Function Analysis Of MiSCG5L Gene From The Root-knot Nematode Meloidogyne Incognita

Root knot nematodes(Meloidogyne spp.)are among the most devastating plant-parasitic nematodes and can lead to significant yield losses worldwide.Nematode effector proteins secreted through the stylet into plant cells,where they play essential roles in parasitism initiation and maintenance.In this paper,the function of Meloidogyne incognita effector MiSCG5L was preliminarily studied by using bioinformatics analysis,developmental expression analysis,subcellular localization,transient expression,in vitro RNAi and overexpression.The main results are summarized as follow:1.Bioinformatics analysis show that MiSCG5L contains a nuclear localization signal and a signal peptide.MiSCG5L was located in plant nuclei,and the it was showed that MiSCG5L was mainly expressed at parasitic J2s stage.These results indicated that MiSCG5L protein was secreted from M.incognita and has a primary role during the early stages of nematode parasitism.2.Transient expression of MiSCG5L gene in tobacco show that MiSCG5L suppresses ROS burst and expression levels of plant defence genes WRKY7,WRKR8,PTI5,ACRE31and GRAS2.This provided direct evidence that MiSCG5L can function as a suppressor of the PTI response in plants.Further,the nuclear localization signal mutant MiSCG5L^?SP?NLScould not suppress the PTI response in plants,which indicated that the nuclear localization signal plays essential roles in the function of MiSCG5L.3.In vitro RNAi of MiSCG5L exhibited a significant reduction on the number of galls.However,the MiSCG5L transgenic lines could reinstate parasitic ability of nematodes treated with ds RNA silencing.These results indicated that MiSCG5L play an important role in parasitic ability of M.incognita.