title: Nitric Oxide Mediates 5-Aminolevulinic Acid-Induced Antioxidant Defense in Leaves of Elymus nutans Griseb. Exposed to Chilling Stress.
abstract: Nitric oxide (NO) and 5-aminolevulinic acid (ALA) are both extremely important signalling molecules employed by plants to control many aspects of physiology. In the present study, the role of NO in ALA-induced antioxidant defense in leaves of two sources of Elymus nutans Griseb. (Damxung, DX and Zhengdao, ZD) was investigated. Chilling stress enhanced electrolyte leakage, accumulation of malondialdehyde (MDA), hydrogen peroxide (H2O2) and superoxide radical in two E. nutans, which were substantially alleviated by exogenous ALA and NO application. Pretreatment with NO scavenger PTIO or NOS inhibitor L-NNA alone and in combination with ALA induced enhancements in electrolyte leakage and the accumulation of MDA, H2O2 and superoxide radical in leaves of DX and ZD exposed to chilling stress, indicating that the inhibition of NO biosynthesis reduced the chilling resistance of E. nutans and the ALA-enhanced chilling resistance. Further analyses showed that ALA and NO enhanced antioxidant defense and activated plasma membrane (PM) H+-ATPase and decreased the accumulation of ROS induced by chilling stress. A pronounced increase in nitric oxide synthase (NOS) activity and NO release by exogenous ALA treatment was found in chilling-resistant DX plants exposed to chilling stress, while only a little increase was observed in chilling-sensitive ZD. Furthermore, inhibition of NO accumulation by PTIO or L-NNA blocked the protective effect of exogenous ALA, while both exogenous NO treatment and inhibition of endogenous NO accumulation did not induce ALA production. These results suggested that NO might be a downstream signal mediating ALA-induced chilling resistance in E. nutans.
authors.affiliation: Department of grassland science, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, China.
authors.forename: Juanjuan
authors.initials: J
authors.lastname: Fu
authors.affiliation: Department of grassland science, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, China.
authors.forename: Xitong
authors.initials: X
authors.lastname: Chu
authors.affiliation: Department of grassland science, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, China.
authors.forename: Yongfang
authors.initials: Y
authors.lastname: Sun
authors.affiliation: College of Plant Science, Tibet Agriculture and Animal Husbandry College, Linzhi, Tibet 860000, China.
authors.forename: Yanjun
authors.initials: Y
authors.lastname: Miao
authors.affiliation: Department of grassland science, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, China.
authors.forename: Yuefei
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Department of grassland science, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, China.
authors.forename: Tianming
authors.initials: T
authors.lastname: Hu
mesh_terms: D000622:Aminolevulinic Acid / Q000494:pharmacology*; D000975:Antioxidants / Q000378:metabolism; D003080:Cold Temperature; D003497:Cyclic N-Oxides / Q000494:pharmacology; D031749:Elymus / Q000737:chemistry* / Q000187:drug effects* / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005978:Glutathione / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism; D007093:Imidazoles / Q000494:pharmacology; D008315:Malondialdehyde / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors / Q000378:metabolism; D018515:Plant Leaves / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism; D010940:Plant Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D013312:Stress, Physiological / Q000187:drug effects; D013481:Superoxides / Q000378:metabolism
chemical_list: D000975:Antioxidants; D003497:Cyclic N-Oxides; D004791:Enzyme Inhibitors; D007093:Imidazoles; D010940:Plant Proteins; D017382:Reactive Oxygen Species; D013481:Superoxides; C079391:2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide; D009569:Nitric Oxide; D008315:Malondialdehyde; D000622:Aminolevulinic Acid; D006861:Hydrogen Peroxide; D019001:Nitric Oxide Synthase; D005978:Glutathione