Marine algae use a unique pigment, siphonein, to shield photosynthesis from excess light.
Marine algae use a unique pigment, siphonein, to shield photosynthesis from excess light.
Too much sun can ruin a day at the beach. It can also ruin photosynthesis, scorching plants and other organisms that depend on capturing sunlight for energy. Beneath the waves, though, algae have found a clever shield. Osaka Metropolitan University researchers and their colleagues discovered that a pigment called siphonein helps marine green algae keep photosynthesis humming, without the burn.
Photosynthetic organisms rely on delicate light-harvesting complexes (LHCs) to capture sunlight for energy. During photosynthesis, chlorophyll absorbs light and enters an excited singlet state. Under normal light conditions, this energy is efficiently transferred to the photosynthetic reaction center to drive chemical reactions. But excessive light can push chlorophyll molecules into a dangerous “triplet” state, which is a source of reactive oxygen species capable of causing oxidative damage.
“Organisms use carotenoids to quickly dissipate excess energy, or quench these triplet states, through a process called triplet-triplet energy transfer (TTET),” said Ritsuko Fujii, lead author and associate professor at the Graduate School of Science and Research Center for Artificial Photosynthesis at Osaka Metropolitan University.
Read More: Osaka Metropolitan University
Photo Credit: grom900 via Pixabay
