Candidate odorant‐binding protein and chemosensory protein genes in the turnip aphid Lipaphis erysimi

The turnip aphid, Lipaphis erysimi Kaltenbach, inflicts heavy damage on cruciferous crops worldwide. In these insects, olfactory perception is crucial for mating, host location, and oviposition. Both odorant‐binding proteins (OBPs) and chemosensory proteins (CSPs) are responsible for the delivery of host odorants and pheromones during initial molecular interactions. In this study, antennal and body transcriptomes of L. erysimi were generated through the deep sequencing of RNA libraries. A dataset of 11 LeryOBP and four LeryCSP transcripts was identified among assembled unigenes and subjected to sequence analysis. Phylogenetic analysis found a one‐to‐one orthologous relationship between LeryOBP/LeryCSP and its corresponding homologs from other aphid species. Further quantitative real‐time PCR analyses across developmental stages and tissues showed that five LeryOBP genes (i.e., LeryGOBP, LeryOBP6, LeryOBP7, LeryOBP9, and LeryOBP13) and LeryCSP10 were specifically or significantly elevated in the antennae compared with other tissues. Moreover, two transcripts (i.e., LeryGOBP and LeryOBP6) exhibited remarkably higher expression levels in alate aphids, implying their potentially functional role in the perception of new host plant locations. These results present the identification and expression of OBP/CSP genes in L. erysimi, providing valuable insights into their putative role in olfactory signal transduction. A dataset of 11 LeryOBP and four LeryCSP transcripts was identified from the turnip aphid Lipaphis erysimi by antennal and body transcriptome analysis. Two transcripts (i.e., LeryGOBP and LeryOBP6) were expressed in an antenna‐biased manner and exhibited remarkably higher expression levels in alate aphids. Research Highlights Antennal and body transcriptomes were generated to screen candidate odorant‐binding protein (OBP) and chemosensory protein (CSP) genes in Lipaphis erysimi. Eleven LeryOBP and four LeryCSP genes were identified and subjected to sequence analysis. Five LeryOBP genes and one LeryCSP showed antennae‐biased expression profiles. Among these, the expressions of LeryGOBP and LeryOBP6 were >10‐fold higher in alate adults relative to apterous aphids.