Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: November 20, 2006
Publication Date: N/A
Technical Abstract: Aflatoxin contamination caused by Aspergillus fungi is a great concern in peanut production worldwide. Pre-harvest Aspergillii infection and aflatoxin contamination are usually severe in peanuts that are grown under drought stressed conditions. Genomic research can provide new tools and resources to study plant-microbio interaction and enhance crop genetic improvement. However, genome research in peanut is far behind other crops due to the shortage of essential genome infrastructure, tools, and resources. Because of the large genome and polyploidy of peanut, one of many challenges the peanut crop faces is the improvement using genetic and genomic approaches. The objectives are to develop tools and resources and provide putative genes and sequence-based markers for peanut researchers and provide microarray technology for the peanut community to study peanut-Aspergillus interaction and to mitigate aflatoxin contamination in peanut. We have completed sequencing the 5’ ends of total 44,064 clones from 10 cDNA libraries, resulting 10,091 UniESTs, which will be used for production of peanut oligo microarray for the peanut community. A small pilot study has been completed to study gene expression profiles using a cDNA microarray of peanut in responding to A. parasiticus infection and drought stress. The microarray data were re-evaluated by quantitative real-time PCR. Peanut genotype A13 which is drought tolerant with reduced aflatoxin contamination was used in this study. The cDNA microarray was spotted twice on the glass slides of each of the selected unigenes (384 unigenes) selected from two Expressed Sequenced Tag (EST) cDNA libraries challenged by biotic and abiotic stresses. The top 20 up-regulated gene from samples challenged by A. parasiticus and drought stress were selected for validation of their expression levels using real-time PCR. Although the spotted cDNA array had a small set of genes, it demonstrated the power and utility in functional global gene expression overview. Therefore, much more ESTs are needed for the peanut research community in order to generate microarray with a large set of genes.