Beijing, March 26 (China Youth Daily, China Youth Daily reporter Qiu Chenhui) reporters learned today from the Institute of Vegetables and Flowers of the Chinese Academy of Agricultural Sciences that after 20 years of follow-up research, The zhang youjun team of the institute found that the whitefly "hijacked" a plant detoxification gene to metabolize plant toxins, thus forming a molecular mechanism for the wide host adaptability of whiteflies. This is the first time in more than 100 years since the birth of modern biology that studies have confirmed the phenomenon of horizontal transfer of functional genes between plants and animals.
On March 25, Beijing time, the paper of this scientific research result was published online in the top international academic journal "Cell" magazine, and will be published as a cover article on April 1. This is the first paper in the field of agricultural pest research in China in the journal Cell, revealing how insects use horizontal transfer genes to overcome host defenses, opening up a new perspective for exploring the adaptive evolution of insects, and providing new ideas for the research and development of precision green prevention and control technology for a new generation of target gene-oriented whitefly fields.
Research team members Zhang Youjun (first from right), Xia Jixing (second from right), and Guo Zhao will observe the experiments of whitefed on tomatoes in the laboratory. Photo courtesy of Vegetable Institute of Chinese Academy of Agricultural Sciences
According to Zhang Youjun, director of the Institute of Vegetables and Flowers of the Chinese Academy of Agricultural Sciences, the whitefly, as an invasive alien species, has been recognized by the Food and Agriculture Organization of the United Nations as the world's second largest pest. It not only sucks up plant sap and induces fungal diseases, but also spreads more than 300 viruses, causing billions of dollars in economic losses around the world every year. Extreme polyphagia and extensive host adaptability are the main causes of its outbreak.
Since 2001, Zhang Youjun's team has been exploring the mechanism of host adaptation of whitefly. In this study, researchers found defensive toxin phenolic sugars on tomato leaves. Since excess phenolic sugars are not good for tomato growth, tomatoes use a PMaT gene to metabolize phenolic sugars. In the corresponding study of whitefly, the researchers used bioinformatics and molecular biology methods to find that a gene BtPMaT1 is also present in the genome of whitefly, and that this gene is specifically expressed in the intestines of adult worms.
Whitefly obtains the PMaT1 detoxification gene from plants through horizontal gene transfer events. Photo courtesy of Vegetable Institute of Chinese Academy of Agricultural Sciences
Virulence measurements and tests have shown that the BtPMaT1 gene has a detoxifying function on the phenolic sugar secreted by tomatoes, and the gene only comes from plants or a few fungi, unlike the vertical transfer of general gene parents to offspring, which is passed into the body of whitefly through the horizontal transfer of genes by plants in the process of evolution, and is retained from generation to generation. The researchers speculate that the horizontal transfer of the gene may have occurred due to the infection of the whitefly with viruses containing plant genes, and the transfer time is 350 million to 860 million years ago, and the specific process needs to be further studied.
Zhang Youjun said that the scientific community has previously found that horizontal transfer of genes exists in bacteria and higher organisms. This study is the first to use bioinformatics, molecular biology, biochemistry and other methods to prove that the BtPMaT1 gene of whiteflies is a horizontal transfer gene of plant origin, and whiteflies protect themselves against plant toxins by "stealing" the plant gene. Just like the ancients' "spear of the child to attack the shield of the child", it is through this ingenious evolutionary way that the whitefly promotes its wide host adaptability.
This is also the first time in the world that animals have obtained plant-derived genes through horizontal gene transfer, and the genes have biological functions. Reviewers of the journal Cell believe that the results are a major breakthrough in the field of insect chemical ecology research.
Source: China Youth Daily client