The aerial surface of plants, known as the phyllosphere, covers an area of approximately one billion square kilometers on Earth and is the primary habitat for a multitude of microbes. A key reason is because plants release nutritional compounds that microbes need to survive, and in return, many plant-associated microbes enhance plant health. One prominent genus in the phyllosphere, Methylobacterium, can consume the one-carbon compounds plants release as a sole source of energy. These bacteria and plants have been previously shown to have a growth-promoting mutualistic relationship with each other. Methylobacterium in particular have the ability to secrete plant growth promoting hormones and provide protection against harmful pathogens, enforcing this dynamic. Though this relationship has been highly researched, it has been derived from a select few Methylobacterium species. Additionally, minimal research has examined how species-level differences in the ability to consume different metabolic substrates (known as substrate utilization diversity) can affect microbial colonization and plant growth. Therefore, this study aimed to determine how substrate utilization diversity within the Methylobacterium genus affects the growth of Zea mays (corn) by inoculating seeds with Methylobacterium species of natural corn bacterial isolates with differing substrate utilization profiles and monitoring their growth through measurements such as germination rate. Samples were also taken for 16S sequencing to assess how each strain competed with one another, thus analyzing the community dynamics of these strains. The information gained gives insight on the utilization of microbes to generate healthier crops.

Volatile organic compounds (VOCs) are a large group of carbon-based species that evaporate easily at room temperature. Once they are emitted into the air, they can form secondary organic aerosols through complex reactions. The monoterpene limonene is a VOC commonly emitted from citrus plants. This study examines the synthesis of various limonene derivatives. Oxidized derivatives of limonene were synthesized by hydrolysis of epoxides and oxidative cleavage. The products were characterized with GC/MS, NMR, and IR. Derivatizing VOCs such as styrene and alpha-pinene is also planned. The oxidized derivative’s ability to make secondary organic aerosol will be compared to ascertain the effect of oxidation level.

Globisporangium (formerly Pythium) is one of the major plant pathogens causing crop loss all over the globe. It’s an oomycete (fungal-like) pathogen with a wide range of hosts, including soy, corn, wheat, and potatoes, and it easily overwinters in the soil. It infects small seedlings, causing the diseases known as “damping off” and root rot. My project is working to determine whether Tiny Earth bacterial strains with antibacterial activity can also act as a biocontrol agent against this pathogen. Previous research identified 19 bacterial isolates that were antagonistic to Globisporangium ultimum in vitro, so the next step is exploring which ones also show activity in live plant trials using soybeans (Glycine max). Over the Spring 2025 semester, assays were completed in pots containing sterilized soil, surface-sterilized and germinated soybeans, G. ultimum inoculum, and liquid cultures of bacterial isolates. Pots were placed in a self-contained growth chamber and over 2-3 weeks each plant was rated for emergence (rising above the surface of the soil) and thriving (growing “true leaves”). Due to the high number of variables and logistical restrictions, my project has switched to using hydroponic pouches, where roots can be directly observed and the disease severity ranked. Once we identify the isolates with the most promise, we will do chemical and genetic analysis to determine the mechanism(s) of antagonism.

In situ resource utilization will be essential for self-sufficiency for astronauts in future space missions on other planets. One of the most abundant materials available is regolith, the loose rock and dust covering planetary surfaces. This research investigates how we can improve the conditions of the regolith to be better suited for growing plants. The overarching research question for this project is will the fungi (Rhizophagus irregularis) assist in plant resource acquisition, water stress reduction, and improved growth for the sunflowers (Helianthus annuus) grown in the regolith? The research questions that were answered during this experiment were as follows. How does the overall growth of sunflowers change based on which substrate and treatment the plant receives? Do the plants with the fungi treatment grow more successfully compared to without? Factors such as temperature and light are maintained at fixed levels in a plant growth tent. Using measurements to monitor growth rates and plant physiology, progress can be tracked for each plant within the different regolith with two treatment types (plants with fungi and plants without fungi). Preliminary results show that fungi assisted differently in each regolith. The fungi improved root development in the Martian regolith and improved growth height in the Lunar regolith. Current results from the plants grown in only Lunar regolith simulant indicated that when the sunflowers were inoculated with the fungi, they showed improved growth and photosynthetic rates. Further measurements are needed to understand the fungi’s impact fully. Mycorrhizae could improve plant resource acquisition and reduce water stress, benefiting extraterrestrial agriculture and boosting food productivity in drought-affected regions.