Virulence Mechanism Of Phytophthora Infestans RXLR Effector E49

Potato is the fourth largest food crop in the world.China has the largest planting area yield.The potato late blight caused by Phytophthora infestans seriously threatens potato production.Therefore,studying the pathogenicity mechanisms of Phytophthora infestans will help to control the disease.During the infection process,Phytophthora infestans secretes a large number of RXLR effectors into plant cells.These effectors regulate the physiological processes of host plants and interact with disease-resistant or susceptible host target proteins to inhibit plant immune responses and thereby promote infection by pathogens.In this paper,we studied the virulence function of Phytophthora infestans RXLR effector protein E49,the host target of E49,the function of host target protein and the mechanism under E49 regulation of host target.The main results are as follows:(1)By confocal microscopy we observed that E49 localized in nucleus and cytoplasm;transient expression assays showed that E49 promotes the infection of Phytophthora infestans;the nuclear,cytoplasmic and plasma membrane localized E49 significantly promote the infection of Phytophthora infestans.(2)E49 was used as bait and screened against a Y2 H library,and RIP37 was identified as a putative target.RIP37 is involved in the MAPK signaling pathway and belongs to the family of protein kinases,which has phosphorylation function.(3)The interaction between E49 and RIP37 was verified by yeast double hybrid(Y2H),Co-Immunoprecipitation(Co-IP)and bimolecular fluorescence complementation(BiFC).(4)Overexpression in N.benthamiana significantly promotes the infection of Phytophthora infestans and RIP37 negatively regulates plant immunity.(5)It was detected by Western Blot that E49 had no effect on the protein accumulation of RIP37 and the phosphorylation function of MPK.