Divergence of chemical plant defence mechanisms within the Brassicaceae can be utilized to identify means against specialized pest insects. Using a bioassay‐driven approach, we (a) screened 24 different Brassica napus cultivars, B. napus resyntheses and related brassicaceous species for natural plant resistance against feeding adults of the pollen beetle (Brassicogethes aeneus), (b) tested for gender‐specific feeding resistance, (c) analysed the flower bud metabolomes by a non‐targeted approach and (d) tested single candidate compounds for their antifeedant activity. (a) In no‐choice assays, beetles were allowed to feed on intact plants. Reduced feeding activity was mainly observed on Sinapis alba and Barbarea vulgaris but not on B. napus cultivars. (b) Males fed less and discriminated more in feeding than females. (c) Correlation of the metabolite abundances with the beetles' feeding activity revealed several glucosinolates, phenylpropanoids, flavonoids and saponins as potential antifeedants. (d) These were tested in dual‐bud‐choice assays developed for medium‐throughput compound screening. Application of standard compounds on single oilseed rape flower buds revealed highly deterrent effects of glucobarbarin, oleanolic acid and hederagenin. These results help to understand chemical plant defence in the Brassicaceae and are of key importance for further breeding strategies for insect‐resistant oilseed rape cultivars.

中文翻译：

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代谢组学和花蕾操纵方法揭示了十字花科对花粉甲虫的化学防御作用

十字花科内的化学植物防御机制的多样性可用于确定针对专门害虫的手段。使用生物分析驱动的方法，我们（a）筛选了24种不同的甘蓝型油菜品种，甘蓝型油菜再合成和相关的十字花科物种对花粉甲虫（Brassicogethes aeneus）的成年饲喂的天然植物抗性，（b）测试了针对性别的进食抗性，（c）通过非靶向方法分析了花蕾代谢组，（d）测试了单一候选化合物的抗饲料活性。（a）在非选择试验中，允许甲虫以完整的植物为食。进食活性降低主要在白叶芥和寻常巴氏杆菌中观察到但不适用于甘蓝型油菜。（b）男性的进食量少于女性，并且在进食方面有更多的歧视。（c）代谢物丰度与甲虫的摄食活性之间的关系表明，有几种芥子油苷，苯基丙烷，类黄酮和皂苷是潜在的拒食剂。（d）在针对中通量化合物筛选而开发的双预算选择分析中进行了测试。在单一油料油菜花芽上施用标准化合物显示出了高糖素，齐墩果酸和二十碳三烯皂苷的高度抑制作用。这些结果有助于了解十字花科的化学植物防御作用，对于进一步提高抗虫油菜品种的育种策略至关重要。