Abstract: C6-type transcription factor plays an important role in regulating the growth, development and pathogenicity of plant pathogenic fungi. A C6-type transcription factor gene Cgctf1 was identified from C. gloeosporioides, which encodes 405 amino acids and contains a GAL4 domain. Gene-knockout mutants of Cgctf1 were obtained by homologous recombination, and the complementary strain was obtained on the basis of the mutants. Phenotypic analysis showed that there was no significant difference in vegetative growth between the knockout mutant and the wild type, but the mutant was more sensitive to salt stress and more resistant to H2O2 and SDS. The conidia yield, spore germination rate and appressorium formation rate of the knockout mutant were significantly lower than those of the wild type. Onion epidermis infection and cellophane invasion tests showed that the penetration ability of conidia of the knockout mutant was weakened. On the rubber leaves, the disease spot formed by knockout mutants was smaller than that of wild type, and the mutants had reduced virulence. These results suggest that Cgctf1 is involved in the regulation of conidial development, appressorium formation and invasion, stress response and pathogenicity of C. gloeosporioides.

Key words: Rubber anthracnose, Colletotrichum gloeosporioides, C6-type transcription factor, conidium, pathogenicity