PHOTOPHYSICS OF THE CAROTENOIDS ASSOCIATED WITH THE XANTHOPHYLL CYCLE IN PHOTOSYNTHESIS
PHOTOPHYSICS OF THE CAROTENOIDS ASSOCIATED WITH THE XANTHOPHYLL CYCLE IN PHOTOSYNTHESIS
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DOI：
10.1007/bf02183041
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发表时间：
1994-09-01
影响因子：
3.7
通讯作者：
WASIELEWSKI, MR
中科院分区：
文献类型：
--
作者：
FRANK, HA;CUA, A;WASIELEWSKI, MR
绿色植物利用叶黄素循环来调节光合蛋白中叶绿素a的能量流动。在弱光条件下，紫黄质是一种具有9个共轭双键的类胡萝卜素，它通过将能量从其最低激发单线态转移到捕光蛋白质中的叶绿素a而起到天线色素的作用。当光照强度增加时，紫黄质被生化转化为玉米黄质，玉米黄质是一种具有11个共轭双键的类胡萝卜素。结果表明，类胡萝卜素的pi共轭延长使类胡萝卜素最低激发单态的能量低于叶绿素a。因此，玉米黄质可以捕获蛋白质中叶绿素a色素的过量激发能量，从而调节光合作用捕光蛋白内的能量流动。
Green plants use the xanthophyll cycle to regulate the flow of energy to chlorophyll a within photosynthetic proteins. Under conditions of low light intensity violaxanthin, a carotenoid possessing nine conjugated double bonds, functions as an antenna pigment by transferring energy from its lowest excited singlet state to that of chlorophyll a within light-harvesting proteins. When the light intensity increases, violaxanthin is biochemically transformed into zeaxanthin, a carotenoid that possesses eleven conjugated double bonds. The results presented here show that extension of the pi conjugation of the polyene lowers the energy of the lowest excited singlet state of the carotenoid below that of chlorophyll a. As a consequence zeaxanthin can act as a trap for the excess excitation energy on chlorophyll a pigments within the protein, thus regulating the flow of energy within photosynthetic light-harvesting proteins.