Biology

Long-lost "tasty genes" could soon be spliced back into store-bought tomatoes

Researchers have completed a pan-genome of all cultivated tomato breeds, uncovering thousands of unknown genes that could be spliced in to improve commercial crops
Researchers have completed a pan-genome of all cultivated tomato breeds, uncovering thousands of unknown genes that could be spliced in to improve commercial crops
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Researchers have completed a pan-genome of all cultivated tomato breeds, uncovering thousands of unknown genes that could be spliced in to improve commercial crops
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Researchers have completed a pan-genome of all cultivated tomato breeds, uncovering thousands of unknown genes that could be spliced in to improve commercial crops

It's no secret that tomatoes plucked from the supermarket aisles just aren't as tasty as those fresh from your garden patch or a local market. That difference is tomato growers select for genes that help the fruit survive the long journey, sacrificing taste in the process. To find taste genes that could be spliced back into commercial crops, researchers have now complied a pan-genome of all cultivated and related wild tomato species, uncovering almost 5,000 previously-unknown genes.

The domestic tomato genome was fully sequenced back in 2012, but that was only one particular breed, known as Heinz 1706. More recent work has gone into studying other varieties, including heirloom tomatoes that are more flavorful, before they were bred out of the modern commercially produced fruit in favor of appearance and shelf life.

The new work has expanded that view out to a full genome of all regularly-grown tomato breeds and their closest relatives. That includes all genes from 725 different types of tomatoes, and in doing so the team discovered an extra 4,873 genes that weren't included in the base Heinz 1706 genome.

That gives growers plenty of new tools to work with for growing tastier, healthier or longer-lasting tomatoes. And in terms of flavor, one gene in particular caught their attention. TomLoxC was found to add floral and fruity notes to tomatoes by producing more of a certain group of apocarotenoids.

"One of the most important discoveries from constructing this pan-genome is a rare form of a gene labeled TomLoxC, which mostly differs in the version of its DNA gene promoter," says James Giovannoni, co-author of the study. "The gene influences fruit flavor by catalyzing the biosynthesis of a number of lipid (fat)-involved volatiles — compounds that evaporate easily and contribute to aroma."

This form of TomLoxC turned up in only two percent of heirloom tomato breeds, but it was found in over 90 percent of the smaller, wild tomatoes. Interestingly, the team discovered that this version of the gene was starting to appear more in new varieties of tomato. Although the gene's role has only just been discovered, it seems that breeders have a nose for these things.

"It appears that there may have been strong selection pressure against or at least no selection for the presence of this version of TomLoxC early in the domestication of tomatoes," says Giovannoni. "The increase in prevalence of this form in modern tomatoes likely reflects breeders' renewed interest in improved flavor."

The researchers say that having access to such detailed data on the genomes of so many tomato varieties will help breeders design tastier crops that still retain the genes allowing them to be shipped long distances to supermarkets. And if scientists want to get really creative, they might also start making spicy tomatoes.

The research was published in the journal Nature Genetics.

Source: US Department of Agriculture

9 comments
paul314
I was under the impression that a lot of the flavor-related genes were directly opposed to long-distance shipping survival, because of softness and rotting. Perhaps an engineered UberTomato could have those genes, but repressed so that they were only activated after shipping.
owlbeyou
As a tomato lover I welcome any improvements in the taste of supermarket hybrids. It's tiresome to have to wait for Aug-Sept for tasty field tomatoes.
KungfuSteve
You can not get something for nothing. Everything has a price to it. It wont matter what switches you tweak, for example... if you starve the crops of nutrients... As well as the dumping toxic pesticide chemicals all over them, into the soil, and in the very water supply / rains. The more toxic and 'dead' the enviornment... the worse things will get. Another example is trying to tweak a crop to be larger in size. They tend to be far less flavorful as a result. You would likely need double the nutrient levels, and maybe even a different internal biological system of delivery... to get the same flavor levels, found in the natural sized crops. Todays crops are toxic, due to roundup... and are likely the main cause of major health issues... such as massive Gall Bladder removal operations being performed. Not only that.. but most crops barely have any nutrient values anymore... due again...to nutrient starved soils. The whole gmo game is a Dangerous game. A single change, could cause massive health issues within people. These issues might not show up for several generations. Ohh... but maybe we are already seeing it? The rise in allergic reactions, such as Gluten, Nuts, Autism...etc... is out of control... But keep trying to play God... and keep making the problems exponentially worse... >_<
jd_dunerider
I’d rather they work on making kale taste like beef jerky.
whatever
This... "tomato growers select for genes that help the fruit survive the long journey, sacrificing taste in the process" ...is exactly why people hate GMOs. With rare exceptions (golden rice and ?) these modifications consistently sacrifice human health and pleasure for cold hard cash.
jetserf
Attack of the killer tomatoes! Attack of the killer tomatoes! They'll beat you, bash you, squish you, mash you, chew you up for brunch! And finish you off For dinner and lunch!
bullfrog84
You mean they're going to continue to gmo food so it taste like what is should taste like as they've bastardized it so much it doesn't taste like it should...**** them. I'll grow my own or buy from farmers markets and people should grow a brain and do the same. Get a clue.
aksdad
News flash: it's not the "floral and fruity notes" that consumers miss in store-bought tomatoes. It's the sweetness. Adding more "flavor" won't overcome the bitter taste of tomatoes that were picked green in order to last long enough for the trip to the grocery store. Some fruit becomes sweeter when ripening, even after picking. Tomatoes do not.
JagtygerII
I will buy that if they can duplicate the flavor of the heirloom "Black Krim" tomato. Not only does it have the best flavor, if grown in the correct soil, it comes pre-salted in flavor