Multicoloured cotton fields could be on the horizon
Textile production is still grounded in practices established during the Industrial Revolution which are not suitable for a long-term, sustainable future. Dyeing and finishing are the steps that have the most environmental impact. Textiles contribute to 10 % of global greenhouse gas emissions annually, more than aviation and maritime shipping combined(opens in new window), and the dyeing and finishing process is the main culprit. It’s a process that is demanding of natural resources: over 1 billion metric tonnes of global carbon emissions stem from textile and garment manufacturing(opens in new window), while 17-20 % of global water pollution arises from the textile industry alone(opens in new window). Production and consumption of textiles also contribute to the climate crisis(opens in new window). According to a European Environment Agency(opens in new window) report, textile purchases in the EU in 2022 generated about 355 kg of CO2 emissions per person, the equivalent of 1 800 km of travel by a standard petrol car. “Not only is this hard on the environment, but it’s also a very inefficient process,” says Filipe Natalio(opens in new window), associate professor at the NOVA University of Lisbon(opens in new window). “Most of the water contains dyes that did not bind to the textiles.” So HYDROCOLTON, a pioneering textile sustainability initiative funded by the European Research Council(opens in new window), set out to make cotton plants produce coloured crops as they grow. By altering how cotton absorbs, or expresses, pigments internally, the project targets a complete phase-out of the heavy water and chemical processing required downstream. “Sounds a bit like science fiction, I know,” adds Natalio. “But we have shown the concept works.”
Glucose-derived molecules work their way through the cotton plant by capillarity
The traditional way of creating coloured cotton, in the growing plant, would be by using genetics. But the project chose a different approach, harnessing the plant’s own biochemistry. “We call this concept ‘material farming’. The idea is that, in the future, we could grow materials with built-in properties rather than manufacture and chemically process them afterwards,” Natalio explains. To achieve this, the team put specially designed, glucose-derived molecules into the water. These molecules were naturally transported through the plant and reached the developing cotton fibres, where they became incorporated during growth. “It’s as natural as it gets. The analogy is the classic school experiment, in which a white flower is placed in dyed water to demonstrate water transport – but perhaps a little more advanced!”
Exploring the reasons behind the uptake of dye within the growing cotton plant
One of the most exciting findings, feels Natalio, was that this approach worked in whole plants. “We do not yet fully understand the underlying biological mechanisms, and answering those fundamental questions is exactly why this type of early-stage, curiosity-driven research is so important,” he notes. Beyond the scientific discovery, this strategy could also avoid many of the regulatory barriers and hurdles surrounding public acceptance associated with genetically modified crops, while opening a new way to produce sustainable materials.
Hydroponics helping to reduce water consumption in cotton growing
The HYDROCOLTON project is exploring the technology in real agricultural settings using hydroponic cotton production, which provides a simplified and highly controlled system for testing. “We are teaming up with a women-led Portuguese start-up Agromethod Labs(opens in new window) which is pioneering hydroponic cotton cultivation in Portugal. They made Portugal the only European country, and one of the few in the world, to have the full cotton supply chain grown this way,” explains Natalio. By combining their production system with HYDROCOLTON’s technology, the project is creating innovative approaches to cotton cultivation in Europe, adding value and demonstrating how cotton can be grown more sustainably. “Our ambition is not simply to bring cotton production back to Europe, but to develop transformative practices here that can ultimately be adopted around the world,” he remarks. It’s early days, acknowledges Natalio. The team is working with collaborators to validate the technology and advance its market readiness. As he notes: “These collaborations are helping us assess the technical and commercial potential, while engaging with relevant stakeholders across the cotton value chain. Our next major step is to secure additional funding to scale up the technology and move it closer to market adoption. I am sincerely proud of my team and their resilience and motivation throughout this project.”
