Five 91探花 researchers have been named AAAS Fellows, according to a . They are among 471 newly elected fellows from around the world, who are recognized for their 鈥渟cientifically and socially distinguished achievements鈥� in science and engineering. A tradition dating back to 1874, election as an AAAS Fellow is a lifetime honor. All fellows are expected to meet the commonly held standards of professional ethics and scientific integrity.

This year鈥檚 91探花AAAS fellows are:

, professor of genome sciences in 91探花Medicine, was recognized for her distinguished contributions to the field of the evolution of tissue development by signaling pathways and to the training of junior scientists. She studies developmental biology, and her work focuses on the patterns and shapes that appear as an organism forms into a living creature composed of a variety of cell types and organs. Her laboratory models are fruit flies, and her investigations begin in the egg chamber and the laid egg. Among her research interests are cell signals and cell migration critical to development, and the evolution of these processes. In addition, new genomic technologies are enabling her research team to manipulate the timing and location of gene activity within developing fly cells. Berg and her team also have designed a system to obtain live imaging of some of the developmental events that take place. Among Berg鈥檚 overarching goals is to better understand the genetic and molecular dysfunctions that lead to prenatal malformations and other disorders. The hope, Berg says, is that basic research, over the long term, might lead to clinical diagnostics for risk factors and to evaluation of potential treatments. Berg鈥檚 course topics are wide-ranging, and include introductory biology, biomedical ethics and forensic genetics at crime scenes.

, the David R. M. Scott Endowed Professor in Forest Resources and professor of plant microbiology in the 91探花School of Environmental and Forest Sciences, was recognized for distinguished contributions to unraveling mechanisms by which microbes colonize plants, increase plant growth and yields in nutrient-limited conditions, increase water use efficiency and drought tolerance, and improve plant health. Her research is on the importance of the plant microbiome as a resource for nature-based solutions to environmental challenges including pollution, climate change and colonizing the moon. A 91探花faculty member since 2003, she has received several awards and honors including the Lockwood Endowed Professorship (2013-2021), Director鈥檚 Faculty Award for 鈥渆xemplary contributions to student mentoring鈥� and the Faculty Member of the Year award (2014). She serves on the executive teams of the International Poplar Commission (Co-Vice Chair, Environmental and Ecosystem Services) and the International Symbiosis Society (VP, Education). She holds an adjunct faculty appointment in the Department of Microbiology.

, professor of microbiology in 91探花Medicine, was recognized for his distinguished contributions to the field of microbial interactions, particularly with regard to unraveling mechanisms responsible for the formation of surface-attached communities called biofilms. Parsek explores the social biology of bacterial communities. One of his areas of investigation is quorum-sensing 鈥� how bacteria use signaling molecules to sense the presence of others of the same species. This communication system allows them to coordinate their behavior as a group. Another of his related fields of interest is biofilms. These are bacteria that produce an extracellular matrix to bind themselves together. The matrix protects the community and plays a role, for example, in resistance to antimicrobials and antibiotics and in the persistence of chronic infection. Parsek鈥檚 lab studies the composition of this matrix and how it is assembled. They are especially interested in Pseudomonas aeruginosa, which lives in several different environmental niches, but is notorious for infecting the lungs of cystic fibrosis patients and for colonizing burn wounds and growing on implanted biomaterials. In recent work his lab looked at how these bacteria can sense surfaces. A 91探花faculty member since 2011, Parsek is a member of the American Academy of Microbiology and was named a Kavli fellow by the National Academy of Sciences.

, the Lloyd and Kay Chapman Endowed Chair for Oral Health in the 91探花School of Dentistry, was recognized for translating knowledge from the behavioral and social sciences to address the causes of children鈥檚 oral health inequities. In recent years Chi has studied why some parents reject fluoride for their children and worked with Yup鈥檌k communities to improve the oral health of Alaska Native children. In 2018 he was named Pediatric Dentist of the Year by the American Academy of Pediatric Dentistry, and in 2025 he received the Presidential Early Career Award for Scientists and Engineers (PECASE) from President Joe Biden. A member of the 91探花faculty since 2010, Chi is also the associate dean for research in the School of Dentistry and a professor of health systems and population health in the 91探花School of Public Health. He is editor-in-chief the International Journal of Paediatric Dentistry and treats patients at the Odessa Brown Children鈥檚 Clinic in Seattle.

, the Larry R. Dalton Endowed Chair in Chemistry and associate dean for research in the College of Arts & Sciences, is honored for his contributions to the development and application of time-dependent quantum theory and relativistic electronic structure theory, and for advancing educational pathways and diversity in STEM. Li conducts research at the intersection of physics, chemistry, materials science, mathematics and scientific computing, and he has developed widely used computational software. A 91探花faculty member since 2005, Li’s honors include a Sloan Research Fellowship, the NSF CAREER Award, the American Chemical Society Jack Simons Award in Theoretical Physical Chemistry and the 91探花Distinguished Teaching Award. He is a fellow of the American Physical Society (APS) and the Royal Society of Chemistry (RSC), a Lab Fellow at Pacific Northwest National Laboratory and an elected member of the Washington State Academy of Sciences.

Phosphorus is a necessary nutrient for plants to grow. But when it鈥檚 applied to plants as part of a chemical fertilizer, phosphorus can react strongly with minerals in the soil, forming complexes with iron, aluminum and calcium. This locks up the phosphorus, preventing plants from being able to access this crucial nutrient.

To overcome this, farmers often apply an excess of chemical fertilizers to agricultural crops, leading to phosphorus buildup in soils. The application of these fertilizers, which contain chemicals other than just phosphorus, also leads to harmful agricultural runoff that can pollute nearby aquatic ecosystems.

Now a research team led by the 91探花 and Pacific Northwest National Laboratory has shown that microbes taken from trees growing beside pristine mountain-fed streams in Western Washington could make phosphorus trapped in soils more accessible to agricultural crops. The were published in October in the journal Frontiers in Plant Science.

Endophytes, which are bacteria or fungi that live inside a plant for at least some of their lifecycle, can be thought of as 鈥減robiotics鈥� for plants, said senior author , a professor in the 91探花School of Environmental and Forest Sciences. Doty鈥檚 lab has shown in previous studies that microbes can help plants survive and even thrive in nutrient-poor environments 鈥� and .

In this new study, Doty and collaborators found that endophytic microbes isolated from wild-growing plants helped unlock valuable phosphorus from the environment, breaking apart the chemical complexes that had rendered the phosphorus unavailable to plants.

鈥淲e鈥檙e harnessing a natural plant-microbe partnership,鈥� Doty said. 鈥淭his can be a tool to advance agriculture because it鈥檚 providing this essential nutrient without damaging the environment.鈥�

Doty鈥檚 research scientist, Andrew Sher, and 91探花undergraduate researcher Jackson Hall demonstrated in lab experiments that the microbes could dissolve the phosphate complexes. Poplar plants inoculated with the bacteria in Doty鈥檚 lab were sent to collaborator , a materials scientist at the Environmental Molecular Sciences Laboratory at Pacific Northwest National Laboratory in Richland, Washington. There researchers used advanced imaging technologies at their lab and at other U.S. Department of Energy national laboratories to provide clear evidence that the phosphorus made available by the microbes did make it up into the plant鈥檚 roots.

The imaging also revealed that the phosphorus gets bound up in mineral complexes within the plant. Endophytes, living inside plants, are uniquely positioned to re-dissolve those complexes, potentially maintaining the supply of this essential nutrient.

While in Doty鈥檚 lab demonstrated that endophytes can supply nitrogen, obtained from the air, to plants, such direct evidence of plants using phosphorus dissolved by endophytes was previously unavailable.

The bacteria used in these experiments came from wild poplar trees growing along the Snoqualmie River in Western Washington. In this natural environment, poplars are able to thrive on rocky riverbanks, despite low availability of nutrients like phosphorus in their natural habitat. Microbes help these trees capture and use the nutrients they need for growth.

These findings can be applied to agriculture crops, which , unused, from years of fertilizer applications. Microbes could be applied in the soil among young crop plants, or as a coating on seeds, helping to unlock phosphorus held captive and making it available for use by plants to grow. Reducing the use of fertilizers and employing endophytes 鈥� such as those studied by Doty and Varga 鈥� opens the door for more sustainable food production.

鈥淭his is something that can easily be scaled up and used in agriculture,鈥� Doty said.

91探花has already licensed the endophyte strains used in this study to Intrinsyx Bio, a California-based company working to commercialize a collection of endophyte microbes. The direct evidence provided by Doty and Varga鈥檚 research of endophyte-promoted phosphorus uptake is 鈥済ame-changing for our research on crops,鈥� said John Freeman, chief science officer of Intrinsyx Bio.

Co-authors are Kim Hixson, Amir Ahkami, Rosalie Chu, Anil Battu, Loren Reno, Carrie Nicora and Tanya Winkler of Pacific Northwest National Laboratory; Morgan Barnes of the University of California, Merced; Sirine Fakra and Dilworth Parkinson of Lawrence Berkeley National Laboratory; and Olga Antipova of Argonne National Laboratory.

This research was funded by the Byron and Alice Lockwood Foundation and the U.S. Department of Energy Office of Science.

For more information, contact Doty at sldoty@uw.edu.

See a from the Environmental Molecular Sciences Laboratory.

Astronauts at the International Space Station are spending more time away from Earth, but they still need their daily serving of vegetables. In the quest to find a viable way for crew to grow their own veggies while orbiting 鈥� and possibly one day on the moon or Mars 鈥� student researchers are sending broccoli seeds coated with a healthy dose of probiotics to space.

Six broccoli seeds were aboard the Orbital ATK Cygnus spacecraft that from Wallops Island, Virginia, as part of a space station . Three of the seeds are traveling to space as is, while the other three were coated with two different species of bacteria, developed at the 91探花, that can live inside crop plants and improve their growth. These “beneficial” microbes, also called endophytes, may also help plants grow better in extreme low-gravity environments, and where nutrients or water could be lacking.

The goal of the experiment, conducted by students at in San Jose, California, is to learn how to grow vegetables in the challenging, microgravity conditions of the space station 鈥� and eventually on the moon and Mars 鈥� as human space exploration expands. Developed by a team of 11 students, the initial ground experiments proved successful, as the broccoli grew faster and significantly larger than the control study.

“It would be ideal if we could grow crops for astronauts at the space station or who are lunar- or Mars-based without needing to ship potting mix or fertilizer,” said , a 91探花professor in the School of Environmental and Forest Sciences and a plant microbiologist who isolated and characterized the microbes used in this experiment. “We would like to be able to get plants to grow in what is available with a minimum input.”

The students are participating in Quest Institute for Quality Education’s “” program and are mentored by David Bubenheim of NASA-Ames Research Center’s Biospheric Science Branch and John Freeman of Intrinsyx Technologies. The experiment was prepped in a flight laboratory located at NASA-Ames Research Center in California.

Freeman has test-grown many plants aboard the International Space Station, and also has used these same microbes to enhance the growth of crop plants such as tomatoes, lettuce, soybeans, wheat, corn and broccoli. Freeman has found that the plants thrive, even when given less water and essential nutrients like nitrogen and phosphorus.

His work also confirms a 2016 study in which Doty and co-authors found that plants can with the help of natural microbes that .

These specific endophytes and broccoli plants were chosen for the space flight experiment because they performed well together in greenhouse tests under growing conditions similar to Mars, where nitrogen and phosphorus are limited, Freeman said.

While a number of different have been conducted aboard the International Space Station, this is the first that studies natural microbes to possibly help plants grow under nutrient limitations and in microgravity, he said.

“In space, plants are very stressed and don’t grow or reproduce well,” Freeman explained. “We want plants to grow better. We are trying broccoli because it’s considered an anti-carcinogenic food source that is a good dietary candidate for deep-space explorers.”

The microbes are first encapsulated inside a coating that covers the broccoli seeds, which protects the seeds from dehydration and allows for safe dry storage before the seeds are hydrated and grown in orbit. When the endophyte-coated broccoli seeds reach the space station, they will be hydrated in a small plant-growth chamber that provides constant light to promote photosynthesis. Cameras will take images of the seedlings at regular intervals, which will help the high school researchers and their mentors track overall seedling growth.

After the plants return from space, the students will measure their growth and chlorophyll content and compare the inoculated broccoli to those that were grown without microbes.

Separately, Doty and her team will receive plant samples to investigate how well the two microbe species colonized the broccoli in space, and whether they were as effective as when grown on Earth.

“We want to know whether the microbes still find their way inside the plant even in microgravity, and if any of the required plant signals are terrestrial-based,” Doty said. “We need to test if they are still functioning the way we would expect when growing in a different environment like microgravity.”

Doty and her 91探花team isolated the microbes used in this experiment more than a decade ago from wild willow plants growing on nutrient-deficient land among the rocks and sand along the Snoqualmie River. The plants had already selected the best microbes to help them grow in harsh conditions, so the researchers tapped into these key microbial strains and used them to help crop plants, grasses and trees grow in difficult environments.

These microbes can benefit plants of all kinds, helping them for the plant and reduce the need for synthetic fertilizer, in the case of crop plants like broccoli.

In separate projects, Doty and her lab, along with Bubenheim and Freeman, are starting to test whether plants given natural willow and poplar microbes can grow in conditions that exist on the moon and on Mars. They use regolith simulant 鈥� ground-up rocky material with no organic matter 鈥� that mimics extraterrestrial conditions in both locations to see whether microbes can help plants grow in otherwise harsh conditions. The work is also part of the , which was the first university program of its kind 20 years ago.

“This is the first step in what I hope becomes a really long-term research program to develop habitation on Mars and on the moon in a very efficient way using natural symbiosis instead of trying to bring chemical fertilizer to those environments,” Doty said.

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For more information, contact Doty at sldoty@uw.edu and Freeman at jfreeman@intrinsyx.com.

This educational research flight opportunity was made available to Valley Christian High School of San Jose, California, via a partnership with the Quest Institute for Quality Education, and by Space Tango via its Space Act Agreement with NASA鈥檚 U.S. National Lab on the International Space Station.

Now, a probiotic bacteria for trees can boost the speed and effectiveness of this natural cycle, providing a microbial partner to help protect trees from the toxic effects of the pollutants and break down the聽toxic pollutants plants bring in from contaminated groundwater.

Researchers from the 91探花 and several small companies have conducted the first large-scale experiment on a Superfund site using poplar trees fortified with a probiotic 鈥� or natural microbe 鈥� to clean up groundwater contaminated with (TCE), a common pollutant found in industrial areas that is harmful to humans when ingested through water or inhaled from the air. Their were published in final form Aug. 11 in the journal .

The successful field trial could be a game changer to quickly and effectively clean up Superfund sites around the country and polluted sites abroad that have high levels of TCE, the authors say.

“These results open the door,” said corresponding author , a 91探花professor in the School of Environmental and Forest Sciences. “We have known about this process for a long time from our laboratory research, but it hasn’t been used in practice because there were no field results. Now, engineering companies can start using this in real life.”

Contaminated sites containing TCE and other pollutants can be expensive to clean up when using engineering methods such as excavating or pumping toxic pollutants聽from underground. As a result, many sites sit untreated. This new method allows contaminated sites to be dealt with more effectively, often at lower costs, promoting human health.

Doty’s lab worked to find the best microbe strain that could effectively break down TCE and boost tree growth. Jun Won Kang, a former 91探花graduate student, had obtained poplar wood from a site in the Midwest where trees were already growing in TCE-contaminated soil. After grinding down small samples of the trees and isolating over a hundred different microbes, each strain was then placed in a flask containing high levels of TCE.

The microbe that ultimately was selected eliminated nearly all of the TCE in its flask. The researchers had a clear winner.

“The poplar at the older site in the Midwest selected for the best microbes to help it do its job,” Doty explained. “We took advantage of that natural selection process. We just had to find the best ones that the plant already chose.”

The pollutant TCE has been used widely as a degreaser and a solvent in industrial manufacturing sites across the country. The U.S. Environmental Protection Agency cites TCE as one of the most common pollutants in soil or water, and it is present in more than 1,000 sites the agency lists as priorities for cleanup. TCE is a known carcinogen to humans, affecting the liver and even transferring the toxic pollutant to nursing babies .

Given the prevalence and toxicity of TCE, the researchers used the chemical to test the ability of poplar trees infused with microbes to clean up groundwater in the Superfund research area in California’s Silicon Valley after it had subsequently flowed into the NASA Research Park at NASA’s Ames Research Center. At NASA Ames, in coordination with NASA Ames’ Environmental Division, the researchers planted rows of young poplar trees 鈥� some inoculated with the specific microbe, and others without 鈥� on a field above a known groundwater plume contaminated with TCE.

After only a year, the trees given the microbe were bigger and healthier than the poplars with no special treatment. After three years, the inoculated trees were still more robust, and a sample of tree trunks revealed greatly reduced levels of TCE inside the trees.

When trees take up and degrade chemicals, called phytoremediation, it often comes at the expense of their own health. This manifests as stunted growth, yellow leaves, withering brown leaves and branches, and sometimes death as the pollutant hampers the tree’s ability to survive. But when the microbe selected specifically to deal with TCE is introduced, the trees destroyed the TCE 鈥� and experienced more robust growth and increased survival rates, clear benefits of the probiotic.

“The real goal is to try to improve performance,” said co-author , president and CEO of Edenspace Systems Corporation in Virginia. “If we have something that speeds up and improves performance and makes it so the trees can grow better, that’s really what we were trying to accomplish with this project.”

Additionally, the researchers found that groundwater samples taken directly downstream from the test site showed much lower levels of the pollutant, compared with higher levels up-gradient from the testing area. They also found evidence of increased chloride in the soil around the poplar roots, a harmless, naturally occurring element and byproduct of TCE as it is degraded by the bacteria inside trees.

A number of organizations have expressed interest in using this technology, said co-author , chief science officer for Intrinsyx Technologies Corporation based at NASA’s Research Park. And landowners hampered by the high costs associated with traditional clean-up methods are starting to use the technology.

“This has the potential to make a huge impact on a lot of legacy sites where you have contaminated groundwater issues, including TCE, and where funding is currently less available,” Freeman said. “This is definitely a big cost savings to everyone involved. It’s a real win-win situation because it’s green, it’s long-term sustainable, publicly acceptable and it’s solar powered by the trees themselves.”

Other co-authors are Christopher Cohu of Phytoremediation and Phytomining Consultants United; Joel Burken of Missouri University of Science and Technology; Andrea Firrincieli of Tuscia University in Italy; Andrew Simon of Edenspace Systems Corporation; Zareen Khan of the UW; Jud Isebrands of Environmental Forestry Consultants; and Joseph Lukas of Earth Resources Technology.

The work was funded by the National Institutes of Health through a Small Business Innovation Research grant. Support for Doty’s research was also provided by the Byron and Alice Lockwood Foundation.

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For more information, contact Doty at sldoty@uw.edu or 206-616-6255; Blaylock at blaylock@edenspace.com or 703-961-8700; and Freeman at Jfreeman@intrinsyx.com or 650-210-9219.

NIH grant: R44ES020099

Agricultural crops, grasses and garden plants alike can get sick and die when factors such as drought and excess sun force them to work harder to survive.

Now, plants can better tolerate drought and other stressors with the help of natural microbes, 91探花 research has found. Specifically, plants that are given a dose of microbes stay green longer and are able to withstand drought conditions by growing more leaves and roots and using less water.

“Plants are less stressed if they have these natural microbes,” said senior author , a 91探花professor of environmental and forest sciences. “They will help plants deal with environmental challenges, especially with climate change.”

The were published online this month in the journal .

Microbes and their benefits to plants is a burgeoning field, and Doty’s lab in the last 15 years has explored many different aspects of this mutual symbiosis. Earlier this year, her team demonstrated that in otherwise inhospitable environments 鈥� essentially serving as a natural fertilizer.

Naturally providing nutrients and boosting drought resistance could make it easier and more environmentally friendly to grow grain and vegetable crops, fruit and nut trees, and even keep golf courses looking lush and green without using excess amounts of water and chemical fertilizer.

“The more I learn, the more I do research in this field, the more exciting it gets, especially in the applied aspects,” said lead author , a 91探花research scientist in environmental and forest sciences. “I think this knowledge can be used to develop strategies to face the challenges of climate change.”

In this study, the researchers looked at the ability of young poplar trees to tolerate drought conditions over a month-long period, with and without the help of added microbes, called , bacteria that live inside a plant without causing disease.

Researchers inoculated the young poplar cuttings with a cocktail of microbes isolated from wild poplar and willow trees growing in unfavorable conditions. They poured the mixture at the base of the stems of 10 poplars, while the other 10 cuttings did not receive any microbes. After a short growth period in a greenhouse, all 20 plants were subjected to drought conditions for a month.

It’s important to note that all of the poplars had microbes inside 鈥� they are naturally present in every living thing. But when the researchers added microbes from wild poplar and willow, they noticed a benefit to the plants.

Specifically, the poplars that were given the probiotics doubled their root biomass and experienced nearly 30 percent more leaf and stem growth than poplars without the added microbes. When exposed to drought conditions, the poplars with microbes also stayed green with robust leaves and stems, while their counterparts browned and wilted.

“Plants are overall greener and healthier if they have these microbes,” Doty said.

The researchers chose poplar trees to demonstrate this beneficial relationship because the fast-growing trees are important for biofuels, or plant-based renewable energy.

“One of the limitations of biofuel is large-scale production,” Khan said. “If we can reduce water usage on poplar-tree plantations by adding naturally occurring endophytes, then that could provide huge economic and environmental benefits.”

Microbes also help crop plants such as tomatoes, corn and peppers be more tolerant of drought. The researchers are collaborating with an engineering company,聽,聽to show this same beneficial relationship between microbes and agricultural plants, with crops given the beneficial microbes yielding more vegetables and responding better in dry, hot weather.

“Having microbes that can help plants establish early, grow fast and protect them from some of the stresses in their environment, especially drought, is a big deal,” said John Freeman, chief science officer at Intrinsyx who works with Doty’s team at the UW. “Using these endophytes in agricultural settings holds a lot of promise for growers and farmers.”

The researchers suspect a number of factors are at work. Microbes enable plants to accumulate more nutrients like nitrogen and phosphorus. The microbes also help plants use water more efficiently, and even produce molecules that promote plant growth and help them stay green.

Gaining more root, stem and leaf mass also makes plants able to store more water.

“Endophytes are helping plants make more roots, so they have more surface area to hang onto water and survive the stress of drought longer,” Khan said.

Next steps include better understanding exactly how microbes bolster plants, and finding the best strains to help different plants deal with various stresses.

“Finding the most beneficial ones for the job is the key in using this technology,” Khan said.

Other co-authors are , Shang Han Hung and of the UW’s School of Environmental and Forest Sciences; Andrea Firrincieli of the University of Tuscia in Italy; and Virginia Luna and Oscar Masciarelli of Universidad Nacional de R铆o Cuarto in Argentina.

This research was funded by the U.S. Department of Agriculture.

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For more information, contact Doty at sldoty@uw.edu and Khan at zareen@uw.edu.

John Freeman at Intrinsyx Technologies can talk about using microbes in agriculture: jfreeman@intrinsyx.com.

Grant number: USDA AFRI 2010-05080.

The bacteria in and on our bodies have been shown to be vital for human health, influencing nutrition, obesity and protection from diseases.

But science has only recently delved into the importance of the microbiome of plants. Since plants can’t move, they are especially reliant on partnerships with microbes to help them get nutrients.

Now, 91探花 plant microbiologist , along with her team of undergraduate and graduate students and staff, has demonstrated that poplar trees growing in rocky, inhospitable terrain harbor bacteria within them that could provide valuable nutrients to help the plant grow. Their , which could have implications for agriculture crop and bioenergy crop productivity, were published May 19 in the journal .

The researchers found that microbial communities are highly diverse, varying dramatically even in cuttings next to each other.

“This variability made it especially difficult to quantify the activity, but is the key to the biology since it is probably only specific groupings of microorganisms that are working together to provide this nutrient to the host,” said Doty, a professor in the 91探花.

is a natural process that is essential to sustain all forms of life. In naturally occurring low-nutrient environments such as rocky, barren terrain, plants associate with nitrogen-fixing bacteria to acquire this essential nutrient.

It’s well documented that nitrogen fixation happens in bacteria-rich nodules on the roots of legumes such as soybeans, clovers, alfalfa and lupines. Bacteria help the roots fix atmospheric nitrogen gas into a form which can be used by the plant.

There is a strongly held belief that only plants with root nodules can benefit from this type of symbiosis. This research provides the first direct evidence that nitrogen fixation can occur in the branches of trees, with no root nodule required.

This could have significant implications for common agricultural crop plants. The microbes the team has isolated from wild poplar and willow plants help corn, tomatoes and peppers, as well as turf grasses and forest trees to grow with less fertilizer.

Fertilizers are synthesized using fossil fuels, so costs can fluctuate wildly. Because fertilizers are used for growing everything from agricultural and bioenergy crops and trees for lumber to the grass in golf courses, this volatile pricing and uncertain availability affects everyone.

“Having access to the key microbial strains that help wild plants thrive on just rocks and sand will be crucial for moving agriculture, bioenergy and forestry away from a dependence on chemical fertilizers and towards a more natural way of boosting plant productivity,” Doty said.

The researchers plan to work with the Pacific Northwest National Laboratory to try to find out exactly which microbes are doing the most work in the wild trees.

Other co-authors are Andrew Sher, Neil Fleck, Mahsa Khorasani, Zareen Khan, Andrew W. K. Ko, Soo-Hyung Kim and Thomas DeLuca of the UW’s School of Environmental and Forest Sciences; and Roger Bumgarner of the UW’s Department of Microbiology.

This research was funded by the U.S. Department of Agriculture and the Byron and Alice Lockwood Professorship.

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For more information, contact Doty at sldoty@uw.edu.

John Freeman, chief scientific officer of Intrinsyx Technologies, is working with the organic farming community to bring this science to application. The company has licensed many of microbes described in this paper and is currently working toward commercializing them. Contact Freeman at jfreeman@intrinsyx.com for more information.

Grant information: Agriculture and Food Research Initiative (USDA); grant #2010-05080

The approach could avoid the regulatory hurdles imposed on transgenic plants 鈥� plants with genes inserted from or exchanged with other plant or animal species 鈥� that have shown promise in phytoremediation, the process of using plants to remove toxins from contaminated sites, according to , associate professor of and corresponding author on a about the new work in Environmental Science & Technology.

“Our approach is much like when humans take probiotic pills or eat yogurt with probiotics to supplement the ‘good’ microbes in their guts,” she said.

The microbe from the cottonwood was encouraged to colonize the roots of willows simply by dipping rooted and trimmed cuttings in solutions with the microbe. Grasses were treated with microbes in solution as seeds sprouted in soil. Once integrated into the plants, the microbe supplemented their own microbial defenses.

Microbes that take up residence in the inner tissue of plants and don’t cause negative symptoms are called endophytes. In nature, endophytes have a welcomed, symbiotic relationship with plants. In polluted soil, for instance, if the right endophytes are present they consume toxins coming up through plant roots. The endophytes get fed and the plant gets help neutralizing pollutants that could kill it.

That’s been one challenge of phytoremediation: plants removing pollutants can, all too quickly, succumb to the toxins.

“When the endophyte in these experiments was given to willow and grasses, it reduced the phytotoxic effects of phenanthrene compared to the control plants that did not receive the endophyte and died,” said lead author , a 91探花research scientist in environmental and forest sciences.

Phenanthrene is carcinogenic, on the Environmental Protection Agency’s priority pollutants list and belongs to a class of polycyclic aromatic hydrocarbons that get deposited into the environment via fossil fuel combustion, waste incineration or as byproducts of industrial processes. Soils that become contaminated can be capped with layers of uncontaminated soil or dug up and removed for cleaning at soil remediation facilities or storage at waste disposal facilities.

In their search, 91探花researchers tested six different endophytes from cottonwood and willow varieties and found one 鈥� lab name PD1 鈥� from the eastern cottonwood to be superior at breaking down phenanthrene.

They introduced this endophyte into willow cuttings and lawn grass. Willows were chosen because some varieties have already proven adept at removing toxins and the shrubs have extensive root systems, take up a lot of water and grow rapidly. Lawn grass was included because it also grows fast and could be useful in parks and open-space areas.

In lab experiments, the willow cuttings with added endophyte protection continued to grow, kept their leaves and had denser root systems. Untreated plants wilted, lost leaves and their roots turned brown. When soils were analyzed, the treated willows took up 65 percent of the phenanthrene compared with untreated plants that removed 40 percent, an improvement of 25 percent.

Grass seed planted in contaminated soils and watered with solutions containing the PD1 endophyte germinated five days quicker, grew taller and had 100 more tillers, or new offshoots, after 13 days. Treated grass removed 50 percent of the phenanthrene from the soil, compared with untreated grass that removed 10 percent, an improvement of 40 percent.

In phytoremediation, plants that take up pollutants but don’t degrade them have to be removed and treated as hazardous waste or otherwise disposed of safely. The willows treated in the 91探花experiment appear to have degraded some 90 percent of the phenanthrene to harmless components. The researchers said they’d like to determine if that promising finding holds up in mass-balance studies and want to examine the possible effects on bugs or animals that might bite the plants processing the toxins and other environmental considerations. Interestingly, other studies have shown that bugs can smell similar semi-volatile pollutants and avoid eating the plants containing them, Doty said.

The work was funded by a Small Business Innovation Research grant from the National Institute of Environmental Health Sciences that came through the company , and by funds provided through the Byron and Alice Lockwood Endowed Professorship that Doty holds. The other four co-authors on the paper were undergraduate volunteers: David Roman and Trent Kintz have since graduated while May delas Alas and Raymond Yap are still working on their bachelor’s degrees.

Just down the road from 91探花is Seattle’s , a site Doty thinks is a prime candidate for the approach her lab reported. Contaminants in the soil, including phenanthrene, are from a now-dismantled gasification plant. Soils have been covered with uncontaminated soil.

“The idea of leaving a known carcinogen in a public place is not right,” she said. “What about problems of erosion? We should do what we can to remove it. We spend so much money treating cancer, I’d like us to take steps to prevent it instead.”

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For more information;
Doty, 206-616-6255, sldoty@uw.edu (NOTE: Doty will be traveling Nov. 19-21 and best reached via email those days)
Khan, 206-543-5774, zareen@uw.edu

NIH/NIEHS-SBIR Grant No. 2R44ES020099-02