Mutation of ABC transporter ABCA2 confers resistance to Bt toxin Cry2Ab in Trichoplusia ni

Yang, Xiaowei; Chen, Wenbo; Song, Xiaozhao; Xiang, Ma; Cotto-Rivera, Rey O.; Kain, Wendy; Chu, Hannah; Chen, Yun‐Ru; Fei, Zhangjun; Wang, Ping

doi:10.1016/j.ibmb.2019.103209

Cited by 40 publications

(26 citation statements)

References 52 publications

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“…ABCA2 was first suggested to be linked to Cry2Ab resistance in H. armigera [20]. This was confirmed by generating an ABCA2 knockout strain via CRISPR/Cas9 mutagenesis in which the resistance of H. armigera and T. ni larvae to Cry2Ab was linked to defects in ABCA2 [21,22], indicating that ABCA2 plays an important role in the mode of action of Cry2A toxins. Although the resistance was slightly lower than that of the C-terminal half-deleted strains (Figure 2B,C), toxicity testing of the strains with BmABCA2s that had 1-3 amino acids deleted from the C-terminal end of TM7 (A2T03, A2T08, and A2T11) showed that they were also resistant to Cry2Ab (Figure 2B,C).…”

Section: Discussionmentioning

confidence: 86%

“…This was confirmed using CRISPR/Cas9-mediated genome editing, leading to the conclusion that HaABCA2 determines the susceptibility of H. armigera to Cry2Aa and Cry2Ab [21]. The knockout of ABCA2 using CRISPR/Cas9 conferred resistance to Cry2Ab on Trichoplusia ni [22]. Furthermore, in Cry2Ab-resistant P. gossypiella strains, PgABCA2 was disrupted in several ways, indicating that the Cry2Ab-resistance of P. gossypiella is associated with an ABCA2 deficiency [23].…”

Section: Introductionmentioning

confidence: 77%

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ATP-Binding Cassette Subfamily a Member 2 Is a Functional Receptor for Bacillus thuringiensis Cry2A Toxins in Bombyx mori, But Not for Cry1A, Cry1C, Cry1D, Cry1F, or Cry9A Toxins

Miyamoto

Takasu

et al. 2020

Toxins

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Cry toxins are insecticidal proteins produced by Bacillus thuringiensis (Bt). They are used commercially to control insect pests since they are very active in specific insects and are harmless to the environment and human health. The gene encoding ATP-binding cassette subfamily A member 2 (ABCA2) was identified in an analysis of Cry2A toxin resistance genes. However, we do not have direct evidence for the role of ABCA2 for Cry2A toxins or why Cry2A toxin resistance does not cross to other Cry toxins. Therefore, we performed two experiments. First, we edited the ABCA2 sequence in Bombyx mori using transcription activator-like effector-nucleases (TALENs) and confirmed the susceptibility-determining ability in a diet overlay bioassay. Strains with C-terminal half-deleted BmABCA2 showed strong and specific resistance to Cry2A toxins; even strains carrying a deletion of 1 to 3 amino acids showed resistance. However, the C-terminal half-deleted strains did not show cross-resistance to other toxins. Second, we conducted a cell swelling assay and confirmed the specific ability of BmABCA2 to Cry2A toxins in HEK239T cells. Those demonstrated that BmABCA2 is a functional receptor for Cry2A toxins and that BmABCA2 deficiency-dependent Cry2A resistance does not confer cross-resistance to Cry1A, Cry1Ca, Cry1Da, Cry1Fa or Cry9Aa toxins.

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Section: Discussionmentioning

confidence: 86%

Section: Introductionmentioning

confidence: 77%

ATP-Binding Cassette Subfamily a Member 2 Is a Functional Receptor for Bacillus thuringiensis Cry2A Toxins in Bombyx mori, But Not for Cry1A, Cry1C, Cry1D, Cry1F, or Cry9A Toxins

Miyamoto

Takasu

et al. 2020

Toxins

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“…The most common and most potent mechanism of insect resistance to Bt toxins is disruption of toxin binding to larval midgut receptors, particularly cadherins and ATP-binding cassette (ABC) transporter proteins [17][18][19]. Resistance to crystalline (Cry) toxins of Bt in the Cry1, Cry2 or Cry3 families is associated with ABC transporter proteins in some lab-selected strains and field-selected populations of at least nine insect species [19][20][21][22][23][24][25][26][27]. In addition to studies implicating several ABC transporter proteins in resistance to Cry toxins, extensive evidence indicates many members of the superfamily of ABC transporter proteins protect cells by excreting xenobiotics, including ABC transporters that confer resistance to drugs and chemotherapy agents in humans and resistance to insecticides other than Bt in arthropods [20,28,29].…”

Section: Introductionmentioning

confidence: 99%

Functional redundancy of two ABC transporter proteins in mediating toxicity of Bacillus thuringiensis to cotton bollworm

Wang

Zhao

et al. 2020

PLoS Pathog

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Evolution of pest resistance reduces the efficacy of insecticidal proteins from the gram-positive bacterium Bacillus thuringiensis (Bt) used widely in sprays and transgenic crops. Better understanding of the genetic basis of resistance is needed to more effectively monitor, manage, and counter pest resistance to Bt toxins. Here we used CRISPR/Cas9 gene editing to clarify the genetics of Bt resistance and the associated effects on susceptibility to other microbial insecticides in one of the world's most damaging pests, the cotton bollworm (Helicoverpa armigera). We discovered that CRISPR-mediated knockouts of ATP-binding cassette (ABC) transporter genes HaABCC2 and HaABCC3 together caused >15,000-fold resistance to Bt toxin Cry1Ac, whereas knocking out either HaABCC2 or HaABCC3 alone had little or no effect. Inheritance of resistance was autosomal and recessive. Bioassays of progeny from interstrain crosses revealed that one wild type allele of either HaABCC2 or HaABCC3 is sufficient to sustain substantial susceptibility to Cry1Ac. In contrast with previous results, susceptibility to two insecticides derived from bacteria other than Bt (abamectin and spinetoram), was not affected by knocking out HaABCC2, HaABCC3, or both. The results here provide the first evidence that either HaABCC2 or HaABCC3 protein is sufficient to confer substantial susceptibility to Cry1Ac. The functional redundancy of these two proteins in toxicity of Cry1Ac to H. armigera is expected to reduce the likelihood of field-evolved resistance relative to disruption of a toxic process where mutations affecting a single protein can confer resistance.

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“…Unlike Cry1Ac, little is known about the mode of action of Cry2Ab. Recently, ATP binding cassette (ABC) subfamily A member 2 (ABCA2) [49][50][51][52] and ABC subfamily C member 1 (ABCC1) 53 were identified as Cry2Ab receptors in H. armigera due to their involvement in Cry2Ab resistance and their abilities to bind with Cry2Ab toxins. However, the details of their modes of action and their effects on the activities of insect life are elusive.…”

Section: Discussionmentioning

confidence: 99%

Suppressing calcineurin activity increases the toxicity of Cry2Ab to Helicoverpa armigera

Wei

Yang

Zhou

et al. 2021

Pest Management Science

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BACKGROUND Extensive planting of transgenetic Bacillus thuringiensis crops has driven the evolution of pest resistance to Cry1Ac. Adjustment of cropping structures has promoted further outbreak of Helicoverpa armigera in China. To control this pest, a combination of pyramiding RNA interference (RNAi) and Cry2Ab is considered a promising strategy for countering cross‐resistance and enhancing the toxicity of Cry2Ab to cotton bollworm. We explored the possibility of using calcineurin (CAN) as a target RNAi gene, because it is involved in cotton bollworm responses to the toxicity of Cry2Ab. RESULTS Cry2Ab treatment led to a significant increase in HaCAN mRNA level and HaCAN activity. Suppression of HaCAN activity due to RNAi‐mediated knockdown of HaCAN increased the susceptibility of midgut cells to Cry2Ab. The increase in HaCAN activity shown by heterologous expression of HaCAN reduced the cytotoxicity of Cry2Ab to Sf9 cells. Moreover, ingestion of HaCAN‐specific inhibitor FK506 increased the toxicity of Cry2Ab in larvae. Interestingly, HaCAN does not function as a Cry2Ab direct binding protein that participates in Cry2Ab toxicity. CONCLUSIONS The results in this study provide evidence that suppression of HaCAN not only affected the development of the cotton bollworm, but also enhanced the toxicity of Cry2Ab to the pest. HaCAN is therefore an important candidate gene in cotton bollworm that can be targeted for pest control when the pest infests RNAi+Cry2Ab crops. Meanwhile, the mechanism of action of HaCAN in Cry2Ab toxicity suggested that protein dephosphorylation was involved. © 2020 Society of Chemical Industry

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Mutation of ABC transporter ABCA2 confers resistance to Bt toxin Cry2Ab in Trichoplusia ni

Cited by 40 publications

References 52 publications

ATP-Binding Cassette Subfamily a Member 2 Is a Functional Receptor for Bacillus thuringiensis Cry2A Toxins in Bombyx mori, But Not for Cry1A, Cry1C, Cry1D, Cry1F, or Cry9A Toxins

ATP-Binding Cassette Subfamily a Member 2 Is a Functional Receptor for Bacillus thuringiensis Cry2A Toxins in Bombyx mori, But Not for Cry1A, Cry1C, Cry1D, Cry1F, or Cry9A Toxins

Functional redundancy of two ABC transporter proteins in mediating toxicity of Bacillus thuringiensis to cotton bollworm

Suppressing calcineurin activity increases the toxicity of Cry2Ab to Helicoverpa armigera

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