ABSTRACT
This chapter considers a number of situations, such as seed development, tissue senescence, and low temperature acclimation, in which major changes in lipid metabolism occur within a relatively short time period, and highlights the lipid pathways most active under these circumstances. One of the unique developmental processes in plants is the assembly of photosynthetically capable chloroplasts. In most species, light is required for the assembly of functional thylakoid membranes. Seedlings form chloroplasts from preexisting proplastids as the young leaves are exposed to light. The seeds of many plant species store energy in the form of oil, mainly triglycerides. Fruit ripening has many features in common with senescence in vegetative tissues, but special metabolic changes, such as the hydrolysis of cell wall polysaccharides and the accumulation of pigments, are often most characteristic of the ripening process. Changes in lipid metabolism are thought to be largely responsible for the ability of plants to acclimate to low environmental temperatures.
