ISOLATION AND MOLECULAR CHARACTERIZATION OF A NOVEL INSECTICIDAL PROTEIN OF THE ENTOMOPATHOGENIC BACTERIUM BACILLUS THURINGIENSIS
Safaa Thabet Hussein Mohamed;
Abstract
Great efforts have been made to control the cotton leaf worm S. littoralis (Bosid.) which is considered as the major pest causing great damage to cotton plants and other field and vegetable crops in Egypt.
Since the use of chemical pesticides is well known to endanger man and his farm animals, so the magic solution to solve this problem was in using the biological control in terms of the gram positive bacterium B.thuringiensis which produces a protoxin during Sporulation that is proteolytically converted into toxic polypeptides in the insect midgut, causing cell swelling and lysis after a series of chemical reactions that cause eventual death of the larvae.
This entomopathogenic bacterium is the most important biopesticide sold worldwide, and its share of the world market of pesticides is expected to rise in the coming years. B. thuringiensis based products are, however, limited with respect to the diversity of strains used in commercial products, and more toxins are needed to target other insect pests and to manage the emerging problem of insect resistance.
Consequently the need for novel crystal proteins has prompted the development of molecular approaches to quickly and easily characterize toxin genes present in B. thuringiensis isolates. In the last few years, several PCR-based methodologies, allowed the accurate determination of families of cry genes or specific δ-endotoxin genes .Although powerful, PCR approaches are limited to the detection of already-known genes and fail to detect and identify novel cry genes.In the present investigation, we have used a set of oligonucleotide pirmers to amplify the whole open reading frame for those genes. The primers were designed for the amplification of cry1A genes based on the analysis of conserved regions by multiple alignment of all cry1 DNA sequences in the B. thuringiensis toxin nomenclature website.This strategy allows the determination of known and potentially novel cry1A genes.
Since the use of chemical pesticides is well known to endanger man and his farm animals, so the magic solution to solve this problem was in using the biological control in terms of the gram positive bacterium B.thuringiensis which produces a protoxin during Sporulation that is proteolytically converted into toxic polypeptides in the insect midgut, causing cell swelling and lysis after a series of chemical reactions that cause eventual death of the larvae.
This entomopathogenic bacterium is the most important biopesticide sold worldwide, and its share of the world market of pesticides is expected to rise in the coming years. B. thuringiensis based products are, however, limited with respect to the diversity of strains used in commercial products, and more toxins are needed to target other insect pests and to manage the emerging problem of insect resistance.
Consequently the need for novel crystal proteins has prompted the development of molecular approaches to quickly and easily characterize toxin genes present in B. thuringiensis isolates. In the last few years, several PCR-based methodologies, allowed the accurate determination of families of cry genes or specific δ-endotoxin genes .Although powerful, PCR approaches are limited to the detection of already-known genes and fail to detect and identify novel cry genes.In the present investigation, we have used a set of oligonucleotide pirmers to amplify the whole open reading frame for those genes. The primers were designed for the amplification of cry1A genes based on the analysis of conserved regions by multiple alignment of all cry1 DNA sequences in the B. thuringiensis toxin nomenclature website.This strategy allows the determination of known and potentially novel cry1A genes.
Other data
| Title | ISOLATION AND MOLECULAR CHARACTERIZATION OF A NOVEL INSECTICIDAL PROTEIN OF THE ENTOMOPATHOGENIC BACTERIUM BACILLUS THURINGIENSIS | Other Titles | عزل وتوصيف جزيئي لبروتين جديد مميت للحشرات من بكتريا باسيللس ثيورنجينسيس الممرضه للحشرات | Authors | Safaa Thabet Hussein Mohamed | Issue Date | 2015 |
Recommend this item
Similar Items from Core Recommender Database
Items in Ain Shams Scholar are protected by copyright, with all rights reserved, unless otherwise indicated.