Soybean transcription factors GmHSF-01 and GmNF-YC03 regulate the GmSRC7TN-mediated immune pathway

Soybean (Glycine max) is a globally important oilseed and forage crop. Soybean mosaic virus (SMV) infection reduces the yield and quality of soybeans. Previously, our laboratory cloned an atypical TNB (TIR‑NBS‑BSP) type disease‑resistance protein, GmSRC7 (SMV resistance cluster 7) from soybean. Its TIR‑NBS domain (GmSRC7TN) displays strong antiviral activity, however, the molecular mechanisms underlying this domain‑mediated disease resistance remain to be elucidated. Using GmSRC7TN as bait, we screened a soybean cDNA library and identified 42 candidate proteins that potentially interact with GmSRC7TN. Through yeast two‑hybrid, bimolecular fluorescence complementation, and luciferase complementation assays, the transcription factors GmHSF‑01 and GmNF‑YC03 were confirmed to interact with GmSRC7TN, with the TIR domain of GmSRC7 playing a critical role in these interactions. Further functional studies showed that GmHSF‑01 possesses intrinsic antiviral activity and enhances the antiviral function of GmSRC7TN, whereas GmNF‑YC03 interacts with the SMV‑encoded 6K1 protein, thereby interfering with viral replication and movement. Knockdown experiments demonstrated that silencing GmHSF‑01 or GmNF‑YC03 in transgenic soybean plants overexpressing GmSRC7TN compromises disease resistance, suggesting that both transcription factors cooperate with GmSRC7TN to regulate host antiviral defense. Our results demonstrate that upon sensing SMV infection, GmSRC7TN acts as a central hub, initiating downstream defense programs by specifically recruiting the transcription factors GmHSF-01 and GmNF-YC03. The findings provide a foundation for further dissection of the GmSRC7TN‑dependent disease resistance signaling pathway and offer potential molecular targets for the genetic improvement of SMV‑resistant soybean varieties.