Department of Plant Biology, University of California, 94720-3102, Berkeley, CA, USA.
Photosynth Res. 1996 Mar;47(3):253-65. doi: 10.1007/BF02184286.
The work addressed the adjustment of the photosystem ratio in the green algaChlamydomonas reinhardtii. It is shown that green algae, much like cyanophytes and higher plants, adjust and optimize the ratio of the two photosystems in chloroplasts in response to the quality of irradiance during growth. Such adjustments are compensation reactions and helpC. reinhardtii to retain a quantum efficiency of oxygen evolution near the theoretical maximum. Results show variable amounts of PS I and a fairly constant amount of PS II in chloroplasts and suggest that photosystem stoichiometry adjustments, occurring in response to the quality of irradiance during plant growth, are mainly an adjustment in the concentration of PS I. The work delineates chromatic effects on chlorophyll accumulation in the chloroplast ofC. reinhardtii from those pertaining to the regulation of the PS I/PS II ratio. The detection of the operation of a molecular feedback mechanism for the PS I/PS II ratio adjustment in green algae strengthens the notion of the highly conserved nature of this mechanism among probably all oxygen evolving photosynthetic organisms. Findings in this work are expected to serve as the basis of future biochemical and mutagenesis experiments for the elucidation of the photosystem ratio adjustment in oxygenic photosynthesis.
这项工作针对的是绿藻莱茵衣藻中光系统比的调整。研究表明，绿藻与蓝藻和高等植物非常相似，会根据生长过程中光照质量来调整和优化叶绿体中两个光系统的比例。这种调整是一种补偿反应，可以帮助莱茵衣藻保持接近理论最大值的氧气演化量子效率。结果表明，叶绿体中 PS I 的数量可变，而 PS II 的数量相当恒定，这表明响应植物生长过程中光照质量的光系统化学计量学调整主要是 PS I 浓度的调整。这项工作描绘了叶绿体中叶绿素积累的色度效应与 PS I/PS II 比调节的关系。在绿藻中检测到 PS I/PS II 比调整的分子反馈机制的运作，加强了这种机制在可能所有产氧光合作用生物中高度保守的概念。这项工作的发现有望为未来的生化和诱变实验提供基础，以阐明产氧光合作用中的光系统比调整。
