Flower power to help improve corn yield
Wednesday, 4 May 2011 Anna Salleh
Reposted from ABC Radio Australia
Genes normally only active in the flowers of plants could be used to protect the whole plant from resist fungal disease, say Australian researchers.
Professor Marilyn Anderson of La Trobe University is presenting her work at an Australian Academy of Science seminar in Canberra today.
Anderson and colleagues in agricultural biotechnology company Hexima are working together with seed giant Pioneer to develop transgenic corn that is resistant to the major fungal diseases that decrease yield.
“With climate change and growing population, we know that within the next couple of decades we’re going to have to increase cereal production by 70 per cent,” says Anderson. “So all companies are looking at ways to improve the yield of grains, especially rice, corn and wheat.”
Anderson’s earlier work focussed on the molecular mechanism underlying how flowers recognise pollen and decide whether to accept it or reject it.
During that time she discovered a family of molecules called defensins, which are potent anti-fungal molecules.
“We call them ancient immunity molecules because similar molecules are present in insects, and even in humans, and they are involved as the first barriers against disease,” says Anderson.
Tobacco flower chemical
She and colleagues have been focussing on one key defensin, called NaD1, found in only the flowers of ornamental tobacco.
“This molecule seems to attack all sorts of fungal diseases,” says Anderson.
Her team is now engineering transgenic crops to express anti-fungal chemicals throughout the whole plant.
Anderson and colleagues are also tweaking the tobacco defensin to make it more potent and able to kill an even broader range of fungi.
With the help of colleague Professor David Craik at the University of Queensland, the researchers analysed the structure of the defensin.
“Now that we know its structure in detail we can start changing little bits of it and tailoring it,” says Anderson.
The researchers have also developed new gene stacking technology and are testing combinations of defensins and other anti-fungal chemicals, which they hope will ward off fungal resistance to the chemicals in the field.
Trials of defensin-producing transgenic corn in glasshouse trials at La Trobe University are underway and still have several years to run, says Anderson.
Testing will continue until the team finds the best genes and best gene combinations, she says.
Anderson says her current research is aimed at the major fungal diseases of corn in North America. But the research could also be of interest to the Australian wheat industry, which shares some of the same fungal diseases.
Anderson’s early work was funded by Australian Research Council.
Together with Dr Robyn Heath and Professor Adrienne Clark, Anderson set up Hexima, which developed and tested transgenic cotton engineered to contain defensins.
The current partnership with Pioneer is a result of the success of cotton field trials, she says.
Anderson says her company’s philosophy is only to use genes from plants in developing transgenic crops.
“We feel the public will be much happier if they were natural genes that plants use anyway for protection against disease,” she says.
Tags: pest-management, biotechnology, pests