BOB HIRSHON (host):
How spring is sprung…I’m Bob Hirshon and this is Science Update.
The first signs of a new season prompted listener Todd Pangburn of St. Paul, Minnesota, to ask: With the coming of spring, how do plants decide when to form buds? We asked plant biologist Sue Rhee, a staff scientist at the Carnegie Institution in Stanford, California. She says a combination of the cold temperatures and shortened day length of winter tells a plant to get ready.
SUE RHEE (Carnegie Institution):
And then after the cold spell breaks as spring comes, the increase in temperature and increase in day length tell the plants to flower.
The process is called vernalization, and its molecular mechanism is now well understood. But Rhee says figuring out how plants evolved to do this is still a hot topic of research in plant biology. And if you’ve got a budding science question, call us at 1-800-WHY-ISIT. I’m Bob Hirshon for AAAS, the science society.