Expression in Spodoptera frugiperda (Sf21) Insect Cells of BT-R1, a Cadherin-Related Receptor from Manduca sexta for Bacillus thuringiensis Cry1Ab Toxin

2001 ◽  
Vol 22 (1) ◽  
pp. 141-147 ◽  
Author(s):  
Jianxin Meng ◽  
Mehmet Candas ◽  
Timothy P Keeton ◽  
Lee A Bulla
Keyword(s):  
Bacillus Thuringiensis ◽  
Manduca Sexta ◽  
Spodoptera Frugiperda ◽  
Insect Cells ◽  
Cry1ab Toxin

Southern analysis of BT-R 1, the Manduca sexta gene encoding the receptor for the Cry1Ab toxin of Bacillus thuringiensis

1997 ◽  
Vol 256 (5) ◽  
pp. 517-524 ◽  
Author(s):  
S. E. Franklin ◽  
L. Young ◽  
D. Watson ◽  
A. Cigan ◽  
T. Meyer ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Manduca Sexta ◽  
Southern Analysis ◽  
Gene Encoding ◽  
Cry1ab Toxin

scholarly journals Enhancement ofBacillus thuringiensisCry1Ab and Cry1Fa Toxicity toSpodoptera frugiperdaby Domain III Mutations Indicates There Are Two Limiting Steps in Toxicity as Defined by Receptor Binding and Protein Stability

2018 ◽  
Vol 84 (20) ◽  
Author(s):  
Isabel Gómez ◽  
Josue Ocelotl ◽  
Jorge Sánchez ◽  
Christina Lima ◽  
Erica Martins ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Manduca Sexta ◽  
Spodoptera Frugiperda ◽  
Transgenic Maize ◽  
Invasive Pest ◽  
Effective Control ◽  
Alanine Scanning Mutagenesis ◽  
Content Type ◽  
Lepidopteran Pests ◽  
Domain Iii

ABSTRACTBacillus thuringiensisCry1Ab and Cry1Fa toxins are environmentally safe insecticides that control important insect pests.Spodoptera frugiperdais an important maize pest that shows low susceptibility to Cry1A toxins, in contrast to Cry1Fa, which is highly active against this pest and is used in transgenic maize forS. frugiperdacontrol. The β16 region from domain III of Cry1Ab has been shown to be involved in interactions with receptors such as alkaline phosphatase (ALP) or aminopeptidase (APN) in different lepidopteran insects. Alanine-scanning mutagenesis of amino acids of Cry1Ab β16 (509STLRVN514) revealed that certain β16 mutations, such as N514A, resulted in increased toxicity of Cry1Ab forS. frugiperdawithout affecting the toxicity for other lepidopteran larvae, such asManduca sextalarvae. Exhaustive mutagenesis of N514 was performed, showing that the Cry1Ab N514F, N514H, N514K, N514L, N514Q, and N514S mutations increased the toxicity towardS. frugiperda. A corresponding mutation was constructed in Cry1Fa (N507A). Toxicity assays of wild-type and mutant toxins (Cry1Ab, Cry1AbN514A, Cry1AbN514F, Cry1Fa, and Cry1FaN507A) against fourS. frugiperdapopulations from Mexico and one from Brazil revealed that Cry1AbN514A and Cry1FaN507A consistently showed 3- to 18-fold increased toxicity against four of fiveS. frugiperdapopulations. In contrast, Cry1AbN514F showed increased toxicity in only two of theS. frugiperdapopulations analyzed. The mutants Cry1AbN514A and Cry1AbN514F showed greater stability to midgut protease treatment. In addition, binding analysis of the Cry1Ab mutants showed that the increased toxicity correlated with increased binding to brush border membrane vesicles and increased binding affinity forS. frugiperdaALP, APN, and cadherin receptors.IMPORTANCESpodoptera frugiperdais the main maize pest in South and North America and also is an invasive pest in different African countries. However, it is poorly controlled byBacillus thuringiensisCry1A toxins expressed in transgenic crops, which effectively control other lepidopteran pests. In contrast, maize expressing Cry1Fa is effective in the control ofS. frugiperda, although its effectiveness is being lost due to resistance evolution. Some of the Cry1Ab domain III mutants characterized here show enhanced toxicity forS. frugiperdawithout loss of toxicity toManduca sexta. Thus, these Cry1Ab mutants could provide useful engineered toxins that, along with other Cry toxins, would be useful for developing transgenic maize expressing stacked proteins for the effective control ofS. frugiperdaand other lepidopteran pests in the field.

scholarly journals Bacillus thuringiensisCry1Da_7 and Cry1B.868 Protein Interactions with Novel Receptors Allow Control of Resistant Fall Armyworms,Spodoptera frugiperda(J.E. Smith)

2019 ◽  
Vol 85 (16) ◽  
Author(s):  
Yanfei Wang ◽  
Jinling Wang ◽  
Xiaoran Fu ◽  
Jeffrey R. Nageotte ◽  
Jennifer Silverman ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Protein Interactions ◽  
Spodoptera Frugiperda ◽  
Insect Cells ◽  
Fall Armyworm ◽  
Insecticidal Protein ◽  
Row Crops ◽  
Content Type ◽  
Resistance Risk ◽  
Important Pest

ABSTRACTTwo new modifiedBacillus thuringiensis(Bt) proteins, Cry1Da_7 and Cry1B.868, with activity against fall armyworms (FAW),Spodoptera frugiperda(J.E. Smith), were evaluated for their potential to bind new insect receptors compared to proteins currently deployed as plant-incorporated protectants (PIPs) in row crops. Results from resistant insect bioassays, disabled insecticidal protein (DIP) bioassays, and cell-based assays using insect cells expressing individual receptors demonstrate that receptor utilizations of the newly modified Cry1Da_7 and Cry1B.868 proteins are distinct from each other and from those of commercially availableBtproteins such as Cry1F, Cry1A.105, Cry2Ab, and Vip3A. Accordingly, these two proteins target different insect proteins in FAW midgut cells and when pyramided together should provide durability in the field against this economically important pest.IMPORTANCEThere is increased concern with the development of resistance to insecticidal proteins currently expressed in crop plants, especially against high-resistance-risk pests such as fall armyworm (FAW),Spodoptera frugiperda, a maize pest that already has developed resistance toBacillus thuringiensis(Bt) proteins such as Cry1F. Lepidopteran-specific proteins that bind new insect receptors will be critical in managing current Cry1F-resistant FAW and delaying future resistance development. Results from resistant insect assays, disabled insecticidal protein (DIP) bioassays, and cell-based assays using insect cells expressing individual receptors demonstrate that target receptors of the Cry1Da_7 and Cry1B.868 proteins are different from each other and from those of commercially availableBtproteins such as Cry1F, Cry1A.105, Cry2Ab, and Vip3A. Therefore, pyramiding these two new proteins in maize will provide durable control of this economically important pest in production agriculture.

scholarly journals The pre-pore from Bacillus thuringiensis Cry1Ab toxin is necessary to induce insect death in Manduca sexta

Peptides ◽  
2008 ◽  
Vol 29 (2) ◽  
pp. 318-323 ◽  
Author(s):  
N. Jiménez-Juárez ◽  
C. Muñoz-Garay ◽  
I. Gómez ◽  
S.S. Gill ◽  
M. Soberón ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Manduca Sexta ◽  
Cry1ab Toxin

Nitric oxide participates in the toxicity of Bacillus thuringiensis Cry1Ab toxin to kill Manduca sexta larvae

Peptides ◽  
2015 ◽  
Vol 68 ◽  
pp. 134-139 ◽  
Author(s):  
Carolina Chavez ◽  
Benito Recio-Tótoro ◽  
Biviana Flores-Escobar ◽  
Humberto Lanz-Mendoza ◽  
Jorge Sanchez ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Bacillus Thuringiensis ◽  
Manduca Sexta ◽  
Cry1ab Toxin ◽  
Manduca Sexta Larvae
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