title: Durum wheat seedling responses to simultaneous high light and salinity involve a fine reconfiguration of amino acids and carbohydrate metabolism.
abstract: Durum wheat plants are extremely sensitive to drought and salinity during seedling and early development stages. Their responses to stresses have been extensively studied to provide new metabolic targets and improving the tolerance to adverse environments. Most of these studies have been performed in growth chambers under low light [300-350 µmol m-2s-1photosynthetically active radiation (PAR), LL]. However, in nature plants have to face frequent fluctuations of light intensities that often exceed their photosynthetic capacity (900-2000 µmol m-2s-1). In this study we investigated the physiological and metabolic changes potentially involved in osmotic adjustment and antioxidant defense in durum wheat seedlings under high light (HL) and salinity. The combined application of the two stresses decreased the water potential and stomatal conductance without reducing the photosynthetic efficiency of the plants. Glycine betaine (GB) synthesis was inhibited, proline and glutamate content decreased, while γ-aminobutyric acid (GABA), amides and minor amino acids increased. The expression level and enzymatic activities of Δ1-pyrroline-5-carboxylate synthetase, asparagine synthetase and glutamate decarboxylase, as well as other enzymatic activities of nitrogen and carbon metabolism, were analyzed. Antioxidant enzymes and metabolites were also considered. The results showed that the complex interplay seen in durum wheat plants under salinity at LL was simplified: GB and antioxidants did not play a main role. On the contrary, the fine tuning of few specific primary metabolites (GABA, amides, minor amino acids and hexoses) remodeled metabolism and defense processes, playing a key role in the response to simultaneous stresses.
authors.affiliation: Dipartimento di Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Seconda Università degli Studi di Napoli, Caserta, 81100, Italy.
authors.forename: Pasqualina
authors.initials: P
authors.lastname: Woodrow
authors.affiliation: Dipartimento di Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Seconda Università degli Studi di Napoli, Caserta, 81100, Italy.
authors.forename: Loredana F
authors.initials: LF
authors.lastname: Ciarmiello
authors.affiliation: Department of Metabolic Networks, Max Planck Institute of Molecular Plant Physiology, Potsdam-Golm, 14476, Germany.
authors.forename: Maria Grazia
authors.initials: MG
authors.lastname: Annunziata
authors.affiliation: Dipartimento di Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Seconda Università degli Studi di Napoli, Caserta, 81100, Italy.
authors.forename: Severina
authors.initials: S
authors.lastname: Pacifico
authors.affiliation: Dipartimento di Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Seconda Università degli Studi di Napoli, Caserta, 81100, Italy.
authors.forename: Federica
authors.initials: F
authors.lastname: Iannuzzi
authors.affiliation: Dipartimento di Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Seconda Università degli Studi di Napoli, Caserta, 81100, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Mirto
authors.affiliation: Dipartimento di Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Seconda Università degli Studi di Napoli, Caserta, 81100, Italy.
authors.forename: Luisa
authors.initials: L
authors.lastname: D'Amelia
authors.affiliation: Dipartimento di Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Seconda Università degli Studi di Napoli, Caserta, 81100, Italy.
authors.forename: Emilia
authors.initials: E
authors.lastname: Dell'Aversana
authors.affiliation: Dipartimento di Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Seconda Università degli Studi di Napoli, Caserta, 81100, Italy.
authors.forename: Simona
authors.initials: S
authors.lastname: Piccolella
authors.affiliation: Dipartimento di Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Seconda Università degli Studi di Napoli, Caserta, 81100, Italy.
authors.forename: Amodio
authors.initials: A
authors.lastname: Fuggi
authors.affiliation: Dipartimento di Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Seconda Università degli Studi di Napoli, Caserta, 81100, Italy.|Department of Metabolic Networks, Max Planck Institute of Molecular Plant Physiology, Potsdam-Golm, 14476, Germany.
authors.forename: Petronia
authors.initials: P
authors.lastname: Carillo
mesh_terms: D000596:Amino Acids / Q000378:metabolism*; D050260:Carbohydrate Metabolism / Q000187:drug effects / Q000528:radiation effects; D002244:Carbon / Q000378:metabolism; D008027:Light; D008954:Models, Biological; D009584:Nitrogen / Q000378:metabolism; D010788:Photosynthesis / Q000187:drug effects / Q000528:radiation effects; D011758:Pyrroles / Q000378:metabolism; D054712:Salinity; D036226:Seedlings / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects; D012965:Sodium Chloride / Q000494:pharmacology; D013312:Stress, Physiological; D014908:Triticum / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects; D014867:Water / Q000502:physiology; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
chemical_list: D000596:Amino Acids; D011758:Pyrroles; D014867:Water; C015485:delta-1-pyrroline-5-carboxylate; D012965:Sodium Chloride; D005680:gamma-Aminobutyric Acid; D002244:Carbon; D009584:Nitrogen