NBS-LRR Gene is Positively Associated with the High-Temperature Seedling Plant Resistance of Wheat Against f. sp. .

Xiaoyan6 (XY6) is a wheat () cultivar possessing nonrace-specific high-temperature seedling plant (HTSP) resistance against stripe rust, caused by f. sp. . Previously, we identified one particular gene, , for its involvement in the HTSP resistance. To elucidate the role of in the HTSP resistance, we cloned the full length of from XY6. The transcriptional expression of was rapidly upregulated (19.11-fold) under the normal-high-normal temperature treatment that induces the HTSP resistance. The expression level of in leaves was higher than that in the stems and roots. Quantification of the endogenous hormones in wheat leaves after f. sp. inoculation showed that 1-aminocyclopropane-1-carboxylic acid, salicylic acid (SA), and jasmonic acid were involved in the HTSP resistance. In addition, detection of hydrogen peroxide (HO) accumulation indicated that reactive oxygen species burst was also associated with the HTSP resistance. Two hours after exogenous HO treatment or 0.5 h after SA treatment, the expression level of was increased by 2.66 and 2.35 times, respectively. The subcellular localization of enhanced green fluorescent protein-TaRPS2 fusion protein was in the nuclei and plasma membranes. Virus-induced gene silencing of reduced the level of HTSP resistance in XY6. Compared with the nonsilenced leaves, the -silenced leaves had the reduction of necrotic cells but a greater number of uredinia. These results indicated that positively regulates the HTSP resistance of XY6 against f. sp. and is related to the SA and HO signaling pathways.