Liu Jinlong, Zhao Wenzhen, Hu Changyuan, Xia Yidan, Li Lei, Zhang Fangping, Wang Man-Qun, Zhou Aiming
College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China; Key Laboratory of Integrated Pest Management on Tropical Crops, Ministry of Agriculture and Rural Affairs, Environment and Plant Protection Institute, Chinese Academy of Tropical Agricultural Sciences, Haikou 571101, China.
College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
Int J Biol Macromol. 2025 Mar;293:139416. doi: 10.1016/j.ijbiomac.2024.139416. Epub 2024 Dec 31.
Odorant binding proteins (OBPs) play a key role in the crosstalk between the external environment and dendritic neuron activation. Ham sausage is an efficient bait widely used for monitoring the invasive ant Solenopsis invicta in the field, whereas the chemoreceptors involved in bait odorant perception in S. invicta have not been functionally characterized. Here, we investigated the role of SiOBP2, an OBP specifically expressed in the antenna, from S. invicta in detecting bait odorants. SiOBP2 was specifically expressed in sensillum basiconca in S. invicta antennae and displayed strong binding affinity and diverse binding mechanisms with specific bait odorants, such as static quenching and multiple binding characteristics with 3-mercapto-2-butanone and furfuryl mercaptan. Knockdown of SiOBP2 abolished the electroantennogram and behavioral responses of S. invicta to these odorants. S. invicta with SiOBP2 knockdown exhibited inactivation of odorant receptor neuron signaling and reduced bait searching efficiency. Foraging behavior and sensory cone responses to bait odorant stimuli in S. invicta demonstrate the sensillum basiconca is particularly tuned to 3-mercapto-2-butanone and furfuryl mercaptan. Collectively, SiOBP2 is essential for the perception of S. invicta on bait odorants and can be used as an important molecular target to develop novel attractants for S. invicta.
气味结合蛋白（OBPs）在外部环境与树突状神经元激活之间的相互作用中起关键作用。火腿肠是一种高效诱饵，广泛用于野外监测入侵红火蚁，然而，参与红火蚁诱饵气味感知的化学感受器尚未得到功能表征。在此，我们研究了红火蚁中一种在触角中特异性表达的OBP——SiOBP2在检测诱饵气味中的作用。SiOBP2在红火蚁触角的锥形感器中特异性表达，并与特定诱饵气味剂表现出强烈的结合亲和力和多样的结合机制，如与3-巯基-2-丁酮和糠硫醇的静态猝灭及多重结合特性。敲低SiOBP2消除了红火蚁对这些气味剂的触角电位和行为反应。敲低SiOBP2的红火蚁表现出气味受体神经元信号失活和诱饵搜索效率降低。红火蚁的觅食行为和对诱饵气味刺激的感觉锥反应表明，锥形感器对3-巯基-2-丁酮和糠硫醇具有特殊的适应性。总体而言，SiOBP2对红火蚁感知诱饵气味至关重要，可作为开发新型红火蚁引诱剂的重要分子靶点。
