Protein Tyrosine Phosphatases Mediate the Signaling Pathway of Stomatal Closure of Vicia faba L.

Protein Tyrosine Phosphatases Mediate the Signaling Pathway of Stomatal Closure of Vicia

faba L.

Wu-Liang SHI;Xin LIU;Wen-Suo JIA;Shu-Qiu ZHANG

【期刊名称】《植物学报（英文版）》 【年(卷),期】2005(047)003

【摘要】The regulation of stomatal movement is one of the most important signaling networks in plants.The H+-ATPase at the plasma membrane of guard cells plays a critical role in the stomata opening, while there are some conflicting results regarding the effectiveness of the plasma membrane H+-ATPase inhibitor,vanadate, in inhibiting stomata opening. We observed that 2 mmol/L vanadate hardly inhibited light-stimulated stomata opening in epidermal peels of Viciafaba L., but significantly inhibited dark- and ABA-induced stomatal closure. These results cannot be explained with the previous findings that H+-ATPase was inhibited by vanadate. In view of the fact that vanadate is an inhibitor of protein tyrosine phosphatases (PTPases),we investigated whether the stomatal movement regulated by vanadate is through the regulation of PTPase.As expected, phenylarsine oxide (PAO), a specific inhibitor of PTPase, has very similar effects and even more effective than vanadate. Typical PTPase activity was found in guard cells of V. faba; moreover, the phosphatase activity could be inhibited by both vanadate