CU-Boulder iGEM Project

Engineering Self Fertilizing Plants


All plants need nitrogen to survive, but cannot use nitrogen (N2) directly from the atmosphere. They must receive their nitrogen as ammonia (NH3) that has been fixated by other sources such as symbiotic bacteria, decomposing plants, or synthetic fertilizers. Today, the world population is only sustainable if ammonia-rich fertilizers are used to increase crop production. However, fertilizer is an environmental hazard due to the extensive release of carbon dioxide. Also, fertilizer runoff causes algae populations to grow faster than the ecosystem can handle, creating oxygen-depleted dead zones within the ocean. Due to growing environmental concerns, genetically engineering plants to contain the bacterial enzyme, nitrogenase, may allow plants to become self-fertilizing. Nitrogenase is extremely sensitive to radical oxygen and may not survive in plant cells. Our team has proposed a protein engineering solution by coupling an enzyme that scavenges radical oxygen (superoxide dismutase) directly to nitrogenase, thus allowing for self-fertilization.