Cuticle thickening mediates insecticide penetration resistance in Spodoptera litura

作者：Bingjie Wang, Minghui Yi, Mengyu Wang, Hengji Wang, Zi Tang, Hui Zhao, Peng Wei, Xiaolan Liao, Wenxin Xue, Lang Pan, Li Shi · 发表于：Journal of Advanced Research · 年份：2025 · DOI：10.1016/j.jare.2025.02.027 · 被引用次数：15 · 研究领域：Studies on Chitinases and Chitosanases、Invertebrate Immune Response Mechanisms、Neurobiology and Insect Physiology Research

INTRODUCTION: Long-term and extensive use of chemical pesticides has led to the development of resistance in many important agricultural pests. The mechanisms of resistance formation in pests are complex and variable, and unraveling the resistance mechanisms is the key to control resistant pests. Insect cuticle, as the first line of defense for insecticides, plays a non-negligible role in insecticide penetration resistance. Although penetration resistance is widespread in insects, the multiple molecular mechanisms that impede insecticide penetration are unclear, especially in Spodoptera litura. OBJECTIVES: This study aims to reveal the molecular mechanisms of insecticide penetration resistance in S. litura. METHODS: The structure and thickness of cuticle were analyzed by TEM, and the role of cuticle in penetration resistance was determined by different application methods. The molecular mechanism of cuticular proteins overexpression was analyzed using RNAi, TEM, dual-luciferase assay and EMSA from cis- and trans-acting factors. In addition, the relationship between the chitin synthetic pathway and insecticide resistance was explored through enzyme activity, inhibitor assay, molecular docking and RNAi. Furthermore, the role of 20E in penetration resistance was analyzed. RESULTS: The cuticle of the resistant populations was significantly thickened and accompanied by extrusion, which contributed significantly to indoxacarb resistance. Constitutive upregulation of trans-acting fa...