Climate-Ready Crop

Dec 06, 2024

By Carl R. Woese

A team from the University of Illinois has engineered potato to be more resilient to global warming showing 30% increases in tuber mass under heatwave conditions. This adaptation may provide greater food security for families dependent on potatoes, as these are often the same areas where the changing climate has already affected multiple crop seasons.

“We need to produce crops that can withstand more frequent and intense heatwave events if we are going to meet the population’s need for food in regions most at risk from reduced yields due to global warming,” said Katherine Meacham-Hensold, scientific project manager for the Realizing Increased Photosynthetic Efficiency (RIPE) at Illinois. "The 30% increase in tuber mass observed in our field trials shows the promise of improving photosynthesis to enable climate-ready crops."

Meacham-Hensold led this work for RIPE, an international research project that aims to increase global food access to food by developing food crops that turn the sun’s energy into food more efficiently. RIPE was supported from 2017-2023 by the Bill & Melinda Gates Foundation, Foundation for Food & Agriculture Research, and U.K. Foreign, Commonwealth & Development Office and is currently supported by Bill & Melinda Gates Agricultural Innovations (Gates Ag One).

The Challenge
Photorespiration is a photosynthetic process that has been shown to reduce the yield of soybean, rice, and vegetable crops by up to 40%. Photorespiration occurs when Rubisco reacts with an oxygen molecule rather than CO₂, which occurs around 25% of the time under ideal conditions but more frequently in high temperatures. Plants then have to use a large amount of energy to metabolize the toxic byproduct caused by photorespiration (glycolate). Energy that could have been used for greater growth.

“Photorespiration is a large energy cost for the plant,” said Meacham-Hensold. “It takes away from food production as energy is diverted to metabolizing the toxin. Our goal was to reduce the amount of wasted energy by bypassing the plant’s original photorespiratory pathway.”

Previous RIPE team members had shown that by adding two new genes, glycolate dehydrogenase and malate synthase, to model plants’ pathways, they could improve photosynthetic efficiency. The new genetics would metabolize the toxin (glycolate) in the chloroplast, the leaf compartment responsible for photosynthesis, rather than needing to move it through other regions of the cell.

The solution
These energy savings drove growth gains in the model crop, which the current team hoped would translate to increased mass in their food crop. Not only did they see a difference, the benefits, recently published in Global Change Biology, were tripled under heatwave conditions, which are becoming more frequent and more intense as global warming progresses.

Three weeks into the 2022 field season, while the potatoes were still in their early vegetative growth phase, a heatwave kept temperatures above 95°F (35°C) for four straight days, breaking 100°F (38°C) twice. After a couple of days of reprieve the temperatures shot up near 100° again.

Rather than withering in the heat, the modified potatoes grew 30% more tubers than the control group potatoes, taking full advantage of their increased thermotolerance of photosynthetic efficiency.

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Video: Can Gene Editing Give Seeds a Stronger Start?

Reagan Reed has a way of describing his research that might make a plant breeder pause.

“I’m the sort of person who likes to break things to understand them,” he says.

What he breaks are genes involved in seed germination. Reed, a Ph.D. candidate at the University of California, Davis, is investigating whether changing those genes can help seeds establish healthy plants under a wider range of conditions.

Reed recently attended the National Association for Plant Breeding meeting in College Station, Texas, as an NAPB Borlaug Scholar. His work speaks to a question that matters well beyond a research lab: what does it take for a seed to get a crop off to a strong start?

A seed that germinates quickly, alongside the others planted with it, spends less time vulnerable to stresses before seedlings become established.

“If you’re able to bridge that gap between germination to stand establishment, then that’s going to give you the highest probability of having a solid yield that year,” Reed says. “There’s a bunch that can go wrong after that, but it maximises your yield from the start, at least.”

Reed works in Dr. Imtiyaz Khanday’s lab at UC Davis, where his research focuses on seed quality in tomatoes and potatoes. He brings an unusual academic background to the work: at Skidmore College, he studied both biology and Latin.

Reed believes that combination prepared him for research. Translating an ancient text means studying each word, weighing its possible meanings and using context to reach the best interpretation. There is rarely a way to know with complete certainty what an author intended. Science, he says, requires a similar willingness to work through uncertainty.

“Attention to detail and comfortability working with uncertainty,” is how he sums up what Latin taught him.

In the lab, uncertainty can produce a surprise. Reed describes changing one gene and seeing little effect. Changing a second gene also appears to do little. Put both changes in the same genetic background, though, and the result can be substantial.

“I break this gene, nothing really happens. I break this other gene, nothing really happens. I combine them into the same genetic background, and now there’s a massive effect,” he says.

Those interactions matter as researchers gain the ability to edit multiple genes at once. They also complicate any simple account of how a trait works: improving a seed may depend on understanding what several genes do together.

For Reed, the question is whether that knowledge could help seeds germinate reliably when conditions are difficult. Some of the genes he studies prevent germination under certain conditions. That response may serve a plant well in one setting while limiting its usefulness in agriculture. He wants to learn what happens when those genes are changed, and whether the result improves establishment.

Yet a discovery that works in a lab still has a long way to travel before it reaches a field. Reed argues that agricultural biotechnology faces an economic challenge as well as a scientific one. New tools can create value for farmers, he says, but developing them requires a way to support the work in an industry where margins can be thin.

His fellowship with Flagship Pioneering gave him a view across AI, agriculture-related work and human health research. It also reinforced the importance of bringing people with different expertise into the same conversation—a benefit of gatherings such as the NAPB meeting.

“You need to have a team of people with different backgrounds who are willing to work together and approach the same problem in different perspectives and different ways,” he says.

That thinking connects the different parts of Reed’s path. Latin taught him to examine details without expecting a perfect answer. Gene editing lets him test what individual genes do—and what happens when their effects combine. Working with people beyond his own field helps him ask what those findings could become.

He came to agriculture because of its reach: the possibility that work by a small group of researchers could eventually make a difference on a much larger scale. His immediate focus is smaller and more precise. He wants to understand what helps a seed get through its first days and become a healthy plant.