The transduction of light signal to ion transport in stomatal guard cells.

2014 Fiscal Year Final Research Report

• Project/Area Number: 21227001
• Research Category: Grant-in-Aid for Scientific Research (S)
• Allocation Type: Single-year Grants
• Research Field: Plant molecular biology/Plant physiology
• Research Institution: Kyushu University
• Principal Investigator: SHIMAZAKI Ken-ichiro 九州大学, 理学(系)研究科(研究院), 教授 (00124347)
• Co-Investigator(Kenkyū-buntansha): KINOSHITA Toshinori 名古屋大学, 大学院理学研究科, 教授 (50271101)
• Co-Investigator(Renkei-kenkyūsha): TAKEMIYA Atsushi 九州大学, 大学院理学研究院, 助教 (80448406) ; INOUE Shin-ichiro 九州大学, 大学院理学研究院, 学術研究員 (40532693) ; TAKAHASHI Yohei 九州大学, 大学院理学研究院, 学術研究員 (80592964)
• Project Period (FY): 2009-04-01 – 2015-03-31
• Keywords: 気孔 / 光情報伝達 / フォトトロピン / 細胞膜H+-ATPase / イオン輸送

Outline of Final Research Achievements

We studied phototropin-mediated signaling components in guard cells as a model case for plant light signaling. We showed that phosphatidic acid, a phospholipid second messenger produced by ABA, inhibited protein phosphatase 1 (PP1), a positive regulator of stomatal blue light signaling. The result suggests that PP1 is a crosstalk point between blue light and ABA signaling. We identified autophosphorylation sites in phot2 by mass analysis and showed the phosphorylation of Ser-761 and Ser-763 is required for the signaling. We found a novel protein kinase named BLUS1 as a substrate for phototropins and demonstrated phosphorylation of Ser-348 in response to blue light. We demonstrated that the phosphorylation of Ser-348 is essential for the signaling and that the Ser-348 is directly phosphorylated by phototropins. We showed the expression of 11 isoforms of the H+-ATPases in guard cells and identified the isoform responsible for blue light-dependent stomatal opening as AHA1.

Free Research Field

植物生理学