Functional analysis of aquaporins involved in flower opening and closing movements

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K06024
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 39030:Horticultural science-related
• Research Institution: Iwate Biotechnology Research Center
• Principal Investigator: Nemoto Keiichiro 公益財団法人岩手生物工学研究センター, 園芸資源研究部, 主任研究員 (60566727)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 開花 / アクアポリン / プロテインキナーゼ

Outline of Final Research Achievements

Flower opening is important for successful pollination in many plant species, and some species repeat reversible flower opening and closing movements. This is primarily due to the turgor pressure change caused by the water influx/efflux, which depends on osmotic oscillation in the cells. However, the molecular mechanism(s) involved in flower movement are largely unknown. Using Gentiana flowers, we showed that reversible flower opening is regulated by water channel aquaporin GsPIP2. Phosphorylation of the C-terminal serine residue of GsPIP2 is important for the transport activity and correlates closely with the flower re-opening rate. Furthermore, GsPIP2 is phosphorylated and activated by GsCPK16, which is activated by elevated cytosolic Ca2+ levels in response to temperature and light stimuli. We propose that reversible flower opening is regulated by GsCPK16-dependent GsPIP2 phosphorylation and activation, with stimulus-induced calcium signals acting as triggers.

Free Research Field

植物生理学

Academic Significance and Societal Importance of the Research Achievements

本成果は、花の開花が水の力を利用する仕組みを初めて明らかにしたものである。さらに、花は繁殖に適した環境でのみ花びらを開かせるシステムを有するという植物の巧みな生存戦略の可能性を示す重要な知見になることが期待される。さらに、本成果を発展させることで、花の開花を制御する新たな技術の開発に繋がることが期待できる。