Ancient grain has huge climate potential and could play a key role in Europe’s future

It is rich in plant proteins, fiber and minerals – and naturally gluten-free. Sorghum is also more efficient in its use of soil nitrogen, reducing the need for fertilizers – which benefits both climate and biodiversity. Moreover, it can withstand both drought and floods. The sorghum plant, also known as durra, boasts a long list of qualities.

Indeed, there are many reasons why sorghum has been attracting more and more attention from researchers and industry alike, who see great potential for sorghum in a future of increased climate change, drought frequency and flooding.

There’s just one problem: how it manages to do all this remains a mystery.

Now, a new technique called ‘FIND-IT’ can efficiently identify new mutations in specific genes within large seed collections, offering hope for the plant’s potential to be unlocked. Along with a newly established large seed collection, the researchers behind the project expect that crop variants capable of being cultivated effectively in both northern and southern latitudes can be developed in record time.

A scientific article published in a special edition of the plant journal Physiologia Plantarum focuses on new breeding techniques. In it, the researchers present each of these two new research resources developed through close collaboration between the University of Copenhagen, the Carlsberg Laboratory and the University of Queensland in Australia.

Sorghum is naturally resistant to genetic transformation. Even modern genetic tools like CRISPR and GMO, which typically allow for more precise and rapid genetic modifications than traditional breeding, have limited effectiveness in sorghum.

This poses a challenge for developing agricultural traits in the plant since traditional breeding takes a long time. However, these new research resources create a completely new opportunity.

"The project has provided us with a larger haystack – almost literally – in the form of a comprehensive collection of sorghum plants and their seeds, one that represents nearly the entire genetic variation of sorghum. At the same time, with 'FIND-IT,' we’ve acquired a technique that makes it possible to quickly and efficiently find the needle in the haystack – in the form of the variants in specific genes that we suspect to be crucial for the plant's traits," says Associate Professor Nanna Bjarnholt from the University of Copenhagen Department of Plant and Environmental Sciences.

Great potential in both Europe and the Global South

Sorghum is already one of the most important crops in the Global South – particularly in Central and Southern Africa. At the same time, there is significant potential for the cultivation of sorghum at European latitudes.

"In Europe, we can greatly benefit from sorghum’s high nutritional content and resilience to challenges such as drought. With these new resources, we now have the opportunity to develop an efficient sorghum crop that is both optimised for European growing conditions and capable of producing seeds with a favourable nutritional composition and desirable properties for the production of new plant-based foods. At the same time, this provides a strong foundation for developing improved varieties that can be cultivated more efficiently further south, for example in sub-Saharan Africa, where the need for drought resistance and optimal utilisation of soil nutrients may become even more critical," says Professor Birger Lindberg Møller, also from the Department of Plant and Environmental Sciences at the University of Copenhagen.

The researchers already have several leads that they are eager to pursue for unlocking the plant’s potential.

"Specifically, we have identified a number of candidate genes in the plant that we believe may be linked to drought resistance, as well as other important qualities in sorghum. We can now put these ideas to the test. Likewise, other researchers can build on this work for their own studies of the plant. There are good grounds for optimism, as we know that sorghum has enormous potential," says Nanna Bjarnholt.

The right soil, the right technique – and the right connection

Researchers at the University of Copenhagen and the Carlsberg Laboratory have provided expertise on the sorghum plant and the selection of the right gene variants from a vast collection of 150,000 seed variants. They have also served as a link to the practical know-how of researchers in the hot and dry state of Queensland, Australia, who are experts in cultivating plants under stressed soil conditions.

Both the new seed collection and the technique have been made available to other researchers, opening the door to sorghum research at a new scale.

Together, they represent a major research resource, as the vast collection of variants can now be rapidly screened for specific genes. This is achieved by dividing the collection into smaller groups and narrowing down the search using PCR tests –  as we know from COVID-19 testing – on each group to identify the correct DNA sequences. The method has dramatically increased the number of variants that can be effectively studied durinhg research.

"We are already witnessing great interest from research communities around the world. Though we have studied the plant for many years, it remains mysterious. There is still so much that we don’t know about it and why it carries the traits it does. Nevertheless, there is a growing awareness in many places that this plant has tremendous potential," says Nanna Bjarnholt.