A whitetalk from plants has taken a gene that makes plant antibodies harmless. A team led by Youjun Zhang from the Chinese Academy of Agricultural Science in Beijing reported this In the magazine »Sale«. This is the first time a case has been reported in which an insect takes a gene from a plant.
The insect’s scientific name is tobacco or whitark. Bemisia Tabassi. It is one of the most economically important insects in the world. The animals sleep in the sap, leaving behind the sticky honeydew, in which the mildew settles. They also transmit disease-causing viruses. Plants have little to counter this attack, as scale pests are immune to at least a certain class of defense substances, phenol glycosides, thanks to inherited genes. It provides building instructions for an enzyme that neutralizes glycosides. Originally it probably came from the very cellular machinery with which plants still produce glycosides. It was found in large-scale insect DNA several million years ago, perhaps through a virus.
This special ability can now turn into a whitefill’s weak point. The insect, which has already become resistant to many pesticides, could possibly be added with the help of active ingredients that specifically harbor the enzyme. Zhang’s team has already demonstrated this in an experiment. It modulates genetically modified tomatoes in such a way that they produce a genetic switch to the enzyme with the help of RNA interference. Scale insects sucking these tomatoes were not suddenly immune to glycosides and died. This opens up opportunities for a highly specialized control agent, said Joanna Gershenzon from the Max Planck Institute for Chemical Ecology in Jena, who was not involved in the study. “You can keep the whitelist away, but at the same time leave out useful insects such as pollinators,” He says in the science magazine “Nature”.
The fact that genes release from one organism to another is a common occurrence in simple organisms such as protozoa or fungi, but also in plants themselves. Microorganisms. The fact that the enzyme that Zhang and his colleagues now discovered actually comes from plants is a result of genetic similarity to enzymes with similar function in the plant kingdom.
Not all species are known as a whitefly: a similar-looking greenhouse whitefly should do without it. However, the team writes, it may be worthwhile to search for such inherited genes in other pests. Thanks to an increasingly comprehensive gene database, this should become easier in the future. Some of these genes may then prove to be very promising targets for targeted insect control via RNA interference.
UPDATE, March 29, 2021: The present study is unequivocally, contrary to what the authors have suggested, not the first to discover signs of horizontal gene transfer in tobacco insect scallops. In 2020, scientists working with Maximiliano Jury Ajub of Argentina Universidad National de San Luis published a one discoveryIn which they prove that genes and mosquitoes have taken over the genes from plants.