PI: Elizabeth Ainsworth (University of Illinois, Urbana-Champaign/USDA-ARS)
CoPIs: Andrew Leakey and Patrick Brown (University of Illinois, Urbana-Champaign) and Lauren McIntyre (University of Florida)
Key Collaborator: Thomas Brutnell (Donald Danforth Plant Science Center)
Tropospheric ozone is the most damaging air pollutant to crops. Today, oxidative stress arising from ozone exposure is reducing potential maize yields by up to 10%, which in 2011 would have been valued at $7646 million. This project couples the unique capabilities of Free Air Concentration Enrichment (FACE) technology, which provides controlled elevation of ozone in open-air at field scale, with the power of the vast genetic resources in maize and transcriptome profiling. It will provide a foundation for crop improvement by quantifying genetic variation in response to elevated ozone among 200 inbred and 100 hybrid maize lines in the field. The project will use high-throughput phenotyping of ozone impacts on maize growth, senescence, leaf metabolism and reproductive processes to identify traits that correlate with yield loss. It will identify the genes and gene networks underpinning the ozone response in the most extreme tolerant and susceptible lines, and their hybrids, by integrating transcriptome analysis and detailed physiological analysis in inbred and hybrid maize. The project will develop or select existing biparental populations derived from tolerant and sensitive parents to identify QTL and eQTL for ozone tolerance. Finally, the project will assess crosstalk between ozone and biotic stress response gene networks in maize.
This work will address key mechanistic hypotheses about how oxidative stress leads to transcriptional reprogramming of antioxidant and carbon metabolism, as well as hormone, senescence and defense pathways. This multifaceted approach is essential because multiple physiological drivers of yield are sensitive to oxidative stress from ozone exposure. Consequently, oxidative stress tolerance is undoubtedly a complex, polygenic trait. The broad application of quantitative genetic tools coupled to gene expression profiling and biochemical and physiological analyses of diverse germplasm makes the challenge of discovering the foundation for ozone tolerance tractable for the first time. With regard to outreach and training, this Mid-Career Investigator Award in Plant Genome Research (MCA-PGR) will help re-tool two mid-career plant physiologists who study plant physiological and agronomic responses to environmental change with training in genomics and quantitative genetics. This new expertise will allow them and their post-docs and graduate students to address major challenges in agriculture and ecology by leveraging the full power of genomics through bioinformatics, quantitative genetics and expression profiling using next-generation sequencing technologies. In addition, the project will provide outreach through an after-school program on plant biology at a local middle school and a summer science camp for high school girls. Pollen images and pollen viability data, sequencing and proteomics datasets developed in this project will be publicly available at public repositories such as the iPlant Collaborative, NCBI GEO (www.ncbi.nlm.nih.gov/geo/), and EMBL-EBI PRIDE (www.ebi.ac.uk/pride/). Germplasm developed in this project will be available through the Maize Genetics Cooperation Stock Center (http://maizecoop.cropsci.uiuc.edu/).
