title: The scutellar vascular bundle-specific promoter of the wheat HD-Zip IV transcription factor shows similar spatial and temporal activity in transgenic wheat, barley and rice.
abstract: An HD-Zip IV gene from wheat, TaGL9, was isolated using a Y1H screen of a cDNA library prepared from developing wheat grain. TaGL9 has an amino acid sequence distinct from other reported members of the HD-Zip IV family. The 3' untranslated region of TaGL9 was used as a probe to isolate a genomic clone of the TaGL9 homologue from a BAC library prepared from Triticum durum L. cv. Langdon. The full-length gene containing a 3-kb-long promoter region was designated TdGL9H1. Spatial and temporal activity of TdGL9H1 was examined using promoter-GUS fusion constructs in transgenic wheat, barley and rice plants. Whole-mount and histochemical GUS staining patterns revealed grain-specific expression of TdGL9H1. GUS expression was initially observed between 3 and 8 days after pollination (DAP) in embryos at the globular stage and adjacent to the embryo fraction of the endosperm. Expression was strongest in the outer cell layer of the embryo. In developed wheat and barley embryos, strong activity of the promoter was only detected in the main vascular bundle of the scutellum, which is known to be responsible for the uptake of nutrients from the endosperm during germination and the endosperm-dependent phase of seedling development. Furthermore, this pattern of GUS staining was observed in dry seeds several weeks after harvesting but quickly disappeared during imbibition. The promoter of this gene could be a useful tool for engineering of early seedling vigour and protecting the endosperm to embryo axis pathway from pathogens during grain desiccation and storage.
authors.affiliation: Australian Centre for Plant Functional Genomics, University of Adelaide, Hartley Grove, Urrbrae, South Australia, Australia.
authors.forename: Nataliya
authors.initials: N
authors.lastname: Kovalchuk
authors.forename: Wei
authors.initials: W
authors.lastname: Wu
authors.forename: Omid
authors.initials: O
authors.lastname: Eini
authors.forename: Natalia
authors.initials: N
authors.lastname: Bazanova
authors.forename: Margaret
authors.initials: M
authors.lastname: Pallotta
authors.forename: Neil
authors.initials: N
authors.lastname: Shirley
authors.forename: Rohan
authors.initials: R
authors.lastname: Singh
authors.forename: Ainur
authors.initials: A
authors.lastname: Ismagul
authors.forename: Serik
authors.initials: S
authors.lastname: Eliby
authors.forename: Alexander
authors.initials: A
authors.lastname: Johnson
authors.forename: Peter
authors.initials: P
authors.lastname: Langridge
authors.forename: Sergiy
authors.initials: S
authors.lastname: Lopato
mesh_terms: D003001:Cloning, Molecular; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant / Q000235:genetics; D005966:Glucuronidase / Q000378:metabolism; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism*; D001467:Hordeum / Q000166:cytology / Q000235:genetics* / Q000254:growth & development; D016350:Leucine Zippers / Q000235:genetics; D008969:Molecular Sequence Data; D009928:Organ Specificity / Q000235:genetics; D012275:Oryza / Q000166:cytology / Q000235:genetics* / Q000254:growth & development; D010802:Phylogeny; D058526:Plant Vascular Bundle / Q000235:genetics*; D030821:Plants, Genetically Modified; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic / Q000235:genetics*; D011485:Protein Binding; D015203:Reproducibility of Results; D012639:Seeds / Q000166:cytology / Q000235:genetics / Q000254:growth & development; D017422:Sequence Analysis, DNA; D013997:Time Factors; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014908:Triticum / Q000166:cytology / Q000235:genetics* / Q000254:growth & development
chemical_list: D018398:Homeodomain Proteins; D014157:Transcription Factors; D005966:Glucuronidase