College of Life Sciences, Engineering Research Center of the Chinese Ministry of Education for Bioreactor and Pharmaceutical Development, Jilin Agricultural University, Changchun 130118, China.
Key Laboratory of Water Cycle and Related Land Surface Processes, Institute of Geographic Science and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China.
Funct Plant Biol. 2022 Jun;49(7):589-599. doi: 10.1071/FP22012.
Calcium signals serve an important function as secondary messengers between cells in various biological processes due to their robust homeostatic mechanism, maintaining an intracellular free Ca2+ concentration. Plant growth, development, and biotic and abiotic stress are all regulated by Ca2+ signals. Ca2+ binding proteins decode and convey the messages encoded by Ca2+ ions. In the presence of high quantities of Mg2+ and monovalent cations, such sensors bind to Ca2+ ions and modify their conformation in a Ca2+ -dependent manner. Calcium-dependent protein kinases (CPKs), calmodulins (CaMs), and calcineurin B-like proteins are all calcium sensors (CBLs). To transmit Ca2+ signals, CPKs, CBLs, and CaMs interact with target proteins and regulate the expression of their genes. These target proteins may be protein kinases, metabolic enzymes, or cytoskeletal-associated proteins. Beyond its role in plant nutrition as a macroelement and its involvement in the plant cell wall structure, calcium modulates many aspects of development, growth and adaptation to environmental constraints such as drought, salinity and osmotic stresses. This review summarises current knowledge on calcium sensors in plant responses to osmotic stress signalling.
钙信号作为细胞间的第二信使，在各种生物过程中发挥着重要作用，因为它们具有强大的稳态机制，维持着细胞内游离 Ca2+浓度。植物的生长、发育以及生物和非生物胁迫都受到 Ca2+信号的调节。钙结合蛋白对 Ca2+离子编码的信息进行解码和传递。在存在大量 Mg2+和单价阳离子的情况下，这些传感器以 Ca2+依赖性的方式结合 Ca2+离子并改变其构象。钙依赖性蛋白激酶（CPKs）、钙调蛋白（CaMs）和钙调磷酸酶 B 样蛋白（CBLs）都是钙传感器。为了传递 Ca2+信号，CPKs、CBLs 和 CaMs 与靶蛋白相互作用并调节其基因的表达。这些靶蛋白可能是蛋白激酶、代谢酶或细胞骨架相关蛋白。钙不仅作为一种宏量元素参与植物营养，还参与植物细胞壁结构，它还调节许多方面的发育、生长以及对干旱、盐度和渗透胁迫等环境限制的适应。本文综述了钙传感器在植物渗透胁迫信号响应中的最新研究进展。
