Genes From Engineered Grass Spread for Miles, Study Finds

Genes From Engineered Grass Spread for Miles, Study Finds

September 21, 2004

A new study shows that genes from genetically engineered
grass can spread much farther than previously known, a
finding that raises questions about the straying of other
plants altered through biotechnology and that could hurt
the efforts of two companies to win approval for the first
bioengineered grass.

The two companies, Monsanto and Scotts, have developed a
strain of creeping bentgrass for use on golf courses that
is resistant to the widely used herbicide Roundup. The
altered plants would allow groundskeepers to spray the
herbicide on their greens and fairways to kill weeds while
leaving the grass unscathed.

But the companies' plans have been opposed by some
environmental groups as well as by the federal Forest
Service and the Bureau of Land Management. Critics worry
that the grass could spread to areas where it is not wanted
or transfer its herbicide resistance to weedy relatives,
creating superweeds that would be immune to the most widely
used weed killer. The Forest Service said earlier this year
that the grass "has the potential to adversely impact all
175 national forests and grasslands."

Some scientists said the new results, to be published
online this week by the journal Proceedings of the National
Academy of Sciences, did not necessarily raise alarms about
existing genetically modified crops like soybeans, corn,
cotton and canola. There are special circumstances, they
say, that make the creeping bentgrass more environmentally
worrisome, like its extraordinarily light pollen.

Because Scotts has plans to develop other varieties of
bioengineered grasses for use on household lawns, the new
findings could have implications well beyond the golf
course. And the study suggests that some previous studies
of the environmental impact of genetically modified plants
have been too small to capture the full spread of altered

Scotts says that because naturally occurring bentgrass has
not caused major weed problems, the bioengineered version
would pose no new hazards. And any Roundup-resistant
strains that might somehow develop outside of intentionally
planted areas could be treated with other weed killers, the
company said.

In the new study, scientists with the Environmental
Protection Agency found that the genetically engineered
bentgrass pollinated test plants of the same species as far
away as they measured -about 13 miles downwind from a test
farm in Oregon. Natural growths of wild grass of a
different species were pollinated by the gene-modified
grass nearly nine miles away.

Previous studies had measured pollination between various
types of genetically modified plants and wild relatives at
no more than about one mile, according to the paper.
"It's the longest distance gene-flow study that I know of,"
said Norman C. Ellstrand, an expert on this subject at the
University of California, Riverside, who was not involved
in the study but read the paper.

"The gene really is essentially going to get out," he
added. "What this study shows is it's going to get out a
lot faster and a lot further than people anticipated."
One reason the grass pollen was detected so far downwind
was the size of the farm - 400 acres with thousands of
plants. Most previous studies of gene flow have been done
on far smaller fields, meaning there was less pollen and a
lower chance that some would travel long distances. Those
small studies, the new findings suggest, might not
accurately reflect what would happen once a plant covers a
large area.

"This is one of the first really realistic studies that has
been done," said Joseph K. Wipff, an Oregon grass breeder.
Dr. Wipff was not involved in the latest study but had
conducted an earlier one that found pollen from genetically
engineered grass traveling only about 1,400 feet. That
test, though, used less than 300 plants covering one-tenth
of an acre.

The effort to commercialize the bentgrass has attracted
attention because it raises issues somewhat different from
those surrounding the existing genetically modified crops.
It would be the first real use of genetic engineering in a
suburban setting, for example, rather than on farms. And
the grass is perennial, while corn, soybeans, cotton and
canola are planted anew each year, making them easier to

Bentgrass can also cross-pollinate with at least 12 other
species of grass, while the existing crops, except for
canola, have no wild relatives in the places they are grown
in the United States. And crops like corn and soybeans have
trouble surviving off the farm, while grass can easily
survive in the wild.

The bentgrass, moreover, besides having very light pollen -
a cloud can be seen rising from grass farms - has very
light seeds that disperse readily in the wind. It can also
reproduce asexually using stems that creep along the ground
and establish new roots, giving rise to its name.
Because of the environmental questions, the application for
approval of the bioengineered bentgrass is encountering
delays at the Department of Agriculture, which must decide
whether to allow the plant to be commercialized.
After hearing public comments earlier this year, the
department has now decided to produce a full environmental
impact statement, which could take a year or more,
according to Cindy Smith, who is in charge of biotech

Ms. Smith, in an interview yesterday, said the new study
"gives some preliminary information that's different from
previous studies that we're aware of." But more conclusive
research is needed, she said.

Bentgrass is already widely used in its nonengineered form
by golf course operators, mainly for greens but also for
fairways and tee areas, in part because it is sturdy even
when closely mown. It is rarely used on home lawns because
it must be cared for intensively. And creeping bentgrass
does not cross-pollinate with the types of grass typically
used on lawns, scientists said.

Executives at Scotts, a major producer of lawn and turf
products based in Marysville, Ohio, said the genetically
engineered bentgrass would be sold only for golf courses.
They said golf courses cut their grass so often that the
pollen-producing part of the plants would never develop.
And because nonengineered creeping bentgrass has not caused
weed problems despite being used on golf courses for
decades, they said, the genetically modified version would
pose no new problems.

"There has been pollen flow but it has not created weeds,"
Michael P. Kelty, the executive vice president and vice
chairman of Scotts, said in an interview yesterday. He said
Scotts and Monsanto, the world's largest developer of
genetically modified crops, had spent tens of millions of
dollars since 1998 developing the bioengineered bentgrass.
The questions about the grass come after Monsanto, which
is based in St. Louis, said earlier this year that it was
dropping its effort to introduce the world's first
genetically engineered wheat, citing concerns by farmers
that its use in foods might face market opposition.
Scotts is also developing genetically modified grass for
home lawns, like herbicide-tolerant and slow-growing types
that would need less mowing. But those products still need
several more years of testing, Dr. Kelty said, adding that
the company would avoid types of grass that could become
weeds. "We don't want to put a product out there that is
going to be a threat," he said.

Scotts and Monsanto have received some support for their
argument from the Weed Science Society of America, a
professional group, which conducted a review of the weed
tendencies of creeping bentgrass and its close relatives at
the request of the Department of Agriculture.
"In the majority of the country these species have not
presented themselves as a significant weed problem,
historically," said Rob Hedberg, director of science policy
for the society, summarizing the conclusions of the review.
He said that because people have generally not tried to
control bentgrass and similar species with Roundup, known
generically as glyphosate, "the inability to control them
with this herbicide is a less significant issue."

Still, the society's report noted that bentgrass could be
considered a weed by farms that are trying to grow other
grass seeds. And the Forest Service, in comments to the
Agriculture Department earlier this year, said that
bentgrass has threatened to displace native species in some
national forests.

John M. Randall, acting director of the Invasive Species
Initiative at the Nature Conservancy, said bentgrass and
related species had been a threat to native grasses in
certain preserves that the group helps manage, including a
couple near Montauk Point on eastern Long Island.
Other opponents of the genetically modified grass seized on
the results. "This does confirm what a lot of people feared
- expected, really," said Margaret Mellon, director of the
food and environment program for the Union of Concerned
Scientists in Washington. "These kinds of distances are

The new study was done by Lidia S. Watrud and colleagues at
an E.P.A. research center in Corvallis, Ore., who were
trying to develop new methods to assess gene flow, not
specifically to study the bentgrass.

They put out 178 potted and unmodified creeping bentgrass
plants, which they called sentinel plants, at various
distances around the test farm. They also surveyed wild
bentgrass and other grasses. They collected more than a
million seeds from the plants, growing them into seedlings
to test for herbicide resistance and doing genetic tests.
The number of seeds found to be genetically engineered was
only 2 percent for the sentinel plants, 0.03 percent for
wild creeping bentgrass and 0.04 percent for another wild
grass. Most of those seeds were found in the first two
miles or so, with the number dropping sharply after that.
Still, said Anne Fairbrother, one of the authors of the
report, finding even some cross pollination at 13 miles "is
a paradigm shift in how far pollen might move."