A Failed Antibiotic Could Be the New Herbicide of Tomorrow

In Australia, scientists at the Univ. of Adelaide’s Waite Research Institute have discovered a new technique for herbicide development by repurposing a molecule that failed as an antibiotic.

The breakthrough approach could provide a shortcut for faster development of new, more effective weed killers, according to Tatiana Soares da Costa, head of the university’s Herbicide and Antibiotic Innovation Lab.

Herbicide resistance, similar to antibiotic resistance, is a growing crisis. Over the past 40 years, few new herbicides with novel mechanisms of action have been developed, says Andrew Barrow, a chemist from the research team. Many weeds are now resistant to the existing products on the market, threatening the global food supply and costing farmers billions of dollars each year.

But studying the failed antibiotic led the study scientists to uncover a novel herbicide mechanism that had never been commercially explored. It works by blocking the production of the amino acid lysine, which both plants and bacteria need for growth. This is achieved using a molecule known as an enzyme inhibitor. The inhibitor binds to the enzymes responsible for lysine biosynthesis, disrupting their normal activity and stopping growth.

Over the past 30 years, numerous studies have explored the inhibition of lysine production as a potential pathway to antibiotic development — albeit unsuccessfully. Research has shown that in bacteria, the inhibitor exhibits activity against the...