title: Isolation and expression analysis of low temperature-induced genes in white poplar (Populus alba).
abstract: Poplar is an important crop and a model system to understand molecular processes of growth, development and responses to environmental stimuli in trees. In this study, we analyzed gene expression in white poplar (Populus alba) plants subjected to chilling. Two forward suppression-subtractive-hybridization libraries were constructed from P. alba plants exposed to low non-freezing temperature for 6 or 48h. Hundred and sixty-two cDNAs, 54 from the 6-h library and 108 from the 48-h library, were obtained. Isolated genes belonged to six categories of genes, specifically those that: (i) encode stress and defense proteins; (ii) are involved in signal transduction; (iii) are related to regulation of gene expression; (iv) encode proteins involved in cell cycle and DNA processing; (v) encode proteins involved in metabolism and energetic processes; and (vi) are involved in protein fate. Different expression patterns at 3, 6, 12, 24, 48h at 4 degrees C and after a recovery of 24h at 20 degrees C were observed for isolated genes, as expected according to the class in which the gene putatively belongs. Forty-four of 162 genes contained DRE/LTRE cis-elements in the 5' proximal promoter of their orthologs in Populus trichocarpa, suggesting that they putatively belong to the CBF regulon. The results contribute new data to the list of possible candidate genes involved in cold response in poplar.
authors.affiliation: Dipartimento di Biologia delle Piante Agrarie della Università, Via del Borghetto 80, I-56124 Pisa, Italy.
authors.forename: Pierluigi
authors.initials: P
authors.lastname: Maestrini
authors.forename: Andrea
authors.initials: A
authors.lastname: Cavallini
authors.forename: Milena
authors.initials: M
authors.lastname: Rizzo
authors.forename: Tommaso
authors.initials: T
authors.lastname: Giordani
authors.forename: Rodolfo
authors.initials: R
authors.lastname: Bernardi
authors.forename: Mauro
authors.initials: M
authors.lastname: Durante
authors.forename: Lucia
authors.initials: L
authors.lastname: Natali
mesh_terms: D003080:Cold Temperature; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant / Q000235:genetics*; D018515:Plant Leaves / Q000378:metabolism; D032107:Populus / Q000235:genetics* / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction