BIFC Assay

The constructed GmGAMYB-TOPO was transferred to the expression vector pSITE-nEYFP-C1 through LR reaction (named as 35S:GmGAMYB-nYFP). GmGBP1-TOPO-F, and GmGBP1-TOPO-R primers (Supplementary Table 2) were used for PCR amplification of GmGBP1 gene cDNA fragment, which was cloned into pENTR/D-TOPO vector (named as GmGBP1-TOPO) and transferred to the expression vector pSITE-cEYFP-C1 vector by LR reaction (named 35S:GmGBP1-cYFP). All the above plasmids were introduced into Agrobacterium GV3101 for transforming into N. benthamiana (Hu et al., 2013). Red nuclear marker plasmid (H2B-RFP) was used to confirm the location of the cell nucleus. After infiltration, tobacco leaves were grown for 2 days, and YFP signals were detected by fluorescence microscope.