Use of RNAi as a preliminary tool for screening putative receptors of nematicidal toxins from Bacillus thuringiensis

• Published in: Archives of microbiology Vol. 203; no. 4; pp. 1649 - 1656
• Main Authors: García-Montelongo, Mónica, González-Villarreal, Sebastián E., Del Rincón-Castro, Ma. Cristina, Ibarra, Jorge E.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-05-2021; Springer Nature B.V
• Subjects: Animals; Antinematodal Agents - chemistry; Antinematodal Agents - metabolism; Bacillus thuringiensis; Bacillus thuringiensis - chemistry; Bacillus thuringiensis - genetics; Bacillus thuringiensis Toxins - chemistry; Bacillus thuringiensis Toxins - pharmacology; Biochemistry; Biomedical and Life Sciences; Biotechnology; Caenorhabditis elegans - drug effects; Cell Biology; E coli; Ecology; Escherichia coli - genetics; Escherichia coli - metabolism; Gene silencing; Genes; Intestine; Life Sciences; Membrane proteins; Membrane Proteins - genetics; Microbial Ecology; Microbiology; Nematodes; Original Paper; Proteins; Receptors; RNA Interference; RNA-mediated interference; Toxins; Nematicidal; RNAi; Receptor protein; Mode of action; B. thuringiensis; C. elegans
• ISSN: 0302-8933; 1432-072X
• DOI: 10.1007/s00203-020-02179-1

Bacillus thuringiensis
is a potential control agent for plant–parasitic nematodes. Nematode intestinal receptors for Cry21-type toxins are poorly known. Therefore, a strategy was tested as a primary screening tool to find possible Cry toxin receptors, using a nematicidal Bt strain and the RNAi technique on
Caenorhabditis elegans
. Six genes encoding intestinal membrane proteins were selected (
abt-4, bre-1, bre-2, bre-3, asps-1, abl-1
) as possible targets for Cry proteins. Fractions of each selected gene were amplified by PCR. Amplicons were cloned into the L4440 vector to transform the
E. coli
HT155 (DE3) strain. Transformed bacteria were used to silence the selected genes using the RNAi feeding method. Nematodes with silenced genes were tested with the Bt strain LBIT-107, which harbors the nematicidal protein Cry21Aa3, among others. Results indicated that nematodes with the silenced
abt-4
gene were 69.5% more resistant to the LBIT-107 strain, in general, and 79% to the Cry21Aa3 toxin, specifically.