Virulence Research Of Effector Protein PST₁4594 And PST₂3981 Of Puccinia Striiformis F.sp.tritici

Wheat stripe rust,caused by Puccinia striiformis f.sp.tritici?Pst?,is an important fungal disease in wheat production,affect seriously the food production and security.The lack of a stable transformation system for Pst and the rapid variation of Pst,make the research on the function of pathogenicity related genes of wheat stripe rust fungus very difficult.Pst,an obligate biotrophic pathogen,can form haustoria during infection.Pst can not only establish relationship with host through haustoria,but also take nutrients and secret effector proteins from haustoria into host cells,which cause the stripe rust disease.Our lab obtained a lot of secreted proteins of Pst,based on wheat stripe rust haustoria genome sequencing and transcriptome sequencing.And through the expression experiment,some effectors were able to inhibit the cell death caused by BAX.In this study,two of them containing nuclear localization signal,named PST₁4594 and PST₂3981,were selected for further study.By studying pathogenic mechanism of PST₁4594 and PST₂3981,we aimed to provide the theoretical basis for the prevention and control of wheat stripe rust.The main results are as follows:?1?Bioinformatics analysis showed that full length of PST₁4594 was 1767 bp,encoding 588 amino acids,lacking of conserved domain and transmembrane structure,containing NLs,and signal peptide.PST₁4594 was not specific gene for rust fungi and showed low polymorphism among different isolates of stripe rust fungus.The full length of PST₂3981 was 894 bp,encoding 297 amino acids,lacking of transmembrane structure,containing NLs,signal peptide and chloroplast transit peptide.It was a conservative and specific gene for the rust fungi,and showed higher polymorphism among different Pst isolates.?2?Both PST₁4594 and PST₂3981 can inhibit cell death induced by BAX,no matter full length and without signal peptide;and were induced in wheat infected by Pst;the growth and development were inhibited when PST₁4594 was silenced by HIGS.?3?We obtained a host target of PST₁4594,cysteine protease 1?TaCP?;and got two candidate targets of PST₂3981,one was hypothetical protein PSTG₁1069,the other was transmembrane BAX inhibitor motif-containing protein?TaTBI?.?4?Both PST₁4594 and PST₁4594nosp were localized in the whole cells of tobacco.PST₂3981 was localized in chloroplasts,and PST₂3981nosp was localized in nuclei.TaCP and TaTBI were localized in the whole cells of tobacco.