Wang Guilin, Zhang Dayong, Wang Haitang, Kong Jinmin, Chen Zhiguo, Ruan Chaofeng, Deng Chaoyang, Zheng Qihang, Guo Zhan, Liu Hanqiao, Li Weixi, Wang Xinyu, Guo Wangzhen
State Key Laboratory of Crop Genetics & Germplasm Enhancement and Utilization, Nanjing Agricultural University, Nanjing, 210095, China.
Engineering Research Center of Ministry of Education for Cotton Germplasm Enhancement and Application, Nanjing Agricultural University, Nanjing, 210095, China.
Adv Sci (Weinh). 2024 Dec;11(45):e2406522. doi: 10.1002/advs.202406522. Epub 2024 Oct 16.
Osmotin is classified as the pathogenesis-related protein 5 group. However, its molecular mechanism involved in plant disease resistance remains largely unknown. Here, a Verticillium wilt (VW) resistance-related osmotin gene is identified in Gossypium barbadense (Gb), GbOSM1. GbOSM1 is preferentially expressed in the roots of disease-resistant G. barbadense acc. Hai7124 and highly induced by Verticillium dahliae (Vd). Silencing GbOSM1 reduces the VW resistance of Hai7124, while overexpression of GbOSM1 in disease-susceptible G. hirsutum improves tolerance. GbOSM1 predominantly localizes in tonoplasts, while it relocates to the apoplast upon exposure to osmotic stress or Vd infection. GbOSM1 confers VW resistance by hydrolyzing cell wall polysaccharides of Vd and activating plant immune pathways. Natural variation contributes to a differential CCAAT/CCGAT elements in the OSM1 promoter in cotton accessions. All G. hirsutum (Gh) exhibit the CCAAT haplotype, while there are two haplotypes of CCAAT/CCGAT in G. barbadense, with higher expression and stronger VW resistance in CCGAT haplotype. A NFYA5 transcription factor binds to the CCAAT element of GhOSM1 promoter and inhibits its transcription. Silencing GhNFYA5 results in higher GhOSM1 expression and enhances VW resistance. These results broaden the insights into the functional mechanisms of osmotin and provide an effective strategy to breed VW-resistant cotton.
渗调蛋白被归类为病程相关蛋白5组。然而，其参与植物抗病性的分子机制仍 largely 未知。在此，在海岛棉（Gb）中鉴定出一个与黄萎病（VW）抗性相关的渗调蛋白基因，即GbOSM1。GbOSM1在抗病海岛棉品种海7124的根中优先表达，并受到大丽轮枝菌（Vd）的高度诱导。沉默GbOSM1会降低海7124对黄萎病的抗性，而在感病陆地棉中过表达GbOSM1则可提高耐受性。GbOSM1主要定位于液泡膜，而在受到渗透胁迫或Vd感染时会重新定位到质外体。GbOSM1通过水解Vd的细胞壁多糖并激活植物免疫途径来赋予黄萎病抗性。自然变异导致棉花种质中OSM1启动子的CCAAT/CCGAT元件存在差异。所有陆地棉（Gh）均表现出CCAAT单倍型，而海岛棉中有两种CCAAT/CCGAT单倍型，CCGAT单倍型具有更高的表达水平和更强的黄萎病抗性。一种NFYA5转录因子与GhOSM1启动子的CCAAT元件结合并抑制其转录。沉默GhNFYA5会导致GhOSM1表达升高并增强黄萎病抗性。这些结果拓宽了对渗调蛋白功能机制的认识，并为培育抗黄萎病棉花提供了一种有效策略。
