jbs11 at psu.edu
Thu Nov 13 16:38:53 EST 1997
I am interested in the mechanism of senescence in leaves of plants and the more general question of
how senescence in clonal organisms compares to that of unitary (non-clonal) organisms. Here is a
question I put to the photosynthesis newsgroup. Perhaps the followers of this group will also have
some thoughts on this...
> Here's a question Doug Bielenberg and I have been pondering that might
> be interesting for the group to consider:
> What is the mechanism by which a plant recognizes that a leaf is below
> the CO2 compensation point? This is often used to explain why shaded
> leaves begin to senesce. Why doesn't the leaf just become a sink for
> carbon? It doesn't just starve does it? If the CO2 compensation point
> or a negative carbon budget is the cue for leaf senescence what is the
> mechanism? It may be pertinent to recall that leaves can have functions
> other than just carboon acquisition; e.g. nutrient stores used for
> growth elsewhere in the plant, transpirational "sinks" driving nutrient
> uptake, modifiers of canopy microclimate, etc. etc.
> Any ideas on this topic?
> John Skillman
More information about the Ageing