scholarly journals Comparative genome analysis of Bacillus thuringiensis strain HD521 and HS18-1

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hongwei Sun ◽  
Xing Xiang ◽  
Qiao Li ◽  
Hui Lin ◽  
Xiaolin Wang ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Phospholipase C ◽  
Insertion Sequence ◽  
Antagonistic Effect ◽  
Agricultural Pests ◽  
Circular Chromosome ◽  
Biological Insecticide ◽  
Zwittermicin A ◽  
Virulence Protein ◽  
Parasporal Crystals

AbstractBacillus thuringiensis (Bt) is an important biological insecticide used to management of different agricultural pests by producing toxic parasporal crystals proteins. Strain HD521 has an antagonistic effect against Rhizoctonia solani AG1IA, the causal agent of rice sheath blight. This strain with three cry7 genes can the formation of bipyramidal parasporal crystals (BPCs). BPCs are used for insecticidal activities against Henosepilachna vigintioctomaculata larva (Coleoptera). Strain HS18-1 contains different types of BPCs encoding genes and has effective toxicity for Lepidoptera and Diptera insects. Here we report the whole genome sequencing and assembly of HD521 and HS18-1 strains and analyzed the genome constitution covering virulence factors, types of plasmid, insertion sequences, and prophage sequences. The results showed that the genome of strain HD521 contains a circular chromosome and six circular plasmids, encoding eight types of virulence protein factors [Immune Inhibitor A, Hemolytic Enterotoxin, S-layer protein, Phospholipase C, Zwittermicin A-resistance protein, Metalloprotease, Chitinase, and N-acyl homoserine lactonase (AiiA)], four families of insertion sequence, and comprises six pro-phage sequences. The genome of strain HS18-1 contains one circular chromosome and nine circular plasmids, encoding five types of virulence protein factors [Hemolytic Enterotoxin, S-layer protein, Phospholipase C, Chitinase, and N-acyl homoserine lactonase (AiiA)] and four families of insertion sequence, and comprises of three pro-phage sequences. The obtained results will contribute to deeply understand the B. thuringiensis strain HD521 and HS18-1 at the genomic level.

scholarly journals Structural and genetic organization of IS232, a new insertion sequence of Bacillus thuringiensis.

1990 ◽  
Vol 172 (12) ◽  
pp. 6689-6696 ◽  
Author(s):  
G Menou ◽  
J Mahillon ◽  
M M Lecadet ◽  
D Lereclus
Keyword(s):  
Bacillus Thuringiensis ◽  
Insertion Sequence ◽  
Genetic Organization

scholarly journals How Does Bacillus thuringiensis Crystallize Such a Large Diversity of Toxins?

Toxins ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 443
Author(s):  
Guillaume Tetreau
Keyword(s):  
Bacillus Thuringiensis ◽  
Structural Biology ◽  
Structural Information ◽  
Future Evolution ◽  
Mechanisms Of Toxicity ◽  
Bt Toxin ◽  
Natural Crystal ◽  
Biological Insecticide ◽  
Key Drivers

Bacillus thuringiensis (Bt) is a natural crystal-making bacterium. Bt diversified into many subspecies that have evolved to produce crystals of hundreds of pesticidal proteins with radically different structures. Their crystalline form ensures stability and controlled release of these major virulence factors. They are responsible for the toxicity and host specificity of Bt, explaining its worldwide use as a biological insecticide. Most research has been devoted to understanding the mechanisms of toxicity of these toxins while the features driving their crystallization have long remained elusive, essentially due to technical limitations. The evolution of methods in structural biology, pushing back the limits of the resolution attainable, now allows access to be gained to structural information hidden within natural crystals of such toxins. In this review, I present the main parameters that have been identified as key drivers of toxin crystallization in Bt, notably in the light of recent discoveries driven by structural biology studies. Then, I develop how the future evolution of structural biology will hopefully unveil new mechanisms of Bt toxin crystallization, opening the door to their hijacking with the aim of developing a versatile in vivo crystallization platform of high academic and industrial interest.

Insertion sequence elements in Bacillus thuringiensis subsp. darmstadiensis

1993 ◽  
Vol 39 (7) ◽  
pp. 649-658 ◽  
Author(s):  
Margret Ryan ◽  
Jerry D. Johnson ◽  
Lee A. Bulla Jr.
Keyword(s):  
Bacillus Thuringiensis ◽  
Insertion Sequence ◽  
Tandem Repeats ◽  
Close Correlation ◽  
Direct Repeats ◽  
Chromosomal Dna ◽  
Base Pairs ◽  
Bacillus Thuringiensis Subsp ◽  
Sequence Elements ◽  
Insertion Sequence Elements

Two variants of insertion sequence IS231, named IS231G and H, were isolated from Bacillus thuringiensis subsp. darmstadiensis 73-E-10-2 (BTD2), an isolate toxic to dipteran insects, and characterized by DNA sequence analysis. They are encoded consecutively as direct repeats on an EcoRI fragment of 5.6 kilo base pairs. Direct tandem repeats of IS231 elements have not been previously reported. Both elements are closely related to other members of the IS231 family that have been isolated from B. thuringiensis strains toxic to lepidopteran as well as to dipteran insects. A close correlation exists between the evolutionary relationships of the IS231 sequences determined to date and the toxicity spectrum of the host cell. Probing of BTD2 DNA with a radiolabeled IS231G fragment demonstrated that IS231 elements are located on 55- and 34-MDa plasmids as well as on chromosomal DNA. Chromosomal DNA, but not plasmids, from BTD2 also hybridizes to another, unrelated insertion sequence, IS240, from B. thuringiensis subsp. israelensis, an isolate toxic to dipteran insects. BTD2, therefore, contains IS elements once thought to reside exclusively in either dipteran- or lepidopteran-specific subspecies of B. thuringiensis.Key words: IS231, IS240, mobile elements.

scholarly journals Effects of gallic acid and Zn, Cu, and Ni on antioxidant enzyme activities of Hyphantria cunea larvae infected with Bacillus thuringiensis

2021 ◽  
Author(s):  
Elif Fatma Topkara ◽  
Oğuzhan Yanar ◽  
Fatma Gönül Solmaz
Keyword(s):  
Bacillus Thuringiensis ◽  
Gallic Acid ◽  
Antioxidant Enzyme ◽  
Enzyme Activities ◽  
Antagonistic Effect ◽  
Metal Exposure ◽  
Antioxidant Enzyme Activities ◽  
Glutathione Peroxidase Activity ◽  
Hyphantria Cunea ◽  
Antagonistic Effects

Abstract The effects of copper, nickel, and zinc and the potent antioxidant gallic acid on the antioxidant enzyme activities of Hyphantria cunea larvae infected with Bacillus thuringiensis subsp. kurstaki have been identified in this study. With metal exposure, all the enzyme activities have increased. Antagonistic effects were observed in the combination of gallic acid with all three metals on the activities of superoxide dismutase and catalase. In glutathione peroxidase activity, an antagonistic effect was observed in gallic acid plus nickel group, while there was a synergistic effect for gallic acid plus zinc and gallic acid plus copper. Activities of these enzymes in larvae exposed only to the metals increased in the infected groups; while exposure to gallic acid alone elicited a decrease. As a consequence, it was found that enzyme activities were affected by both metals and gallic acid and infection.

scholarly journals Vegetative Insecticidal Protein (Vip): A Potential Contender From Bacillus thuringiensis for Efficient Management of Various Detrimental Agricultural Pests

2021 ◽  
Vol 12 ◽  
Author(s):  
Mamta Gupta ◽  
Harish Kumar ◽  
Sarvjeet Kaur
Keyword(s):  
Bacillus Thuringiensis ◽  
Insecticidal Protein ◽  
Current Status ◽  
Specific Class ◽  
Agricultural Pests ◽  
Cry Proteins ◽  
Vegetative Insecticidal Protein ◽  
Receptor Sites ◽  
Vip Proteins ◽  
The Difference

Bacillus thuringiensis (Bt) bacterium is found in various ecological habitats, and has natural entomo-pesticidal properties, due to the production of crystalline and soluble proteins during different growth phases. In addition to Cry and Cyt proteins, this bacterium also produces Vegetative insecticidal protein (Vip) during its vegetative growth phase, which is considered an excellent toxic candidate because of the difference in sequence homology and receptor sites from Cry proteins. Vip proteins are referred as second-generation insecticidal proteins, which can be used either alone or in complementarity with Cry proteins for the management of various detrimental pests. Among these Vip proteins, Vip1 and Vip2 act as binary toxins and have toxicity toward pests belonging to Hemiptera and Coleoptera orders, whereas the most important Vip3 proteins have insecticidal activity against Lepidopteran pests. These Vip3 proteins are similar to Cry proteins in terms of toxicity potential against susceptible insects. They are reported to be toxic toward pests, which can’t be controlled with Cry proteins. The Vip3 proteins have been successfully pyramided along with Cry proteins in transgenic rice, corn, and cotton to combat resistant pest populations. This review provides detailed information about the history and importance of Vip proteins, their types, structure, newly identified specific receptors, and action mechanism of this specific class of proteins. Various studies conducted on Vip proteins all over the world and the current status have been discussed. This review will give insights into the significance of Vip proteins as alternative promising candidate toxic proteins from Bt for the management of pests in most sustainable manner.

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