Location: Biological Control of Insects Research2012 Annual Report
1a. Objectives (from AD-416):
Objective 1. Use established procedures to obtain basic understanding of eicosanoid-mediated immune signaling in pest (squash bug, Anasa tristis) and beneficial (spined soldier bug, Podisus maculiventris) insect species. Objective 2. Generate new knowledge for future deployment of dsRNA to silence genes involved in immune signaling, particularly eicosanoid-mediated signaling, in a pest insect (squash bug, Anasa tristis) and test for species specificity using a beneficial insect (spined soldier bug, Podisus maculiventris).
1b. Approach (from AD-416):
1) Determine the influence of infection on PLA2 activity in immune tissues from squash bugs and spined soldier bugs; 2) Characterize and determine the influence of infection on prostaglandin production in immune tissues from squash bugs and spined soldier bugs; 3) Test the idea that prostaglandins and other eicosanoids mediate cellular reactions to infection; 4) Design dsRNA to silence genes involved in immune signaling; and 5) Determine the influence of dsRNA on immune signaling in intact squash bugs.
3. Progress Report:
For Objective 1a we characterized an enzyme responsible for signaling infections in a lepidopteran pest, the tobacco budworm. This work demonstrated the presence of a gene for the enzyme in the pest insect and showed the basic properties of the enzyme, such as the temperature range required for enzyme activity. This prepares the groundwork for more detailed research aimed to silence expression of the enzyme and thereby cripple the ability of pest insects to respond to natural infections and some biopesticides. For Objective 2a we completed the design of tools to silence expression of an enzyme responsible for signaling infections in a lepidopteran pest and other critical components of immune signaling in squash bugs. These tools will be deployed to cripple the ability of pest insects to respond to natural infections and some biopesticides.
Srikanth, K., Park, J., Stanley, D.W., Kim, Y. 2011. Plasmatocyte spreading peptide influences hemocyte behavior via eicosanoids. Archives of Insect Biochemistry and Physiology. 78:145-160.