The present invention provides nucleic acid constructs, including plasmids, expression vectors or expression cassettes comprising polynucleotides encoding CCAAT-binding transcription factor polypeptides that have the ability to increase a plant's tolerance to abiotic stress. Polynucleotides encoding functional CCAAT-binding transcription factors were incorporated into expression vectors, introduced into plants, and ectopically expressed. The encoded polypeptides of the invention significantly increased the cold and water deficit tolerance of the transgenic plants, as compared to tolerance to these stresses of control plants.