title: Exogenous proline mitigates the detrimental effects of salt stress more than exogenous betaine by increasing antioxidant enzyme activities.
abstract: Proline and betaine accumulate in plant cells under environmental stresses including salt stress. Here, we investigated effects of proline and betaine on the growth and activities of antioxidant enzymes in tobacco Bright Yellow-2 (BY-2) culture cells in suspension under salt stress. Both proline and betaine mitigated the inhibition of growth of BY-2 cells under salt stress and the mitigating effect of proline was more than that of betaine. Salt stress significantly decreased the activities of superoxide dismutase (SOD), catalase and peroxidase in BY-2 cells. Exogenous application of proline or betaine alleviated the reduction in catalase and peroxidase activities but not SOD activity under salt stress. In addition, proline was found to be effective in alleviating the inhibition of salt stress-induced catalase and peroxidase activities in BY-2 cells. Neither proline nor betaine directly scavenged superoxide (O(2)(-)) or hydrogen peroxide (H(2)O(2)). It is concluded that exogenous proline mitigates the detrimental effects of salt stress more than exogenous betaine because of its superior ability to increase the activities of antioxidant enzymes.
authors.affiliation: Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530, Japan.
authors.forename: Md Anamul
authors.initials: MA
authors.lastname: Hoque
authors.forename: Eiji
authors.initials: E
authors.lastname: Okuma
authors.forename: Mst Nasrin Akhter
authors.initials: MN
authors.lastname: Banu
authors.forename: Yoshimasa
authors.initials: Y
authors.lastname: Nakamura
authors.forename: Yasuaki
authors.initials: Y
authors.lastname: Shimoishi
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Murata
mesh_terms: D000975:Antioxidants / Q000378:metabolism*; D001622:Betaine / Q000494:pharmacology*; D002478:Cells, Cultured; D016166:Free Radical Scavengers / Q000494:pharmacology; D011392:Proline / Q000494:pharmacology*; D026082:Singlet Oxygen; D012965:Sodium Chloride / Q000494:pharmacology*; D014026:Nicotiana / Q000187:drug effects* / Q000201:enzymology* / Q000378:metabolism
chemical_list: D000975:Antioxidants; D016166:Free Radical Scavengers; D026082:Singlet Oxygen; D001622:Betaine; D012965:Sodium Chloride; D011392:Proline