title: Induced tyramine overproduction in transgenic rice plants expressing a rice tyrosine decarboxylase under the control of methanol-inducible rice tryptophan decarboxylase promoter.
abstract: Tyramine, one of the various biogenic amines found in plants, is derived from the aromatic L-amino acid tyrosine through the catalytic reaction of tyrosine decarboxylase (TYDC). Tyramine overproduction by constitutive expression of TYDC in rice plants leads to stunted growth, but an increased number of tillers. To regulate tyramine production in rice plants, we expressed TYDC under the control of a methanol-inducible plant tryptophan decarboxylase (TDC) promoter and generated transgenic T(2) homozygous rice plants. The transgenic rice plants showed normal growth phenotypes with slightly increased levels of tyramine in seeds relative to wild type. Upon treatment with 1% methanol, the transgenic rice leaves produced large amounts of tyramine, whereas no increase in tyramine production was observed in wild-type plants. The methanol-induced accumulation of tyramine in the transgenic rice leaves was inversely correlated with the tyrosine level. These data indicate that tyramine production in rice plants can be artificially controlled using the methanol-inducible TDC promoter, suggesting that this promoter could be used to selectively induce the expression of other proteins or metabolites in rice plants.
authors: Department of Biotechnology, Interdisciplinary Program of Graduate School for Bioenergy and Biomaterials, Bioenergy Research Center, Chonnam National University, Gwangju, 500-757, Korea.
authors: Sangkyu
authors: S
authors: Park
authors: Kyungjin
authors: K
authors: Lee
authors: Young Soon
authors: YS
authors: Kim
authors: Youn-Tae
authors: YT
authors: Chi
authors: Jeong Sheop
authors: JS
authors: Shin
authors: Kyoungwhan
authors: K
authors: Back
mesh_terms: D001142:Aromatic-L-Amino-Acid Decarboxylases / Q000235:genetics; D024861:Genetic Enhancement / Q000379:methods*; D000432:Methanol / Q000378:metabolism*; D012275:Oryza / Q000502:physiology*; D030821:Plants, Genetically Modified / Q000378:metabolism*; D011401:Promoter Regions, Genetic / Q000235:genetics*; D014439:Tyramine / Q000096:biosynthesis*; D014445:Tyrosine Decarboxylase / Q000502:physiology*
chemical_list: D014445:Tyrosine Decarboxylase; D001142:Aromatic-L-Amino-Acid Decarboxylases; D014439:Tyramine; D000432:Methanol