Molecular Interaction Ecology, German Center for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig; PuschStraße 4, 04103, Leipzig, Germany.
Institute of Biodiversity, Friedrich-Schiller-Universität-Jena; DornburgerStraße 159, 07743 Jena, Germany.
J Exp Bot. 2021 Dec 4;72(22):7909-7926. doi: 10.1093/jxb/erab370.
Studies on plant-mediated interactions between root parasitic nematodes and aboveground herbivores are rapidly increasing. However, outcomes for the interacting organisms vary, and the mechanisms involved remain ambiguous. We hypothesized that the impact of root infection by the root-knot nematode Meloidogyne incognita on the performance of the aboveground caterpillar Spodoptera exigua is modulated by the nematode's infection cycle. We challenged root-knot nematode-infected tomato plants with caterpillars when the nematode's infection cycle was at the invasion, galling, and reproduction stages. We found that M. incognita root infection enhanced S. exigua performance during the galling stage, while it did not affect the caterpillar's performance at the invasion and reproduction stages. Molecular and chemical analyses performed at the different stages of the nematode infection cycle revealed that M. incognita root infection systemically affected the jasmonic acid-, salicylic acid-, and abscisic acid-related responses, as well as the changes in the leaf metabolome triggered during S. exigua feeding. The M. incognita-induced leaf responses varied over the nematode's root infection cycle. These findings suggest that specific leaf responses triggered systemically by the nematode at its different life-cycle stages underlie the differential impact of M. incognita on plant resistance against the caterpillar S. exigua.
关于植物介导的根寄生线虫和地上食草动物之间相互作用的研究正在迅速增加。然而，相互作用的生物体的结果各不相同，所涉及的机制仍不清楚。我们假设，根结线虫 Meloidogyne incognita 对地上毛毛虫 Spodoptera exigua 的性能的影响是由线虫的感染周期调节的。当线虫的感染周期处于入侵、结瘤和繁殖阶段时，我们用毛毛虫挑战感染了根结线虫的番茄植物。我们发现，M. incognita 根感染在结瘤阶段增强了 S. exigua 的性能，而在入侵和繁殖阶段对毛毛虫的性能没有影响。在不同的线虫感染周期阶段进行的分子和化学分析表明，M. incognita 根感染系统地影响了茉莉酸、水杨酸和脱落酸相关的反应，以及 S. exigua 取食过程中引发的叶片代谢组的变化。M. incognita 诱导的叶片反应随线虫的根感染周期而变化。这些发现表明，线虫在不同的生命周期阶段系统地引发的特定叶片反应是 M. incognita 对线虫对植物抵抗毛毛虫 S. exigua 的影响的差异的基础。
