title: Functional analysis of the DAT gene promoter using transient Catharanthus roseus and stable Nicotiana tabacum transformation systems.
abstract: The Catharanthus roseus DAT gene encodes the enzyme acetyl-CoA:deacetylvindoline-4-O-acetyltransferase involved in the last step of the indole alkaloid pathway leading to vindoline. This gene is characterized by specific cell type expression in idioblasts and laticifers. To understand the specific transcriptional regulation mechanism(s) of DAT, several DAT promoter GUS constructs were cloned into pCAMBIA1305.1. Agroinfiltration of different explant types of C. roseus resulted in organ-specific accumulation of GUS, albeit at various levels. Heterologous accumulation of GUS in transgenic tobacco revealed both general and non-specific expression with the exception of a stomata-specific expression when 2.3 kb of the DAT promoter was coupled with a portion of the DAT ORF. These results suggest that in addition to the 2.3 kb upstream of the DAT transcriptional start site, additional cis-acting elements may be responsible for the specific spatial expression of DAT in vivo. Furthermore, hairy roots transformed with DAT promoter GUS constructs demonstrated GUS expression in root tissues (visualized through GUS enzyme activity), even though DAT is repressed in non-transformed roots.
authors.affiliation: Department of Biology and The Biotron, The University of Western Ontario, London, ON, Canada. abmakhzoum@hotmail.com
authors.forename: Abdullah
authors.initials: A
authors.lastname: Makhzoum
authors.forename: Geneviève
authors.initials: G
authors.lastname: Petit-Paly
authors.forename: Benoit
authors.initials: B
authors.lastname: St Pierre
authors.forename: Mark A
authors.initials: MA
authors.lastname: Bernards
mesh_terms: D000123:Acetyltransferases / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D030008:Catharanthus / Q000235:genetics* / Q000378:metabolism; D003001:Cloning, Molecular; D018274:Electroporation; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D017930:Genes, Reporter; D005822:Genetic Vectors; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000201:enzymology* / Q000235:genetics; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism; D011401:Promoter Regions, Genetic; D036226:Seedlings / Q000235:genetics / Q000378:metabolism; D014026:Nicotiana / Q000235:genetics / Q000378:metabolism; D024363:Transcription Initiation Site; D014162:Transfection; D014170:Transformation, Genetic
chemical_list: D000123:Acetyltransferases; C064442:acetylcoenzyme A-deacetylvindoline 4-O-acetyltransferase