Time running out to discover new climate resistant crops

Time is running out for scientists to expand the range of climate-resistant food crops that humans can use to adapt to the temperature extremes posed by climate change, according to a recent study.

The world holds a broad array of “underutilized crops” — traditional, locally-grown and wild plants that are little consumed outside their region — whose genomes contain powerful tools for adapting to harsh conditions like drought and climate stress, and whose wider cultivation could help alleviate global hunger, according to a study published Wednesday in botany journal New Phytologist.

The looming wheat shortages following Russia’s invasion of Ukraine highlight the world’s critical, potentially crippling dependence on just a few cereal crops — wheat, rice, soybeans, maize — all of which face significant reductions in yield and range because of climate change, according to NASA.  

But these crops are just a tiny sliver of the wealth of species that humans have domesticated, but that haven’t reached global markets — and which represent both exciting possibilities for food security and storehouses of resilience-enhancing genetic traits. 

For a clear example, just think of quinoa and chickpeas — once fringe crops that, over the past 20 years, have achieved mainstream acceptance far beyond their home regions.  

That commercial popularity has built on itself, as it has sped the availability of scientific funding — leading to a “significant boost in research and recognition,” the scientists note. 

There are plenty of other crops that could receive similar treatment: widely cultivated in specific regions, but almost unknown outside them. Some of the better-known ones include foxtail millet, a grain variety grown across dry regions of Asia; teff, an ancient grain native to the Horn of Africa; and amaranth, a heat-tolerant, protein-rich “pseudocereal” native to central America. 

And even these are the tip of the iceberg. Earth has an estimated 50,000 edible plant species — but the world’s population gets 60 percent of its calories from wheat, rice and maize,   

Part of what has held many such crops back is the same relationship between limited market demand and the limited availability of research dollars for genetic research and modification.   

Many have strange or strong tastes; difficulties with cultivation; the presence of “anti-nutrients” that have to be washed out, like the soap-like saponin chemicals in quinoa or the cyanide compounds in cassava — all qualities which could potentially be changed with sufficient research and funding.  

But an equally important reason is often neglect: few local varietals can compete in a market dominated by the three main cereals poured out from major breadbaskets like the U.S. Great Plains — crops which have also benefited from decades of intense genetic study and modification aimed at increasing their yields.  

A classic example — which helps show what researchers imagine for crops like amaranth or foxtail millet — is the ongoing attempt to transform current staples wheat and rice from what’s known as C3 photosynthesis to C4 photosynthesis. 

That distinction describes the number of atoms of carbon — three or four — that are produced when the plant binds sunlight into sugars. 

Because they bind carbon at higher rates, C4 plants — which genetic research suggests wheat and rice once were, and perhaps could be changed back into — produce higher yields with better root growth and less need for nitrogen, according to Carleton University. 

Then there are apples. A study out on Wednesday from the Public Library of Science found that modern apples are bigger, less acidic, and store and ship better than their wild ancestors — which likely contributes to why they, and not a different fruit crop, has pride of place in supermarket produce aisles.  

That’s the attention the scientists want to see given to underutilized crops. Genetic scientists attempting to adapt these species to wider use are hobbled by the lack of broad genetic surveys which would allow them to reliably connect valuable traits — like drought or heat tolerance — to specific genes. 

For most such species, scientists have, at best, a single “reference genome” from a single sample, the study found.  

While a valuable start, this is akin to trying to tackle genetic diseases in humans — everything from cystic fibrosis to sickle cell anemia — based on a single person’s 23andMe results.  

“It is becoming clear that significant advances in breeding improved varieties are only possible when the genomic variants are identified,” which requires a far wider array of testing across species.  

But researchers say time is of the essence to begin this work. The human ability to use many of these species — and to even identify them for further testing — is under significant risk, both from climate change itself and from the more insidious risk of the loss of indigenous and local knowledge on how to find, care for, cook and cultivate them — particular as globalization accelerates the move of rural populations to cities.  

Across the broad array of underutilized species, researchers propose that “efforts should be made not only to generate a reference genome but also to carry out population-level sequencing.”  

In doing so, they write, researchers should make their data “free to use” and focus on “collaborations between institutes worldwide” to avoid duplicating work and to produce results quickly.