Plants not only respond to herbivorous damage but adjust their defense system after egg deposition by pest insects. Thereby, parasitoids use oviposition-induced plant volatiles to locate their hosts. We investigated the olfactory behavioral responses of Trichogramma pretiosum Riley, 1879 (Hymenoptera: Trichogrammatidae) to volatile blends emitted by maize (Zea mays L.) with singular and stacked events after oviposition by Spodoptera frugiperda Smith, 1797 (Hymenoptera: Trichogrammatidae) moths. Additionally, we examined possible variations in gene expression and on oviposition-induced volatiles. We used a Y-tube olfactometer to test for the wasp responses to volatiles released by maize plants oviposited by S. frugiperda and not-oviposited plants. Using the real-time PCR technique (qRT-PCR), we analyzed the expression of lipoxygenase and three terpene synthases genes, which are enzymes involved in the synthesis of volatile compounds that attract parasitoids of S. frugiperda. Olfactometer tests showed that T. pretiosum is strongly attracted by volatiles from transgenic maize emitted by S. frugiperda oviposition (VTPRO 3, more than 75% individuals were attracted). The relative expression of genes TPS10, LOX e STC was higher in transgenic hybrids than in the conventional (isogenic line) hybrids. The GC-MS analysis revealed that some volatile compounds are released exclusively by transgenic maize. This study provides evidence that transgenic hybrids enhanced chemical cues under oviposition-induction and helped to increase T. pretiosum efficiency in S. frugiperda control. This finding shows that among the evaluated hybrids, genetically modified hybrids can improve the biological control programs, since they potentialize the egg parasitoid foraging, integrating pest management.

中文翻译：

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转基因玉米诱导的赤眼蜂（膜翅目：赤眼蜂科）对挥发物的嗅觉反应


植物不仅对食草性损害做出反应，而且在害虫产卵后调整其防御系统。因此，寄生蜂利用产卵诱导的植物挥发物来定位其宿主。我们研究了嗅觉行为反应赤眼蜂Riley，1879（膜翅目：赤眼蜂科）对玉米释放的挥发性混合物（玉米L.) 产卵后发生单一事件和堆叠事件草地贪夜蛾Smith, 1797（膜翅目：赤眼蜂科）飞蛾。此外，我们还检查了基因表达和产卵诱导的挥发物的可能变化。我们使用 Y 形管嗅觉计来测试黄蜂对由产卵的玉米植物释放的挥发物的反应。草地贪夜蛾和非产卵植物。使用实时 PCR 技术 (qRT-PCR)，我们分析了脂氧合酶和三种萜合酶基因的表达，这些酶参与合成吸引寄生蜂的挥发性化合物。果蝇。嗅觉计测试表明T. pretiosum被转基因玉米散发的挥发物强烈吸引草地贪夜蛾产卵（VTPRO 3，超过75%的个体被吸引）。转基因杂种中基因 TPS10、LOX e STC 的相对表达高于传统（等基因系）杂种。 GC-MS 分析表明，一些挥发性化合物仅由转基因玉米释放。这项研究提供的证据表明，转基因杂种在产卵诱导下增强了化学信号，并有助于增加T. pretiosum效率草地贪夜蛾控制。 这一发现表明，在评估的杂交品种中，转基因杂交品种可以改善生物控制计划，因为它们可以促进卵寄生蜂的觅食，从而整合害虫防治。