title: Exogenous proline and glycine betaine mediated upregulation of antioxidant defense and glyoxalase systems provides better protection against salt-induced oxidative stress in two rice (Oryza sativa L.) varieties.
abstract: The present study investigates the roles of exogenous proline (Pro, 5 mM) and glycine betaine (GB, 5 mM) in improving salt stress tolerance in salt sensitive (BRRI dhan49) and salt tolerant (BRRI dhan54) rice (Oryza sativa L.) varieties. Salt stresses (150 and 300 mM NaCl for 48 h) significantly reduced leaf relative water (RWC) and chlorophyll (chl) content and increased endogenous Pro and increased lipid peroxidation and H2O2 levels. Ascorbate (AsA), glutathione (GSH) and GSH/GSSG, ascorbate peroxidae (APX), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), glutathione reductase (GR), glutathione peroxidase (GPX), catalase (CAT), and glyoxalase I (Gly I) activities were reduced in sensitive variety and these were increased in tolerant variety due to salt stress. The glyoxalase II (Gly II), glutathione S-transferase (GST), and superoxide dismutase (SOD) activities were increased in both cultivars by salt stress. Exogenous Pro and GB application with salt stress improved physiological parameters and reduced oxidative damage in both cultivars where BRRI dhan54 showed better tolerance. The result suggests that exogenous application of Pro and GB increased rice seedlings' tolerance to salt-induced oxidative damage by upregulating their antioxidant defense system where these protectants rendered better performance to BRRI dhan54 and Pro can be considered as better protectant than GB.
authors.affiliation: Department of Agronomy, Faculty of Agriculture, Sher-e-Bangla Agricultural University, Sher-e-Bangla Nagar, Dhaka 1207, Bangladesh.
authors.forename: Mirza
authors.initials: M
authors.lastname: Hasanuzzaman
authors.affiliation: Laboratory of Plant Stress Responses, Department of Applied Biological Science, Faculty of Agriculture, Kagawa University, 2393 Ikenobe, Miki-cho, Kita-gun, Kagawa 761-0795, Japan.
authors.forename: Md Mahabub
authors.initials: MM
authors.lastname: Alam
authors.affiliation: Department of Agronomy, Faculty of Agriculture, Sher-e-Bangla Agricultural University, Sher-e-Bangla Nagar, Dhaka 1207, Bangladesh ; Laboratory of Plant Stress Responses, Department of Applied Biological Science, Faculty of Agriculture, Kagawa University, 2393 Ikenobe, Miki-cho, Kita-gun, Kagawa 761-0795, Japan.
authors.forename: Anisur
authors.initials: A
authors.lastname: Rahman
authors.affiliation: Department of Agronomy, Faculty of Agriculture, Sher-e-Bangla Agricultural University, Sher-e-Bangla Nagar, Dhaka 1207, Bangladesh.
authors.forename: Md
authors.initials: M
authors.lastname: Hasanuzzaman
authors.affiliation: Laboratory of Plant Stress Responses, Department of Applied Biological Science, Faculty of Agriculture, Kagawa University, 2393 Ikenobe, Miki-cho, Kita-gun, Kagawa 761-0795, Japan ; Department of Agricultural Botany, Faculty of Agriculture, Sher-e-Bangla Agricultural University, Sher-e-Bangla Nagar, Dhaka 1207, Bangladesh.
authors.forename: Kamrun
authors.initials: K
authors.lastname: Nahar
authors.affiliation: Laboratory of Plant Stress Responses, Department of Applied Biological Science, Faculty of Agriculture, Kagawa University, 2393 Ikenobe, Miki-cho, Kita-gun, Kagawa 761-0795, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Fujita
mesh_terms: D000975:Antioxidants / Q000378:metabolism*; D001622:Betaine / Q000008:administration & dosage; D006861:Hydrogen Peroxide / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects; D012275:Oryza / Q000187:drug effects / Q000254:growth & development*; D018384:Oxidative Stress / Q000187:drug effects*; D011392:Proline / Q000008:administration & dosage; D017382:Reactive Oxygen Species / Q000378:metabolism; D055049:Salt Tolerance / Q000502:physiology; D036226:Seedlings / Q000187:drug effects*; D012965:Sodium Chloride / Q000633:toxicity; D013869:Thiolester Hydrolases / Q000378:metabolism; D000099301:Hydroxyacylglutathione Hydrolase
chemical_list: D000975:Antioxidants; D001622:Betaine; D006861:Hydrogen Peroxide; D011392:Proline; D017382:Reactive Oxygen Species; D012965:Sodium Chloride; D013869:Thiolester Hydrolases; D000099301:Hydroxyacylglutathione Hydrolase