ABSTRACT
There are two pathways of glycerolipid biosynthesis, one in the plastid (the prokaryotic pathway) and one in the endoplasmic reticulum (the eukaryotic pathway). Phosphatidic acid produced in the plastids or endoplasmic reticulum is a central intermediate in glycerolipid biosynthesis. Lipids are not classified on the basis of their chemical structure but instead by their solubility properties. A saponifiable lipid or glycerolipid is made of a glycerol backbone and fatty acids. During plant development lipid composition often changes throughout the plant. In addition to the turnover of fatty acids within lipids, the formation of oxidized polyunsaturated fatty acids is an extremely important process in lipid metabolism. Elongation of long-chain fatty acid pathways is performed for generating carbon skeletons for cuticular lipids. Plant storage lipids are a highly reduced form of carbon, which is available as an energy source during germination and early seedling development. The major site of fatty oxidation in plants occurs in the peroxisomes and glyoxysomes.
