Genetic editing has enabled the cultivation of tomatoes with enhanced sweetness by targeting two specific genes. A study published in Nature revealed that the removal of these genes increased glucose and fructose levels in modified tomatoes by up to 30% compared to mass-produced varieties.
The edited tomatoes maintain similar weight and yield to current market varieties. This advancement not only aims to improve tomatoes globally but also enhances understanding of sugar production and storage in fruits.
Tomatoes are a significant crop, with over 186 million tons produced annually worldwide. The domestication of tomatoes has focused on traits favored by human preference, such as fruit size, leading to cultivated tomatoes being up to 100 times larger than their wild ancestors.
However, larger fruit typically results in lower sugar content, affecting flavor. Jinzhe Zhang, co-author and plant geneticist at the Chinese Academy of Agricultural Sciences, noted that supermarket tomatoes often lack flavor, describing them as tasting like water.
To tackle this issue, Zhang and colleagues compared the genomes of cultivated tomatoes (Solanum lycopersicum) with sweeter wild counterparts. They identified two genes responsible for producing enzymes that degrade sugars. Using CRISPR-Cas9 technology, they disabled these genes, resulting in significantly sweeter fruit.
The modified tomatoes could also reduce time and resources needed for processing products like tomato paste, which requires water removal from the fruit. The findings may extend to other plant species, as these genes are present in various plants, and the mechanisms of sugar production in fruits have long puzzled scientists.