Progress and perspectives in nitrogenase engineering in plants and yeast.

Recovery of nitrogenase core components with in vitro activity from mitochondria and chloroplasts, plus in vitro FeMo-co biosynthesis from yeast mitochondria proteins, advances eukaryotic nitrogenase engineering.

• Why it matters: Synthetic nitrogen fertilizers carry economic and environmental costs, and engineering crops to fix atmospheric nitrogen could enable sustainable agriculture despite oxygen sensitivity and high energy demands.
• What they did: The review summarizes a stepwise modular approach with a functional validation pipeline, including recovery of NifH from mitochondria/chloroplasts, active NifB after isolation or FeMo-co reconstitution, and in vitro FeMo-co biosynthesis using yeast mitochondrial proteins.
• The result: Complete nitrogenase activity in engineered yeast or plants has not yet been demonstrated, highlighting remaining obstacles like functional NifDK assembly in plants and coordinated integration with host metabolism and regulation.