GhPTP1和GhANN5调控棉花耐盐的生理生化机制

Cotton (Gossypium spp.) production is limited by various abiotic stresses, in particular salinity stress, which cause substantial losses of cotton yield and fiber quality worldwide. Thus, to understand how cotton responds to salt stress at the genome and proteome level and leverage genetic resources for developing tolerant cotton cultivars is essential to sustainable cotton industry and reducing the tension between crop production and available soil supply. With the previous screen of cotton virus-induced gene silencing (VIGS) cDNA library, GhPTP1 was picked out for silencing of GhPTP1 strongly enhanced salt tolerance of cotton seedlings. Both shoot and root biomasses were dramatically increased compared with the biomasses of Ctrl seedlings. GhPTP1 gene expression was also induced under salt treatment. Moreover, by using yeast 2 hybrid (Y-2-H), GhANN5 was pulled out interacting with GhPTP1. For the further study, our objectives will be a) By silencing of GhPTP1 or GhANN5 with VIGS, analysis the physiological and biochemical indexes of salt tolerance to reveal the gene function of GhPTP1 and GhANN5 in response to salt stress. b) Identify the upstream kinase phosphorylating GhANN5 upon salt stress, and demonstrate the molecular mechanism of the interaction between GhANN5 and GhPTP1, and uncover the dynamic phosphorylation process of GhANN5 modulating by kinase and GhPTP1. c) By phosphoproteomics and RNA-seq, dissect GhPTP1-mediated regulatory signaling network in response to salinity. Our proposed work will not only provide novel insights into understanding the molecular and biochemical processes under salt stress in cotton, but also supply the genetic resources for developing drought tolerant cotton cultivars.

土壤盐渍化严重影响棉花产量和品质，揭示棉花耐盐机理为棉花耐盐性种质改良，有效利用盐碱地提供理论基础。申请人构建了基于病毒诱导基因沉默体系(VIGS)的棉花cDNA 文库，并筛选获得敏盐基因GhPTP1。VIGS-GhPTP1棉花植株对盐胁迫耐受性增强。利用棉花酵母双杂cDNA文库，获得与GhPTP1互作的膜联蛋白GhANN5。本项目拟分析棉花GhPTP1和GhANN5基因沉默植株以及转基因拟南芥植株的耐盐特性，明确GhPTP1和 GhANN5在耐盐信号途径中的作用机制；鉴定盐胁迫下激活GhANN5的蛋白激酶，阐明GhPTP1与GhANN5互作模式，揭示由蛋白激酶和磷酸酶GhPTP1动态调控GhANN5磷酸化水平的耐盐新机制；利用磷酸化蛋白质组学以及转录组学手段，挖掘GhPTP1介导的棉花耐盐信号调控网络。研究结果将会揭示GhPTP1调控棉花耐盐新机制，为棉花耐盐分子育种提供优良的候选基因。

土壤盐渍化严重影响棉花的产量和品质，而我国植棉区逐年向西北内陆以及滨海盐碱地转移，从细胞和分子水平揭示棉花耐盐机制并创建耐盐种质资源具有重要的理论和现实意义。本研究通过筛选棉花VIGS（Virus-induced gene silencing）文库，获得棉花响应盐胁迫的基因GhPTP1后命名为GhDsPTP3，该基因编码双功能酪氨酸蛋白磷酸酶。经棉花酵母双杂文库筛选获得了与GhDsPTP3互作的膜联蛋白GhANN5后命名为GhANN8。进一步研究明确了盐胁迫能够诱导GhANN8的磷酸化，而GhDsPTP3能够去除盐诱导的GhANN8磷酸化。探明了盐胁迫下GhDsPTP3和GhANN8参与调控细胞内的钙离子平衡，VIGS-GhDsPTP3增强钙离子内流，而沉默GhANN8抑制钙离子内流。此外，沉默GhDsPTP3诱导GhSOS1表达，沉默GhANN8抑制GhSOS1表达，钙通道抑制剂氯化镧能够消除GhDsPTP3和GhANN8对GhSOS1的表达调控，表明GhDsPTP3和GhANN8介导的钙信号可通过进一步调控重要的钠通道GhSOS1响应盐胁迫。在国际期刊New Phytologist上发表SCI研究论文1篇，培养研究生1人。