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ABSTRACT: Recently, there have been many exciting new developments relating to the use of Trichoderma spp. as agents for biocontrol of pathogens and as plant growth promoters. Several mechanisms have been proposed to explain the positive effects of these microorganisms on the plant host. One factor that contributes to their beneficial biological activities is related to the wide variety of metabolites that they produce. These metabolites have been found not only to directly inhibit the growth and pathogenic activities of the parasites, but also to increase disease resistance by triggering the system of defence in the plant host. In addition, these metabolites are also capable of enhancing plant growth, which enables the plant to counteract the disease with compensatory vegetative growth by the augmented production of root and shoot systems. This review takes into account the Trichoderma secondary metabolites that affect plant metabolism and that may play an important role in the complex interactions of this biocontrol agent with the plant and pathogens.
Natural product communications 11/2012; 7(11):1545-50. · 1.24 Impact Factor
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Microbiology 01/2012; 158(Pt 1):1-2. · 3.06 Impact Factor
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ABSTRACT: A novel metabolite, 3-hydroxy-5-(6-isopropyl-3-methylene-3,4,4a,5,6,7,8,8a-octahydronaphthalen-2-yl)dihydrofuran-2-one, trivially named cerinolactone (1), has been isolated from culture filtrates of Trichoderma cerinum together with three known butenolides containing the 3,4-dialkylfuran-2(5H)-one nucleus, harzianolide (2), T39butenolide (3), and dehydroharzianolide (4). The structure of 1 was determined by spectroscopic methods, including UV, MS, and 1D and 2D NMR analyses. In vitro tests with the purified compound exhibited activity against Pythium ultimum, Rhizoctonia solani, and Botrytis cinerea.
Journal of Natural Products 12/2011; 75(1):103-6. · 3.13 Impact Factor
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ABSTRACT: Pleiotropic drug resistant (PDR/ABCG) genes are involved in plant response to biotic and abiotic stresses. In this work, we cloned, from Solanum tuberosum, four PDR/ABCG transporter genes named StPDR1, StPDR2, StPDR3 and StPDR4, which were differentially expressed in plant tissues and cell cultures. A number of different chemically unrelated compounds were found to regulate the transcript levels of the four genes in cultured cells. In particular, StPDR2 was highly up-regulated in the presence of Botrytis cinerea cell walls, NaCl, 2,4-dichlorophenol, sclareol and α-solanin and biological compounds. The expression of the genes was also investigated by real time RT-PCR during infection by Phytophthora infestans. StPDR1 and StPDR2 were up-regulated about 13- and 37-fold at 48 h post-infection (hpi), StPDR3 was expressed (4-5-fold) at 24 and 48 hpi and then rapidly decreased, while StPDR4 RNA accumulation was stimulated (about 4-fold) at 12 and 24 hpi, decreased at 48 hpi and increased again at 96 hpi. We discuss the role of StPDR1-4 genes in response to pathogens and abiotic stresses.
Journal of plant physiology 09/2011; 168(18):2225-33. · 2.50 Impact Factor
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ABSTRACT: Rhizosphere-competent fungi of the genus Trichoderma are widely used as biofertilizers and biopesticides in commercial formulates because of the multiple beneficial effects on plant growth and disease resistance. In this work, we demonstrate that genetic variability among wild and cultivated tomato lines affects the outcome of the interaction with two 'elite' biocontrol strains of T. atroviride and T. harzianum. The beneficial response, which included enhanced growth and systemic resistance against Botrytis cinerea, was clearly evident for some, but not all, the tested lines. At least in one case (line M82), treatment with the biocontrol agents had no effect or was even detrimental. Expression studies on defence-related genes suggested that the fungus is able to trigger, in the responsive lines, a long-lasting up-regulation of the salicylic acid pathway in the absence of a pathogen, possibly activating a priming mechanism in the plant. Consequently, infection with B. cinerea on plants pretreated with Trichoderma is followed by enhanced activation of jasmonate-responsive genes, eventually boosting systemic resistance to the pathogen in a plant genotype-dependent manner. Our data indicate that, at least in tomato, the Trichoderma induced systemic resistance mechanism is much more complex than considered so far, and the ability of the plant to benefit from this symbiotic-like interaction can be genetically improved.
Molecular Plant Pathology 05/2011; 12(4):341-54. · 3.90 Impact Factor
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ABSTRACT: Serine protease inhibitors (PIs) are a large and complex group of plant proteins. Members of the potato type I (Pin1) and II (Pin2) proteinase inhibitor families are among the first and most extensively characterized plant PIs. Many insects and phytopathogenic microorganisms use intracellular and extracellular serine proteases playing important roles in pathogenesis. Plants, however, are able to fight these pathogens through the activation of an intricate defence system that leads to the accumulation of various PIs, including Pin1 and Pin2. Several transgenic plants over-expressing members of the Pin1 and Pin2 families have been obtained in the last twenty years and their enhanced defensive capabilities demonstrated against insects, fungi and bacteria. Furthermore, Pin1 and Pin2 genetically engineered plants showed altered regulation of different plant physiological processes (e.g., dehydratation response, programmed cell death, plant growth, trichome density and branching), supporting an endogenous role in various plant species in addition to the well established defensive one. This review summarizes the current knowledge about Pin1 and Pin2 structure, the role of these proteins in plant defence and physiology, and their potential exploitation in biotechnology.
Current Protein and Peptide Science 03/2011; 12(5):374-85. · 2.89 Impact Factor
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ABSTRACT: Structural and functional genomics investigations are making an important impact on the current understanding and application of microbial agents used for plant disease control. Here, we review the case of Trichoderma spp., the most widely applied biocontrol fungi, which have been extensively studied using a variety of research approaches, including genomics, transcriptomics, proteomics, metabolomics, etc. Known for almost a century for their beneficial effects on plants and the soil, these fungi are the subject of investigations that represent a successful case of translational research, in which 'omics-generated novel understanding is directly translated in to new or improved crop treatments and management methods. We present an overview of the latest discoveries on the Trichoderma expressome and metabolome, of the complex and diverse biotic interactions established in nature by these microbes, and of their proven or potential importance to agriculture and industry.
Annual Review of Phytopathology 05/2010; 48:395-417. · 9.88 Impact Factor
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ABSTRACT: A Trichoderma harzianum strain, isolated from composted hardwood bark in Western Australia, was found to produce a metabolite with antifungal and plant growth promoting activity. The structure and absolute configuration of the fungal compound, harzianic acid (1), were determined by X-ray diffraction studies. Harzianic acid showed antibiotic activity against Pythium irregulare, Sclerotinia sclerotiorum, and Rhizoctonia solani. A plant growth promotion effect was observed at low concentrations of 1.
Journal of Natural Products 11/2009; 72(11):2032-5. · 3.13 Impact Factor
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ABSTRACT: Considering the complexity of the in vivo interactions established by a mycoparasitic biocontrol agent at the plant rhizosphere, proteomic, genomic, and transcriptomic approaches were used to study a novel Trichoderma gene coding for a plant cell wall (PCW)-degrading enzyme. A proteome analysis, using a three-component (Trichoderma spp.-tomato plantlets-pathogen) system, allowed us to identify a differentially expressed Trichoderma harzianum endopolygalacturonase (endoPG). Spot 0303 remarkably increased only in the presence of the soilborne pathogens Rhizoctonia solani and Pythium ultimum, and corresponded to an expressed sequence tag from a T. harzianum T34 cDNA library that was constructed in the presence of PCW polymers and used to isolate the Thpg1 gene. Compared with the wild-type strain, Thpg1-silenced transformants showed lower PG activity, less growth on pectin medium, and reduced capability to colonize tomato roots. These results were combined with microarray comparative data from the transcriptome of Arabidopsis plants inoculated with the wild type or a Thpg1-silenced transformant (ePG5). The endoPG-encoding gene was found to be required for active root colonization and plant defense induction by T. harzianum T34. In vivo assays showed that Botrytis cinerea leaf necrotic lesions were slightly smaller in plants colonized by ePG5, although no statistically significant differences were observed.
Molecular Plant-Microbe Interactions 09/2009; 22(8):1021-31. · 4.43 Impact Factor
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ABSTRACT: Successful biocontrol interactions often require that the beneficial microbes involved are resistant or tolerant to a variety of toxicants, including antibiotics produced by themselves or phytopathogens, plant antimicrobial compounds, and synthetic chemicals or contaminants. The ability of Trichoderma spp., the most widely applied biocontrol fungi, to withstand different chemical stresses, including those associated with mycoparasitism, is well known. In this work, we identified an ATP-binding cassette transporter cell membrane pump as an important component of the above indicated resistance mechanisms that appears to be supported by an extensive and powerful cell detoxification system. The encoding gene, named Taabc2, was cloned from a strain of Trichoderma atroviride and characterized. Its expression was found to be upregulated in the presence of pathogen-secreted metabolites, specific mycotoxins and some fungicides, and in conditions that stimulate the production in Trichoderma spp. of antagonism-related factors (toxins and enzymes). The key role of this gene in antagonism and biocontrol was demonstrated by the characterization of the obtained deletion mutants. They suffered an increased susceptibility to inhibitory compounds either secreted by pathogenic fungi or possibly produced by the biocontrol microbe itself and lost, partially or entirely, the ability to protect tomato plants from Pythium ultimum and Rhizoctonia solani attack.
Molecular Plant-Microbe Interactions 04/2009; 22(3):291-301. · 4.43 Impact Factor
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ABSTRACT: Protease inhibitors (PIs) are small ubiquitous proteins with a variety of biological functions in plants, including protein stabilization, modulation of apoptosis and defense against pathogens. Kunitz-like inhibitors (PKPIs) and proteinase inhibitors 1 (PI-1) are abundant in storage organs of potato plants and are up-regulated in other tissues in response to biotic and abiotic stress. However, little information is available on genotype-dependent regulation of individual PKPI group- and PI-1 genes. We isolated, sequenced and characterized four novel full-length PI-1 cDNAs (PPI3A2, PPI3A4, PPI2C4 and PPI2C1A) from Solanum tuberosum cv. Desirée. Specific primers were developed for PI-1 genes PPI3A2, PPI3B2 and PPI2C4 and the three PKPI homology groups A, B and C. Their expression profiles were studied by semi-quantitative RT-PCR in comparison with transcripts of the PI-1, Pin2 and PR1 gene families in various tissues, after wounding and Globodera rostochiensis infection of nematode-resistant genotypes P40 and LB7/4/c-I-7, and susceptible cv. Desirée. Individual PI-1 genes and PKPI homology groups were expressed in a tissue- and genotype-dependent manner after wounding and nematode infection. The differences in PI expression patterns were related to the intensity, type of inhibitors produced, and the kinetics of induction. Therefore, different genotype-environment combinations produce different sets of PI transcripts. Potato plants reacted to G. rostochiensis infection by modulating PKPI, PI-1 and Pin2, but not PR1 gene expression, suggesting that the jasmonic acid but not the salicylic acid defense signaling pathway is activated. PI expression profiles were not correlated with the resistance status of the potato genotype infected with G. rostochiensis.
Journal of plant physiology 01/2009; 166(7):762-74. · 2.50 Impact Factor
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ABSTRACT: Biotechnology has allowed the development of novel strategies to obtain plants that are more resistant to pests, fungal pathogens and other agents of biotic stress. The obvious advantages of having genotypes with multiple beneficial traits have recently fostered the development of gene pyramiding strategies, but less attention has been given to the study of genes that can increase resistance to different types of harmful organisms. Here we report that a recombinant Chitinase A protein of the Autographa californica nuclear polyhedrosis virus (AcMNPV) has both antifungal and insecticide properties in vitro. Transgenic tobacco plants expressing an active ChiA protein showed reduced damages caused by fungal pathogens and lepidopteran larvae, while did not have an effect on aphid populations. To our knowledge, this is the first report on the characterisation and expression in plants of a single gene that increases resistance against herbivorous pests and fungal pathogens and not affecting non-target insects. The implications and the potential of the ChiA gene for plant molecular breeding and biotechnology are discussed.
Transgenic Research 09/2008; 17(4):557-71. · 2.75 Impact Factor
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ABSTRACT: The worldwide commercial production of the oyster mushroom Pleurotus ostreatus is currently threatened by massive attacks of green mold disease. Using an integrated approach to species recognition comprising analyses of morphological and physiological characters and application of the genealogical concordance of multiple phylogenetic markers (internal transcribed spacer 1 [ITS1] and ITS2 sequences; partial sequences of tef1 and chi18-5), we determined that the causal agents of this disease were two genetically closely related, but phenotypically strongly different, species of Trichoderma, which have been recently described as Trichoderma pleurotum and Trichoderma pleuroticola. They belong to the Harzianum clade of Hypocrea/Trichoderma which also includes Trichoderma aggressivum, the causative agent of green mold disease of Agaricus. Both species have been found on cultivated Pleurotus and its substratum in Europe, Iran, and South Korea, but T. pleuroticola has also been isolated from soil and wood in Canada, the United States, Europe, Iran, and New Zealand. T. pleuroticola displays pachybasium-like morphological characteristics typical of its neighbors in the Harzianum clade, whereas T. pleurotum is characterized by a gliocladium-like conidiophore morphology which is uncharacteristic of the Harzianum clade. Phenotype MicroArrays revealed the generally impaired growth of T. pleurotum on numerous carbon sources readily assimilated by T. pleuroticola and T. aggressivum. In contrast, the Phenotype MicroArray profile of T. pleuroticola is very similar to that of T. aggressivum, which is suggestive of a close genetic relationship. In vitro confrontation reactions with Agaricus bisporus revealed that the antagonistic potential of the two new species against this mushroom is perhaps equal to T. aggressivum. The P. ostreatus confrontation assays showed that T. pleuroticola has the highest affinity to overgrow mushroom mycelium among the green mold species. We conclude that the evolutionary pathway of T. pleuroticola could be in parallel to other saprotrophic and mycoparasitic species from the Harzianum clade and that this species poses the highest infection risk for mushroom farms, whereas T. pleurotum could be specialized for an ecological niche connected to components of Pleurotus substrata in cultivation. A DNA BarCode for identification of these species based on ITS1 and ITS2 sequences has been provided and integrated in the main database for Hypocrea/Trichoderma (www.ISTH.info).
Applied and Environmental Microbiology 12/2007; 73(22):7415-26. · 3.83 Impact Factor
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ABSTRACT: Trichoderma is one of the most promising biocontrol agents against plant fungal diseases. In this study, a transgenic strain of Trichoderma atroviride was characterized. The transgenic strain contains an endochitinase gene (ThEn-42) driven by the cellulase promoter cbh1 of T. reesei for overexpression of ThEn-42. The culture filtrates of the transformant and the parental strain grown in eight different media were evaluated for chitinase and antifungal enzyme production based on activity gels, protein profiles, and antifungal activities. Results demonstrated that chitinases are important components and synergistic interactions play a key role in the antagonistic action of T. atroviride. Moreover, altering medium nutrient concentration and composition led to enhanced production of antifungal enzymes, a potential strategy for mass production. Two of the culture filtrates contained almost pure endochitinase, and could be excellent commercial sources for this enzyme. Several culture filtrates were highly antifungal. Two filtrates were so effective in biocontrol of a fungal pathogen, Penicillium digitatum, that they not only inhibited spore germination but destroyed the spores completely when 20 microl of culture filtrate (corresponding to approximately 104 microg of total protein) was applied in a total volume of 150 microl (approximately 0.7 mg protein ml(-1)).
Applied Biochemistry and Biotechnology 08/2007; 142(1):81-94. · 1.94 Impact Factor
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ABSTRACT: Amadoriase I is a fructosyl amine oxidase from Aspergillus fumigatus that catalyzes the oxidation of Amadori products (APs) producing glucosone, H2O2, and the corresponding free amine. All the enzymes of this family discovered so far only deglycate small molecular weight products and are inactive toward large molecular weight substrates, such as glycated BSA or ribonuclease A. Therefore, they cannot be used to reverse protein glycation occurring in diabetes or in foods. In this paper, the effect of Amadoriase I added during the in vitro reaction between glucose and peptides having different polarities or proteins with molecular weights ranging from to 5 to 66 kDa was tested. The formation of APs was monitored by ESI-MS of intact glycated protein or peptides and by measuring the Nepsilon-(1-deoxy-d-fructos-1-yl)-L-lysine and furosine concentrations. Results showed that the formation of APs is reduced up to 80% when peptides and glucose are incubated in the presence of Amadoriase. The effect is more evident for hydrophobic peptides. In protein-glucose systems, the effect was dependent on the molecular weight and steric hindrance being negligible for BSA and at a maximum for insulin, where the formation of APs was reduced up to 60%. These findings indicate new potential applications of Amadoriase I as an efficient tool for inhibiting protein glycation in real food systems.
Journal of Agricultural and Food Chemistry 06/2007; 55(10):4189-95. · 2.82 Impact Factor
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ABSTRACT: Calcium is commonly involved as intracellular messenger in the transduction by plants of a wide range of biotic stimuli, including signals from pathogenic and symbiotic fungi. Trichoderma spp. are largely used in the biological control of plant diseases caused by fungal phytopathogens and are able to colonize plant roots. Early molecular events underlying their association with plants are relatively unknown.
Here, we investigated the effects on plant cells of metabolite complexes secreted by Trichoderma atroviride wild type P1 and a deletion mutant of this strain on the level of cytosolic free Ca2+ and activation of defense responses. Trichoderma culture filtrates were obtained by growing the fungus alone or in direct antagonism with its fungal host, the necrotrophic pathogen Botrytis cinerea, and then separated in two fractions (>3 and <3 kDa). When applied to aequorin-expressing soybean (Glycine max L.) cell suspension cultures, Trichoderma and Botrytis metabolite mixtures were distinctively perceived and activated transient intracellular Ca2+ elevations with different kinetics, specific patterns of intracellular accumulation of reactive oxygen species and induction of cell death. Both Ca2+ signature and cellular effects were modified by the culture medium from the knock-out mutant of Trichoderma, defective for the production of the secreted 42 kDa endochitinase.
New insights are provided into the mechanism of interaction between Trichoderma and plants, indicating that secreted fungal molecules are sensed by plant cells through intracellular Ca2+ changes. Plant cells are able to discriminate signals originating in the single or two-fungal partner interaction and modulate defense responses.
BMC Plant Biology 01/2007; 7:41. · 3.45 Impact Factor
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Roberta Marra,
Patrizia Ambrosino,
Virginia Carbone,
Francesco Vinale,
Sheridan L Woo,
Michelina Ruocco,
Rosalia Ciliento,
Stefania Lanzuise,
Simona Ferraioli,
Ida Soriente,
Sarah Gigante,
David Turrà,
Vincenzo Fogliano,
Felice Scala, Matteo Lorito
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ABSTRACT: The main molecular factors involved in the complex interactions occurring between plants (bean), two different fungal pathogens (Botrytis cinerea, Rhizoctonia solani) and an antagonistic strain of the genus Trichoderma were investigated. Two-dimensional (2-D) electrophoresis was used to analyze separately collected proteomes from each single, two- or three-partner interaction (i.e., plant, pathogenic and antagonistic fungus alone and in all possible combinations). Differential proteins were subjected to mass spectrometry and in silico analysis to search for homologies with known proteins. In the plant proteome, specific pathogenesis-related proteins and other disease-related factors (i.e., potential resistance genes) seem to be associated with the interaction with either one of the two pathogens and/or T. atroviride. This finding is in agreement with the demonstrated ability of Trichoderma spp. to induce systemic resistance against various microbial pathogens. On the other side, many differential proteins obtained from the T. atroviride interaction proteome showed interesting homologies with a fungal hydrophobin, ABC transporters, etc. Virulence factors, like cyclophilins, were up-regulated in the pathogen proteome during the interaction with the plant alone or with the antagonist too. We isolated and confidently identified a large number of protein factors associated to the multi-player interactions examined.
Current Genetics 12/2006; 50(5):307-21. · 2.56 Impact Factor
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ABSTRACT: Nutritionists recommend increasing the intake of soluble dietary fiber (SDF), which is very low in most cereal-based products. Conversion of insoluble DF (IDF) into SDF can be achieved by chemical treatments, but this affects the sensorial properties of the products. In this study, the possibility of getting a substantial increase of SDF from cereal products using a tailored preparation of Trichoderma enzymes is reported. Enzymes were produced cultivating Trichoderma using durum wheat fiber (DWF) and barley spent grain (BSG) as unique carbon sources. Many Trichoderma strains were screened, and the hydrolysis conditions able to increase by enzymatic treatment the amount of SDF in DWF and BSG were determined. Results demonstrate in both products that it is possible to triple the amount of SDF without a marked decrease of total DF. The enzymatic treatment also causes the release of hydroxycinnamic acids, mainly ferulic acid, that are linked to the polysaccharides chains. This increases the free phenolic concentration, the water-soluble antioxidant activity, and, in turn, the phenol compounds bioavailability.
Journal of Agricultural and Food Chemistry 11/2006; 54(20):7863-9. · 2.82 Impact Factor
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ABSTRACT: Biocontrol agents generally do not perform well enough under field conditions to compete with chemical fungicides. We determined whether transgenic strain SJ3-4 of Trichoderma atroviride, which expresses the Aspergillus niger glucose oxidase-encoding gene, goxA, under a homologous chitinase (nag1) promoter had increased capabilities as a fungal biocontrol agent. The transgenic strain differed only slightly from the wild-type in sporulation or the growth rate. goxA expression occurred immediately after contact with the plant pathogen, and the glucose oxidase formed was secreted. SJ3-4 had significantly less N-acetylglucosaminidase and endochitinase activities than its nontransformed parent. Glucose oxidase-containing culture filtrates exhibited threefold-greater inhibition of germination of spores of Botrytis cinerea. The transgenic strain also more quickly overgrew and lysed the plant pathogens Rhizoctonia solani and Pythium ultimum. In planta, SJ3-4 had no detectable improved effect against low inoculum levels of these pathogens. Beans planted in heavily infested soil and treated with conidia of the transgenic Trichoderma strain germinated, but beans treated with wild-type spores did not germinate. SJ3-4 also was more effective in inducing systemic resistance in plants. Beans with SJ3-4 root protection were highly resistant to leaf lesions caused by the foliar pathogen B. cinerea. This work demonstrates that heterologous genes driven by pathogen-inducible promoters can increase the biocontrol and systemic resistance-inducing properties of fungal biocontrol agents, such as Trichoderma spp., and that these microbes can be used as vectors to provide plants with useful molecules (e.g., glucose oxidase) that can increase their resistance to pathogens.
Applied and Environmental Microbiology 08/2005; 71(7):3959-65. · 3.83 Impact Factor
