Japanese university research team produces 30% sweeter tomato via gene-editing tech

The Yomiuri Shimbun

November 16, 2021

A tomato that is about 30% sweeter than usual has been produced using gene-editing technology, a Nagoya University research team announced.

The team was led by Associate Prof. Katsuhiro Shiratake, an expert on plant physiology, and the findings were published in international science magazine Scientific Reports.

Sweet tomatoes tend to be expensive due to low yields, and Shiratake believes such tomatoes will become more accessible to consumers because of the breakthrough.

The team focused on modifying an invertase inhibitor, a gene involved in the process of sweetening tomatoes in which sugars produced through photosynthesis are carried from the plant’s leaves to the fruit.

More sugars accumulate in the fruit when breaking the inhibitor via gene-editing technology, and the sugar content rises by about 30%, from 5 to 6.5 on the Brix scale.

Conventional high-sugar content tomatoes would require advanced culturing technology, such as extensively minimizing the amount of water given to a plant while being cultured, which would result in tomatoes less than half the size of regular ones.

By editing the gene, the team was able to culture tomatoes via conventional methods that resulted in fruit the same size as usual.

“We’d like to sell our tomatoes to the market through seed and seedling companies in the future,” Shiratake said.

“This is the fruit of the knowledge accumulated to date,” said Osaka University Prof. Toshiya Muranaka, an expert on plant metabolic engineering. “We can expect that selective breeding of plants will spread further with the gene-editing technology in the future.”