Genetic modification is a process that sometimes happens naturally at the hands of bacteria, a new study concludes. Dozens of plants, including bananas, peanuts, hops, cranberries, and tea were found to contain the Agrobacterium microbe — the exact bacterium that scientists use to create GM crops.
“Horizontal gene transfer from Agrobacterium to dicots is remarkably widespread,” the study reads, reporting that around 1 in 20 plants are naturally transgenic.
Transgenic means that one or more DNA sequences from another species have been introduced by artificial means — in other words, an organism that has been modified genetically. In unicellular prokaryotes, this is a fairly common process, but it is less understood (and less common) in macroscopic, complex organisms.
In 2015, an impactful study found that sweet potatoes are naturally transgenic — they’ve been GM’d by Agrobacterium. This came as a surprise for many consumers, but many biologists suspected that sweet potatoes weren’t that unique, and several other plants went through a similar process. Tatiana Matveeva and Léon Otten studied the genomes of some 356 dicot species and found 15 naturally occurring transgenic species.
It’s still a rare occurrence, but 1 in 20 is too much to just chalk it up to a freak accident. “This particular type of horizontal gene transfer (HGT) could play a role in plant evolution,” the researchers say.