The Glucose Sensor MdHXK1 Phosphorylates a Tonoplast Na+/H+ Exchanger to Improve Salt Tolerance
The Glucose Sensor MdHXK1 Phosphorylates a Tonoplast Na+/H+ Exchanger to Improve Salt Tolerance
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葡萄糖传感器 MdHXK1 磷酸化液泡膜 Na /H 交换剂以提高耐盐性
DOI：
10.1104/pp.17.01472
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发表时间：
2018
期刊：
影响因子：
7.4
通讯作者：
Hao Yu Jin
中科院分区：
文献类型：
--
作者：
Sun Mei Hong;Ma Qi Jun;Hu Da Gang;Zhu Xiao Ping;You Chun Xiang;Shu Huai Rui;Hao Yu Jin
葡萄糖调节许多生命过程，包括植物生长、发育、代谢以及对生物和非生物胁迫的响应。然而，葡萄糖作为信号调节耐盐性的分子机制仍不清楚。在这项研究中，我们发现苹果（Malus domesticaBorkh.）葡萄糖传感器己糖激酶1（MdHXK 1）有助于葡萄糖介导的耐盐性。一个组合的分割泛素系统，下拉，免疫共沉淀，和双分子荧光互补分析表明，MdHXK 1相互作用，并磷酸化的Na+/H+交换MdNHX 1在其Ser-275残基。在MdNHX 1过表达的苹果和酵母互补细胞中，磷酸化修饰提高了MdNHX 1的稳定性，增强了其Na+/H+转运活性。此外，MdNHX 1的Ser-275被发现是MdHXK 1介导的磷酸化的关键。最后，一系列转基因分析表明，MdHXK 1介导的耐盐性部分依赖于MdNHX 1。总的来说，我们的研究结果提供了糖如何招募和调节MdNHX 1以应对植物中的高盐度的见解。
Glc regulates many vital processes, including plant growth, development, metabolism, and responses to biotic and abiotic stress. However, the molecular mechanism by which Glc acts as a signal to regulate salinity tolerance remains unclear. In this study, we found that the apple (Malus domesticaBorkh.) Glc sensor hexokinase1 (MdHXK1) contributes to Glc-mediated salinity tolerance. A combination of split ubiquitin system, pull-down, co-immunoprecipitation, and bimolecular fluorescence complementation assays demonstrated that MdHXK1 interacts with and phosphorylates the Na+/H+exchanger MdNHX1 at its Ser-275 residue. Phosphorylation improved the stability of MdNHX1 and enhanced its Na+/H+transport activity inMdNHX1overexpression transgenic apple and yeast complementation cells. Furthermore, Ser-275 of MdNHX1 was found to be crucial for MdHXK1-mediated phosphorylation. Finally, a series of transgenic analyses demonstrated that salt tolerance mediated by MdHXK1 partially depended on MdNHX1. Overall, our findings provide insights into how sugar recruits and regulates MdNHX1 in response to high salinity in plants.