Vernalization

Vernalization (from Latin vernus 'of the spring') is the induction of a plant's flowering process by exposure to the prolonged cold of winter, or by an artificial equivalent.

The term is sometimes used to refer to the need of herbal (non-woody) plants for a period of cold dormancy in order to produce new shoots and leaves,[1] but this usage is discouraged.

[2] Many plants grown in temperate climates require vernalization and must experience a period of low winter temperature to initiate or accelerate the flowering process.

In 1857 an American agriculturist John Hancock Klippart, Secretary of the Ohio Board of Agriculture, reported the importance and effect of winter temperature on the germination of wheat.

After Lysenko the term was used to explain the ability of flowering in some plants after a period of chilling due to physiological changes and external factors.

"[7] Lysenko's 1928 paper on vernalization and plant physiology drew wide attention due to its practical consequences for Russian agriculture.

"[10] Early research on vernalization focused on plant physiology; the increasing availability of molecular biology has made it possible to unravel its underlying mechanisms.

[9] For example, a lengthening daylight period (longer days), as well as cold temperatures are required for winter wheat plants to go from the vegetative to the reproductive state; the three interacting genes are called VRN1, VRN2, and FT (VRN3).

[3][14] Winter annual ecotypes of Arabidopsis have an active copy of the gene FRIGIDA (FRI), which promotes FLC expression, thus repression of flowering.