SE156:/MS4

Sample Set Information

ID	TSE1312
Title	Metabolic Profiling of Developing Pear Fruits Reveals Dynamic Variation in Primary and Secondary Metabolites, Including Plant Hormones.
Description	Metabolites in the fruits of edible plants include sweet sugars, visually appealing pigments, various products with human nutritional value, and biologically active plant hormones. Although quantities of these metabolites vary during fruit development and ripening because of cell division and enlargement, there are few reports describing the actual dynamics of these changes. Therefore, we applied multiple metabolomic techniques to identify the changes in metabolite levels during the development and ripening of pear fruits (Pyrus communis L. ‘La France’). We quantified and classified over 250 metabolites into six groups depending on their specific patterns of variation during development and ripening. Approximately half the total number of metabolites, including histidine and malate, accumulated transiently around the blooming period, during which cells are actively dividing, and then decreased either rapidly or slowly. Furthermore, the amounts of sulfur-containing amino acids also increased in pear fruits around 3–4 months after the blooming period, when fruit cells are enlarging, but virtually disappeared from ripened fruits. Some metabolites, including the plant hormone abscisic acid, accumulated particularly in the receptacle prior to blooming and/or fruit ripening. Our results show several patterns of variation in metabolite levels in developing and ripening pear fruits, and provide fundamental metabolomic data that is useful for understanding pear fruit physiology and enhancing the nutritional traits of new cultivars.
Authors	Oikawa A, Otsuka T, Nakabayashi R, Jikumaru Y, Isuzugawa K, Murayama H, Saito K, Shiratake K.
Reference	PLoS One. 2015 Jul 13;10(7):e0131408. doi: 10.1371/journal.pone.0131408. eCollection 2015.
Comment

PubMed

Analytical Method Details Information

ID	MS4
Title	Sugar and starch analysis
Instrument
Instrument Type
Ionization
Ion Mode
Description	Sample extraction Crushed and frozen samples (10 g) were resuspended in 50 mL of MeOH, including internal standards for standardization of peak areas, and centrifuged (16,000 × g, 3 min, 4°C). Supernatants were dispensed for each analysis as follows: 0.5 mL for ionic metabolites, 1 mL for neutral metabolites, 1 mL for sugars, and 47.5 mL for plant hormones. Because of the small amounts of pear fruit samples obtained in the early periods (2WBB, 1WBB, and B), the initial amounts of these samples were 1 g, extracted in 20 mL of MeOH, and were separately used for each analysis as described above. The residues were subsequently used for starch analysis. Sugar and starch analysis One milliliter of the MeOH extract obtained for sugar analysis was evaporated to dryness and dissolved in 0.75 mL of water. The same volume of 1% (w/v) mannitol (as an internal standard) solution was added to the sample solution, and this mixture was used for subsequent sugar analysis. Sugars (glucose, fructose, sucrose, and sorbitol) were quantified by HPLC according to the conditions described below. The analytical conditions of HPLC were as follows: column, Shim-pack SCR101-C column, 70°C; solvent, distilled water; flow rate, 1 mL/min, isocratic; detection, RI detector (HITACHI L-7490). For starch analysis, the residues of sample extracts were used. An alcohol-insoluble residue was prepared using the method described by Murayama et al. For starch quantification, the dried alcohol-insoluble residue was first suspended in distilled water and boiled for 30 min. After cooling, the gelatinized starch was digested with amyloglucosidase (from Aspergillus niger; Roche Applied Science) in 50 mM sodium acetate buffer (pH 4.5). The released glucose was measured using the glucose oxidase–peroxidase method of Barham and Trinder.
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