title: Engineering plants with increased levels of the antioxidant chlorogenic acid.
abstract: The trend to view many foods not only as sustenance but also as medicine, so-called functional foods, is increasing. Phenolics are the most widespread dietary antioxidants, and among these, chlorogenic acid (CGA) accumulates to high levels in some crop plants. CGA acts as an antioxidant in plants and protects against degenerative, age-related diseases in animals when supplied in their diet. cDNA clones encoding the enzyme that synthesizes CGA, hydroxycinnamoyl-CoA quinate: hydroxycinnamoyl transferase (HQT), were characterized from tomato and tobacco. Gene silencing proved HQT to be the principal route for accumulation of CGA in solanaceous species. Overexpression of HQT in tomato caused plants to accumulate higher levels of CGA, with no side-effects on the levels of other soluble phenolics, and to show improved antioxidant capacity and resistance to infection by a bacterial pathogen. Tomatoes with elevated CGA levels could be used in foods with specific benefits for human health.
authors.affiliation: John Innes Centre, Norwich Research Park, Colney, Norwich, NR4 7UH, UK.
authors.forename: Ricarda
authors.initials: R
authors.lastname: Niggeweg
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Michael
authors.forename: Cathie
authors.initials: C
authors.lastname: Martin
mesh_terms: D000214:Acyl Coenzyme A / Q000378:metabolism; D000217:Acyltransferases / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D016960:Agrobacterium tumefaciens / Q000235:genetics; D000595:Amino Acid Sequence; D015152:Blotting, Northern; D015153:Blotting, Western; D002726:Chlorogenic Acid / Q000032:analysis / Q000378:metabolism*; D015256:Coenzyme A-Transferases / Q000235:genetics; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D004573:Electrolytes / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D005818:Genetic Engineering / Q000379:methods; D007700:Kinetics; D018551:Solanum lycopersicum / Q000201:enzymology / Q000235:genetics / Q000378:metabolism; D013058:Mass Spectrometry; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D018384:Oxidative Stress / Q000502:physiology; D010269:Paraquat / Q000494:pharmacology; D010788:Photosynthesis / Q000187:drug effects / Q000502:physiology; D010802:Phylogeny; D018515:Plant Leaves / Q000737:chemistry / Q000201:enzymology / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism* / Q000382:microbiology; D044224:Pseudomonas syringae / Q000254:growth & development; D011801:Quinic Acid / Q000378:metabolism; D034622:RNA Interference; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D014026:Nicotiana / Q000201:enzymology / Q000235:genetics / Q000378:metabolism; D014162:Transfection
chemical_list: D000214:Acyl Coenzyme A; D018076:DNA, Complementary; D004573:Electrolytes; D011993:Recombinant Fusion Proteins; D011801:Quinic Acid; D002726:Chlorogenic Acid; C058645:caffeoyl-coenzyme A; D000217:Acyltransferases; C021394:hydroxycinnamoyl-CoA-quinate transferase; D015256:Coenzyme A-Transferases; D010269:Paraquat