World joins forces on wheat genes

A revolution in agricultural biotechnology based on a template of the rice genome is on the way, but researchers are finding the task to be larger than originally anticipated.

When the rice genome was fully sequenced last year, researchers established a worldwide effort to find similarities between the combinations of genetic code in rice, wheat and barley.

The International Genome Research on Wheat project (IGROW) led by Prof Rudi Appels and Prof. Bikram Gill (Kansas, USA) has provided a focus for groups to collaborate in these large-scale genome studies.

Now six months down the track, the research teams have completed their initial scans and have found that they have only scratched the tip of the iceberg.

“Wheat has about 40 times more DNA than rice, and so it was thought that an inter-species comparison would provide us with a window of understanding into the genes of wheat and barley,” Professor Rudi Appels said. Appels is the team leader of a research collaboration from Murdoch University, the WA Department of Agriculture and the CRC for Molecular Plant Breeding.

Professor Appels and his team are focusing on unraveling the mysteries of areas in Chromosome 4 holding genes for dwarfing and pre-harvest sprouting, which are two genetic traits of immense importance to wheat and barley producers.

“Pre-harvest sprouting in particular causes lots of problems in both the wheat and barley industries in Australia, where wet environmental conditions seem to induce this early germination before harvest,” said Dr Chengdao Li.

“Early germination in wheat creates a degraded product with fewer nutrients, and so wheat end-product users do not want to buy the grains with pre-harvest sprouting.

Pre-harvest sprouting also resulted in loss of seed viability and the seeds may not germinate in wheat growers’ fields. In barley the problem is even more of a delicate balance, with breweries needing to induce germination for the malting process.

” Initial genome scans now completed, the research team is concentrating on identifying molecular markers for traits that were common to all the species to create a starting point to unraveling the mechanisms behind crop qualities.

“Now that we can delve into the detail of the genes with help from the Centre for Bioinformatics and Biological Computing at Murdoch University, it is becoming apparent that nothing is ever that easy,” said Dr Mike Francki.

“We have found genes that appear in rice, wheat and barley, but interestingly the order of the genes do not match up completely. Some groups of genes are flipped around and moved closer to different genes, slightly rearranged in ways that can create entirely new ways for that gene to be expressed.”

Results of the initial worldwide efforts to scan the wheat and barley genomes will be published later this year.