Agrobacterium-mediated transformation and particle bombardment are the two most widely used methods for genetically modifying grasses.
Here, these two systems are compared for transformation efficiency, transgene integration and transgene expression when used
to transform tall fescue (
Festuca arundinacea Schreb.). The
bar gene was used as a selectable marker and selection during tissue culture was performed using 2 mg/l bialaphos in both callus
induction and regeneration media. Average transformation efficiency across the four callus lines used in the experiments was
10.5% for
Agrobacterium-mediated transformation and 11.5% for particle bombardment. Similar transgene integration patterns and co-integration frequencies
of
bar and
uidA were observed in both gene transfer systems. However, while GUS activity was detected in leaves of 53% of the
Agrobacterium transformed lines, only 20% of the bombarded lines showed GUS activity. Thus,
Agrobacterium-mediated transformation appears to be the preferred method for producing transgenic tall fescue plants.
Keywords Tall fescue (Festuca arundinacea Schreb.) - Particle bombardment -
Agrobacterium transformation - Bialaphos selection - Transgene analysis
Communicated by P. Lakshmanan.
Caixia Gao and Danfeng Long have contributed equally to the work.