Co-PIs Gurmukh (Guri) Johal (Purdue University) and Brian Dilkes (Purdue University)
There are many diseases that can infect crop plants, leading to lower yields and even crop loss. The ability of crop plants to fight off diseases is therefore a very important agricultural trait. Farmers can avoid some diseases with pesticides, or breeders can develop crop varieties that resist diseases. Crops have the ability to fight off diseases by reacting to the disease-causing microorganism with defensive mechanisms, known as the plant hypersensitive response (HR). This refers to a process whereby an infected cell dies before the infection can spread to other cells in the plant. Despite its importance to maintain healthy crops, much remains unknown about the HR. In this work, a multi-disciplinary approach involving a number of field and lab-based techniques will be used to gain a better understanding of the HR in corn, the most economically valuable crop in the US. The genes and processes involved in controlling the HR will be identified and characterized. While this work will be performed primarily in corn, it is likely that many features of the HR are shared among different crops. As such this work will provide fundamental insights into one of the most important ways plants defend themselves against diseases, and the knowledge will be useful to develop improved crop plants by making them more resistant to diseases. Outreach activities with the North Carolina Museum of Natural Sciences will focus on educational activities on genetics, plant breeding, biotechnology and associated societal implications and will build on an existing collaboration with the museum that has developed several instructional modules for middle, high school, home school and mature students and their teachers. These continuing programs will be supported and several new programs will be developed around DNA sequence analysis, biotechnology and society.
In previous work, a novel genetic screen was used to identify loci, genes and pathways associated with natural genetic variation that controlled HR. In this project, a multi-disciplinary approach involving mutagenesis, field genetics, high-throughput genomic and transcriptomic sequencing, metabolomics, bioinformatics, microscopy and molecular biology will be used to gain an understanding of the HR from molecular genetic, transcriptional, biochemical and histological perspectives. Genes and pathways controlling the HR response will be identified and characterized. The HR will be observed at cellular, transcriptional and metabolic levels. The utility of a novel and potentially widely-applicable approach for the identification and characterization of mutations conferring quantitative phenotypes will be demonstrated. Public access to sequencing data generated this project will be made possible through deposition at the Short Read Archive (www.ncbi.nlm.nih.gov/sra). Information on the position of genes controlling the HR at the transcriptional level (expression Quantitative Trait Loci ? eQTL) will be made available at MaizeGDB (maizegdb.org). Biological materials will be disseminated via the Maize Genetics Coop and germplasm descriptions will be included in MaizeGDB.
