Key Points
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Trichoderma spp. are free-living fungi that are common in soil and root ecosystems. These fungi are well known for their ability to produce a wide range of antibiotic substances and for their ability to parasitize other fungi.
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Until recently, these direct effects on other fungi were thought to be the basis for the beneficial effects of Trichoderma spp. on plant growth and development. However, recent evidence indicates that many Trichoderma spp., including Trichoderma virens, Trichoderma atroviride and Trichoderma harzianum, can induce both localized and systemic resistance in a range of plants to a variety of plant pathogens, and certain strains can also have substantial influence on plant growth and development.
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When propagative Trichoderma structures, such as spores, are added to soil, they come into contact with plant roots and can germinate and grow on root surfaces, and some Trichoderma strains can infect the outer few root cells. Trichoderma spp. produce at least three classes of compound that elicit plant defence responses: peptides, proteins and low-molecular-weight compounds.
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Induced resistance by Trichoderma spp. increases the expression of defence-related genes throughout the plant, at least in the short term, and is therefore similar to systemic acquired resistance (SAR). For one interaction — that between T. asperellum and cucumber — a longer-term response has elements in common with rhizobacteria-induced systemic resistance (RISR).
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Root colonization by Trichoderma spp. also frequently enhances root growth and development, and can therefore improve crop productivity. The greatest long-term effects on productivity are probably associated with rhizosphere-competent strains. These responses are often the result of direct effects on plants, decreased activity of deleterious root microflora, and inactivated toxic compounds in the root zone. Trichoderma spp. also increase nutrient uptake and the efficiency of nitrogen use, and can solubilize nutrients in the soil. At present, the genetic and molecular bases of these effects are unknown.
Abstract
Trichoderma spp. are free-living fungi that are common in soil and root ecosystems. Recent discoveries show that they are opportunistic, avirulent plant symbionts, as well as being parasites of other fungi. At least some strains establish robust and long-lasting colonizations of root surfaces and penetrate into the epidermis and a few cells below this level. They produce or release a variety of compounds that induce localized or systemic resistance responses, and this explains their lack of pathogenicity to plants. These root–microorganism associations cause substantial changes to the plant proteome and metabolism. Plants are protected from numerous classes of plant pathogen by responses that are similar to systemic acquired resistance and rhizobacteria-induced systemic resistance. Root colonization by Trichoderma spp. also frequently enhances root growth and development, crop productivity, resistance to abiotic stresses and the uptake and use of nutrients.
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References
Sivasithamparam, K. & Ghisalberti, E. L. in Trichoderma and Gliocladium Vol. 1 (eds Kubicek, C. P. & Harman, G. E.) 139–191 (Taylor and Francis, London, 1998).
Howell, C. R. Cotton seedling preemergence damping-off incited by Rhizopus oryzae and Pythium spp. and its biological control with Trichoderma spp. Phytopathology 92, 177–180 (2002).
Elad, Y. Mechanisms involved in the biological control of Botrytis cinerea incited diseases. Eur. J. Plant Pathol. 102, 719–732 (1996).
Zimand, G., Elad, Y. & Chet, I. Effect of Trichoderma harzianum on Botrytis cinerea pathogenicity. Phytopathology 86, 1255–1260 (1996).
Benitez, T., Limon, C., Delgado-Jarana, J. & Rey, M. in Trichoderma and Gliocladium Vol. 2 (eds Kubicek, C. P. & Harman, G. E.) 101–127 (Taylor and Francis, London, 1998).
Chet, I., Benhamou, N. & Haran, S. in Trichoderma and Gliocladium Vol. 2 (eds Kubicek, C. P. & Harman, G. E.) 153–172 (Taylor and Francis, London, 1998).
Howell, C. R. Mechanisms employed by Trichoderma species in the biological control of plant diseases: the history and evolution of current concepts. Plant Dis. 87, 4–10 (2003).
Lorito, M. in Trichoderma and Gliocladium Vol. 2 (eds Kubicek, C. P. & Harman, G. E.) 73–99 (Taylor and Francis, London, 1998).
Bolar, J. P. et al. Expression of endochitinase from Trichoderma harzianum in transgenic apple increases resistance to apple scab and reduces vigor. Phytopathology 90, 72–77 (2000).
Bolar, J. P. et al. Synergistic activity of endochitinase and exochitinase from Trichoderma atroviride (T. harzianum) against the pathogenic fungus (Venturia inaequalis) in transgenic apple plants. Trans. Res. 10, 533–543 (2001).
Lorito, M. et al. Genes from mycoparasitic fungi as a source for improving plant resistance to fungal pathogens. Proc. Natl Acad. Sci. USA 95, 7860–7865 (1998).
Donzelli, B. G. G., Ostroff, G. & Harman, G. E. Enhanced enzymatic hydrolysis of langostino shell chitin with mixtures of enzymes from bacterial and fungal sources. Carbohydr. Res. 338, 1823–1833 (2003).
Lindsey, D. L. & Baker, R. Effect of certain fungi on dwarf tomatoes grown under gnotobiotic conditions. Phytopathology 57, 1262–1263 (1967).
Yedidia, I., Srivastva, A. K., Kapulnik, Y. & Chet, I. Effect of Trichoderma harzianum on microelement concentrations and increased growth of cucumber plants. Plant Soil 235, 235–242 (2001).
Chang, Y. -C., Chang, Y. -C., Baker, R., Kleifeld, O. & Chet, I. Increased growth of plants in the presence of the biological control agent Trichoderma harzianum. Plant Dis. 70, 145–148 (1986).
Harman, G. E. Myths and dogmas of biocontrol. Changes in perceptions derived from research on Trichoderma harzianum T22. Plant Dis. 84, 377–393 (2000). Summarizes and synthesizes much that was known about the use of Trichoderma spp., with an emphasis on T-22 and rhizosphere competence, including new evaluations of uses and mechanisms of the organisms.
Baek, J. -M., Howell, C. R. & Kenerley, C. M. The role of an extracellular chitinase from Trichoderma virens Gv29-8 in the biocontrol of Rhizoctonia solani. Curr. Genet. 35, 41–50 (1999).
Limon, M. C., Pintor-Toro, J. A. & Benitez, T. Increased antifungal activity of Trichoderma harzianum transformants that overexpress a 33-kDa chitinase. Phytopathology 89, 254–261 (1999).
Shapira, R., Ordentlich, A., Chet, I. & Oppenheim, A. B. Control of plant diseases by chitinase expressed from cloned DNA in Escherichia coli. Phytopathology 79, 1246–1249 (1989).
Flores, A., Chet, I. & Herrera-Estrella, A. Improved biocontrol activity of Trichoderma harzianum by over-expression of the proteinase-encoding gene prb1. Curr. Genet. 31, 30–37 (1997).
Brunner, K. et al. The Nag1 N-acetylglucosaminidase of Trichoderma atroviride is essential for chitinase induction by chitin and of major relevance to biocontrol. Curr. Genet. 43, 289–295 (2003).
Carsolio, C. et al. Role of the Trichoderma harzianum endochitinase gene, ech42, in mycoparasitism. Appl. Environ. Microbiol. 65, 929–935 (1999).
Woo, S. L. et al. Disruption of the ech42 (endochitinase-encoding) gene affects biocontrol activity in Trichoderma harzianum P1. Mol. Plant Microbe Interact. 12, 419–429 (1999).
Migheli, Q. et al. Transformants of Trichoderma longibrachiatum overexpressing the β-1,4-endoglucanase gene egl1 show enhanced biocontrol of Pythium ultimum on cucumber. Phytopathology 88, 673–677 (1998).
Kuc, J. Concepts and direction of induced systemic resistance in plants and its application. Eur. J. Plant Pathol. 107, 7–12 (2001).
Oostendorp, M., Kunz, W., Dietrich, B. & Staub, T. Induced disease resistance in plants by chemicals. Eur. J. Plant Pathol. 107, 19–28 (2001).
Hammerschmidt, R., Metraux, J. -P. & van Loon, L. C. Inducing resistance: a summary of papers presented at the First International Symposium on Induced Resistance to Plant Diseases, Corfu, May 2000. Eur. J. Plant Pathol. 107, 1–6 (2001).
van Loon, L. C., Bakker, P. A. H. M. & Pieterse, C. M. J. Systemic resistance induced by rhizosphere bacteria. Annu. Rev. Phytopathol. 36, 453–483 (1998).
Bostock, R. M. et al. Signal interactions in induced resistance to pathogens and insect herbivores. Eur. J. Plant Pathol. 107, 103–111 (2001).
Bakker, P. A. H. M., Ran, L. X., Pieterse, C. M. J. & van Loon, L. C. Understanding the involvement of rhizobacteria-mediated induction of systemic resistance in biocontrol of plant diseases. Can. J. Plant Pathol. 25, 5–9 (2003).
Pieterse, C. M. J. & van Loon, L. C. Salicylic acid-independent plant defense pathways. Trends Plant Sci. 4, 52–58 (1999). Describes the nature of RISR and its relationship to other pathways.
Kloepper, J. W., Tuzun, S., Liu, L. & Wei, G. in Pest Management: Biologically Based Technologies: Proceeding of the Beltsville Symposium XVII (eds Lumsden, R. D. & Vaughn, J. L.) 10–20 (American Chemical Society, Washington DC, 1993).
Benhamou, N., Garand, C. & Goulet, A. Ability of non-pathogenic Fusarium oxysporum strain Fo47 to induce resistance against Pythium ultimum infection in cucumber. Appl. Environ. Microbiol. 68, 4044–4060 (2002).
Fuchs, J. G., Moenne-Loccoz, Y. & DeFago, G. Non-pathogenic Fusarium oxysporum strain Fo47 induces resistance to Fusarium wilt of tomato. Plant Dis. 81, 492–496 (1997).
Duijff, B. J. et al. Implication of systemic induced resistance in the suppression of Fusarium wilt of tomato by Pseudomonas fluorescens WCS417r and by non-pathogenic Fusarium oxysporum Fo47. Eur. J. Plant Pathol. 104, 903–910 (1998).
Fravel, D., Olivain, C. & Alabouvette, C. Fusarium oxysporum and its biocontrol. New Phytol. 157, 493–502 (2003).
Hwang, J. & Benson, D. M. Expression of induced resistance in poinsietta cuttings against Rhizoctonia stem rot by treatment of stock plants with binucleate Rhizoctonia. Biol. Control 27, 73–80 (2003).
Guenoune, D. et al. The defense response elicited by Rhizoctonia solani is suppressed by colonization of the AM-fungus Glomus intraradices. Plant Sci. 160, 925–932 (2001).
Pozo, M. J. et al. Localized versus systemic effect of arbuscular mycorrhizal fungi on defence responses of Phytophthora infection in tomato plants. J. Exp. Bot. 53, 525–534 (2002).
Koike, N. et al. Induction of systemic resistance in cucumber against several diseases by plant growth-promoting fungi: lignification and superoxide generation. Eur. J. Plant Pathol. 107, 523–533 (2001). Describes similarities in activity of several beneficial fungi, including some with plant-pathogenic strains of the same species or genera, in their abilities to induce systemic resistance.
Bigirimana, J. et al. Induction of systemic resistance on bean (Phaseolus vulgaris) by Trichoderma harzianum. Med. Fac. Landbouww. Univ. Gent 62, 1001–1007 (1997). Probably the first paper to clearly show induced systemic resistance resulting from an interaction between a plant and a Trichoderma strain.
De Meyer, G., Bigirimana, J., Elad, Y. & Hofte, M. Induced systemic resistance in Trichoderma harzianum T39 biocontrol of Botrytis cinerea. Eur. J. Plant Pathol. 104, 279–286 (1998).
Howell, C. R., Hanson, L. E., Stipanovic, R. D. & Puckhaber, L. S. Induction of terpenoid synthesis in cotton roots and control of Rhizoctonia solani by seed treatment with Trichoderma virens. Phytopathology 90, 248–252 (2000).
Harman, G. E. et al. Biological and integrated control of Botrytis bunch rot of grape using Trichoderma spp. Biol. Control 7, 259–266 (1996).
Lanzuise, S. et al. Cloning of ABC transporter-encoding genes in Trichoderma spp. to determine their involvement in biocontrol. J. Plant Pathol. 84, 184 (2002).
Ruocco, M. et al. ABC transporters in Trichoderma harzianum. The 7th International Mycological Congress, Book of Abstracts, Oslo, Norway, 11–17 August 2002, 354 (2002).
Anderson, R. D. et al. in Cellular and Molecular Aspects of the Plant Hormone Ethylene (eds Pech, J. C., Latché, A. & Balague, C.) 197–204 (Kluwer, Dordrecht, 1993).
Lotan, T. & Fluhr, R. Xylanase, a novel elicitor of pathogenesis-related proteins in tobacco, uses a non-ethylene pathway for induction. Plant Physiol. 93, 811–817 (1990).
Fuchs, Y., Saxena, A., Gamble, H. R. & Anderson, J. D. Ethylene biosynthesis-inducing protein from cellulysin is an endoxylanase. Plant Physiol. 89, 138–143 (1989).
Bailey, B. A., Taylor, R., Dean, J. F. D. & Anderson, J. D. Ethylene biosynthesis-inducing endoxylanase is translocated through the xylem of Nicotiana tabacum cv. xanthi plants. Plant Physiol. 97, 1181–1186 (1991).
Hanson, L. E. & Howell, C. R. Elicitors of plant defense responses from biological control strains of Trichoderma virens. Phytopathology (in the press).
de Wit, P. J. G. M. et al. The molecular basis of co-evolution between Cladosporium fulvum and tomato. Antonie van Leeuwenhoek 81, 409–412 (2002).
Baker, B., Zambryski, P., Staskawicz, B. & Dinesh-Kumar, S. P. Signaling in plant–microbe interactions. Science 276, 726–733 (1997).
Woo, S. L. et al. Identifying biocontrol genes in Trichoderma spp. and mechanisms for activating biocontrol processes. 8th International Congress of Plant Pathology, Christchurch, New Zealand Abstracts, 268 (2003).
Mach, R. L. et al. Expression of two major chitinase genes of Trichoderma atroviride (T. harzianum P1) is triggered by different regulatory signals. Appl. Environ. Microbiol. 65, 1858–1863 (1999).
Zeilinger, S. et al. Chitinase gene expression during mycoparasitic interaction of Trichoderma harzianum with its host. Fungal Genet. Biol. 26, 131–140 (1999).
Woo, S. L. et al. Mycoparasitic Trichoderma strains are activated by host-derived molecules. 6th European Conference on Fungal Genetics, Abstract Book, 6–9 April 2002, Pisa, Italy, 306 (2002).
Kubicek, C. P., Mach, R. L., Peterbauer, C. K. & Lorito, M. Trichoderma: from genes to biocontrol. J. Plant Pathol. 83, 11–23 (2001).
Dubos, B. in Innovative Approaches To Plant Disease Control (ed. Chet, I.) 107–135 (John Wiley and Sons, New York, 1987).
Elad, Y. Biological control of grape grey mould by Trichoderma harzianum. Crop Protect. 13, 35–38 (1994).
Metcalf, D. A. & Wilson, C. R. The process of antagonism of Sclerotium cepivorum in white rot affected onion roots by Trichoderma koningii. Plant Pathol. 50, 249–257 ( 2001).
Thrane, C., Tronsmo, A. & Jensen, D. F. Endo-1,3-β-glucanase and cellulase from Trichoderma harzianum: purification and partial characterization, induction of and biological activity against plant pathogenic Pythium spp. Eur. J. Plant Pathol. 103, 331–344 (1997).
Yedidia, I., Benhamou, N. & Chet, I. Induction of defense responses in cucumber plants (Cucumis sativus L.) by the biocontrol agent Trichoderma harzianum. Appl. Environ. Microbiol. 65, 1061–1070 (1999).
Yedidia, I., Benhamou, N., Kapulnik, Y. & Chet, I. Induction and accumulation of PR protein activity during early stages of root colonization by the mycoparasite Trichoderma harzianum strain T-203. Plant Physiol. Biochem. 38, 863–873 (2000).
Evans, H. C., Holmes, K. A. & Thomas, S. E. Mycobiota of an indigenous Theobroma species (Sterculiaceae) in Ecuador: assessing its potential for biological control of cocoa diseases. Mycol. Prog. 2, 149–160 (2003).
Yedidia, I. et al. Concomitant induction of systemic resistance to Pseudomonas syringae pv. lachrymans in cucumber by Trichoderma asperellum (T-203) and the accumulation of phytoalexins. Appl. Environ. Microbiol. (in the press).
Bailey, B. A. & Lumsden, R. D. in Trichoderma and Gliocladium Vol. 2 (eds Kubicek, C. P. & Harman, G. E.) 185–204 (Taylor and Francis, London, 1998).
Harman, G. E. & Kubicek, C. P. Trichoderma and Gliocladium Vol. 2 (Taylor and Francis, London, 1998). Together with reference 87, this reference presents much of what was known about Trichoderma in 1998.
Lo, C. -T., Nelson, E. B., Hayes, C. K. & Harman, G. E. Ecological studies of transformed Trichoderma harzianum strain 1295-22 in the rhizosphere and on the phylloplane of creeping bentgrass. Phytopathology 88, 129–136 (1998).
Elad, Y. et al. in Modern Fungicides and Antifungal Compounds II (ed. Lyr, H.) 459–467 (Intercept Ltd., 1999).
Elad, Y. & Kapat, A. The role of Trichoderma harzianum protease in the biocontrol of Botrytis cinerea. Eur. J. Plant Pathol. 105, 177–189 (1999).
Harman, G. E., Petzoldt, R., Comis, A. & Chen, J. Interactions between Trichoderma harzianum strain T22 and maize inbred line Mo17 and effects of this interaction on diseases caused by Pythium ultimum and Colletotrichum graminicola. Phytopathology (in the press). References 43, 51, 63, 64, 66 and 72 provide the primary basis of this article and provide the data upon which many of our new concepts are based.
Woo, S. L. et al. Molecular factors involved in the interaction between plants, pathogens and biocontrol fungi. 11th International Congress on Molecular Plant–Microbe Interactions, Volume of Abstracts, St. Petersburg, Russia, July 18–26, 368 (2003).
Datnoff, L. E., Nemec, S. & Pernezny, K. Biological control of Fusarium crown and root rot of tomato in Florida using Trichoderma harzianum and Glomus intraradices. Biol. Control 5, 427–431 (1995).
Nemec, S., Datnoff, L. E. & Strandberg, J. Efficacy of biocontrol agents in planting mixes to colonize plant roots and control root diseases of vegetables and citrus. Crop Protect. 15, 735–742 (1996).
Woo, S., Fogliano, V., Scala, F. & Lorito, M. Synergism between fungal enzymes and bacterial antibiotics may enhance biocontrol. Antonie van Leeuwenhoek 81, 353–356 (2002).
Whipps, J. M. Microbial interactions and biocontrol in the rhizosphere. J. Exp. Bot. 52, 487–511 (2001).
Burr, T. J., Schroth, M. N. & Suslow, T. Increased potato yields by treatment of seedpieces with specific strains of Pseudomonas fluorescens and P. putida. Phytopathology 68, 1377–1383 (1978).
Bakker, A. W. & Schippers, B. Microbial cyanide production in the rhizosphere in relation to potato yield reduction and Pseudomonas spp-mediated plant growth-stimulation. Soil Biol. Biochem. 19, 451–457 (1987).
Ezzi, M. I. & Lynch, J. M. Cyanide catabolizing enzymes in Trichoderma spp. Enzymol. Microb. Technol. 31, 1042–1047 (2002).
Harman, G. E. in Proceedings of International Symposium on Biological Control of Plant Diseases for the New Century — Mode of Action and Application Technology (eds Tzeng, D. D.-S. & Huang, J. W.) 71–84 (National Chung Hsing Univ., Taichung City, 2001).
Harman, G. E. & Donzelli, B. G. G. in Enhancing Biocontrol Agents and Handling Risks (eds Vurro, M. et al.) 114–125 (IOS, Amsterdam, 2001).
Altomare, C., Norvell, W. A., Björkman, T. & Harman, G. E. Solubilization of phosphates and micronutrients by the plant-growth-promoting and biocontrol fungus Trichoderma harzianum Rifai 1295-22. Appl. Environ. Microbiol. 65, 2926–2933 (1999).
Ryu, C. -M. et al. Bacterial volatiles promote growth in Arabidopsis. Proc. Natl Acad. Sci. USA 100, 4927–4932 ( 2003).
Hammond-Kosack, K. E., Staskawicz, B. J., Jones, J. D. G. & Baulcombe, D. C. Functional expression of a fungal avirulence gene from a modified potato virus X genome. Mol. Plant Microbe Interact. 8, 181–185 (1995).
Harman, G. E., Hayes, C. K. & Ondik, K. L. in Trichoderma and Gliocladium Vol. 1 (eds Kubicek, C. P. & Harman, G. E.) 243–270 (Taylor and Francis, London, 1998).
Kubicek, C. P. & Harman, G. E. Trichoderma and Gliocladium Vol. 1. (Taylor and Francis, London, 1998).
Chet, I., Harman, G. E. & Baker, R. Trichoderma hamatum: its hyphal interactions with Rhizoctonia solani and Pythium spp. Microb. Ecol. 7, 29–38 (1981).
Viterbo, A. et al. Expression regulation of the endochitinase chit36 from Trichoderma asperellum (T. harzianum T-203). Curr. Genet. 42, 114–122 (2002).
Inbar, J., Menendez, A. & Chet, I. Hyphal interaction between Trichoderma harzianum and Sclerotinia sclerotiorum and its role in biological control. Soil Biol. Biochem. 28, 757–763 (1996).
Schirmböck, M. et al. Parallel formation and synergism of hydrolytic enzymes and peptaibol antibiotics, molecular mechanisms involved in the antagonistic action of Trichoderma harzianum against phytopathogenic fungi. Appl. Environ. Microbiol. 60, 4364–4370 (1994).
Elad, Y., Sadowsky, Z. & Chet, I. Scanning electron microscopical observations of early stages of interaction of Trichoderma harzianum and Rhizoctonia solani. Trans. Br. Mycol. Soc. 88, 259–263 (1987).
Elad, Y., Chet, I. & Henis, Y. Parasitism of Trichoderma spp. on Rhizoctonia solani and Sclerotium rolfsii — scanning electron microscopy and fluorescence microscopy. Phytopathology 73, 85–88 (1983).
Pieterse, C. M. J. et al. Rhizobacteria-mediated induced systemic resistance: triggering, signalling and expression. Eur. J. Plant Pathol. 107, 51–61 (2001).
Eur. J. Plant Pathol. 107 Issue 1 (2001).
Lumsden, R. D., Locke, J. C., Adkins, S. T., Walter, J. F. & Ridout, C. J. Isolation and localization of the antibiotic gliotoxin produced by Gliocladium virens from alginate prill in soil and soilless media. Phytopathology 82, 230–235 (1992).
Lumsden, R. D. et al. Characterization of major secondary metabolites produced in soilless mix by a formulated strain of the biocontrol fungus Gliocladium virens. Can. J. Microbiol. 38, 1274–1280 (1992).
Wilhite, S. E. & Straney, D. C. Timing of gliotoxin biosynthesis in the fungal biological control agent Gliocladium virens (Trichoderma virens). Appl. Microbiol. Biotechnol. 45, 513–518 (1996).
Lo, C. -T., Liao, T. F. & Deng, T. C. Induction of systemic resistance of cucumber to cucumber green mosaic virus by the root-colonizing Trichoderma spp. Phytopathology 90 (Suppl.), S47 (2000).
Seaman, A. Efficacy of OMRI-approved products for tomato foliar disease control. New York State Integrated Pest Management Program publication 129, 164–167 (New York State Integrated Pest Management Program, New York, 2003).
Ahmed, A. S., Sanchez, C. P. & Candela, M. E. Evaluation of induction of systemic resistance in pepper plants (Capsicum annuum) to Phytopthora capsici using Trichoderma harzianum and its relation with capsidiol accumulation. Eur. J. Plant Pathol. 106, 817–824 (2000).
Acknowledgements
We are grateful to K. Ondik and T. Björkman for suggestions and corrections, to R. Bostock for use of the illustration in Box 3, to J. Bissett for contributions to the text in Box 1, to G. Samuels for helpful discussions and to T. Xu for unpublished information on his research on rice. This work was supported in part by the US–Israel Binational Agricultural Research and Development Fund (G.E.H. and I.C.), the Cornell Center for Advanced Technology and Advanced Biological Marketing and BioWorks, Inc. Research by M.L. was supported by the following projects: FIRB-MIUR 2002; PON-MIUR 2002; EU TRICHOEST; Project EU FAIR 98PL-4140; MIUR-MIPAF 2002; and MIUR PRIN 2002.
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Competing interests
G. E. Harman is co-founder, co-principal investigator and a shareholder in BioWorks, Inc., which manufactures and sells Trichoderma harzianum strain T-22, and is a co-principal inventor, consultant and shareholder in Advanced Biological Marketing, which sells T-22 to the field-crop market.
Glossary
- AXENIC
-
An axenic system comprises a single type of microorganism.
- TELEOMORPH
-
The sexual form of a fungus.
- HETEROKARYOTIC
-
A fungus or other organism that contains multiple types of nucleus.
- RHIZOBACTERIA
-
Bacteria that are commonly associated with, and colonize, roots.
- MYCORRHIZAL FUNGI
-
Mycorrhizae are associations (usually mutualistic) between a fungus and the root of a plant, and are found in most plants. The fungi associate with the primary cortex of the root.
- MYCOPARASITISM
-
Parasitism of one fungus by another fungus.
- ANTIBIOSIS
-
Strains acting through antibiosis produce antifungal metabolites.
- DICOTYLEDONOUS PLANTS
-
Flowering plants, the seedlings of which have two seed leaves (cotyledons).
- MONOCOTYLEDONS
-
Flowering plants that have only one seed leaf (cotyledon).
- APPRESSORIA
-
Specialized pressing organs from which a minute infection peg can grow and infect a cell.
- PHYTOALEXINS
-
Low-molecular-weight compounds that have antimicrobial activity and are produced by plants in response to attack by pathogens.
- XENOBIOTIC
-
A chemical that is present in a natural environment that does not normally occur in nature.
- PETIOLE
-
A slender stem that supports a leaf.
- ENDOPHYTE
-
A non-pathogenic organism living within a plant.
- PHYLLOSPHERE
-
The area immediately adjacent to a root surface.
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Harman, G., Howell, C., Viterbo, A. et al. Trichoderma species — opportunistic, avirulent plant symbionts. Nat Rev Microbiol 2, 43–56 (2004). https://doi.org/10.1038/nrmicro797
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DOI: https://doi.org/10.1038/nrmicro797
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