scholarly journals Variations in the Specific Activity of Ribulose-1,5-bisphosphate Carboxylase between Species Utilizing Differing Photosynthetic Pathways

1984 ◽  
Vol 74 (4) ◽  
pp. 791-794 ◽  
Author(s):  
Jeffrey R. Seemann ◽  
Murray R. Badger ◽  
Joseph A. Berry
Keyword(s):  
Specific Activity ◽  
Bisphosphate Carboxylase ◽  
Photosynthetic Pathways

High specific activity ribulose 1,5-bisphosphate carboxylase-oxygenase from Nicotiana tabacum

1981 ◽  
Vol 2 (4) ◽  
pp. 235-242 ◽  
Author(s):  
James T. Bahr ◽  
Sarjit Johal ◽  
Malcolm Capel ◽  
Don P. Bourque
Keyword(s):  
Nicotiana Tabacum ◽  
Specific Activity ◽  
High Specific Activity ◽  
Bisphosphate Carboxylase

scholarly journals Purification and properties of a phosphatase in French bean (Phaseolus vulgaris L.) leaves that hydrolyses 2′-carboxy-d-arabinitol 1-phosphate

1992 ◽  
Vol 287 (3) ◽  
pp. 821-825 ◽  
Author(s):  
A H Kingston-Smith ◽  
I Major ◽  
M A J Parry ◽  
A J Keys
Keyword(s):  
Specific Activity ◽  
French Bean ◽  
Inorganic Salts ◽  
Phosphate Ester ◽  
Phaseolus Vulgaris L ◽  
Ph Optimum ◽  
Bisphosphate Carboxylase ◽  
Naturally Occurring ◽  
Purification And Properties ◽  
Fructose 1,6 Bisphosphate

An enzyme that releases P(i) from 2-carboxy-D-arabinitol 1-phosphate, a naturally occurring tightly binding inhibitor of ribulose 1,5-bisphosphate carboxylase/oxygenase (EC 4.1.1.39), was purified from leaves of French bean seedlings. It was a monomeric protein of M(r) about 56,000. Catalytic activity was stimulated by increased concentrations of inorganic salts to a maximum at an ionic strength above 0.2. NADPH and D-fructose 1,6-bisphosphate increased the activity of the enzyme in both the presence and absence of 0.2 M-KCl. The pure enzyme did not require dithiothreitol for activity. The pH optimum was 7, the Km for 2-carboxy-D-arabinitol 1-phosphate was 0.43 mM and the specific activity 6.8 mumol/min per mg of protein. The enzyme had little or no activity against phosphate ester intermediates of photosynthetic metabolism and glycolysis but hydrolysed the 1,5-bisphosphates of 2′-carboxy-D-ribitol and 2′-carboxy-D-arabinitol more rapidly than 2′-carboxy-D-arabinitol 1-phosphate.

Effects of nitrogen limitation on uptake of inorganic carbon and specific activity of ribulose-1,5-bisphosphate carboxylase/oxygenase in green microalgae

1991 ◽  
Vol 69 (5) ◽  
pp. 1146-1150 ◽  
Author(s):  
John Beardall ◽  
Simon Roberts ◽  
Jenny Millhouse
Keyword(s):  
Growth Rate ◽  
Key Words ◽  
Growth Rates ◽  
Nitrogen Limitation ◽  
Inorganic Carbon ◽  
Marked Decrease ◽  
Specific Activity ◽  
Green Microalgae ◽  
Bisphosphate Carboxylase ◽  
Cell Basis

The effects of nitrogen limitation on the characteristics of inorganic carbon-dependent O2 evolution have been examined in the green microalgae Chlorella emersonii and Gloeomonas sp. When cells were grown under 5% CO2 or air, decreasing the growth rate (increasing nitrogen limitation) caused a decrease in maximum rates of photosynthetic O2 evolution, although when expressed on a per cell basis such changes were only evident at growth rates below 0.16 day−1. Severe nitrogen limitation also caused a marked decrease in k1/2 (CO2) in light- and CO2-dependent O2 evolution. Although values for this parameter were not as low as for low CO2 grown cells with a fully induced CO2-concentrating mechanism, they were less than one-half the corresponding values from cells with the mechanism fully repressed. Nitrogen-limitation also resulted in decreases in the activity and cellular content of ribulose-1,5-bisphosphate carboxylase/oxygenase. The changes to activity and levels of this enzyme were not equivalent so the specific activity decreased dramatically between growth rates of 0.57 and 0.25 day−1. Similar effects were noted in Gloeomonas and in air-grown Chlorella. The results are discussed in relation to regulation of CO2 uptake and assimilation in microalgae. Key words: microalgae, CO2 assimilation, nitrogen limitation, Rubisco, Chlorella.

An Analysis of Photosynthetic Response to Salt Treatment in Vitis vinifera

1981 ◽  
Vol 8 (3) ◽  
pp. 359 ◽  
Author(s):  
RR Walker ◽  
E Torokfalvy ◽  
NS Scott ◽  
PE Kriedemann
Keyword(s):  
Vitis Vinifera ◽  
Shoot Growth ◽  
Specific Activity ◽  
Photochemical Efficiency ◽  
Stress Relief ◽  
Vitis Vinifera L ◽  
Photosynthetic Response ◽  
Salt Treatment ◽  
Bisphosphate Carboxylase ◽  
Fraction I

Rooted cuttings of grapevines (Vitis vinifera L. cv. Sultana; syn. Thompson Seedless) were grown under glasshouse conditions and supplied with dilute nutrient solution containing either 0 or 90 mM of added NaCl. Growth and photosynthetic response to salt treatment and subsequent recovery were followed over 80 days. Shoot growth and photosynthesis were reduced by salt treatment. At relatively low concentrations of leaf chloride (< c. 150 mM, on a tissue water basis), photosynthetic reduction was largely due to increased stomatal resistance. Internal disturbances were involved at higher leaf Cl- concentrations (> c. 150 mM) and included an apparent reduction in photochemical efficiency and a faster rate of photorespiration. Levels of fraction I protein, and specific activity of ribulose-1,5-bisphosphate carboxylase measured in vitro, were not reduced by salt treatment. Vines showed remarkable adaptation to salinity insofar as leaves maintained positive turgor despite leaf Cl- concentrations exceeding 300 mM, implying osmotic adjustment. Cessation of salt treatment led to an immediate decrease in leaf Cl-, a promotion of shoot growth and a progressive recovery in photosynthesis accompanied by a marked but not necessarily concurrent reduction in both stomatal and internal resistances. Leaves tolerated Cl- levels up to 200 mM (under glasshouse conditions) without sustaining permanent reduction in photosynthetic activity. New shoots formed subsequent to stress relief are not a prerequisite for Cl- retranslocation from mature leaves as decapitation at the time of stress relief did not prevent attenuation of leaf Cl- or recovery in photosynthesis.

A metabolic comparison between progressive and monocarpic senescence of soybean

1984 ◽  
Vol 62 (4) ◽  
pp. 806-811 ◽  
Author(s):  
J. Secor ◽  
R. Shibles ◽  
C. R. Stewart
Keyword(s):  
Specific Activity ◽  
Bisphosphate Carboxylase ◽  
Vegetative Period ◽  
Diffusive Resistance ◽  
Plant Ontogeny ◽  
Glycine Max L ◽  
Chlorophyll Protein ◽  
Rate Of Decline ◽  
Soybean Leaves ◽  
Monocarpic Senescence

The onset of senescence, defined as the time that photosynthesis began to decline irreversibly, was compared with ribulose-1,5-bisphosphate carboxylase (EC 4.1.1.39) (RuBPCase) activity, chlorophyll content, protein content, and leaf diffusive resistance in outdoor-grown soybean (Glycine max (L.) Merr. cv. Amsoy 71) leaves that had emerged and senesced during different stages of plant ontogeny. The purpose was to compare metabolic events in soybean leaves associated with progressive and monocarpic senescence. Soluble protein, chlorophyll, and RuBPCase activity declined coincidently with photosynthesis in all leaves. In leaves that emerged before flowering, the decline in RuBPCase activity could be accounted for by protein degradation, whereas in a leaf that emerged after flowering had begun, the decline also was attributable to, but to a much lesser extent, a change in specific activity. All parameters declined more rapidly in leaves at nodes higher on the plant. There was an indication that developing pods temporarily retarded the rate of decline in photosynthesis. Regression of photosynthesis on chlorophyll, protein, and RuBPCase activity yielded coefficients that were different in a leaf that developed during the vegetative period from those of leaves that developed later, whereas no differences were detected among the later leaves. We conclude from our results that the factors associated with senescence are similar among leaves that senesce during different stages of plant development. But there is evidence that the rate of senescence may be differentially regulated.

scholarly journals Transcriptional and post-transcriptional regulation of ribulose 1,5-bisphosphate carboxylase gene expression in light- and dark-grown amaranth cotyledons.

1985 ◽  
Vol 5 (9) ◽  
pp. 2238-2246 ◽  
Author(s):  
J O Berry ◽  
B J Nikolau ◽  
J P Carr ◽  
D F Klessig
Keyword(s):  
Specific Activity ◽  
Large Subunit ◽  
Growth Conditions ◽  
Small Subunit ◽  
Northern Analysis ◽  
Mrna Levels ◽  
Regulation Of Expression ◽  
Bisphosphate Carboxylase

The regulation of expression of the genes encoding the large subunit (LSU) and small subunit (SSU) of ribulose 1,5-bisphosphate carboxylase (RuBPCase) was examined in 1- through 8-day-old, dark-grown (etiolated) and light-grown amaranth cotyledons. RuBPCase specific activity in light-grown cotyledons increased during this 8-day period to a level 15-fold higher than in dark-grown cotyledons. Under both growth conditions, the accumulation of the LSU and SSU polypeptides was not coordinated. Initial detection of the SSU occurred 1 and 2 days after the appearance of the LSU in light- and dark-grown cotyledons, respectively. Furthermore, although the levels of the LSU were similar in both light- and dark-grown seedlings, the amount of the SSU followed clearly the changes in enzyme activity. Synthesis of these two polypeptides was dramatically different in etiolated versus light-grown cotyledons. In light the synthesis of both subunits was first observed on day 2 and continued throughout the growth of the cotyledons. In darkness the rate of synthesis of both subunits was much lower than in light and occurred only as a burst between days 2 and 5 after planting. However, mRNAs for both subunits were present in etiolated cotyledons at similar levels on days 4 through 7 (by Northern analysis) and were functional in vitro, despite their apparent inactivity in vivo after day 5. In addition, since both LSU and SSU mRNA levels were lower in dark- than in light-grown seedlings, our results indicate that both transcriptional and post-transcriptional controls modulate RuBPCase production in developing amaranth cotyledons.

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