We review a recently discovered white spruce (Picea glauca) chemical defense against spruce budworm (Choristoneura fumiferana) involving hydroxyacetophenones. These defense metabolites detected in the foliage accumulate variably as the aglycons, piceol and pungenol, or the corresponding glucosides, picein and pungenin. We summarize current knowledge of the genetic, genomic, molecular, and biochemical underpinnings of this defense and its effects on C. fumiferana. We present an update with new results on the ontogenic variation and the phenological window of this defense, including analysis of transcript responses in P. glauca to C. fumiferana herbivory. We also discuss this chemical defense from an evolutionary and a breeding context.

中文翻译：

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白云杉中的羟基苯乙酮对云杉芽虫的防御作用。

我们回顾了最近发现的白云杉（Picea glauca）对涉及羟基苯乙酮的云杉芽虫（Choristoneura fumiferana）的化学防御作用。在叶子中检测到的这些防御代谢物以苷元、白云杉醇和红松酚或相应的糖苷、云杉元和红松素的形式不同地积累。我们总结了这种防御的遗传、基因组、分子和生化基础及其对C. fumiferana的影响的当前知识。我们提出了关于这种防御的个体发生变异和物候窗口的新结果的更新，包括对P. glauca对C. fumiferana草食性的转录反应的分析。我们还从进化和育种的角度讨论了这种化学防御。