H. Yunovitz et Kc. Gross, DEOXYMANNOJIRIMYCIN INHIBITS DE-NOVO SYNTHESIS OF COMPLEX N-GLYCANS AND DELAYS TOMATO FRUIT RIPENING, Journal of carbohydrate chemistry, 14(4-5), 1995, pp. 653-657
Unconjugated N-glycans (UNGs) of the high mannosyl-type extracted from
tomato fruit delay ripening of fruit pericarp discs by 2 days when ap
plied exogenously. Since the amount of high mannosyl-type UNGs decreas
es while the amount of complex-type UNGs increases during early ripeni
ng, we postulated that high mannosyl UNGs are converted to complex-typ
e by Golgi enzymes to relieve inhibition of ripening-inhibition by the
high mannosyl-type UNGs. In this paper, we investigated the effect of
deoxymannojirimycin, an inhibitor of mannosidase I involved in comple
x N-glycan synthesis. Deoxymannojirimycin, applied to pericarp discs,
both inhibited synthesis of complex-type N-glycans and delayed ripenin
g, supporting our hypothesis on modulation of tomato ripening by UNGs.