title: A chimaeric tryptophan decarboxylase gene as a novel selectable marker in plant cells.
abstract: A novel selection system for plant genetic transformation was developed based on the enzyme tryptophan decarboxylase (TDC; EC 4.1.1.28) from Catharanthus roseus. This enzyme converts the toxic tryptophan analogue 4-methyl tryptophan (4-mT) into the non-toxic compound 4-methyl tryptamine. Expression of tdc in transgenic plants that have no endogenous TDC-activity allows selection on 4-mT. A vector was constructed containing a tdc cDNA clone under control of the constitutively expressed cauliflower mosaic virus 35S promoter. This vector was used in Agrobacterium-mediated tobacco leaf disc transformation experiments. The optimal concentration for selection with 4-mT was found to be 0.1 mM. The transformed nature of shoots obtained after tdc gene transfer and subsequent selection on 0.1 mM 4-mT was confirmed by northern blot analysis.
authors.affiliation: Institute of Molecular Plant Sciences, Leiden University, Clusius Laboratory, Netherlands.
authors.forename: O J
authors.initials: OJ
authors.lastname: Goddijn
authors.forename: P M
authors.initials: PM
authors.lastname: van der Duyn Schouten
authors.forename: R A
authors.initials: RA
authors.lastname: Schilperoort
authors.forename: J H
authors.initials: JH
authors.lastname: Hoge
mesh_terms: D001142:Aromatic-L-Amino-Acid Decarboxylases / Q000235:genetics* / Q000378:metabolism; D003001:Cloning, Molecular; D005819:Genetic Markers; D007612:Kanamycin / Q000494:pharmacology; D030821:Plants, Genetically Modified; D010947:Plants, Toxic; D015183:Restriction Mapping; D014026:Nicotiana / Q000166:cytology / Q000201:enzymology / Q000235:genetics*; D014170:Transformation, Genetic; D014364:Tryptophan / Q000031:analogs & derivatives / Q000494:pharmacology
chemical_list: D005819:Genetic Markers; C082802:4-methyltryptophan; D007612:Kanamycin; D014364:Tryptophan; D001142:Aromatic-L-Amino-Acid Decarboxylases