kearns at EDU.MIT wrote:
: Hi everyone, I may have accidently deleted the answer to this question, but I
: am still wondering why a C12/C13 usage ratio for RUBISCO would tell one about
: stomatal opening. Ellen
I once spent all day peeling epidermis off *both* sides of Commelina
communis leaves to get enough material to do C12/C13 ratios, I freeze
dried it and set in off to (*****)'s lab for analysis - I never got an
answer!
If the carbon 13 isotope is/isn't discrimiated against during fixation
it tells you which enzyne is responsible for fixing it. I thought the
CO2 was fixed by PEP carboxlyase is guard cells and so measuring the
C12/C13 ratio would indicate if it was. Certainly a lot of externally
supplied C14 C02/bicarbonate ends up in malate.
Tony.
--
Dr. A.J.Travis, | JANET: <ajt at uk.ac.sari.rri>
Rowett Research Institute, | other: <ajt at rri.sari.ac.uk>
Greenburn Road, Bucksburn, | phone: +44 (0)224 712751
Aberdeen, AB2 9SB. UK. | fax: +44 (0)224 715349
