150 research outputs found
Genetic engineering of woody plants: current and future targets in a stressful environment
Characterization of the tissue-specific expression of phenylalanine ammonia-lyase gene promoter from loblolly pine (Pinus taeda) in Nicotiana tabacum
We isolated the 50. We isolated the 50 flanking region of a gene for phenylalanine ammonia-lyase (PAL; EC 4.3.1.5) from Pinus taeda, PtaPAL. To investigate the tissue-specific expression of the PtaPAL promoter, histochemical assay of GUS activity was performed using the transgenic tobacco expressing the PtaPAL promoter-GUS. The region of -897 to -420 in PtaPAL promoter showed high activities in the secondary xylem and response to bending stress. To characterize the cis-regulatory functions of the promoters for enzymes in phenylpropanoid biosynthesis, we examined the activity of chimeric promoters of PtaPAL and a 4-coumarate CoA ligase, Pta4CLa. The chimeric promoter showed similar activity as the Pta4CLa promoter. Electrophoretic mobility shift assays implicated -897 to -674 of PtaPAL promoter containing cis-elements of the expression in xylem of Pinus taeda. The results suggested that AC elements of PtaPAL have multiple functions in the expression under the various developmental stages and stress conditions in the transgenic tobacco
Isolation of 4-coumarate Co-A ligase gene promoter from loblolly pine (Pinus taeda) and characterization of tissue-specific activity in transgenic tobacco
We characterized promoter activity of a phenylpropanoid biosynthetic gene encoding 4-coumarate Co-A ligase (4CL), Pta4Clα, from Pinus taeda. Histochemical- and quantitative assays of GUS expression in the vascular tissue were performed using transgenic tobacco plants expressing promoter-GUS reporters. Deletion analysis of the Pta4Clα promoter showed that the region -524 to -252, which has two AC elements, controls the high expression levels in ray-parenchyma cells of older tobacco stems. High activity level of the promoter domain of Pta4CLα was also detected in the xylem cells under bending stress. DNA-protein complexes were detected in the reactions of the Pta4CLα promoter fragments with the nuclear proteins of xylem of P. taeda. The AC elements in the Pta4CLα promoter appeared to have individual roles during xylem development that are activated in a coordinated manner in response to stress in transgenic tobacco
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