title: Isolation and characterization of the 4-coumarate:coenzyme A ligase (4CL1) promoter fromEucalyptus camaldulensis.
abstract: The most important enzyme of the phenylpropanoid pathway, 4-coumarate:coenzyme A ligase (4CL), is encoded by several homologous genes including4CL1. The 4CL1 promoter is a tissue-specific gene expression element, particularly active in the secondary xylem or older stems. In this study, the 1127 bp 5'- upstream region of the4CL1coding sequence fromEucalyptus camaldulensis, Euc4CL1, was isolated and characterized. Essential putativecis-elements in theEuc4CL1 promoter included: a TATA-box at -22/-28 position, two CCAAT-boxes at -256/-260 and -277/-281 positions, respectively, an AC-element at -328/-336 and A-boxes at -115/-120 and -990/-995 positions. To investigate the effect of theEuc4CL1 promoter on gene expression, a plant transformation vector, pEuc4CL1p, containing the reporter gene for β-glucuronidase (GUS) under the control ofEuc4CL1 promoter was constructed based on the pBI101 backbone and introduced in tobacco plants. Stable expression of the GUS gene in transgenic lines was analysed by a histochemical GUS assay. The results indicated the specific expression of the GUS gene in the stem xylem cells of transgenic tobacco lines was controlled by theEuc4CL1 promoter. The observations suggest the isolatedEuc4CL1 promoter is a potential candidate for driving the expression of a foreign gene in plant xylem tissues.
authors.affiliation: Institute of Genome Research (IGR), Vietnam Academy of Science and Technology (VAST), 18 Hoang Quoc Viet, Cau Giay, Hanoi, Vietnam.
authors.forename: Huynh Thi Thu
authors.initials: HT
authors.lastname: Hue
authors.affiliation: Institute of Genome Research (IGR), Vietnam Academy of Science and Technology (VAST), 18 Hoang Quoc Viet, Cau Giay, Hanoi, Vietnam.
authors.forename: Duong Thi Thu
authors.initials: DT
authors.lastname: Ha
authors.affiliation: Institute of Genome Research (IGR), Vietnam Academy of Science and Technology (VAST), 18 Hoang Quoc Viet, Cau Giay, Hanoi, Vietnam.
authors.forename: Nong Van
authors.initials: NV
authors.lastname: Hai
authors.affiliation: Institute of Genome Research (IGR), Vietnam Academy of Science and Technology (VAST), 18 Hoang Quoc Viet, Cau Giay, Hanoi, Vietnam.
authors.forename: Le Thi Thu
authors.initials: LT
authors.lastname: Hien
keywords: 4-coumarate:coenzyme A ligase; 4CL1 promoter; Eucalyptus camaldulensis; GUS gene; Transgenic plant