title: Increase of free cysteine and citric acid in plant cells exposed to cobalt ions.
abstract: Cobalt complexation was investigated in a suspension cell culture of the cobalt hyperaccumulator Crotalaria cobalticola. C. cobalticola cells were more tolerant towards cobalt ions than the suspension cells of the non-accumulators Rauvolfia serpentina and Silene cucubalus. While the concentration of various compounds increased in cells of C. cobalticola challenged with cobalt ions, phytochelatin biosynthesis was not induced. Instead, the exposure to cobalt ions resulted in the increase of citrate and cysteine in cells. Size exclusion chromatography demonstrated the co-elution of cobalt and cysteine in C. cobalticola cell extracts. A significant increase in cysteine was observed also in cells of R. serpentina and S. cucubalus when they were exposed to cobalt ions. These results suggest that free cysteine is involved in cobalt ion complexation in plant cells.
authors.affiliation: Lehrstuhl für Botanik, Technische Universität München, Am Hochanger 4, D-85350, Freising, Germany.
authors.forename: Matjaz
authors.initials: M
authors.lastname: Oven
authors.forename: Erwin
authors.initials: E
authors.lastname: Grill
authors.forename: Avi
authors.initials: A
authors.lastname: Golan-Goldhirsh
authors.forename: Toni M
authors.initials: TM
authors.lastname: Kutchan
authors.forename: Meinhart H
authors.initials: MH
authors.lastname: Zenk
mesh_terms: D001692:Biological Transport / Q000187:drug effects; D002478:Cells, Cultured; D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D019343:Citric Acid / Q000378:metabolism*; D003035:Cobalt / Q000378:metabolism / Q000494:pharmacology*; D029864:Crotalaria / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D003545:Cysteine / Q000378:metabolism*; D008970:Molecular Weight; D011926:Rauwolfia / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D013997:Time Factors
chemical_list: D019343:Citric Acid; D003035:Cobalt; D003545:Cysteine