title: Promoter trapping in Lotus japonicus reveals novel root and nodule GUS expression domains.
abstract: Agrobacterium-based transformation was used to introduce a promoter-less glucuronidase uidA gene (beta-glucuronidase; GUS) into Lotus japonicus. Transgenic plants were screened for GUS activation at different stages after inoculation with its symbiont, Mesorhizobium loti. Functional GUS fusion frequencies ranged from about 2 to 5% of the total number of transgenic lines. These lines provide excellent histological markers for tissue ontogeny analysis. Some of the activations generated GUS expression patterns that correspond to well-known tissue types, such as lateral root and nodule primordia, root tips and developing nodules (line CHEETAH). Others generated GUS activation associated with predictable but previously unknown (i) tissue types, such as the vascular bundle of the nodule (line VASCO); or (ii) expression domains, such as pericycle, nodule primordia, nodule and flower connective/vascular tissue (line FATA MORGANA) or inner root cortex cells in the vicinity of a curled root hair, nodule primordia and nodule cortex (line TIMPA). Putative members of two gene superfamilies, EH (Esp homolog) and AAA ATPase (ATPase associated with various cellular activities), were located next to the CHEETAH and VASCO insertions, respectively, and a nodulin gene, LjENOD40-2, was located next to the FATA MORGANA insertion. We utilized promoter GUS fusions to investigate the genetic regulation of LjENOD40-2 and FATA MORGANA GUS. The LjENOD40-2 promoter defined a novel expression domain and the FATA MORGANA nodule expression was reiterated by the 2 kb sequence upstream of the T-DNA insertion.
authors.affiliation: ARC Centre of Excellence for Integrative Legume Research, The University of Queensland, 4072 Australia. d.buzas@uq.edu.au
authors.forename: Diana Mihaela
authors.initials: DM
authors.lastname: Buzas
authors.forename: Dasharath
authors.initials: D
authors.lastname: Lohar
authors.forename: Shusei
authors.initials: S
authors.lastname: Sato
authors.forename: Yasukazu
authors.initials: Y
authors.lastname: Nakamura
authors.forename: Satoshi
authors.initials: S
authors.lastname: Tabata
authors.forename: Claudia Estelle
authors.initials: CE
authors.lastname: Vickers
authors.forename: Jiri
authors.initials: J
authors.lastname: Stiller
authors.forename: Peter Michael
authors.initials: PM
authors.lastname: Gresshoff
mesh_terms: D001483:Base Sequence; D017931:DNA Primers; D004269:DNA, Bacterial / Q000235:genetics; D005966:Glucuronidase / Q000235:genetics*; D000070116:Lotus / Q000235:genetics*; D008969:Molecular Sequence Data; D018517:Plant Roots / Q000201:enzymology / Q000235:genetics*; D030821:Plants, Genetically Modified; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic
chemical_list: D017931:DNA Primers; D004269:DNA, Bacterial; C036483:T-DNA; D005966:Glucuronidase