The lack of significant induction in ZmWRKY21 expression (Fig.1CeD) in response to A. flavus inoculation indicates that it may respond primarily to environmental stress and not to pathogen infections. Its ortholog in Arabidopsis AtWRKY39 (NP_566236.1), functions in regulating thermotolerance, and has been demonstrated to interact with calmodulin, to be induced by H 2 O 2 accumulation, and potentially be regulated by ethylene-dependent signaling pathways [23,48,51].