Different Stimulation Conditions On Scleroderma Sichuanensis Effects Of Olfactory Learning And Memory

Parasitic wasps have a certain ability to learn and remember the environment and behavior they experience,and learning plays an important role in the process of parasitic wasps searching for hosts.As an excellent parasitic wasp for controlling longhorn beetles,Scleroderma sichuanense’s ability to search for hosts can be further enhanced through learning experience.However,what kind of learning stimulation can make Scleroderma sichuanensis obtain better learning and memory effect and its mechanism is unknown.Therefore,in this experiment,the learning and memory of Scleroderma sichuanensis under different stimulation conditions were determined by behavioral methods,and the stimulation conditions conducive to improving the learning and memory effect of Scleroderma sichuanensis were clarified.The transcriptome analysis of Scleroderma sichuanensis with significant differences in learning and memory under different stimulation conditions was carried out to compare the differences in transcriptional expression related to learning and memory,and the main differentially expressed genes were analyzed to provide reference for further study on the learning and memory mechanism of Scleroderma sichuanensis.Conclusions are as follows:（1）Y-type olfactometer was used to determine the response of Scleroderma sichuanensis under different treatment conditions of host plant volatiles.Under different concentration stimulation conditions,low concentration（5 g）of walnut volatiles had obvious learning and memory effects on Scleroderma sichuanensis,while high concentration（20 g）would make it have certain repellent effect.Under the condition of different stimulation duration,24 h stimulation duration was more conducive to the learning of different odors by Scleroderma sichuanensis;under the condition of different stimulation times,the learning and memory effect of Scleroderma sichuanensis who experienced three times of volatile learning was stronger than that of Scleroderma sichuanensis who experienced one time.（2）The non-parametric transcriptome sequencing technology was used to sequence and assemble the genes of Scleroderma sichuanensis under different treatments.The results are as follows:The total number of genes assembled by Scleroderma sichuanensis was 39842,and the total base number was 44107945.Six databases（NCBI＿nr,GO,KEGG,Pfam,Swiss-Prot and egg NOG）were used to annotate the assembled genes.A total of 19307 genes were successfully annotated in the GO database,and 9824 genes were successfully annotated in the KEGG database.The number of differentially expressed genes between different groups was different.The number of differentially expressed genes in hcf5g group and CK group was 245,while that in hz5g group and hz12h group was only 16.（3）GO enrichment analysis showed that the differential gene DDC was involved in long-term memory,learning or memory,anti-anesthetic memory and other related regulation.Compared with the control group,only the hz5g group had significant differences and down-regulated expression.Compared with the hz5g group,the DDC gene expression in the hz3t group was up-regulated,indicating that the number of stimuli regulated the up-regulation and down-regulation of DDC gene expression,which may be related to the formation of long-term memory.（4）One memory-related pathway was identified by KEGG enrichment analysis,which was phosphatidylinositol signaling pathway（KO 04070）.A total of two differential genes were involved in this pathway,namely CAM and IMPA.In the ck group vs hz3t group,hz5g group vs hz3t group,when the pathway is regulated,IP3 binds to the IP3 ligand gate calcium channel on the endoplasmic reticulum,opens the calcium channel,increases the intracellular Ca²⁺concentration,up-regulates the expression of CAM,and then promotes the expression of IMPA gene,indicating that multiple stimulations will promote the CAM and IMPA genes in this pathway.（5）The physical and chemical properties,hydrophilicity,transmembrane domain,signal peptide and subcellular localization of CAM,IMPA and DDC proteins were predicted by online software.It was found that the three proteins were hydrophilic and no signal peptide located in the cytoplasm,and IMPA was a transmembrane protein.The subcellular localization experiments of CAM,IMPA and DDC proteins showed that all three proteins existed in mitochondria,which was consistent with the predicted results.