Detoxification of HCN

Steve Hinkson sphinkson at worldnet.att.net
Tue Jul 13 19:25:19 EST 1999


Good going, Stefanie !
But does the central vacuole count as an excretory system?
But, I'll admit, that's sorta' a liver-type function, for sure, and I stand
corrected.
Steve

Stefanie Galgon wrote:

> Steve & all,
>
> Watch out -- I've had my coffee!!! ;-)
>
> I do not recall if someone already discussed HCN!  Bare with me here...
> (if you would rather check out Wink's version, you'll find the information
> in Dey & Harborne pp 454-6).
>
> Cyanogenic glycosides are hydrolyzed and decomposed to aldehydes / ketones
> plus HCN.  HCN is toxic to mammals, insects, microorganisms, and...
> PLANTS! (you knew I'd get there sooner or later, right?).  All organisms
> have a biochemical process of detoxifying this stuff.  Plants are amazing
> in that they can get rid of it, by using it (I know, I know... plants do
> not have a will) as a defense mechanism.  Fine line here?  Maybe.
> Cyanogenic glycosides are stored in the central vacuole (I believe someone
> did bring this up... sorry if I am being repetitive).  HCN is probably
> carriered or vesicled from cytoplasm to vacuole.  Since HCN IS toxic to
> plants, hey, a detoxification pathway exists!
>
> Detoxification of HCN by plants:
> HCN + cysteine --> 3-cyanoalanine --> asn --> asparagine
>
> asparagine is a storage and transport compound (catalyzes the
> deamination of asparagine).
>
> I think that is a darn good example. Please feel free to correct me on
> any misrepresented information.
>
> Ref: Dey & Harborne, 1997, Plant Biochemistry -- aka The Bible!
>
> Steffi
>
> ******************************************************************
> Stefanie Galgon                 lab/message: (520) 523-7735
> Department of Biology
> Northern Arizona University     smg4 at dana.ucc.nau.edu
>
> "Life is a banquet, and most poor suckers are starving to death"
> Auntie Mame
> ******************************************************************






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