Promising sugar-based natural herbicide targets same pathway as glyphosate
A team of scientists from Germany's University of Tübingen has discovered a novel and unusual sugar molecule that is harmless to animals and humans but can effectively disrupt the growth of various plants and microorganisms. The researchers propose the new molecule as a possible natural herbicide with the same efficacy as the increasingly controversial glyphosate, commonly known as Roundup.
The impressive new research began with the identification of a new sugar molecule that was isolated from a freshwater cyanobacteria called Synechococcus elongatus. The researchers knew this particular organism could significantly inhibit the growth of other similar bacterial strains, however, exactly how it did this was unknown.
Eventually, the research team homed in on a previously undiscovered, and unusual, sugar molecule they referred to as an antimetabolite, due to the molecule's novel ability to disrupt metabolic processes. The molecule is called 7-deoxy-sedoheptulose (7dSh) and after developing a new process to synthesize the compound, its mechanism of action was extensively studied.
It was discovered that 7dSh exerts its inhibitory actions by blocking an enzyme that plays a role in the shikimate pathway. This pathway is a metabolic route fundamental to the growth of many plants, bacteria and fungi, but it is not found in humans or animals. This means a targeted disruption of the shikimate pathway is ideal for herbicides used to manage weeds in farming.
Glyphosate (aka Roundup), one of the world's most widely used commercial herbicides, exerts its renowned weed-killing actions by targeting this same shikimate pathway. In recent years, however, concerns have been growing surrounding the human safety of glyphosate, and many countries are beginning to regulate the infamous chemical's use.
"In contrast to glyphosate, the newly discovered deoxy sugar is an entirely natural product," says Klaus Brilisauer, one of the researchers on the project. "We believed it to have good degradability and low ecotoxicity. We see an excellent opportunity here to use it as a natural herbicide."
Needless to say, there is much more work yet to be done before 7dSh could be commercially deployed as a natural herbicide. While early indications suggest the compound is an effective herbicide, and also non-toxic to human cells, broader studies are needed for verification. The signs are promising though, with the compound offering not just potential as a natural herbicide but also demonstrating antibacterial and antifungal properties, suggesting human medical potential as well.
The research was published in the journal Nature Communications.
Source: University of Tübingen