© 1994 Heron Publishing—Victoria, Canada
Enhancement of the endogenous cytokinin concentration in poplar by transformation with Agrobacterium T-DNA gene ipt
Klaus von Schwartzenberg (1), Patrick Doumas (1), Lise Jouanin (2) and Gilles Pilate (1)
1. Institut National de la Recherche Agronomique, Centre de Recherches Orléans, Station d'Amélioration des Arbres Forestiers,
45160 Ardon, France / 2. Institut National de la Recherche Agronomique, Centre de Recherches Versailles, Laboratoire de Biologie Cellulaire, 78026
Versailles, France / Received April 27, 1993
Summary
The agrobacterial isopentenyltransferase (ipt) gene, under the control of its native promoter, was transferred to poplar (Populus tremula × P. alba) by an Agrobacterium co-cultivation method. The ipt-transformed stem explants developed calli that regenerated many buds in the absence of exogenous cytokinins. Microcuttings
of the ipt transformants exhibited frequently branching shoots with short internodes that were unable to root. In this material, the
concentrations of zeatin, zeatin riboside and isopentenyladenosine, determined by an indirect enzyme-linked immunosorbent
assay (ELISA), were 4.8-. 17.1- and 14.6-fold higher, respectively, than in non-transformed shoots. Results are discussed
with regard to cytokinin metabolism.
Keywords:
Agrobacterium tumefaciens, isopentenyladenosine, isopentenyltransferase gene, Populus, transgenic plant, zeatin, zeatin riboside.
