Potential roles of WRKY transcription factors in regulating host defense responses during Aspergillus flavus infection of immature maize kernels

The mechanisms regulating the expression of maize resistance genes against Aspergillus flavus are poorly understood. This study examined the potential roles of six WRKY transcription factors and the expression of three pathway indicator genes in response to A. flavus inoculation in B73 (susceptible) and TZAR101 (resistant). The genes ZmWRKY19, ZmWRKY53, and ZmWRKY67 were found to possess elevated expression in TZAR101. ZmNPR1 expression was induced by inoculation in TZAR101 without concurrent induction of ZmPR-1, possibly due to the induction of ZmERF1. These findings indicate that WRKY transcription factors are involved in resistance and that salicylic acid and ethylene signaling may coordinate defense responses.