Contact chemosensation, or tasting, is a complex process governed by nonvolatile phytochemicals that tell host-seeking insects whether they should accept or reject a plant. During this process, insect gustatory receptors (GRs) contribute to deciphering a host plant's metabolic code. GRs recognise many different classes of nonvolatile compounds; some GRs are likely to be narrowly tuned and others, broadly tuned. Although primary and/or secondary plant metabolites influence the insect's feeding choice, their decoding by GRs is challenging, because metabolites in planta occur in complex mixtures that have additive or inhibitory effects; in diverse forms composed of structurally unrelated molecules; and at different concentrations depending on the plant species, its tissue and developmental stage. Future studies of the mechanism of insect herbivore GRs will benefit from functional characterisation taking into account the spatio-temporal dynamics and diversity of the plant's metabolome. Metabolic information, in turn, will help to elucidate the impact of single ligands and complex natural mixtures on the insect's feeding choice.

中文翻译：

---

食草动物对植物化学物质的接触化学感知

接触化学感受或品尝是一个复杂的过程，由非易失性植物化学物质控制，它告诉寻找宿主的昆虫它们应该接受还是拒绝植物。在此过程中，昆虫的味觉受体（GRs）有助于破译宿主植物的代谢密码。GRs识别许多不同类别的非挥发性化合物；有些遗传资源可能会进行狭义调整，而其他遗传资源则可能进行广义调整。尽管主要和/或次要植物代谢物会影响昆虫的取食选择，但由于植物中的代谢物，利用遗传资源对其进行解码具有挑战性发生在具有加和或抑制作用的复杂混合物中；由结构上不相关的分子组成的各种形式；根据植物的种类，组织和发育阶段的不同，其浓度也不同。考虑到时空动态和植物代谢组的多样性，昆虫食草动物GRs机理的未来研究将受益于功能表征。反过来，代谢信息将有助于阐明单一配体和复杂的天然混合物对昆虫摄食选择的影响。