Chemical biologists have collaborated with plant and structural biologists to design and develop herbicides to overcome the increasing problem of herbicide resistance.
Researchers from The University of Western Australia's School of Molecular Sciences, including Dr Karen Deane and Associate Professor Keith Stubbs, collaborated with Dr Joel Haywood and Professor Joshua Mylne, from Curtin University on the studies published in RSC Chemical Biology and Molecular Plant.
"Continued innovation in weed control is important for Australian agriculture and a necessity to meet the food needs of society," Dr Deane said.
The agricultural chemistry research built on previous studies by re-envisioning old herbicides, developing new herbicides and new modes of action to overcome herbicide resistance.
"In the past 30 years, no new herbicidal mode of action has entered the agrochemical market but over 500 new cases of herbicide resistance have emerged," Associate Professor Stubbs said.
"We need to develop methods to prolong the use of herbicides, which are integral for modern day agriculture but increasing costs to develop new herbicides has stymied progress."
Researchers targeted the plant enzyme dihydrofolate reductase, which is essential for seed development, with antifolates.
"Dihydrofolate reductase has been extensively studied and is a drug target for the treatment of tropical diseases, bacterial infections and cancer therapies but little is known about this enzyme in plants," Associate Professor Stubbs said.
"Our findings provide understanding of how plant-specific inhibitors that target this enzyme might be developed, which is currently not done by commercial herbicides."
In the second study, researchers focused on the synthetic herbicide dicamba – a potent and useful herbicide that has off-target drift (volatility) issues. The study found adding carbohydrates, environmentally benign molecules, reduced volatility.
"Dicamba has been used for over 50 years and is well known for its ability to control weed growth," Dr Deane said.
"The potential to change the molecular structure to reduce volatility will enable it to be used for future weed management practices."
Structural insights into a plant-conserved DHFR-TS reveal a selective herbicide target was supported by Australian Research Council grants and Sweet dicamba: a carbohydrate pro-herbicide strategy was supported by Demagtech.
