Monday, 18 November 2002 - 2:12 PM

This presentation is part of : Student Competition Ten-Minute Papers, Section B. Physiology, Biochemistry, Toxicology and Molecular Biology

The effect of transgenic tobacco with teratocyte gene in controlling tobacco pests

Torrence A Gill, Entomology, Kentucky University, Entomology, S-225 Agricultural Science Center-North, Lexington, KY

Microplitis croceipes wasps are endoparasitoids that release cells (teratocytes) derived from the egg’s serosal membrane into hemolymph of the parasitized hosts. Teratocytes circulate in host hemolymph after the egg hatches and synthesize multiple teratocyte secretory proteins. The 14kDa teratocyte secretory protein (TSP14) is linked to inhibition of growth and development of the parasitized lepidopteran host. TSP14 gene was previously isolated and expressed in transgenic tobacco (Nicotiana tabacum cv Samsun NN) under the regulation of the peanut chlorotic streak virus (PCISV) full-length transcript (FLt) promoter, with an rbcSE9 terminator, either with or without secretory signals. Feeding studies with tobacco budworm (Heliothis virescens) and tobacco hornworm (Manduca sexta) demonstrated insecticidal activity. In an attempt to optimize the insecticidal activity of TSP14, and the transgene was modified to have codon usage more appropriate for plant expression, the M24 promoter was used. Three variant constructs of TSP14 were analyzed: unmodified TSP14 gene, a modified and truncated TSP14 gene, also modified and truncated TSP14 fused with GlnH (Glutamine Binding Protein). RT-PCR and hybridizations were performed on transgenic tobacco lines to verify TSP14 transcription. Western blotting has been performed on all transgenic lines to detect the protein. Feeding experiments conducted using modified TSP14 genes have shown inhibited growth of tobacco budworm and tobacco hornworm. Comparison of the modified and truncated TSP14 constructs with the initial TSP14 lines will assess changes in insecticidal activity.

Species 1: Lepidoptera Noctuidae Heliothis virescens (Tobacco budworm)
Species 2: Lepidoptera Sphingidae Manduca sexta (Tobacco Hornworm)
Species 3: Homoptera Aphididae Myzus persicae (Green Peach Aphid)
Keywords: Teratocytes, Tobacco

Back to Student Competition Ten-Minute Papers, Section B. Physiology, Biochemistry, Toxicology and Molecular Biology
Back to Student Competition 10-minute Paper
Back to The 2002 ESA Annual Meeting and Exhibition