Profile comparisons of stored mRNA in dry maize seeds from two closely-related geneotypes varying in aflatoxin accumulation

Aflatoxin contamination occurring after infection by Aspergillus flavus is a major concern in maize production both pre- and post-harvest. A recent gene expression study of imbibed kernels highlighted induced resistance and gene regulation in kernels. In the present study, stored mRNA was profiled using oligo-nucleotide array. This comparison of stored mRNAs would enhance our understanding of the difference between resistant and susceptible lines at the kernel storage phase. To minimize the effect of different genetic backgrounds on the differential genes between resistant and susceptible lines, two closely related inbred lines were used. Of the two lines, Eyl25 is aflatoxin-resistant (R), and Eyl31 is –susceptible (S). These were derived from a cross between two resistant lines, 1368 and GT-MASK:gk, in the IITA and USDA- ARS collaborative breeding project. Direct comparisons were designed between Eyl25 and Eyl31. Dry kernels from the two lines were selected randomly into four groups to extract total RNA. Four biological replications were performed in the comparison including two dye-swaps.