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He X, Yang Y, Soberón M, Bravo A, Zhang L, Zhang J, Wang Z. Bacillus thuringiensis Cry9Aa Insecticidal Protein Domain I Helices α3 and α4 Are Two Core Regions Involved in Oligomerization and Toxicity. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024; 72:1321-1329. [PMID: 38175929 DOI: 10.1021/acs.jafc.3c08070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2024]
Abstract
Bacillus thuringiensis Cry9 proteins show high insecticidal activity against different lepidopteran pests. Cry9 could be a valuable alternative to Cry1 proteins because it showed a synergistic effect with no cross-resistance. However, the pore-formation region of the Cry9 proteins is still unclear. In this study, nine mutations of certain Cry9Aa helices α3 and α4 residues resulted in a complete loss of insecticidal activity against the rice pest Chilo suppressalis; however, the protein stability and receptor binding ability of these mutants were not affected. Among these mutants, Cry9Aa-D121R, Cry9Aa-D125R, Cry9Aa-D163R, Cry9Aa-E165R, and Cry9Aa-D167R are unable to form oligomers in vitro, while the oligomers formed by Cry9Aa-R156D, Cry9Aa-R158D, and Cry9Aa-R160D are unstable and failed to insert into the membrane. These data confirmed that helices α3 and α4 of Cry9Aa are involved in oligomerization, membrane insertion, and toxicity. The knowledge of Cry9 pore-forming action may promote its application as an alternative to Cry1 insecticidal proteins.
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Affiliation(s)
- Xiang He
- Anhui Province Engineering Laboratory for Green Pesticide Development and Application, School of Plant Protection, Anhui Agricultural University, Hefei, Anhui Province 230036, China
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Yanchao Yang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Mario Soberón
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Apdo. Postal 510-3, Morelos 62250, Mexico
| | - Alejandra Bravo
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Apdo. Postal 510-3, Morelos 62250, Mexico
| | - Lihong Zhang
- Anhui Province Engineering Laboratory for Green Pesticide Development and Application, School of Plant Protection, Anhui Agricultural University, Hefei, Anhui Province 230036, China
| | - Jie Zhang
- Anhui Province Engineering Laboratory for Green Pesticide Development and Application, School of Plant Protection, Anhui Agricultural University, Hefei, Anhui Province 230036, China
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Zeyu Wang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
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Wu P, Huang Y, Zheng J, Zhang Y, Qiu L. Regulation of CncC in insecticide-induced expression of cytochrome P450 CYP9A14 and CYP6AE11 in Helicoverpa armigera. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2023; 197:105707. [PMID: 38072560 DOI: 10.1016/j.pestbp.2023.105707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Revised: 11/18/2023] [Accepted: 11/21/2023] [Indexed: 12/18/2023]
Abstract
The expression of many detoxification genes can be regulated by CncC pathway and contributes to insecticide tolerance in insects. Our previous study has demonstrated that the transcripts of CncC and cytochrome P450s (CYP9A14, CYP6AE11) were significantly up-regulated after different insecticides treatment in Helicoverpa armigera. Further study indicated that H2O2, GSH, and MDA contents and antioxidant enzyme activities of H. armigera were enhanced after chlorantraniliprole, cyantraniliprole, indoxacarb, and spinosad exposure. Silencing CncC by RNA interference significantly down-regulated the expression levels of CYP9A14 and CYP6AE11, and increased the susceptibility of dsRNA-injected larvae to λ-cyhalothrin, chlorantraniliprole, and cyantraniliprole. On the contrary, applying CncC agonist curcumin on H. armigera induced the expression of CYP9A14 and CYP6AE11, and enhanced the tolerance of H. armigera to insecticides. Treatment of ROS scavenger N-acetylcysteine on H. armigera reduced the H2O2 content and antioxidant enzyme activities, suppressed the transcripts of CncC, CYP9A14, and CYP6AE11, and decreased the larval tolerance to insecticides. These results demonstrated that the induced-expression of CYP9A14 and CYP6AE11 related with insecticides tolerance in H. armigera was regulated by CncC, which may be activated by ROS generated by insecticides. This study will help to better understand the underlying regulation mechanisms of CncC pathway in H. armigera tolerance to insecticides.
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Affiliation(s)
- Peizhuo Wu
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Science, China Agricultural University, Beijing 100193, China
| | - Yun Huang
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Science, China Agricultural University, Beijing 100193, China
| | - Junyue Zheng
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Science, China Agricultural University, Beijing 100193, China
| | - Yu Zhang
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Science, China Agricultural University, Beijing 100193, China
| | - Lihong Qiu
- Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Science, China Agricultural University, Beijing 100193, China.
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Wu LH, Chen YZ, Hsieh FC, Lai CT, Hsieh C. Combined effect of Photorhabdus luminescens and Bacillus thuringiensis subsp. aizawai on Plutella xylostella. Appl Microbiol Biotechnol 2022; 106:2917-2926. [PMID: 35384447 DOI: 10.1007/s00253-022-11905-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 03/16/2022] [Accepted: 03/29/2022] [Indexed: 11/29/2022]
Abstract
In this study, we evaluated a new biopesticide containing different combinations of Photorhabdus luminescens (ATCC 29,999; Pl) and Bacillus thuringiensis subsp. aizawai (Bt) to leverage their insecticidal activity against Plutella xylostella. Mixtures containing proteins of various sizes were assayed to determine which combination of the two bacteria would yield the maximum insecticidal activity. A histopathologic slide revealed vacuole formations and rifts near the apical membrane (a symptom of Bt) and severe thinning of the intestinal wall (a symptom of Pl). When the two bacteria were cultured separately and then mixed, the insecticidal activity of the treatment reached 83.33% ± 8.82%. The insecticidal activity was elevated and significantly accelerated when Bt was mixed with both the Pl supernatant and the isolated protein with a molecular mass [Formula: see text] 100 kDa of Pl. These results highlight the potential of Pl as a potent bioinsecticide to economically and sustainably control Pl. xylostella and other lepidopteran pests. KEY POINTS: • Growth inhibition by Bacillus thuringiensis exerted a significant effect on insecticidal activity. • Large Photorhabdus luminescens proteins can accelerate the synergistic insecticidal effect on Plutella xylostella.
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Affiliation(s)
- L H Wu
- Department of Plant Medicine, National Pingtung University of Science and Technology, Pintung, 91201, Taiwan
| | - Y Z Chen
- Department of Biotechnology, National Kaohsiung Normal University, Kaohsiung, 824444, Taiwan
| | - Feng-Chia Hsieh
- Biopesticides Division, Taiwan Agricultural Chemicals and Toxic Substances Research Institute, Council of Agriculture, Executive Yuan, Taichung, Taiwan
| | - C T Lai
- Department of Plant Medicine, National Pingtung University of Science and Technology, Pintung, 91201, Taiwan
| | - Chienyan Hsieh
- Department of Biotechnology, National Kaohsiung Normal University, Kaohsiung, 824444, Taiwan.
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Tudoran A, Nordlander G, Karlberg A, Puentes A. A major forest insect pest, the pine weevil Hylobius abietis, is more susceptible to Diptera- than Coleoptera-targeted Bacillus thuringiensis strains. PEST MANAGEMENT SCIENCE 2021; 77:1303-1315. [PMID: 33078548 PMCID: PMC7894551 DOI: 10.1002/ps.6144] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 10/05/2020] [Accepted: 10/19/2020] [Indexed: 05/13/2023]
Abstract
BACKGROUND The pine weevil (Hylobius abietis) is a major forest regeneration pest causing high levels of seedling mortality and economic losses. Current management relies on silviculture, stem coatings and insecticides. Here we evaluated for the first time the effects of Bacillus thuringiensis (Bt) strains on H. abietis adults: two producing the Coleoptera-targeted toxins Cry3Aa (Bt tenebrionis NB-176) and Cry8Da (Bt galleriae SDS-502), and one producing the Diptera-targeted Cry10A (Bt israelensis AM65-52). Choice and nonchoice assays using individual and mixtures of Bt formulations, containing these strains respectively, were conducted. RESULTS We found that Bt had toxic and lethal effects on H. abietis, but effects varied with strain and formulation concentration. The Diptera-targeted Bt israelensis had the most negative effects on weevil weight, feeding and mortality (70-82% feeding reduction, 65-82% greater mortality than control), whereas the effect was lower for the Coleoptera-specific Bt tenebrionis (38-42%; 37-42%) and Bt galleriae (11-30%; 15-32%). Reduced weevil feeding was observed after 3 days, and the highest mortality occurred 7-14 days following Bt exposure. However, we found no synergistic toxic effects, and no formulation combination was better than Bt israelensis alone at reducing consumption and survival. Also, pine weevils were not deterred by Bt, feeding equally on Bt-treated and non-Bt treated food. CONCLUSION There is potential to develop forest pest management measures against H. abietis that include Bt, but only the Diptera-targeted Bt israelensis would provide effective seedling protection. Its Diptera-specificity may need reconsideration, and evaluation of other Bt strains/toxins against H. abietis would be of interest. © 2020 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
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Affiliation(s)
- Amelia Tudoran
- Department of EcologySwedish University of Agricultural Sciences (SLU)UppsalaSweden
- Department of Plant ProtectionUniversity of Agricultural Sciences and Veterinary Medicine of Cluj‐Napoca (USAMV Cluj Napoca)Cluj‐NapocaRomania
| | - Göran Nordlander
- Department of EcologySwedish University of Agricultural Sciences (SLU)UppsalaSweden
| | | | - Adriana Puentes
- Department of EcologySwedish University of Agricultural Sciences (SLU)UppsalaSweden
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Shwe SM, Wang Y, Gao Z, Li X, Liu S, Bai S, Zhang T, He K, Wang Z. Toxicity of Cry1-Class, Cry2Aa, and Vip3Aa19 Bt proteins and their interactions against yellow peach Moth, Conogethes punctiferalis (Guenée) (Lepidoptera: Crambidae). J Invertebr Pathol 2020; 178:107507. [PMID: 33249063 DOI: 10.1016/j.jip.2020.107507] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 11/20/2020] [Accepted: 11/21/2020] [Indexed: 12/30/2022]
Abstract
Transgenic plants expressing insecticidal proteins from the Bacillus thuringiensis (Bt) have provided an effective way to control target pests. However, the toxicity of Bt proteins against yellow peach moth (YPM), Conogethes punctiferalis (Guenée), one of the most serious maize pests in China, has not received much study. Therefore, we performed diet-overlay bioassays to evaluate the insecticidal activities of Cry1Ab, Cry1Ac, Cry1Fa, Cry1Ah, Cry1Ie, Cry2Aa, and Vip3Aa19, as well as the interaction between Cry1-Class, Cry2Aa, and Vip3Aa19 against YPM. Results showed that the LC50 values ranged from 1.08 to 178.12 ng/cm2 (protein/diet). Among these proteins, Cry1Ab and Cry1Ac had lower LC50 values and LC90 values. In YPM bioassays, the combinations of Cry2Aa with Cry1Ac, Cry1Ie, and Cry1Ab showed antagonism while a mixture of Cry2Aa with Cry1Fa and Cry1Ah exhibited synergism. When Vip3Aa19 was combined with Cry proteins, all combinations interacted positively, with variation in synergistic factors (SF). Three ratios 1:1, 1:2, and 2:1 of Cry1Ah and Vip3Aa19 protein combination showed SF values of 5.20, 5.63, and 8.98, respectively. These findings can be applied in the establishment of new pyramided transgenic crops with suitable candidates as well as in resistance management strategies.
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Affiliation(s)
- Su Mon Shwe
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, No. 2, West Yuanmingyuan Road, Beijing 100193, China
| | - Yueqin Wang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, No. 2, West Yuanmingyuan Road, Beijing 100193, China
| | - Zupeng Gao
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, No. 2, West Yuanmingyuan Road, Beijing 100193, China; Engineering Research Center of Natural Enemy Insects/Institute of Biological Control, Jilin Agricultural University, Changchun 130118, China
| | - Xue Li
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, No. 2, West Yuanmingyuan Road, Beijing 100193, China; Plant Protection College, Hebei Agricultural University, Baoding 071000, China
| | - Shen Liu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, No. 2, West Yuanmingyuan Road, Beijing 100193, China
| | - Shuxiong Bai
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, No. 2, West Yuanmingyuan Road, Beijing 100193, China
| | - Tiantao Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, No. 2, West Yuanmingyuan Road, Beijing 100193, China
| | - Kanglai He
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, No. 2, West Yuanmingyuan Road, Beijing 100193, China
| | - Zhenying Wang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, No. 2, West Yuanmingyuan Road, Beijing 100193, China.
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González-Villarreal SE, García-Montelongo M, Ibarra JE. Insecticidal Activity of a Cry1Ca toxin of Bacillus thuringiensis Berliner (Firmicutes: Bacillaceae) and Its Synergism with the Cyt1Aa Toxin Against Aedes aegypti (Diptera: Culicidae). JOURNAL OF MEDICAL ENTOMOLOGY 2020; 57:1852-1856. [PMID: 32537634 DOI: 10.1093/jme/tjaa116] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Indexed: 06/11/2023]
Abstract
The Cry1C protein family of Bacillus thuringiensis form bipyramidal crystals, which are commonly associated with toxic activity against lepidopteran species; however, some members of this family may also be toxic to dipterans. In the present work, the Cry1Ca16 protein, synthesized by the B. thuringiensis LBIT-1217 strain, was analyzed. The gene coding for this protein was amplified, sequenced, and cloned into the pSTAB vector, which was electro-transferred into the acrystalliferous B. thuringiensis 4Q7 strain. The recombinant strain showed the expected bipyramidal crystal morphology, identical to the original LBIT-1217 strain and exhibited toxicity against larvae of Aedes aegypti (Diptera). Pure crystals from the recombinant strain were used in bioassays against Ae. aegypti larvae, estimating an LC50 of 4.61 μg/ml. Further studies on Cry1Ca16 mosquitocidal potential included joint-action tests with the Cyt1Aa protein crystals from B. thuringiensis israelensis. An LC50 using pure Cyt1Aa crystals was estimated at 0.73 μg/ml, whereas an LC50 of 0.61 μg/ml was estimated when both toxins were tested together. Data from these bioassays was analyzed using joint-action tests such as the Tammes-Bakuniak graphical method and the formula proposed by Tabashnik (1992). Both tests clearly showed a synergistic effect between these two toxins.
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Affiliation(s)
| | - Mónica García-Montelongo
- Centro de Investigación y Estudios Avanzados del IPN, Unidad Irapuato, Irapuato, Guanajuato, Mexico
| | - Jorge E Ibarra
- Centro de Investigación y Estudios Avanzados del IPN, Unidad Irapuato, Irapuato, Guanajuato, Mexico
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7
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Baranek J, Pogodziński B, Szipluk N, Zielezinski A. TOXiTAXi: a web resource for toxicity of Bacillus thuringiensis protein compositions towards species of various taxonomic groups. Sci Rep 2020; 10:19767. [PMID: 33188218 PMCID: PMC7666212 DOI: 10.1038/s41598-020-75932-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 09/29/2020] [Indexed: 11/20/2022] Open
Abstract
Bioinsecticides consisting of different sets of Bacillus thuringiensis (Bt) Cry, Cyt and Vip toxins are broadly used in pest control. Possible interactions (synergistic, additive or antagonistic) between these proteins can not only influence the overall efficacy of certain Bt-based bioinsecticide, but also raise questions regarding environmental safety. Here, we assemble, summarize and analyze the outcomes of experiments published over 30 years, investigating combinatorial effects among Bt Cry, Cyt and Vip toxins. We collected the results on 118 various two-to-five-component combinations that have been bioassayed against 38 invertebrate species. Synergism, additive effect and antagonism was indicated in 54%, 32% and 14% of experiments, respectively. Synergism was noted most frequently for Cry/Cyt combinations, followed by Cyt/Vip and Cry/Cry. In Cry/Vip combinations, antagonism is more frequent and higher in magnitude compared to other categories. Despite a significant number of tested Bt toxin combinations, most of them have been bioassayed only against one pest species. To aid the research on Bt pesticidal protein activity, we present TOXiTAXi ( http://www.combio.pl/toxitaxi/ ), a universal database and a dedicated web tool to conveniently gather and analyze the existing and future bioassay results on biocidal activity of toxins against various taxonomic groups.
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Affiliation(s)
- Jakub Baranek
- Department of Microbiology, Faculty of Biology, Adam Mickiewicz University in Poznan, Uniwersytetu Poznanskiego 6, 61-614, Poznan, Poland.
| | - Bartłomiej Pogodziński
- Department of Computational Biology, Faculty of Biology, Adam Mickiewicz University in Poznan, Uniwersytetu Poznanskiego 6, 61-614, Poznan, Poland
| | - Norbert Szipluk
- Department of Microbiology, Faculty of Biology, Adam Mickiewicz University in Poznan, Uniwersytetu Poznanskiego 6, 61-614, Poznan, Poland
| | - Andrzej Zielezinski
- Department of Computational Biology, Faculty of Biology, Adam Mickiewicz University in Poznan, Uniwersytetu Poznanskiego 6, 61-614, Poznan, Poland
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Sato R, Adegawa S, Li X, Tanaka S, Endo H. Function and Role of ATP-Binding Cassette Transporters as Receptors for 3D-Cry Toxins. Toxins (Basel) 2019; 11:E124. [PMID: 30791434 PMCID: PMC6409751 DOI: 10.3390/toxins11020124] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 02/13/2019] [Accepted: 02/15/2019] [Indexed: 12/20/2022] Open
Abstract
When ABC transporter family C2 (ABCC2) and ABC transporter family B1 (ABCB1) were heterologously expressed in non-susceptible cultured cells, the cells swelled in response to Cry1A and Cry3 toxins, respectively. Consistent with the notion that 3D-Cry toxins form cation-permeable pores, Bombyx mori ABCC2 (BmABCC2) facilitated cation-permeable pore formation by Cry1A when expressed in Xenopus oocytes. Furthermore, BmABCC2 had a high binding affinity (KD) to Cry1Aa of 3.1 × 10-10 M. These findings suggest that ABC transporters, including ABCC2 and ABCB1, are functional receptors for 3D-Cry toxins. In addition, the Cry2 toxins most distant from Cry1A toxins on the phylogenetic tree used ABC transporter A2 as a receptor. These data suggest that 3D-Cry toxins use ABC transporters as receptors. In terms of inducing cell swelling, ABCC2 has greater activity than cadherin-like receptor. The pore opening of ABC transporters was hypothesized to be linked to their receptor function, but this was repudiated by experiments using mutants deficient in export activity. The synergistic relationship between ABCC2 and cadherin-like receptor explains their ability to cause resistance in one species of insect.
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Affiliation(s)
- Ryoichi Sato
- Graduate School of Bio-Applications and Systems Engineering, Tokyo University of Agriculture and Technology, Naka 2-24-16, Koganei, Tokyo 184-8588, Japan.
| | - Satomi Adegawa
- Graduate School of Bio-Applications and Systems Engineering, Tokyo University of Agriculture and Technology, Naka 2-24-16, Koganei, Tokyo 184-8588, Japan.
| | - Xiaoyi Li
- Graduate School of Bio-Applications and Systems Engineering, Tokyo University of Agriculture and Technology, Naka 2-24-16, Koganei, Tokyo 184-8588, Japan.
| | - Shiho Tanaka
- Graduate School of Bio-Applications and Systems Engineering, Tokyo University of Agriculture and Technology, Naka 2-24-16, Koganei, Tokyo 184-8588, Japan.
| | - Haruka Endo
- Graduate School of Bio-Applications and Systems Engineering, Tokyo University of Agriculture and Technology, Naka 2-24-16, Koganei, Tokyo 184-8588, Japan.
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Qiu X, Lu X, Ren X, Li R, Wu B, Yang S, Qi L, Mo X, Ding X, Xia L, Sun Y. Solubility enhancement of Cry2Aa crystal through carboxy-terminal extension and synergism between the chimeric protein and Cry1Ac. Appl Microbiol Biotechnol 2019; 103:2243-2250. [PMID: 30617818 DOI: 10.1007/s00253-018-09606-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 12/26/2018] [Accepted: 12/28/2018] [Indexed: 11/26/2022]
Abstract
It was reported that the highly conserved C-terminal region of Bacillus thuringiensis Cry1A protoxins was very important for parasporal crystal formation and solubility feature in alkaline environment. In order to improve the solubilization efficiency of Cry2Aa crystal, the coding sequences of Cry2Aa protein and the C-terminal half of Cry1Ac were fused seamlessly through Red/ET homologous recombination and expressed in an acrystalliferous B. thuringiensis strain under the control of the cry1Ac promoter and terminator. Microscopic observation revealed that the recombinant strain containing the chimeric gene cry2Aa-1Ac produced distinct parasporal inclusion with semispherical to approximately cuboidal shape during sporulation. SDS-PAGE analysis showed that this strain expressed stable 130-kDa Cry2Aa-1Ac chimeric protein, which was confirmed to be the correctly expressed product by LC-MS/MS. The chimeric protein inclusion could be effectively dissolved at pH 10.5 and activated by trypsin like the parental Cry1Ac crystal. While, the parental Cry2Aa crystal exhibited very low solubility under this condition. Bioassays against third-instar larvae of Helicoverpa armigera proved that the chimeric protein was more toxic than Cry2Aa. Additionally, synergistic effect was clearly detected between the chimeric protein and Cry1Ac against H. armigera, while there was only additive effect for the combination of wild Cry2Aa and Cry1Ac. These results indicated that the developed chimeric protein might serve as a potent insecticidal toxin used in the field against lepidopteran pests.
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Affiliation(s)
- Xianfeng Qiu
- College of Life Science, State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Normal University, Changsha, 410081, People's Republic of China
| | - Xiuqing Lu
- College of Life Science, State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Normal University, Changsha, 410081, People's Republic of China
| | - Xiaomeng Ren
- College of Life Science, State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Normal University, Changsha, 410081, People's Republic of China
| | - Ran Li
- College of Life Science, State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Normal University, Changsha, 410081, People's Republic of China
| | - Binbin Wu
- College of Life Science, State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Normal University, Changsha, 410081, People's Republic of China
| | - Sisi Yang
- College of Life Science, State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Normal University, Changsha, 410081, People's Republic of China
| | - Lingling Qi
- College of Life Science, State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Normal University, Changsha, 410081, People's Republic of China
| | - Xiangtao Mo
- College of Life Science, State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Normal University, Changsha, 410081, People's Republic of China
| | - Xuezhi Ding
- College of Life Science, State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Normal University, Changsha, 410081, People's Republic of China
| | - Liqiu Xia
- College of Life Science, State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Normal University, Changsha, 410081, People's Republic of China
| | - Yunjun Sun
- College of Life Science, State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Normal University, Changsha, 410081, People's Republic of China.
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Walters FS, Graser G, Burns A, Raybould A. When the Whole is Not Greater than the Sum of the Parts: A Critical Review of Laboratory Bioassay Effects Testing for Insecticidal Protein Interactions. ENVIRONMENTAL ENTOMOLOGY 2018; 47:484-497. [PMID: 29432611 PMCID: PMC5888968 DOI: 10.1093/ee/nvx207] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Many studies have been conducted to investigate synergism among insecticidal proteins; however, a consensus on minimal data requirements and interpretation is lacking. While some have concluded that all additive predictive-type models should be abandoned, we advocate that additivity models can remain useful as assessment tools and that an appropriately designed interaction study will never systematically underestimate the existence of synergism, irrespective of which additivity model (or none at all) may be used. To generate the most meaningful synergy assessment datasets in support of safety assessments, we highlight two beneficial steps to follow: (i) select a testing model which is the most consistent with current knowledge regarding the action of the insecticidal proteins and (ii) avoid using bioassay methods which may result in excess response heterogeneity. We also outline other experimental design elements to consider, which may be crucial for conducting future studies of this type. A contrast of underlying testing assumptions associated with the additivity models is provided, along with a comprehensive review of interaction data for Cry1, Cry2, Cry3, Cry9, and Vip3A insecticidal proteins. Our review captures four recurrent findings: i) experiments reporting synergistic interactions are a minority, ii) the degree of synergism reported is low in magnitude, iii) reported interactions are sometimes equivocal/inconclusive due to unconfirmed model assumptions or other bioassay challenges, and iv) due to biological response variation many of the reported interactions may be artefactual. A brief overview of the positioning of interaction testing data in safety assessments of GM food crops is also provided.
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Affiliation(s)
| | - Gerson Graser
- Syngenta Crop Protection, LLC, Davis Drive, Durham, NC, USA
| | - Andrea Burns
- Syngenta Crop Protection, LLC, Davis Drive, Durham, NC, USA
| | - Alan Raybould
- Syngenta Crop Protection AG, Schwarzwaldallee, Basel, Switzerl
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Moore MR, Cave RD, Branham MA. Annotated catalog and bibliography of the cyclocephaline scarab beetles (Coleoptera, Scarabaeidae, Dynastinae, Cyclocephalini). Zookeys 2018; 745:101-378. [PMID: 29670449 PMCID: PMC5904534 DOI: 10.3897/zookeys.745.23685] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Indexed: 11/12/2022] Open
Abstract
Cyclocephaline scarab beetles represent the second largest tribe of the subfamily Dynastinae, and the group includes the most speciose genus of dynastines, Cyclocephala. The period following publication of Sebő Endrődi's The Dynastinae of the World has seen a huge increase in research interest on cyclocephalines, and much of this research has not been synthesized. The objective of this catalog and bibliography is to compile an exhaustive list of taxa in Cyclocephalini. This paper provides an updated foundation for understanding the taxonomy and classification of 14 genera and over 500 species in the tribe. It discusses the history of cataloging dynastine species, clarifies issues surrounding the neotype designations in Endrődi's revision of Cyclocephalini, synthesizes all published distribution data for cyclocephaline species, and increases accessibility to the voluminous literature on the group by providing an easily searchable bibliography for each species. We propose the nomen novum Cyclocephala rogerpauli, new replacement name, for C. nigra Dechambre.
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Affiliation(s)
- Matthew R. Moore
- Department of Entomology and Nematology, University of Florida, Building 1881 Natural Area Drive, Steinmetz Hall, Gainesville, FL 32611, USA
| | - Ronald D. Cave
- Department of Entomology and Nematology, University of Florida, Indian River Research and Education Center, 2199 South Rock Road, Fort Pierce, FL 34945, USA
| | - Marc A. Branham
- Department of Entomology and Nematology, University of Florida, Building 1881 Natural Area Drive, Steinmetz Hall, Gainesville, FL 32611, USA
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12
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Hatting JL, Moore SD, Malan AP. Microbial control of phytophagous invertebrate pests in South Africa: Current status and future prospects. J Invertebr Pathol 2018; 165:54-66. [PMID: 29427636 DOI: 10.1016/j.jip.2018.02.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 01/26/2018] [Accepted: 02/06/2018] [Indexed: 01/08/2023]
Abstract
Invertebrate pests pose a significant threat to food security on the African continent. In response, South Africa has become one of the largest importers of chemical pesticides in sub-Saharan Africa, with several hundred active ingredients registered. To address the over-reliance on such chemicals, the South African Department of Agriculture, Forestry and Fisheries (DAFF) has eliminated or restricted several pesticides since the late 1970s. The recent launch of the South African National Bio-Economy Strategy and establishment of the South African Bioproducts Organisation (SABO), together with new guidelines for registration of biopesticides in 2015, also support this endeavour. Concurrently, entomopathogen-related research and bioproduct development has increased over the past decade. Currently, 31 products (seven manufactured locally) are registered under the Fertilizers, Farm Feeds, Agricultural Remedies and Stock Remedies Act 36 of 1947. Commercially important microbes include Beauveria bassiana (Cordycipitaceae), Metarhizium anisopliae (Clavicipitaceae), Cydia pomonella granulovirus, Cryptophlebia leucotreta granulovirus, Helicoverpa armigera nucleopolyhedrovirus (Baculoviridae) and Bacillus thuringiensis subsp. kurstaki and B. thuringiensis subsp. aizawai (Bacillaceae). Both parasitic and entomopathogenic nematodes (EPNs) show potential for development as bioinsecticides with one commercial EPN product, based on Heterorhabditis bacteriophora (Heterorhabditidae), registered under the Act. Rapid scientific progression, supported by a favourable legislative environment, should facilitate further advances in microbial control of phytophagous invertebrate pests in South Africa.
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Affiliation(s)
- Justin L Hatting
- Agricultural Research Council-Small Grain, Bethlehem 9700, South Africa.
| | - Sean D Moore
- Citrus Research International, Port Elizabeth 6065, South Africa; Centre for Biological Control, Department of Zoology and Entomology, Rhodes University, Grahamstown 6140, South Africa
| | - Antoinette P Malan
- Department of Conservation Ecology and Entomology, Stellenbosch University, 7602, South Africa
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Yilmaz S, Azizoglu U, Ayvaz A, Temizgul R, Atciyurt ZB, Karabörklü S. Cloning and expression of cry2Aa from native Bacillus thuringiensis strain SY49-1 and its insecticidal activity against Culex pipiens (Diptera: Culicidae). Microb Pathog 2017; 105:81-85. [PMID: 28215855 DOI: 10.1016/j.micpath.2017.02.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Revised: 02/10/2017] [Accepted: 02/10/2017] [Indexed: 01/20/2023]
Abstract
Bacillus thuringiensis (Berliner) (Bt) is well known for having toxicity against pest insects because of their ability to form endospores and broad-range activity of their parasporal inclusions. In this study, a new member of cry2A gene from previously characterized native B. thuringiensis SY49-1 strain was cloned, expressed and used for its activity against Culex pipiens (Diptera: Culicidae) larvae. The sequence analysis of the cloned cry2A gene revealed that it encodes a polypeptide of 633 aa residues with 99% identity to Cry2Aa protein with expected molecular weight of 70.7 kDa. Bacillus thuringiensis delta-endotoxin nomenclature committee designed our sequence as Cry2Aa18 being a new member of Bt toxins. Bioassays against last instar larvae of C. pipiens indicated that Cry2Aa18 has considerable toxicity with LC50 of 630 μg ml-1. In order to prevent the spread of infectious diseases mediated by C. pipiens, this newly characterized cry2Aa18 gene could constitute as an important biological control tool for controlling mosquito larvae living in freshwater systems and can be used as a good alternative for minimizing the use of chemicals.
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Affiliation(s)
- Semih Yilmaz
- Department of Agricultural Biotechnology, Erciyes University, Kayseri, Turkey.
| | - Ugur Azizoglu
- Department of Crop and Animal Production, Erciyes University, Tomarza Mustafa Akıncıoğlu Vocational College, Kayseri, Turkey.
| | - Abdurrahman Ayvaz
- Department of Biology, Faculty of Science, Erciyes University, Kayseri, Turkey.
| | | | - Zehra Büşra Atciyurt
- Graduate School of Natural and Applied Sciences, Erciyes University, Kayseri, Turkey.
| | - Salih Karabörklü
- Department of Field Crops, Faculty of Agriculture and Natural Science, Düzce University, Düzce, Turkey.
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Lemes ARN, Figueiredo CS, Sebastião I, Marques da Silva L, da Costa Alves R, de Siqueira HÁA, Lemos MVF, Fernandes OA, Desidério JA. Cry1Ac and Vip3Aa proteins from Bacillus thuringiensis targeting Cry toxin resistance in Diatraea flavipennella and Elasmopalpus lignosellus from sugarcane. PeerJ 2017; 5:e2866. [PMID: 28123906 PMCID: PMC5244881 DOI: 10.7717/peerj.2866] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 12/06/2016] [Indexed: 01/30/2023] Open
Abstract
The biological potential of Vip and Cry proteins from Bacillus is well known and widely established. Thus, it is important to look for new genes showing different modes of action, selecting those with differentiated entomotoxic activity against Diatraea flavipennella and Elasmopalpus lignosellus, which are secondary pests of sugarcane. Therefore, Cry1 and Vip3 proteins were expressed in Escherichia coli, and their toxicities were evaluated based on bioassays using neonate larvae. Of those, the most toxic were Cry1Ac and Vip3Aa considering the LC50 values. Toxins from E. coli were purified, solubilized, trypsinized, and biotinylated. Brush Border Membrane Vesicles (BBMVs) were prepared from intestines of the two species to perform homologous and heterologous competition assays. The binding assays demonstrated interactions between Cry1Aa, Cry1Ac, and Vip3Aa toxins and proteins from the BBMV of D. flavipennella and E. lignosellus. Homologous competition assays demonstrated that binding to one of the BBMV proteins was specific for each toxin. Heterologous competition assays indicated that Vip3Aa was unable to compete for Cry1Ac toxin binding. Our results suggest that Cry1Ac and Vip3Aa may have potential in future production of transgenic sugarcane for control of D. flavipennella and E. lignosellus, but more research is needed on the potential antagonism or synergism of the toxins in these pests.
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Affiliation(s)
- Ana Rita Nunes Lemes
- Department of Biologia Aplicada á Agropecuária, Universidade Estadual Paulista, Jaboticabal, São Paulo, Brazil
| | - Camila Soares Figueiredo
- Department of Biologia Aplicada á Agropecuária, Universidade Estadual Paulista, Jaboticabal, São Paulo, Brazil
| | - Isis Sebastião
- Department of Biologia Aplicada á Agropecuária, Universidade Estadual Paulista, Jaboticabal, São Paulo, Brazil
| | | | - Rebeka da Costa Alves
- Department of Agronomia, Universidade Federal Rural de Pernambuco, Recife, Pernambuco, Brazil
| | | | - Manoel Victor Franco Lemos
- Department of Biologia Aplicada á Agropecuária, Universidade Estadual Paulista, Jaboticabal, São Paulo, Brazil
| | - Odair Aparecido Fernandes
- Departamento de Fitossanidade/FCAV/UNESP, Universidade Estadual Paulista, Jaboticabal, São Paulo, Brazil
| | - Janete Apparecida Desidério
- Department of Biologia Aplicada á Agropecuária, Universidade Estadual Paulista, Jaboticabal, São Paulo, Brazil
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Elleuch J, Jaoua S, Ginibre C, Chandre F, Tounsi S, Zghal RZ. Toxin stability improvement and toxicity increase against dipteran and lepidopteran larvae of Bacillus thuringiensis crystal protein Cry2Aa. PEST MANAGEMENT SCIENCE 2016; 72:2240-2246. [PMID: 26910489 DOI: 10.1002/ps.4261] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Revised: 01/24/2016] [Accepted: 02/17/2016] [Indexed: 06/05/2023]
Abstract
BACKGROUND Bacillus thuringiensis δ-endotoxins are the most widely used biopesticides for controlling economically important crop pests and disease vectors. Improving their efficacy is of great benefit. Here, an improvement in Cry2Aa δ-endotoxin toxicity was attempted via a cry gene over expression system using P20 from B. thuringiensis israelensis. RESULTS The coexpression of Cry2Aa with P20 resulted in a seven fold increase in its production yield in B. thuringiensis. Generated crystals proved to be significantly more toxic (505.207 µg g-1 , 1.99 mg L-1 and 1.49 mg L-1 ) than the P20-lacking control (720.78 µg g-1 , 705.69 mg L-1 and 508.51 mg L-1 ) against Ephestia kuehniella, Aedes aegypti and Culex pipiens larvae respectively. In vitro, processing experiments revealed a P20-mediated protection of Cry2Aa against degradation under larval gut conditions. Thus, P20 could promote the maintenance of a tightly packaged conformation of Cry2Aa toxins in the larval midgut upon correct activation and binding to its membrane receptors. CONCLUSION Based on their resistance against excessive proteolysis, Cry2Aa δ-endotoxins, produced in the presence of P20, could be considered as a successful control agent for E. kuehniella and an effective alternative for mosquito control, implying its possible exploitation in pest management programmes. © 2016 Society of Chemical Industry.
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Affiliation(s)
- Jihen Elleuch
- Laboratory of Biopesticides, Centre of Biotechnology of Sfax, University of Sfax, Sfax, Tunisia
| | - Samir Jaoua
- Department of Biological and Environmental Sciences, College of Arts Sciences, Qatar University, Doha, Qatar
| | - Carole Ginibre
- Institut de Recherche pour le Développement (IRD), UMR MIVEGEC (UM1-UM2-CNRS 5290-IRD 224) Maladies Infectieuses et Vecteurs, Ecologie, Génétique, Evolution et Contrôle, Laboratoire de Lutte contre les Insectes Nuisibles (LIN), Montpellier, France
| | - Fabrice Chandre
- Institut de Recherche pour le Développement (IRD), UMR MIVEGEC (UM1-UM2-CNRS 5290-IRD 224) Maladies Infectieuses et Vecteurs, Ecologie, Génétique, Evolution et Contrôle, Laboratoire de Lutte contre les Insectes Nuisibles (LIN), Montpellier, France
| | - Slim Tounsi
- Laboratory of Biopesticides, Centre of Biotechnology of Sfax, University of Sfax, Sfax, Tunisia
| | - Raida Z Zghal
- Laboratory of Biopesticides, Centre of Biotechnology of Sfax, University of Sfax, Sfax, Tunisia.
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Katara JL, Kaur S, Kumari GK, Singh NK. Prevalence of cry2-type genes in Bacillus thuringiensis isolates recovered from diverse habitats in India and isolation of a novel cry2Af2 gene toxic to Helicoverpa armigera (cotton boll worm). Can J Microbiol 2016; 62:1003-1012. [DOI: 10.1139/cjm-2016-0042] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Insecticidal cry and vip genes from Bacillus thuringiensis (Bt) have been used for control of lepidopteran insects in transgenic crops. However, novel genes are required for gene pyramiding to delay evolution of resistance to the currently deployed genes. Two PCR-based techniques were employed for screening of cry2-type genes in 129 Bt isolates from diverse habitats in India and 27 known Bt strains. cry2Ab-type genes were more prevalent than cry2Aa- and cry2Ac-type genes. Correlation between source of isolates and abundance of cry2-type genes was not observed. Full-length cry2A-type genes were amplified by PCR from 9 Bt isolates and 4 Bt strains. The genes from Bt isolates SK-758 from Sorghum grain dust and SK-793 from Chilli seeds warehouse, Andhra Pradesh, were cloned and sequenced. The gene from SK-758 (NCBI GenBank accession No. GQ866915) was novel, while that from SK-793 (NCBI GenBank accession No. GQ866914) was identical to the cry2Ab1 gene. The Bacillus thuringiensis Nomenclature Committee ( http://www.lifesci.sussex.ac.uk/home/Neil_Crickmore/Bt/toxins2.html ) named these genes cry2Af2 and cry2Ab16, respectively. The cry2Af2 gene was expressed in Escherichia coli and found to be toxic towards Helicoverpa armigera. The cry2Af2 gene will be useful for pyramiding in transgenic crops.
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Affiliation(s)
- Jawahar Lal Katara
- Indian Council of Agricultural Research (ICAR) – National Research Centre on Plant Biotechnology, Indian Agricultural Research Institute Campus, New Delhi 110012, India
- Indian Council of Agricultural Research (ICAR) – National Research Centre on Plant Biotechnology, Indian Agricultural Research Institute Campus, New Delhi 110012, India
| | - Sarvjeet Kaur
- Indian Council of Agricultural Research (ICAR) – National Research Centre on Plant Biotechnology, Indian Agricultural Research Institute Campus, New Delhi 110012, India
- Indian Council of Agricultural Research (ICAR) – National Research Centre on Plant Biotechnology, Indian Agricultural Research Institute Campus, New Delhi 110012, India
| | - Gouthami Krishna Kumari
- Indian Council of Agricultural Research (ICAR) – National Research Centre on Plant Biotechnology, Indian Agricultural Research Institute Campus, New Delhi 110012, India
- Indian Council of Agricultural Research (ICAR) – National Research Centre on Plant Biotechnology, Indian Agricultural Research Institute Campus, New Delhi 110012, India
| | - Nagendra Kumar Singh
- Indian Council of Agricultural Research (ICAR) – National Research Centre on Plant Biotechnology, Indian Agricultural Research Institute Campus, New Delhi 110012, India
- Indian Council of Agricultural Research (ICAR) – National Research Centre on Plant Biotechnology, Indian Agricultural Research Institute Campus, New Delhi 110012, India
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Azizoglu U, Ayvaz A, Yılmaz S, Karabörklü S, Temizgul R. Expression of cry1Ab gene from a novel Bacillus thuringiensis strain SY49-1 active on pest insects. Braz J Microbiol 2016; 47:597-602. [PMID: 27143037 PMCID: PMC4927682 DOI: 10.1016/j.bjm.2016.04.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 11/24/2015] [Indexed: 11/17/2022] Open
Abstract
In this study, the cry1Ab gene of previously characterized and Lepidoptera-, Diptera-, and Coleoptera-active Bacillus thuringiensis SY49-1 strain was cloned, expressed and individually tested on Ephestia kuehniella (Lepidoptera: Pyralidae) and Plodia interpunctella (Lepidoptera: Pyralidae) larvae. pET-cry1Ab plasmids were constructed by ligating the cry1Ab into pET28a (+) expression vector. Constructed plasmids were transferred to an Escherichia coli BL21 (DE3) strain rendered competent with CaCl2. Isopropyl β-d-1-thiogalactopyranoside was used to induce the expression of cry1Ab in E. coli BL21(DE3), and consequently, ∼130kDa of Cry1Ab was obtained. Bioassay results indicated that recombinant Cry1Ab at a dose of 1000μgg(-1) caused 40% and 64% mortality on P. interpunctella and E. kuehniella larvae, respectively. However, the mortality rates of Bt SY49-1 strains' spore-crystal mixture at the same dose were observed to be 70% on P. interpunctella and 90% on E. kuehniella larvae. The results indicated that cry1Ab may be considered as a good candidate in transgenic crop production and as an alternative biocontrol agent in controlling stored product moths.
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Affiliation(s)
- Ugur Azizoglu
- Erciyes University, Department of Crop and Animal Production, Kayseri, Turkey.
| | | | - Semih Yılmaz
- Erciyes University, Department of Agricultural Biotechnology, Kayseri, Turkey
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Fang L, Wang B, Zhou Z, Yang S, Shu C, Song F, Bravo A, Soberón M, Zhang J. Oligomerization of Cry9Aa in solution without receptor binding, is not related with insecticidal activity. ELECTRON J BIOTECHN 2016. [DOI: 10.1016/j.ejbt.2016.02.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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