One 2021 study looked at the genome of Solanum sitiens a wild tomato species which grows in the extremely harsh environment of the Atacama Desert in Chile, and can be found at altitudes as high as 3,300m (10,826ft). The study identified several genes related to drought-resistance in Solanum sitiens, including one aptly named YUCCA7 (yucca are draught-resistant shrubs and trees popular as houseplants).

They are far from the only genes that could be used to give the humble tomato a boost. In 2020 Chinese and American scientists performed a genome-wide association study of 369tomato cultivars, breeding lines and landraces, and pinpointed a gene called SlHAK20 as crucial for salt tolerance.

Once the climate-smart genes such as these are identified, they can be targeted using Crispr to delete certain unwanted genes, to tune others or insert new ones. This has recently been done with salt tolerance, resistance to various tomato pathogens, and even to create dwarf plants which could withstand strong winds (another side effect of climate change). However, scientists such as Cermak go even further and start at the roots they are using Crispr to domesticate wild plant species from scratch, "de novo" in science speak. Not only can they achieve in a single generation what previously took thousands of years, but also with a much greater precision.

De novo domestication of Solanum pimpinellifolium was how Cermak and his colleagues at the University of Minnesota arrived at their 2018 plant. They targeted five genes in the wild species to obtain a tomato that would be still resistant to various stresses, yet more adapted to modern commercial farming more compact for easier mechanical harvesting, for example. The new plant also had larger fruits than the wild original.

"The size and weight was about double," Cermak says. Yet this still wasn't the ideal tomato he strives to obtain for that more work needs to be done. "By adding additional genes, we could make the fruit even bigger and more abundant, increase the amount of sugar to improve taste, and the concentration of antioxidants, vitamin C and other nutrients," he says. And, of course, resistance to various forms of stress, from heat and pests to draught and salinity.

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The tomatoes at the forefront of a food revolution - BBC News