Effects Of OCT Gene On The Regulation Of Sitotroga Cerealella (Olivier) Reproduction By Diallyl Trisulfide

Sitotroga cerealella Olivier is a serious primary stored grain pest.Chemical control is still the main control method at present,but with the aggravation of"3R"problem,it is particularly urgent to find environmentally friendly control methods.The preliminary experimental results of our lab showed that the treatment of diallyl trisulfide（DAT）,the main active substance of garlic essential oil,decreased the reproductive ability of female moth,but the mechanism is not clear.In this paper,female adults S.cerealella were fumigated by DAT(LC₂₀=0.015μL/L air)for 14 h after emergence 6 h.And then,the spermatheca and spermathecal gland of females 4 hours after mating were collected for transcriptome sequencing.Differentially expressed genes（DEGs）that may be involved in reproductive regulation were screened and the functional verification was performed.The main results are as follows:1.A total of 241 DEGs were found in the transcriptome data of spermatheca and spermathecal gland of female moths at 4 hours after mating.Among them,174 DEGs were up-regulated and 67 DEGs were down-regulated.DEGs were mainly enriched in transport catabolism,signal transduction,cell growth and apoptosis,energy metabolism and other pathways.Some DEGs were selected for tissue expression analysis,and the organic cation transporter（OCT）with high expression level in the reproductive organs and the highest expression in the spermathecal gland was screened,and its function was verificated.2.Scer OCT gene was cloned and the sequence was conducted bioinformatics analysis.The results showed that Scer OCT gene was closely related to Lepidoptera insects such as Galleria mellonella and Amyelois transitella,which accorded with the law of biological evolution.After ds OCT was injected to the females and silenced,the reproductive ability of the females was determined.The results showed that there was no difference in the average mating times between the ds OCT groups and the ds GFP groups,but the mating rate of females in the ds OCT groups decreased（P<0.05）,and the fecundity in the ds OCT groups significantly decreased within 3 days comapared with control groups（P<0.05）.Further study showed that after mating,the number of sperm transferred to the females in the ds OCT group was significantly decreased（P<0.01）,and the transfer time of these sperm in the reproductive organs of the female in the ds OCT group was also delayed compared with the ds GFP groups,and the long-wave and short-wave wavelengths of sperm movement in the female were significantly higher than the ds GFP group（P<0.001）.At the same time,after silencing Scer OCT gene,the content of neurotransmitter 5-hydroxytryptamine of females in the ds OCT group was significantly higher than the ds GFP group.However,the content of triacylglycerol was significantly lower than the ds GFP group.In conclusion,the expression of some genes in spermatheca and spermathecal gland were abnormal after DAT treatment female moth.The silencing of Scer OCT led to the decrease of reproductive ability of female moth affecting the content of neurotransmitter5-HT and energy substance TG.The results provide a new theoretical basis for the regulation of diallyl trisulfide regulation of S.cerealella female reproduction.