California Ag Network

Tag: CRISPR

  • Wheat That Makes Its Own Fertilizer

    Scientists at the University of California, Davis, have developed wheat plants that stimulate the production of their own fertilizer, opening the path toward less air and water pollution worldwide and lower costs for farmers.

    The technology was pioneered by a team led by Eduardo Blumwald, a distinguished professor in the Department of Plant Sciences. The team used the gene-editing tool CRIPSR to get wheat plants to produce more of one of their own naturally occurring chemicals. When the plant releases the excess chemical into the soil, the chemical helps certain bacteria in the soil convert nitrogen from the air into a form the nearby plants can use to grow. That conversion process is called nitrogen fixation.

    The study was published online in Plant Biotechnology Journal.

    In developing countries, the breakthrough could be a boon for food security.

    “In Africa, people don’t use fertilizers because they don’t have money, and farms are small, not larger than six to eight acres,” Blumwald said. “Imagine, you are planting crops that stimulate bacteria in the soil to create the fertilizer that the crops need, naturally. Wow! That’s a big difference!”

    The breakthrough in wheat builds on the team’s earlier work in rice. Research also is underway to extend this technology to other cereals.

    Worldwide, wheat is the No. 2 cereal crop by yield and takes the biggest share of nitrogen fertilizer, using about 18% of the total. Globally, more than 800 million tons of fertilizer were produced in 2020 alone, according to figures from the United Nations Food and Agriculture Organization.

    But plants take up only about 30 to 50% of the nitrogen in fertilizer. Much of what they don’t use flows into waterways, which can create “dead zones” that lack oxygen, suffocating fish and other aquatic life. Some excess nitrogen in the soil produces nitrous oxide, a potent climate-warming gas.

    The work-around: Protect the fixer

    Nitrogen-fixing bacteria produce an enzyme called nitrogenase, the “fixer” in nitrogen fixation. Nitrogenase is only located in the bacteria, and it can only work in environments with very little oxygen.

    Legumes such as beans and peas have root structures, called nodules, that provide a cozy, low-oxygen home for nitrogen-fixing bacteria to live.

    Unlike legumes, wheat and most other plants don’t have root nodules. This is why farmers use nitrogen-containing fertilizer.

    “For decades, scientists have been trying to develop cereal crops that produce active root nodules, or trying to colonize cereals with nitrogen-fixing bacteria, without much success. We used a different approach,” Blumwald said. “We said the location of the nitrogen-fixing bacteria is not important, so long as the fixed nitrogen can reach the plant, and the plant can use it.”

    To find a work-around, the team first looked at 2,800 chemicals the plants produce naturally. They found 20 that, among other jobs useful to the plant, also stimulate bacteria to produce biofilms. Biofilms are a sticky layer that surround the bacteria and create a low-oxygen environment, allowing nitrogenase to work. The scientists determined how the plant makes those chemicals and which genes control that process.

    Then, the team used the gene-editing tool CRISPR to modify wheat plants to produce more of one of those chemicals, a flavone called apigenin. The wheat, now with more apigenin than it needs, releases the excess through its roots into the soil. In experiments they conducted, apigenin from the wheat stimulated bacteria in the soil to create the protective biofilms, allowing nitrogenase to fix nitrogen and the wheat plants to assimilate it.

    The wheat also showed a higher yield than control plants when grown in a very low concentration of nitrogen fertilizer.

    Farmers could save billions

    Farmers in the United States spent nearly $36 billion on fertilizers in 2023, according to U.S. Department of Agriculture estimates. Blumwald calculates that nearly 500 million acres in the U.S. are planted with cereals.

    “Imagine, if you could save 10% of the amount of fertilizer being used on that land,” he pondered. “I’m calculating conservatively: That should be a savings of more than a billion dollars every year.”

    Other authors include Hiromi Tajima, Akhilesh Yadav, Javier Hidalgo Castellanos, Dawei Yan, Benjamin P. Brookbank and Eiji Nambara.

    A patent application has been filed by the University of California and is pending. Bayer Crop Science and the UC Davis Will Lester Endowment have supported the research.

    Read about the earlier work of the Blumwald team to develop rice that can stimulate its own nitrogen fertilizer here. — By Trina Kleist, UC Davis

  • Agriculture and Science vs. Climate Change

    An ancient proverb states that the longest journey begins with a single step. Now, a group with the Agricultural Research Service (ARS) has taken one such step in the worldwide struggle against climate change.

    Roger Thilmony, molecular biologist with the ARS Crop Improvement and Genetics Research unit in Albany, CA, and his team have developed a new variety of wheat that has shown modest improvements in the plant’s ability to withstand drought.

    “Global climate change is a grand challenge for agricultural production,” Thilmony said. “Drought is one of the primary stresses that limit crop productivity and cause economic losses. The creation of drought stress-tolerant crops, like wheat, is important to mitigate these problems and enable good agricultural yields, despite environmental challenges.”

    Thilmony’s team used advanced gene editing technology, known as CRISPR, to locate, isolate, and inactivate wheat’s six Sal1 genes. Sal1 encodes a protein that acts as a sensor of plant stress. When the gene is inactivated in some plants, they appear to have increased tolerance to drought, he explained.

    The result was a moderately successful crop of test plants.

    “The process was relatively efficient at producing the desired [results],” he said. “The modified wheat plants stayed green longer than unmodified wheat plants, but they did not produce more seed than the unmodified plants under drought conditions. That could be interpreted as a form of drought tolerance.”

    Wheat is one of the most widely grown crops in the world and is a critically important food source for its nutritional and health benefits.

    CRISPR gene editing technology is often used to speed up the process of selecting for agriculturally beneficial traits, cutting years – even decades – from the time it would take to produce them using traditional animal husbandry and plant breeding programs.

    “Gene editing can be applied to a wide array of crops, and it is possible that editing can be used in other plants to make them more drought stress-tolerant,” Thilmony said.

    While the project did not produce the “giant leap” of a lunar landing, it was a successful step in the right direction toward mitigating the effects of climate change.

    “Although we did not produce wheat plants that were more productive under drought stress, the research does demonstrate how gene editing is a powerful tool in testing ideas and determining if specific genes [like Sal1] play a role in the tolerance of crops to environmental stresses,” Thilmony said. – By Scott Elliott, USDA-ARS Office of Communications

  • NASA Funds Tiny Tomatoes for Vertical Farming on Earth and Space

    Urban agriculture offers many benefits for food production but often has higher costs relative to traditional farming and is limited to only a few crops. By 2050, there will be nine billion people on the planet, but arable land is decreasing. Global food production will need to double to meet food needs, though climate change complicates the problem more.

    Robert Jinkerson, an assistant professor of chemical and environmental engineering at UC Riverside, is working to change this by engineering the size and nutritional value of tomato plants to increase both the diversity and value of crops that can be grown in urban controlled environment agriculture, or CEA.

    Jinkerson has received a $450,000 New Innovator grant from the Foundation for Food & Agriculture Research, or FFAR, to advance this research. FFAR’s New Innovator in Food & Agriculture Research Award provides early career scientists with funding to conduct audacious food and agriculture research.

    “Urban controlled environment agriculture can offer many benefits for the production of crops and is likely to supply more food in the future as worldwide food demand increases,” Jinkerson said.

    Often these urban CEA systems are designed to have plant growth areas stacked vertically to save space. However, this also decreases the height available for plant growth, limiting the size of crops that can be cultivated in vertical farms to small leafy greens.

    “In order to overcome these size limitations and to increase the variety of crops that can be grown in vertical farms, we are engineering tomato plants to have a small stature and are optimized for this unique growing environment,” said Jinkerson, who uses CRISPR/Cas9 gene editing to modulate key genes involved in plant development and architecture.

    In addition to reducing the size of plants, this project will also increase the nutritional value of these crops by increasing their vitamin content, making urban agriculture more profitable.

    The potential applications for these tiny tomatoes don’t end on Earth.

    Jinkerson, along with Martha Orozco-Cárdenas, director of the UCR Plant Transformation Research Center, have been awarded a NASA Space Biology grant to evaluate tomatoes from their prior work on the International Space Station. These plants, also engineered with gene editing technology and dubbed Small Plants for Agriculture in Controlled Environments, or SPACE tomatoes, will be grown in the Advanced Plant Habitat onboard the ISS to determine how these plants grow in microgravity. The SPACE tomatoes will be grown ‘seed-to-seed,’ meaning seeds will be harvested and the next generation grown in space, completing an entire lifecycle. These experiments, which will happen after several years of trials on Earth, will help establish methodologies to grow food on long duration space missions.

    “We are extremely excited to receive support for these projects and hope that the results will help transform the way we produce food here on Earth and beyond,” said Jinkerson.

    About UC Riverside

    The University of California, Riverside (www.ucr.edu) is a doctoral research university, a living laboratory for groundbreaking exploration of issues critical to Inland Southern California, the state and communities around the world. Reflecting California’s diverse culture, UCR’s enrollment is more than 24,000 students. The campus opened a medical school in 2013 and has reached the heart of the Coachella Valley by way of the UCR Palm Desert Center. The campus has an annual statewide economic impact of almost $2 billion. To learn more, email news@ucr.edu.