The potential roles of different metacaspases in maize defense response.

Metacaspases (MCs), a class of cysteine-dependent proteases, act as important regulators in plant defense response. In maize genome, there are 11 which have been categorized into two types (type I and II) based on their structural differences. In this study, we investigated the different transcript patterns of 11 in maize defense response mediated by the nucleotide-binding, leucine-rich-repeat protein Rp1-D21. We further predicted that many -elements responsive to salicylic acid (SA), methyl jasmonate (MeJA), abscisic acid (ABA) and auxin were identified in the promoter regions of , and several different transcription factors were predicted to bind to their promoters. We analyzed the localization of with previously identified quantitative trait loci (QTLs) in maize disease resistance, and found that all other , except for , are co-located with at least one QTL associated with disease resistance to southern leaf blight, northern leaf blight, gray leaf spot or ear rot. Based on previous RNA-seq analysis, different display different transcript levels in response to and . All the results imply that the members of might have differential functions to different maize diseases. This study lays the basis for further investigating the roles of in maize disease resistance.