NSF Postdoctoral Fellowship in Biology FY 2021: Correlating Maize Metabolic and Phenotypic Responses to Heat Stress ...

This action funds an NSF Plant Genome Postdoctoral Research Fellowship in Biology for FY 2021. The fellowship supports a research and training plan in a host laboratory for the Fellow who also presents a plan to broaden participation in biology. The title of the research and training plan for this fellowship to Katherine Murphy is "Correlating Maize Metabolic and Phenotypic Responses to Heat Stress for a Mechanistic Understanding of Plant Temperature Stress Tolerance".

The host institution for the fellowship is the Donald Danforth Plant Science Center and the sponsoring scientists are Dr. Malia Gehan and Dr. Doug Allen.

Maize, also known as corn, is the most important crop in the USA, and contributes significantly to diets world-wide. As global temperatures rise and become more erratic, it is essential that we have crops that can grow under less-than-ideal conditions in order to feed a growing global population. High temperatures, in particular, affects plants’ ability to grow and reduces crop yields.

In this project, the investigators will better understand the fundamental processes occurring in plants under high temperatures. To do so, they will investigate the molecules in corn and how they change over the course of growth at high temperatures, as well as how the whole-plant growth changes using plant images, known as high-throughput phenotyping.

They will compare corn varieties that grow well or poorly under high temperatures. This will provide foundational knowledge for breeding and engineering next-generation crops of the future, especially corn. This project will also provide training to the investigator as a postdoctoral associate to develop her into a leader in agriculture.

An associated outreach project will take data from this project for a course module for community college students in St. Louis, MO, to gain a valuable research experience.

As both a model plant species and important crop, maize (Zea mays) represents a wealth of genetic resources and opportunities for crop improvement. In the face of a growing population and a warming climate, it is essential to understand the fundamental maize response to heat stress in order to maintain and increase crop yields. However, the cellular-level molecular mechanisms underlying the maize heat stress response, and importantly how some maize lines are more resilient to heat stress, are poorly understood.

The objective of this project is to determine: What metabolites and their flux are affected by heat stress, and how do these metabolic hallmarks correlate to whole-plant heat stress phenotypes? First, a model maize line of short generation time and stature, Mini Maize, will be analyzed under heat stress conditions using carbon isotope labeling and high-throughput phenotyping.

This will address hypotheses that heat stress is realized and mitigated through potential changes in light harvesting, photosynthesis, molecular shunts, small molecule antioxidants, and possibly photorespiration. Coupling this data to whole-plant phenotype, such as biomass and leaf damage, will provide metabolic hallmarks for large-scale heat damage.

Next, this research will expand upon these techniques to investigate maize varieties previously characterized as tolerant and susceptible to heat stress. This will provide metabolic markers for heat stress tolerance, as well as provide mechanistic insight into plant stress resilience, such as through a hypothesized increase in flux to small molecule antioxidants.

This project will provide important foundations for informing plant breeding and engineering efforts towards resilient crops.

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.