State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China.
Shenzhen Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, 518120, China.
BMC Biol. 2024 Mar 13;22(1):61. doi: 10.1186/s12915-024-01862-9.
Ecosystems are brimming with myriad compounds, including some at very low concentrations that are indispensable for insect survival and reproduction. Screening strategies for identifying active compounds are typically based on bioassay-guided approaches.
Here, we selected two candidate odorant receptors from a major pest of cruciferous plants-the diamondback moth Plutella xylostella-as targets to screen for active semiochemicals. One of these ORs, PxylOR16, exhibited a specific, sensitive response to heptanal, with both larvae and adult P. xylostella displaying heptanal avoidance behavior. Gene knockout studies based on CRISPR/Cas9 experimentally confirmed that PxylOR16 mediates this avoidance. Intriguingly, rather than being involved in P. xylostella-host plant interaction, we discovered that P. xylostella recognizes heptanal from the cuticular volatiles of the parasitoid wasp Cotesia vestalis, possibly to avoid parasitization.
Our study thus showcases how the deorphanization of odorant receptors can drive discoveries about their complex functions in mediating insect survival. We also demonstrate that the use of odorant receptors as a screening platform could be efficient in identifying new behavioral regulators for application in pest management.
生态系统中充满了无数的化合物，包括一些浓度非常低的化合物，这些化合物对昆虫的生存和繁殖是必不可少的。用于识别活性化合物的筛选策略通常基于基于生物测定指导的方法。
在这里，我们选择了十字花科蔬菜主要害虫小菜蛾的两个候选气味受体作为目标，以筛选活性信息素。这些 OR 中的一种，PxylOR16，对庚醛表现出特异性、敏感性反应，小菜蛾幼虫和成虫都表现出对庚醛的回避行为。基于 CRISPR/Cas9 的基因敲除研究实验证实，PxylOR16 介导了这种回避。有趣的是，我们发现 P. xylostella 识别的庚醛不是来自其寄主植物，而是来自寄生蜂 Cotesia vestalis 的表皮挥发物，可能是为了避免被寄生。
因此，我们的研究展示了如何通过去孤儿化气味受体来推动对其在介导昆虫生存方面的复杂功能的发现。我们还证明，使用气味受体作为筛选平台可以有效地识别新的行为调节剂，用于害虫管理。
