Silencing of an ABC transporter, but not a cadherin, decreases the susceptibility of Colorado potato beetle larvae to Bacillus thuringiensis ssp. tenebrionis Cry3Aa toxin


Guney G., Cedden D., Hanniger S., Heckel D. G. , Coutu C., Hegedus D. D. , ...More

ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY, vol.108, no.2, 2021 (Journal Indexed in SCI) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 108 Issue: 2
  • Publication Date: 2021
  • Doi Number: 10.1002/arch.21834
  • Title of Journal : ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY
  • Keywords: ABC transporter, Bacillus thuringiensis ssp, tenebrionis, Cadherin, Leptinotarsa decemlineata, RNAi, WESTERN CORN-ROOTWORM, INSECT RESISTANCE, MOLITOR CADHERIN, CABBAGE-LOOPER, BINDING, COLEOPTERA, RECEPTOR, PROTEIN, CHRYSOMELIDAE, POPULATION

Abstract

The Colorado potato beetle, Leptinotarsa decemlineata (Coleoptera: Chrysomelidae), is a major pest of potato plants worldwide and is notorious for its ability to develop resistance to insecticides. Cry3 toxins synthesized by Bacillus thuringiensis ssp. tenebrionis have been used successfully to manage this pest. Resistance to Cry toxins is a concerning problem for many insect pests; therefore, it is important to determine the mechanisms by which insects acquire resistance to these toxins. Cadherin-like and ABC transporter proteins have been implicated in the mode of action of Cry toxins as mutations in these genes render lepidopterans resistant to them; however, clear consensus does not exist on whether these proteins also play a role in Cry3 toxin activity and/or development of resistance in coleopterans. In the current study, we identified the L. decemlineata orthologues of the cadherin (LdCAD) and the ABCB transporter (LdABCB1) that have been implicated in the mode of action of Cry toxins in other coleopterans. Suppression of LdABCB1 via RNA interference reduced toxin-related larval mortality, whereas partial silencing of LdCAD did not. Our results suggest that the ABCB is involved in the mode of action of Cry3Aa toxins; however, no evidence was found to support the role of cadherin as a receptor of Cry3Aa in L. decemlineata.