Turning on a gene found in wheat could boost levels of protein, iron and zinc, scientists have discovered.

The gene occurs naturally in wheat, but has largely been silenced during the evolution of domestic varieties.

Researchers found evidence that turning it back on could raise levels of the nutrients in wheat grains.

Writing in the journal Science, they suggest that new
varieties with a fully functioning gene can be created through
cross-breeding with wild wheat.

"Wheat is one of the world's major crops, providing
approximately one-fifth of all calories consumed by humans," said
project leader Professor Jorge Dubcovsky from the University of
California at Davis.

"Therefore, even small increases in wheat's nutritional value may help decrease deficiencies in protein and key micronutrients."

'Spectacular' results

The researchers identified a gene called GPC-B1, GPC standing for Grain Protein Content.

It is found in both wild and domesticated varieties of
wheat, but in subtly different forms, indicating that it has been
changed by the long history of domestication.

The results were spectacular, confirming that this single gene was responsible for all these changes Jorge Dubcovsky

Working with a variety of wheat called Bobwhite, a staple crop whose
grains are commonly used in bread, scientists "turned down" GPC-B1
activity even further using RNA interference.

RNA interference is a recently-discovered technique which blocks the expression of genes.

"The results were spectacular," said Professor Dubcovsky.

"The grains from the genetically modified plants matured
several weeks later than the control plants and showed 30% less grain
protein, zinc and iron, without differences in grain size.

"This experiment confirmed that this single gene was responsible for all these changes."

The researchers deduced that the reverse process -
enhancing GPC-B1 activity - ought to produce plants which have higher
levels of these nutrients in their grains and mature faster.

The UC Davis team is already making such varieties, not
by genetic engineering but through crossing domesticated wheat plants
with wild relatives.

The key is a technology called Marker Assisted Selection
(MAS). This allows scientists to select which plants to cross using
genetic information, rather than simply choosing them by their
attributes, as farmers have done throughout the history of agriculture.

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