Physiologia Plantarum 132: 220–235. 2008 Copyright ª Physiologia Plantarum 2007, ISSN 0031-9317 REVIEW Metabolomics of temperature stress Charles Guy a, *, Fatma Kaplan a,b , Joachim Kopka c , Joachim Selbig c and Dirk K. Hincha c a Plant Molecular and Cellular Biology Program, Department of Environmental Horticulture, University of Florida, Gainesville, FL 32611, USA b Department of Biochemistry and Molecular Biology, College of Medicine, University of Florida, Gainesville, FL 32610, USA c Max Planck Institute of Molecular Plant Physiology, Wissenschaftspark Golm, Am Muehlenberg 1, Potsdam-Golm, 14476, Germany Correspondence *Corresponding author, e-mail: clguy@ufl.edu Received 2 September 2007; revised 4 October 2007 doi: 10.1111/j.1399-3054.2007.00999.x Plants possess inducible tolerance mechanisms that extend the temperature range for survival during acute temperature stress. The inducible mechanisms of cold acclimation and acquired thermotolerance involve highly complex processes. These include perception and signal transduction of non-optimal temperatures or their physical consequences on cellular components that program extensive modification of the transcriptome, proteome, metabolome and composition and physical structure of the cytoplasm, membranes and cell walls. Therefore, a systems biology approach will be necessary to advance the understanding of plant stress responses and tolerance mechanisms. One promise of systems biology is that it will greatly enhance our understanding of individual and collective functions and thereby provide a more holistic view of plant stress responses. Past studies have found that several metabolites that could functionally contribute to induced stress tolerance have been associated with stress responses. Recent metabolite-profiling studies have refocused attention on these and other potentially important components found in the ‘temperature-stress metabolome’. These metabolomic studies have demon- strated that active reconfiguration of the metabolome is regulated in part by changes in gene expression initiated by temperature-stress-activated signaling and stress-related transcription factors. One aspect of metabolism that is consistent across all of the temperature-stress metabolomic studies to date is the prominent role of central carbohydrate metabolism, which seems to be a major feature of the reprogramming of the metabolome during temperature stress. Future metabolomic studies of plant temperature-stress responses should reveal additional metabolic pathways that have important functions in temperature-stress tolerance mechanisms. Introduction Plant temperature stress Higher plants, like all other organisms, exhibit a maxi- mum rate of growth and development at an optimum temperature or over a diurnal range of temperatures for which they have become adapted (Fitter and Hay 1981, Levitt 1972). As ambient temperature deviates more and more from optimal, physiological, biochemical, meta- bolic and molecular changes occur within plants in an effort to maximize growth and developmental processes and to maintain cellular homeostasis. Under increasingly stressful conditions, plants experience progressively more abnormal, impaired or dysfunctional cellular and Abbreviations – CBF, C-repeat-binding factor; GABA, g-aminobutyric acid; GAD, glutamic acid decarboxylase; HSF, heat-shock transcription factor; HSP, heat-shock protein; ICE1, Inducer of CBF Expression; RuBisCO, ribulose-1,5 bisphosphate carboxylase oxygenase; SA, salicylic acid; SPS, sucrose phosphate synthase. 220 Physiol. Plant. 132, 2008