title: Transcription factor RF2a alters expression of the rice tungro bacilliform virus promoter in transgenic tobacco plants.
abstract: The promoter from rice tungro bacilliform badnavirus (RTBV) is expressed only in phloem tissues in transgenic rice plants. RF2a, a b-Zip protein from rice, is known to bind to the Box II cis element near the TATA box of the promoter. Here, we report that the full-length RTBV promoter and a truncated fragment E of the promoter, comprising nucleotides -164 to +45, result in phloem-specific expression of beta-glucuronidase (GUS) reporter genes in transgenic tobacco plants. When a fusion gene comprising the cauliflower mosaic virus 35S promoter and RF2a cDNA was coexpressed with the GUS reporter genes, GUS activity was increased by 2-20-fold. The increase in GUS activity was positively correlated with the amount of RF2a, and the expression pattern of the RTBV promoter was altered from phloem-specific to constitutive. Constitutive expression of RF2a did not induce morphological changes in the transgenic plants. In contrast, constitutive overexpression of the b-ZIP domain of RF2a had a strong effect on the development of transgenic plants. These studies suggest that expression of the b-Zip domain can interfere with the function of homologues of RF2a that regulate development of tobacco plants.
authors.affiliation: The Scripps Research Institute, La Jolla, CA 92037, USA.
authors.forename: S
authors.initials: S
authors.lastname: Petruccelli
authors.forename: S
authors.initials: S
authors.lastname: Dai
authors.forename: R
authors.initials: R
authors.lastname: Carcamo
authors.forename: Y
authors.initials: Y
authors.lastname: Yin
authors.forename: S
authors.initials: S
authors.lastname: Chen
authors.forename: R N
authors.initials: RN
authors.lastname: Beachy
mesh_terms: D016960:Agrobacterium tumefaciens / Q000235:genetics; D019195:Badnavirus / Q000235:genetics*; D050976:Basic-Leucine Zipper Transcription Factors; D017796:Caulimovirus / Q000235:genetics; D003001:Cloning, Molecular; D004926:Escherichia coli; D015967:Gene Expression Regulation, Viral / Q000502:physiology*; D017930:Genes, Reporter; D005966:Glucuronidase / Q000032:analysis* / Q000235:genetics; D010641:Phenotype; D018515:Plant Leaves; D010940:Plant Proteins / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000821:virology*; D010947:Plants, Toxic; D011401:Promoter Regions, Genetic; D011994:Recombinant Proteins / Q000378:metabolism; D017384:Sequence Deletion; D016385:TATA Box; D014026:Nicotiana / Q000235:genetics* / Q000502:physiology / Q000821:virology*; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism*
chemical_list: D050976:Basic-Leucine Zipper Transcription Factors; D010940:Plant Proteins; D011994:Recombinant Proteins; D015534:Trans-Activators; D014157:Transcription Factors; D005966:Glucuronidase