The roles of β-oxidation and autophagy in peroxisomal distribution and function in Arabidopsis thaliana

Abstract: Key steps of vital metabolic pathways are housed in peroxisomes, essential organelles. I conducted a microscopy-based screen for aberrant distribution of peroxisomally-targeted fluorescence in Arabidopsis  thaliana. This screen uncovered novel alleles defective in lipid body mobilization, fatty acid β-oxidation, the glyoxylate cycle, peroxisome fission, auxin metabolism, pexophagy and other peroxisomal processes. Analysis of these mutants revealed that fatty acid β-oxidation was needed for peroxisomal matrix protein import and wild-type peroxisome morphology, and that NAD + import contributes to the peroxisomal pool and to β-oxidation. Mutants defective in PECTIN METHYLESTERASE 31 were also recovered, suggesting a role in lipid mobilization for this cytosolic protein. Additionally, I characterised a mutant in PEX1, a main factor for peroxisome biogenesis and maintenance. I also discuss recent findings on the roles of autophagy in peroxisome turnover and function.