title: Transcriptomic responses to cadmium in the ectomycorrhizal fungus Paxillus involutus.
abstract: The molecular mechanisms underlying the response of ectomycorrhizal fungi to heavy metals in general and cadmium in particular remain poorly understood. We screened 2040 arrayed cDNAs of the ectomycorrhizal fungus Paxillus involutus to identify cadmium-responsive genes by using differential hybridization. Forty nine (2.4%) of the 2040 cDNAs were differentially expressed, among which transcripts coding a laccase, an aconitase, and a metallothionein were upregulated by 3.9-, 3.7- and 2.8-fold, respectively, whereas genes coding hydrophobins and threonine dehydratase were strongly downregulated. Our results suggest that complexation of cadmium by phenolic compounds, or by complexing peptides such as metallothioneins, is probably key determinant of the cellular response to cadmium in P. involutus. In addition, the present study suggests that the synthesis of hydrophobins may be efficiently reduced, thus redirecting Cys to the manufacture of Cys-enriched compounds.
authors.affiliation: UMR INRA/UHP 1136, Interactions Arbres Micro-organismes, Université Henri Poincaré-Nancy I, Faculté des Sciences et Techniques, BP239, 54506 Vandoeuvre-les-Nancy, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Jacob
authors.forename: Mikaël
authors.initials: M
authors.lastname: Courbot
authors.forename: Francis
authors.initials: F
authors.lastname: Martin
authors.forename: Annick
authors.initials: A
authors.lastname: Brun
authors.forename: Michel
authors.initials: M
authors.lastname: Chalot
mesh_terms: D001487:Basidiomycota / Q000187:drug effects / Q000235:genetics*; D002104:Cadmium / Q000494:pharmacology*; D004156:Catechol Oxidase / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics; D005656:Fungal Proteins / Q000235:genetics; D015966:Gene Expression Regulation, Fungal / Q000187:drug effects; D042845:Laccase / Q000235:genetics; D020411:Oligonucleotide Array Sequence Analysis; D012331:RNA, Fungal / Q000235:genetics / Q000302:isolation & purification; D014158:Transcription, Genetic / Q000187:drug effects*
chemical_list: D018076:DNA, Complementary; D005656:Fungal Proteins; D012331:RNA, Fungal; D002104:Cadmium; D004156:Catechol Oxidase; D042845:Laccase