title: Expression of a spider venom peptide in transgenic tobacco confers insect resistance.
abstract: Spider venom contains a mixture of peptide toxins, some able to kill insects specifically to those considered as important pest. In this study, a peptide toxin produced by the Macrothele gigas spider, Magi 6, was cloned and expressed in tobacco plants, as this toxin has been shown to constitute an effective insecticide. For this purpose, a genetic construction for the cDNA that codifies for Magi 6 was subcloned in a plant expression vector using the 35S promoter and the 5'-end leader from tobacco mosaic virus, in order to transform tobacco leaf disks. The resulting plants demonstrated the presence of Magi 6 gene in the tobacco genome using PCR, and transcription of the cDNA was verified by means of RT-PCR. The expression of the Magi 6 peptide in tobacco was demonstrated by Western blot, which exhibited the expected size, thus suggesting a correct processing of the signal peptide. No morphological alterations in the different transgenic lines were observed, nor any change in plant growth. Subsequently, experiments were carried out challenging detached leaves or whole plants with the herbivorous insect Spodoptera frugiperda. The bioassays indicated that the transgenic lines were significantly more resistant than the wild type plants. This work demonstrated that the expression of Magi 6 peptide in transgenic plants conferred resistance to insect attack and opens the possibility of employing this peptide to improve the resistance of diverse plants.
authors.affiliation: Centro de Investigación en Biotecnología-UAEM, Av. Universidad 1001, Col. Chamilpa, Cuernavaca 62209, Mexico.
authors.forename: Benjamín
authors.initials: B
authors.lastname: Hernández-Campuzano
authors.forename: Ramón
authors.initials: R
authors.lastname: Suárez
authors.forename: Laura
authors.initials: L
authors.lastname: Lina
authors.forename: Victor
authors.initials: V
authors.lastname: Hernández
authors.forename: Elba
authors.initials: E
authors.lastname: Villegas
authors.forename: Gerardo
authors.initials: G
authors.lastname: Corzo
authors.forename: Gabriel
authors.initials: G
authors.lastname: Iturriaga
mesh_terms: D000818:Animals; D005247:Feeding Behavior / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000502:physiology; D007814:Larva / Q000187:drug effects; D009036:Moths / Q000187:drug effects; D010455:Peptides / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D010572:Pest Control, Biological / Q000379:methods; D030821:Plants, Genetically Modified; D013111:Spider Venoms / Q000737:chemistry*; D013112:Spiders; D014026:Nicotiana / Q000235:genetics* / Q000378:metabolism*; D014118:Toxins, Biological / Q000737:chemistry / Q000235:genetics / Q000494:pharmacology*
chemical_list: D010455:Peptides; D013111:Spider Venoms; D014118:Toxins, Biological