Screening of useful duckweed strains and development of dormant state regulation techniques for improving starch productivity in duckweed plants

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K06342
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 41050:Environmental agriculture-related
• Research Institution: Kyoto University
• Principal Investigator: Ito Shogo 京都大学, 理学研究科, 助教 (60632586)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: 光周性 / 環境応答 / 概日時計 / 休眠 / ウキクサ / バイオマス

Outline of Final Research Achievements

We have recently found that growing L. turionifera 6619 in short-day conditions induced growth cessation and turion formation. Turions have relatively high starch content and lack the aerenchyma (air space). These features allow turions to overwinter on the bottom in the aquatic habitat. In L. turionifera, it was also found that a plant hormone salicylic acid as well as abscisic acid could induce a dormant state.
Based on the transcriptome analysis during the dormancy induction in L. turionifera, we show several differentially expressed genes (DEGs) that would be involved in its regulation. We focused on one of the DE gene encoding Dof DNA binding domain containing transcription factor (LtDOF) and produced L. turionifera and L. japonica transgenic plants expressing LtDOF by chemical inducible system (XVE system). Transgenic L.t. plants showed the phenotypes of growth cessation, premature senescence with estradiol treatment however L.j. plants did not show such phenotypes.

Free Research Field

植物生理学

Academic Significance and Societal Importance of the Research Achievements

ウキクサ植物は増殖速度が非常に速く、非食料のバイオマス植物として注目されています。1年あたり最大で100トン/乾燥重量・ヘクタールという驚異的な生産能力を備えている事がわかっています。通常生育時の植物内にはタンパク質が豊富（乾燥重量あたりタンパク質含量約30%）ですが、休眠誘導時にはタンパク質をデンプン系化合物へと変化させます。この変化が特に顕著なのが休眠芽を発達させるキタグニコウキクサです。本研究はウキクサが日長情報を感知し、休眠を誘導する分子機構を解明することを目的としますが、この知見は、バイオマス生産技術へと繋がり、植物を用いた再生エネルギー資源利用による循環型社会の形成に貢献します。