Rhamnogalacturonans (RGs) are pectic polysaccharides found in the cell wall, which contain a repeating dissacharides backbone:α-D-GalpA-(1,2)-α-L-Rhap-(1)The antibody was raised against seed mucilage/MeBSA complex and binds to Rha-(1,4)-GalA-(1,2)-Rha-(1,4)-GalA-(1,2)-Rha-(1,4) pectic backbone.