title: The expression ofCBFgenes atFr-2locus is associated with the level of frost tolerance in Bulgarian winter wheat cultivars.
abstract: The regulation of the majority of cold-regulated genes in plants is mediated byCBF(C-repeat binding factors) transcription factor family. Natural differences in frost tolerance (FT) of wheat have been mapped to theFr-2(Frost Resistance-2) locus on chromosome group 5 and are associated with variation in threshold induction temperatures and/or transcript levels ofCBFgenes. This study used real-time reverse-transcription polymerase chain reaction (qRT-PCR) to compare the relative expression levels of fourT. aestivum CBFgenes (TaCBF15.2, TaCBFA19, TaCBFA2andTaCBFD21) in crown tissue of two Bulgarian hexaploid winter wheat cultivars (Milena and Russalka) with distinct levels of low-temperature (LT) tolerance but same vernalization requirement, and the spring cultivar Chinese Spring. The transcription profiles of the selectedTaCBFgenes showed that they are induced by cold treatment at 2 °C. Analysis of transcript abundance revealed that the fourTaCBFgenes were expressed at higher levels in the frost tolerant Milena than in the susceptible Russalka. Largest differences (fivefold and fourfold) in expression levels between both winter cultivars were observed in two of the analysed genes,TaCBF15.2andTaCBFA19, respectively. The higher steady-state expression levels ofTaCBFgenes before the onset of the LT treatment in Milena, combined with stronger induction by cold treatment, suggest that these molecular responses to LT are associated with superior FT development capacity. The results expand our understanding of the molecular mechanisms underlying LT acclimation in Bulgarian wheat and can be used for development of functional markers for improvement of FT wheat-breeding programmes.
authors.affiliation: AgroBioInstitute, Agricultural Academy , Sofia , Bulgaria.
authors.forename: Elena Georgieva
authors.initials: EG
authors.lastname: Todorovska
authors.affiliation: AgroBioInstitute, Agricultural Academy , Sofia , Bulgaria.
authors.forename: Stanislav
authors.initials: S
authors.lastname: Kolev
authors.affiliation: AgroBioInstitute, Agricultural Academy , Sofia , Bulgaria.
authors.forename: Nikolai Kirilov
authors.initials: NK
authors.lastname: Christov
authors.affiliation: Agricultural Institute, Centre for Agricultural Research, Hungarian Academy of Sciences , Martonvásár , Hungary.
authors.forename: Andras
authors.initials: A
authors.lastname: Balint
authors.affiliation: Agricultural Institute, Centre for Agricultural Research, Hungarian Academy of Sciences , Martonvásár , Hungary.
authors.forename: Gabor
authors.initials: G
authors.lastname: Kocsy
authors.affiliation: Agricultural Institute, Centre for Agricultural Research, Hungarian Academy of Sciences , Martonvásár , Hungary.
authors.forename: Attila
authors.initials: A
authors.lastname: Vágújfalvi
authors.affiliation: Agricultural Institute, Centre for Agricultural Research, Hungarian Academy of Sciences , Martonvásár , Hungary.
authors.forename: Gabor
authors.initials: G
authors.lastname: Galiba
keywords: CBF (C-repeat binding factors) genes; cold acclimation; frost tolerance; gene expression; wheat (T. aestivum L.)