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OVERCOMING
HEAVY METALS
Up
to 12 percent of soils under cultivation around the world contain metals
that stunt plant growth and development and result in poor harvests.
In the past, plant breeders dealt with this problem by crossing metal-sensitive
plant varieties with species that thrive in this type of poor soil. NSF-funded
researchers are using genetic
engineering
to improve plant traits, ranging from pest resistance to nutritional value,
from developing plants that flourish on metal-rich soils, to helping other
plants clean up heavy-metal contamination.
NSF-funded researchers at Cornell University are studying aluminum toxicity
and tolerance levels in plants, since aluminum
levels in plants are a major factor limiting crop productivity.This
research has shown that aluminum starts a process through which certain
acids are discharged into the soil. These acids in the soil protect the
roots from the harmful effects of the aluminum.
Improving food production
A better understanding of the mechanisms involved in this process will
have important implications for agricultural food production.
Understanding plant iron uptake is highly important because one-third
of the world's soils are iron deficient. Iron deficiency in humans is
the most prevalent nutritional problem in the world today, affecting an
estimated 2.7 billion people in industrial and developing countries.
Plants and nutrition
Plants
are the major source of iron for most of the world;ensuring
that plants have higher amounts of iron would help in solving an important
human nutritional problem.
In the future, crops could be manipulated to become several times richer
in iron, or to become so efficient at extracting iron from the ground
that they could grow in soils that would not normally support them.
Research may also lead to the discovery of genes responsible for uptake
or absorption of other metals, such as copper, by plants. Manipulating
these genes could lead to phytoremediation, a method of removing pollutants
from industrial wasteland by growing plants on it. This process may become
more efficient if plants become able to absorb greater quantities of metals
from the ground.
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