The Effect of Sodium Nutrition on the Pool Sizes of Intermediates of the C Photosynthetic Pathway

1988 ◽  
Vol 15 (6) ◽  
pp. 749 ◽  
Author(s):  
M Johnston ◽  
CPL Grof ◽  
PF Brownell
Keyword(s):  
Direct Application ◽  
Photosynthetic Pathway ◽  
Growth Responses ◽  
Amaranthus Tricolor ◽  
Mesophyll Cells ◽  
Sodium Deficiency ◽  
C4 Species ◽  
C3 Species ◽  
Chloris Gayana ◽  
Group 1

Changes in C4 pathway intermediates in response to sodium nutrition, consistent with the hypothesis that there is a limitation in the conversion of pyruvate to phosphoenolpyruvate (PEP) in the mesophyll cells in sodium-deficiency, were observed in the C4 species, Kochia childsii, Chloris gayana, Amaranthus edulis, Amaranthus tricolor and Atriplex spongiosa. In the C3 species Lycopersicon esculentum (tomato), no differences were observed when grown with or without added sodium. Of the group 1 elements, only sodium, irrespective of the salt supplied to deficient cultures, effected these changes in the C4 species. In the light, concentrations of aspartate, PEP and 3-phosphoglycerate (3-PGA) were lower and those of pyruvate and alanine were greater in sodium-deficient than normal plants. In the dark, concentrations of aspartate, pyruvate, alanine, PEP and 3-PGA were similar in sodium-deficient and normal plants. In the C4 species Atriplex spongiosa, the concentration of sodium required to bring about these changes corresponded to that required for growth responses. Rapid increases in the concentrations of malate, PEP and 3-PGA and decreases in pyruvate and alanine were observed following the direct application of sodium to leaves.

scholarly journals Effect of Sodium Nutrition on Chlorophyll a/b Ratios in C4 Plants

1984 ◽  
Vol 11 (4) ◽  
pp. 325 ◽  
Author(s):  
M Johnston ◽  
CPL Grof ◽  
PF Brownell
Keyword(s):  
Chlorophyll A ◽  
Early Stage ◽  
Chlorophyll Concentration ◽  
C4 Plants ◽  
Growth Responses ◽  
Amaranthus Tricolor ◽  
Sodium Deficiency ◽  
Group I ◽  
Chloris Gayana

Methods for the determination of chlorophyll were compared in Amaranthus tricolor, Kochia childsii and Chloris gayana. From sequential extraction data, 96% ethanol appeared to be more efficient than 80% acetone in extracting chlorophyll from these plants. The chlorophyll a/b ratio was significantly lower in sodium-deficient compared to normal C4 plants. Of the group I elements, only sodium, irrespective of the salt supplied to deficient cultures, restored the chlorophyll a/b ratios to the value observed in normal plants. The concentration of sodium required to increase the chlorophyll a/b ratio in leaves of sodium-deficient plants was similar to that required to bring about the growth responses. The increase of the chlorophyll a/b ratio occurred at an early stage during recovery from sodium deficiency preceding the increase in chlorophyll concentration and the growth response. It is therefore likely that the low chlorophyll a/b ratio may be intrinsically associated with the condition of sodium deficiency.

Characterisation of Leaf Fluorescence of Sodium-Deficient C4 Plants: Kinetics of Emissions From Whole Leaves and Fluorescence Properties of Isolated Thylakoids

1989 ◽  
Vol 16 (6) ◽  
pp. 459 ◽  
Author(s):  
CPL Grof ◽  
DBC Richards ◽  
M Johnston ◽  
PF Brownell
Keyword(s):  
Light Harvesting ◽  
Polynomial Function ◽  
Bundle Sheath ◽  
C4 Plants ◽  
Degree Polynomial ◽  
Amaranthus Tricolor ◽  
Fluorescence Kinetics ◽  
C4 Species ◽  
Chloris Gayana ◽  
Kinetics Of

Examination of whole-leaf fluorescence kinetics by means of a second-degree polynomial function showed a decrease in the rate of the rise from Fd to Fp in sodium-deficient compared with normal leaves of the C4 species Kochia childsii and Amaranthus tricolor. This suggests a decreased efficiency in light harvesting and/or utilisation in sodium-deficient plants. Fluorescence ratios (Fv/Fo) of separated mesophyll and bundle sheath thylakoids were both lower from leaves of sodium-deficient compared with normal plants of K. childsii, Chloris gayana, A. edulis and A. tricolor.

Free Amino Acid Concentrations in Leaves of Sodium-Deficient C4 Plants

1986 ◽  
Vol 13 (3) ◽  
pp. 343 ◽  
Author(s):  
CPL Grof ◽  
M Johnston ◽  
PF Brownell
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Free Amino Acid ◽  
Free Amino ◽  
Aminobutyric Acid ◽  
Amaranthus Tricolor ◽  
Mature Leaves ◽  
C4 Species ◽  
Chloris Gayana ◽  
Amino Acid Concentrations

Consistent changes in the free amino acid concentrations in response to sodium nutrition were observed in mature leaves of the C4 species Amaranthus tricolor and Chloris gayana. The amino acids alanine, γ-aminobutyric acid and glycine were present in greater and aspartate and arginine in lower concentrations in mature leaves of sodium-deficient than in normal plants of both species.

Responses to Ambient CO2 Concentrations by Sodium-Deficient C4 Plants

1984 ◽  
Vol 11 (3) ◽  
pp. 137 ◽  
Author(s):  
M Johnston ◽  
CPL Grof ◽  
PF Brownell
Keyword(s):  
Co2 Concentration ◽  
C4 Plants ◽  
C3 Plants ◽  
Amaranthus Tricolor ◽  
Sodium Deficiency ◽  
Low Co2 ◽  
C3 Species ◽  
High Co2 Concentration ◽  
Increased Co2 Concentration ◽  
Ambient Co2

The signs of sodium deficiency in the C4 species Amaranthus tricolor and Atriplex spongiosa were alleviated when the species were grown in conditions of high CO2 concentration (1 500 �l CO2 1-1). In experiments in which A. tricolor was grown in conditions of low CO2 concentration (15 �l CO2 1-1), the signs of sodium deficiency were accentuated. The sodium-deficient plants resembled the C3 species Atriplex hastata and tomato in their response to the CO2 treatments. Growth and chlorophyll concentrations increased in both the sodium-deficient C4 plants and the C3 plants when they were grown in conditions of increased CO2 concentration. Sodium-sufficient C4 plants were relatively unaffected by the CO2 treatments.

Occurrence and distribution of native and introduced C4 grasses in Tasmania

2002 ◽  
Vol 50 (6) ◽  
pp. 667 ◽  
Author(s):  
Mark J. Hovenden ◽  
Dennis I. Morris
Keyword(s):  
Urban Areas ◽  
General Distribution ◽  
Grass Species ◽  
Past Century ◽  
C4 Grasses ◽  
Photosynthetic Pathway ◽  
Limited Distribution ◽  
The Past ◽  
C4 Species ◽  
C4 Grass

Of the 137 species of grass considered native to Tasmania, only eight use the C4 photosynthetic pathway. There are also approximately 137 grass species considered as introduced to Tasmania and 21% of these are C4. In total, there are 41 species from 20 genera of C4 grass recorded from Tasmania. Many of the introduced C4 species have a very limited distribution, however, and are generally confined to urban areas and along roadsides. Overall, Tasmania has fewer C4 grasses than would be expected from climate alone and few of the C4 grass species are widely distributed or abundant. However, the proportion of grasses recorded from Tasmania that use the C4 pathway has been increasing for the past century and is still increasing. General distribution and habitat notes are provided for all C4 grasses known to be native or naturalised in Tasmania.

The distribution and ultrastructure of chloroplasts in leaves differing in photosynthetic carbon metabolism. I. Wheat, Sorghum, and Aristida (Gramineae)

1969 ◽  
Vol 47 (1) ◽  
pp. 15-21 ◽  
Author(s):  
T. Bisalputra ◽  
W. J. S. Downton ◽  
E. B. Tregunna
Keyword(s):  
Carbon Dioxide ◽  
Bundle Sheath ◽  
Vascular Bundles ◽  
Photosynthetic Pathway ◽  
Low Carbon ◽  
Mesophyll Cells ◽  
Cytological Evidence ◽  
Bundle Sheath Cells ◽  
Photosynthetic Carbon Metabolism ◽  
High Carbon Dioxide

The ultrastructure of the chlorenchymatous tissues around the vascular bundles of three different types of grass leaves is described. In the temperate grass leaf, as exemplified by wheat, the inner mestom sheath contains proplastids. Normal chloroplasts are found only within the mesophyll cells. Smaller chloroplasts occur in cells of the ill-defined parenchymatic bundle sheath. This type of leaf has the photosynthetic pathway described by Calvin and a high carbon dioxide compensation value. In the tropical grasses, Sorghum and Aristida, the new photosynthetic pathway proposed by Hatch et al. and low carbon dioxide compensation are correlated with development of the parenchymatic bundle sheath. Cytological evidence indicates that cells of the bundle sheath are much more active than the surrounding mesophyll tissue. The specialized chloroplasts of the bundle sheath cells may be responsible for the physiological and biochemical differences between leaves of tropical and temperate grasses.

Photosynthesis in Phosphoenolpyruvate Carboxykinase-Type C4 Species: Properties of Nad-Malic Enzyme From Urochloa panicoides

1987 ◽  
Vol 14 (5) ◽  
pp. 517 ◽  
Author(s):  
JN Burnell
Keyword(s):  
Malic Enzyme ◽  
Phosphoenolpyruvate Carboxykinase ◽  
Bundle Sheath ◽  
Photosynthetic Pathway ◽  
C4 Plant ◽  
C4 Species ◽  
Absolute Requirement ◽  
Pep Carboxykinase ◽  
Fructose 1,6 Bisphosphate ◽  
Regulatory Properties

NAD-malic enzyme (EC 1.1.1.39) was purified from bundle sheath strands of Urochloa panicoides (a phosphoenolpyruvate carboxykinase-type C4 plant) and its kinetic and regulatory properties were investigated. The native enzyme has a molecular weight of about 470 000 and is an octomer composed of two slightly different monomers which occur in a 1 : 1 ratio. The enzyme has an absolute requirement for Mn2+, is stimulated by CoA, acetyl CoA, fructose 1,6-bisphosphate and SO42- and is inhibited by HCO3, oxaloacetate, 2-oxoglutarate and pyruvate. The enzyme is shown to be localised in the mito- chondria. The purified NAD-malic enzyme is unable to catalyse the carboxylation of pyruvate according to the reverse reaction. These findings are discussed in relation to the C4 photosynthetic pathway and its possible role in PEP carboxykinase-type C4 plants.

Photosynthesis in Gomphrena celosioides and Its Classification Amongst C4-pathway Plants

1976 ◽  
Vol 3 (6) ◽  
pp. 863 ◽  
Author(s):  
E Repo ◽  
MD Hatch
Keyword(s):  
Malate Dehydrogenase ◽  
Malic Enzyme ◽  
Bundle Sheath ◽  
Mesophyll Cells ◽  
C4 Species ◽  
Bundle Sheath Cells ◽  
Major Route ◽  
Gomphrena Celosioides ◽  
A Minor ◽  
Sheath Cells

Monocotyledonous C4 species classified as NADP-ME-type transfer malate from mesophyll to bundle sheath cells where this acid is decarboxylated via NADP malic enzyme (EC 1.1.1.40) to yield pyruvate and CO2. The dicotyledon G. celosioides is most appropriately classified in thls group on the basis of high leaf activities of NADP malic enzyme and NADP malate dehydrogenase (EC 1.1.1.82). However, this species contains high aspartate aminotransferase (EC 2.6.1.1) and alanine aminotransferase (EC 2.6.1.2) activities and centripetally located bundle sheath chloroplasts, features more typical of other groups of C4 species that cycle aspartate and alanine between mesophyll and bundle sheath cells. During the present study, we found that these aminotransferases and NADP malate dehydrogenase were predominantly located in mesophyll cells, that malate was the major C4 acid labelled when leaves were exposed to 14CO2, and that label was initially lost most rapidly from the C-4 of malate during a chase in 12CO2. These results are consistent with the major route of photosynthetic metabolism being the same as that operative in other NADP-ME-type species, although this may be supplemented by a minor route utilizing aspartate. In contrast to monocotyledonous NADP-ME-type C4 species, isolated bundle sheath cells from G. celosioides were capable of rapid photoreduction of NADP as judged by products formed during assimilation of 14CO2 and their capacity for light-dependent oxygen evolution. This was related to a relatively high frequency of single unstacked granum in the chloroplasts of these cells.

Correlation between carbon isotope discrimination and transpiration efficiency in lines of the C4 species Sorghum bicolor in the glasshouse and the field

1998 ◽  
Vol 25 (1) ◽  
pp. 111 ◽  
Author(s):  
S. Henderson ◽  
S. von Caemmerer ◽  
G.D. Farquhar ◽  
L. Wade ◽  
G. Hammer
Keyword(s):  
Sorghum Bicolor ◽  
Carbon Isotope ◽  
Carbon Isotope Discrimination ◽  
Negative Slope ◽  
Environment Interaction ◽  
Transpiration Efficiency ◽  
Isotope Discrimination ◽  
C4 Species ◽  
C3 Species ◽  
The Mean

Transpiration efficiency, W, the ratio of plant carbon produced to water transpired and carbon isotope discrimination of leaf dry matter, Δd, were measured together on 30 lines of the C4 species, Sorghum bicolor, in the glasshouse and on eight lines grown in the field. In the glasshouse, the mean W observed was 4.9 mmol C mol-1 H2O and the range was 0.8 mmol C mol -1 H2O. The mean Δd was 3.0 and the observed range was 0.4‰. In the field, the mean W was lower at 2.8 mmol C mol-1 H2O and the mean Δd was 4.6‰. Significant positive correlations between W and Δd were observed for plants grown in the glasshouse and in the field. The observed correlations were consistent with theory, opposite to those for C3 species, and showed that variation in Δd was an integrated measure of long-term variation in the ratio of intercellular to ambient CO2 partial pressure, pi/pa. Detailed gas exchange measurements of carbon isotope discrimination during CO2 uptake, ΔA, and pi/pa were made on leaves of eight S. bicolorlines. The observed relationship between ΔA and pi/pa was linear with a negative slope of 3.7‰ in ΔA for a unit change in pi/pa. The slope of this linear relationship between ΔA and pi/pa in C4 species is dependent on the leakiness of the CO2 concentrating mechanism of the C4 pathway. We estimated the leakiness (defined as the fraction of CO2 released in the bundle sheath by C4 acid decarboxylations, which is lost by leakage) to be 0.2. We conclude that, although variation in Δd observed in the 30 lines of S. bicolor is smaller than that commonly observed in C3 species, it also reflects variation in transpiration efficiency, W. Among the eight lines examined in detail and in the environments used, there was considerable genotype × environment interaction.

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