Why plants produce alkaloids

MEK104 at psuvm.psu.edu MEK104 at psuvm.psu.edu
Fri Dec 11 08:43:51 EST 1992

in article <945 at rc1.vub.ac.be> Thierry Sornasse wrote:

>Hi Networkers,

>I red an paper about the brain and the influence of a large number of
>vegetal products on the nervous system of the animal.  It is rather far
>from my field and I am wondering why the plants have developped during the
>evolution the capacity to produce substances which are able to "modify" the
>behaviour of animals?  .

>I 'll be really pleased to discuss this point with plant specialist.  By
>the way,I am an immunologist.

>(I hope you 'll forgive my poor english .)

>Thank you for your answers

>Thierry Sornasse

There was a discussion some time ago in Bionet.plants about this very
subject.  One idea is:  could some narcotic substances encourage herbivory
perhaps to facilitate seed dispersal?  Especially for species in which seed
dormancy is broken by passage through an animal's digestive system.  Do any
such species exist?  I don't know, just speculation.  Also, I seem to recall
a theory that some plants species encourage herbivory so that the older,
less productive foliage will be eaten and nutrients recycled through the
soil to stimulate growth of younger, more productive foliage.  I don't mean
to imply that the plants thought these things up, but the question is
whether the production of narcotic substances is a product of co-evolution
with herbivores, or is it merely coincidental that some defensive compounds,
perhaps against insects or fungi, can alter the brain chemistry of some
higher animals.

Mark Kubiske                < MEK104 at PSUVM.PSU.EDU >
School of Forest Resources
Penn State University

More information about the Plantbio mailing list