Frequency of resistance alleles to Cry1Ac toxin from cotton bollworm, Helicoverpa armigera (Hübner) collected from Bt-cotton growing areas of Telangana state of India

Singh, T. V. K.; Kukanur, Vinod S.; G.B, Supriya

doi:10.1016/j.jip.2021.107559

Cited by 7 publications

(8 citation statements)

References 27 publications

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“…In the wake of pink bollworm resistance, the benefits of Bt cotton in India have been debated [ 74 , 75 ]. Factors favoring its continued high adoption may include limited availability of non-Bt cotton and the lack of practical resistance to Bt cotton in the major pest Helicoverpa armigera [ 76 ]. In India, abundant refuges of non-Bt host plants other than cotton may have helped to delay the evolution of practical resistance in this polyphagous pest [ 76 ].…”

Section: Field Outcomes: Pink Bollworm and Bt Cotton In The Us China ...mentioning

confidence: 99%

Molecular Genetic Basis of Lab- and Field-Selected Bt Resistance in Pink Bollworm

Fabrick

Carrière

et al. 2023

Insects

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Transgenic crops producing insecticidal proteins from the bacterium Bacillus thuringiensis (Bt) control some important insect pests. However, evolution of resistance by pests reduces the efficacy of Bt crops. Here we review resistance to Bt cotton in the pink bollworm, Pectinophora gossypiella, one of the world’s most damaging pests of cotton. Field outcomes with Bt cotton and pink bollworm during the past quarter century differ markedly among the world’s top three cotton-producing countries: practical resistance in India, sustained susceptibility in China, and eradication of this invasive lepidopteran pest from the United States achieved with Bt cotton and other tactics. We compared the molecular genetic basis of pink bollworm resistance between lab-selected strains from the U.S. and China and field-selected populations from India for two Bt proteins (Cry1Ac and Cry2Ab) produced in widely adopted Bt cotton. Both lab- and field-selected resistance are associated with mutations affecting the cadherin protein PgCad1 for Cry1Ac and the ATP-binding cassette transporter protein PgABCA2 for Cry2Ab. The results imply lab selection is useful for identifying genes important in field-evolved resistance to Bt crops, but not necessarily the specific mutations in those genes. The results also suggest that differences in management practices, rather than genetic constraints, caused the strikingly different outcomes among countries.

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Section: Field Outcomes: Pink Bollworm and Bt Cotton In The Us China ...mentioning

confidence: 99%

Molecular Genetic Basis of Lab- and Field-Selected Bt Resistance in Pink Bollworm

Fabrick

Carrière

et al. 2023

Insects

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“…The frequent use of insecticides has led to the development of resistance to synthetic pyrethroids, oxadiazines, organophosphates, organochlorines, and carbamates (Bird 2017, Tay et al 2017). Populations of H. armigera have also developed resistance to Cry1Ac, Cry2Aa, and Cry2Ab toxins expressed in transgenic crops that protect against other lepidopteran species (Mahon et al 2007, Alvi et al 2012, Wei et al 2017, Singh et al 2021).…”

Section: Introductionmentioning

confidence: 99%

Field-based recombinase polymerase amplification and lab-based qPCR assays for detection of Helicoverpa armigera

Rich

Noh

Wang

et al. 2023

Journal of Economic Entomology

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Helicoverpa armigera (Hübner) is a major crop pest native to Europe, Asia, Australia, and Africa which has recently invaded South America and has caused billions of dollars in agricultural losses. Because of challenges in differentiating between H. armigera and Helicoverpa zea (Boddie), a closely related species native to North and South America, genetic tests have previously been developed to detect H. armigera DNA in pooled samples of moth legs. In this study, a field-based recombinase polymerase amplification (RPA) assay using a lateral flow strip and a qPCR melt curve assay were developed for specific detection of H. armigera DNA in pooled moth samples. In addition, a crude DNA extraction protocol for whole moths was developed to allow rapid preparation of DNA samples. The RPA field test was able to detect ≥ 10 pg of purified H. armigera DNA and the crude DNA of one H. armigera sample in a background of 999 H. zea equivalents. The qPCR assay was able to detect ≥ 100 fg of purified H. armigera DNA and the crude DNA of one H. armigera sample in a background of up to 99,999 H. zea equivalents. Both RPA and qPCR assays detected H. armigera in the crude DNA extracted in the field from a pool of one H. armigera moth and 999 H. zea moths. These newly developed molecular assays to detect H. armigera will contribute to large-scale surveillance programs of H. armigera.

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“…[2][3][4] Although Bt cotton has reduced the burden of H. armigera without harming the environment or human health, the efficacy of Bt cotton has decreased due to field-evolved resistance in insect pests over time. 5,6 Currently, chemical insecticides are widely used to control H. armigera in non-Bt crops. However, the long-term use of pesticides has led to the development of resistance in several insects, including H. armigera.…”

Section: Introductionmentioning

confidence: 99%

“…It has a wide range of host plants and damages many crops, such as cotton, soybeans, tobacco, tomatoes, and corn 2–4 . Although Bt cotton has reduced the burden of H. armigera without harming the environment or human health, the efficacy of Bt cotton has decreased due to field‐evolved resistance in insect pests over time 5,6 . Currently, chemical insecticides are widely used to control H. armigera in non‐Bt crops.…”

Section: Introductionmentioning

confidence: 99%

Effect of silencing the E74B gene on the development and metamorphosis of Helicoverpa armigera

Xu,

Li,

Zhang

et al. 2023

Pest Management Science

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BACKGROUNDThe growth and development transition of insects are mainly mediated by ecdysone. As one of the ecdysone‐induced transcription factors, E74 is involved in many physiological processes of insect growth and development. However, E74 and its function in Helicoverpa armigera remains unclear.RESULTSIn this study, E74B, a subtype of the E74, was identified for the first time in H. armigera. Bioinformatics analysis showed that H. armigera E74B shared the highest homology with E74B in Bombyx mori, which belongs to the E26 transformation‐specific (ETS) superfamily. The expression profile showed that the transcription level of HaE74B increased in the late stages of fourth to sixth instars compared with the early stages; it was also high in the pupa and midgut. Moreover, we investigated the function of HaE74B through RNA interference and 20E rescue experiments. The results showed silencing of E74B affected the molting and growth of larvae, resulting in the death of more than 60% of larvae. In addition, it also seriously affected the metamorphosis of H. armigera, which reduced the pupae rate, the eclosion rate of the pupae, and fecundity. Application of 20E partially restored the defects in the molting, development and pupae rate of H. armigera.CONCLUSIONTaken together, these results demonstrated that HaE74B plays a critical role in the growth, development, and metamorphosis of H. armigera, which serves as a molecular target and sets out a theoretical foundation for RNAi‐mediated control of this key pest. © 2023 Society of Chemical Industry.

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Frequency of resistance alleles to Cry1Ac toxin from cotton bollworm, Helicoverpa armigera (Hübner) collected from Bt-cotton growing areas of Telangana state of India

Cited by 7 publications

References 27 publications

Molecular Genetic Basis of Lab- and Field-Selected Bt Resistance in Pink Bollworm

Molecular Genetic Basis of Lab- and Field-Selected Bt Resistance in Pink Bollworm

Field-based recombinase polymerase amplification and lab-based qPCR assays for detection of Helicoverpa armigera

Effect of silencing the E74B gene on the development and metamorphosis of Helicoverpa armigera

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