Knockout of ABC transporter gene ABCA2 confers resistance to Bt toxin Cry2Ab in Helicoverpa zea

• Published in: Scientific reports Vol. 12; no. 1; pp. 16706 - 8
• Main Authors: Fabrick, Jeffrey A., Heu, Chan C., LeRoy, Dannialle M., DeGain, Ben A., Yelich, Alex J., Unnithan, Gopalan C., Wu, Yidong, Li, Xianchun, Carrière, Yves, Tabashnik, Bruce E.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 06-10-2022; Nature Publishing Group; Nature Portfolio
• Subjects: 631/181/735; 631/208/8; 631/337; 631/61/191; 631/61/447/8; ABC transporter; Adenosine Triphosphate - metabolism; Animals; ATP-Binding Cassette Transporters - genetics; ATP-Binding Cassette Transporters - metabolism; Bacillus thuringiensis - genetics; Bacillus thuringiensis - metabolism; Bacillus thuringiensis Toxins; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Bioassays; CRISPR; Crops; Crops, Agricultural - genetics; Endotoxins - genetics; Endotoxins - metabolism; Gene deletion; Genetic engineering; Genetically engineered microorganisms; Genome editing; Helicoverpa zea; Hemolysin Proteins - genetics; Hemolysin Proteins - metabolism; Hemolysin Proteins - pharmacology; Humanities and Social Sciences; Humans; Insecticide Resistance - genetics; Larva - genetics; Moths - genetics; Moths - metabolism; multidisciplinary; Mutation; Pest resistance; Pests; Plants, Genetically Modified - genetics; RNA, Guide, CRISPR-Cas Systems - metabolism; Science; Science & Technology - Other Topics; Science (multidisciplinary); Toxins; Zea mays - genetics
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-022-21061-2

Evolution of pest resistance reduces the benefits of widely cultivated genetically engineered crops that produce insecticidal proteins derived from
Bacillus thuringiensis
(Bt). Better understanding of the genetic basis of pest resistance to Bt crops is needed to monitor, manage, and counter resistance. Previous work shows that in several lepidopterans, resistance to Bt toxin Cry2Ab is associated with mutations in the gene encoding the ATP-binding cassette protein ABCA2. The results here show that mutations introduced by CRISPR/Cas9 gene editing in the
Helicoverpa zea
(corn earworm or bollworm) gene encoding ABCA2 (
HzABCA2
) can cause resistance to Cry2Ab. Disruptive mutations in
HzABCA2
facilitated the creation of two Cry2Ab-resistant strains. A multiple concentration bioassay with one of these strains revealed it had > 200-fold resistance to Cry2Ab relative to its parental susceptible strain. All Cry2Ab-resistant individuals tested had disruptive mutations in
HzABCA2
. We identified five disruptive mutations in
HzABCA2
gDNA. The most common mutation was a 4-bp deletion in the expected Cas9 guide RNA target site. The results here indicate that
HzABCA2
is a leading candidate for monitoring Cry2Ab resistance in field populations of
H. zea
.