Carbon monoxide alleviates cadmium-induced oxidative damage by modulating glutathione metabolism in the roots of Medicago sativa.
Using pharmacological and biochemical approaches, the role of cadmium (Cd)-induced carbon monoxide (CO) release and the relationship between CO and oxidative stress conferred by Cd exposure in the root tissues of alfalfa (Medicago sativa) plants were investigated. Cd treatments showed a dose-dependent enhancement in lipid peroxidation. Both 100 and 200 microm CdCl(2 )treatments caused the increase of CO release, which is consistent with the changes in the activity of the CO synthetic enzyme heme oxygenase (HO) and its HO-1 transcript. A 100 microm CdCl(2) exposure enhanced the formation of nonprotein thiols (NPT), and reduced glutathione (GSH) to oxidized glutathione (GSSG), which was potentiated by the pretreatment of CO scavenger hemoglobin (Hb). Plants pretreated for 6 h with 50% CO-saturated aqueous solution, which induced the rapid endogenous CO release followed by a gradual decrease when subsequently exposed to 100 microm CdCl(2) for 72 h, effectively decreased oxidative damage. Meanwhile, CO pretreatment modulated several enzymes responsible for GSH metabolism, thus resulting in the partial restoration of GSH : GSSG ratio, which was significantly blocked by Hb. These results are suggestive of a role for CO release as a signal element for the alleviation of Cd-induced oxidative damage by modulating glutathione metabolism.
Han
Yi
Y
College of Life Sciences, Co. Laboratory of Nanjing Agricultural University and Carl Zeiss Far East, Nanjing Agricultural University, Nanjing 210095, PR China; These authors contributed equally to this work.
Zhang
Jing
J
College of Life Sciences, Co. Laboratory of Nanjing Agricultural University and Carl Zeiss Far East, Nanjing Agricultural University, Nanjing 210095, PR China; These authors contributed equally to this work.
Chen
Xiaoyue
X
College of Life Sciences, Co. Laboratory of Nanjing Agricultural University and Carl Zeiss Far East, Nanjing Agricultural University, Nanjing 210095, PR China; These authors contributed equally to this work.
Gao
Zhaozhou
Z
College of Life Sciences, Co. Laboratory of Nanjing Agricultural University and Carl Zeiss Far East, Nanjing Agricultural University, Nanjing 210095, PR China; These authors contributed equally to this work.
Xuan
Wei
W
College of Life Sciences, Co. Laboratory of Nanjing Agricultural University and Carl Zeiss Far East, Nanjing Agricultural University, Nanjing 210095, PR China; These authors contributed equally to this work.
Xu
Sheng
S
College of Life Sciences, Co. Laboratory of Nanjing Agricultural University and Carl Zeiss Far East, Nanjing Agricultural University, Nanjing 210095, PR China; These authors contributed equally to this work.
Ding
Xiao
X
College of Life Sciences, Co. Laboratory of Nanjing Agricultural University and Carl Zeiss Far East, Nanjing Agricultural University, Nanjing 210095, PR China; These authors contributed equally to this work.
Shen
Wenbiao
W
College of Life Sciences, Co. Laboratory of Nanjing Agricultural University and Carl Zeiss Far East, Nanjing Agricultural University, Nanjing 210095, PR China; These authors contributed equally to this work.
D002104:Cadmium / Q000633:toxicity*; D002248:Carbon Monoxide / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D018506:Gene Expression Regulation, Plant; D005978:Glutathione / Q000378:metabolism*; D006878:Hydroxides / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects; D000455:Medicago sativa / Q000187:drug effects / Q000378:metabolism*; D018384:Oxidative Stress; D009195:Peroxidase; D018517:Plant Roots / Q000187:drug effects / Q000378:metabolism*; D036226:Seedlings / Q000187:drug effects / Q000378:metabolism; D013482:Superoxide Dismutase
D006878:Hydroxides; D002104:Cadmium; D002248:Carbon Monoxide; C031356:hydroxide ion; D009195:Peroxidase; D013482:Superoxide Dismutase; D005978:Glutathione