Maize putative WRKY transcription factor sequences, 202 in total, were obtained from the Plant Transcription Factor Database v3.0 [30]. In order to determine which of these many putative WRKY TFs to examine in this study, the sequences obtained from the database were then searched using the National Center for Biotechnology Information (NCBI) Basic Local Alignment Search Tool (BLAST) in the Maize Oligonucleotide Microarray Project database (http://www.maizearray.org). After identifying the annotated WRKY transcription factors available on the 58k array
(v.1.0), we examined the results of a previously performed microarray study by Luo et al. [26] in which the expression profiles in kernels of maize lines Eyl25 (Resistant) and Eyl31 (Susceptible) upon infection with A. flavus in kernel screening assay (KSA) conditions described by Brown et al. [31]. Maize WRKY TFs showing significant up- or down-regulation by A. flavus infection were selected for examination in the present study (Table S1). In addition, PTZm631 (NM_001196138.1), which was found to be significantly induced in response to A. flavus inoculation in immature kernel tissues of the susceptible commercial hybrid N83-N5 (Syngenta, Basel, Switzerland) by Han et al. [32] was also included in the present study. The identities of these above selected putative WRKY accessions were then determined using BLASTx of the available cDNA sequences of the genes and were numbered according to their close homologs in maize, rice, or wheat (Table 1).