Development of a Genome-Edited Tomato With High Ascorbate Content During Later Stage of Fruit Ripening Through Mutation of .

Ascorbate is an essential antioxidant substance for humans. Due to the lack of ascorbate biosynthetic enzyme, a human must intake ascorbate from the food source. Tomato is one of the most widely consumed fruits, thus elevation of ascorbate content in tomato fruits will improve their nutritional value. Here we characterized () as a gene specifically induced during fruit ripening. In tomatoes, ascorbate accumulates in the yellow stage of fruits, then decreases during later stages of fruit ripening. To investigate whether is involved in the decrease of ascorbate, the expression of s was analyzed during fruit maturation. Among nine s, is the only gene whose expression was induced during fruit ripening. Mutation of by the CRISPR/Cas9 system increased ascorbate content in ripened tomato fruits, while ascorbate content in leaves was not significantly changed by mutation of . Phenotype analysis revealed that mutation of did not induce an adverse effect on the growth of tomato plants. Collectively, we suggest that mediates a decrease of ascorbate content during the later stage of fruit ripening, and mutation of can be used for the development of genome-edited tomatoes with elevated ascorbate content in fruits.