Cross-Resistance to Bacillus thuringiensis Toxin Cry1Ja in a Strain of Diamondback Moth Adapted to Artificial Diet

Tabashnik, Bruce E.; Johnson, Kenneth W.; Engleman, James T.; Baum, James A.

doi:10.1006/jipa.2000.4941

Cited by 27 publications

(32 citation statements)

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“…Varied cross resistance patterns for different Bt proteins have been reported in several other lepidopteran species targeted by Bt crops (Tabashnik et al, 1994;Ferré and Van Rie, 2002;Siqueria et al, 2004;Li et al, 2005;Pereira et al, 2010;Crespo et al, 2011). In most cases, the underlying physiological mechanisms of crossresistance among Bt proteins are complex and somewhat unpredictable (Bauer, 1995).…”

Section: Discussionmentioning

confidence: 99%

“…Cross-resistance is common among Bt toxins (Tabashnik et al, 1994(Tabashnik et al, , 2000Zhao et al, 2001;Siqueria et al, 2004;Li et al, 2005;Ali and Luttrell, 2007;Wu et al, 2009;Crespo et al, 2011), but several studies also showed that no or low level of cross-resistance can exist among Bt proteins in some cases. For example, a Cry1Ab resistant strain of O. nubilalis was not resistant to Cry9C and had only a very low level of cross-resistance to Cry1F (Siqueria et al, 2004).…”

Section: Introductionmentioning

confidence: 99%

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Susceptibility of Cry1Ab maize-resistant and -susceptible strains of sugarcane borer (Lepidoptera: Crambidae) to four individual Cry proteins

Zhang

Huang

Leonard

et al. 2013

Journal of Invertebrate Pathology

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a b s t r a c tSugarcane borer, Diatraea saccharalis (F.), is a major target of Bt maize in South America and many areas of the US mid-south region. Six laboratory strains of D. saccharalis were established from six single-pair F 2 families possessing major resistance alleles to Cry1Ab maize hybrids. Susceptibility of the six strains was evaluated on diet treated with each of four purified trypsin-activated Bt proteins, Cry1Ab, Cry1Aa, Cry1Ac and Cry1F. Bt susceptibility of the six strains was compared with that of known Cry1Ab-susceptible and -resistant strains of D. saccharalis. At least two of the six strains demonstrated a similar level (>526-fold) of resistance to Cry1Ab as shown in the known Cry1Ab-resistant strain, while resistance levels were relatively lower for other strains (116-to 129-fold). All the six strains were highly cross-resistant to Cry1Aa (71-to 292-fold) and Cry1Ac (30-to 248-fold), but only with a low level to Cry1F (<7-fold). Larval growth of all six strains was also inhibited on Bt-treated diet, but, except for Cry1F, the growth inhibition of the six strains was considerably less than that of the Cry1Ab-susceptible larvae. The results provide clear evidence that the observed resistance to Cry1Ab maize in the six strains is a result of resistance to the Cry1Ab protein in the plants. The low level of cross-resistance between Cry1A and Cry1F suggests that pyramiding these two types of Bt proteins into a plant could be a good strategy for managing D. saccharalis.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Susceptibility of Cry1Ab maize-resistant and -susceptible strains of sugarcane borer (Lepidoptera: Crambidae) to four individual Cry proteins

Zhang

Huang

Leonard

et al. 2013

Journal of Invertebrate Pathology

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“…36 The NO-QAGE strain was derived from a field population in Hawaii that evolved resistance to Bt sprays containing Cry1Ab, Cry1Ac, and other Bt toxins. 35 In this strain, resistance is associated with reduced toxin binding to larval midgut membranes, and a major gene confers resistance to at least five Bt toxins including Cry1Ab and Cry1Ac. 35,37 Complementation tests show that the genetic locus conferring resistance in NO-QAGE also confers resistance in at least three other field-selected strains of P. xylostella from the continental US and Asia.…”

Section: P Xylostellamentioning

confidence: 99%

Efficacy of genetically modified Bt toxins against insects with different genetic mechanisms of resistance

et al. 2011

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Transgenic crops that produce Bacillus thuringiensis (Bt) toxins are grown widely for pest control, 1 but insect adaptation can reduce their efficacy. [2][3][4][5][6] The genetically modified Bt toxins Cry1AbMod and Cry1AcMod were designed to counter insect resistance to native Bt toxins Cry1Ab and Cry1Ac. 7 Previous results suggested that the modified toxins would be effective only if resistance was linked T A B A S H N I K E T A L ., N A T U R E B I O T E C H N O L O G Y 2 9 : 1 2 ( D E C E M B E R 2 0 1 1 )2 with mutations in genes encoding toxin-binding cadherin proteins. 7 Here we report evidence from five major crop pests refuting this hypothesis. Relative to native toxins, the potency of modified toxins was >350-fold higher against resistant strains of Plutella xylostella and Ostrinia nubilalis in which resistance was not linked with cadherin mutations. Conversely, the modified toxins provided little or no advantage against some resistant strains of three other pests with altered cadherin. Independent of the presence of cadherin mutations, the relative potency of the modified toxins was generally higher against the most resistant strains.The toxins produced by Bt kill some major insect pests but cause little or no harm to people and most other organisms. 8 Bt toxins have been used in sprays for decades and in transgenic plants since 1996 (ref. 6). Transgenic corn and cotton producing Bt toxins were planted on >58 million hectares worldwide in 2010 (ref. 1). The primary threat to the longterm efficacy of Bt toxins is the evolution of resistance by pests. [2][3][4][5][6] Many insects have been selected for resistance to Bt toxins in the laboratory, and some populations of at least eight crop pests have evolved resistance to Bt toxins outside of the laboratory, including two species resistant to Bt sprays and at least six species resistant to Bt crops. [2][3][4][5][6][9][10][11][12][13] The most widely used Bt toxins are crystalline proteins in the Cry1A family, particularly Cry1Ab in transgenic Bt corn and Cry1Ac in transgenic Bt cotton, which kill some lepidopteran larvae. 3 Cry1A toxins bind to the extracellular domains of cadherin, aminopeptidase, and alkaline phosphatase in larval midgut membranes. 14,15 Disruption of Bt toxin binding to midgut receptors is the most common general mechanism of insect resistance. 9 Mutations in the genes encoding midgut cadherins that bind Cry1Ac are linked with resistance in at least three lepidopteran pests of cotton, [16][17][18] but such cadherin mutations are not the primary cause of many other cases of field-and laboratory-selected resistance. 9,19,20 Although some aspects of the mode of action of Bt toxins remain unresolved, extensive evidence shows that after Cry1A protoxins are ingested by larvae, they are solubilized in the gut and cleaved by mid-gut proteases such as trypsin to yield activated 60-kD monomeric toxins that bind with membrane-associated receptors. 14,15 The signaling model suggests that after protease-activated monomeric toxins bind to ca...

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“…One strategy to delay resistance is to use alternative insecticidal proteins with different modes of action (Bosch et al 1994;Saraswathy and Kumar 2004). Researchers found that the resistance allele of P. xylostella confers cross-resistance to Cry1Aa, Cry1Ab, Cry1Ac, Cry1Fa and Cry1Ja, but not to Cry1Ba, Cry1Bb, Cry1Ca, Cry1Da, Cry1Ia or Cry2Aa (Tabashnik et al 1997(Tabashnik et al , 2000Heckel et al 1999). Ferré and van Rie (2002) asserted that the binding site of latter toxins in P. xylostella was different from those toxins to which P. xylostella have evolved resistance.…”

Section: Discussionmentioning

confidence: 99%

“…Its expression product, Cry1Ba3 protein, was extracted, and assayed against P. xylostella larvae using the leaf dip method. The bioassay results indicated that Cry1Ba3 protein exhibited high activity to P. xylostella (LC 50 = 0AE96 lg ml -1 ), and was more toxic than Cry1Ba1 protein (LC 50 = 6.2 lg ml -1 ) described by Tabashnik et al (1994).…”

Section: Cloning and Expression Of The Insecticidal Crystal Protein Gmentioning

confidence: 99%

RecombinantBacillus thuringiensisstrain shows high insecticidal activity againstPlutella xylostellaandLeptinotarsa decemlineatawithout affecting nontarget species in the field

Wang

Zhang

Song

et al. 2008

Journal of Applied Microbiology

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Aims: To construct a recombinant Bacillus thuringiensis (Bt) strain with broad insecticidal spectrum and investigate its impact on nontarget organisms in field. Method and Results: The cry‐type gene of wild Bt strain UV17 was identified and a novel cry1Ba gene was cloned. The cry3Aa7 gene, which was highly toxic to coleopteran pests, was introduced into UV17, and a recombinant strain designated as UV173A was obtained. Bioassay results showed that UV173A was not only highly toxic against Plutella xylostella (50% lethal concentration [LC50] = 18·03 μg ml–1), but also against coleopteran Leptinotarsa decernlineata (LC50 = 0·19 mg ml–1). The recombinant strain was then tested in field trials to monitor its spatial variation of population and to investigate the impact on nontarget invertebrates. Conclusions: A recombinant Bt stain UV173A with broad insecticidal spectrum was obtained, and it did not cause adverse effects on the population of nontarget organisms. Significance and Impact of the Study: The results obtained here indicated that cry1Ba3 gene may be useful for the resistance management of P. xylostella, and the recombinant stain UV173A was potential for field application against some crucifer vegetable pests as well as L. decemlineata.

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Cross-Resistance to Bacillus thuringiensis Toxin Cry1Ja in a Strain of Diamondback Moth Adapted to Artificial Diet

Cited by 27 publications

References 10 publications

Susceptibility of Cry1Ab maize-resistant and -susceptible strains of sugarcane borer (Lepidoptera: Crambidae) to four individual Cry proteins

Susceptibility of Cry1Ab maize-resistant and -susceptible strains of sugarcane borer (Lepidoptera: Crambidae) to four individual Cry proteins

Efficacy of genetically modified Bt toxins against insects with different genetic mechanisms of resistance

RecombinantBacillus thuringiensisstrain shows high insecticidal activity againstPlutella xylostellaandLeptinotarsa decemlineatawithout affecting nontarget species in the field

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