Des Moines Register
12-02-07
A hotter planet demands crops that tolerate drought
By, Philip Brasher
Washington, D.C. - A warmer planet will require food crops that need less water.
Some genetically engineered tobacco plants developed by scientists in California
could help fill the need. No, that's not because we'll have to eat tobacco or
smoke our way through climate change.
It's because these research plants contain a bacterium gene that can render
them remarkably impervious to drought, according to research reported in the
Proceedings of the National Academy of Sciences. The gene can delay the death
of a plant's leaves when the plant goes without water.
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In one experiment at the University of California at Davis, the transgenic tobacco
produced nearly as much seed as conventional plants on just 30 percent of the
water.
In another experiment, the biotech plants were able to recover and thrive even
after water had been withheld for two weeks. Conventional plants could not.
Eduardo Blumwald, one of the biologists working with the biotech tobacco, says
the same technology can be used in a variety of crops, including corn, wheat and
cotton.
Whether this gene will turn out to be the key to helping the world cope with
climate change remains to be seen. But drought tolerance may be the hottest
area of crop research. It's the "trait du jour" for plant breeders, said Stephen
Howell, director of Iowa State University's Plant Sciences Institute. He calls
the results of the California research "a fairly interesting finding" and one of many
ways being looked at to help plants survive with less water.
The long-range goal is to develop drought-resistant crops to deal with climate
change. Many areas of the world, including the southern United States, are
expected to become drier as well as hotter.
But there's a more immediate need for drought tolerance to fill the demand for
grain to make fuel ethanol. Biotech seed giants such as Monsanto Co. and
Pioneer Hi-Bred International, based in Johnston, are testing varieties of corn
that can be grown in dry areas of the Plains states with no irrigation or less
irrigation than is required now.
The National Research Council recently warned that expanding corn acreage to
produce fuel ethanol will significantly increase pressure on water supplies in
areas where the crops have to be irrigated.
The companies also think there will be interest from farmers in states such as
Iowa and Illinois, which normally have enough rainfall but occasionally
experience dry spells that can reduce yields and cut into profits.
Monsanto recently published research on biotech corn plants that could recover
after two spells without water. Monsanto hopes to have drought-tolerant seeds
commercialized in the next decade.
Pioneer aims to develop corn varieties that can get good yields with a quarter to
a third less water than is required now. Some new varieties are being tested in
dry areas of California and Chile. But engineering corn plants that need less
water and produce the yields farmers demand is a complex process. It is likely to
be 2012 before the first varieties are commercialized, said Joe Keaschall, a
regional corn research director for Pioneer.
Getting the research done is one problem. Getting the biotech crops to market
outside the United States will be another challenge altogether, given the
resistance to agricultural biotechnology in much of the world, including poor
regions where climate models show drought-tolerant crops will be most needed.
Greg Jaffe, who follows biotech issues for the Center for Science in the Public
Interest, a consumer advocacy group, says overcoming opposition to transgenic
crops will require agribusiness to convince the public of the need for droughtresistant crops. And that, he says, will require frank talk about the impact
agriculture has on water supplies.
"If explained properly, I think consumers will see the benefits," Jaffe said. "There
are many consumers who care about climate change and use of water and
reducing humans' impact on our globe and our environment."
Developments such as the California tobacco plants at least give hope for ways
to cope with a changed climate.