Subcellular Lipid Trafficking and Membrane Specialization in Plants

Membrane lipid composition underpins the structural and functional identity of all plant membranes. This review examines membrane lipid metabolism and trafficking, with an emphasis on how lipid diversity and interorganelle movement support plant cell function. We explore the biophysical and biochemical specialization of subcellular membranes, with discussion of the endoplasmic reticulum, plasma membrane, apoplastic vesicles and barriers, tonoplast, peroxisomes, mitochondria, plastids, and thylakoids. We review both vesicular and nonvesicular lipid transport pathways, including membrane contact sites. Particular attention is given to glycerolipids, including phospholipids and galactolipids, sphingolipids, sterols, and, to a lesser extent, fatty acid exchange. By focusing on mechanisms of lipid transfer and remodeling, this review synthesizes our understanding of subcellular membrane lipid composition in the context of dynamic cellular processes including cell plate expansion, environmental stress responses, and photosynthetic membrane assembly.