The fall armyworm (FAW), Spodoptera frugiperda, is a polyphagous insect pest feeding on many host plants, including some major crops such as corn and rice. This pest has also developed resistance to many insecticides. Recent genome and transcriptome sequencing efforts identified 117–425 P450 genes in the FAW, but their function in detoxifying plant toxins and insecticides is largely unknown. This study found that a P450 gene, SfCYP321A8, is upregulated in the first instar FAW larvae fed on deltamethrin. A transgenic FAW overexpressing SfCYP321A8 was produced to investigate its function in deltamethrin resistance. Transgenic FAW expressing the gene coding for a P450 known to metabolize deltamethrin in Tribolium castaneum, TcCYP6BQ9, was also produced. P450 genes are highly expressed in different tissues of transgenic larvae. The P450 activity in the midgut and fat body of both transgenic FAW lines is significantly higher than in wild-type larvae. Deltamethrin bioassays showed that the transgenic larvae expressing SfCYP321A8 or TcCYP6BQ9 are 10.3- or 15.3-fold more tolerant, respectively, than the wild-type larvae. These studies report on the production of FAW transgenic lines expressing P450 genes and show that SfCYP321A8 contributes to deltamethrin resistance in FAW. The transformation methods developed could be used in functional genomics studies in FAW and other lepidopteran pests.

秋粘虫 (FAW)草地夜蛾是一种多食性害虫，以许多寄主植物为食，包括一些主要作物，如玉米和水稻。这种害虫还对许多杀虫剂产生了抗药性。最近的基因组和转录组测序工作在 FAW 中鉴定了 117-425 个 P450 基因，但它们在解毒植物毒素和杀虫剂方面的功能在很大程度上是未知的。该研究发现，在以溴氰菊酯为食的一龄秋粘虫幼虫中，P450 基因SfCYP321A8上调。生产过表达SfCYP321A8的转基因 FAW以研究其在溴氰菊酯抗性中的功能。转基因秋粘虫表达 P450 的基因编码，已知该 P450 可代谢Tribolium castaneum 中的溴氰菊酯，TcCYP6BQ9也产生了。P450 基因在转基因幼虫的不同组织中高度表达。两种转基因秋粘虫系的中肠和脂肪体中的 P450 活性显着高于野生型幼虫。溴氰菊酯生物测定表明，表达SfCYP321A8或TcCYP6BQ9的转基因幼虫的耐受性分别比野生型幼虫高 10.3 或 15.3 倍。这些研究报告了表达 P450 基因的 FAW 转基因品系的产生，并表明SfCYP321A8有助于 FAW 中的溴氰菊酯抗性。开发的转化方法可用于秋粘虫和其他鳞翅目害虫的功能基因组学研究。