USING FUNCTIONAL AND APPLIED GENOMICS TO IMPROVE STRESS AND DISEASE RESISTANCE IN FRUIT TREES
Location: Appalachian Fruit Research Laboratory: Innovative Fruit Production, Improvement and Protection
Title: Sequence and expression analysis of three CBF-like genes from apple (Malus x domestica)
Submitted to: Plant and Animal Genome Conference
Publication Type: Abstract Only
Publication Acceptance Date: October 30, 2007
Publication Date: January 12, 2008
Citation: Wisniewski, M.E., Bassett, C.L., Macarisin, D., Artlip, T.S., Norelli, J.L., Han, Y., Korban, S.S. 2008. Sequence and expression analysis of three CBF-like genes from apple (Malus x domestica). Plant and Animal Genome Conference.
The CBF/DREB family of transcription factors has been demonstrated to play an integral role in the response of plants to low temperatures and water deficit, binding to a cis-acting regulatory element called the C-repeat/dehydration response element (CRT/DRE) in genes induced by those stresses. In the model plant Arabidopsis thaliana, four members have been reported, and all are induced by dehydrative abiotic stresses such as low temperature or water deficit. In an effort to better understand the response of apple trees to these abiotic stresses, we have cloned three CBF-like genes from apple. MdCBFL1, MdCBFL2, and MdCBFL3 are cDNA clones obtained from leaf tissue collected after a 4h exposure to 4 deg C. All three have predicted amino acid sequences consistent with other CBFs. BLAST and phylogenetic analyses indicate that MdCBFL1 and MdCBFL2 are most closely related to two Prunus avium CBF sequences, while MdCBFL3 is more closely related to the Arabidopsis thaliana CBFs. BAC clones have been isolated containing these clones, and efforts are ongoing to establish their relation to a physical map of the apple genome. Data from RT-PCR suggest that the expression kinetics of MdCBFL1-3 in leaves and bark exposed to low temperatures are complex and differ from that observed in Arabidopsis. Complex kinetics for CBF-induction have also been observed in grape, poplar, and eucalyptus, suggesting that CBF-regulation in herbaceous and perennial woody plants may have evolved fundamental differences related to the need for winter dormancy in perennial plants.