title: Regulation of polyphenols accumulation by combined overexpression/silencing key enzymes of phenylpropanoid pathway.
abstract: There is a growing interest in the metabolic engineering of plant with increased desirable polyphenols such as chlorogenic acid (CGA) and rutin. In this study, the effects of overexpression of both phenylalanine ammonia lyase (AtPAL2), the first enzyme of the phenylpropanoid pathway, and hydroxycinnamoyl-CoA quinate:hydroxycinnamoyl transferase (NtHQT), the last enzyme of CGA biosynthesis, and the overexpression of AtPAL2 together with silencing of NtHQT were investigated in tobacco. Transgenic tobacco plants overexpressing AtPAL2 showed two and five times increases of CGA and rutin levels than the wild-type (WT) plants, respectively. Overexpression of NtHQT further increases the accumulation of CGA in the AtPAL2 plants to about three times than that of the WT level, while silencing of NtHQT in AtPAL2 plants results in about 12 times increase in rutin level than that of the WT plants. Simultaneous overexpression of phenylalanine ammonia lyase (PAL) and overexpression/silencing HQT could be used for the production of functional food with increased polyphenols.
authors.affiliation: China-UK HUST-RRes Genetic Engineering and Genomics Joint Laboratory, Key Laboratory of Molecular Biophysics, Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China.
authors.forename: Junli
authors.initials: J
authors.lastname: Chang
authors.forename: Jie
authors.initials: J
authors.lastname: Luo
authors.forename: Guangyuan
authors.initials: G
authors.lastname: He
mesh_terms: D000217:Acyltransferases / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism*; D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics; D001483:Base Sequence; D002726:Chlorogenic Acid / Q000378:metabolism; D017931:DNA Primers / Q000235:genetics; D018744:DNA, Plant / Q000235:genetics; D005419:Flavonoids / Q000378:metabolism*; D015870:Gene Expression; D020868:Gene Silencing; D017343:Genes, Plant; D005818:Genetic Engineering; D005822:Genetic Vectors; D010636:Phenols / Q000378:metabolism*; D010650:Phenylalanine Ammonia-Lyase / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism*; D030821:Plants, Genetically Modified; D059808:Polyphenols; D012431:Rutin / Q000378:metabolism; D014026:Nicotiana / Q000235:genetics / Q000378:metabolism
chemical_list: D017931:DNA Primers; D018744:DNA, Plant; D005419:Flavonoids; D010636:Phenols; D059808:Polyphenols; D002726:Chlorogenic Acid; D012431:Rutin; D000217:Acyltransferases; C021394:hydroxycinnamoyl-CoA-quinate transferase; D010650:Phenylalanine Ammonia-Lyase