title: Analysis of Arabidopsis PsbQA gene expression in transgenic tobacco reveals differential role of its promoter and transcribed region in organ-specific and light-mediated regulation.
abstract: Arabidopsis PsbQ, encoding a 16 kDa protein of the oxygen-evolving complex, is regulated by light and is expressed preferentially in leaf tissues. To analyze the components required for light-regulated and organ-specific expression of PsbQA, several promoter constructs were generated and expressed in tobacco. The 2.2 kb promoter could confer organ-specific expression of the reporter gene, whereas regulatory elements for light-dependent induction could not be located within this promoter and the transcribed region extending up to a second exon, represented by a genomic fragment encompassing the gene. The genomic fragment representing the transcribed region, however, could confer light regulation even on a constitutive promoter, as observed by steady-state mRNA analysis in T0 and T1 tobacco plants. The results obtained have led to the conclusion that regulatory elements for organ-specificity mainly reside in the promoter region whereas the transcribed region of the gene has an important role in light regulation.
authors.affiliation: Centre for Plant Molecular Biology, Department of Plant Molecular Biology, University of Delhi South Campus, New Delhi-110021, India.
authors.forename: Tripti
authors.initials: T
authors.lastname: Gaur
authors.forename: Akhilesh K
authors.initials: AK
authors.lastname: Tyagi
mesh_terms: D020121:5' Untranslated Regions / Q000235:genetics; D029681:Arabidopsis Proteins / Q000235:genetics*; D015152:Blotting, Northern; D017796:Caulimovirus / Q000235:genetics; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D017930:Genes, Reporter / Q000235:genetics; D005966:Glucuronidase / Q000032:analysis; D008027:Light; D009928:Organ Specificity; D010788:Photosynthesis / Q000235:genetics; D045332:Photosystem II Protein Complex / Q000235:genetics*; D030821:Plants, Genetically Modified / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics*; D012333:RNA, Messenger / Q000032:analysis; D012045:Regulatory Sequences, Nucleic Acid / Q000235:genetics; D014026:Nicotiana / Q000235:genetics* / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D020121:5' Untranslated Regions; D029681:Arabidopsis Proteins; D045332:Photosystem II Protein Complex; D012333:RNA, Messenger; C121497:psbQ protein, Arabidopsis; D005966:Glucuronidase