绿盲蝽气味结合蛋白AlucOBP31配体筛选及EAG测定OA北大核心CSTPCD

The mirid bug,Apolygus lucorum,is a major agricultural pest,and understanding its chemical sensing mechanism is crucial for pest control.Odorant-binding proteins(OBPs)play a key role in the insect chemoreception process.To investigate the function of AlucOBP31,a member of the OBP family in A.lucorum,we conducted fluorescence competitive binding assays and electroantennogram(EAG)recordings to systematically analyze the binding characteristics of AlucOBP31 and electrophysiological activities of candidate ligands.The results of the fluorescence competitive binding assays showed that the recombinant AlucOBP31 protein could bind to 16 compounds to varying degrees.AlucOBP31 exhibited the strongest binding affinity to the plant volatile β-ionone,while its binding affinities to dodecyl aldehyde and cis-3-hexenyl butyrate were relatively weak.Interestingly,AlucOBP31 could also bind to(2E)-4-oxo-2-hexenal,a sex pheromone component of A.lucorum,suggesting its potential involvement in sex pheromone recognition.Furthermore,AlucOBP31 demonstrated strong binding to four non-volatile bitter substances,including quercetin,rutin hydrate,gossypol hydrate,and tannic acid,implying its possible role in taste recognition of A.lucorum.EAG experiments further verified the electrophysiological activities of AlucOBP31 binding ligands.The antennae of both male and female A.lucorum adults exhibited significant EAG responses to 12 volatile ligands bound by AlucOBP31,with the EAG response values to cis-3-hexenyl butyrate and(2E)-4-oxo-2-hexenal being significantly higher than those to other ligands.Intriguingly,the EAG responses of male antennae to these ligands were generally significantly stronger than those of females,suggesting potential sex-specific differences in the AlucOBP31-mediated chemoreception process.In conclusion,this study systematically analyzed the binding characteristics and electrophysiological activities of AlucOBP31 in A.lucorum,revealing that this protein can widely bind to host plant volatiles,sex pheromone components of mirid bug,and various non-volatile bitter substances.These findings indicate that AlucOBP31 may play multiple biological functions in the olfactory and gustatory recognition of A.lucorum.Our result provides a research foundation for further exploring the biological significance of AlucOBP31 and its ligands in important life activities of A.lucorum,such as host selection and mating.It deepens our understanding of the chemical sensing mechanism in A.lucorum and offers new molecular targets for the green control of this pest.