Memory Effect On Host Plant Selection And Transcriptome Analysis Of Hyphantria Cunea(Drury)

Hyphantria cunea(Drury)is an omnivorous pest of Lepidoptera,which seriously damaged flowers,crops and garden trees.In recent years,the feeding habit and harmful range of H.cunea in China have been expanding day by day.From the perspective of the learning and memory behavior of herbivorous insects,this paper studied the selection behavior of H.cunea adults to experienced plants by wind tunnel,Y-tube olfactometer and field experiments.In addition,we used scanning electron microscope to observe the mouthparts characteristics of larvae.We also used Illumina Hiseq to sequencing the transcriptome and expression profile of H.cunea which were induced by quercetin.Then,we focus on the function and metabolic pathway analysis of differentially expressed genes.The main research results are as follows:1.We used wind tunnel and Y-tube olfactometer to test the sensitivity of H.cunea adult to prexperienced host plants.The results shows that H.cunea adults did not show obvious "memory effect" on Platanus orientalis after the larval stage was affected by P.orientalis,however H.cunea adults did show slightly obvious "memory effect" on Fraxinus americana after the larval stage was affected by F.pennsylvanica.In field experiments,H.cunea adults with plant experience in larval stage had no obvious "memory effect" on host species in larval stage when both experienced plants and hobby hosts were present,regardless of the size of the available space.2.We used scanning electron microscopy to observe the head sensilla of H.cunea larvae.The results show that H.cunea larvae are similar to common Lepidoptera larvae taste sensor,including labium,maxilla and tongue.The maxillary palpus has six sensilla basiconica which pattern is 3-1-2 different from Spodoptera exigua(Hübner),Ostrinia furnacalis(Guenée),Bombyx mori L.3.We used high-throughput sequencing to obtain 47,251 Unigenes and 375 differentially expressed genes of transcriptome and expression profile.Gene Ontology analysis of differentially expressed genes showed that the up-regulated genes most annotated subclasses in cellular component was cell part,organelle part,organelle and macromolecular complex.The down-regulated genes most annotated subclasses in cellular component was cell part,membrane part,extracellular region.The up-regulated genes most annotated subclasses in biological process was cellular process,metabolic process,developmental process,biological regulation and cellular component organization or biogenesis.The down-regulated genes most annotated subclasses in biological process was metabolic process,cellular process,biological regulation.The up-regulated and down-regulated genes most annotated subclasses in molecular function was binding and catalytic activity.Analysis of the KEGG metabolic pathways in the treatment group and the control group showed that the differentially expressed genes were enriched to 134 pathways,and the metabolic pathways with the most annotations were ECM-receptor-interaction,apoptosis,protein digestion and absorption,respectively.4.We used bioinformatics method to identified 8 gustatory receptor genes in the transcriptome data of the head of H.cunea larvae,among which 6 gustatory receptor genes had complete open reading frame,5 gustatory receptor genes had transmembrane domain structure and 1 conserved c-terminal sequence.This study enriched the transcriptome data of H.cunea and provided basic data for further study on the adaptation mechanism of H.cunea to bitter secondary metabolites of host plants.