ERN1 and infection: For instance, ERN1 (ERF REQUIRED FOR NODULATION 1), an important transcription factor (TF) regulating the progression of the infection thread (IT), began its expression at pre-infection stage, as previously reported32–34, and ceased to be expressed at 10 dpi (Fig. 2g), consistent with our anatomical observation that IT branches were barely detectable during this stage (Supplementary Fig. 1d).