Scientists at the University of Adelaide have achieved a significant breakthrough by repurposing a failed tuberculosis antibiotic into a potent herbicide capable of eradicating two invasive weed species prevalent in Australia. This groundbreaking approach involves modifying the molecule’s structure to hinder weed growth, potentially revolutionizing herbicide development. Moreover, this innovative solution promises faster and more cost-effective relief for farmers and homeowners grappling with weed infestations, without harming human or bacterial cells.
The Future of Weed Control: Failed Antibiotics as Herbicides
A molecule originally designed to combat tuberculosis, although unsuccessful as an antibiotic, now demonstrates remarkable potential as a formidable adversary against invasive weeds that wreak havoc in gardens and cause billions of dollars in annual losses for farmers.
While the initial antibiotic proved inadequate for its intended use, researchers at the University of Adelaide discovered that by making structural adjustments to the molecule, it became effective in eliminating two of Australia’s most problematic weeds—annual ryegrass and wild radish—without causing harm to bacterial or human cells.
“This discovery has the potential to revolutionize the agricultural industry. With many weeds becoming resistant to existing herbicides on the market, farmers incur billions of dollars in losses each year,” explained lead researcher Dr. Tatiana Soares da Costa from the University of Adelaide’s Waite Research Institute.
“Utilizing failed antibiotics as herbicides provides a shortcut for the accelerated development of new and more effective weed killers, specifically targeting damaging and invasive weeds that are challenging to control.”
Scientists at the University’s Herbicide and Antibiotic Innovation Lab identified molecular-level similarities between bacterial superbugs and weeds, which they exploited. By chemically modifying the structure of the failed antibiotic, they successfully impeded the production of the amino acid lysine, essential for weed growth.
“Currently, there are no commercially available herbicides that function in this manner. In fact, over the past four decades, there have been minimal additions to the market in terms of new herbicides with novel mechanisms of action,” stated Dr. Andrew Barrow, a postdoctoral researcher in Dr. Soares da Costa’s team at the University of Adelaide’s Waite Research Institute.
Weeds inflict an estimated cost of more than $5 billion annually on the Australian agriculture industry, with annual ryegrass being particularly detrimental and costly in southern regions.
“The expedited strategy saves valuable time and resources, potentially hastening the commercialization of much-needed new herbicides,” emphasized Dr. Soares da Costa.
She further clarified, “It’s crucial to note that the utilization of failed antibiotics will not contribute to antibiotic resistance because the herbicidal molecules we discovered do not harm bacteria. They exclusively target weeds, leaving no impact on human cells.”
This groundbreaking discovery extends beyond the benefits for farmers. Researchers anticipate that it could lead to the development of new weed killers tailored to combat troublesome weeds growing in residential gardens and driveways.
“Our repurposing approach holds the potential to unveil herbicides with broad applications, capable of eradicating a variety of weeds,” added Dr. Barrow.
Dr. Tatiana Soares da Costa and her team are now focused on exploring additional herbicidal molecules by repurposing other failed antibiotics. They are also seeking collaborations with the industry to introduce new and safe herbicides to the market.
Reference: “Repurposed inhibitor of bacterial dihydrodipicolinate reductase exhibits effective herbicidal activity” by Emily R. R. Mackie, Andrew S. Barrow, Marie-Claire Giel, Mark D. Hulett, Anthony R. Gendall, Santosh Panjikar, and Tatiana P. Soares da Costa, 22 May 2023, Communications Biology.
Funding for this research was provided by the Australian Research Council through a DECRA Fellowship and a Discovery Project awarded to Dr. Tatiana Soares da Costa.
Emily Mackie, a PhD student in Dr. Soares da Costa’s team, supported by scholarships from the Grains and Research Development Corporation and Research Training Program, served as the first author on the paper. Other co-authors include Dr. Andrew Barrow, Dr. Marie-Claire Giel, Dr. Anthony Gendall, and Dr. Santosh Panjikar.
The Waite Research Institute stimulates and supports research and innovation across the University of Adelaide and its partners to enhance Australia’s agriculture, food, and wine sectors.
Frequently Asked Questions (FAQs) about herbicide development
What is the research about?
The research focuses on repurposing a failed tuberculosis antibiotic as a potent herbicide to combat invasive weeds without harming human or bacterial cells.
How does the repurposed antibiotic work as a herbicide?
By making structural modifications to the molecule, researchers were able to block the production of the amino acid lysine, which is essential for weed growth. This inhibits the growth of invasive weeds while leaving human and bacterial cells unharmed.
What are the potential benefits of this discovery?
The discovery has the potential to revolutionize herbicide development, providing a faster and more cost-effective solution for farmers and homeowners dealing with weed infestations. It could lead to the development of new and effective weed killers that target problematic and resistant weeds.
What makes this approach different from existing herbicides?
Most herbicides currently on the market have similar mechanisms of action. This repurposed antibiotic, however, introduces a novel approach by targeting weed growth through blocking lysine production. It offers a unique alternative to existing herbicides that could help overcome weed resistance.
How does this research benefit the agricultural industry?
Weeds cause significant financial losses for the agricultural industry, with many weeds becoming resistant to existing herbicides. The repurposing of failed antibiotics as herbicides provides a shortcut for the development of new and more effective weed killers, addressing the challenges faced by farmers and reducing financial losses.
Does using failed antibiotics contribute to antibiotic resistance?
No, using failed antibiotics as herbicides does not contribute to antibiotic resistance. The herbicidal molecules specifically target weeds and do not affect bacterial cells, ensuring that the development and use of these herbicides will not drive antibiotic resistance.
Can this research benefit homeowners as well?
Yes, this discovery has the potential to lead to the development of new weed killers that can be used by homeowners to address weed problems in their gardens, backyards, and driveways. It offers a broader application beyond the agricultural industry.
What are the next steps for the researchers?
The researchers are now looking to discover more herbicidal molecules by repurposing other failed antibiotics. They also aim to collaborate with the industry to introduce new and safe herbicides to the market, further advancing the field of weed control and sustainable farming practices.
More about herbicide development
- University of Adelaide: Link
- Communications Biology: Link
- Australian Research Council: Link
- Waite Research Institute: Link
- Grains and Research Development Corporation: Link
- Research Training Program: Link
- DOI: 10.1038/s42003-023-04895-y