Location: Food and Feed Safety Research
Title: Identification of resistance genes to Aspergillus flavus infection in peanut through genetic and genomic strategies Authors
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: April 12, 2013
Publication Date: June 17, 2013
Citation: Yu, J., Nierman, W.C., Guo, B. 2013. Identification of resistance genes to Aspergillus flavus infection in peanut through genetic and genomic strategies [abstract]. 6th Advances in Arachis through Genomics and Biotechnology Conference. p. 26. Technical Abstract: Aspergillus flavus and A. parasiticus infect peanut before harvest in the field and after harvest during storage. These fungal moulds produce aflatoxins, the most toxic compounds and the most potent carcinogens. Contamination of aflatoxins to agricultural commodities such as peanut poses serious health hazard to human and animal and causes significant economic losses in developed countries. The most cost-effective strategy to minimize aflatoxin contamination involves the development of peanut cultivars that are resistant to fungal infection and/or aflatoxin production. In order to identify genes that are resistant to Aspergillus infection and/or aflatoxin formation in peanut, a large scale peanut Expressed Sequence Tag (EST) project was carried out and a peanut glass slide oligonucleotide microarray was designed and constructed. The fabricated microarray represents over 40% of the protein coding genes in the peanut genome. For expression profiling, resistant and susceptible peanut cultivars were infected with a mixture of Aspergillus flavus and parasiticus spores. Gene profiling by microarray analysis identified 62 genes in resistant cultivars that were up-expressed 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. Further studies on the gene expression by RT-PCR demonstrated that the mechanism of peanut resistant to fungal invasion through a combination of genes that were expressed at different time frame to offer resistance. Further studies by RNA-Seq under infected condition have been planned to decipher the mechanism of resistance at genome scale.