Adaptive significance and mechanism of environment-dependent sex determination in flowers

2022 Fiscal Year Final Research Report

• Project/Area Number: 19K06855
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 45040:Ecology and environment-related
• Research Institution: Okayama University
• Principal Investigator: Miyazaki Yuko 岡山大学, 学術研究院環境生命科学学域, 准教授 (20443583)
• Co-Investigator(Kenkyū-buntansha): 丑丸 敦史 神戸大学, 人間発達環境学研究科, 教授 (70399327) ; 井上 智美 国立研究開発法人国立環境研究所, 生物・生態系環境研究センター, 主任研究員 (80435578)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: 環境依存的性決定 / 花の性 / ツユクサ / 日長

Outline of Final Research Achievements

The purpose of this study was to clarify how plants respond to environmental signals to determine the sex of individual flowers and the adaptive significance of using these environmental signals in the natural environment, using andromonoecious species. We focused on the mechanism by which daylength conditions and nutrient availability within the inflorescence induce staminate flowers. We found that when the first perfect flower in the inflorescence (B1) succeeds in fruiting, the next flower (B2) becomes a staminate flower, but that short-day conditions induce the B2 flower to become perfect. Furthermore, the results suggest that nutrient availability plays a role in the responsiveness to daylength conditions. It was hypothesized that this annual herbaceous plant species may be adaptive to produce seed-producible perfect flowers in response to short-day conditions in the fall, the last stage of its growth.

Free Research Field

植物生態学

Academic Significance and Societal Importance of the Research Achievements

環境依存的な生物の性決定については動物や収量に直結する作物においてその仕組みの解明が進んでいるが、野生植物における環境依存的な個々の花の性表現の決定機構についてはほとんど明らかになっていなかった。本研究で新たに得られた知見は、進行する気候変動に対して自然生態系の一部である植物個体群が種子生産を介してどのように応答するかを検討する材料になり得る。