Regulation of zeaxanthin epoxidation

玉米黄质环氧化的调控

• 批准号: 50827813
• 负责人: Professor Dr. Peter Jahns
• 金额: --
• 依托单位: Institut für Biochemie der Pflanzen
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2007
• 资助国家: 德国
• 起止时间: 2006-12-31 至 2008-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/50827813?language=en
• 关键词: Regulation; zeaxanthin; epoxidation

The light-induced formation of reactive oxygen species (ROS) is an extremely harmful stress factor for photosynthetic organisms. Higher plants have developed a number of strategies to avoid or minimize damage related to such photo-oxidative stress. The carotenoid zeaxanthin (Zx), which is formed from violaxanthin (Vx) in the de-epoxidation reactions of the so-called xanthophyll cycle, plays a central role in different photoprotective mechanisms in chloroplasts. Zx has not only essential functions in the thermal dissipation of excess light energy in photosystem II (PSII) but also contributes to the deactivation of ROS in the thylakoid membrane. The Zx content in the thylakoid membrane has to be regulated very carefully to avoid undesirable annihilation of absorbed light energy at non-saturating light intensities on the one hand and to allow rapid activation of protective mechanisms under stress conditions on the other hand. The regulation of the activity of the Zx epoxidase - which reconverts Zx to Vx under non-saturating light conditions - is central to these regulatory processes. The goal of this project is to characterize the regulation of the Zx epoxidase and the biochemical properties of this enzyme.

活性氧（ROS）的光引起的形成是光合生物的极其有害的应激因素。较高的植物已经制定了许多策略，以避免或最大程度地减少与这种光氧化应激相关的损害。类胡萝卜素Zeaxanthin（ZX）是由紫红蛋白（VX）在所谓的Xanthophyll循环的去氧化反应中形成的，在叶绿体中不同光保护机制中起着核心作用。 ZX不仅在光系统II（PSII）中过量光能的热量耗散中具有重要功能，而且还有助于在类囊体膜中ROS失活。必须非常仔细地调节类囊体膜中的ZX含量，以避免一方面在非饱和光强度下对吸收光能的不良an灭，并允许在应力条件下快速激活保护机制。在非饱和光条件下将ZX重新转化为VX的ZX环氧酶的活性的调节对于这些调节过程至关重要。该项目的目的是表征该酶的ZX环氧酶的调节和生化特性。