Induction of plant defences can show various levels of localization, which can optimize their efficiency. Locally induced responses may be particularly important in large plants, such as trees, that show high variability in traits and herbivory rates across their canopies. We studied the branch-localized induction of polyphenols, volatiles (VOCs), and changes in leaf protein content in Carpinus betulus L., Quercus robur L., and Tilia cordata L. in a common garden experiment. To induce the trees, we treated ten individuals per species on one branch with methyl jasmonate. Five other individuals per species served as controls. We measured the traits in the treated branches, in control branches on treated trees, and in control trees. Additionally, we ran predation assays and caterpillar food-choice trials to assess the effects of our treatment on other trophic levels. Induced VOCs included mainly mono- and sesquiterpenes. Their production was strongly localized to the treated branches in all three tree species studied. Treated trees showed more predation events than control trees. The polyphenol levels and total protein content showed a limited response to the treatment. Yet, winter moth caterpillars preferred leaves from control branches over leaves from treated branches within C. betulus individuals and leaves from control Q. robur individuals over leaves from treated Q. robur individuals. Our results suggest that there is a significant level of localization in induction of VOCs and probably also in unknown traits with direct effects on herbivores. Such localization allows trees to upregulate defences wherever and whenever they are needed.

植物防御的归纳可以显示各种级别的本地化，从而可以优化其效率。在大型植物（例如树木）中，局部诱导的响应可能尤其重要，这些大型植物在其冠层之间的性状和草食率表现出很高的变异性。我们研究了多酚，挥发物（VOC）的分支定位诱导作用，以及甜菜Car，栎Qu和紫T的叶片蛋白质含量变化L.在一个普通的花园实验中。为了诱导树木，我们在每个树枝上用茉莉酸甲酯处理了10个个体。每个物种另外五个人作为对照。我们测量了处理过的树枝，处理过的树木的对照树枝和对照树中的性状。此外，我们进行了捕食试验和毛毛虫食物选择试验，以评估我们的治疗对其他营养水平的影响。诱导的VOC主要包括单萜和倍半萜。在所研究的所有三个树种中，它们的产生都强烈地定位于处理过的树枝上。处理过的树木比对照树显示出更多的掠食事件。多酚水平和总蛋白含量显示出对治疗的有限反应。然而，冬季蛾毛虫更喜欢对照树枝上的叶子而不是处理过的树枝上的叶子。桔梗个体和对照Q. robur个体的叶片超过处理过的Q. robur个体的叶片。我们的结果表明，在挥发性有机化合物的诱导中可能存在较高水平的定位，并且可能还存在对草食动物有直接影响的未知性状。这种本地化使树木无论何时何地都可以上调防御力。