title: Vitis CBF1 and Vitis CBF4 differ in their effect on Arabidopsis abiotic stress tolerance, development and gene expression.
abstract: Plants growing in temperate regions encode several C-repeat binding factor/dehydration responsive element binding factors (CBF/DREB1) and the question is whether these transcription factors have different functions. In this study, Arabidopsis transformed with grape CBF1 (VrCBF1) or grape CBF4 (VrCBF4) were characterized. Electrolyte leakage assays showed that the freezing tolerance of transgenic lines was correlated with the level of VrCBF expression irrespective of the type of CBF, while drought tolerance was most increased by VrCBF1. VrCBF overexpression coincided with an increase in the expression of the cold-regulated genes AtCOR15a, AtRD29A, AtCOR6.6 and AtCOR47. In addition, the development of grape CBF overexpressing plants was seen to be altered and resulted in dwarf plants which flowered later and had thicker rosette leaves with a higher stomatal density. Analysis of gene expression showed that these morphological changes may be because of an increase in the expression of AtRGL3 in VrCBF4 lines or AtGA2ox7 in VrCBF1 lines, and AtFLC in both. In addition, the results show for the first time that CBFs can positively affect the expression of AtICE1/SCREAM1, the gene that is known to induce AtCBF3 expression. The difference in gene induction by VrCBF1 compared with VrCBF4 suggests that these CBFs have different regulons.
authors.affiliation: Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada N1G 2W1.
authors.forename: Mahbuba
authors.initials: M
authors.lastname: Siddiqua
authors.forename: Annette
authors.initials: A
authors.lastname: Nassuth
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics; D058639:Cold-Shock Response / Q000235:genetics; D055864:Droughts; D004573:Electrolytes; D018506:Gene Expression Regulation, Plant; D026161:MADS Domain Proteins; D006899:Mixed Function Oxygenases; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D054046:Plant Stomata / Q000254:growth & development; D030821:Plants, Genetically Modified / Q000235:genetics / Q000254:growth & development; D018085:Regulon; D013312:Stress, Physiological; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors; D027843:Vitis / Q000235:genetics*
chemical_list: D029681:Arabidopsis Proteins; D004573:Electrolytes; C418902:At5g10140 protein, Arabidopsis; C510502:ICE1 protein, Arabidopsis; D026161:MADS Domain Proteins; D010940:Plant Proteins; C520629:RD29a protein, Arabidopsis; C485889:RGL3 protein, Arabidopsis; D015534:Trans-Activators; D014157:Transcription Factors; C072393:COR47 protein, Arabidopsis; C072392:COR6.6 protein, Arabidopsis; D006899:Mixed Function Oxygenases; C499575:AtGA2ox7 protein, Arabidopsis