Fig. 6. Alteration of pathways for sucrose and sorbitol metabolism in leaves from transgenic apple.

Increased FRK activity contributes to the upregulation of sorbitol metabolism (synthesis and dehydrogenation) and downregulation of sucrose metabolism (synthesis and disassembly). Red boxes indicate increases in sugar concentrations or enzyme activity; yellow boxes, reduction in sugar concentrations or enzyme activity; blue boxes, no change in photosynthetic rate or sugar concentrations. Bold lines indicate that metabolism is accelerated