In article <s1091865.15.2CEBCF28 at cedarville.edu>
s1091865 at cedarville.edu (Andrew Smith) writes:
> A group of students, including myself, are involved in a BLIP (Botany
> Laboratory Inquiry Project) project studying the effects of touch on soybean
> plants. One of our test groups receives a gentle 'rub down' of two minutes
> per day. After about a week of this treatment, the leaves began to curl and
> look frazzled along the margins. The control group receives no touch at
> all, and the leaves appear normal. After implimenting the treatment I find
> my fingers are slick, I suppose they are being 'lubricated' by the cuticle
> my fingers are picking up. Are my fingers removing enough of the cuticle so
> that the leaves are loosing moisture, thus the curling and frazzled
> appearance, or could there be substances on my fingers that are being
> deposited on the leaves that could have an effect?
I'm not familiar with soybean cuticles. However, I suspect that your
treatment is removing epicuticular wax rather than the cuticle proper.
That would reduce cuticular resistance to water loss significantly.
Any other plant cuticle types care to comment? For a good though
somewhat dated reference, try Martin and Juniper's 1970 book, The Plant
Richard.L.Boyce at dartmouth.edu