Abstract
Organelles in eukaryotic cells not only perform individual functions but also form regulatory systems that require coordinated interactions among multiple organelles to carry out various biological processes. For example, many metabolic systems depend on spatiotemporally regulated organelle-organelle interactions to facilitate the exchange of metabolites between organelles. Peroxisomes, which are ubiquitously present in eukaryotic cells, play key roles in processes such as fatty acid metabolism, reactive oxygen species (ROS) detoxification, photorespiration, and the biosynthesis of jasmonic acid. Defects in these functions can lead to seed germination failure, dwarfism, reproductive abnormalities, and embryonic lethality. Photorespiration, a metabolic pathway involving peroxisomes, chloroplasts, and mitochondria, requires the light-dependent interaction of these three organelles. During this process, changes in peroxisome morphology and increased adhesion to chloroplasts occur. Additionally, during the germination of oilseed plants, fatty acids produced by lipase-mediated hydrolysis of triacylglycerol in the oil body are transported to peroxisomes, where direct interaction between peroxisomes and oil bodies takes place. It is now clear that these organelle-organelle interactions occur via membrane contact sites, facilitating lipid transport between organelles. This review focuses on the molecular mechanisms underlying the interactions between peroxisomes and other organelles, with a particular emphasis on studies in Arabidopsis thaliana.
