International Journal of Biological Macromolecules, 2023,https:// doi: 10.1016/j.ijbiomac.2023.127668  

Abstract

Rapid evolution of pest resistance to Bt insecticidal proteins presents a serious threat to the sustainable use of Bt crops. The cotton bollworm has been extensively exposed to Bt cotton worldwide and has evolved resistance in laboratory and field. Previous studies have highlighted the significant roles played by the ABC transporter proteins in Bt resistance. In this study, the ORF of  HaABCB1  was cloned and analyzed. The expression of  HaABCB1  was detected in all developmental stages and tissues, with the highest expression in third instar larvae stage and hindgut tissue. Compared with susceptible strain, a remarkable decrease of  HaABCB1  expression in Cry1Ac resistant strain while no significant change in Cry2Ab resistant strain were found. The  HaABCB1  expression reduced after susceptible larvae induced by Cry1Ac, but no obvious expression changes after Cry2Ab exposure. RNAi-mediated down-regulation of  HaABCB1  could lead to a significant reduction in larval susceptibility to Cry1Ac, but not to Cry2Ab, in susceptible strain. Genetic linkage analysis confirmed that decreased expression of the  HaABCB1  mediates resistance to Cry1Ac, but not Cry2Ab resistance. This knowledge contributes to better understanding of the complex molecular mechanisms underlying Bt resistance and provide theoretical foundation for the development of new strategies for pest resistance management.

International Journal of Biological Macromolecules,IF=8.2

https://pubmed.ncbi.nlm.nih.gov/37884238/