Impact of Bt Cottons Expressing One or Two Insecticidal Proteins of &lt;I&gt;Bacillus thuringiensis&lt;/I&gt; Berliner on Growth and Survival of Noctuid (Lepidoptera) Larvae

Stewart, Scott; Adamczyk, John J.; Knighten, K. S.; Davis, Frank M.

doi:10.1603/0022-0493-94.3.752

Cited by 162 publications

(118 citation statements)

References 9 publications

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“…However, not all lepidopteran pest species are equally susceptible to Bt. Some experiments emphasized on the direct negative effects of Bt toxins on non-target herbivores [15,16,41].…”

Section: Discussionmentioning

confidence: 99%

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Temporal allocation of metabolic tolerance to transgenic Bt cotton in beet armyworm, Spodoptera exigua (Hübner)

Guo

Wan

2011

Sci. China Life Sci.

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Digestive and detoxification enzyme activity and nutrient composition were examined in the body of fourth instar beet armyworms, Spodoptera exigua (Hübner), fed on transgenic Bacillus thuringiensis (Bt) and non-Bt cotton for different time periods. Nutrient composition and specific enzyme activities differed significantly between the S. exigua fed Bt vs. non-Bt cotton. At 1, 6 and 24 h, free fatty acid and glucose levels were significantly lower in S. exigua fed on Bt cotton than those fed on non-Bt cotton. S. exigua fed on Bt cotton had significantly higher trypsin and total superoxide dismutase (T-SOD) activities and significantly lower lipase, carboxylesterase and acetylcholinesterase activities than non-Bt fed worms for all feeding time periods. Differences were also observed among feeding times within each cotton variety group. Significantly lower free fatty acid and total amino acid were observed in S. exigua fed on Bt cotton for 24 h than in those fed for 1 h. Significantly lower activities of lipase and trypsin were detected in S. exigua fed on Bt cotton for 24 h than those for 1 and 4 h. However, carboxylesterase and acetylcholinesterase activities in S. exigua fed on Bt cotton for 24 h were significantly higher than those for 1, 4 and 6 h. The interaction between cotton variety and feeding time significantly affected the activities of lipase, trypsin, acetylcholinesterase and T-SOD enzymes in S. exigua. Measuring the temporal allocation of protection and detoxification enzyme activities in the body of S. exigua in response to B. thuringiensis can provide a meaningful evaluation on the metabolic tolerance of herbivorous insects under the continuous selection pressure of a toxic protein.

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“…However, not all lepidopteran pest species are equally susceptible to Bt. Some experiments emphasized on the direct negative effects of Bt toxins on non-target herbivores [15,16,41].…”

Section: Discussionmentioning

confidence: 99%

“…Some lepidopteran species can survive after feeding on transgenic Bt cotton expressing Cry1Ac toxin [15,16]. Some non-lepidopteran herbivores are also unaffected by the toxin.…”

mentioning

confidence: 99%

Temporal allocation of metabolic tolerance to transgenic Bt cotton in beet armyworm, Spodoptera exigua (Hübner)

Guo

Wan

2011

Sci. China Life Sci.

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“…This typically addresses the mode of action of Bt proteins, disrupting the intestinal systems of target arthropods. Target pest insects are reported to be synergistically affected by combinations between Cry1Ab, Cry1Ac, Cry1F and/or Cry2Ab2 (Lee et al, 1996;Stewart et al, 2001;Khasdan et al, 2007;Sharma et al, 2010). If susceptible to Bt proteins, even to a small extent, non-target organisms need consideration on synergistic toxicity issues.…”

Section: Toxicity Of Cry Proteins and Cp4mentioning

confidence: 99%

“…toxicity effects (Wolt, 2011). Target lepidopteran pest insects are reported to be synergistically affected by the different combinations of Cry1Ab, Cry1Ac, Cry1F and/or Cry2Ab2 (Lee et al, 1996;Stewart et al, 2001;Khasdan et al, 2007;Sharma et al, 2010).…”

Section: Introductionmentioning

confidence: 99%

Effects of multiple Bt proteins and GNA lectin on in vitro-reared honey bee larvae

Hendriksma¹,

Härtel²,

Babendreier³

et al. 2012

Apidologie

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-The honey bee is a key non-target arthropod in environmental risk assessments of genetically modified crops. We analyzed for the first time combined effects of three Bt proteins conferring insect resistances, and a CP4-protein conferring an herbicide resistance as simultaneously expressed in one GM maize. Furthermore, the biosafety of Galanthus nivalis agglutinin (GNA lectin), a candidate protein for pest control was tested. Under worst-case exposure scenario, by using controlled in vitro larvae rearing, the combination of Bt proteins showed no adverse effects on bee larvae. In contrast, the GNA lectin was toxic at a 144 h LD 50 of 16.3 μg/larva. The prepupal weight was found to differ between the larvae collection days and between the colonies used for the experiment, explaining up to five times more data variance than the protein treatments (N=709 prepupae). In conclusion, neither single nor a mix of different Bt proteins were found harmful to honey bee larvae.Apis mellifera / Bacillus thuringiensis / environmental risk assessment / genetically modified crops / Cry protein

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“…Commercial use of transgenic cotton containing two Bt genes began in 1999, 3 years after the release of the original single Bt variety. Cotton plants expressing both Cry1Ac and Cry2Ab proteins were more toxic to bollworms (Helicoverpa zea; target pest) and two species of armyworms (Spodoptera frugiperda and Spodoptera exigua; secondary pests) than cotton expressing Cry1Ac alone in laboratory trials (Stewart et al, 2001) and in greenhouse and field trials (Chitkowski et al, 2003).…”

Section: Plants Expressing Multiple Toxinsmentioning

confidence: 99%

Biotechnological Prospects for Engineering Insect-Resistant Plants

Gatehouse

2008

Plant Physiology

189

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Insect-resistant crops have been one of the major successes of applying plant genetic engineering technology to agriculture; cotton (Gossypium hirsutum) resistant to lepidopteran larvae (caterpillars) and maize (Zea mays) resistant to both lepidopteran and coleopteran larvae (rootworms) have become widely used in global agriculture and have led to reductions in pesticide usage and lower production costs (Toenniessen et al., 2003;Brookes and Barfoot, 2005).The source of the insecticidal toxins produced in commercial transgenic plants is the soil bacterium Bacillus thuringiensis (Bt). Bt strains show differing specificities of insecticidal activity toward pests, and constitute a large reservoir of genes encoding insecticidal proteins, which are accumulated in the crystalline inclusion bodies produced by the bacterium on sporulation (Cry proteins, Cyt proteins) or expressed during bacterial growth (Vip proteins). The threedomain Cry proteins have been extensively studied; their mechanism of action involves a proteolytic activation step, which occurs in the insect gut after ingestion, followed by interaction of one or both of domains II and III with ''receptors'' on the surface of cells of the insect gut epithelium. This interaction leads to oligomerization of the protein, and domain I is then responsible for the formation of an open channel through the cell membrane . The resulting ionic leakage destroys the cell, leading to breakdown of the gut, bacterial proliferation, and insect death.However, not all pests are adequately targeted by the Bt toxins used at present, and there is still a need to develop solutions to specific problems, such as resistance to sap-sucking pests and pests of stored products. This Update will review some developments to the basic Bt strategy and selected alternative methods for engineering insect resistance.

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Impact of Bt Cottons Expressing One or Two Insecticidal Proteins of <I>Bacillus thuringiensis</I> Berliner on Growth and Survival of Noctuid (Lepidoptera) Larvae

Cited by 162 publications

References 9 publications

Temporal allocation of metabolic tolerance to transgenic Bt cotton in beet armyworm, Spodoptera exigua (Hübner)

Temporal allocation of metabolic tolerance to transgenic Bt cotton in beet armyworm, Spodoptera exigua (Hübner)

Effects of multiple Bt proteins and GNA lectin on in vitro-reared honey bee larvae

Biotechnological Prospects for Engineering Insect-Resistant Plants

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