Regulation Roles Of Juvenile Hormone Receptor And Ecdysone Receptor On The Reproduction Of Adelphocoris Suturalis

Adelphocoris suturalis is an important agricultural pest,mainly harming cotton,fruit trees and grass crops.Previous studies in the laboratory found that the Fatty acyl-coenzyme A reductase(FAR)plays a role in the reproductive development of A.suturalis.Insect hormones are one of the main factors that regulate insect fertility.However,the relationship between the hormone pathway and reproductive regulation of A.suturalis is still unclear.Therefore,in this study,gene cloning,gene silencing(RNAi),real-time quantitative PCR(q PCR)and other techniques were used to clarify the roles of juvenile hormone(JH)receptors Met,Tai and 20-Hydroxyecdysone(20E)receptors Ec R and USP in the reproductive regulation of A.suturalis.The upstream and downstream relationships between the above-mentioned receptor genes and FAR genes were determined by q PCR to explore the possibility of hormonal pathway regulation of FAR,and to analyze the reproductive regulation mechanism of A.suturalis.1.Cloning and sequence analysis of ORF of Met and TaiThe full length ORF of Met gene was 2247 bp,encoding 748 AAR.The predicted molecular weight of the corresponding protein was 83.37 k Da,and the p I value was 5.61.The Met protein was most closely related to Rhodnius prolixus.The full-length ORF sequence of Tai gene was 4068 bp,encoding 1355 AAR.The predicted molecular weight of the corresponding protein was 144.88 k Da,and the p I value was 6.61.Cimex lectularius and Halyomorpha halys were most closely related to Tai protein.2.Interference with Met and Tai genes affected the fertility of A.suturalisThe expression of Met gene decreased significantly 6-18 days after ds Met injection.The amount of egg hanging in the ovary decreased by 40% compared with the control group.A 41% reduction in lifetime spawning quantity;There was no significant difference between the adult longevity and the pre-oviposition period.After ds Tai injection,the expression level of Tai gene decreased significantly at 3-18 days.Compared with the control,the amount of ovary hanging decreased by 73.8%,and the development of ovary was delayed.The lifetime spawning quantity decreased by 67.6%.There was no significant difference between the adult longevity and the pre-oviposition period.3.Cloning and sequence analysis of ORF of Ec R and USPThe ORF sequence of Ec R gene was 1413 bp,encoding 470 AAR.The predicted molecular weight of the corresponding protein was 53.65 k Da,and the p I value of 7.79.The Ec R protein was most closely related to Apolygus lucorum.The ORF sequence of USP gene was 1209 bp,encoding 402 AAR.The predicted molecular weight of the corresponding was 44.99 k Da,and the isoelectric point p I value was 7.94.The USP protein was most closely related to C.lectularius.4.Interference with Ec R and USP genes affected the fertility of A.suturalisAfter ds Ec R injection,the expression of Ec R gene decreased significantly at 3-18 days.The amount of egg hanging in ovary was only 31.5% of that in control group.The lifetime spawning quantity decreased by 80.4%.There was no significant difference in preoviposition period.The adult lifespan was reduced by 5 days compared with the control group.After ds USP injection,the expression of USP gene decreased significantly at 3-18 days.The amount of egg hanging in ovary decreased by 13% compared with the control.A36% reduction in lifetime spawning;There was no significant difference in pre-oviposition period.The adult lifespan was 2.4 days shorter than that of the control group.5.Relationship between JH receptor and 20 E receptor and FARThe transcription level of FAR was significantly reduced by 40% on day 6 after interference with Met.The transcription level of FAR decreased significantly on day 6 and18 after Tai with interference.However,on the 3rd and 12 th days,the transcript level of FAR increased significantly;on the 9th and 15 th days,there was no significant change in the transcript level of FAR.Injection of USP and Ec R had no significant effect on the expression of FAR.FAR interference had no significant effect on the expression level of Met,Tai,Ec R and USP.Moreover,JHA and 20 E supplementation after FAR interference could not restore the fecundity of A.suturalis.These results indicated that the JH receptors Met,Tai and 20 E receptor Ec R and USP were involved in the reproductive regulation of female A.suturalis.Interference with JH receptors Met and Tai led to a decrease in the expression of FAR,while FAR interference had no significant effect on the titer and receptor expression of JH and 20 E of A.suturalis.Therefore,it is speculated that FAR acts downstream of the hormone pathway,thus affecting the reproduction of A.suturalis.