Top-down effects from parasitoids may mediate plant defence and plant fitness
Top-down effects from parasitoids may mediate plant defence and plant fitness
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寄生蜂的自上而下的影响可能会介导植物防御和植物适应性
DOI：
10.1111/1365-2435.13617
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发表时间：
2020
影响因子：
5.2
通讯作者：
Felton, Gary w.
中科院分区：
文献类型：
--
作者：
Tan, C.-W.;Peiffer, Michelle;Ali, Jared G.;Luthe, D.S.;Felton, Gary w.
植物面临着许多环境胁迫，这些胁迫会影响它们的生存、发育和适应性。昆虫是自然界中种类最多、数量最多、最具威胁性的食草动物。因此，植物产生直接的化学和物理防御，以减少食草动物。它们还释放挥发物来招募天敌，间接保护它们免受食草动物的侵害。寄生蜂的招募可以提高植物的适应性，因为它们最终会杀死寄主昆虫。最近的研究表明，寄生蜂可以通过调节植食性昆虫的口腔分泌物间接介导植物的防御。除了寄生蜂在减少食草动物生存方面的直接好处外，我们测试了与非寄生毛虫相比，寄生毛虫诱导防御的减少是否可以降低与防御表达相关的成本。我们提供的证据表明，用寄生毛虫的唾液处理的番茄植株具有显着更高的适应性参数，包括增加的花朵数量（16.3%）和更重的果实重量（13.5%）。由于植物生长没有实际的食草动物，这些健身参数的较高值是由于诱导防御的成本较低，而不是由于减少寄生毛虫的食草动物。此外，与对照（未处理）植物相比，当母体植物预先暴露于寄生食草动物处理时，所产生的种子萌发时间更短，萌发率更高。总体而言，唾液的施用不会导致后代防御反应的跨代启动。然而，暴露于毛虫唾液的亲本的后代比未暴露的亲本的后代具有较低的组成水平和较高的诱导水平的胰蛋白酶抑制剂。这项研究表明，被寄生的毛虫的唾液可以调节植物防御，并进一步证明，在没有草食动物喂养的情况下，植物防御的较低诱导与植物适合度的提高有关。这表明诱导植物防御是昂贵的。在本文的支持信息中可以找到免费的简明语言摘要。
Plants face many environmental stresses that can impact their survival, development and fitness. Insects are the most diverse, abundant and threatening herbivores in nature. As a consequence, plants produce direct chemical and physical defences to reduce herbivory. They also release volatiles to recruit natural enemies that indirectly protect them from herbivory. The recruitment of parasitic wasps can benefit plant fitness because they ultimately kill their insect hosts.Recently, studies showed that parasitoids can indirectly mediate plant defences by modulating herbivore oral secretions. In addition to the direct benefits of parasitoids in terms of reducing herbivore survival, we tested if the reduction in induced defences by parasitized caterpillars compared to non‐parasitized caterpillars may reduce the costs associated with defence expression.We provide evidence that tomato plants treated with saliva from parasitized caterpillars have significantly higher fitness parameters including increased flower numbers (16.3%) and heavier fruit weight (13.5%), compared to plants treated with saliva from non‐parasitized caterpillars. Since plants were grown without actual herbivores, the higher values for these fitness parameters were due to lower costs of induced defences and not due to reduced herbivory by parasitized caterpillars. Furthermore, the resulting seed germination time was shorter and the germination rate was higher when the maternal plants were previously exposed to parasitized herbivore treatment compared to control (non‐treated) plants.Overall, application of saliva did not result in transgenerational priming of offspring defence responses. However, offspring of parents exposed to caterpillar saliva had lower constitutive levels and higher induced levels of trypsin inhibitor than offspring from unexposed parents.This study shows that the saliva of parasitized caterpillars can modulate plant defences and further demonstrates that the lower induction of plant defences is associated with elevated plant fitness in the absence of herbivore feeding, suggesting that induced plant defences are costly.A free Plain Language Summary can be found within the Supporting Information of this article.