The Evolution of Your Coffee's Caffeine: Scientists Sequence Coffee Plant Genome

Most people start their days with a cup of coffee. But what do you know about what you're drinking? Scientists may have uncovered new information about your morning brew by sequencing the genome of the coffee plant, revealing a bit more about the evolution of caffeine.

More than 2.25 billion cups of coffee are consumed daily worldwide, and coffee is the principal agricultural product in many tropical countries. In fact, a staggering 8.7 million tons of coffee was produced in 2013.

"Coffee is as important to everday early risers as it is to the global economy," said Philippe Lashermes, one of the researchers, in a news release. "Accordingly, a genome sequence could be a significant step toward improving coffee. By looking at the coffee genome and genes specific to coffee, we were able to draw some conclusions about what makes coffee special."

The scientists actually created a high-quality draft of the genome of Coffea canephora, which accounts for about 30 percent of the world's coffee production. Then, the researchers examined how coffee's genetic makeup is different from other species, comparing it to the grape and tomato.

So what did they find? It turns out that coffee has larger families of genes that relate to the production of alkaloid and flavonoid compounds, which contribute to coffee aroma and bitterness. Coffee also has an expanded collection of N-methyltransferases, which are enzymes that are involved in making caffeine. In fact, these caffeine enzymes are more closely related to other genes within the coffee plant than to caffeine enzymes in tea and chocolate. This suggests that caffeine production developed independently in coffee.

"The coffee genome helps us understand what's exciting about coffee-other than that it wakes me up in the morning," said Victor Albert, one of the researchers. "By looking at which families of genes expanded in the plant, and the relationship between the genome structure of coffee and other species, we were able to learn about coffee's independent pathway in evolution, including-excitingly-the story of caffeine."

The findings could give scientists a new way to potentially improve coffee plants in the future. More specifically, it shows that coffee had a unique evolutionary history and that caffeine production evolved separately.

The findings are published in the journal Science.