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Comparative transcriptome analysis of toxic metal responses in Arabidopsis thaliana and the Cd 2+ ‐hypertolerant facultative metallophyte Arabidopsis halleri
Author(s) -
WEBER MICHAEL,
TRAMPCZYNSKA ALEKSANDRA,
CLEMENS STEPHAN
Publication year - 2006
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1111/j.1365-3040.2005.01479.x
Subject(s) - arabidopsis , transcriptome , arabidopsis thaliana , biology , gene , dna microarray , genetics , microarray analysis techniques , tiling array , microbiology and biotechnology , gene expression , mutant
Toxic effects of both essential and non‐essential heavy metals are well documented in plants. Very little is known, however, about their modes of toxicity, about tolerance mechanisms and the signalling cascades involved in mediating transcriptional responses to toxic metal excess. We analysed transcriptome changes upon Cd 2+ and Cu 2+ exposure in roots of Arabidopsis thaliana and the Cd 2+ ‐hypertolerant metallophyte Arabidopsis halleri . Particularly, three categories of genes were identified with the help of this comparative approach: (1) common responses, which might indicate stable and functionally relevant changes conserved across plant species; (2) metallophyte‐specific responses as well as transcripts differentially regulated between the two species, representing candidate genes for Cd 2+ hypertolerance; and (3) those specifically responsive to Cd 2+ and therefore indicative of toxicity mechanisms or potentially involved in signalling cascades. Our data define, for instance, Arabidopsis core responses to Cd 2+ and Cu 2+ . In addition, they suggest that Cd 2+ exposure very rapidly results in apparent Zn deficiency, and they show the existence of highly specific Cd 2+ responses and distinct signalling cascades. Array results were independently confirmed by real‐time quantitative PCR, thereby further validating cross‐species transcriptome analysis with oligonucleotide microarrays.