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ORIGINAL RESEARCH article

Front. Physiol.
Sec. Invertebrate Physiology
Volume 15 - 2024 | doi: 10.3389/fphys.2024.1475489
This article is part of the Research Topic Insect Physiology Aspects of Environmentally Friendly Strategies for Crop Pests and Invertebrate Vectors Control, Volume II View all 9 articles

Characterization of the ligand-binding properties of odorant-binding protein 38 from Riptortus pedestris when interacting with soybean volatiles

Provisionally accepted
Jianglong Guo Jianglong Guo 1Panjing Liu Panjing Liu 1Xiaofang Zhang Xiaofang Zhang 1Jingjie An Jingjie An 1Yaofa Li Yaofa Li 1Tao Zhang Tao Zhang 1*Zhanlin Gao Zhanlin Gao 1,2*
  • 1 Plant Protection Institute, Hebei Academy of Agriculture and Forestry Sciences, Baoding, China
  • 2 Hebei Academy of Agriculture and Forestry Sciences (HAAFS), Shijiazhuang, China

The final, formatted version of the article will be published soon.

    Riptortus pedestris (Fabricius) (Hemiptera: Alydidae) is a major soybean pest throughout East Asia that relies on its advanced olfactory system for the perception of plant-derived volatile compounds and aggregation pheromones for conspecific and host plant localization. Odorant binding proteins (OBPs) facilitate the transport of odorant compounds across the sensillum lymph within the insect olfactory system, enabling their interaction with odorant receptors (ORs). RpedOBP38, a member of a classic OBP family, was selected for evaluation in this study. Real-time quantitative PCR (qRT-PCR) analyses revealed high levels of RpedOBP38 expression in the antennae without any apparent sex bias, and it was also highly expressed in the adult stage. Recombinant RpedOBP38 was prepared by expressing it in E. coli BL21 (DE3) followed by its purification with a Ni-chelating affinity column. When fluorescence-based competitive binding assays were performed with 36 volatile compounds, RpedOBP38 was found to bind most strongly to trans-2-decenal (Ki = 7.440) and trans-2-nonenal (Ki = 10.973), followed by β-pinene, (+) -4-terpineol, carvacrol, methyl salicylate, and (-)carvone. To elucidate the molecular mechanism of RpedOBP38-ligands binding, the 3D structure of RpedOBP38 was modeled with the I-TASSER server, revealing that it contains six α-helices and three interlocked disulfide bridges comprising a stable hydrophobic binding pocket. In a final series of molecular docking analyses, several polar (e.g., His 94, Glu97) and nonpolar (e.g., Leu29, Ile59) residues were found to be involved in RpedOBP38-ligand binding. Together, these data support a role for RpedOBP38 in the perception of volatiles derived from host plants, providing important insight into the mechanisms that govern olfactory recognition in R. pedestris, thereby informing the development of ecologically friendly approaches to managing R. pedestris infestations.

    Keywords: Riptortus pedestris, OBPs, soybean volatiles, Fluorescence competitive binding, molecular docking

    Received: 04 Aug 2024; Accepted: 09 Dec 2024.

    Copyright: © 2024 Guo, Liu, Zhang, An, Li, Zhang and Gao. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence:
    Tao Zhang, Plant Protection Institute, Hebei Academy of Agriculture and Forestry Sciences, Baoding, China
    Zhanlin Gao, Hebei Academy of Agriculture and Forestry Sciences (HAAFS), Shijiazhuang, China

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