Analysis Of Two PR Protein Genes From Wheat In The Defense Responses To Puccinia Triticina

In host-pathogen interactions, various novel proteins coded by the host plant butinduced specifically in pathological or related situations. are collectively referred to as“pathogenesis-related proteins”(PRP), In this research, PR5and PR1in PRs family werestudied in order to understand their roles in the response of wheat to leaf rust pathogeninfection. One thaumatin-like proteins gene named TaLr19TLP1from wheat near-isogeniclines TcLr19infected by leaf rust was obtained and semi-quantitative PCR was used todetect the expression profiles of TaLr19TLP1in the interactions between wheat and leafrust and signal molecule. In addition, the expression profiles of TaLr19TLP1protein inwheat were detected by western blotting. In our earlier study, TaLr19PR1gene has beencloned successfully and its expression profiles suggested that the TaLr19PR1was relatedto leaf rust resistance in wheat. In this study, the expression profiles of TaLr19PR1geneinteracted with signal molecular were analyzed. In the meanwhile, the positive transgenicplants transformed with TaLr19PR1gene were obtaind, and found that TcLr19PR1geneplay an important role in wheat development and resistance to leaf rust pathogen attack byphenotypic analysis, histological analysis and Western blotting. Main contents were asfollowed:1. One PR5gene named TaLr19TLP1from the gDNA and cDNA of wheatnear-isogenic lines TcLr19infected by leaf rust was obtained by RT-PCR and silico cloning.The characterization of the TaLr19TLP1was analyzed by bioinformatics software andonline tools, and the sequence was accepted by GenBank as KJ764822.2. Temporal and spatial expression profiles of TaLr19TLP1and TaLr19PR1weredetected by semi-quantitative PCR. The results showed that TaLr19TLP1transcripts wereup-regulated inoculated with leaf rust and more transcripts were accumulated inincompatible interaction than compatible interaction. More transcripts of TaLr19TLP1were detected in stem than leave and root, while more transcripts of TaLr19PR1weredetected in leave than stem and root. In addition, TaLr19TLP1and TaLr19PR1could beinduced by abscisic acid (ABA) and salicylic acid (SA).3. The prokaryotic expression vectors pEASY-TaLr19TLP1and pEASY-TaLr19PR1 were successfully constructed and the optimal conditions for producing target protein weredetermined. The expression profiles of TaLr19TLP1protein in TcLr19and TaLr19PR1protein in positive transgenic plants were detected by western blotting. The results showedthat the accumulation of TaLr19TLP1were higher in incompatible interaction thancompatible interaction, while the accumulation of TaLr19PR1were higher in transgenicpositive plants than control (Zhengzhou5389).4. The phenotypic and histological analysis of transgenic plants inoculated with leafrust was conducted by using Coomassie brilliant blue staining. The results showed thatTaLr19PR1could inhibit the germination of leaf rust spore and the growth of mycelia to acertain extent.All these results suggest that TaLr19TLP1and TcLr19PR1related to wheat resistanceto leaf rust pathogen, which will not only enrich the wheat genetic resources, but alsoprovide new theoretical basis for resistance mechanism.