Date of Graduation
Spring 2026
Degree
Master of Science in Chemistry
Department
Chemistry & Biochemistry
Committee Chair
Cyren Rico
Abstract
Perfluorooctanesulfonic acid (PFOS) is an environmental contaminant that is commonly detected in water and soil. The ability of PFOS to resist degradation in the environment, along with its known toxicity to agricultural plants and human health, makes its presence in the environment and its ability to accumulate in plants a concern. In this study, soybean plants chlorophyll content and stress level were measured and their associated soil microbial community within the bulk and rhizosphere soil were analyzed after 96 days of exposure to 0 mg/kg, 25 mg/kg, and 50 mg/kg of PFOS. 16S rRNA gene sequencing was conducted on the bulk and rhizosphere soil to measure changes in the Chao1 and Shannon alpha diversity indices, beta diversity through nonmetric multidimensional scaling (NMDS), and shifts in microbial abundance. NMDS data showed that the PFOS significantly affected the microbial composition in the bulk soil but not in the rhizosphere soil. There was also an increase in many known plant growth-promoting rhizobacteria (PGPR) in both PFOS-treated rhizosphere soil, which may be attributed to the increased growth of plants observed at 25 mg/kg PFOS. Additionally, PFOS accumulation, elemental changes, and seed metabolomics were measured to understand the effect of PFOS on soybeans and were measured 131 days after planting. Results also showed an increased accumulation of PFOS in the roots and shoots in both PFOS treatments. However, there was only an increased accumulation of PFOS in the seeds at 50 mg/kg PFOS, which was likely the cause of decreased biomass in pods and seeds at this treatment. Although there was only a decrease in seed biomass at 50 mg/kg PFOS, there were 44 seed metabolites affected in both PFOS treatments, 38 of which were either upregulated or downregulated concomitantly at both PFOS treatments compared to the control. The accumulation of PFOS in the seeds along with the changes in metabolite composition suggests that the nutritional value of soybean seeds is compromised and is a cause for concern for human and animal consumption.
Keywords
PFOS, environmental contaminant, plant stress, 16S rRNA, nutritional value, metabolites
Subject Categories
Environmental Chemistry
Copyright
© Riley Elizabeth Pope-Buss
Recommended Citation
Pope-Buss, Riley Elizabeth, "Soybean-Microbe System Response to Perfluorooctanesulfonic Acid: Investigating Stress Responses, Metabolite and Elemental Compositions, and Microbial Community Shifts" (2026). Graduate Theses/Dissertations. 4146.
https://bearworks.missouristate.edu/theses/4146
