Proline accumulation in plants as response to osmotic stress

Abstract

Increase of aquaporines, compatible osmolytes, reactive oxygen species and abscisic acid levels were found among the molecular responses in plants subjected to osmotic stress. The proline accumulation is one ofthe most common responses to osmotic stress in plants, and results from decrease of celular hydric potential. This accumulation results from stimulation of enzymes glutamate synthase, pirrolyne-5-carboxylate synthase and pirrolyne-5-carboxylate reductase, and proline dehydrogenase inhibition. For a long time its had been thÓught that the principal function of proline was as osmolyte. In this review evidences are presented that show a diversity of functions for this molecule, and all them render posssible the osmotic stress tolerance.