MAPK激酶EqFus3在橡胶树白粉菌寄主识别和侵染过程中的功能研究OA

The MAPK kinase Fus3 plays an important regulatory role in host signal recognition and pathogenic proc-esses of various pathogenic fungi,yet its functions in powdery mildew fungi remains uncharacterized.Erysiphe querci-cola,the causal agent of rubber tree powdery mildew,is a pathogenic fungus infecting rubber trees(Hevea brasiliensis),and this study focused on the functions of EqFus3 in host signal recognition and pathogenicity of this pathogen.Gene expression analysis demonstrated that EqFus3 was significantly up-regulated at the early infection stage and reached its expression peak at 13 hours post-inoculation.The dsRNA-mediated silencing of EqFus3 in fungal spores at the time of inoculation resulted in a marked decrease in fungal invasion rate and attenuated pathogenicity.Exogenous application of cellulose and potassium ions enabled the pathogen to form hyphae and haustoria on glass slides(a non-plant surface),which suggested that cellulose(a major component of plant cell walls)and environmental potassium ions may act as signal molecules for the pathogen to recognize and induce the formation of infection structures.Notably,dsRNA-mediated silencing of EqFus3 abrogated the inductive effects of cellulose and potassium ions on the pathogen,indicating that EqFus3 is involved in the recognition of host-derived and environmental signals.This study clarifies the functional role of Fus3 kinase in host recognition and infection processes of the pathogen.