NSF Postdoctoral Fellowship in Biology: Crop yield enhancement strategies

This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2022, Broadening Participation of Groups Underrepresented in Biology. The Fellowship supports a research and training plan for the Fellow that will increase the participation of groups underrepresented in biology. Transforming global agriculture practices is critical to meet current and future food demands in the face of climate change, and necessary to minimize environmental impacts that damage terrestrial and aquatic environments, and ultimately affect human health and well-being.

Current practices used to increase crop yields rely heavily on fertilizers that threaten the environment and weaken crop resilience. Understanding and harnessing the diverse properties of microorganisms that live in the soil near the roots of crops (called the rhizosphere) has the potential to help find new, more sustainable farming strategies. This research project seeks to understand a specific microbial process that has the potential to help plants better access phosphorus in soil.

The investigator will determine if certain compounds released by bacteria (for example, phenazines) that liberate mineral-bound phosphorus can make a difference to plant nutrition. The results of this work have the potential to provide alternative strategies enabling the reduction of synthetic fertilizer application and increased phosphorus bioavailability for plants.

This project will directly broaden participation of groups underrepresented in biology by enabling the research of a Latinx postdoctoral fellow in Biology who will engage other underrepresented scholars through mentoring in the lab. The fellow will also work with the non-profit Clean Water Science Network’s virtual mentorship program to increase the network and mentorship skills of postdoctoral scholar participants at Caltech and around the country.

The fellow will test the hypothesis that microbially secreted phenazines can solubilize iron-mineral-adsorbed phosphate by reductive dissolution, subsequently enhancing plant bioavailability and uptake. Single-species and microbial community studies in a gnotobiotic plant model will be implemented. Fluorescent microscopy techniques, reporter gene fusions, and gene knockouts will be used to visualize and validate the proposed gene regulation and biogeochemical process.

Analytical techniques (LC-MS, ICP-MS) will be used to quantify phenazine production and plant phosphorus content. The fellow will gain expertise and training in microbial physiology and genetics, plant-microbe co-culturing, microbial community design, and state-of-the-art microcopy. Additionally, the fellow will gain mentoring experience through research and by contributing to a virtual mentoring program.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.