Photosynthetic Light Reactions in Diatoms. II. The Dynamic Regulation of the Various Light Reactions

Photosynthesis in diatoms is performed using the same basic modules as cyanobacteria and plants. It can be regulated on multiple levels depending on the environmental cues, allowing diatoms to adjust their photosynthetic light reaction toward optimum while at the same time minimizing photodamage induced by light. In recent years, tremendous progress has been gained in understanding these acclimation processes, revealing several diatom-specific features. In this chapter, we trace several paths through the photosynthetic electron transport chain to optimize photosynthesis. We review how diatoms repair photoinactivated reaction centers and which mechanisms they have to pre-empt photodamage. Finally, photoprotection is set in an ecophysiological context, highlighting differences in photoprotection of diatoms from different habitats.