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RESEARCH PRODUCT

Lipids of the Plant Plasma Membrane

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description

The plasma membrane (PM) is arguably the most diverse membrane of the plant cell. Furthermore, the protein and lipid composition of the PM varies with cell type, developmental stage, and environment. Physical properties of lipids and associate proteins allow the formation of a barrier that is selectively permeable to macromolecules and solutes. As the plasma membrane delineates the interface between the cell and the environment, it is the primary part of signal recognition and transduction into intracellular responses for nutritional uptake/distribution, environmental responses, and developmental signaling. Many essential PM functions are carried out by proteinaceous components. However, PM lipids play a crucial role in determining cell structures regulating membrane fluidity and transducing signals. The composition and physical state of the lipid bilayer influence lipid–protein and protein–protein associations, membrane-bound enzyme activities, and transport capacity of membranes. Analyses of membrane function require highly selective and efficient purification methods. In this chapter, we first briefly review the methods to isolate PM from plant tissue and describe the lipid content of purified membranes. We further examine the involvement of different lipid species on signaling events that allow the plant cell to cope with environmental fluctuations. Finally, we discuss how regulated segregation of lipids inside the PM is of crucial importance to understand signaling mechanisms.