Photoinhibition of photosystem II in Phytoplankton: Processes and patterns

All the diverse lineages of phytoplankters use conserved Photosystem II complexes to mediate photochemical extraction of electrons from water, with concomitant release of oxygen. Photosystem II suffers light-dependent photoinactivation through multiple mechanisms, which is in turn countered by protein subunit removal and replacement. This cycle imposes both direct costs and also delayed opportunity costs. The effective quantum yield for photoinactivation of Photosystem II depends upon taxa, cell size, prior acclimation state, the instantaneous spectral regime and light level. Low temperature or constraints upon metabolism can drive up excitation pressure and photoinactivation, while slowing counteracting repair. Environmental shifts in nutrients or CO2 alter resource allocations and electron flows, with sometimes counter-intuitive effects upon susceptibility to photoinactivation across taxa. These interacting factors generate a wide range of susceptibilities to photoinactivation across ...

所有不同谱系的浮游植物均利用保守的光系统II（Photosystem II）复合物介导从水中光化学提取电子，同时释放氧气。光系统II通过多种机制发生光依赖性光失活，而这一过程又通过蛋白质亚基的移除与替换得到抵消。该循环既产生直接成本，也带来延迟的机会成本。光系统II光失活的有效量子产率取决于类群、细胞大小、先前的驯化状态、瞬时光谱条件及光照水平。低温或代谢限制会提高激发压力与光失活程度，同时减缓抵消性修复过程。营养物质或CO₂的环境变化会改变资源分配与电子流，对不同类群的光失活敏感性产生有时反直觉的影响。这些相互作用的因素在不同...之间产生了广泛的光失活敏感性差异。