WRKY7 positively regulates plant immunity by transcriptionally activating N REQUIREMENT GENE 1 in Nicotiana benthamiana

Abstract

N REQUIREMENT GENE 1 (NRG1) is a pivotal player in the basal immune system and in Toll/Interleukin-1 receptor nucleotide-binding domain leucine-rich repeat (TNL)-mediated effector-triggered immunity (ETI), yet its transcriptional regulation remains poorly investigated. In this study, we identified NbWRKY7, a WRKY transcription factor that enhances both basal immunity and TNL-mediated ETI by regulating NRG1 transcription and accumulation. NbWRKY7 directly binds to the W-box cis-elements within the NRG1 promoter and induces its transcription. Silencing NbWRKY7 compromises basal defense and impairs TNL-mediated resistance to both viral and bacterial pathogens, as well as hypersensitive response-type programmed cell death (HR-PCD). Notably, effectors trigger resistosome formation to activate NRG1-dependent immune responses, which, in turn, further enhances NbWRKY7 transcription, thereby reinforcing NRG1 transcription. The WRKY7–NRG1 module orchestrates TNL-mediated immune responses through a positive feedback loop in Nicotiana benthamiana. Our findings provide perspective on the regulatory mechanisms of NRG1 during basal and TNL-mediated immune responses, offering insights into the complex interplay of transcription factors in plant immunity.