Understanding the molecular mechanism of B3-MAPKKK-mediated plant osmostress response

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K06713
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 44030:Plant molecular biology and physiology-related
• Research Institution: Tokyo University of Agriculture
• Principal Investigator: Sakata Yoichi 東京農業大学, 生命科学部, 教授 (50277240)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: ABA / 浸透圧 / SnRK2 / RAFカイネース / シロイヌナズナ / ヒメツリガネゴケ

Outline of Final Research Achievements

A protein kinase SnRK2 plays an essential role in osmostress responses of plants; however, a mechanism how SnRK2 is activated by osmostress was unknown. Our research group showed using the moss that B3-RAF is an upstream kinase of SnRK2 in ABA and osomostress signaling. In this research project we further showed that B3-RAF is evolutionarily conserved in Arabidopsis, which is a model plant of angiosperms, and also regulates osmostress-responsive SnRK2 activity via direct phosphorylation. Our research demonstrates that B3-RAF mediated osmostress-dependent SnRK2 activation is evolutionarily conserved among land plants. On the other hand, the mechanism by which B3-RAF is activated is suggested to be different between Arabidopsis and the moss.

Free Research Field

植物分子生理学

Academic Significance and Societal Importance of the Research Achievements

本研究グループによる乾燥応答の制御因子としてのRAFの発見がシロイヌナズナRAFの機能解明につながったように、ヒメツリガネゴケの解析はコケ植物の知見にとどまらず、被子植物が有しながらもこれまで明らかにされてこなかった環境情報処理システムの解明に繋がることが期待できる。進行する地球規模の環境変化において、水環境に対する作物のレジリエンス向上は重要課題である。植物の水環境情報統御の分子基盤を明らかにしていくことは、食糧・エネルギー問題解決への基盤技術構築に貢献すると考える。