Agrobacterium rhizogenes Genes Induce Dwarfism in Arabidopsis

Plant transformation using the Ri plasmid T-DNA of Agrobacterium rhizogenes is a promising technique for developing compact plants. However, knowledge of this technique is still limited. The rolB and ORF13 genes of A. rhizogenes show promise in breeding, but have not been studied. Researchers from the University of Copenhagen in Denmark evaluated the morphological impact of specific genes of the Ri plasmid in order to study and hopefully optimize plant transformation using the Ri plasmid T-DNA.

RolB and ORF13 were inserted into Arabidopsis thaliana and their effects were assessed. rolB-lines exhibited dwarfing, early necrosis of rosette leaves, altered leaf and flower morphology, and developed an increased number of inflorescences per rosette area. On the other hand, ORF13-lines were extremely dwarfed, attaining only 1% of the rosette area of the wild type. Leaf and flower size was also reduced, and the shape was modified.

The rolB oncogene yield plants with increased formation of generative shoots, however, also results in premature senescence of vegetative organs. The extreme dwarfism seen in ORF13-lines suggests that this gene is vital in dwarfing response of plants transformed using Ri plasmid T-DNA.

For more information, read the article in BMC Plant Biology.