Plant silicon effects on insect feeding dynamics are influenced by plant nitrogen availability
Plant silicon effects on insect feeding dynamics are influenced by plant nitrogen availability
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DOI：
10.1111/eea.12750
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发表时间：
2019-02
影响因子：
1.9
通讯作者：
Eric R. D. Moise;J. McNeil;S. Hartley;H. Henry
中科院分区：
文献类型：
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作者：
Eric R. D. Moise;J. McNeil;S. Hartley;H. Henry
尽管越来越多的证据表明，硅（Si）基植物防御有效地降低了叶片的适口性和消化率，从而影响了昆虫食草动物的营养吸收，但关于这是如何受到外在和内在因素影响的知之甚少。例如，食草动物是否对含硅的劣质饲料表现出补偿性摄食，或者在高氮可用性提高植物质量的农业生态系统中，硅防御是否不太有效？为了研究氮硅互作对昆虫摄食的影响，以玉米为材料，进行了昆虫生产性能和补偿摄食生物测定。（禾本科），和真正的粘虫，Pseudeletia unipuncta Haworth（鳞翅目：夜蛾科）。在性能测定中，与对照相比，单独添加Si导致幼虫死亡率增加，这可能是因为下颌发育不良的早期幼虫不能有效进食。然而，幼虫喂养的植物与Si和N处理的存活率比仅与Si处理的植物，虽然蛹的质量没有不同的治疗。在我们的补偿试验中，Si的添加减少了玉米的消耗，但增加了粘虫的近似消化率和N同化效率，这表明增强了摄食后的摄食生理，而不是补偿性食物摄入，可能是缺乏Si对蛹重的影响。总体而言，我们的研究结果表明，类似于其他化学和机械防御，植物硅防御的有效性受到植物营养状况和消费者补偿能力的影响。
Although there is growing evidence that silicon (Si)‐based plant defenses effectively reduce both the palatability and digestibility of leaves, and thus impact nutrient assimilation by insect herbivores, much less is known about how this is affected by extrinsic and intrinsic factors. For example, do herbivores exhibit compensatory feeding on poor‐quality diets with Si or are Si defenses less effective in agroecosystems where high N availability increases plant quality? To investigate the interactive effects of N and Si on insect feeding, we conducted insect performance and compensatory feeding bioassays using maize, Zea mays L. (Poaceae), and the true armyworm, Pseudeletia unipuncta Haworth (Lepidoptera: Noctuidae). In the performance assay, the addition of Si alone resulted in increased larval mortality compared with the controls, likely because early instars with poorly developed mandibles could not feed effectively. However, larvae fed on plants treated with both Si and N survived better than on plants treated with Si only, although pupal mass did not differ between treatments. In our compensatory assay, Si addition reduced maize consumption, but increased both armyworm approximate digestibility and N assimilation efficiency, suggesting that enhanced post‐ingestion feeding physiology, rather than compensatory food intake, could have accounted for the lack of Si effects on pupal weight. Overall, our results demonstrate that, similar to other chemical and mechanical defenses, the effectiveness of plant Si defense is influenced by plant nutrient status and consumer compensatory ability.