The biosynthesis and catabolism of sucrose is an important part of carbohydrate
metabolism. Sucrose is the major form of transport sugar and is translocated through the
phloem tissues to other parts of the plant. It is conceivable that photosynthetically fixed carbon
from leaf tissues may be transported to the fruits as sucrose during fruit development.
Sucrose is biosynthesized from glucose-1-phosphate by three major steps (Fig. 3.3). The first
reaction involves the conversion of glucose-1-phosphate to UDP-glucose, by UDP-glucose