Contact: Maribel Alonso
Email: Maribel.Alonso@usda.gov

BUSHLAND, Texas, Jan. 8, 2025 –A new study from USDA’s Agricultural Research Service (ARS) and Iowa State University (ISU) reveals that generative Artificial Intelligence (AI) can help expedite the search for solutions to reduce enteric methane emissions caused by cows in animal agriculture, which accounts for about 33 percent of U.S. agriculture and 3 percent of total U.S. greenhouse gas emissions.

"Developing solutions to address methane emissions from animal agriculture is a critical priority. Our scientists continue to use innovative and data-driven strategies to help cattle producers achieve emission reduction goals that will safeguard the environment and promote a more sustainable future for agriculture," said ARS Administrator Simon Liu.

One of these innovative solutions starts in the cow’s stomach, where microorganisms contribute to enteric fermentation and cause cows to belch methane as part of normal digestion processes. The team of scientists found a group of compound molecules capable of inhibiting methane production in the largest of the cow’s four stomach compartments, the rumen, which can be tested to help mitigate methane emissions.

One molecule in particular, bromoform, which is naturally found in seaweed, has been identified by the scientific community to demonstrate properties that can result in reducing cattle enteric methane production by 80-98 percent when fed to cattle. Unfortunately, bromoform is known to be a carcinogen, limiting its potential use in cattle for food safety reasons. Therefore, scientists continue to search for molecules with similar potential to inhibit enteric methane. However, this type of research presents challenges of being especially time-consuming and expensive. 

In response to these challenges, a team of scientists at the ARS Livestock Nutrient Management Research Unit and ISU’s Department of Chemical and Biological Engineering combined generative AI with large computational models to jumpstart the quest for bromoform-like molecules that can do the same job without toxicity.

"We are using advanced molecular simulations and AI to identify novel methane inhibitors based on the properties of previously investigated inhibitors [like bromoform], but that are safe, scalable, and have a large potential to inhibit methane emissions,” said Matthew Beck, a research animal scientist working with ARS at the time the study was completed and is now with Texas A&M University’s Department of Animal Science. "Iowa State University is leading the computer simulation and AI work, while ARS is taking the lead in identifying compounds and truth testing them using a combination of in vitro [laboratory] and in vivo [live cattle] studies."

Publicly available databases that contained scientific data collected from previous studies on the cows’ rumen were used to build large computational models. AI, along with these models, was used to predict the behavior of molecules and to identify those that can be further tested in a laboratory. The results from the laboratory tests feed the computer models for AI to make more accurate predictions, creating a feedback loop process known as a graph neural network.

"Our graph neural network is a machine learning model, which learns the properties of molecules, including details of the atoms and the chemical bonds that hold them, while retaining useful information about the molecules' properties to help us study how they are likely to behave in the cow's stomach," said ISU Assistant Professor Ratul Chowdhury. "We studied their biochemical fingerprint to identify what makes them do the job successfully as opposed to the other fifty thousand molecules that are lurking around in the cow’s rumen but don’t actively stop the production of methane."

"This study successfully demonstrated that fifteen molecules cluster very close to each other in what we call a ‘functional methanogenesis inhibition space,’ meaning they seem to contain the same enteric methane inhibition potential, chemical similarity, and cell permeability as bromoform," added Chowdhury.

Scientists believe AI can play a significant role in understanding how known molecules interact with both proteins and the microbial community of the rumen and thereby discover novel molecules and potentially key interactions within the rumen microbiome. This type of predictive modeling can be particularly helpful for animal nutritionists.

"There are other promising strategies currently available to mitigate enteric methane emissions, but the available solutions are relatively limited," said USDA-ARS Research Leader Jacek Koziel. "This is why combining AI with laboratory research, through iterative refinement, is a valuable scientific tool. AI can fast-forward the research and accelerate these several pathways that animal nutritionists, researchers, and companies can pursue to get us closer to a very ambitious goal of limiting greenhouse gas emissions and helping mitigate climate change."

The study also presents a total computational and monetary cost breakdown to conduct this research on a per molecule basis. This analysis was conducted to show an estimate of potential costs and foreseeable pitfalls of this research. This estimate can be used to guide decision-making on investments for this type of research to be done entirely in a laboratory.

Chowdhury, Beck, and Koziel are co-authors in the paper published in Animal Frontiers, along with Nathan Frazier (ARS) and Logan Thompson (Kansas State University).  Mohammed Sakib Noor, an ISU graduate student, is working with Chowdhury to develop the graph neural networks.

The Agricultural Research Service is the U.S. Department of Agriculture's chief scientific in-house research agency. Daily, ARS focuses on solutions to agricultural problems affecting America. Each dollar invested in U.S. agricultural research results in $20 of economic impact.

Contact: Jan Suszkiw
Email: Jan.Suszkiw@usda.gov

December 17, 2024

Quinoa’s grain-like seed offers a flavorful, nutrition-packed addition to soups, salads and side dishes, as well as ingredient for cereals, snacks and pasta. But in order for this versatile seed to get from farm field to table, quinoa growers must be vigilant for signs of downy mildew, a disease that can decimate the crop if left unchecked.   

To help growers, a team of researchers led by Agricultural Research Service (ARS) plant pathologist Anna Testen devised a fast new test to genetically detect the pathogen in both quinoa seed and leaf tissue.   

The advance, reported in the September 3, 2024, issue of Plant Disease, opens the door to countering downy mildew on several fronts—with benefits to U.S. growers hoping to expand the crop and to consumers, who prize the seed’s flavor and offering of protein, fiber, vitamins and essential amino acids. 

Caused by the fungus-like pathogen Peronospora variabilis, downy mildew appears as yellow to pinkish lesions on the leaves of infected quinoa plants. Infected leaves can also take on a cupped appearance, among other malformations as well as tissue death and discoloration. Under favorable conditions, outbreaks of downy mildew in susceptible quinoa varieties can inflict seed yield losses of up to 100 percent. 

The test—or "assay," as the scientists call it—uses a laboratory procedure known as quantitative polymerase chain reaction (qPCR) to help detect specific segments of the downy mildew pathogen’s DNA—so long as it’s present in a seed or leaf sample.

Additionally, with the qPCR-based test being quantitative, it can determine how much of the pathogen is present based on readings of light emitted by the procedure’s amplification of its DNA. This feature also distinguishes the test from other PCR-based methods that have been developed.

A new test from an ARS-led research team could give growers an edge against downy mildew disease of quinoa, a crop whose grain-like seed is prized for its flavor, versatility and nutrients. (Photo by Anna Testen, ARS)

"Quantitative PCR is much more sensitive (meaning, it can detect smaller amounts of DNA) than standard PCR, so there are fewer false negatives," explained Testen, who is with the ARS Application Technology Research Unit in Wooster, Ohio. It’s also more specific and faster, allowing for more samples to be screened, she added.

Among potential uses is providing quinoa growers with an early warning system. In other susceptible crops, for example, "spore traps that catch airborne spores paired with qPCR assays have been used to detect the downy mildew pathogen early and warn growers to treat their crops," said Testen.

Another potential use is helping speed the identification of plants from quinoa breeding lines that can resist or tolerate downy mildew. Plant breeders can then pass the genes for that trait into elite quinoa varieties, shoring up their defenses against the disease. 

And on the phytosanitary front, the tests could help ensure that commercial shipments or germplasm exchanges of quinoa seed for research purposes are free of downy mildew, preventing new or re-introductions of the disease.

And as quinoa’s U.S. popularity grows, "this tool will also help us track the quinoa downy mildew pathogen in the environment, potentially teaching us more about its epidemiology to improve disease management," added Testen, whose co-authors on the Plant Disease paper are Scott Shaw (ARS) and Purnima Puri, Evan Domsic, Deirdre Griffin-LaHue, Kevin Murphy and Chakradhar Mattupalli—all with Washington State University.

The Agricultural Research Service is the U.S. Department of Agriculture's chief scientific in-house research agency. Daily, ARS focuses on solutions to agricultural problems affecting America. Each dollar invested in U.S. agricultural research results in $20 of economic impact.

Contact: Nirav Shah
Email: Nirav Shah

WASHINGTON, December 6, 2024 – The United States National Arboretum (USNA) will commemorate the 90th anniversary of the Civilian Conservation Corps (CCC) Company 1360 tomorrow with the unveiling of an exhibit dedicated to the African American men whose contributions to the Arboretum live on today.

The CCC was a public works program that provided men with jobs during the Great Depression. Company 1360 was an African American unit situated on the grounds of the U.S. National Arboretum in a location known as Camp NA-1.

"The Arboretum owes these men a debt of gratitude. We are thrilled to commemorate the enduring impact of Civilian Conservation Corps Company 1360, whose presence and hard work have shaped the Arboretum for the past nine decades. Their influence continues to enrich the landscape, and we are truly grateful for their legacy," said USDA Agricultural Research Service Administrator Simon Liu.

In March 1933, President Franklin D. Roosevelt initiated the CCC as a constructive component of the New Deal, effectively addressing the pressing issue of high unemployment among young men during the Great Depression. This program engaged over 2.5 million individuals, known as "Roosevelt's Tree Army," before its conclusion in June 1942. 

The new exhibit highlights two years of research conducted by USNA on the history of Company 1360, identifying enrollees and their CCC service records, documenting work performed at the Arboretum, and refining the camp's location and layout.

"When Company 1360 arrived at the Arboretum, the land was a patchwork of small farms, a lot of overgrowth, abandoned and dilapidated structures, and no effective way to travel across the terrain. When they left, the Arboretum looked like something that merited the name," said USNA Director Richard Olsen. 

USNA is a distinguished public garden and a leading institution for horticultural scientific research. Spanning over 451 acres in northeast Washington, D.C., the Arboretum actively promotes and supports discovery by offering a diverse array of scientific expertise, collaboration, and training opportunities. The grounds are accessible to the public at no charge, operating daily from 8 a.m. to 5 p.m. ET, except on December 25.

The Agricultural Research Service is the U.S. Department of Agriculture's chief scientific in-house research agency. Daily, ARS focuses on solutions to agricultural problems affecting America. Each dollar invested in U.S. agricultural research results in $20 of economic impact.

Contact: Maribel Alonso
Email: maribel.alonso@usda.gov

MILES CITY, Mont., May 31, 2024- U.S. Department of Agriculture (USDA) Agricultural Research Service (ARS) today celebrated the 100-year anniversary of Fort Keogh Livestock and Range Research Laboratory and its past and present contributions to the livestock industry and scientific community. 

For a century, ARS Fort Keogh Livestock and Range Research Laboratory, in partnership with Montana State University’s (MSU) Montana Agricultural Experiment Station, have been at the forefront of livestock, poultry, and swine performance and genetic enhancement through their innovative work on animal breeding and nutrition. Their work has helped producers improve agricultural production nationwide since 1924.

“The ARS scientists at Fort Keogh have a long-standing history of collaborating with stakeholders to address the challenges of the livestock industry,” said ARS Administrator Dr. Simon Liu. “Through their pioneering practices, they have made significant strides in research related to cattle nutrition, reproductive efficiency, and genetic improvement.”

The development of a closed herd of purebred Hereford cattle named Line One is the product of 90 years of ARS’ collaborative work with MSU. This research project is one of the world's oldest beef cattle selection experiments, and it has become a cornerstone for modern genetic evaluation of beef cattle.

The Laboratory's long-term research on stocking rates (numbers of livestock or unit area over a given period) on Northern Great Plains rangelands provides stakeholders with a guide for improving rangeland health in semi-arid rangelands dominated by cool-season plants. In addition, research on the impact of livestock grazing after fire activity during the growing season, focusing primarily on the effects on rangeland vegetation types commonly found in the Northern Great Plains, resulted in revisions to the post-fire grazing recommendations used by land management agencies.

USDA-ARS Fort Keogh Livestock and Range Research Laboratory celebrates 100 years of significant contributions to livestock reproduction, nutrition, and genetics research, and rangeland management research, to the industry and scientific community. (Photo courtesy of Jay Angerer, ARS-USDA) 

These accomplishments wouldn't have been possible without collaborations with a diverse group of organizations, universities, beef commodity interest groups, and federal and state government agencies.

"The historic partnerships at Fort Keogh have led to dozens of Montana State students, staff, and faculty working with ARS scientists on hands-on research to benefit our state's largest industry," said Sreekala Bajwa, Vice President, Dean & Director, MSU, College of Agriculture & Montana Agricultural Experiment Station. "I would like to extend sincere gratitude to all of our past and present collaborators at Fort Keogh and look forward to another 100 years of productive partnership that will keep Montana agriculture strong."

The USDA-Agricultural Research Service Fort Keogh Livestock and Range Research Laboratory's scientific legacy is rooted in decades of combined research on inbreeding and selection, spanning the performance of sheep, milking shorthorn cattle, horses, turkeys, swine, and beef cattle. This research, which began in 1924, has evolved over the years. Since 1986, the Laboratory has transitioned to a more specific focus on beef cattle, including research on cattle genetics, reproductive physiology, and nutrition.

“Our goal is to continue our mission to collaboratively research and develop ecologically and economically sustainable range management and livestock production practices that meet customer needs for the next 100 years,” said Jay Angerer, research leader and supervisory research rangeland management specialist at the Livestock and Range Research Laboratory.

Leaders from MSU, Montana Dept. of Agriculture, Montana Stockgrowers Association, and U.S. Representative Matt Rosendale (Montana) also provided remarks during the event highlighting the Laboratory's accomplishments.

The Agricultural Research Service is the U.S. Department of Agriculture's chief scientific in-house research agency. Daily, ARS focuses on solutions to agricultural problems affecting America. Each dollar invested in agricultural research results in $20 of economic impact.

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Contact: Maribel Alonso
Email: Maribel.Alonso@usda.gov

MANDAN, N.D., March 28, 2024—The U.S.  Department of Agriculture (USDA) Agricultural Research Service (ARS) announces a cooperative agreement with the Nueta Hidatsa Sahnish (NHS) College to conduct research supporting Indigenous Seed Sovereignty. This collaborative effort will increase the number of traditional varieties of seeds of the Mandan, Hidatsa, and Arikara (MHA) Nation crops within NHS College's traditional seed cache.

This agreement builds upon USDA’s strengthened partnerships with tribal communities to advance food sovereignty and ARS’ efforts to further incorporate tribal research priorities, including Indigenous Traditional Ecological Knowledge, into its research portfolio. This partnership came to life in 2023 with a blessing of garden space, a traditional way of preparing for a successful harvest, after discussions between ARS and NHS College emphasized the need to expand NHS's seed cache and increase seed accessibility to MHA's Tribal members.

“As we celebrate our one-year anniversary, ARS is excited to announce that we have produced new seeds and seedlings of vital native crops which will be distributed to MHA Tribal members this spring via NHS College,” said Dr. Simon Liu, ARS Administrator. “Our partnership with NHS College enables us to gain a better understanding of the unique agricultural research needs of tribal communities. This achievement reflects ARS' ongoing commitment to integrating the needs and practices of Indigenous Traditional Ecological Knowledge into our research portfolio to support the priorities of tribal communities and indigenous agriculture.”

ARS’ partnership with NHS College will improve seed health through multiplication, germination, and viability. It also includes data collection to determine the traditional use and characteristics of MHA Nation’s traditional varieties. This work is important for protecting seed intellectual property, providing data to support increased consumption, and demonstrating the link between traditional varieties and health while sharing cultural protocols and traditional ecological knowledge throughout the project.

During the project’s first year, ARS researchers at the Northern Great Plains Research Laboratory (NGPRL) in Mandan, North Dakota, successfully grew a wide range of traditional crops necessary for seed and seedling distribution.  The yield included eight varieties of corn (totaling 28 gallons of corn seeds), seven varieties of squashes (totaling over 500 squashes), four varieties of beans (producing a half a gallon of seeds), and more than 150 of one variety of watermelon (over 150 watermelons) grown on half an acre. 

Seed and seedlings of varieties of corn, squash beans, and watermelon [one variety]. (Photo courtesy of Dr. Ruth Plenty Sweetgrass-She Kills).

The NHS College established a Project Advisory Team that includes representatives from each of the three Tribes. This team provides direction on strategies to increase the number of seeds, to determine seed distribution, to collect program data, and to integrate Traditional Ecological Knowledge within the project.

“By reconnecting the Mandan, Hidatsa, and Arikara people with our traditional seeds, we are bringing life back into the relationship between our seeds, our people, and our land,” said Dr. Ruth Plenty Sweetgrass-She Kills, Director of NHS College's Food Sovereignty Program. “This act of seed sovereignty also strengthens our Tribal food system and provides access to nutrient-dense foods that our people’s DNA recognizes and remembers.”

Since 1998, NHS College has stewarded MHA traditional varieties through its Four Sisters Garden. NHS College’s traditional seed cache was established and has been maintained through donations by Tribal members and scholars and the rematriation [retrieval] of seeds from various institutions. In 1953, the Garrison Dam flooded the fertile agricultural land on Fort Berthold and forced MHA Nation Tribal members to re-establish new homes and communities on infertile dryland. This has contributed to the loss of cultural identity of MHA Nation tribe members, including the growth and consumption of their traditional crops.

“Seeds need to be regrown at least every ten years to remain viable, as the viability of seeds decreases by about 10 percent each year,” said Dr. Claire Friedrichsen, an NGPRL research social scientist. “ARS’ role is to increase the health of seeds within NHS College’s traditional seed cache. This includes ensuring seeds are free from disease or rot, have limited disease susceptibility, and are free from other detrimental developmental conditions. Maintaining the health of seeds is important for the ability of a collection to continuously adapt to climate, land, and culture to produce healthy crops.”

For inquiries regarding the distribution of new seeds, donations of old seeds that need to be grown to maintain their viability, or to become a member of the Nueta Hidatsa Project Advisory Team, email Dr. Ruth Plenty Sweetgrass-She Kills at NHS College at rhall@nhsc.edu.

This USDA-funded is a pilot project to create a roadmap for other Tribal institutions to collaborate with USDA ARS to support indigenous seed sovereignty.

The effort supports the USDA Indigenous Food Sovereignty Initiative announced by Secretary Tom Vilsack in 2022 (See, “USDA Announces New Resources to Empower Indigenous Food Sovereignty”).

The Agricultural Research Service is the U.S. Department of Agriculture's chief scientific in-house research agency. Daily, ARS focuses on solutions to agricultural problems affecting America. Each dollar invested in U.S. agricultural research results in $20 of economic impact.

Contact: Maribel Alonso
Email: Maribel.Alonso@usda.gov

SOMERVILLE, TEXAS, March 27, 2024—The Pecan Breeding and Genetics Program of the U.S. Department of Agriculture's Agricultural Research Service (USDA-ARS) recently completed a 2.5 million dollars laboratory modernization to accelerate pecan breeding through innovations in genetics and plant disease research. A ribbon-cutting ceremony was held on March 26 to commemorate the completion of the project.

Pecan trees represent North America's native nut tree and a multimillion-dollar crop. These trees have been cultivated commercially for less than 150 years. It takes an average of 28 years from planting a new seedling to releasing a new pecan cultivar with traditional methods of pecan breeding. This is due to the long waiting period for pecan trees to start producing nuts, which takes up more than half of the time. With the new modernized laboratory, the Pecan Breeding and Genetics Program will now be able to incorporate genetic techniques into pecan breeding to accurately predict mature nut traits on young seedlings, saving up to a decade in the breeding process.

Breeding new pecan cultivars is a lengthy process with long waiting periods of 7-10 years before a pecan tree can produce nuts and long testing phases to evaluate potential cultivars. It is challenging to support pecan breeding efforts due to their high resource demands and extended timelines, which make it impractical for private or commercial entities and challenging for academic programs.

The event was hosted by USDA's ARS and the Texas Pecan Grower’s Association. ARS leaders, State Representatives, scientists, and members of the pecan industry organizations toured the new laboratory with now dedicated research spaces for plant genetics, microscopy, tissue culture, controlled-environment growth chambers, and plant disease research.

"Today marks the celebration of the opening of a new genetics and pathology laboratory," said Warren Chatwin, the Lead Scientist at the Pecan Breeding and Genetics Program in Somerville, Texas. "This facility will enable ARS' researchers here at Somerville to advance pecan breeding and support modern genetics and plant disease research, which hasn't been possible since this site was established in the 1980s."

"This event also highlights the significant impact of our stakeholders, the pecan industry organizations. They have unified their voice through the National Pecan Federation to express the need for increased quality, accuracy, and speed of pecan breeding, genetics, and plant disease research, leading to the establishment of this laboratory space. The success of our research is only possible through partnerships with stakeholders including the Texas Pecan Grower’s Association, which has provided decades of support and significant contributions, most recently through the National Pecan Federation," added Chatwin.

The USDA Pecan Breeding and Genetics Program's new genetics and pathology laboratory meets biosafety containment standards and is equipped with modern research spaces that will advance pecan breeding, genetics, and plant disease studies. (Photos provided by Warren Chatwin, ARS).

In addition, researchers will now be able to do controlled evaluations of promising breeding lines with different regional strains of pecan scab. Pecan scab, caused by the fungal pathogen Venturia effusa, is the most economically significant disease in the pecan industry and has high diversity across the geographic range of cultivated pecans. For the first time, the Pecan Breeding and Genetics Program will now be able to screen pecan scab cultures from all areas of the country in controlled environments to identify new sources of disease resistance and incorporate those unique samples into the breeding program. Researchers will also be able to do controlled evaluations for other significant and emerging pathogens of pecan, including the heavily quarantined international pathogen, Xylella fastidiosa.

The Pecan Breeding and Genetics program has released 32 pecan cultivars to the industry, with notable releases like 'Pawnee,' which moved the commercial harvest window forward to mid-September, 'Lakota,' which has high scab resistance, and 'Wichita,' a high-yielding cultivar that performs well in the West. USDA-ARS’ most recently released cultivars include 'Pueblo,' 'Seneca,' and 'Zuni,' which were patented in 2022.

The Agricultural Research Service is the U.S. Department of Agriculture's chief scientific in-house research agency. Daily, ARS focuses on solutions to agricultural problems affecting America. Each dollar invested in U.S. agricultural research results in $20 of economic impact.

Contact: Autumn Canaday
Email: Autumn Canaday

WASHINGTON, May 6, 2021 – The U.S. Department of Agriculture’s Agricultural Research Service (ARS) today announced that an African Swine Fever Virus vaccine candidate has been adapted to grow in a cell line, which means that those involved in vaccine production will no longer have to rely on live pigs and their fresh cells for vaccine production.

“This opens the door for large-scale vaccine production, which is a valuable tool for the possible eradication of the virus,” said senior ARS scientist Dr. Manuel Borca.

African Swine Fever is known to cause virulent, deadly outbreaks in wild and domestic swine, causing widespread and lethal outbreaks in various countries in Eastern Europe and throughout Asia.

African Swine Fever is not a threat to humans and cannot be transmitted from pigs to humans. However, outbreaks have led to significant economic losses and pork shortages on local and global scales.

No commercial vaccines are currently available to prevent the virus from spreading.  There have not been any outbreaks in the United States, but it’s estimated that a national outbreak could cost at least $14 billion over two years, and $50 billion over 10 years.

This discovery, highlighted in the Journal of Virology, overcomes one of the major challenges for manufacturing of an African Swine Fever Virus vaccine. The newly developed vaccine, grown in a continuous cell line — which means immortalized cells that divide continuously or otherwise indefinitely—has the same characteristics as the original vaccine produced with fresh swine cells.

“Traditionally we used freshly isolated swine cells to produce vaccine candidates and this constitutes a significant limitation for large-scale production” said senior ARS scientist Dr. Douglas Gladue. “But now we can retain the vaccine characteristics while simultaneously replicating the vaccine in lab-grown cell cultures. We no longer have to rely on gathering fresh cells from live swine.”

The continuous cell line vaccine candidate was tested in a commercial breed of pigs and determined to be safe, protecting pigs against the virus. No negative effects were observed.

This research was supported in part by an interagency agreement between the U.S. Department of Homeland Security and the U.S. Department of Agriculture. Some of the scientific personnel were part of the Plum Island Animal Disease Center Research Participation Program, administered by the Oak Ridge Institute for Science and Education. All animal studies were performed at the Plum Island Animal Disease Center, following a protocol approved by the Institutional Animal Care and Use Committee.

The Agricultural Research Service is the U.S. Department of Agriculture's chief scientific in-house research agency. Daily, ARS focuses on solutions to agricultural problems affecting America. Each dollar invested in agricultural research results in $17 of economic impact.

Contact: Kim Kaplan
Email: Kim.Kaplan@usda.gov

BELTSVILLE, MARYLAND, February 18, 2021—An Agricultural Research Service entomologist has discovered the Nosema ceranae parasite that causes major problems and death in honey bees works by hijacking its host's iron for itself.

Iron is as essential a micronutrient for honey bees as it is for people. Honey bees usually get enough to meet their needs from their flower pollen diet. They use iron in their immune system and for reproduction and development. As does Nosema ceranae.

"In a number of mammal species, there is an iron tug-of-war between host and pathogen that is part of the central battlefield that determines the outcome of an infection. But this has not been explored before in honey bees and not with Nosema," explained entomologist Yan Ping "Judy" Chen. She is with the ARS Bee Research Laboratory in Beltsville, Maryland.

When Chen tracked iron in N. ceranae-infected honey bees, she found iron is also a part of the honey bee's physiological struggle with the parasite, as it is in the mammalian system.

If honey bees lose the battle of infection with N. ceranae, the gut parasite begins to hijack the iron in the flower pollen that the honey bee has eaten before the bee can absorb it, diverting the iron into its own spore reproduction.

How the N. ceranae does that involves a protein called transferrin that, in honey bees, is responsible for binding and transporting iron from pollen out of the gut and throughout the bee. N. ceranae uses the honey bee's transferrin to divert the iron to its own use, causing the honey bee to produce more and more transferrin as the bee's system becomes more and more starved for iron.

New studies show that Nosema ceranae, a major intracellular pest of honey bees, hijacks the pollinator's iron, diverting it to the parasite's own needs.

"This only results in greater iron deficiency for the honey bee as the increasing transferrin level just gives the N. ceranae the opportunity to scavenge even more iron from the bee host for its own proliferation and survival," Chen said.

She further found that reducing transferrin production was accompanied by reduced iron loss and improved immune function and improving survival of N. ceranae-infected bees.

Since there is no truly effective treatment for N. ceranae, this study suggests a welcome possibility for a new treatment that might be based on regulating iron or the synthesis of transferrin, Chen added. This will be of interest for beekeepers, researchers, and policymakers worldwide.

N. ceranea is one of the major parasite problems causing beekeepers' colony losses today. It is a microsporidia, a member of a group of single-celled parasites closely related to fungi. Originally, N. ceranae was a parasite only of Asian honey bees (Apis cerana). But in the late 1990s, it jumped species to the European honey bees (Apis mellifera) that we have in this country.

This research was published in Plos Pathogen.

The Agricultural Research Service is the U.S. Department of Agriculture's chief scientific in-house research agency. Daily, ARS focuses on solutions to agricultural problems affecting America. Each dollar invested in agricultural research results in $17 of economic impact.