Minisymposium 27: Temperature

Abs # 48005: The temperature stress metabolome of Arabidopsis

Presenter:	Kaplan, Fatma , fkaplan@ufl.edu
Authors	Kaplan, Fatma  (A)   Kopka, Joachim  (C)   Gatzke, Nicole  (C)   Zhao, Wei  (B)   Guy, Charles  (A)
Affiliations:	(A): Plant Molecular & Cellular Biology Program, Department of Environmental Horticulture, University of Florida (B): Department of Statistics, University of Florida (C): Max Planck Institute of Molecular Plant Physiology

Metabolite profiling is an emerging tool in the omics revolution that is transforming all areas of biology and life sciences research. In one perspective, the metabolome embodies the end-product of all cellular regulatory processes, and metabolite steady-state levels represent the ultimate response of the system to all internal and external effectors. To this end, metabolomics is the application of a global perspective to the metabolite composition of an organelle, cell, organ, or organism. In the present work, metabolite profiling was performed for a time-course experiment to determine the temporal responses of metabolites during the induction of acquired thermotolerance in response to heat shock (40°C), and with the induction of acquired freezing tolerance in response to cold acclimation (4°C). Polar metabolite analysis was done using a GC-MS platform. Nearly 500 metabolite signals were present in the analysis and approximately 420 were found to represent unique compounds. Based on statistical analyses, the concentrations of 311 metabolites were influenced by cold shock. In contrast, less than half as many metabolites (145) exhibited changes in concentration in response to heat shock. Interestingly, the concentrations of 87 metabolites were increased by both heat and cold shock. Of the 87 temperature stress metabolites, 44 could be assigned a chemical identity. We compared the list of 44 metabolites with published studies, but could find only 26 that had previously been reported to accumulate in response to biotic and abiotic stress conditions. Examples of temperature stress responsive metabolites included salicylic acid, beta-alanine, and gamma-aminobutyric acid just to list a few. Comparing global metabolite responses during temperature shock when induced stress tolerance is developing can help to identify individual metabolites as well as metabolic processes important in stress tolerance mechanisms. The present findings will help to broaden our perspective of plant responses at the metabolite level to temperature extremes. Future integrative analyses of metabolite and expression profiles analyses will provide considerable new insight to the processes involved in acquired tolerances.