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Protein Tyrosine Phosphatases Mediate the Signaling Pathway of Stomatal Closure of Vicia faba L.
Author(s) -
SHI WuLiang,
LIU Xin,
JIA WenSuo,
ZHANG ShuQiu
Publication year - 2005
Publication title -
journal of integrative plant biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.734
H-Index - 83
eISSN - 1744-7909
pISSN - 1672-9072
DOI - 10.1111/j.1744-7909.2005.00032.x
Subject(s) - guard cell , vanadate , phenylarsine oxide , vicia faba , phosphatase , protein tyrosine phosphatase , atpase , sodium orthovanadate , microbiology and biotechnology , signal transduction , biology , biochemistry , chemistry , botany , enzyme , phosphorylation
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 Vicia faba 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 and PAO. These results not only provide a novel explanation for conflicting results about vanadate modulating stomatal movement, but also provide further evidence for the involvement of PTPases in modulating signal transduction of stomatal movement. (Managing editor: Ping HE)