The recent sequencing of coffee DNA has led to a number of discoveries, rendering future innovations to protect coffee production possible.
There are 120 different species of coffee, but one of them, Arabica, accounts for 60% of the world’s coffee production, its flavor being the most appreciated. Yet its production is threatened by climate change and disease, jeopardizing a sector on which 125 million people depend for their livelihoods, according to the International Coffee Organization.
The coffee plant has therefore become the focus of concern and research. The latest was published on April 15 in Nature, using genome sequencing, the detailed mapping of coffee DNA, to discover which gene might make it more resistant to disease.
Seventeen countries took part in the study, including two from South America, the world’s leading coffee producers. Their participation in this research may enable them to avoid the fate of Mexico, the world’s 9th largest coffee producer in 2011, until the rust epidemic affected its plantations and contributed to the country’s deforestation.
It is precisely this pathogenic fungus that has motivated scientists’ research. They aim to protect Arabica from this disease by finding a gene resistant to it in related species such as Coffea stenophylla or Robusta, which is more resilient, as its name implies, but whose taste is less subtle than Arabica’s.
International researchers were able to sequence not only the coffee genome but also its entire pangenome — the complete set of the species’ genes. As a result, they identified 30 genes out of 60,000 responsible for resisting coffee leaf rust disease.
Genetically modified coffee?
But the plant’s genes tell much more than that. The team of scientists has also identified genes related to coffee aroma, making it possible to genetically manipulate seeds to make them even tastier, and to improve crop yields.
In addition, the ability to predict flavor through genetic identification allows for anticipation of taste and production quality, thereby saving the years of waiting required to grow the plant. However, the cultivation of genetically modified organisms (GMOs) endangers biodiversity due to the potential for genetic pollution.
Coffee, older than humans
Among the secrets uncovered by the plant’s genetics is the age of coffee, which is revealed to be older than humans! While the previous, rather imprecise estimate was between 50,000 and 1 million years ago, it is now certain that the Arabica plant was born between 350,000 and 600,000 years ago, when Coffea eugenioides crossed with Coffea canephora. For reference, the first Homo Sapiens appeared no more than 300,000 years ago.
The geographical origins of coffee have also been unveiled: Arabica originated from the forests of Ethiopia and was first cultivated there and in Yemen, before spreading throughout the world. The name given by the Swedish biologist Carl von Linné, who believed it to come from Arabia, was therefore quite far from the truth.
The threat of climate change
In response to the pressing threat of climate change, which is threatening 50% of Arabica’s cultivable area, scientists have sought to identify a gene in wild cousins that would facilitate plantation adaptation. Optimum growth conditions are around 22 degrees Celsius in a tropical climate.
The economies of countries within the coffee belt are threatened by the already perceptible warming of the climate, at a time when demand for coffee is set to double by 2050.
With all this new information, many doors are opening for the coffee industry. Douglas Sila Domingues, co-author of the paper, is now leading a new study with the Institut de Recherche pour le Développement de Marseille to identify the genes that give wild coffee climatic resilience and drought resistance, intending to pass them on to Arabica.
How do we achieve this? Domingues explains: “With the knowledge of the genome, it is possible to obtain information that allows us to go in two directions: the development of varieties by directing crossbreeding, in other words, as a reference to guide us in future crossbreeding that produces new varieties; and more direct interventions, such as modifying a gene specifically.”
