Submitted to: International Symposium on Plant Cold Hardiness
Publication Type: Abstract Only
Publication Acceptance Date: August 2, 2008
Publication Date: August 3, 2008
Citation: Wisniewski, M.E., Bassett, C.L., Artlip, T.S. 2008. Sequence analysis of three CBF-like genes from apple (Malus x domestica). International Symposium on Plant Cold Hardiness. Saskatoon, Canada. Book of Abstracts. Pg.17. Technical Abstract: The CBF/DREB family of transcription factors has been demonstrated to have 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. CBFs are part of a large superfamily of transcription factors containing the AP2/ERF domain and also contain conserved motifs specific to them. In the model plant Arabidopsis thaliana, four members have been reported, CBF1-4 (DREB1C, 1A, 1B and 1D, respectively), 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 and have begun to characterize them. MdCBFL1, MdCBFL2, and MdCBFL3 are cDNA clones obtained from leaf tissue collected after a 4h exposure to 4 deg C. All three have conceptually translated amino acid residues consistent with the AP2/ ERF and CBF-specific domains. BLAST and phylogenetic analyses indicate that MdCBFL1 and 2 are most closely related to two Prunus avium CBF sequences. MdCBFL3 is identical to a cDNA from apple previously deposited in GenBank and is more closely related to CBF1-4 from Arabidopsis thaliana, as well as, CBF1 and 2 from Betula pubescens, than to MdCBFL1 and 2. Transcript data on MdCBFL1 indicates that it is responsive to low temperature and appears to be upregulated in apple leaf tissue within 30 min of exposure to 4 deg C. This transcript is present up to 2 hours after exposure and declines 4 and 6 h after exposure. Transcript evaluation of the other two clones and evaluation of other tissues are in progress and will be presented.