Brassica napus ) caused by Sclerotinia sclerotiorum is one of the most serious of plant diseases. From 30 Trichoderma isolates, three different species T. harzianum-8, T. atroviride PTCC5220 and T. longibrachiatum PTCC5140, were selected on the basis of their high level of chitinase and/or glucanase activity, along with their rapid growth rate in vitro. These showed high growth inhibition of two phytopathogenic isolates of Sclerotinia sclerotiorum (S1and S2), with T. atroviride the greatest effect, reducing growth by 85-93%. They showed coil formation and penetration structures against the hyphae of the pathogenic isolates. T. atroviride PTCC5220 can be used for assessment of field biocontrol against S. sclerotiorum.
This study was designed to explore the in vitro antioxidant and antibacterial activities of Camptotheca acuminate D. seed oil, which were extracted by supercritical fluid extraction (SFE) or petroleum ether extraction methods. The major constituent of the oil were described as (Z,Z,Z)-9,12,15-Octadecatrien-1ol (54.92%) and 2-[(trimethylsilyl)oxy]-3-[4-[(trimethylsilyl)oxy]phenyl]-trimethylsilyl ester (26.53%) in supercritical fluid and petroleum ether extracts. The oil and the components were subjected to screen for their possible antioxidant activity by 2, 2-diphenyl-1-picrylhydrazyl (DPPH) assay and β-carotene bleaching test. In the DPPH test system, free radical scavenging activities of supercritical fluid extracts and petroleum ether extracts were determined to be 7.55 ± 0.11% and 4.38 ± 0.08% (v/v), respectively. As to the β-carotene bleaching test system, the two values were 15.93 ± 0.11% and 6.87 ± 0.15% (v/v), respectively. The activities of antioxidant and antibacterial in components of petroleum ether were more efficient than in components of supercritical fluid extraction. As to the antimicrobial activities of the essential oil against 8 species bacterium, C. acuminate D. seed oil had remarkable antibacterial activity, especially to staphylococcus aureus (ATCC 6538). Thus, C. acuminate D. seed oil could be judged as a kind of patent drug which has antioxidant and antibacterial activity effectively.
Sclerotinia stem rot caused by Sclerotinia sclerotiorum, is the main fungal disease of oilseed rape (Brassica napus) in Jiangsu Province of China, causing oil quality declines and yield losses from 10 to 80 %. Chemical control, such as carbendazim (MBC) and dimethachlon, remains the major method to reduce the incidence of S. sclerotiorum. Isolates collected from Sclerotinia-infected stems of oilseed crops in Jiangsu province between 2010 and 2012, were tested for their sensitivity to carbendazim and dimethachlon in order to determine the level of resistance to these fungicides in the population of S. sclerotiorum in that province. Sensitivity tests showed that 375 isolates were resistant to carbendazim among the 3,701 isolates with a resistance frequency of 10.1 %; only one isolate in the Lian Yungang region of Jiangsu Province in 2010 showed normal growth at 5 μg/ml dimethachlon. The proportion of carbendazim-resistant isolates ranged from 0 to 44 % in different regions of Jiangsu. The field MBC-resistant isolates showed comparable mycelial growth, sclerotial production, pathogenicity and osmotic sensitivity to the MBC-sensitive isolates, which suggested that the field MBC-resistant isolates might have sufficient parasitic fitness to compete with the field sensitive isolates in the field; whereas the dimethachlon-resistant isolates were less fit than their parental isolates in terms above. Moreover, S. sclerotiorum exhibited positive cross-resistance between dimethachlon and other dicarboximide fungicides such as iprodione and procymidone.
Trichoderma spp. are known for their biocontrol activity against several plant pathogens. A specific isolate of Trichoderma harzianum, 303/02, has the potential to inhibit the growth of Sclerotinia sclerotiorum, an important agent involved in several crop diseases. In this study, the interaction between T. harzianum 303/02 and mycelia, sclerotia and apothecia of S. sclerotiorum was studied by scanning electron microscopy. RT-qPCR was used to examine the expression of 11 genes potentially involved in biocontrol. T. harzianum 303/02 parasitizes S. sclerotiorum by forming branches that coil around the hyphae. The fungus multiplied abundantly at the sclerotia and apothecia surface, forming a dense mycelium that penetrated the inner surface of these structures. The levels of gene expression varied according to the type of structure with which T. harzianum was interacting. The data also showed the presence of synergistic action between the cell-wall degrading enzymes.
Azoxystrobin acts as an inhibitor of electron transport by binding to the Qo center of cytochrome b (cyt b). Resistance to azoxystrobin was usually caused by the point mutation of cyt b gene or by the induction of alternative respiration. Oxygen consumption test for mycelia of Colletotrichum capsici showed that azoxystrobin inhibited mycelial respiration within 12 h; however, as time went on, the respiration of the mycelia recovered when the mycelia were treated with azoxystrobin and salicylhydroxamic acid (SHAM, a known inhibitor of alternative respiration), and the oxygen consumption of the mycelia could not be inhibited. Meanwhile, cytochrome b (cyt b) gene expression increased with the recovery of mycelial respiration. The increased cyt b gene expression might play a role in the development of resistance to azoxystrobin in C. capsici.
One isolate each of Trichoderma viride, Epicoccum nigrum, Fusarium tricinctum, Alternaria alternata, Sclerotinia sclerotiorum and Cytospora (teleomorph: Valsa sp.) present in epigeous declining oak tissues was evaluated for its ability to control Diplodia corticola (isolate 79). This fungus is the causal agent of cankers, vascular necrosis and dieback on various oak species. Among the
isolates tested, T. viride and F. tricinctum showed maximum in vitro inhibition of mycelial growth of D. corticola (isolate 79). Species were also evaluated for their ability to reduce mortality caused by D. corticola (isolate 79) of Quercus cerris and Q. pubescens seedlings under controlled conditions. Two series of inoculations were carried out through wounds in the stem; in the first,
the distance between the point of inoculation of the antagonist and the pathogen was 6cm, whereas in the second series the
distance was shortened to 3cm. In seedlings of Q. cerris and Q. pubescens at a distance of 3cm, inoculation with F. tricinctum and A. alternata significantly reduced mortality caused by D. corticola (isolate 79). Inoculation of T. viride through artificial cuticular wounds in the stem of seedlings prevented the proliferation of D. corticola (isolate 79) only on seedlings of Q. cerris. All Q. pubescens seedlings treated with T. viride manifested pathological symptoms subsequent to proliferation of D. corticola (isolate 79). These observations indicate that the interactions between endophytes in planta and D. corticola (isolate 79) are complex and merit further study.
Fusarium oxysporum f. sp. gladioli represent one of the problems of greater importance in the culture of gladiolus. The resistance of this fungus to the fungicides has stimulated the search of new alternatives control measures. The natural plant extracts used in the study were safer to the environment and effective in the control of the plant pathogen tested. The present paper describes the in vitro fungicidal or fungistatic effect of powders (20 mg mL-1) and of aqueou, methanol and hexane extracts (5%) of 15 plant species on the development of F. oxysporum f. sp. gladioli on artificial growth media and volatile compound identification. Twelve plant species showed antifungal activity. The hexane extract of Chenopodium ambrosioides (by its fungicidal activity), the methanol extract with Spondias purpurea and Psidium guajava, as well as the aqueous extract of L. esculenta and Guazuma ulmifolia inhibited the mycelia growth with a percentage superior to 50%. Also, the powders of Byrsonima crassifolia diminished the percentage germination and sporulation of the pathogen. All the species presented antifungal activity in form of methanol extract. The 80% of the plant powders increased the rate of mycelial growth of the fungus. By chromatography of gases and spectrometry of masses, 90 volatile compounds in the powders and extracts were identified that showed activity on the fungus. The majority of the compounds were fatty acids (18.8%), monoterpenes (4.2%), sesquiterpenes (23.6%) and phenolic compound (6.3%). The high chemical diversity of the analyzed plant species, differentially affected the development of the fungus, either for the individual compounds or for synergism of some of them.
Antimicrobial metabolites produced by Trichoderma koningii SMF2 exhibited antimicrobial activity against a range of Gram-positive bacterial and fungal phytopathogens. Purification of these metabolites was achieved using combinations of gel filtration and high-performance liquid chromatography. Identified by liquid chromatography electrospray ionization tandem mass spectrometry, the active metabolites proved to be three known peptaibols: Trichokonin VI, VII and VIII. The Trichokonins were stable and remained biological active over a wide pH range and at every temperature tested, showing no loss of activity even after autoclaving. Trichokonins were insensitive to proteolytic enzymes. Trichokonin VI takes on typical helical structure and the structure changes only slightly at different temperatures and pH values. The present study presented the potential of Trichokonins to be used as biological control agents.
Variability in production of extra cellular hydrolytic enzymes by Trichoderma spp. and induction of disease resistance in gram (Ciccer arietinum)
- S Bhagat
- S Pan
Bhagat, S., Pan, S., 2008. Variability in production of extra cellular hydrolytic enzymes by
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Molecular characterization of Trichoderma viride and Trichoderma harzianum isolated from soils of North Bengal based on rDNA markers and analysis of their PCR-RAPD profiles
- B N Chakraborty
- U Chakraborty
- A Saha
- P L Dey
- K Sunar
Chakraborty, B.N., Chakraborty, U., Saha, A., Dey, P.L., Sunar, K., 2010. Molecular
characterization of Trichoderma viride and Trichoderma harzianum isolated from soils
of North Bengal based on rDNA markers and analysis of their PCR-RAPD profiles.
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The study of cellobiohydrolase production from Trichoderma reesei
- F Ghoujeghi
- M Motalebi
- M R Zamani
Ghoujeghi, F., Motalebi, M., Zamani, M.R., 2005. The study of cellobiohydrolase production from Trichoderma reesei. Iranian J. Biol. 18 (1), 15-23.
Cloning and sequencing of a cellobiohydrolase gene from Trichoderma harzianum FP108
- P Guilfoile
- R Burns
- Z Gu
- M Amundson
- F Chang
Guilfoile, P., Burns, R., Gu, Z., Amundson, M., Chang, F., 1999. Cloning and sequencing of
a cellobiohydrolase gene from Trichoderma harzianum FP108. J. Minn. Acad. Sci. 64
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Statistical data, http://nhb.gov.in/area-pro/NHB_ Database_2015.pdf
- Indian Horticulture Database
Indian Horticulture Database. Statistical data, http://nhb.gov.in/area-pro/NHB_
Database_2015.pdf. 2014.