RNA Vaccine For Plant Viruses

Description and Advantages

Researchers at Australia's CSIRO Plant Industry have developed a technique using 'hairpin RNA' that effectively vaccinates crop plants against viruses. "Just as vaccines are used to prevent human diseases, such as flu, measles or tuberculosis, we have used gene technology to induce immunization in plants against a virus before it attacks," says Peter Waterhouse, one of the scientists on the project. "Scientists have the potential to target viruses that, before now, have proven to be virtually unbeatable:'

The new technique is called post-transcriptional gene silencing (PTGS) with intron-spliced 'hairpin RNA' (ihpRNA). "It involves inserting plant DNA that has a small, incomplete piece of virus RNA added to it," Waterhouse said in a statement. "That produces double stranded RNA. We called it 'hairpin' (hpRNA). The plant sees the hpRNA as foreign, and activates its latent defense mechanism. This degrades the hpRNA. Like a fire drill, this process is a practice run for the plant's defense mechanism, teaching it to recognize the specific sequence of the virus so, if attacked, the defense mechanism leaps into action, degrading the invading virus RNA before it can multiply. The result is immunity to that specific virus."

Waterhouse says the team at CS1RO has already developed potatoes resistant to Potato Leaf Roll Virus (PLRV) using this technique. These plants have been tested in the laboratory and greenhouse, and have undergone field trials.

The research suggests that the hpRNA technique will provide a simple approach for producing reliable virus immunity that can be passed down through plant generations. Now that scientists know how to activate this natural mechanism, they may also be able to use the technique to silence unwanted genes like those that make allergens in nuts or pollen.

Source

Nick Goldie of CSIRO at
phone +61 2 6276 6478,
fax +61 2 6276 6821,
email Nick.Goldie@nap.csiro.au

AgBIOTECH Reporter,
July 2001