title: [Promoter specificity of LE-ACS6 gene in LE-ACS6::GUS transgenic arabidopsis plants].
abstract: The LE-ACS6 gene encodes ACC synthase, the key enzyme of ethylene biosynthesis pathway. Accumulation of LE-ACS6 transcripts is concomitant with the system 1 ethylene production in the pre-climacteric tomato fruit, and both are down regulated by exogenous ethylene treatment. To elucidate the possible role of system 1 ethylene in plant development and investigate the promoter tissue specificity of LE-ACS6 gene, stable transformation of Arabidopsis with a LE-ACS6 promoter-GUS fusion construct by Agrobacterium method has been done. Histochemical localization of GUS activity and beta-glucuronidase enzyme assay in transgenic LE-ACS6::GUS plants showed strong expression of GUS in cotyledons and hypocotyls of 6 d seedlings, but no GUS activity was detected in roots. The GUS activity of 6 d seedling was increased significantly when treated with NAA 10(-4)mol/L. In 40 d rosette leaf LE-ACS6 promoter driven GUS gene was predominantly expressed in mature leaves. Lower level of GUS expression was detected in younger and older leaves. Wounding was found to increase GUS gene expression in transgenic leaves. Again, exogenous NAA was found to increase the GUS activity in wounded leaf tissue. Strong staining reaction was observed in the top part of rapidly growing stems. In different developmental stages of Arabidopsis seeds, "mature green" pods were strongly stained, but "ripening fruits" were not colored. These observations are concomitant with the system 1 ethylene production, suggesting a popular mechanism in regulating ethylene biosynthesis in different plants, at least in tomato and Arabidopsis.
authors.affiliation: Department of Biochemistry and Molecular Biology, College of Life Sciences, Nankai University, Tianjin 300071, China.
authors.forename: Rong
authors.initials: R
authors.lastname: Fan
authors.forename: Xiao-Rong
authors.initials: XR
authors.lastname: Wan
authors.forename: Wen-Tao
authors.initials: WT
authors.lastname: Zhang
authors.forename: Shu-Fang
authors.initials: SF
authors.lastname: Wang
authors.forename: Yong
authors.initials: Y
authors.lastname: Wang
authors.forename: Liang-Ji
authors.initials: LJ
authors.lastname: Zhu
authors.forename: Ning-Ning
authors.initials: NN
authors.lastname: Wang
authors.forename: Ming-Che
authors.initials: MC
authors.lastname: Shih
authors.forename: Yee-Yung
authors.initials: YY
authors.lastname: Charng
authors.forename: Shang Fa
authors.initials: SF
authors.lastname: Yang
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics*; D005030:Ethylenes / Q000378:metabolism*; D008190:Lyases / Q000235:genetics*; D008969:Molecular Sequence Data; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic
chemical_list: D005030:Ethylenes; C036216:ethylene; D008190:Lyases; C021773:1-aminocyclopropanecarboxylate synthase