The Function Analysis Of MoSnc1 And Its Relationship With MoVps35 In Magnarporthe Oryzae

Rice blast is one of the most important diseases on rice caused by rice blast fungus（Magnaporthe oryzae）,which seriously affects the world’s rice production.Further study of the growth regulation and pathogenic mechanism of rice blast fungus,is the basis for the prevention and control of rice blast disease.The retromer complex is one of the important members of the endosome protein sorting pathway,which plays an important physiological role by mediating the transport of specific cargoes to specific organelles.In this study,it was confirmed that MoVps35,a core element of retromer complex in rice blast fungus,could mediate the transport of autophagy key gene,MoAtg8,through regulating the autophagy process in appressorium-mediated initiation of blast disease on rice.In spite of this,MoVps35 also exhibits a biological function other than MoAtg8 trafficking,indicating that the retromer complex may also regulate other unknown cargo protein transport in addition to the transport of MoAtg8.In order to elucidate the reverse transporter of the retromer complex,we have identified a series of related proteins,such as SNARE family members MoSncl and MoNyvl,by Pull-down and mass spectrometry technologies.The SNARE protein is a large family of transmembrane proteins located on organelles and vesicles,and plays an important role in membrane fusion processes,endocytosis and exocrine processes.In this paper,the function of SNARE protein（MoSncl）and its interaction with MoVps35 in reverse transport were discussed and studied.Through bioinformatics and phylogenetic analysis,we found that there were two V-SNAREs:Sncl and Snc2 present in S.cerevisiae,but only one V-SNAREs（encoded by MGG₁2614,named MoSncl）was present in the rice blast fungus.In order to clarify the biological function of MoSNC1 gene in rice blast fungus,we knocked out the gene,and then analyzed the related phenotype of the knockout mutant.It was found that there was no significant difference between wild type and the mutations of ΔMosncl in sporulation,appressorium formation and pathogenicity,but the growth rate was weaker than wild type.In order to clarify the relationship between MoSncl and retromer complexes,GFP-MoSncl was expressed in ΔMosncl and ΔMovps35,respectively.It was found that GFP-MoSncl in ΔMosnc1 could complement the growth defects of ΔMosnc1 mutant,and MoSncl is localized to the endosome of conidium and hyphae cell with dotted structure.In ΔMovps35,however,a large number of GFP-MoSncl is positioned in the vacuoles of the rice blast fungus.This result shows that MoVps35 plays an important role in normal localization of MoSnc1.In addition,we also analyzed the localization of MoSncl homologue,MoNyv1,in the wild-type and ΔMovps35,and consistent with the results of GFP-MoSncl,GFP-MoNyvl was also misplaced in vacuoles after the deletion of MoVPS35 gene.In summary,our results show that the SNARE protein MoSncl is involved in the growth and development of M.oryzae,and MoSncl and MoNyvl are located in the endosome in a manner that relies on the retromer complex.