In a collaborative effort involving 74 researchers from 38 research institutes, scientists have produced the full genome of a wild strawberry plant. The research was published on December 26 in Nature Genetics online.
Drs. Asaph Aharoni and Avital Adato of the Weizmann Institute of Science’s Department of Plant Sciences were the sole Israeli scientists participating in the project, but they made a major contribution in mapping the genes and gene families responsible for the strawberry’s flavor and aroma.
The woodland strawberry (Fragaria vesca) is closely related to the garden-variety cultivated strawberry. The fruit of this berry contains large amounts of antioxidants (mainly tannins, the substances that give wine their astringency), as well as vitamins A, C, and B12, and minerals; potassium, calcium, and magnesium. In addition, the strawberry fruit is uniquely rich in substances for flavor and aroma.
Participation in this project is something of a circle-closer for Dr. Aharoni: For a number of years he has been investigating the metabolic pathways of ripening, in which the substances that give fruit its flavor and aroma are produced. Dr. Aharoni was one of the first to use biological chips to analyze the genetic networks involved in creating these substances. He has also conducted a comparative analysis of these genes in wild and cultivated plants, looking for the differences. Now that the full genome of the wild strawberry plant is available for research, he is able not only to conduct deeper and broader investigations, but to shed new light on some of his past findings. Thus, for instance, in carrying out a computerized analysis of the woodland strawberry genome, Dr. Adato was able to place an enzyme that Dr. Aharoni had previously characterized in a relatively small enzyme family. This small family is responsible for the production of a large number of aromatic substances, and the finding helped clarify their means of production.
Dr. Aharoni hopes that, among other things, the newly sequenced genome will help scientists understand how to return the flavors and aromas that have been lost over years of breeding in the cultivated cousin of the wild strawberry. The intense, concentrated aroma and flavor of the woodland strawberry are, he says, something to aspire to.
The woodland strawberry has now joined the elite list of plants, including rice, grapes, and soya, which have had their genomes sequenced. The length of the genome is about 240 million bases and contains around 35,000 genes. (In comparison, the human genome has three billion bases, but only 23,000 genes.) The woodland strawberry genome is relatively short, simple, and easy to manipulate, and the plant grows quickly and easily. These qualities make it an ideal model plant that might provide insight into related agricultural crops (the rose family), including cultivated strawberries and such fruit trees as apples, peaches, cherries, and almonds.
Dr. Asaph Aharoni’s research is supported by the De Benedetti Foundation-Cherasco 1547; the Minna James Heineman Stiftung; the Willner Family Foundation; and Roberto and Renata Ruhman, Brazil. Dr. Aharoni is the incumbent of the Adolpho and Evelyn Blum Career Development Chair of Cancer Research.