Study Reveals Limits of Photosynthesis on Exoplanets Orbiting Cool M-Dwarf Stars
August 2, 2024A collaborative research effort from Queen Mary University of London explores the dynamics of photosynthesis under varying stellar light conditions.
The study investigates the feasibility of oxygenic photosynthesis on exoplanets orbiting low mass M-dwarf stars, contributing to the understanding of extraterrestrial light-harvesting antennas.
Findings suggest that plant-like antennas struggle to adapt efficiently to light from stars with temperatures below 3400 K, indicating limitations in increasing antenna size.
The research examines how spectral fluxes from lower mass stars affect photosynthetic performance and explores enhancements through the addition of more light-harvesting complex II (LHCII) trimers.
A complementary lattice diffusion model is proposed, treating excitations as localized entities that 'hop' between clusters of pigments, which could optimize light capture.
The study suggests that while existing antenna structures may adapt to low light, further evolution and optimization of designs are necessary to overcome entropic barriers.
Introducing an energetic gradient to the antenna significantly improves efficiency and electron output, enhancing the overall light-harvesting capabilities.
Plants have mechanisms to regulate photon absorption and down-regulate their antenna size to combat photoinhibition in low light environments.
The architecture of the antenna-reaction center is crucial for optimizing light capture in low-light environments, suggesting potential adaptations for exoplanetary organisms.
The authors, including Thomas J. Haworth and Edward Gillen from the Astronomy Unit, acknowledge support from various research councils for their work.
No conflicts of interest were reported by the authors, indicating an objective approach to their research.
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