Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 60
Filter
1.
Proc Natl Acad Sci U S A ; 121(28): e2402407121, 2024 Jul 09.
Article in English | MEDLINE | ID: mdl-38959045

ABSTRACT

Trade-offs between evolutionary gain and loss are prevalent in nature, yet their genetic basis is not well resolved. The evolution of insect resistance to insecticide is often associated with strong fitness costs; however, how the fitness trade-offs operates remains poorly understood. Here, we show that the mitogen-activated protein kinase (MAPK) pathway and its upstream and downstream actors underlie the fitness trade-offs associated with insecticide resistance in the whitefly Bemisia tabaci. Specifically, we find a key cytochrome P450 gene CYP6CM1, that confers neonicotinoids resistance to in B. tabaci, is regulated by the MAPKs p38 and ERK through their activation of the transcription factor cAMP-response element binding protein. However, phosphorylation of p38 and ERK also leads to the activation of the transcription repressor Cap "n" collar isoform C (CncC) that negatively regulates exuperantia (Ex), vasa (Va), and benign gonial cell neoplasm (Bg), key genes involved in oogenesis, leading to abnormal ovary growth and a reduction in female fecundity. We further demonstrate that the transmembrane G protein-coupled receptor (GPCR) neuropeptide FF receptor 2 (NPFF2) triggers the p38 and ERK pathways via phosphorylation. Additionally, a positive feedback loop between p38 and NPFF2 leads to the continuous activation of the MAPK pathways, thereby constitutively promoting neonicotinoids resistance but with a significant reproductive cost. Collectively, these findings provide fundamental insights into the role of cis-trans regulatory networks incurred by GPCR-MAPK signaling pathways in evolutionary trade-offs and applied knowledge that can inform the development of strategies for the sustainable pest control.


Subject(s)
Hemiptera , Insect Proteins , Insecticide Resistance , MAP Kinase Signaling System , Receptors, G-Protein-Coupled , Animals , Hemiptera/genetics , Hemiptera/metabolism , Insecticide Resistance/genetics , Receptors, G-Protein-Coupled/metabolism , Receptors, G-Protein-Coupled/genetics , Insect Proteins/metabolism , Insect Proteins/genetics , Female , Insecticides/pharmacology , Cytochrome P-450 Enzyme System/metabolism , Cytochrome P-450 Enzyme System/genetics
2.
Bioorg Chem ; 145: 107253, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38452588

ABSTRACT

Phytochemical study on Euphorbia milii, a common ornamental plant, resulted in the identification of thirteen new ent-rosane diterpenoids (1-13), three new ent-atisane diterpenoids (14-16), and a known ent-rosane (17). Their structures were delineated using spectroscopic data, quantum chemical calculations, and X-ray diffraction experiments. Euphomilone F (1) represented a rare ent-rosane-type diterpenoid with a 5/7/6 skeleton. Euphoainoid G (8) was a rare rosane diterpenic acid. Compounds 9 and 10 carried infrequent tetrahydrofuran rings, and compounds 11-13 was 18-nor-ent-rosane diterpenoids. All isolates were evaluated for their inhibitory effects on RANKL-induced osteoclasts. Notably, compounds with aromatic ester groups (2-7) showed promising activities (IC50 < 10 µM), underscoring the significance of acylated A-ring moieties in the ent-rosane skeleton for anti-osteoclastogenesis. Thirteen synthetic derivatives were obtained through esterification of 17. Of these, compound 27 exhibited remarkable improvement, with an IC50 of 0.8 µM, more than a 12-fold increase in potency compared to the parent compound 17 (IC50 > 10 µM). This work presents a series of new ent-rosane diterpenoids with potential antiosteoporosis agents.


Subject(s)
Diterpenes , Euphorbia , Osteogenesis , Euphorbia/chemistry , Plant Extracts/chemistry , Osteoclasts , Diterpenes/pharmacology , Diterpenes/chemistry , Molecular Structure
3.
J Agric Food Chem ; 72(10): 5153-5164, 2024 Mar 13.
Article in English | MEDLINE | ID: mdl-38427964

ABSTRACT

Being a destructive pest worldwide, the whitefly Bemisia tabaci has evolved resistance to neonicotinoid insecticides. The third-generation neonicotinoid dinotefuran has commonly been applied to the control of the whitefly, but its underlying mechanism is currently unknown. On the base of our transcriptome data, here we aim to investigate whether the cytochrome P450 CYP6EM1 underlies dinotefuran resistance in the whitefly. Compared to the susceptible strain, the CYP6EM1 gene was found to be highly expressed in both laboratory and field dinotefuran-resistant populations. Upon exposure to dinotefuran, the mRNA levels of CYP6EM1 were increased. These results demonstrate the involvement of this gene in dinotefuran resistance. Loss and gain of functional studies in vivo were conducted through RNAi and transgenic Drosophila melanogaster assays, confirming the role of CYP6EM1 in conferring such resistance. In a metabolism assay in vitro, the CYP6EM1 protein could metabolize 28.11% of dinotefuran with a possible dinotefuran-dm-NNO metabolite via UPLC-QTOF/MS. Docking of dinotefuran to the CYP6EM1 protein showed a good binding affinity, with an energy of less than -6.0 kcal/mol. Overall, these results provide compelling evidence that CYP6EM1 plays a crucial role in the metabolic resistance of B. tabaci to dinotefuran. Our work provides new insights into the mechanism underlying neonicotinoid resistance and applied knowledge that can contribute to sustainable control of a global pest such as whitefly.


Subject(s)
Guanidines , Hemiptera , Insecticides , Animals , Hemiptera/metabolism , Drosophila melanogaster/metabolism , Insecticide Resistance/genetics , Neonicotinoids/metabolism , Nitro Compounds/metabolism , Insecticides/pharmacology , Cytochrome P-450 Enzyme System/metabolism
4.
Angew Chem Int Ed Engl ; 63(13): e202317161, 2024 Mar 22.
Article in English | MEDLINE | ID: mdl-38308582

ABSTRACT

Pyridoxal 5'-phosphate (PLP)-dependent enzymes that catalyze γ-replacement reactions are prevalent, yet their utilization of carbon nucleophile substrates is rare. The recent discovery of two PLP-dependent enzymes, CndF and Fub7, has unveiled unique C-C bond forming capabilities, enabling the biocatalytic synthesis of alkyl- substituted pipecolic acids from O-acetyl-L-homoserine and ß-keto acid or aldehyde derived enolates. This breakthrough presents fresh avenues for the biosynthesis of pipecolic acid derivatives. However, the catalytic mechanisms of these enzymes remain elusive, and a dearth of structural information hampers their extensive application. Here, we have broadened the catalytic scope of Fub7 by employing ketone-derived enolates as carbon nucleophiles, revealing Fub7's capacity for substrate-dependent regioselective α-alkylation of unsymmetrical ketones. Through an integrated approach combining X-ray crystallography, spectroscopy, mutagenesis, and computational docking studies, we offer a detailed mechanistic insight into Fub7 catalysis. Our findings elucidate the structural basis for its substrate specificity, stereoselectivity, and regioselectivity. Our work sets the stage ready for subsequent protein engineering effort aimed at expanding the synthetic utility of Fub7, potentially unlocking novel methods to access a broader array of noncanonical amino acids.


Subject(s)
Amino Acids , Pyridoxal Phosphate , Pyridoxal Phosphate/chemistry , Pyridoxal Phosphate/metabolism , Crystallography, X-Ray , Substrate Specificity , Carbon , Catalysis
5.
PLoS Genet ; 20(2): e1011163, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38377137

ABSTRACT

Neonicotinoid insecticides, which target insect nicotinic acetylcholine receptors (nAChRs), have been widely and intensively used to control the whitefly, Bemisia tabaci, a highly damaging, globally distributed, crop pest. This has inevitably led to the emergence of populations with resistance to neonicotinoids. However, to date, there have been no reports of target-site resistance involving mutation of B. tabaci nAChR genes. Here we characterize the nAChR subunit gene family of B. tabaci and identify dual mutations (A58T&R79E) in one of these genes (BTß1) that confer resistance to multiple neonicotinoids. Transgenic D. melanogaster, where the native nAChR Dß1 was replaced with BTß1A58T&R79E, were significantly more resistant to neonicotinoids than flies where Dß1 were replaced with the wildtype BTß1 sequence, demonstrating the causal role of the mutations in resistance. The two mutations identified in this study replace two amino acids that are highly conserved in >200 insect species. Three-dimensional modelling suggests a molecular mechanism for this resistance, whereby A58T forms a hydrogen bond with the R79E side chain, which positions its negatively-charged carboxylate group to electrostatically repulse a neonicotinoid at the orthosteric site. Together these findings describe the first case of target-site resistance to neonicotinoids in B. tabaci and provide insight into the molecular determinants of neonicotinoid binding and selectivity.


Subject(s)
Hemiptera , Insecticides , Receptors, Nicotinic , Animals , Receptors, Nicotinic/genetics , Insecticides/pharmacology , Hemiptera/genetics , Drosophila melanogaster , Neonicotinoids/pharmacology , Mutation
6.
IEEE Trans Med Imaging ; 43(5): 1853-1865, 2024 May.
Article in English | MEDLINE | ID: mdl-38194398

ABSTRACT

Diffusion models with continuous stochastic differential equations (SDEs) have shown superior performances in image generation. It can serve as a deep generative prior to solving the inverse problem in magnetic resonance (MR) reconstruction. However, low-frequency regions of k -space data are typically fully sampled in fast MR imaging, while existing diffusion models are performed throughout the entire image or k -space, inevitably introducing uncertainty in the reconstruction of low-frequency regions. Additionally, existing diffusion models often demand substantial iterations to converge, resulting in time-consuming reconstructions. To address these challenges, we propose a novel SDE tailored specifically for MR reconstruction with the diffusion process in high-frequency space (referred to as HFS-SDE). This approach ensures determinism in the fully sampled low-frequency regions and accelerates the sampling procedure of reverse diffusion. Experiments conducted on the publicly available fastMRI dataset demonstrate that the proposed HFS-SDE method outperforms traditional parallel imaging methods, supervised deep learning, and existing diffusion models in terms of reconstruction accuracy and stability. The fast convergence properties are also confirmed through theoretical and experimental validation. Our code and weights are available at https://github.com/Aboriginer/HFS-SDE.


Subject(s)
Algorithms , Brain , Image Processing, Computer-Assisted , Magnetic Resonance Imaging , Humans , Image Processing, Computer-Assisted/methods , Magnetic Resonance Imaging/methods , Brain/diagnostic imaging , Diffusion Magnetic Resonance Imaging/methods
7.
Pest Manag Sci ; 80(2): 341-354, 2024 Feb.
Article in English | MEDLINE | ID: mdl-37688583

ABSTRACT

BACKGROUND: Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a major agricultural insect pest that causes severe economic losses worldwide. Several insecticides have been applied to effectively control this key pest. However, owing to the indiscriminate use of chemical insecticides, B. tabaci has developed resistance against these chemical compounds over the past several years. RESULTS: From 2019 to 2021, 23 field samples of B. tabaci were collected across China. Twenty species were identified as the Mediterranean 'Q' type (MED) and three were identified as MED/ Middle East-Asia Minor 1 mixtures. Subsequently, resistance of the selected populations to different insecticides was evaluated. The results showed that 13 populations developed low levels of resistance to abamectin. An overall upward trend in B. tabaci resistance toward spirotetramat, cyantraniliprole and pyriproxyfen was observed. In addition, resistance to thiamethoxam remained low-to-moderate in the 23 field populations. CONCLUSION: These findings suggest that the overall resistance of the field-collected B. tabaci populations has shown an upward trend over the years in China. We believe our study can provide basic data to support integrated pest management and insecticide resistance management of field B. tabaci in China. © 2023 Society of Chemical Industry.


Subject(s)
Hemiptera , Insecticides , Animals , Insecticides/pharmacology , Insecticide Resistance , China , Thiamethoxam
8.
Pest Manag Sci ; 80(2): 910-921, 2024 Feb.
Article in English | MEDLINE | ID: mdl-37822143

ABSTRACT

BACKGROUND: Understanding the trade-offs between insecticide resistance and the associated fitness is of particular importance to sustainable pest control. One of the most devastating pest worldwide, the whitefly Bemisia tabaci, has developed resistance to various insecticides, especially the neonicotinoid group. Although neonicotinoid resistance often is conferred by P450s-mediated metabolic resistance, the relationship between such resistance and the associated fitness phenotype remains largely elusive. By gene cloning, quantitative reverse transcription (qRT)-PCR, RNA interference (RNAi), transgenic Drosophila melanogaster, metabolism capacity in vitro and 'two sex-age stage' life table study, this study aims to explore the molecular role of a P450 gene CYP4CS5 in neonicotinoid resistance and to investigate whether such resistance mechanism carries fitness costs in the whitefly. RESULTS: Our bioassay tests showed that a total of 13 field-collected populations of B. tabaci MED biotype displayed low-to-moderate resistance to thiamethoxam and clothianidin. Compared to the laboratory susceptible strain, we then found that an important P450 CYP4CS5 was remarkably upregulated in the field resistant populations. Such overexpression of CYP4CS5 had a good match with the resistance level among the whitefly samples. Further exposure to the two neonicotinoids resulted in an increase in CYP4CS5 expression. These results implicate that overexpression of CYP4CS5 is closely correlated with thiamethoxam and clothianidin resistance. RNAi knockdown of CYP4CS5 increased mortality of the resistant and susceptible populations after treatment with thiamethoxam and clothianidin in bioassay, but obtained an opposite result when using a transgenic line of D. melanogaster expressing CYP4CS5. Metabolic assays in vitro revealed that CYP4CS5 exhibited certain capacity of metabolizing thiamethoxam and clothianidin. These in vivo and in vitro assays indicate an essential role of CYP4CS5 in conferring thiamethoxam and clothianidin resistance in whitefly. Additionally, our life-table analysis demonstrate that the field resistant whitefly exhibited a prolonged development time, shortened longevity and reduced fecundity compared to the susceptible, suggesting an existing fitness cost as a result of the resistance. CONCLUSION: Collectively, in addition to the important role of CYP4CS5 in conferring thiamethoxam and clothianidin resistance, this resistance mechanism is associated with fitness costs in the whitefly. These findings not only contribute to the development of neonicotinoids resistance management strategies, but also provide a new target for sustainable whitefly control. © 2023 Society of Chemical Industry.


Subject(s)
Guanidines , Hemiptera , Insecticides , Thiazoles , Animals , Thiamethoxam/metabolism , Drosophila melanogaster/genetics , Nitro Compounds/pharmacology , Nitro Compounds/metabolism , Oxazines , Neonicotinoids/pharmacology , Neonicotinoids/metabolism , Insecticides/pharmacology , Insecticides/metabolism , Animals, Genetically Modified , Insecticide Resistance/genetics
9.
Patient Educ Couns ; 118: 108027, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37918218

ABSTRACT

OBJECTIVE: Patient participation is essential for Core Outcome Set (COS) development studies. Patient education during participation may help patients better express their views in COS studies. This study aimed to investigate the current status of patient participation and the specified educational information in COS studies. METHODS: We conducted a systematic review of COS development studies. Information on patient participation in COS research, and especially details of patient education, was analyzed. RESULTS: In total, 146 COS development studies were included in this review. Of these, 125 studies (85.6%) mentioned patient participation. Most studies did not provide explicit information on patient participation. Some studies mentioned recruiting patients, but ultimately, none of them responded. Six studies reported conducting patient education through workshops, creating patient forums, or providing videos and slides. However, these studies did not provide details on education. Twenty-three studies used the plain language to explain patient outcomes. CONCLUSION: COS developers are increasingly focusing on patient participation. However, only a few COS studies have explicitly reported conducting measures related to patient education. Further patient education is necessary when they participate in the development of a new Core Outcome Set. PRACTICE IMPLICATION: This article provides implementation strategies related to patient education for future COS development studies.


Subject(s)
Outcome Assessment, Health Care , Patient Education as Topic , Humans , Research Design
10.
Nat Chem Biol ; 19(12): 1440-1442, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37968360
11.
Pestic Biochem Physiol ; 196: 105635, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37945266

ABSTRACT

The whitefly, Bemisia tabaci, comes up high metabolic resistance to most neonicotinoids in long-term evolution, which is the key problem of pest control. UGT glycosyltransferase, as a secondary detoxification enzyme, plays an indispensable role in detoxification metabolism. In this study, UGT inhibitors, 5-nitrouracil and sulfinpyrazone, dramatically augmented the toxic damage of neonicotinoids to B. tabaci. A UGT named UGT353G2 was identified in whitefly, which was notably up-regulated in resistant strain (3.92 folds), and could be induced by most neonicotinoids. Additionally, the using of RNA interference (RNAi) suppresses UGT353G2 substantially increased sensitivity to neonicotinoids in resistant strain. Our results support that UGT353G2 may be involved in the neonicotinoids resistance of whitefly. These findings will help further verify the functional role of UGTs in neonicotinoid resistance.


Subject(s)
Hemiptera , Insecticides , Animals , Neonicotinoids/pharmacology , Neonicotinoids/metabolism , Insecticides/pharmacology , Insecticides/metabolism , Hemiptera/metabolism , Nitro Compounds/pharmacology , Nitro Compounds/metabolism , Insecticide Resistance/genetics , Uridine Diphosphate/metabolism
12.
J Am Chem Soc ; 145(49): 26569-26579, 2023 12 13.
Article in English | MEDLINE | ID: mdl-38032297

ABSTRACT

The macrodaphniphyllamine-type, calyciphylline A-type, daphnilongeranin A-type, and daphnicyclidin D-type alkaloids are four structurally related classes of Daphniphyllum alkaloids. On the basis of a systematic analysis of the biogenetic network of these classes, we developed synthetic strategies centered on the C4-N and C1-C8 bonds of calyciphylline A, which took full advantage of the suitable substrates, reactions, and pathways that are altered from their counterparts in the postulated biogenetic network. Through this generalized biomimetic approach, we achieved the first synthesis of 14 Daphniphyllum alkaloids from the four subfamilies.


Subject(s)
Alkaloids , Daphniphyllum , Molecular Structure , Alkaloids/chemistry
13.
Pestic Biochem Physiol ; 194: 105468, 2023 Aug.
Article in English | MEDLINE | ID: mdl-37532309

ABSTRACT

High level resistance for a variety of insecticides has emerged in Bemisia tabaci, a globally notorious insect. Neonicotinoid insecticides have been applied widely to control B. tabaci. Whether a differentially expressed gene CYP6DB3 discovered from transcriptome data of B. tabaci is involved in the resistance to neonicotinoid insecticides remains unclear. In the study, CYP6DB3 expression was significantly up-regulated in both thiamethoxam- and imidacloprid-resistant strains relative to the susceptive strains. We also found that CYP6DB3 expression was up-regulated after B. tabaci adults were exposed to thiamethoxam and imidacloprid. Moreover, knocking down CYP6DB3 expression via feeding corresponding dsRNA significantly reduced CYP6DB3 mRNA levels by 34.1%. Silencing CYP6DB3 expression increased the sensitivity of B. tabaci Q adults against both thiamethoxam and imidacloprid. Overexpression of CYP6DB3 gene reduced the toxicity of imidacloprid and thiamethoxam to transgenic D. melanogaster. In addition, metabolic studies showed that CYP6DB3 can metabolize 24.41% imidacloprid in vitro. Collectively, these results strongly support that CYP6DB3 plays an important role in the resistance of B. tabaci Q to imidacloprid and thiamethoxam. This work will facilitate a deeper insight into the part of cytochrome P450s in the evolution of insecticide resistance and provide a theoretical basis for the development of new integrated pest resistance management.


Subject(s)
Hemiptera , Insecticides , Animals , Thiamethoxam/metabolism , Insecticides/pharmacology , Insecticides/metabolism , Hemiptera/genetics , Hemiptera/metabolism , Drosophila melanogaster/metabolism , Neonicotinoids/pharmacology , Neonicotinoids/metabolism , Nitro Compounds/pharmacology , Nitro Compounds/metabolism , Insecticide Resistance/genetics , Cytochrome P-450 Enzyme System/genetics , Cytochrome P-450 Enzyme System/metabolism
14.
Pestic Biochem Physiol ; 194: 105469, 2023 Aug.
Article in English | MEDLINE | ID: mdl-37532310

ABSTRACT

Bemisia tabaci (Hemiptera: Gennadius) is a notorious pest that is capable of feeding on >600 kinds of agricultural crops. Imidacloprid is critical in managing pest with sucking mouthparts, such as B. tabaci. However, the field population of B. tabaci has evolved resistance because of insecticide overuse. The overexpression of the detoxification enzyme cytochrome P450 monooxygenase is considered the main mechanism of imidacloprid resistance, but the mechanism underlying gene regulation remains unclear. MicroRNAs are a type of endogenous small molecule compounds that is fundamental in regulating gene expression at the post-transcriptional level. Whether miRNAs are related to the imidacloprid resistance of B. tabaci remains unknown. To gain deep insight into imidacloprid resistance, we conducted on miRNAs expression profiling of two B. tabaci Mediterranean (MED) strains with 19-fold resistance through deep sequencing of small RNAs. A total of 8 known and 1591 novel miRNAs were identified. In addition, 16 miRNAs showed significant difference in expression levels between the two strains, as verified by quantitative reverse transcription PCR. Among these, novel_miR-376, 1517, and 1136 significantly expressed at low levels in resistant samples, decreasing by 36.9%, 60.2%, and 15.6%, respectively. Moreover, modulating novel_miR-1517 expression by feeding with 1517 inhibitor and 1517 mimic significantly affected B. tabaci imidacloprid susceptibility by regulating CYP6CM1 expression. In this article, miRNAs related to imidacloprid resistance of B. tabaci were systematically screened and identified, providing important information for the miRNA-based technological innovation for this pest management.


Subject(s)
Hemiptera , Insecticides , MicroRNAs , Animals , Hemiptera/metabolism , Insecticide Resistance/genetics , Neonicotinoids/pharmacology , Neonicotinoids/metabolism , Insecticides/pharmacology , Insecticides/metabolism , Nitro Compounds/pharmacology , Nitro Compounds/metabolism , MicroRNAs/genetics
16.
Pest Manag Sci ; 79(10): 3883-3892, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37226658

ABSTRACT

BACKGROUND: Difference in physiology level between the immature and mature stages of insects likely contribute to different mechanisms of insecticide resistance. It is well acknowledged that insect 20-hydroxyecdysone (20E) plays an important role in many biological processes in the immature stage, whether 20E confers insecticide resistance at this specific stage is still poorly understood. By gene cloning, reverse transcription quantitative real-time PCR, RNA interference (RNAi) and in vitro metabolism experiments, this study aimed to investigate the potential role of 20E-related genes in conferring imidacloprid (IMD) resistance in the immature stage of the whitefly Bemisia tabaci Mediterranean. RESULTS: After identification of low to moderate IMD resistance in the whitefly, we found CYP306A1 of the six 20E-related genes was overexpressed in the nymph stage of the three resistant strains compared to a laboratory reference susceptible strain, but not in the adult stage. Further exposure to IMD resulted in an increase in CYP306A1 expression in the nymph stage. These results together imply that CYP306A1 may be implicated in IMD resistance in the nymph stage of the whitefly. RNAi knockdown of CYP306A1 increased the mortality of nymphs after treatment with IMD in bioassay, suggesting a pivotal role of CYP306A1 in conferring IMD resistance in the nymph stage. Additionally, our metabolism experiments in vivo showed that the content of IMD reduced by 20% along with cytochrome P450 reductase and heterologously expressed CYP306A1, which provides additional evidence for the important function of CYP306A1 in metabolizing IMD that leads to the resistance. CONCLUSION: This study uncovers a novel function of the 20E biosynthesis gene CYP306A1 in metabolizing imidacloprid, thus contributing to such resistance in the immature stage of the insect. These findings not only advance our understanding of 20E-mediated insecticide resistance, but also provide a new target for sustainable pest control of global insect pests such as whitefly. © 2023 Society of Chemical Industry.


Subject(s)
Hemiptera , Insecticides , Animals , Insecticides/pharmacology , Insecticides/metabolism , Nymph/genetics , Neonicotinoids/pharmacology , Neonicotinoids/metabolism , Insecta , Nitro Compounds/pharmacology , Nitro Compounds/metabolism , Insecticide Resistance/genetics
17.
J Econ Entomol ; 116(4): 1342-1351, 2023 08 10.
Article in English | MEDLINE | ID: mdl-37208311

ABSTRACT

Cytochrome P450 monooxygenases (P450s) are well-known for their crucial roles in the detoxification of xenobiotics. However, whether CYP6CX2 and CYP6CX3, 2 genes from our Bemisia tabaci (B. tabaci) MED/Q genome data were associated with detoxification metabolism and confer resistance to thiamethoxam is unclear. In this study, we investigated the role of CYP6CX2 and CYP6CX3 in mediating whitefly thiamethoxam resistance. Our results showed that mRNA levels of CYP6CX2 and CYP6CX3 were up-regulated after exposure to thiamethoxam. Transcriptional levels of 2 genes were overexpressed in laboratory and field thiamethoxam resistant strains by RT-qPCR. These results indicate that the enhanced expression of CYP6CX2 and CYP6CX3 appears to confer thiamethoxam resistance in B. tabaci. Moreover, linear regression analysis showed that the expression levels of CYP6CX2 and CYP6CX3 were positively correlated with thiamethoxam resistance levels among populations. The susceptibility of whitefly adults was markedly increased after silencing 2 genes by RNA interference (RNAi) which further confirming their major role in thiamethoxam resistance. Our findings provide information to better understand the roles of P450s in resistance to neonicotinoids and suggest that these genes may be applied to develop target genes for sustainable management tactic of agricultural pests such as B. tabaci.


Subject(s)
Hemiptera , Insecticides , Animals , Thiamethoxam/metabolism , Hemiptera/genetics , Hemiptera/metabolism , Nitro Compounds/pharmacology , Insecticide Resistance/genetics , Neonicotinoids , Insecticides/pharmacology , Insecticides/metabolism
18.
Complement Ther Med ; 75: 102956, 2023 Aug.
Article in English | MEDLINE | ID: mdl-37257728

ABSTRACT

OBJECTIVE: Acupuncture is a widely used asthma therapy, but the benefits remain uncertain. This study aimed to access the effectiveness of acupuncture for treatment of asthma in adults. METHODS: Five English databases and four Chinese databases were searched from inception to November 2021. Randomised sham/placebo-controlled trials meeting inclusion criteria were included. Risk of bias was evaluated according to the Cochrane Review Handbook, and data analysis was performed in RevMan 5.4.1. Quality of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluations (GRADE) profiler. RESULTS: Sixteen randomised controlled trials (RCTs) were included in the meta-analysis. Results indicated that acupuncture was well-tolerated and could improve FEV1% compared with sham/placebo acupuncture [MD 6.11, 95% CI 0.54-11.68, I2 = 93%, number of participants (n) = 603]. Acupuncture also improved Cai's Asthma Quality of Life Questionnaire (AQLQ) (MD 7.26, 95% CI 5.02-9.50, I2 = 0, n = 358), and reduced the asthma symptom score (SMD -2.73, 95% CI -3.59 to -1.87, I2 = 65%, n = 120). One study showed acupuncture increased the Asthma Control Test (ACT) score (MD 2.00, 95% CI 0.90-3.10, n = 111), and decreased exacerbation frequency (MD -1.00, 95% CI -1.55 to -1.45, n = 111). Other lung function and medication use parameters were not statistically significant. CONCLUSIONS: Acupuncture versus sham/placebo control appeared to improve quality of life, FEV1%, symptoms, and asthma control, and reduced exacerbation frequency per year. Further studies with appropriate controls, more participants, and high-quality evidence are needed.


Subject(s)
Acupuncture Therapy , Asthma , Humans , Adult , Acupuncture Therapy/methods , Asthma/therapy , Randomized Controlled Trials as Topic
19.
J Agric Food Chem ; 71(19): 7221-7229, 2023 May 17.
Article in English | MEDLINE | ID: mdl-37157975

ABSTRACT

The sweet potato whitefly, Bemisia tabaci, (Gennadius) (Hemiptera:Aleyrodidae) is a global pest of crops. Neonicotinoids are efficient insecticides used for control of this pest. Insecticidal targets of neonicotinoids are insect nicotinic acetylcholine receptors (nAChRs). Here, we characterized and cloned the full length of the nAChR ß1 subunit (BTß1) in B. tabaci and confirmed the consistency of BTß1 in B. tabaci MEAM1 and MED. Expression levels of BTß1 in different developmental stages and body parts of adults were investigated and compared in B. tabaci MED. dsRNA was prepared to knock down BTß1 in adult B. tabaci and significantly decreases the susceptibility to five neonicotinoid insecticides, including imidacloprid, clothianidin, thiacloprid, nitenpyram, and dinotefuran. This study indicated BTß1 as a notable site influencing the susceptibility of B. tabaci to neonicotinoids.


Subject(s)
Hemiptera , Insecticides , Receptors, Nicotinic , Animals , Insecticides/toxicity , Insecticides/metabolism , Receptors, Nicotinic/genetics , Receptors, Nicotinic/metabolism , Insecticide Resistance/genetics , Neonicotinoids/metabolism , Nitro Compounds/pharmacology , Nitro Compounds/metabolism
20.
Int J Biol Macromol ; 233: 123647, 2023 Apr 01.
Article in English | MEDLINE | ID: mdl-36780959

ABSTRACT

Cuticular proteins (CPs) play an important role in protecting insects from adverse environmental conditions, like neonicotinoid insecticides, which are heavily used for numerous pests and caused environmental problems and public health concerns worldwide. However, the relationship between CPs and insecticides resistance in Bemisia tabaci, a serious and developed high insecticide resistance, is lacking. In this study, 125 CPs genes were identified in B. tabaci. Further phylogenetic tree showed the RR-2-type genes formed large gene groups in B. tabaci. Transcriptional expression levels of CPs genes at different developmental stages revealed that some CPs genes may play a specific role in insect development. The TEM results indicated that the cuticle thickness of susceptible strain was thinner than imidacloprid-resistance strain. Furthermore, 16 CPs genes (5 in RR-1 subfamily, 7 in RR-2 subfamily, 3 in CPAP3 subfamily and 1 in CPCFC subfamily) were activated in response to imidacloprid. And RNAi results indicated that CP9 and CP83 involved in imidacloprid resistance. In conclusion, this study was the first time to establish a basic information framework and evolutionary relationship between CPs and imidacloprid resistance in B. tabaci, which provides a basis for proposing integrated pest management strategies.


Subject(s)
Hemiptera , Insecticides , Animals , Insecticides/pharmacology , Insecticides/metabolism , Hemiptera/metabolism , Phylogeny , Neonicotinoids/pharmacology , Neonicotinoids/metabolism , Nitro Compounds/pharmacology
SELECTION OF CITATIONS
SEARCH DETAIL