Submitted to: American Peanut Research and Education Society Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 10/31/2003
Publication Date: 3/1/2004
Citation: Luo, M., Dang, P.M., Guo, B., Holbrook, Jr., C.C., Bausher, M.G. 2003. Application of EST technology in fuctional genomics of Arachis hypogaea L. [abstract]. Proceedings of the American Peanut Research and Education Society, July 8-11, 2003, Clearwater, Florida. 35:35-36.
Technical Abstract: The genome size of peanut (Arachis hypogaea L.) is about 2800 Mb in comparison with the genome size 128 Mb and 425 Mb of Arabidopsis thaliana and rice (Oryza sativa), respectively, which have been completely sequenced. EST (expressed sequence tag) technology is the most cost-effective route for studying A. hypogaea genome and studying the complicated problem of host resistance and preharvest aflatoxin contamination. We constructed two cDNA libraries for EST analysis of gene expression profiles in two tissues of leaves and immature-pods from the field. We sequenced 769 ESTs from leaf cDNA library and 1056 ESTs from immature-pod cDNA library, and there are 536 and 769 unique sequences respectively. The BLASTx research results 52.8% and 78.6% ESTs with known functions from these two libraries, respectively. There are about 27.3% and 22.1% ESTs matching homologous sequences in dbEST of GenBank based on BLASTn algorithm with un-known functions. We are interested in identifying the adversity tolerance genes especially in drought tolerance and disease resistance and marker development. The disease resistance related genes are relative abundant such as glycosyl hydrolase family, PR-1, PR10, GST 8, GST 9, beta-glucosidase, defensin protein precursor. Stress induced genes are also found such as dehydration stress-induced protein, osmotin-like protein, hydroxyproline-rich glycoprotein, heat-shock protein, low temperature and salt responsive protein, ultraviolet-ß-repressible protein, aluminium-induced protein. Several genes reported with adversity tolerance were also found such as nonspecific lipid-transfer protein, 10 kDa protein precursor, caffeic acid O-methyltransferase, drought inducible protein, 22kD protein, metallothionein, catalase, proteinase inhibitor, F-box protein, defensin protein, drought induced protein. We also found some redundant ESTs without known function, and some do not have homologous sequences in the GenBank. SSR (simple sequence repeat) markers could be developed from ESTs.