Transcriptome-Based Identification of Highly Similar Odorant-Binding Proteins among Neotropical Stink Bugs and Their Egg Parasitoid

Abstract

Olfaction plays a fundamental role in insect survival through resource location and intra and interspecific communications. We used RNA-Seq to analyze transcriptomes for odorant-binding proteins (OBPs) from major stink bug pest species in Brazil, Euschistus heros, Chinavia ubica, and Dichelops melacanthus, and from their egg parasitoid, Telenomus podisi. We identified 23 OBPs in E. heros, 25 OBPs in C. ubica, 9 OBPs in D. melacanthus, and 7 OBPs in T. podisi. The deduced amino acid sequences of the full-length OBPs had low intraspecific similarity, but very high similarity between two pairs of OBPs from E. heros and C. ubica (76.4 and 84.0%) and between two pairs of OBPs from the parasitoid and its preferred host E. heros (82.4 and 88.5%), confirmed by a high similarity of their predicted tertiary structures. The similar pairs of OBPs from E. heros and C. ubica may suggest that they have derived from a common ancestor, and retain the same biological function to bind a ligand perceived or produced in both species. The T. podisi OBPs similar to E. heros were not orthologous to any known hymenopteran OBPs, and may have evolved independently and converged to the host OBPs, providing a possible basis for the host location of T. podisi using E. heros semiochemical cues.

Identification and expression profile of odorant‐binding proteins in Halyomorpha halys (Hemiptera: Pentatomidae)

“…(), Farias et al . () and Gong et al (). As expected, all of the HhalOBPs had an amino terminal signal peptide, comprising the first 16 to 26 residues.…”

“…Eight putative HhalOBPs had additional conserved Cys (C1a, C1b, C1c, C6a, C6b and C6c), a proline (Pro or P) after the C6a and an extended carboxy‐terminal end, and were classified as Plus‐C OBPs. Plus‐C OBPs have also been found in other hemipterans (Zhou et al ., ; Gu et al ., ; Ji et al ., ; Hull et al ., ; Farias et al ., ). In this work, all putative OBPs had the strictly conserved three residues between C2–C3, which is the expected OBP motif C‐pattern in insects (Xu et al ., ).…”

“…The phylogenetic analysis for the HhalOBPs with the other 325 hemipteran sequences (Fig. A) confirmed again the intraspecific divergence of the putative OBPs (Farias et al ., ). The HhalOBPs did not form a single clade, although three pairs formed sister pairs (HhalOBP3/HhalOBP28, HhalOBP7/HhalOBP19 and HhalOBP24/HhalOBP26) with bootstrap support ranging from 84% to 95%.…”

“…lucorum (Ji et al ., ), although the antenna of the BMSB had higher richness of biological processes and molecular function. However, the annotations were not similar to the most common biological processes and molecular functions found in the antennal transcriptomes of the pentatomids Chinavia ubica , Dichelops melacanthus or Euschistus heros (Farias et al ., ). The BMSB transcriptome also revealed the presence of enzymes belonging to energy, amino acid, nucleotide, cofactor, vitamin, carbohydrate, glycan and lipid metabolic pathways (Fig.…”

“…lucorum , from which 38 putative OBPs were found (Yuan et al ., ). The BMSB had a similar number of putative OBPs as other stink bugs: 25 for E. heros and C. ubica (Farias et al ., ). These polyphagous stink bugs have a broad range of host plants, with some overlap amongst them.…”