Submitted to: Meeting Abstract
Publication Type: Abstract only
Publication Acceptance Date: 3/2/2002
Publication Date: 4/17/2002
Citation: Hanson, L.E., Lawrence, C., Djonivic, S. 2002. Mechanisms of biological control of plant diseases with trichoderma. Meeting Abstract. Interpretive Summary:
Technical Abstract: Research on biological control with Trichoderma species has demonstrated that different mechanisms are important for different host/disease/biocontrol agent interactions. While antibiosis is important in the control of seedling disease caused by Pythium species, antibiosis and mycoparasitism have little role in control of diseases caused by fungi such as Rhizoctonia solani. Recent work in several laboratories has demonstrated that some strains of Trichoderma can induce a systemic resistance in plants. Tests with Arabidopsis demonstrated that a systemic resistance could be induced by some T. virens strains in this model organism. The resistance pathway is being investigated with Arabidopsis mutants. In addition, a localized resistance response, apparently root-specific, is induced by certain strains of T. virens in crops such as cotton, dry bean, muskmelon, and sugar beet. Sterile culture filtrate from effective biocontrol strains induces similar host responses, and evidence indicates that the active components are proteins. One of these proteins cross-reacts in western blot analysis with an ethylene-inducing xylanase found in T. viride, indicating that a similar protein may be acting in T. virens. However, this is not the most active fraction of the culture filtrate. Work is ongoing to characterize the other active fractions.