Yu Gao,Dong-Yang Liu,Quan Deng,Wen-Long Feng,Jia-Min Yu,Mao-Ye Li,Su Liu
Exposure to insecticides can cause abnormally high accumulation of reactive oxygen species (ROS) and oxidative stress in insects. Thioredoxin peroxidases (TPXs) play critical roles in protecting insects from insecticide-induced oxidative injury. The black cutworm, Agrotis ipsilon (Hufnagel) (Lepidoptera: Noctuidae), is an important agricultural pest. Lambda-cyhalothrin (LCT) is a pyrethroid insecticide used to control A. ipsilon . However, whether LCT causes oxidative stress and whether TPXs are involved in the antioxidant defense in A. ipsilon remain unknown. In this study, a TPX gene, AiTPX6 , was identified from A. ipsilon . AiTPX6 consists of five exons and four introns and encodes a protein of 227 amino acid residues. The AiTPX6 protein has characteristic features of TPXs, including the peroxidase active site motif PVCTTE with a conserved catalytic cysteine residue. Phylogenetic analysis revealed that AiTPX6 belongs to the “1-Cys” TPX group. The mRNA transcripts of AiTPX6 were most abundant in the larval midgut and at the fifth- and sixth-instar larval stages. Exposure to a sublethal concentration (LC 50 ) of LCT significantly increased the H 2 O 2 and malondialdehyde (MDA) concentrations and elevated the mRNA level of AiTPX6 , suggesting that LCT-induced oxidative stress activates AiTPX6 transcription. Recombinant AiTPX6 expressed in Escherichia coli displayed potent antioxidant activity, protecting the cells against oxidative stress. Knockdown of AiTPX6 via RNA interference (RNAi) significantly increased the mortality rate of A. ipsilon following LCT exposure. These findings revealed that AiTPX6 contributes to LCT tolerance via antioxidant defense and could therefore be used as a potential target for RNAi-based control of A. ipsilon .
Pesticides play a crucial role in securing food production, their safety usage remains a pressing concern. Traditional pesticide formulations have been scrutinized for their inefficiency, environmental hazards, and negative impacts on human health. Here, sulfonated cellulose nanocrystals (sCNC) were utilized to stabilize molten lambda-cyhalothrin (LC), forming stable Pickering emulsions via high-pressure homogenization (HPH). This process was followed by the generation of microcapsules through interfacial polymerization, a method that entirely forgoes the use of surfactants and organic solvents. The synthesized microcapsules showcased a size ranging from 250 to 1000 nm, with an impressive LC encapsulation efficiency of up to 99.29 %. These microcapsules maintained excellent stability, prolonging pest control duration in field applications, and exhibited reduced toxicity to zebrafish. A particularly groundbreaking discovery was the ability of microcapsules to mitigate skin irritation, a benefit previously unexplored in LC microencapsulation. Furthermore, these microcapsules demonstrated significant degradation within 14 days post-application, effectively minimizing prolonged pesticide residue on crops. This study highlights the eco-friendly production of microcapsules and their capacity to diminish the negative impacts associated with pesticide application. It paves the way for the wider implementation of encapsulation technologies in pesticides and offers critical insights into the creation of sustainable, safe, and effective pesticide formulations.
危险品化学品经营许可证（带存储）