Ehime Women's College

About: Ehime Women's College is a education organization based out in Uwajima, Japan. It is known for research contribution in the topics: Metabolome & Mass spectrometry. The organization has 12 authors who have published 26 publications receiving 2911 citations. The organization is also known as: IPU Women's College & Kan-taiheiyou Daigaku Tanki Daigakubu.

Functional genomics by integrated analysis of metabolome and transcriptome of Arabidopsis plants over-expressing an MYB transcription factor.

Abstract: The integration of metabolomics and transcriptomics can provide precise information on gene-to-metabolite networks for identifying the function of unknown genes unless there has been a post-transcriptional modification. Here, we report a comprehensive analysis of the metabolome and transcriptome of Arabidopsis thaliana over-expressing the PAP1 gene encoding an MYB transcription factor, for the identification of novel gene functions involved in flavonoid biosynthesis. For metabolome analysis, we performed flavonoid-targeted analysis by high-performance liquid chromatography-mass spectrometry and non-targeted analysis by Fourier-transform ion-cyclotron mass spectrometry with an ultrahigh-resolution capacity. This combined analysis revealed the specific accumulation of cyanidin and quercetin derivatives, and identified eight novel anthocyanins from an array of putative 1800 metabolites in PAP1 over-expressing plants. The transcriptome analysis of 22,810 genes on a DNA microarray revealed the induction of 38 genes by ectopic PAP1 over-expression. In addition to well-known genes involved in anthocyanin production, several genes with unidentified functions or annotated with putative functions, encoding putative glycosyltransferase, acyltransferase, glutathione S-transferase, sugar transporters and transcription factors, were induced by PAP1. Two putative glycosyltransferase genes (At5g17050 and At4g14090) induced by PAP1 expression were confirmed to encode flavonoid 3-O-glucosyltransferase and anthocyanin 5-O-glucosyltransferase, respectively, from the enzymatic activity of their recombinant proteins in vitro and results of the analysis of anthocyanins in the respective T-DNA-inserted mutants. The functional genomics approach through the integration of metabolomics and transcriptomics presented here provides an innovative means of identifying novel gene functions involved in plant metabolism.

Loss of anthocyanins in red-wine grape under high temperature

Abstract: To determine the mechanism of inhibition of anthocyanin accumulation in the skin of grape berries due to high temperature, the effects of high temperature on anthocyanin composition and the responses in terms of gene transcript levels were examined using Vitis vinifera L. cv. Cabernet Sauvignon. High temperature (maximum 35 degrees C) reduced the total anthocyanin content to less than half of that in the control berries (maximum 25 degrees C). HPLC analysis showed that the concentrations of anthocyanins, with the exception of malvidin derivatives (3-glucoside, 3-acetylglucoside, and 3-p-coumaroylglucoside), decreased considerably in the berries grown under high temperature as compared with the control. However, Affymetrix Vitis GeneChip microarray analysis indicated that the anthocyanin biosynthetic genes were not strongly down-regulated at high temperature. A quantitative real time PCR analysis confirmed this finding. To demonstrate the possibility that high temperature increases anthocyanin degradation in grape skin, stable isotope-labelled tracer experiments were carried out. Softened green berries of Cabernet Sauvignon were cut and aseptically incubated on filter paper with 1 mM aqueous L-[1-(13)C]phenylalanine solution for 1 week. Thereafter, the changes in (13)C-labelled anthocyanins were examined under different temperatures (15, 25, and 35 degrees C). In the berries cultured at 35 degrees C, the content of total (13)C-labelled anthocyanins that were produced before exposure to high temperature was markedly reduced as compared with those cultured at 15 degrees C and 25 degrees C. These data suggest that the decrease in anthocyanin accumulation under high temperature results from factors such as anthocyanin degradation as well as the inhibition of mRNA transcription of the anthocyanin biosynthetic genes.

Metabolite annotations based on the integration of mass spectral information

Abstract: A large number of metabolites are found in each plant, most of which have not yet been identified. Development of a methodology is required to deal systematically with unknown metabolites, and to elucidate their biological roles in an integrated 'omics' framework. Here we report the development of a 'metabolite annotation' procedure. The metabolite annotation is a process by which structures and functions are inferred for metabolites. Tomato (Solanum lycopersicum cv. Micro-Tom) was used as a model for this study using LC-FTICR-MS. Collected mass spectral features, together with predicted molecular formulae and putative structures, were provided as metabolite annotations for 869 metabolites. Comparison with public databases suggests that 494 metabolites are novel. A grading system was introduced to describe the evidence supporting the annotations. Based on the comprehensive characterization of tomato fruit metabolites, we identified chemical building blocks that are frequently found in tomato fruit tissues, and predicted novel metabolic pathways for flavonoids and glycoalkaloids. These results demonstrate that metabolite annotation facilitates the systematic analysis of unknown metabolites and biological interpretation of their relationships, which provide a basis for integrating metabolite information into the system-level study of plant biology.

KNApSAcK: A Comprehensive Species-Metabolite Relationship Database

Abstract: We prepared a database, KNApSAcK for accumulation and search of metabolite-species relationships. The power-law distribution observed in the present study is likely to be associated with research activity for finding novel metabolites from nature. In addition, it seems to be derived from searching rare metabolites from the organisms originally exhibiting power-law in the degree distribution of their metabolic networks. This suggests that the database contains chemical diversity of metabolites which occurred through evolution of species. Graph clustering is shown to be useful to extract taxonomic relationships on the basis of common metabolites. As we are continuously accumulating metabolite-species pairs in the database, we continue to advance our understanding of species-metabolite relations in taxonomic hierarchy. Furthermore, we plan to add an option for searching metabolite structures by entering partial structures, which will be helpful for metabolite research.