Two cyanobacteria species that perform photosynthesis under low-light
conditions were investigated by scientists from the Imperial College
London to understand the trade-offs that happen between efficiency and
resilience when using lower-energy far-red light. Using this new
knowledge, researchers can potentially develop plants that are more
efficient in crop and biomass production since far-red light is less
energy intensive.

In their work, the scientists found that photosystem II, an enzyme that
performs the first step of photosynthesis by using light to extract
electrons from water, in the cyanobacteria/Acaryochloris marina/is
efficient in collecting and using far-red light. But when exposed to too
much light, it becomes overwhelmed and produces harmful reactive oxygen
species which can kill the cells. Another
cyanobacteria,/Chroococcidiopsis thermalis/, was found to use
chlorophyll-f when visible light is limited or absent. Though less
efficient in collecting and using far-red light than the/Acaryochloris
marina/, its exposure to excess light does not over-produce harmful
reactive oxygen species.

These two types of far-red photosystem II exhibit different
photosynthetic mechanisms to work using less energy in low-light
conditions. When combined with more data about the molecular and
chemical mechanisms responsible for the functional differences between
the two mechanisms, it is possible to introduce far-red photosynthesis
in crop plants or algae to increase yield production or biomass potentially.

[www.imperial.ac.uk]