王存等《New Phytologist》2022年

论文题目：Plasma Membrane-associated Calcium Signaling Modulates Cadmium Transport

论文作者：Yanting Zhang，Zhangqing Wang，Yisong Liu，Tianqi Zhang，Jiaming Liu，Zhang You，Panpan Huang，Zhenqian Zhang，Cun Wang

论文摘要：

Cadmium (Cd) is a toxic heavy element for plant growth and development, plants have evolved many strategies to cope with Cd stress. However, the mechanisms how plants sense Cd stress and regulate the function of transporters remain very rudimentary. Here, we found that Cd stress induces obvious Ca²⁺ signals in Arabidopsis roots. Furthermore, we identified the calcium-dependent protein kinases CPK21 and CPK23 that interacted with the Cd transporter NRAMP6 through a variety of protein interaction techniques. Then we confirmed that the  cpk21 23  double mutants significantly enhanced the sensitive phenotype of cpk23 single mutant under Cd stress, while the overexpression and continuous activation of CPK21 and CPK23 enhanced plants tolerance to Cd stress. Multiple biochemical and physiological analyses in yeast and plants demonstrated that CPK21/23 phosphorylate NRAMP6 primarily at Ser489 and Thr505 to inhibit the Cd transport activity of NRAMP6, thereby improving the Cd tolerance of plants. Taken together, we found a plasma membrane-associated calcium signaling that modulates Cd tolerance. These results provide new insights into the molecular breeding of crop tolerance to Cd stress.

镉(Cd)是一种对植物生长发育有害的重金属元素，植物已经进化出许多应对镉胁迫的策略。然而，植物如何感知Cd胁迫以及调节Cd转运体功能的分子机制仍知之甚少。在这里，我们发现Cd胁迫可以诱导拟南芥根部产生显著的Ca²⁺信号。此外，我们通过多种蛋白质相互作用技术鉴定到了与Cd转运蛋白NRAMP6相互作用的钙依赖性蛋白激酶CPK21和CPK23。进一步证实 cpk21/23 双突变体在Cd胁迫下显著增强了 cpk23 单突变体的敏感表型，而CPK21和CPK23的过表达和持续激活增强了植株对Cd胁迫的耐受性。酵母和植物中的多种生化和生理实验分析表明，CPK21/23主要通过磷酸化NRAMP6的Ser489和Thr505位点以抑制NRAMP6的Cd转运活性，从而提高植物对Cd胁迫的耐受性。综上所述，我们发现了一种质膜相关的钙信号调控植物Cd耐受的新机制。这些结果为耐镉作物的分子育种提供了新的思路。

文章链接：https://pubmed.ncbi.nlm.nih.gov/36567524/