Kailiu Xie;İsmail Çakmak;Shiyu Wang;Fusuo Zhang;Shiwei Gu

School of Land Resources and Environment, Jiangxi Agricultural University, Nanchang 330045, Jiangxi, China;Faculty of Engineering and Natural Sciences, Sabanci University, 34956 Istanbul, Turkey; Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center of Solid Organic Wastes, Educational Ministry Engineering Center of Resource-saving Fertilizers, Nanjing Agricultural University, Nanjing 210095, Jiangsu, Chin;College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China; International Magnesium Institute, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, Fujian, China;International Magnesium Institute, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, Fujian, China;Jiangsu Provincial Key Lab of Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center of Solid Organic Wastes, Educational Ministry Engineering Center of Resource-saving Fertilizers, Nanjing Agricultural University, Nanjing 210095, Jiangsu, China

Antagonism;Functional replacement;Magnesium;Potassium;Synerg

Magnesium (Mg) affects various critical physiological and biochemical processes in higher plants, and its deficiency impedes plant growth and development. Although potassium (K)-induced Mg deficiency in agricultural production is widespread, the specific relationship of K with Mg and especially its competitive nature is poorly understood. This review summarizes current knowledge on the interactions between K and Mg with respect to their root uptake, root-to-shoot translocation and distribution in plants. Their synergistic effects on certain physiological functions are also described. The antagonistic effect of K on Mg is stronger than that of Mg on K in root absorption and transport within plants, indicating that the balanced use of K and Mg fertilizers is necessary for sustaining high plant-available Mg and alleviating K-induced Mg deficiency, especially in plant species with high K demand or in high-available-K soil. The relationship between Mg and K in plant tissues may be antagonistic or synergistic depending on plant species, cell type, leaf age, source- and sink organs. There are synergistic effects of K and Mg on photosynthesis, carbohydrate transport and allocation, nitrogen metabolism, and turgor regulation. Definition of optimal K/Mg ratios for soils and plant tissues is desirable for maintaining proper nutritional status in plants, leading to a physiological state supporting crop production. Future research should concentrate on identifying the physiological and molecular mechanisms underlying the interactions between K and Mg in a given physiological function.