Knockdown of cadherin genes decreases susceptibility of Chilo suppressalis larvae to Bacillus thuringiensis produced Crystal toxins

2020 ◽  
Vol 29 (3) ◽  
pp. 301-308
Author(s):  
H. Zhou ◽  
W. Hu ◽  
Q. Huang ◽  
M. Abouzaid ◽  
H. Jin ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Chilo Suppressalis ◽  
Crystal Toxins

scholarly journals Co-production of parasporal crystal toxins and antimicrobial substances by Bacillus thuringiensis BAR 3

2017 ◽  
Vol 32 (1) ◽  
pp. 41
Author(s):  
D. Chuka-Ogwude ◽  
C.O. Nwuche ◽  
J.C. Ogbonna
Keyword(s):  
Bacillus Thuringiensis ◽  
Parasporal Crystal ◽  
Antimicrobial Substances ◽  
Crystal Toxins

scholarly journals Bacillus thuringiensis Spores and Vegetative Bacteria: Infection Capacity and Role of the Virulence Regulon PlcR Following Intrahaemocoel Injection of Galleria mellonella

Insects ◽  
2019 ◽  
Vol 10 (5) ◽  
pp. 129 ◽  
Author(s):  
Christophe Buisson ◽  
Michel Gohar ◽  
Eugénie Huillet ◽  
Christina Nielsen-LeRoux
Keyword(s):  
Bacillus Thuringiensis ◽  
Galleria Mellonella ◽  
Lethal Dose ◽  
Intestinal Barrier ◽  
Oral Route ◽  
Infection Model ◽  
Wild Type ◽  
Response Curves ◽  
Vegetative Cells ◽  
Crystal Toxins

Bacillus thuringiensis is an invertebrate pathogen that produces insecticidal crystal toxins acting on the intestinal barrier. In the Galleria mellonella larvae infection model, toxins from the PlcR virulence regulon contribute to pathogenicity by the oral route. While B. thuringiensis is principally an oral pathogen, bacteria may also reach the insect haemocoel following injury of the cuticle. Here, we address the question of spore virulence as compared to vegetative cells when the wild-type Bt407cry- strain and its isogenic ∆plcR mutant are inoculated directly into G. mellonella haemocoel. Mortality dose-response curves were constructed at 25 and 37 °C using spores or vegetative cell inocula, and the 50% lethal dose (LD50) in all infection conditions was determined after 48 h of infection. Our findings show that (i) the LD50 is lower for spores than for vegetative cells for both strains, while the temperature has no significant influence, and (ii) the ∆plcR mutant is four to six times less virulent than the wild-type strain in all infection conditions. Our results suggest that the environmental resistant spores are the most infecting form in haemocoel and that the PlcR virulence regulon plays an important role in toxicity when reaching the haemocoel from the cuticle and not only following ingestion.

scholarly journals Knockdown of the MAPK p38 pathway increases the susceptibility of Chilo suppressalis larvae to Bacillus thuringiensis Cry1Ca toxin

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Lin Qiu ◽  
Jinxing Fan ◽  
Lang Liu ◽  
Boyao Zhang ◽  
Xiaoping Wang ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Chilo Suppressalis ◽  
P38 Pathway

Geographic Variation in Susceptibility of Chilo suppressalis (Lepidoptera: Pyralidae) to Bacillus thuringiensis Toxins in China

2003 ◽  
Vol 96 (6) ◽  
pp. 1838-1842 ◽  
Author(s):  
Fengxia Meng ◽  
Kongming Wu ◽  
Xiwu Gao ◽  
Yufa Peng ◽  
Yuyuan Guo
Keyword(s):  
Bacillus Thuringiensis ◽  
Geographic Variation ◽  
Chilo Suppressalis ◽  
Lepidoptera Pyralidae

Evaluation of Bt (Bacillus thuringiensis) Rice Varieties Against Stem Borer (Chilo suppressalis)

2008 ◽  
Vol 11 (4) ◽  
pp. 648-651 ◽  
Author(s):  
Ghaffar Kiani ◽  
Ghorban Ali Nematzadeh ◽  
Behzad Ghareyazie ◽  
Majid Sattari
Keyword(s):  
Bacillus Thuringiensis ◽  
Stem Borer ◽  
Chilo Suppressalis ◽  
Rice Varieties

scholarly journals Differential Effects of pH on the Pore-Forming Properties of Bacillus thuringiensis Insecticidal Crystal Toxins

2001 ◽  
Vol 67 (10) ◽  
pp. 4488-4494 ◽  
Author(s):  
Le Binh Tran ◽  
Vincent Vachon ◽  
Jean-Louis Schwartz ◽  
Raynald Laprade
Keyword(s):  
Bacillus Thuringiensis ◽  
Brush Border Membrane ◽  
Membrane Vesicles ◽  
Insect Midgut ◽  
Tetramethylammonium Chloride ◽  
Effects Of Ph ◽  
Alkaline Conditions ◽  
Crystal Toxins ◽  
Ph Range ◽  
Reduced Activity

ABSTRACT The effect of pH on the pore-forming ability of two Bacillus thuringiensis toxins, Cry1Ac and Cry1C, was examined with midgut brush border membrane vesicles isolated from the tobacco hornworm,Manduca sexta, and a light-scattering assay. In the presence of Cry1Ac, membrane permeability remained high over the entire pH range tested (6.5 to 10.5) for KCl and tetramethylammonium chloride, but was much lower at pH 6.5 than at higher pHs for potassium gluconate, sucrose, and raffinose. On the other hand, the Cry1C-induced permeability to all substrates tested was much higher at pH 6.5, 7.5, and 8.5 than at pH 9.5 and 10.5. These results indicate that the pores formed by Cry1Ac are significantly smaller at pH 6.5 than under alkaline conditions, whereas the pore-forming ability of Cry1C decreases sharply above pH 8.5. The reduced activity of Cry1C at high pH correlates well with the fact that its toxicity for M. sexta is considerably weaker than that of Cry1Aa, Cry1Ab, and Cry1Ac. However, Cry1E, despite having a toxicity comparable to that of Cry1C, formed channels as efficiently as the Cry1A toxins at pH 10.5. These results strongly suggest that although pH can influence toxin activity, additional factors also modulate toxin potency in the insect midgut.

Screen of Bacillus thuringiensis toxins for transgenic rice to control Sesamia inferens and Chilo suppressalis

2010 ◽  
Vol 105 (1) ◽  
pp. 11-15 ◽  
Author(s):  
Yulin Gao ◽  
Yang Hu ◽  
Qiang Fu ◽  
Jie Zhang ◽  
Brenda Oppert ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Transgenic Rice ◽  
Chilo Suppressalis ◽  
Sesamia Inferens

Bacillus thuringiensis insecticidal crystal toxins: Gene structure and mode of action

1988 ◽  
Vol 6 (4) ◽  
pp. 697-724 ◽  
Author(s):  
Roland Brousseau ◽  
Luke Masson
Keyword(s):  
Bacillus Thuringiensis ◽  
Gene Structure ◽  
Mode Of Action ◽  
Crystal Toxins
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