title: Phytoremediation of chromium using Salix species: cloning ESTs and candidate genes involved in the Cr response.
abstract: In this research a differential display based on the detection of cDNA-AFLP markers was used to identify candidate genes potentially involved in the regulation of the response to chromium in four different willow species (Salix alba, Salix eleagnos, Salix fragilis and Salix matsudana) chosen on the basis of their suitability in phytoremediation techniques. Our approach enabled the assay of a large set of mRNA-related fragments and increased the reliability of amplification-based transcriptome analysis. The vast majority of transcript-derived fragments were shared among samples within species and thus attributable to constitutively expressed genes. However, a number of differentially expressed mRNAs were scored in each species and a total of 68 transcripts displaying an altered expression in response to Cr were isolated and sequenced. Public database querying revealed that 44.1% and 4.4% of the cloned ESTs score significant similarity with genes encoding proteins having known or putative function, or with genes coding for unknown proteins, respectively, whereas the remaining 51.5% did not retrieve any homology. Semi-quantitative RT-PCR analysis of seven candidate genes fully confirmed the expression patterns obtained by cDNA-AFLP. Our results indicate the existence of common mechanisms of gene regulation in response to Cr, pathogen attack and senescence-mediated programmed cell death, and suggest a role for the genes isolated in the cross-talk of the signaling pathways governing the adaptation to biotic and abiotic stresses.
authors.affiliation: Department of Agricultural Biotechnology, University of Padova, Campus of Agripolis -- Viale dell'Università 16, 35020 Legnaro, Padova, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Quaggiotti
authors.forename: Gianni
authors.initials: G
authors.lastname: Barcaccia
authors.forename: Michela
authors.initials: M
authors.lastname: Schiavon
authors.forename: Silvia
authors.initials: S
authors.lastname: Nicolé
authors.forename: Giulio
authors.initials: G
authors.lastname: Galla
authors.forename: Virginia
authors.initials: V
authors.lastname: Rossignolo
authors.forename: Marica
authors.initials: M
authors.lastname: Soattin
authors.forename: Mario
authors.initials: M
authors.lastname: Malagoli
mesh_terms: D000595:Amino Acid Sequence; D001673:Biodegradation, Environmental; D002857:Chromium / Q000378:metabolism*; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000378:metabolism; D020224:Expressed Sequence Tags; D020869:Gene Expression Profiling; D017343:Genes, Plant; D008969:Molecular Sequence Data; D018515:Plant Leaves / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D032108:Salix / Q000145:classification / Q000235:genetics* / Q000378:metabolism*
chemical_list: D018076:DNA, Complementary; D010940:Plant Proteins; D012333:RNA, Messenger; D002857:Chromium