Proline, A Peculiar Amino Acid with Astucious Functions in Development and Salt Tolerance Process in Plants

Proline is known to play diverse functions in plants. Some aspects of its biological functions are still unclear. This review highlights some cases in the proline, structure, metabolism, functions in development and also its involvement in salt tolerance process in planta. Indeed, we report the clever roles of proline in cellular homeostasis, including redox balance and their implication as effector during some causal enzymological and physiological processes. Furthermore, the proline functions under abiotic stresses are not yet completely understood. The engineering of proline metabolism could lead to new opportunities to improve plant tolerance against environmental stresses, especially salinity. Eventually, we note that the purpose through this review is to provide a rich, concise and mostly cohesive source on proline, considered as a platform and an anchor between several disciplines and biological functions. We also provide insight on some important research gaps that need to be filled to advance our scientific understanding in this area of research on proline in soil-plant systems.