Botrytis cinerea virulence is drastically reduced after disruption of chitin synthase class III gene (Bcchs3a)

• Author(s): Boccara, M.; Choquer, M.; Cimerman, A.; Kunz, C.; Malfatti, P.; Perino, C.; Piffeteau, A.; Soulie, M.; Vidal-Cros, A.;
• Abstract: Botrytis cinerea is an important phytopathogenic fungus requiring new methods of control. Chitin biosynthesis, which involves seven classes of chitin synthases, could be an attractive target. A fragment encoding one of the class III enzymes was used to disrupt the corresponding Bcchs3a gene in the B. cinerea genome. The resulting mutant exhibited a 39% reduction in its chitin content and an 89% reduction in its in vitro chitin synthase activity, compared with the wild-type strain. Bcchs3a mutant was not affected in its growth in liquid medium, neither in its production of sclerotia, micro- and macroconidia. In contrast, the mutant Bcchs3a was severely impaired in its growth on solid medium. Counterbalancing this defect in radial growth, Bcchs3a mutant presented a large increase in hyphal ramification, resulting in an enhanced aerial growth. Observations by different techniques of microscopy revealed a thick extracellular matrix around the hyphal tips. Moreover, Bcchs3a mutant had a largely reduced virulence on Vitis vinifera and Arabidopsis thaliana leaves.
• Publication Date: Aug 2006
• Journal: Cellular Microbiology