MAPKK-encoding gene CfMKK1 in Colletotrichum fructicola is required for its growth and pathogenicity

Abstract:

[Objective] Colletotrichum fructicola is an important pathogen that results in yield loss of Camellia oleifera. We studied the functions of the mitogen-activated protein kinase gene CfMKK1 in C. fructicola for analyzing the pathogenic mechanism of oil-tea tree anthracnose.[Methods] The homologous recombination method was used to construct the CfMKK1 gene-deleted fragment, which was transformed into the protoplasts generated by using PEG-mediated method to obtain the mutant strain △Cfmkk1. The PCR-amplified CfMKK1 gene-containing complement of the promoter of C. fructicola was taken to construct a complementary vector pYF11::CfMKK1, then the complementary vector was transformed into the mutant protoplasts by using PEG-mediated method to screen the complementary strain △Cfmkk1-C. The biological phenotypes of the wild-type strain CFLH16, the mutant strain △Cfmkk1, and the complementary strain △Cfmkk1-C were measured in vegetative growth, appressorium formation, stress response and pathogenicity. [Results] The mycelial growth rate of △Cfmkk1 was significant slowed down compared to the wild-type strain CFLH16 and the complementary strain △Cfmkk1-C, more sensitive to Congo red, lost the ability to infect hosts and was unable to form appressoria.[Conclusion] CfMkk1 is involved in regulating the growth, response to external stress and appressorium formation of C. fructicola, affecting the pathogenicity.