Benzoxazinoids are a class of indole-derived plant chemical defenses comprising compounds with a 2-hydroxy-2H-1,4-benzoxazin-3(4H)-one skeleton and their derivatives. These phytochemicals are widespread in grasses, including important cereal crops such as maize, wheat and rye, as well as a few dicot species, and display a wide range of antifeedant, insecticidal, antimicrobial, and allelopathic activities. Although their overall effects against insect herbivores are frequently reported, much less is known about how their modes of action specifically influence insect physiology. The present review summarizes the biological activities of benzoxazinoids on chewing, piercing-sucking, and root insect herbivores. We show how within-plant distribution modulates the exposure of different herbivore feeding guilds to these defenses, and how benzoxazinoids may act as toxins, feeding deterrents and digestibility-reducing compounds under different conditions. In addition, recent results on the metabolism of benzoxazinoids by insects and their consequences for plant-herbivore interactions are addressed, as well as directions for future research.

中文翻译：

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植物防御和草食动物的防御：苯并嗪类和昆虫草食动物。

苯并恶嗪类化合物是一类由吲哚衍生的植物化学防御剂，包括具有2-羟基-2H-1,4-苯并恶嗪-3（4H）-一个骨架的化合物及其衍生物。这些植物化学物质广泛存在于草丛中，包括重要的谷物作物，例如玉米，小麦和黑麦，以及一些双子叶植物，并表现出广泛的拒食，杀虫，抗菌和化感作用。尽管经常报道它们对昆虫食草动物的总体作用，但关于它们的作用方式如何特别影响昆虫生理的知之甚少。本综述总结了苯并恶嗪类化合物对咀嚼，刺吸和根部昆虫食草动物的生物活性。我们展示了植物内部的分布如何调节不同草食动物喂食公会对这些防御的暴露，以及苯并恶嗪类化合物如何在不同条件下充当毒素，喂养威慑剂和降低消化率的化合物。此外，本文还讨论了昆虫对苯并恶嗪类化合物代谢的最新研究结果及其对植物与草食动物相互作用的影响，以及今后的研究方向。