Plasma Membrane H+-ATPases: Key Regulators of Plant Physiology

Abstract

Plasma membrane H+-ATPases(PM-H+-ATPases) areimportant ion pumps in the plant cell membrane that play key roles in plant physiology. They extrude protons outof the cell, generating a membrane potential that provides the driving forcefor the transport of ions and metabolites through channels and transporters. PMH+-ATPaseactivity is essential for several physiological responses, such as cell expansion,phloem loading/unloading, stress adaptation and plant growth and development. PM H+-ATPases have beendescribed in many plant species and are encoded by a family of approximately 10 genes classified into5 gene subfamilies. Thischapter describes the structural and enzymatic properties of plant PM-H+-ATPases,their regulation and physiological roles.