pH作为逆境胁迫信号的研究进展

植物经历逆境胁迫时，木质部汁液pH常常升高，pH升高本身可诱导气孔开放，导致过度失水，对植物的生存具有危害作用，然而，木质部汁液pH升高与植物中普遍存在的低浓度ABA交互作用，却使气孔开度减小，蒸腾速度下降，本文就有关逆境胁迫下植株木质部汁液pH的变化，木质部汁液pH升高与汁液中低浓度的ABA联合关闭气孔的机理，以及逆境胁迫诱导木质部汁液pH升高的可能机制等诸方面的研究进展了综述。

Advances in Studies on pH as a Stress Signal

When plants experience a range of stress conditions, their xylem sap pH often rises. The higher pH could have induced stomatal opening,resulting in excessive water loss,which is harmful to the plants. However,the higher xylem sap pH also raises the concentration of ABA which is ubiquitous in all land plants, which reduces the stomatal opening and the transpiration rate. In this review, we summarize the progresses of the studies related to 1) xylem sap pH changes in plants under various stress conditions; 2) the mechanism by which higher pH acts on the accumulation of ABA to close stomata; 3) and the potential mechanism(s) that might control xylem sap pH under stress conditions.