GENET archive


2-Plants: GE plants to warn of terrorism

genet-news mailing list

-------------------------------- GENET-news --------------------------------

TITLE:  Modifying plants to warn of terrorism
SOURCE: The Philadelphia Inquirer, USA, by Christine Schiavo
DATE:   Apr 27, 2003

------------------ archive: ------------------

Modifying plants to warn of terrorism

In the color-coded lexicon of Homeland Security, green is serene. But if
it someday starts to glow, grab the duct tape.

In a laboratory at Pennsylvania State University, researchers are
reengineering the DNA of a common weed to create a species that
fluoresces when exposed to chemicals and pathogens in the air or
explosives in the soil.

Strategically set around government buildings and military installations,
at ports and offices, and even in subways, the plants would serve as
silent sirens in an unseen terror attack.

Too Star Trekian to be true? Not to molecular biologist Ramesh Raina.

He and Penn State colleague Jack Schultz, a chemical ecologist, already
have inserted a green fluorescent protein from jellyfish into the lowly
Arabidopsis , the white rat of lab plants. When exposed to salicylic acid
(a familiar compound from which aspirin is made) and bathed in laser
light, the leaves become noticeably luminescent. It is the start of what
the team envisions as an arsenal of 300 Arabidopsis lines, each able to
detect a specific chemical or biological agent, from mustard gas to
anthrax to TNT.

"Scientifically," Raina assured, "there is no reason to believe it can't
be done."

The U.S. Defense Department is betting $3.5 million on it - the sum of a
three-year grant to grow Penn State's sentinel garden. Millions more are
being channeled to nine other universities for related research. Among
them is Princeton, where electrical engineering professor Ron Weiss is
programming bacteria to light up when in contact with certain toxins and

As he followed the Iraq war, Weiss saw potential applications. When
troops found suspected chemical weapons, samples had to be sent to the
United States for analysis. His bacteria, on the other hand, could be
taken into the field like a mobile lab.

"You spray it on the spot, and, two hours later, you observe the spot,"
said Weiss, whose project, a joint effort with the California Institute
of Technology in Pasadena, got a $3.7 million three-year grant.

"One can imagine engineering cells to recognize a variety of agents," he
said, "and having them report their analyses by fluorescing in different

Turning science fiction into fact, at high cost and high risk of failure,
is the mission of the Defense Advanced Research Projects Agency, the U.S.
military's research arm. Established in 1958 in response to the Soviet
Union's launch of Sputnik, it underwrites projects aimed at giving the
United States the technological edge.

Research funded by the agency gave the military the advanced cruise
missile and the M16 assault rifle. It gave the world the ceramic ball
bearing, the computer mouse, and the network that became the Internet.

Since 1966, the military agency has been investing in research on
biowarfare defenses, with spending this year reaching $162 million. But
it was the attacks of Sept. 11, 2001, followed by the rash of anthrax-
laced letters, that prompted the agency to focus on the possibilities of
bioluminescent sentries, said spokeswoman Jan Walker. It has dispensed
$6.3 million in grants this year to the participating universities.

The Pentagon already uses living sensors, with varying degrees of
success. In the Iraq war, worried that wind-blown sand and the smoke from
burning oil wells could foul electronic detectors, the Marines hatched a
plan to carry 43 chickens with them - a variation on the old canary-in-
the-mine theme. In 11/2 weeks, 42 were dead, for reasons no one could
pinpoint but that had nothing to do with weapons of mass destruction.

"There's no sensor that is 100 percent effective," said Keith LeJeune,
CEO of Argentase LLC in Pittsburgh and codeveloper of a device called the
Traffic Light that goes from green to red in the presence of less than a
nanogram of nerve gas.

Plants and bacteria would not be foolproof either. Yet, the researchers
say, they would have advantages.

Unlike sentinel animals, they could detect a pathogen without risk of
being infected and carrying it beyond the contaminated site, said
Princeton's Weiss.

The plants would not likely be used in combat, but grown in areas
vulnerable to terror attack. Within six weeks of seeding, the fast-
sprouting weeds could be at work even in a minefield, fluorescing
wherever buried explosives are leaking.

In the Princeton-California Institute project, the jellyfish's
fluorescent protein has likewise been attached to the bacteria's DNA. But
unlike the plants, the bacteria's glow is visible without a laser.

Engineering sentient cells is mind-bendingly complex and slow, as
evidenced by one of the rules Weiss has tacked up in his lab: "No
screaming or yelling."

In three years, the military research agency expects the universities to
have gone far enough with the research for the military to take over. The
next step would be to tailor the plants and bacteria to react to whatever
stimuli those scientists choose - a process that could take four to seven

That assurance does not calm critics such as Philip L. Bereano, a
professor of technology and public policy at the University of Washington
in Seattle and former board member of the Council for Responsible
Genetics, in Cambridge, Mass.

To develop such a defense against weapons of mass destruction, he argues,
these weapons must be used in the testing, which he considers a violation
of international law.

The time and money spent on the projects should be plowed into diplomacy,
he added. "Rather than tackle complicated social and political issues,"
he complained, "we prefer to look at technology to solve them."

Sentinel plants could be a waste of money for a different reason, said Ed
Hammond, U.S. director of the Sunshine Project, an international advocacy
group for bioweapon control.

"Once these systems are known, they can be evaded," Hammond said. He also
cited what has become the stock concern about genetically altered plants.

"The environmental issues are the same as genetically modified corn or
soybeans," he said. "Animals might eat them, insects might pollinate
them. What happens if the sentinel [enters] the wild population?"

Weiss, of Princeton, said he does not believe his bacteria would pose an
ecological threat.

"These lab strains are very weak," he said. "You put them out in nature,
and they die in less than a day."