Functional Characterization Of Alpha-SNAP-Associated Proteins In Soybean And Soybean Cyst Nematode Interaction

Soybeans(Glycine max)is one of the important grain and oil crops in the world,with very high nutritional and economic value.Recently,China's soybean capacity has been insufficient,soy supplies are highly dependent on imports.Soybean quality and yield loss caused by soybean cyst nematode(SCN)is increasing year by year.It is recommended to control SCN in two ways: non-host plant rotation and planting resistant varieties.At present,the resistance of commercial resistant soybean varieties is gradually losing,so the resistance gene screening and analysis of its mechanism is imminent.At rhg1 locus,three genes related to SCN resistance were encoded encoding a putative amino acid permease,an ?-SNAP and a predicted wound-inducible protein.Polymorphism was found at the C-terminus of ?-SNAP proteins,which participate in the SNARE complex recycling process.This study is mainly to continue the functional analysis of ?-SNAP gene.1.The results of ?-SNAP(HC)yeast two-hybrid library screening showed that the majority of the interacting proteins obtained are components of SNARE complex,and the preliminary phenotypic characterization of three R-SNAREs indicated that R-SNARE is involved in SCN resistance,and functional difference was observed between its subfamilies 2.?-SNAP(WT/HC)interacts with GmSYP31 A and GmVDAC1 D,respectively,and GmSYP31 A interacts directly with GmVDAC1 D in yeast.3.GmSYP31 A and the homologous gene GmSYP31 B can induce cell death,and GmSYP31 A co-infiltrated with ?-SNAP can accelerate cell death.The transmembrane domain of GmSYP31 A is important for the process,with cytotoxicity diminished after TM domain deletion.4.GmSYP31 A can induce mitochondrial membrane depolarization,VDAC anion channel inhibitor DIDS treatment can reduce cytotoxicity significantly,suggesting that GmSYP31A-induced cell death is dependent on VDAC.5.GmSYP31 A affects the secretion pathways of ER-Golgi and secretory proteins with Sec-GFP and PR1-GFP tested.6.GmSYP31 A gene silencing increased sensitivity to SCN and over-expression increased SCN resistance in susceptible soybean variety.In resistant variety,the phenotype to SCN was opposite,indicating function of GmSYP31 A was background dependent.In summary,this study mainly explored the function of GmSYP31 A on soybean cyst nematode resistance.We found that GmSYP31A-mediated cell death is dependent on VDAC,which might further contribute to Rhg1-mediated SCN resistance.The results will be useful for further understanding of the SCN resistance mechanism and for breeding new varieties of nematode resistant soybeans.