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Something is wrong with the tomato flavor these days. If you are used to today's tomato in supermarkets, you may not have noticed it. But your taste buds are unintentionally deprived of the flavors that your great-grandparents once savored.
We may have the opportunity to give the tomato its former glory. Harry Klee, professor of horticultural science at the University of Florida, uses it to identify the essential chemical elements that give tomatoes a vivid flavor, with the ultimate goal of creating the ubiquitous fruit to regain an identical taste to that of 100 years ago. Phys.org.
"We are repairing what has been damaged over the last fifty years to restore them to the state they were in a century ago," said Klee. "We can significantly improve the tomato taste of the supermarket."
Klee wants to clarify that he is not interested in genetic modification. He wishes to use the methodology of classical genetics to restore the flavors of tomato by raising them to the old. However, he had to first identify exactly what had changed in their flavor.
The answer lies in the alleles
The Klee team has examined the chemical fundamentals of how our olfactory senses function when we taste a tomato. What should we expect from the sugar content of these fruits? Which volatile chemicals are essential for better flavor? The team then analyzed the genetics behind the production of these chemicals and was able to identify multiple alleles – or genetic variations – unintentionally from many modern tomato varieties that control taste.
"We wanted to understand why modern tomato varieties are deficient in flavoring chemicals," Klee said. "It's because they've lost the most desirable alleles of a number of genes."
The 2017 research, published in the journal Science, used a genome-wide assessment study to map the key genes at play, which should allow for focusing on these traits and identifying them. identify effectively in breeding programs. Because Klee does not want to go the route of genetic modification, it is estimated that it will take about 3-4 years for breeders to return tomatoes to their current state of flavor.
Fast forward a few years
To achieve this goal, Klee has partnered with an international team of researchers led by Zhangjun Fei, a plant breeder at Cornell University in Ithaca, NY, and James Giovannoni, a molecular biologist. at Cornell and scientist at the USDA. In 2019, this team deepened the missing genes of the modern tomato, creating a pan-genome for 725 varieties of tomatoes. The group published its work in Nature Genetics in May 2019.
This is exactly what it looks like: A set of genes from all strains, which facilitates the separation of the central genome from the variable genome. They compared these data to a reference genome. What they found has amplified Klee's theory, revealing nearly 5,000 missing genes that explain why this store-bought tomato almost always lacks some zing.
They focused on a specific gene called TomLoxCwhich has been set aside by regular domestication. TomLoxC was known to control color, but we now know that it is also a key contributor to flavor. And as Discovery reported in its cover of the study, this flavor gene makes a slow but sure return.
The rare version of TomLoxCused was present in only about 2% of the tomato varieties. But in recent years, as breeders have started to become more interested in flavor, more and more varieties of modern tomatoes have the gene. Today, about 7% of tomatoes have some, which means that breeders have started to select it.
So, if you are fond of tomatoes, your patience will be rewarded. In a few years, even those who will not have a nearby farmers' market will be able to fall back in love with the tomato.
Editor's Note: This story has been updated since it was written in January 2017.
Tomatoes taste better 100 years ago. Can we restore their flavor?
Researchers are studying more and more the evolution of tomato tastes over time. They have now discovered a specific gene that is lacking in many modern varieties.
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