You don't know why coffee is synthetic caffeine when you drink coffee every day.

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We drink 2.25 billion cups of coffee every day, which adds up to about 3-4 people who drink one cup a day. With so many people drinking coffee, the area of growing coffee will not be too small. Coffee is grown on an area of 11 million acres worldwide.

Recently, the genome of coffee has been sequenced. Although Arabica coffee (Coffea arabica, 44 chromosomes) is not used for sequencing, but Coffea canephora (C. canephora,22 chromosomes, also known as C. robusta, which accounts for about 30% of the world's total coffee production), Arabica coffee is a hybrid of C. canephora and C. eugenioides.

C. canephora's flowers. Photo Source: wiki

C. the genome of canephora coffee consists of 22 chromosomes with a total size of 710 Mb (Megabase). How big is the 710 Mb? Imagine that the whole genetic body of coffee is printed in front of us, and we read it at the rate of one word per second, which takes 22 years and more than six months to finish. The results of the analysis showed that coffee had a total of 25574 protein-producing genes and 92 microRNA-producing genes. In addition, about half of the entire genome is transposable element.

The special part of the genomes of coffee is that the genes related to disease resistance (R genes) have the phenomenon of tandem repeats (tandem duplication) in the evolution, and the genes that synthesize phenolic secondary compounds (phenylpropanoids) have also increased. These genes include enzymes for the synthesis of flavonoids (isoflavone and flavnoids), alkaloids (alkaloids), monoterpenes (monoterpene), and caffeine (caffeine).

Have you ever wondered why coffee synthesizes caffeine? In fact, coffee synthesizes caffeine mainly to resist insects (in leaves) and to inhibit seed germination of other plants. People living in Ethiopia inadvertently discovered that it had a refreshing effect and began to take its fruit.

C. the fruit of canephora. Fully ripe fruit is bright red. Photo Source: wiki

The production of caffeine is obviously important for the viability of coffee. In the genome, the team saw a cluster of 23 genes, distinct from the other two plants that produce caffeine (tea Camellia sinensis and cocoa cacaoTheobroma cacao).

Although many plants have polyploidy in the process of evolution (such as wheat, corn, cabbage, tomato, etc.), coffee does not appear polyploid, but only selectively repeats in tandem to expand some of the genes to improve their competitiveness.

Whenever I see this evidence, I will think: we use the "toxins" that plants use to ward off insects as Bora to smoke (such as cigarettes) and drink (such as coffee and tea). If the plants know about it, they will certainly laugh. Of course, whether a substance is a drug or a poison is often just a difference in dose. Recently, it is often mentioned in research reports that a cup of coffee a day is more appropriate. For example, in recent years, for the sake of the health of the heart and nerves, coffee has long been limited to one cup a day (the most serious time was four cups a day). Everything is controlled in the "middle way" as far as possible, isn't it?