Tag Archives: plant pathology

Brian Hudelson MS’89 PhD’90

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Brian Hudelson MS'89 PhD'90

Brian Hudelson MS’89 PhD’90

As director of the Plant Disease Diagnostic Clinic, Hudelson serves the state from his base on the UW–Madison campus. “My primary job is to identify plant diseases and provide my clients with diagnoses and information on disease control,” he says. His clients include agribusinesses, home gardeners and plant health consultants (for example, crop scouts and arborists). Hudelson does his share of teaching—he’s a co-instructor in several plant pathology courses and teaches plant disease diagnostics to graduate students each summer—and “tons of outreach,” he says, encompassing 60–80 talks each year as well as producing fact sheets and appearing frequently on Larry Meiller’s “Garden Talk” on Wisconsin Public Radio. “I love the variety of what I get to do and that I’m always learning new things, even after 17 years,” Hudelson says.

Eyes on the Green

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Traveling around the windswept golf course called The Straits, with its massive greens of bentgrass and rumpled, horizon-bound fairways of fescue, it’s easy to see why course manager Michael Lee BS’87 would arrange to keep his own yardwork to a minimum.

“My lawn takes me 20 minutes,” says Lee. It’s a cool spring morning, and we’re bouncing his pickup around the stunning environs of The Straits, one of two Kohler Company 18-hole courses that comprise Whistling Straits on the shores of a steely-surfaced Lake Michigan in Haven, Wisconsin.

“I have mostly mulch and woody ornamentals,” Lee says of his home lawn. “Everything I have to do for weed control I can do while I mow my lawn.”

This is in great contrast to the daunting challenge Lee faces in maintaining what has been deemed one of the country’s great championship golf courses.

And now the task has become almost herculean. The Straits, built and owned as part of The American Club by the Kohler Company, is hosting the prestigious PGA Championship this summer. From August 10 to 16, the eyes of the world will be on that course.

Though Lee will be toiling anonymously that week, guiding a staff of hundreds, his hard-earned skills as a golf course manager will be very much on display. Few, however, will truly understand what Lee and his staff do behind the scenes to maintain fairway and tee and rough and allow the television cameras to create what, in effect, is golf course art on our screens—sweeping vistas of perfectly tended dune and grass and emerald greens, with the big lake shining in the background.

But more than artful views are at stake. Lee, personable and easygoing and quick to smile, stands up well to pressure, those who know him say. And pressure there will be.

The PGA Championship, which dates back to 1916, is one of the most heralded events in golf. Each of the last two PGA Championships played at Whistling Straits, in 2004 and in 2010, drew upward of 300,000 people, and millions of households around the world tuned in to television broadcasts. The Wisconsin economy benefited to the tune of more than $76 million for each of the tournaments.

Lee is the first to say he could not shoulder the responsibilities of preparing The Straits for such worldwide scrutiny without plenty of help. And one of the places he counts on most for guidance in dealing with the course’s fussy turf is his alma mater, the College of Agricultural and Life Sciences at the University of Wisconsin–Madison—and, more specifically, the CALS-affiliated O.J. Noer Turfgrass Research and Education Facility, named for Oyvind Juul Noer, a CALS alumnus and one of the earliest internationally known turfgrass agronomists.

The facility, where scientists use tools ranging from high-powered microscopes to lawn mowers, opened in Verona, Wisconsin, in 1992 as a partnership between the Wisconsin Turfgrass Association, the University of Wisconsin Foundation, and the CALS-based Agricultural Research Stations.

Toiling in its maze of test plots, often on their hands and knees, are researchers who study everything from insects and soil to plant disease. For Lee, they are like a staff of doctors who can, at a moment’s notice, diagnose what is ailing a green or a fairway and prescribe a treatment. The Kohler Company (like many other golf course operators) contracts with the facility annually for these services.

Before and during the PGA championships, that role becomes even more crucial. The university specialists help Lee keep disease and insect problems at bay throughout the year. But in the weeks leading up to the championship they become his urgent care clinic, providing immediate help if something suspicious shows up. During the week of the championship they staff on-site, portable laboratories.

“We’re kind of at Mike’s beck and call,” says Bruce Schweiger BS’84, a CALS plant pathology researcher who serves as manager of the Turfgrass Diagnostics Lab housed at O.J. Noer. “If he calls, we’ll be there. We’re CSI Turf! That’s who we are.”

Of course, such high-profile events are just a small—albeit exciting—part of the facility’s wide-ranging mission. And you certainly don’t have to be running a world-class golf course to seek help from the scientists at O.J. Noer.

The turfgrass industry is a $1 billion-a-year business in Wisconsin and keeps about 30,000 people in jobs. Chances are, if you manage a sod farm or a park, maintain an athletic field, try to keep a 9-hole golf course at the edge of town up and running, or just wonder why your lawn looks like a bombing range, you could benefit from expert advice.

Paul Koch BS’05 MS’07 PhD’12, a CALS professor of plant pathology and a UW–Extension turf specialist who once worked as an intern for Lee, says the broad reach of the CALS turfgrass program, throughout the state and the country, is a fine example of the Wisconsin Idea at work.

“Just think of all the mom-and-pop golf courses around the state,” Koch says. “There are all these excellent little 9-hole courses. The owners have to manage their problems within the confines of the budgets they have. They really rely on our experts.”

Lee, preparing his course for the world stage, takes full advantage of the sharing of knowledge upon which the Wisconsin Idea is based. He long ago learned how important the concept is to people in all corners of the state. It was part of his education at UW–Madison, he says. Lee graduated in 1987 with a degree from CALS in soil science, specializing in turf and grounds management. He also worked as a student hourly helping conduct research in the Department of Plant Pathology.

Lee credits that education and several crucial golf course jobs—including five years as assistant superintendent at the Blue Mounds Golf and Country Club in Wauwatosa—with equipping him to handle the rigors of managing a course such as The Straits.

It was mostly his work afield at CALS that best prepared him, Lee says. He remembers long days spent crawling around test plots with a magnifying glass looking for diseases with names like dollar spot or nearly invisible insects such as chinch bugs. He literally learned his craft on the ground, he says.

“I learned the technical side of the business,” Lee says. “The need to know what’s going on at deeper and deeper levels.”

The willingness to work hard and learn has long been one of Lee’s most noticeable traits. At age 14, he went to work at the Blackhawk Country Club golf course in the Madison suburb of Shorewood Hills. His boss was Monroe Miller BS’68, now retired but for many years the respected and colorful superintendent at Blackhawk.

“He was a real special kid,” Miller says. “There were two things about Mike. He was smart and he had a great work ethic. He was probably never, ever, ever once, late for work.”

Miller recalls that off-season was always a time for catching up on chores such as painting. Around Thanksgiving in 1982, he told Lee and another young worker that among the jobs on their list was painting the inside of a pump station.

“They went down there on Thanksgiving Day and went to work,” Miller says. “I had to go down and kick them out so they would go home and spend time with their families.”

As for Lee, he says of Blackhawk and his apprenticeship with Miller: “I learned to work. I learned discipline.”

It was apparent even in those days, Miller says, that Lee had a special talent for everything to do with maintaining a golf course, from a love of the machinery to understanding the special care grass needs to become the meticulously groomed stage necessary for the game.

“Mike is one of those guys you could call a turfgrass clairvoyant,” Miller says.

Whistling Straits is a world unto itself, a haunting landscape that seems to have been dropped from the ancient countryside of the British Isles onto the Lake Michigan shoreline. That was exactly the intent of Kohler Company CEO Herbert Kohler and legendary golf course designer Pete Dye when they created both The Straits and The Irish, the other 18-hole course on the property.

The Straits, especially, evokes the rugged environs of renowned seaside courses such as the Old Course at St. Andrews in Scotland, frequent site of the British Open. These are known in the golfing world as links courses, dramatically different from the grassy, intensely manicured courses most Americans are familiar with. Greens are connected less by fairways than by long reaches of rugged, seemingly unkempt terrain pocked by deep, cylindrical bunkers known as pot bunkers. These are another naturally occurring feature of the old courses, terrifying hazards into which unlucky golfers can disappear for long moments before chopping their wayward ball out again.

The old links courses in Ireland, Scotland and England are characterized by a coastal topography of dune and scrub-covered ridges. They evolved as the setting for a terribly frustrating game called golf because they were good for little else other than grazing the sheep that chomped away while early golfers swung away.

Though some may associate the word “links” with linked golf holes, the word actually comes from Old English and predates the game. It is the name given to that particular harsh and scrubby landscape behind a beach.

This is the world that Dye wanted to create with The Straits. He started with a wasteland along the shore of Lake Michigan, a flat and dismal area that had been the site of a military antiaircraft training range. He ordered up 7,000 truckloads of sand and went to work.
What emerged was a course of bluff and dune along two miles of Lake Michigan shoreline with holes named Gremlin’s Ear and Snake and Cliff Hanger and Widow’s Watch and Pinched Nerve. Each hole has a view of the lake. There are four stone bridges and a stone clubhouse that looks as though it were transported rock by rock from the Scottish countryside. A flock of Scottish blackface sheep roam the grounds.

“We had to hire a shepherd,” Lee says. “Sometimes one of the sheep gets lost and we all have to look for it. You can spend hours out there looking for that one last sheep. It’s like something straight out of the Bible.”

But few characteristics connect The Straits to the old-style links courses more strongly than the wind. Lee, traveling the course, seemed almost always aware of the wind off the big lake.

“Out of the north today,” he says, during our drive. “Look at those waves.”

The wind gave the course its name. Herbert Kohler was walking the property during construction and, apparently teetering in a steady gale that whistled along the course’s heights and raised whitecaps on the lake, the name came to him very naturally.

The attention to detail in the course’s design, construction and maintenance has impressed the world’s best golfers. Lee keeps a file of comments from professional golfers, and he pulled out one from Tom Lehman, three-time winner of the PGA’s Player of the Year, who was interviewed about the course during the 2004 PGA Championship.

“It’s quite a feat of construction,” Lehman said. “I mean, it’s quite a vision they had . . . This golf course is almost otherworldly.”
Lehman also spoke of the course’s ruggedness. Players and spectators alike generally come off The Straits exhausted, Lee notes. During the 2010 championship he spent part of his time giving rides to exhausted spectators worn out by walking the up-and-down course.

Lee enjoys banging around the course in his truck, sharing its charms and its quirks, especially now as preparations for this summer’s championship are well under way. On one jaunt he points out the paths that are designed like narrow country lanes (no carts here; every golfer walks with a caddy). He pauses at the large staging areas for gravel and sand that will serve as platforms for the big corporate suites and viewing stands.

The course is being set up, Lee says, to make it more spectator-friendly, with better walking areas and viewing locations that place golf fans close to the action.

And Lee shares an interesting and somewhat startling detail that, upon reflection, makes perfect sense for a course owned by the Kohlers of bathroom fixture fame. He stops his pickup truck and points to what looks like gravel along the side of the road.
“We used crushed toilets to make that,” Lee says matter-of-factly, but with a faint smile playing on his face.

On this early spring day, the bentgrass on the greens and the fescue in the fairways has yet to begin changing from winter’s browns to the green of spring. But that green will soon enough begin creeping across the course—and Lee will be paying close attention to any disease or other problems that may try to establish a foothold.

For Lee and his staff, preparation for the PGA Championship has been going on for years: the close monitoring and treatment for disease and insects, the careful maintenance of the course throughout the playing season, when Lee’s crews are out morning and night raking, mowing and grooming.

Staff with the PGA have been on the site for two years, working from a large office trailer and keeping track of preparations, figuring out such details as where structures are going to go and where ropes will be placed to guide and control spectators.

The PGA course conditioning guidelines for championship competition give some indication of just how much attention to detail is necessary—consistent green speeds that are calculated with an instrument called a stimpmeter, mowers that are very precisely calculated to mow greens between .150 and .100 of an inch, the required use of bunker sand with grains that are measured so that no more than 25 percent of them are .25 mm or smaller.

“We go out all day with the guys from the PGA,” says Lee. “We’ve learned to pack a lunch.”

So it’s easy to see why Lee’s relationship with the experts at CALS becomes even more important as the championship draws near. Though Lee is adept at dealing with most of the challenges turf has to offer, the researchers at the Turfgrass Diagnostics Lab can often spot problems that remain invisible to most.

Back at the lab, Bruce Schweiger remembers puzzling over disease samples sent in by another client. To the client, the problem looked like dollar spot, but Schweiger knew that was not the issue. CALS entomology professor and UW–Extension specialist Chris Williamson was working nearby, and Schweiger asked him to take a look.

“Oh,” Williamson said. “Ants.”

It turned out that Williamson had done research on the problem some time before and had discovered that, during the mating season, some ant species go to war. They attack each other by spraying a nerve toxin that contains formic acid. That acid burns the turf and leaves lesions that look suspiciously like dollar spots, Schweiger recounts.

Such are the strange problems that could arise to plague Lee and his crew as they tend the course during the championship.

And those worries are on top of the intense maintenance that requires around-the-clock diligence once the event begins. Most crew members stay on-site working hours on end during championship week, Lee says, sleeping in big shelters set up for that purpose, snoozing in reclining chairs and watching the golf action on television screens.

Plant pathologist Paul Koch worked during the 2004 championship as an intern on one of the two- and three-person green crews that are charged with caring for a particular green and making sure during the week that it is cut morning and night and maintained to the PGA’s exacting specifications.

Sometimes, Koch says, that requires a cut of a mere sliver, no more than the depth of three credit cards or so stacked one upon the other.

One damp early morning during the championship, Koch recalls, Lee dispatched crews to squeegee the dew from tees. Koch was met during the chore by one of the professional golfers, who marveled at what Koch was doing.

“He said, ‘I can’t believe you guys are doing this so that we don’t have to walk in dew,’” Koch recalls.

Through the entire championship, Koch says, Lee remained cool and collected.

Of course, going into the week of a championship, Lee has already made sure there is little that can go wrong. A recent tour of the course included a visit to the maintenance building garage, located just outside the door from Lee’s spartan office (aerial shots of the course being the most elaborate decoration).

Lee walked to one of the 60 big mowers lined up and gleaming in neat rows. He tilted one up and suggested running a finger across one of the blades.

It was razor sharp.

Learn more at the following websites:
O.J. Noer Turfgrass Research and Education Facility: http://ojnoer.ars.wisc.edu
Whistling Straits: www.americanclubresort.com/golf/whistling-straits
PGA Championship: www.pga.com/pgachampionship

Plant Prowess

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It may look jury-rigged, but it’s cutting-edge science.

In a back room in the university’s Seeds Building, researchers scan ears of corn—three at a time—on a flatbed scanner, the kind you’d find at any office supply store. After running the ears through a shelling machine, they image the de-kerneled cobs on a second scanner.

The resulting image files—up to 40 gigabytes’ worth per day—are then run through a custom-made software program that outputs an array of yield-related data for each individual ear. Ultimately, the scientists hope to link this type of information—along with lots of other descriptive data about how the plants grow and what they look like—back to the genes that govern those physical traits. It’s part of a massive national effort to deliver on the promise of the corn genome, which was sequenced back in 2009, and help speed the plant breeding process for this widely grown crop.

“When it comes to crop improvement, the genotype is more or less useless without attaching it to performance,” explains Bill Tracy, professor and chair of the Department of Agronomy. “The big thing is phenotyping—getting an accurate and useful description of the organism—and connecting that information back to specific genes. It’s the biggest thing in our area of plant sciences right now, and we as a college are playing a big role in that.”

No surprise there. Since the college’s founding, plant scientists at CALS have been tackling some of the biggest issues of their day. Established in 1889 to help fulfill the University of Wisconsin’s land grant mission, the college focused on supporting the state’s fledgling farmers, helping them figure out how to grow crops and make a living at it. At the same time, this practical assistance almost always included a more basic research component, as researchers sought to understand the underlying biology, chemistry and physics of agricultural problems.

That approach continues to this day, with CALS plant scientists working to address the ever-evolving agricultural and natural resource challenges facing the state, the nation and the world. Taken together, this group constitutes a research powerhouse, with members based in almost half of the college’s departments, including agronomy, bacteriology, biochemistry, entomology, forest and wildlife ecology, genetics, horticulture, plant pathology and soil science.

“One of our big strengths here is that we span the complete breadth of the plant sciences,” notes Rick Lindroth, associate dean for research at CALS and a professor of entomology. “We have expertise across the full spectrum—from laboratory to field, from molecules to ecosystems.”

This puts the college in the exciting position of tackling some of the most complex and important issues of our time, including those on the applied science front, the basic science front—and at the exciting new interface where the two approaches are starting to intersect, such as the corn phenotyping project.

“The tools of genomics, informatics and computation are creating unprecedented opportunities to investigate and improve plants for humans, livestock and the natural world,” says Lindroth. “With our historic strength in both basic and applied plant sciences, the college is well positioned to help lead the nation at this scientific frontier.”

It’s hard to imagine what Wisconsin’s agricultural economy would look like today without the assistance of CALS’ applied plant scientists.

The college’s early horticulturalists helped the first generation of cranberry growers turn a wild bog berry into an economic crop. Pioneering plant pathologists identified devastating diseases in cabbage and potato, and then developed new disease-resistant varieties. CALS agronomists led the development of the key forage crops—including alfalfa and corn—that feed our state’s dairy cows.

Fast-forward to 2015: Wisconsin is the top producer of cranberries, is third in the nation in potatoes and has become America’s Dairyland. And CALS continues to serve the state’s agricultural industry.

The college’s robust program covers a wide variety of crops and cropping systems, with researchers addressing issues of disease, insect and weed control; water and soil conservation; nutrient management; crop rotation and more. The college is also home to a dozen public plant-breeding programs—for sweet corn, beet, carrot, onion, potato, cranberry, cucumber, melon, bean, pepper, squash, field corn and oats—that have produced scores of valuable new varieties over the years, including a number of “home runs” such as the Snowden potato, a popular potato chip variety, and the HyRed cranberry, a fast-ripening berry designed for Wisconsin’s short growing season.

While CALS plant scientists do this work, they also train the next generation of researchers—lots of them. The college’s Plant Breeding and Plant Genetics Program, with faculty from nine departments, has trained more graduate students than any other such program in the nation. Just this past fall, the Biology Major launched a new plant biology option in response to growing interest among undergraduates.

“If you go to any major seed company, you’ll find people in the very top leadership positions who were students here in our plant-breeding program,” says Irwin Goldman PhD’91, professor and chair of the Department of Horticulture.

Among the college’s longstanding partnerships, CALS’ relationship with the state’s potato growers is particularly strong, with generations of potato growers working alongside generations of CALS scientists. The Wisconsin Potato and Vegetable Growers Association (WPVGA), the commodity group that supports the industry, spends more than $300,000 on CALS-led research each year, and the group helped fund the professorship that brought Jeff Endelman, a national leader in statistical genetics, to campus in 2013 to lead the university’s potato-breeding program.

“Research is the watchword of the Wisconsin potato and vegetable industry,” says Tamas Houlihan, executive director of the WPVGA. “We enjoy a strong partnership with CALS researchers in an ongoing effort to solve problems and improve crops, all with the goal of enhancing the economic vitality of Wisconsin farmers.”

Over the decades, multi-disciplinary teams of CALS experts have coalesced around certain crops, including potato, pooling their expertise.

“Once you get this kind of core group working, it allows you to do really high-impact work,” notes Patty McManus, professor and chair of the Department of Plant Pathology and a UW–Extension fruit crops specialist.

CALS’ prowess in potato, for instance, helped the college land a five-year, $7.6 million grant from the U.S. Department of Agriculture to help reduce levels of acrylamide, a potential carcinogen, in French fries and potato chips. The multistate project involves plant breeders developing new lines of potato that contain lower amounts of reducing sugars (glucose and fructose) and asparagine, which combine to form acrylamide when potatoes are fried. More than a handful of conventionally bred, low-acrylamide potato varieties are expected to be ready for commercial evaluations within a couple of growing seasons.

“It’s a national effort,” says project manager Paul Bethke, associate professor of horticulture and USDA-ARS plant physiologist. “And by its nature, there’s a lot of cross-talk between the scientists and the industry.”

Working with industry and other partners, CALS researchers are responding to other emerging trends, including the growing interest in sustainable agricultural systems.

“Maybe 50 years ago, people focused solely on yield, but that’s not the way people think anymore. Our crop production people cannot just think about crop production, they have to think about agroecology, about sustainability,” notes Tracy. “Every faculty member doing production research in the agronomy department, I believe, has done some kind of organic research at one time or another.”

Embracing this new focus, over the past two years CALS has hired two new assistant professors—Erin Silva, in plant pathology, who has responsibilities in organic agriculture, and Julie Dawson, in horticulture, who specializes in urban and regional food systems.

“We still have strong partnerships with the commodity groups, the cranberries, the potatoes, but we’ve also started serving a new clientele—the people in urban agriculture and organics that weren’t on the scene for us 30 years ago,” says Goldman. “So we have a lot of longtime partners, and then some new ones, too.”

Working alongside their applied colleagues, the college’s basic plant scientists have engaged in parallel efforts to reveal fundamental truths about plant biology—truths that often underpin future advances on the applied side of things.

For example, a team led by Aurélie Rakotondrafara, an assistant professor of plant pathology, recently found a genetic element—a stretch of genetic code—in an RNA-based plant virus that has a very useful property. The element, known as an internal ribosome entry site, or IRES, functions like a “landing pad” for the type of cellular machine that turns genes—once they’ve been encoded in RNA—into proteins. (A Biology 101 refresher: DNA—>RNA—>Protein.)

This viral element, when harnessed as a tool of biotechnology, has the power to transform the way scientists do their work, allowing them to bypass a longstanding roadblock faced by plant researchers.

“Under the traditional mechanism of translation, one RNA codes for one protein,” explains Rakotondrafara. “With this IRES, however, we will be able to express several proteins at once from the same RNA.”

Rakotondrafara’s discovery, which won an Innovation Award from the Wisconsin Alumni Research Foundation (WARF) this past fall and is in the process of being patented, opens new doors for basic researchers, and it could also be a boon for biotech companies that want to produce biopharmaceuticals, including multicomponent drug cocktails, from plants.

Already, Rakotondrafara is working with Madison-based PhylloTech LLC to see if her new IRES can improve the company’s tobacco plant-based biofarming system.

“The idea is to produce the proteins we need from plants,” says Jennifer Gottwald, a technology officer at WARF. “There hasn’t been a good way to do this before, and Rakotondrafara’s discovery could actually get this over the hump and make it work.”

While Rakotondrafara is a basic scientist whose research happened to yield a powerful application, CALS has a growing number of scientists—including those involved in the corn phenotyping project—who are working at the exciting new interface where basic and applied research overlap. This new space, created through the mind-boggling advances in genomics, informatics and computation made in recent years, is home to an emerging scientific field where genetic information and other forms of “big data” will soon be used to guide in-the-field plant-breeding efforts.

Sequencing the genome of an organism, for instance, “is almost trivial in both cost and difficulty now,” notes agronomy’s Bill Tracy. But a genome—or even a set of 1,000 genomes—is only so helpful.

What plant scientists and farmers want is the ability to link the genetic information inside different corn varieties—that is, the activity of specific genes inside various corn plants—to particular plant traits observed in the greenhouse or the field. The work of chronicling these traits, known as phenotyping, is complex because plants behave differently in different environments—for instance, growing taller in some regions and shorter in others.

“That’s one of the things that the de Leon and Kaeppler labs are now moving their focus to—massive phenotyping. They’ve been doing it for a while, but they’re really ramping up now,” says Tracy, referring to agronomy faculty members Natalia de Leon MS’00 PhD’02 and Shawn Kaeppler.

After receiving a large grant from the Great Lakes Bioenergy Research Center in 2007, de Leon and Kaeppler decided to integrate their two research programs. They haven’t looked back. With de Leon’s more applied background in plant breeding and field evaluation, plus quantitative genetics, and with Kaeppler’s more basic corn genetics expertise, the two complement each other well. The duo have had great success securing funding for their various projects from agencies including the National Science Foundation, the U.S. Department of Agriculture and the U.S. Department of Energy.

“A lot of our focus has been on biofuel traits, but we measure other types of economically valuable traits as well, such as yield, drought tolerance, cold tolerance and others,” says Kaeppler. Part of the work involves collaborating with bioinformatics experts to develop advanced imaging technologies to quantify plant traits, projects that can involve assessing hundreds of plants at a time using tools such as lasers, drone-mounted cameras and hyperspectral cameras.

This work requires a lot of space to grow and evaluate plants, including greenhouse space with reliable climate control in which scientists can precisely measure the effects of environmental conditions on plant growth. That space, however, is in short supply on campus.

“A number of our researchers have multimillion-dollar grants that require thousands of plants to be grown, and we don’t always have the capacity for it,” says Goldman.

That’s because the Walnut Street Greenhouses, the main research greenhouses on campus, are already packed to the gills with potato plants, corn plants, cranberries, cucumbers, beans, alfalfa and dozens of other plant types. At any given moment, the facility has around 120 research projects under way, led by 50 or so different faculty members from across campus.

Another bottleneck is that half of the greenhouse space at Walnut Street is old and sorely outdated. The facility’s newer greenhouses, built in 2005, feature automated climate control, with overlapping systems of fans, vents, air conditioners and heaters that help maintain a pre-set temperature. The older houses, constructed of single-pane glass, date back to the early 1960s and present a number of challenges to run and maintain. Some don’t even have air conditioning—the existing electrical system can’t handle it. Temperatures in those houses can spike to more than 100 degrees during the summer.

“Most researchers need to keep their plants under fairly specific and constant conditions,” notes horticultural technician Deena Patterson. “So the new section greenhouse space is in much higher demand, as it provides the reliability that good research requires.”

To help ameliorate the situation, the college is gearing up to demolish the old structures and expand the newer structure, adding five more wings of greenhouse rooms, just slightly north of the current location—out from under the shadow of the cooling tower of the West Campus Co-Generation Facility power plant, which went online in 2005. The project, which will be funded through a combination of state and private money, is one of the university’s top building priorities.

Fortunately, despite the existing limitations, the college’s plant sciences research enterprise continues apace. Kaeppler and de Leon, for example, are involved in an exciting phenotyping project known as Genomes to Fields, which is being championed by corn grower groups around the nation. These same groups helped jump-start an earlier federal effort to sequence the genomes of many important plants, including corn.

“Now they’re pushing for the next step, which is taking that sequence and turning it into products,” says Kaeppler. “They are providing initial funding to try to grow Genomes to Fields into a big, federally funded initiative, similar to the sequencing project.”

It’s a massive undertaking. Over 1,000 different varieties of corn are being grown and evaluated in 22 environments across 13 states and one Canadian province. Scientists from more than a dozen institutions are involved, gathering traditional information about yield, plant height and flowering times, as well as more complex phenotypic information generated through advanced imaging technologies. To this mountain of data, they add each corn plant’s unique genetic sequence.

“You take all of this data and just run millions and billions of associations for all of these different traits and genotypes,” says de Leon, who is a co-principal investigator on the project. “Then you start needing supercomputers.”

Once all of the dots are connected—when scientists understand how each individual gene impacts plant growth under various environmental conditions—the process of plant breeding will enter a new sphere.

“The idea is that instead of having to wait for a corn plant to grow for five months to measure a certain trait out in the field, we can now take DNA from the leaves of little corn seedlings, genotype them and make decisions within a couple of weeks regarding which ones to advance and which to discard,” says de Leon. “The challenge now is how to be able to make those types of predictions across many environments, including some that we have never measured before.”

To get to that point, notes de Leon, a lot more phenotypic information still needs to be collected—including hundreds and perhaps thousands more images of corn ears and cobs taken using flatbed scanners.

“Our enhanced understanding of how all of these traits are genetically controlled under variable environmental conditions allows us to continue to increase the efficiency of plant improvement to help meet the feed, food and fiber needs of the world’s growing population,” she says.

Sidebar:

The Bigger Picture

Crop breeders aren’t the only scientists doing large-scale phenotyping work. Ecologists, too, are increasingly using that approach to identify the genetic factors that impact the lives of plants, as well as shape the effects of plants on their natural surroundings.

“Scientists are starting to look at how particular genes in dominant organisms in an environment—often trees—eventually shape how the ecosystem functions,” says entomology professor Rick Lindroth, who also serves as CALS’ associate dean for research. “Certain key genes are driving many fantastically interesting and important community- and ecosystem-level interactions.”

How can tree genes have such broad impacts? Scientists are discovering that the answer, in many cases, lies in plant chemistry.
“A tree’s chemical composition, which is largely determined by its genes, affects the community of insects that live on it, and also the birds that visit to eat the insects,” explains Lindroth. “Similarly, chemicals in a tree’s leaves affect the quality of the leaf litter on the ground below it, impacting nutrient cycling and nitrogen availability in nearby soils.”

A number of years ago Lindroth’s team embarked on a long-term “genes-to-ecosystems” project (as these kinds of studies are called) involving aspen trees. They scoured the Wisconsin landscape, collecting root samples from 500 different aspens. From each sample, they propagated three or four baby trees, and then in 2010 planted all 1,800 saplings in a so-called “common garden” at the CALS-based Arlington Agricultural Research Station.

“The way a common garden works is, you put many genetic strains of a single species in a similar environment. If phenotypic differences are expressed within the group, then the likelihood is that those differences are due to their genetics, not the environment,” explains Lindroth.

Now that the trees have had some time to grow, Lindroth’s team has started gathering data about each tree—information such as bud break, bud set, tree size, leaf shape, leaf chemistry, numbers and types of bugs on the trees, and more.

Lindroth and his partners will soon have access to the genetic sequence of all 500 aspen genetic types. Graduate student Hilary Bultman and postdoctoral researcher Jennifer Riehl will do the advanced statistical analysis involved—number crunching that will reveal which genes underlie the phenotypic differences they see.

In this and in other projects, Lindroth has called upon the expertise of colleagues across campus, developing strategic collaborations as needed. That’s easy to do at UW–Madison, notes Lindroth, where there are world-class plant scientists working across the full spectrum of the natural resources field—from tree physiology to carbon cycling to climate change.

“That’s the beauty of being at a place like Wisconsin,” Lindroth says.

Want to help? The college welcomes your gift toward modernizing the Walnut Street Greenhouses. To donate, please visit: supportuw.org/giveto/WalnutGreenhouse. We thank you for your contribution. Continue reading →

Science for Citizens

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Entomology professors Walter Goodman and David Hogg

Entomology professors Walter Goodman and David Hogg

CALS is acclaimed as one of the best schools in the nation for training top-notch researchers and practitioners. Less known is the fact that CALS offers challenging, creative courses to undergraduates from outside of the natural sciences as well—in keeping with the college’s mission to cultivate science literacy as a vital component of good citizenship. For many students, these classes may be their only exposure to college-level science.

Two classes exemplifying that mission are Entomology 201—“Insects and Human Culture” —and Plant Pathology 123, “Plants, Parasites and People.” Both are highly popular classes that use insects and plants as ways to connect students with essential information about the natural world.

“It offers a window to science as it relates to their everyday lives,” says plant pathology professor Mehdi Kabbage.

“This is really biology with insects on top of it,” says entomology professor Walter Goodman, who’s been teaching Ent 201 for more than 20 years. “We use insects as a vehicle for describing biology and looking at the practical aspects of biology, like agricultural entomology as well as medical entomology.”

Both classes engage students in a range of hands-on activities. In Entmology 201, students take home the tiny eggs of a tobacco hornworm, or Manduca sexta, and over a period of two months raise it to maturation, keeping a daily logbook in which they describe its metamorphosis from fat turquoise caterpillar to large brown moth. In Plant Pathology 123, each student is given a “mystery microbe” in a petri dish—a Pseudomonas aureofaciens bacterium, for example, or a Fusarium oxysporum fungus—and devise various experiments to determine which microbe they have.

The students are having fun—but they’re also sharpening their observational skills and learning about the scientific process as well as how to make and critique a scientific argument. Their engagement with science often has deep and far-reaching consequences.

Education major Tess Bashaw signed up for Entomology 201 simply to fulfill her science requirement— and instead, “It opened up so many roads to me,” she says. In addition to gaining new skills and information—“learning how to catch and pin insects, how to collect leeches in floods, how camouflage really works”—the course made her grow as a writer, she says.

The lessons stuck. And as a teacher of lowincome children, she’s been sharing those lessons in her classroom for the past decade. “I love teaching writing, and science is a favorite of mine,” Bashaw says.

Given the important mission and high student demand for this signature style of science education, CALS would like to expand offerings to more departments and more students.

To learn more about supporting those efforts, please contact Sarah Pfatteicher, CALS’ associate dean for academic affairs, at sarah.pfatteicher@wisc.edu, tel. (608) 262-3003. To make a gift, please visit supportuw.org/giveto/calssignature.

Of Pests and Pathogens

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Imagine you’re standing in a sun-drenched field full of lettuce plants. There’s a gentle breeze and a smattering of tiny insects flitting about. It’s a pleasant scene, right?

Now let’s say one corner of the plot is contami- nated with the deadly human food-borne pathogen Salmonella enterica, due to dirty irrigation water.

Could the insects, which hop from leaf to leaf feeding on plant sugars, play a role in spreading the contamination further afield?

“As insects feed and wander around on contami- nated plant surfaces, it’s possible that they pick up Salmonella, so we decided to ask if they are playing a role in food safety,” says Jeri Barak, a CALS professor of plant pathology.

It’s an important question. Salmonellosis is one of the leading causes of acute bacterial gastroenteritis in the United States, responsible for an estimated 1.4 million illnesses, 15,000 hospitalizations and 400 deaths annually. In recent years, there have been more salmonellosis illnesses linked to fresh produce than to animal products. Yet very little is understood about produce-associated outbreaks, including basic information about how human pathogens survive and spread on plants.

To test whether plant-eating insects play a role, Barak teamed up with CALS entomology professor Russell Groves to design experiments assessing the ability of two common crop insect pests—the aster leafhopper and the green peach aphid—to pick up and spread Salmonella.

“Because we work with human pathogens in my lab, we never get to do research outside, so it was important to have someone like Russ Groves on board,” notes Barak. “He’s a UW–Extension ento- mologist, so he has a lot of experience in the field, and he pushed us to be as practical as possible.”

In one set of experiments, insects were given a piece of Salmonella-contaminated leaf material to munch on for 24 hours. In another, they spent the day drinking Salmonella-laced sugar water through a protective barrier that prevented physical contact between Salmonella and

insect. In both setups, the insects were then transferred into a series of clean environ- ments over the next 48 hours to see if—and how long—the contamination lasted.

In both cases, the insects readily picked up Salmonella, and once contaminated, most stayed contaminated.

Those that ate tainted leaves became contaminated inside and out, harboring Salmonella in their guts as well as on their feet and antennae, and when they were trans- ferred to clean tubes, they spread the bacteria to fresh leaf material.

For insects that drank the Salmonella- laced sugar water, the bacteria got into their guts—and also found a way out.

“They excreted the Salmonella through honeydew—that’s a nice word for insect poop. Even after 48 hours, they were still pooping it out,” says Barak.

Honeydew, they also found, serves as a nutrient-rich fertilizer that helps Salmonella grow on plant surfaces that would otherwise be inhospitable.

On the practical side, notes Barak, farmers can now add these insects to the list of risk factors they consider when making crop management decisions.

“Now when a raw-produce grower looks out and it’s been a bad year for insect infestation, it might sig- nal to them that they may have a higher food safety risk,” she says.

Catch up with … Michelle Moyer

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SHE’S NEVER SET FOOT IN AFGHANISTAN , but Michelle Moyer is helping farmers there nevertheless. Moyer, who earned her Ph.D. in plant pathology at Cornell University, is now an assistant professor of horticulture at Washington State University, where she also serves as an Extension specialist for viticulture. This put her in a prime position to help U.S. troops being sent to Afghanistan to better understand the significance and cultivation of the country’s No. 1 fruit crop: the grape.

Moyer developed a presentation for the national Grape Community of Practice (GCoP), an Extension network of 87 grape production professionals from 31 states and Ontario, Canada. The GCoP is distributing Moyer’s presentation to its members at universities and government agencies who are involved in training U.S. troops.

With this work Moyer joins a number of experts in the CALS community who are helping the U.S. military improve agriculture in Afghanistan. For example, CALS serves as a training and “reachback” resource for Wisconsin National Guard agribusiness development troops serving in Afghanistan.

Why is it important for U.S. troops to know about Afghanistan’s grape cultivation?
Grapes, the leading horticulture crop in Afghanistan, are used predominately for fresh eating and raisin production. Many troops arrive in country during the growing season, so being aware of what they’re seeing will help minimize damage. That’s critical in establishing rapport with local communities. There are many U.S.-based economic development teams working in Afghanistan to help promote agricultural production, so clearly everyone wants to be on the same page. If other U.S. and international aid agencies are promoting the growth and development of the viticulture industry, it is imperative that military efforts do not hinder it.

How does grape cultivation in Afghanistan and in the United States differ?
The biggest differences are the extent and level of infrastructure. Afghan vineyards often are not arranged in rows. In many cases, vines are trellised on any available structure or grow in a bush form. Irrigation systems are still predominately in the form of ditches, and we highlight the need to be careful when operating machinery through them as it could negatively impact farmland downstream.

Vineyards growing raisin grapes often have large structures called “kishmish khanas” located in their center. These are drying houses for raisins. Grapes are dried in a similar fashion as tobacco is in Wisconsin: they’re hung on various levels inside a dark building with sufficient air circulation. As they dry, the raisins drop to the ground, where they are collected. Unfortunately, khanas also are likely spots for insurgent activity, so we highlight being careful when scouting—for many reasons!—as you could damage produce worth thousands of dollars.

What did you learn from the experience of preparing a group for this particular need?
It really highlighted the global and cultural significance of grape production. In the United States, we tend to focus on wine grape production when we think of grapes. But grapes have so many more uses that are equally vital and are an integral part of a culture’s heritage. It was fascinating to learn about this type, style and level of grape production, particularly relating to raisin production in Afghanistan. I am impressed that the U.S. military reaches out to Extension for this education. It highlights that the U.S.’s intention in these types of operations is to help, even if that message gets lost in the political and emotional strains of conflict.

Rising to the Top

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Imagine, as a young biology student, trying to explain stem cells to Jamie Thomson, the UW scientist who first isolated them in a lab. Or, as a budding computer scientist, pitching an iPhone software upgrade—in person—to Steve Jobs. That will give you some idea of how students in “Microbiology 375: Introduction to Brewing” felt about their final project.

After delving into the science of brewing, the class broke into small groups to concoct their own beers from scratch using state-of-the-art microbrewery equipment—a capstone project that made them the envy of their peers. And as a final exam, the students presented the suds of their labors—a Scotch ale, an Irish red ale, an American lager and a bock—to an expert panel of brewing heavyweights. The panel included experienced homebrewers, brewmasters from Wisconsin’s Capital Brewery, Lake Louie Brewing and New Glarus Brewing Company, and perhaps most intimidatingly—here’s where the Jamie Thomson/Steve Jobs thing comes in—David Ryder, vice president of brewing and research at MillerCoors and a world authority on fermentation and yeast physiology.

Drawing on all they’d learned about microbiology, biochemistry and engineering, the students described the ingredients they chose, the time and temperatures they used for each step and how they treated the brewing yeast. “Although they were nervous about it, that experience was a highlight for them,” says Jon Roll, a CALS faculty associate in bacteriology who led the brewing lab. “Having that audience in that situation was an incredible opportunity.”

Of the experts on the panel, no one was more engaged than Ryder. For him, it was a shining moment in the course of a strategic partnership in which the Milwaukee-based brewing giant is helping the college ramp up its offerings in fermentation science. That field underlies the production of not only beer but also other products critical to the state’s economy—including cheese, sausage, sauerkraut, soy sauce and bioethanol, to name a few. As an overture to the budding alliance, in 2007 Ryder arranged MillerCoors’ donation of more than $100,000 worth of pilot-scale brewing equipment to the college—the guts of Roll’s brewing lab. Now, with a lecture-style fermentation course available, CALS is gearing up to offer an undergraduate certificate in fermentation science.

“This will give UW students an opportunity to see what’s out there in the fermentation industries,” says Ryder. “They don’t have to come to Miller-Coors, but what helps the industry helps us, by implication. The program will help MillerCoors find great people for the future.”

The certificate is just the first step. Down the line, Ryder and leaders in the food science department hope to establish a Food and Beverage Fermentations Center to help focus and expand the university’s teaching, research and outreach in this field. While the spark came from the brewing business, the center will serve all of Wisconsin’s many fermentation-based industries and help prepare students for careers in the state’s cheese plants, food processing facilities, breweries and biorefineries alike. It’s an ambitious plan, but there’s no doubt that Ryder, known affectionately as “Dr. Bubbles” in the brewing world, will see that it happens.

“David is the champion of getting brewing on campus,” says food science department chair Scott Rankin. “He’s a man of action, and it’s his personal mission to see this through.”

The nickname “Dr. Bubbles” reflects not just the products that David Ryder creates, but also his manner. With his charming British accent—Ryder was born and raised in London—and easy enthusiasm, Ryder can be effervescent, particularly when he’s bantering about his favorite topic: happy yeast. “Our yeast has to be happy. Under no circumstances can it be sad,” he explains. “Happy yeast is good yeast because it enables us to create superior beers, so we always look to the yeast.”

Ryder got into the brewing industry by chance when he took a job at Associated British Maltsters during college. Throughout graduate school he worked and traveled, troubleshooting and conducting research for South African Breweries in South Africa and Zimbabwe and Artois Breweries in Belgium. By the time he completed his doctorate in biochemistry in 1985, he was already a sought-after commodity. In 1986 he took a position at Chicago’s J.E. Siebel Sons’ Company Inc., a brewing research, analysis and education outfit, where he served as vice president of technical services and education director of the company’s brewing school, the Siebel Institute of Technology.

Ryder joined Miller Brewing Company in 1992, which in 2008 merged with Molson Coors Brewing Company to form MillerCoors, the nation’s second largest brewing company. In labs in Milwaukee and Golden, Colorado, he leads a crew of brewers, microbiologists, chemists, biochemists and engineers who spend their days examining the brewing process in excruciating detail. The tiniest thing that affects beer’s 3,000 chemical compounds and 97 detectable flavors is fair game for study. Among the endless list of research targets, Ryder’s team has figured out why beer turns “skunky” in sunlight, developed a colorless beer, and come to understand a head of beer so well that they can now dial the foam up—or down—with pinpoint precision. In 19 years, Ryder has published more than 32 scientific articles and racked up 19 U.S. patents, all centered on improving or diversifying the company’s products.

“Brewing is one of these things that can keep a curious mind very interested and very active,” Ryder says.

When Ryder moved to Wisconsin, he was bothered by the lack of ties between one of the state’s signature industries and UW–Madison. MillerCoors needs scientists, he says, if not for Milwaukee’s research division or brewing plant, then for the company’s seven other breweries around the nation. “I was surprised to learn that brewers in the state hadn’t taken more interest in UW–Madison in the past, to have a brewing school in Madison or a school of fermentation science there,” he says. “It makes a lot of sense to take advantage of it, because it’s just down the road and it’s such a great university.”

So when Anjali Sridharan, a university-business liaison at the UW–Madison Office for Corporate Relations, reached out to Ryder to explore opportunities, it didn’t take the brewing expert long to lay out an ambitious plan. “My big dream is to have UW–Madison be the preeminent brewing university in the world,” he says.

Ryder’s idea sparked the food science department’s plan to create a broader Food and Beverage Fermentations Center, which will house the brewing program. The center will capitalize on the department’s strong ties to industry, plus the extensive scientific expertise available across campus—in food science, the Center for Dairy Research, the bacteriology department, the Great Lakes Bioenergy Research Center and the College of Engineering—to help prepare students for jobs throughout the state’s vibrant fermentation sector.

About one-third of what the world eats consists of fermented foods. And in Wisconsin, thanks to the state’s cultural history, the proportion is much higher, says Jim Steele, professor of food science, who studies the microbes that grow in cheese. “Cheese, beer, sausage, sauerkraut—any of those ring a bell?” Steele asks. “Fermented foods are a significant portion of a typical Wisconsinite’s diet.”

People have been fermenting food and drink for thousands of years, often to help preserve foods with a short shelf life, such as milk and juice. It wasn’t until 1854, however, that French chemist Louis Pasteur discovered that tiny microbes are what drive the process. Yeast cells, he found, control the most important step in beer making: converting the sugars in malted barley into ethanol and carbon dioxide. Cheesemakers, in much the same way, rely on bacteria to turn milk sugars into lactic acid, which helps milk curdle.

Fermentation’s primary value today is in creating complex, palette-pleasing flavors. In addition to beer, wine and cheese, fermentation brings us whiskey, vodka and bread (from grains); vinegar, cider and brandy (from fruit); mead (from honey); miso and tempeh (from beans); pepperoni and salami (from meat); and crème fraiche and yogurt (from milk). Thank you, microbial metabolism!

But Wisconsin doesn’t just eat and drink fermented products. The Badger State makes them, in a big way. The state’s dairy industry, where 90 percent of milk goes into cheese, contributes about $20 billion to the state’s economy. The beer industry adds another $6 billion. In the southern Wisconsin village of Walworth, a Kikkoman soy sauce fermentation plant—one of the largest in the world—produces more than 33 million gallons of the salty condiment each year. In Waupaca County, one of the world’s largest sauerkraut producers, the Great Lakes Kraut Company, goes through a lot of cabbage.

“This is a fermented foods-rich state,” says Steele. “Incredibly rich.”

But fermentation isn’t just about food. It turns corn waste into silage, an important feed for Wisconsin’s dairy cows. Fermentation also drives Wisconsin’s corn ethanol industry, which generates more than $1 billion annually by using yeast to turn corn sugar into fuel. It will be equally important for creating cellulosic ethanol, a next-generation biofuel made from stalks, wood chips and other non-edibles, which is now under development at the UW-based Great Lakes Bioenergy Research Center. And a number of Wisconsin’s biotech companies, including Promega Corporation, Cardinal Health and Bio-Technical Resources, use microbial fermentation to produce drugs and other valuable compounds.

If all goes according to plan, a new undergraduate certificate in fermentation science—followed by a master’s program—will soon help open up new and better jobs for UW–Madison students in a variety of departments. “In food science, we currently place 100 percent of our undergraduate majors already, but I think that we can place them at higher-level positions and at places that have even stronger career tracks,” Steele says. “And for students in microbiology and other fields, going through the certificate program will provide much broader exposure to the basic food chemistry and food engineering principles that people need to work in industry.”

The shiny, stainless steel microbrewery equipment donated by MillerCoors currently sits in the bacteriology department’s Kikkoman Fermentations Laboratory, where it’s clearly visible to diners in the Microbial Sciences Building’s atrium cafe. This is where Roll ran his brewing lab in spring 2009 and spring 2010, with about 10 enthusiastic students each time.

About one-third of what the world eats consists of fermented foods

“Brewing is such a great hook to get students into deeper science,” he says. “When they taste something surprising in a beer they made, they ask, ‘What is that? Oh, it’s this chemical compound. Well, where does it come from? It comes from this biochemical pathway in yeast.’ It makes what they learned in biochemistry tangible and gives them a genuine interest in why various chemicals appear.”

To give more students a taste, this past spring Jim Steele offered a lecture-style course on fermentation science while the brewing lab took a hiatus. “Food Science 375: Beer and Food Fermentations” quickly filled to 95 seats. “The interest has been overwhelming,” says Steele, who is leading the college’s push into fermentation science.

Starting next spring, the food science department will offer Steele’s course alongside an expanded lab course with both brewing and cheese-making units. By then, MillerCoors’ microbrew equipment will likely be installed in a larger, food-grade-certified classroom in Babcock Hall and the department should have a new associate faculty member on board, selected with an eye toward building the department’s fermentation science program. “This hire will have a big impact on the direction that our department goes,” says Steele.

This past fall, the food science department also hired David Ryder as an adjunct professor, enlisting his help right away in Steele’s fermentation course. During the brewing section, which spanned five weeks, Ryder drove out to Madison to give a lecture on hops and another on the future of the brewing industry. He clearly enjoyed sharing his knowledge with the students and stayed late both times to answer a long string of questions, even sending home two bags of pungent MillerCoors hops with an inquisitive homebrewer.

The pleasure Ryder gets from teaching mirrors his enthusiasm for the whole effort to bolster fermentation education on campus. He’s excited about creating new opportunities for UW–Madison students to follow a path that he’s found to be challenging, fun and fulfilling. “If those students want to come to MillerCoors, great,” he says. “But if they want to do something else in the fermentation industries, that’s fine, too. They will have this really great grounding that will help them along—whatever they choose.

“It’s fantastic to think that we’ll have graduates from UW–Madison going into the brewing industry worldwide,” says Ryder. “That’s great. That’s what it’s all about.”

Class Act: Farm Workers' Daughter

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Alejandra Huerta’s parents may be forgiven for their distress when Huerta announced she was pursuing a career in agriculture. As native Mexicans who spent their lives picking crops around Salinas, California, they had hoped that a good education would be their children’s ticket to a better life.

“What? You went to college for four years and now you’re going back to the fields?” was their reaction, Huerta recalls with a laugh. “I explained that I’m doing something very different. My job is not to pick. I think about the work I do.”

But convincing her parents that a career in science was right for her was nothing compared to the doubt Huerta had to overcome in herself.

She had always loved science, but in her first foray at a university, she fell behind in the science course sequence and her grades were disappointing. By contrast, the Spanish and Portuguese department wooed her with opportunities to study abroad. With some misgivings, she switched majors.

Living abroad gave her confidence. “I was like, I can do anything. I’ve lived here, I survived, I’ve nailed the language,” Huerta recalls. “That’s when I said, ‘I’m going back to the sciences.’”

Now a second-year Ph.D. student in plant pathology, Huerta’s research in Caitilyn Allen’s lab focuses on the bacterial plant pathogen Ralstonia, which causes disease in tomatoes, potatoes, tobacco and other valuable crops.

Last spring Huerta was awarded a three-year research fellowship from the National Science Foundation. The coveted honor includes a $30,000 annual stipend and a $10,500 cost-of-education allowance.

Huerta plans to stay in academia, but she also wants to help farm worker children back in Salinas. She’d like to develop an intensive science program for elementary school students.

“We don’t grow up thinking about biology or chemistry, so when we see it in high school it’s a completely different language. That’s why a lot of us struggle with it,” she says. “Sometimes we’re the first ones in our families taking that course. The only people we can really ask for help are our teachers, but sometimes we’re just so afraid—‘Oh my gosh, he’s going to think we’re dumb or something’—that we don’t do it.”

The Pathogen Path

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To dine with Jeri Barak is to take a lesson in applied food safety. Barak, an assistant professor of plant pathology, begins by sorting through her salad, plucking out any greens that appear dark and wet and moving them to another plate. It’s not the appearance that bothers her—it’s the small, but deadly, chance that those leaves host colonies of Salmonella enterica.

Why would salmonella, bacteria that thrive in the warm-blooded environs of an animal, hang out in a pile of lettuce? That’s what Barak would like to know. For the past 10 years, she’s been studying how the bacteria use plants as a mode of transportation to arrive at a more favorable destination.

Given the choice between alighting upon a plant or an animal, salmonella cells would pick an animal every time, Barak explains. Animals provide just the right milieu for the bacteria to grow and reproduce. By comparison, plants are inhospitable wastelands. But Barak has found that when salmonella cells wind up on a tomato or cauliflower plant, they are capable of hunkering down and waiting for something better to come along. “They want to get to an animal host, so why not get onto the food that your host eats?” Barak says. “It’s a smart strategy.”

That strategy is abetted by Americans buying more fresh produce. In the past, most families boiled vegetables like spinach, helping kill off pathogens. But as more veggies are eaten raw, foodborne illnesses from contaminated produce have increased significantly. Over the past 40 years, the incidence of produce-related outbreaks has grown from less than 1 percent to more than 12 percent of reported cases. “There is even some evidence that the number of salmonellosis outbreaks caused by people eating produce is now higher than those caused by eating eggs, chicken and other animal products,” says Barak.

Barak was among the first handful of researchers to start studying human pathogens in the context of plant systems. She was just launching her research career in 1996, when a major E. coli outbreak in Japan caused 17 deaths and more than 6,000 illnesses. The source in that case was sprouts, and it motivated the U.S. government to fund research on pathogens in produce.

In the lab, Barak has been working to identify the genes that enable salmonella to hang on for the ride, with the long-term goal of using this knowledge to improve food safety. So far she has pinpointed more than a dozen key genes involved in attaching and adhering to plants. She is also exploring a number of important extrinsic factors. She discovered, for instance, that salmonella thrives when tomato plants are infected with Xanthamonas vesicatoria, a common plant pathogen. “During disease,” she explains, “there are nutrients leaking out, so there’s a lot of stuff for salmonella to eat and everything just grows.” On the positive side, Barak has found a number of heirloom tomato varieties that salmonella can’t attach to. She is in the process of figuring out what makes these plants impervious to the bacterium, which could help speed the breeding of salmonella-free tomato varieties down the line.

In the meantime, Barak has no plans to swear off her vegetarian diet and hopes no one else will either. “That would be the worst thing that could happen,” she says. Just watch out for the slimy lettuce.

Tomatoes Ripen Students' Training

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BARELY SIX MONTHS into his graduate studies, Jonathan Jacobs BS’07 has already realized something critical about becoming a plant pathologist. And his epiphany had little to do with science.

Instead, it came as Jacobs stood in a dying tomato field in the central highlands of Guatemala, where he was completing a month-long research trip to gather information on a bacterium known as Ralstonia solanacearum. In plants such as potatoes, tobacco, bananas and tomatoes, Ralstonia can produce a devastating wilting disease that can leave plants—and farmers—ruined. And that’s exactly what Jacobs saw surrounding him—acres of limp, wilted tomato plants and a farmer desperate for answers.

“It changed my whole perspective on plant pathology,” says Jacobs, whose trip was funded with a grant from UW-Madison’s Latin American and Caribbean studies program. “To see it right in front of me, it made me want to understand this plant-microbe interaction even more, so that hopefully my research can help to reduce this disease in the future.”

Jacobs is not the first CALS student to have an eye-opening experience in Guatemala, where plant pathology professors Caitilyn Allen and Douglas Maxwell have maintained an active partnership with scientists studying bacterial wilt and other tropical plant diseases. Allen and Maxwell have sent a half dozen students to the Central American country to participate in research collaborations and see firsthand the effects of the tropical diseases they study.

“Few of our students have experience with the kind of devastating crop loss you see in developing countries,” says Maxwell. He notes that geminiviruses—a group of tropical plant viruses that are the focus of his research—have been blamed for destroying up to 20 percent of Guatemala’s tomato crop. “I’ve seen entire fields just abandoned. It’s heartbreaking.”

Yet also motivating. Since turning his attention to geminiviruses in 1998, Maxwell has led a multinational effort to develop hybrid tomatoes resistant to the viruses, which are spread by whiteflies. A seed company in Guatemala now markets four varieties that stand up to the disease.

Four years ago, the breeding project expanded to take on another scourge for farmers in the subtropics: the bacterial wilt caused by Ralstonia. The Guatemala-based team’s efforts are aided by the expertise of Allen’s lab, which has identified the bacterial genes that are active when Ralstonia infects a plant. Trials are still in their early stages, but Maxwell is optimistic.

“We’re growing these tomatoes on two sites, and they look very promising,” says Maxwell. “One of the farmers we work with told us he had never seen tomatoes grow in his field before. He wants seeds right now.”

MySpace: Caitilyn Allen

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  • job: Professor of Plant Pathology
  • lab: Located on the eighth floor of the Russell Labs building
  • team: Six researchers, including five students
  • current research: Investigating how certain bacteria cause wilt disease in crop plants

What’s the goal of your research?
I study bacteria that cause plant diseases, with the ultimate goal of improving the lives of subsistence farmers in the developing tropics.

Is work in the lab 9-to-5 or 24/7?
Not quite 24/7, but almost. My students and postdocs often work at night and usually on weekends. Since most of my work now involves the computer rather than plants and pipettes, I work at home nights and weekends to be near my kids.

What’s the view from the window?
Pretty wonderful. We look out on Lake Mendota and Picnic Point. It can make you feel a little wistful on sunny summer days when the lake is dotted with sailboats.

What’s playing on the lab radio?
I made a no-radio rule about 10 years ago after an ugly dispute broke out between country and hard rock factions in the lab. But the radio does play at night and on weekends, everything from salsa to bluegrass to 80s dance music.

If you had to evacuate your lab, what would you grab first?
My laptop––but only because my culture collection is too big to carry.

Clean desk or messy desk?
Messy, in spite of all my resolutions.

Eat out or brown bag?
Brown bag––the workday’s too short as it is. But it does lead to crumbs in the keyboard.

Any personal items in the lab?
My yoga mat––stretching keeps my back from getting too knotted up.

What’s your desktop picture?
My daughters. Also one of my bacterium inside a tomato stem. I’m afraid the picture of my bacterium is bigger.

Where do you get your best work done?
For working with people on my team, I need to be in the lab. For grading, a coffee shop is great. And for serious writing, you can’t beat the back corner of Steenbock library near the annual reports of the Southeast Asian Tuna Fishing Commission.

What’s the coolest thing you’ve learned by doing research?
That bacteria can sense when they are near a host plant and swim over to start an infection.

In a Land of Rice, a Potato Crop Blossoms

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SEVEN YEARS AGO IN THAILAND, Patchara Pongam MS’93 PhD’97 found herself with a potato problem.

A graduate of the CALS plant pathology department, Pongam was working at Kasetsart University to help establish Thailand’s potato industry, a pet project of Thai King Bhumibol Adulydej. The king’s negotiations had helped land a Frito-Lay potato processing plant in the northern city of Chiang Mai, and he hoped farmers in the region would supply the plant with locally grown potatoes. But the crop was struggling. The combination of Thailand’s wet and hot growing seasons proved ideal for late blight, and Pongam was beginning to think it would be nearly impossible to produce potatoes year round.

Seeking a crash course in potato pest management, Pongam contacted Walt Stevenson PhD’73, a CALS professor of plant pathology. She traveled to UW-Madison in 2000, and her visit sparked a cross-continental effort to increase the productivity of Thailand’s potato crop through sustainable growing and pest management practices. Since then, Stevenson has made numerous trips to educate students and researchers on the integrated pest management system used by the Wisconsin potato industry. He also works closely with Somsiri Sanchote, a fruit and vegetable pathologist at Kasetsart University who has succeeded Pongam in monitoring the country’s potato crop. The two scientists now co-advise a graduate student, who will spend at least a semester in Wisconsin learning about seed certification techniques, as well as improved diagnosis and disease-resistance screening. Ultimately, the goal is to breed new disease-resistant potatoes for use in Thailand that would allow farmers to produce crops year-round and help supply the Frito-Lay plant.

In Thailand, Stevenson has taught classes, assisted with research projects, met with growers and industry representatives and even helped install a weather station. “It helps to put them on notice that the conditions have been favorable for late blight,” he says. “As the crop comes up, we run the data through software we developed here at the University of Wisconsin and that would indicate when to initiate sprays and the timing of the subsequent sprays.”

On one of his trips, Stevenson observed workers spraying 60 acres of potatoes by hand with limited protection. “When they walked across the field, their clothes become soaked with pesticide,” he says. “That’s not sustainable, and it’s pretty risky.” After discussing the problem with the grower and Sanchote, a simple change was implemented: The workers now walk backward while applying the sprays.

“It all goes back to, ‘How do we have a sustainable potato crop in Thailand that protects their environment and protects their workers, and yet produces a quality crop that Frito-Lay can use for chipping?'” says Stevenson.”This project capitalizes on our experiences here in Wisconsin and North America (using) solid, science-based integrated pest-management programs.”