title: Exogenous nitric oxide improves salt tolerance during establishment of Jatropha curcas seedlings by ameliorating oxidative damage and toxic ion accumulation.
abstract: Jatropha curcas is an oilseed species that is considered an excellent alternative energy source for fossil-based fuels for growing in arid and semiarid regions, where salinity is becoming a stringent problem to crop production. Our working hypothesis was that nitric oxide (NO) priming enhances salt tolerance of J. curcas during early seedling development. Under NaCl stress, seedlings arising from NO-treated seeds showed lower accumulation of Na+and Cl-than those salinized seedlings only, which was consistent with a better growth for all analyzed time points. Also, although salinity promoted a significant increase in hydrogen peroxide (H2O2) content and membrane damage, the harmful effects were less aggressive in NO-primed seedlings. The lower oxidative damage in NO-primed stressed seedlings was attributed to operation of a powerful antioxidant system, including greater glutathione (GSH) and ascorbate (AsA) contents as well as catalase (CAT) and glutathione reductase (GR) enzyme activities in both endosperm and embryo axis. Priming with NO also was found to rapidly up-regulate the JcCAT1, JcCAT2, JcGR1 and JcGR2 gene expression in embryo axis, suggesting that NO-induced salt responses include functional and transcriptional regulations. Thus, NO almost completely abolished the deleterious salinity effects on reserve mobilization and seedling growth. In conclusion, NO priming improves salt tolerance of J. curcas during seedling establishment by inducing an effective antioxidant system and limiting toxic ion and reactive oxygen species (ROS) accumulation.
authors.affiliation: Departamento de Bioquímica e Biologia Molecular and Instituto Nacional de Ciência e Tecnologia em Salinidade (INCTSal)/CNPq, Universidade Federal do Ceará, 60440-970, Fortaleza, Ceará, Brazil. Electronic address: cibellegadelha@outlook.com.br.
authors.forename: Cibelle Gomes
authors.initials: CG
authors.lastname: Gadelha
authors.affiliation: Departamento de Bioquímica e Biologia Molecular and Instituto Nacional de Ciência e Tecnologia em Salinidade (INCTSal)/CNPq, Universidade Federal do Ceará, 60440-970, Fortaleza, Ceará, Brazil. Electronic address: rafaelmyranda@hotmail.com.
authors.forename: Rafael de Souza
authors.initials: RS
authors.lastname: Miranda
authors.affiliation: Instituto Federal de Educação, Ciência e Tecnologia do Ceará, Crateús, Ce, Brazil. Electronic address: nlidi@yahoo.com.br.
authors.forename: Nara Lídia M
authors.initials: NLM
authors.lastname: Alencar
authors.affiliation: Departamento de Bioquímica e Biologia Molecular and Instituto Nacional de Ciência e Tecnologia em Salinidade (INCTSal)/CNPq, Universidade Federal do Ceará, 60440-970, Fortaleza, Ceará, Brazil. Electronic address: helio.costa@ufc.br.
authors.forename: José Hélio
authors.initials: JH
authors.lastname: Costa
authors.affiliation: Departamento de Bioquímica e Biologia Molecular and Instituto Nacional de Ciência e Tecnologia em Salinidade (INCTSal)/CNPq, Universidade Federal do Ceará, 60440-970, Fortaleza, Ceará, Brazil. Electronic address: jtprisco@uol.com.br.
authors.forename: José Tarquinio
authors.initials: JT
authors.lastname: Prisco
authors.affiliation: Departamento de Bioquímica e Biologia Molecular and Instituto Nacional de Ciência e Tecnologia em Salinidade (INCTSal)/CNPq, Universidade Federal do Ceará, 60440-970, Fortaleza, Ceará, Brazil. Electronic address: egomesf@ufc.br.
authors.forename: Enéas
authors.initials: E
authors.lastname: Gomes-Filho
mesh_terms: D000222:Adaptation, Physiological / Q000187:drug effects; D000975:Antioxidants / Q000378:metabolism; D001205:Ascorbic Acid / Q000378:metabolism; D002374:Catalase / Q000378:metabolism; D002712:Chlorides / Q000378:metabolism / Q000633:toxicity; D004789:Enzyme Activation; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant / Q000187:drug effects / Q000235:genetics; D005978:Glutathione / Q000378:metabolism; D005980:Glutathione Reductase / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism; D031286:Jatropha / Q000201:enzymology / Q000254:growth & development / Q000378:metabolism*; D009569:Nitric Oxide / Q000494:pharmacology*; D010084:Oxidation-Reduction / Q000187:drug effects*; D018384:Oxidative Stress / Q000187:drug effects; D010940:Plant Proteins / Q000187:drug effects / Q000235:genetics; D017382:Reactive Oxygen Species / Q000378:metabolism; D054712:Salinity; D055049:Salt Tolerance / Q000187:drug effects*; D036226:Seedlings / Q000187:drug effects*; D012639:Seeds / Q000187:drug effects / Q000235:genetics; D012964:Sodium / Q000378:metabolism / Q000633:toxicity; D012965:Sodium Chloride / Q000009:adverse effects / Q000378:metabolism; D013312:Stress, Physiological / Q000187:drug effects; D013997:Time Factors; D015854:Up-Regulation
chemical_list: D000975:Antioxidants; D002712:Chlorides; D010940:Plant Proteins; D017382:Reactive Oxygen Species; D009569:Nitric Oxide; D012965:Sodium Chloride; D012964:Sodium; D006861:Hydrogen Peroxide; D002374:Catalase; D005980:Glutathione Reductase; D005978:Glutathione; D001205:Ascorbic Acid
keywords: Antioxidative metabolism; Gene expression; Ionic homeostasis; Jatropha; Salinity; Seed pretreatment