Adaptation of light-harvesting functions of unicellular green algae to different light qualities
Adaptation of light-harvesting functions of unicellular green algae to different light qualities
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DOI：
10.1007/s11120-018-0523-y
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发表时间：
2018-05
影响因子：
3.7
通讯作者：
Y. Ueno;Shimpei Aikawa;A. Kondo;S. Akimoto
中科院分区：
文献类型：
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作者：
Y. Ueno;Shimpei Aikawa;A. Kondo;S. Akimoto
产氧光合作用生物通过将捕获的光能以适当的平衡分配给光系统(PSS)来高效地进行光合作用。在变化的光条件下保持光合作用效率需要改变光收集和能量转移过程。在目前的研究中，我们研究了绿藻如何调节它们的捕光功能来响应不同的光质。我们测量了在不同光质下生长的单细胞绿藻、坚硬衣藻和可变小球藻的低温时间分辨荧光光谱。通过观察延迟荧光光谱，我们证明两种类型的绿藻都主要改变了捕光叶绿素蛋白复合体(LHCs)和PSS(PSII和PSI)之间的联系。在蓝光下，衣藻将更多的能量从LHC传递到远离PSII反应中心的叶绿素(Chl)，而小球藻则通过不同的能量传递途径将能量从LHC传递到PSI。在绿光下，两种绿藻都表现出从LHC到PSS的能量转移增强。红光诱导衣藻PSS和小球藻LHC的荧光猝灭。在小球藻中，从PSII到PSI的能量传递似乎在平衡PSII和PSI之间的激发方面发挥了重要作用。
Oxygenic photosynthetic organisms perform photosynthesis efficiently by distributing captured light energy to photosystems (PSs) at an appropriate balance. Maintaining photosynthetic efficiency under changing light conditions requires modification of light-harvesting and energy-transfer processes. In the current study, we examined how green algae regulate their light-harvesting functions in response to different light qualities. We measured low-temperature time-resolved fluorescence spectra of unicellular green algaeChlamydomonas reinhardtiiandChlorella variabiliscells grown under different light qualities. By observing the delayed fluorescence spectra, we demonstrated that both types of green algae primarily modified the associations between light-harvesting chlorophyll protein complexes (LHCs) and PSs (PSII and PSI). Under blue light,Chlamydomonastransferred more energy from LHC to chlorophyll (Chl) located far from the PSII reaction center, while energy was transferred from LHC to PSI via different energy-transfer pathways inChlorella. Under green light, both green algae exhibited enhanced energy transfer from LHCs to both PSs. Red light induced fluorescence quenching within PSs inChlamydomonasand LHCs inChlorella. InChlorella, energy transfer from PSII to PSI appears to play an important role in balancing excitation between PSII and PSI.