Figure 2.

Cold Enhances CBF1 Transcript and GFP-RGA Protein Levels.

(A) Immunodetection of GFP-RGA (with an antibody to GFP) in 7-d-old pRGA:GFP-RGA seedlings that had been subjected to cold (4°C) for the time (2, 4, 8, and 24 h) indicated (and controls, M). PSTAIRE serves as sample loading control. Numbers below the gels represent the fold increase in GFP-RGA protein levels relative to PSTAIRE levels.

(B) Expression of CBF1, RD29a, and RGA genes and the GFP-RGA transgene upon cold for the time as in (A) determined by RNA gel blot analysis. Each lane was loaded with 15 μg of total RNA prepared from 7-d-old pRGA:GFP-RGA seedlings.

(C) Levels of GAI, RGA, RGL1, RGL2, and RGL3 gene transcripts determined by a quantitative RT-PCR experiment in 7-d-old wild-type seedlings that had been subjected to cold for 4 and 12 h as indicated (and controls, M). ELF1α transcripts provide loading control.