Bacterial DNA may have made sweet potatoes more attractive to farmers
Farmed sweet potatoes have been found to be made of more than just starch, sugars, beta-carotene and fiber. Genetic analysis has found their DNA includes segments from bacterial DNA, and it may be part of why we farm them in the first place.
The bacteria in question originated from Agrobacterium, which seems to be especially adept at entering a plant’s DNA. Modern genetic modification of crops uses bacteria from the same genus, but not the same species found in this study. The fact that these segments of DNA are found in over 291 samples of sweet potato from around the world indicate that this first gene insertion happened long ago, allowing it time to have propagated to so many breeds in segments of varying length.
The appeal of the modified potatoes
While the bacteria likely wormed their way into the potatoes on their own, humans may have still played a role in the process. Agrobacterium DNA was not found in wild varieties of sweet potato, so the bacterial addition may have made the potatoes more attractive to early farmers, who then aided in their reproduction by planting them more often.
Source: Bits of bacterial DNA naturally lurk inside sweet potatoes by Susan Milius, ScienceNews