Tomato fruit that accumulates hexose increased AIV
activity with fruit maturation, but fruit accumulating
sucrose decreased AIV activity markedly (Stommel,
1992). However, definite increases in SuSy and SPS
activities did not occur with fruit maturation. Comparing
tomato fruit cultured in the cool season with tomato fruit
cultured in the warm season, activities of AIV and SuSy
were higher in the cool season when more sugars
accumulate, but SPS activity did not change (Islam and
Khan, 2001). Therefore, SuSy and AIV are considered