freezing point depression
nounPronunciation: /ˈfriːzɪŋ pɔɪnt dɪˈpreʃən/
The lowering of a plant cell's freezing point below 0°C due to accumulation of solutes and cryoprotectants such as sugars, alcohols, and amino acids. This adaptation allows cells to remain in liquid state at subzero temperatures, preventing intracellular ice formation.
Plain English
When plants lower their cell freezing point below 0°C by accumulating sugars and other protective substances to survive frost.
Etymology & History
Usage
"Perennial plants exhibited significant freezing point depression in autumn tissues, enabling survival of -15°C winter temperatures."
Style guide notes: Clarify whether discussing extracellular or intracellular freezing point depression, as mechanisms and consequences differ substantially.
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Frequently Asked Questions
What solutes most effectively depress freezing points?
Glucose, fructose, sucrose, proline, and polyols like sorbitol provide the strongest colligative freezing point reduction per mole.
Is freezing point depression reversible?
Yes, solutes are metabolized during spring, raising freezing points back to near 0°C as frost risk decreases.
Why Test Candidates on This?
Essential for understanding cold hardiness mechanisms and breeding frost-tolerant varieties for regions with unpredictable spring freezes.
Required skill level: Mid