The sunflowers that Vincent Van Gogh painted more than a century ago carried an unknown genetic mutation that was not discovered until 2012 . Normally, the inflorescence of the sunflower is composed of two different types of flowers. One on the outer perimeter, in the form of a single series of long, flattened, yellow, fertile petals. And another in its center, formed by hundreds or thousands of small tube-shaped flowers that produce the seeds.
However, the sunflowers in Van Gogh’s paintings are slightly different from the normal ones. They have multiple bands of yellow petals and a much smaller proportion of tubular flowers in the center. “The little flowers of the internal disk have been transformed and are very similar to those of the external one,” explained to the SINC agency researcher John Burke, coordinator of a study at the University of Georgia (USA) published in the journal PLoS Genetics . Researchers have discovered that the appearance of mutant sunflowers is due to the HaCYC2c gene being activated in the wrong place . “Normally this gene is active only in the outer flowers, but in mutants it is also active in the central disk,” says Burke.
In the study, John Burke and his colleagues crossed normal sunflowers with mutants to discover that there were two mutations, a dominant one that caused double flowers and a recessive one that gave a third type of tubular flower with intermediate characteristics. Using more modern techniques, the researchers sequenced the mutated gene as well as hundreds of sunflower varieties. They found that normal flowers always had intact HaCYC2c, and double and tubular flowers always had the same mutation. Are these results the evidence that the mutation we have identified is the same one that van Gogh captured at the time? Burke concludes.
In addition to their historical interest, the discovery may have economic repercussions, since these ornamental flowers are highly valued in the market.
