Ecological evidence concerning the adaptive significance of the C4 dicarboxylic acid pathway of photosynthesis

Oecologia ◽  
1979 ◽  
Vol 38 (1) ◽  
pp. 23-34 ◽  
Author(s):  
L. H. Doliner ◽  
P. A. Jolliffe
Keyword(s):  
Dicarboxylic Acid ◽  
Adaptive Significance ◽  
Acid Pathway

scholarly journals Properties and regulation of leaf nicotinamide–adenine dinucleotide phosphate–malate dehydrogenase and ‘malic’ enzyme in plants with the C4-dicarboxylic acid pathway of photosynthesis

1970 ◽  
Vol 119 (2) ◽  
pp. 273-280 ◽  
Author(s):  
Hilary S. Johnson ◽  
M. D. Hatch
Keyword(s):  
Dicarboxylic Acid ◽  
Malate Dehydrogenase ◽  
Malic Enzyme ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Maximum Velocity ◽  
Enzyme Reaction ◽  
Reverse Direction ◽  
Leaf Extracts ◽  
Ph Optimum ◽  
Acid Pathway

1. NADP–malate dehydrogenase and `malic' enzyme in maize leaf extracts were separated from NAD–malate dehydrogenase and their properties were examined. 2. The NADP–malate dehydrogenase was nicotinamide nucleotide-specific but otherwise catalysed a reaction comparable with that with the NAD-specific enzyme. By contrast with the latter enzyme, a thiol was absolutely essential for maintaining the activity of the NADP–malate dehydrogenase, and the initial velocity in the direction of malate formation, relative to the reverse direction, was faster. 3. For the `malic' enzyme reaction the Km for malate was dependent on pH and the pH optimum varied with the malate concentration. At their respective optimum concentrations the maximum velocity for this enzyme was higher with Mg2+ than with Mn2+. 4. The NADP–malate dehydrogenase in green leaves was rapidly inactivated in the dark and was reactivated when plants were illuminated. Reactivation of the enzyme extracted from darkened leaves was achieved simply by adding a thiol compound. 5. The activity of both enzymes was low in etiolated leaves of maize plants grown in the dark but increased 10–20-fold, together with chlorophyll, when leaves were illuminated. 6. The activity of these enzymes in different species with the C4-dicarboxylic acid pathway was compared and their possible role in photosynthesis was considered.

Light-induced formation of enzymes of the C4-dicarboxylic acid pathway of photosynthesis in detached leaves

1970 ◽  
Vol 9 (3) ◽  
pp. 521-532 ◽  
Author(s):  
D. Graham ◽  
M.D. Hatch ◽  
C.R. Slack ◽  
Robert M. Smillie
Keyword(s):  
Dicarboxylic Acid ◽  
Detached Leaves ◽  
Acid Pathway

scholarly journals The C4-dicarboxylic acid pathway of photosynthesis. Identification of intermediates and products and quantitative evidence for the route of carbon flow

1969 ◽  
Vol 114 (1) ◽  
pp. 127-134 ◽  
Author(s):  
Hilary S. Johnson ◽  
M. D. Hatch
Keyword(s):  
Carbon Dioxide ◽  
Steady State ◽  
Dicarboxylic Acid ◽  
Dicarboxylic Acids ◽  
Main Flow ◽  
Carbon Flow ◽  
Dihydroxyacetone Phosphate ◽  
Carboxyl Group ◽  
Quantitative Evidence ◽  
Acid Pathway

1. When leaves with the C4-dicarboxylic acid pathway of photosynthesis are exposed to 14CO2 the major labelled compounds formed, in order of labelling, are dicarboxylic acids, 3-phosphoglycerate, bexose phosphates and sucrose. During the present studies several quantitatively minor intermediates were identified and their labelling behaviour is described. 2. The pattern of labelling of dihydroxyacetone phosphate, fructose 1,6-diphosphate and ribulose di- and mono-phosphates during radiotracer pulse–chase experiments was consistent with their operation as intermediates in the pathway of carbon dioxide fixation. 3. Serine, glycine, alanine and glutamate had labelling patterns typical of products secondary to the main flow of carbon. 4. The mechanism of the transfer of label from C-4 of dicarboxylic acids to C-1 of 3-phosphoglycerate was also examined. Evidence consistent with pyruvate being derived from C-1, C-2 and C-3 of oxaloacetate, and for a relationship between ribulose 1,5-diphosphate and the acceptor for the C-4 carboxyl group, was obtained. 5. Evidence is provided that, under steady-state conditions, essentially all the label incorporated from 14CO2 into C-1 of 3 phosphoglycerate enters via C-4 of the dicarboxylic acids. These and other studies indicated that the route via dicarboxylic acids is essentially the sole route for entry of carbon into 3-phosphoglycerate.

Sign in / Sign up

Export Citation Format

Share Document