Minor mutations in an enzyme have turned wild ginger’s scent into a powerful tool for survival. Researchers in Japan have found the exact gene responsible for the flower’s foul smell—similar to that of rotting flesh. The surprising discovery shows how a gene mutation affecting an everyday enzyme can turn a plant into a specialist in attracting insects.
The team, led by Dr. Yudai Okuyama from Japan’s National Museum of Nature and Science, studied several wild ginger species in the Asarum genus. Their work identified a small change in a gene coding for a selenium-binding protein. This protein, normally used to detoxify sulfur compounds, had evolved to produce dimethyl disulfide (DMDS)—a chemical responsible for the flower’s bad odor.
How Wild Ginger Produces a Rotten Scent
Wild ginger doesn’t smell sweet. Instead, it gives off a strong, sulfur-like odor. This rotten scent comes from DMDS, a compound that also appears in decomposing organic matter. It attracts carrion-loving flies that help the plant with pollination.
In animals and many plants, methanethiol—a sulfur-rich gas linked to bad breath—is broken down by selenium-binding proteins into less harmful substances. But in Asarum fudsinoi, one wild ginger species, that process takes a different turn.
To trace how this happened, the researchers fed the plants carbon-13-labeled methionine, an amino acid, and later found the same carbon marker inside the DMDS. This proved that the plant was making DMDS from methionine using a two-step process: first converting it to methanethiol, then turning that into the foul-smelling DMDS.
Gene Mutation Turns Detox Protein into Odor Creator
The key to this transformation lies in the gene encoding selenium-binding proteins. In Asarum, this gene has mutated in a way that changes just two or three amino acids in the protein it produces. These small tweaks gave the protein a new function—producing DMDS instead of detoxifying sulfur.
That small change had a big effect. The smell helps the plant mimic the scent of decaying meat, tricking flies into visiting and pollinating its flowers. This is a classic example of how evolution can act quickly, using simple genetic changes to create new traits that boost survival and reproduction.
Not Just Ginger: Other Plants Took the Same Route
The scientists also studied other smelly plants such as Eurya and Symplocarpus. Surprisingly, these unrelated species had developed similar mutations in the same family of proteins, resulting in the same type of smell. This kind of phenomenon, where different species evolve the same solution independently, is known as convergent evolution.
However, not all foul-smelling flowers use this approach. The famous “corpse flower” (Amorphophallus titanum), for instance, produces a similar scent but does not rely on selenium-binding proteins. Researchers believe that in such cases, a completely different group of enzymes may be at work.
Small Genetic Changes, Big Evolutionary Impact
Dr. Okuyama, the lead researcher, said the results show how nature often works in simple ways. “Some organisms have an extraordinary trait which is seemingly difficult to evolve, but such characteristics can evolve in a simpler manner than one would imagine,” he explained.
The findings suggest that just a few mutations can lead to major changes in behavior, ecology, and even the shape of evolution itself. In this case, a slight shift in one gene allowed wild ginger to develop a novel survival tool—using scent to attract the right kind of pollinators.
What This Means for Science and Industry
Beyond its evolutionary insights, the study could also impact fields like biotechnology and agriculture. Understanding how plants make DMDS and other sulfur compounds could help scientists design natural pest control methods or even new types of plant-based scents for use in industry.
This research also raises questions about how biochemical diversity develops in plants and how enzymes can be engineered to perform new tasks. As scientists continue to explore the connections between genes and traits, this study adds a powerful example of how small mutations can have wide-reaching effects.