Chlorophyllase Activity and Chlorophyll Content in Wild Type and eti 5 Mutant of Arabidopsis thaliana Subjected to Low and High Temperatures

2003 ◽  
Vol 46 (4) ◽  
pp. 633-636 ◽  
Author(s):  
D.T. Todorov ◽  
E.N. Karanov ◽  
A.R. Smith ◽  
M.A. Hall
Keyword(s):  
Arabidopsis Thaliana ◽  
Chlorophyll Content ◽  
High Temperatures ◽  
Wild Type

scholarly journals Analysis of secondary metabolism and total chlorophyll content provides new insights into the role of A-tocopherol for wild type and VTE4 mutant Arabidopsis thaliana under different abiotic stresses

Genetika ◽  
2016 ◽  
Vol 48 (2) ◽  
pp. 445-462 ◽  
Author(s):  
Amir Khalatbari ◽  
Hawa Jaafar ◽  
Amir Khalatbari ◽  
Maziah Mahmood ◽  
Radziah Othman
Keyword(s):  
Arabidopsis Thaliana ◽  
Salt Stress ◽  
Water Stress ◽  
Secondary Metabolites ◽  
Chlorophyll Content ◽  
Abiotic Stresses ◽  
Total Chlorophyll ◽  
Water Deficiency ◽  
Wild Type ◽  
Total Chlorophyll Content

Plants experience different abiotic stresses under natural conditions including salinity, water deficit, low temperature and high light. Once plants are exposed to these stresses they might have a variety of responses physiologically and biochemically. In this study, we test this hypothesis in wild type Col-0 and vte4 mutant of Arabidopsis thaliana by measuring major secondary metabolites alongside with total chlorophyll content under different abiotic stresses namely salt stress, water stress and prolonged water deficiency. These stresses were imposed to the plants in separate experiments in which each treatment was replicated three times in a complete randomized design with factorial arrangement. It was concluded that under all abiotic stresses wild type Col-0 Arabidopsis plants showed stronger performance in terms of all major metabolites compared to vte4 mutant. ?-tocopherol deficiency in vte4 mutant plants led to lower accumulation of proline, total protein and total amino acids as well as starch and total sugars in comparison with wild type A. thaliana. Furthermore, all five secondary metabolites obtained the highest value under 100mM NaCl concentration (Salt stress), under 50% of field capacity (water stress) and under 8 days of water withholding (prolonged water deficiency). Wild type Col-0 resulted in higher level of total chlorophyll content under all abiotic stresses compared to mutant plants. Therefore, our results suggested that the loss of ?-tocopherol in vte4 mutant A.thaliana under different abiotic stresses affected the efficiency and the stability of central metabolism and photosynthetic apparatus.

scholarly journals Temperature-Sensitive, Vitamin-Requiring Mutants of Arabidopsis Thaliana

1965 ◽  
Vol 18 (2) ◽  
pp. 311 ◽  
Author(s):  
J Langridge
Keyword(s):  
Arabidopsis Thaliana ◽  
High Temperatures ◽  
Temperature Sensitive ◽  
Wild Type ◽  
X Ray ◽  
Recessive Mutations ◽  
Naturally Occurring ◽  
Induced Mutant

Three mutants of Arabidopsi8 requiring specific vitamins for growth at certain temperatures are described. All are due to recessive mutations of single wild-type genes. One X-ray-induced mutant is unable to synthesize thiamine at low tempera-tures because of a block in the phosphorylation or coupling of the immediate precursors. Two mutants which require biotin for growth at high temperatures are determined by recessive alleles of the same gene. These mutants comprise naturally occurring ecotypes in Spain and Austria. Experiments indicate that an inability to make biotin at high temperatures may be adaptively advantageous. The consequent cessation in growth is a balanced one, readily reversible by a lowering of temperature, which allows the plant to escape the irreversible sterilizing effect of heat.

scholarly journals Inhibition of cell expansion enhances cortical microtubule stability in the root apex of Arabidopsis thaliana

2021 ◽  
Vol 28 (1) ◽  
Author(s):  
Veronica Giourieva ◽  
Emmanuel Panteris
Keyword(s):  
Arabidopsis Thaliana ◽  
Cell Wall ◽  
Cell Expansion ◽  
Cortical Microtubule ◽  
Root Apex ◽  
Cellulose Synthase ◽  
Cellulose Biosynthesis ◽  
Cortical Microtubules ◽  
Wild Type ◽  
Microtubule Stability

Abstract Background Cortical microtubules regulate cell expansion by determining cellulose microfibril orientation in the root apex of Arabidopsis thaliana. While the regulation of cell wall properties by cortical microtubules is well studied, the data on the influence of cell wall to cortical microtubule organization and stability remain scarce. Studies on cellulose biosynthesis mutants revealed that cortical microtubules depend on Cellulose Synthase A (CESA) function and/or cell expansion. Furthermore, it has been reported that cortical microtubules in cellulose-deficient mutants are hypersensitive to oryzalin. In this work, the persistence of cortical microtubules against anti-microtubule treatment was thoroughly studied in the roots of several cesa mutants, namely thanatos, mre1, any1, prc1-1 and rsw1, and the Cellulose Synthase Interacting 1 protein (csi1) mutant pom2-4. In addition, various treatments with drugs affecting cell expansion were performed on wild-type roots. Whole mount tubulin immunolabeling was applied in the above roots and observations were performed by confocal microscopy. Results Cortical microtubules in all mutants showed statistically significant increased persistence against anti-microtubule drugs, compared to those of the wild-type. Furthermore, to examine if the enhanced stability of cortical microtubules was due to reduced cellulose biosynthesis or to suppression of cell expansion, treatments of wild-type roots with 2,6-dichlorobenzonitrile (DCB) and Congo red were performed. After these treatments, cortical microtubules appeared more resistant to oryzalin, than in the control. Conclusions According to these findings, it may be concluded that inhibition of cell expansion, irrespective of the cause, results in increased microtubule stability in A. thaliana root. In addition, cell expansion does not only rely on cortical microtubule orientation but also plays a regulatory role in microtubule dynamics, as well. Various hypotheses may explain the increased cortical microtubule stability under decreased cell expansion such as the role of cell wall sensors and the presence of less dynamic cortical microtubules.

scholarly journals Molecular Dynamics of Chloroplast Membranes Isolated from Wild-Type Barley and a Brassinosteroid-Deficient Mutant Acclimated to Low and High Temperatures

Biomolecules ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 27
Author(s):  
Iwona Sadura ◽  
Dariusz Latowski ◽  
Jana Oklestkova ◽  
Damian Gruszka ◽  
Marek Chyc ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Temperature Stress ◽  
High Temperatures ◽  
Biological Membrane ◽  
Hydrophobic Core ◽  
Wild Type ◽  
Chloroplast Membranes ◽  
Paramagnetic Resonance ◽  
Photosynthetic Membranes

Plants have developed various acclimation strategies in order to counteract the negative effects of abiotic stresses (including temperature stress), and biological membranes are important elements in these strategies. Brassinosteroids (BR) are plant steroid hormones that regulate plant growth and development and modulate their reaction against many environmental stresses including temperature stress, but their role in modifying the properties of the biological membrane is poorly known. In this paper, we characterise the molecular dynamics of chloroplast membranes that had been isolated from wild-type and a BR-deficient barley mutant that had been acclimated to low and high temperatures in order to enrich the knowledge about the role of BR as regulators of the dynamics of the photosynthetic membranes. The molecular dynamics of the membranes was investigated using electron paramagnetic resonance (EPR) spectroscopy in both a hydrophilic and hydrophobic area of the membranes. The content of BR was determined, and other important membrane components that affect their molecular dynamics such as chlorophylls, carotenoids and fatty acids in these membranes were also determined. The chloroplast membranes of the BR-mutant had a higher degree of rigidification than the membranes of the wild type. In the hydrophilic area, the most visible differences were observed in plants that had been grown at 20 °C, whereas in the hydrophobic core, they were visible at both 20 and 5 °C. There were no differences in the molecular dynamics of the studied membranes in the chloroplast membranes that had been isolated from plants that had been grown at 27 °C. The role of BR in regulating the molecular dynamics of the photosynthetic membranes will be discussed against the background of an analysis of the photosynthetic pigments and fatty acid composition in the chloroplasts.

Caffeoyl Shikimate Esterase (CSE) Is an Enzyme in the Lignin Biosynthetic Pathway in Arabidopsis

Science ◽  
2013 ◽  
Vol 341 (6150) ◽  
pp. 1103-1106 ◽  
Author(s):  
Ruben Vanholme ◽  
Igor Cesarino ◽  
Katarzyna Rataj ◽  
Yuguo Xiao ◽  
Lisa Sundin ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Cell Walls ◽  
Metabolite Profiling ◽  
Biosynthetic Pathway ◽  
Wild Type ◽  
Secondary Cell Walls ◽  
Phenolic Metabolite ◽  
In The Wild ◽  
Lignin Biosynthetic Pathway

Lignin is a major component of plant secondary cell walls. Here we describe caffeoyl shikimate esterase (CSE) as an enzyme central to the lignin biosynthetic pathway. Arabidopsis thaliana cse mutants deposit less lignin than do wild-type plants, and the remaining lignin is enriched in p-hydroxyphenyl units. Phenolic metabolite profiling identified accumulation of the lignin pathway intermediate caffeoyl shikimate in cse mutants as compared to caffeoyl shikimate levels in the wild type, suggesting caffeoyl shikimate as a substrate for CSE. Accordingly, recombinant CSE hydrolyzed caffeoyl shikimate into caffeate. Associated with the changes in lignin, the conversion of cellulose to glucose in cse mutants increased up to fourfold as compared to that in the wild type upon saccharification without pretreatment. Collectively, these data necessitate the revision of currently accepted models of the lignin biosynthetic pathway.

Expression of calmodulin genes in wild type and calmodulin mutants of Arabidopsis thaliana under heat stress

2010 ◽  
Vol 48 (8) ◽  
pp. 697-702 ◽  
Author(s):  
Nisreen A. AL-Quraan ◽  
Robert D. Locy ◽  
Narendra K. Singh
Keyword(s):  
Arabidopsis Thaliana ◽  
Heat Stress ◽  
Wild Type

Sucrose Transporter Gene AtSUC4 Responds to Drought Stress by Regulating the Sucrose Distribution and Metabolism in Arabidopsis thaliana

2013 ◽  
Vol 765-767 ◽  
pp. 2971-2975 ◽  
Author(s):  
Xue Gong ◽  
Ming Li Liu ◽  
Li Jun Zhang ◽  
Wei Liu ◽  
Che Wang
Keyword(s):  
Arabidopsis Thaliana ◽  
Drought Stress ◽  
Plant Stress ◽  
Homozygous Mutation ◽  
Transporter Gene ◽  
Wild Type ◽  
Sucrose Transporters ◽  
Whole Plant ◽  
Plant Stress Tolerance ◽  
Plant Level

Sucrose transporters (SUCs or SUTs) are considered as the important carriers and responsible for the loading, unloading and distribution of sucrose, but at present there is no report that SUCs are involved in sucrose distribution and metabolism under drought stress at the whole-plant level. AtSUC4, as the unique member of SUT4-clade inArabidopsis thaliana, may be important for plant stress tolerance. Here, by analyzing two homozygous mutation lines ofAtSUC4(Atsuc4-1andAtsuc4-2), we found drought stress induced higher sucrose, lower fructose and glucose contents in shoots, and lower sucrose, higher fructose and glucose contents in roots of these mutants compared with the wild-type (WT), leading to an imbalance of sucrose distribution, fructose and glucose (sucrose metabolites) accumulation changes at the whole-plant level. Thus we believe thatAtSUC4regulates sucrose distribution and metabolism in response to drought stress.

scholarly journals MNB1 gene is involved in regulating the iron-deficiency stress response in Arabidopsis thaliana

2021 ◽  
Author(s):  
Hui Song ◽  
Feng Chen ◽  
Xi Wu ◽  
Min Hu ◽  
Qingliu Geng ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Arabidopsis Thaliana ◽  
Normal Growth ◽  
Developmental Changes ◽  
Fe Deficiency ◽  
Oxygen Species ◽  
Mineral Element ◽  
Wild Type ◽  
Transcription Level ◽  
Fe Uptake

Abstract Abstract Iron (Fe) is an indispensable mineral element for normal growth of plants. Fe deficiency induces a complex series of responses in plants, involving physiological and developmental changes, to increase Fe uptake from soil. However, the molecular mechanism involved in plant Fe-deficiency is not well understood. Here, we found that the MNB1 gene is involved in modulating Fe-deficiency response in Arabidopsis thaliana . The expression of MNB1 was inhabited by Fe-deficiency stress. Knockout of MNB1 led to enhanced Fe accumulation and tolerance, whereas the MNB1-overexpressing plants were sensitive to Fe-deficiency stress. Lower H 2 O 2 concentrations in mnb1 mutant plants were examined under Fe deficiency circumstances compared to wild-type. On the contray, higher H 2 O 2 concentrations were found in MNB1-overexpressing plants, which was adversely linked with malondialdehyde (MDA) concentrations. Furthermore, in mnb1 mutants, the transcription level of the Fe-uptake and translocation genes, FIT , IRT1 , FRO2 , Z IF , FRD3 , NAS4 , PYE and MYB72 , were considerably elevated during Fe-deficiency stress, resulting in higher Fe accumulation. Together, our findings show that the MNB1 gene negatively controls the Fe-deficiency response in Arabidopsis via modulating reactive oxygen species (ROS) levels and the ROS-mediated signaling pathway, thereby affecting the expression of Fe-uptake and translocation genes.

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