Cytokinin-induced changes in the chlorophyll content and fluorescence of in vitro apple leaves

2014 ◽  
Vol 171 (16) ◽  
pp. 1472-1478 ◽  
Author(s):  
Judit Dobránszki ◽  
Nóra Mendler-Drienyovszki
Keyword(s):  
Chlorophyll Content ◽  
Chlorophyll Content And Fluorescence ◽  
Apple Leaves ◽  
Induced Changes

Systemic Effects of ADP-induced Platelet Aggregation and Their Modification by Aspirin and by Pyridinolcarbamate

1973 ◽  
Vol 30 (01) ◽  
pp. 178-190 ◽  
Author(s):  
Itsuro Kobayashi ◽  
Paul Didisheim
Keyword(s):  
Platelet Aggregation ◽  
Venous Pressure ◽  
Systemic Effects ◽  
Central Venous ◽  
Platelet Aggregates ◽  
Induced Changes ◽  
Second Wave ◽  
Carotid Arterial ◽  
Arterial Po2

SummaryADP, AMP, or ATP was injected rapidly intravenously in rats. ADP injection resulted in the f olio wing transient changes: a drop in platelet count, a rise in central venous pressure, a fall in carotid arterial PO2, bradycardia, arrhythmia, flutter-fibrillation, and arterial hypotension. AMP and ATP produced some of these same effects; but except for hypotension, their frequency and severity Avere much less than those following ADP.Prior intravenous administration of acetylsalicylic acid or pyridinolcarbamate, two inhibitors of the second wave of ADP-induced platelet aggregation in vitro, significantly reduced the frequency and severity of all the above ADP-induced changes except hypotension. These observations suggest that many of the changes (except hypotension) observed to follow ADP injection are produced by platelet aggregates which lodge transiently in various microcirculatory beds then rapidly disaggregate and recirculate.

scholarly journals Potassium Application Positively Modulates Physiological Responses of Cocoa Seedlings to Drought Stress

Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 563
Author(s):  
Esther Anokye ◽  
Samuel T. Lowor ◽  
Jerome A. Dogbatse ◽  
Francis K. Padi
Keyword(s):  
Water Stress ◽  
Soil Water ◽  
Chlorophyll Content ◽  
Electrolyte Leakage ◽  
Seedling Survival ◽  
Biomass Accumulation ◽  
Biomass Partitioning ◽  
Chlorophyll Content And Fluorescence ◽  
Physiological Functions ◽  
Soil Water Stress

With increasing frequency and intensity of dry spells in the cocoa production zones of West Africa, strategies for mitigating impact of water stress on cocoa seedling survival are urgently required. We investigated the effects of applied potassium on biomass accumulation, physiological processes and survival of cocoa varieties subjected to water stress in pot experiments in a gauzehouse facility. Four levels of potassium (0, 1, 2, or 3 g/plant as muriate of potash) were used. Soil water stress reduced plant biomass accumulation (shoot and roots), relative water content (RWC), chlorophyll content and fluorescence. Leaf phenol and proline contents were increased under water stress. Additionally, compared to the well-watered conditions, soils under water stress treatments had higher contents of exchangeable potassium and available phosphorus at the end of the experimental period. Potassium applied under well-watered conditions reduced leaf chlorophyll content and fluorescence and increased leaf electrolyte leakage, but improved the growth and integrity of physiological functions under soil water stress. Potassium addition increased biomass partitioning to roots, improved RWC and leaf membrane stability, and significantly improved cocoa seedling survival under water stress. Under water stress, the variety with the highest seedling mortality accumulated the highest contents of phenol and proline. A significant effect of variety on plant physiological functions was observed. Generally, varieties with PA 7 parentage had higher biomass partitioning to roots and better seedling survival under soil moisture stress. Proportion of biomass partitioned to roots, RWC, chlorophyll fluorescence and leaf electrolyte leakage appear to be the most reliable indicators of cocoa seedling tolerance to drought.

scholarly journals Insulin induces rapid and specific rearrangement of the cytoskeleton of rat mesangial cells in vitro.

1996 ◽  
Vol 44 (2) ◽  
pp. 91-101 ◽  
Author(s):  
A K Berfield ◽  
G J Raugi ◽  
C K Abrass
Keyword(s):  
Mesangial Cells ◽  
Focal Adhesions ◽  
Cytoskeletal Proteins ◽  
Direct Effects ◽  
Ligand Effects ◽  
Igf I ◽  
Induced Changes ◽  
Secondary Ligand

Mesangial cells (MCs) grown without supplemental insulin (SI-MCs) express a quiescent phenotype and extracellular matrix (ECM) composition similar to MCs in vivo. In contrast, MCs routinely propagated in insulin (SI+MCs) are stimulated to proliferate, change their phenotype, and produce large amounts of collagens I and III. These effects of insulin may in part be mediated through cytoskeletal rearrangement. Differences in cytoskeletal arrangement were compared between SI-MCs and SI+MCs and 1 hr after addition of insulin (1 nM) or IGF-1 (100 nM) to SI-MCs. Cells were examined by light microscopy, electron microscopy, and immunostaining for specific cytoskeletal proteins and fibronectin. Insulin induced rapid rearrangement of stress fibers. Surface ruffling, actin aggregation, vimentin retraction, rearrangement of vinculin in focal adhesions, and fibronectin extraction were apparent. These direct effects of insulin on the SI-MC cytoskeleton occurred before insulin-induced changes in ECM composition. IGF-I induced cytoskeletal reorganization distinct from insulin. These observations demonstrate that insulin and IGF-I have unique effects on the MC cytoskeleton, which is turn may mediate secondary ligand effects on MCs.

scholarly journals Activation of two distinct Sox9-EGFP-expressing intestinal stem cell populations during crypt regeneration after irradiation

2012 ◽  
Vol 302 (10) ◽  
pp. G1111-G1132 ◽  
Author(s):  
Laurianne Van Landeghem ◽  
M. Agostina Santoro ◽  
Adrienne E. Krebs ◽  
Amanda T. Mah ◽  
Jeffrey J. Dehmer ◽  
...  
Keyword(s):  
Stem Cell ◽  
Cell Populations ◽  
Intestinal Epithelial ◽  
P53 Signaling ◽  
Reporter Mice ◽  
Radiation Induced ◽  
Molecular Phenotypes ◽  
Stem Cell Populations ◽  
Induced Changes

Recent identification of intestinal epithelial stem cell (ISC) markers and development of ISC reporter mice permit visualization and isolation of regenerating ISCs after radiation to define their functional and molecular phenotypes. Previous studies in uninjured intestine of Sox9-EGFP reporter mice demonstrate that ISCs express low levels of Sox9-EGFP (Sox9-EGFP Low), whereas enteroendocrine cells (EEC) express high levels of Sox9-EGFP (Sox9-EGFP High). We hypothesized that Sox9-EGFP Low ISCs would expand after radiation, exhibit enhanced proliferative capacities, and adopt a distinct gene expression profile associated with rapid proliferation. Sox9-EGFP mice were given 14 Gy abdominal radiation and studied between days 3 and 9 postradiation. Radiation-induced changes in number, growth, and transcriptome of the different Sox9-EGFP cell populations were determined by histology, flow cytometry, in vitro culture assays, and microarray. Microarray confirmed that nonirradiated Sox9-EGFP Low cells are enriched for Lgr5 mRNA and mRNAs enriched in Lgr5-ISCs and identified additional putative ISC markers. Sox9-EGFP High cells were enriched for EEC markers, as well as Bmi1 and Hopx, which are putative markers of quiescent ISCs. Irradiation caused complete crypt loss, followed by expansion and hyperproliferation of Sox9-EGFP Low cells. From nonirradiated intestine, only Sox9-EGFP Low cells exhibited ISC characteristics of forming organoids in culture, whereas during regeneration both Sox9-EGFP Low and High cells formed organoids. Microarray demonstrated that regenerating Sox9-EGFP High cells exhibited transcriptomic changes linked to p53-signaling and ISC-like functions including DNA repair and reduced oxidative metabolism. These findings support a model in which Sox9-EGFP Low cells represent active ISCs, Sox9-EGFP High cells contain radiation-activatable cells with ISC characteristics, and both participate in crypt regeneration.

scholarly journals The Salt-Stress Response of the Transgenic Plum Line J8-1 and Its Interaction with the Salicylic Acid Biosynthetic Pathway from Mandelonitrile

2018 ◽  
Vol 19 (11) ◽  
pp. 3519 ◽  
Author(s):  
Agustina Bernal-Vicente ◽  
Daniel Cantabella ◽  
Cesar Petri ◽  
José Hernández ◽  
Pedro Diaz-Vivancos
Keyword(s):  
Salicylic Acid ◽  
Salt Stress ◽  
Biosynthetic Pathway ◽  
In Vitro Assays ◽  
Photochemical Quenching ◽  
Plant Responses ◽  
Enzymatic Antioxidants ◽  
Chlorophyll Content And Fluorescence ◽  
Salt Stress Response

Salinity is considered as one of the most important abiotic challenges that affect crop productivity. Plant hormones, including salicylic acid (SA), are key factors in the defence signalling output triggered during plant responses against environmental stresses. We have previously reported in peach a new SA biosynthetic pathway from mandelonitrile (MD), the molecule at the hub of the cyanogenic glucoside turnover in Prunus sp. In this work, we have studied whether this new SA biosynthetic pathway is also present in plum and the possible role this pathway plays in plant plasticity under salinity, focusing on the transgenic plum line J8-1, which displays stress tolerance via an enhanced antioxidant capacity. The SA biosynthesis from MD in non-transgenic and J8-1 micropropagated plum shoots was studied by metabolomics. Then the response of J8-1 to salt stress in presence of MD or Phe (MD precursor) was assayed by measuring: chlorophyll content and fluorescence parameters, stress related hormones, levels of non-enzymatic antioxidants, the expression of two genes coding redox-related proteins, and the content of soluble nutrients. The results from in vitro assays suggest that the SA synthesis from the MD pathway demonstrated in peach is not clearly present in plum, at least under the tested conditions. Nevertheless, in J8-1 NaCl-stressed seedlings, an increase in SA was recorded as a result of the MD treatment, suggesting that MD could be involved in the SA biosynthesis under NaCl stress conditions in plum plants. We have also shown that the plum line J8-1 was tolerant to NaCl under greenhouse conditions, and this response was quite similar in MD-treated plants. Nevertheless, the MD treatment produced an increase in SA, jasmonic acid (JA) and reduced ascorbate (ASC) contents, as well as in the coefficient of non-photochemical quenching (qN) and the gene expression of Non-Expressor of Pathogenesis-Related 1 (NPR1) and thioredoxin H (TrxH) under salinity conditions. This response suggested a crosstalk between different signalling pathways (NPR1/Trx and SA/JA) leading to salinity tolerance in the transgenic plum line J8-1.

scholarly journals Exercise-induced changes in β-adrenergic-receptor mRNA level measured by competitive RT-PCR

1997 ◽  
Vol 82 (6) ◽  
pp. 1926-1931 ◽  
Author(s):  
Nobuharu Fujii ◽  
Takeshi Shibata ◽  
Sachiko Homma ◽  
Haruo Ikegami ◽  
Kazuo Murakami ◽  
...  
Keyword(s):  
Adrenergic Receptor ◽  
Human Lymphocytes ◽  
Mrna Level ◽  
Mrna Levels ◽  
Rt Pcr ◽  
Receptor Mrna ◽  
Exercise Induced ◽  
Induced Changes ◽  
Receptor Mrna Level

Fujii, Nobuharu, Takeshi Shibata, Sachiko Homma, Haruo Ikegami, Kazuo Murakami, and Hitoshi Miyazaki. Exercise-induced changes in β-adrenergic-receptor mRNA level measured by competitive RT-PCR. J. Appl. Physiol. 82(6): 1926–1931, 1997.—Competitive reverse transcription-polymerase chain reaction (RT-PCR) analysis was used to clarify whether dynamic exercise-induced increases in β-adrenergic-receptor (β-AR) number in human lymphocytes are accompanied by increases in the β-AR mRNA level. Sixteen healthy subjects performed cycle ergometry until exhaustion. Before and immediately after exercise, peripheral blood was drawn from a forearm vein for preparation of lymphocytes. Both the β-AR mRNA level and the β-AR number were significantly increased by exercise. The changes in β-AR mRNA level and β-AR number were significantly correlated ( r = 0.63, P < 0.01). This finding suggests that a rapid increase in β-AR mRNA level might be an early adaptive response of the sympathetic nervous system to dynamic exercise. In vitro incubation of lymphocytes with epinephrine had no effect on β-AR mRNA levels, nor did adenosine 3′,5′-cyclic monophosphate, protein kinase C, or intracellular Ca2+ increase the β-AR mRNA level in vitro. Therefore, it appears that other mechanisms underlie the exercise-induced elevation of β-AR mRNA levels in human lymphocytes.

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