ISSN:
1432-2048
Keywords:
Key words: Abscisic acid
;
Electron transport
;
Rosa (photosynthesis
;
stress)
;
Ribulose-1
;
5-bisphosphate carboxylase-oxygenase
;
Stomatal and metabolic inhibition
;
Water stress
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract. The contribution of changes in stomatal conductance and metabolism in determining heterogeneous photosynthesis inhibition during dehydration and abscisic acid (ABA) feeding was investigated using detached leaves of Rosa rubiginosa L. The steady-state and maximal rates of electron transport under a transient high CO2 concentration were monitored using chlorophyll fluorescence imaging. The decrease in electron transport rate induced by dehydration and ABA treatment almost reverted to the control rate under transient high CO2 availability. Therefore, inhibition of photosynthesis was mainly mediated through stomatal closure. However, since reversion was not complete, a metabolic inhibition was also identified as a decrease in the maximal electron transport rate driven by carboxylation. Under dehydration or ABA feeding, as under low ambient CO2 treatment, in 21% or 0.4% O2, the lower the steady-state electron transport was, the lower was the maximal electron transport rate during transient high CO2 availability. We conclude that low CO2 availability reduced the capacity of ribulose-1,5-bisphosphate carboxylase-oxygenase (Rubisco) to drive electron transport. The potential contribution of Rubisco deactivation mediated by stomatal closure is discussed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s004250050661
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