frozen plants
- To: s*@MAELSTROM.STJOHNS.EDU
- Subject: frozen plants
- From: J* S*
- Date: Sun, 16 Jan 2000 18:39:45 -0500
Plants which cannot resist freezing temperatures die because ice crystals
from inside their tissues, and the crystals pierce the cell walls. When
the ice melts, the cells loose their contents.
So why don't all plant cells just up and die when temperatures drop below
freezing?
Basically, like everything else about plants and animals, it all goes back
to their genes. Plants which can resist freezing temperatures have genes
which produce substances that protect against freezing. These may act in
any of several ways. Some of them can change the plant's metabolism to
produce extra sugars or glycerol inside the cells, lowering the cell's
interior freezing point.
Other substances act more directly, by preventing the ice crystals which
may start to form, from growing large enough to break the cell walls.
The more of these protective substances that the plant's genes direct to be
formed, the more freezing the plant can withstand.
Jim
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Jim Shields USDA Zone 5 Shields Gardens, Ltd.
P.O. Box 92 WWW: http://a1.com/daylily/
Westfield, Indiana 46074, USA Tel. +1-317-896-3925
