Analysis of the CBF pathway in grapes and its role in enhancing abiotic stress tolerance

AGFD 21

Annette Nassuth, anassuth@uoguelph.ca, Mahbuba Siddiqua, and Huogen Xiao. Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON N1G 2W1, Canada
Dehydration, salt and freezing tolerance in plants are controlled by CBF transcription factors. CBF gene families are present in all plants that have been examined thus far, indicating that the CBF signalling pathway is conserved and important. Abscisic acid, light and/or cold trigger CBF expression, which in turn leads to an increase in compounds that are thought to protect plants against abiotic stress. These compounds include antifreeze proteins, dehydrins and enzymes involved in the metabolism of carbohydrates, lipids, phenylpropanoids and antioxidants. Vitis vinifera, the winegrape, sustains severe damage by temperatures around -200C. However, V. riparia, a wild grape, is tolerant to temperatures as low as -300C. We analyze CBF-like genes from these two grape species, including their ability to confer increased freezing, drought and salt tolerance in Arabidopsis, to elucidate the specific roles of each gene in protecting the perennial grape plant from freezing stress.