Embryo Microinjection and Knockout Mutant Identification of CRISPR/Cas9 Genome-Edited Helicoverpa Armigera (Hübner)

10.3791/62068 ◽  
2021 ◽  
Author(s):  
Dong Ai ◽  
Bing Wang ◽  
Zhennan Fan ◽  
Yuyao Fu ◽  
Caihong Yu ◽  
...  
Keyword(s):  
Helicoverpa Armigera ◽  
Knockout Mutant ◽  
Helicoverpa Armígera ◽  
Mutant Identification

scholarly journals Bacillus thuringiensis Bel Protein Enhances the Toxicity of Cry1Ac Protein to Helicoverpa armigera Larvae by Degrading Insect Intestinal Mucin

2009 ◽  
Vol 75 (16) ◽  
pp. 5237-5243 ◽  
Author(s):  
Shangling Fang ◽  
Li Wang ◽  
Wei Guo ◽  
Xia Zhang ◽  
Donghai Peng ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Helicoverpa Armigera ◽  
Trichoplusia Ni ◽  
Knockout Mutant ◽  
Gene Encoding ◽  
In Vitro Degradation ◽  
Intestinal Mucin ◽  
Helicoverpa Armígera ◽  
Cry1ac Protein

ABSTRACT Bacillus thuringiensis has been used as a bioinsecticide to control agricultural insects. Bacillus cereus group genomes were found to have a Bacillus enhancin-like (bel) gene, encoding a peptide with 20 to 30% identity to viral enhancin protein, which can enhance viral infection by degradation of the peritrophic matrix (PM) of the insect midgut. In this study, the bel gene was found to have an activity similar to that of the viral enhancin gene. A bel knockout mutant was constructed by using a plasmid-free B. thuringiensis derivative, BMB171. The 50% lethal concentrations of this mutant plus the cry1Ac insecticidal protein gene were about 5.8-fold higher than those of the BMB171 strain. When purified Bel was mixed with the Cry1Ac protein and fed to Helicoverpa armigera larvae, 3 μg/ml Cry1Ac alone induced 34.2% mortality. Meanwhile, the mortality rate rose to 74.4% when the same amount of Cry1Ac was mixed with 0.8 μg/ml of Bel. Microscopic observation showed a significant disruption detected on the midgut PM of H. armigera larvae after they were fed Bel. In vitro degradation assays showed that Bel digested the intestinal mucin (IIM) of Trichoplusia ni and H. armigera larvae to various degrading products, similar to findings for viral enhancin. These results imply Bel toxicity enhancement depends on the destruction of midgut PM and IIM, similar to the case with viral enhancin. This discovery showed that Bel has the potential to enhance insecticidal activity of B. thuringiensis-based biopesticides and transgenic crops.

Field Efficiency of Certain Biopesticides and Neem Products Against Helicoverpa armigera (Hubner) on Chickpea (Cicer arietinumL.)

2019 ◽  
Vol 10 (01) ◽  
Author(s):  
Nihad H. Mutlag ◽  
Ameer S. A. Al-Haddad
Keyword(s):  
Helicoverpa Armigera ◽  
Block Design ◽  
Individual Treatment ◽  
Neem Oil ◽  
Larval Population ◽  
Neem Cake ◽  
Combination Treatments ◽  
Randomized Block Design ◽  
Helicoverpa Armígera ◽  
Nuclear Polyhedrosis

A field study was conducted to evaluate the efficiency of four microbial insecticides viz. Beauveria bassiana; HaNPV (Helicoverpa armigera Nuclear Polyhedrosis virus); (Bacillus thuringiensisvar.kurstaki 2 gm/L); HaNPV+Bt; neem oil; neem cake and D.D.V.P EC 76% @0.05% at Research Farm SHIATS,Allahabad during rabi season of 2011-2012. The experiment was laid out in randomized block design with seven treatment and replicated thrice. The observation larval populations of H. armigera were recorded one day before treatment was recorded at 3,7, and 10 days after treatments. The larva population of H. armigera appeared in the third week of February (8 the Standard week) and reached its peak of 14.65 larvae in first week of April and decline rapidly with maturation of crop. There was only one peak in the larval population observation in the 1st week. Bacillus thuringiensis was the most effective chemical by D.D.V.P.76%@0.05% . Among the microbial insecticides. HaNPV ,was the most effective followed by HaNPV+Bt and neem cake . The combination treatments were less effective than the individual treatment neem oil and B. bassiana were the least effective treatment in reducing the larval population of Heliverpa armigera.

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