title: Wheat CBF gene family: identification of polymorphisms in the CBF coding sequence.
abstract: Expression of cold-regulated genes needed for protection against freezing stress is mediated, in part, by the CBF transcription factor family. Previous studies with temperate cereals suggested that the CBF gene family in wheat was large, and that CBF genes were at the base of an important low temperature tolerance trait. Therefore, the goal of our study was to identify the CBF repertoire in the freezing-tolerant hexaploid wheat cultivar Norstar, and then to examine if the coding region of CBF genes in two spring cultivars contain polymorphisms that could affect the protein sequence and structure. Our analyses reveal that hexaploid wheat contains a complex CBF family consisting of at least 65 CBF genes of which 60 are known to be expressed in the cultivar Norstar. They represent 27 paralogous genes with 1-3 homeologous copies for the A, B, and D genomes. The cultivar Norstar contains two pseudogenes and at least 24 additional proteins having sequences and (or) structures that deviate from the consensus in the conserved AP2 DNA-binding and (or) C-terminal activation-domains. This suggests that in cultivars such as Norstar, low temperature tolerance may be increased through breeding of additional optimal alleles. The examination of the CBF repertoire present in the two spring cultivars, Chinese Spring and Manitou, reveals that they have additional polymorphisms affecting conserved positions in these domains. Understanding the effects of these polymorphisms will provide additional information for the selection of optimum CBF alleles in Triticeae breeding programs.
authors.affiliation: Département des Sciences Biologiques, Université du Québec à Montréal, Case Postale 8888, Succursale Centre-ville, Montréal, QC H3C 3P8, Canada.
authors.forename: Sara
authors.initials: S
authors.lastname: Mohseni
authors.forename: Hua
authors.initials: H
authors.lastname: Che
authors.forename: Zakia
authors.initials: Z
authors.lastname: Djillali
authors.forename: Estelle
authors.initials: E
authors.lastname: Dumont
authors.forename: Joseph
authors.initials: J
authors.lastname: Nankeu
authors.forename: Jean
authors.initials: J
authors.lastname: Danyluk
mesh_terms: D000064:Acclimatization / Q000235:genetics; D000483:Alleles; D001947:Breeding; D003080:Cold Temperature; D017343:Genes, Plant; D005810:Multigene Family; D016366:Open Reading Frames; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics*; D011110:Polymorphism, Genetic; D011123:Polyploidy; D017434:Protein Structure, Tertiary; D011544:Pseudogenes; D015534:Trans-Activators / Q000737:chemistry / Q000235:genetics*; D014908:Triticum / Q000235:genetics*
chemical_list: D010940:Plant Proteins; D015534:Trans-Activators