The sunflowers series of paintings are among the best known works by Vincent van Gogh. Some of the sunflowers painted were rather peculiar what that wasn’t due to the mental problems of the famous painter, in fact they were mutants flowers, of the “double-flowered” type that come in a number of varieties such as the one called “teddy bear” (photo ©Mike Peel).
The origin of the mutation of these special sunflowers was mysterious but a recent study by a team of scientists at the University of Georgia has identified the gene responsible.
To understand the genetic basis of this mutation, the Professor of Plant Biology John Burke and his colleagues used classical techniques used in the nineteenth century by Gregor Mendel. They have in fact crossed the common varieties of sunflowers with the mutant strain.
The first findings suggested that a single dominant gene was responsible for the mutation. Further crossings of the sunflowers revealed that a second mutation, recessive in both the double-flowered mutants and in the common flowers, resulted in a third type of flower that has an intermediate form but tubular.
The scientists identified the gene responsible and have proceeded to its sequencing to show that in the mutation the portion of the gene that acts as an on / off switch is malfunctioning. The consequence is that the instructions that produce the petals are activated even in the part of the flower where there’s normally the inner disc. In the second mutation, a “jumping gene” prevents the production of normal petals.
The scientists analyzed hundreds of flowers of different varieties and found that the common ones have never any mutations in the gene called HaCYC2c, while the double-flowered ones have the same mutation. The tubular type flowers have a damaged copy of that gene.
The evidence suggests that the mutation discovered is the same of the flowers painted by Vincent van Gogh. This research, however, hasn’t only a value for its scientific discovery or its connection to art but also because there’s a market for those mutant flowers. These double-flowered sunflowers are sometimes too sterile to be able to reproduce and the study of their DNA will allow us to better understand how to produce more of them.