Location: Subtropical Plant Pathology Research
2011 Annual Report
Our goal to produce a fusion protein between a Tomato spotted wilt virus surface protein and Bacillius Thuringensis toxin that will kill its thrips vector is progressing as planned. In this grant period we have re-engineered the viral protein to include several smaller forms of the original molecule to produce a more efficient expression system. Several of these are now constructed and we are testing them for binding to the mid-gut receptor. Funds were used to support an undergraduate research project involving expression in and recovery from plants of prototype fusions using transient Agrobacterium infiltration techniques. This project provided important data for use going forward to develop systems to deliver these molecules to insects in a realistic feeding array. The student wrote this up as a report that will be used by new students to move the work forward. We also used funds for supplies for a senior postdoctoral researcher who worked pro bono for several months and has now been hired full time on other funds. Post Doc is currently expressing the modified viral ligand using a Baculovirus system currently being optimized for production of the new ligands and Bt fusions that will be subsequently test fed to insects. In preliminary experiments we have shown that fusions between full length Bt toxin (Cry3A) and our viral ligand remain toxic to Colorado potato beetles. This confirms that the fusion construct does not inactivate the toxic moiety of the molecule. We are now creating fusions between the toxic Bt domain and omitting the beetle binding domain to test for thrips lethality and specificity. This work was reported at the Entomological Society of America Annual Meeting in 2010, San Diego, Ca. at a symposium Emerging Pests and Research Approaches in Vegetable Pest Management. Developing a strategy to control thrips with Bt toxin.
Progress was monitored via through direct involvement in lab and field activities, research meetings, telephone calls and email communications.