A Novel Intracellular K+/H+ Antiporter Related to Na+/H+ Antiporters Is Important for K+ Ion Homeostasis in Plants

In this study we have identified the first plant K+/H+ exchanger, LeNHX2 from tomato (Lycopersicon esculentum Mill. cv. Moneymaker), which is a member of the intracellular NHX exchanger protein family. The LeNHX2 protein, belonging to a subfamily of plant NHX proteins closely related to the yeast NHX1 protein, is abundant in roots and stems and is induced in leaves by short term salt or abscisic acid treatment. LeNHX2 complements the salt- and hygromycin-sensitive phenotype caused by NHX1 gene disruption in yeast, but affects accumulation of K+ and not Na+ in intracellular compartments. The LeNHX2 protein co-localizes and in a in yeast and of this protein and to K+/H+ but in of the the of K+ and by K+/H+ In this study we have identified the first plant K+/H+ exchanger, LeNHX2 from tomato (Lycopersicon esculentum Mill. cv. Moneymaker), which is a member of the intracellular NHX exchanger protein family. The LeNHX2 protein, belonging to a subfamily of plant NHX proteins closely related to the yeast NHX1 protein, is abundant in roots and stems and is induced in leaves by short term salt or abscisic acid treatment. LeNHX2 complements the salt- and hygromycin-sensitive phenotype caused by NHX1 gene disruption in yeast, but affects accumulation of K+ and not Na+ in intracellular compartments. The LeNHX2 protein co-localizes and in a in yeast and of this protein and to K+/H+ but in of the the of K+ and by K+/H+ and is the abundant in plant The of the plant is in the The of in this is to to to K+ the of K+ in the by to of salt from to the of K+ and the and of K+ in in from a K+ K+ in from the is in of the is and protein and In the from to from the and is to by the of by the to the In of the of K+ in the K+/H+ to in and of intracellular of K+ the the of is to the K+/H+ have the of in The first exchanger identified and of this gene in salt of identified in to to and yeast or NHX and K+/H+ the this is in the of and of intracellular by K+/H+ or is of by the the NHX1 protein is and protein in yeast plant NHX not to in but in and to induced by and or have identified the first NHX proteins in LeNHX2 is from the In this study we this and by in The LeNHX2 protein to the first intracellular K+/H+ protein in which the of K+ in intracellular of salt in NHX and in intracellular of and 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