Subject: Mimosa ,expert help required

From: [email-masked] (Phil Whitehead)
Date: 6 Oct 1995 11:22:58 GMT

My six y/o son and I have planted seeds of the sensitive plant mimosa
pudica,
Ihave every confidence that we will get plants butthen my problems will
start because being inquisitive he will want to know how the leavs fold
down. Dads ofcourse are meant to know everything unfortunatly this one
hasn,t got a clue about movement in plants. 
could any of you botanists explain this phenomina in language that a simple
bio chemist can understand so that I can maintain my status as font of all
(useless )information.

please reply by E-Mail

phil whitehead

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From: [email-masked] (Sean Stinson)
Date: 18 Oct 1995 23:31:24 GMT

Phil Whitehead ([email-masked]) wrote:
: could any of you botanists explain this phenomina- folding
of leaves in Mimosa pudica.

Sean replied,
	These plants contain cells similar to guard cells called
motor cells.  Most(all?) cells maintain a high inner concentration
of potaassium, via the sodium-potassium pump.  The stimulus in this
case cuases pottasium channels in the membrane to open which allows
the K+ to rush out and this in turn alters the water balance.  The water
floods out of the cell.  The shrinkage is used to alter the leaf's 
posture.  
	This is pretty general but I think this should be enough for
you to explain it to your son.
ref. Mauseth,J.D.,(1991) Botany: An introduction to plant biology.,
Saunders college publ.,pp.300?