GmERF109 Positively Enhances Soybean Resistance to Phytophthora sojae by Transcriptionally Activating GmG4DT‐Like to Promote Glyceollin I Accumulation

Abstract

Phytophthora root rot, a devastating disease caused by Phytophthora sojae, poses a significant threat to worldwide soybean (Glycine max) production. Therefore, enhancing crop resistance to this pathogen is a major breeding objective. However, the signalling mechanisms underlying the response of soybean plants to P. sojae infection, and the networks and targets of key transcription factors TFs, are not yet fully understood. Here, we reveal the mechanisms and function of GmERF109, which differs in expression between soybean cultivars resistant and susceptible to P. sojae race 1 and encodes an AP2/ERF transcription factor. Molecular evaluation and disease resistance analysis show that GmERF109 is a nucleus‐localized transcription factor that positively regulates soybean resistance to P. sojae. We also demonstrate that GmERF109 targets and activates the expression of GmG4DT‐like, a gene whose role in the biosynthesis of the phytoalexin glyceollin was confirmed through overexpression and RNA interference (RNAi) analyses. GmG4DT‐like also enhances P. sojae resistance. GmG4DT‐like and GmERF109 greatly increased the content of the glyceollin I isomer. Overall, our results suggest that GmERF109 enhances glyceollin accumulation by positively regulating the expression of its target gene GmG4DT‐like, thereby improving soybean resistance to P. sojae. These findings provide novel insights into soybean resistance to Phytophthora root rot and will be useful in efforts to create resistant soybean cultivars.