Wily weeds can develop resistance to herbicides, allowing them to compete with genetically modified crops designed to tolerate weed-killing chemicals. Now, a team is proposing another approach to genetically engineering crops to outwit weeds: cotton that feeds on an alternative fertilizer, one that weeds can’t use (read study here). The scientists haven’t yet tested the crops in actual fields, but they say if proven effective, their tactic may suppress weeds and prevent environmental pollution caused by overuse of the traditional fertilizer phosphate.
“This work is exactly the sort of genetic engineering that I would like to see more of, traits that expand the realm of what farmers can do while protecting the environment,” says Anastasia Bodnar, a plant geneticist who was not involved with the work and is the policy director for Biology Fortified, a nonprofit organization that fosters discussion around biotechnology and agriculture.
Regular plants need phosphate to grow, but the new cotton can survive on phosphite instead, because the crop is engineered to contain a bacterial gene that confers the ability to convert phosphite to phosphate, explains Luis Herrera-Estrella, who co-led the work.