title: Responses of seedling growth and antioxidant activity to excess iron and copper in Triticum aestivum L.
abstract: The purpose of this study was to analyze phytotoxicity mechanism involved in root growth and to compare physiological changes in the leaves of wheat seedlings exposed to short term iron (Fe) and copper (Cu) stresses (0, 100, 300 and 500μM). All applied Fe or Cu concentrations reduced root and shoot lengths, but seed germination was inhibited by Cu only at 500μM. Analyses using fluorescent dye 2',7'-dichlorodihydrofluorescein diacetate indicated enhanced H(2)O(2) levels in seedling roots under Fe and Cu treatments. Cu stress at the same concentration induced a great reduction in cell viability and a strong damage on membrane lipid in the roots with respect to Fe treatment. Significant increases in the total chlorophyll (chl) content including chl a and chl b were observed in response to higher Fe concentrations, whereas the highest Cu concentration (500μM) led to significant decreases in the total chl content including chl a. Additionally, leaf peroxidase (POD) and ascorbate peroxidase (APX) were stimulated by Fe stress, but the highest Fe concentration exhibited inhibitory effect on leaf APX activity. In contrast, copper treatment resulted in an elevation in leaf catalase and POD activities. Therefore, H(2)O(2) content in the leaves associated with copper was significantly lower than that with iron at the same concentration.
authors.affiliation: Life Science of College, Northwest Normal University, Lanzhou 730070, Gansu, China.
authors.forename: Xiaoning
authors.initials: X
authors.lastname: Li
authors.forename: Haizhen
authors.initials: H
authors.lastname: Ma
authors.forename: Pengxiang
authors.initials: P
authors.lastname: Jia
authors.forename: Juan
authors.initials: J
authors.lastname: Wang
authors.forename: Lingyun
authors.initials: L
authors.lastname: Jia
authors.forename: Tengguo
authors.initials: T
authors.lastname: Zhang
authors.forename: Yingli
authors.initials: Y
authors.lastname: Yang
authors.forename: Haijian
authors.initials: H
authors.lastname: Chen
authors.forename: Xia
authors.initials: X
authors.lastname: Wei
mesh_terms: D060387:Ascorbate Peroxidases / Q000378:metabolism; D002374:Catalase / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D002734:Chlorophyll / Q000378:metabolism; D003300:Copper / Q000633:toxicity*; D004789:Enzyme Activation / Q000187:drug effects; D018525:Germination / Q000187:drug effects; D006861:Hydrogen Peroxide / Q000378:metabolism; D007501:Iron / Q000633:toxicity*; D010084:Oxidation-Reduction; D010544:Peroxidases / Q000378:metabolism; D018515:Plant Leaves / Q000187:drug effects / Q000201:enzymology; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development; D036226:Seedlings / Q000187:drug effects* / Q000254:growth & development; D014908:Triticum / Q000187:drug effects* / Q000201:enzymology / Q000254:growth & development
chemical_list: D002734:Chlorophyll; D003300:Copper; D006861:Hydrogen Peroxide; D007501:Iron; D010544:Peroxidases; D060387:Ascorbate Peroxidases; D002374:Catalase