Functional Analysis Of Proteins With CFEM Motifs That Induce Plant Cell Death In Magnaporthe Oryzae

Interactions between rice and Magnaporthe oryzae involve the recognition of cellular components and the exchange of complex molecular signals from both partners.In our previous study,we had verified nine of the predicted effectors from Magnaporthe oryzae induced cell death in N.benthamiana.We identified two genes with CFEM domain(Common in Fungal Extracellular Membrane proteins),previously identified by Dr.Ralph Dean’s group.The structure of CFEM family contains eight-cysteine which is unique to fungal membrane proteins/secreted proteins.In this study,we investigated the function of CFEM by applying molecular genetics approach.We retrieved all the CFEM domain proteins in M.oryzae from NCBI database,19 predicted effector proteins were identified.We have cloned eight MoCFEM genes,and used N.benthamiana transient expression system to assess their function in inducing plant cell death.We found another two MoCFEM genes(MoCFEM3,MoCFEM4)that induced cell death.In order to analysis the function of MoCFEM genes,gene deletion and over-expression strategy were used to detect the potential roles of MoCFEMs in Guyll.We found that the relative growth rate of MoCFEM 1 knock-out mutants was decreased,but the pathogenicity was not reduced when compared with the wild type.We reintroduced the intact MoCFEM 1 gene into knocked out mutant and the phenotypic defect can be restored.Next we need do functional analysis on the mutants completely.Over-expression of MoCFEM3 declined the pathogenicity,the over-expression and knock-out of MoCFEM2 and MoCFEM4 showed no obvious phenotype difference.Taken together,the multiple genes of the rice blast fungus CFEM domain family that induce cell death in N.benthamiana transient expression system.Knocking-out and overexpression study indicated that the CFEM domain family genes may play an important role during the development and plant-pathogen interaction in M.oryzae.