Submitted to: Proceedings of Int'l Association of Plant Tissue Culture and Biotechnology
Publication Type: Abstract Only
Publication Acceptance Date: 6/1/2002
Publication Date: 6/15/2002
Citation: Federico, M.L., Skadsen, R.W., Kaeppler, H.F. 2002. Cloning and promoter analysis of a barley gene encoding a lipid transfer protein. Proceedings of 10th Int'l Association of Plant Tissue Culture and Biotechnology. p. 54A. Interpretive Summary:
Technical Abstract: Fusarium head blight, or scab, is a fungal disease that causes significant yield and quality reductions in barley and wheat worldwide. Sources of immunity have not been identified, limiting breeding efforts for enhanced resistance. Genetic transformation, therefore, represents a promising means for controlling this disease. Currently, constitutive promoters are chosen to drive expression and test the efficacy of candidate antifungal proteins against Fusarium graminearum. Ideally, expression of antifungal genes should be restricted to the spike tissues where infection takes place, resulting in stopping the fungus before it spreads and colonizes the endosperm. With that goal in mind, we cloned and characterized a novel barley gene, EpiLTP, which is highly expressed in the epicarp, one of the first spike tissues to be colonized by F. graminearum. Several putative cis-acting DNA elements, which are responsive during plant development and environmental stimuli, were found in the promoter and 5'UTR regions of EpiLTP. Northern blot analyses revealed that EpiLTP is also highly expressed in coleoptile and embryo, but not in endosperm, anther, rachis, awn, leaf, stem or root tissues. The promoter region, 5'UTR, and the sequence encoding a putative signal peptide were cloned using PCR-based methods. A series of 5' and 3' promoter deletions were studied in transient expression assays. A minimal construct containing 244 bp of promoter and the 5'UTR (-244/+84) was sufficient to drive preferential expression in the epicarp, coleoptile and embryo tissues. Stable transformation barley cv. Golden Promise with a EpiLTP-GFP promoter fusion is underway in order to study the regulation and tissue-specificity of this novel barley gene.