title: Antioxidative systems, metal ion homeostasis and cadmium distribution in Iris lactea exposed to cadmium stress.
abstract: Iris lactea is a perennial halophyte and is tolerant to Cd. However, the mechanisms underlying this Cd tolerance are still poorly understood. In this study, morphological, physiological and biochemical responses of I. lactea to a 21 d exposure to different concentrations of Cd (0-150mgL-1) were investigated. I. lactea plants showed no toxicity symptoms except for a small reduction in growth at 100 and 150mgL-1Cd, along with the enhancement of H2O2and MDA content in comparison to the control. The activities of SOD and POD were significantly enhanced and Ca accumulated with increasing Cd concentrations. Moreover, most Cd was retained in roots and only a small amount was transported to the shoots with increasing external Cd concentrations. Cd content had a negative correlation with content of K, Fe, Zn, and Mn and a positive correlation with Mg content in shoots and roots, which had no influence on these contents of mineral nutrients in shoots and chlorophyll levels with the increase of Cd concentrations. The Cd translocation factors were always less than 1 and bioaccumulation factors ranged from 3.43 to 15.6 across all treatments, suggesting that I. lactea might be effectively used in phytostabilization of Cd contaminated soils. Overall, the findings suggest that I. lactea could reduce photoinhibition and oxidative damage and maintain metal ion homeostasis in plant tissue by limiting translocation of Cd from roots to shoots and enhancing induction of antioxidant enzyme activities, thereby improving its Cd tolerance.
authors.affiliation: Beijing Research and Development Center for Grass and Environment, Beijing Academy of Agriculture and Forestry Science, Beijing 100097, PR China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Guo
authors.affiliation: Beijing Research and Development Center for Grass and Environment, Beijing Academy of Agriculture and Forestry Science, Beijing 100097, PR China. Electronic address: menglin9599@sina.com.
authors.forename: Lin
authors.initials: L
authors.lastname: Meng
authors.affiliation: Beijing Research and Development Center for Grass and Environment, Beijing Academy of Agriculture and Forestry Science, Beijing 100097, PR China.
authors.forename: Ya-Nan
authors.initials: YN
authors.lastname: Zhang
authors.affiliation: Beijing Research and Development Center for Grass and Environment, Beijing Academy of Agriculture and Forestry Science, Beijing 100097, PR China.
authors.forename: Pei-Chun
authors.initials: PC
authors.lastname: Mao
authors.affiliation: Beijing Research and Development Center for Grass and Environment, Beijing Academy of Agriculture and Forestry Science, Beijing 100097, PR China.
authors.forename: Xiao-Xia
authors.initials: XX
authors.lastname: Tian
authors.affiliation: Beijing Research and Development Center for Grass and Environment, Beijing Academy of Agriculture and Forestry Science, Beijing 100097, PR China.
authors.forename: Shan-Shan
authors.initials: SS
authors.lastname: Li
authors.affiliation: Beijing Research and Development Center for Grass and Environment, Beijing Academy of Agriculture and Forestry Science, Beijing 100097, PR China.
authors.forename: Lin
authors.initials: L
authors.lastname: Zhang
mesh_terms: D000975:Antioxidants / Q000378:metabolism*; D001692:Biological Transport; D002104:Cadmium / Q000378:metabolism* / Q000633:toxicity; D002734:Chlorophyll / Q000378:metabolism; D004781:Environmental Exposure; D006706:Homeostasis; D006861:Hydrogen Peroxide / Q000378:metabolism; D031323:Iris Plant / Q000254:growth & development / Q000378:metabolism*; D010544:Peroxidases / Q000378:metabolism*; D018517:Plant Roots / Q000378:metabolism; D018520:Plant Shoots / Q000378:metabolism; D012989:Soil Pollutants / Q000378:metabolism* / Q000633:toxicity; D013312:Stress, Physiological; D013482:Superoxide Dismutase / Q000378:metabolism*; D014131:Trace Elements / Q000378:metabolism*
chemical_list: D000975:Antioxidants; D012989:Soil Pollutants; D014131:Trace Elements; D002104:Cadmium; D002734:Chlorophyll; D006861:Hydrogen Peroxide; D010544:Peroxidases; D013482:Superoxide Dismutase
keywords: Cadmium; Iris lactea var. chinensis (Fisch.) Koidz.; Mineral nutrients; Oxidative stress; Phytoremediation