title: Impact of dissolved organic matter on bioavailability of chlorotoluron to wheat.
abstract: Chlorotoluron (Chl) is a phenylurea herbicide and is widely used for controlling weeds. While it has brought great benefits to crop production, it has also resulted in contamination to ecosystem. In this study, we investigated accumulation of chlorotoluron (Chl) and biological responses of wheat plants as affected by dissolved organic matter (DOM). Wheat seedlings grown under 10 mg kg(-1) Chl for 4 d showed a low level of chlorophyll accumulation and damage to plasma membrane. The growth was inhibited by exposure of chlorotoluron. Treatment with 50 mg DOC kg(-1) DOM derived either from sludge (DOM-SL) or straw (DOM-ST) attenuated the chlorotoluron toxicity to plants. Both DOMs decreased activities of catalase, peroxidase and superoxide dismutase in Chl-treated seedlings. However, an increased glutathione S-transferases activity was observed under the same condition. Wheat plants treated with Chl in the presence of DOM accumulated less Chl than those treated with Chl alone. Moreover, in the presence of DOM, bioconcentration factor (BCF) decreased whereas translocation factors increased. Analyses with FT-IR spectra confirmed the regulatory role of DOMs in reducing Chl accumulation in wheat.
authors.affiliation: Department of Applied Chemistry, College of Sciences, Nanjing Agricultural University, Weigang No. 1, Building of Chemistry, Nanjing 210095, China.
authors.forename: Ning Hui
authors.initials: NH
authors.lastname: Song
authors.forename: Shuang
authors.initials: S
authors.lastname: Zhang
authors.forename: Min
authors.initials: M
authors.lastname: Hong
authors.forename: Hong
authors.initials: H
authors.lastname: Yang
mesh_terms: D002374:Catalase / Q000378:metabolism; D002734:Chlorophyll / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism; D006540:Herbicides / Q000032:analysis / Q000633:toxicity*; D006812:Humic Substances / Q000032:analysis*; D010671:Phenylurea Compounds / Q000032:analysis / Q000633:toxicity*; D010940:Plant Proteins / Q000378:metabolism; D014908:Triticum / Q000187:drug effects* / Q000201:enzymology / Q000254:growth & development / Q000378:metabolism
chemical_list: D006540:Herbicides; D006812:Humic Substances; D010671:Phenylurea Compounds; D010940:Plant Proteins; D002734:Chlorophyll; D002374:Catalase; D005982:Glutathione Transferase; C007033:chlortoluron