A new molecule discovered in a common rice disease could help in the battle against HIV, biologists have said.

A team of international researchers found a new molecule seen in rice disease, bacterial leaf blight, has similar molecular mechanisms to that of HIV.

Researchers found the rice plant's immune system is triggered by a molecule called RaxX, which is secreted by the disease.

The disease is detrimental to rice crops across the globe, with half of the world's population reliant on the grain for food security.

Bacterial leaf blight can destroy up to 80 per cent of a crop in some countries if it develops early.

Australian National University researcher Dr Benjamin Schwessinger said the discovery may give insight into human health, as the "chemistry is similar to that of HIV entering human cells".

He said the chemical properties of RaxX, a tyrosine-sulfated protein, have a wider significance than just rice diseases.

"Several major human diseases, for example HIV, involve tyrosine-sulfated proteins. The sulfation stabilises the molecules but its role in binding and cell entry is not precisely understood," he said.

"The new understanding could lead to the development of novel methods to block such diseases."

Dr Schwessinger said the molecule "has never been seen before", and could boost crop yields and lead to more disease-resistant types of rice.

"We've realised that the type of molecule plays an important role in the immune response of rice plants," he said.

"The plant transfers water and nutrients into vessels and the bacteria normally clogs those up which leads to the death of the plant.

"It will now be much easier to develop containment strategies against the disease and breed more robust rice plants."

RaxX prone rice crops used in the study. ( Photo: Ramesh Sonti )

Some strains of rice are naturally resistant to the disease, which has given the team a clue as to what was affecting the plants.

The team discovered the rice plant's XA21 immune system was triggered when the RaxX molecule was secreted by the leaf blight bacterium Xanthomonas oryzae pv. oryzae (Xoo).

The team generated mutants of Xoo that did not produce RaxX and tested whether they triggered the rice immune response, which allowed them to isolate the Xoo gene that was creating the RaxX molecule.

Dr Schwessinger said the modified proteins have a similar make-up to the HIV cells, however any application was "far off".

"The proteins we recognised were modified and similar modifications were required for HIV to enter the human cells," he said.

"So if we look to future research of the molecular mechanism ... it could lead to insight to its application to HIV."

Dr Schwessinger said he hoped the research could help rice immunity and methods to produce more food in regions where it is needed.

"It is a little bit like a flu shot, each flu shot has a mixture which would most likely protect you to the next season flu and similarly these farms can grow rice plants which would most likely be resistant to the bacteria in the field," he said.

The research has been published in the journal Science Advances.