Functional Analysis Of The Effector Protein Pst03724 In Puccinia Striiformis F.sp.tritici And Creations Of New Disease-resistant Materials Using HIGs Technology

Wheat Stripe rust,caused by fungus Puccinia striiformis f.sp.tritici(Pst)is a devastating disease and can cause serious yield losses of wheat.Although it is one of the most destructive diseases of wheat the pathogenic mechanism of Pst still not well studied.Therefore understanding the pathogenic mechanism of Pst is one of the significant ways to the prevention and control of this disease.The purpose of this study was to elucidate the function of the stripe rust effector gene Pst03724 and to provide a theoretical basis for the functional study of this gene.The full-length cDNA and genomic DNA of Pst03724 were cloned by RT-PCR and PCR and their sequence characteristics were analyzed by means of signal peptide.Gene function has been identified by transient expression,real-time quantitative RT-PCR(qRT-PCR),subcelluar localization,and virus-induced gene silencing(HIGS).Sequence analysis showed that Pst03724 was 387 bp in length.The signal peptide of this effector protein is 1-36 amino acids at the N-terminus,encoding 129 amino acids and containing no transmembrane structure and nuclear localization signals was predicted by the website.Analysis by the yeast secretion system,the signal peptide of Pst03724 has a secretory function which indicated Pst03724 is a typical secreted protein.The results of qRT-PCR showed that Pst03724 was up-regulated during the infection of stripe rust and the expression level was higher at 18 h and 24 h,and peaked at 24 h.The necrosis caused by Pst322 can be significantly suppressed after the injection of the Agrobacterium contained Pst03724.Intracellular localization analysis indicated that Pst03724 was only distributed in the chloroplasts of wheat protoplasts.Silencing Pst03724 reduced the growth and dvelopment of stripe rust and a significant reduction in sporulation.In conclusion,the results indicated that wheat stripe rust effector protein Pst03724 may play an important role in the virulence of stripe rust fungus.