NBS-LRR gene TaRPS2 is positively associated with the high-temperature seedling plant resistance of wheat against Puccinia striiformis f. sp. tritici
Yangshan Hu, Fei Tao, Chang Su, Yue Zhang, Juan Li, Jiahui Wang, Xiangming Xu, Xianming Chen, Hongsheng Shang, Xiaoping Hu
Xiaoyan6 (XY6) is a wheat (Triticum aestivum L.) cultivar possessing non-race-specific high-temperature seedling plant (HTSP) resistance against stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst). Previously, we identified one particular gene, TaRPS2, for its involvement in the HTSP resistance. To elucidate the role of TaRPS2 in the HTSP resistance, we cloned the full length of TaRPS2 from XY6. The transcriptional expression of TaRPS2 was rapidly up-regulated (19.11-fold) under the normal-high-normal temperature treatment that induces the HTSP resistance. The expression level of TaRPS2 in leaves was higher than that in the stems and roots. Quantification of the endogenous hormones in wheat leaves after Pst-inoculation showed that 1-aminocyclopropane-1-carboxylic acid (ACC), salicylic acid (SA), and jasmonic acid (JA) were involved in the HTSP resistance. In addition, detection of the H2O2 accumulation indicated that reactive oxygen species (ROS) burst was also associated with the HTSP resistance. Two hours after exogenous H2O2 treatment or 0.5 h after SA treatment, the expression level of TaRPS2 was increased by 2.66 times and 2.35 times, respectively. The subcellular localization of eGFP-TaRPS2 fusion protein was in the nucleus and plasma membranes. Virus-induced gene silencing of TaRPS2 reduced the level of HTSP resistance in XY6. Compared with the non-silenced leaves, the TaRPS2-silenced leaves had the reduction of necrotic cells but a greater number of uredinia. These results indicated that TaRPS2 positively regulates the HTSP resistance of XY6 against Pst and is related to the SA and H2O2 signaling pathways.