Ascorbate Peroxidase of Moss Dicranum scoparium: Gene Identification and Enzyme Activity

In present work, the APX gene encoding ascorbate peroxidase in the moss Dicranum scoparium was for the first time cloned and sequenced, high homology of APX with ascorbate peroxidase genes of the mosses Grimmia pilifera and Physcomitrella patens was shown. The structure of the protein was characterized using bioinfomatics approach and the activity of the enzyme under abiotic stresses was studied. An increase in the activity of ascorbate peroxidase was detected during desiccation of D. scoparium shoots. When exposed to heat shock, a decrease in the acti-vity of ascorbate peroxidase correlated with a decrease in the expression of APX. Conserved elements, which were found in the structure of ascorbate peroxidase gene and protein, indicate that these sequences are preserved in the plant genome during evolution, in support of the importance of this enzyme in maintaining cellular redox status.

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The cDNA Structures and Expression Profile of the Ascorbate Peroxidase Gene Family During Drought Stress in Wild Watermelon

Journal of Agricultural Science ◽

10.5539/jas.v10n8p56 ◽

2018 ◽

Vol 10 (8) ◽

pp. 56

Author(s):

Goitseone Malambane ◽

Hisashi Tsujimoto ◽

Kinya Akashi

Keyword(s):

Enzyme Activity ◽

Transcriptional Regulation ◽

Alternative Splicing ◽

Drought Stress ◽

Gene Family ◽

Ascorbate Peroxidase ◽

Co2 Assimilation ◽

Amino Acid Sequences ◽

Drought Tolerant ◽

C Terminus

Ascorbate peroxidase (APX) plays an important role in detoxifying reactive oxygen species under environmental stress. Although previous work in drought-tolerant wild watermelon has shown an increase in chloroplast APX enzyme activity under drought, molecular entities of APX have remained uncharacterized. In this study, structure and transcriptional regulation of the APX gene family in watermelon were characterized. Five APX genes, designated as CLAPX1 to CLAPX5, were identified from watermelon genome. The mRNA alternative splicing was suggested for CLAPX5, which generated two distinct deduced amino acid sequences at their C-terminus, in resemblance to a reported alternative splicing of chloroplast APXs in pumpkin. This observation suggests that two isoenzymes for stromal and thylakoid-bound APXs may be generated from the CLAPX5 gene. Phylogenetic analysis classified CLAPX isoenzymes into three clades, i.e., chloroplast, microbody, and cytosolic. Physiological analyses of wild watermelon under drought showed a decline in stomatal conductance and CO2 assimilation rate, and a significant increase in the enzyme activities of both chloroplast and cytosolic APXs. Profiles of mRNA abundance during drought were markedly different among CLAPX genes, suggesting distinct transcriptional regulation for the APX isoenzymes. Up-regulation of CLAPX5-I and CLAPX5-II was observed at the early phase of drought stress, which was temporally correlated with the observed increase in chloroplast APX enzyme activity, suggesting that transcriptional up-regulation of the CLAPX5 gene may contribute to the fortification of chloroplast APX activity under drought. Our study has provided an insight into the functional significance of the CLAPX gene family in the drought tolerance mechanism in this plant.

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Extraction, Storage Duration, and Storage Temperature Affect the Activity of Ascorbate Peroxidase, Glutathione Reductase, and Superoxide Dismutase in Rice Tissue

Biology ◽

10.3390/biology8040070 ◽

2019 ◽

Vol 8 (4) ◽

pp. 70

Author(s):

Julia Hartmann ◽

Folkard Asch

Keyword(s):

Superoxide Dismutase ◽

Enzyme Activity ◽

Glutathione Reductase ◽

Enzyme Kinetics ◽

Ascorbate Peroxidase ◽

Experimental Studies ◽

Experimental Plant ◽

Specific Storage ◽

Tissue Samples ◽

Storage Methods

In experimental plant science, research often faces large numbers of tissue samples resulting from sequential harvests of a larger number of genotypes and treatments combinations. Analyses of biological processes such as enzyme kinetics are often time-consuming or need specific sample preparation procedures before the actual measurements can be done. Time is thus often the critical factor and the possibility to store plant samples either as tissue or as extracts increases the available timeframe for analyses. Biological molecules such as enzymes often change their activities when stored and thus do not reflect the processes occurring in living tissue. We investigated the effect of different storage methods such as freeze-drying, freezing at −20 °C, and freezing at −80 °C on the activity of three enzymes known as antioxidants, namely ascorbate peroxidase, glutathione reductase, and superoxide dismutase from two rice varieties. Varieties differed in enzyme activity in extracts of fresh material from leaf blades, leaf sheaths, and roots. When subjected to different storage methods, there were no differences between varieties, but strong effects of the different storage methods on enzyme activities were found. The effects of the storage methods on enzyme activity strongly differed between extracts from stored tissue samples or extracts stored from freshly sampled material. We propose enzyme-specific storage methods and durations that allow for expanding the window for analyses in large experimental studies involving destructive samplings for enzyme kinetics.

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Improvement of Germination Characteristics and Enhancement of Antioxidant Enzymes Activity of Safflower (Carthamus tinctorius L.) Aged Seeds by Used of Gibberellin

Cercetari Agronomice in Moldova ◽

10.1515/cerce-2015-0039 ◽

2015 ◽

Vol 48 (3) ◽

pp. 33-41

Author(s):

M. Khajeh ◽

S.A. Tabatabaei ◽

O. Ansari ◽

F. Sharif Zadeh

Keyword(s):

Enzyme Activity ◽

Antioxidant Enzymes ◽

Ascorbate Peroxidase ◽

Seed Priming ◽

Germination Percentage ◽

Percentage Germination ◽

Vigor Index ◽

Seedling Length ◽

Germination Characteristics ◽

Normal Seedling

AbstractSeed priming is one of the methods that can be taken to counteract the adverse effects of abiotic stress, also Seed priming treatments have been used to reduce the damage of aging and invigorate their performance in many crops. Objective of this study was to evaluation the effect of gibberellin on germination characteristics and antioxidant enzymes of safflower seeds after aging. Experimental design was a factorial one with complete randomized design with three replications. The first factor was priming by gibberellin (0 and 50 ppm) and non-primed seeds (control) and the secondary factor was combinations of four levels of aging (0, 1, 3 and 5 days of aging, at 43°C). The results showed that the priming and aging effects on germination percentage, germination index, normal seedling percentage, seedling length, vigor index, catalase and ascorbate peroxidase were significant, but on mean time to germination not significant. Results showed that, the highest germination characteristics such as; germination percentage, germination index, normal seedling percentage, seedling length, vigor index, catalase and ascorbate peroxidase were attained from priming by gibberellins, under non aged conditions. Also, our results indicated that seed aging is related to decrease of enzymes activity and may contribute to low seed germination efficiency, also priming increases enzyme activity and increases enzyme activity with priming treatment may contribute to improve germination characteristics. The general decreases in enzyme activity in the seed lowers the respiratory capacity, which in turn lowers both the energy (ATP) and assimilates supply of the germinating seed.

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Characterization and expression analysis of ascorbate peroxidase from the moss Dicranum scoparium during abiotic stresses

The Bryologist ◽

10.1639/0007-2745-124.1.068 ◽

2021 ◽

Vol 124 (1) ◽

Author(s):

Alfred O. Onele ◽

Andrei V. Chasov ◽

Larisa V. Viktorova ◽

Farida V. Minibayeva ◽

Richard P. Beckett

Keyword(s):

Expression Analysis ◽

Ascorbate Peroxidase ◽

Abiotic Stresses ◽

Dicranum Scoparium

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Paphiopedilum insigne Morphological and Physiological Features during In Vitro Rooting and Ex Vitro Acclimatization Depending on the Types of Auxin and Substrate

Plants ◽

10.3390/plants10030582 ◽

2021 ◽

Vol 10 (3) ◽

pp. 582

Author(s):

Monika Poniewozik ◽

Marzena Parzymies ◽

Paweł Szot ◽

Katarzyna Rubinowska

Keyword(s):

Enzyme Activity ◽

Chlorophyll Fluorescence ◽

Water Balance ◽

Ascorbate Peroxidase ◽

Morphological Features ◽

In Vitro Rooting ◽

Sphagnum Moss ◽

In Vitro Cultivation ◽

Ex Vitro

To obtain healthy and good quality plants from in vitro cultivation, it is necessary to produce plantlets with well-developed rooting systems because they must undergo acclimatization, a final and a very difficult stage of micropropagation. In the present research, the effect of auxins NAA, IAA and IBA in concentrations of 0.5; 1; 2.5 and 5 mg·dm−3 on the Paphiopediluminsigne in vitro rooting was studied, and it was noted that 1 mg·dm−3 of IAA or IBA enabled the obtaining of a lot of rooted and good quality plantlets. The subsequent influence of the two most advantageous auxins on the acclimatization of plantlets in different substrates (sphagnum moss, sphagnum moss + substrate for orchids, substrate for orchids, substrate for orchids + acid peat) was tested, in the means of morphological features of plants and their physiological parameters, i.e., chlorophyll fluorescence (FV, Fm, Fv/Fm), stress enzyme activity (catalase, ascorbate peroxidase), and water balance. Considering all the tested features, it might be stated that the best results were obtained when explants were rooted in vitro in the presence of 1 mg·dm−3 of IAA and then planted ex vitro in substrate for orchids.

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Morphological and biochemical analyses of changes in rat hepatocytes related to wine and ethanol consumption

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100111276 ◽

1984 ◽

Vol 42 ◽

pp. 232-233

Author(s):

S.M. Geyer ◽

C.L. Mendenhall ◽

J.T. Hung ◽

E.L. Cardell ◽

R.L. Drake ◽

...

Keyword(s):

Electron Microscopy ◽

Endoplasmic Reticulum ◽

Enzyme Activity ◽

Malic Enzyme ◽

Smooth Endoplasmic Reticulum ◽

Rat Hepatocytes ◽

Mature Male ◽

Treatment Groups ◽

Malic Enzyme Activity ◽

Biochemical Analyses

Thirty-three mature male Holtzman rats were randomly placed in 3 treatment groups: Controls (C); Ethanolics (E); and Wine drinkers (W). The animals were fed synthetic diets (Lieber type) with ethanol or wine substituted isocalorically for carbohydrates in the diet of E and W groups, respectively. W received a volume of wine which provided the same gram quantity of alcohol consumed by E. The animals were sacrificed by decapitation after 6 weeks and the livers processed for quantitative triglycerides (T3), proteins, malic enzyme activity (MEA), light microscopy (LM) and electron microscopy (EM). Morphometric analysis of randomly selected LM and EM micrographs was performed to determine organellar changes in centrilobular (CV) and periportal (PV) regions of the liver. This analysis (Table 1) showed that hepatocytes from E were larger than those in C and W groups. Smooth endoplasmic reticulum decreased in E and increased in W compared to C values.

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