Chloroplast glycerolipid metabolism during maintenance and under stress

Chloroplasts are the defining organelles in green plant tissues, converting light into chemical energy with the help of an intricate and extensive membrane system, the thylakoids. In the process, they release oxygen and assimilate carbon and other elements into molecules that constitute a plant cell's building blocks. Molecules leave and enter the chloroplast through two envelope membranes, which are also two major locations of glycerolipid assembly. A third location for lipid assembly is the endoplasmic reticulum (ER), and there is an intricate interplay between these three membranes that is necessary for the biogenesis of the bulk of cellular membranes in plant cells, including the photosynthetic membrane of the thylakoids. Here, we focus on what is known about the dynamic interactions between these three membranes in green plant tissues during glycerolipid assembly under maintenance or stress conditions, the latter encompassing lipid remodeling of membranes and the formation of lipid droplets. Along the way, we will provide examples of foundational papers describing key discoveries in the field.