Description
Plants represent an interesting model for studies of metabolism because of the degree to which they rely on biochemical strategies to survive environmental stresses. Advances in high-throughput metabolite quantification in the form of liquid chromatography mass spectrometry, as well as the development of bioinformatics analysis software, have allowed assays of entire plant tissue metabolomes. In this project, a metabolomics analysis of the soldier rock cress, Boechera depauperata, was performed in order to determine what metabolic qualities may contribute to its superior ability to withstand high temperatures when compared to related species, a crucial biological asset in a warming climate. Boechera depauperata seedlings were grown in sterile media in standard light and temperature conditions, and then half were exposed to a basal heat stress of 45oC for three hours. Immediately afterward, all leaf and stem tissues were collected and frozen for storage. After sample pre-processing and metabolite extraction, compounds within the samples were isolated and measured using liquid chromatography mass spectrometry (LCMS) and the identities of these metabolic features were predicted using the XCMS Online metabolomics platform. The metabolomics assay identified thousands of statistically significant metabolic features with differential expression between control and experimental pooled samples. Of these, more than half were upregulated in the heat-shocked tissues, and the rest were downregulated in this group. Some of the dysregulated metabolic pathways predicted by the metabolism matching algorithm included the production of secondary metabolites with antioxidant properties, cell wall lignification, chloroplast detoxification and membrane lipid desaturation. While some of these metabolic processes have been shown to aid other plants under abiotic stress, future analyses targeting these compounds specifically in B. depauperata could result in a greater understanding of how it resists temperature and oxidative damage.
