Location: Sunflower and Plant Biology ResearchTitle: BAC library development, and clone characterization for dormancy-responsive DREB4A, DAM, and FT from leafy spurge (Euphorbia esula L.) identifies differential splicing and conserved promoter motifs Author
Submitted to: Weed Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/16/2012
Publication Date: 4/26/2013
Citation: Horvath, D.P., Kudrna, D., Talag, J., Anderson, J.V., Chao, W.S., Wing, R., Foley, M.E., Dogramaci, M. 2013. BAC library development, and clone characterization for dormancy-responsive DREB4A, DAM, and FT from leafy spurge (Euphorbia esula L.) identifies differential splicing and conserved promoter motifs. Weed Science. 61(2):303-309. Interpretive Summary: We have developed a new tool for examining the genome of the invasive perennial weed leafy spurge. Specifically, we have developed a collection of DNA fragments from the leafy spurge genome that each spans about 143,000 bases with enough fragments to cover the leafy spurge genome 5 times over. Each fragment has been cloned into bacteria for easy retrieval and also has been spotted out on a membrane to allow one to clone any gene of interest. We have used these membranes to identify and sequence fragments that contained one of several genes that are likely to play some role in controlling dormancy of buds in leafy spurge. We have characterized these gene sequences and identified short sequences that may allow the genes to be turned on or off in buds as they become dormant or are released from dormancy and begin actively growing.
Technical Abstract: We developed two leafy spurge BAC libraries that together represent approximately 5X coverage of the leafy spurge genome. The BAC libraries have an average insert size of approximately 143 kb, and copies of the library and filters for hybridization-based screening are publicly available through the Arizona Genomics Institute. These libraries were used to clone full length genomic copies of an AP2/ERF transcription factor of the A4 subfamily of DEHYDRATION-RESPONSIVE ELEMENT BINDING PROTEINS (DREB) known to be differentially expressed in crown buds of leafy spurge during endodormancy, a DORMANCY ASSOCIATED MADS-BOX (DAM) gene, and several FLOWERING LOCUS T (FT) genes. Sequencing of these BAC clones revealed the presence of multiple FT genes in leafy spurge. Sequencing also provided evidence that two different DAM transcripts expressed in crown buds of leafy spurge during endo- and eco-dormancy result from alternate splicing of a single DAM gene. Sequence data from the FT promoters was used to identify several conserved elements previously recognized in arabidopsis, as well as potential novel transcription factor binding sites that may regulate FT. These leafy spurge BAC libraries represent a new genomics-based tool that complements existing genomics resources for the study of plant growth and development in this model perennial weed. Furthermore, phylogenetic foot-printing using genes identified with this resource demonstrate the usefulness of studying weedy species to further our general knowledge of agriculturally important genes.