Characterization and in planta tolerance of a phosphinothricin acetyltransferase enzyme from Streptomyces coelicolor A3 (2)
Year: 2026
Type: article
Abstract: BACKGROUND Phosphinothricin N ‐acetyltransferase enzymes have been utilized extensively in genetically modified crops to confer herbicide resistance. These include the phosphinothricin N ‐acetyltransferase ( PAT ) and bialaphos resistance ( Bar ) proteins identified in Streptomyces viridochromogenes and Streptomyces hygroscopicus , respectively. The proteins have been shown to confer high levels of in planta tolerance to glufosinate‐containing herbicide formulations in a variety of commercial applications. RESULTS A new enzyme from Streptomyces coelicolor A3(2) was identified with low levels of homology (30% and 28%, respectively) to the previously characterized PAT and Bar enzymes. The gene coding for this protein was initially identified from the National Center for Biotechnology Information database (accession AAA26705), conferring bialaphos resistance. This trait now designated Dow Selectable Marker ( DSM‐2 ) had not been previously characterized with respect to providing commercially relevant levels of herbicide resistance. In vitro enzyme kinetic data shows that DSM‐2 has lower catalytic efficiency (catalytic constant/Michaelis constant or k cat / K m ) for acetylating phosphinothricin than PAT. CONCLUSION Here we show for the first time that when the DSM‐2 trait is transgenically overexpressed in soybean and corn plants, it provides a similar level of herbicide tolerance as other previously characterized PAT or Bar enzymes. Protein structure modeling also supports the conclusion that DSM‐2 is in the same protein family as PAT and Bar. As such, although DSM‐2 shares little homology from a primary protein sequence standpoint, the trait is still a viable alternative for use in commercial herbicide tolerance programs. © 2026 Society of Chemical Industry.
Source: Pest Management Science
DOI: 10.1002/ps.70572
Authors: Justin M Lira, Samantha L Griffin, Jonathan P DiNitto, Kiheon Baek, Kevin McGregor
Institution: Corteva (United States)
Language: English
Subfield: Plant Science
Domain: Life Sciences
SDG: Zero hunger
Open Access status: bronze
OpenAlex ID: W7124732957