Hardening in botany is the process by which an individual plant becomes tolerant to the effects of freezing during a period of weeks to months. It is a three stage process. During the first stage, carbohydrates are translocated to the roots of the plant and cell membrane permeability increases. By the end of the first stage, the plant will be able to tolerate temperatures to -5 to -10 C. In the second stage, cell membranes are chemically altered, and this process will allow plants to survive temperatures of -20 C. In the third stage, which occurs in plants that survive at temperatures as low as -50 C, vitrification may occur.

[edit] See also

• Antifreeze protein
• Cryopreservation
• Cryobiology

[edit] References

Plants in Agriculture (1992) Forbes and Watson [1]