Genome helps breed better breads

Murdoch University’s Rudi Appels is at the vanguard of food science research efforts to produce a refined wheat genome sequence this year.

Professor Appels is one of four leading scientists among the 200 co-authors worldwide to develop the genome sequence over the past 10 years.

Once published to publicly available databases across the world, the sequence (a list of an organism’s DNA) will allow crop breeders and flour producers to analyse and select desirable properties for their ideal wheat, Professor Appels told Business News.

Among those to utilise the new wheat genome would be Australia’s major crop breeding companies – InterGrain in Western Australia, AGT (Australian Grain Technologies) in South Australia, and LongReach (Plant Breeders) on the east coast.

“There are younger breeders (at those companies) who are across a lot of that data analysis part, which you have to do to access those databases, and they can hammer away and design their probes, their diagnostics, to then work into their breeding programs,” Professor Appels said.

The process the breeders would undertake is not genetic modification, but rather the development of what are known as synthetic wheats, achieved through naturally cross-breeding different wheat varieties.

About 30 per cent of breeding programs are currently devoted to producing synthetic wheats, Professor Appels said.

He said the various genomes within wheats (the sets of genes and genetic material present within an organism) were responsible for this ability to select properties, such as water-efficiency, heat-resistance and improved proteins for people with Coeliac disease.

“If we think of the wheat we eat every day, bread wheat, it’s got three sets of what we call chromosomes, three sets of genomes, A B and D, and the D genome comes from goat grass,” Professor Appels said.

“If you turn the clock back 10,000 years or so, they had what we now call pasta wheat or durum wheat, which is just A and B.

“It was not planned but the D genome, the goat grass, naturally fertilised the durum, and so it formed a couple of plants that had bigger grain than usual, which were ABD,” he said.

He said that specific variety of goat grass grew in Iran and, over time, the resilient properties that came from the D genome had diminished within the ABD wheat we use for bread today.

“We think that’s because when it got incorporated into the ABD environment, things got lost; if things (properties) don’t get selected for you, you often lose them,” Professor Appels said.

By re-evaluating the goat grass DNA and creating a genome sequence that allows for property selection, Professor Appels hopes to bring back the benefits of the D genome.

Synthetic wheats were first generated in the 1980s, Professor Appels said, with 420 goat grass varieties from Syria to Afghanistan crossed with AABB varieties of standard wheat, creating much more genetic variation than the original cross-bred crop that grew in Iran 10,000 years ago.

The exciting part of current research knowledge was the capacity to understand this at the DNA code level, he said, with the multitude of benefits stemming from the goat grass D genome able to be exploited by having this high-quality AABBDD genome reference sequence.

“There’s a big database in Europe and in America and in Japan, which will all have the sequence.

It’s sort of like looking up at the stars, you can pick your galaxy and work away at it,” Professor Appels said.

“As our population expands, and our climate grows more extreme, it is very important we are able to produce wheat varieties that survive and thrive.

“This is my dream; we could, say, go into the supermarkets and see some sort risk factor for carrying these, what we might call the ‘bad proteins’ (aggravating Coeliac disease), so if people want to avoid them (in flour or bread), they can.”

He said the food industry was aiming to improve synthetic wheats, but currently found it more efficient to invest with academics.