Role of lipids and fatty acids in stress tolerance in cyanobacteria

Lipids are the most effective source of storage energy, function as insulators of delicate internal organs and hormones and play an important role as the structural constituents of most of the cellular membranes. They also have a vital role in tolerance to several physiological stressors in a variety of organisms including cyanobacteria. The mechanism of desiccation tolerance relies on phospholipid bilayers which are stabilized during water stress by sugars, especially by trehalose. Unsaturation of fatty acids also counteracts water or salt stress. Hydrogen atoms adjacent to olefinic bonds are susceptible to oxidative attack. Lipids are rich in these bonds and are a primary target for oxidative reactions. Lipid oxidation is problematic as enzymes do not control many oxidative chemical reactions and some of the products of the attack are highly reactive species that modify proteins and DNA. This review deals with the role of lipids and fatty acids in stress tolerance in cyanobacteria.