Researchers say they have found a wheat gene which will help fight one of the biggest threats to global wheat production.

The gene helps give wheat resistance to a deadly strain of stem rust called Ug99 which is capable of wiping out entire wheat crops.

Currently, Ug99 can overcome most of the wheat varieties that are thought to have stem rust resistance.

Evans Lagudah, from the CSIRO, says this strain of rust isn't in Australia yet, but it is easily transported and considered a serious biosecurity threat.

"To actually say we've got a 100 per cent guarantee that it will not happen, I think that no-one will be brave enough to say that, but what it's going to enable us to do is to try to be one or at least two steps ahead of the pathogen," he said.

The new gene is called Sr-33 and will be given to plant breeders to insert into new lines of wheat as part of a gene package to help create and maintain resistance to stem rust.

"To make it easier to use this gene, because we have the information on the DNA sequence we are able to develop a simple molecular diagnostic marker that can tell you the presence of this resistance gene," Dr Lagudah said.

"The issue here is really trying to look further down the track.

"What we are aiming to be able to do in the medium to long term, apart from those genes being used in varietal releases, is to take this molecular information and see whether specific changes can be made to this resistance protein that allows it to recognise a broad spectrum of rust pathogens."

The research work was supported by the GRDC and the Bill and Melinda Gates Foundation.