Do polyamines contribute to plant cell wall assembly by forming amide bonds with pectins?

Model compounds possessing galacturonate-putrescine amide bonds (e.g., GalA-Put-GalA; illustrated), were synthesised and characterised. Methods were devised by which to search for their natural occurrence. In the cell walls of cultured Rosa and Arabidopsis cells and of chickpea internodes, amide bonds between pectin and putrescine, spermidine or spermine are (if present at all) very minor components.