How far are we from N-Fixing Wheat, Corn & Canola?


Dry atmospheric air contains about 20% oxygen and over 78% nitrogen. Nitrogen, in its molecular, gaseous form (N2(g)) is very stable, and does not react easily with other compounds (HEY! Wake up, it gets better). In order to be used, then, the coupled nitrogen atoms must first be split. Consider it similar to asking a new couple for help with harvest. If you leave the couple to their own devices, you will likely grow frustrated with their lack of efficiency. They are good at staying together, not so good at anything else. Once you split them up, however, they are more obedient, reactive and less…nauseating.
The process of splitting up coupled nitrogen atoms is called nitrogen-fixation, and essentially converts atmospheric nitrogen to ammonia. It occurs industrially (through the Haber Process, for example) and naturally (through lightning and in certain species of bacteria). Leguminous crops have long been known for their symbiotic relationship with Rhizobia, a nitrogen-fixing genus of bacteria, making them an important addition to crop rotations. But, imagine if all major cropshad the same potential!
Well, according to the University of Nottingham, the ability for non-leguminous plants to work symbiotically with nitrogen-fixing bacteria is not just possible, it’s been studied for over ten years!
Edward Cocking, professor and director of The University of Nottingham’s Centre for Crop Nitrogen Fixation, has studied a bacteria identified in sugar-cane, and found it is entirely capable of colonizing the cells of all major crop plants. His hopes now are to see it to use in cropland worldwide, increasing food security and sustainability.
“If fully successful, it would make the crops self-fertilizing for nitrogen and this is a key requirement for sustainable agriculture now and in the years ahead,” said Cocking, in a recent media release from the University of Nottingham.
The bacteria, labeled “N-Fix” invades young root cells of sugarcane, colonizing the cytoplasm (the jelly-like substance that fills the cell) and using sucrose derived from the plant’s photosynthesis as energy for nitrogen-fixation. What’s unique about this particular bacterium? Well, in the right conditions, N-Fix bacteria does not discriminate in host or cell selection! Where Rhizobium are known to only colonize root nodules of legumes, N-Fix moves up from roots to invade other cells as well.
But, applying the technology wasn’t an easy endeavour. Right off the bat, Cocking and his team encountered trouble, as the bacterium would not enter the roots of crops besides sugarcane. They found, however, that they could stimulate the bacterium by simply giving it sucrose. And, once inside, the bacterium no longer needed additional sucrose, finding all it needs within the cells of the plant.
“We’re coating the seeds with this N-fixing bacteria,” explains Cocking. “You use the equivalent of a hairspray-sticker to get the bacteria to attach to the seed…and as the seeds germinate, the bacterium will be waiting…to interact with the emerging root of the seed.”