title: Hydrogen-rich water confers plant tolerance to mercury toxicity in alfalfa seedlings.
abstract: In this report, the effect of hydrogen-rich water (HRW), which was used to investigate the physiological roles of hydrogen gas (H2) in plants recently, on the regulation of plant adaptation to mercury (Hg) toxicity was studied. Firstly, we observed that the exposure of alfalfa seedlings to HgCl2 triggered production of reactive oxygen species (ROS), growth stunt and increased lipid peroxidation. However, such effects could be obviously blocked by HRW. Meanwhile, significant decreases in the relative ion leakage and Hg accumulation were observed. Hg-induced increases in total and isozymatic activities of superoxide dismutase (SOD) were significantly reversed by HRW. Further results suggested that HRW-induced the activities of guaiacol peroxidase (POD) and ascorbate peroxidase (APX), two hydrogen peroxide-scavenging enzymes, was at transcriptional levels. Meanwhile, obvious increases of the ratios of reduced/oxidized glutathione (GSH), homoglutathione (hGSH), and ascorbic acid (AsA) and corresponding gene expression were consistent with the decreased oxidative damage in seedling roots. In summary, the results of this investigation indicated that HRW was able to alleviate Hg toxicity in alfalfa seedlings by (i) alleviating growth stunt and reducing Hg accumulation, and (ii) avoidance of oxidative stress and reestablishment of redox homeostasis.
authors.affiliation: College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Weiti
authors.initials: W
authors.lastname: Cui
authors.affiliation: College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Fang
authors.affiliation: College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Kaikai
authors.initials: K
authors.lastname: Zhu
authors.affiliation: College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Mao
authors.affiliation: College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Cunyi
authors.initials: C
authors.lastname: Gao
authors.affiliation: College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Yanjie
authors.initials: Y
authors.lastname: Xie
authors.affiliation: Laboratory Center of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Jin
authors.initials: J
authors.lastname: Wang
authors.affiliation: College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China. Electronic address: wbshenh@njau.edu.cn.
authors.forename: Wenbiao
authors.initials: W
authors.lastname: Shen
mesh_terms: D000222:Adaptation, Physiological / Q000187:drug effects; D005786:Gene Expression Regulation / Q000187:drug effects; D006859:Hydrogen / Q000494:pharmacology*; D000455:Medicago sativa / Q000187:drug effects*; D008628:Mercury / Q000633:toxicity*; D018384:Oxidative Stress / Q000187:drug effects; D036226:Seedlings / Q000187:drug effects*; D012989:Soil Pollutants / Q000633:toxicity; D014867:Water / Q000737:chemistry*
chemical_list: D012989:Soil Pollutants; D014867:Water; D006859:Hydrogen; D008628:Mercury
keywords: Hydrogen-rich water; Medicago sativa; Mercury toxicity; Oxidative damage