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ARS Home » Midwest Area » Urbana, Illinois » Global Change and Photosynthesis Research » Research » Research Project #434586

Research Project: Optimizing Photosynthesis for Global Change and Improved Yield

Location: Global Change and Photosynthesis Research

Project Number: 5012-21000-030-00-D
Project Type: In-House Appropriated

Start Date: Jun 21, 2018
End Date: Jun 20, 2023

Objective:
Objective 1: Improve photosynthetic efficiency along with water/nitrogen use efficiency in crops for greater food production and bioenergy crop yields. 1.1 Decrease leaf chlorophyll content to maximize water and nitrogen use efficiency without reduction in the daily integral of canopy carbon. 1.2 Lower energetic costs of photorespiration by installing improved engineered chloroplast photorespiratory bypass pathways. 1.3 Stack best performing reduced chlorophyll and photorespiratory traits to combine efficiencies. 1.4 Determine the heritability of photosynthetic traits in maize, and map QTL for photosynthetic traits and their response to abiotic stress. Objective 2: Identify key regulatory factors controlling carbon and nitrogen assimilation and partitioning in crop plants for improving seed composition and yields. 2.1 Determine the impact of canopy microenvironment on soybean seed composition as affected by canopy position. 2.2 Optimize Rubisco activase (Rca) regulation for dynamic light and temperature environments. Objective 3: Identify new genetic loci for enhancing crop resilience to environmental extremes (higher temperature and increased drought) by determining the major loci and physiological mechanisms that modulate crop performance in response to elevated atmospheric CO2 and tropospheric ozone (GxE). 3.1 Test the response of diverse soybean cultivars to elevated [CO2] and advance genetic populations for mapping CO2 response in soybean. 3.2 Use functional genomic and metabolomic approaches to dissect the mechanistic basis for O3 response in maize. 3.3 Investigate the interactive effects of elevated [O3] and drought stress or high temperature stress on crops. Objective 4: Advance the optimization of central ecosystem services for current and alternative food and bioenergy production systems for carbon, water, nutrient cycling, and energy partitioning, by determining the linkages among genetic, physiological, whole-plant, and ecosystem processes (GxE). 4.1 Quantify direct and indirect ecosystem services for traditional and alternative agroecosystem including but extending beyond harvestable yield. 4.2 Dissociate the impacts of rising temperature and increasing vapor pressure deficit on key ecosystem processes and crop yield. 4.3 Develop techniques for high-throughput phenotyping of leaf and canopy physiological properties to better associate genotype to phenotype. 4.4 Incorporate improved physiological understanding of crop responses to global change and stress conditions into mechanistic crop production models.

Approach:
The overall goal of this project is to identify factors affecting food and bioenergy crop production, with an emphasis on photosynthetic performance and intensifying environmental stress. Overall, the experimental approaches combine biophysics, biochemistry, physiology, molecular biology, genetics and genomics. The research will include both laboratory- and field-based studies. Specific approaches for each objective are: Objective 1 – utilize systems biology and transgenic approaches to decrease canopy chlorophyll and reduce flux through photorespiration, as well as to identify genetic variation in photosynthetic traits. Objective 2 – assess the impact of canopy microenvironment on soybean seed composition and engineer Rubisco activase to improve function in dynamic light and temperature environments. Objective 3 – identify genetic loci and the mechanistic basis for enhancing crop responses to global climate change by using free air concentration enrichment and functional genomic and metabolic approaches. Objective 4 – optimize food and bioenergy production systems by high-throughput phenotyping and modeling. Mechanistic crop production models will be developed to improve understanding of carbon, water and nutrient cycling responses to environmental changes.