The Coffee Genome Has Been Sequenced. Here's What That Means For You.

Now that the coffee plant genome has been sequenced, it's only a matter of time until we're all brewing up genetically engineered, super-caffeinated coffee beans, right? Maybe. Here's what we know now about coffee that we never knew before.

An international team of scientists has sequenced and published the coffee genome. More specifically, researchers have sequenced the genome of Coffea canephora. Better known as "robusta" coffee, C. canephora makes up roughly 30% of the world's commercial coffee production. The remaining 70% is accounted for primarily by C. arabica, a hybridized offspring of C. canephora.

Together, these species comprise one of the world's most treasured agricultural commodities, and are the starting materials for what is arguably the most highly prized beverage on Earth. Caffeine, after all, is far and away humanity's favorite psychoactive drug, and coffee is the vehicle by which most of us consume it to the tune of roughly 2.25-billion cups a day.

It's safe to wager, then, that coffee would not be so popular were it not for its caffeine content. And that's what makes the publication of the C. canephora genome so exciting. The researchers, it turns out, have done more than identified over 25,000 protein-making genes in the robusta coffee genome. By examining which families of genes expanded in the course of coffee's evolution, and comparing its genome to those of other plant species, researchers co-led by University of Buffalo genome scientist Victor Albert, were able to, in his words, "learn about coffee's independent pathway in evolution, including excitingly the story of caffeine."

The genes responsible for coffee's caffeine-production code for a group of enzymes called N-methyltransferases. The N-methyltransferase family is ancient, and has evolved and diversified over many millions of years to perform a variety of tasks in innumerable species of plants. Previous research has shown that the caffeine in plants like tea and cacao is also produced by N-methyltransferases. What the newly sequenced coffee genome reveals is that these C. canephora's caffeine-producing enzymes evolved independently from those in cacao and tea.

"If you were to look at the family tree of N-methyltransferases, you would find that the genes responsible for caffeine synthesis in coffee have evolved along an entirely separate branch from those in charge of caffeine synthesis in chocolate," says Albert. You might find enzymes in chocolate that are closely related to the caffeine-producing enzymes in coffee, he explains, but they would have nothing to do with chocolate's caffeine-producing enzymes. Both plants rely on N-methyltransferases to generate caffeine, but they took different evolutionary routes to do so. It's a classic example of what evolutionary biologists call "convergent evolution."

All this talk of N-methyltransferases and caffeine production likely has you wondering: Will having a sequenced coffee genome complete with brand new insights into the evolution of coffee's caffeine-production enable us to breed strains of highly caffeinated super-coffee?http://io9.com/5861402/10-rea...

In a word: Yes. In any agricultural plant, genome sequences have become a prerequisite to doing any sort of advanced breeding or genetic modification.

The same could theoretically be said for traits like flavor and aroma. The researchers identify six genes responsible for the production of linoleic acid, a fatty acid that contributes to the the taste and smell of coffee. "We don't know the precise role of those genes in that flavor production," says Albert, but a sequenced genome will serve as a useful reference for anyone looking to develop new varieties of coffee."For [the contributions] we know about," says study co-author Patrick Wincker, a geneticist at France's Institut de Gnomique du CEA, "these findings open a new way to correlate aroma and gene families, and potentially to try new combinations of these genes."

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The Coffee Genome Has Been Sequenced. Here's What That Means For You.