Lönneborg A, Lind L K, Kalla S R, Gustafsson P, Oquist G
Department of Plant Physiology, University of Umeå, S-901 87 Umeå, Sweden.
Plant Physiol. 1985 May;78(1):110-4. doi: 10.1104/pp.78.1.110.
Cyanobacteria acclimate to changes in light by adjusting the amounts of different cellular compounds, for example the light-harvesting macromolecular complex. Described are the acclimatization responses in the light-harvesting system of the cyanobacterium Anacystis nidulans following a shift from high intensity, white light to low intensity, red light.The phycocyanin and chlorophyll content and the relative amount of the two linker peptides (33 and 30 kilodaltons) in the phycobilisome were studied. Both the phycocyanin and chlorophyll content per cell increased after the shift, although the phycocyanin increased relatively more. The increase in phycocyanin was biphasic in nature, a fast initial phase and a slower second phase, while the chlorophyll increase was completed in one phase. The phycocyanin and chlorophyll responses to red light were immediate and were completed within 30 and 80 hours for chlorophyll and phycocyanin, respectively. An immediate response was also seen for the two phycobilisome linker peptides. The amount of both of them increased after the shift, although the 33 kilodalton linker peptide increased faster than the 30 kilodalton linker peptide. The increase of the content of the two linker peptides stopped when the phycocyanin increase shifted from the first to the second phase. We believe that the first phase of phycocyanin increase was due mainly to an increase in the phycobilisome size while the second phase was caused only by an increase in the amount of phycobilisomes. The termination of chlorophyll accumulation, which indicates that no further reaction center chlorophyll antennae were formed, occurred parallel to the onset of the second phase of phycocyanin accumulation.
蓝细菌通过调节不同细胞化合物的量来适应光照变化，例如光捕获大分子复合物。本文描述了集胞藻从高强度白光转变为低强度红光后，其光捕获系统中的适应性反应。研究了藻蓝蛋白和叶绿素含量以及藻胆体中两种连接肽（33千道尔顿和30千道尔顿）的相对含量。转变后，每个细胞的藻蓝蛋白和叶绿素含量均增加，尽管藻蓝蛋白增加得相对更多。藻蓝蛋白的增加本质上是双相的，一个快速的初始阶段和一个较慢的第二阶段，而叶绿素的增加在一个阶段内完成。藻蓝蛋白和叶绿素对红光的反应是即时的，叶绿素和藻蓝蛋白分别在30小时和80小时内完成反应。对于两种藻胆体连接肽也观察到即时反应。转变后它们的量均增加，尽管33千道尔顿的连接肽比30千道尔顿的连接肽增加得更快。当藻蓝蛋白增加从第一阶段转变为第二阶段时，两种连接肽含量的增加停止。我们认为藻蓝蛋白增加的第一阶段主要是由于藻胆体大小的增加，而第二阶段仅由藻胆体数量的增加引起。叶绿素积累的终止表明没有形成进一步的反应中心叶绿素天线，这与藻蓝蛋白积累第二阶段的开始同时发生。
