Exogenous proline mitigates the detrimental effects of salt stress more than exogenous betaine by increasing antioxidant enzyme activities.
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.
Hoque
Md Anamul
MA
Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530, Japan.
Okuma
Eiji
E
Banu
Mst Nasrin Akhter
MN
Nakamura
Yoshimasa
Y
Shimoishi
Yasuaki
Y
Murata
Yoshiyuki
Y
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
D000975:Antioxidants; D016166:Free Radical Scavengers; D026082:Singlet Oxygen; D001622:Betaine; D012965:Sodium Chloride; D011392:Proline