Hewitt Tim C, Sharma Keshav, Zhang Jianping, Chen Chunhong, Bajgain Prabin, Bhatt Dhara, Singh Smriti, Olivera Firpo Pablo D, Yang Jun, Wang Qiaoli, Upadhyaya Narayana, Pozniak Curtis, McIntosh Robert, Lagudah Evans, Zhang Peng, Rouse Matthew N
CSIRO Agriculture & Food, Canberra, ACT, Australia.
Immunology & Infectious Diseases, John Curtin School of Medical Research, Australian National University, Canberra, ACT, Australia.
Nat Commun. 2025 May 28;16(1):4905. doi: 10.1038/s41467-025-60030-x.
The wheat stem rust pathogen Puccinia graminis f. sp. tritici (Pgt) causes severe crop losses worldwide. Several stem rust resistance (Sr) genes exhibit temperature-dependent immune responses. Sr6-mediated resistance is enhanced at lower temperatures, whereas Sr13 and Sr21 resistances are enhanced at higher temperatures. Here, we clone Sr6 using mutagenesis and resistance gene enrichment and sequencing (MutRenSeq), identifying it to encode a nucleotide-binding leucine-rich repeat (NLR) protein with an integrated BED domain. Sr6 temperature sensitivity is also transferred to wheat plants transformed with the Sr6 gene. Differential gene expression analysis of near-isogenic lines inoculated with Pgt at varying temperatures reveals that genes upregulated in the low-temperature-effective Sr6 response differ from those upregulated in the high-temperature-effective responses associated with Sr13 and Sr21. These findings highlight divergent molecular pathways involved in temperature-sensitive immunity and inform future strategies for deployment and engineering of genetic resistance in response to a changing climate.
小麦秆锈病病原菌小麦柄锈菌（Puccinia graminis f. sp. tritici，Pgt）在全球范围内造成严重的作物损失。几个秆锈病抗性（Sr）基因表现出温度依赖性免疫反应。Sr6介导的抗性在较低温度下增强，而Sr13和Sr21抗性在较高温度下增强。在这里，我们使用诱变和抗性基因富集与测序（MutRenSeq）克隆了Sr6，确定它编码一种具有整合BED结构域的核苷酸结合富含亮氨酸重复序列（NLR）蛋白。Sr6的温度敏感性也转移到了用Sr6基因转化的小麦植株中。对在不同温度下接种Pgt的近等基因系进行差异基因表达分析表明，在低温有效Sr6反应中上调的基因与在与Sr13和Sr21相关的高温有效反应中上调的基因不同。这些发现突出了参与温度敏感免疫的不同分子途径，并为应对气候变化的遗传抗性部署和工程设计提供了未来策略。
