The Receptor-Like Cytoplasmic Kinase STRK1 Phosphorylates and Activates CatC, Thereby Regulating H2O2 Homeostasis and Improving Salt Tolerance in Rice
The Receptor-Like Cytoplasmic Kinase STRK1 Phosphorylates and Activates CatC, Thereby Regulating H2O2 Homeostasis and Improving Salt Tolerance in Rice
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DOI：
10.1105/tpc.17.01000
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发表时间：
2018-05-01
期刊：
影响因子：
11.6
通讯作者：
Liu, Xuan-Ming
中科院分区：
文献类型：
--
作者：
Zhou, Yan-Biao;Liu, Cong;Liu, Xuan-Ming
盐胁迫可显着影响植物生长和农业生产力。类受体激酶（RLK）被认为在植物生长、发育和对非生物胁迫的反应中发挥重要作用。在这里，我们从水稻 (Oryza sativa) 中鉴定出一种受体样细胞质激酶，即耐盐受体样细胞质激酶 1 (STRK1)，它可以积极调节盐和氧化应激耐受性。我们的结果表明 STRK1 通过棕榈酰化在质膜上锚定并与 CatC 相互作用。 CatC 主要在 Tyr-210 处被磷酸化，并被 STRK1 激活。 CatC (Y210D) 的磷酸化模拟形式在体外和植物中均表现出较高的过氧化氢酶活性，并且盐胁迫增强了 STRK1 介导的 CatC 上的酪氨酸磷酸化。与野生型植物相比，STRK1过表达植物表现出更高的过氧化氢酶活性和更低的H2O2积累以及更高的盐和氧化胁迫耐受性。我们的研究结果表明，STRK1 通过磷酸化和激活 CatC 来改善盐和氧化耐受性，从而调节 H2O2 稳态。此外，水稻中STRK1的过度表达不仅改善了苗期的生长，而且显着限制了盐胁迫条件下的籽粒产量损失。总之，这些结果为在盐胁迫下提高水稻产量提供了机会。
Salt stress can significantly affect plant growth and agricultural productivity. Receptor-like kinases (RLKs) are believed to play essential roles in plant growth, development, and responses to abiotic stresses. Here, we identify a receptor-like cytoplasmic kinase, salt tolerance receptor-like cytoplasmic kinase 1 (STRK1), from rice (Oryza sativa) that positively regulates salt and oxidative stress tolerance. Our results show that STRK1 anchors and interacts with CatC at the plasma membrane via palmitoylation. CatC is phosphorylated mainly at Tyr-210 and is activated by STRK1. The phosphorylation mimic form CatC(Y210D) exhibits higher catalase activity both in vitro and in planta, and salt stress enhances STRK1-mediated tyrosine phosphorylation on CatC. Compared with wild-type plants, STRK1-overexpressing plants exhibited higher catalase activity and lower accumulation of H2O2 as well as higher tolerance to salt and oxidative stress. Our findings demonstrate that STRK1 improves salt and oxidative tolerance by phosphorylating and activating CatC and thereby regulating H2O2 homeostasis. Moreover, overexpression of STRK1 in rice not only improved growth at the seedling stage but also markedly limited the grain yield loss under salt stress conditions. Together, these results offer an opportunity to improve rice grain yield under salt stress.