title: Transcriptome divergence between introduced and native populations of Canada thistle, Cirsium arvense.
abstract: Introduced plants may quickly evolve new adaptive traits upon their introduction. Canada thistle (Cirsium arvense - Cardueae, Asteraceae) is one of the worst invasive weeds worldwide. The goal of this study is to compare gene expression profiles of native (European) and introduced (North American) populations of this species, to elucidate the genetic mechanisms that may underlie such rapid adaptation. We explored the transcriptome of ten populations (five per range) of C. arvense in response to three treatments (control, nutrient deficiency and shading) using a customized microarray chip containing 63 690 expressed sequence tags (ESTs), and verified the expression level of 13 loci through real-time quantitative PCR. Only 2116 ESTs (3.5%) were found to be differentially expressed between the ranges, and 4458 ESTs (7.1%) exhibited a significant treatment-by-range effect. Among them was an overrepresentation of loci involved in stimulus and stress responses. Cirsium arvense has evolved different life history strategies on each continent. The two ranges notably differ with regard to R-protein mediated defence, sensitivity to abiotic stresses, and developmental timing. The fact that genotypes from the Midwest exhibit different expression kinetics than remaining North American samples further corroborates the hypothesis that the New World has been colonized twice, independently.
authors.affiliation: Botany Department, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada.|Institute of Integrative Biology (IBZ), ETH Zürich, Universitätstrasse 16, 8092, Zürich, Switzerland.
authors.forename: Alessia
authors.initials: A
authors.lastname: Guggisberg
authors.affiliation: Department of Biology and Center for Genomics and Bioinformatics, Indiana University, Bloomington, IN 47405, USA.
authors.forename: Zhao
authors.initials: Z
authors.lastname: Lai
authors.affiliation: Department of Biology and Center for Genomics and Bioinformatics, Indiana University, Bloomington, IN 47405, USA.
authors.forename: Jie
authors.initials: J
authors.lastname: Huang
authors.affiliation: Botany Department, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada.|Department of Biology and Center for Genomics and Bioinformatics, Indiana University, Bloomington, IN 47405, USA.
authors.forename: Loren H
authors.initials: LH
authors.lastname: Rieseberg
mesh_terms: D002170:Canada; D031180:Cirsium / Q000235:genetics*; D016000:Cluster Analysis; D020224:Expressed Sequence Tags; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D063990:Gene Ontology; D053263:Gene Regulatory Networks / Q000235:genetics; D056726:Genetic Association Studies; D058865:Introduced Species; D020411:Oligonucleotide Array Sequence Analysis; D060888:Real-Time Polymerase Chain Reaction; D015203:Reproducibility of Results; D059467:Transcriptome / Q000235:genetics*