| The brown planthopper(BPH),Nilaparvata lugens St?l(Hemiptera: Delphacidae),is a migratory insect pest and outbreaks frequently in recent decades.BPH gathers in the leaf sheaths of sole hostrice plant to suckthe rice sap.It can migrate with the monsoon,has strong adaptability to the environment and is prone to outbreak when the external conditions are suitable.It is one of the most destructive insect pests in China and many southeastern Asian countries.The cuticular proteins of insects play an important role in the growth,development,reproduction and other physiological processes.Therefore,it is important to understand functions of the cuticular proteins,so that to provide important theoretical basis for insect pest control.In this study,we cloned the cDNA sequences of five cuticular proteins from BPH.The ORF of NlugCpr1 was 390 bp in length and was potential to encode a 14.06 k Da protein containing 129 amino acid residues.The ORF of NlugCpr2 was 423 bp in length and was potential to encode a 14.67 k Da protein containing 140 amino acid residues.The ORF of NlugCpr3 was 360 bp in length and was potential to encode a 12.53 k Da protein containing 119 amino acid residues.The ORF of NlugCpr8 was 696 bp in length and was potential to encode a 23.75 k Da protein containing 231 amino acid residues.The ORF of NlugCpr90 was 1317 bp in length and was potential to encode a 49.00 k Da protein containing 438 amino acid residues.They all have the typical conserved Chitin＿bind＿4 domain of CPR family.q RT-PCR analysis showed that NlugCpr1,NlugCpr2,NlugCpr3,NlugCpr8 and NlugCpr90 have the highest expression in embryonic stage.Then we employed RNA interference(RNAi)technique to study the functions of NlugCpr1,NlugCpr2,NlugCpr3,NlugCpr8,NlugCpr90,and found that the knockdown of NlugCpr2 didn’t influence the embryonic development of BPH,however,the knockdown of NlugCpr1,NlugCpr3,NlugCpr8 and NlugCpr90 could affect embryonic development and hatchabilities.Our results may enhance our understanding functions of the embryo-specific cuticular proteins and provides potentialtargets for RNAi-based pest control. |
