title: Transcriptome profiling reveals similarities and differences in plant responses to cadmium and lead.
abstract: We analyzed the influence of salts of two heavy metals--lead and cadmium (Pb2+ and Cd2+) on plants, including plant and root size, plant genome stability as well as global genome expression. Measurement of the metal uptake showed that there was a significantly higher incorporation of Cd than of Pb, 0.6 and 0.15 uM per gram of dry weight, respectively. The analysis of the root length and plant size showed a dose dependent decrease in plants exposed to cadmium. In contrast there was little difference in the size of plants exposed to lead, although there was nearly four-fold increase of the root length. Analysis of the genome stability revealed that cadmium led to a dose dependent increase of homologous recombination whereas lead had no effect. Analysis of the global genome expression of plants chronically exposed to 50 uM of Cd and Pb revealed 65 and 338 up- and down-regulated genes by Cd and 19 and 76 by Pb, respectively. Interestingly, half of the genes that changed their expression in Pb-treated plants also changed their expression in Cd-treated ones. The greater number of genes regulated by Cd reflects generally higher genome instability of plants as well as higher uptake as compared to Pb.
authors.affiliation: Department of Biological Sciences, University of Lethbridge, Alta., Canada T1K 3M4.
authors.forename: Igor
authors.initials: I
authors.lastname: Kovalchuk
authors.forename: Victor
authors.initials: V
authors.lastname: Titov
authors.forename: Barbara
authors.initials: B
authors.lastname: Hohn
authors.forename: Olga
authors.initials: O
authors.lastname: Kovalchuk
mesh_terms: D017360:Arabidopsis / Q000187:drug effects; D001483:Base Sequence; D002104:Cadmium / Q000494:pharmacology*; D017931:DNA Primers; D007854:Lead / Q000494:pharmacology*; D030821:Plants, Genetically Modified / Q000187:drug effects*; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000235:genetics*; D011995:Recombination, Genetic
chemical_list: D017931:DNA Primers; D012333:RNA, Messenger; D002104:Cadmium; D007854:Lead