SE183:/DS1

Sample Set Information

ID	TSE1341
Title	Metabolomics reveals comprehensive reprogramming involving two independent metabolic responses of Arabidopsis to UV-B light.
Description	Because of ever-increasing environmental deterioration it is likely that the influx of UV-B radiation (280-320 nm) will increase as a result of the depletion of stratospheric ozone. Given this fact it is essential that we better understand both the rapid and the adaptive responses of plants to UV-B stress. Here, we compare the metabolic responses of wild-type Arabidopsis with that of mutants impaired in flavonoid (transparent testa 4, tt4; transparent testa 5, tt5) or sinapoyl-malate (sinapoylglucose accumulator 1, sng1) biosynthesis, exposed to a short 24-h or a longer 96-h exposure to this photo-oxidative stress. In control experiments we subjected the genotypes to long-day conditions as well as to 24- and 96-h treatments of continuous light. Following these treatments we evaluated the dynamic response of metabolites including flavonoids, sinapoyl-malate precursors and ascorbate, which are well known to play a role in cellular protection from UV-B stress, as well as a broader range of primary metabolites, in an attempt to more fully comprehend the metabolic shift following the cellular perception of this stress. Our data reveals that short-term responses occur only at the level of primary metabolites, suggesting that these effectively prime the cell to facilitate the later production of UV-B-absorbing secondary metabolites. The combined results of these studies together with transcript profiles using samples irradiated by 24-h UV-B light are discussed in the context of current models concerning the metabolic response of plants to the stress imposed by excessive UV-B irradiation.
Authors	Kusano, M., Tohge, T., Fukushima, A., Kobayashi, M., Hayashi, N., Otsuki, H., Kondou, Y., Goto, H.,Kawashima, M., Matsuda, F., Niida, R., Matsui, M., Saito, K. and Fernie, A. R.
Reference	Plant J. 2011 Jul;67(2):354-69. doi: 10.1111/j.1365-313X.2011.04599.x
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PubMed

Data Analysis Details Information

ID	DS1
Title	Data processing (GC-TOF-MS)
Description	Data processing for GC-TOF-MS data: Nonprocessed MS data from GC-TOF-MS analysis were exported in NetCDF format generated by chromatography processing and mass spectral deconvolutionsoftware, Leco ChromaTOF version 3.22 (LECO, St. Joseph, MI, USA) to MATLAB 6.5 (Mathworks, Natick, MA, USA), where all data-pretreatment procedures, such as smoothing, alignment, time-window setting, and H-MCR, were carried out (Jonsson et al., 2005). The resolved MS spectra were matched against reference mass spectra using the NIST mass spectral search program for the NIST/EPA/NIH mass spectral library (version 2.0) and our custom software for peak annotation written in JAVA. Peaks were identified or annotated based on RIs and the reference mass spectra comparison to the Golm Metabolome Database (GMD; http://csbdb.mpimp-golm.mpg.de/csbdb/gmd/msri/gmd_msri.html) released from CSB.DB (Kopka et al., 2004) and our in-house spectral library. The metabolites were identified by comparison with RIs from the library databases (GMD and our own library) and with those of authentic standards, and the metabolites were defined as annotated metabolites on comparison with mass spectra and RIs from these two libraries. The normalized response for the calculation of the signal intensity of each metabolite from the mass-detector response was obtained by each selected ion current that was unique in each metabolite MS spectrum to normalize the peak response. The normalized responses are peak areas corrected using the CCMN method (Redestig et al., 2009).
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