Acclimation of the photosynthetic apparatus to fluctuating light environment

2016 Fiscal Year Final Research Report

• Project/Area Number: 26291055
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Plant molecular biology/Plant physiology
• Research Institution: The University of Tokyo
• Principal Investigator: TERASHIMA Ichiro 東京大学, 理学(系)研究科(研究院), 教授 (40211388)
• Research Collaborator: KONO Masaru 東京大学, 大学院理学系研究科, 博士研究員 ; MIYATA Kazunori 東京大学, 大学院理学系研究科・生物科学専攻
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: 光阻害 / 光化学系 I / 光化学系II

Outline of Final Research Achievements

In field grown plants, photosystem II (PSII) photoinhibitory rate constant shows strong correlations to the excess energy and energy dissipated in non-regulatory ways.
It has been reported that PSI photoinhibition is induced even in wild-type plants of Arabidopsis thaliana, rice and other species by exposure of leaves to fluctuating light (FL) for a few hours. Because plants are exposed to FL in nature, they must possess protective mechanisms against the FL induced photodamage. We examined PSI photoprotection by far-red (FR) light at intensities comparable with those observed in nature. The addition of continuous FR light during the FL suppressed this damage almost completely. With FR light, P700 was kept in a more oxidized state in both low- and high-light phases. The protective effect of FR light was diminished in the mutants of cyclic electron flow around PSI, indicating important roles of the cyclic electron flow in protection of PSI from photoinhibition.

Free Research Field

植物生理生態学