Student Research Assistant Georgia Southern University Savannah, Georgia
Body of Abstract: Poly(aspartic acid) (PASP) is an environmentally friendly biopolymer produced industrially by thermal polymerization. It is used as a fertilizer synergist to enhance agricultural plant growth through improved yields. This PASP enhancement mechanism has not been established, although the general hypothesis is that the negatively charged PASP functions to hold nutrients closer to the root zone. The objective of this study was to identify the physiological and molecular changes that occur when plants are exposed to PASP, with future directions leading to a proposed mode of action. To address this objective, a whole genome transcriptome study was conducted. Arabidopsis thaliana seeds were germinated and grown in sterile plates treated with 250 ppm PASP under continuous light. After 12 days of growth, total RNA was extracted from whole seedlings and sent for sequencing. Additional physiological assessments were also carried out on the plants throughout the growing period. Results show significant differences in leaf area, root growth and the total amount of chlorophyll between control and treated plants. RNA- seq results revealed 462 differentially expressed genes, 245 of which were upregulated and 217 downregulated. The associated metabolic pathways of the upregulated genes were also revealed. This information will help to identify the potential mechanisms underlying PASP enhanced plant growth.