Article Figures & Data
Figures
- Fig. 1.
Transcript levels of CBF3 and targetCOR genes in transgenic plants overexpressingCBF3. Northern analysis of total RNA (20 μg forCBF3; 5 μg for the other genes) prepared from control Arabidopsis Ws-2 and B6 plants and from CBF3-expressing A40, A28, and A30 plants. Plants were either grown at 20°C (W) or at 20°C and then cold treated at 5°C for 7 d (C).eIF4a (eukaryotic initiation factor 4a) is a constitutively expressed gene used as a loading control (Metz et al., 1992). Upon long exposure, CBF3 transcripts can be detected in the total RNA samples prepared from cold-treated Ws-2 and B6 plants (not shown).
- Fig. 2.
Protein levels of COR15am and COR6.6 in transgenic plants overexpressing CBF3. Western analysis of total soluble protein (50 μg) prepared from control Arabidopsis Ws-2 and B6 plants and from CBF3-expressing A40, A30, and A28 plants. Plants were either grown at 20°C (W), or grown at 20°C and then cold treated at 5°C for 7 d (C). Protein transfers were treated with antiserum made to recombinant COR15am and COR6.6 polypeptides (Gilmour et al., 1996).
- Fig. 3.
Growth characteristics ofCBF3-expressing transgenic plants. A, Non-transformed Ws-2 plants and transgenic CBF3-expressing A30 plants after 2 weeks growth at 20°C. B, Non-transformed Ws-2 and transgenic B6 “control” plants and transgenic CBF3-expressing A40, A30, and A28 plants after 15 d growth at 20°C. C and D, Non-transformed Ws-2 plants and transgenic CBF3-expressing A28 plants after 16 d growth at 20°C. E, Non-transformed Ws-2 plants and CBF3-expressing A30 and A28 plants after 5 weeks growth at 20°C. F, As in E except after 9 weeks of growth at 20°C.
- Fig. 4.
Effect of CBF3 overexpression on plant freezing tolerance. A, Seedlings of control Arabidopsis Ws-2 plants andCBF3-expressing A30 plants were grown at 20°C on solid medium and then frozen at −2°C for 24 h followed by 24 h at −6°C. B, Control Arabidopsis Ws-2 plants andCBF3-expressing A40, A30, and A28 plants were grown at 20°C, and the freezing tolerance of leaves was measured using the electrolyte leakage test. C and D, Same as B except that plants were grown at 20°C followed by 7-d-cold acclimation at 5°C.
- Fig. 5.
Effect of CBF3 expression on Pro levels. Free Pro levels were determined in leaf tissue from control Arabidopsis Ws-2 and B6 plants and CBF3-expressing A40, A30, and A28 plants grown at 20°C (warm), or plants grown at 20°C and cold-treated at 5°C for 7 d (7-d cold).
- Fig. 6.
Effect of CBF3 expression on transcript levels of genes involved in Pro and sugar metabolism. Northern analysis of total RNA (20 μg for CBF3; 5 μg for other genes) isolated from control Arabidopsis Ws-2 and B6 plants and fromCBF3-expressing A40, A30, and A28 plants. Plants were grown at 20°C then cold-treated at 5°C for the times indicated. The blots were hybridized with probes for CBF3, COR78,P5CS2, Suc synthase (SuSy), Suc-phosphate synthase (SPS), and eIF4a, a constitutively expressed gene used as a loading control (Metz et al., 1992).
- Fig. 7.
Effect of CBF3 expression on levels of total soluble sugars. Total soluble sugars were determined for leaf tissue from control Ws-2 and B6 plants and CBF3-expressing A40, A30, and A28 plants grown at 20°C (warm) or plants grown at 20°C and cold treated at 5°C for 7 d (7-d cold).
- Fig. 8.
Effect of CBF3 expression on the levels of specific soluble sugars. Total sugars were prepared from leaf tissue of control Ws-2 plants and CBF3-expressing A28 plants grown at 20°C (white bars) or at 20°C followed by 7 d at 5°C (black bars) and the levels of individual sugars determined by gas chromatography.
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