ThepreferenceofpaddyriceforNH4+ratherthanNO3ˉisassociatedwithitstolerancetolowpHsincearhizosphereacidificationoccursduringNH4+absorption.However,theadaptationofriceroottolowpHhasnotbeenfullyelucidated.TheplasmamembraneH+-ATPaseisauniversalelectronicH+pump,whichusesATPasenergysourcetopumpH+acrosstheplasmamembranesintotheapoplast.ThekeyfunctionofthisenzymeistokeeppHhomeostasisofplantcellsandgenerateaH+electrochemicalgradient,there...