PEST MANAGEMENT SCIENCE
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2020
·Vol. 77
·期 4
·2129-2141
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IF 3.75
Li-Sha Bai,Jing-Jing Xu,Cai-Xia Zhao,Ya-Li Chang,Yan-Ling Dong,Kai-Ge Zhang,Yong-Qiang Li,Yi-Ping Li,Zhi-Qing Ma,Xi-Li Liu
BACKGROUND Carboxylesterase (CarE) is a major class of enzyme involved in the detoxification of toxic xenobiotics in various insect species. Previous work has shown that the carboxylesterase gene CarE001G found in Helicoverpa armigera is more active and can metabolize synthesized pyrethroids, such as β -cypermethrin, one of the commonly used commercial insecticides for lepidopteran pest control. In addition, CarE001G is very special as it has a very specific glycine-rich region located adjacent to its C-terminal. But whether mutations in this unique sequence can change the biochemistry and function of CarE001G are unknown. RESULTS In this study, four variants of CarE001G with different deletions in the glycine-rich region were obtained and functionally expressed in Escherichia coli . The recombinant proteins were purified and confirmed by Western blot and mass spectrometry analyses. These mutant enzymes showed high catalytic efficiency toward the model substrate α -naphthyl acetate. Inhibition study showed that β -cypermethrin had relatively strong inhibition on CarE activities. In vitro metabolism assay showed that the mutant enzymes significantly enhanced their metabolic activities toward β -cypermethrin with specific activities between 4.0 and 5.6 nmol L -1 min −1 mg −1 protein. Molecular docking analyses consistently demonstrated that deletion mutations in the glycine-rich region may facilitate the anchoring of the β -cypermethrin molecule in the active binding pocket of the mutant enzymes. CONCLUSION The data show that deletion mutations can cause qualitative change in the capacity of CarEs in the detoxification of β -cypermethrin. This indicates that deletion mutations in the glycine-rich region may have the potential to cause synthesized pyrethroid (SP) resistance in H. armigera in the future. © 2020 Society of Chemical Industry
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高影响因子
PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY
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2024
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IF 4.2
Junyue Zheng,Peizhuo Wu,Yun Huang,Yu Zhang,Lihong Qiu
Insect cuticular protein (ICP) plays an important role in insect growth and development . However, research on the role of ICP in insecticide resistance is very limited. In this study, insect cuticular protein genes LCP17 and SgAbd5 were cloned and characterized in Helicoverpa armigera based on previous transcriptome data. The functions of LCP17 and SgAbd5 genes in fenvalerate resistance were assessed by RNA interference (RNAi), and their response to fenvalerate was further detected. The results showed that LCP17 and SgAbd5 were overexpressed in the fenvalerate-resistant strain comparing with a susceptible strain. The open reading frames of LCP17 and SgAbd5 genes were 423 bp and 369 bp, encoding 141 and 123 amino acids , respectively. LCP17 and SgAbd5 genes were highly expressed in the larval stage, but less expressed in the adult and pupal stages. The expression level of LCP17 and SgAbd5 genes increased significantly after fenvalerate treatment at 24 h. When the cotton bollworms larvae were exposed to fenvalerate at LD 50 level, RNAi-mediated silencing of LCP17 and SgAbd5 genes increased the mortality from 50.68% to 68.67% and 63.89%, respectively; the mortality increased to even higher level, which was 73.61%, when these two genes were co-silenced. Moreover, silencing of these two genes caused the cuticle lamellar structure to become loose, which led to increased penetration of fenvalerate into the larvae. The results suggested that LCP17 and SgAbd5 may be involved in the resistance of cotton bollworm to fenvalerate, and LCP17 and SgAbd5 could serve as potential targets for H. armigera control.
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高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2024
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IF 7.7
Tengfei Xiong,Mingyue Yu,Mei Li,Christopher A. Reilly,Xinghui Qiu
Capsaicin and dihydrocapsaicin are the principal pungent compounds in hot peppers. The generalist Helicoverpa armigera and the specialist H. assulta are two of the few insects that can feed on hot pepper fruits. To further understand the mechanisms behind physiological adaptation to capsaicinoids in the two agricultural pests, we investigated the transcriptional response and metabolism capacity of CYP6B6 orthologs from the two closely related species to the capsaicinoids. The results showed that the expression of CYP6B6 was either weakly or moderately induced by capsaicin in a tissue-specific and dose-dependent manner. CYP6B6 induction to greater extent was observed in the larval midguts of the cotton bollworms, indicating that inducible defense is more robust in the generalist. The two CYP6B6 enzymes were able to efficiently metabolize both capsaicin and dihydrocapsaicin, and HassCYP6B6 exhibit a slightly higher activity towards capsaicin than HarmCYP6B6, as evaluated by the specific activity and Vmax values. Multiple known and yet to be elucidated metabolites were detected in the reactions catalyzed by CYP6B6s, with dehydrogenation at the terminal carbon followed by N-macrocyclization and aliphatic hydroxylation being the dominant pathways. The data support the hypothesis that these two Helicoverpa species have well adapted to capsaicinoids via their high P450-mediated detoxification ability.
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CHEMISTRY AND ECOLOGY
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2017
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IF 1.463
Haixia Zhan,Jinping Zhang,Zhu Chen,Yongjie Huang,Teija Ruuhola,Shiyong Yang
Cadmium (Cd) is a toxic non-essential element accumulated easily in living organisms due to its non-biodegradable nature. A slight increase in Cd levels will threaten the health of terrestrial and aquatic organisms. Therefore, Cd contamination and its effects on the ecosystems and organisms have become a major topic of eco-toxicological research. The present study investigated the eco-toxicological effects of Cd-supplemented diet on some life history traits and specific enzyme activities of carboxylesterase (CarE), glutathione S-transferase (GST), acetylcholinesterase (AChE) and cytochrome P450 monooxygenases (P450s) in the cotton bollworm, Helicoverpa armigera. The results showed that Cd significantly decreased larval survival, pupation and emergence, and reduced body mass of the sixth instar larvae, pupae, adult moths and female fecundity. Cd-supplemented diet also delayed the development of larvae and pupae and shortened the life span of the cotton bollworm moth. In addition, dietary Cd inhibited the activities of GST, CarE and P450, but increased AChE activity of the sixth instar larvae. We concluded that life history traits and metabolic enzymes are sensitive to Cd stress in the cotton bollworm. These parameters are potential biomarkers for monitoring environmental stress in Lepidopteran insect pests.
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PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY
·
2024
·
IF 4.2
Yun Huang,Junyue Zheng,Peizhuo Wu,Yu Zhang,Lihong Qiu
Transcription factors play an important role in regulating the expression of detoxification genes (e.g. P450s ) that confer insecticide resistance. Our previous study identified a series of candidate transcription factors ( CYP6B7 -fenvalerate association proteins, CAPs) that may be related to fenvalerate-induced expression of CYP6B7 in a field HDTJ strain of H. armigera . Whether these CAPs can mediate the transcript of CYP6B7 induced by fenvalerate in a susceptible HDS strain of H. armigera remains unknown. Further study showed that the expression levels of multiple CAPs were significantly induced by fenvalerate in HDS strain. Knockdown of CAP19 [fatty acid synthase-like (FAS)], CAP22 [polysaccharide biosynthesis domain-containing protein 1 (PBDC1)], CAP24 [5-formyltetrahydrofolate cycloligase (5-FCL)], CAP30 [peptidoglycan recognition protein LB-like (PGRP)] and CAP33 [NADH dehydrogenase [ubiquinone] 1 alpha subcomplex subunit 11 (NDUFA11)] resulted in significant inhibition of CYP6B7 and some other P450 genes expression; meanwhile, the sensitivity of HDS strain larvae to fenvalerate was significantly increased. In addition, PBDC1, PGRP and NDUFA11, either alone or in combination, could significantly enhance the activity of CYP6B7 promoter in HDS strain, as well as the expression level of CYP6B7 gene in Sf9 cells line. These results suggested that PBDC1, PGRP and NDUFA11 may be involved in the transcript regulation of key detoxifying genes in response to fenvalerate in HDS strain of H. armigera .
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REACTIVE & FUNCTIONAL POLYMERS
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2019
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IF 3.074
Chuang Zhou,Ziming Yang,Li Zhang,Enming Dong,Zuyu He,Xianwu Liu,Chao Wang,Yan Yang,Jing Jiao,Yunhao Liu,Yu Chen,Puwang Li
In this work, carboxymethyl chitosan-graft-eleostearic acid (CMCS-g-EA) was synthesized via the amide reaction between the amino groups of carboxymethyl chitosan and the carboxyl group of eleostearic acid, and then mPEG-NH 2 was grafted to CMCS-g-EA to prepare amphiphilic polymers (mPEG-CMCS-g-EA). The chemical structures of the above conjugates were characterized by FT-IR and 1 H NMR. Both CMCS-g-EA and mPEG-CMCS-g-EA based nano-vesicles were prepared by ultrasonic self-assembly method and they exhibited a low critical aggregation concentration (CAC) of 14.97 μg/mL, 16.82 μg/mL, respectively. The spinosad-loaded mPEG-CMCS-g-EA nano-vesicles (SSD@mPEG-CMCS-g-EA NVs) were spherical in shape with an average diameter of 502.8 nm and the zeta potential of −25.60 mV. The encapsulation efficiency (EE) and drug loading content (LC) of SSD@mPEG-CMCS-g-EA nano-vesicles were 42.00%, 23.07%, respectively. In vitro release revealed that the SSD@mPEG-CMCS-g-EA nano-vesicles exhibited a sustained and pH-responsive drug release property, and could significantly enhance the photostability of spinosad . Furthermore, the toxicological tests demonstrated that the SSD@mPEG-CMCS-g-EA nano-vesicles could efficiently inhibit the growth and development of Helicoverpa armigera . These results indicated that the SSD@mPEG-CMCS-g-EA nano-vesicles were highly potential for the treatment of Helicoverpa armigera .
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高影响因子
危险品化学品经营许可证（带存储）