On the Way to Nitrogen-Fixing Cereals

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Cereal crops that fix their own nitrogen? Achieving this dream could result in major benefits for agriculture and the environment.

Scientists around the world are pursuing this goal, including a group in Alberta. The Lethbridge-based researchers have already made impressive advances towards developing nitrogen-fixing triticale plants as a first step to creating other nitrogen-fixing cereals.

“The idea of nitrogen-fixing cereals is not new. The discovery in the late 1880s of symbiosis between nitrogen-fixing bacteria and legumes spurred the eventual question of whether it is possible in non-legume plants, including cereals. However, the path from the idea to its successful realization is in this case quite bumpy,” says Dr. Alicja Ziemienowicz, a research biologist with Agriculture and Agri-Food Canada (AAFC) and an adjunct professor at the University of Lethbridge. She is co-leading this nitrogen fixation research with her AAFC colleague Dr. François Eudes.

“There are three biotechnological approaches for biological nitrogen fixation in cereals, and all require genetic engineering of bacteria or plants or both,” she explains. “The first one is to create rhizobium-legume-like symbiosis in cereals; in other words, to convince rhizobia and cereals to form an interaction similar to the interaction of rhizobia with legumes. The second approach aims at improving bacteria that live inside cereal plants or in the soil right next to cereal roots so these bacteria can perform nitrogen fixation more efficiently.”

However, these two strategies would rely on the use of bio-fertilizer inoculants, which are not always as effective as crop growers would like and are not as convenient as having the trait in the seed.

“When I joined the team of Dr. François Eudes at AAFC’s Lethbridge Research and Development Centre about five years ago, we decided to take the third approach to the biotechnological solutions for the nitrogen fixation problem,” adds Ziemienowicz. “This approach is perhaps the most challenging one but also the most promising. It involves the direct transfer of bacterial nitrogen fixation (nif) genes into the plant.”

Ziemienowicz is an expert in this type of research and has been working on development of better technologies for plant improvement for over 20 years. She is excited to be applying her knowledge and skills to nitrogen fixation in cereals “to achieve practical and applicable outcomes in a research area that is so important for Canadian and global agriculture.”

“Many have labelled nitrogen-fixing cereal crops as the ‘holy grail,’” notes Lauren Comin, research manager with the Alberta Wheat Commission (AWC). “Nitrogen-fixing cereals could bring a lot of significant benefits. First of all is the benefit to the farmer’s profit. Obviously producers would save money by reducing input costs, and there could be time savings as well. Those benefits alone are enough for us to get excited.”

Ziemienowicz states, “Nitrogen fertilizers contribute about 20 per cent of cereal crop production costs, not including costs of fertilizer application: fuel, machinery, labour. Cereal crops capable of fixing nitrogen for their own needs will reduce crop dependence on nitrogen fertilizers, and will increase their performance and productivity in nitrogen-deficient soils.”

Both Comin and Ziemienowicz point out that nitrogen-fixing cereals would also contribute to sustainability. “There is an ever-growing interest in sustainability from those on the farm and off the farm. Plants that could fix all or some of their nitrogen would mean fewer synthetic applications, less nitrogen loss to the atmosphere and less leaching into the waterways,” says Comin.

Eudes and Ziemienowicz began this research in 2014 with a two-year proof-of-concept study, funded by AWC and Alberta Innovates. Last year’s research was funded by AWC and the Saskatchewan Wheat Development Commission. Recently, the research was approved for three-year co-funding by all three of these agencies. In this upcoming work, Ziemienowicz and Eudes will be collaborating with AAFC wheat breeders Drs. Robert Graf and Harpinder Randhawa.

Ziemienowicz and Eudes’ research so far has involved triticale. “Most procedures that we employ in this project work more efficiently in triticale than in wheat,” says Ziemienowicz. “Once we obtain nitrogen-fixing triticale, we will transfer this trait into wheat using interspecies breeding techniques. Moreover, lessons learned from development of this trait in triticale will help us to apply it to other crop species.”

If all goes as expected, they will produce triticale plants that have all the characteristics of the triticale parent plus the ability to fix nitrogen. Ziemienowicz thinks it will take at least 10 more years to develop nitrogen-fixing wheat. “We need about three years to produce and test the nitrogen-fixing triticale plants. Then, we need a few years to transfer the trait to wheat. Also, it takes years for commercialization of a plant with a novel trait.”

Even though it is many years away, the path to commercialization could be as challenging as the scientific path to develop nitrogen-fixing cereals.

“The Canadian ‘plants with novel traits’ approach is different from much of the rest of the world. [In Canada] it doesn’t really matter what process you used [to introduce a trait]; it’s whether it is a new trait that has never appeared before,” explains Cam Dahl, president of Cereals Canada Inc., a not-for-profit organization that brings together partners from all sectors of the cereals value chain.

“However, there would be some significant regulatory hurdles [for GE nitrogen-fixing wheat] in other markets like the EU or Japan because of the unfounded public perception around recombinant DNA technology.”

From Dahl’s point of view, recombinant DNA technology has provided great benefits, both economic and environmental, in crops like corn, soybeans and canola. But he is uncertain about what the cereals industry could do to change negative public perceptions of the technology. “That’s a question I have been asking for 20 years. I’m not quite sure of the answer, whether it’s an issue around technology in plant breeding or technology in pesticides, herbicides and fungicides. Very often public perception does not match up with the science and what science is telling us. The gap between scientific understanding and public perception sometimes can be very large, and that is difficult to cross.”

Dahl notes another consideration in commercialization. “We would have to ensure that, if a new product is commercialized, it would be done in a way that doesn’t jeopardize our current exports.” That would require such steps as obtaining regulatory approvals in importing countries and using identity-preserved systems to keep the GE grain separate from other grain. Another factor would be development of a policy on the low-level presence of GE crop material in grain shipments.

Despite the challenges, AWC hasn’t shied away from funding Eudes and Ziemienowicz’s work. “Investing in genetic engineering technology today does not mean that we’ll be harvesting a GE crop in August. Developing new varieties is really a long-term game. And depending on which novel traits we’re seeking, the benefits could far outweigh the perceived negatives,” says Comin.

Ed. Note: A longer in-depth story on this topic will appear in the Fall 2018 issue of Alberta Seed Guide.