Effects of Methyl Jasmonate and Jasmonic Acid Loaded Nanoparticles on Defensive Secondary Metabolites in Hairy Root Cells

Secondary metabolites in plants help with defense mechanisms against pathogen infection and abiotic stresses, including drought, extreme temperatures, etc. While an increase in these metabolites will benefit plants, they also provide potential benefits to humans as possible therapeutics. Methyl jasmonate (MeJ) and jasmonic acid (JA) are both known to elicit defensive secondary metabolites when delivered to plant cell cultures. Amine functionalized mesoporous silica nanoparticles (MSNPAs) loaded with these elicitors are hypothesized as carriers for delivery into the plant cell. This work focuses on the delivery of methyl jasmonate and jasmonic acid into Lobelia cardinalis hairy root cells using high surface area MSNPAs (with 2.5 nm diameter pores). Synthesis and amine functionalization of these nanoparticles are performed first, resulting in a porous particle with a positive surface charge, confirmed by zeta potential. Using evaporative loading techniques, MeJ/JA is loaded into the pores and quantified using thermogravimetric analysis (TGA). JA is expected to bind more strongly to the cationic MSNPA vector than MeJ. Isotherms will show the relative binding strength and capacity for both elicitors. Hairy root cell cultures are then treated with one of five different treatments of elicitor and particle combinations. The control group contains hairy root cells in plant media. Other treatments include root cells with elicitor in media, nanoparticles in media, elicitor loaded nanoparticles in media, and unloaded nanoparticles and elicitor suspended in the same media. Ultra high-performance liquid chromatography (UHPLC) coupled with electrospray mass spectrometry (ESI-MS) is used to analyze the metabolites synthesized with each treatment. Focusing on jasmonic acid as the elicitor, data manipulation is performed to determine which secondary metabolites are elicited in significant amounts. T-tests are then performed to determine which treatments are statistically significant from the control group. 1,808 metabolite features were found in common between all treatments. 133 features, or 7%, were found to be statistically significant with either a greater than 20% upregulation or downregulation within JA loaded MNSPAs compared to the control. Current work focuses on analysis of each metabolite and determining which treatment showed the greatest impact on area counts.