Priming of pine defence against insect infestation

已知植物对植食性昆虫的诱导防御受侵染前暴露于环境线索的影响。对虫害指示线索的反应可以引发和改善植物防御。该项目解决了引发防御苏格兰松（樟子松）对叶蜂松叶蜂侵扰的分子生态学问题。已知苏格兰松对草食性D. pini幼虫对D.在幼虫取食之前，松树卵沉积在其针叶上。此外，苏格兰松增强了它对叶蜂卵的直接防御，当它以前暴露于D。松树性信息素到目前为止，对樟子松对白僵菌的启动防御机制还知之甚少。皮尼。相反，对于被子植物，研究表明，卵介导的启动防御幼虫取食依赖于植物转录组和植物激素和次生植物代谢产物浓度的显着变化。因此，我们将研究卵介导的樟子松防御机制。松幼虫我们将测试的假设，被子植物和裸子植物（在这里，P. sylvestris）显示一些共同的，保守的转录组和植物激素的反应，在这个启动过程。此外，我们将研究是否卵介导的，喂养诱导的次生松树代谢产物（在这里，苯丙素衍生物和植物甾醇）的浓度变化可以提供一个解释D的性能较差。松仁对以前的鸡蛋负载松树相比，无卵松树。我们还将探讨信息素介导的樟子松防御机制。松卵，并研究转录组和植物激素的反应，在这个引发过程。因此，我们还想研究这些反应是否与卵介导的防御幼虫的启动相似。这将提供证据表明，指示昆虫侵扰的刺激也会引起一般的“警报”反应。除了信息素介导的防御卵的机制，我们将进一步调查松暴露于叶蜂性信息素的生态效应。我们想测试是否不仅直接，而且间接防御反应卵（通过吸引卵寄生蜂）后，信息素暴露放大，是否对幼虫的直接防御也受到影响，以及是否产卵D。松树雌性表现出对松树防御其后代的反适应。

Induced defences of plants against herbivorous insect are known to be affected by exposure to environmental cues preceding the infestation. Response to infestation-indicating cues can prime and improve plant defences. This project addresses molecular-ecological questions on priming defence of Scots pine (Pinus sylvestris) against infestation by the sawfly Diprion pini. Scots pine is known to show improved defence against herbivorous D. pini larvae when it has responded to D. pini egg depositions on its needles prior to larval feeding. Furthermore, Scots pine enhances its direct defence against sawfly eggs when it has previously been exposed to D. pini sex pheromones. So far, little is known about the mechanisms of priming defence of P. sylvestris against D. pini. In contrast, for angiosperms, it is well studied that egg-mediated priming of defence against larval feeding relies on significant changes in the plant transcriptome and concentrations of phytohormones and secondary plant metabolites. Therefore, we will investigate mechanisms of egg-mediated priming of Scots pine defence against D. pini larvae. We will test the hypothesis that angiosperms and gymnosperms (here, P. sylvestris) show some common, conserved transcriptomic and phytohormonal responses in this priming process. Furthermore, we will study whether egg-mediated, feeding-induced changes in concentrations of secondary pine metabolites (here, phenylpropanoid derivatives and phytosterols) can offer an explanation for the worse performance of D. pini on previously egg-laden pine when compared to egg-free pine. We will also investigate mechanisms of pheromone-mediated priming of P. sylvestris defence against D. pini eggs and study the transcriptomic and phytohormonal responses in this priming process. Thereby, we also want to examine whether these responses show parallels to egg-mediated priming of defence against larvae. This would provide evidence that stimuli that indicate insect infestation also elicit general "alarm” responses. In addition to the mechanisms of pheromone-mediated defence against eggs, we will further investigate the ecological effects of pine exposure to sawfly sex pheromones. We want to test whether not only direct, but also indirect defence responses to eggs (by attracting egg parasitoids) are amplified after pheromone exposure, whether direct defence against larvae is also affected, and whether egg-laying D. pini females show counter-adaptations to pine defence against their offspring.