Reduction of Ribulose Bisphosphate Carboxylase Activase Levels in Tobacco (Nicotiana tabacum) by Antisense RNA Reduces Ribulose Bisphosphate Carboxylase Carbamylation and Impairs Photosynthesis
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چکیده
منابع مشابه
Ribulose-1,5-bisphosphate carboxylase/oxygenase activase cDNAs from Nicotiana tabacum.
Rubisco-the key regulatory enzyme in photosynthetic carbon assimilation-is activated in vivo by the chloroplast enzyme Rubisco activase (Portis, 1990). Previous studies in which Rubisco antisense DNA mutants of tobacco were used have revealed that under some circumstances Rubisco activase can play a central role in regulating the photosynthetic process (Rodermel et al., 1988; Quick et al., 1991...
متن کاملRibulose-1,5-bisphosphate carboxylase/oxygenase activase protein prevents the in vitro decline in activity of ribulose-1,5-bisphosphate carboxylase/oxygenase.
The rate of CO(2) fixation by ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco) following addition of ribulose 1,5-bisphosphate (RuBP) to fully activated enzyme, declined with first-order kinetics, resulting in 50% loss of rubisco activity after 10 to 12 minutes. This in vitro decline in rubisco activity, termed fall-over, was prevented if purified rubisco activase protein and ATP were ...
متن کاملRubisco Activase Mediates ATP-Dependent Activation of Ribulose Bisphosphate Carboxylase.
The activation level of ribulosebisphosphate carboxylase following preincubation with ribulose 1,5-bisphosphate was increased by ATP and ribulosebisphosphate carboxylase activase in the absence of thylakoids or illumination. Maximal activation was obtained with 0.5 millimolar ATP in the presence of an ATP regenerating system (phosphoenolpyruvate and pyruvate kinase). Without the ATP regeneratin...
متن کاملPhotorespiration-induced reduction of ribulose bisphosphate carboxylase activation level.
Leaf photosynthesis and ribulose bisphosphate carboxylase activation level were inhibited in several mutants of the C(3) crucifer Arabidopsis thaliana which possess lesions in the photorespiratory pathway. This inhibition occurred when leaves were illuminated under a photorespiratory atmosphere (50% O(2), 350 microliters per liter CO(2), balance N(2)), but not in nonphotorespiratory conditions ...
متن کاملRegulation of ribulose-1,5-bisphosphate Carboxylase/Oxygenase by carbamylation and 2-carboxyarabinitol 1-phosphate in tobacco: insights from studies of antisense plants containing reduced amounts of rubisco activase
The regulation of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) activity by 2-carboxyarabinitol 1-phosphate (CA1P) was investigated using gas-exchange analysis of antisense tobacco (Nicotiana tabacum) plants containing reduced levels of Rubisco activase. When an increase in light flux from darkness to 1200 &mgr;mol quanta m-2 s-1 was followed, the slow increase in CO2 assimilation b...
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ژورنال
عنوان ژورنال: Plant Physiology
سال: 1993
ISSN: 0032-0889,1532-2548
DOI: 10.1104/pp.102.4.1119