Enhanced antioxidant enzymes are associated with reduced hydrogen peroxide in barley roots under saline stress

Yong Kim Sang, Jung Hyun Lim, Ryoul Park Myoung, Jin Kim Young, Il Park Tae, Won Seo Yong, Gu Choi Kyeong, Joong Yun Song

Research output: Contribution to journalArticle

115 Citations (Scopus)

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 was most highly correlated with the CAT activity, indicating an increased role of CAT in hydrogen peroxide detoxification under salinity stress. In addition, the results suggest the significance of temporal and spatial regulation of each antioxidant isoform in determining the competence of the antioxidant capacity under saline stress.

Original languageEnglish
Pages (from-to)218-224
Number of pages7
JournalJournal of Biochemistry and Molecular Biology
Volume38
Issue number2
Publication statusPublished - 2005

Keywords

  • Antioxidant enzymes
  • Barley
  • Hydrogen peroxide
  • Salt stress

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology

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    Sang, Y. K., Lim, J. H., Myoung, R. P., Young, J. K., Tae, I. P., Yong, W. S., Kyeong, G. C., & Song, J. Y. (2005). Enhanced antioxidant enzymes are associated with reduced hydrogen peroxide in barley roots under saline stress. Journal of Biochemistry and Molecular Biology, 38(2), 218-224.