They have deciphered the complete genome of the olive, which will lead to better olives and oil.
Researchers at the Genomic Regulation Centre (CRG in Spanish) in Barcelona, the Madrid Royal Botanical Garden and the National Centre for Genomic Analysis (CNAG in Spanish) in Barcelona have together made the breakthrough.
Their work has been published today in the magazine ‘GigaScience’ and shows they have sequenced for the first time the more than 56,000 gens in the genome, from an olive tree of more than 1,300 years old and of the variety Farga, one of the most important in Spain.
The olive is one of the first trees to be cultivated in the history of humankind, surely some 6,000 years ago, and is the most emblematic tree of the Mediterranean, with economic relevance in Spain, Italy, Greece and Portugal.
Spain is largest producer of olive oil in the world, with a third of world production, three million tons of olives a year.
The chief of the group for comparative genomics from the CRG, Toni Gabaldón, who led the research, explained that until now the olive genome was unknown, which regulates all the differences between varieties, sizes and taste of the olives, given their longevity and adaptation to dryness.
According to Gabaldón, the sequencing of the complete genome of the olive, will serve to help the olive in its development, such as building defences against infections which cause destruction, such as the bacteria Xylella fastidiosa and the fungus Verticillium dahliae.
‘It is , without doubt, an emblematic tree which takes at least 12 years to develop for us to see the morphological characteristics and to develop more research into , for example crossing’, said Gabaldón.
Four years ago, Gabaldón participated with Pablo Vargas, a researcher from the CSIC in the Royal Botanical Garden, in the presentation of scientific results on threatened species, such as the Iberian Lynx.
Then, Pablo Vargas proposed to the former president of Banco Santander, Emilio Botín, to finance the completion of the full genome using exactly the same methodology in the sequencing of the Lynx.
Five months later, he signed the contract for the first complete sequencing of the DNA of the olive, an investigation which has lasted three years.
‘In the sequencing of the genome there are three phases; the first to isolate the genes, the second to assemble the genome, ordering one gene behind another as if connecting odd phrases in a book. And finally identify all the genes, and print the research. These two last phases are what we have realised and present now’ explained Vargas.
According to Tyler Alioto, a scientist from the CNAG-CRG, ‘this genome has generated more than 1,000 Giga Bytes of data. We are surprised because we have detected more than 56,000 genes, more than double the genomes sequenced in related plants and double the human genome’.
In addition to the complete sequencing of the olive genome, the researchers have also compared DNA from this tree to other varieties such as the acebuche (European olive), and obtained transcriptome, to say the genes which express genetic differences in leaves, roots and fruits.
The next step, they say, is to decipher the historical evolution of the olive, which formed part of the lives in the populations of the old world from the Bronze Age when the process of ‘domestication’ began from the acebuche in the East Mediterranean, which are now the olives we see today, which could have lived for 4,000 years.
‘In fact, this longevity has converted the olive which we have sequenced into nearly a living monument’, underlined Gabaldón.
‘Until now all the sequencing, from the vinegar fly to the first human analysed, which had lived a determined time, but then have died out. This is the first time that DNA has been sequenced from an individual of more than 1,000 years old which could survive, perhaps, for another million’ said Gabaldón with pride.