Add Publication. 2 g developing siliques were harvested from the pMYB5:MYB5-GFP/myb5-2 complementary plants treated with 100 μM GA3 or 50 μM PAC. The 35S:GFP transgenic plants served as a negative control. Siliques were immediately crosslinked with 1% paraformaldehyde for 30 min on ice in a vacuum chamber. Total proteins were extracted using the Plant Cell lysis buffer for Western and IP (Beyotime, P0043) supplemented with phenylmethylsulfonyl fluoride (Solabio) and a proteinase inhibitor cocktail (Calbiochem). To reduce non-specific binding, protein extracts were pre-cleared with 50 μL of Binding control Agarose beads (ChromTek) for 1 h at 4 °C with gentle rotation. After brief centrifugation, the supernatant was incubated with 50 μL of GFP-Trap Agarose beads (ChromTek) for 2 h at 4 °C with gentle rotation. After 10 washes of the beads with phosphate-buffered saline, proteins on the beads were eluted through boiling in SDS-PAGE sample buffer for 10 min and then briefly separated in 10% SDS-PAGE gel. The gel regions containing proteins were cut and then subjected to LC-MS/MS analysis at Applied Protein Technology (Zhejiang). Three biological replicates were performed. The MS/MS database search was performed using the Maxquant software against the NCBI database with the default parameters (FDR < 0.01).