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Multiple origins of a single point mutation in the cotton bollworm tetraspanin gene confers dominant resistance to Bt cotton
Author(s) -
Guan Fang,
Hou Bofeng,
Dai Xiaoguang,
Liu Sitong,
Liu Juanjuan,
Gu Yan,
Jin Lin,
Yang Yihua,
Fabrick Jeffrey A,
Wu Yidong
Publication year - 2021
Publication title -
pest management science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.296
H-Index - 125
eISSN - 1526-4998
pISSN - 1526-498X
DOI - 10.1002/ps.6192
Subject(s) - cry1ac , biology , bt cotton , helicoverpa armigera , bacillus thuringiensis , bollworm , resistance (ecology) , gossypium , pest analysis , tetraspanin , mutation , genetically modified crops , microbiology and biotechnology , helicoverpa , genetics , gene , agronomy , transgene , botany , lepidoptera genitalia , larva , bacteria , cell
BACKGROUND Transgenic crops producing insecticidal proteins derived from Bacillus thuringiensis (Bt) are used globally to kill key insect pests and provide numerous benefits, including improved pest management, increased profits, reduced insecticide use, and increased biological control. Unfortunately, such benefits are rapidly being lost by the evolution of Bt resistance by pests. RESULTS The main strategy to delay resistance relies on the use of non‐Bt refuge plants to produce sufficient susceptible insects that mate with rare resistant insects emerging from Bt crops, essentially diluting and/or removing resistance alleles from pest populations. A key assumption for the success of this refuge strategy is that inheritance of resistance is recessive. In China, dominant resistance to Cry1Ac Bt cotton by the cotton bollworm Helicoverpa armigera is increasing and is associated with a mutation in the tetraspanin HaTSPAN1 gene, conferring more than 125‐fold resistance. Here, we used amplicon sequencing to test the hypotheses that the HaTSPAN1 mutation either arose from a single event and spread or that the mutation evolved independently several times throughout northern China. From three laboratory strains and 28 field populations sampled from northern China, we identified six resistant and 50 susceptible haplotypes. Phylogenetic analysis indicates that the HaTSPAN1 mutation arose from at least four independent origins and spread to their current distributions. CONCLUSION The results provide valuable information about the evolutionary origins of dominant resistance to Cry1Ac Bt cotton in northern China and offer rationale for the rapid increase in field‐evolved resistance in these areas, where the implementation of additional practical resistance management is needed. © 2020 Society of Chemical Industry