title: Isolation of a maize beta-glucosidase gene promoter and characterization of its activity in transgenic tobacco.
abstract: The beta-glucosidase gene of maize (ZmGLU1) was suggested to hydrolyze cytokinin-conjugate and release free cytokinin during plant growth and development. A clone containing the upstream region of ZmGLU1 was isolated and sequenced from a maize genomic library. The full-length ZmGLU1 promoter and a series of its 5' deletions were fused to the beta-glucuronidase (GUS) reporter gene and transferred into tobacco. The GUS activity of transgenic plants was assayed at various developmental stages. The results showed that ZmGLU1 promoter-driven GUS gene had the highest expression level in the roots and that the expression of GUS gene declined during seed maturation and down to the lowest level in mature seeds. The ZmGLU1 promoter-driven GUS expression increased during seed germination, reaching a peak on day 11. The results also showed that this promoter could be inhibited by 6-BA, trans-zeatin, and NAA, but was not affected by GA(3), ABA, SA, cold, salt, drought, and submergence treatments. The histochemical staining revealed that GUS activity was located in vigorous cell division zones with dominant staining associated with vascular tissues. Deletion analysis showed that the promoter contained a putative leaf-specific and stem-specific negative regulative element and two putative enhancers.
authors.affiliation: State Key Laboratory for Agrobiotechnology and National Center for Maize Improvement, China Agricultural University, Beijing, 100094, China.
authors.forename: Riliang
authors.initials: R
authors.lastname: Gu
authors.forename: Li
authors.initials: L
authors.lastname: Zhao
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhang
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Chen
authors.forename: Juan
authors.initials: J
authors.lastname: Bao
authors.forename: Jinfeng
authors.initials: J
authors.lastname: Zhao
authors.forename: Zhangying
authors.initials: Z
authors.lastname: Wang
authors.forename: Junjie
authors.initials: J
authors.lastname: Fu
authors.forename: Tingsong
authors.initials: T
authors.lastname: Liu
authors.forename: Jianhua
authors.initials: J
authors.lastname: Wang
authors.forename: Guoying
authors.initials: G
authors.lastname: Wang
mesh_terms: D001483:Base Sequence; D004789:Enzyme Activation; D017343:Genes, Plant; D008969:Molecular Sequence Data; D009928:Organ Specificity; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic; D014026:Nicotiana / Q000235:genetics / Q000502:physiology*; D024363:Transcription Initiation Site; D003313:Zea mays / Q000235:genetics*; D001617:beta-Glucosidase / Q000235:genetics / Q000378:metabolism*
chemical_list: D001617:beta-Glucosidase