The relationship between carbon-dioxide-limited photosynthetic rate and ribulose-1,5-bisphosphate-carboxylase content in two nuclear-cytoplasm substitution lines of wheat, and the coordination of ribulose-bisphosphate-carboxylation and electron-transport capacities

Planta ◽  
1986 ◽  
Vol 167 (3) ◽  
pp. 351-358 ◽  
Author(s):  
J. R. Evans
Keyword(s):  
Carbon Dioxide ◽  
Electron Transport ◽  
Photosynthetic Rate ◽  
Ribulose Bisphosphate ◽  
Substitution Lines ◽  
Bisphosphate Carboxylase ◽  
The Relationship

Ribulose bisphosphate carboxylase—oxygenase: its role in photosynthesis

1986 ◽  
Vol 313 (1162) ◽  
pp. 305-324 ◽  
Keyword(s):  
Electron Transport ◽  
Carbon Assimilation ◽  
Kinetic Properties ◽  
Ribulose Bisphosphate Carboxylase ◽  
Ribulose Bisphosphate ◽  
Rubp Carboxylase ◽  
Bisphosphate Carboxylase ◽  
Triose Phosphate ◽  
Ribulose Bisphosphate Carboxylase Oxygenase

Synthesis of triose phosphate by the chloroplast requires three substrates: light, CO 2 and orthophosphate (P i ). In the response of the rate of carbon assimilation to the concentration of CO 2 , the kinetic properties of RuBP carboxylase-oxygenase (Rubisco) constitute the main limitation at low CO 2 concentrations, while at higher concentrations of CO 2 the limitation is shifted towards the reactions leading to the regeneration of the substrate, RuBP, driven by electron transport. In these circumstances, light or P i or both, can become limiting. The characteristics of Rubisco that can affect photosynthesis fall under three main headings: (1) amount and kinetic constants; (2) activation state; and (3) regulation of catalysis (including the role of effectors, such as Pt and glycerate 3-phosphate (PGA)). These characteristics are analysed, and the role of changes in activity of the enzyme is discussed in the context of limitation and regulation of the photosynthetic process. Other factors considered are the regeneration of RuBP and its relation to electron transport, P i supply, and photorespiration. The influence that expected increases in atmospheric CO 2 concentration, and/or genetic improvements in the characteristics of the enzyme, may have on the present balance between the partial processes of photosynthesis, is discussed.

scholarly journals Comparison of the kinetic properties of ribulose bisphosphate carboxylase in chloroplast extracts of spinach, sunflower and four other reductive pentose phosphate-pathway species

1978 ◽  
Vol 171 (2) ◽  
pp. 477-482 ◽  
Author(s):  
M E Delaney ◽  
D A Walker
Keyword(s):  
Electron Transport ◽  
Pentose Phosphate Pathway ◽  
Pentose Phosphate ◽  
The Other ◽  
Kinetic Properties ◽  
Ribulose Bisphosphate Carboxylase ◽  
Ribulose Bisphosphate ◽  
Bisphosphate Carboxylase

Extracts from chloroplasts of spinach, sunflower and four other reductive pentose phosphate (C3)-pathway species were measured spectrophotometrically with or without a modified preactivation procedure. In all six species this modification yielded Km (CO2) values in the range of 7-15 micron and maximum velocities, at 20 degrees C, of 129-431 mumol of CO2 carboxylated/h per mg of chlorophyll. In general, both the carboxylation and electron-transport capacities of sunflower were somewhat greater than that of the other species, and this is discussed in relation to the superior rates of photosynthesis believed to be displayed by the parent tissue.

scholarly journals Methylotrophic Autotrophy in Beijerinckia mobilis

2005 ◽  
Vol 187 (11) ◽  
pp. 3884-3888 ◽  
Author(s):  
Svetlana N. Dedysh ◽  
Ksenia V. Smirnova ◽  
Valentina N. Khmelenina ◽  
Natalia E. Suzina ◽  
Werner Liesack ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Sequence Analysis ◽  
Methanol Dehydrogenase ◽  
Partial Sequence ◽  
Ribulose Bisphosphate ◽  
Bisphosphate Carboxylase ◽  
Oxidation Of Methanol ◽  
Cell Extracts ◽  
Wide Range ◽  
Genes Encoding

ABSTRACT Representatives of the genus Beijerinckia are known as heterotrophic, dinitrogen-fixing bacteria which utilize a wide range of multicarbon compounds. Here we show that at least one of the currently known species of this genus, i.e., Beijerinckia mobilis, is also capable of methylotrophic metabolism coupled with the ribulose bisphosphate (RuBP) pathway of C1 assimilation. A complete suite of dehydrogenases commonly involved in the sequential oxidation of methanol via formaldehyde and formate to CO2 was detected in cell extracts of B. mobilis grown on CH3OH. Carbon dioxide produced by oxidation of methanol was further assimilated via the RuBP pathway as evidenced by reasonably high activities of phosphoribulokinase and ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO). Detection and partial sequence analysis of genes encoding the large subunits of methanol dehydrogenase (mxaF) and form I RubisCO (cbbL) provided genotypic evidence for methylotrophic autotrophy in B. mobilis.

scholarly journals Differences in Characteristics of Photosynthesis and Nitrogen Utilization in Leaves of the Black Locust (Robinia pseudoacacia L.) According to Leaf Position

Forests ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 348
Author(s):  
Dongsu Choi ◽  
Woongsoon Jang ◽  
Hiroto Toda ◽  
Masato Yoshikawa
Keyword(s):  
Electron Transport ◽  
Net Photosynthetic Rate ◽  
Photosynthetic Rate ◽  
Environmental Changes ◽  
Robinia Pseudoacacia ◽  
The Sun ◽  
Bisphosphate Carboxylase ◽  
Robinia Pseudoacacia L ◽  
Shade Leaves ◽  
Sun Leaves

Robinia pseudoacacia L. has been widely planted worldwide for a variety of purposes, but it is a nonindigenous species currently invading the central part of Japanese river terraces. To understand and control this invasion, we investigated how this species invests nitrogen resources in different functions depending on the leaf location, and how these resources are used in physiological reactions such as photosynthesis. The Tama river terrace was examined in Tokyo, Japan. The leaf nitrogen (N) concentration, chlorophyll (Chl) concentration, Chl a/b ratio, leaf mass per unit area (LMA) and ribulose-1,5-bisphosphate carboxylase oxygenase (RuBisCo) concentration were all significantly lower in shade leaves than in leaves exposed to the sun. Conversely, the net photosynthetic rate in saturated light conditions (Pmax), the net photosynthetic rate under enhanced CO2 concentration and light saturation (Amax), the maximum carboxylation rate of RuBisCo (Vcmax) and the maximum rate of electron transport driving RUBP regeneration (Jmax) were all significantly lower in shade leaves than in leaves exposed to the sun. We also found that RuBisCo/N and Chl/N were significantly less in shade leaves, and values of Jmax/N, Vcmax/N less in shade leaves than in sun leaves, but not significantly. Allocation of nitrogen in leaves to photosynthetic proteins, RuBisCo (NR) was broadly less in shade leaves, and NL (light-harvesting complex: LHC, photosystem I and II: PSI and PSII) and NE (electron transport) were also lower. The N remaining was much greater in shade leaves than in sun leaves. We suggest that N remobilization from RuBisCo is more efficient than remobilization from proteins of NE, and from NL. This study shows that R. pseudoacacia has an enhanced ability to adapt to environmental changes via characteristic changes in N allocation trade-offs and physiological traits in its sun and shade leaves.

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