title: Methane alleviates copper-induced seed germination inhibition and oxidative stress in Medicago sativa.
abstract: Recent results discovered the protective roles of methane (CH4) against oxidative stress in animals. However, the possible physiological roles of CH4in plants are still unknown. By using physiological, histochemical and molecular approaches, the beneficial role of CH4in germinating alfalfa seeds upon copper (Cu) stress was evaluated. Endogenous production of CH4was significantly increased in Cu-stressed alfalfa seeds, which was mimicked by 0.39 mM CH4. The pretreatment with CH4significantly alleviated the inhibition of seed germination and seedling growth induced by Cu stress. Cu accumulation was obviously blocked as well. Meanwhile, α/β amylase activities and sugar contents were increased, all of which were consistent with the alleviation of seed germination inhibition triggered by CH4. The Cu-triggered oxidative stress was also mitigated, which was confirmed by the decrease of lipid peroxidation and reduction of Cu-induced loss of plasma membrane integrity in CH4-pretreated alfalfa seedlings. The results of antioxidant enzymes, including ascorbate peroxidase (APX), superoxide dismutase (SOD), catalase (CAT), and guaiacol peroxidase (POD) total or isozymatic activities, and corresponding transcripts (APX1/2, Cu/Zn SOD and Mn-SOD), indicated that CH4reestablished cellular redox homeostasis. Further, Cu-induced proline accumulation was partly impaired by CH4, which was supported by the alternation of proline metabolism. Together, these results indicated that CH4performs an advantageous effect on the alleviation of seed germination inhibition caused by Cu stress, and reestablishment of redox homeostasis mainly via increasing antioxidant defence.
authors.affiliation: College of Life Sciences, Laboratory Center of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Muhammad Kaleem
authors.initials: MK
authors.lastname: Samma
authors.affiliation: College of Life Sciences, Laboratory Center of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Heng
authors.initials: H
authors.lastname: Zhou
authors.affiliation: College of Life Sciences, Laboratory Center of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Weiti
authors.initials: W
authors.lastname: Cui
authors.affiliation: College of Life Sciences, Laboratory Center of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Kaikai
authors.initials: K
authors.lastname: Zhu
authors.affiliation: College of Life Sciences, Laboratory Center of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhang
authors.affiliation: College of Life Sciences, Laboratory Center of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China. wbshenh@njau.edu.cn.
authors.forename: Wenbiao
authors.initials: W
authors.lastname: Shen
mesh_terms: D000975:Antioxidants / Q000737:chemistry / Q000378:metabolism; D003300:Copper / Q000737:chemistry / Q000633:toxicity; D018525:Germination / Q000187:drug effects*; D006861:Hydrogen Peroxide / Q000737:chemistry; D015227:Lipid Peroxidation / Q000187:drug effects; D000455:Medicago sativa / Q000235:genetics / Q000254:growth & development; D008697:Methane / Q000737:chemistry / Q000494:pharmacology*; D018384:Oxidative Stress / Q000187:drug effects*; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development; D036226:Seedlings / Q000187:drug effects; D012639:Seeds / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development
chemical_list: D000975:Antioxidants; D003300:Copper; D006861:Hydrogen Peroxide; D008697:Methane
keywords: Copper stress; Medicago sativa; Methane; Oxidative stress; Seed germination