Potassium induced suppression of magnesium uptake and translocation is limited in oat (Avena sativa L.)

Abstract

AbstractThe main cause of magnesium (Mg2+) deficiency in plants is its competition with potassium (K+). Besides uptake antagonism, previous studies also suggested that high [K+] inhibits root‐shoot translocation of Mg2+. In this study on oat, root elemental analysis revealed an evident but, with further increasing K+/Mg2+ ratio, limited suppression of Mg2+ uptake. In contrast, shoot [Mg2+] showed little or no reduction. This indicated a translocation synergism, as the suppression of the root [Mg2+] by K+ was counterbalanced. Oat thus provides new insights and raises new questions about the interactions of K+/Mg2+, in particular on the role of specific Mg2+ transporters. A better understanding of this interaction may help to counter the worldwide Mg deficiency more effectively.