Quinoa genome has been sequenced

The first high-quality sequence of the quinoa genome enables solutions for food security.

Quinoa is a nutritionally impressive food. It’s high in protein and, unlike most grains, has a good balance of amino acids. It’s also high in vitamins and minerals. Now, researchers have sequenced the genome of Chenopodium quinoa, producing the first high-quality quinoa reference genome. This resource paves the way for genetic improvements that could make the crop less costly to produce and accessible to a greater portion of the world’s population. It can also help explain how quinoa grows in harsh, salty environments, so researchers can help other plants do the same. Mark Tester, a desert agriculture specialist at King Abdullah University of Science and Technology (KAUST), tells us more.

ResearchGate: What motivated you to sequence the genome of quinoa?

Mark Tester: I am interested in quinoa because it is very salt tolerant, and understanding how it grows in high salinity—it can even produce a good crop in half sea water—will help us work out how to make other crops more salt tolerant. To do this work well, you need basic, high-quality information on the genome, and there is little out there. So, I thought, why not just sequence the genome? Luckily, one of my postdocs, David Jarvis, had done his Masters on quinoa. He contacted his former supervisors at Brigham Young University, who were fantastic and very generous. With five skilled and keen postdocs here at KAUST on board, it all took off very quickly.

I am also very interested in developing a new agricultural system based on seawater, or at least brackish water. For every drop of freshwater on land, there is a drop of brackish water that currently cannot be used. If only we could unlock this salty water, we could make a major contribution to future food security. Quinoa could be a major component of this new system, because it is already salt-tolerant. It just needs to be further domesticated, commodified, industrialized.

RG: What are some of the most significant things you learned?

Tester: We have seen some pretty amazing complex dynamics of the genome, how chunks of it seem to move around. This is exciting—genomes are highly dynamic things. Although this has been known in general terms for quite a while, it is still great to see it in your own data. Such observations highlight the nonsense of the anti-genetic modification argument that randomly inserting DNA into a genome can have harmful effects. The fact is, there are large numbers of insertions into genomes naturally occurring all the time.

At a more immediately utilitarian level, a major issue for quinoa is that the grain needs to be washed and dried after harvest to remove toxic and bitter chemicals called saponins. Having the genome enabled us to find the mutation that likely causes low saponin accumulation in seeds incredibly quickly. Knowing the precise gene that controls saponin levels means that breeders can more easily reduce seed saponin levels. Whether they decide to will depend on the respective savings made, versus potential costs—for example, there may be more fungal infections or more bird predation with low saponin seeds.

RG:  How might genome data be used to improve quinoa as a crop?

Tester: Well, reducing saponins may make the crop more difficult to manage, as it may increase its susceptibility to fungal infections or bird predation. The significance of this will depend on the location, the climate, the size of the fields, and other factors. But, more generally, having the genome will greatly facilitate the alteration by breeders of many other processes in quinoa, such as plant height, branching, the size and compactness of the seed head, and so on. Reduced processing costs will lower the cost of the grain, and increase the use of quinoa by a wider market.

RG: What effect might that have on the quinoa industry?

Tester: If more quinoa can be grown more widely, it will reduce the cost of quinoa. This is good and bad. The price of quinoa has spiked only in the past decade or so, due to it becoming a fashionable food in the West. A drop will undoubtedly make things more difficult in the short-term for some current producers, as they will need to adjust to a reduction in price. However, the wider benefits will be far greater. The ability to grow nutritious crops in marginal lands globally will benefit large numbers of poor people in many countries across all inhabited continents.

RG:  What will you be working on next?

Tester: Where do I start! The first thing to do is develop a core collection of about 400 lines of quinoa that will be thoroughly genotyped and encompass as much of the genetic diversity of quinoa as possible. Then we will use this collection to undertake a series of genetic studies to identify the basis for naturally occurring variation in a range of traits, such as height, branching, grain size, early vigor, pest and disease resistance, day length insensitivity, heat tolerance, and so on.

RG: Do you personally eat much quinoa? 

Tester: Yes, I think quinoa is delicious. Inspired by a Yotam Ottolenghi recipe, I like to cook it 50/50 with rice—which, incidentally, I think will be a great way to deliver this grain more widely. I then make a salad by mixing it with pistachios, dried apricots, orange juice, rocket, and whatever else takes my fancy and is in my kitchen at the time.

Featured image courtesy of Linda Polik, KAUST.