title: Enhanced antioxidant enzymes are associated with reduced hydrogen peroxide in barley roots under saline stress.
abstract: Antioxidant enzymes are related to the resistance to various abiotic stresses including salinity. Barley is relatively tolerant to saline stress among crop plants, but little information is available on barley antioxidant enzymes under salinity stress. We investigated temporal and spatial responses of activities and isoform profiles of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), non-specific peroxidase (POX), and glutathione reductase (GR) to saline stress in barley seedlings treated with 200 mM NaCl for 0, 1, 2, 5 days, respectively. In the control plant, hydrogen peroxide content was about 2-fold higher in the root than in the shoot. Under saline stress, hydrogen peroxide content was decreased drastically by 70% at 2 d after NaCl treatment (DAT) in the root. In the leaf, however, the content was remained unchanged by 2 DAT and increased about 14 % at 5 DAT. In general, the activities of antioxidant enzymes were increased in the root and shoot under saline stress. But the increase was more significant and consistent in the root. The activities of SOD, CAT, APX, POX, and GR were increased significantly in the root within 1 DAT, and various elevated levels were maintained by 5 DAT. Among the antioxidant enzymes, CAT activity was increased the most drastically. The significant increase in the activities of SOD, CAT, APX, POX, and GR in the NaCl-stressed barley root was highly correlated with the increased expression of the constitutive isoforms as well as the induced ones. The hydrogen peroxide content in the root.
authors.affiliation: Division of Biological Resources Sciences, and Institute of Agricultural Science and Technology, Chonbuk Natl University, Chonju 561-756, Korea.
authors.forename: Sang Yong
authors.initials: SY
authors.lastname: Kim
authors.forename: Jung-Hyun
authors.initials: JH
authors.lastname: Lim
authors.forename: Myoung Ryoul
authors.initials: MR
authors.lastname: Park
authors.forename: Young Jin
authors.initials: YJ
authors.lastname: Kim
authors.forename: Tae Il
authors.initials: TI
authors.lastname: Park
authors.forename: Yong Won
authors.initials: YW
authors.lastname: Seo
authors.forename: Kyeong Gu
authors.initials: KG
authors.lastname: Choi
authors.forename: Song Joong
authors.initials: SJ
authors.lastname: Yun
mesh_terms: D000975:Antioxidants / Q000378:metabolism*; D060387:Ascorbate Peroxidases; D002374:Catalase / Q000378:metabolism; D005980:Glutathione Reductase / Q000378:metabolism; D001467:Hordeum / Q000187:drug effects / Q000201:enzymology*; D006861:Hydrogen Peroxide / Q000378:metabolism*; D010544:Peroxidases / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000201:enzymology; D012965:Sodium Chloride / Q000494:pharmacology*; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D000975:Antioxidants; D012965:Sodium Chloride; D006861:Hydrogen Peroxide; D010544:Peroxidases; D060387:Ascorbate Peroxidases; D002374:Catalase; D013482:Superoxide Dismutase; D005980:Glutathione Reductase