title: Enhanced biocontrol activity of Trichoderma through inactivation of a mitogen-activated protein kinase.
abstract: The production of lytic enzymes in Trichoderma is considered determinant in its parasitic response against fungal species. A mitogen-activated protein kinase encoding gene, tvk1, from Trichoderma virens was cloned, and its role during the mycoparasitism, conidiation, and biocontrol was examined in tvk1 null mutants. These mutants showed a clear increase in the level of the expression of mycoparasitism-related genes under simulated mycoparasitism and during direct confrontation with the plant pathogen Rhizoctonia solani. The null mutants displayed an increased protein secretion phenotype as measured by the production of lytic enzymes in culture supernatant compared to the wild type. Consistently, biocontrol assays demonstrated that the null mutants were considerably more effective in disease control than the wild-type strain or a chemical fungicide. In addition, tvk1 gene disruptant strains sporulated abundantly in submerged cultures, a condition that is not conducive to sporulation in the wild type. These data suggest that Tvk1 acts as a negative modulator during host sensing and sporulation in T. virens.
authors.affiliation: Department of Plant Genetic Engineering, Centro de Investigación y Estudios Avanzados, Unidad Irapuato, Apartado Postal 629, 36500, Irapuato, Guanajuato, México.
authors.forename: Artemio
authors.initials: A
authors.lastname: Mendoza-Mendoza
authors.forename: María J
authors.initials: MJ
authors.lastname: Pozo
authors.forename: Darlene
authors.initials: D
authors.lastname: Grzegorski
authors.forename: Pedro
authors.initials: P
authors.lastname: Martínez
authors.forename: Juan M
authors.initials: JM
authors.lastname: García
authors.forename: Vianey
authors.initials: V
authors.lastname: Olmedo-Monfil
authors.forename: Carlos
authors.initials: C
authors.lastname: Cortés
authors.forename: Charles
authors.initials: C
authors.lastname: Kenerley
authors.forename: Alfredo
authors.initials: A
authors.lastname: Herrera-Estrella
mesh_terms: D003001:Cloning, Molecular; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005822:Genetic Vectors; D003368:Gossypium / Q000382:microbiology; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors* / Q000235:genetics; D008969:Molecular Sequence Data; D010572:Pest Control, Biological / Q000379:methods; D018517:Plant Roots / Q000382:microbiology; D014242:Trichoderma / Q000187:drug effects / Q000235:genetics / Q000472:pathogenicity*
chemical_list: D004791:Enzyme Inhibitors; D020928:Mitogen-Activated Protein Kinases