Suetsugu Noriyuki, Wada Masamitsu
Graduate School of Biostudies, Kyoto University Kyoto, Japan.
Department of Biological Sciences, Graduate School of Science and Engineering, Tokyo Metropolitan University Tokyo, Japan.
Front Plant Sci. 2016 May 3;7:561. doi: 10.3389/fpls.2016.00561. eCollection 2016.
During the course of green plant evolution, numerous light responses have arisen that optimize their growth under fluctuating light conditions. The blue light receptor phototropin mediates several photomovement responses at the tissue, cellular and organelle levels. Chloroplast photorelocation movement is one such photomovement response, and is found not only in most green plants, but also in some red algae and photosynthetic stramenopiles. In general, chloroplasts move toward weak light to maximally capture photosynthetically active radiation (the chloroplast accumulation response), and they move away from strong light to avoid photodamage (the avoidance response). In land plants, chloroplast movement is dependent on specialized actin filaments, chloroplast-actin filaments (cp-actin filaments). Through molecular genetic analysis using Arabidopsis thaliana, many molecular factors that regulate chloroplast photorelocation were identified. In this Perspective, we discuss the evolutionary history of the molecular mechanism for chloroplast photorelocation movement in green plants in view of cp-actin filaments.
在绿色植物的进化过程中，出现了许多光反应，以优化它们在波动光照条件下的生长。蓝光受体向光素在组织、细胞和细胞器水平介导多种光运动反应。叶绿体的重新定位运动就是这样一种光运动反应，不仅在大多数绿色植物中存在，在一些红藻和光合不等鞭毛藻中也能发现。一般来说，叶绿体向弱光移动以最大程度地捕获光合有效辐射（叶绿体积累反应），并远离强光以避免光损伤（回避反应）。在陆地植物中，叶绿体运动依赖于特殊的肌动蛋白丝，即叶绿体-肌动蛋白丝（cp-肌动蛋白丝）。通过利用拟南芥进行分子遗传学分析，鉴定出了许多调节叶绿体重新定位的分子因子。在这篇观点文章中，我们基于cp-肌动蛋白丝探讨绿色植物中叶绿体重新定位运动分子机制的进化历程。
