In tomatoes, fructokinase 1 (Frk 1) mRNA is expressed at a constant level during fruit development. However, fructokinase 2 (Frk 2) mRNA has a high expression level in young tomato fruit but then decreases during the later stages of fruit development.
The expression levels of fructokinase 1 (Frk 1) mRNA remain steady throughout tomato fruit development. In contrast, fructokinase 2 (Frk 2) mRNA is highly expressed in early-stage fruit but decreases as the fruit reaches maturity.