title: Melatonin combined with ascorbic acid provides salt adaptation in Citrus aurantium L. seedlings.
abstract: Ascorbic acid (AsA) and melatonin (Mel) are known molecules participating in stress resistance, however, their combined role in counteracting the impact of salinity in plants is still unknown. In this work the effect of exogenous application of 0.50 mΜ AsA, 1 μΜ Mel and their combination (AsA + Mel) on various stress responses in leaves and roots of Citrus aurantium L. seedlings grown under 100 mΜ NaCl for 30 days was investigated. Application of AsA, Mel or AsA + Mel to saline solution decreased NaCl-induced electrolyte leakage and lipid peroxidation and prevented NaCl-associated toxicity symptoms and pigments degradation. Also, leaves exposed to combined AsA + Mel treatment displayed lower Cl(-) accumulation. Treatments with AsA and/or Mel modulated differently carbohydrates, proline, phenols, glutathione and the total antioxidant power of tissues as well as the activities of SOD, APX, POD, GR and PPO compared to NaCl alone treatment. Exposure of leaves and roots to chemical treatments and especially to combined AsA and Mel application was able to regulate CaMIPS, CaSLAH1 and CaMYB73 expression, indicating that sugar metabolism, ion homeostasis and transcription regulation were triggered by AsA and Mel. These results provide evidence that the activation of the metabolic pathways associated with combined AsA and Mel application are linked with salt adaptation in citrus plants.
authors.affiliation: Laboratory of Pomology, Department of Horticulture, School of Agriculture, Aristotle University of Thessaloniki, 541 24 Thessaloniki, Greece. Electronic address: zrkostopoulou@gmail.com.
authors.forename: Zacharoula
authors.initials: Z
authors.lastname: Kostopoulou
authors.affiliation: Laboratory of Pomology, Department of Horticulture, School of Agriculture, Aristotle University of Thessaloniki, 541 24 Thessaloniki, Greece.
authors.forename: Ioannis
authors.initials: I
authors.lastname: Therios
authors.affiliation: Group of Biotechnology of Pharmaceutical Plants, Laboratory of Pharmacognosy, Department of Pharmaceutical Sciences, Aristotle University of Thessaloniki, 541 24 Thessaloniki, Greece.
authors.forename: Efstathios
authors.initials: E
authors.lastname: Roumeliotis
authors.affiliation: Group of Biotechnology of Pharmaceutical Plants, Laboratory of Pharmacognosy, Department of Pharmaceutical Sciences, Aristotle University of Thessaloniki, 541 24 Thessaloniki, Greece.
authors.forename: Angelos K
authors.initials: AK
authors.lastname: Kanellis
authors.affiliation: Laboratory of Pomology, Department of Horticulture, School of Agriculture, Aristotle University of Thessaloniki, 541 24 Thessaloniki, Greece.
authors.forename: Athanassios
authors.initials: A
authors.lastname: Molassiotis
mesh_terms: D000975:Antioxidants / Q000378:metabolism / Q000494:pharmacology; D060387:Ascorbate Peroxidases / Q000378:metabolism; D001205:Ascorbic Acid / Q000494:pharmacology*; D002241:Carbohydrates / Q000032:analysis; D004156:Catechol Oxidase / Q000378:metabolism; D002712:Chlorides / Q000378:metabolism; D002957:Citrus / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D005978:Glutathione / Q000378:metabolism; D005980:Glutathione Reductase / Q000378:metabolism; D008550:Melatonin / Q000494:pharmacology*; D009195:Peroxidase / Q000378:metabolism; D010636:Phenols / Q000378:metabolism; D018515:Plant Leaves / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D010940:Plant Proteins / Q000235:genetics; D018517:Plant Roots / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D011392:Proline / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D055049:Salt Tolerance / Q000187:drug effects* / Q000502:physiology; D036226:Seedlings / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D012965:Sodium Chloride / Q000494:pharmacology; D013482:Superoxide Dismutase / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics
chemical_list: D000975:Antioxidants; D002241:Carbohydrates; D002712:Chlorides; D010636:Phenols; D010940:Plant Proteins; D014157:Transcription Factors; D012965:Sodium Chloride; D011392:Proline; D004156:Catechol Oxidase; D060387:Ascorbate Peroxidases; D009195:Peroxidase; D013482:Superoxide Dismutase; D005980:Glutathione Reductase; D005978:Glutathione; D008550:Melatonin; D001205:Ascorbic Acid
keywords: Antioxidants; Ascorbic acid; Citrus; Melatonin; Osmolytes; Salt stress