Histopathology and the lethal effect of Cry proteins and strains of Bacillus thuringiensis Berliner in Spodoptera frugiperda J.E. Smith Caterpillars (Lepidoptera, Noctuidae)
Among the phytophagous insects which attack crops, the fall armyworm, Spodoptera frugiperda (J.E. Smith, 1797) (Lepidoptera, Noctuidae) is particularly harmful in the initial growth phase of rice plants. As a potential means of controlling this pest, and considering that the entomopathogen Bacillus...
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| Format: | Article |
| Language: | English |
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Instituto Internacional de Ecologia
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| Series: | Brazilian Journal of Biology |
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| Online Access: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1519-69842010000300028&lng=en&tlng=en |
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| author | N. Knaak AR. Franz GF. Santos LM. Fiuza |
| author_facet | N. Knaak AR. Franz GF. Santos LM. Fiuza |
| author_sort | N. Knaak |
| collection | DOAJ |
| description | Among the phytophagous insects which attack crops, the fall armyworm, Spodoptera frugiperda (J.E. Smith, 1797) (Lepidoptera, Noctuidae) is particularly harmful in the initial growth phase of rice plants. As a potential means of controlling this pest, and considering that the entomopathogen Bacillus thuringiensis Berliner demonstrates toxicity due to synthesis of the Cry protein, the present study was undertaken to evaluate this toxic effect of B. thuringiensis thuringiensis 407 (pH 408) and B. thuringiensis kurstaki HD-73 on S. frugiperda. The following method was used. Both bacterial strains were evaluated in vitro in 1st instar S. frugiperda caterpillars, by means of histopathological assays. The Cry1Ab and Cry1Ac proteins, codified by the respective strains of B. thuringiensis, were evaluated in vivo by bioassays of 1st instar S. frugiperda caterpillars in order to determine the Mean Lethal Concentration (LC50). The results of the histopathological analysis of the midget of S. frugiperda caterpillars demonstrate that treatment with the B. thuringiensis thuringiensis strain was more efficient, because the degradations of the microvilosities started 9 hours after treatment application (HAT), while in the B. thuringiensis kurstaki the same effect was noticed only after 12 HAT. Toxicity data of the Cry1Ab and Cry1Ac proteins presented for the target-species LC50 levels of 9.29 and 1.79 μg.cm-2 respectively. The strains and proteins synthesised by B. thuringiensis thuringiensis and B. thuringiensis kurstaki are effective in controlling S. frugiperda, and may be used to produce new biopesticides or the genes may be utilised in the genetic transformation of Oryza sativa L. |
| first_indexed | 2024-12-23T06:03:49Z |
| format | Article |
| id | doaj.art-2625cf971d2e44ce99cac2dbbe232b84 |
| institution | Directory Open Access Journal |
| issn | 1678-4375 |
| language | English |
| last_indexed | 2024-12-23T06:03:49Z |
| publisher | Instituto Internacional de Ecologia |
| record_format | Article |
| series | Brazilian Journal of Biology |
| spelling | doaj.art-2625cf971d2e44ce99cac2dbbe232b842022-12-21T17:57:37ZengInstituto Internacional de EcologiaBrazilian Journal of Biology1678-437570367768410.1590/S1519-69842010000300028S1519-69842010000300028Histopathology and the lethal effect of Cry proteins and strains of Bacillus thuringiensis Berliner in Spodoptera frugiperda J.E. Smith Caterpillars (Lepidoptera, Noctuidae)N. Knaak0AR. FranzGF. Santos1LM. Fiuza2Universidade do Vale do Rio dos SinosUniversidade do Vale do Rio dos SinosUniversidade do Vale do Rio dos SinosAmong the phytophagous insects which attack crops, the fall armyworm, Spodoptera frugiperda (J.E. Smith, 1797) (Lepidoptera, Noctuidae) is particularly harmful in the initial growth phase of rice plants. As a potential means of controlling this pest, and considering that the entomopathogen Bacillus thuringiensis Berliner demonstrates toxicity due to synthesis of the Cry protein, the present study was undertaken to evaluate this toxic effect of B. thuringiensis thuringiensis 407 (pH 408) and B. thuringiensis kurstaki HD-73 on S. frugiperda. The following method was used. Both bacterial strains were evaluated in vitro in 1st instar S. frugiperda caterpillars, by means of histopathological assays. The Cry1Ab and Cry1Ac proteins, codified by the respective strains of B. thuringiensis, were evaluated in vivo by bioassays of 1st instar S. frugiperda caterpillars in order to determine the Mean Lethal Concentration (LC50). The results of the histopathological analysis of the midget of S. frugiperda caterpillars demonstrate that treatment with the B. thuringiensis thuringiensis strain was more efficient, because the degradations of the microvilosities started 9 hours after treatment application (HAT), while in the B. thuringiensis kurstaki the same effect was noticed only after 12 HAT. Toxicity data of the Cry1Ab and Cry1Ac proteins presented for the target-species LC50 levels of 9.29 and 1.79 μg.cm-2 respectively. The strains and proteins synthesised by B. thuringiensis thuringiensis and B. thuringiensis kurstaki are effective in controlling S. frugiperda, and may be used to produce new biopesticides or the genes may be utilised in the genetic transformation of Oryza sativa L.http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1519-69842010000300028&lng=en&tlng=enBacillus thuringiensisbioassayshistopathologyCry proteinsSpodoptera frugiperda |
| spellingShingle | N. Knaak AR. Franz GF. Santos LM. Fiuza Histopathology and the lethal effect of Cry proteins and strains of Bacillus thuringiensis Berliner in Spodoptera frugiperda J.E. Smith Caterpillars (Lepidoptera, Noctuidae) Brazilian Journal of Biology Bacillus thuringiensis bioassays histopathology Cry proteins Spodoptera frugiperda |
| title | Histopathology and the lethal effect of Cry proteins and strains of Bacillus thuringiensis Berliner in Spodoptera frugiperda J.E. Smith Caterpillars (Lepidoptera, Noctuidae) |
| title_full | Histopathology and the lethal effect of Cry proteins and strains of Bacillus thuringiensis Berliner in Spodoptera frugiperda J.E. Smith Caterpillars (Lepidoptera, Noctuidae) |
| title_fullStr | Histopathology and the lethal effect of Cry proteins and strains of Bacillus thuringiensis Berliner in Spodoptera frugiperda J.E. Smith Caterpillars (Lepidoptera, Noctuidae) |
| title_full_unstemmed | Histopathology and the lethal effect of Cry proteins and strains of Bacillus thuringiensis Berliner in Spodoptera frugiperda J.E. Smith Caterpillars (Lepidoptera, Noctuidae) |
| title_short | Histopathology and the lethal effect of Cry proteins and strains of Bacillus thuringiensis Berliner in Spodoptera frugiperda J.E. Smith Caterpillars (Lepidoptera, Noctuidae) |
| title_sort | histopathology and the lethal effect of cry proteins and strains of bacillus thuringiensis berliner in spodoptera frugiperda j e smith caterpillars lepidoptera noctuidae |
| topic | Bacillus thuringiensis bioassays histopathology Cry proteins Spodoptera frugiperda |
| url | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1519-69842010000300028&lng=en&tlng=en |
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