the sps expression level increased from 15 to 35 d after anthesis and SPS activity relatively declined slightly, indicating that SPS activity, to some extent, was inhibited. Similarly, in S. chmielewskii fruit, SPS activity changed little from 5 to 15 d after anthesis but sps expression level declined obviously, indicating SPS activity at 5 d after anthese was probably down-regulated. Besides, the correlation coefficient between the relative expression level of sps and SPS activity in Micro-Tom fruit was 0.667. In other words, it implied that SPS activity has been changed. As a regulatory factor, 14-3-3 protein was highly possible to participate in the regulation by protein-protein interaction.