SE142:/DS1

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Sample Set Information

ID	TSE1243
Title	Physiological roles of the beta-substituted alanine synthase gene family in Arabidopsis.
Description	The beta-substituted alanine (Ala) synthase (Bsas) family in the large superfamily of pyridoxal 5'-phosphate-dependent enzymes comprises cysteine (Cys) synthase (CSase) [O-acetyl-serine (thiol) lyase] and beta-cyano-Ala synthase (CASase) in plants. Nine genomic sequences encode putative Bsas proteins in Arabidopsis thaliana. The physiological roles of these Bsas isoforms in vivo were investigated by the characterization of T-DNA insertion mutants. Analyses of gene expression, activities of CSase and CASase, and levels of Cys and glutathione in the bsas mutants indicated that cytosolic Bsas1;1, plastidic Bsas2;1, and mitochondrial Bsas2;2 play major roles in Cys biosynthesis. Cytosolic Bsas1;1 has the most dominant contribution both in leaf and root, and mitochondrial Bsas2;2 plays a significant role in root. Mitochondrial Bsas3;1 is a genuine CASase. Nontargeted metabolome analyses of knockout mutants were carried out by a combination of gas chromatography time-of-flight mass spectrometry and capillary electrophoresis time-of-flight mass spectrometry. The level of gamma-glutamyl-beta-cyano-Ala decreased in the mutant bsas3;1, indicating the crucial role of Bsas3;1 in beta-cyano-Ala metabolism in vivo.
Authors	Watanabe M, Kusano M, Oikawa A, Fukushima A, Noji M, Saito K.
Reference	Plant Physiol. 2008 Jan;146(1):310-20. Epub 2007 Nov 16.
Comment

ID	DS1
Title	Statistical Data Analysis
Description	The obtained data matrix (observations: samples, variables: 337 peaks, including peaks with mass spectral tags [137 annotated peaks from GC-TOF/MS plus 200 annotated or stably appearing peaks from CE-TOF/MS analysis; Supplemental Tables S4 and S5]) was used for statistical analysis. For statistical multivariate analysis, principal component analysis was performed with SIMCA-P 11.0 software, using log10-transformed and autoscaled data (Umetrics AB). Simple comparisons of means of obtained peak areas were performed by Welch's t test. A difference of P < 0.05 was considered to be significant. In terms of minimizing the effect of zero substitution, we scaled all normalized peak areas by 10,000 and then added 1 uniformly.
Comment_of_details