NANOSCALE MANGANESE AND IRON MICRONUTRIENTS TO INCREASE PHOTOSYNTHESIS, CROP YIELD AND ABIOTIC STRESS TOLERANCE

Nanoscale manganese and iron micronutrients to increase photosynthesis, crop yield, and abiotic stress tolerance. PI-Jose Hernandez-Viezcas, Co-PI-Jorge Gardea-Torresdey, University of Texas at El Paso (UTEP)Co-PI-Jason C. White, Co-PI-Nubia Zuverza-Mena, Connecticut Agricultural Experiment Station (CAES)Co-Pi-Vinka Craver, University of Rhode Island (URI)This is a Grant submitted to the USDA AFRI Priority Code A1511, "Nanotechnology for Agricultural and Food Systems" Over the next thirty years, the global agricultural system will face unprecedented challenges to provide nutritious and environmentally sustainable food for the growing population. By 2050, the world's agricultural production will need to increase by 60% to meet the projected population of 9.7 billion. Furthermore, droughts, heatwaves, and floods brought on by climate change are placing added pressure on food production. There is growing certainty that nanotechnology can be a critical tool to increase agricultural productivity to achieve and maintain global food security. Our previous work shows that nanoscale micronutrients Mn and Fe have multifunctionality, uniquely increasing photosynthesis as a function of small particle size while simultaneously up-regulating the production of antioxidant enzymes and reducing the effects of abiotic stress. However, there are gaps in knowledge about the mechanisms that are activated by nanoscale Mn and Fe species. Furthermore, there is a lack of understanding of the fate and transport of engineered nanomaterials (ENM) upon foliar and seed application. Toward the goal of creating an optimal nano-enabled fertilizer, we aim to evaluate the effects of four synthesized (three chemically and one biosynthesized) nanoscale Mn and Fe species on four model crops under two abiotic stressors, drought, and salinity. Our experimental plan consists of three interconnected objectives.Objective 1. Evaluate and understand the factors and mechanisms affecting four model plants under foliar and seed exposure to nanoscale Mn and Fe species. -A preliminary study will identify the optimal dosage (Foliar and seed) of micronutrient ENMs for all plant species.-A large experimental setup will expose (foliar and seed) the model plants, which will be sampled and analyzed during the full life cycle.-Analysis will include physiological measurements, crop gas exchange, metabolomics, enzyme activity, trace analysis and imaging (hyperspectral, two-photon, Micro XRF/XANES, submicron IR/Raman mapping and TEM)Objective 2. Elucidate the efficacy of nanoscale Mn and Fe species to reduce plant abiotic stress effects. An experimental setup will evaluate the nanoscale micronutrient effects on the plant's response to abiotic stress.Objective 3. Validate a nanoscale micronutrient ENM performance on the crop's response to abiotic stress in a field experiment. Building on the preliminary studies, one or more nanoscale micronutrients will be evaluated against crop abiotic stress in a field study. Crop growth, yield and nutritional quality of the edible tissue in a real environment will be evaluated.We anticipate that the outcomes will enable us to have a thorough mechanistic understanding of critical Mn and Fe micronutrient ENM-plant interactions, which in turn will enable us to maximize the effect ofnanoscale materials on crops.