A Possible Role for Abscisic Acid in Coupling Stomatal Conductance and Photosynthetic Carbon Metabolism in Leaves

1982 ◽  
Vol 9 (4) ◽  
pp. 489 ◽  
Author(s):  
I.R Cowan ◽  
J.A Raven ◽  
W. Hartung ◽  
G.D Farquhar

Data on pH in free space, cytoplasm, chloroplasts and vacuoles in leaf tissue are used to calculate the distribution of abscisic acid (ABA) amongst these compartments, assuming that the intervening membranes are permeable to undissociated ABA only. Data on the permeability of membranes to ABA are used to calculate the time constant for equilibration between the free space and the other components. It is concluded that changes in pH in the chloroplast stroma due to irradiance, or other factors, will change the amount of ABA available to the guard cells via the free space, and that the time constant is similar to that for light-induced stomatal movement. The possibility that such changes play a role in modulating stomatal aperture is discussed.

2014 ◽  
Vol 51 (2) ◽  
pp. 229-240 ◽  
Author(s):  
Maria Faltynowicz ◽  
Waldemar Lechowicz ◽  
Jerzy Poskuta

The influence of abscisic acid (ABA) on carbon metabolism and the activity of ribulosebisphosphate (RuBP) and phosphoenolpyruvate (PEP) carboxylases in 8-day-old pea seedlings was investigated. It was endeavoured to correlate the changes observed in metabolic processes with the endogenous ABA level. In plants treated with ABA incorporation of labeled carbon into sucrose, glucose, fructose and sugar phosphates was depressed, while <sup>14</sup>C incorporation into starch, ribulose and malic acid was enhanced. The activity of RuBP carboxylase was considerably lowered, whereas that of PEP carboxylase was slightly increased. It is considered that inhibition of photosynthesis due to the action of ABA is caused to a great extent by the obstruction of the C-3 pathway and reduced activity of RuBP carboxylase, whereas (β-carboxylation was not blocked.


Author(s):  
Masahiro Tamoi ◽  
Yoshie Hiramatsu ◽  
Shigeki Nedachi ◽  
Tomoki Tabuchi ◽  
Kumi Otori ◽  
...  

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