Expression Pattern And RNAi Study Of P450 Genes Of Phenacoccus Solenopsis After Feeding On Three Hosts

In the long-term interaction between plants and insects,plants have formed a variety of mechanisms to resist insect feeding,and insects have also formed a mechanism in adapting to various plants in this process.Further study on the relationship between insects and host plants are of great significance for the control of pests,which provides new ideas for comprehensive control.Phenacoccus solenopsis,a kind of quarantine pest with a wide range of hosts,belongs to Hemiptera and Pseudococcidae,which reduces the cotton production of many regions and countries dramatically,causing enormous economic losses.In order to study the adaptability more effectively of P.solenopsis in different hosts,the paper analyzed the transcriptome sequencing results of the P.solenopsis living on tomato,cotton and hibiscus for a long time,then the cytochrome P450 gene were screened from the transcriptome and identified.Through the detection of CYPs gene expression profile in different development stages of P.solenopsis,combined with CYP6PY1 RNA interference experiment,the role of cytochrome P450 gene played in the adaption process of P.solenopsis in hosts had been further explored,which may offer new ways of pest prevention and control of P.solenopsis.The main findings are as follows:1.The results of transcriptome data showed that 47,635,589 clean reads were produced and N50 was 1297 bp.By classifying GO,KEGG and eggNOG,CYPs gene related to "metabolism of terpenoids and polyketides" and "secondary metabolites,biosynthesis,transport and catabolism" were found.A total of 37 CYP genes were identified from the transcriptome,and their sequences were compared and analyzed.Results showed that 37 CYPs had conserved motifs in the P450 family,and these motifs were more conserved in the same family.2.The expression profile of CYPs gene showed that there were significant differences in the expression levels of 22 cytochrome P450 genes in P.solenopsis at different developmental stages(p<0.05).Most of the genes had high expression levels at nymphal stage,while the expression levels in adult stage were relatively low.Among three hosts,it was found that most of the 22 CYPs had a high expression level on tomato or cotton,and a comparatively low expression level on hibiscus.3.The RNAi results of the CYP6PY1 showed that the relative expression of CYP6PY1 at 24h,48h,and 72h after interference on the three hosts was significantly down-regulated at 24h,and the expression levels of CYP6PY1 were up-regulated gradually with the extension of time.After the interference,the weight detection results of P.solenopsis showed that compared with CK,the weight of dsCYP6PY1 on tomatoes decreased by 10.9%,13.9%and 15.9%at 24h,48h and 72h,respectively.In cotton,dsCYP6PY1 decreased by 5.2%,9.7%and 10.9%at 24h,48h and 72h,respectively,compared with CK.On hibiscus,the body weight of dsCYP6PY1 decreased by 4.0%,7.2%and 9.2%respectively at 24h,48h and 72h compared with CK.The results of the average spawning amount showed that compared with CK and dsGFP,the average spawning amount of dsCYP6PY1 decreased by 18.0%and 14.9%respectively.Cotton and hibiscus were 15.0%,13.5%,15.6%and 12.4%,respectively.In this paper,we studied the adaptability of P.solenopsis and the role of CYPs gene in the host adaptation process from transcriptome sequencing,relative expression level of CYPs gene and RNAi.It is expected to shed light on the cause of P.solenopsis polyphagous,providing theoretical basis for its prevention and control at the molecular level,and offer new ideas for green prevention and control.