Li Shumin, Li Tian, Zhang Peiyin, Wang Xuemin, Feng Wenxuan, Zhang Yifang, Chen Bin, Liu Yuling, Zhan Gangming, Hao Chenyang, Zhang Xueyong, Kang Zhensheng, Mao Hude
State Key Laboratory for Crop Stress Resistance and High-Efficiency Production, College of Agronomy, Northwest A&F University, Yangling, Shaanxi, China.
State Key Laboratory of Crop Gene Resources and Breeding, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, China.
Plant Biotechnol J. 2025 Mar;23(3):750-765. doi: 10.1111/pbi.14536. Epub 2024 Dec 3.
Wheat stripe rust, caused by the fungal pathogen Puccinia striiformis f. sp. tritici (Pst), threatens global wheat production, and therefore discovering genes involved in stripe rust susceptibility is essential for balancing yield with disease resistance in sustainable breeding strategies. Although TaGW2 is well known to negatively regulate wheat kernel size and weight, its role in stress response remains unclear. Here, we found that TaGW2 transcription levels increased following inoculation with Pst or treatment with flg22 or chitin. TaGW2 knockdown lines showed enhanced resistance to multiple Pst races, while TaGW2 overexpression reduced host defence response, promoted Pst growth and development and increased wheat susceptibility to Pst. Additionally, TaGW2 could mediate the ubiquitination and degradation of both TaSnRK1γ and TaVPS24 via the 26S proteasome pathway. Silencing TaSnRK1γ or TaVPS24 in wheat increased sensitivity to Pst, whereas overexpressing either gene enhanced wheat defence response, indicating that TaSnRK1γ and TaVPS24 act as positive regulators of Pst resistance. This study reveals a previously unrecognized mechanism inhibiting plant immunity to Pst through TaGW2-mediated ubiquitination and degradation of TaSnRK1γ and TaVPS24. This work also provides crucial genetic resources for breeding high-yield, stripe rust-resistant wheat varieties.
小麦条锈病由真菌病原体条形柄锈菌小麦专化型（Pst）引起，威胁着全球小麦生产，因此，在可持续育种策略中，发现与条锈病感病性相关的基因对于平衡产量和抗病性至关重要。尽管众所周知TaGW2负调控小麦籽粒大小和重量，但其在胁迫响应中的作用仍不清楚。在此，我们发现接种Pst或用flg22或几丁质处理后TaGW2转录水平升高。TaGW2基因敲低系对多个Pst小种表现出增强的抗性，而TaGW2过表达降低了宿主防御反应，促进了Pst的生长发育，并增加了小麦对Pst的易感性。此外，TaGW2可通过26S蛋白酶体途径介导TaSnRK1γ和TaVPS24的泛素化和降解。在小麦中沉默TaSnRK1γ或TaVPS24增加了对Pst的敏感性，而过表达这两个基因中的任何一个都增强了小麦的防御反应，表明TaSnRK1γ和TaVPS24作为Pst抗性的正调控因子发挥作用。本研究揭示了一种以前未被认识的机制，即通过TaGW2介导的TaSnRK1γ和TaVPS24的泛素化和降解来抑制植物对Pst的免疫。这项工作还为培育高产、抗条锈病的小麦品种提供了关键的遗传资源。
