RESUMO
Potassium (K) is an integral part of plant nutrition, playing essential roles in plant growth and development. Despite its abundance in soils, the limitedly available form of K ion (K+) for plant uptake is a critical factor for agricultural production. Plants have evolved complex transport systems to maintain appropriate K+ levels in tissues under changing environmental conditions. Adequate stimulation and coordinated actions of multiple K+-channels and K+-transporters are required for nutrient homeostasis, reproductive growth, cellular signaling and stress adaptation responses in plants. Various contemporary studies revealed that K+-homeostasis plays a substantial role in plant responses and tolerance to abiotic stresses. The beneficial effects of K+ in plant responses to abiotic stresses include its roles in physiological and biochemical mechanisms involved in photosynthesis, osmoprotection, stomatal regulation, water-nutrient absorption, nutrient translocation and enzyme activation. Over the last decade, we have seen considerable breakthroughs in K research, owing to the advances in omics technologies. In this aspect, omics investigations (e.g., transcriptomics, metabolomics, and proteomics) in systems biology manner have broadened our understanding of how K+ signals are perceived, conveyed, and integrated for improving plant physiological resilience to abiotic stresses. Here, we update on how K+-uptake and K+-distribution are regulated under various types of abiotic stress. We discuss the effects of K+ on several physiological functions and the interaction of K+ with other nutrients to improve plant potential against abiotic stress-induced adverse consequences. Understanding of how K+ orchestrates physiological mechanisms and contributes to abiotic stress tolerance in plants is essential for practicing sustainable agriculture amidst the climate crisis in global agriculture.
