Abstract Eucalypts (including Angophora, Corymbia, Eucalyptus) comprise a large and hyper-diverse group of ecologically important trees providing habitats for many forest dependent species. Eucalypts synthesize a plethora of specialized metabolites that moderate biotic and abiotic interactions. Until now, studies on eucalypt volatile organic compounds (VOCs) have primarily focused on isoprene and monoterpenoid emission from forest plantations. As a result, little is known about the volatile profile of adult eucalypt trees under natural conditions. Here we present an in-depth study of leaf and flower branch volatile emissions from mature trees of nine eucalypt species in south-eastern Australia. VOCs were captured using a non-invasive, dynamic flow-through enclosure technique enabling volatile collection into adsorbent cartridges, analyzed by GC–MS. For comparison, terpenoid extracts were also analyzed. Complex emission profiles composed of more than 100 different VOCs were recorded, including isoprene, mono- and sesquiterpenoids, and benzenoids. Emission profiles from eucalypts were highly species-specific, tissue dependent, diurnally regulated and affected by environmental conditions. The composition of stored terpenoids did not mirror the emission profiles, supporting differential regulation of formation, storage and emission of terpenoids. These results provide important knowledge about the entangled dynamics of eucalypt volatiles, and have wider implications for predictions of volatile emission from eucalypt forests and plantations.

中文翻译：

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桉树叶和花挥发物排放的纠缠动力学

摘要 桉树（包括 Angophora、Corymbia、Eucalyptus）包括一大群高度多样化的具有重要生态意义的树木，为许多依赖森林的物种提供栖息地。桉树合成了大量可调节生物和非生物相互作用的特殊代谢物。到目前为止，对桉树挥发性有机化合物 (VOC) 的研究主要集中在森林种植园的异戊二烯和单萜类化合物排放上。因此，人们对自然条件下成年桉树的挥发性特征知之甚少。在这里，我们对澳大利亚东南部九种桉树树种的成熟树的叶和花枝挥发性排放物进行了深入研究。使用非侵入性、动态流通外壳技术捕获 VOC，可将挥发性物质收集到吸附剂盒中，并通过 GC-MS 进行分析。为了比较，还分析了萜类提取物。记录了由 100 多种不同 VOC 组成的复杂排放曲线，包括异戊二烯、单萜和倍半萜类化合物以及苯类。桉树的排放特征具有高度的物种特异性、组织依赖性、昼夜调节和环境条件的影响。存储的萜类化合物的组成并未反映排放特征，支持萜类化合物的形成、存储和排放的差异调节。这些结果提供了关于桉树挥发物纠缠动力学的重要知识，并对桉树森林和人工林挥发物排放的预测具有更广泛的意义。单萜和倍半萜，以及苯类。桉树的排放特征具有高度的物种特异性、组织依赖性、昼夜调节和环境条件的影响。存储的萜类化合物的组成并未反映排放特征，支持萜类化合物的形成、存储和排放的差异调节。这些结果提供了关于桉树挥发物纠缠动力学的重要知识，并对桉树森林和人工林挥发物排放的预测具有更广泛的意义。单萜和倍半萜，以及苯类。桉树的排放特征具有高度的物种特异性、组织依赖性、昼夜调节和环境条件的影响。存储的萜类化合物的组成并未反映排放特征，支持萜类化合物的形成、存储和排放的差异调节。这些结果提供了关于桉树挥发物纠缠动力学的重要知识，并对桉树森林和人工林挥发物排放的预测具有更广泛的意义。萜类化合物的储存和排放。这些结果提供了关于桉树挥发物纠缠动力学的重要知识，并对桉树森林和人工林挥发物排放的预测具有更广泛的意义。萜类化合物的储存和排放。这些结果提供了关于桉树挥发物纠缠动力学的重要知识，并对桉树森林和人工林挥发物排放的预测具有更广泛的意义。