Yang Lu-Lu, Wang Bing, Shen Jie, Wang Gui-Rong
State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China.
Department of Entomology and Ministry of Agriculture (MOA) Key Laboratory for Monitory and Green Control of Crop Pest, China Agricultural University, Beijing, China.
Front Cell Neurosci. 2023 Apr 27;17:1162349. doi: 10.3389/fncel.2023.1162349. eCollection 2023.
Olfaction is important for mediating aphid behaviors and is involved in host location and mating. Antennal primary rhinaria play a key role in the chemoreception of aphids. The function of the peripheral olfactory system in the subfamily Aphidinae has been intensively studied, but little is known about other subfamilies of Aphididae. Therefore, three aphid species were selected to study the olfactory reception of plant volatiles: (Lachninae), (Eriosomatinae), and (Calaphidinae). In this study, the morphology and distribution of the antennal sensilla of apterous adults were observed by scanning electron microscopy. Three morphological types were identified (placoid sensilla, coeloconic sensilla, and trichoid sensilla); the first two were distributed on the antennal primary rhinaria. A pattern of primary rhinaria in was found that differed from that of and and consists of 1 large placoid sensillum (LP) on the 4th segment, 2 LPs on the 5th segment, and a group of sensilla on the 6th antennal segments. Later, we recorded and compared neuronal responses of the distinct placoid sensilla in the primary rhinaria of the three aphid species to 18 plant volatiles using a single sensillum recording (SSR) technique. The results indicated that the functional profiles based on the tested odorants of the primary rhinaria of the three investigated aphid species were clustered into three classes, and exhibited excitatory responses to certain types of odorants, especially terpenes. In , the ORNs in LP6 exhibited the highest responses to (±)-citronellal across all tested chemicals, and showed greater sensitivity to (±)-citronellal than to (+)-limonene. ORNs in LP5 were partially responsive to α-pinene and (-)-β-pinene in a dose-dependent manner. Across different species, showed significantly stronger neuronal responses of LP5 to several terpenes, such as (-)-linalool and α-terpineol, compared to other species. In , the neuronal activities in LP6 showed a greater response to methyl salicylate as compared to LP5. Overall, our results preliminarily illustrate the functional divergence of ORNs in the primary rhinaria of aphids from three subfamilies of Aphididae and provide a basis for better understanding the mechanism of olfactory recognition in aphids.
嗅觉对于介导蚜虫行为很重要，并且参与寄主定位和交配过程。触角初生感觉孔在蚜虫的化学感受中起关键作用。蚜亚科外周嗅觉系统的功能已得到深入研究，但对于蚜科的其他亚科却知之甚少。因此，选择了三种蚜虫来研究其对植物挥发物的嗅觉感受：（毛蚜亚科）、（绵蚜亚科）和（平翅绵蚜亚科）。在本研究中，通过扫描电子显微镜观察了无翅成虫触角感器的形态和分布。鉴定出三种形态类型（板形感器、腔锥形感器和毛形感器）；前两种分布在触角初生感觉孔上。发现一种蚜虫的初生感觉孔模式与另外两种不同，其在第4节有1个大板形感器（LP），第5节有2个LP，第6触角节有一组感器。之后，我们使用单感器记录（SSR）技术记录并比较了三种蚜虫初生感觉孔中不同板形感器对18种植物挥发物的神经元反应。结果表明，基于所测试气味剂的三种被研究蚜虫初生感觉孔的功能概况可分为三类，并且对某些类型的气味剂，尤其是萜类化合物表现出兴奋反应。在某种蚜虫中，LP6中的嗅觉感受神经元（ORN）对所有测试化学物质中的（±）-香茅醛反应最高，并且对（±）-香茅醛的敏感性高于对（+）-柠檬烯的敏感性。LP5中的ORN对α-蒎烯和（-）-β-蒎烯呈剂量依赖性的部分反应。在不同物种中，与其他物种相比，某种蚜虫的LP5对几种萜类化合物，如（-）-芳樟醇和α-松油醇，表现出明显更强的神经元反应。在另一种蚜虫中，与LP5相比，LP6中的神经元活动对水杨酸甲酯表现出更大的反应。总体而言，我们的结果初步阐明了蚜科三个亚科蚜虫初生感觉孔中ORN的功能差异，并为更好地理解蚜虫嗅觉识别机制提供了依据。
