On 22 Apr 1997 11:00:19 -0700 Doug Jensen <dpjensen at berea.edu> wrote:
> I have some personal confusion regarding the adaptiveness of CAM
>photosynthesis. It is usually portrayed as a pathway that decreases
>photorespiration, and, as such, it is presented an alternative to C-4
>photosynthesis. To decrease photorespiration, there should be a mechanism to
>decrease [oxygen] in the region of the chloroplasts. I don't see that. It
>appears to me that the primary purpose of CAM is water conservation.
>> Am I missing something here?
No, CAM is primarily water conservation hence the stomata rhythm.
Photorespiration is not detectable (outside of plant) for most of the day as
a) CO2 relatively high
b) stomata are closed
In some you can detect in early in the day before full closure, and a little spike
appears towards the end of the day as organic acids depleted and stomata begin to
open. As far as I know.
Dr Kevin Reiling
Division of Biology