Some of the fruits, vegetables and grains of the future will be designed with challenges like a changing climate, growing population and fragile ecology in mind. 

Southern California researchers are part of the effort to craft food crops that are more productive, easier to grow and less affected by reduced amounts of water and fertilizer – and they’re achieving these goals through a mixture of breeding, gene editing and everyday experimentation.

From finding ways to make rice that can withstand both wet and dry conditions to making lettuce that requires less water to grow, researchers in the region gave us some insight into what they are exploring. 

Gene editing and selective breeding are among the methods used to deal with a changing climate and growing population. (Getty Images)

Resilient rice

When you think of plant breeding at UC Riverside, the university’s work with citrus to combat Huanglongbing, or citrus green disease, might be what comes to mind, but researchers there are also working to advance the way rice and even tomatoes are grown. 

The Center for Plant Cell Biology is leading research into such topics as how to increase crop yield and resistance to pests, as well as creating sustainable biofuels. The center utilizes the skills of UCR’s graduate students through a graduate training program called Plants3D (the 3D stands for discover, design and deploy). 

Professor Julia Bailey-Serres, director of the Center for Plant Cell Biology, and her group of researchers are examining ways to make rice that can better withstand a wide variety of conditions. She said rice does well in the wet conditions of paddies, but it’s possible that the paddies can dry in drought. 

“What we’re working on is trying to figure out what we can do with rice that will allow it to do well, whether it’s in a paddy or it’s in dry soil,” Bailey-Serres said.

Earlier research led by Bailey-Serres looked into the stress responses of rice and how these responses could be modified to potentially make the rice more resilient. 

One possibility Bailey-Serre’s lab is looking into now is how to attract beneficial fungi and whether those fungi could help in drought conditions. 

She said that might be possible due to the fungi’s hyphae, which are straw-like, stringy structures that could pull up water from the ground and get it closer to the rice’s root system. 

Tomorrow’s tomatoes 

Claire Mauss, a third-year Ph.D. candidate and a member of Plants3D, is trying to genetically optimize tomatoes for controlled environment agriculture using CRISPR/Cas9 technology. 

Mauss said that as climate change continues, there will be less arable land, reduced access to reliable water sources and greater soil salinity, making the ability to grow things indoors under controlled conditions more important.

“You can have much more precise control of the nutrients that you’re feeding the plants – the light, the water,” Mauss said. “And so you can be very resource efficient. And because of all of this, you can fine-tune the growth conditions to be exactly what the crop you’re interested in growing needs.”

The challenge though is that while leafy greens and herbs can be grown in those settings easily and quickly enough to support the overhead of growing them, tomatoes take much longer and can be much larger. 

Mauss’s gene editing research is focused on tomato hormones and “tomato architecture.” She has been editing the plants to produce more fruit but less vegetative material. 

For her research, Mauss has been using the variety Micro-Tom, although its fruit might not be the tastiest.

Mauss said she plans to do the same gene editing in a more flavorful tomato line, “so that we can just, from the get-go, have this tasty, more compact tomato.”

Lettuce that takes less 

David Still, executive director of the California State University Agricultural Research Institute and a Cal Poly Pomona professor, has been researching how to make lettuce use less water and less nitrogen. 

Still said that producing lettuces that use less water is important given climate models that showed that California would face drought years followed by extremely wet years, meaning people in agriculture would have less water for crops. 

Limiting the number of nitrogen fertilizers the plants used was also important because of the role nitrogen has in the surrounding ecology. 

“All of these nitrogen fertilizers and phosphorus, too, but mostly nitrogen fertilizers here in California, produce greenhouse gasses, and then they also produce nitrates that go into the groundwater, which are, of course, a hazard to human health,” Still said. He added that the nitrous oxides volatilized from fertilizers have about 300 times the global warming potential of a molecule of CO2.

The research involves breeding domesticated cultivars of lettuce with more primitive species and weeds before growing them at fields on the Pomona campus and Yuma, Arizona, where they are given less water and less nitrogen before being evaluated.

Still said researchers then make statistical associations between a plant’s characteristics — how it grows under less water and nitrogen — to regions within its genome to identify a specific gene responsible for making it need less of those things. 

“By identifying first that gene and then, with more study, that specific allele that is different than the commercial cultivar, then we can either just use traditional breeding and breed that specific allele into the commercial cultivars, or we can use gene editing, like CRISPR technology,” he said. 

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Still said that his research has already identified some genes of interest, but it could be several years or more before that research results in a commercially viable lettuce from breeders. 

He said that after identifying specific genes and developing markers, his research team will give these to their colleagues in public universities as well as breeders working at private seed companies. These individuals will then be able to use the findings for “the materials that they have already developed and wished to develop.”

Still said that the easiest way to develop a lettuce with the desired gene or genes is to use gene editing, but he notes that there’s still a lot of skepticism over the process. 

“It’s something that is absolutely well studied, well understood, and very safe for the environment and for humans,” he said. “So I really think that that’s something that science needs to get ahead of in that message to the public.”