scholarly journals Characterization of Chimeric Bacillus thuringiensis Vip3 Toxins

2006 ◽  
Vol 73 (3) ◽  
pp. 956-961 ◽  
Author(s):  
Jun Fang ◽  
Xiaoli Xu ◽  
Ping Wang ◽  
Jian-Zhou Zhao ◽  
Anthony M. Shelton ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Trichoplusia Ni ◽  
European Corn Borer ◽  
Insect Pest ◽  
Chimeric Protein ◽  
Fall Armyworm ◽  
Terminal Region ◽  
Cabbage Looper ◽  
Cross Resistance ◽  
Corn Borer

ABSTRACT Bacillus thuringiensis vegetative insecticidal proteins (Vip) are potential alternatives for B. thuringiensis endotoxins that are currently utilized in commercial transgenic insect-resistant crops. Screening a large number of B. thuringiensis isolates resulted in the cloning of vip3Ac1. Vip3Ac1 showed high insecticidal activity against the fall armyworm Spodoptera frugiperda and the cotton bollworm Helicoverpa zea but very low activity against the silkworm Bombyx mori. The host specificity of this Vip3 toxin was altered by sequence swapping with a previously identified toxin, Vip3Aa1. While both Vip3Aa1 and Vip3Ac1 showed no detectable toxicity against the European corn borer Ostrinia nubilalis, the chimeric protein Vip3AcAa, consisting of the N-terminal region of Vip3Ac1 and the C-terminal region of Vip3Aa1, became insecticidal to the European corn borer. In addition, the chimeric Vip3AcAa had increased toxicity to the fall armyworm. Furthermore, both Vip3Ac1 and Vip3AcAa are highly insecticidal to a strain of cabbage looper (Trichoplusia ni) that is highly resistant to the B. thuringiensis endotoxin Cry1Ac, thus experimentally showing for the first time the lack of cross-resistance between B. thuringiensis Cry1A proteins and Vip3A toxins. The results in this study demonstrated that vip3Ac1 and its chimeric vip3 genes can be excellent candidates for engineering a new generation of transgenic plants for insect pest control.

Four Species of Noctuid Moths Degrade Sex Pheromone by a Common Antennal Metabolic Pathway

1996 ◽  
Vol 31 (4) ◽  
pp. 404-413 ◽  
Author(s):  
Jerome A . Klun ◽  
William J. E. Potts ◽  
James E. Oliver
Keyword(s):  
Sex Pheromone ◽  
Trichoplusia Ni ◽  
European Corn Borer ◽  
Time Course ◽  
Fall Armyworm ◽  
Cabbage Looper ◽  
Beet Armyworm ◽  
Corn Borer ◽  
Black Cutworm

Z-9-tetradecenyl acetate (Z-9-14:OAc) is a component in the female sex pheromones of the cabbage looper, Trichoplusia ni (Hübner), beet armyworm, Spodoptera exigua (Hübner), fall armyworm, Spodoptera frugiperda (J. E. Smith), and black cutworm, Agrotis ipsilon (Hufnagel). We compared the in vivo catabolism of Z-9-14:OAc in time course fashion after the tritiated compound was applied topically to the antennae of males in the four species. Catabolism of tritiated European corn borer, Ostrinia nubilalis (Hübner), sex pheromone (Z-11-14:OAc) was monitored concomitantly so direct comparisons could be made between the male borer and the noctuid males. Results showed that catabolism of pheromone in all four noctuid moths proceeded along the same hydrolysis-alcohol oxidation pathway as has been observed in the European corn borer male. Catabolism was mathematically modeled with first-order differential equations as a four-compartment degradative system in which tritiated pheromonal acetate was sequentially converted to tetradecenol, tetradecenoic acid and water. The modeling revealed subtle differences in catabolism from one species to another and that most species exhibited a finite capacity to catabolize the pheromone.

scholarly journals Mechanism of Resistance to Bacillus thuringiensis Toxin Cry1Ac in a Greenhouse Population of the Cabbage Looper, Trichoplusia ni

2006 ◽  
Vol 73 (4) ◽  
pp. 1199-1207 ◽  
Author(s):  
Ping Wang ◽  
Jian-Zhou Zhao ◽  
Ana Rodrigo-Sim�n ◽  
Wendy Kain ◽  
Alida F. Janmaat ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Binding Site ◽  
Trichoplusia Ni ◽  
Specific Binding ◽  
Laboratory Strain ◽  
Cabbage Looper ◽  
Cross Resistance ◽  
Resistance Pattern ◽  
Recessive Trait ◽  
Mechanism Of Resistance

ABSTRACT The cabbage looper, Trichoplusia ni, is one of only two insect species that have evolved resistance to Bacillus thuringiensis in agricultural situations. The trait of resistance to B. thuringiensis toxin Cry1Ac from a greenhouse-evolved resistant population of T. ni was introgressed into a highly inbred susceptible laboratory strain. The resulting introgression strain, GLEN-Cry1Ac-BCS, and its nearly isogenic susceptible strain were subjected to comparative genetic and biochemical studies to determine the mechanism of resistance. Results showed that midgut proteases, hemolymph melanization activity, and midgut esterase were not altered in the GLEN-Cry1Ac-BCS strain. The pattern of cross-resistance of the GLEN-Cry1Ac-BCS strain to 11 B. thuringiensis Cry toxins showed a correlation of the resistance with the Cry1Ab/Cry1Ac binding site in T. ni. This cross-resistance pattern is different from that found in a previously reported laboratory-selected Cry1Ab-resistant T. ni strain, evidently indicating that the greenhouse-evolved resistance involves a mechanism different from the laboratory-selected resistance. Determination of specific binding of B. thuringiensis toxins Cry1Ab and Cry1Ac to the midgut brush border membranes confirmed the loss of midgut binding to Cry1Ab and Cry1Ac in the resistant larvae. The loss of midgut binding to Cry1Ab/Cry1Ac is inherited as a recessive trait, which is consistent with the recessive inheritance of Cry1Ab/Cry1Ac resistance in this greenhouse-derived T. ni population. Therefore, it is concluded that the mechanism for the greenhouse-evolved Cry1Ac resistance in T. ni is an alteration affecting the binding of Cry1Ab and Cry1Ac to the Cry1Ab/Cry1Ac binding site in the midgut.

Specificity of Ukrainian Bacillus thuringiensis Berliner Strains for Agricultural Pests of the Southeastern United States

2007 ◽  
Vol 42 (2) ◽  
pp. 272-285 ◽  
Author(s):  
Iryna A. Isakova ◽  
Yegor B. Isakov ◽  
Svetlana E. Rymar ◽  
Vitalii A. Kordium ◽  
James R. Fuxa
Keyword(s):  
Bacillus Thuringiensis ◽  
Trichoplusia Ni ◽  
Fall Armyworm ◽  
Boll Weevil ◽  
Cabbage Looper ◽  
Tobacco Budworm ◽  
Anthonomus Grandis ◽  
Agricultural Pests ◽  
Genes Encoding ◽  
Soybean Looper

Insecticidal proteins naturally produced by Bacillus thuringiensis Berliner (Bt) present an environmentally friendly alternative to the conventional chemicals used for the pest control. We identified crylA, crylB, and cry1C genes encoding the toxic proteins in 13 Bt strains isolated in Ukraine and then determined the toxicity of these strains against lepidopteran and coleopteran pests from the southeastern U.S. Five of the Bt strains were highly toxic to two lepidopteran pests: three against the soybean looper (Pseudoplusia includens Walker), and two others against the cabbage looper (Trichoplusia ni Hübner). None of the strains had more than moderate toxicity against the tobacco budworm (Heliothis virescens F.), the sugarcane borer (Diatraea saccharalis F.), or fall armyworm (Spodoptera frugiperda J.E. Smith). Cry1 toxins from three Bt strains were solubilized and trypsinized for bioassay against the boll weevil (Anthonomus grandis grandis Boheman) and sweet potato weevil (Cylas formicarius Summers). Toxicity of all three strains was higher or comparable to that of the commercial Bt product Foil® (ECOGEN Inc., Langhorne, PA) containing Cry3 toxin specific for coleopterans. Two of the Ukrainian Bt strains containing Cry1B toxins were toxic to both lepidopteran and coleopteran pests. This study thus revealed new Bt strains toxic to lepidopteran and coleopteran pests from the southeastern U.S. indicating specific target pests for a broad spectrum of Cry1 toxins, including natural and trypsin-activated forms of CrylB proteins.

scholarly journals Cross-resistance and mechanism of resistance to Cry1Ab toxin from Bacillus thuringiensis in a field-derived strain of European corn borer, Ostrinia nubilalis

2011 ◽  
Vol 107 (3) ◽  
pp. 185-192 ◽  
Author(s):  
André L.B. Crespo ◽  
Ana Rodrigo-Simón ◽  
Herbert A.A. Siqueira ◽  
Eliseu J.G. Pereira ◽  
Juan Ferré ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Ostrinia Nubilalis ◽  
European Corn Borer ◽  
Cross Resistance ◽  
Corn Borer ◽  
Mechanism Of Resistance ◽  
Cry1ab Toxin

Potential of controlling insect pests of corn using entomopathogenic nematodes

2001 ◽  
Vol 81 (4) ◽  
pp. 783-787 ◽  
Author(s):  
E. Riga ◽  
J. Whistlecraft ◽  
J. Potter
Keyword(s):  
European Corn Borer ◽  
Entomopathogenic Nematodes ◽  
Insect Pests ◽  
Insect Pest ◽  
Fall Armyworm ◽  
Nematode Species ◽  
Western Corn Rootworm ◽  
Corn Rootworm ◽  
Pest Species ◽  
Corn Borer

A series of experiments was performed in the laboratory and in the greenhouse to assess the efficacy of the entomopathogenic nematodes, Steinernema glaseri or S. feltiae in decreasing the numbers of European corn borer, fall armyworm, western corn rootworm and the seedcorn maggot in corn. Both nematode species effectively controlled the four insect pest species. During greenhouse experiments, the number of plants protected with entomopathogenic nematodes against these insect pests was significantly higher than in the untreated controls. Similar results were obtained in a microplot study of corn infected with the European corn borer, the western corn rootworm and the seedcorn maggot. The application of a single nematode species against several insect pests has economic advantages. In addition, both S. glaseri and S. feltiae overwintered and survived in the field until the next growing season. Key words: Entomopathogenic nematodes, sweet corn, European corn borer, fall armyworm, seedcorn maggot, western corn rootworm

scholarly journals Genetic Basis of Cry1F-Resistance in a Laboratory Selected Asian Corn Borer Strain and Its Cross-Resistance to Other Bacillus thuringiensis Toxins

PLoS ONE ◽  
2016 ◽  
Vol 11 (8) ◽  
pp. e0161189 ◽  
Author(s):  
Yueqin Wang ◽  
Yidong Wang ◽  
Zhenying Wang ◽  
Alejandra Bravo ◽  
Mario Soberón ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Genetic Basis ◽  
Cross Resistance ◽  
Corn Borer ◽  
Asian Corn Borer

scholarly journals Aboveground Herbivory Influences Belowground Defense Responses in Maize

2021 ◽  
Vol 9 ◽  
Author(s):  
Lise Pingault ◽  
Saumik Basu ◽  
Prince Zogli ◽  
W. Paul Williams ◽  
Nathan Palmer ◽  
...  
Keyword(s):  
European Corn Borer ◽  
Proteinase Inhibitors ◽  
Insect Pest ◽  
Diabrotica Virgifera Virgifera ◽  
Defense Responses ◽  
Short Term ◽  
Long Distance ◽  
Corn Borer ◽  
Root Physiology ◽  
Aboveground Herbivory

The European corn borer (ECB; Ostrinia nubilalis) is an economically damaging insect pest of maize (Zea mays L.), an important cereal crop widely grown globally. Among inbred lines, the maize genotype Mp708 has shown resistance to diverse herbivorous insects, although several aspects of the defense mechanisms of Mp708 plants are yet to be explored. Here, the changes in root physiology arising from short-term feeding by ECB on the shoot tissues of Mp708 plants was evaluated directly using transcriptomics, and indirectly by monitoring changes in growth of western corn rootworm (WCR; Diabrotica virgifera virgifera) larvae. Mp708 defense responses negatively impacted both ECB and WCR larval weights, providing evidence for changes in root physiology in response to ECB feeding on shoot tissues. There was a significant downregulation of genes in the root tissues following short-term ECB feeding, including genes needed for direct defense (e.g., proteinase inhibitors and chitinases). Our transcriptomic analysis also revealed specific regulation of the genes involved in hormonal and metabolite pathways in the roots of Mp708 plants subjected to ECB herbivory. These data provide support for the long-distance signaling-mediated defense in Mp708 plants and suggest that altered metabolite profiles of roots in response to ECB feeding of shoots likely negatively impacted WCR growth.

scholarly journals Weekly Applications of Bacillus Thuringiensis for European Corn Borer Control on Peppers, 1993

1995 ◽  
Vol 20 (1) ◽  
pp. 101-101
Author(s):  
J. Boucher ◽  
R. Adams ◽  
G. Nixon ◽  
J. Clark
Keyword(s):  
Bacillus Thuringiensis ◽  
European Corn Borer ◽  
Corn Borer
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