title: Enhanced expression of the proline synthesis gene P5CSA in relation to seed osmopriming improvement of Brassica napus germination under salinity stress.
abstract: Osmopriming is a pre-sowing treatment that enhances germination performance and stress tolerance of germinating seeds. Brassica napus seeds showed osmopriming-improved germination and seedling growth under salinity stress. To understand the molecular and biochemical mechanisms of osmopriming-induced salinity tolerance, the accumulation of proline, gene expression and activity of enzymes involved in proline metabolism and the level of endogenous hydrogen peroxide were investigated in rape seeds during osmopriming and post-priming germination under control (H2O) and stress conditions (100 mM NaCl). The relationship between gene expression and enzymatic activity of pyrroline-5-carboxylate synthetase (P5CS), ornithine-δ-aminotransferase (OAT) and proline dehydrogenase (PDH) was determined. The improved germination performance of osmoprimed seeds was accompanied by a significant increase in proline content. The accumulation of proline during priming and post-priming germination was associated with strong up-regulation of the P5CSA gene, down-regulation of the PDH gene and accumulation of hydrogen peroxide. The up-regulated transcript level of P5CSA was consistent with the increase in P5CS activity. This study shows, for the first time, the role of priming-induced modulation of activities of particular genes and enzymes of proline turnover, and its relationship with higher content of hydrogen peroxide, in improving seed germination under salinity stress. Following initial stress-exposure, the primed seeds acquired stronger salinity stress tolerance during post-priming germination, a feature likely linked to a 'priming memory'.
authors.affiliation: Adam Mickiewicz University in Poznań, Department of Plant Physiology, ul. Umultowska 89, 61-614 Poznań, Poland; Max Planck Institute for Plant Breeding Research, Carl von Linné Weg 10, 50829 Köln, Germany.
authors.forename: Szymon
authors.initials: S
authors.lastname: Kubala
authors.affiliation: Adam Mickiewicz University in Poznań, Department of Plant Physiology, ul. Umultowska 89, 61-614 Poznań, Poland.
authors.forename: Łukasz
authors.initials: Ł
authors.lastname: Wojtyla
authors.affiliation: Groupe de Recherche en Physiologie Végétale (GRPV), Earth and Life Institute-Agronomy (ELI-A), Université catholique de Louvain, Croix du Sud 4-5, boîte L7.07.13, B-1348 Louvain-la-Neuve, Belgium.
authors.forename: Muriel
authors.initials: M
authors.lastname: Quinet
authors.affiliation: Adam Mickiewicz University in Poznań, Department of Plant Physiology, ul. Umultowska 89, 61-614 Poznań, Poland.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Lechowska
authors.affiliation: Groupe de Recherche en Physiologie Végétale (GRPV), Earth and Life Institute-Agronomy (ELI-A), Université catholique de Louvain, Croix du Sud 4-5, boîte L7.07.13, B-1348 Louvain-la-Neuve, Belgium.
authors.forename: Stanley
authors.initials: S
authors.lastname: Lutts
authors.affiliation: Adam Mickiewicz University in Poznań, Department of Plant Physiology, ul. Umultowska 89, 61-614 Poznań, Poland. Electronic address: garnczar@amu.edu.pl.
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Garnczarska
mesh_terms: D029688:Brassica napus / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D018506:Gene Expression Regulation, Plant; D018525:Germination / Q000187:drug effects; D009953:Ornithine-Oxo-Acid Transaminase / Q000235:genetics / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D011392:Proline / Q000378:metabolism*; D011394:Proline Oxidase / Q000235:genetics / Q000378:metabolism; D055049:Salt Tolerance; D036226:Seedlings / Q000254:growth & development / Q000502:physiology; D012639:Seeds / Q000502:physiology; D012965:Sodium Chloride / Q000494:pharmacology*; D013312:Stress, Physiological
chemical_list: D010940:Plant Proteins; D012965:Sodium Chloride; D011392:Proline; D011394:Proline Oxidase; D009953:Ornithine-Oxo-Acid Transaminase
keywords: Germination; Osmopriming; P5SCA; Proline; Salinity tolerance