title: Is proline accumulation per se correlated with stress tolerance or is proline homeostasis a more critical issue?
abstract: Proline has been recognized as a multi-functional molecule, accumulating in high concentrations in response to a variety of abiotic stresses. It is able to protect cells from damage by acting as both an osmotic agent and a radical scavenger. Proline accumulated during a stress episode is degraded to provide a supply of energy to drive growth once the stress is relieved. Proline homeostasis is important for actively dividing cells as it helps to maintain sustainable growth under long-term stress. It also underpins the importance of the expansion of the proline sink during the transition from vegetative to reproductive growth and the initiation of seed development. Its role in the reproductive tissue is to stabilize seed set and productivity. Thus, to cope with abiotic stress, it is important to develop strategies to increase the proline sink in the reproductive tissue. We give a holistic account of proline homeostasis, taking into account the regulation of proline synthesis, its catabolism, and intra- and intercellular transport, all of which are vital components of growth and development in plants challenged by stress.
authors.affiliation: Leibniz Institute of Plant Genetics and Crop Plant Research, Gatersleben, 06466, Germany; Department of Genetics, Osmania University, Hyderabad, 500007, India.
authors.forename: Polavarapu B
authors.initials: PB
authors.lastname: Kavi Kishor
authors.forename: Nese
authors.initials: N
authors.lastname: Sreenivasulu
mesh_terms: D000975:Antioxidants / Q000378:metabolism; D017209:Apoptosis; D001692:Biological Transport; D035264:Flowers / Q000254:growth & development / Q000378:metabolism; D006706:Homeostasis; D053858:Metabolic Networks and Pathways; D008954:Models, Biological; D009997:Osmotic Pressure; D063245:Plant Development; D010944:Plants / Q000378:metabolism*; D011392:Proline / Q000378:metabolism* / Q000502:physiology; D012639:Seeds / Q000254:growth & development / Q000378:metabolism; D015398:Signal Transduction; D013312:Stress, Physiological
chemical_list: D000975:Antioxidants; D011392:Proline
keywords: abiotic stress tolerance; osmolyte; proline cycle; proline homeostasis; yield stability