Enhanced soluble sugar content in tomato fruit using CRISPR/Cas9-mediated and gene editing.

Soluble sugar is known to improve the sweetness and increase tomato sauce yield. Studies have focused on improving the content of soluble sugar in tomato fruits, usually by promoting functional genes. We studied two genes ( and ) that inhibited the accumulation of soluble sugar in tomato fruits and obtained two genes' knocked-out lines (CRISPR- or CRISPR-) using CRISPR/Cas9. Aggregated lines with CRISPR- and CRISPR- were gained by hybridization and self-pollination. Compared to wild-type lines, the glucose, fructose, and total soluble solid (TSS) contents of CRISPR- and CRISPR- increased significantly. Glucose, fructose, and TSS levels further improved simultaneously with CRISPR- and CRISPR- than with single gene knock-out lines. This indicates that these genes have a synergistic effect and will increase the soluble sugar content. Thus, the knock-out and may provide a practical basis for improving the sweetness of tomato fruits and their processing quality.