Bialaphos is a natural herbicide produced by the bacteria Streptomyces hygroscopicus[1] and Streptomyces viridochromogenes. It is also known by the ISO common name bilanafos.[2] Bialaphos is a protoxin and nontoxic as is. When it is metabolized by a plant, the glutamic acid analog glufosinate is released which inhibits glutamine synthetase. This results in the accumulation of ammonium and disruption of primary metabolism.[3]
Bialaphos is made up of two alanine residues and glufosinate, and is commonly used as a selection marker in plants. Resistance plasmids include pGreenII 0229 and pGreenII 0229 62-SK. pGreenII 0229 is derived from pGreenII 0000, a nos- cassette has been inserted into the HpaI site of the left border, providing resistance to bialaphos or phosphinothricin during plant transformation selection. pGreenII 0229 62-SK is derived from pGreenII 0229, the LacZ blue/white cloning selection has been replaced with a 35S-MCS-CaMV cassette that allows the insertion of a gene of interest into a 35S overexpression cassette.[4]