Alfalfa (Medicago sativa L.) MsCML46 gene encoding calmodulin-like protein confers tolerance to abiotic stress in tobacco

• Published in: Plant cell reports 2021-10, Vol.40 (10), p.1907-1922
• Main Authors: Du, Binghao, Chen, Naiyu, Song, Lili, Wang, Dan, Cai, Hongsheng, Yao, Lin, Li, Xiuting, Guo, Changhong
• Format: Article
• Language: English
• Subjects: Abiotic stress; Abscisic acid; Alfalfa; Antioxidants; Antioxidants - metabolism; Biomedical and Life Sciences; Biotechnology; Calcium; Calcium (intracellular); Calcium ions; Calcium signalling; Calcium-binding protein; Calmodulin; Cell Biology; Cold tolerance; Cold-Shock Response - genetics; Conserved sequence; Crop production; Cytoplasm; Cytoplasm - metabolism; Damage tolerance; Drought; Droughts; Environmental factors; Enzymatic activity; Enzyme activity; Enzymes; Enzymes - genetics; Enzymes - metabolism; Freezing; Gene expression; Gene Expression Regulation, Plant; Genes; Genetic engineering; Homeostasis; Hydrogen Peroxide - metabolism; Intracellular; Life Sciences; Medicago sativa; Medicago sativa - genetics; Nicotiana - genetics; Nicotiana - physiology; Original Article; Osmotic stress; Phylogeny; Plant Biochemistry; Plant Proteins - genetics; Plant Proteins - metabolism; Plant Sciences; Plants, Genetically Modified; Proteins; Reactive oxygen species; Salt Stress - genetics; Salts; Signal transduction; Sodium; Solutes; Stress, Physiological; Stresses; Tobacco; Toxicity; Transgenic plants
• ISSN: 0721-7714; 1432-203X
• DOI: 10.1007/s00299-021-02757-7

Key message MsCML46 enhances tolerance to abiotic stresses through alleviating osmotic stress and oxidative damage by regulating the expression of stress-related genes to optimize osmolytes levels and antioxidant enzyme activity in transgenic tobacco. Abiotic stresses are major environmental factors that constraint crop productivity worldwide. Various stimuli regulate intracellular calcium levels and calcium-mediated signal transduction, and cellular responses. Ca 2+ signals are perceived by different Ca 2+ receptors. Calmodulin-like protein (CML) is one of the best-characterized Ca 2+ sensors which shares sequence similarity with highly conserved calmodulin (CaM) ubiquitously expressed in plants. Currently, the molecular and physiological functions of CMLs are largely unknown. In this study, the MsCML46 was characterized in alfalfa ( Medicago sativa cv. Zhaodong) under freezing stress. Results showed that MsCML46 was localized to the cytoplasm of Arabidopsis , and its expression was strongly elevated by cold, drought, salt, saline-alkali, and ABA treatments. Overexpressing MsCML46 in tobacco enhanced tolerance to freezing, drought, and salt stresses as evidenced by improved contents of osmotic regulatory solutes and antioxidant enzyme activity but decreased reactive oxygen species (ROS) accumulation. Furthermore, cold, drought, and salt stresses increased the expression of stress-related genes in transgenic tobacco. MsCML46 binds free Ca 2+ to promote signal transduction and maintain higher K + /Na + ratio. In this way, it protects intracellular homeostasis under sodium ion toxicity. These results suggest that MsCML46 plays a crucial role in resisting abiotic stresses and can be exploited in genetic engineering for crops.