The total proteins from transgenic plants overexpressing Exo70A1 coding sequence in a translational fusion of a GFP-tag were extracted from root stele tissues using a lysis buffer composed of 20 mM Tris-HCl pH 7.5, 150 mM NaCl, 0.5 mM EDTA pH 8.0, 0.5% NP-40, and freshly added 1 mM PMSF, 1 mM DTT, 1× protease inhibitor cocktail. After incubation for 40 min at 4 °C, the lysates were centrifuged twice at 13,400 g for 10 min at 4 °C. The cleared protein extracts were then subjected to immunoprecipitation using an GFP Nanoab Agarose beads (NuoyiBio, Cat#AGA-50-1K). The mixture was incubated for 3 h at 4 °C. Subsequently, the precipitated samples were washed 3 times with a wash buffer containing 20 mM Tris-HCl pH 7.5, 150 mM NaCl, 0.5 mM EDTA, pH 8.0, 0.5% NP-40. Finally, the precipitated samples were washed 3 times with 1× PBS (EASYBIO, Cat#BE6258). The resulting protein samples were analyzed by western blotting using an anti-GFP (ABclonal, Cat#AE012) and further processed for LC-MS/MS analysis.