Cold hardening

Cold hardening

Cold hardening is the physiological and biochemical process by which an organism prepares for cold weather.


Schematic of typical plant cell

During the winter months, as the leaves fall off deciduous species and the temperature drops, the cold forces a stop to water movement in plants. Freezing water can also cause irreversible damage to cells in plants as water solidifies. To guard against this, plants prepare for winter with a process called cold hardening. The process begins as the cell membrane permeability undergoes a change that permits water to seep into the intracellular voids. In addition, the cells store large amounts of sugars in the protoplasm, decreasing its freezing point.

Cold hardening protects plants from both chilling injury and freezing injury. Chilling injury occurs at 0-10 degrees Celsius, as a result of membrane damage, metabolic changes, and toxic buildup. Symptoms include wilting, water soaking, necrosis, chlorosis, ion leakage, and decreased growth. Freezing injury occurs at temperatures below 0 degrees Celsius. Symptoms of extracellular freezing include structural damage, dehydration, and necrosis. If intracellular freezing occurs, it will lead to death. Freezing injury is a result of lost permeability, plasmolysis, and post-thaw cell bursting.

See Also

Wikimedia Foundation. 2010.

Look at other dictionaries:

  • cold hardening — Смотри Нагартовка …   Энциклопедический словарь по металлургии

  • cold hardening mixtures — Смотри холоднотвердеющие смеси (ХТС) …   Энциклопедический словарь по металлургии

  • Cold rolling — is a metal working process in which metal is deformed by passing it through rollers at a temperature below its recrystallization temperature. Cold rolling increases the yield strength and hardness of a metal by introducing defects into the metal… …   Wikipedia

  • Cold formed steel — (CFS) is the common term for products made by rolling or pressing thin gauges of sheet steel into goods. Cold formed steel goods are created by the working of sheet steel using stamping, rolling, or presses to deform the sheet into a usable… …   Wikipedia

  • Cold saw blade — Cold saw blades are circular metal cutting saw blades categorized into two types: Solid High Speed Steel (HSS) or Tungsten Carbide Tipped (TCT). Both types of blades are resharpenable and may be used many times before being discarded. Cold saw… …   Wikipedia

  • Cold forming — or cold forging, is a manufacturing process in which metal is shaped at ambient temperature to produce metal components to a close tolerance and net shape. Techniques include bending, cold drawing, cold heading, coining extrusion (forward or… …   Wikipedia

  • Hardening (metallurgy) — In metallurgy, hardening describes techniques to increase the hardness of a material. There are five main hardening mechanisms: * Hall Petch hardening, a hardening that result due to a decrease in grain size. * Cold working, also called strain… …   Wikipedia

  • Cold saw — A 185 mm (7.3 in) hand held cold saw A cold saw bl …   Wikipedia

  • cold (work) hardening — Смотри Нагартовка …   Энциклопедический словарь по металлургии

  • Work hardening — Work hardening, also known as strain hardening or cold working, is the strengthening of a metal by plastic deformation. This strengthening occurs because of dislocation movements within the crystal structure of the material.[1] Any material with… …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”