Expression of HvCbf3 in barley seedlings. Plant materials were 6-d-old seedlings growing with a 16-h photoperiod at 20°C or 2°C, and greenhouse-grown 6-d-old seedlings sprayed with 100 μm ABA. Total RNA was used for standard reverse transcription PCR (A, semiquantitative) and real-time reverse transcription PCR (B, quantitative). Gene-specific primers for HvCbf3, the cold-inducible gene Dhn8, the dehydration- and ABA-inducible gene Dhn4, and 28S rRNA were used (see “Materials and Methods”). A, PCR products were electrophoresed in 1.8% (w/v) agarose gels. B, The RNA amount is expressed relative to the highest value found for each gene and the values are normalized against the expression values of 28S rRNA used as an internal control (see “Materials and Methods”). Insets show the expression data on a logarithmic scale during the first 2 h. Bars are the sd of the mean of four amplifications. ●, HvCbf3; ▪, Dhn8; □, Dhn4.