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General Information

Document type
  • Peer-reviewed journal article
GE organism
  • cotton
GE trait
  • insect resistance
  • China


  • negative effect

Diverse cadherin mutations conferring resistance to Bacillus thuringiensis toxin Cry1Ac in Helicoverpa armigera

Zhao, J; Jin, L; Yang, Y; Wu, Y
Insect Biochemistry and Molecular Biology. 2010 February. 40(2):113–118

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PMID: 20079435 DOI: 10.1016/j.ibmb.2010.01.001 ISSN: 0965-1748


Transgenic cotton expressing Bacillus thuringiensis (Bt) toxins has been widely adopted to control some key lepidopteran pests including the bollworm Helicoverpa armigera. Evolution of resistance to Bt cotton by target pests is a major threat to the continued success of Bt cotton. Previous results revealed 3 null alleles (r1-r3) of a cadherin gene (Ha_BtR) conferring Cry1Ac resistance in H. armigera. An F(1) screen of 123 single-pair families was conducted between a Cry1Ac-resistant strain (the SCD-r1 strain, homozygous for the r1 allele of Ha_BtR) and field-derived insects from Jiangpu population (Jiangsu province, China) in 2008. Five new null alleles of Ha_BtR (r4-r8) were identified in six candidate single-pair families. These null alleles were created through either an insertion or a point mutation. Interestingly, intact alleles of Ha_BtR were found in two field-derived insects from another two candidate single-pair families. It suggests that these two field-derived insects may carry novel resistance alleles of Ha_BtR, with missense mutations resulting in a non-functional cadherin protein, or a major dominant mutation at a locus other than cadherin. The resistance allele frequency of Ha_BtR was detected at an appreciable level (0.024) in the Jiangpu population of H. armigera in 2008. Together with previous findings, a total of eight different resistance alleles of Ha_BtR were identified from three Chinese strains of H. armigera. Mutational diversity of Ha_BtR could impair DNA screening for Bt resistance allele frequency in the field, and an F(1) screen should be used routinely for monitoring cadherin-based resistance allele frequencies in H. armigera.


Helicoverpa armigera; Bacillus thuringiensis; Cadherin; Resistance; Bt cotton


Funding source
  • Ministry of Science and Technology of China
  • National Natural Science Foundation of China
Funding country
  • China
Funding type
  • government

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Cite this study


Zhao, J, L Jin, Y Yang, Y Wu. "Diverse cadherin mutations conferring resistance to Bacillus thuringiensis toxin Cry1Ac in Helicoverpa armigera." Insect Biochemistry and Molecular Biology 40.2 (2010): 113–118. Web. 28 May. 2024.


Zhao, J., Jin, L., Yang, Y., & Wu, Y. (2010). Diverse cadherin mutations conferring resistance to Bacillus thuringiensis toxin Cry1Ac in Helicoverpa armigera. Insect Biochemistry and Molecular Biology, 40(2), 113–118. doi:10.1016/j.ibmb.2010.01.001

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