title: Transcription factor CBF4 is a regulator of drought adaptation in Arabidopsis.
abstract: In plants, low temperature and dehydration activate a set of genes containing C-repeat/dehydration-responsive elements in their promoter. It has been shown previously that the Arabidopsis CBF/DREB1 transcription activators are critical regulators of gene expression in the signal transduction of cold acclimation. Here, we report the isolation of an apparent homolog of the CBF/DREB1 proteins (CBF4) that plays the equivalent role during drought adaptation. In contrast to the three already identified CBF/DREB1 homologs, which are induced under cold stress, CBF4 gene expression is up-regulated by drought stress, but not by low temperature. Overexpression of CBF4 in transgenic Arabidopsis plants results in the activation of C-repeat/dehydration-responsive element containing downstream genes that are involved in cold acclimation and drought adaptation. As a result, the transgenic plants are more tolerant to freezing and drought stress. Because of the physiological similarity between freezing and drought stress, and the sequence and structural similarity of the CBF/DREB1 and the CBF4 proteins, we propose that the plant's response to cold and drought evolved from a common CBF-like transcription factor, first through gene duplication and then through promoter evolution.
authors.affiliation: Mendel Biotechnology, 21375 Cabot Boulevard, Hayward, CA 94545, USA.
authors.forename: Volker
authors.initials: V
authors.lastname: Haake
authors.forename: Daniel
authors.initials: D
authors.lastname: Cook
authors.forename: José Luis
authors.initials: JL
authors.lastname: Riechmann
authors.forename: Omaira
authors.initials: O
authors.lastname: Pineda
authors.forename: Michael F
authors.initials: MF
authors.lastname: Thomashow
authors.forename: James Z
authors.initials: JZ
authors.lastname: Zhang
mesh_terms: D000040:Abscisic Acid / Q000494:pharmacology; D000064:Acclimatization / Q000235:genetics* / Q000502:physiology; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D004190:Disasters; D019143:Evolution, Molecular; D005615:Freezing; D020440:Gene Duplication; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D008969:Molecular Sequence Data; D010802:Phylogeny; D030821:Plants, Genetically Modified; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction / Q000235:genetics; D015534:Trans-Activators / Q000235:genetics* / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism / Q000502:physiology
chemical_list: D029681:Arabidopsis Proteins; C104387:CBF1 protein, Arabidopsis; C470668:CBF4 protein, Arabidopsis; C116166:COR15 protein, Arabidopsis; D004268:DNA-Binding Proteins; C114578:DREB1A protein, Arabidopsis; C465973:ELF4 protein, Arabidopsis; D015534:Trans-Activators; D014157:Transcription Factors; D000040:Abscisic Acid