Professor Chen Xuexin’s team from Zhejiang University College of Agriculture published a paper on PLoS Pathogens to reveal the new mechanism of parasitic wasps regulating host nutrient metabolism
By: Date: 2021-03-27 Categories: foodtechnology Tags: ,
   On March 1, 2021, the internationally renowned pathogenic journal PLoS Pathogens published online the latest research results of the team of Professor Chen Xuexin from the School of Agriculture and Biotechnology of Zhejiang University”Symbiotic bracovirus of a parasite manipulates host lipid metabolism via tachykinin signaling”, reveals a new mechanism for parasites to regulate host nutritional metabolism, and provides a new theoretical basis for the efficient breeding of natural enemy insects and the development of new technologies for pest control.

   Parasitic insects, especially parasitic wasps, are purely natural factors that effectively control the population of agricultural and forestry pests in nature, and are widely used in sustainable pest control. Parasitic insects are different from predatory insects. They usually do not directly kill their prey. Instead, they regulate the growth and development, immunity and nutritional metabolism of the host to ensure the normal survival of their offspring and ultimately kill the host. In the long-term arms race with the host, parasitic wasps have some special weapons, such as venom, polydnavirus (PDV), teratocyte and other parasitic factors to regulate the physiological process of pests. Ensure that its offspring complete development in or on the host body. PDV is a kind of symbiotic virus unique to parasitic wasps, divided into Bracovirus and Ichovirus, whose genome is embedded in the genome of parasitic wasps. But so far, the mechanism of how parasitic wasps use parasitic factors to regulate host nutritional metabolism is still unclear.

   Based on the research of the important international vegetable pest—Plutella xylostella and its natural enemy—Cotesia vestalis, the cocoon of the plutella xylostella was found Bee parasitism can cause a significant decrease in the lipid content of the host Plutella xylostella, and it is caused by the weakened lipid synthesis level in the host’s intestinal tract. The study also found that the neuropeptide tachykinin (TK) secreted by endocrine cells in the midgut of Plutella xylostella played a key negative regulatory role in intestinal lipid synthesis and the overall lipid content in the body. The parasitism of Cotesia plutellae can cause an increase in the number of enteroendocrine cells in the host’s midgut, promote the secretion of TK, and cause a significant decrease in the host’s internal lipid content. Further research found that the parasitic factor Cotesia vestalis Bracovirus (CvBV) affects the expression of TK in the midgut, thereby regulating the lipid metabolism of the host Plutella xylostella. Subsequently, the transcriptome analysis of the host midgut cells infected with CvBV revealed that the three CvBV genes CvBV 9-2, CvBV 9-5 and CvBV 22-6 maintained high levels of expression in the host intestine at different developmental stages. These three CvBV genes were analyzed for gene deletion and gene overexpression, and it was confirmed that CvBV 9-2 played a role in regulating the changes of TK and host lipid content in the parasitism of Cotesia plutellae. At the same time, the research team also found that the internal lipid content of the host body changed by parasitism plays a very important role in ensuring the growth and development of the offspring of the parasitic wasp and its parasitic ability. So far, the study found for the first time that parasitic wasps can use a CvBV gene of Cotesia plutellae virus, CvBV 9-2, to affect the ability of the host Plutella xylostella to secrete TK, thereby effectively regulating host lipid synthesis and its The overall lipid content is ultimately conducive to the growth and development and parasitic ability of offspring. For example, the judges of the paper pointed out:”This study reported for the first time the molecular mechanism of the parasitic wasp PDV gene regulating host nutritional metabolism, filling the gap in this field, and it is of great significance.”
Professor Chen Xuexin’s team from Zhejiang University College of Agriculture published a paper on PLoS Pathogens to reveal the new mechanism of parasitic wasps regulating host nutrient metabolismimage
  parasitic wasp regulation of host lipid metabolism model diagram

   In recent years, Professor Chen Xuexin’s team has made a series of breakthrough research results in the field of parasitic wasp control mechanisms. This study on the regulation of host nutritional metabolism by parasitic wasps is also another important discovery of the team following the work of regulating host growth and development (Nature Communications, 2018) and host immunity (Nature Communications, 2021). Researcher Huang Jianhua from the Institute of Insect Science of Zhejiang University is the corresponding author of the paper, and PhD student Yanping Wang is the first author of the paper. This research was supported by the National Natural Science Foundation of China Key Project (31630060), Excellent Youth Project (31622048), General Project (31772522, 31672079), and National Key Research and Development Program (2019YFD0300104 and 2017YFD0200400).

   link to the paper:https://doi.org/10.1371/journal.ppat.1009365