Vernalization
From
The Crumb Trail:
bq. In late December Philip Stott posted about vernalization, mentioned
here. While farmers have always known about vernalization no one knew how it worked in detail. Researchers at University of Wisconsin-Madison have
discovered a mechanism.
bq. The researchers report that the VIN3 gene is expressed only after plants have been exposed to conditions effective for vernalization, suggesting that the VIN3 gene functions as an alarm clock rousing biennial plants to bloom.
bq. But how do plants know they've been exposed to the right temperature for the right amount of time? "This is an intriguing question," says Sung. "Without a nervous system, plants must have a mechanism by which they can remember they have been through the winter season." Although plants don't have a brain like humans do, they do have cellular machinery that appears to remember cold exposure, according to the new research.
bq. The Wisconsin scientists show that the expression of VIN3, which occurs after exposure to cold, initiates a series of changes in one of the flower-suppressing genes. Specifically, VIN3 activation permanently modifies the structure of histones, a group of proteins over which DNA is wrapped. These changes block the flower-suppressing gene, switching the plant from a fixed state where it won't flower to a fixed state where it can flower.
and more:
bq. "This new molecular understanding could provide information to help design tools to manipulate flowering," the biochemistry professor says. For example, agronomists could engineer biennial crops that lack VIN3 and never flower, potentially increasing yield. But as Amasino clarifies, he's in the business of basic science - it's up to others to use the information.
Very cool...
Posted by DaveH at January 8, 2004 2:38 PM