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

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.

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Characterization of Chimeric Bacillus thuringiensis Vip3 Toxins

Applied and Environmental Microbiology ◽

10.1128/aem.02079-06 ◽

2006 ◽

Vol 73 (3) ◽

pp. 956-961 ◽

Cited By ~ 82

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.

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Susceptibility of Anthonomus grandis (Cotton Boll Weevil) and Spodoptera frugiperda (Fall Armyworm) to a Cry1Ia-type Toxin from a Brazilian Bacillus thuringiensis Strain

BMB Reports ◽

10.5483/bmbrep.2007.40.5.773 ◽

2007 ◽

Vol 40 (5) ◽

pp. 773-782 ◽

Cited By ~ 19

Author(s):

Maria Fatima Grossi-De-Sa ◽

Mariana Quezado De Magalhaes ◽

Marilia Santos Silva ◽

Shirley Margareth.Buffon Silva ◽

Simoni Campos Dias ◽

...

Keyword(s):

Bacillus Thuringiensis ◽

Spodoptera Frugiperda ◽

Fall Armyworm ◽

Boll Weevil ◽

Anthonomus Grandis ◽

Cotton Boll ◽

Cotton Boll Weevil ◽

Thuringiensis Strain

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A Tale of Two Transcriptomic Responses in Agricultural Pests via Host Defenses and Viral Replication

International Journal of Molecular Sciences ◽

10.3390/ijms22073568 ◽

2021 ◽

Vol 22 (7) ◽

pp. 3568

Author(s):

Pramod Pantha ◽

Subbaiah Chalivendra ◽

Dong-Ha Oh ◽

Bret D. Elderd ◽

Maheshi Dassanayake

Keyword(s):

Trichoplusia Ni ◽

Systemic Infection ◽

Fall Armyworm ◽

Transcript Abundance ◽

Cabbage Looper ◽

Agricultural Pests ◽

Transcriptional Responses ◽

Viral Transcript ◽

Host Pathogen ◽

Arthropod Pests

Autographa californica Multiple Nucleopolyhedrovirus (AcMNPV) is a baculovirus that causes systemic infections in many arthropod pests. The specific molecular processes underlying the biocidal activity of AcMNPV on its insect hosts are largely unknown. We describe the transcriptional responses in two major pests, Spodoptera frugiperda (fall armyworm) and Trichoplusia ni (cabbage looper), to determine the host–pathogen responses during systemic infection, concurrently with the viral response to the host. We assembled species-specific transcriptomes of the hemolymph to identify host transcriptional responses during systemic infection and assessed the viral transcript abundance in infected hemolymph from both species. We found transcriptional suppression of chitin metabolism and tracheal development in infected hosts. Synergistic transcriptional support was observed to suggest suppression of immune responses and induction of oxidative stress indicating disease progression in the host. The entire AcMNPV core genome was expressed in the infected host hemolymph with a proportional high abundance detected for viral transcripts associated with replication, structure, and movement. Interestingly, several of the host genes that were targeted by AcMNPV as revealed by our study are also targets of chemical insecticides currently used commercially to control arthropod pests. Our results reveal an extensive overlap between biological processes represented by transcriptional responses in both hosts, as well as convergence on highly abundant viral genes expressed in the two hosts, providing an overview of the host–pathogen transcriptomic landscape during systemic infection.

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Genetic Resistance to Bacillus thuringiensis Alters Feeding Behaviour in the Cabbage Looper, Trichoplusia ni

PLoS ONE ◽

10.1371/journal.pone.0085709 ◽

2014 ◽

Vol 9 (1) ◽

pp. e85709 ◽

Cited By ~ 14

Author(s):

Ikkei Shikano ◽

Jenny S. Cory

Keyword(s):

Bacillus Thuringiensis ◽

Trichoplusia Ni ◽

Feeding Behaviour ◽

Genetic Resistance ◽

Cabbage Looper

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Modified Bacillus thuringiensis Toxins and a Hybrid B. thuringiensis Strain Counter Greenhouse-Selected Resistance in Trichoplusia ni

Applied and Environmental Microbiology ◽

10.1128/aem.00664-09 ◽

2009 ◽

Vol 75 (17) ◽

pp. 5739-5741 ◽

Cited By ~ 17

Author(s):

Michelle T. Franklin ◽

Christal L. Nieman ◽

Alida F. Janmaat ◽

Mario Soberï¿½n ◽

Alejandra Bravo ◽

...

Keyword(s):

Bacillus Thuringiensis ◽

Trichoplusia Ni ◽

Genetically Modified ◽

Cabbage Looper ◽

Hybrid Strain ◽

Thuringiensis Strain

ABSTRACT Resistance of greenhouse-selected strains of the cabbage looper, Trichoplusia ni, to Bacillus thuringiensis subsp. kurstaki was countered by a hybrid strain of B. thuringiensis and genetically modified toxins Cry1AbMod and Cry1AcMod, which lack helix α-1. Resistance to Cry1AbMod and Cry1AcMod was >100-fold less than resistance to native toxins Cry1Ab and Cry1Ac.

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Characterization of deoxyribonucleic acid isolated from the granulosis viruses of the cabbage looper, Trichoplusia ni and the fall armyworm, Spodoptera frugiperda

Virology ◽

10.1016/0042-6822(72)90397-2 ◽

1972 ◽

Vol 50 (2) ◽

pp. 459-471 ◽

Cited By ~ 29

Author(s):

Max D. Summers ◽

David L. Anderson

Keyword(s):

Spodoptera Frugiperda ◽

Trichoplusia Ni ◽

Deoxyribonucleic Acid ◽

Fall Armyworm ◽

Cabbage Looper

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Novel Isolate of Bacillus thuringiensis subsp. thuringiensis That Produces a Quasicuboidal Crystal of Cry1Ab21 Toxic to Larvae of Trichoplusia ni

Applied and Environmental Microbiology ◽

10.1128/aem.01955-07 ◽

2007 ◽

Vol 74 (4) ◽

pp. 923-930 ◽

Cited By ~ 24

Author(s):

Izabela Swiecicka ◽

Dennis K. Bideshi ◽

Brian A. Federici

Keyword(s):

Bacillus Thuringiensis ◽

Trichoplusia Ni ◽

Single Copy ◽

Cabbage Looper ◽

Beet Armyworm ◽

Vegetable Crops ◽

Gene Coding ◽

Novel Variant ◽

Northeastern Poland ◽

Midgut Lumen

ABSTRACT A new isolate (IS5056) of Bacillus thuringiensis subsp. thuringiensis that produces a novel variant of Cry1Ab, Cry1Ab21, was isolated from soil collected in northeastern Poland. Cry1Ab21 was composed of 1,155 amino acids and had a molecular mass of 130.5 kDa, and a single copy of the gene coding for this endotoxin was located on a ∼75-kbp plasmid. When synthesized by the wild-type strain, Cry1Ab21 produced a unique, irregular, bipyramidal crystal whose long and short axes were both approximately 1 μm long, which gave it a cuboidal appearance in wet mount preparations. In diet incorporation bioassays, the 50% lethal concentrations of the crystal-spore complex were 16.9 and 29.7 μg ml−1 for second- and fourth-instar larvae of the cabbage looper, Trichoplusia ni, respectively, but the isolate was essentially nontoxic to larvae of the beet armyworm, Spodoptera exigua. A bioassay of autoclaved spore-crystal preparations showed no evidence of β-exotoxin activity, indicating that toxicity was due primarily to Cry1Ab21. Studies of the pathogenesis of isolate IS5056 in second-instar larvae of T. ni showed that after larval death the bacterium colonized and subsequently sporulated extensively throughout the cadaver, suggesting that other bacteria inhabiting the midgut lumen played little if any role in mortality. As T. ni is among the most destructive pests of vegetable crops in North America and has developed resistance to B. thuringiensis, this new isolate may have applied value.

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