ABSTRACT
The need for an intracellular transport of lipids in plants was suggested from various studies devoted to lipid metabolism. One example is given by the biosynthesis of a phospholipid, phosphatidylcholine (PC), which is a ubiquitous component of higher plant membranes. The main steps of lipid metabolism are now well-established the mechanisms of lipid transport are nowadays a matter of controversy, since different hypotheses are proposed, including first, transport of lipid monomers within the cytosolic phase; second, transport mediated by carrier proteins; and third, vesicular lipid transfer linked to membrane flow. This chapter focuses on the mechanisms which have been considered in higher plants. The involvement of a vesicular lipid transfer has been suggested particularly for the biogenesis of plasma membranes. Assaying lipid transfer proteins (LTPs) is quite laborious and makes their monitoring in the purification steps somewhat difficult. However, improvements in these assays were recently obtained by using spectrophotometric techniques.
