title: Fluorescence microscopy: a powerful technique to detect low GUS activity in vascular tissues.
abstract: We have previously shown that the Eucalyptus gunnii EgCAD2 promoter was preferentially expressed in vascular tissues in different transgenic plants (poplar, tobacco, Arabidopsis and grapevine). In order to delineate the cis elements governing this vascular expression pattern, promoter deletion analysis was performed allowing us to identify the proximal region [-340/-124] as essential for vascular cambium/xylem-specific expression. In plants transformed with the smallest promoter region [-124/+117], the GUS activity was difficult to detect using conventional bright field microscopy. To overcome this problem, we used fluorescence microscopy, enabling us to show that the [-124/+117] region contained cis-elements driving activity in phloem fibres but not in secondary xylem. The technical improvement of the histochemical detection of GUS activity using fluorescence microscopy enables accurate investigation of low GUS activity in phenol-rich tissues.
authors.affiliation: IFR40, UMR CNRS-UPS 5546, Signaux et Messages Cellulaires chez les Végétaux, Pôle de Biotechnologie Végétale, BP 17, Auzeville, 31326 Castanet Tolosan, France. rech@smcv.ups-tlse.fr
authors.forename: Philippe
authors.initials: P
authors.lastname: Rech
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Grima-Pettenati
authors.forename: Alain
authors.initials: A
authors.lastname: Jauneau
mesh_terms: D005052:Eucalyptus / Q000166:cytology / Q000201:enzymology* / Q000235:genetics; D005966:Glucuronidase / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D006651:Histocytochemistry; D008856:Microscopy, Fluorescence / Q000379:methods; D016296:Mutagenesis; D011993:Recombinant Fusion Proteins / Q000032:analysis / Q000378:metabolism; D012680:Sensitivity and Specificity; D017384:Sequence Deletion
chemical_list: D011993:Recombinant Fusion Proteins; D005966:Glucuronidase