Crop Journal (Apr 2021)

Synergistic and antagonistic interactions between potassium and magnesium in higher plants

  • Kailiu Xie,
  • Ismail Cakmak,
  • Shiyu Wang,
  • Fusuo Zhang,
  • Shiwei Guo

Journal volume & issue
Vol. 9, no. 2
pp. 249 – 256

Abstract

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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.

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