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United States Department of Agriculture

Agricultural Research Service

Research Project: Disease Defense Responses Signaling in Maize

Location: Chemistry Research

Project Number: 6036-21000-011-00-D
Project Type: In-House Appropriated

Start Date: Jul 2, 2013
End Date: Jul 1, 2018

Objective:
1. Identify defense-related genes via bioinformatics followed by isolation of mutations in those genes to generate a novel collection of maize mutants as genetic tools for determining the function of genes involved in responses to insect and pathogen attack. 2. Identify and characterize insect-and pathogen-induced defense components in maize and determine the response of these components to abiotic stessors, including the effects of climate change.

Approach:
To generate a novel collection of maize mutants to be used as genetic tools for determining the function of genes involved in physical, chemical and biological responses to insect and pathogen attack we will first identify genes involved in plant defense using systems biology based bioinformatics approaches to mine existing gene expression databases for genes that are co-regulated with known defense pathways. Once genes of interest have been selected we will prioritize them for further characterization and mine mutant resources such as the UniformMu maize collection, a publically available maize population developed specifically for genetics research, for mutations in those genes and confirm the presence of mutant alleles using gene-by-gene PCR genotyping. We will also generate mutants in genes of interest using CRISPR/Cas9 technology. To identify shared and specific molecular, metabolic, and physiological responses to diverse maize pathogens and insects we will initiate bioassays to quantify disease progression and insect performance for fungal pathogens (including Cochilobolus heterostrophus, Fusarium verticillioides and Colletorichum graminicola) and insect pests (including Spodoptera exigua, Spodoptera frugiperda and Ostrinia nubialis). Moreover, we will initiate metabolic profiling of defense-related compounds in response to pathogen and insect attack across relevant maize varieties (inbred lines and commercial hybrids) and identify and test candidate genes to serve as robust markers of defense-related gene expression during biotic attack. In order to determine the potential impact of global climate change on plant defense in maize we will quantify disease progression and insect performance under controlled environmental conditions including elevated temperature and CO2, and drought stress in maize inbred lines and/or commercial hybrids.

Last Modified: 2/23/2016
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