Lack of Cry1Fa binding to the midgut brush border membrane in a resistant colony of Plutella xylostella moths with a mutaton in the ABCC2 locus
ABSTRACT Previous studies reported “mode 1” Bacillus thuringiensis resistance in a colony of diamondback moths (NO-QA), and recently, this resistance has been mapped to an ABC transporter ( ABCC2 ) locus. We report the lack of binding of Cry1Fa to insects derived from this colony and compare our data with those from other insects with ABCC2 -associated resistance.
Common, but Complex, Mode of Resistance of Plutella xylostella to Bacillus thuringiensis Toxins Cry1Ab and Cry1Ac
ABSTRACT A field collected population of Plutella xylostella (SERD4) was selected in the laboratory with Bacillus thuringiensis endotoxins Cry1Ac (Cry1Ac-SEL) and Cry1Ab (Cry1Ab-SEL). Both subpopulations showed similar phenotypes: high resistance to the Cry1A toxins and little cross-resistance to Cry1Ca or Cry1D. A previous analysis of the Cry1Ac-SEL showed incompletely dominant resistance to Cry1Ac with more than one factor, at least one of which was sex influenced. In the present study reciprocal mass crosses between Cry1Ab-SEL and a laboratory susceptible population (ROTH) provided evidence that Cry1Ab resistance was also inherited as incompletely dominant trait with more than one factor…