Role of Calcium in Regulating Potassium-Sodium Homeostasis and Potassium as Nutrient Signal during Abiotic Stress Conditions

Calcium is a ubiquitous cation, which serves as a second messenger for numerous signals and confers specific cellular responses in eukaryotes. Recent studies have established a concept termed ‘Ca signature’ that specifies Ca changes triggered by each signal. However, it is very fascinating how this pervasive cation can translate an infinite number of stimuli into unique stimulus-dependent responses. Ca is a fundamental component of nutrition signaling under stress condition. It interacts with various calcium sensors, which are directly involved in various molecular, biochemical and cellular changes occurring during the plant’s adaptation to nutritional stress. Recently, in calcium signaling in plants, the CBL-CIPK protein network has been implicated in phytohormone (ABA), abiotic stress and potassium nutrition signaling. This review will mainly focus on the functional relationship of calcium-mediated salt stress tolerance, potassium nutrition, and potassium-sodium homeostasis by involvement of the CBL-CIPK complex. _____________________________________________________________________________________________________________