Biochemical Genetics of the Bacterial Insect-Control Agent<i>Bacillus thuringiensis:</i>Basic Principles and Prospects for Genetic Engineering

Dean, Donald H.

doi:10.1080/02648725.1984.10647804

Cited by 53 publications

(25 citation statements)

References 70 publications

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“…Durante o processo de esporulação, ocorre a produção de uma inclusão cristalina, composta por um ou mais polipeptídios, denominados δ-endotoxinas, que são codificadas pelos genes Cry. Estes cristais são tóxicos a larvas de insetos das ordens Lepidoptera, Diptera, Coleoptera e ainda nematóides e ácaros (Dean, 1984).…”

Section: Fungistatic Effect Of Bacillus Thuringiensis and Of Other Baunclassified

Efeito fungistático de Bacillus thuringiensis e de outras bactérias sobre alguns fungos fitopatogênicos

Batista

Albino

Martines

et al. 2002

Pesq. agropec. bras.

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Quatro isolados bacterianos da rizosfera de Drosera villosa var. villosa (B1, B2, B3, B4) e dois isolados de Bacillus thuringiensis (B5 e B6), sendo B6 produtor da toxina bioinseticida Cry1Ab, foram avaliados quanto à capacidade de inibir os fungos fitopatogênicos Fusarium solani f. sp. phaseoli, Fusarium solani f. sp. glycines, Fusarium oxysporum e Colletotrichum sp. A cepa mais efetiva foi B1 que inibiu o crescimento dos quatro fungos até o 26º dia. B. thuringiensis inibiu o crescimento de três destes, o que indica que possui atividade antifúngica e abre um novo campo de estudo para a utilização do B. thuringiensis.

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Section: Fungistatic Effect Of Bacillus Thuringiensis and Of Other Baunclassified

Efeito fungistático de Bacillus thuringiensis e de outras bactérias sobre alguns fungos fitopatogênicos

Batista

Albino

Martines

et al. 2002

Pesq. agropec. bras.

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“…Crystal formation is not a stable characteristic (6,30). Synthesis of the paracrystalline protoxin is controlled by large plasmids (11,12,30), the maintenance of which is sensitive to frequency of transfer (6) and incubation conditions, such as temperature (30). Interestingly, to some researchers, strains of B. thurine'ensis are virtually indistinguishable phenotypically from Bacillus cereus except for crystal formation (5, 13, 26), but other workers have observed distinct differences between the two taxa (8,15).…”

mentioning

confidence: 99%

“…The protein is solubilized at the alkaline pHs that occur in the intestines of susceptible insect larvae and is then cleaved by proteases into peptides which produce the toxic effects (29). Crystal formation is not a stable characteristic (6,30). Synthesis of the paracrystalline protoxin is controlled by large plasmids (11,12,30), the maintenance of which is sensitive to frequency of transfer (6) and incubation conditions, such as temperature (30).…”

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confidence: 99%

DNA Relatedness among Bacillus thuringiensis Serovars

Nakamura

1994

International Journal of Systematic Bacteriology

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The genetic relationships of Bacillus cereus and of the Bacillus thuringiensis serovars were assessed from measurements of DNA reassociation. A study of 8 to 10 strains each of 13 of the most commonly encountered serovars revealed that the levels of intragroup DNA relatedness for most serovars ranged from 90 to 100%. In contrast, B. thuringiensis serovars canadensis and kenyae consisted of two DNA relatedness groups, each of which exhibited levels of intragroup relatedness of 80% or higher and levels of intergroup relatedness of 60 to 70%. Analyses of DNA relatedness performed with all of the serovars revealed that the taxa were segregated into 11 phena differentiated from each other at about the 65% level; within each phenon the level of relatedness was 80% or higher. Three phena contained strains belonging to more than one serovar; B. thuringiensis serovars alesti and dendrolimus clustered in phenon 1, serovars aizawai, kurstaki, galleriae, and morrisoni clustered in phenon 7, and serovar darmstadiensis and some strains of serovar kenyae clustered in phenon 11.The levels of DNA relatedness between B. cereus and B. thuringiensis strains ranged between 65 and 70%. My results suggest that many of the B. thuringiensis serovars are genetically distinct but closely related.Bacillus thuringiensis was first isolated by Ishiwata (17) in 1901 from diseased silkworms, the larvae of the moth Bombyx mori (L.). A subsequent isolation was made by Berliner (4) in 1911 from diseased larvae of the Mediterranean flour moth, Anagasta kuehniella (Zeller). Discovery of the biocidal activity on the larvae of many lepidopterids suggested that B. thuringiensis could be used as a biological control agent for protection of crops and forests from insects.A striking morphological and taxonomically distinguishing characteristic of B. thuringiensis is the formation of parasporal crystals. These parasporal bodies consist of crystallized protein which is responsible for the insecticidal activity of the organism (1, 16). The protein is solubilized at the alkaline pHs that occur in the intestines of susceptible insect larvae and is then cleaved by proteases into peptides which produce the toxic effects (29). Crystal formation is not a stable characteristic (6,30). Synthesis of the paracrystalline protoxin is controlled by large plasmids (11,12,30), the maintenance of which is sensitive to frequency of transfer (6) and incubation conditions, such as temperature (30). Interestingly, to some researchers, strains of B. thurine'ensis are virtually indistinguishable phenotypically from Bacillus cereus except for crystal formation (5, 13, 26), but other workers have observed distinct differences between the two taxa (8, 15).de Barjac and Bonnefoi (7) noted that B. thuringz*ensis strains could be divided into 24 serovars on the basis of the immunological reactions of the flagellum antigen. Numerical analyses of phenotypic characteristics failed to differentiate the serovars from each other and B. cereus from B. thuringiensis (3). Opinions regarding the...

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“…Progress in engineering insect resistance in transgenic plants has been achieved through the expression in plants of the insect toxin gene of Bacillus thuringiensis (B.O. An excellent review by Dean (1984) of the biochemical genetics of B.t. can be found in volume 2 of this series.…”

Section: Insect Resistancementioning

confidence: 99%