Pawar Sahil V, Paranjape Sujay M, Kalowsky Grace K, Peiffer Michelle, McCartney Nate, Ali Jared G, Felton Gary W
Department of Entomology, The Pennsylvania State University, University Park, Pennsylvania, USA.
Plant Cell Environ. 2025 May;48(5):3647-3659. doi: 10.1111/pce.15353. Epub 2025 Jan 13.
Abiotic stressors, such as salt stress, can reduce crop productivity, and when combined with biotic pressures, such as insect herbivory, can exacerbate yield losses. However, salinity-induced changes to plant quality and defenses can in turn affect insect herbivores feeding on plants. This study investigates how salinity stress in tomato plants (Solanum Lycopersicum cv. Better Boy) impacts the behavior and performance of a devastating insect pest, the tomato fruitworm caterpillar (Helicoverpa zea). Through choice assays and performance experiments, we demonstrate that salt-stressed tomato plants are poor hosts for H. zea, negatively affecting caterpillar feeding preferences and growth rates. While changes in plant nutritional quality were observed, the primary factor influencing insect performance appears to be direct ionic toxicity, which significantly impairs multiple life history parameters of H. zea including survival, pupation, adult emergence, and fecundity. Plant defense responses show complex interactions between salt stress and herbivory, with two proteinase inhibitor genes - PIN2 and AspPI, showing a higher induced response to insect herbivory under salt conditions. However, plant defenses do not seem to be the main driver of reduced caterpillar performance on salt-treated plants. Furthermore, we report reduced oviposition by H. zea moths on salt-treated plants, which was correlated with altered volatile emissions. Our findings reveal that H. zea exhibits optimal host selection behaviours for both larval feeding and adult oviposition decisions, which likely contribute to its success as an agricultural pest. This research provides insights into the complex interactions between abiotic stress, plant physiology, and insect behaviour, with potential implications for pest management strategies in saline agricultural environments.
非生物胁迫因素，如盐胁迫，会降低作物产量，而当与生物胁迫因素，如昆虫取食相结合时，会加剧产量损失。然而，盐度诱导的植物质量和防御变化反过来又会影响以植物为食的昆虫食草动物。本研究调查了番茄植株（Solanum Lycopersicum cv. Better Boy）中的盐胁迫如何影响一种毁灭性害虫番茄果虫（Helicoverpa zea）的行为和表现。通过选择试验和性能实验，我们证明盐胁迫的番茄植株对棉铃虫来说是不良寄主，对幼虫的取食偏好和生长速率有负面影响。虽然观察到了植物营养质量的变化，但影响昆虫表现的主要因素似乎是直接的离子毒性，这显著损害了棉铃虫的多个生活史参数，包括存活、化蛹、成虫羽化和繁殖力。植物防御反应显示出盐胁迫和食草作用之间的复杂相互作用，两个蛋白酶抑制剂基因——PIN2和AspPI，在盐胁迫条件下对昆虫取食表现出更高的诱导反应。然而，植物防御似乎不是盐处理植株上幼虫表现降低的主要驱动因素。此外，我们报告了棉铃虫蛾在盐处理植株上的产卵减少，这与挥发性物质排放的改变有关。我们的研究结果表明，棉铃虫在幼虫取食和成虫产卵决策方面都表现出最佳的寄主选择行为，这可能有助于其成为一种农业害虫。这项研究深入了解了非生物胁迫、植物生理学和昆虫行为之间的复杂相互作用，对盐碱农业环境中的害虫管理策略具有潜在意义。
