A flower that changes from white to red. Water the petunia with a dilute ethanol solution and it blooms red in 24 hours, for up to a week. Water with regular H20 and all of the new flowers will be white.
A pathway for anthocyanins--colored small molecules produced by brightly colored flowers--is broken. Scientists design a DNA sequence with a gene expression--one that responds to the presence of a small molecule (for example, dilute ethanol solution)--that results in repair of the broken pathway.