THE LONGEVITY OF BIOLOGICALLY-ACTIVE OLIGOGALACTURONIDES IN ROSE CELL-CULTURES - DEGRADATION BY EXO-POLYGALACTURONASE

To study the metabolism of oligosaccharins, we monitored the fate of ( 6-C-14)-labelled oligo-alpha-(1-->4)-D-galacturonides of degree of pol ymerization 8 and 9 (GalA(8) and GalA(9)) when administered at similar to 1 mu M to cell suspension cultures of 'Paul's Scarlet' rose (Rosa sp.). Neither GalA, nor GalA, was appreciably taken up by or bound to the cells. Both GalA(8) and GalA(9) were rapidly hydrolysed by the cul ture (half-life 2-4 h). The products were smaller oligogalacturonides and galacturonic acid, indicating the action of exo-polygalacturonase. It is suggested that exo-polygalacturonase plays an important role in controlling the concentrations of biologically-active oligogalacturon ides in uninfected plant tissues.