Calcium-Dependent Protein Kinase CPK6 Positively Functions in Induction by Yeast Elicitor of Stomatal Closure and Inhibition by Yeast Elicitor of Light-Induced Stomatal Opening in Arabidopsis

• Published in: Plant physiology (Bethesda) 2013-10, Vol.163 (2), p.591-599
• Main Authors: Ye, Wenxiu, Muroyama, Daichi, Munemasa, Shintaro, Nakamura, Yoshimasa, Mori, Izumi C., Murata, Yoshiyuki
• Format: Article
• Language: English
• Subjects: Anions; Arabidopsis; Arabidopsis - enzymology; Arabidopsis - microbiology; Arabidopsis - physiology; Arabidopsis - radiation effects; Arabidopsis Proteins - metabolism; Calcium-Calmodulin-Dependent Protein Kinases - metabolism; elicitors; Fluorescence; Gene expression regulation; Guard cells; Hydrogen Peroxide - metabolism; Ion Channel Gating - radiation effects; Light; Mutation - genetics; Physiological regulation; Plant cells; Plant Stomata - cytology; Plant Stomata - microbiology; Plant Stomata - physiology; Plant Stomata - radiation effects; Plants; Protoplasts - metabolism; Protoplasts - radiation effects; s - Focus Issue; Saccharomyces cerevisiae - metabolism; Stomata; stomatal movement; Yeasts
• ISSN: 0032-0889; 1532-2548; 1532-2548
• DOI: 10.1104/pp.113.224055

Yeast elicitor (YEL) induces stomatal closure that is mediated by a Ca 2+ -dependent signaling pathway. A Ca 2+ -dependent protein kinase, CPK6, positively regulates activation of ion channels in abscisic acid and methyl jasmonate signaling, leading to stomatal closure in Arabidopsis (Arabidopsis thaliana). YEL also inhibits light-induced stomatal opening. However, it remains unknown whether CPK6 is involved in induction by YEL of stomatal closure or in inhibition by YEL of light-induced stomatal opening. In this study, we investigated the roles of CPK6 in induction by YEL of stomatal closure and inhibition by YEL of light-induced stomatal opening in Arabidopsis. Disruption of CPK6 gene impaired induction by YEL of stomatal closure and inhibition by YEL of light-induced stomatal opening. Activation by YEL of nonselective Ca 2+ -permeable cation channels was impaired in cpk6-2 guard cells, and transient elevations elicited by YEL in cytosolic-free Ca 2+ concentration were suppressed in cpk6-2 and cpk6-1 guard cells. YEL activated slow anion channels in wild-type guard cells but not in cpk6-2 or cpk6-1 and inhibited inward-rectifying K + channels in wild-type guard cells but not in cpk6-2 or cpk6-1. The cpk6-2 and cpk6-1 mutations inhibited YEL-induced hydrogen peroxide accumulation in guard cells and apoplast of rosette leaves but did not affect YEL-induced hydrogen peroxide production in the apoplast of rosette leaves. These results suggest that CPK6 positively functions in induction by YEL of stomatal closure and inhibition by YEL of light-induced stomatal opening in Arabidopsis and is a convergent point of signaling pathways for stomatal closure in response to abiotic and biotic stress.