论文题目：Functional Dissection of a Wheat NLR Protein Reveals a Minimal Active Region and Key Regulatory Sites for Immune Signalling
论文作者：Xiaoxu Zhu, Shuo Jiang, Jinchen Zhao, Fangfang Peng, Ran Zhao, Xinnuo Li, Yi Luo, Zhihao Xiong, Qi Li, Filip Rolland, Zhensheng Kang, Xiaojie Wang, Yunqi Liu, Li Huang, Xiaojing Wang
论文摘要：Nucleotide-binding site (NBS) leucine-rich repeat (LRR) receptors (NLRs) are crucial for plant immunity but often come with trade-offs in plant growth. Understanding the mechanisms of their self-regulating activity for controlled immune responses is essential for optimising crop resistance. In this study, we investigated the activity fine-tuning of the wheat NLR protein NLRMoro, derived from the cultivars Moro and AvS + Yr10. Overexpression in Nicotiana benthamiana and wheat demonstrated that NLRMoro, or its N-terminal coiled-coil (CC) domain alone, auto-activated cell death and that plasma membrane-localised NLRMoro-CC conferred stripe rust resistance through induction of hypersensitive response, reactive oxygen species accumulation and Ca2+ influx. Through truncation analysis, we identified the amino acids 62–116 region within the CC domain as the minimal active region, essential and sufficient for its activity. Further investigation revealed that the adjacent central NBS domain suppresses the signalling activity of CC, while the C-terminal LRR domain alleviates this suppression, both exclusively via intramolecular interactions. Critical sites outside the CC domain, including the P-loop, RNBS-A and MHD motifs and the phosphorylation site S198, were found to significantly influence NLRMoro-induced cell death, presenting potential targets for fine-tuning NLR activity. This study advances our understanding of CC-NLR protein regulation and provides a theoretical foundation for optimising NLR activity to balance growth–defence trade-offs in plants.
核苷酸结合位点(NBS)富含亮氨酸重复序列(LRR)受体(NLRs)对植物免疫至关重要，但通常伴随着植物生长的权衡。了解它们对受控免疫反应的自我调节活性的机制对于优化作物抗性是至关重要的。在本研究中，我们研究了来自品种Moro和AvS + Yr10的小麦NLR蛋白NLRMoro的活性微调。在本氏烟草和小麦中的过量表达证明了NLRMoro，或其N-末端卷曲螺旋(CC)结构域本身，自动激活细胞死亡，并且质膜定位的NLRMoro-CC通过诱导过敏反应、活性氧物质积累和Ca2+内流而赋予条锈病抗性。通过截短分析，我们确定CC结构域内的氨基酸62-116区域是最小的活性区域，对于其活性是必需的和充分的。进一步的研究表明，相邻的中央NBS结构域抑制CC的信号传导活性，而C-末端LRR结构域减轻这种抑制，两者都仅仅通过分子内相互作用。CC结构域外的关键位点，包括P-环、RNBS-A和MHD基序以及磷酸化位点S198，被发现显著影响NLRMoro诱导的细胞死亡，为微调NLR活性提供了潜在的靶点。这项研究推进了我们对CC-NLR蛋白调控的理解，并为优化NLR活性以平衡植物生长-防御权衡提供了理论基础。
论文链接：https://pmc.ncbi.nlm.nih.gov/articles/PMC12971249/