Genetic analysis of passage cell numbers in roots: towards optimization of water use efficiency of crops

2024 Fiscal Year Final Research Report

• Project/Area Number: 23K23574
• Project/Area Number (Other): 22H02308 (2022-2023)
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Multi-year Fund (2024); Single-year Grants (2022-2023)
• Section: 一般
• Review Section: Basic Section 39010:Science in plant genetics and breeding-related
• Research Institution: Nagoya University
• Principal Investigator: Yamauchi Takaki 名古屋大学, 生物機能開発利用研究センター, 准教授 (50726966)
• Co-Investigator(Kenkyū-buntansha): 田中 佑 岡山大学, 環境生命自然科学学域, 研究教授 (50634474) ; 野下 浩司 九州大学, 理学研究院, 助教 (10758494)
• Project Period (FY): 2024-04-01 – 2025-03-31
• Keywords: イネ / 根 / 通過細胞 / 光合成 / 画像解析 / 内皮 / スベリン

Outline of Final Research Achievements

Water uptake from the surface of roots is transported through the epidermis and cortex to the xylem inside the stele and used for photosynthesis in the leaves. Hydrophobic substances (e.g. suberin) in the endodermis inhibit water transport, whereas passage cells that do not accumulate suberin are responsible for selective water transport. We found that a high-yielding rice cultivar has a higher number of passage cells than a standard cultivar.
We identified the gene locus that controls the number of passage cells by genetic analysis of standard and high-yielding rice cultivars. Moreover, we demonstrated that the candidate gene affects the photosynthetic rate and stomatal conductance. These results suggest that passage cells contribute to water transport efficiency.

Free Research Field

遺伝育種科学

Academic Significance and Societal Importance of the Research Achievements

本研究課題では全ての高等植物が共通してもつ根の内皮のスベリン化が植物体内における水の輸送効率に関連することを明らかにした．実際に多収水稲品種では根の内皮に占めるスベリン化されない通過細胞の数が標準水稲品種と比べて有意に多いことから, 作物の通過細胞数を適切に制御することで, 多収化や水輸送効率の改善による環境ストレス耐性の強化などに応用することが期待される．