The soybean line A5547-127 was developed to allow for the use of
glufosinate ammonium, the active ingredient in phosphinothricin
herbicides (Basta®, Ignite®, Rely®, Liberty®, Harvest®, and
Finale®) as a weed control option. This genetically engineered
soybean line contains the fungal enzyme
phosphinothricin-N-acetyltransferase (PAT), which allows these
plants to survive the otherwise lethal application of glufosinate.
The pat gene inserted into A5547-127 was isolated from a common
soil fungus, Streptomyces viridochromogenes, and introduced into
the soybean genome by particle acceleration (biolistic)
The PAT enzyme in soybean line A5547-127 converts
L-phosphinothricin (PPT), the active ingredient in glufosinate
ammonium, to an inactive form thereby conferring resistance to the
herbicide. In the absence of PAT, application of glufosinate leads
to reduced production of the amino acid glutamine and increased
ammonia levels in the plant tissues, which are lethal to the plant.
The PAT enzyme is not known to have any toxic properties.