Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: June 9, 2011
Publication Date: June 10, 2011
Citation: Guo, B., Yu, J. 2011. Identification of resistance genes to Aspergillus flavus infection in peanut through EST, microarray and genetic mapping strategies. Meeting Abstract. 5th International Conference of the Peanut Research Community, in Brasilia, Brazil on June 13-18, 2011. Technical Abstract: Aspergillus flavus and A. parasiticus infect peanut seeds and produce aflatoxins, which are associated with various diseases in domestic animals and humans throughout the world. The most cost-effective strategy to again aflatoxin contamination involves the development of peanut cultivars that are resistant to fungal infection and/or aflatoxin production. To identify peanut Aspergillus-interactive and Aspergillus-resistance genes, we carried out a large scale peanut Expressed Sequence Tag (EST) project of two cultivars Tifrunner and GT-C20 followed by a peanut microarray construction. A recombinant inbred line (RIL) mapping population derived from Tifrunner and GT-C20 was also developed to apply in mapping A. flavus resistance trait in peanut. The fabricated microarray represents over 40% protein coding genes in the peanut genome. For expression profiling, resistant and susceptible peanut cultivars were infected with a mixture of A. flavus and parasiticus spores. Microarray analysis identified 62 genes in resistant cultivars, which were up-regulated in response to Aspergillus infection. In addition we identified 22 putative Aspergillus-resistance genes that were constitutively up-expressed in the resistant cultivar in comparison to the susceptible cultivar. Some of these genes were homologous to peanut, corn, and soybean genes that were previously shown to confer resistance to fungal infection. Out of 4,576 primer pairs, 260 primer pairs amplified polymorphic fragments between the parents. The linkage map consisted of 26 linkage groups (LGT1 to LGT21, including 5 linkage groups with only two markers each) with 239 loci derived from 216 primer pairs and covered 1,213.4 cM These studies is a step towards a comprehensive genome-scale platform for developing Aspergillus-resistant peanut cultivars through targeted marker-assisted breeding and genetic engineering.