杏吧原创

ARABLE farmers may soon be able to reclaim huge tracts of barren farmland
tainted by poisonous forms of aluminium. Government researchers in the US have
pinpointed the gene responsible for giving a unique strain of barley its ability
to tolerate high levels of toxic aluminium without loss of yield. They hope that
breeders may be able to cross or transfer the trait into different barley
strains or other crops.

Aluminium toxicity doesn鈥檛 harm people directly, but the problem does blight
half the world鈥檚 arable land, including a belt of 35 million hectares in the US,
says David Garvin of the Agricultural Research Service鈥檚 Plant, Soil and
Nutrition Laboratory in Ithaca, New York. Although aluminium is the third most
abundant element in the Earth鈥檚 crust, it creates problems for crops wherever
the soil is acidic.

In acidic soil the metal is converted into ionic complexes that damage the
root systems of plants. 鈥淭he results range from complete failure of crops to
reduced productivity,鈥� says Garvin. Some farmers tackle the problem by
neutralising the soil with lime, but a more sustainable solution would be to
breed tolerant plants, he says.

Garvin, Leon Kochian and their colleagues isolated the gene from Dayton, a
strain of aluminium-tolerant barley bred in Dayton, Ohio. Now they have traced
the location of the gene, and found that it is a variant of the gene that makes
some wheat strains withstand aluminium. 鈥淭his suggests that aluminium tolerance
may be conferred by a recurring mutation in many crop species,鈥� says Garvin.