MAPK kinase and CDP kinase modulate hydrogen peroxide levels during dark-induced stomatal closure in guard cells of Vicia faba

作者：Song Xi Gui; She Xiao Ping; Guo Lin Ying; Meng Zhao Ni; Huang Ai Xia

来源：Botanical Studies, 2008, 49(4): 323-334.

• Dark
• Hydrogen peroxide
• MAPK kinase and CDP kinase
• Stomatal closure
• Vicia faba

We used 2'-amino-3'-methoxyflavone (PD98059) (an inhibitor of mitogen-activated protein kinase kinase, MEK) and Trifluoperazine (TFP) (a specific inhibitor of calcium-dependent protein kinase, CDPK) to investigate the role of MEK/CDPK and its effects on H(2)O(2) levels of guard cells in the dark-induced stomatal closure in Vicia faba. We provide evidence that both PD98059 and TFP reduced H(2)O(2) levels in guard cells and promoted stomatal opening significantly in the dark, implying that MEK/CDPK mediated dark-induced stomatal closure by influencing H(2)O(2) levels of guard cells. In addition, like ascorbic acid (ASA), an important reducing substrate for H(2)O(2) removal, but unlike diphenylene iodonium (DPI), an inhibitor of the H(2)O(2)-generating enzyme NADPH oxidase, PD98059 and TFP not only reduced exogenous H(2)O(2) levels in guard cells in light, but also eliminated the H(2)O(2) that had been generated during a dark period and promoted stomatal opening. The results suggest MEK and CDPK are probably involved in restraining the H(2)O(2) scavenging enzyme and elevating H(2)O(2) levels in guard cells during dark-induced stomatal closure. Of course, the probability of MEK and CDPK acting as the target downstream of H(2)O(2) in the signaling transduction chain is not excluded.

• 出版日期2008-10
• 单位陕西师范大学