No abstract

Botrytis cinerea is an important necrotrophic fungus that causes gray mold disease in various important crop plants, leading to substantial economic losses. Herein, Agrobacterium tumefaciens-mediated transformation (ATMT) technique was used to create an insertional mutant library of B. cinerea to investigate its pathogenicity-related genes. Among 1,734 transformations only 46 mutants decreased the pathogenicity on tomato leaves. C2M52 is one of the 46 mutants that its pathogenicity reduction was analyzed deeply. The T-DNA integrated into the promoter region of the hypothetical protein (BcHP) gene. The gene replacement approach via homologous recombination was used to generate knock-out mutant (△bchp) and its functional complementary (△bchp-C) strains. The results warranted that the △bchp mutant strain displayed a significant difference in the virulence on tomato leaves relative to the wild type. These results were consistent with the attenuated pathogenicity caused by T-DNA integration mutant (C2M52). That subsequently revealed the crucial role of BcHP gene in the pathogenicity of B. cinerea.