|KELLEY, ROWENA - Mississippi State University
|ANKALA, ARUNKANTH - Mississippi State University
|MYLROIE, J - Mississippi State University
|BRIDGES, SUSAN - Mississippi State University
|THANTHIRIWATTE, CHAMALI - Mississippi State University
Submitted to: Aflatoxin Workshop
Publication Type: Abstract Only
Publication Acceptance Date: 10/21/2009
Publication Date: 10/26/2009
Citation: Kelley, R.Y., Ankala, A., Sakhanokho, H.F., Mylroie, J.E., Boykin, D.L., Bridges, S., Thanthiriwatte, C., Hawkins, L.K., Windham, G.L., Warburton, M.L., Williams, W.P. 2009. Microarray-Based Mapping for the Detection of Molecular Markers in Response to Aspergillus flavus Infection in Susceptible and Resistant Maize Lines. Aflatoxin Workshop.
Technical Abstract: The objectives of this study were (1) to evaluate differential gene expression levels for resistance to A. flavus kernel infection in susceptible (Va35) and resistant (Mp313E) maize lines using Oligonucleotide and cDNA microarray analysis, (2) to evaluate differences in A. flavus accumulation between the resistant and susceptible maize lines and between inoculation treatments using ears harvested at physiological maturity, and (3) to identify genetic locations of any significantly expressed ESTs from linkage mapping on the Maize Genetics and Genomics Database, and the Maize Sequence Database. Oligonucleotide and cDNA microarrays were used to examine changes in the expression levels of thousands of genes simultaneously over two and four days post inoculation with Aspergillus flavus of two maize lines. A comparison of Mp313E and Va35 inbred maize lines two days post-A. flavus infection identified 236 genes as significant while four days post-A. flavus infection identified 256 genes. Mapping information for 64 of the 234 ESTs significantly expressed in the cDNA microarray experiment and 100 of the 256 ESTs significantly expressed from the 4 day post inoculation experiment were obtained from the Maize Genetic and Genomics Database and the Maize Sequence Database and compared with Quantitative Trait Loci (QTL) analysis data identified in Mp313E x B73 and Mp313E x Va35 mapping population. Several of the 164 ESTs located on chromosomes 1, 3, 4 and 6 matched the location of four previously published QTLs and these findings provide justification for using other ESTs from cDNA microarray experiments in future QTL studies. The coupling of microarray data with QTL analysis of candidate genes in our lab has led to a more comprehensive understanding of the molecular basis of maize response to aflatoxin. Results presented here provide an overview of A. flavus response at two and four days after inoculation and up-regulated functional genes found in both Va35 and Mp313E. These important sequences will be used as markers for the identification of A. flavus resistance genes. They will also be used to facilitate screening of other maize lines and with the introgression of A. flavus resistance into maize lines.