The relations of brassinosteroid-induced stomatal closure with hydrogen dioxide and nitric oxide production in guard cells of broad bean
SHI Chenyu1,2， SHE Xiaoping1*
(1 School of Life Sciences, Shaanxi Normal University, Xi′an 710119, Shaanxi，China; 2 School of Chemistry and Bioengineering, Hechi University, Yizhou 546300, Guangxi, China)
Abstract:
The effect of brassinosteroid (BR) on stomatal aperture and the roles of hydrogen dioxide (H2O2) and nitric oxide (NO) in BR-induced stomatal closure in broad bean were investigated. The results showed that BR obviously induces stomatal closure, and it′s optimal concentration and treating time were 5 μmol/L and 3 h, respectively. BR-induced closure of stomata is largely inhibited not only by H2O2 scavengers ascorbic acid catalase, NO scavengers cPTIO and hemoglobin, but also by NADPH oxidase inhibitor diphenylene iodonium and NO synthase (NOS) inhibitor L-NAME, indicating that both H2O2 generated by NADPH oxidase and NO produced by NOS mediate BR-induced stomatal closure. Additionally, abscisic acid-induced stomatal closure is repressed significantly by BR.
KeyWords:
brassinosteroid; H2O2; NO; stomatal closure
