More often than not, the tomatoes you buy in the supermarket taste, well, a bit meh. But your sandwiches and salads don’t always have to be laced with anemic, tasteless tomatoes that fail to live up to their former glory. As researchers from the Boyce Thompson Institute (BTI) have just discovered, the secret to a hearty and rich tomato appears to have something to do with a rare version of a gene called TomLoxC.
They found that TomLoxC is heavily involved in the production of fats and carotenoids, the stuff that adds fruity and floral odors to the flavor of the tomato. While over 91 percent of wild tomatoes are enriched with the TomLoxC gene, just 7 percent of modern tomato varieties have it.
Armed with this new knowledge, the team argues they might have what it takes to make tomatoes great again.
"These new genes could enable plant breeders to develop elite varieties of tomatoes that have genetic resistance to diseases that we currently address by treating the plants with pesticides or other cost-intensive and environmentally unfriendly measures,” James Giovannoni, a plant molecular biologist and BTI faculty member, said in a statement.
Reporting their results in the journal Nature Genetics, a team of scientists created a pangenome – the entire gene set of all strains of a species – that contains all genetic information from 725 breeds of tomatoes, both wild and domesticated, which allowed them to identify the TomLoxC gene along with over 4,870 new genes.
The rise of the bland tomato started with domestication. Typically, this process leads to juicier, tastier, and bigger crops. Just think, maize started off as a wispy grass-like plant, but it can now produce a corn-on-the-cob. However, tomatoes seem to be selected for practical properties like size and yield, not taste. The team's analysis showed that around 200 genes were lost in domestication that took place in northern Ecuador, followed by more gene losses through further domestication in South America and then Central America.
“During the domestication and improvement of the tomato, people mostly focused on traits that would increase production, like fruit size and shelf life, so some genes involved in other important fruit quality traits and stress tolerance were lost during this process,” explained Zhangjun Fei, BTI faculty member and adjunct professor in Cornell University's School of Integrative Plant Science.
Although the tasty TomLoxC variant is rare in domestic mass-produced tomatoes, it seems to have been making a come back, despite farmers and scientists not even being aware of the gene. The rare version of TomLoxC now appears in 7 percent of modern tomato varieties, but only 2.2 percent of older domesticated tomatoes.
“How many times do you hear someone say that tomatoes from the store just don’t quite measure up to heirloom varieties?” asked Clifford Weil, program director of the National Science Foundation’s Plant Genome Research Program, which supported the work. “This study gets to why that might be the case and shows that better tasting tomatoes appear to be on their way back.”