title: Insights into spermine-induced combined high temperature and drought tolerance in mung bean: osmoregulation and roles of antioxidant and glyoxalase system.
abstract: High temperature and drought stress often occur simultaneously, and due to global climate change, this kind of phenomenon occurs more frequently and severely, which exerts devastating effects on plants. Polyamines (PAs) play crucial roles in conferring abiotic stress tolerance in plants. Present study investigated how exogenous pretreatment of spermine (Spm, 0.2 mM) enhances mung bean (Vigna radiata L. cv. BARI Mung-2) seedlings tolerance to high temperature (HT, 40 °C) and drought [induced by 5 % polyethyleneglycol (PEG)] stress individually and in combination. Spm pretreatment reduced reactive oxygen species (ROS) production including H2O2and O2•-, lipoxygenase (LOX) activity, and membrane lipid peroxidation (indicated by malondialdehyde, MDA) under HT and/or drought stress. Histochemical staining of leaves with diaminobenzidine and nitro blue tetrazolium chloride also confirmed that Spm-pretreated seedlings accumulated less H2O2and O2•-under HT and/or drought stress. Spermine pretreatment maintained the ascorbate (AsA) and glutathione (GSH) levels high, and upregulated the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), dehydroascorbate reductase (DHAR), and glutathione reductase (GR) which were vital for imparting ROS-induced oxidative stress tolerance under HT and/or drought stress. The cytotoxic compound methylglyoxal (MG) was overproduced due to HT and/or drought, but exogenous Spm pretreatment reduced MG toxicity enhancing the glyoxalase system. Spermine pretreatment modulated endogenous PA levels. Osmoregulation and restoration of plant water status were other major contributions of Spm under HT and/or drought stress. Preventing photosynthetic pigments and improving seedling growth parameters, Spm further confirmed its influential roles in HT and/or drought tolerance.
authors.affiliation: Laboratory of Plant Stress Responses, Faculty of Agriculture, Kagawa University, Miki-cho, Kita-gun, Kagawa, 761-0795, Japan.|Department of Agricultural Botany, Faculty of Agriculture, Sher-e-Bangla Agricultural University, Dhaka, 1207, Bangladesh.
authors.forename: Kamrun
authors.initials: K
authors.lastname: Nahar
authors.affiliation: Department of Agronomy, Faculty of Agriculture, Sher-e-Bangla Agricultural University, Dhaka, 1207, Bangladesh.
authors.forename: Mirza
authors.initials: M
authors.lastname: Hasanuzzaman
authors.affiliation: Laboratory of Plant Stress Responses, Faculty of Agriculture, Kagawa University, Miki-cho, Kita-gun, Kagawa, 761-0795, Japan.
authors.forename: Md Mahabub
authors.initials: MM
authors.lastname: Alam
authors.affiliation: Laboratory of Plant Stress Responses, Faculty of Agriculture, Kagawa University, Miki-cho, Kita-gun, Kagawa, 761-0795, Japan.|Department of Agronomy, Faculty of Agriculture, Sher-e-Bangla Agricultural University, Dhaka, 1207, Bangladesh.
authors.forename: Anisur
authors.initials: A
authors.lastname: Rahman
authors.affiliation: Laboratory of Plant Stress Responses, Faculty of Agriculture, Kagawa University, Miki-cho, Kita-gun, Kagawa, 761-0795, Japan.|Department of Agroforestry and Environmental Science, Faculty of Agriculture, Sher-e-Bangla Agricultural University, Dhaka, 1207, Bangladesh.
authors.forename: Jubayer-Al
authors.initials: JA
authors.lastname: Mahmud
authors.affiliation: Biomass Chemistry Laboratory, Bioresource Science for Manufacturing, Department of Applied Bioresource Science, Faculty of Agriculture, Kagawa University, Miki-cho, Kita-gun, Kagawa, 761-0795, Japan.
authors.forename: Toshisada
authors.initials: T
authors.lastname: Suzuki
authors.affiliation: Laboratory of Plant Stress Responses, Faculty of Agriculture, Kagawa University, Miki-cho, Kita-gun, Kagawa, 761-0795, Japan. fujita@ag.kagawa-u.ac.jp.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Fujita
mesh_terms: D000222:Adaptation, Physiological / Q000187:drug effects*; D000445:Aldehyde Oxidoreductases / Q000378:metabolism*; D000975:Antioxidants / Q000378:metabolism*; D002374:Catalase / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D003683:Dehydroascorbic Acid / Q000378:metabolism; D055864:Droughts; D005979:Glutathione Peroxidase / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism; D008084:Lipoxygenase / Q000378:metabolism; D008315:Malondialdehyde; D064587:Osmoregulation / Q000187:drug effects*; D018384:Oxidative Stress / Q000187:drug effects; D018515:Plant Leaves / Q000187:drug effects / Q000201:enzymology; D013096:Spermine / Q000494:pharmacology*; D013482:Superoxide Dismutase / Q000378:metabolism; D013481:Superoxides / Q000378:metabolism; D013696:Temperature; D000070658:Vigna / Q000187:drug effects / Q000201:enzymology / Q000502:physiology*
chemical_list: D000975:Antioxidants; D013481:Superoxides; D013096:Spermine; D008315:Malondialdehyde; D006861:Hydrogen Peroxide; D002374:Catalase; D005979:Glutathione Peroxidase; D008084:Lipoxygenase; D013482:Superoxide Dismutase; D000445:Aldehyde Oxidoreductases; D005982:Glutathione Transferase; D003683:Dehydroascorbic Acid
keywords: Abiotic stress; Antioxidant system; Global climate change; Methylglyoxal; Osmoregulation; Plant growth regulator