Coffee genome sequenced

The draft genome of the coffee plant, Coffea canephora, has been sequenced by an international research effort including Australians.

Commonly known as Robusta coffee, C. canephora is the source of about 30% of the coffee produced worldwide.

The analysis sheds light on the evolution of caffeine in plants and shows that coffee plants evolved convergently with cacao and tea plants.

“Coffee, cacao and tea appear to share an ability to produce caffeine in their leaves, shoots or stems,” said Professor Robert Henry from the University of Queensland’s Queensland Alliance for Agriculture and Food Innovation (QAAFI). Henry contributed to the DNA sequence data used in assembling the coffee genome.

“Although such plants are not closely related, they all synthesise caffeine. It seems that during their evolution, each plant independently developed the ability to make caffeine,” he added.

It is anticipated the genome sequence will accelerate the development of new coffee varieties, providing the ability to select and grow coffee with a pre-determined level of caffeine including premium-quality, zero-caffeine coffee, tea and cacao.

Because traditional methods of minimising caffeine often result in a corresponding loss of flavour, this will mean a less processed product with a more full-bodied flavour for the 12% of coffee drinkers who choose decaf.

The results are also expected to lead to work on increasing the resistance of coffee plants to environmental stresses like climate change and pests.

“We think caffeine offers plants several advantages, including insecticidal properties and an inhibitory function that prevents seed germination in competing species,” Henry said.

QAAFI, which is tasked with pursuing scientific methods to add value to Queensland produce, is also working with flavour scientists and industry partners to unpick the genomic component of premium coffee.

Australia currently produces a small fraction of the global coffee market, exporting a few hundred tonnes a year; it is estimated that 7.8 million tonnes of coffee was shipped globally in 2013.

“Potentially, Queensland could develop a multimillion-dollar market for high-quality, premium coffees, ranging from full strength to decaffeinated,” Henry said.

The study has been published in Science