title: Molecular cloning and expression of gene encoding aromatic amino acid decarboxylase in 'Vidal blanc' grape berries.
abstract: The pleasantly fruity and floral 2-phenylethanol are a dominant aroma compound in post-ripening 'Vidal blanc' grapes. However, to date little has been reported about its synthetic pathway in grapevine. In the present study, a full-length cDNA of VvAADC (encoding aromatic amino acid decarboxylase) was firstly cloned from the berries of 'Vidal blanc', an interspecific hybrid variety of Vitis vinifera × Vitis riparia. This sequence encodes a complete open reading frame of 482 amino acids with a calculated molecular mass of 54 kDa and isoelectric point value (pI) of 5.73. The amino acid sequence deduced shared about 79% identity with that of aromatic L: -amino acid decarboxylases (AADCs) from tomato. Real-time PCR analysis indicated that VvAADC transcript abundance presented a small peak at 110 days after full bloom and then a continuous increase at the berry post-ripening stage, which was consistent with the accumulation of 2-phenylethanol, but did not correspond to the trends of two potential intermediates, phenethylamine and 2-phenylacetaldehyde. Furthermore, phenylalanine still exhibited a continuous increase even in post-ripening period. It is thus suggested that 2-phenylethanol biosynthetic pathway mediated by AADC exists in grape berries, but it has possibly little contribution to a considerable accumulation of 2-phenylethanol in post-ripening 'Vidal blanc' grapes.
authors.affiliation: Center for Viticulture and Enology, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, 100083, China.
authors.forename: Qiu-Hong
authors.initials: QH
authors.lastname: Pan
authors.forename: Fang
authors.initials: F
authors.lastname: Chen
authors.forename: Bao-Qing
authors.initials: BQ
authors.lastname: Zhu
authors.forename: Li-Yan
authors.initials: LY
authors.lastname: Ma
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.forename: Jing-Ming
authors.initials: JM
authors.lastname: Li
mesh_terms: D000079:Acetaldehyde / Q000031:analogs & derivatives; D001142:Aromatic-L-Amino-Acid Decarboxylases / Q000235:genetics* / Q000378:metabolism; D053898:Biosynthetic Pathways / Q000235:genetics; D003001:Cloning, Molecular; D003433:Crosses, Genetic; D005638:Fruit / Q000201:enzymology* / Q000235:genetics* / Q000254:growth & development; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant / Q000235:genetics*; D010627:Phenethylamines / Q000378:metabolism; D010649:Phenylalanine / Q000378:metabolism; D010626:Phenylethyl Alcohol / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017422:Sequence Analysis, DNA; D027843:Vitis / Q000201:enzymology* / Q000235:genetics* / Q000254:growth & development
chemical_list: D010627:Phenethylamines; D012333:RNA, Messenger; C029261:phenethylamine; D010649:Phenylalanine; D001142:Aromatic-L-Amino-Acid Decarboxylases; D000079:Acetaldehyde; D010626:Phenylethyl Alcohol; C013192:phenylacetaldehyde