ARS | Publication request: CLONING THE LEMMA- AND PALEA-SPECIFIC LEM2 GENE IN BARLEY

Submitted to: American Society of Plant Biologists Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: August 1, 2002
Publication Date: August 2, 2002
Citation: Abebe, T., Fu, J., Federico, M.L., Skadsen, R.W., Kaeppler, H.F. 2002. Cloning the lemma- and palea-specific lem2 gene in barley. Proceedings of American Society of Plant Biologists Annual Meeting. p. 45.

Technical Abstract: Organ-specific promoters are important tools for expressing desirable genes in specific organs, avoiding unwanted expression of trangenes in non-target parts. We have been developing organ-specific promoters for expressing antifungal genes in the lemma and palea of barley spikes. The lemma and palea are sepal equivalents that nourish and protect florets and developing kernels. Using the suppression subtractive hybridization (SSH) method, we have isolated a lemma- and palea-specific Lem2 gene from barley (Hordeum vulgare L. cv Morex). The Lem2 mRNA encodes a polypeptide of 302 amino acids with a predicted Mr or 31.9 kDa. The Lem2 protein contains two jacalin-like lectin domains and is potentially involved in disease resistance. Southern analysis showed that Lem2 is part of a multigene family with three copies per genome. We have cloned and sequenced a 1.6 kb promoter region of one of the Lem2 genes. The promoter contains cis-acting elements involved in ethylene-, wounding- and SA-response, characteristics of disease resistance genes. Transient studies using the full promoter-GFP fusion showed strong expression in the lemma and palea. Deletion studies are underway to identify the promoter region that confers Lem2 its lemma-and palea-specificity.