Scientists have engineered tobacco plants to produce five powerful psychedelic compounds normally found in other plants, fungi and animals in a single crop. They argue that using plants to manufacture the drugs would be simpler and more sustainable than existing processes, making research into therapeutic uses and production of future medicines easier.

at the Weizmann Institute of Science in Israel and his colleagues modified Nicotiana benthamiana plants using a technique called agroinfiltration, which involves using a bacterium to introduce genes from other organisms into a plant. The modified plant then makes the proteins encoded by those genes, but the DNA isn’t incorporated into the plant’s genome, so the effect is short-lived.

With the addition of nine genes, the plants were able to produce psilocin and psilocybin, usually found in mushrooms; DMT from various plants; and bufotenin and 5-methoxy-DMT, compounds secreted by the Colorado river toad (Incilius alvarius).

Plants could easily be altered permanently with changes that become inheritable, but doing so could be problematic, given that the compounds produced are commonly used as recreational drugs, says Aharoni. “It’s a little bit tricky if we have it inherited, and then people will ask for seeds,” he says. “We can do it also in tomato, potato, corn.”

The medical uses of psychedelic compounds are becoming more popular and better understood, says Aharoni, but harvesting them from natural sources risks populations threatened by habitat loss and overexploitation. The drugs are chemically synthesised for use in research, but producing them in tobacco plants, which are easily cultivated in greenhouses, would be much simpler.

The idea of growing drugs through pharmaceutical farming, or “pharming”, certainly isn’t new. Plant-produced protein drugs have been approved in the US since 2012, and as far back as 2002, maize has been modified to produce a pharmaceutical protein. Another research team used tobacco plants in 2022 to synthesise cocaine, discovering that it could produce about 400 nanograms of cocaine per milligram of dried leaf – about a 25th of the level in a coca plant.

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at the University of Nottingham, UK, says around 25 per cent of prescription drugs are derived wholly or partially from plants, and there are massive opportunities to create “green factories” that can grow new compounds in greenhouses.

“If you want to understand something, you’ve got to be able to build something, so showing that you can make it in tobacco plants is useful,” says Fray. “As a technical accomplishment, to show that you understand the pathways and can do it, I think it has value.”

If you like your tomatoes sweet, the smaller cherry tomato varieties are currently the ones to go for. But bigger tomato varieties could soon get a sweetness boost with the help of CRISPR gene editing.

The bigger a tomato is, the lower its sugar content usually is, says Jinzhe Zhang at the Chinese Academy of Agricultural Sciences in Beijing. Efforts to boost the sweetness of larger varieties have had downsides such as lowering yields.

So Zhang and colleagues compared different varieties to identify genetic variants that affect sweetness. They found that two closely related genes called SlCDPK27 and SlCDPK26 are more active in large varieties. These genes code for proteins that lower the levels of an enzyme that produces sugars.

When the team used CRISPR gene editing to disable these genes in a variety called Moneymaker, the levels of glucose and fructose in the fruits increased by up to 30 per cent with no decrease in yield. The fruits were also rated as sweeter in a taste test. The only other effect was fewer and smaller seeds, which consumers may prefer.

“We are working with some companies to develop some commercial varieties by knocking out these genes,” says Zhang. “It is still at the beginning stages.”

Besides tasting sweeter, another potential benefit is that fewer tomatoes will be needed to make tomato ketchup with the same sweetness level.

The gene-edited Moneymaker tomatoes aren’t as sweet as cherry varieties such as Sungold, but it should be possible to boost sweetness even further, says Zhang. “There are still many important genes that regulate sugar waiting to be discovered.”

A CRISPR-edited tomato that has high levels of a beneficial nutrient called GABA is already being sold in Japan – the first CRISPR food to go on sale – as well as being given away as seedlings.

The first ever genetically modified food to be sold commercially was also a tomato. Called Flavr Savr, it was sold in the US in paste form from 1994, but was later discontinued. Since last year, a purple GM tomato high in anthocyanins has been available in the US in fruit and seedling form.

Several countries, including Japan and China, have regulations that make it easier for gene-edited crops to get approval compared with other forms of genetic modification, not counting conventional breeding. China approved a soya bean with raised levels of oleic acid.