Shanshan Gao,Ruixue Lu,Yonglei Zhang,Haidi Sun,Siying Li,Kunpeng Zhang,Ruimin Li
Tribolium castaneum ( T. castaneum ) is a worldwide pest of stored grain that mainly harms flour, and not only causes serious loss of flour quality but also leads to deterioration of flour quality. Chemical detection plays a key role in insect behavior, and the role of odorant-binding proteins (OBPs) in insect chemical detection has been widely studied. However, the mechanism of OBPs in insect defense against exogenous toxic substances is still unclear. In this study, biochemical analysis showed that eugenol , the active component of A. vulgaris essential oil , significantly induced the expression of the OBP gene OBPC12 from T. castaneum ( TcOBPC12 ). The mortality of late larvae treated with eugenol was higher than that of the control group after RNA interference (RNAi) against TcOBPC12 , which indicates that the OBP gene is involved in the eugenol defense mechanism and leads to a decrease in sensitivity to eugenol. Tissue expression profiling showed that the expression of TcOBPC12 in the epidermis, hemolymph, and intestine was higher than in other larval tissues, and TcOBPC12 was expressed mainly in the epidermis, head, and fat body of adults. The developmental expression profile showed that the expression of TcOBPC12 in late eggs, early and late larval stages, and late adult stages was higher than in other developmental stages. These data suggest that TcOBPC12 may be involved in the absorption of exogenous toxic substances by the larvae from T. castaneum . Our results provide a theoretical basis for the metabolism and degradation mechanism of exogenous toxic substances and help explore more potential target genes of insect pests .
Cong Rao,Chao Yuan,Wangjin He,Hailiang Guo,Kuitun Liu,Jianfeng Fan,Jianya Su
This study elucidates the molecular mechanism by which flavin-containing monooxygenase (FMO) mediates metabolic resistance to nereistoxin insecticides in lepidopteran pests. A field population of Spodoptera exigua exhibited 50-fold resistance with upregulated SeFMO expression. Using FMO-specific inhibitors, recombinant protein expression, and mass spectrometry, we confirmed that FMO catalyzes N-oxidation of nereistoxin insecticide at the tertiary amine nitrogen. Molecular docking revealed that insect FMO’s catalytic mechanism resembles that of human FMO. Transgenic Drosophila models demonstrated that the FMO-mediated N-oxidation enhances insecticide resistance, indicating evolutionary conservation. This highlights FMO’s role in insecticide detoxification and its conserved function across species, providing new insights into pest resistance mechanisms.
Fungal diseases caused by Botrytis cinerea and insect infestations by aphids often occur simultaneously during plant growth. A co-delivery nanosystem for dual-pesticide may enhance pesticide efficiency and reduce the required dosage of pesticides through synergistic effects. Therefore, in this study, we developed a dual pH-responsive nanocomposite AZOX/Thi@BMMs@MIL-88B (ATBM) based on bimodal mesoporous silica (BMMs) and metal organic framework MIL-88B, which was loaded with fungicide azoxystrobin (AZOX) and insecticide thiamethoxam (Thi) to control grey mould and aphid pests. The loading capacities of the two pesticides in the nanocomposite were 18.56 % (AZOX) and 37.38 % (Thi). The nanoparticles (NPs) were spindle-shaped with a hydrated particle size of 771.60 ± 12.55 nm and possessed excellent pH-responsive controlled release behavior. The NPs also demonstrated good wettability and stability due to the entrapment of nanocarriers. Fluorescence tracking experiments verified that the NPs could be effectively absorbed and translocated by pathogenic fungal mycelium and pea seedlings. The bioactivities of ATBM against B. cinerea and A. pisum increased by 9.58 % (AZOX) and 39.48 % (Thi), respectively, compared to the commercialized technical control (TC). This nanocomplex promoted the growth of pea seedlings through the introduction of iron ions and by activating the oxidative stress system, and the excellent biosafety of NPs could minimize environmental risk. In summary, this hybrid bi-carrier dual-pesticide nanopesticide-fertilizer showed significant promise for application in sustainable agriculture.
危险品化学品经营许可证（带存储）