Fundamental studies for improving hydrotropic ability of roots and developing water-saving plant culture system

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K07955
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Agricultural environmental engineering/Agricultural information engineering
• Research Institution: Tohoku University
• Principal Investigator: Takahashi Hideyuki 東北大学, 生命科学研究科, 教授 (70179513)
• Research Collaborator: Kobayashi Akie
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 水分屈性 / MIZ1 / 皮層 / オーキシン / 根冠 / シロイヌナズナ / イネ / キュウリ

Outline of Final Research Achievements

In this study, we attempted to reveal the molecular function of MIZ1 essential for root hydrotropism and comparatively analyzed the involvement of auxin and the root tip (the cap and meristem) in hydrotropism of different plant species. It was found that in Arabidopsis roots MIZ1 functions at the cortex of elongation zone and that neither the root tip nor auxin transport/redistribution were required for the induction of hydrotropism. Roots of Lotus japonicus also displayed hydrotropism in an auxin-independent manner. On the other hand, auxin transport and redistribution were required for hydrotropic responses of rice, pea and cucumber roots, although it occurred even in the de-tipped roots of rice and cucumber seedlings. These results implied that mechanistic aspect of hydrotropism differs from that of gravitropism and also differs among plant species. We thereby proposed two types of mechanism unique to hydrotropic response in seedling roots.

Free Research Field

植物分子・生理学

Academic Significance and Societal Importance of the Research Achievements

本研究成果は、新奇の成長制御メカニズムを明らかにし、植物の感覚生物学にブレークスルーをもたらしただけでなく、根の水分屈性制御因子の調節によって、植物の水獲得能・効率的な水利用を大幅に改善できる革新的技術開発への糸口を見出した。すなわち、根の水分屈性を制御するユニークな分子メカニズムとその植物種間差は、地球上の半乾燥地や宇宙空間のような閉鎖生態系における植物工場をも視野に入れた技術開発の基盤となり、砂漠の緑化や耕地拡大と増収、さらには制御環境下における効率的植物生産を確保するための独創的かつ革新的な技術に発展する可能性をもたらした。