scholarly journals Re-induction of desiccation tolerance after germination of Cedrela fissilis Vell. seeds

2014 ◽  
Vol 86 (3) ◽  
pp. 1273-1286 ◽  
Author(s):  
TATHIANA E. MASETTO ◽  
JOSE M. FARIA ◽  
ANA C.R. FRAIZ
Keyword(s):  
Polyethylene Glycol ◽  
Moisture Content ◽  
Cell Viability ◽  
Desiccation Tolerance ◽  
Dna Integrity ◽  
Electronic Microscopy ◽  
Percentage Points ◽  
Cell Changes ◽  
Peg 8000 ◽  
Germinated Seeds

This work aimed to characterize the re-induction of desiccation tolerance (DT) in germinated seeds, using polyethylene glycol (PEG 8000). Cell changes were investigated through cytological assays (cell viability and transmission electronic microscopy) as well as DNA integrity during loss and re-establishment of DT. The loss of DT was characterized by drying germinated seeds with different radicle lengths (1, 2, 3, 4 and 5 mm) in silica gel, decreasing the moisture content to ten percentage points intervals, followed by pre-humidification (100% RH / 24 h) and rehydration. To re-induce DT, germinated seeds were treated for 72 h with PEG (-2.04 MPa) and PEG (-2.04 MPa) + ABA (100 µM) before dehydration. Germinated seeds did not tolerate desiccation to 10% moisture content, irrespectively of the radicle length. However, when incubated in PEG, those with 1 and 2 mm long radicle attained 71% and 29% survival, respectively. The PEG+ABA treatment was efficient to re-establish DT in seeds with 1 mm long radicles (100% survival). The ultrastructural assays of the cells of germinated seeds with 2 and 5 mm length confirmed the obtained physiological results. Germinated seeds of C. fissilis constitute a useful tool for desiccation tolerance investigations.

scholarly journals In situ DNA fragmentation during the re-establishment of desiccation tolerance in germinated seeds of Cedrela fissilis Vell.

2019 ◽  
Vol 41 (2) ◽  
pp. 244-249
Author(s):  
Tathiana Elisa Masetto ◽  
José Marcio Rocha Faria
Keyword(s):  
Cell Death ◽  
Moisture Content ◽  
Dna Fragmentation ◽  
Desiccation Tolerance ◽  
Cell Injury ◽  
Tunel Staining ◽  
Long Term Storage ◽  
Germinated Seeds

Abstract: Dehydration is a necessary procedure prior to exposing seeds to long term storage, but this is associated with metabolism-linked injury mediated by cell injury. In order to assess cellular alterations during re-establishment of desiccation tolerance (DT) in C. fissilis germinated seeds and their relation to DNA damage, we verified the occurrence of DNA fragmentation through the TUNEL test and its evidence through the cytological analyses. To re-establish DT, germinated seeds were incubated for 72 h in polyethylene glycol (PEG, -2.04 MPa) before dehydration in silica gel (at 10% moisture content) followed by rehydration. The moisture content changes during the reestablishment of the desiccation tolerance was accomplished. (DT)TdT-dUPT terminal nick-end labeling (TUNEL) was used to assess rates of cell death. TUNEL staining was performed using Click-iT-TUNEL Alexa Flour imaging assay. The TUNEL test showed a consistent DNA fragmentation in the 2 and 5 mm long radicles. Moreover, nuclear and chromosomal alterations were observed in the 5 mm meristematic root cell cycle, contributing to the identification of diagnostic markers of cell death.

The re-establishment of desiccation tolerance in germinated radicles of Medicago truncatula Gaertn. seeds

2003 ◽  
Vol 13 (4) ◽  
pp. 273-286 ◽  
Author(s):  
Julia Buitink ◽  
Benoit Ly Vu ◽  
Pascale Satour ◽  
Olivier Leprince
Keyword(s):  
Gene Expression ◽  
Polyethylene Glycol ◽  
Medicago Truncatula ◽  
Desiccation Tolerance ◽  
Cold Treatment ◽  
Induced Expression ◽  
Peg Treatment ◽  
Osmotic Treatment ◽  
Dehydrin Gene ◽  
Germinated Seeds

Germinated seeds of Medicago truncatula Gaertn. with a protruded radicle length of 2.7 mm did not survive drying below 0.2 g H2O g–1 dw, as indicated by vital stain assays and the absence of growth resumption after rehydration. The re-establishment of desiccation tolerance was achieved using an osmotic treatment with polyethylene glycol (PEG), combined with a cold treatment. The ability to regain desiccation tolerance after germination was restricted to a period of growth characterized by radicle lengths between 1 and 3 mm. After PEG treatment of germinated seeds with 2.7 mm long radicles at –1.7 MPa at 10°C for 3 d and subsequent drying to 0.04 g H2O g–1 dw, 90% survived and developed into normal seedlings after rehydration. Desiccation tolerance could also be re-established in excised radicles, demonstrating that cotyledons were not essential for this process. Upon PEG incubation, sucrose accumulated rapidly prior to the re-establishment of desiccation tolerance in germinated radicles, regardless of the presence of cotyledons. Induction of MtDHN (a dehydrin) gene expression was correlated with the re-establishment of desiccation tolerance. Furthermore, the PEG-induced expression of MtDHN was repressed when fluridone was added to the PEG solution.

scholarly journals ULTRASTRUCTURAL CHANGES AND INTEGRITY OF GENOMIC DNA IN GERMINATED SEEDS OF Peltophorum dubium (Spreng.) TAUBERT SUBJECTED TO DRYING1

2018 ◽  
Vol 41 (4) ◽  
Author(s):  
Cristiane Carvalho Guimarães ◽  
Julio Maia Oliveira ◽  
José Marcio Rocha Faria ◽  
Edvaldo Aparecido Amaral da Silva
Keyword(s):  
Moisture Content ◽  
Genomic Dna ◽  
Primary Root ◽  
Cell Ultrastructure ◽  
Ultrastructural Changes ◽  
Dna Integrity ◽  
Root Cells ◽  
Points Of Interest ◽  
Primary Roots ◽  
Germinated Seeds

ABSTRACT The aim of this study was to evaluate DNA integrity and to identify ultrastructural changes in the primary root of Peltophorum dubium seeds subjected to drying, since these changes may reflect the germination capacity. Seeds were germinated and were dehydrated when reached 1 mm in length of the primary root, until reaching different moisture contents, being then rehydrated and evaluated in relation to survival. After this procedure, different points of interest (control, 20% and 10% moisture content) were selected to evaluate DNA and cell ultrastructure integrity in order to detect possible cellular changes in primary roots after dehydration. When dried down to 32% moisture, there was no influence on the growth resumption of the germinated seeds, but when they were dehydrated to 20% moisture, the survival was reduced to 67%, reaching nullity in the survival with drying to 8% moisture. By the evaluation of ultrastructural changes in root cells, it was observed that drying to approximately 20% moisture content marked the onset of damages by desiccation, both physiologically and ultrastructurally. Drying to levels close to 10% moisture content was not only responsible for total disorganization and rupture of membranes, but also promoted intracellular collapse. Loss of genomic DNA integrity was observed during drying.

scholarly journals Cell changes during the re-induction of desiccation tolerance in germinated seeds of Sesbania virgata (Cav.) Pers.

2016 ◽  
Vol 38 (3) ◽  
pp. 254-258 ◽  
Author(s):  
Tathiana Elisa Masetto ◽  
Ana Carla Resende Fraiz ◽  
José Márcio Rocha Faria
Keyword(s):  
Desiccation Tolerance ◽  
Dna Degradation ◽  
Recalcitrant Seeds ◽  
Cell Nuclei ◽  
Green Fluorescence ◽  
Transmission Electron ◽  
Sesbania Virgata ◽  
Orthodox Seeds ◽  
Cell Changes ◽  
Germinated Seeds

Abstract During germination, orthodox seeds lose their ability to tolerate desiccation resembling recalcitrant seeds. This research aimed to investigate the cell changes during the re-induction of the desiccation tolerance (DT) in Sesbania virgata germinated seeds with 1, 3 and 5 mm long radicles. To re-establish DT, germinated seeds were incubated for 72 h in polyethylene glycol (PEG, -2.04 MPa) before dehydration in silica gel (at 10% moisture content) followed by rehydration. Cell viability was assessed through TUNEL test in dry radicles and transmission electron microscopy in both fresh and dry radicles. The positive-TUNEL confirmed the DNA degradation, through the green fluorescence of the cell nuclei from 5 mm radicle length and the ultra structural evaluations detected loss of cellular content integrity in 3 and 5 mm cell radicles that did not survive dehydration to 10%.

Seed development in Malva parviflora: onset of germinability, dormancy and desiccation tolerance

2007 ◽  
Vol 47 (6) ◽  
pp. 683 ◽  
Author(s):  
Pippa J. Michael ◽  
Kathryn J. Steadman ◽  
Julie A. Plummer
Keyword(s):  
Moisture Content ◽  
Seed Development ◽  
Desiccation Tolerance ◽  
Dry Weight ◽  
Physical Dormancy ◽  
Seed Moisture Content ◽  
Physiological Maturity ◽  
Seed Moisture ◽  
Physiological Dormancy ◽  
Malva Parviflora

Seed development was examined in Malva parviflora. The first flower opened 51 days after germination; flowers were tagged on the day that they opened and monitored for 33 days. Seeds were collected at 12 stages during this period and used to determine moisture content, germination of fresh seeds and desiccation tolerance (seeds dried to 10% moisture content followed by germination testing). Seed moisture content decreased as seeds developed, whereas fresh (max. 296 mg) and dry weight (max. 212 mg) increased to peak at 12–15 and ~21 days after flowering (DAF), respectively. Therefore, physiological maturity occurred at 21 DAF, when seed moisture content was 16–21%. Seeds were capable of germinating early in development, reaching a maximum of 63% at 9 DAF, but germination declined as development continued, presumably due to the imposition of physiological dormancy. Physical dormancy developed at or after physiological maturity, once seed moisture content declined below 20%. Seeds were able to tolerate desiccation from 18 DAF; desiccation hastened development of physical dormancy and improved germination. These results provide important information regarding M. parviflora seed development, which will ultimately improve weed control techniques aimed at preventing seed set and further additions to the seed bank.

scholarly journals Effects of Matric and Osmotic Priming Treatments on Broccoli Seed Germination

1996 ◽  
Vol 121 (3) ◽  
pp. 423-429 ◽  
Author(s):  
Lewis W. Jett ◽  
Gregory E. Welbaum ◽  
Ronald D. Morse
Keyword(s):  
Polyethylene Glycol ◽  
Seed Germination ◽  
Root Growth ◽  
Growth Rates ◽  
Germination Rate ◽  
Membrane Integrity ◽  
Seed Vigor ◽  
Radicle Emergence ◽  
The Mean ◽  
Peg 8000

Priming, a controlled-hydration treatment followed by redrying, improves the germination and emergence of seeds from many species. We compared osmotic and matric priming to determine which was the most effective treatment for improving broccoli seed germination and to gain a greater understanding of how seed vigor is enhanced by priming. Broccoli (Brassica oleracea L. var. italica) seeds were osmotically primed in polyethylene glycol (PEG 8000) at -1.1 MPa or matrically primed in a ratio of 1.0 g seed:0.8 g synthetic calcium silicate (Micro-Cel E):1.8 ml water at -1.2 MPa. In the laboratory, germination rates and root lengths were recorded from 5 to 42C and 10 to 35C, respectively. Broccoli seeds germinated poorly at >35C. Root growth after germination was more sensitive to temperatures >30C and <15C than radicle emergence. Matric and osmotic priming increased germination rate in the laboratory, greenhouse, and field. However, matric priming had a greater effect on germination and root growth rates from 15 to 30C. Neither priming treatment affected minimum or maximum germination or root growth temperatures. Both priming treatments decreased the mean thermal time for germination by >35%. The greater germination performance of matrically primed seeds was most likely the result of increased oxygen availability during priming, increased seed Ca content, or improved membrane integrity.

scholarly journals Neural cell responses to wear debris from metal-on-metal total disc replacements

2019 ◽  
Vol 29 (11) ◽  
pp. 2701-2712
Author(s):  
H. Lee ◽  
J. B. Phillips ◽  
R. M. Hall ◽  
Joanne L. Tipper
Keyword(s):  
Stainless Steel ◽  
Cell Viability ◽  
Glial Cell ◽  
Wear Debris ◽  
Particle Production ◽  
3D Culture ◽  
Dna Integrity ◽  
Wear Particles ◽  
Astrocyte Activation ◽  
2D And 3D

Purpose Abstract Total disc replacements, comprising all-metal articulations, are compromised by wear and particle production. Metallic wear debris and ions trigger a range of biological responses including inflammation, genotoxicity, cytotoxicity, hypersensitivity and pseudotumour formation, therefore we hypothesise that, due to proximity to the spinal cord, glial cells may be adversely affected. Methods Clinically relevant cobalt chrome (CoCr) and stainless steel (SS) wear particles were generated using a six-station pin-on-plate wear simulator. The effects of metallic particles (0.5–50 μm3 debris per cell) and metal ions on glial cell viability, cellular activity (glial fibrillary acidic protein (GFAP) expression) and DNA integrity were investigated in 2D and 3D culture using live/dead, immunocytochemistry and a comet assay, respectively. Results CoCr wear particles and ions caused significant reductions in glial cell viability in both 2D and 3D culture systems. Stainless steel particles did not affect glial cell viability or astrocyte activation. In contrast, ions released from SS caused significant reductions in glial cell viability, an effect that was especially noticeable when astrocytes were cultured in isolation without microglia. DNA damage was observed in both cell types and with both biomaterials tested. CoCr wear particles had a dose-dependent effect on astrocyte activation, measured through expression of GFAP. Conclusions The results from this study suggest that microglia influence the effects that metal particles have on astrocytes, that SS ions and particles play a role in the adverse effects observed and that SS is a less toxic biomaterial than CoCr alloy for use in spinal devices. Graphic abstract These slides can be retrieved under Electronic Supplementary Material.

Improving water stress tolerance of the biocontrol yeastCandida sakegrown in molasses-based media by physiological manipulation

2001 ◽  
Vol 47 (2) ◽  
pp. 123-129 ◽  
Author(s):  
M Abadias ◽  
N Teixidó ◽  
J Usall ◽  
I Viñas ◽  
N Magan
Keyword(s):  
Polyethylene Glycol ◽  
Water Stress ◽  
Amino Acid ◽  
Cell Viability ◽  
Stress Tolerance ◽  
Biocontrol Agent ◽  
Compatible Solutes ◽  
Intracellular Concentration ◽  
Water Stress Tolerance ◽  
Candida Sake

The biocontrol agent Candida sake was cultured on either an unmodified molasses-based medium (water activity, aw0.996) or on water stressed media produced by the addition of glycerol, glucose, NaCl, sorbitol, or proline to 0.98, and 0.96 awfor 24, 48, and 72 h, to study their impact on subsequent cell viability, and on concentrations of endogenous sugars (trehalose and glucose) and polyols (glycerol, erythritol, arabitol, and mannitol). The viability of cells of different ages cultured on these media was evaluated on NYDA medium with freely available water (aw0.995), and on medium modified with polyethylene glycol to aw0.95. Regardless of solute used, viable counts of cells grown on molasses-based medium (aw0.98) were equal to or higher than those obtained from the medium with water freely available. The amino acid proline stimulated growth at 10% concentration. In contrast, water stress induced by addition of NaCl, glucose, or sorbitol at aw0.96 caused a significant reduction in viable counts. Older cultures were more resistant to water stress. Glycerol and arabitol were the main solutes accumulated by C. sake cells in response to lowered aw. Intracellular concentration of these polyols depended more on the solute used to adjust the awthan on the awitself. Candida sake was more resistant to water stress with higher intracellular concentration of glycerol and erythritol.Key words: compatible solutes, polyols, sugars, improved viability, formulation.

scholarly journals Loss and re-establishment of desiccation tolerance in the germinated seeds of Sesbania virgata (Cav.) (Pers.)

2015 ◽  
Vol 37 (3) ◽  
pp. 313 ◽  
Author(s):  
Tathiana Elisa Masetto ◽  
José Marcio Rocha Faria ◽  
Ana Carla Rezende Fraiz
Keyword(s):  
Desiccation Tolerance ◽  
Sesbania Virgata ◽  
Germinated Seeds

scholarly journals A New Concept of Applying Methanol to Dry Cellulose Insulation at the Stage of Manufacturing a Transformer

Energies ◽  
2018 ◽  
Vol 11 (7) ◽  
pp. 1658 ◽  
Author(s):  
Piotr Przybylek
Keyword(s):  
High Temperature ◽  
Moisture Content ◽  
Power Transformers ◽  
Technical Challenge ◽  
Moisture Contents ◽  
Percentage Points ◽  
Time Period ◽  
Drying Techniques ◽  
Heating Up ◽  
Cellulose Insulation

A decisive technical challenge for transformer manufacturers is correctly drying the cellulose insulation. During the production of a transformer, it is necessary to reduce its insulation’s moisture content from about 8% to less than 1% in the shortest possible time period. The drying of insulation is a time-consuming process, and for high-power transformers, it can last up to three weeks. Several drying techniques are used during the production of a transformer, and all of them require heating up the insulation to a high temperature and applying a vacuum. Unfortunately, the use of a high drying temperature above 100 °C can cause a decrease in the degree of cellulose polymerization by over a dozen percentage points. This paper presents a new concept for drying cellulose insulation that does not require heating insulation and applying a vacuum. In this solution, methanol is used as the drying medium. The research results showed the possibility of drying cellulose insulation by means of methanol with different initial moisture contents. The possibility of completely drying pressboard of various thicknesses for a sufficient period of time was also proven. The paper also presents a new concept of both the device and the procedure for drying cellulose insulation by means of methanol.

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