Abstract:

【Aim】In order to provide theoretical basis for studying the roles of odorant-binding proteins (OBPs) and chemosensory proteins (CSPs) in olfactory recognition of Schlechtendalia chinensis by the gene identification and expression profiling of OBPs and CSPs of S. chinensis. 【Methods】Based on the genome and transcriptome data of different developmental stages of S. chinensis, the gene sequences of OBPs and CSPs were identified and screened by bioinformatics methods. Phylogenetic analysis of OBPs and CSPs 

from S. chinensis and other Hemiptera insects based on amino acid sequences was performed using the neighbor-joining method. According to the TPM (tags per million) values of OBP and CSP genes in the transcriptome of different developmental stages (fundatrigeniae, fundatrix, spring migrant aphids, autumn migrant aphids, overwintering nymphs, sexual females and sexual males) of S. chinensis, the expression abundance was analyzed, and the relative expression levels of OBP and CSP genes were detected by qRT-PCR method. 【Results】 A total of 12 OBP genes (SchiOBP2-10, SchiOBP13-15) and 9 CSP genes (SchiCSP1-2, SchiCSP4-10) were identified from the genome and transcriptome data of S. chinensis. The phylogenetic analysis showed that OBPs/CSPs of S. chinensis were clustered together with OBPs/CSPs of other aphids and formed multiple homologous subgroups, indicating a credible homologous evolutionary relationship. According to the expression abundance in the transcriptome of different developmental stages and spatiotemporal expression profiles detected by qRT-PCR, SchiOBP3/6 and SchiCSP1/4/6/9/10 were highly expressed in fundatrix, SchiOBP4/10/14 and SchiCSP2/5/7 were highly expressed in sexual males, SchiOBP2 was highly expressed in fundatrix and sexual males, SchiOBP7 and SchiCSP8 were highly expressed in spring migrant aphids, SchiOBP8/13/15 were highly expressed in autumn migrant aphids, and SchiOBP9 was highly expressed in overwintering nymphs, indicating that these genes may play 
important roles in the olfactory recognition of S. chinensis in searching for host plants and mates.【Conclusion】 In this study, the OBP/CSP genes and their expression characteristics in different developmental stages of S. chinensis were identified and 

clarified, which provide a basis for further study on the function of olfactory-related proteins of S. chinensis and the chemical communication mechanism between gall aphids and their host plants.

Key words:  Schlechtendalia chinensis, odorant-binding protein, chemosensory protein; phylogeny, expression profile