Agrobacterium-mediated transformation of buddleia species

Abstract

Two Buddleia cultivars, B. davidii 'Potters Purple' and Buddleia 'Lochinch', were transformed using Agrobacterium tumefaciens strain EHA105 harboring the binary vector pBI121 carrying the neomycin phosphotransferase gene and β-glucuronidase gene (uidA). Transgenic plants were recovered from the Agrobacterium-infected leaf tissues through organogenesis in the selection medium (woody plant medium containing 250 mg·L-1 cefotaxime plus 500 mg·L-1 carbenicillin plus 40 mg·L-1 kanamycin). The rate of shoot regeneration from transformed leaf tissues increased from 5.7% to 32% through extending cocultivation time from 3 to 9 days. Integration of marker genes was verified with polymerase chain reaction (PCR) and Southern blot analysis. Southern blot analysis confirmed that one to three copies of transgenes were integrated into the buddleia genome. This transformation system could be used for improvement of buddleia or other related species. Chemical names used: 6-benzyladenine (BA), naphthalene acetic acid (NAA), acetosyringone (AS), 5-Bromo-4-chloro-3-indoxyl-beta-D-glucuronide cyclohexylammonium (X-Glu), cefotaxime (Cef), carbenicillin (Carb), kanamycin (Km).