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United States Department of Agriculture

Agricultural Research Service

Research Project: Impact of Climate Change on Plant Defense Responses Induced by Insect Herbivores and Plant Pathogens

Location: Chemistry Research Unit

Project Number: 6036-11220-001-00
Project Type: Appropriated

Start Date: Aug 10, 2011
End Date: Aug 09, 2016

Objective:
1. Determine the impacts of high temperatures, limited water availability, and elevated carbon dioxide (CO2) concentrations on: A) plant-grazing insect pest interactions and signaling; and B) plant pathogen relationships with host plants. C) Elucidate chemical mechanisms responsible for regulation of nematode repellence and attraction to hosts and development of nematodes. 2. Determine plant physiological mechanisms that mediate the effects of elevated atmospheric CO2, temperature, and limited water availability on plant-grazing insect pest interactions and plant pathogen interactions.

Approach:
Experiments will be carried out in controlled environment chambers. Studies for objectives 1a, b and 2 will focus on maize (cultivar golden Queen) as the host crop plant, on European corn borer as the insect herbivore, and on Fusarium graminearum as the fungal pathogen. The main focus will be on determining the impact of treatments on generation of plant volatiles that may contribute to changes in plant defense mechanisms and signaling, or generation of plant toxins, but measurements will also be made to assess the impacts on plant productive capacity as well. Experiments will determine the effects of elevated carbon dioxide concentrations and limited water availability, individually and jointly, on the induction of plant defense chemicals in response to planned infestation of maize plants with European corn borer or with infections of F. graminearum. The second experiments will determine the effects on interactions of elevated carbon dioxide and high temperatures (associated with predicted climate change). Studies on sub-objective 1c will focus on plant and nematode produced compounds that repel, attract or inhibit development of Meloidogyne (root knot) nematodes. We will collect volatiles and water soluble exudates from plants and nematodes and conduct bioassays to determine repellence, attractiveness and developmental regulators. Chemicals will be purified by chromatographic methods coupled with bioassays. Compounds will be identified by mass spectrometry, FTIR and NMR and synthesized. Synthesized compounds will be tested in laboratory and field assays to determine efficacy.

Last Modified: 11/1/2014
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