Effectiveness of Purified Bacillus thuringiensis Berliner Insecticidal Proteins in Controlling Three Insect Pests of Australian Eucalypt Plantations

1996 ◽  
Vol 89 (6) ◽  
pp. 1392-1398 ◽  
Author(s):  
Rebecca L. Harcourt ◽  
Danny Llewellyn ◽  
Richard Morton ◽  
Elizabeth S. Dennis ◽  
W. Jim Peacock
Keyword(s):  
Bacillus Thuringiensis ◽  
Insect Pests ◽  
Insecticidal Proteins ◽  
Eucalypt Plantations

scholarly journals Cry75Aa (Mpp75Aa) Insecticidal Proteins for Controlling the Western Corn Rootworm, Diabrotica virgifera virgifera, (Coleoptera: Chrysomelidae), Isolated from the Insect Pathogenic Bacteria Brevibacillus laterosporus.

2020 ◽  
Author(s):  
David Bowen ◽  
Yong Yin ◽  
Stanislaw Flasinski ◽  
Catherine Chay ◽  
Gregory Bean ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Pathogenic Bacteria ◽  
Insect Pests ◽  
Diabrotica Virgifera Virgifera ◽  
Western Corn Rootworm ◽  
Cross Resistance ◽  
Corn Rootworm ◽  
Diabrotica Virgifera ◽  
Insecticidal Proteins ◽  
Brevibacillus Laterosporus

This study describes three closely related proteins, cloned from Brevibacillus laterosporus strains, that are lethal upon feeding to Diabrotica virgifera virgifera LeConte, the western corn rootworm (WCR). Mpp75Aa1, Mpp75Aa2 and Mpp75Aa3 were toxic to WCR larvae when fed purified protein. Transgenic plants expressing each mMpp75Aa protein were protected from feeding damage and showed significant reduction in adult emergence from infested plants by both susceptible and Cry3Bb1 and Cry34Ab1/Cry35Ab1-resistant WCR. These results demonstrate that proteins from B. laterosporus are as efficacious as the well-known Bacillus thuringiensis (Bt) insecticidal proteins in controlling major insect pests such as WCR. The deployment of transgenic maize expressing mMpp75Aa along with other active molecules lacking cross-resistance have the potential to be a useful tool for control of WCR populations resistant to current Bt traits. IMPORTANCE Insects feeding on roots of crops can damage the plant roots resulting in yield loss due to poor water and nutrient uptake and plant lodging. In maize the western corn rootworm (WCR) can cause severe damage to the roots resulting in significant economic loss for farmers. Genetically modified (GM) expressing Bacillus thuringiensis (Bt) insect control proteins, has provided a solution for control of these pests. In recent years populations of WCR resistant to the Bt proteins in commercial GM maize have emerged. There is a need to develop new insecticidal traits for the control of WCR populations resistant to current commercial traits. New proteins with commercial level efficacy on WCR from sources other than Bt are becoming more critical. The Mpp75Aa proteins, from B. laterosporus, when expressed in maize, are efficacious against the resistant populations of WCR and have the potential to provide solutions for control of resistant WCR.

scholarly journals Isolation of Bacillus thuringiensis strains from Saudi Arabia soil and study of their potential efficiency against the lepidopteran pest Ephestia kuehniella

2021 ◽  
Vol 12 (2) ◽  
pp. 238-245
Author(s):  
Fidaa Ibrahim Kallaf ◽  
Hanen Boukedi ◽  
Dalel Daâssi ◽  
Lobna Abdelkefi-Mesrati
Keyword(s):  
Saudi Arabia ◽  
Bacillus Thuringiensis ◽  
Insect Pests ◽  
Ephestia Kuehniella ◽  
Environment Friendly ◽  
Insecticidal Proteins ◽  
Insect Pathogens ◽  
Bacterium Bacillus ◽  
Parasporal Crystals ◽  
Lepidopteran Pest

Insect pests represent a major threat to food crops and human health, and therefore have to be combated in several ways, including chemical methods. However, researchers demonstrated that these molecules are dangerous for the farmers, consumers and the environment in general. For this reason, scientists permanently searched environment friendly alternatives such as the use of the bacterium Bacillus thuringiensis classified as one of the best insect pathogens. This microorganism is known by its ability to produce two types of insecticidal proteins, Vegetative insecticidal proteins (Vip) and delta-endotoxins produced during vegetative and sporulation stages of growth, respectively. In the present study, 15 B. thuringiensis strains were isolated from soil collected from different regions in Saudi Arabia (Al Baha, Jeddah, Khulis and Yanbu). B. thuringiensis isolates were then classified according to the shape of their parasporal crystals identified under microscope and proteins content of these crystals. Delta-endotoxins efficiency of the different isolates was investigated and promising strains were identified as very active. After 5 days-treatment, B. thuringiensis isolates 14 and 7 killed Ephestia kuehniella larvae with low LC50 of about 59.18 and 65.67 mg/cm2, respectively. The results described in the present study proved that the new B. thuringiensis isolates could be of a great interest in the control of lepidopteran pests by using their delta-endotoxins in bioinsecticide formulations.

scholarly journals Response Mechanisms of Invertebrates to Bacillus thuringiensis and Its Pesticidal Proteins

2021 ◽  
Vol 85 (1) ◽  
Author(s):  
Daniel Pinos ◽  
Ascensión Andrés-Garrido ◽  
Juan Ferré ◽  
Patricia Hernández-Martínez
Keyword(s):  
Bacillus Thuringiensis ◽  
Pest Control ◽  
Insect Pests ◽  
Relevant Literature ◽  
Nematode Species ◽  
Biological Pest Control ◽  
Insecticidal Proteins ◽  
Content Type ◽  
Resistance Evolution ◽  
Control Insect

SUMMARY Extensive use of chemical insecticides adversely affects both environment and human health. One of the most popular biological pest control alternatives is bioinsecticides based on Bacillus thuringiensis. This entomopathogenic bacterium produces different protein types which are toxic to several insect, mite, and nematode species. Currently, insecticidal proteins belonging to the Cry and Vip3 groups are widely used to control insect pests both in formulated sprays and in transgenic crops. However, the benefits of B. thuringiensis-based products are threatened by insect resistance evolution. Numerous studies have highlighted that mutations in genes coding for surrogate receptors are responsible for conferring resistance to B. thuringiensis. Nevertheless, other mechanisms may also contribute to the reduction of the effectiveness of B. thuringiensis-based products for managing insect pests and even to the acquisition of resistance. Here, we review the relevant literature reporting how invertebrates (mainly insects and Caenorhabditis elegans) respond to exposure to B. thuringiensis as either whole bacteria, spores, and/or its pesticidal proteins.

scholarly journals Retargeting of the Bacillus thuringiensis toxin Cyt2Aa against hemipteran insect pests

2013 ◽  
Vol 110 (21) ◽  
pp. 8465-8470 ◽  
Author(s):  
N. P. Chougule ◽  
H. Li ◽  
S. Liu ◽  
L. B. Linz ◽  
K. E. Narva ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Insect Pests ◽  
Bacillus Thuringiensis Toxin ◽  
Hemipteran Insect

Mechanism of action of Bacillus thuringiensis insecticidal toxins and their use in the control of insect pests

2015 ◽  
pp. 858-873 ◽  
Author(s):  
Alejandra Bravo ◽  
Diana L. Martínez de Castro ◽  
Jorge Sánchez ◽  
Pablo Emiliano Cantón ◽  
Gretel Mendoza ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Mechanism Of Action ◽  
Insect Pests ◽  
Insecticidal Toxins

scholarly journals A Strain of Bacillus thuringiensis Containing a Novel cry7Aa2 Gene that Is Toxic to Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae)

Insects ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 259 ◽  
Author(s):  
Mikel Domínguez-Arrizabalaga ◽  
Maite Villanueva ◽  
Ana Beatriz Fernandez ◽  
Primitivo Caballero
Keyword(s):  
Amino Acid ◽  
Bacillus Thuringiensis ◽  
Molecular Mass ◽  
Leptinotarsa Decemlineata ◽  
Insect Pests ◽  
Amino Acid Residues ◽  
Cry Protein ◽  
Lc50 Value ◽  
Leptinotarsa Decemlineata Say

The genome of the Bacillus thuringiensis BM311.1 strain was sequenced and assembled in 359 contigs containing a total of 6,390,221 bp. The plasmidic ORF of a putative cry gene from this strain was identified as a potential novel Cry protein of 1138 amino acid residues with a 98% identity compared to Cry7Aa1 and a predicted molecular mass of 129.4 kDa. The primary structure of Cry7Aa2, which had eight conserved blocks and the classical structure of three domains, differed in 28 amino acid residues from that of Cry7Aa1. The cry7Aa2 gene was amplified by PCR and then expressed in the acrystalliferous strain BMB171. SDS-PAGE analysis confirmed the predicted molecular mass for the Cry7Aa2 protein and revealed that after in vitro trypsin incubation, the protein was degraded to a toxin of 62 kDa. However, when treated with digestive fluids from Leptinotarsa decemlineata larvae, one major proteinase-resistant fragment of slightly smaller size was produced. The spore and crystal mixture produced by the wild-type BM311.1 strain against L. decemlineata neonate larvae resulted in a LC50 value of 18.8 μg/mL, which was statistically similar to the estimated LC50 of 20.8 μg/mL for the recombinant BMB17-Cry7Aa2 strain. In addition, when this novel toxin was activated in vitro with commercial trypsin, the LC50 value was reduced 3.8-fold to LC50 = 4.9 μg/mL. The potential advantages of Cry7Aa2 protoxin compared to Cry7Aa1 protoxin when used in the control of insect pests are discussed.

scholarly journals Bacillus thuringiensis Vip1 Functions as a Receptor of Vip2 Toxin for Binary Insecticidal Activity against Holotrichia parallela

Toxins ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 440 ◽  
Author(s):  
Jianxun Geng ◽  
Jian Jiang ◽  
Changlong Shu ◽  
Zeyu Wang ◽  
Fuping Song ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Affinity Chromatography ◽  
Insecticidal Activity ◽  
Brush Border ◽  
Brush Border Membrane ◽  
Lethal Concentration ◽  
Insecticidal Proteins ◽  
Vegetative Phase ◽  
Holotrichia Parallela ◽  
Weak Binding

Bacillus thuringiensis is a well-known entomopathogenic bacterium that produces vegetative insecticidal proteins (Vips, including Vip1, Vip2, Vip3, and Vip4) during the vegetative phase. Here, we purified Vip1 and Vip2 from B. thuringiensis and characterized the insecticidal effects of these protoxins. Bioassay results showed that a 1:1 mixture of Vip1Ad and Vip2Ag, purified by ion-affinity chromatography independently, exhibited insecticidal activity against Holotrichia parallela larvae, with a 50% lethal concentration value of 2.33 μg/g soil. The brush border membrane (BBM) in the midgut of H. parallela larvae was destroyed after feeding the Vip1Ad and Vip2Ag mixture. Vacuolization of the cytoplasm and slight destruction of BBM were detected with Vip2Ag alone, but not with Vip1Ad alone. Notably, Vip1Ad bound to BBM vesicles (BBMVs) strongly, whereas Vip2Ag showed weak binding; however, binding of Vip2Ag to BBMV was increased when Vip1Ad was added. Ligand blotting showed that Vip2Ag did not bind to Vip1Ad but bound to Vip1Ad-t (Vip1Ad was activated by trypsin), suggesting the activation of Vip1Ad was important for their binary toxicity. Thus, our findings suggested that Vip1Ad may facilitate the binding of Vip2Ag to BBMVs, providing a basis for studies of the insecticidal mechanisms of Vip1Ad and Vip2Ag.

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