Fig. 9

Schematic representation of trans-acting factors and cis-acting mutation involved in the overexpression of CYP321B1 gene conferring resistance to insecticides in S. exigua. In the resistant strain, constitutive overexpression of trans-acting factors CncC and Maf, and cis-acting mutations in the resistant promoter creating the binding site for the POU/homeodomain transcription factor Nubbin synergistically enhance the expression of CYP321B1 gene associated with insecticide resistance; In the susceptible strain, CncC and Maf only regulate the basic expression of CYP321B1 gene, and there is no binding site for Nubbin. Therefore, the expression level of CYP321B1 gene is low which makes the larvae susceptible to insecticides