Thermal adaptation and acclimation of higher plants at the enzyme level: kinetic properties of NAD malate dehydrogenase and glutamate oxaloacetate transaminase in two genotypes of Arabidopsis thaliana (Brassicaceae)

Oecologia ◽  
1983 ◽  
Vol 60 (2) ◽  
pp. 143-148 ◽  
Author(s):  
Jean-Pierre Simon ◽  
Catherine Potvin ◽  
Marie-H�l�ne Blanchard
Keyword(s):  
Arabidopsis Thaliana ◽  
Malate Dehydrogenase ◽  
Higher Plants ◽  
Enzyme Level ◽  
Thermal Adaptation ◽  
Kinetic Properties ◽  
Glutamate Oxaloacetate Transaminase

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.

Utilization of a hydrate cellulose film for investigation of Arabidopsis thaliana L. root system growth and development

2020 ◽  
Vol 36 (1) ◽  
pp. 36-43
Author(s):  
I.O. Konovalova ◽  
T.N. Kudelina ◽  
S.O. Smolyanina ◽  
A.I. Lilienberg ◽  
T.N. Bibikova
Keyword(s):  
Arabidopsis Thaliana ◽  
Root System ◽  
Life Support ◽  
Higher Plants ◽  
Plant Root ◽  
Lateral Roots ◽  
Basic Research ◽  
Cellulose Film ◽  
A New Technique ◽  
Basic Research Project

A new technique for Arabidopsis thaliana cultivation has been proposed that combines the use of a phytogel-based nutrient medium and a hydrophilic membrane of hydrate cellulose film, separating the root system of the plant from the medium thickness. Growth rates of both main and lateral roots were faster in the plants cultivated on the surface of hydrate cellulose film than in the plants grown in the phytogel volume. The location of the root system on the surface of the transparent hydrate film simplifies its observation and analysis and facilitates plant transplantation with preservation of the root system configuration. The proposed technique allowed us to first assess the effect of exogenous auxin on the growth of lateral roots at the 5-6 developmental stage. methods to study plant root systems, hydrate cellulose film, A. thaliana, lateral roots, differential root growth rate, auxin The work was financially supported by the Russian Foundation for Basic Research (Project Bel_mol_a 19-54-04015) and the basic topic of the Russian Academy of Sciences - IBMP RAS «Regularities of the Influence of Extreme Environmental Factors on the Processes of Cultivation of Higher Plants and the Development of Japanese Quail Tissues at Different Stages of its Ontogenesis under the Conditions of Regenerative Life Support Systems».

Inheritance of isozymes in seed and bud tissues of blue and Engelmann spruce

Genome ◽  
1987 ◽  
Vol 29 (2) ◽  
pp. 239-246 ◽  
Author(s):  
S. G. Ernst ◽  
D. E. Keathley ◽  
J. W. Hanover
Keyword(s):  
Acid Phosphatase ◽  
Key Words ◽  
Malate Dehydrogenase ◽  
Glutamate Oxaloacetate Transaminase ◽  
Blue Spruce ◽  
Mating Design ◽  
Engelmann Spruce ◽  
Enzyme Systems ◽  
Segregation Ratios ◽  
Mode Of Inheritance

Thirteen loci from 11 enzyme systems were identified among full-sib and half-sib progeny of blue and Engelmann spruce. Eleven of the loci were expressed in bud, embryo, and megagametophyte tissue; the remaining two loci were expressed only in embryo and megagametophyte tissue. There were no mobility differences observed between loci expressed in seed and bud tissues. The mode of inheritance for 10 of the loci was confirmed based on progeny genotypic distributions. For the two loci not expressed in bud tissue, acid phosphatase (Acp-2) and diaphorase (Dia-2), inheritance was inferred from pooled segregation ratios of megagametophytes from open-pollinated seed from heterozygous females. The inheritance of glutamate oxaloacetate transaminase (Got-3) was also inferred from segregation ratios and diploid embryo phenotypes of open-pollinated progeny owing to a lack of variability at this locus among the 40 parents in the mating design. Two loci, aldolase (Ald) and malate dehydrogenase (Mdh-2), were monomorphic among the 20 parents of both species. Key words: isozymes, Engelmann spruce, blue spruce, Picea.

scholarly journals ATP compartmentation in plastids and cytosol ofArabidopsis thalianarevealed by fluorescent protein sensing

2018 ◽  
Vol 115 (45) ◽  
pp. E10778-E10787 ◽  
Author(s):  
Chia Pao Voon ◽  
Xiaoqian Guan ◽  
Yuzhe Sun ◽  
Abira Sahu ◽  
May Ngor Chan ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Fluorescent Protein ◽  
Higher Plants ◽  
Electron Flow ◽  
Cyclic Electron Flow ◽  
Linear Electron ◽  
Protein Sensing ◽  
Atp Production ◽  
Respiratory Inhibitors ◽  
Sensor Protein

Matching ATP:NADPH provision and consumption in the chloroplast is a prerequisite for efficient photosynthesis. In terms of ATP:NADPH ratio, the amount of ATP generated from the linear electron flow does not meet the demand of the Calvin–Benson–Bassham (CBB) cycle. Several different mechanisms to increase ATP availability have evolved, including cyclic electron flow in higher plants and the direct import of mitochondrial-derived ATP in diatoms. By imaging a fluorescent ATP sensor protein expressed in livingArabidopsis thalianaseedlings, we found that MgATP2−concentrations were lower in the stroma of mature chloroplasts than in the cytosol, and exogenous ATP was able to enter chloroplasts isolated from 4- and 5-day-old seedlings, but not chloroplasts isolated from 10- or 20-day-old photosynthetic tissues. This observation is in line with the previous finding that the expression of chloroplast nucleotide transporters (NTTs) inArabidopsismesophyll is limited to very young seedlings. Employing a combination of photosynthetic and respiratory inhibitors with compartment-specific imaging of ATP, we corroborate the dependency of stromal ATP production on mitochondrial dissipation of photosynthetic reductant. Our data suggest that, during illumination, the provision and consumption of ATP:NADPH in chloroplasts can be balanced by exporting excess reductants rather than importing ATP from the cytosol.

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