Were ancient farmers motivated by bread or beer?

Two Adelaide researchers are among a group of scientists who have discovered the ‘snooze button’ in barley, a gene involved in the ‘waking up’ process that is important for beer production.

Ancient farmers noticed that some barley grain would ‘wake up’ (or germinate) much quicker than other, more wild varieties that ‘snoozed’ (lay dormant) for many months. The farmers selected the faster-germinating barley for sowing their crops, a decision that also enabled the farmers to start brewing immediately after harvest.

“Beer production involves the controlled germination of barley grain to produce fermentable extracts, and a long dormancy period of several months severely delayed the process,” said Professor Geoff Fincher, Emeritus Professor in the University of Adelaide’s School of Agriculture, Food and Wine, who, along with his colleagues, compared domesticated and wild barley to identify the gene controlling dormancy.

In a study published in Nature Communications, the researchers identified a barley dormancy gene that encodes an enzyme, known as alanine aminotransferase (AlaAT). Although the precise mechanism through which the enzyme shortens dormancy is not clear, the enzyme sits at an important junction in biochemical pathways of nitrogen and carbon metabolism and is known to be affected by low oxygen concentrations, as might be found in stored grain.

“The discovery adds fuel to the debate as to whether the bringing together of ancient human groups into the first agrarian societies was driven by our appetite for wheat, flour and bread or for barley, beer and alcohol,” said Professor Fincher.