Biology Department, Nuclear Research Center Demokritos, Greek Atomic Energy Commission, Athens, Greece.
Plant Physiol. 1985 Oct;79(2):425-31. doi: 10.1104/pp.79.2.425.
It was shown earlier that in etiolated bean (Phaseolus vulgaris, var. red kidney) leaves exposed to continuous light for a short time and then transferred to darkness a reorganization of their photosystem II (PSII) unit components occurs. This reorganization involves disorganization of the light-harvesting complex of PSII (LHC-II), destruction of its chlorophyll b and the 25 kilodalton polypeptide, and reuse of its chlorophyll a for the formation of additional, small in size, PSII units (Argyroudi-Akoyunoglou, Akoyunoglou, Kalosakas, Akoyunoglou 1982 Plant Physiol 70: 1242-1248). The present study further shows that parallel to the PSII unit reorganization a reorganization of the PSI unit components also occurs: upon transfer to darkness the 24, 23, and 21 kilodalton polypeptides, components of the light-harvesting complex of PSI (LHC-I), are decreased, the 69 kilodalton polypeptide, component of the chlorophyll a-rich P700-protein complex (CPI), is increased and new smallsized PSI units are formed. Concomitantly, the cytochrome f/chlorophyll and the cytochrome b/chlorophyll ratios are gradually increased. This suggests that the concentration of the electron transport components is also modulated in darkness to allow for adequate electron flow to occur between the newly synthesized PSII and PSI units.
先前的研究表明，在连续光照下培养的黄化菜豆（Phaseolus vulgaris，var. red kidney）叶片，转移到黑暗环境中短时间后，其光合系统 II（PSII）单元组件会发生重组。这种重组涉及 PSII 光捕获复合物（LHC-II）的解体、其叶绿素 b 和 25kDa 多肽的破坏，以及其叶绿素 a 的再利用，用于形成额外的、较小的 PSII 单元（Argyroudi-Akoyunoglou、Akoyunoglou、Kalosakas、Akoyunoglou 1982 年《植物生理学》第 70 卷：1242-1248）。本研究进一步表明，与 PSII 单元重组平行，PSI 单元组件也发生重组：转移到黑暗环境后，PSI 光捕获复合物（LHC-I）的 24、23 和 21kDa 多肽减少，富含叶绿素 a 的 P700-蛋白复合物（CPI）的 69kDa 多肽增加，并形成新的小型 PSI 单元。同时，细胞色素 f/叶绿素和细胞色素 b/叶绿素的比值逐渐增加。这表明，在黑暗中电子传递组件的浓度也被调节，以允许新合成的 PSII 和 PSI 单元之间发生足够的电子流动。
