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) transformation.

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.