A marine pennate diatom Phaeodactylum tricornutum (Pt) and a marine centric diatom Chaetoceros gracilis (Cg) possess unique light-harvesting complexes, fucoxanthin chlorophyll a/c-binding proteins (FCPs). FCPs have dual functions: light harvesting in the blue to green regions and quenching of excess energy. So far, excitation dynamics including FCPs have been studied by altering continuous light conditions. In the present study, we examined responses of the diatom cells to fluctuating light (FL) conditions. Excitation dynamics in the cells incubated under the FL conditions were analyzed by time-resolved fluorescence measurements followed by global analysis. As responses common to the Pt and Cg cells, quenching behaviors were observed in photosystem (PS) II with time constants of hundreds of picoseconds. The PSII → PSI energy transfer was modified only in the Pt cells, whereas quenching in FCPs was suggested only in the Cg cells, indicating different strategy for the dissipation of excess energy under the FL conditions.

中文翻译：

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通过荧光光谱探测，响应波动光的硅藻激发弛豫的变化。

海洋羽状硅藻 Phaeodactylum tricornutum (Pt) 和海洋中心硅藻 Chaetoceros gracilis (Cg) 具有独特的捕光复合物，岩藻黄质叶绿素 a/c 结合蛋白 (FCP)。FCP 具有双重功能：在蓝色到绿色区域收集光和抑制多余能量。到目前为止，已经通过改变连续光照条件研究了包括 FCP 在内的激发动力学。在本研究中，我们检查了硅藻细胞对波动光 (FL) 条件的反应。在 FL 条件下培养的细胞中的激发动力学通过时间分辨荧光测量进行分析，然后进行全局分析。作为 Pt 和 Cg 电池常见的响应，在光系统 (PS) II 中观察到淬灭行为，时间常数为数百皮秒。