title: Metabolomic changes in grains of well-watered and drought-stressed transgenic rice.
abstract: BACKGROUND
  Drought induces a number of physiological and biochemical responses in cereals. This study was designed to examine the metabolite changes in grains of drought-tolerant transgenic rice (Oryza sativa L.) that overexpresses AtCYP78A7 encoding cytochrome P450 protein using proton nuclear magnetic resonance ((1)H-NMR) and gas chromatography/mass spectrometry.
  
  
  RESULTS
  Principal component analysis showed that the (1)H-NMR-based profile was clearly separated by soil water status of well-watered and water-deficit. A discrimination of metabolites between transgenic and non-transgenic grains appeared under both watering regimes. Variations in the levels of amino acids and sugars led to the discrimination of metabolites among genotypes. In particular, drought significantly enhanced the levels of γ-aminobutyric acid (GABA, 244.6%), fructose (155.7%), glucose (211.0%), glycerol (57.2%), glycine (65.8%) and aminoethanol (192.4%) in the transgenic grains compared with the non-transgenic control grains.
  
  
  CONCLUSIONS
  These changes in amounts of metabolites may assist in improving drought tolerance in transgenic rice by playing crucial roles in stress-responsive pathways including GABA biosynthesis, sucrose metabolism and antioxidant defenses.
authors.affiliation: Bio-Evaluation Center, KRIBB, Cheongju 363-883, Republic of Korea.
authors.forename: Kyong-Hee
authors.initials: KH
authors.lastname: Nam
authors.affiliation: Bio-Evaluation Center, KRIBB, Cheongju 363-883, Republic of Korea.
authors.forename: Hee Jae
authors.initials: HJ
authors.lastname: Shin
authors.affiliation: Bio-Evaluation Center, KRIBB, Cheongju 363-883, Republic of Korea.
authors.forename: In-Soon
authors.initials: IS
authors.lastname: Pack
authors.affiliation: Bio-Evaluation Center, KRIBB, Cheongju 363-883, Republic of Korea.
authors.forename: Jung-Ho
authors.initials: JH
authors.lastname: Park
authors.affiliation: Life Sciences Research Institute, Biomedic Co., Ltd, Bucheon 420-020, Republic of Korea.
authors.forename: Ho Bang
authors.initials: HB
authors.lastname: Kim
authors.affiliation: Bio-Evaluation Center, KRIBB, Cheongju 363-883, Republic of Korea.
authors.forename: Chang-Gi
authors.initials: CG
authors.lastname: Kim
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics; D000596:Amino Acids / Q000032:analysis; D002241:Carbohydrates / Q000032:analysis; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics / Q000378:metabolism*; D055864:Droughts; D004983:Ethanolamines / Q000032:analysis; D005632:Fructose / Q000032:analysis; D015870:Gene Expression; D005947:Glucose / Q000032:analysis; D005990:Glycerol / Q000032:analysis; D005998:Glycine / Q000032:analysis; D009682:Magnetic Resonance Spectroscopy; D055432:Metabolomics; D012275:Oryza / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D012639:Seeds / Q000737:chemistry / Q000378:metabolism; D013312:Stress, Physiological / Q000235:genetics; D014867:Water; D005680:gamma-Aminobutyric Acid / Q000032:analysis
chemical_list: D000596:Amino Acids; D002241:Carbohydrates; D004983:Ethanolamines; D014867:Water; D005632:Fructose; D005680:gamma-Aminobutyric Acid; D003577:Cytochrome P-450 Enzyme System; D005947:Glucose; D005990:Glycerol; D005998:Glycine
keywords: Oryza sativa L; cytochrome P450; drought stress; metabolomics