title: The Vitis vinifera C-repeat binding protein 4 (VvCBF4) transcriptional factor enhances freezing tolerance in wine grape.
abstract: Chilling and freezing can reduce significantly vine survival and fruit set in Vitis vinifera wine grape. To overcome such production losses, a recently identified grapevine C-repeat binding factor (CBF) gene, VvCBF4, was overexpressed in grape vine cv. 'Freedom' and found to improve freezing survival and reduced freezing-induced electrolyte leakage by up to 2 °C in non-cold-acclimated vines. In addition, overexpression of this transgene caused a reduced growth phenotype similar to that observed for CBF overexpression in Arabidopsis and other species. Both freezing tolerance and reduced growth phenotypes were manifested in a transgene dose-dependent manner. To understand the mechanistic basis of VvCBF4 transgene action, one transgenic line (9-12) was genotyped using microarray-based mRNA expression profiling. Forty-seven and 12 genes were identified in unstressed transgenic shoots with either a >1.5-fold increase or decrease in mRNA abundance, respectively. Comparison of mRNA changes with characterized CBF regulons in woody and herbaceous species revealed partial overlaps, suggesting that CBF-mediated cold acclimation responses are widely conserved. Putative VvCBF4-regulon targets included genes with functions in cell wall structure, lipid metabolism, epicuticular wax formation and stress-responses suggesting that the observed cold tolerance and dwarf phenotypes are the result of a complex network of diverse functional determinants.
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Nevada, Reno, NV, USA.
authors.forename: Richard L
authors.initials: RL
authors.lastname: Tillett
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Wheatley
authors.forename: Elizabeth A R
authors.initials: EA
authors.lastname: Tattersall
authors.forename: Karen A
authors.initials: KA
authors.lastname: Schlauch
authors.forename: Grant R
authors.initials: GR
authors.lastname: Cramer
authors.forename: John C
authors.initials: JC
authors.lastname: Cushman
mesh_terms: D000222:Adaptation, Physiological; D000595:Amino Acid Sequence; D015180:Electrophoresis, Gel, Two-Dimensional; D005615:Freezing; D018506:Gene Expression Regulation, Plant; D008969:Molecular Sequence Data; D020411:Oligonucleotide Array Sequence Analysis; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D018520:Plant Shoots / Q000254:growth & development; D025341:Principal Component Analysis; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D018085:Regulon / Q000235:genetics; D015203:Reproducibility of Results; D020133:Reverse Transcriptase Polymerase Chain Reaction; D020539:Sequence Analysis, Protein; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D027843:Vitis / Q000235:genetics / Q000378:metabolism*; D014920:Wine; D014934:Wood
chemical_list: D010940:Plant Proteins; D012333:RNA, Messenger; D014157:Transcription Factors