Changes in Peroxidase in Isolated Aleurone Layers in Response to Gibberellic Acid

1983 ◽  
Vol 10 (1) ◽  
pp. 87 ◽  
Author(s):  
F Gubler ◽  
AE Ashford
Keyword(s):  
Gibberellic Acid ◽  
Peroxidase Activity ◽  
Time Course ◽  
Disc Electrophoresis ◽  
Peroxidase Isoenzymes ◽  
Total Peroxidase Activity ◽  
High Level

The effect of gibberellic acid (GA3) on peroxidase activity and isoenzyme complement was followed in isolated aleurone layers of barley (Hordeurn vulgare L.) over a 48-h period. A high level of peroxidase activity was initially present in freshly isolated aleurone layers. Disc electrophoresis resolved nine peroxidase isoenzymes. By 36 h incubation, total peroxidase activity had doubled in response to GA3 and two new peroxidase isoenzymes were observed. Peroxidase release from isolated aleurone layers was also greatly stimulated by GA3 and more isoenzymes were found in the medium. The time course of release was similar to that for α-amylase. Peroxidase activity in endosperm of whole germinating grains began to increase after 2 days, peaked at 4 days and subsequently declined.

A basic peroxidase isoenzyme from the grape pedicel is induced by gibberellic acid

1999 ◽  
Vol 26 (4) ◽  
pp. 387 ◽  
Author(s):  
Francisco J. Pérez ◽  
Verónica Morales
Keyword(s):  
Ascorbic Acid ◽  
Gibberellic Acid ◽  
Peroxidase Activity ◽  
Hormone Treatment ◽  
Table Grape ◽  
Guaiacol Peroxidase ◽  
Peroxidase Isoenzymes ◽  
Peroxidase Isoenzyme ◽  
Soluble Peroxidase

Soluble peroxidase activity from pedicels of seedless table grape cv. Sultana was highly stimulated by post-bloom applications of gibberellic acid (GA3) to vines. The increase in peroxidase activity was mainly due to the induction of a basic peroxidase isoenzyme (pI > 9; BPrx-HpI). The activity of two other peroxidase isoenzymes of pI 6.5 and 3.2 was not altered by the hormone treatment. BPrx-HpI was induced by GA3 in pedicels and rachis but not in berries, although in berries peroxidase activity was also stimulated by post-bloom GA3 applications. BPrx-HpI oxidised guaiacol and ortho-phenylenediamine (o-PDA), while the others peroxidases found in the pedicel and in the berry oxidised only o-PDA. Hence, BPrx-HpI was characterised as a guaiacol-peroxidase showing no activity towards ascorbic acid (ASC). The possible role of BPrx-HpI in pedicel lignification and berry-drop caused by GA3 applications to cv. Sultana vines is discussed.

Effects of Photoperiod on Growth and Peroxidase in Three Hybrid Poplars

1975 ◽  
Vol 5 (4) ◽  
pp. 735-738 ◽  
Author(s):  
Paul H. Wray ◽  
John C. Gordon
Keyword(s):  
Peroxidase Activity ◽  
Dry Weight ◽  
Height Growth ◽  
Peroxidase Isoenzymes ◽  
Hybrid Poplars ◽  
Total Peroxidase Activity ◽  
Growth Chambers

Three Populus hybrids (Tristis No. 1, Crandon, and Wisconsin No. 5) were grown for 5 weeks under 12- or 18- photoperiods in growth chambers. At four times during growth, dry weight and total peroxidase activity and isoenzyme expression were determined. The 12-h photoperiod resulted in less dry weight accumulation and height growth in all clones. Total peroxidase activity in the first mature internode was related to growth in the Crandon clone, whereas changes in the activity of specific anodic peroxidase isoenzymes were related to growth in the Tristis No. 1 and Wisconsin No. 5 clones.

scholarly journals Complete heart block in cardiac sarcoidosis reversed by corticosteroid therapy: time course of resolution

2021 ◽  
Vol 14 (3) ◽  
pp. e240834
Author(s):  
Anna Tomdio ◽  
Huzaefah Syed ◽  
Kenneth Ellenbogen ◽  
Jordana Kron
Keyword(s):  
Heart Block ◽  
Time Course ◽  
Cardiac Sarcoidosis ◽  
Complete Heart Block ◽  
Positron Emission ◽  
Av Conduction ◽  
Magnetic Resonance Imaging Mri ◽  
High Level ◽  
Active Inflammation ◽  
Lateral Walls

A 53-year-old man was admitted for recurrent syncope and found to have complete heart block (CHB). Cardiac magnetic resonance imaging MRI) showed extensive patchy late gadolinium enhancement in the apical and lateral walls, consistent with cardiac sarcoidosis (CS) but no scar in the septum. A fluorodeoxyglucose (FDG)–positron emission tomography showed FDG uptake in the septum and basal lateral walls. Imaging suggested active inflammation in the septum affecting atrioventricular (AV) conduction but no irreversible fibrosis. Diagnosis of isolated CS requires a high level of suspicion and multidisciplinary teamwork involving heart failure specialists, electrophysiologists and rheumatologists. After specialist and patient discussion, treatment of the disease was initiated with prednisone 40 mg daily, 11 months after presenting with CHB. Three weeks later, ECG with pacing inhibited showed second-degree AV block Mobitz type II and 4 weeks later, AV conduction recovery. This highlights the importance of immediate therapy in reversing AV conduction abnormalities in CS.

scholarly journals The Rapid Extraction of Gist—Early Neural Correlates of High-level Visual Processing

2012 ◽  
Vol 24 (2) ◽  
pp. 521-529 ◽  
Author(s):  
Frank Oppermann ◽  
Uwe Hassler ◽  
Jörg D. Jescheniak ◽  
Thomas Gruber
Keyword(s):  
Visual Processing ◽  
Time Course ◽  
Occipital Cortex ◽  
Stimulus Onset ◽  
Gamma Band ◽  
Oscillatory Activity ◽  
Rapid Extraction ◽  
The Right ◽  
High Level ◽  
Individual Objects

The human cognitive system is highly efficient in extracting information from our visual environment. This efficiency is based on acquired knowledge that guides our attention toward relevant events and promotes the recognition of individual objects as they appear in visual scenes. The experience-based representation of such knowledge contains not only information about the individual objects but also about relations between them, such as the typical context in which individual objects co-occur. The present EEG study aimed at exploring the availability of such relational knowledge in the time course of visual scene processing, using oscillatory evoked gamma-band responses as a neural correlate for a currently activated cortical stimulus representation. Participants decided whether two simultaneously presented objects were conceptually coherent (e.g., mouse–cheese) or not (e.g., crown–mushroom). We obtained increased evoked gamma-band responses for coherent scenes compared with incoherent scenes beginning as early as 70 msec after stimulus onset within a distributed cortical network, including the right temporal, the right frontal, and the bilateral occipital cortex. This finding provides empirical evidence for the functional importance of evoked oscillatory activity in high-level vision beyond the visual cortex and, thus, gives new insights into the functional relevance of neuronal interactions. It also indicates the very early availability of experience-based knowledge that might be regarded as a fundamental mechanism for the rapid extraction of the gist of a scene.

scholarly journals A Method for Prediction of Graft Incompatibility in Sweet Cherry

2012 ◽  
Vol 40 (1) ◽  
pp. 243 ◽  
Author(s):  
S. Filiz GUCLU ◽  
Fatma KOYUNCU
Keyword(s):  
Peroxidase Activity ◽  
Sweet Cherry ◽  
Prunus Avium ◽  
Ground Tissue ◽  
Tissue Samples ◽  
Total Peroxidase Activity ◽  
Graft Incompatibility ◽  
Old Trees

This study was carried out on 1-year old trees of ‘0900 Ziraat’ variety grafted onto ‘Kuş kirazi’, ‘Kara idris’, ‘Sari idris’, ‘MaxMa 14’, ‘MaxMa 60’ and ‘Gisela 5’ in order to determine their compatibility. For this purpose, total peroxidase activity was determined by spectrophotomery assay. Taking ground tissue samples were planned three times as before the grafting (beginning), and then 8 and 12 months after grafting. Total peroxidase activities of rootstocks before grafting varied between 10.80 ΔAg.min. (‘Kuş kirazi’) and 7.83 ΔAg.min. (‘Kara idris’) and were found to be statistically important. The peroxidase activity of ‘0900 Ziraat’ was 11.07ΔAg.min. and the closest value occurred in Prunus avium rootstock. The most different values occurred in rootstocks of ‘Kara idris’ and ‘Gisela 5’. The results showed that peroxidase activity increased in rootstock and graft scion. This increase had higher values in heterogenetic combinations especially in ‘0900 Ziraat’/‘Gisela 5’ and ‘0900 Ziraat’/‘Kara idris’ grafts. Peroxidase activity was decreased at the 12th month for all combinations. The highest value was obtained from ‘0900 Ziraat’/‘MaxMa 14’ combinaion with 29.17 ΔAg.min. while lowest one was ‘0900 Ziraat’/‘Kuş kirazi’ with 17.39. The findings showed that peroxidase activity could be used as a parameter in early determination of graft incompatibility.

Monosomic analysis of leaf peroxidase Px0 and Px9 loci in hexaploid oats

Genome ◽  
1988 ◽  
Vol 30 (2) ◽  
pp. 99-102 ◽  
Author(s):  
Toshinobu Morikawa
Keyword(s):  
Enzymatic Activity ◽  
Peroxidase Activity ◽  
Avena Sativa ◽  
Leaf Blade ◽  
Flag Leaf ◽  
Phenotypic Expression ◽  
Avena Fatua ◽  
Monosomic Analysis ◽  
Peroxidase Isoenzymes

Inheritance of the peroxidase isoenzymes of the flag leaf blade was examined by isoelectrofocusing in the hexaploid oats Avena byzantina cv. Kanota, Avena fatua ssp. compacta, and Avena sativa cv. Cherokee. Two independent peroxidase loci (Px0 and Px9) were detected in the F2 from the 'Kanota' × compacta cross. The Px0a derived from compacta expressed the highest peroxidase activity and was accompanied by a post-transcriptionally modified form or mozyme. A monosomic analysis of the Px0 and Px9 loci revealed that they were located on chromosomes 18 and 6, respectively. Phenotypic expression of the peroxidases varied in each genotye at the Px0 and Px9 loci. Phenotypes of the homozygote (Px0aPx0a) and the hemizygote (Px0a—) were similar to each other. The heterozygote (Px0aPx0b) had half the enzymatic activity of the others. Px9b of compacta was functional as a suppressor but that of 'Cherokee' was nonfunctional.Key words: monosomic analysis, peroxidase loci, isoenzyme, hexaploid oats.

Ca2+ signals mediated by Ins(1,4,5)P3-gated channels in rat ureteric myocytes

2000 ◽  
Vol 349 (1) ◽  
pp. 323-332 ◽  
Author(s):  
François-Xavier BOITTIN ◽  
Frédéric COUSSIN ◽  
Jean-Luc MOREL ◽  
Guillaume HALET ◽  
Nathalie MACREZ ◽  
...  
Keyword(s):  
Ryanodine Receptor ◽  
Time Course ◽  
Binding Capacity ◽  
Ryanodine Receptors ◽  
Initiation Site ◽  
Variable Number ◽  
Spatial Spread ◽  
Receptor Antibody ◽  
Low Concentrations ◽  
High Level

Localized Ca2+-release signals (puffs) and propagated Ca2+ waves were characterized in rat ureteric myocytes by confocal microscopy. Ca2+ puffs were evoked by photorelease of low concentrations of Ins(1,4,5)P3 from a caged precursor and by low concentrations of acetylcholine; they were also observed spontaneously in Ca2+-overloaded myocytes. Ca2+ puffs showed some variability in amplitude, time course and spatial spread, suggesting that Ins(1,4,5)P3-gated channels exist in clusters containing variable numbers of channels and that within these clusters a variable number of channels can be recruited. Immunodetection of Ins(1,4,5)P3 receptors revealed the existence of several spots of fluorescence in the confocal cell sections, supporting the existence of clusters of Ins(1,4,5)P3 receptors. Strong Ins(1,4,5)P3 photorelease and high concentrations of acetylcholine induced Ca2+ waves that originated from an initiation site and propagated in the whole cell by spatial recruitment of neighbouring Ca2+-release sites. Both Ca2+ puffs and Ca2+ waves were blocked selectively by intracellular applications of heparin and an anti-Ins(1,4,5)P3-receptor antibody, but were unaffected by ryanodine and intracellular application of an anti-ryanodine receptor antibody. mRNAs encoding for the three subtypes of Ins(1,4,5)P3 receptor and subtype 3 of ryanodine receptor were detected in these myocytes, and the maximal binding capacity of [3H]Ins(1,4,5)P3 was 10- to 12-fold higher than that of [3H]ryanodine. These results suggest that Ins(1,4,5)P3-gated channels mediate a continuum of Ca2+ signalling in smooth-muscle cells expressing a high level of Ins(1,4,5)P3 receptors and no subtypes 1 and 2 of ryanodine receptors.

Measurement of regional gastroduodenal blood flow with iodo [14C]antipyrine autoradiography

1985 ◽  
Vol 248 (5) ◽  
pp. G539-G544 ◽  
Author(s):  
D. Hudson ◽  
O. U. Scremin ◽  
P. H. Guth
Keyword(s):  
Blood Flow ◽  
Time Course ◽  
Regional Blood Flow ◽  
Pictorial Representation ◽  
Frozen Sections ◽  
Operational Equation ◽  
Short Period ◽  
Quick Freezing ◽  
High Level ◽  
Blood Radioactivity

Regional blood flow was measured in the gastroduodenal area by means of iodo[14C]antipyrine autoradiography. The tracer was given intravenously over a short period of time in awake rats followed by cardiac arrest and quick freezing of stomach and duodenum. Dry autoradiography of frozen sections provide a pictorial representation of radioactivity in the different tissue layers. This could be converted to blood flow after incorporation of the time course of blood radioactivity into an operational equation. A high level of resolution was achieved, allowing delineation of blood flow compartments of small dimensions such as single villi and regions within the fundic mucosa. The value of blood flow recorded in resting conditions were in agreement with previous observations with the microspheres technique. Hypotension induced a generalized decrease in blood flow, most marked in the corpus mucosa.

Gibberellic acid and norflurazon affecting the time-course of flavedo pigment and abscisic acid content in ‘Valencia’ sweet orange

2014 ◽  
Vol 180 ◽  
pp. 94-101 ◽  
Author(s):  
Giuliana Gambetta ◽  
Carlos Mesejo ◽  
Amparo Martínez-Fuentes ◽  
Carmina Reig ◽  
Alfredo Gravina ◽  
...  
Keyword(s):  
Abscisic Acid ◽  
Gibberellic Acid ◽  
Acid Content ◽  
Time Course ◽  
Sweet Orange ◽  
Abscisic Acid Content
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