Abstract: 【Aim】 This study aims to explore the developmental expression pattern and functional analysis of bursicon genes  bursicon-α and  bursicon-β in Rhopalosiphum padi (Linnaeus). 【Methods】 In this study, the cDNA sequences encoding bursicon-α and bursicon-β were obtained from RNA-seq transcriptome sequencing of  R. padi . The expression patterns of  bursicon-α  and  bursicon-β are analyzed by real-time quantitative PCR and the functional analyses of bursicon-α and bursicon-β were carried out through RNA interference technology. 【Results】 The sequence analysis showed that the open reading frame (ORF) of bursicon-α from R. padi  is 480 bp in length, encoding a protein with 159 amino acid residues. The ORF of bursicon-β  is 417 bp in length, encoding a protein with 138 amino acid residues. The developmental expression patterns showed that bursicon-α and bursicon-β were ordinarily expressed during the whole developmental stage of  R. padi, and arrived at the highest expression level in the 1st instar nymph. The expression levels of these two genes in winged adult aphids were significantly higher than those in wingless adult aphids. RNA interference-mediated knockdown of bursicon-α and bursicon-β significantly inhibited the cuticular melanization of adult aphids. 【Conclusion】 These results revealed that bursicon plays an important role in the process of the cuticular melanization in R. padi, providing a foundation for further study for the physiological functions of bursicon in aphids.

Key words: Rhopalosiphum padi , bursicon, cuticular tanning, developmental expression pattern, real-time quantitative PCR, RNA interference