Cloning And Functional Analysis Of TaRPM1 Gene Invovled In High Temperature Resistance To Stripe Rust Of Xiaoyan 6

Wheat stripe rust caused by Puccinia striiformis f.sp.tritici（Pst）,is one of the important diseases of wheat（Triticum aestivum）around the worldwide.It seriously threatens safety in Chinese food production.Wheat high temperature resistance to stripe rust is a kind of low response type,race-non-specific and durable resistance,which is induced by relative high temperature.Xiaoyan 6（XY 6）,an all-stage high-temperature resistant cultivar,can be used as a new method to solve the loss of rust resistance in wheat varieties.Based on the sequencing and analysis of transcriptome in our group,1395 differential genes were found.Hub protein PP2C10,NBS-LRR resistance genes,WRKY transcriptional factors and protein kinases were identified as key genes involved in high temperature resistance of XY 6.Among them,TaRPM1gene,belongs to NBS-LRR resistance gene,was up-regulated 2.6-fold after high temperature treatment compared with normal temperature.Therefore,in our study,we cloned TaRPM1 gene and studied its function in the resistance using virus-induced gene silencing technology（VIGS）,in order to provide materials and ideas for the exploration of rust-resistant genes and for molecular breeding.The main results were as followings:1.The TaRPM1 gene was cloned.The full-length gene is 3325 bp and encodes 917 amino acids with molecular mass of 103.31 k Da and an isoelectric point of 6.84.The protein shares100%with the Aet RPM1-like protein of Aegilops tauschii.The similarities between TaRPM1and TaRPM1-1AS,TaRPM1-1DS,and TaRPM1-1BS in wheat genome database were 99%,96%,and 89%,respectively.2.TaRPM1 was expressed in roots,stems,and leaves of XY 6,and the expression level in leaves was significantly higher than that in roots and stems.The expression of TaRPM1 was increased in plants treated with SA and H₂O₂,decreased in plants treated with ABA at late stage,and no significant change in plants treated with ET and Me JA.3.The expression of TaRPM1 gene in XY 6 was dual-induced by temperature and stripe rust.The expression pattern of TaRPM1 was detected by fluorescence quantitative PCR technology.The results showed that temperature change have no effect on the expression level of TaRPM1 under non-inoculation,but the expression of TaRPM1 was up-regulated at HT（Transfer from 15℃to 20℃for 24 h in necrotic lesion and back to 15℃）compared with NT（Normal temperature 15℃）,especially 2.4 and 3.3 folds at 204 h and 216 h post inoculation.4.TaRPM1 positively involved in high temperature resistance to Pst of XY 6.Silencing TaRPM1 led to significantly weaker resistance to Pst,decrease on the number of necrotic cells,and increase on the linear length of spores.In addition,related defense genes Ta PR1 and Ta CAT were down-regulated in SA and ROS signaling pathway.