Scientists are trying to create genetically modified spicy tomatoes in the hope of mass-producing the spice molecule found in chilli peppers – something that could, in turn, lead to cheaper over the counter pain relief.
The modification is theoretically possible because the tomato shared a common ancestor with the chilli some 19 million years ago. Using the gene-editing technique known as Crispr-Cas9, plant biologists from Brazil and Ireland hope to switch the spice-producing genes back on.
Capsaicinoids, the molecules present in chilli peppers that gives the fruit its spicy taste, are used in over the counter creams, gels, lotions and patches to provide pain relief.
Because spice isn’t a taste – it’s the nerve cells in the tongue reacting to heat-induced pain – the molecule is also used in the manufacture of pepper spray.
And with tomatoes returning a much higher crop yield than chillis, successfully engineering spicy tomatoes could bring down the costs of both pain relief products and pepper spray.
“Engineering the capsaicinoid genetic pathway to the tomato would make it easier and cheaper to produce this compound, which has very interesting applications,” said the study’s senior author Agustin Zsögön, a plant biologist at the Federal University of Viçosa in Brazil.
“We have the tools powerful enough to engineer the genome of any species; the challenge is to know which gene to engineer and where.”
Creating spicy tomatoes will involve trial and error
Scientists have been genetically modifying various fruits and vegetables for decades, usually to improve product yields, such as with soy beans. In other cases, it has been to create interesting hybrids, such as the lemato (a lemon and tomato hybrid).
And a spicy tomato could, of course, become a popular fruit in its own right.
Zsögön and his peers expect to have an update on their progress by the end of the year.
Because there are at least 23 different types of capsaicinoids, the process will involve a lot of trial and error to find the correct genetic combination to activate the spice gene in tomatoes.
“Since we don’t have solid data about the expression patterns of the capsaicinoid pathway in the tomato fruit, we have to try alternative approaches,” said Zsögön. One is to activate candidate genes one at a time and see what happens, which compounds are produced. We are trying this and a few other things.”
The findings were published in scientific journal Trends in Plant Science.