Gene technology yields plant virus cure

Scientists compare an immunized ear of barley (top) with one infected with a virus

By CNN's Grant Holloway

CANBERRA, Australia (CNN) -- An Australian breakthrough in gene technology has the potential to prevent agricultural crop losses caused by plant viruses.

It also could be used to reduce the use of pesticides.

Researchers at the Commonwealth Scientific Industrial Research Organization have developed a genetic-modification technique that enables plants to immunize themselves against a virus attack.

Working in much the same way as vaccines do in humans, the CSIRO technology inserts into a plant's DNA -- or genetic blueprint -- a small sequence of a viral genetic material called RNA.

Usually the plant would interact with the viral RNA, replicating it and allowing the virus to destroy or damage the plant. But the CSIRO has modified the RNA into a double strand which the plant recognizes as foreign immediately, triggering its natural defenses against the virus.

When the real virus invades the plant, it is countered straight away because the plant's system has been primed to fight it.

The technology has the potential to not only increase food production, but also reduce the use of pesticides currently applied to counter insects that carry certain viruses.

Allergy genes 'silenced'

It can also be used to "silence" unwanted genes that produce such things as allergens in peanuts and pollens.

One of the project's leaders Dr Peter Waterhouse told CNN the technology has the potential to target viruses that up until now had proven "unbeatable".

He said the research team had already developed genetically modified potatoes which were resistant to potato leaf roll virus.

The technique developed by CSIRO would provide a simple approach to providing virus immunity that could be passed down through plant generations, he said.

Viruses such as barley yellow dwarf virus each year destroys 25 percent of Australia's oat crop, 17 percent of the wheat crop and 15 percent of the barley grown, costing many millions of dollars in lost revenue.

Applied worldwide, the technology could be worth billions, he said.