Immunoblot analysis
Protein extraction buffer [(10% glycerol, 25 mM Tris-HCl pH 7.5, 150 mM sodium chloride, 1 mM ethylenediamine tetraoxalic acid (EDTA), 1% Triton X-100, 10 mM dithiothreitol, 1 × plant protease inhibitor, 2% (w/w) poly (ethylene pyrrolidone) (PVPP)] was used to extract the total protein of pepper samples. At 4 ℃, the extracted protein was incubated with anti-hemagglutinin (anti-GFP) agarose (Thermo Fisher Scientific, Waltham, MA, USA) overnight. Beads were collected using a magnetic rack and washed three times with Tris-buffered saline and Tween-20 (0.05%). Eluted protein was examined by immunoblotting using anti-GFP–peroxidase antibodies (Abcam, Cambridge, UK).