Effects Of Imidacloprid On Ambrostoma Quadriimpressum Gut And Its Microbiota

Imidacloprid is a neonicotinoid insecticide that acts on the central nervous system of insects and has tactile and gastric toxic effects.However,the effects of imidacloprid on intestinal tract and microflora of Ambrostoma quadriimpressum are not completely clear.There are relatively few studies on detoxification enzymes and related genes involved in drug resistance,and few studies on the mechanism of drug resistance regulation of related detoxification enzyme gene expression.During the long-term evolution of insects,when they are stressed by many adverse conditions,they will maintain normal physiological activities by adjusting the number and type of their intestinal flora.The structure and composition of intestinal flora play an important role in the growth and development of insects and physiological process.In this study,based on the FPKM value of high-throughput sequencing data from the transcriptome of adult Ambrostoma quadriimpressum,high expression genes were screened for GO functional annotation and KEGG enrichment analysis.24147 genes were annotated in the GO database,including molecular functions,biological processes and cellular processes.In KEGG pathway analysis,18892 highly expressed genes were involved in four metabolic pathways,including cellular processes,environmental information processing,genetic information processing,and metabolism.The representative genes of detoxification enzymes in the intestines of 7 adults were screened,and the gene expression was quantitatively analyzed and verified by q RT-PCR,and the relationship between the genes and drug resistance was further studied by transcriptome assay.By determining the effect of imidacloprid on Glutathione S-transferase(GST),Carboxylesterase(Car E),Cytochrome(P450),the activity of three detoxifying enzymes and the association between enzyme activity and insecticide degradation.This study provides theoretical basis and research for the development direction of drug resistance and the use of intestinal flora to better target control of Ambrostoma quadriimpressum.The main research results of this paper are as follows:1 、 Under the stress of imidacloprid,cytochrome oxidase in the intestinal tract of Ambrostoma quadriimpressum showed activation,while glutathione S transferase and carboxylesterase showed inhibition.2、Through the analysis of 16 S r RNA data,the intestinal flora abundance of Ambrostoma quadriimpressum has changed significantly,and after the treatment of imidacloprid,Klebsiella and Salmonella have increased significantly.Because the enterobacterium mainly includes:Eesherichia,Klebsiella,Salmonella,Proteus,etc,of which Escherichia and Klebsiella are closely related to drug resistance problems.3 、 In KEGG enrichment analysis,most Unigenes were annotated in cellular process,metabolic process,and biological regulation regulation,detoxification,cell killing,etc.At the second level of metabolic pathways,373 Unigenes annotated the middle nucleotide metabolic pathway,141 Unigenes annotated the terpenoid and polyketone metabolic pathways,562 Unigenes annotated the glycan bioanabolic pathway,and 806 Unigene annotated the lipid metabolic pathway.496 Unigenes are related to energy metabolism,329 to other amino acid metabolism,561 to cofactors and 224 to vitamin metabolic pathways,and 781 to xenobiodegradation and metabolic pathways.4 、 Seven differentially identified genes were glutathione S-transferase(GST),glucuronide transferase(UGT),fatty acid synthetase(FASN),aldose-1-episomerase(AEP),glutathione hydrolase(GGT),carboxylesterase(CES2),cytochrome oxidase(CYP2E1)Genes involved in metabolism of toxic substances.The expression of q RT-PCR gene was consistent with that of transcriptome,which verified the accuracy of transcriptome analysis.5、Transcriptome sequencing and 16 S r RNA sequencing were used to analyze the effects of the intestinal tract and bacteria of Ulmus purpurea.The results showed that carboxylesterase activity and glutathione S-transferase were related to the intestinal tract of Ambrostoma quadriimpressum,and the enhancement of cytochrome oxidase activity was related to the intestinal bacteria of beetles.6 、 The expression of aldose 1-episomerase in glycolysis pathway is upregulated.The glucose in insect intestine is decomposed into glucose-6-phosphate under the action of hexose inositase and polyphosphate glycokinase,and the resulting product is catalyzed by glucose wphosphate isomerization to form barium glucose phosphate,which then enters the pentose acid pathway.In the process of coping with pesticide stress,it plays a role in regulating physiological functions and providing energy to achieve detoxification.7、The genes of Car E and GST were significantly up-regulated under imidacloprid stress,and the enzyme activities of Car E and GST were significantly down regulated,indicating that P450 was used to detoxify the intestinal tract of Ambrostoma quadriimpressum under imidacloprid stress to reduce intestinal damage.