Closer to the aluminium gene

Molecular biologists at Wagga Wagga have developed functional gene markers associated with aluminium tolerance in barley.

Gene markers enhance selection efficiency and enable faster release of new varieties.

Aluminium is the major factor limiting productivity of many crops in acidic soils, and among winter cereals, barley is the most sensitive to it.

"In order to grow barley in acidic soils, it is important to develop aluminium tolerant varieties," said NSW Department of Primary Industries (DPI) plant geneticist, Dr Harsh Raman.

Approximately 33 million hectares of Australian and 40 per cent of the world’s farming lands are highly acidic.

The financial cost of soil acidity to Australia is estimated to be about $1 billion each year. The gene was designated as HvMATE and is a member of Multidrug and toxic efflux (MATE) protein family.

New markers identified by Dr Junping Wang at NSW DPI’s Wagga Wagga Agricultural Institute are closer to the aluminium tolerance gene than previous ones and therefore should be more efficient in predicting tolerance in barley.

"We have established that HvMATE is involved in the release of citric acid from barley roots," Dr Raman, a senior research scientist at the Institute, said.

"Organic acids such as citric acid cheat aluminium in the rhizosphere, therefore preventing the toxic aluminium ions from entering into barley roots.

"The research team also demonstrated that release of citric acid correlates highly with aluminium tolerance and expression of the candidate HvMATE gene," Dr Raman said.

The research is supported in part by the NSW Agricultural Genomics Centre under Biofirst Initiative of the NSW Government, Grains Research and Development Corporation, and the Tasmanian Institute of Agricultural Research.