0000000000424148

AUTHOR

Thomas M. Malvar

showing 3 related works from this author

Global variation in the genetic and biochemical basis of diamondback moth resistance to Bacillus thuringiensis

1997

Insecticidal proteins from the soil bacterium Bacillus thuringiensis (Bt) are becoming a cornerstone of ecologically sound pest management. However, if pests quickly adapt, the benefits of environmentally benign Bt toxins in sprays and genetically engineered crops will be short-lived. The diamondback moth ( Plutella xylostella ) is the first insect to evolve resistance to Bt in open-field populations. Here we report that populations from Hawaii and Pennsylvania share a genetic locus at which a recessive mutation associated with reduced toxin binding confers extremely high resistance to four Bt toxins. In contrast, resistance in a population from the Philippines shows multilocus control, a …

Bacterial ToxinsPopulationBacillus thuringiensisGenetically modified cropsMothsGenomic ImprintingHemolysin ProteinsBacterial ProteinsBacillus thuringiensisGenetic variationAnimalsAllelePest Control BiologicaleducationGeneticseducation.field_of_studyMultidisciplinaryDiamondback mothBacillus thuringiensis Toxinsbiologybusiness.industryGenetic Complementation TestfungiPest controlfood and beveragesChromosome MappingGenetic VariationPlutellaBiological Sciencesbiology.organism_classificationEndotoxinsFemalebusinessProtein Binding
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Integrative Model for Binding of Bacillus thuringiensis Toxins in Susceptible and Resistant Larvae of the Diamondback Moth (Plutella xylostella)

1999

ABSTRACT Insecticidal crystal proteins from Bacillus thuringiensis in sprays and transgenic crops are extremely useful for environmentally sound pest management, but their long-term efficacy is threatened by evolution of resistance by target pests. The diamondback moth ( Plutella xylostella ) is the first insect to evolve resistance to B. thuringiensis in open-field populations. The only known mechanism of resistance to B. thuringiensis in the diamondback moth is reduced binding of toxin to midgut binding sites. In the present work we analyzed competitive binding of B. thuringiensis toxins Cry1Aa, Cry1Ab, Cry1Ac, and Cry1F to brush border membrane vesicles from larval midguts in a susceptib…

Bacterial ToxinsBacillus thuringiensisGenetically modified cropsMothsApplied Microbiology and BiotechnologyBinding CompetitiveModels BiologicalHemolysin ProteinsBacterial ProteinsBacillus thuringiensisBotanyInvertebrate MicrobiologyAnimalsBinding sitePest Control BiologicalGeneticsBacillaceaeDiamondback mothBinding SitesEcologybiologyBacillus thuringiensis ToxinsParasporal bodyfungiPlutellafood and beveragesbiology.organism_classificationEndotoxinsCry1AcLarvaFood ScienceBiotechnology
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Mitochondrial Dna Sequence Variation among Geographic Strains of Diamondback Moth (Lepidoptera: Plutellidae)

1997

We examined genetic variation among 6 geographic strains of diamondback moth, Plutella xylostella (L.), using 365 base pairs of the mitochondrial gene encoding cytochrome oxidase I (COI). No sequence variation was detected within 5 of the 6 strains; 1 strain contained 2 haplotypes that differed by a single base substitution (0.27%). Sequence differences between strains of diamondback moth from Hawaii, the Philippines, and Pennsylvania ranged from 0 to 0.82%. With one exception, base pair substitutions among strains resulted in synonymous codons and did not alter amino acid sequence. Genetic divergence between strains of diamondback moth was not correlated with geographic distances between t…

GeneticsMitochondrial DNADiamondback mothbiologyfungiPopulation geneticsPlutellabiology.organism_classificationGenetic divergenceLepidoptera genitaliaPlutellidaeInsect ScienceGenetic variationBotanyAnnals of the Entomological Society of America
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