Adaptation and acclimation of higher plants at the enzyme level: Latitudinal variations of thermal properties of NAD malate dehydrogenase in Lathyrus japonicus Willd. (Leguminosae)

Oecologia ◽  
1979 ◽  
Vol 39 (3) ◽  
pp. 273-287 ◽  
Author(s):  
Jean-Pierre Simon
Keyword(s):  
Thermal Properties ◽  
Malate Dehydrogenase ◽  
Higher Plants ◽  
Enzyme Level ◽  
Latitudinal Variations

Adaptation and acclimation of higher plants at the enzyme level: thermal properties of NAD malate dehydrogenase of two species of Aster (Asteraceae) and their hybrid adapted to contrasting habitats

1980 ◽  
Vol 58 (13) ◽  
pp. 1474-1481 ◽  
Author(s):  
Luc Brouillet ◽  
Jean-Pierre Simon
Keyword(s):  
Malate Dehydrogenase ◽  
Higher Plants ◽  
Enzyme Level ◽  
Leaf Tissue ◽  
Forest Understory ◽  
Kinetic Properties ◽  
Peptidase Activity ◽  
Crude Extracts ◽  
Contrasting Habitats ◽  
Sphagnum Bog

Thermal and kinetic properties of NAD malate dehydrogenase (MDH) were investigated in clonal populations of two species of Aster and their hybrid: A. acuminatus, a forest understory species; A. nemoralis, a sphagnum-bog species; and A. blakei, their hybrid occurring at the bog–forest ecotone. The populations were collected within a 300 m radius in southwestern Quebec. Compared with A. acuminatus, the MDH of crude extracts from A. nemoralis had lower thermostability in both 5- and 10-min assays at 55 °C, and reduced apparent energy of activation (Ea) in the temperature range of 15–25 °C. However, these differences were not maintained in purified extracts of the species and may be attributed to higher phenolase and peptidase activity in crude extracts of A. nemoralis. The ratio of MDH activity over total protein concentration, or fresh weight leaf tissue, was higher in A. acuminatus than in A. nemoralis. Most values for these MDH properties of A. blakei were intermediate between those of the two parents. No differences, however, were observed for the substrate binding ability (Km) of MDH in the three taxa. Electrophoretic analyses show no qualitative differentiation in the enzyme profiles of MDH of the three taxa, which consist of two mitochondrial and six cytosolic isozymes. Mitochondrial isozymes were more thermostable but no differences in thermostability were observed among the forms of the species. The thermal and kinetic properties of malate dehydrogenase, as measured in situ, have not been substantially modified by the contrasting microclimatic regimes associated with the habitats of A. acuminatus and A. nemoralis.

scholarly journals Aconitase: To Be or not to Be Inside Plant Glyoxysomes, That Is the Question

Biology ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 162
Author(s):  
Luigi De Bellis ◽  
Andrea Luvisi ◽  
Amedeo Alpi
Keyword(s):  
Malate Dehydrogenase ◽  
Metabolic Pathways ◽  
Higher Plants ◽  
Glyoxylate Cycle ◽  
Genetic Research ◽  
Transcriptomic Analysis ◽  
Plant Biology ◽  
New Model ◽  
The Glyoxylate Cycle

After the discovery in 1967 of plant glyoxysomes, aconitase, one the five enzymes involved in the glyoxylate cycle, was thought to be present in the organelles, and although this was found not to be the case around 25 years ago, it is still suggested in some textbooks and recent scientific articles. Genetic research (including the study of mutants and transcriptomic analysis) is becoming increasingly important in plant biology, so metabolic pathways must be presented correctly to avoid misinterpretation and the dissemination of bad science. The focus of our study is therefore aconitase, from its first localization inside the glyoxysomes to its relocation. We also examine data concerning the role of the enzyme malate dehydrogenase in the glyoxylate cycle and data of the expression of aconitase genes in Arabidopsis and other selected higher plants. We then propose a new model concerning the interaction between glyoxysomes, mitochondria and cytosol in cotyledons or endosperm during the germination of oil-rich seeds.

scholarly journals Thioredoxin-h1 Reduces and Reactivates the Oxidized Cytosolic Malate Dehydrogenase Dimer in Higher Plants

2006 ◽  
Vol 281 (43) ◽  
pp. 32065-32071 ◽  
Author(s):  
Satoshi Hara ◽  
Ken Motohashi ◽  
Fumio Arisaka ◽  
Patrick G. N. Romano ◽  
Naomi Hosoya-Matsuda ◽  
...  
Keyword(s):  
Affinity Chromatography ◽  
Malate Dehydrogenase ◽  
Higher Plants ◽  
Peptide Mapping ◽  
Target Protein ◽  
Reduced Form ◽  
Mutant Analysis ◽  
Low Concentrations ◽  
Mapping Analysis ◽  
Cytosolic Malate Dehydrogenase

Cytosolic malate dehydrogenase (cytMDH) was captured by thioredoxin affinity chromatography as a possible target protein of cytosolic thioredoxin (Yamazaki, D., Motohashi, K., Kasama, T., Hara, Y., and Hisabori, T. (2004) Plant Cell Physiol. 45, 18–27). To further dissect this interaction, we aimed to determine whether cytMDH can interact with the cytosolic thioredoxin and whether its activity is redox-regulated. We obtained the active recombinant cytMDH that could be oxidized and rendered inactive. Inactivation was reversed by incubation with low concentrations of dithiothreitol in the presence of recombinant Arabidopsis thaliana thioredoxin-h1. Inactivation of cytMDH was found to result from formation of a homodimer. By cysteine mutant analysis and peptide mapping analysis, we were able to determine that the cytMDH homodimer occurs by formation of a disulfide bond via the Cys330 residue. Moreover, we found this bond to be efficiently reduced by the reduced form of thioredoxin-h1. These results demonstrate that the oxidized form cytMDH dimer is a preferable target protein of the reduced form thioredoxin-h1 as suggested by thioredoxin affinity chromatography.

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