California Ag Network

Tag: UC Riverside

  • UC Riverside Research Team Fuels the Hemp Revolution

    For many years, a federal ban on growing hemp, a nonpsychoactive type of cannabis, dimmed the promise it holds for sustainable construction materials, textiles, and many other products.

    While the 2018 Agricultural Act legalized industrial hemp, methods for processing hemp stalks are stuck in the past. Pulping, the process of extracting valuable cellulose fibers from plant stalks, for example, releases environmentally dangerous gasses and leaves behind a toxic residue called “black liquor,” which is expensive to treat and make safe for disposal or incineration.

    In a strange twist, growers in states that have legalized recreational or medical cannabis are struggling due to market saturation and the fact that over 90% of what they grow is considered refuse or plant waste for which disposal is expensive. This dual situation has created a burgeoning industry to explore new methods for using the whole hemp plant and more sustainable ways to extract value from its stalk and hurd, the woody inner part of the stalk.

    Charles Cai

    Charles Cai, a research engineer and adjunct professor at UC Riverside’s College of Engineering Center for Environmental Research and Technology, has developed and patented an improved pulping method that uses a naturally derived solvent, creates no toxic waste, emits no carbon dioxide, and converts nearly 100% of the hemp plant into useable components, such as cellulose fiber for use in textiles and construction, resinous lignin for use in bioplastics, sugars for use as sweeteners, and extractives for use in wellness products.

    The method, called Co-solvent Enhanced Lignocellulosic Fractionation, or CELF, uses a renewable and highly recyclable solvent to perform pulping under mild conditions, saving process energy while generating zero harmful emissions. The only waste is a small amount of mineral ash that is filtered out of the process and can be used as a soil amendment. CELF was originally conceived to help convert plant waste into biofuels. However, its effectiveness at deconstructing plant matter makes it a Swiss Army knife for all plant processing. Its scientific merit was recently proven by one of the world’s fastest supercomputers.

    Now, Cai is working with a team of undergraduate students to commercialize the hemp-processing technology through funding from the EPA’s People, Prosperity and the Planet Program, or EPA P3. Last year, the team demonstrated proof of concept for using the CELF pulping method, using it to make an improved type of hempcrete, a concrete-like, carbon sequestering building material made from hemp fibers.

    This year, the UC Riverside team has been awarded Phase II funding from the P3 program to continue to improve CELF for hemp processing. In an effort to identify new products and market opportunities, the research team has joined forces with startup InnovaCan, as well as companies Hempire USA, a member of the US Hemp Building Association; Match Patch Pro; and The Hurd Co.; to identify new products and market opportunities.

    The team will build a custom CELF reactor able to handle larger quantities of hemp and optimize the reaction to tune the properties of the resulting fiber and lignin products. — By Holly Ober, UC Riverside

    Traditional hempcrete made with untreated hemp hurds (left). Experimental hempcrete, made with CELF-treated hemp fibers (center) and agitated CELF-treated fibers (right). (Charles Cai)

  • Pest Colonizes Grape Vines, Forms Tumors, Repels other Predators

    Following a decade-long effort, scientists have mapped out the genome of an aphid-like pest capable of decimating vineyards. In so doing, they have discovered how it spreads — and potentially how to stop it.

    The research team’s work on the genome was published this past week in a BMC Biology paper. In it, they identified nearly 3,000 genes enabling the insect, phylloxera, to colonize and feed on grape vines by creating what are essentially nutritionally enhanced tumors. The insects live in and feed off of the structures they create.

    Phylloxera feeding on a grape root.

    “In effect, phylloxera creates its own refrigerator on the plant that it can feed from whenever it wants,” said Paul Nabity, an assistant professor of plant-insect ecology at UC Riverside. In addition to feeding the insects, these structures also protect them from attack by other parasites.

    A heavy phylloxera infestation, as occurred in the Pacific Northwest last year, could cause grapevines to lose their leaves. If the infestation reaches the roots, the plants could die.

    The tumor-like structures, known as galls, disrupt the vine’s ability to move nutrients and feed itself. They also create wounds in roots that make grapevines more susceptible to fungi and other pathogens, ultimately killing the vines.

    Claude Rispe from the French National Institute for Agriculture, Food, and Environment led the research team, while Nabity helped identify how phylloxera secrete molecules that can change the immune system of grapevines.

    “These molecules alter the plant’s defense systems and make it so that the plant doesn’t know it’s being attacked,” Nabity said.

    Native North American grapevines co-evolved with phylloxera and are now resistant to it. However, most of the grapes we eat and drink are European varieties. As a result, growers have to graft North American roots onto their European grapevines to give them tolerance to this insect.

    Now that the genes involved in the attack on non-native grapes have been identified, it may be possible to engineer phylloxera-resistant grapevines.

    “Growers currently have to graft roots to make their plants viable,” Nabity said. “A lot of money and effort could be saved with pest-resistant rootstocks.”

    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.

  • UC Riverside Discovers First Effective Treatment for Citrus-Destroying Disease

    UC Riverside scientists have found the first substance capable of controlling Citrus Greening Disease, which has devastated citrus farms in Florida and also threatens California.

    The new treatment effectively kills the bacterium causing the disease with a naturally occurring molecule found in wild citrus relatives. This molecule, an antimicrobial peptide, offers numerous advantages over the antibiotics currently used to treat the disease.

    Orange afflicted with Citrus Greening Disease. (UCR)

    UCR geneticist Hailing Jin, who discovered the cure after a five-year search, explained that unlike antibiotic sprays, the peptide is stable even when used outdoors in high heat, easy to manufacture, and safe for humans. 

    “This peptide is found in the fruit of greening-tolerant Australian finger limes, which has been consumed for hundreds of years,” Jin said. “It is much safer to use this natural plant product on agricultural crops than other synthetic chemicals.”

    Currently, some growers in Florida are spraying antibiotics and pesticides in an attempt to save trees from the CLas bacterium that causes citrus greening, also known as Huanglongbing or HLB. 

    “Most antibiotics are temperature sensitive, so their effects are largely reduced when applied in the hot weather,” Jin said. “By contrast, this peptide is stable even when used in 130-degree heat.”

    Jin found the peptide by examining plants such as the Australian finger lime known to possess natural tolerance for the bacteria that causes Citrus Greening Disease, and she isolated the genes that contribute to this innate immunity. One of these genes produces the peptide, which she then tested over the course of two years. Improvement was soon visible. 

    “You can see the bacteria drastically reduced, and the leaves appear healthy again only a few months after treatment,” Jin said.

    Because the peptide only needs to be reapplied a few times per year, it is highly cost effective for growers. This peptide can also be developed into a vaccine-like solution to protect young healthy plants from infection, as it is able to induce the plant’s innate immunity to the bacteria.

    Jin’s peptide can be applied by injection or foliage spray, and it moves systemically through plants and remains stable, which makes the effect of the treatment stronger.

    The treatment will be further enhanced with proprietary injection technology made by Invaio Sciences. UC Riverside has entered into an exclusive, worldwide license agreement with Invaio, ensuring this new treatment goes exactly where it’s needed in plants. 

    “Invaio is enthusiastic to partner with UC Riverside and advance this innovative technology for combating the disease known as Citrus Greening or Huanglongbing,” said Invaio Chief Science Officer Gerardo Ramos. “The prospect of addressing this previously incurable and devastating crop disease, helping agricultural communities and improving the environmental impact of production is exciting and rewarding,” he said. “This is crop protection in harmony with nature.”

    Hailing Jin, Geneticist, UC Riverside

    The need for an HLB cure is a global problem, but hits especially close to home as California produces 80 percent of all the fresh citrus in the United States, said Brian Suh, director of technology commercialization in UCR’s Office of Technology Partnerships, which helps bring university technology to market for the benefit of society through licenses, partnerships, and startup companies. 

    “This license to Invaio opens up the opportunity for a product to get to market faster,” Suh said. “Cutting edge research from UCR, like the peptide identified by Dr. Jin, has a tremendous amount of commercial potential and can transform the trajectory of real-world problems with these innovative solutions.”

    While the long-term effectiveness of this research has not yet been confirmed or published in a scientific journal and the project is still in its early stages, Dr. Jin’s promising findings have resulted in a commercial licensing agreement between UCR and Invaio Sciences. It is not uncommon for researchers to team with commercial licensing partners during the early phases of their studies. In this case, more work still needs to be done to confirm the robustness and viability of this treatment. Additional greenhouse trials are being initiated by Dr. Jin and her team at the citrus-specific Bio-Safety Level-3 Laboratory in Riverside, California. It also is expected that field trials will be conducted to show the effectiveness of the treatment under commercial grove conditions. — By Jules Bernstein, UC Riverside

    Regarding the announcement, Marcy Martin from the California Citrus Research Board shared, “While the release was understandably enthusiastic about potentially promising research and we are heartened by the commercial interest in this peptide, we are looking forward to reviewing complete studies on the effectiveness of this therapy in greenhouse and field studies.

    Importantly, this is not the time to let down our guard.  It continues to be critical for all citrus growers in the state to remain extremely vigilant in protecting their groves against the Asian citrus psyllid and HLB. The psyllid arrived from Mexico in 2008 and is now firmly established in southern California. The first HLB-positive tree was found in residential Los Angeles County in 2012. As of July 3, 2020, 1,926 HLB-affected trees have been identified and removed to slow the spread of the disease in residential areas of Los Angeles, Orange, Riverside and San Bernardino counties. Unlike Florida, where HLB has decimated commercial citrus groves, California growers invested in research early through the CRB and have been diligent in applying best-management practices; therefore, the disease has not yet been detected in any commercial groves. The CRB will continue to focus intensive efforts on a variety of promising research to find a solution to HLB.

    Moving forward, we at the CRB are proud to work on behalf of the 3,300-plus California citrus growers to invest in key studies to find a solution to HLB. Citrus growers always have been resilient and resourceful. Together, we will look toward the horizon for a solution to HLB.

    Marcy Martin, President, California Citrus Research Board

    In the meantime, we continue to monitor and review progress in potential therapies, new HLB-resistant varieties, better psyllid control strategies and more. We are enthusiastic about the commercial interest in HLB therapies and look forward to being able to share a range of potential approaches for California citrus growers as research progresses and matures. If you have any questions or would like additional information about the status of this research, please contact CRB President Marcy Martin at 559.708.3791 or marcy@citrusresearch.org.”

  • Bringing the Next Generation of Avocados to Market

    UC Riverside has entered into a $2.25 million partnership with Spain-based Eurosemillas S.A., a global leader in the commercialization of agriculture innovations, to help the university bring to market the most promising and advanced avocado scions and rootstocks in its collection.

    If successful, these varieties would meet diverse regional growing requirements, exhibit better post-harvest characteristics, increase yields, provide resistance against disease, and expand consumer market diversity.

    “Eurosemillas has successfully commercialized citrus varieties developed at UC Riverside in the past. They have the global network and expertise to do the same with the next generation of avocados,” said Brian Suh, director of technology commercialization in the Office of Technology Partnerships at UC Riverside, who worked with a team on this initiative for the past four years.

    Eurosemillas will obtain access to a small subset of the overall university avocado variety and rootstock collection for evaluation and testing on various continents to see if they perform as well as they do in California. At the same time, they will forge partnerships for commercialization that could lead to global market penetration of some of these selections.

    Niwala Abeysekara uses a leaf sensor on avocado plants in the Manosalva lab at UC Riverside. (UCR/Stan Lim)

    “After 31 years of working with UC on many other crops, we are delighted to partner with UCR again in a new product like avocado,” said Javier Cano Pecci, Chief Executive and Development Officer of Eurosemillas. “The avocado market is growing and is currently dominated by the Hass variety. This is a great opportunity for growers, marketers, retailers, and consumers to have options and diversify to include better avocado varieties and rootstocks adapted to their regions.”

    UC Riverside’s 70-year old avocado breeding programs house one of the most elite germplasm collections of scion and rootstock breeding material in the world. The University of California has partnered with California avocado growers since the inception of the industry a century ago and has had several plant breeders developing new varieties and rootstocks for the industry.

    Bob Bergh headed the variety improvement program for nearly 40 years, which released among other varieties, the ‘Lamb Hass’ and ‘GEM.’  This program is under the leadership of Mary Lu Arpaia, an extension horticulturist. The goal of the variety breeding program is to develop trees with high eating and market quality while increasing yield efficiency.

    Arpaia said for the California industry to remain viable, growers must have new varieties that yield more than Hass, are more tolerant to environmental stress, and can be produced reliably under high-density planting systems.

    “I am delighted by this partnership with Eurosemillas since it will help UC take this vision for the future toward reality,” Arpaia said.

    Mary Lu Arpaia, UC Riverside Extension Horticulturist

    The variety improvement program has four selections being readied for release that can augment the ‘Hass’ variety in terms of seasonality and have potential for expanded environmental adaptation within California.

    The rootstock breeding program was started in the 1940s by George Zentmyer and is currently directed by Patricia Manosalva, an assistant professor of plant pathology at UCR. The UCR Rootstock Breeding Program is one of the few well-recognized rootstock breeding programs worldwide and has been historically funded by the California industry through the California Avocado Commission. The main goal of the rootstock program is to develop and release the next generation of rootstocks that meet the most pressing needs of growers using traditional breeding complemented with genomic-assisted breeding approaches.

    The program is selecting rootstocks that can resist Phytophthora root rot, the most common avocado disease worldwide, as well as salinity, drought, and heat, all of which are expected to become worse as the climate warms. In collaboration with the California Avocado Commission, five UC Riverside advanced rootstocks exhibiting resistance to these major challenges are being evaluated by growers throughout California.

    “This partnership with Eurosemillas will allow us to test our five advanced rootstocks in combination with ‘Hass’ and local scions in other countries to determine their potential outside California,” Manosalva said.

    Peggy Mauk, director of agricultural operations and cooperative extension horticulture specialist, has been active in avocado research and extension for more than two decades. Over the past 25 years, avocado production in California and worldwide has been challenged by declining water quality. Avocado is the most salinity sensitive tree crop and ‘Hass’ is very susceptible to damage caused by salts. She initiated a program to find rootstocks tolerant to saline water.

    “Our UCR team in partnership with Eurosemillas is focused on finding rootstock/scion combinations that increase salinity tolerance,” Mauk said.

    Over the last 30 years, the avocado market has increased 2.5-fold and per capita consumption has quadrupled, generating interest in avocado production in many other countries, Manosalva said. But diseases, climate change, and the worldwide market’s dependence on the Hass variety threaten this burgeoning market.

    “The funding from Eurosemillas will allow UC Riverside to maintain the plant material and support and complement the current California Avocado Commission funding of the avocado scion and rootstock breeding programs, respectively, which have significant value given their uniqueness,” said Kathryn Uhrich, dean of UC Riverside’s College of Natural and Agricultural Sciences. — By Holly Ober, UC Riverside

    For more information on this avocado program contact Joyce Patrona: joyce.patrona@ucr.edu

  • Innovative Virus Research May Save Wheat and Other Crops

    UC Riverside scientists have solved a 20-year-old genetics puzzle that could result in ways to protect wheat, barley, and other crops from a devastating infection. Ayala Rao, professor of plant pathology and microbiology, has been studying Brome Mosaic virus for decades. Unlike some viruses, the genetic material of this virus is divided into three particles that until now were impossible to tell apart.

    Photo Caption: Visually indistinguishable particles of Brome Mosaic Virus. (Ayala Rao/UCR)

    “Without a more definitive picture of the differences between these particles, we couldn’t fully understand how they work together to initiate an infection that destroys food crops,” Rao said. “Our approach to this problem has brought an important part of this picture into very clear focus.”

    A paper describing the work Rao’s team did to differentiate these particles was recently published in the Proceedings of the National Academy of Sciences.

    Inside each of the particles is a strand of RNA, the genetic material that controls the production of proteins. The proteins perform different tasks, some of which cause stunted growth, lesions, and ultimately death of infected host plants.

    Two decades ago, scientists used the average of all three particles to create a basic description of their structure. In order to differentiate them, Rao first needed to separate them, and get them into their most pure form.

    Using a genetic engineering technique, Rao’s team disabled the pathogenic aspects of the virus and infused the viral genes with a host plant. 

    “This bacterium inserts its genome into the plant’s cells, similar to the way HIV inserts itself into human cells,” Rao said. “We were then able to isolate the viral particles in the plants and determine their structure using electron microscopes and computer-based technology.”

    Now that one of the particles is fully mapped, it’s clear the first two particles are more stable than the third. 

    “Once we alter the stability, we can manipulate how RNA gets released into the plants,” Rao said. “We can make the third particle more stable, so it doesn’t release RNA and the infection gets delayed.”

    This work was made possible by a grant from the University of California Multicampus Research Program and Initiatives. Professors Wiliam Gelbart, Chuck Knobler, and Hong Zhou of UCLA, as well as graduate students Antara Chakravarthy of UCR and Christian Beren of UCLA, made significant contributions to this project.

    Moving forward, Rao is hoping to bring the other two viral particles into sharper focus with the expertise of scientists at UCLA and UC San Diego. 

    Brome Mosaic virus primarily affects grasses such as wheat and barley, and occasionally affects soybeans as well. According to Rao, it is nearly identical to Cucumber Mosaic virus, which infects cucumbers as well as tomatoes and other crops that are important to California agriculture. 

    Not only could this research lead to the protection of multiple kinds of crops, it could advance the understanding of any virus.

    “It is much easier to work with plant viruses because they’re easier and less expensive to grow and isolate,” Rao said. “But what we learn about the principles of replication are applicable to human and animal viruses too.” — By Jules Bernstein, UC Riverside

  • News Accounts Exaggerate Current Threat of Asian Giant Hornets

    Though “murder hornets” are dominating recent headlines, there are no Asian Giant Hornets currently known to be living in the U.S. or Canada, according to UC Riverside Entomology Research Museum Senior Scientist Doug Yanega.

    Yanega is one of the country’s foremost insect identification experts. Beekeepers in Canada consulted him when a colony of the 2-inch-long hornets — the world’s largest hornet species — was discovered in the Canadian city of Nanaimo on Vancouver Island in September 2019.

    Entomologist Doug Yanega holds two Asian Giant Hornet specimens to demonstrate their relative size. (Doug Yanega/UCR)

    This was the first sighting of the hornet in North America, and authorities eradicated that nest to prevent it from becoming established. According to Yanega, “There have not been any sightings in 2020 that would suggest the eradication attempt was unsuccessful.”

    A resident on the U.S. side of the border, about 50 miles from Nanaimo in Blaine, Washington, reported two additional Asian Giant Hornet sightings in December 2019. The Washington State Department of Agriculture collected one of these hornets, which was dead. The other reportedly flew into a nearby forest. 

    Neither that live hornet nor its nest were ever found, but it is unlikely that the insect is still alive, Yanega said. 

    Recent genetic tests confirm that the dead hornet was not genetically related to the eradicated Nanaimo nest.

    “The fact that the second hornet turned out to be genetically different somewhat raises the odds that there could be more of them,” Yanega said. “However, right now all authorities are doing is asking people to keep their eyes peeled in case there were queens that escaped destruction and established their own nests nearby.” 

    The sighting is a concern, as Asian Giant Hornets can destroy honeybee hives and their venom is more toxic to humans than that of a honeybee.

    The hornet spotted in December was likely introduced to North America at the same time as those eradicated in Nanaimo. Therefore, if any of them are still living, they would be in the immediate vicinity of Vancouver Island, he said.

    There are an estimated 10 million insects, less than 2 million of which are “known species.” Yanega can identify about 90 percent or more of them, both known and unknown, to the rank of family or better.

    – By Jules Bernstein, UC Riverside

  • $3 Million Program to Train Tomorrow’s Plant Scientists

    If you’re eating fruits, nuts, grains, or vegetables in a few years, you’ll likely owe a debt of gratitude to UC Riverside. The university has created a program to transition today’s undergraduates into professional scientists solving tomorrow’s farming challenges.

    The program, called Plants-3D, will train students to discover, design, and deploy biology and engineering solutions to the projected problem of massive-scale food insecurity due to climate change. 

    “It’s exciting that 50 students, many of whom are traditionally underrepresented in academia and the biotech sector, will now learn to use the most cutting-edge technologies in biology and engineering to help increase crop yields and nutritional value, while also helping themselves professionally,” said Julia Bailey-Serres, a UC Riverside professor of genetics who is leading the new program. 

    The program was made possible by a $3 million grant from the National Science Foundation Research Traineeship program. It will fund a total of 50 students who will receive academic and entrepreneurial training, as well as mentorship and stipends to help them travel to professional conferences.

    Plants-3D will foster a synthetic biology approach to solving agricultural problems, meaning students will learn to design biological systems that do not already exist in the natural world. This approach will enable plants to tolerate increased levels of stress due to drought, flooding, and extreme heat, as well as boost protection from pests, pathogens, and invasive plants. 

    An example project would be the discovery and design of chemical compounds to attract beneficial microbes that could reduce plant requirements for fertilizer. 

    “Not only will our trainees help improve crop resilience and yields, but many plant metabolites they discover will have applications in other fields as well, including medicine and nutrition,” said Plants-3D co-leader Ian Wheeldon, associate professor of chemical and environmental engineering.

    The program has already established relationships with companies for internships, helping ensure participants will go on to leadership positions in agricultural fields after graduate school. 

    The program will provide opportunities for UC Riverside undergraduates to participate in team research, enhancing their candidacy for graduate programs and jobs in agriculture and biotechnology. 

    Agriculture and related industries provide nearly 10% of U.S. employment opportunities, but the number of students graduating with degrees that would prepare them for these jobs is not meeting industry demand. Nearly 40% of positions are projected to go unfilled, according to the U.S. Department of Agriculture. 

    Making the problem even more dire is the rapid pace of retirement from the current agricultural workforce, which is the oldest and least diverse of all scientific workforces in the U.S., the USDA reported.

    “There is a giant, gaping need for scientists who can not only update the aging agricultural technologies of today, but who can find solutions to the challenges that climate change will pose for the farmers of tomorrow,” said Sean Cutler, UCR professor of plant cell biology. “This program will definitely help fill that need.” 

    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.