This is a common complaint in the produce section. Today's tomatoes may be big, but they have no flavor. Researchers now say they can solve the problem by tweaking the genes that affect sugar content in fruit.
While its wild relatives produce small, sweet fruits, industrially cultivated tomatoes have been bred for higher yields, resulting in varieties that are 10 to 100 times larger. .
Chinese scientists have now announced that they have identified two genes that put the brakes on sugar production during ripening in tomatoes and have created gene-edited cultivars that produce larger, sweeter fruits.
Professor Sanwen Fan, director of the Institute of Agricultural Genomics at the Chinese Academy of Agricultural Sciences in Shenzhen, said there is a need to balance the needs of consumers with the needs of producers and farmers.
“Farmers want bigger tomatoes and higher yields, but consumers want sweeter tomatoes,” he said. “With the discovery of the sugar brake gene, [breeding of a] Achieve sweeter tomatoes without sacrificing fruit size or yield, breaking the negative relationship between yield and quality. ”
Writing for Nature magazineResearchers describe how they first examined the genomes of wild and cultivated tomato plants and identified two similar genes related to sugar content in fruit. They say versions of these genes associated with high sweetness are prevalent in wild tomato plants but have been largely lost in modern varieties.
Further research revealed that a version of the gene found in domesticated tomato plants enables the production of an enzyme that tags another sugar-producing enzyme for destruction inside the cell. In contrast, versions of these genes found in wild plants limited production of this enzyme, resulting in sweeter tomatoes.
When the research team used the gene editing tool Crispr-Cas9 to make precise changes to the DNA of cultivated tomato plants so that these genes no longer function properly, the resulting fruit It was found that the sugar content was up to 30% higher than the modified plant. However, unexpectedly, there were no significant differences in fruit weight or yield. The seeds of the gene-edited tomatoes were fewer and lighter, but they germinated normally.
The researchers say their findings suggest that the two genes act as a sugar brake during fruit ripening, perhaps to ensure there is enough energy for seed development. .
Huang said the new tomatoes could be in supermarkets within three to five years. The research team noted that other gene-edited tomatoes are already available in Japan.
But it may be a while before others can enjoy the fruits of such science. New legislation has been enacted in England and Wales to support the cultivation of gene-edited crops, but the secondary legalization required to implement the legislation is not given yet.
