EFFECT OF PHOTOPERIOD ON PHOTOSYNTHETIC CHARACTERISTICS OF 2-MARINE DIATOMS
EFFECT OF PHOTOPERIOD ON PHOTOSYNTHETIC CHARACTERISTICS OF 2-MARINE DIATOMS
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DOI：
10.1016/0022-0981(88)90043-3
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发表时间：
1988-01-01
影响因子：
2
通讯作者：
JUPIN, H
中科院分区：
文献类型：
--
作者：
CARON, L;MORTAINBERTRAND, A;JUPIN, H
研究了海洋硅藻骨藻在光周期变化中的光适应性。克利夫和三角褐指藻。在2h:2h和12h:12h光暗循环周期下生长藻类。每日C同化。细胞-1在2:2光照条件下增强了1.5倍。在12:12 h光照条件下生长的细胞中，色素含量、PSI数量、PSUO2大小以及光系统ii -天线大小在较小程度上受到光暗变化的调节，而在2:2光照条件下，这些特征在昼夜周期中几乎是恒定的。光合色素细胞含量的变化与光合单位相对色素组成的变化无关。在海苔中，当细胞从2:2光态（光周期）转移到12:12光态时，色素含量的变化与PSI:PSII比值的增加（至少以2.12倍强调）和光系统天线尺寸的改变（PSII增加28%，PSI减少40%）相对应。不同种类的硅藻对光周期变化的响应不同。事实上，三角草在色素和PSI的细胞含量上没有表现出相同的变化；此外，光系统天线尺寸受光周期变化的影响较小。在S. costatum中观察到的诱导PSI:PSII比值变化的修饰，与硅藻中PSI周围存在一个活跃的循环光磷酸化有关，该磷酸化根据代谢过程的需要调节ATP:NADPH2比值。
Photoadaptation in changes in photoperiod was studied in the marine diatoms Skeletonema costatum (Grev.) Cleve and Phaeodactylum tricornutum Bohlin. The algae were grown under cycling light of 2h:2h and 12h:12h light-dark periods. The daily C assimilation .cntdot. cell-1 enhanced by a factor 1.5 in 2:2 light regime. In cells grown under 12:12 h light regime, the pigment content, the number of PSI, PSUO2 size, and to a lesser extent, the photosystem II-antenna size were modulated by the light-dark alterations, whereas these characterizations were almost constant over the circadian cycle in 2:2 cells. The modifications in the cellular content of photosynthetic pigments were correlated with no change in the relative pigment composition of the photosynthetic units. In S. costatium, the changes in pigment content corresponded to an increase of the ratio PSI:PSII which is emphasized at least by a factor 2.12 and to modifications of the photosystem-antenna sizes (increase of 28% for PSII and decrease of 40% for PSI) when the cells are transferred from 2:2 to 12:12 light regime (ligth period). The responses of diatoms to a change of the photoperiod is different according to the species. Indeed, P. tricornutum did not show the same variations in cellular contents of pigments and PSI; moreover, the photosystem-antenna sizes were weakly affected by a change in the photoperiod. The modifications observed in S. costatum, inducing variations of PSI:PSII ratio, were related to the existence of an active cyclic photophosphorylation around PSI in diatoms which modulate the ATP:NADPH2 ratio in response to the requirements of the metabolic processes.