Overexpression of ZmEREB211 confers enhanced susceptibility to Pseudomonas syringae pv. tomato DC3000 in Arabidopsis.

Genes in the ERF family encode trasnscripiton regulators involved in plant developmental and physiological processes. However, the function of the ERF family gene in regulation of plant susceptibility to pathogens has rarely been reported. In this study, An ERF family gene ZmEREB211 (AP2-EREBP-transcription factor 211), whose expression was significantly upregulated in response to biotic stress (Bipolaris maydis), was isolated from maize (Zea mays L.). Based on sequence homology and phylogenetic analysis, ZmEREB211 has 792 bp in length and was characterized as an ERF family trasnscripiton regulator with single conserved APETALA2 (AP2) domain. Transient expression of ZmEREB211 in Nicotiana benthamiana revealed that its subcellular localization was distributed in the nucleus. Moreover, overexpression of ZmEREB211 in Arabidopsis thaliana resulted in increased susceptibility to Pseudomonas syringae pv. tomato DC3000 (Pst DC3000). Examination of disease-related physiological indicators showed that overexpression of ZmEREB211 in A. thaliana led to the accumulation of membrane lipid peroxide malondialdehyde, reduced levels of hydrogen peroxide, phenylalanine ammonia lyase (PAL) activity, and peroxidase (POD) Activity, thereby enhancing the plant susceptibility. Additionally, transcriptome and qRT-PCR data indicated that the expression of genes related to the salicylic acid (SA) pathway was suppressed upon Pst DC3000 inoculation in ZmEREB211-overexpressing A. thaliana compared with wild type, while the expression of genes related to the ethylene (ET) pathway was induced at the same time. These findings collectively suggest that the transfer of ZmEREB211 gene into A. thaliana may confer increased susceptibility to the plant by inhibiting the SA pathway and inducing ET pathway, and provide novel susceptible gene resources for crop disease resistance breeding.