title: Melatonin and nitric oxide regulate sunflower seedling growth under salt stress accompanying differential expression of Cu/Zn SOD and Mn SOD.
abstract: Salinity results in significant reduction in sunflower (Helianthus annuus L.) seedling growth and excessive generation of reactive oxygen species (ROS). Present work highlights the possible role of melatonin as an antioxidant through its interaction with nitric oxide (NO), and as an early and long distance NaCl-stress sensing signaling molecule in seedling cotyledons. Exogenous melatonin (15µM)±NaCl (120mM) inhibit seedling growth, which is also correlated with NO availability, accumulation of potential superoxide anion (O2•-) and peroxynitrite anion (ONOO-), extent of tyrosine-nitration of proteins, spatial localization and activity of superoxide dismutase (SOD) isoforms. NO acts as a positive modulator of melatonin accumulation in seedling cotyledons as a long-distance signaling response. Modulation of superoxide anion and peroxynitrite anion content by melatonin highlights its crucial role in combating deleterious effects of ROS and reactive nitrogen species (RNS). Present findings provide evidence for an interaction between melatonin and NO in their effect on seedling growth under salt stress accompanying differential modulation of two SOD isoforms, i.e. Cu/Zn SOD and Mn SOD.
authors.affiliation: Laboratory of Plant Physiology and Biochemistry, Department of Botany, University of Delhi, Delhi 110007, India. Electronic address: spillcanvas29@gmail.com.
authors.forename: Dhara
authors.initials: D
authors.lastname: Arora
authors.affiliation: Laboratory of Plant Physiology and Biochemistry, Department of Botany, University of Delhi, Delhi 110007, India. Electronic address: bhatlasc@gmail.com.
authors.forename: Satish C
authors.initials: SC
authors.lastname: Bhatla
mesh_terms: D000975:Antioxidants / Q000378:metabolism; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D006368:Helianthus / Q000254:growth & development / Q000378:metabolism; D008550:Melatonin / Q000378:metabolism*; D009569:Nitric Oxide / Q000378:metabolism*; D018384:Oxidative Stress / Q000187:drug effects / Q000235:genetics*; D026361:Reactive Nitrogen Species / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D055051:Salt-Tolerant Plants / Q000254:growth & development / Q000378:metabolism; D036226:Seedlings / Q000254:growth & development / Q000378:metabolism; D012965:Sodium Chloride / Q000633:toxicity; D013312:Stress, Physiological / Q000187:drug effects / Q000235:genetics*; D013482:Superoxide Dismutase / Q000235:genetics*; D000072105:Superoxide Dismutase-1 / Q000235:genetics*
chemical_list: D000975:Antioxidants; D026361:Reactive Nitrogen Species; D017382:Reactive Oxygen Species; D009569:Nitric Oxide; D012965:Sodium Chloride; D013482:Superoxide Dismutase; D000072105:Superoxide Dismutase-1; D008550:Melatonin
keywords: Helianthus annuus; Long distance signaling; Melatonin; Nitric oxide; Salinity; Seedling growth; Sunflower; Superoxide dismutase