Horizontal gene transfer: plant to insect pest (Introduction)

by David Turell , Saturday, March 27, 2021, 14:38 (1337 days ago) @ David Turell

First example found:

https://www.nature.com/articles/d41586-021-00782-w

"The finding, reported today in Cell1, is the first known example of a natural gene transfer from a plant to an insect. It also explains one reason why the whitefly Bemisia tabaci is so adept at munching on crops: the gene that it swiped from plants enables it to neutralize a toxin that some plants produce to defend against insects.

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"That some species of whitefly could owe part of their predatory prowess to genes from other organisms is not entirely surprising, because genetic thievery is common in the arms race between plants and their pests. Over millions of years, plants and insects alike have borrowed heavily from microbial genomes, sometimes using their newly acquired genes to develop defensive or offensive strategies.

"Some insects, such as the coffee berry borer (Hypothenemus hampei), have plundered microbial genes to extract more nutrition from hard-to-digest plant cell walls2, and a wild relative of wheat has pilfered a fungal gene to fight off a fungal disease called head blight3. But plants and insects were not known to steal from each other before now.

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"study showed that the gene can transfer a chemical group on to defensive compounds called phenolic glucosides. Such compounds are made by many plants, including tomatoes, to ward off pests. But the modification caused by the whitefly gene rendered the compounds harmless.

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"The results were surprising, but convincing, says Yannick Pauchet, a molecular entomologist also at the Max Planck Institute for Chemical Ecology. “According to the data they provide, horizontal gene transfer is the most parsimonious explanation,” he says.

"But how the whitefly managed to swipe a plant gene is unclear. One possibility, says Turlings, is that a virus served as an intermediate, shuttling genetic material from a plant into the whitefly genome.

"As researchers sequence more genomes, it’s possible that they’ll uncover more examples of gene transfer between plants and animals, says Gloss.

“'Insects taking the genes from the plants themselves is just that last bit of the arsenal that we hadn’t found yet,” he says. “In the battle between plants and their insect pests or pathogens, there are genes being drawn from all over the tree of life.'”

Comment: Undoubtedly more of this type of transfer will be found, and virus is the best guess as the agent. Horizontal gene transfer is shown again to be a driver of evolutionary change. This may be another answer/reason to why viruses are present at all?