An evaluation of metabolic photoacclimation in Chlamydomonas reinhardtii
|Institution:||University of New Brunswick|
|Keywords:||Metabolomics; Photoacclimation; High-Light stress; Chlamydomonas reinhardtii|
|Full text PDF:||http://hdl.handle.net/1882/35383|
Green algae have evolved several photo-protective responses to cope with high-light stress. The present study examines the metabolic changes during photoacclimation to high-light in Chlamydomonas reinhardtii using nuclear magnetic resonance and mass spectrometry. Using principal component analysis, a clear metabolic response to highlight intensity was observed on global metabolite pools in Chlamydomonas, with major changes in the levels of amino acids and related nitrogen metabolites. Amino acid biosynthesis was induced during short-term photoacclimation presumably to alleviate excess excitation pressure in the plastid. An increase in mitochondrial metabolism through downstream photorespiratory and glyoxylate metabolism, pathways thought to act in a photo-protective capacity, was also observed. Long-term light stress resulted in a significant increase in antioxidant metabolites, ascorbate and dehydroascorbate. These results suggest that metabolism plays a direct role in coping with the imbalance in the excess excitation pressure generated during high-light stress; however, this metabolomics survey has generated additional questions about the roles of nitrogen assimilation associated metabolites in photoacclimatory responses to high-light in Chlamydomonas.