UC Davis News: Agriculture

Plant Protein 'Doorkeepers' Block Invading Microbes, Study Finds

Tue, 30 Jun 2009 00:00:00 -0700

A group of plant proteins that “shut the door” on bacteria that would otherwise infect the plant’s leaves has been identified for the first time by a team of researchers in Denmark, at the University of California, Davis, and at UC Berkeley.

Findings from the study, which appears in the June 29 issue of the online journal Public Library of Science Biology, provide a better understanding of plants’ immune systems and will likely find application in better protecting agricultural crops and horticultural plants against diseases.

“The ability of a plant’s immune system to recognize disease-causing microorganisms is critical to the plant’s survival and productivity,” said Gitta Coaker, a UC Davis plant pathologist and lead author on the study.

“In this study, we identified a complex of proteins in the common research plant Arabidopsis that appear to play important roles in the biochemical mechanisms that enable plants to recognize and block out invading bacteria,” Coaker said.

She noted that, over the last 20 years, scientists have identified a number of proteins that are important for regulating the plant immune system but still do not have a good sense of what protein complexes these proteins belong to and how they signal to confer disease resistance.

“Our ability to purify an immune protein complex will serve as a starting point to understand how these proteins signal in the plant,” Coaker said. “A greater understanding of how these proteins function is fundamental knowledge that can be applied to prevent plant disease.”

Plant immunity

Plants are continually exposed to bacteria, viruses and other microorganisms, many of which have the ability to infect the plant and cause disease.

Animals have what are known as innate, or preformed, immune systems as well as adaptive immune systems that learn to recognize and defend against disease-causing microbes. Plants, however, only have innate immune systems. Rather than developing immunity as they are exposed to various microbes, plants make use of certain built-in cells and genetically programmed systems to protect themselves against microbial invasion and related diseases.

This type of innate immune system has two branches: one makes use of receptor proteins outside the cell to recognize specific molecular features of an invading microbe, while the other branch uses similar proteins within the cell to recognize an invading microbe during the infection process.

Up until now, scientists had identified only one protein, known as RIN4, which is able to regulate these two branches of the plant immune system in Arabidopsis. The protein is found in the permeable plasma membrane that encases the cell on the inside of the cell wall. It has been unclear exactly how the protein and the two branches of the immune system interact to trigger an immune response in the plant.

The new findings

In studying the RIN4 protein, Coaker and her colleagues identified six previously uncharacterized proteins that can associate with RIN4 inside plant cells. One protein, called AHA1, was characterized in-depth and found to be key to the immune response in Arabidopsis plants.

AHA1 can act to regulate the opening and closing of tiny holes called stomata, found on the underside of the leaf. The stomata allow gases and water to pass in and out of the leaf. This is the same opening that allows bacteria and other invading microbes to gain entrance to the plant.

The stomata are each flanked by two guard cells, which control these vitally important portals to the leaf. When the guard cells swell, the stomata close. Conversely, when the water content of the guard cells decreases, the stomata open.

The six proteins identified in this study were found to be intricately involved with the biochemical processes that enable the plant to recognize and block out invading bacteria.

The researchers found that RIN4 can act to regulate AHA1 and that both proteins work together to control stomatal openings in response to a disease-causing microorganism.

“These findings highlight how important regulation of the stomata is in Arabidopsis immunity,” Coaker said. “Further research is needed to determine if RIN4 and its associated proteins play the same role in other plant species.”

Funding for the study was provided by the National Institutes of Health and the National Science Foundation.

Collaborators on this study were Coaker, Jun Liu and James M. Elmore, all of UC Davis; Anja T. Fuglsang and Michael G. Palmgren, both of the Danish National Research Foundation and the University of Copenhagen, Denmark; and Brian J. Staskawicz of UC Berkeley.

About UC Davis

For 100 years, UC Davis has engaged in teaching, research and public service that matter to California and transform the world. Located close to the state capital, UC Davis has 31,000 students, an annual research budget that exceeds $500 million, a comprehensive health system and 13 specialized research centers. The university offers interdisciplinary graduate study and more than 100 undergraduate majors in four colleges -- Agricultural and Environmental Sciences, Biological Sciences, Engineering, and Letters and Science -- and advanced degrees from six professional schools -- Education, Law, Management, Medicine, Veterinary Medicine and the Betty Irene Moore School of Nursing.

New UC Davis Study Asks: How Green Is Our Valley?

Tue, 23 Jun 2009 00:00:00 -0700

The population of California's Central Valley is expected to balloon from 7 million to 12 million people in the next 30 years, making it the fastest growing region anywhere in the U.S. or Mexico. Can the valley's communities be that big and green as well?

"I am actually pretty pessimistic about the possibility," says the lead author of a new UC Davis review of 100 Central Valley cities' growth policies.

"Sustainable growth is growth that minimizes environmental impact while meeting goals for economic viability and quality of life, for both present and future generations," said associate professor Mark Lubell. "Our study identified some very serious obstacles to achieving the goal, but also identifies some variables and recommendations that might help."

Lubell found that the valley's biggest cities have the greatest number of sustainable-growth policies and projects.

Fresno had the highest score on the Sustainability Index, at 33 points (out of 50). Sacramento followed with 31.5 and Davis was third, at 30. The lowest score, for the fewest policies, went to Maricopa, at 5.5.

"Bigger cities have a lot of problems, but they also have lots of policies in place," Lubell said. "That is a good example of the challenges — a community might try really hard but the policies may still fail in the end."

Fresno's high score on the Sustainability Index was due to two Fresno initiatives -- “Fresno Green,” an action-oriented plan intended to transform Fresno into a sustainable city, and the "Southeast Growth Area" (SEGA), a 14-square-mile area targeted to absorb at least 20 percent of Fresno’s growth over the next 20 years in a high-density, multi-use development incorporating "new types of open space and walkable communities."

The researchers also wrote case studies of seven Central Valley cities (Fresno, Modesto, Davis, Wheatland, Lincoln, Sacramento and Citrus Heights), which inform their advice for building sustainable communities, including:

• Stop relying on big-box stores and sprawl for city revenues -- even if it means revisiting Proposition 13. Dependence on sales tax from retail, and user fees on new development, is called "the fiscalization of land use," and it discourages policies that restrict growth or encourage high-density and in-fill development. These financial issues are particularly acute in California because of Proposition 13, passed in 1978, which reduced the availability of property taxes and caused many cities to view growth as the only way to balance budgets.

• Don't wait until too late. State policies should put a high priority on "transitioning cities" -- those that don't have a history of poor development but are now growing fast and making irrevocable decisions about their future.

• Focus city general-plan updates on sustainability from the start. The vision should encompass environmental, economic and social issues.

• Establish a city sustainability program with a dedicated budget and staff. This program should evaluate priority problems for the city and seek the most cost-effective solutions, with input from city departments, city officials and citizens.

• Keep learning. Help city staff benefit from others' experiences through conferences, training and online peer networks. Spread knowledge through community meetings. City officials should give citizens opportunities to be heard, and should respond publicly. State agencies and university research programs should help cities discover which sustainability efforts will provide the greatest return on investment.

The report, "Achieving Sustainability in California’s Central Valley," was written by researchers in the UC Davis Sustainable Transportation Center, a program of the Institute of Transportation Studies. All are members of the Department of Environmental Science and Policy: Lubell; Bret Beheim and Vicken Hillis, research assistants; and professor Susan Handy, also the center's director.

The Sustainable Transportation Center is funded in part by the U.S. Department of Transportation and Caltrans, the California Department of Transportation, through the University Transportation Centers program. Additional funding for this study came from the National Science Foundation.

The executive summary and full research report are available online at: http://pubs.its.ucdavis.edu/publication_detail.php?id=1286.

About UC Davis

Olive Oil Tour Highlights Beyond Extra Virgin Conference

Thu, 18 Jun 2009 00:00:00 -0700

An international group of olive oil experts will tour olive processing facilities and orchards in advance of the June 21-23 Beyond Extra Virgin olive oil conference, to be held at UC Davis. Members of the news media are invited to join the bus tour or meet it at any of the stops along the way.

Information on olive growing, olive-oil processing, culinary uses of olive oil and potential health benefits of extra virgin olive oil will be provided.

Media interested in participating in the tour should contact Dan Flynn, executive director of the UC Davis Olive Center at (916) 798-5847 or jdflynn@ucdavis.edu.

UC Davis Begins $2.8 Million in Studies of Agricultural Nitrogen's Impacts

Thu, 11 Jun 2009 00:00:00 -0700

UC Davis researchers will receive $2.8 million in new grants to study the use and impacts of nitrogen, a hero of the agricultural revolution that is increasingly viewed as a worrisome source of water and air pollution and potent greenhouse gases.

"This is one of the most important and least publicized environmental issues we face: Escaped nitrogen from agricultural production affects the quality of our air, water, and soil and has huge potential to contribute to climate change," said Tom Tomich, director of the Agricultural Sustainability Institute at UC Davis.

"Many members of the public and politicians are unaware of the scope of this challenge. And many farmers are increasingly interested in nitrogen management to cut costs."

Nitrogen is a chemical element that occurs naturally in Earth's air, water and soil. It is essential to life, and cycles through all plants, animals and people. Nitrogen-based fertilizers help California farmers produce more than 400 agricultural commodities -- vegetables, fruits, meats and dairy products worth $36 billion a year.

But excess nitrogen is emitted from soils, seeps into groundwater and runs off into surface waters. Wastes from cattle, chickens and other livestock include nitrogen. Farm machines burning oil, gasoline and diesel release nitrogen to the air.

The resulting environmental impacts include:

Trapped solar radiation in the atmosphere, contributing to the "greenhouse effect" that is changing the Earth's climate;
Decreased high-altitude ozone, which allows more solar radiation to reach Earth's surface, causing skin cancer and adding to the greenhouse effect;
Increased smog and ground-level ozone, which can cause or worsen respiratory diseases such as asthma and viral infections such as the common cold;
High concentrations of nitrates in groundwater, which can cause methemoglobinemia, or "blue baby disease," and possibly bladder and ovarian cancers; and
Nitrogen runoff in bays and coastal areas, where it makes algae numbers spike then crash, drawing oxygen from the water and leading to "dead zones" -- areas that cannot support finfish, shellfish or most other aquatic life.

Those environmental impacts are not fully documented, Tomich said.

"With this new funding, we can start to fill in those blanks, and improve management of nitrogen, carbon and water to help move agriculture toward sustainability in significant ways," he said.

Data on agricultural nitrogen pollution are limited, and some nitrogen pollution forms are difficult to monitor. Measurements can be labor-intensive and expensive and are influenced by variables such as weather conditions, irrigation timing and method, and crop-specific fertilization practices.

The new studies should improve data-collection methods, said Agricultural Sustainability Institute researcher Johan Six, a professor in the Department of Plant Sciences.

"It's urgent that we know how much nitrous oxide and other greenhouse gases are released during irrigation and fertilization of farm lands in California," Six said. "The good news is we know that it is economically feasible to reduce these emissions. The first step is quantifying the necessary reductions."

The new Agricultural Sustainability Institute grants and objectives include:

$1.5 million from the David and Lucile Packard Foundation for a statewide assessment of existing scientific evidence on nitrogen use in conventional and alternative farming systems, and relevant practices and policy options. Also: a program to improve communication about nitrogen concerns among California farmers, ranchers, extension advisors, environmental and community groups, agribusiness (including the fertilizer industry) and government agencies (including California Department of Food and Agriculture and U.S. Environmental Protection Agency). This grant is to the Agricultural Sustainability Institute, in collaboration with the University of California Agricultural Issues Center, Kearney Foundation for Soil Science, and the UC Sustainable Agriculture Research and Education Program.
$500,000 from the California Energy Commission and $350,000 from the David and Lucile Packard Foundation to Johan Six for new research on nitrous oxide emissions in various farming systems.
$300,000 from the California Air Resources Board to Will Horwath, professor in the UC Davis Department of Land, Air and Water Resources, for research on practical ways to reduce nitrous oxide emissions in California agriculture.
$150,000 from the California Department of Food and Agriculture's Fertilizer Research and Education Program to Horwath, Six and David Goorahoo, an assistant professor at the Center for Irrigation Technology at California State University, Fresno, to measure nitrous oxide emissions from cotton, corn and vegetable cropping systems.

About the Agricultural Sustainability Institute

Established in 2006 by the UC Davis College of Agricultural and Environmental Sciences, the Agricultural Sustainability Institute includes the University of California's statewide Sustainable Agriculture Research and Education Program (SAREP), the Student Farm at UC Davis, and the Russell Ranch Sustainable Agriculture Facility at UC Davis, as well as programs at other campuses across California. More information: http://asi.ucdavis.edu.

About UC Davis

At Long Last, How Plants Make Eggs

Thu, 04 Jun 2009 00:00:00 -0700

A long-standing mystery surrounding a fundamental process in plant biology has been solved by a team of scientists at the University of California, Davis.

The group’s groundbreaking discovery that a plant hormone called auxin is responsible for egg production has several major implications.

First, this is the first definitive report of a plant hormone acting as a morphogen, that is, a substance that directs the pattern of development of cells based on its concentration.

Also, the study’s results provide tantalizing new insights into the evolutionary pathway that flowering plants took 135 million years ago when they split off from gymnosperms, the “naked-seeded” plant group that includes conifers, cycads and ginkgo trees.

Finally, the group used their discovery to make additional egg cells within plant reproductive structures, raising the prospects that these techniques may someday be used for enhancing the reproduction and fertility of crop plants.

“So the sequence becomes clear now,” said Venkatesan Sundaresan, the UC Davis professor of plant biology and plant sciences who led the study. “The plant triggers auxin synthesis at one end of the female reproductive unit called the embryo sac, creating an auxin gradient. The eight nuclei in the sac are then exposed to different levels of auxin, but only the nucleus in the correct position in the gradient becomes an egg cell. And that cell is subsequently fertilized to make the next generation.”

A paper describing the study was published June 4 in the journal Science’s online site, Science Express, in advance of its publication in the journal later this month.

Development of sperm and egg cells in plants

In humans and other animals, the germ cells for production of eggs and sperm are established at birth. But cells in flowering plants are assigned more or less randomly to become reproductive units when the plant reaches sexual maturity. Within the flower, sperm cells are produced by pollen at the tips of stamens, while egg cells develop in ovules, tiny structures embedded in the ovary at the base of the pistil.

At the start of the process of egg-cell development, a “mother cell” in the ovule divides several times, in a sequence involving both meiosis and mitotic divisions. These divisions result in the creation of an oblong, cell-like structure called the embryo sac, which contains eight nuclei, three of which are clustered near the open end of the ovule.

Within hours cell membranes start forming, eventually, creating seven cells: the all-important egg cell near the ovule opening where pollen will enter, and six other supporting cells, with essential functions for seed formation.

“The big question in our field for the past 50 years or more has been: How does this process happen in such a beautifully orchestrated pattern?” Sundaresan said. “It’s been clear that there’s a program here telling the plants exactly what to do, and that it is working not on cells, but on nuclei.”

Auxin concentrations determine fate of nuclei

Two years ago Sundaresan and a postdoctoral fellow in his laboratory, Gabriela Pagnussat, used genetic tools to shift the position of a single nucleus at one end of an embryo sac in the plant Arabidopsis. When they examined the mature sac, they found that it had produced two egg cells instead of one.

Sundaresan recognized that a pattern shift like this was similar to the response that had been reported two decades earlier in Drosophila fruit flies in experiments that provided the first direct evidence for the existence of morphogens.

This prompted him to begin searching for a substance in Arabadopsis that might be acting as a morphogen. When the group discovered that auxin was accumulating at the open end of the ovule, they turned their attention to this ubiquitous hormone, which is known to play myriad signaling roles in plant growth and behavioral processes. (The hormone’s existence was first guessed by Charles Darwin when he was studying how plants grow towards light.)

After many tests, Sundaresan and his group found that during embryo sac formation, auxin concentrations did indeed follow a gradient, with the highest levels occurring in the ovule at the end of the embryo sac where the pollen enters and lowest levels occurring at the opposite end of the sac.

To test the theory that this gradient was determining the fate of nuclei in the sac, Sundaresan and his group created a series of genetically manipulated Arabadopsis plants. In some plants they ratcheted up production of auxin in the embryo sac, and in others they decreased the sac’s sensitivity to auxin, creating the same effect that a decline in auxin would make.

When they examined these experimental plants, their hypothesis was confirmed: Auxin concentrations determined the fate of the nuclei. Knowing whether auxin levels were high or low, it became possible to predict the appearance or disappearance of egg cells at different positions within the embryo sac.

Finally, the group employed a long series of bio-manipulative techniques to determine that the auxin gradient they had discovered within the embryo sac was due to on-site synthesis rather than transport from a source outside the sac.

“What we have found about the way auxin works here is amazing,” Sundaresan said. “The idea that you can have a small molecule like this being maintained in a gradient within this eight-nucleate structure through synthesis alone is mind-boggling.”

Implications for flowering plant evolution

Development of the embryo sac is arguably the key element in the evolution from gymnosperms to flowering plants, also known as angiosperms.

Yet the fossil record reveals very little about the stages that led from gymnosperm seed production to angiosperm seed production when the transition occurred around 135 million years ago. The rapid expansion of flowering plants and their eventual domination of the Earth’s vegetation was called “an abominable mystery” by Darwin.

By elucidating the mechanism of embryo sac development, Sundaresan and his team have opened the door to new work into the evolutionary pathway between these two major plant groups. The discovery supports what is known as the modular theory, which posits that the first angiosperms underwent a drastic reduction of their female reproductive unit compared to the gymnosperms, allowing flowering plants to reproduce more efficiently and eventually supplant their naked-seeded forebears.

Most remarkably, perhaps, the new work suggests that the eight nuclei of the angiosperm embryo sac have retained developmental plasticity in their evolution from gymnosperms. “It’s amazing that even though the split supposedly happened over a hundred million years ago,” Sundaresan said, “all these nuclei still have the capacity to become egg cells.”

Collaborators in the study are lead author Gabriela Pagnussat and Monica Alandete-Saez, who were postdoctoral researchers with Sundaresan when they did the work, and John L. Bowman, a professor of plant biology at UC Davis at the time of the study, now at Monash University in Melbourne, Australia.

The work was supported by grants from the National Science Foundation.

About UC Davis

For 100 years, UC Davis has engaged in teaching, research and public service that matter to California and transform the world. Located close to the state capital, UC Davis has 31,000 students, an annual research budget that exceeds $500 million, a comprehensive health system and 13 specialized research centers. The university offers interdisciplinary graduate study and more than 100 undergraduate majors in four colleges — Agricultural and Environmental Sciences, Biological Sciences, Engineering, and Letters and Science — and advanced degrees from six professional schools — Education, Law, Management, Medicine, Veterinary Medicine and the Betty Irene Moore School of Nursing.

'Graduation' Leads to the Auction Arena for Students and Horses

Wed, 03 Jun 2009 00:00:00 -0700

Not all finals at UC Davis take place in a lecture hall. For more than a dozen animal science students, the year’s toughest test will come Saturday, June 20, when they take the young horses they have bred, raised and trained into the auction arena for the annual horse production sale.

The public auction, this year called the “Proof Is in the Progeny” sale, will be held at 6 p.m. in the horse barn arena on La Rue Road on the UC Davis campus. It will feature four weanlings, eight yearlings and two adult horses and will be preceded by a 2 p.m. preview of the horses and a 4:30 p.m. barbecue dinner.

“This is a great opportunity for these students to work with horses, from foaling to the sale ring,” said Joel Viloria, equine facilities supervisor for the Department of Animal Science. “The horses that we put through the sale have been introduced to everything under the sun, and most of them have even had saddles on their backs already.”

“We welcome both potential buyers and members of the community who just want to enjoy the sale to come out and support the horse barn program. The student interns have put a lot of sweat and tears into these horses,” he said.

Reporters interested in interviewing or photographing students working with the horses in preparation for the auction should contact Viloria at (530) 754-4156, jeviloria@ucdavis.edu.

The group will include registered American quarter horses, American paint horses, Appaloosa horses, warmbloods eligible for registration with the Selle Francais Association and a registered mule.

The sale is the culmination of a six-month internship for the students serving as foal managers. During the internship, the students learn how to handle and train weanlings and yearlings, as well as provide care for the mares and foals before and after birth.

The students also are responsible for grooming the horses for the sale and training the foals to stand tied, load into a trailer, and stand to be clipped and shod. They exercise the horses regularly and expose the foals to a variety of activities involving large crowds, heavy equipment and the show ring.

Proceeds from the sale, which traditionally brings in $20,000 to $30,000, will support the animal science department's Equine Management Program. This program provides hands-on experience for students preparing for careers in the horse industry or for further studies in veterinary medicine or graduate school.

Detailed descriptions of the horses and the Equine Management Program, as well as driving directions to the horse barn, are available online at http://animalscience.ucdavis.edu/HorseBarn/ProductionSale/index.htm.

Olive Oil Conference Welcomes Public and Culinary Professionals

Wed, 03 Jun 2009 00:00:00 -0700

Cooking enthusiasts and olive oil aficionados are invited to join food professionals from around the world June 21-23 at UC Davis for an international conference exploring the best production practices, sensory qualities and culinary possibilities for the highest quality extra virgin olive oil.

“Beyond Extra Virgin,” the largest conference on olive-oil excellence ever held in North America, is designed for chefs, journalists, specialty retailers, food-service management executives, olive-oil producers, sensory scientists and anyone with a serious interest in cooking. Co-sponsored by the UC Davis Olive Center and The Culinary Institute of America, it will include two days at UC Davis and a third day at the institute’s Greystone campus in the Napa Valley.

The term “extra virgin” applies to olive oil that is the natural product of the olive, processed without any heat, solvents or other oils. The grade allows for a wide range of quality, including oil that is bland in flavor. The conference will focus on the top tier of extra virgin quality.

During the three-day conference, participants will be instructed about the critical control points — from harvest to storage — that advance or undermine flavors in extra virgin olive oil. They also will experience how leading chefs, including Paul Bartolotta, John Ash, Deborah Madison and Renato Morisco, are melding the modern with the ancient to highlight and even re-invent the best of these flavors.

The conference will begin at 4 p.m. on Sunday, June 21, with all sessions held in Freeborn Hall. On Tuesday, June 23, the participants will travel by chartered bus to The Culinary Institute of America at Greystone.

A complete agenda and registration forms for the conference are provided online by the UC Davis Olive Center at http://www.olivecenter.ucdavis.edu/news-events/events/beyond-extra-virgin-2009. Registration is $495 per person.

Helping to coordinate the conference are Associazione TREE, a nonprofit organization devoted to the improvement of olive oil; Accademia dei Georgofili in Florence, Italy; and the California Institute for Food and Agricultural Research at UC Davis.

The UC Davis Olive Center is one of four research and outreach centers in the Robert Mondavi Institute for Wine and Food Science.

Media Calendar: Grapevine Canopy Symposium

Wed, 03 Jun 2009 00:00:00 -0700

July 16, Thursday — Proper training and care of a grapevine’s shoots, leaves and grape bunches play a critical role in maximizing the productivity of the vine and the quality of the grapes and wine. The industry-focused International Grapevine Canopy Management Symposium will feature scientists from France, Italy, Germany, Australia, Canada and the United States. They will present recent research findings and advances in canopy management practices in their respective countries. The symposium is planned as a tribute to UC Davis viticulture professor emeritus Mark Kliewer, who organized the first international canopy management symposium at UC Davis in 1986. The symposium will be held from 8 a.m. to 5 p.m. in UC Davis’ Freeborn Hall. More information and registration are available online at http://www.cevs.ucdavis.edu/confreg/index.cfm?confid=436.

Informal Seed Exchange and Grain Trade Key to Transgenic Gene Flow in Mexican Maize

Mon, 01 Jun 2009 00:00:00 -0700

The appearance of genetically modified proteins in maize seed stocks throughout Mexico paints a curious pattern that suggests why efforts to prevent the flow of transgenic plant material into that country could fail, reports a team of researchers in Mexico and at the University of California, Davis.

The researchers hope that their findings, published May 29 online in the journal Public Library of Science, will help guide development of methods and public policies for regulating the movement of genetically modified plant material into local seed stocks in centers of crop origin and diversity.

The research team, led by UC Davis agricultural economist and plant biologist George A. Dyer, used enzyme-based tests, mathematical models of crop populations, and knowledge of established seed-use patterns to analyze maize seed stocks in Mexico for the presence of proteins from genetically modified, or transgenic, maize varieties.

“We found that, nationwide, 5 percent of Mexico’s maize seed stocks contained transgenic proteins by 2002,” Dyer said. “That nationwide average included a surprising 13 percent in southeast Mexico and 3 percent in the west-central part of the country.”

Dyer noted that the possible spread of genetically modified seed and grain from the United States might explain how the transgenic plant material found its way into maize seed stocks in Mexico’s west-central region, where informal introduction and sharing of improved seed is quite common. But that route of introduction would not account for the strong presence of transgenic seed in the country’s southeast area, where use of foreign seed is fairly uncommon.

The gene flow controversy

Although there have been no authorized commercial releases of genetically modified corn or other maize species in Mexico, which is the birthplace of maize, the potential for gene flow from transgenic maize into Mexico has been controversial throughout the past decade. In 2001, a highly publicized study by UC Berkeley researchers first reported the appearance of proteins from genetically modified corn in native maize varieties in Oaxaca, Mexico. That study raised concerns that the flow of genes from the transgenic varieties threatened the genetic diversity embodied in Mexico’s native maize species. However, the study’s methods were criticized and its results questioned.

Dyer and colleagues addressed outstanding methodological issues in two previous papers in the scientific journals Proceedings of the National Academy of Science in 2008 and Molecular Ecology in 2009. The first paper discussed how farmers’ practices impact the evolution and diversity of maize in Mexico, and the second paper suggested monitoring protocols for detecting the presence of transgenes among native maize varieties.

New findings on seed use

The research team’s third article, published in the Public Library of Science, builds on the two previous papers, with special attention to how seeds are managed and shared in Mexico. In this recent study, the researchers found that:

informal seed exchange between farmers was the main source of seed dispersal across Mexico and was more important in the southeast than in the north;
seed obtained from neighboring farmers was more likely to be saved from year to year, while seed that was imported or obtained from government programs was more likely to be replaced with other seed in succeeding years; and
marked differences in the rate of spread of proteins from genetically modified maize in different areas of Mexico suggest that the transgenic material was dispersed through different routes in each region.

“Many governments in developing countries are planning to regulate the release of genetically modified crops,” Dyer said.

“In Mexico, current regulatory efforts assume that the spread of genes from genetically modified plants into native plants can be prevented or reversed by restricting commercial release of genetically modified varieties to areas of industrialized agriculture,” he said. “Our study, however, suggests that this approach might be ineffective because controlling or even tracking the flow of grain within Mexico poses such a formidable challenge.”

He noted that, in order to develop systems for protecting genetic diversity in areas where native crops originated, further research is needed to explore how genetic material flows through both formal and informal seed and grain systems.

Funding for this study was provided by UCMEXUS-CONACYT, the William and Flora Hewlett Foundation and various agencies in Mexico.

Collaborating with Dyer on this study were J. Edward Taylor and Paul Gepts, both of UC Davis; Elena R. Alvarez-Buylla and Alma Pineyro-Nelson of the Universidad Nacional Autónoma de Mexico; J. Antonio Serratos-Hernández of Universidad Autónoma de la Ciudad de México; Hugo R. Perales of El Colegio de la Frontera Sur, Mexico; Angeles Chávez and Antonio Yúnez-Naude, both of El Colegio de México; and Noé Salinas-Arreortua of Universidad Autónoma Metropolitana, Unidad Iztapalapa, Mexico.

About UC Davis

For 100 years, UC Davis has engaged in teaching, research and public service that matter to California and transform the world. Located close to the state capital, UC Davis has 31,000 students, an annual research budget that exceeds $500 million, a comprehensive health system and 13 specialized research centers. The university offers interdisciplinary graduate study and more than 100 undergraduate majors in four colleges — Agricultural and Environmental Sciences, Biological Sciences, Engineering, and Letters and Science -- and advanced degrees from six professional schools — Education, Law, Management, Medicine, Veterinary Medicine and the Betty Irene Moore School of Nursing.

Funding Shortage Forces Closure of Fresno Animal Health and Food Safety Laboratory

Wed, 20 May 2009 00:00:00 -0700

Due to budget shortfalls, the California Animal Health and Food Safety Laboratory System, managed by the University of California, Davis, will close its Fresno laboratory on July 19.

The laboratory system provides diagnostic services for diseases in livestock, poultry and horses to veterinarians and animal producers in California’s agricultural heartland. Closure of the 59-year-old Fresno laboratory will shift diagnostic testing to other facilities in the laboratory system.

"We are proud of the Fresno laboratory's long service to California, particularly to the agricultural industry of the southern San Joaquin Valley," said Bennie Osburn, dean of the UC Davis School of Veterinary Medicine, which operates the laboratory network. "Unfortunately, reduced state funding combined with rising costs to manage a sophisticated laboratory system have left it struggling to maintain services."

The laboratory system, managed by UC Davis since 1987, has its reference lab at UC Davis and branch laboratories in Turlock, Fresno, Tulare and San Bernardino. The network of diagnostic labs receives approximately 80 percent of its funding from a contract with the California Department of Food and Agriculture. The remainder of its revenue comes from fee-for-service testing provided to veterinarians and agricultural producers. Rising costs and a reduction in the contract with the state during 2008-2009, compounded by the weak economy, have left the system with a projected funding deficit exceeding $2 million in 2009-2010.

The closure of the Fresno laboratory will affect more than 20 employees, resulting in the reassignment of three faculty positions to the system’s labs in Tulare and Davis and the layoff of the remaining scientific and administrative personnel.

In addition to the closure of the Fresno lab, the laboratory system has eliminated 14.75 positions through staff and faculty attrition at the Davis, San Bernardino and Turlock labs.

"The faculty and staff of our laboratories are dedicated to high-quality service for our animal industry," said Hailu Kinde, director of the California Animal Health and Food Safety Laboratory System. "While we deeply regret the personal and professional impact of this closure upon our colleagues in Fresno, we remain committed to upholding the mission of the laboratory system. We will make every effort to continue to provide excellent, reliable diagnostic service."

Kinde said that the laboratory system has reached out to contact area veterinarians and agricultural producers via e-mail, alerting them to the Fresno lab’s impending closure and informing them of plans for continued diagnostic services.

The Fresno branch laboratory has provided a full range of testing services including poultry disease monitoring, as well as surveillance for brucellosis, tuberculosis and avian viruses. Following the lab’s closure, brucellosis surveillance and poultry pathology will be carried out at the Tulare laboratory. Diagnostic tests for viruses in poultry will be conducted at the laboratory at UC Davis, while blood and serum tests will be done at the Turlock laboratory.

About UC Davis

Gourmet Winkler Dinner to Benefit Students

Thu, 07 May 2009 00:00:00 -0700

The public is invited to a night of gourmet food and wine Saturday, May 16, during the 2009 Winkler Dinner at the Robert Mondavi Institute for Wine and Food Science.

Each of the six courses on the menu will be prepared by a different chef and paired with a donated wine. Winemakers will be present to introduce each wine. Silent and live auctions will be held before and after dinner.

The six-course dinner is the main fundraiser for the Davis Enology and Viticulture Organization (DEVO), a club founded by students of the UC Davis Department of Viticulture and Enology to promote contact between students, the wine industry and the community, and to fund student scholarships, internships and travel.

For the past eight years, the dinner has been held under the Winkler Vine, a majestic California Mission grapevine that spreads over a one-half acre arbor and is named in memory of the late Albert J. Winkler, chair of the Department of Viticulture and Enology from 1935 to 1957. This year’s event will be held in the courtyard of the new Robert Mondavi Institute for Wine and Food Science.

Tickets for the dinner, costing $175 per person or $1,200 for a table of eight, may be purchased online at http://wineserver.ucdavis.edu/devo/. Tickets will be sold through May 11, with limited seating available after that.

More information about the event can be obtained by contacting viticulture and enology graduate student Daniel Person at (707) 536-8451 or dmperson@ucdavis.edu.

Brewing Expert Charles Bamforth to Speak at Wine Literature Event

Thu, 07 May 2009 00:00:00 -0700

Charles Bamforth, the Anheuser-Busch Endowed Professor of Malting and Brewing Sciences at UC Davis, will be one of four authors to speak on May 20 at the second annual Books on Wine Festival, coordinated by the Napa Valley Wine Library Association.

The Wednesday event, which will be held at 6:30 p.m. in the St. Helena Library, is intended to celebrate contributions to the wine literary field from the 2008 publishing year. The presentations by the authors will be followed by book signings from 8:15 to 9 p.m.

Bamforth will discuss his book "Grape vs. Grain: A Historical, Technological, and Social Comparison of Wine and Beer," published in March 2008 by Cambridge University Press. In this book, he weighs the merits of both types of beverages.

"I do not seek to decry wine. Rather, I aim to demonstrate why brewers can hold their heads high in the knowledge that their liquid is every ounce the equal of wines by any yardstick you choose to nominate," writes Bamforth.

The 224-page book includes social commentary on beer and wine, and comparisons of their histories, production techniques, types and styles, healthfulness, and future outlooks.

Bamforth, who has written several books about beer, began his work in the brewing industry in 1978 and joined the UC Davis faculty in 1999. Before coming to UC Davis, he served as deputy director-general of Brewing Research International and research manager and quality assurance manager of Bass Brewers.

He serves as a special professor in the School of Biosciences at the University of Nottingham, England. He also is a fellow of the Institute of Brewing and Distilling, a fellow of the Institute of Biology and a fellow of the International Academy of Food Science and Technology. He is editor-in-chief of the Journal of the American Society of Brewing Chemists.

Other books to be discussed include “Ghost Hunter's Guide to California's Wine Country,” by Jeff Dwyer, “Napa Wine: A History From Mission Days to Present, 2nd Edition,” by Charles L. Sullivan and “Napa Behind the Bottle,” by Bill Tucker.