UNCONJUGATED N-GLYCANS PROBING OR SIGNALING IN PLANT-TISSUES

After unconjugated N-glycans were isolated and characterized either fr om culture media of suspension cultured cells or from the pericarp of tomato fruits, some questions were asked concerning their origin, loca lization, roles, and the circumstances of the deglycosylation process. The time-dependent relationship between deglycosylating activities, s ucrose starvation and unconjugated N-glycans production has been alrea dy established in the case of cell suspension, strongly correlated to biochemical evidence of autophagy starting in the cells. This means th at unconjugated N-glycans could act as probe in a situation of carbon deficiency or senescence differentiation in certain plant tissues. Hav ing shown signalling properties both in growing plantlets and in tuber izing cuttings, unconjugated N-glycans could now be considered as a ne w class of oligosaccharins.