Vacuole transport lab?

Ross Koning Koning at ECSUC.CTSTATEU.EDU
Fri Nov 8 17:42:52 EST 1996


At 11:41 AM 11/8/96 -0800, Scott T. Meissner wrote:

>        Stiles, in 1927, noted that red beet tissue placed in
>water produces an "exosmosis of dissolved substances from
>storage tissue into water."  This implies that beet storage
>tissue is not isotonic with water, and when placed in water
>will take up the water, swell, and produce such high turgor
>that it may damage itself or even burst cells.  I have
>observed this process.  You can too by taking a slice of
>red beet storage parenchyma tissue and placing it in water
>and other slices in up to 0.8 M sorbitol solutions in say
>0.1 M steps.  At one point you will see plasmolysis, and
>and at the other you will see cells with such high turgor
>that they swell, and many will burst over time releasing
>their contents.  The process of cell rupture due to high
>turgor pressure is called plasmoptysis.

This is very interesting.  In several years of doing this
project NEVER has there been measurable leakage from beet
cylinders in distilled water (0 MPa!).  I will have to
look microscopically to see if there is any evidence of
that.  The opposite has been true for us...in our hands
8% NaCl "salts out" considerable betacyanin, so we have
colorless solutions at the hypotonic end of the dilution series
and deeply red solutions at the hypertonic end.

Perhaps the beets I have used have less sugar than those
used by Stiles and Meissner?  Perhaps we both should run
some beet sap through the Wescor?

I'd appreciate other people's comments too.  Do other people
get betacyanin release from fresh, rinsed, beet cylinders in
distilled water?  I just never have...I wonder why?

ross

______________________________________________________________
                            |
Ross Koning                 | Koning at ecsu.ctstateu.edu
Biology Department          | http://koning.ecsu.ctstateu.edu/
Eastern CT State University | Phone: 860-465-5327
Willimantic, CT  06226  USA | Fax: 860-465-5213
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                Plant Physiology is Phun!

 /\|___/\     //\______COOH   NH-CH2-CH=C-CH2OH  \/OH
|  |  |  |    |  |  ||       //\___     \CH3     /\|/\\/\\COOH
 \/ \/|\/|    \\/ \ /       N  ||  N            |  |
 /\ | |__|=        NH       |  || ||           //\//\
  | COOH                    \\ /\ /            O
  COOH        H2C=CH2         N  NH
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