Phys.org November 7, 2023
It has been hypothesized that a specific metabolic pathway in photosynthesis that competes with carbon fixation has a protective function for plants. To test this hypothesis an international team of researchers (Germany, USA – Michigan State University) characterized plants with varying PR enzyme activities under fluctuating and non-fluctuating light conditions. Contrasting their 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 H2O2 production. According to the researchers their results revealed that dynamic light environments buffer plant growth and metabolism against photorespiratory perturbations… read more. Open Access TECHNICAL ARTICLEÂ
Distinct effects of light conditions on different photorespiratory mutants… Credit: Nature Communications volume 14, Article number: 7052, 3 November, 2023Â