BOB HIRSHON (host):
The mystery of the yellowed paintings. I’m Bob Hirshon and this is Science Update.
Just as iron mixes with oxygen to form rust, fiber in paper bonds with oxygen to form compounds called chromophores. These are what make old paper documents and artwork look yellow. Now, in the journal Physical Review Letters, scientists finally describe the chemistry of the paper-yellowing perpetrators. The discovery could lead to new techniques to restore antique papers and artwork.
In other art-related news, many Vincent Van Gogh paintings depict showy sunflowers with multiple rows of yellow petal-like florets around the outside. Common sunflowers have just one row. Now scientists report in the journal PloS Genetics that they’ve found the gene responsible for the flashy flowers. Understanding the genetic basis for this trait could help scientists develop new varieties of the plant optimized for seed production or ornamental gardening. I’m Bob Hirshon, for AAAS, the science society.