Downregulation of Chilo suppressalis alkaline phosphatase genes associated with resistance to three transgenic Bacillus thuringiensis rice lines

2017 ◽  
Vol 27 (1) ◽  
pp. 83-89 ◽  
Author(s):  
L. Qiu ◽  
P. Wang ◽  
T. Wu ◽  
B. Li ◽  
X. Wang ◽  
...  
Keyword(s):  
Alkaline Phosphatase ◽  
Bacillus Thuringiensis ◽  
Chilo Suppressalis

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 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

scholarly journals Aedes aegypti Membrane-Bound Alkaline Phosphatase Expressed in Escherichia coli Retains High-Affinity Binding for Bacillus thuringiensis Cry4Ba Toxin

2011 ◽  
Vol 77 (19) ◽  
pp. 6836-6840 ◽  
Author(s):  
Anon Thammasittirong ◽  
Manasave Dechklar ◽  
Somphob Leetachewa ◽  
Kusol Pootanakit ◽  
Chanan Angsuthanasombat
Keyword(s):  
Escherichia Coli ◽  
Alkaline Phosphatase ◽  
Bacillus Thuringiensis ◽  
Aedes Aegypti ◽  
Nitrilotriacetic Acid ◽  
Affinity Column ◽  
Dot Blot ◽  
Content Type ◽  
Binding Characteristics ◽  
High Affinity

ABSTRACTGlycosylphosphatidylinositol-linked alkaline phosphatase (GPI-ALP) from the epithelial membrane of the larval midgut ofAedes aegyptiwas previously identified as a functional receptor of theBacillus thuringiensisCry4Ba toxin. Here, heterologous expression inEscherichia coliof the cloned ALP, lacking the secretion signal and GPI attachment sequences, and assessment of its binding characteristics were further investigated. The 54-kDa His tag-fused ALP overexpressed as an inclusion body was soluble when phosphate buffer (pH 7.5) was supplemented with 8 M urea. After renaturation in a nickel-nitrilotriacetic acid (Ni-NTA) affinity column, the refolded ALP protein was able to retain its phosphatase activity. This refolded ALP also showed binding to the 65-kDa activated Cry4Ba toxin under nondenaturing (dot blot) conditions. Quantitative binding analysis using a quartz crystal microbalance revealed that the purified ALP immobilized on a gold electrode was bound by the Cry4Ba toxin in a stoichiometry of approximately 1:2 and with high affinity (dissociation constant [Kd] of ∼14 nM) which is comparable to that calculated from kinetic parameters (dissociation rate constant [koff]/binding constant [kon]). Altogether, the data presented here of theE. coli-expressed ALP fromA. aegyptiretaining high-affinity toxin binding support our notion that glycosylation of this receptor is not required for binding to its counterpart toxin, Cry4Ba.

Effet de l'aflatoxine B1 sur les activités enzymatiques de Bacillus thuringiensis (Berliner)

1977 ◽  
Vol 23 (7) ◽  
pp. 931-932 ◽  
Author(s):  
P. Boutibonnes
Keyword(s):  
Alkaline Phosphatase ◽  
Bacillus Thuringiensis ◽  
Leucine Aminopeptidase ◽  
Sublethal Dose ◽  
Bacterial Cells ◽  
Aflatoxin B ◽  
Activités Enzymatiques

At 20 °C, aflatoxin B1, at a sublethal dose, decreases the activity of alkaline phosphatase (EC 3.1.3.1), α-glucosidase (EC 3.2.1.20), esterase (EC 3.1.1.1), chymotrypsin (EC 3.4.21.1), leucine aminopeptidase (EC 3.4.11.1), and phosphoamidase (EC 3.9.1.1) biosynthesis in Bacillus thuringiensis (Berliner).In contrast, at 41 °C no significant decrease was observed. At this temperature, the mycotoxin is not destroyed or metabolized and bacterial cells are resistant to the toxin.

scholarly journals Bacillus thuringiensis Cry4Ba Insecticidal ToxinExploits Leu615 in Its C-terminal Domain to Interact with a Target Receptor—Aedes aegypti Membrane-Bound Alkaline Phosphatase

Toxins ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 553
Author(s):  
Anon Thammasittirong ◽  
Sutticha Na-Ranong Thammasittirong ◽  
Chompounoot Imtong ◽  
Sathapat Charoenjotivadhanakul ◽  
Somsri Sakdee ◽  
...  
Keyword(s):  
Alkaline Phosphatase ◽  
Bacillus Thuringiensis ◽  
Aedes Aegypti ◽  
Receptor Binding ◽  
Sandwich Elisa ◽  
Full Length ◽  
Terminal Domain ◽  
Binding Analysis ◽  
Membrane Bound ◽  
Larval Toxicity

In addition to the receptor-binding domain (DII), the C-terminal domain (DIII) of three-domain Cry insecticidal d-endotoxins from Bacillus thuringiensis has been implicated in target insect specificity, yet its precise mechanistic role remains unclear. Here, the 21kDa high-purity isolated DIII fragment derived from the Cry4Ba mosquito-specific toxin was achieved via optimized preparative FPLC, allowing direct rendering analyses for binding characteristics toward its target receptor—Aedes aegypti membrane-bound alkaline phosphatase (Aa-mALP). Binding analysis via dotblotting revealed that the Cry4Ba-DIII truncate was capable of specific binding to nitrocellulose-bound Aa-mALP, with a binding signal comparable to its 65kDa Cry4Ba-R203Q full-length toxin. Further determination of binding affinity via sandwich ELISA revealed that Cry4Ba-DIII exhibited a rather weak binding to Aa-mALP with a dissociation constant (Kd) of ≈1.1 ×10−7 M as compared with the full-length toxin. Intermolecular docking between the Cry4Ba-R203Q active toxin and Aa-mALP suggested that four Cry4Ba-DIII residues, i.e., Glu522, Asn552, Asn576, and Leu615, are potentially involved in such toxin–receptor interactions. Ala substitutions of each residue (E522A, N552A, N576A and L615A) revealed that only the L615A mutant displayed a drastic decrease in biotoxicity against A. aegypti larvae. Additional binding analysis revealed that the L615A-impaired toxin also exhibited a reduction in binding capability to the surface-immobilized Aa-mALP receptor, while two bio-inactive DII-mutant toxins, Y332A and F364A, which almost entirely lost their biotoxicity, apparently retained a higher degree of binding activity. Altogether, our data disclose a functional importance of the C-terminal domain of Cry4Ba for serving as a potential receptor-binding moiety in which DIII-Leu615 could conceivably be exploited for the binding to Aa-mALP, highlighting its contribution to toxin interactions with such a target receptor in mediating larval toxicity.

scholarly journals Resistance to Bacillus thuringiensis Toxin Cry2Ab in Trichoplusia ni Is Conferred by a Novel Genetic Mechanism

2015 ◽  
Vol 81 (15) ◽  
pp. 5184-5195 ◽  
Author(s):  
Xiaozhao Song ◽  
Wendy Kain ◽  
Douglas Cassidy ◽  
Ping Wang
Keyword(s):  
Alkaline Phosphatase ◽  
Bacillus Thuringiensis ◽  
Trichoplusia Ni ◽  
Genetic Linkage ◽  
Genetic Mechanism ◽  
Cross Resistance ◽  
Genetic Linkage Analysis ◽  
Recessive Trait ◽  
Content Type ◽  
Significant Difference

ABSTRACTThe resistance to theBacillus thuringiensis(Bt) toxin Cry2Ab in a greenhouse-originatedTrichoplusia nistrain resistant to both Bt toxins Cry1Ac and Cry2Ab was characterized. Biological assays determined that the Cry2Ab resistance in theT. nistrain was a monogenic recessive trait independent of Cry1Ac resistance, and there existed no significant cross-resistance between Cry1Ac and Cry2Ab inT. ni. From the dual-toxin-resistantT. nistrain, a strain resistant to Cry2Ab only was isolated, and the Cry2Ab resistance trait was introgressed into a susceptible laboratory strain to facilitate comparative analysis of the Cry2Ab resistance with the susceptibleT. nistrain. Results from biochemical analysis showed no significant difference between the Cry2Ab-resistant and -susceptibleT. nilarvae in midgut proteases, including caseinolytic proteolytic activity and zymogram profile and serine protease activities, in midgut aminopeptidase and alkaline phosphatase activity, and in midgut esterases and hemolymph plasma melanization activity. For analysis of genetic linkage of Cry2Ab resistance with potential Cry toxin receptor genes, molecular markers for the midgut cadherin, alkaline phosphatase (ALP), and aminopeptidase N (APN) genes were identified between the original greenhouse-derived dual-toxin-resistant and the susceptible laboratoryT. nistrains. Genetic linkage analysis showed that the Cry2Ab resistance inT. niwas not genetically associated with the midgut genes coding for the cadherin, ALP, and 6 APNs (APN1 to APN6) nor associated with the ABC transporter geneABCC2. Therefore, the Cry2Ab resistance inT. niis conferred by a novel but unknown genetic mechanism.

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
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