Functional differentiation of phytochrome molecular species

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K06705
• 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: Kyoto University
• Principal Investigator: Nagatani Akira 京都大学, 理学研究科, 名誉教授 (40183082)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: フィトクロム / 分子種 / 舌構造 / N-PASドメイン / 光感度調節 / 避陰応答抑制 / 植物進化 / 野外光環境

Outline of Final Research Achievements

Phytochrome is a plant photoreceptor regulating a wide range of physiological processes. PhyA and phyB are two major molecular species of phytochrome, which share similar structures but respond to light quite differently.
By analyzing hybrid molecules between phyA and phyB, we have identified a few amino acid residues that are critical to determine the light sensitivity of phytochrome. A phylogenetic analysis inferred that modification of these residues occurred after branching of angiosperm plants. In addition, we have found that the phyA N-PAS domain confers responsiveness to continuous light irradiation independent of the Pr/Pfr spectral states.
These findings proved deeper insights into how plants cope with environmental changes by modifying the structure of sensor molecules. The knowledge would help to develop various applications of phytochrome.

Free Research Field

植物生理学

Academic Significance and Societal Importance of the Research Achievements

植物は光環境を感知し適切に応答する能力を発達させてきた。本研究により、植物特有の光受容体であるフィトクロム分子において、そのアミノ酸配列を一部変換するだけで例えば光感度などの性質を大きく変化させることができることが示された。この結果は、進化的、生態学的側面から興味深いだけでなく、フィトクロム分子を植物生産向上に応用する上でも、またフィトクロム分子を光受容体として取り出して利用する上でも重要な知見である。