title: Chromium-induced physiological and proteomic alterations in roots of Miscanthus sinensis.
abstract: Despite the widespread occurrence of chromium toxicity, its molecular mechanism is poorly documented in plants compared to other heavy metals. To investigate the molecular mechanisms that regulate the response of Miscanthus sinensis roots to elevated level of chromium, seedlings were grown for 4 weeks and exposed to potassium dichromate for 3 days. Physiological, biochemical and proteomic changes in roots were investigated. Lipid peroxidation and H₂O₂ content in roots were significantly increased. Protein profiles analyzed by two-dimensional gel electrophoresis revealed that 36 protein spots were differentially expressed in chromium-treated root samples. Of these, 13 protein spots were up-regulated, 21 protein spots were down-regulated and 2 spots were newly induced. These differentially displayed proteins were identified by MALDI-TOF and MALDI-TOF/TOF mass spectrometry. The identified proteins included known heavy metal-inducible proteins such as carbohydrate and nitrogen metabolism, molecular chaperone proteins and novel proteins such as inositol monophosphatase, nitrate reductase, adenine phosphoribosyl transferase, formate dehydrogenase and a putative dihydrolipoamide dehydrogenase that were not known previously as chromium-responsive. Taken together, these results suggest that Cr toxicity is linked to heavy metal tolerance and senescence pathways, and associated with altered vacuole sequestration, nitrogen metabolism and lipid peroxidation in Miscanthus roots.
authors.affiliation: Division of Applied Life Science (BK21 program), IALS, PMBBRC, Gyeongsang National University, Jinju 660-701, Republic of Korea.
authors.forename: Shamima Akhtar
authors.initials: SA
authors.lastname: Sharmin
authors.forename: Iftekhar
authors.initials: I
authors.lastname: Alam
authors.forename: Kyung-Hee
authors.initials: KH
authors.lastname: Kim
authors.forename: Yong-Goo
authors.initials: YG
authors.lastname: Kim
authors.forename: Pil Joo
authors.initials: PJ
authors.lastname: Kim
authors.forename: Jeong Dong
authors.initials: JD
authors.lastname: Bahk
authors.forename: Byung-Hyun
authors.initials: BH
authors.lastname: Lee
mesh_terms: D000222:Adaptation, Physiological; D016922:Cellular Senescence / Q000187:drug effects; D002857:Chromium / Q000378:metabolism / Q000633:toxicity*; D006861:Hydrogen Peroxide / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects; D009584:Nitrogen / Q000378:metabolism; D010940:Plant Proteins / Q000378:metabolism*; D018517:Plant Roots / Q000378:metabolism*; D006109:Poaceae / Q000378:metabolism / Q000502:physiology*; D020543:Proteome / Q000187:drug effects* / Q000378:metabolism; D040901:Proteomics; D015398:Signal Transduction; D013312:Stress, Physiological; D014131:Trace Elements / Q000378:metabolism / Q000633:toxicity; D014617:Vacuoles / Q000378:metabolism
chemical_list: D010940:Plant Proteins; D020543:Proteome; D014131:Trace Elements; D002857:Chromium; D006861:Hydrogen Peroxide; D009584:Nitrogen