Agrobacterium-mediated transformation of the terpenoid indole alkaloid-producing plant species Tabernaemontana pandacaqui

Plants of the Apocynaceae family produce a wide range of terpenoid indole alkaloids (TIAs) which have important pharmaceutical applications. Studies of the molecular mechanisms controlling TIA biosynthesis may eventually provide possibilities to improve product yield by genetic modification of plants or cell cultures. However, these studies suffer from the lack of transformation/regeneration protocols for Apocynaceae plants. We chose to study the feasibility of Agrobacterium tumefaciens-mediated transformation of Tabernaemontana pandacaqui, because of the availability of an efficient regeneration procedure for this member of the Apocynaceae family. A procedure to produce transgenic T. pandacaqui plants was established, albeit with low efficiency. Transgenic expression was demonstrated of an intron-containing β-glucuronidase reporter gene and of a gene coding for the TIA biosynthetic enzyme strictosidine synthase from Catharanthus roseus, another Apocynaceae species.