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Construction of an improved mycoinsecticide overexpressing a toxic protease.
- Source :
-
Proceedings of the National Academy of Sciences of the United States of America [Proc Natl Acad Sci U S A] 1996 Jun 25; Vol. 93 (13), pp. 6349-54. - Publication Year :
- 1996
-
Abstract
- Mycoinsecticides are being used for the control of many insect pests as an environmentally acceptable alternative to chemical insecticides. A key aim of much recent work has been to increase the speed of kill and so improve commercial efficacy of these biocontrol agents. This might he achieved by adding insecticidal genes to the fungus, an approach considered to have enormous potential for the improvement of biological pesticides. We report here the development of a genetically improved entomopathogenic fungus. Additional copies of the gene encoding a regulated cuticle-degrading protease (Pr1) from Metarhizium anisopliae were inserted into the genome of M. anisopliae such that Pr1 was constitutively overproduced in the hemolymph of Manduca sexta, activating the prophenoloxidase system. The combined toxic effects of Pr1 and the reaction products of phenoloxidase caused larvae challenged with the engineered fungus to exhibit a 25% reduction in time of death and reduced food consumption by 40% compared to infections by the wild-type fungus. In addition, infected insects were rapidly melanized, and the resulting cadavers were poor substrates for fungal sporulation. Thus, environmental persistence of the genetically engineered fungus is reduced, thereby providing biological containment.
- Subjects :
- Amino Acid Sequence
Animals
Base Sequence
DNA, Complementary
Enzyme Activation
Enzyme Precursors metabolism
Fungal Proteins toxicity
Lepidoptera enzymology
Molecular Sequence Data
Monophenol Monooxygenase metabolism
Serine Endopeptidases toxicity
Transcription, Genetic
Fungal Proteins genetics
Fungi genetics
Insecticides
Pest Control, Biological
Serine Endopeptidases genetics
Subjects
Details
- Language :
- English
- ISSN :
- 0027-8424
- Volume :
- 93
- Issue :
- 13
- Database :
- MEDLINE
- Journal :
- Proceedings of the National Academy of Sciences of the United States of America
- Publication Type :
- Academic Journal
- Accession number :
- 8692818
- Full Text :
- https://doi.org/10.1073/pnas.93.13.6349