Construction of a T-DNA Insertion Mutant Library of Magnaporthe grisea and Identification of Pathogenicity-related Mutants
According to the transformation system established by our laboratory, Magnaporthe grisea strain Y34 was mutated through T-DNA insertion mediated by Agrobacterium tumefaciens strain AGL-1. The transformation efficiency was 300 transformants per 1.0 ×106 conidia of the fungus on average, and 6 855 transformants were obtained. PCR amplification found that all tested transformants were resistant to hygromycin and contained hph gene, indicating that the transformants were T-DNA inserted mutants. DNA Southern blot analysis of 56 T-DNA inserted mutants indicated that the copy number of T-DNA insertion was 1.43, and that 27 mutants were single-copy insertions. Pathogenicity test of randomly selected 1 600 transformants found that 23 mutants completely lost their virulence on a susceptible rice cultivar.