Faculty of Biology, Moscow State University, Moscow, Russia.
Photosynth Res. 2009 Oct;102(1):67-76. doi: 10.1007/s11120-009-9491-6.
High-resolution light-induced kinetics of chlorophyll fluorescence (OJIP transients) were recorded and analyzed in cultures of diatoms (Thalassiosira weissflogii, Chaetoceros mulleri) and dinoflagellates (Amphidinium carterae, Prorocentrum minimum). Fluorescence transients showed the rapid exponential initial rise from the point O indicating low connectivity between PS II units and high absorption cross-section of PS II antenna. Dark-adapted dinoflagellates revealed capability to maintain the PS I-mediated re-oxidation of the PQ pool at the exposure to strong actinic light that may lead to the underestimation of F(M) value. In OJIP transients recorded in phytoplanktonic algae the fluorescence yield at the point O exceeded F(O) level because Q(A) has been already partly reduced at 50 micros after the illumination onset. PEA was also employed to study the recovery of photosynthetic reactions in T. weissflogii during incubation of nitrogen starved cells in N-replete medium. N limitation caused the impairment of electron transport between Q(A) and PQs, accumulation of closed PS II centers, and the reduced ability to generate transmembrane DeltapH upon illumination, almost fully restored during the recovery period. The recovered cells showed much higher values of NPQ than control ones suggesting maximization of photoprotection mechanisms in the population with a 'stress history.'
高分辨率光诱导叶绿素荧光动力学（OJIP 瞬变）在硅藻（Thalassiosira weissflogii、Chaetoceros mulleri）和甲藻（Amphidinium carterae、Prorocentrum minimum）培养物中进行了记录和分析。荧光瞬变显示了从 O 点快速指数初始上升，表明 PS II 单元之间的连接性低，PS II 天线的吸收截面高。暗适应的甲藻在暴露于强光下，仍具有维持 PS I 介导的 PQ 库再氧化的能力，这可能导致 F(M) 值的低估。在浮游藻类记录的 OJIP 瞬变中，O 点的荧光产率超过了 F(O)水平，因为在光照开始后 50 微秒，Q(A) 已经部分还原。PEA 还用于研究在氮饥饿细胞在富含氮的培养基中孵育期间，T. weissflogii 光合作用反应的恢复。氮限制导致 Q(A) 和 PQs 之间的电子传递受损，关闭的 PS II 中心积累，以及在光照下产生跨膜 DeltapH 的能力降低，在恢复期间几乎完全恢复。恢复后的细胞表现出比对照细胞更高的 NPQ 值，这表明在具有“应激史”的种群中，光保护机制得到了最大化。
