Plants can grow their own glow-in-the-dark cotton, no genetic engineering required

You may have heard about smartphones and smart homes. But scientists are also designing smart clothes, textiles that can harvest energy, light up, detect pollution, and even communicate with the internet. The problem? Even when they work, these often chemically treated fabrics wear out rapidly over time. Now, researchers have figured out a way to “grow” some of these functions directly into cotton fibers. If the work holds, it could lead to stronger, lighter, and brighter textiles that don’t wear out.

Yet, as the new paper went to press today in Science, editors at the journal were made aware of mistakes in a figure in the supplemental material that prompted them to issue an Editorial Expression of Concern, at least until they receive clarification from the authors. Filipe Natalio, lead author and chemist at the Weizmann Institute of Science in Rehovot, Israel, says the mistakes were errors in the names of pigments used in control experiments, which he is working with the editors to fix.

That hasn’t dampened enthusiasm for the work. “I like this paper a lot,” says Michael Strano, a chemical engineer at the Massachusetts Institute of Technology in Cambridge. The study, he says, lays out a new way to add new functions into plants without changing their genes through genetic engineering. Those approaches face steep regulatory hurdles for widespread use. “Assuming the methods claimed are correct, that’s a big advantage,” Strano says.

The new approach to modifying cotton is straightforward. Natalio and his colleagues in Israel and Germany simply link molecules with desired functions, such as fluorescent or magnetic compounds, to sugar molecules that cotton plants absorb through their vasculature and use to build their cells.

The researchers started with hydroponically grown cotton plants that grow in a lab rather than a field. They harvested the plants’ ovules, the portion that, once fertilized, produces the fruit, in this case the cotton fibers. They cultured these ovules separately, allowing them to bypass the plant’s normal approach to using photosynthesis to make sugars that it needs to grow. Then they fed the plants water spiked with glucose molecules linked to other functional molecules, which were absorbed by the ovule’s nutrient-transporting vessels and passed to the fiber-forming cells where they were used to build the plant’s cotton fibers.

In one example, the researchers linked fluorescent molecules to the sugars. After 20 days of growth, about 5% of the fluorescent material made it into the fibers, which appear yellow under normal light but glow a brilliant green when exposed to ultraviolet light, the researchers report today in Science. There’s no indication how long those fluorescent fibers will last. But Natalio notes that because the fluorescent compounds are chemically tethered to the sugars in the fibers, they cannot wash away.

The researchers also linked magnetic compounds to sugars and showed that they, too, were incorporated in the cotton fibers. In the future, this could enable clothingmakers to build data storage capabilities right into our garments.

But Natalio cautions that for this and other future applications to succeed, researchers may need to find ways to increase the amount of functional molecules absorbed by the plants. He adds that because many plants and other organisms can be grown in culture, it may be possible to extend this approach to modifying everything from bacteria to bamboo. That could not just produce brighter attire, but also allow researchers to add new functions to a wide range of materials.