Interorganelle Communication: Peroxisomal MALATE DEHYDROGENASE2 Connects Lipid Catabolism to Photosynthesis through Redox Coupling in Chlamydomonas.

摘要: Plants and algae must tightly coordinate photosynthetic electron transport metabolic activities given that they often face fluctuating light nutrient conditions. The exchange of metabolites signaling molecules between organelles is thought to be central this regulation but evidence for still fragmentary. Here, we show knocking out the peroxisome-located MALATE DEHYDROGENASE2 (MDH2) Chlamydomonas reinhardtii results in dramatic alterations not only peroxisomal fatty acid breakdown also chloroplast starch metabolism photosynthesis. mdh2 mutants accumulated 50% more storage lipid 2-fold than wild type during nitrogen deprivation. In parallel, showed increased photosystem II yield CO2 fixation. Metabolite analyses revealed a >60% reduction malate, together with levels NADPH H2O2 mdh2. Similar phenotypes were found upon high exposure. Furthermore, based on lack accumulation knockout mutant H2O2-producing ACYL-COA OXIDASE2 effects supplementation, propose peroxisome-derived acts as regulator metabolism. We conclude MDH2 helps photoautotrophs cope scarcity by transmitting redox state peroxisome means malate shuttle- H2O2-based signaling.