Article

A study on preventive effects of Lawsonia inermis L. bioformulations against leaf spot disease of maize

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Abstract

Leaf spot disease caused by Curvularia lunata is one of the major constraints affecting the cultivation of maize in India. Recently, it has been reported that the severity of curvularia leaf spot was prevalent in moderate to severe intensities and cause extensive damage to the crop thus lowering the yields. In the present study, in vivo preventive effect of Lawsonia inermis Linn. bioformulation on curvularia leaf spot disease of maize has been studied. All the experiments were conducted in pots. Percent disease index (PDI), percent efficacy of disease control (PEDC), chlorophyll contents, total carotenoids, and others various growth characteristics like plant height, number of leaves per plant, total carbohydrate and protein content were recorded. Percent seed germination was also observed for seeds treated with all formulations. A significant control of leaf spot disease was recorded with bioformulations treatment T3 [seeds were treated with partially purified acetone extract (4 ml): 100% clove bud oil cake (4 ml): 100% cow dung (2 ml)], T4 [seeds were treated with partially purified acetone extract (3 ml): 100% clove bud oil cake (4 ml): 100% cow dung (3 ml)], T2 [seeds were treated with 100% alcoholic crude extract (2 ml): 100% clove bud oil cake (6 ml): 100% cow dung (2 ml)] and T1 [seeds were treated with 100% alcoholic crude extract (4 ml): 100% clove bud oil cake (4 ml): 100% cow dung (2 ml)] as compared to other bioformulation treatments and its PDI and PEDC were recorded 9.10%, 10.00%, 17.50%, 19.00% and 89.47%, 88.43%, 79.76%, 78.03%, respectively. Results showed that treatment with bioformulation treatment T3, notably increased plant height, number of leaves per plant, chlorophyll, carotenoids, and total soluble sugar content followed by formulations number T4, T2, and T1. However, total soluble protein content was observed to be less in T3 as compared to control. This study suggests that these bioformulations could be essential towards sustainable agricultural science deprived of harming the ecosystem. The synthesized bioformulations have enormous potential to be commercially explored for agriculture use.

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... 98−100 The treatment of maize seeds with acetone extract (4 mL) of Lawsonia inermis combined with 4% clove bud oil cake and 100% cow dung (2 mL) was effective in controlling CLS (percent disease control: 89.47%, P ≤ 0.05). 101 Host Resistance. Deployment of resistance variety is expected to be the most effective way to control CLS. ...
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Curvularia leaf spot (CLS), primarily caused by Curvularia lunata (Wakker) Boedijn (C. lunata), is widely distributed in maize production regions in China. It occurs in all the developmental stages of maize and causes economic losses. The epidemic and yield loss estimation models have been constructed for the disease. C. lunata has obvious virulence differentiation and produces multiple virulence factors. CLS is managed by application of chemical and biological agents and by quantitative resistance conferred by 5 to 6 quantitative trait loci (QTL). This review summarizes research on the understanding of CLS biological characteristics, virulence factors of C. lunata, host resistance genetics, and disease management strategies in China.
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In the present study preparation of different bioformulations of Lawsonia inermis Linn. (Henna) leaves and its in vitro antifungal activity were evaluated against Curvularia lunata (Wakker) Boedijn caused leaf spot disease in maize. Thirty herbal formulations were prepared using plant extracts, elicitor and binder, and assayed for antifungal activity by poison food technique. Among all the bioformulations, optimum activity was observed in formulation number 4, 12, 19 and 28 i.e. 77.82%, 79.84%, 83.47% and 81.45%, respectively, against C. lunata. On the basis of results obtained, best bioformulation will be used for eco-friendly in vivo control of disease.
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Seven fungicides were evaluated in vitro against Exserohilum turcicum causing leaf blight of maize The treatment mancozeb 0.25% and combination treatments of carbendazim and mancozeb i.e. saff 0.25% recorded the lowest percent disease index (PDI) reducing the disease by 73.0% and 72.1% respectively. The treatment which had a combination metriram + pyraclostrobin i.e. cabriotop 0.3% was found to be the next best treatment in reducing the disease by 61.5% with PDI of 14.6 following propiconazole with PDI of 18.6.
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Background: Sweet sorghum is an annual C4 crop considered to be one of the most promising bio-energy crops due to its high sugar content in stem, yet it is poorly understood how this plant increases its sugar content in response to salt stress. In response to high NaCl, many of its major processes, such as photosynthesis, protein synthesis, energy and lipid metabolism, are inhibited. Interestingly, sugar content in sweet sorghum stems remains constant or even increases in several salt-tolerant species. Results: In this study, the transcript profiles of two sweet sorghum inbred lines (salt-tolerant M-81E and salt-sensitive Roma) were analyzed in the presence of 0 mM or 150 mM NaCl in order to elucidate the molecular mechanisms that lead to higher sugar content during salt stress. We identified 864 and 930 differentially expressed genes between control plants and those subjected to salt stress in both M-81E and Roma strains. We determined that the majority of these genes are involved in photosynthesis, carbon fixation, and starch and sucrose metabolism. Genes important for maintaining photosystem structure and for regulating electron transport were less affected by salt stress in the M-81E line compared to the salt-sensitive Roma line. In addition, expression of genes encoding NADP(+)-malate enzyme and sucrose synthetase was up-regulated and expression of genes encoding invertase was down-regulated under salt stress in M-81E. In contrast, the expression of these genes showed the opposite trend in Roma under salt stress. Conclusions: The results we obtained revealed that the salt-tolerant genotype M-81E leads to increased sugar content under salt stress by protecting important structures of photosystems, by enhancing the accumulation of photosynthetic products, by increasing the production of sucrose synthetase and by inhibiting sucrose decomposition.
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Investigation on the pesticide residues during 2006–2009 in various crops and natural resources (soil and water) in the study village (Kothapally, Telangana State (TS)) indicated the presence of a wide range of insecticidal residues. Pooled data of the 80 food crop and cotton samples, two rice grain samples (3 %) showed beta endosulfan residues, and two (3 %) soil samples showed alpha and beta endosulfan residues. In vegetables of the 75 tomato samples, 26 (35 %) were found contaminated with residues of which 4 % had residues above MRLs. Among the 80 brinjal samples, 46 (56 %) had residues, of these 4 % samples had residues above MRLs. Only 13 soil samples from vegetable fields were found contaminated. The frequency of contamination in brinjal fields was high and none of the pulses and cotton samples revealed any pesticide contamination. IPM fields showed substantial reduction sprays which in-turn reflected in lower residues. Initial studies on water analysis indicated the presence of residues in all water sources with higher in bore wells compared to open wells, however, by 2009 the water bodies reflected no residues above the detectable level.
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This book includes 25 contributions from vastly experienced, global experts in PGPR research in a comprehensive and influential manner, with the most recent facts and extended case studies. Also, the chapters address the current global issues in biopesticide research.
In various environmental condition plants continually face abiotic and biotic stresses that can cause harmful effects on plants. To overcome stress, some transcription factors act as activators or repressors like WRKY, which reprogramme their transcriptome quickly. This review stated the transcriptional regulation and molecular networks for WRKYs defence signalling during Arabidopsis–Trichoderma interaction. In this sense, the regulation of transcriptome through WRKY transcription suggests an intricate signalling system in this beneficial plant–microbe interaction.
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The rhizosphere is the zone under influence of plant roots where various kinds of microbial activities occur which perform important functions such as increase uptake of nutrients for the host for their better growth and protection from several diseases caused by various phytopathogens. Keeping in this vital role performed by rhizospheric microbes, thirty-nine bacterial isolates were isolated on King's B and nutrient agar media from the rhizosphere region of mung bean plants. Among these isolates, foure were identified as Pseudomonas spp., Bacillus sp., Acinetobacter sp. on the basis of biochemical and 16 S rDNA gene sequencing analysis. All the isolates were screened in vitro for plant growth promoting attributes such as IAA production, phosphate solubilization, ammonia production, catalase production, siderophore production, and antagonistic activity against phytopathogenic Rhizoctonia solani, the causal organism of root rot in mung bean. All the bacterial strains showed significant PGPR attributes and were able to produce indole-3 -acetic acid (ranging from 45.66 µg/ml to 111.94 µg/ml). In addition, the isolated strains enhanced phosphate solubilization activity (ranging from 952.91 µg/ml to 1341.24 µg/ml). Out of all, Pseudomonas spp. showed most potent antifungal activities against R. solani. Thus, the current study has focused on the characterization of rhizobacteria isolated from the rhizosphere of healthy mung bean plant. The results showed that the isolates posses, multiple plant growth-promoting (PGP) traits and can be used as a potential candidate on the soil-plant system to increase their growth as well as productivity.
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Cadmium (Cd) is a non essential and toxic heavy metal that gets incorporated in the soil ecosystem through several anthropogenic activities. The Cd contaminated soils might have devastating affects on seed germination, plant growth and development. In the present work, a comparative evaluation was made to determine and optimize the detrimental level of accumulated toxic Cd metal in the tomato (Solanum lycopersicum; CO-3 variety). The perturbed morpho-physiological, biochemical alterations and molecular responses following the Cd induced stress were found to maximum at 250 μM Cd with having the highest expression of LeNRAMP3 gene. The oxidative burst induced and cell death was visualized through histochemical analysis using Evans blue (cell death) and DAB staining (H2O2 accumulation). The structural modelling of metal transporter protein done through homology modelling was found to acquire typical helical configuration, and revealed the potential active site residues involved in metal chelation. The function of LeNRAMP3 was deduced based on the functional annotation of protein AtNRAMP3. The functional signaling network and evolutionary relationships for LeNRAMP3 were explored and predicted based on comparative genomics and proteomic studies using the interactome pathways available for AtNRAMP3. The study revealed that LeNRAMP3 metal transporters are activily involved in Cd translocation from root to leaves of tomato and sensitive at 250 μM Cd concentration in the tomato plants.
Article
The present study was carried out to evaluate the biochemical changes occurring in tomato leaves following treatment with leaf spot disease causing pathogen Alternaria alternata and two of its phytotoxic metabolites. Results revealed that the pathogen treatment caused severe foliar necrosis and by 10th day of treatment almost 3/4th of the leaf area was necrotized. A significant decline in the chlorophyll content was observed in the leaves treated with the pathogen and its metabolites. Reducing sugars showed a visible decline in the treated leaves in comparison to the control leaves. When compared with the control an increase in total soluble protein was observed in leaves treated with the pathogen and its metabolites. In case of phenol, a significant enhancement in phenol content of the pathogen and metabolite treated leaves was observed than the amount detected in control leaves. The results indicate that infection of tomato by the leaf spot pathogen Alternaria alternata and its metabolites causes severe alterations in the amount of various biochemical components.
Trichoderma spp. are well-known biological agents that have significant antagonistic activity against several plant pathogenic fungi. In the present study, Trichoderma spp. were tested in vitro for their antagonistic activity against different spp. of Fusarium and Alternaria viz. Alternaria alternata, A. brassicae, A. solani, Fusarium oxysporum and F. solani using dual plate assay and by the production of volatile and non-volatile compounds. The results obtained revealed that Trichoderma harzianum and T. viride effectively inhibited the growth and spore production of different spp. of Fusarium and Alternaria. The highest growth inhibition was found in A. alternata 62.50% and 60.00% by non-volatile compounds of T. harzianum and T. viride, respectively. Similarly, the volatile compounds inhibit the maximum growth of A. alternata 40.00% and 35.00% by T. harzianum and T. viride, respectively. Volatile and non-volatile compounds of Trichoderma spp. were analysed by GC-MS technique and the properties of distinguished compounds showed antifungal, antimicrobial and antibiotic activities. Volatile compounds of T. harzianum and T. viride showed highest percent abundance for glacial acetic acid (45.32%) and propyl-benzene (41.75%), respectively. In case of non-volatile compounds, T. harzianum and T. viride showed D-Glucose, 6-O-α-D-galactopyranosyl- (38.45%) and 17-Octadecynoic acid (36.23%), respectively. The results of present study confirmed that T. harzianum can be used as a promising biological control agent against Alternaria and Fusarium spp. that cause diseases in various vegetables and crops.
Tomato is considered as one of the most important sources of nutrients such as lycopene, β-carotene, flavonoids, ascorbic acid (vitamin C) and hydroxyl-cinnamic acid derivatives. The quality and quantity of nutrients in tomato fruits were decreased during the severe infection of Alternaria alternata. The present study deals with the estimation of lycopene, β-carotene, phenolic and ascorbic acid content in tomato fruits which were infected with A. alternata and its toxins such as tenuazonic acid (TeA), alternariol (AOH) and alternariol monomethyl ether (AME). The lycopene, β-carotene, ascorbic acid and phenolic content were found lowest in pathogen-infected fruits i.e. (0.66 ± 0.03 mg/g), (0.14 ± 0.01 mg/g), (1.89 ± 0.2 mg/g) and (0.58 ± 0.05 mg/g), respectively, followed by toxins-treated samples as compared to the control. The results concluded that A. alternata mostly affects the nutritional values of tomato fruits due to the combined effect of the toxins.
Conference Paper
Mannitol is important in pathogenesis to counteract antioxidant defences induced in both plant and animal hosts. Proline accumulation in plants under stressed conditions causes the activation of proline biosynthesis. Both mannitol and proline are scavengers of ROS and play an important role in host-pathogen interaction by allowing the fungus to suppress ROS mediated plant responses. The aim of this study was to characterize the effect on mannitol production and proline accumulation during infection of Alternaria alternata and its toxins with tomato plant leading to cell damage or death. Alternaria alternata was isolated from a naturally infected tomato plant and characterized by molecular techniques using PCR amplification. The production of mannitol in plant tissues infected with the pathogen and its toxins were observed and confirmed by using TLC and HPLC analysis that mannitol being produced in plant infected tissues but not in the healthy plant tissues. Proline content also increased in infected tissues at different time intervals. From the result, it is proved that mannitol is somewhere required by A. alternata for its pathogenicity during interaction with tomato which is important for normal disease development. This study demonstrates that mannitol and proline production in tomato plants were increased during treatment with Alternaria alternata as well as its metabolites namely tenuazonic acid (TeA) and alternariol (AOH).
Article
Pseudomonas fluorescens isolate 4-92 induced systemic resistance against charcoal rot disease in chickpea (Cicer arietinum L.) caused by Macrophomina phaseolina (Tassi) Goidanich. Time-course accumulation of pathogenesis-related (PR) proteins (chitinases and glucanases) in chickpea plants inoculated with P. fluorescens was significantly (P = 0.05) higher than in control plants. The level of chitinases and glucanases increased by 6.6- to 7-fold up to 4 days postinoculation; thereafter, little decrease in the activity of PR proteins was observed. Root-colonizing populations of P. fluorescens were at a maximum 2 days after transplantation at different inoculum concentrations, and decreased over time. Inoculation of root tips of chickpea by P. fluorescens, 2,6-dichloroisonicotinic acid, and o-acetylsalicylic acid induced systemic resistance against charcoal rot. Disease was 33 to 55.5% higher in control plants than in plants inoculated with chemical inducers or P. fluorescens. Single treatment of plants with P. fluorescens increased disease resistance by 33%, whereas combined application of P. fluorescens with either of the chemical inducers was most effective in inducing the resistance by 2- to 2.25-fold. The time-course study shows that an interval of at least 2 days was required between induction treatment and challenge inoculation. Biocontrol efficacy of P. fluorescens against charcoal rot disease in chickpea was demonstrated under greenhouse conditions.
Article
A soil bacterium, Bacillus sp. strain BC121, isolated from the rhizosphere of sorghum, showed high antagonistic activity against Curvularia lunata. A clear inhibition zone of 0.5-1 cm was observed in dual plate assay. After 10 days of incubation, the bacterial strain grew over the fungal mycelial surface and multiplied extensively on it. Scanning electron microscopic observations showed a clear hyphal lysis and degradation of fungal cell wall. In dual cultures, the Bacillus strain BC121 inhibited the C. lunata up to 60% in terms of dry weight. This strain also produced a clear halo region on chitin agar medium plates containing 0.5% colloidal chitin, indicating that it excretes chitinase. The role of the Bacillus strain BC121 in suppressing the fungal growth in vitro was studied in comparison with a mutant of that strain, which lacks both antagonistic activity and chitinolytic activity. The extra-cellular protein precipitate from Bacillus strain BC121 culture filtrate had significant growth-retarding effect and mycolytic activity on C. lunata. The protein extract from the wild strain, when tested on SDS-PAGE gel showed a unique band corresponding to the molecular mass of 25 kDa, which could be the probable chitinase protein.
Article
The rising population demand for food poses major challenges to humankind. In favor of facing this challenge humans used enormous amount of chemically synthesize fungicides to control plant diseases because of their diverse use, easiness of synthesis and extreme effectiveness. However, they are not considered as enduring solutions due to their harmful effects on human being as well as soil health so, nowadays focus is shifting in the direction of biological methods to manage plant diseases as they have no adverse consequence on humans as well as environment. The employ of botanicals / natural products for the control of plant diseases is considered as an interesting alternative way to synthetic fungicides due to their no negative impacts on the environment. The present study attempt will be made to develop the plant extract based bio-formulation for systematic control of leaf spot disease of maize caused by Curvularia lunata.
Article
We report the synthesis and characterization of amorphous iron oxide nanoparticles from iron salts in aqueous extracts of monocotyledonous (Hordeum vulgare) and dicotyledonous (Rumex acetosa) plants. The nanoparticles were characterized by TEM, absorbance spectroscopy, SAED, EELS, XPS and DLS methods and were shown to contain mainly iron oxide and iron oxohydroxide. H. vulgare extracts produced amorphous iron oxide nanoparticles with diameters of up to 30 nm. These iron nanoparticles are intrinsically unstable and prone to aggregation; however we rendered them stable in the long term by addition of 40 mM citrate buffer pH 3.0. In contrast, amorphous iron oxide nanoparticles (diameters of 10-40 nm) produced using R. acetosa extracts are highly stable. The total protein content and antioxidant capacity are similar for both extracts, but pH values differ (H. vulgare pH 5.8 versus R. acetosa pH 3.7). We suggest that the presence of organic acids (such oxalic or citric acids) play an important role in the stabilization of iron nanoparticles, and that plants containing such constituents may be more efficacious for the green synthesis of iron nanoparticles.
Article
In 2002 and 2003, a study was conducted to determine the effect of bacterial strains, Burkholdria OSU 7, Bacillus OSU 142, and Pseudomonas BA 8, on biological control of brown rot disease (Monilinia laxa Ehr.) on apricot cv. Hacıhaliloğlu in Malatya province of Turkey. Apricot orchard at full blooming stage was inoculated with conidial suspension (1 × 106 spores/ml) of M. laxa Ehr. After inoculation, two apricot trees for each application were treated with each of the three biological control agents (Burkholdria gladii OSU 7, Bacillus subtilis OSU 142, and Pseudomonas putida BA 8) by spraying (1 × 109 cfu/ml) on inoculated branches. Disease incidence was evaluated for untreated (control 1) and four different treatment groups including commercial disease management (control 2, positive control: 3% Bourdox in fall, 50% Cupper at pink flower, 30 g/100 l Corus at first blooming, and 300 g/100 l Captan at last blooming stage) and treatments including each of the three bacterial strains (OSU 7, OSU 142, and BA 8). The results showed that disease incidence for negative control (control 1) was 9.94, which was significantly higher than disease incidence for commercial application (2.57%) or bacterial treatments (2.82–5.00%) in the first year. In 2003, the lowest disease incidence observed in OSU 7 treatment (6.80%), while disease incidence rate for positive control and negative control were 9.45% and 28.46%, respectively. This result may suggest that OSU 7 has potential to be used as biopesticide for effective management of brown rot disease on apricot.
Article
Increases in b-proteins were detected in controls only 6 days after challenge. A basal level of chitinases was always detected, but increases in chitinases above this level in immunized plants followed a profile similar to that of the β-1,3-glucanases and other b-proteins. It is likely that β-1,3-glucanases, chitinases, and other b-proteins are coordinately regulated in tobacco. The increases in these proteins coincided with the onset of immunization in plants injected with P. tabacina, and the levels were maintained during the period after challenge, when the development of P. tabacina was restricted
Article
Mercuric chloride treatment of Phaseolus vulgaris (var. ‘Saxa’) leaves, induces the synthesis of four new soluble proteins extractable at pH 2.8. The molecular weights of these proteins were found to be 17 000 for pathogenesis related (PR) 1 and PR 2 proteins, 28 000 for PR 3 protein and 32 000 for PR 4 protein, when determined by sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis. In Alfalfa Mosaic Virus (AMV)-infected bean leaves only three new soluble proteins were found, corresponding to the mercuric chloride-induced PR 1, PR 3 and PR 4 proteins. The four mercuric chloride-induced proteins were purified by a technique including an ammonium sulfate fractionation and a preparative polyacrylamide gel electrophoresis. Some biochemical and serological properties of these proteins have been studied.
Article
Anthracnose of chillies caused by Colletotrichum capsici is a serious disease affecting the yield and quality of fruits. In vitro, greenhouse and field experiments were conducted to evaluate the efficacy of propiconazole, difenoconazole and carbendazim at different concentrations to control the pathogen and disease incidence. Among the fungicides, propiconazole exhibited the highest level of inhibition of in vitro mycelial growth, biomass production, sporulation and spore germination at concentrations as low as 0.1μgml−1. Enzyme (PG, PGTE, PTE and cellulases) production by C. capsici was significantly reduced by incorporation of fungicides into the growth medium. The highest degree of enzyme production inhibition was observed with propiconazole, followed by difenoconazole and carbendazim. Greenhouse and field experiments were conducted to study disease control by spraying propiconazole (0.1%, 0.05%, 0.025% a.i.), difenoconazole (0.05%, 0.025% a.i.) and carbendazim (0.1% a.i.). Application of propiconazole at 0.1% caused a dramatic reduction of disease incidence by 70% when compared to difenoconazole at 0.05% (58%) and carbendazim at 0.1% (44%). Additionally the fruit yield increased in the range of 86%, 63% and 60% for propiconazole, difenoconazole and carbendazim, respectively, when compared to unsprayed controls.