title: Low light and low ammonium are key factors for guayule leaf tissue shoot organogenesis and transformation.
abstract: A new method has been developed for guayule tissue culture and transformation. Guayule leaf explants have a poor survival rate when placed on normal MS medium and under normal culture room light conditions. Low light and low ammonium treatment greatly improved shoot organogenesis and transformation from leaf tissues. Using this method, a 35S promoter driven BAR gene and an ubiquitin-3 promoter driven GUS gene (with intron) have been successfully introduced into guayule. These transgenic guayule plants were resistant to the herbicide ammonium-glufosinate and were positive to GUS staining. Molecular analysis showed the expected band and signal in all GUS positive transformants. The transformation efficiency with glufosinate selection ranged from 3 to 6%. Transformation with a pBIN19-based plasmid containing a NPTII gene and then selection with kanamycin also works well using this method. The ratio of kanamycin-resistant calli to total starting explants reached 50% in some experiments.
authors.affiliation: ARS/WRRC/CIU, U.S. Department of Argiculture, 800 Buchanan St., Albany, CA 94710, USA. ndong@pw.usda.gov
authors.forename: Niu
authors.initials: N
authors.lastname: Dong
authors.forename: Belen
authors.initials: B
authors.lastname: Montanez
authors.forename: Robert A
authors.initials: RA
authors.lastname: Creelman
authors.forename: Katrina
authors.initials: K
authors.lastname: Cornish
mesh_terms: D000613:Aminobutyrates / Q000494:pharmacology; D019659:Asteraceae / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development / Q000528:radiation effects; D004269:DNA, Bacterial / Q000235:genetics; D005966:Glucuronidase / Q000235:genetics; D007612:Kanamycin / Q000494:pharmacology; D008027:Light; D038081:Organogenesis / Q000187:drug effects* / Q000528:radiation effects*; D018515:Plant Leaves / Q000033:anatomy & histology / Q000187:drug effects* / Q000254:growth & development / Q000528:radiation effects; D018520:Plant Shoots / Q000033:anatomy & histology / Q000187:drug effects* / Q000254:growth & development / Q000528:radiation effects; D000644:Quaternary Ammonium Compounds / Q000494:pharmacology*; D013997:Time Factors; D014170:Transformation, Genetic / Q000235:genetics
chemical_list: D000613:Aminobutyrates; D004269:DNA, Bacterial; D000644:Quaternary Ammonium Compounds; C036483:T-DNA; C003121:phosphinothricin; D007612:Kanamycin; D005966:Glucuronidase