ACCLIMATION OF PHOTOSYNTHETIC LIGHT REACTIONS DURING INDUCTION OF INORGANIC CARBON ACCUMULATION IN THE GREEN-ALGA CHLAMYDOMONAS-REINHARDTII
ACCLIMATION OF PHOTOSYNTHETIC LIGHT REACTIONS DURING INDUCTION OF INORGANIC CARBON ACCUMULATION IN THE GREEN-ALGA CHLAMYDOMONAS-REINHARDTII
复制标题
DOI：
10.1104/pp.94.1.357
复制
发表时间：
1990-09-01
期刊：
影响因子：
7.4
通讯作者：
SAMUELSSON, G
中科院分区：
文献类型：
--
作者：
PALMQVIST, K;SUNDBLAD, LG;SAMUELSSON, G
单细胞绿藻衣藻的细胞在高溶解无机碳(DIC)浓度(供应50毫升/升二氧化碳[g])中培养，并转移到低DIC浓度(供应.每升二氧化碳100微升[g])。在从高DIC转移到低DIC后，与光系统II相关的叶绿素a荧光的发射立即基本上被猝灭。假设突然引起的光合作用有机碳限制导致LHCII的磷酸化，导致随后的状态1到状态2的转变。在低DIC驯化2小时后，77K荧光测量表明，由于直接激发，光系统I发出的荧光增加，这表明光系统II/光系统I的化学计量比发生了变化，或者光系统I的捕光能力增加。经过5-6小时的驯化，观察到从光系统II到光系统I的溢出显著增加。这些光合作用光反应的调节在低DIC处理约12小时后进入稳定状态。四种不同光质中的任何一种，都可以通过5分钟的黑暗处理和5分钟的弱光处理来去除荧光猝灭剂。据推测，这种荧光的恢复是由于低DIC习服的细胞从状态2到状态1的转变。与高DIC培养的细胞相比，低DIC处理12小时的细胞紫黄质/玉米黄质的比率也降低。这一比率与荧光猝灭程度无关。讨论了不同过程在诱导DIC累积机制中的作用。
Cells of the unicellular green algae Chlamydomonas reinhardtii were grown in high dissolved inorganic carbon (DIC) concentrations (supplied with 50 milliliters per liter CO2[g]) and transferred to low DIC concentrations (supplied .ltoreq. 100 microliters per liter CO2[g]). Immediately after transfer from high to low DIC the emission of photosystem II related chlorophyll a fluorescence was substantially quenched. It is hypothesized that the suddenly induced organic carbon limitation of photosynthesis resulted in a phosphorylation of LHCII, leading to the subsequent state 1 to state 2 transition. After 2 hours of low-DIC acclimation, 77 K fluorescence measurements revealed an increase in the fluorescence emitted from photosystem I, due to direct excitation, suggesting a change in photosystem II/photosystem I stoichiometry or an increased light harvesting capacity of photosystem I. After 5 to 6 hours of acclimation a considerable increase in spillover from photosystem II to photosystem I was observed. These adjustments of the photosynthetic light reactions reacted steady-state after about 12 hours of low DIC treatment. The quencher of fluorescence could be removed by 5 minutes of dark treatment followed by 5 minutes of weak light treatment, of any of four different light qualities. It is hypothesized that this restoration of fluorescence was due to a state 2 to state 1 transition in low-DIC acclimated cells. A decreased ratio of violaxanthin to zeaxanthin was also observed in 12 hour low DIC treated cells, compared with high DIC grown cells. This ratio was not coupled to the level of fluorescence quenching. The role of different processes during the induction of a DIC accumulating mechanism is discussed.