1. Protein. tyrosine phosphatases involved in signaling of the ABA-induced H2O2 generation in guard cells of Viciafaba L.
- Author
-
Shi Wuiiang, Jia Wensuo, Liu Xin, and Zhang Shuqiu
- Subjects
PROTEIN-tyrosine phosphatase ,MITOGENS ,CELLULAR signal transduction ,ABSCISIC acid ,FAVA bean ,HYDROGEN peroxide ,PLANT hormones ,PHOSPHOPROTEIN phosphatases - Abstract
Although protein tyrosine phosphatases (PTPases) play an important role in signal transduction in animal cells, little is known about the function of PTPases in higher plants. Hydrogen peroxide (H
2 O2 ) and mitogen-activated protein kinases (MAPKs) are the critical components of ABA signaling pathway in guard cells. PTPase is an important regulator of MAPK, which is believed to mediate ABA-induced H2 O2 generation in guard cells of Vicia faba L. Here, we investigate the possible role of PTPases in stomatal movement process. Phenylarsine oxide (PAO), a specific inhibitor of PTPases, could prevent ABA or H2 O2 -induced stomatal closure of Vicia faba L; furthermore, it could promote opening of the stomata closed by ABA or H2 O2 . The activity of PTPases can be effectively inhibited by PAO and H2 O2 . DTT had no effect on the PAO-induced inhibition of PTPases activity, but it could relieve the inhibition of H2 O2 on PTPases activity. PAO could also inhibit the ABA-induced H2 O2 generation in guard cells of Vicia faba L. These results suggested that PTPases is a critical signaling component in ABA-induced stomatal closure, and serve as targets for H2 O2 lying on the signaling pathways downstream of ABA induced H2 O2 generation. [ABSTRACT FROM AUTHOR]- Published
- 2004
- Full Text
- View/download PDF