Submitted to: American Society of Plant Biologists Annual Meeting
Publication Type: Abstract only
Publication Acceptance Date: 3/7/2003
Publication Date: 7/1/2003
Citation: Abebe, T., Skadsen, R.W., Kaeppler, H.F. 2003. Lem2: a novel jacalin-related, lemma- and palea-specific gene of barley. American Society of Plant Biologists Annual Meeting Program. p. 167. Interpretive Summary:
Technical Abstract: The lemma and palea are photosynthetically active organs that supply developing kernels with carbon and nitrogen and protect the kernel from pathogens and herbivory. Little is known about the genes expressed in order for the lemma and palea carry out their functions. Using the suppression subtractive hybridization method, we identified many genes preferentially expressed in the lemma/palea, compared with the flag leaf. Among these we have characterized in detail a novel jacaline-like gene, Lem2. Lem2 is a multigene family with up to four copies in the barley genome. Restriction digestion of BACs indicated that Lem2 genes are located in a single chromosomal region. Lem2 was mapped to chromosome 5(1H) Bin 02 (near the short arm telomere; Kleinhoffs et. al.). Lem2 hybridizes with a single band in Morex but not in Steptoe, Harrington, and Q21861. Northern analysis showed that Lem2 is specifically expressed in the lemma, palea and coleoptile. LEM2 protein contains two jacalin-like domains, which may be involved in pathogen recognition. Furthermore, SA and MeJA treatment of spikes induces Lem2 expression in 2-4 h,suggesting that Lem2 is a defense-related gene. We have cloned the promoter of Lem2 and evaluated its ability to drive gfp reporter gene expression. Transient studies showed strong expression of gfp in the lemma and palea with virtually no expression in the leaf.