Assessment of Combining Biosynthesized Silver Nanoparticles Using Bacillus thuringiensis and Gamma Irradiation for Controlling Pectinophora gossypiella (Saunders) (Lepidoptera: Gelechiidae)

ABSTRACT Crops genetically engineered to produce Bacillus thuringiensis toxins for insect control can reduce use of conventional insecticides, but insect resistance could limit the success of this technology. The first generation of transgenic cotton with B. thuringiensis produces a single toxin, Cry1Ac, that is highly effective against susceptible larvae of pink bollworm (Pectinophora gossypiella), a major cotton pest. To counter potential problems with resistance, second-generation transgenic cotton that produces B. thuringiensis toxin Cry2Ab alone or in combination with Cry1Ac has been developed. In greenhouse bioassays, a pink bollworm strain selected in the laboratory for resistance to Cry1Ac survived equally well on transgenic cotton with Cry1Ac and on cotton without Cry1Ac. In contrast, Cry1Ac-resistant pink bollworm had little or no survival on second-generation transgenic cotton with Cry2Ab alone or with Cry1Ac plus Cry2Ab. Artificial diet bioassays showed that resistance to Cry1Ac did not confer strong cross-resistance to Cry2Aa. Strains with >90% larval survival on diet with 10 μg of Cry1Ac per ml showed 0% survival on diet with 3.2 or 10 μg of Cry2Aa per ml. However, the average survival of larvae fed a diet with 1 μg of Cry2Aa per ml was higher for Cry1Ac-resistant strains (2 to 10%) than for susceptible strains (0%). If plants with Cry1Ac plus Cry2Ab are deployed while genes that confer resistance to each of these toxins are rare, and if the inheritance of resistance to both toxins is recessive, the efficacy of transgenic cotton might be greatly extended.

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Study on antibacterial activity of silver nanoparticles synthesized by gamma irradiation method using different stabilizers

Nanoscale Research Letters ◽

10.1186/1556-276x-9-162 ◽

2014 ◽

Vol 9 (1) ◽

pp. 162 ◽

Cited By ~ 21

Author(s):

Dang Van Phu ◽

Le Quoc ◽

Nguyen Duy ◽

Nguyen Thi Lan ◽

Bui Du ◽

...

Keyword(s):

Silver Nanoparticles ◽

Antibacterial Activity ◽

Gamma Irradiation

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Characterisation of silver nanoparticles synthesised by Bacillus thuringiensis as a nanobiopesticide for insect pest control

Biocontrol Science and Technology ◽

10.1080/09583157.2017.1397597 ◽

2017 ◽

Vol 27 (11) ◽

pp. 1308-1326 ◽

Cited By ~ 3

Author(s):

Atef M. M. Sayed ◽

Sanghoon Kim ◽

Robert W. Behle

Keyword(s):

Silver Nanoparticles ◽

Bacillus Thuringiensis ◽

Pest Control ◽

Insect Pest ◽

Insect Pest Control

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Cross-Resistance of Pink Bollworm (Pectinophora gossypiella) to Bacillus thuringiensis Toxins

Applied and Environmental Microbiology ◽

10.1128/aem.66.10.4582-4584.2000 ◽

2000 ◽

Vol 66 (10) ◽

pp. 4582-4584 ◽

Cited By ~ 48

Author(s):

Bruce E. Tabashnik ◽

Yong-Biao Liu ◽

Ruud A. de Maagd ◽

Timothy J. Dennehy

Keyword(s):

Bacillus Thuringiensis ◽

Pink Bollworm ◽

Pectinophora Gossypiella ◽

Cross Resistance ◽

Mechanism Of Resistance ◽

Narrow Spectrum ◽

Target Sites ◽

The Cross

ABSTRACT Two strains of pink bollworm (Pectinophora gossypiella) selected in the laboratory for resistance to Bacillus thuringiensis toxin Cry1Ac had substantial cross-resistance to Cry1Aa and Cry1Ab but not to Cry1Bb, Cry1Ca, Cry1Da, Cry1Ea, Cry1Ja, Cry2Aa, Cry9Ca, H04, or H205. The narrow spectrum of resistance and the cross-resistance to activated toxin Cry1Ab suggest that reduced binding of toxin to midgut target sites could be an important mechanism of resistance.

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