Unravelling the Underlying Components of Autophagy-mediated Photomorphogenesis of Arabidopsis thaliana

Plant autophagy is a catabolic process recycling cytoplasmic proteins and organelles. Here, proteomic techniques were used to estimate organelle protein abundances in early seedling development, photomorphogenesis, and dark induced senescence of leaves in Arabidopsis thaliana autophagy mutants atg2, atg5, atg7, atg9, and wildtype Col-0.This showed a major effect in each mutant was a slow greening phenotype, lower abundance of key photosynthesis enzymes but higher levels of plastid fatty acid metabolism enzymes during photomorphogenesis. Supporting transcriptomics and physiology data confirmed that autophagy had a role in maximizing carotenoid and chlorophyll biosynthesis and accumulation of photosynthetic apparatus machinery during chloroplast biogenesis.