| The bacterium Agrobacterium is a plant pathogen
causing crown galls or tumours that arise at the site of bacterial
infection. |
| The tumour-inducing agent in grobacterium is a
plasmid called the Ti plasmid that integrates some of its DNA into
the chromosome of its host plant cell. Ti plasmids are maintained
in Agrobacterium because part of the plasmid DNA, called T-DNA
carries essential genes, not found in the chromosomal DNA, coding for the
synthesis of unusual amino acids called opines. The genes on the Ti plasmid
responsible for the tumour growth have been disabled allowing scientists
to use the Agrobacterium infection system to transfer the goc to
different plants. |
|
 |
