Japanese scientists have found that a small change in plant proteins explains why pumpkins and zucchini absorb more pollution than other crops.
The proteins help transport toxins through the plant’s sap. By modifying this process, researchers hope to grow vegetables that resist contamination—or use plants to cleanse toxic soils. The finding could make future harvests both safer and more sustainable.
Plants in the gourd family, which includes pumpkins, zucchini, cucumbers, and melons, have an unusual tendency to take up pollutants from the soil and store them in their edible parts.
Kobe University agricultural scientist Hideyuki Inui explains, “The pollutants don’t easily break down and thus pose a health risk to people who eat the fruit. Interestingly, other plants don’t do this, and so I became interested in why this happens in this group specifically.”
In earlier studies, Inui and his team identified a group of proteins found in gourds that bind to pollutants, allowing them to move through the plant.
Earlier this year, they reported that both the shape of these proteins and how tightly they attach to pollutants determine how much contamination reaches the aboveground portions of the plant.
“However, these proteins exist in many other plants, and even among the gourds, there are varieties that are more prone to accumulating pollutants than others. We then noticed that in the highly accumulating varieties, there are higher concentrations of the protein in the sap,” says Inui. This observation led the researchers to focus on how the pollutant-binding proteins are secreted into the plant sap.
