State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China.
School of Plant Protection, Jilin Agricultural University, Changchun, China.
Insect Mol Biol. 2020 Aug;29(4):381-390. doi: 10.1111/imb.12643. Epub 2020 Apr 28.
Common ragweed (Ambrosia artemisiifolia) is a notorious invasive weed that has spread across most temperate regions of the world. The beetle (Ophraella communa) is considered to be an effective control agent against A. artemisiifolia. As an oligophagous insect, its olfactory system is extremely important for host seeking in the wild. To the best of our knowledge, there is no report on the molecular mechanisms underlying olfaction recognition in this beetle. Hence, in this study, we characterized the odorant receptor co-receptor of O. communa and named it as 'OcomORco'. Real-time quantitative PCR (qRT-PCR) showed that, compared to the control treatment, RNA interference (RNAi) strongly reduced the expression of OcomORco by 89% in male and 90% in female beetles. Electroantennogram assay showed that the antennal response of both male and female beetles to four volatiles of A. artemisiifolia was significantly reduced. The injected male or female beetles lost their preference for plant leaves as observed in the behavioural tests. In addition, disruption of the expression of OcomORco resulted in a reduction of oviposition, while there was no difference in larval hatching rate between control and knockdown females. We demonstrated that OcomORco plays a vital role in olfactory perception and host search in O. communa, and it is involved in oviposition in an indirect way.
普通豚草（Ambrosia artemisiifolia）是一种臭名昭著的入侵杂草，已遍布世界上大多数温带地区。芫菁（Ophraella communa）被认为是防治 A. artemisiifolia 的有效控制剂。作为一种寡食性昆虫，其嗅觉系统对野外的宿主寻找至关重要。据我们所知，目前尚无关于该芫菁嗅觉识别分子机制的报道。因此，在这项研究中，我们对 O. communa 的气味受体共受体进行了表征，并将其命名为“OcomORco”。实时定量 PCR（qRT-PCR）显示，与对照处理相比，RNA 干扰（RNAi）使雄性和雌性芫菁中的 OcomORco 表达分别强烈降低了 89%和 90%。触角电位测定表明，雄性和雌性芫菁对 A. artemisiifolia 的四种挥发物的触角反应均显著降低。行为测试表明，注射后的雄性或雌性芫菁对植物叶片失去了偏好。此外，破坏 OcomORco 的表达导致产卵量减少，而对照和击倒的雌性幼虫孵化率没有差异。我们证明，OcomORco 在 O. communa 的嗅觉感知和宿主搜索中起着至关重要的作用，并且它以间接的方式参与产卵。
