JOURNAL OF INSECT SCIENCE
·
2014
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IF 0.921
Wenping Xu,Qingchun Huang,Xiwei Wu,Xiaoqin Yu,Xuexiao Wang,Liming Tao
Midgut α-amylase is an important digestive enzyme involved in larval energy metabolism and carbohydrate assimilation. In this article, the properties of midgut α-amylase from the Oriental armyworm, Mythimna separata (Lepidoptera: Noctuidae), larvae were characterized, and its in vitro responses to chemical inhibitors were also determined. The kinetic parameters Km and Vmax of midgut α-amylase were 0.064 M, 4.81 U mg pro(-1) in phosphate buffer, and 0.128 M, 1.96 U mg pro(-1) in barbiturate-acetate buffer; α-amylase activity linearly increased as starch concentration increased. α-Amylase activity was not influenced by amino acids such as Pro, Met, Try, His, Ala, and Phe but was strongly activated by antioxidants. Reduced glutathione, 1,4-dithiothreitol, β-mercaptoethanol, and ascorbic acid improved the activity of α-amylase about 2.06, 3.46, 3.37, and 6.38 times, respectively, relative to the control. Ethylenediaminetetraacetic acid, sodium dodecyl sulfonate, and N-bromosuccinimide (NBS) strongly inhibited α-amylase. α-, β-, and γ-cyclodextrin were not the preferred substrates for α-amylase. Kinetic analysis showed that IC50 value of NBS against α-amylase was 1.52 (±0.26) µM, and the mode of action of NBS with Ki as 2.53 (0.35) µM was a mixed-type inhibition that indicated a combination of partial competitive and pure noncompetitive inhibition. The midgut α-amylase of armyworm larvae may be a potential target for novel insecticide development and pest control.
研究领域:
昆虫生理学
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酶学
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害虫控制
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生物化学
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分子生物学
✓ 已验证
DOI
PubMed
高影响因子
CHEMISTRY & BIODIVERSITY
·
2024
·Vol. 21
·期 7
·e202400929
·
IF 2.3
Yuee Tian,Shiyue Ma,Yibo Liu,Yan Li,Genqiang Chen,Zhiping Che
In order to explore novel natural product-based insecticidal agent, two important intermediates ( 2 and 3 ) and 4-acyloxy-2′-bromo-6′-chloropodophyllotoxin derivatives ( 4 a – f and 5 a – f ) were designed and prepared, and their structures were confirmed by 1 H-NMR, 13 C NMR, HRMS, ESI-MS, optical rotation and melting point (mp). The stereochemical configuration of compound 4 b was unambiguously confirmed by single-crystal X-ray diffraction. Moreover, we evaluated the insecticidal activity of target compounds 4 a – f and 5 a – f against a serious agricultural pest of Mythimna separata by using the leaf-dipping method. Among all tested compounds, compounds 4 d , 5 d and 5 f exhibited stronger insecticidal activity with a final mortality rate exceeding 60 %. Especially compound 5 d exhibited the best insecticidal activity, with a final mortality rate of 74.1 %. It has been proven that introducing bromine or chlorine atoms at the C-2′, C-2′ and C-6′ positions of the E ring of podophyllotoxin can produce more potent compounds. In addition, the configuration of the C-4 position is important for insecticidal activity, and 4β-configuration is optimal. This will pave the way for further design, structural modification, and development of derivatives of podophyllotoxin as insecticidal agents. Graphical
研究领域:
有机化学
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植物保护
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农业科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY
·
2018
·
IF 3.44
Xin-Ru Li,Yue Li,Wei Wang,Ning He,Xiao-Ling Tan,Xue-Qing Yang
Lambda-cyhalothrin has long been recommended as an effective insecticide to control the oriental armyworm , Mythimna separata (Walker), a notorious migratory pest of agricultural plants. Previous researches have suggested that survival, development, and reproduction of insects are influenced by sublethal concentrations of insecticides. However, the effects of sublethal concentrations of lambda-cyhalothrin on M. separata are less known. In this study, we determined the toxicity and effects of LC 20 and LC 50 concentration of lambda-cyhalothrin on development and reproduction of M. separata . Results indicate that LC 20 of lambda-cyhalothrin tends to decrease the life traits of M. separate , with a shortening larvae period of offspring and oviposition period, whereas LC 50 of lambda-cyhalothrin stimulates daily maximal fecundity and forwards the oviposition peak, suggesting a stimulation of reproduction by LC 50 of lambda-cyhalothrin. The M. separata population was increased by an LC 50 concentration of lambda-cyhalothrin, resulting in a net reproductive rate ( R 0 ) and intrinsic rate of increase ( r m ) significantly higher than that of the control. Transcripts of vitellogenin ( MsVg ) and vitellogenin receptor ( MsVgR ) genes were suppressed at day 1 after emergence of moth which developed from the larvae exposed to LC 20 and LC 50 of lambda-cyhalothrin, but were significant induced when the moth begin to lay eggs (day 4), with a more remarkable induction by LC 50 of lambda-cyhalothrin than those of LC 20 of lambda-cyhalothrin. Our results indicate that the observed stimulation of reproduction is therefore the results of up-regulation of MsVg and MsVgR by LC 50 of lambda-cyhalothrin.
研究领域:
昆虫学
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毒理学
·
分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
PEST MANAGEMENT SCIENCE
·
2021
·Vol. 78
·期 3
·1194-1205
·
IF 4.845
Xueqing Yang,Xinru Li,Xinzhu Cang,Jianglong Guo,Xiujing Shen,Kongming Wu
BACKGROUND The seasonal long-distance migration of pests amongst different seasonal habitats may encounter different degrees of insecticide selection pressure, but knowledge of the evolution of resistance and the underlying mechanisms remains sparse. Here, we show that the development of resistance of the oriental armyworm Mythimna separata (Walker), a notorious agricultural pest that migrates between northern and northeast China seasonally across the Bohai Gulf, is influenced by seasonal migration. RESULTS There are two conspicuous migrations of M. separata , the northeastwards population in the second half of May and the returning population in the second half of August, between northern and northeast China per year, and the abundance values of migrants from April to October are significantly different. The resistance levels of seasonal migratory populations to λ-cyhalothrin vary in different months, and the resistance levels and estimated frequency of the resistance allele of the first northeastward population (second half of May, May.-2) in spring are significantly higher than those of the returning populations in autumn. Moreover, resistance decline was observed in migrating population Jul.-2, with the resistance levels in the F 1 progeny higher than those in their F 2 progeny. Synergism tests indicate that cytochrome P450 monooxygenases (P450s) play a major role in resistance. Enzymatic assays show that P450 activity is significantly correlated with resistance levels in migratory populations, indicating that increased P450 activity is the main mechanism of resistance. The expression levels and correlation analysis of the relative expression of P450s with resistance levels show that three ( CYP9A144 , CYP9G40 , and CYP6B79 ) out of 23 genes from CYP6 and CYP9 subfamilies are potentially involved in resistance to λ-cyhalothrin. CONCLUSION Our results show that the resistance of M. separata to λ-cyhalothrin is unstable and likely to be metabolically driven by enhanced P450 activity mediated by the overexpression of multiple P450 genes. Notably, the development of resistance is probably affected by seasonal migration.
研究领域:
昆虫学
·
生态毒理学
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分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
GENE
·
2023
·
IF 3.5
Benshui Shu,Yanzheng Lin,Yuting Huang,Luyang Liu,Xueming Cai,Jintian Lin,Jingjing Zhang
The fall armyworm, Spodoptera frugiperda , is a destructive agricultural pest that seriously threatens global food security. Insecticide resistance of this pest has gradually formed in recent years due to improper usage, and alternative methods are badly needed. Toosendanin (TSN) is a botanical compound with broad-spectrum insecticidal activities against many pests. However, the effects of TSN on S. frugiperda are still unclear. In this study, the growth inhibition phenomenon, including weight loss and prolonged developmental duration, in the larvae with TSN exposure was clearly observed. Compared to the control group, a total of 450 and 3314 differentially expressed genes (DEGs) were identified by RNA-Seq in the larvae groups treated with 10 and 20 mg/kg TSN, respectively. Furthermore, the DEGs involved in the juvenile hormone and ecdysone signal pathways and downstream processes, including detoxifying enzyme genes, chitin synthesis and metabolism genes, and cuticular protein genes, were found. Our findings suggest that TSN regulates the expression of key genes in juvenile hormone and ecdysone signal pathways and a series of downstream processes to alter the hormone balance and cuticle formation and eventually inhibit larval growth, which laid the foundation for the molecular toxicological mechanism research of TSN on S. frugiperda larvae.
研究领域:
昆虫学
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分子生物学
·
毒理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INDUSTRIAL CROPS AND PRODUCTS
·
2019
·
IF 4.191
Xiao-Fei Shang,Zhong-Min Zhao,Jun-Cai Li,Guan-Zhou Yang,Ying-Qian Liu,Li-Xia Dai,Zhi-Jun Zhang,Zhi-Gang Yang,Xiao-Lou Miao,Cheng-Jie Yang,Ji-Yu Zhang
As a well-known herb worldwide, rhubarb presents a wide range of pharmacological activities. In our studies, Rheum palmatum L. extracts and five isolated anthraquinones possessed insecticidal activity. The acetone extract (yield, 8.84%), which contained the highest amount of compounds (82.87 mg/g), showed stronger insecticidal activity than did the aqueous extract (yield, 37.17%) and the ethanol extract (yield, 36.92%). Notable amounts of compounds were also found in water extract residues (18.2 mg/g). Among the isolated quinones and structurally related compounds, emodin exhibited the highest insecticidal activity (LC 50 = 84.30 μg/mL) against Nilarparvata lugens ; and very moderate activity against Mythimna separata (LC 50 = 548.74 μg/mL). The LC 50 values of positive agent toosendanin against two insects were 89.34 and 418.24 μg/mL, respectively. Moreover, emodin exhibited significant AChE and GST inhibitory activities (with respective IC 50 values of 11.36 and 4.18 μg/mL). Plumbagin exhibited stronger and broader antifungal activity against eight phytopathogenic fungi (with EC 50 values ranging from 2.84 to 10.53 μg/mL) compared to a commercial fungicide, azoxystrobin (EC 50 ranging from 20.40 to >100.00 μg/mL). Plumbagin significantly damaged the cell and mitochondrial membrane systems, changed the morphology, triggered the release of cellular contents and generate reactive oxygen species in Rhizoctonia solani mycelia. This study laid the foundation for the future development of emodin and plumbagin as alternative, environmentally friendly bioinsecticide and biofungicide, respectively. Rhubarb and its residues can be used as renewable sources of anthraquinone-based products.
研究领域:
药理学
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植物科学
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害虫管理
·
真菌生物学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）