Autophagy is an evolutionarily conserved mechanism that mediates the degradation of cytoplasmic components in eukaryotic cells. In plants, autophagy has been extensively associated with the recycling of proteins during carbon-starvation conditions. Even though lipids constitute a significant energy reserve, our understanding of the function of autophagy in the management of cell lipid reserves and components remains fragmented. To further investigate the significance of autophagy in lipid metabolism, we performed an extensive lipidomic characterization of Arabidopsis (Arabidopsis thaliana) autophagy mutants (atg) subjected to dark-induced senescence conditions. Our results revealed an altered lipid profile in atg mutants, suggesting that autophagy affects the homeostasis of multiple lipid components under dark-induced senescence. The acute degradation of chloroplast lipids coupled with the differential accumulation of triacylglycerols (TAGs) and plastoglobuli indicates an alternative metabolic reprogramming toward lipid storage in atg mutants. The imbalance of lipid metabolism compromises the production of cytosolic lipid droplets and the regulation of peroxisomal lipid oxidation pathways in atg mutants.
Bibliographical noteFunding Information:
This work was made possible through financial support from the Serrapilheira Institute [grant Serra-1812-27067] and FAPEMIG (Foundation for Research Assistance of the Minas Gerais State, Brazil, Grant RED-00053-16). Work at the TAW group is supported by the Israeli Science Foundation [grant 1899/16]. Scholarships granted by the National Council for Scientific and Technological Development (CNPq-Brazil) and Council for Higher Education (Malag-Israel) to J.A.S.B. and research fellowships awarded by CNPq-Brazil to W.L.A. are gratefully acknowledged.
© American Society of Plant Biologists 2021.