Home' Technology Review : January February 2014 Contents 37
MIT TECHNOLOGY REVIEW
vol.117 | no.1
advantages during extreme weather conditions, particularly dur-
ing key times in their growth cycle.
The challenge is to avoid reducing yields under good grow-
ing conditions. So Blumwald has identified a protein that acti-
vates the inserted genes only under adverse conditions. “ There’s
no cure for drought. If there’s no water, the plant dies. I’m not a
magician,” he says. “We just want to delay the stress response as
long as possible in order to maintain yields until the water comes.”
field just north of London on the grounds of Rotham-
sted Research, which bills itself as the world’s longest-
running agricultural research station (founded in
1843), is one of the focal points of Europe’s continuing
battle over genetically modified foods. The controversy here is over
an 80-by-80 -meter field of wheat, some of it genetically modified
to produce a hormone that repels aphids, a common insect pest.
In 2012, a protester climbed a low fence and scattered conven-
tional wheat seeds among the GM plants in an attempt to sabotage
the trial. The scientists at Rothamsted had the seeds vacuumed
up, hired several extra security guards, and built a second fence,
this one three meters high and topped with a curved overhang
to keep it from being scaled. Later, a few
hundred protesters marched arm in arm
to the edge of the fenced-in field before
they were stopped by the police.
The fuss at Rothamsted is just one
hint that the next great GMO contro-
versy could involve transgenic wheat.
After all, wheat is the world’s most widely
planted crop, accounting for 21 percent of the calories consumed
globally. Meddling with a grain that makes the daily bread for
countless millions around the world would be particularly offen-
sive to many opponents of genetically modified foods. What’s
more, wheat is a commodity grain sold in world markets, so
approval of GM wheat in a leading exporting country would likely
have repercussions for food markets everywhere.
Wheat is also emblematic of the struggles facing agricul-
ture as it attempts to keep up with a growing population and a
changing climate. Not only have the gains in yield begun to slow,
but wheat is particularly sensitive to rising temperatures and is
grown in many regions, such as Australia, that are prone to severe
droughts. What’s more, wheat is vulnerable to one of the world’s
most dreaded plant diseases: stem rust, which is threatening the
fertile swath of Pakistan and northern India known as the Indo-
Gangetic Plain. Conventional breeding techniques have made
remarkable progress against these problems, producing variet-
ies that are increasingly drought tolerant and disease resistant.
But biotechnology offers advantages that shouldn’t be ignored.
“Climate change doesn’t change [the challenge for plant
breeders], but it makes it much more urgent,” says Walter Falcon,
deputy director of the Center on Food Security and the Envi-
ronment at Stanford. Falcon was one of the foot soldiers of the
Green Revolution, working in the wheat-growing regions of
Pakistan and in Mexico’s Yaqui Valley. But he says the remark-
able increases in productivity achieved between 1970 and 1995
have largely “played out,” and he worries about whether the
technology-intensive farming in those regions can be sustained.
He says the Yaqui Valley remains highly productive—recent
yields of seven tons of wheat per hectare “blow your mind”—but
the heavy use of fertilizers and water is “pushing the limits” of
current practices. Likewise, Falcon says he is worried about how
climate change will affect agriculture in the Indo-Gangetic Plain,
the home of nearly a billion people.
Asked whether transgenic technology will solve any of these
problems, he answers, “I’m not holding my breath,” citing both
scientific reasons and opposition to GM crops. But he does expect
advances in genetic technologies over the next decade to cre-
ate wheat varieties that are better equipped to withstand pests,
higher temperatures, and drought.
It is quite possible that the first and most dramatic of the
advances will come in adapting crops to the shifting patterns of
disease. And as Teagasc’s Ewen Mullins puts it, “if you want to
study plant diseases, you come to Ireland.”
A hundred kilometers from the idyllic fields in Carlow, Fiona
Doohan, a plant pathologist at University College Dublin, is
developing wheat varieties that stand
up to local diseases and trying to under-
stand how plant pathogens might evolve
with climate change. At the school’s agri-
cultural experiment station, she uses
growing chambers in which the concen-
tration of carbon dioxide can be adjusted
to mimic the higher levels expected in
2050. The experiments have yielded a nasty surprise. When
wheat and the pathogens that commonly afflict it are put in the
chamber with the increased levels of carbon dioxide, the plant
remains resistant to the fungus. But when both are separately
grown through several generations under 2050 conditions and
then placed together, Doohan says, the plants “crash.” This sug-
gests, ominously, that plant pathogens might be far better and
faster than wheat at adapting to increased carbon dioxide.
Next to the building is an apple orchard with representatives
of trees grown all over Ireland, including heirloom varieties that
have been planted for centuries. Doohan looks at them fondly
as she walks past, the ground covered by fallen apples. At the
far end of the orchard is a row of greenhouses, including a small
one in which genetically modified plants are tested. Inside is a
particularly promising transgenic wheat that is proving resistant
to the types of rust disease common in Ireland. The new gene is
also increasing the plant’s grain production, says Doohan, who
created the variety with her colleagues. She’s clearly delighted by
the results. But, she quickly adds, there are no plans to test the
GM wheat out in the field in Ireland, or anywhere else in Europe.
At least for now, the promising variety of wheat is doomed to stay
in the greenhouse.
David Rotman is the editor of MIT Technology Review.
Wheat is vulnerable
to one of the world’s
most devastating plant
diseases: stem rust.
12/11/13 5:16 PM
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