关键词: 液泡, 液泡膜H+-ATPase, 液泡膜H+-PPase, 硝酸盐, 非生物胁迫

Abstract: Two proton pumps, vacuolar H+-ATPase (V-ATPase) and vacuolar H+-PPase (V-PPase), are highly abundant tonoplast proteins and have played important roles in plant growth and development. These 2 proton pumps can hydrolyze substrate to release energy, and meanwhile, create big quantities of proton gradient between cytoplasm and vacuole used to transport compounds against their concentration or electrochemical gradient. These are helpful to maintain the ionic homeostasis and osmotic balance in cells, provide guarantee for all kinds of physiological and biochemical reactions in cells. Besides, when vacuole is used for ion storehouse in plant cell, these 2 proton pumps can regulate the nitrate distribution between cytoplasm and vacuole by changing their activities, leading to different nitrogen use efficiency. The higher activities of two proton pumps are beneficial to improve the resistant ability and reduce the negative effects on plant growth and development under stress conditions. This paper summarized the structure characteristics and physiological function of these 2 proton pumps, and elaborated their important roles in resisting abiotic stress conditions, which  provided direction for further raising crop nitrogen use efficiency and adaptive capability to stress conditions.

Key words: vacuole, vacuolar H+-ATPase, vacuolar H+-PPase, nitrate, abiotic stress