Growth in fluctuating light buffers plants against photorespiratory perturbations.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 37923709.
- Also identified by DOI 10.1038/s41467-023-42648-x and PMC identifier 10624928.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Photorespiration (PR) is the pathway that detoxifies the product of the oxygenation reaction of Rubisco. It has been hypothesized that in dynamic light environments, PR provides a photoprotective function. To test this hypothesis, we characterized plants with varying PR enzyme activities under fluctuating and non-fluctuating light conditions. Contrasting our expectations, growth of mutants with decreased PR enzyme levels was least affected in fluctuating light compared with wild type. Results for growth, photosynthesis and metabolites combined with thermodynamics-based flux analysis revealed two main causal factors for this unanticipated finding: reduced rates of photosynthesis in fluctuating light and complex re-routing of metabolic fluxes. Only in non-fluctuating light, mutants lacking the glutamate:glyoxylate aminotransferase 1 re-routed glycolate processing to the chloroplast, resulting in photooxidative damage through H<sub>2</sub>O<sub>2</sub> production. Our results reveal that dynamic light environments buffer plant growth and metabolism against photorespiratory perturbations.
Medical subject headings
- Hydrogen Peroxide
- Photosynthesis