Multi-Toxin Resistance Enables Pink Bollworm Survival on Pyramided Bt Cotton

Jeffrey A. Fabrick, Gopalan C. Unnithan, Alex J. Yelich, Ben DeGain, Luke Masson, Jie Zhang, Yves Carrière, Bruce E. Tabashnik

Research output: Contribution to journalArticlepeer-review

42 Scopus citations


Transgenic crops producing Bacillus thuringiensis (Bt) proteins kill key insect pests, providing economic and environmental benefits. However, the evolution of pest resistance threatens the continued success of such Bt crops. To delay or counter resistance, transgenic plant "pyramids" producing two or more Bt proteins that kill the same pest have been adopted extensively. Field populations of the pink bollworm (Pectinophora gossypiella) in the United States have remained susceptible to Bt toxins Cry1Ac and Cry2Ab, but field-evolved practical resistance to Bt cotton producing Cry1Ac has occurred widely in India. Here we used two rounds of laboratory selection to achieve 18,000- to 150,000-fold resistance to Cry2Ab in pink bollworm. Inheritance of resistance to Cry2Ab was recessive, autosomal, conferred primarily by one locus, and independent of Cry1Ac resistance. We created a strain with high resistance to both toxins by crossing the Cry2Ab-resistant strain with a Cry1Ac-resistant strain, followed by one selection with Cry2Ab. This multi-toxin resistant strain survived on field-collected Bt cotton bolls producing both toxins. The results here demonstrate the risk of evolution of resistance to pyramided Bt plants, particularly when toxins are deployed sequentially and refuges are scarce, as seen with Bt cotton and pink bollworm in India.

Original languageEnglish (US)
Article number16554
JournalScientific reports
StatePublished - Nov 12 2015

ASJC Scopus subject areas

  • General


Dive into the research topics of 'Multi-Toxin Resistance Enables Pink Bollworm Survival on Pyramided Bt Cotton'. Together they form a unique fingerprint.

Cite this