Low-temperature acclimation of net photosynthesis in the crustaceous lichen Caloplaca trachyphylla

1984 ◽  
Vol 62 (1) ◽  
pp. 86-95 ◽  
Author(s):  
D. S. Coxson ◽  
K. A. Kershaw
Keyword(s):  
Low Temperature ◽  
Full Range ◽  
Net Photosynthesis ◽  
Early Morning ◽  
Temperature Acclimation ◽  
Thunderstorm Activity ◽  
Affinity Constant ◽  
Ribulose Bisphosphate Carboxylase ◽  
Bisphosphate Carboxylase ◽  
Acclimatory Response

The seasonal net photosynthetic and respiratory response matrix is presented for Caloplaca trachyphylla (Tuck.) A. Zahlbr. at 7, 14, 21, 28 and 35 °C, under 0, 300, 600, 900, and 1200 μE m−2 s−1 illumination, over a full range of thallus hydration, in January, May, and July. The maximum rates of net photosynthesis recorded during the summer period, at 14–21 °C, under 1200 μE m−2 s−1 illumination are ca. 3.0 mg CO2 h−1 g−1. They are interpreted in terms of the thallus temperatures documented during early-morning dew events and during sporadic thunderstorm activity. During winter, net photosynthetic rates at 7 °C increase significantly from the summer rates of ca. 2.0 mg CO2 h−1 g−1 to ca. 3.2 mg CO2 h−1 g−1. This low-temperature photosynthetic-capacity change is shown to be temperature acclimation and it is suggested that the mechanism involves a change in the affinity constant (Km) of ribulose bisphosphate carboxylase. This acclimatory response can be readily induced, or reversed in winter, by air-dry storage at an appropriately high or low ambient temperature. In midsummer, however, comparable storage conditions fail to elicit an acclimatory response. The significance of low-temperature photosynthetic acclimation in C. trachyphylla is discussed in relation to winter snowmelt sequences during chinook conditions in Alberta.

The effects of low temperature acclimation of winter rye on catalytic properties of its ribulose bisphosphate carboxylase–oxygenase

1979 ◽  
Vol 57 (7) ◽  
pp. 1036-1041 ◽  
Author(s):  
N. P. A. Huner ◽  
F. D. H. Macdowall
Keyword(s):  
Temperature Acclimation ◽  
Winter Rye ◽  
Ribulose Bisphosphate Carboxylase ◽  
Ribulose Bisphosphate ◽  
Bisphosphate Carboxylase ◽  
Ribulose Bisphosphate Carboxylase Oxygenase ◽  
Secale Cereale L ◽  
Decreasing Ph ◽  
Chemical Groups ◽  
Kinetics Of

A comparison was made of the kinetics of the carboxylation reaction of bicarbonate–magnesium-activated ribulose biphosphate carboxylase–oxygenase purified from cold-hardened and unhardened winter rye (Secale cereale L. cv. Puma). The activity of the (NH4)2SO4− precipitated enzyme from hardened plants was stable at −20 °C for a month, whereas the form from unhardened plants was reversibly cold inactivated. The [Formula: see text] of the unhardened form increased more rapidly with decreasing pH below 8.2, but the estimated pKa of chemical groups associated with the active site was not affected by the cold hardening. The temperature dependencies of the [Formula: see text] of the two forms of the enzyme crossed at 10 °C with the effect that the catalysis of carboxylation by ribulose biphosphate carboxylase–oxygenase from Puma rye was most efficient in the temperature range to which the plants had been adapted.

scholarly journals Photometric Measurements of Rubisco Activity in Leaves of Deciduous Fruit Crops

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 531A-531
Author(s):  
Lailiang Cheng ◽  
Leslie H. Fuchigami
Keyword(s):  
Net Photosynthesis ◽  
Photometric Method ◽  
Ribulose Bisphosphate Carboxylase ◽  
Fruit Crops ◽  
Rubisco Activity ◽  
Bisphosphate Carboxylase ◽  
Ribulose Bisphosphate Carboxylase Oxygenase ◽  
Deciduous Fruit ◽  
Photometric Measurements

Ribulose bisphosphate carboxylase/oxygenase (Rubisco) initiates the photosynthetic carbon metabolism;therefore, its activity has been measured in many physiological studies. However, information on in vitro Rubisco activity from leaves of deciduous fruit crops is very limited and the reported activities are suspiciously low. We measured Rubisco activity in crude extracts of leaves of apple, pear, peach, cherry, and grape by using a photometric method in which RuBP carboxylation was enzymically coupled to NADH oxidation. Replacing polyvinylpyrrolidone with polyvinylpolypyrrolidone in the extraction solution significantly increased extractable Rubisco activity. Depending on species, freezing leaf discs in liquid nitrogen followed by storage at –80°C for only 24 hr reduced both initial and total Rubisco activity to 5% to 50% of that obtained from fresh leaves. Initial Rubisco activity from fresh leaf tissues of all species was well correlated with maximum Rubisco activity (Vcmax) estimated from gas exchange; an exception was pear, where initial Rubisco activity was higher than Vcmax. In most cases, initial Rubisco activity was approximately two to three times higher than net photosynthesis.

Étude comparative du métabolisme photosynthétique des feuilles et des gousses de soja Glycine max

1986 ◽  
Vol 64 (8) ◽  
pp. 1542-1548 ◽  
Author(s):  
J. C. Latché ◽  
G. Bailly-Fenech ◽  
J. Grima-Pettenati ◽  
G. Cavalié
Keyword(s):  
Carbon Fixation ◽  
Leaf Age ◽  
Net Photosynthesis ◽  
Glycolate Oxidase ◽  
Activity Measurement ◽  
Growth Stages ◽  
Ribulose Bisphosphate Carboxylase ◽  
Ribulose Bisphosphate ◽  
Carboxylase Activity ◽  
Bisphosphate Carboxylase

Changes in photosynthetic carbon fixation processes were comparatively studied in soybean leaves and pods harvested at different growth stages. Newly fully expanded leaves exhibited both the highest 14CO2 assimilation rate and the maximum ribulose bisphosphate carboxylase levels. Amino acids biosynthesis was more important in young tissues and this result agreed with the evolution of nitrate reductase activities. The radiocarbon distribution in glycine and serine suggested that photorespiratory metabolism increases with leaf age; the activity of glycolate oxidase was found to be significantly lower in younger leaves than in mature ones. Net photosynthesis, chlorophyll content, and ribulose bisphosphate carboxylase activity were low in isolated pods compared to leaves. However, the study of photosynthate translocations within the pod revealed that the pod wall could contribute to the carbon nutrition of the seeds. Soluble compounds labelled after 14CO2 incorporation and glycolate oxidase activity measurement indicated that organic acids biosynthesis and photorespiratory metabolism are relatively higher in pods than in leaves.

Thermal acclimation of photosynthesis by the arctic plant Saxifraga cernua

1986 ◽  
Vol 64 (1) ◽  
pp. 71-76 ◽  
Author(s):  
Bruce T. Mawson ◽  
Josef Svoboda ◽  
Raymond W. Cummins
Keyword(s):  
Low Temperature ◽  
Growth Temperature ◽  
Dark Respiration ◽  
Photosynthetic Apparatus ◽  
Net Photosynthesis ◽  
Temperature Acclimation ◽  
The Arctic ◽  
Optimum Temperature ◽  
Whole Plants ◽  
Saxifraga Cernua

The thermal acclimations of net photosynthesis, dark respiration, and photorespiration have been studied in the arctic plant Saxifraga cernua. The gas exchange of whole plants grown to maturity under different temperature regimes was analysed for individual plants transferred from (i) 10 to 20 (referred to as high-temperature acclimation) and (ii) 20 to 5 °C (low-temperature acclimation). High- and low-temperature acclimation resulted in shifts of the leaf temperature optimum for net photosynthesis of whole plants in the direction of the new growth temperature. That the acclimating temperature directly affected the photosynthetic apparatus was indicated by (i) changes in the optimum temperature for gross photosynthesis of whole plants and (ii) a change in the oxygen sensitivity of net photosynthesis after acclimation to a new growth temperature. The change in the optimum temperature for net photosynthesis was also due, in part, to altered dark respiration rates which increased during acclimation to low growth temperatures. These results suggest that such acclimation in arctic species like S. cernua arose as a result of the selective pressure of fluctuating temperatures which are experienced during the growth season to maximize annual growth under arctic and subarctic conditions.

Variations in photosynthetic, anatomical, and enzymatic leaf traits and correlations with growth in recently selected Populus hybrids

1987 ◽  
Vol 17 (4) ◽  
pp. 273-283 ◽  
Author(s):  
R. Ceulemans ◽  
I. Impens ◽  
V. Steenackers
Keyword(s):  
Growth Performance ◽  
Principal Component ◽  
Net Photosynthesis ◽  
Leaf Traits ◽  
Photosynthetic Photon Flux Density ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Ribulose Bisphosphate Carboxylase ◽  
Bisphosphate Carboxylase ◽  
Shoot Height

Several photosynthetic, anatomical, and enzymatic leaf traits were studied on 1- and 2-year-old fast growing Populus clones representing interspecific hybrids of P. deltoides, P. trichocarpa, and P. maximowiczii. Growth performance of the clones was studied with container-grown plants and for 5 years in the field. Considerable variation in photosynthetic, anatomical, and enzymatic leaf traits was found, but variation in growth differences among the clonal groups was minimal. Photosynthetic photon flux density saturated net photosynthesis of 1-year-old container-grown plants was significantly correlated with shoot height growth, but none of the other leaf traits measured showed a significant correlation with any of the growth characteristics. Clonal groups could be segregated by taxonomic and genetic affinities with hierarchical clustering and principal component analysis. Although enzymatic and biochemical traits (area leaf weight, ribulose-bisphosphate carboxylase and phosphoenolpyruvate carboxylase activities, protein content) and adaxial stomatal frequency can be used to discriminate among clonal groups, no significant regression of these leaf traits on growth performance was observed.

scholarly journals Four Mutant Alleles Elucidate the Role of the G2 Protein in the Development of C4 and C3 Photosynthesizing Maize Tissues

Genetics ◽  
2001 ◽  
Vol 159 (2) ◽  
pp. 787-797
Author(s):  
Lizzie Cribb ◽  
Lisa N Hall ◽  
Jane A Langdale
Keyword(s):  
Cell Types ◽  
Bundle Sheath ◽  
Primary Role ◽  
Ribulose Bisphosphate Carboxylase ◽  
Sheath Cell ◽  
Mesophyll Cells ◽  
Phenotypic Data ◽  
Bisphosphate Carboxylase ◽  
Bundle Sheath Cell

Abstract Maize leaf blades differentiate dimorphic photosynthetic cell types, the bundle sheath and mesophyll, between which the reactions of C4 photosynthesis are partitioned. Leaf-like organs of maize such as husk leaves, however, develop a C3 pattern of differentiation whereby ribulose bisphosphate carboxylase (RuBPCase) accumulates in all photosynthetic cell types. The Golden2 (G2) gene has previously been shown to play a role in bundle sheath cell differentiation in C4 leaf blades and to play a less well-defined role in C3 maize tissues. To further analyze G2 gene function in maize, four g2 mutations have been characterized. Three of these mutations were induced by the transposable element Spm. In g2-bsd1-m1 and g2-bsd1-s1, the element is inserted in the second intron and in g2-pg14 the element is inserted in the promoter. In the fourth case, g2-R, four amino acid changes and premature polyadenylation of the G2 transcript are observed. The phenotypes conditioned by these four mutations demonstrate that the primary role of G2 in C4 leaf blades is to promote bundle sheath cell chloroplast development. C4 photosynthetic enzymes can accumulate in both bundle sheath and mesophyll cells in the absence of G2. In C3 tissue, however, G2 influences both chloroplast differentiation and photosynthetic enzyme accumulation patterns. On the basis of the phenotypic data obtained, a model that postulates how G2 acts to facilitate C4 and C3 patterns of tissue development is proposed.

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