Re: frozen plants
Jim---Thanks for the clear, concise explanation. And besides that, it makes
sense.
Hank Zumach
Stoddard, WI
zone 4
----- Original Message -----
From: J.E. Shields <jshields@INDY.NET>
To: <shadegardens@MAELSTROM.STJOHNS.EDU>
Sent: Sunday, January 16, 2000 5:39 PM
Subject: [SG] frozen plants
> 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
>
> *************************************************
> 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
>
