Resistance of Diamondback Moth (Lepidoptera: Plutellidae) to Bacillus thuringiensis Subspecies in the Field

Shelton, Anthony M.; Robertson, Jacqueline L.; Tang, Juliet D.; Perez, Cruz; Eigenbrode, Sanford D.; Preisler, Haiganoush K.; Wilsey, W. T.; Cooley, R. J.

doi:10.1093/jee/86.3.697

Cited by 242 publications

(163 citation statements)

References 11 publications

Supporting

Mentioning

155

Contrasting

Unclassified

Order By: Relevance

“…34,35 The susceptible strain (Geneva 88) originated in 1988 from a cabbage field near Geneva, New York. 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.…”

Section: P Xylostellamentioning

confidence: 99%

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

et al. 2011

View full text Add to dashboard Cite

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...

show abstract

Section: P Xylostellamentioning

confidence: 99%

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

et al. 2011

View full text Add to dashboard Cite

show abstract

“…As yet, no significant development of resistance has been reported in Bt crops Morin et al, 2003), although field resistance of Plutella xylostella was generated by Bt sprays (Shelton et al, 1993). Cry-resistant populations have been selected by exposing various lepidopteran larvae to high concentrations of specific Cry proteins in the laboratory (Ferre and Van Rie, 2002).…”

Section: Discussionmentioning

confidence: 99%

Cell-cycle-dependent resistance toBacillus thuringiensisCry1C toxin in Sf9 cells

Avisar

Segal

Sneh

et al. 2005

Journal of Cell Science

View full text Add to dashboard Cite

The Sf9 cell line, derived from the moth Spodoptera frugiperda, is highly and specifically sensitive to the Bacillus thuringiensis Cry1C toxin. Upon exposure to Cry1C, ionic pores are formed in the plasma membrane leading to cell swelling and death. Here, we describe a unique transient tolerance to Cry1C of dividing cells, which allowed completion of the division process in the presence of Cry1C. Correlatively, arresting the cells at G2-M phase by nocodazole treatment rendered them insensitive to Cry1C. When the arresting agent was removed, the cells completed their division and gradually regained Cry1C sensitivity. In comparison to normal cells with 1-2% cell-division frequency, the M-phase arrested cells bound less toxin in binding assays. Moreover, no lipid rafts could be isolated from the membranes of M-phase arrested cells. Caveolin-1, identified here for the first time in insect cells, was immunodetected as a lipid raft component of normal cells, but was only present in the membrane-soluble fraction of G2-M-arrested cells. Thus M-phase-linked changes in lipid raft organization may account for diminished Cry1C binding and toxicity. Furthermore, considering the pivotal role of lipid rafts in different cell functions of many cell types, the lack of organized lipid rafts in dividing cells may transiently affect cell susceptibility to pathogens, toxins and other lipid raft-linked functions.

show abstract

“…The antifeedant activity of these compounds was also carried out by leaf dip method [41,42], using fourth instars larvae of Spodoptera litura. The leaf discs of about 25 cm 2 were prepared and dipped for thirty seconds in various concentrations of the test compounds.…”

Section: Antifeedant Activitymentioning

confidence: 99%

“…The acaricidal activity of these compounds was carried out by leaf dip method [41,42]. Leaf discs of Mulberry (5 cm 2 diameter) were dipped in different concentration for 30 seconds.…”

Section: Acaricidal Activitymentioning

confidence: 99%

Rapid synthesis and biological evaluation of 1,4-dihydropyridine derivatives containing a benzothiazolyl moiety

Mithlesh

Pareek

Kant³

et al. 2010

Open Chemistry

View full text Add to dashboard Cite

Abstract:A series of N-(6-methylbenzothiazolyl)-2,3,5,6-tetrasubstituted-4-(aryl)-1,4-dihydropyridines were synthesized by reaction of 2-amino-6-methylbenzothiazole, aromatic aldehyde and active methylene compound in methanol by conventional, as well as, microwave irradiation (solvent free and solid support) methods. The microwave irradiation technique gives better yield and shorter reaction time. Among solid supported microwave irradiation better yields are obtained in acidic alumina as compared to silica, neutral alumina, and basic alumina. All compounds were tested for antibacterial and antifungal activities and results have been compared with standard drugs. Entomological activities were also tested. The results showed that a change in the substitution pattern in 1,4-dihydropyridine derivatives may cause a marked effect on their antimicrobial activity.

show abstract

Resistance of Diamondback Moth (Lepidoptera: Plutellidae) to Bacillus thuringiensis Subspecies in the Field

Cited by 242 publications

References 11 publications

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

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

Cell-cycle-dependent resistance toBacillus thuringiensisCry1C toxin in Sf9 cells

Rapid synthesis and biological evaluation of 1,4-dihydropyridine derivatives containing a benzothiazolyl moiety

Contact Info

Product

Resources

About