Location: Plant Genetics Research
Project Number: 5070-21220-046-000-D
Project Type: In-House Appropriated
Start Date: Feb 20, 2023
End Date: Feb 19, 2028
Objective:
Objective 1: Investigate through phenotypic trials and predictive modeling how maize and small grains adapt to abiotic environments.
Sub-ojective 1.A: Evaluate diverse maize hybrids in multi-location trials as part of the Genomes To Fields Genotype x Environment Project.
Sub-ojective 1.B: Develop and deploy improved high-throughput phenotyping and analytical methods.
Sub-ojective 1.C: Investigate the natural diversity of C4 photosynthesis responses to abiotic stress in maize and its relatives.
Objective 2: Expand the knowledge base and research tools for managing insect pests of maize by exploring natural resistance, improved artificial diets for rearing pests, resistance mechanisms to toxins, and basic biology.
Sub-objective 2.A: Refine the western corn rootworm artificial diet for continuous rearing.
Sub-objective 2.B: Continue search for natural resistance to western corn rootworm feeding.
Sub-objective2.C: Characterize the role of ATP-binding cassette (ABC) transporters in western corn rootworm resistance to Bt toxins to facilitate better resistance management tactics.
Sub-objective 2.D: Identification and characterization of corn rootworm chemosensory genes.
Sub-objective 2.E: Exploration and characterization of key metabolites and metabolic pathways in the western corn rootworm detoxification of Bt toxins and/or dsRNA (Snf7 and Ssj1) to potentially develop new control tactics.
Sub-objective 2.F: Expand knowledge of the basic biology of the northern corn rootworm.
Objective 3: Dissect the internal biochemical environment controlling plant growth and development by examining the impact of chemical regulators and genetic diversity on major agronomic traits in maize.
Sub-objective 3.A: Characterization of gibberellin (GA) and brassinosteroid (BR) transcription factors (TFs) controlling plant architecture.
Sub-objective 3.B: Quantitation of plant hormones in maize.
Sub-objective 3.C: Development of novel mutant populations to characterize plant architecture genes.
Objective 4: Explore human food quality traits in maize by evaluating flavor, aroma, texture, and key target metabolites in seeds of and in food products from a large collection of heirloom corn varieties from the United States and across the Americas.
Sub-objective 4.A: Genetic Characterization of the U.S. Heirloom Corn Collection.
Sub-objective 4.B: Phenotypic Characterization of the U.S. Heirloom Corn Collection.
Sub-objective 4.C: Identify Heirlooms with Unique Grain Characteristics and Food Properties.
Approach:
Evaluate diverse maize hybrids as part of the Genomes To Fields (G2F) Genotype x Environment Project; manually collect data for core developmental traits, as well as machine harvested yield and grain moisture. Develop and deploy improved high-throughput phenotyping and analytical methods: collect high-throughput phenotypes in growth chamber, greenhouse, and field trials using unoccupied aerial systems (UAS, drones), robots, and rovers; develop improved physiological, machine learning, deep learning, and artificial intelligence models for predicting and understanding productivity. Investigate the natural diversity of C4 photosynthesis responses to abiotic stress in maize and its relatives: perform a series of growth chamber, greenhouse, and field experiments examining the impact of different temperatures and fertilizer regimes; phenotype plants using pulse amplitude modulation fluorometry and gas exchange, as well as final plant biomass; sample plants for gene expression analysis and enzyme activity of key C4 sub-type enzymes such as NADP-ME and PEPCK.
Formulate a Western corn rootworm (WCR) larval diet; analyze the chemical composition of maize roots; determine metabolomic profiles of WCR larvae; develop an efficient system to rear WCR for multiple generations. Annually evaluate 50 new sources of maize germplasm for resistance to WCR larval feeding. Apply a dsRNA-based approach to evaluate changes in ABC transporter expression levels in response to Bt treatment. Identify and functionally characterize odorant receptor (OR) and gustatory receptor (GR) genes in WCR: use bioinformatics to identify candidate receptors based on expression levels. Identify metabolic pathways in the western corn rootworm detoxification of dsRNA (Snf7 and Ssj1): perform metabolomics and transcriptomics analyses of WCR larvae fed on artificial diet with and without the dsRNAs. Characterize northern corn rootworm (NCR) host recognition behavior: expose neonate larvae to host and non-host plant roots; record and analyze larval movement following contact with hosts and non-host roots.
Develop and characterize gibberellin (GA) and brassinosteroid (BR) transcription factor (TF) mutants introgressed into ex-PVP inbreds to identify effects on plant architecture; create high-yielding F1s and evaluate them for plant architecture and yield traits. Accurately quantify endogenous hormone (including GAs, BRs, abscisic acid, jasmonates, auxins, and cytokinin) levels using liquid chromatography mass-spectrometry; perform transcriptomics to identify crosstalk between hormonal pathways. Create sequence-indexed mutant populations; genotype the mutant populations to identify mutations in genetic loci that regulate maize architecture.
Determine the genetic diversity within and phylogenetic relationships among heirlooms from the U.S germplasm collection and compare these to ancestral Mexican heirloom varieties. Collect plant, ear, and kernel phenotypes for 1000 heirloom varieties, and compare phylogenies based on genotypic and phenotypic data. Identify heirlooms with extreme values for kernel characteristics; quantify targeted metabolites known to be involved in flavor and aroma.
