Transgenic regal pelargoniums that express the Rol C gene from Agrobacterium rhizogenes exhibit a dwarf floral and vegetative phenotype

• Published in: In vitro cellular & developmental biology. Plant Vol. 40; no. 1; pp. 46 - 50
• Main Authors: Boase, M R, Winefield, C S, Lill, T A, Bendall, MJ
• Format: Journal Article
• Language: English
• Published: 01-01-2004
• Subjects: Agrobacterium rhizogenes; Agrobacterium tumefaciens; Pelargonium
• ISSN: 1054-5476
• DOI: 10.1043/1054-5476(2004)040(0046:TRPTET)2.0.CO;2

The regal pelargonium, cv. Dubonnet, was transformed using the disarmed Agrobacterium tumefaciens strains LBA4404 or EHA105 containing the binary vector pLN70. This plasmid carries on its T-DNA the rol C gene from Agrobacterium rhizogenes under control of the CaMV 35S promoter and the npt II selectable marker gene under a NOS promoter. Six independent transformants were produced and grouped according to their phenotypic characteristics. Two transformants showed the same phenotype as the untransformed control plants. Three transformants exhibited a dwarf phenotype and one displayed a super-dwarf phenotype. Southern hybridization analyses of the T-DNA left border region using a npt II probe showed that the six transformants all arose from independent transformation events. Northern hybridization analyses showed that the rol C gene was expressed only in the four transformants that exhibited a dwarf phenotype. Our data show that the phenotypic effects of rol C expression in regal pelargoniums include reductions in plant height, leaf area, petal area, and corolla length. Earlier flowering of the rol C transgenics by up to 22 d was also observed.