Bína David, Herbstová Miroslava, Gardian Zdenko, Vácha František, Litvín Radek
Institute of Plant Molecular Biology, Biology Centre CAS, Department of Photosynthesis, Branišovská 31, České Budějovice, 37005, Czech Republic.
Faculty of Science, University of South Bohemia, Institute of Chemistry and Biochemistry, Branišovská 1760, České Budějovice, 37005, Czech Republic.
Sci Rep. 2016 May 5;6:25583. doi: 10.1038/srep25583.
Spatial segregation of photosystems in the thylakoid membrane (lateral heterogeneity) observed in plants and in the green algae is usually considered to be absent in photoautotrophs possessing secondary plastids, such as diatoms. Contrary to this assumption, here we show that thylakoid membranes in the chloroplast of a marine diatom, Phaeodactylum tricornutum, contain large areas occupied exclusively by a supercomplex of photosystem I (PSI) and its associated Lhcr antenna. These membrane areas, hundreds of nanometers in size, comprise hundreds of tightly packed PSI-antenna complexes while lacking other components of the photosynthetic electron transport chain. Analyses of the spatial distribution of the PSI-Lhcr complexes have indicated elliptical particles, each 14 × 17 nm in diameter. On larger scales, the red-enhanced illumination exerts a significant effect on the ultrastructure of chloroplasts, creating superstacks of tens of thylakoid membranes.
在植物和绿藻中观察到的类囊体膜中光系统的空间分离（横向异质性），通常被认为在具有次生质体的光合自养生物（如硅藻）中不存在。与这一假设相反，我们在此表明，海洋硅藻三角褐指藻叶绿体中的类囊体膜含有大片仅由光系统I（PSI）及其相关的Lhcr天线组成的超复合体占据的区域。这些面积达数百纳米的膜区域包含数百个紧密堆积的PSI-天线复合体，同时缺乏光合电子传递链的其他成分。对PSI-Lhcr复合体空间分布的分析表明其为椭圆形颗粒，每个直径为14×17纳米。在更大尺度上，红色增强光照对叶绿体的超微结构有显著影响，形成了数十个类囊体膜的超级堆叠。
