She Loves Me, She Loves Me Not.

Plucking daisies in search of true love? You may need to allow yourself extra time for the task now that U.S. and Mexican scientists have accomplished a botanical tour de force: They've transformed plant leaves into petals.

The international team inserted supercharged versions of five key genes into the mustard plant to make the bizarre mutants. "We've known for a decade how to convert flower organs into leaves, but we haven't been able to convert leaves into flower organs," says Martin Yanofsky of the University of California, San Diego. "Now we know exactly what we were missing."

Making petals from leaves is more than a parlor trick. Finding the right genes "opens up other avenues" for learning genetic rules governing development of complex organisms, says biologist Maria Elena Alvarez Buylla of the Universidad Nacional Autonoma de Mexico. Alvarez Buylla's laboratory created one of the plant series that gave rise to the final product.

There's commercial potential in the discovery and the flower industry has shown interest. "Imagine ... a long-stemmed rose in which the many leaves along the stem are each converted into colorful petals," says Yanofsky.

He acknowledges, however, that viable versions of such ornamentals would be expensive and time-consuming. "The cut flower industry is so fragmented, with so many varieties, it's tough to see a real return on your investment."