title: Physiological mechanism of plant roots exposed to cadmium.
abstract: Physiological experiments on plant roots exposed to cadmium were conducted on carrot and radish using a liquid culture and a pot experiment with a series of cadmium applications. Activities of four enzymes (catalase, peroxidase, polyphenol oxidase, superoxide dismutase), and concentrations of free proline and malonaldehyde in the roots of both plants were investigated. Results showed that the germination rate and growth of roots of both plants were inhibited at the concentration of 20 mg Cd/l, and the inhibition was increased with the increasing concentrations of cadmium, both in the liquid culture and in the pot experiment; activities of the four enzymes declined similarly in both species. The concentration of proline in roots reached the maximum when the application of cadmium was at the level of 20 mg/l in the liquid culture (or 20 mg/kg in soil), and then it declined slowly with the increasing concentration of cadmium. However, the reverse trend was observed for the concentration of malonaldehyde. All of bio-indicators measured here was quite sensitive to the addition of cadmium.
authors.affiliation: Department of Environmental Engineering, Zhejiang University, Huajiachi, Hangzhou 310029, China. yxchen@zju.edu.cn
authors.forename: Y X
authors.initials: YX
authors.lastname: Chen
authors.forename: Y F
authors.initials: YF
authors.lastname: He
authors.forename: Y M
authors.initials: YM
authors.lastname: Luo
authors.forename: Y L
authors.initials: YL
authors.lastname: Yu
authors.forename: Q
authors.initials: Q
authors.lastname: Lin
authors.forename: M H
authors.initials: MH
authors.lastname: Wong
mesh_terms: D018533:Biomass; D002104:Cadmium / Q000494:pharmacology*; D002374:Catalase / Q000378:metabolism; D004156:Catechol Oxidase / Q000378:metabolism; D018552:Daucus carota / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D018525:Germination / Q000187:drug effects; D008315:Malondialdehyde / Q000378:metabolism; D009195:Peroxidase / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D011392:Proline / Q000378:metabolism; D031224:Raphanus / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D012639:Seeds / Q000187:drug effects / Q000254:growth & development; D012987:Soil / Q000032:analysis; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D012987:Soil; D002104:Cadmium; D008315:Malondialdehyde; D011392:Proline; D004156:Catechol Oxidase; D002374:Catalase; D009195:Peroxidase; D013482:Superoxide Dismutase