王存等《Plant Physiology》2023年
论文题目：Plasma-membrane-associated calcium signaling regulates arsenate tolerance in Arabidopsis
论文作者：Yisong Liu,，Yanting Zhang，Zhangqing Wang，Shiyuan Guo，Yanjun Fang，Zhenqian Zhang，Huiling Gao，Huimin Ren，Cun Wang
论文摘要：
Arsenate [As(V)] is a metalloid with heavy metal properties and is widespread in many environments. Dietary intake of food derived from arsenate-contaminated plants constitutes a major fraction of the potentially health-threatening human exposure to arsenic. However, the mechanisms underlying how plants respond to arsenate stress and regulate the function of relevant transporters are poorly understood. Here, we observed that As(V) stress induces a significant Ca2+signal in Arabidopsis (Arabidopsis thaliana) roots. We then identified a calcium-dependent protein kinase, CALCIUM-DEPENDENT PROTEIN KINASE 23 (CPK23), that interacts with the plasma membrane As(V)/Pi transporter PHOSPHATE TRANSPORTER 1; 1 (PHT1; 1)in vitroandin vivo.cpk23mutants displayed a sensitive phenotype under As(V) stress, while transgenic Arabidopsis plants with constitutively activeCPK23showed a tolerant phenotype. Furthermore, CPK23 phosphorylated the C-terminal domain of PHT1; 1, primarily at Ser514 and Ser520. Multiple experiments on PHT1; 1 variants demonstrated that PHT1; 1S514phosphorylation is essential for PHT1; 1 function and localization under As(V) stress. In summary, we revealed that plasma-membrane-associated calcium signaling regulates As(V) tolerance. These results provide insight for crop bioengineering to specifically address arsenate pollution in soils.
砷酸盐[As(V)]是一种广泛存在于环境中的，具有重金属性质的类金属。从膳食中摄入受到砷污染的植物源性食物，是砷污染威胁人体健康的主要潜在方式。然而，关于植物是如何应对砷胁迫以及调控相关转运蛋白功能的，其具体机制目前尚不明晰。在本研究中，我们发现As(V)胁迫诱发了拟南芥(Arabidopsis thaliana)根系中显著Ca2+信号的产生。在此基础上，我们鉴定出了一种钙依赖性蛋白激酶CALCIUM-DEPENDENT PROTEIN KINASE 23 (CPK23)，它与质膜上的As(V)/Pi转运体PHOSPHATE TRANSPORTER 1; 1 (PHT1;1)在植物体外和体内均存在互作。cpk23突变体在As(V)胁迫下表现出敏感表型，而具有持续激活形式CPK23的转基因植株则表现出耐受表型。此外，CPK23主要磷酸化了位于PHT1;1的C端结构域的Ser514和Ser520位点。针对PHT1;1突变体的多种实验显示PHT1;1S514的磷酸化对PHT1;1 在As(V)胁迫下的功能和定位至关重要。综上所述，我们揭示了质膜相关钙信号通路调节As(V)耐受性的机制。此研究成果为通过作物生物工程来具体解决土壤砷污染提供了思路。