Receptor-like cytoplasmic kinases (RLCKs) are receptor kinases that lack extracellular ligand-binding domains and have emerged as a major class of signaling proteins that regulate plant cellular activities in response to biotic/abiotic stresses and endogenous extracellular signaling molecules. We have identified a rice RLCK (OsRLCK311) that was significantly higher in transgenic pSARK-IPT rice (Oryza sativa) that exhibited enhanced growth under saline conditions. Overexpression of OsRLCK311 full-length protein (RLCK311FL) and the C-terminus of OsRLCK311 (ΔN) in Arabidopsis confirmed its role in salinity tolerance, both in seedlings and mature plants. Protein interaction assays indicated that OsRLCK311 and ΔN interacted in-vivo with the plasma membrane AQP AtPIP2;1. The RLCK311-PIP2;1 binding led to alterations in the stomata response to ABA, which was characterized by more open stomata of transgenic plants. Moreover, OsRLCK311-ΔN effect in mediating enhanced plant growth under saline conditions was also observed in the perennial grass Brachypodium sylvaticum, confirming its role in both dicots and monocots species. Lastly, OsRLCK311 interacted with the rice OsPIP2;1. We suggest that the rice OsRLCK311 play a role in regulating the plant growth response under saline conditions via the regulation of the stomata response to stress. This role seems to be independent of the RLCK311 kinase activity, since the overexpression of the RLCK311 C-terminus (ΔN), which lacks the kinase full domain, has a similar phenotype to RLCK311FL.

中文翻译：

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细胞质受体样激酶有助于盐分耐受。

受体样细胞质激酶（RLCKs）是缺乏细胞外配体结合域的受体激酶，已成为一类主要的信号蛋白，可调节植物细胞响应生物/非生物胁迫和内源性细胞外信号分子的活性。我们已经鉴定出水稻RLCK（OsRLCK311）在转基因pSARK-IPT水稻（Oryza sativa）在生理盐水条件下表现出增强的生长。OsRLCK311全长蛋白（RLCK311FL）和OsRLCK311的C末端在拟南芥中的过表达证实了其在幼苗和成熟植物中的耐盐性中的作用。蛋白质相互作用测定表明，OsRLCK311和ΔN在体内与质膜AQP AtPIP2; 1相互作用。RLCK311-PIP2; 1结合导致对ABA的气孔反应发生改变，其特征是转基因植物的气孔更加开放。此外，在介导盐水的条件下增强植物生长OsRLCK311-ΔN效果在多年生草，也观察到短柄草，证实了其在双子叶植物和单子叶植物中的作用。最后，OsRLCK311与水稻OsPIP2; 1相互作用。我们建议水稻OsRLCK311在生理条件下通过调节对胁迫的气孔反应来调节植物的生长反应。此作用似乎与RLCK311激酶活性无关，因为缺少激酶完整域的RLCK311 C末端（ΔN）的过表达具有与RLCK311FL相似的表型。