Submitted to: Aflatoxin Elimination Workshop Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: September 15, 2003
Publication Date: December 15, 2003
Citation: Luo, M., Dang, P., He, G., Guo, B.Z., Holbrook, C.C. 2003. Functional genomics of Arachis hypogaea L. for understanding host peanut and Aspergillus interactions [abstract]. In: Proceedings of the 3rd Fungal Genomics, 4th Fumonisin, and 16th Aflatoxin Elimination Workshops, October 13-15, 2003, Savannah, Georgia. p. 56. Technical Abstract: Expressed sequence tag (EST) libraries for cultivated peanut (Arachis hypogaea L.) were developed from two cDNA libraries constructed using mRNA prepared from immature pods of peanut line A13 (tolerant to drought stress and preharvest aflatoxin contamination) and leaves of peanut line C34-24 (resistant to leaf spots and tomato spotted wilt virus). Randomly selected cDNA clones were partially sequenced to generate a total of 1825 ESTs, 769 from C34-24 cDNA library and 1056 from A13 cDNA library, in which 536 and 769 unique ESTs were identified, respectively. The results of BLASTx search showed that 52.8% of the ESTs from leaf tissue and 78.6% of the ESTs from the pod tissue have homology to known gene function. There are about 27.3% and 22.1% ESTs matching homologous sequences in dbEST of GenBank based on BLASTn algorithm which have unknown functions. These ESTs were queried against MIPS functional catalogue criteria and sorted according to putative function into 15 categories. We have released 1345 ESTs to GenBank under accession numbers CD037499 to CD038843. We have successfully used these ESTs for gene identification and EST-derived SSR marker development. We have arrayed about 400 unigenes of adversity resistance on glass slides for gene expression analysis and characterized 44 EST-derived SSR markers for cultivated peanut, in which over 20% SSR produced polymorphic markers among 24 cultivated peanut genotypes. The microarray chips with the 400 unigenes with putative functions of adversity resistance are in process for gene expression analysis using mRNA probes from different lines under different challenges of drought stress or fungal infection to identify genes related to the abiotic or biotic stresses. This initiative research could contribute considerable information to peanut functional genomics in novel gene discovery and marker development. Further characterization of these adversity resistance genes may explain the resistant mechanisms functioning in these two peanut lines.