Department of Entomology, LSU Agricultural Center, 404 Life Science Building, Baton Rouge, LA 70803, USA.
Department of Biological and Agricultural Engineering, LSU Agricultural Center, 149 E. B. Doran Building, Baton Rouge, LA 70803, USA.
J Econ Entomol. 2023 Aug 10;116(4):1196-1204. doi: 10.1093/jee/toad091.
Previous research suggested that positively charged zein nanoparticles [(+)ZNP] were toxic to neonates of Anticarsia gemmatalis Hübner and deleterious to noctuid pests. However, specific modes of action for ZNP have not been elucidated. Diet overlay bioassays attempted to rule out the hypothesis that A. gemmatalis mortality was caused by surface charges from component surfactants. Overlay bioassays indicated that negatively charged zein nanoparticles [(-)ZNP] and its anionic surfactant, sodium dodecyl sulfate (SDS), exhibited no toxic effects when compared to the untreated check. Nonionic zein nanoparticles [(N)ZNP] appeared to increase mortality compared to the untreated check, though larval weights were unaffected. Overlay results for (+)ZNP and its cationic surfactant, didodecyldimethylammonium bromide (DDAB), were found to be consistent with former research indicating high mortalities, and thus, dosage response curves were conducted. Concentration response tests found the LC50 for DDAB on A. gemmatalis neonates was 208.82 a.i./ml. To rule out possible antifeedant capabilities, dual choice assays were conducted. Results indicated that neither DDAB nor (+)ZNP were antifeedants, while SDS reduced feeding when compared to other treatment solutions. Oxidative stress was tested as a possible mode of action, with antioxidant levels used as a proxy for reactive oxygen species (ROS) in A. gemmatalis neonates, which were fed diet treated with different concentrations of (+)ZNP and DDAB. Results indicated that both (+)ZNP and DDAB decreased antioxidant levels compared to the untreated check, suggesting that both (+)ZNP and DDAB may inhibit antioxidant levels. This paper adds to the literature on potential modes of action by biopolymeric nanoparticles.
先前的研究表明，带正电荷的玉米醇溶蛋白纳米颗粒 [(+)ZNP] 对 Anticarsia gemmatalis Hübner 的幼虫有毒，对夜蛾类害虫有害。然而，ZNP 的具体作用模式尚未阐明。饮食覆盖生物测定试图排除 A. gemmatalis 死亡率是由组成表面活性剂的表面电荷引起的假设。覆盖生物测定表明，与未处理的对照相比，带负电荷的玉米醇溶蛋白纳米颗粒 [(-)ZNP] 和其阴离子表面活性剂十二烷基硫酸钠 (SDS) 没有表现出毒性作用。与未处理的对照相比，非离子玉米醇溶蛋白纳米颗粒 [(N)ZNP] 似乎增加了死亡率，尽管幼虫体重不受影响。(+)ZNP 和其阳离子表面活性剂双十二烷基二甲基溴化铵 (DDAB) 的覆盖结果与之前的研究结果一致，表明死亡率很高，因此进行了剂量反应曲线测试。浓度反应测试发现，DDAB 对 A. gemmatalis 幼虫的 LC50 为 208.82 a.i./ml。为了排除可能的拒食作用，进行了双选择测定。结果表明，DDAB 和 (+)ZNP 都不是拒食剂，而 SDS 与其他处理溶液相比，降低了取食量。氧化应激被测试为一种可能的作用模式，抗氧化剂水平被用作 A. gemmatalis 幼虫中活性氧 (ROS) 的替代物，这些幼虫食用用不同浓度的 (+)ZNP 和 DDAB 处理过的饮食。结果表明，与未处理的对照相比，(+)ZNP 和 DDAB 都降低了抗氧化剂水平，这表明 (+)ZNP 和 DDAB 都可能抑制抗氧化剂水平。本文为生物聚合物纳米颗粒的潜在作用模式增加了文献资料。
