Phytoremediation. Intimidating word, important biological process.
Put simply, phytoremediation is using plants to clean up contaminants in polluted soils and stagnant water. Historically regular plants like sunflowers and hemp have been used to decontaminate lead-laced and even radioactive soils, respectively, but a series of genetically modified plants are taking phytoremediation to new heights or, ahem, depths.
So, for your horticulture enlightenment, instead of selecting just one for our list, we’ve decided to lump together a few genetically modified phytoremediation plants that caught our eye.
TNT, one of the most frequently used explosives ever, is a toxic and mutagenic compound that has contaminated many of the world’s military test ranges and battlefields. Certain bacteria are able to eat TNT, but they are usually not plentiful enough in contaminated soils to make a substantial difference in its toxicity. However, by inserting the gene from these bacteria responsible for metabolizing TNT into tobacco plants, a group of British researchers have created not just a viable means of decontaminating TNT-laced soils but one that additionally seems to boost microbial function and diversity in the soils. (And TNT in a cigarette presents a potent reason to consider quitting.)
The Edenspace Systems Corporation has engineered a fern (which it now calls Edenfern) to extract arsenic from soil and drinking water, concentrating the toxic chemical in its leaves at levels 200 times that of other plants. A less expensive option than excavating contaminated soils for deposit in landfills, Edenfern’s fronds can be easily cut and safely disposed after as little as one year of growth.
Finally, while it’s not removing an actual toxin, the genetically engineered thale cress, developed by the Copenhagen-based company Aresa Biodetection, could be another weapon in the war against landmines. While it likely won’t fully replace other detection methods, this thale cress’ leaves turn from green to red when it is on or near a land mine. The color change occurs when nitrogen dioxide leaks from unexploded mines and is absorbed by the plant’s roots. In addition to helping detect mines, the plants can also serve as a relatively permanent cautionary warning to avoid particular areas until the mines can be removed.