Intracellular trafficking regulation of plasma membrane H⁺-ATPase and environmental response in plants

The plasma membrane H+-ATPase in plant cells functions as a critical transporter, propelling protons against an electrochemical gradient. This action generates pH and potential differences across the plasma membrane, contributing to various plant physiological processes, including cell growth, nutrient absorption, and stomatal movements. Plant plasma membrane H+-ATPase activity is tightly regulated in response to a multitude of abiotic and biotic environmental cues. Recent studies have shed light on the multi-level regulation of H+-ATPase, extending beyond its proton transport activity and recognizing the importance of its abundance at the plasma membrane, achieved by a balance of endocytosis and exocytosis in response to environmental factors. This review provides an overview of the cell biological regulation of plasma membrane H+-ATPase by balancing its exocytosis and endocytosis. As key factors in regulation of the abundance of the plasma membrane H+-ATPase at the plasma membrane, the membrane trafficking proteins PATROL1 and SYP132 have been identified. The intracellular dynamics and functions are suggested to be tightly associated with the environmental response of plant cells. Despite substantial progress in deciphering the intracellular traffic regulation of the plasma membrane H+-ATPase, a comprehensive molecular understanding remains elusive. Elucidating the molecular pathways linking environmental factors with the regulation of membrane trafficking is pivotal for comprehending the cell biological regulation of environmental responses in plants.