Sep 22, 2022 - Science

AI is digging up how plants tolerate drought and heat

Illustration of harvester cutting a Helix DNA shape into farm land

Illustration: Eniola Odetunde/Axios

Artificial intelligence is guiding plant breeding — and helping to speed up the development of crops that scientists hope can better cope with devastating drought and heat.

Why it matters: Droughts in China, Europe, East Africa and North America are damaging crops and contributing to food insecurity and hunger crises around the world.

  • Parts of the American corn belt are experiencing extreme or exceptional drought. In Nebraska, 35% of the corn crop is considered to be in poor or very poor condition.
  • Some of these prolonged dry periods are driven by human-caused climate change, others are worsened by it — but, all together, they are a window into the drier and hotter future predicted in some regions.
  • Those changes in climate and growing global food insecurity are putting pressure on breeders to develop more resilient plants faster.

What's happening: Machine learning algorithms and other AI tools have been used by some companies for about a decade, but they're becoming more widely available to breeders.

  • Breeders use them to analyze data that reflects what's known about plant biology — for example, how high or fast a plant grows, and whether it can withstand hot or dry conditions in a region.
  • That data can help AI predict the combination of genes — and the genes that regulate them — that can improve a plant's tolerance without reducing the yield.
  • Instead of crossing plants for generations to find the best-suited ones, breeders can use AI to more quickly predict which genetics will yield the desired traits.

There are some tradeoffs, though, between how much water a plant uses and how much grain, corn or other product a plant can yield — and debate about how far breeders can go with both.

  • AI can "help breeders walk through this complex labyrinth," says Charlie Messina, a professor of predictive breeding at the University of Florida.

Details: In a recent study, Messina and his colleagues assessed how hybrids of drought-tolerant maize bred with the help of AI grew under different water conditions.

  • In contrast to earlier research, they report the hybrids bred for better drought tolerance had better yields. (The hybrid is commercially available from Corteva, and scientists from the company participated in the study. Messina previously worked for the company.)
  • The scientists also found the hybrid plants had a smaller difference in their yields in normal and dry conditions, meaning they produced a more reliable amount of maize over a range of conditions. One of the challenges climate change presents is hydrological extremes, enhancing both droughts and heavy rains.

But, but, but... A study published earlier this year found gains in corn yields were largely due to climate and improved soil and crop management, not plant genetics.

  • "This is an important debate because it can influence investments — public and private — in technologies to deal with drought and climate change," Messina says.
  • "If we don't figure out the cause of the problem, as a society we may be investing in the wrong solutions," he says.

Potatoes are another staple around the world — and the plants are highly sensitive to heat.

  • AlphaFold, a deep learning system developed by DeepMind that can predict the structure of proteins, was used along with other tools to study the genes and proteins involved in the response of potatoes to elevated temperatures. (AlphaFold's founders won the Breakthrough Prize in Life Sciences today.)

The big picture: Genetics are just one factor in a crop's yield and resilience.

  • There's also a field's environment and how its soil and water are managed and potentially tailored to a crop plant.
  • Farmers are under their own pressures to produce a certain amount of a crop, and can be strained for resources.

Messina says his goal is to integrate information about a plant's genetics, a field's environment and a crop's management.

  • Ultimately, he wants to "move from thinking about drought tolerance in a crop to thinking about crops as systems to combat climate change and improve nutrition and food security."
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