Biomedical Engineering Reference
In-Depth Information
bombardment, may increase in popularity in line with improvements to plastid
transformation. It is now possible to produce fertile transgenics expressing foreign
proteins in their edible fruit (Ruf
et al
., 2001).
The second is by protoplast fusion which is a process whereby the plant cell
wall is removed leaving the cell surrounded only by the much more fragile
membrane. This is made permeable to small fragments of DNA and then the
cells allowed to recover and grow into plants. These methods can be unsuccessful
due to difficulties in recovery of the cells from the rather traumatic treatments
and also because the DNA introduced has a tendency to be inserted randomly
into the genome, rather than at a defined site. However, both methods enjoy the
advantage that DNA enters the cell exactly as constructed and has not passed
through an intermediate vector giving the opportunity for gene rearrangement.
Transformation by the Ti plasmid of
Agrobacterium tumefaciens
, shown dia-
grammatically in Figure 9.4, suffers from few disadvantages other than the
limitation that it does not readily infect some cereal crops. This potential problem
Figure9.4
Tiplasmidof Agrobacterium tumefaciens
Search WWH ::
Custom Search