scholarly journals Organ Regeneration on Excised Roots of Chondrilla Juncea and Its Chemical Regulation

1972 ◽  
Vol 25 (4) ◽  
pp. 691 ◽  
Author(s):  
NP Kefford ◽  
OH Caso
Keyword(s):  
Root Formation ◽  
Bud Formation ◽  
Endogenous Factors ◽  
Chemical Regulation ◽  
Synthetic Auxins ◽  
Organ Regeneration ◽  
Low Concentrations ◽  
Standard Assay ◽  
Gibberellin Treatment ◽  
Regulation Of Regeneration

The effects of endogenous factors (plant age, section length, and section location) and environmental factors (temperature and mineral nutrition) upon organ regeneration on isolated root sections of Ohondrilla juncea L. were used to develop a standard assay system for the study of the chemical regulation of regeneration. Bud and root formation and its polarity in the presence of a variety of regulators alone and in combinations were observed quantitatively. Bud numbers were increased by auxin (low concentrations), cytokinin, and gibberellin treatments. High concentra� tions of auxin inhibited bud formation and this effect was reversed by antiauxin, cytokinin, or gibberellin. Adenine did not counteract auxin� induced bud inhibition but adenine and N�6�benzyladenine did counteract inhibition induced by the purine antagonist 2,6�diaminopurine. Numbers of regenerated roots were increased by auxin treatment and reduced by cytokinin and gibberellin treatment. On control and auxin� treated sections, bud formation was strongly polar and proximal and cytokinin and gibberellin treatments lessened the polarity. Growth retardants inhibited regeneration. Of a number of synthetic auxins tested, 2,4.dichlorophenoxy. acet.O.methylhydroxamic acid and 4�amino.3,5,6.trichloropicolinic acid were the most effective inhibitors of bud formation.

scholarly journals Wpływ kwasu 2-chloroetanofosfonoiuego (Ethrel) na ukorzenianie się zdrewniałych sadzonek czarnych porzeczek [Effect of 2-chloroethylphosphonic acid (Ethrel) on the rooting of the blackcurrant hardwood cuttings]

2015 ◽  
Vol 26 (2) ◽  
pp. 229-235 ◽  
Author(s):  
Janusz Lipecki ◽  
Jan Selwa
Keyword(s):  
Root Formation ◽  
Harmful Effect ◽  
Inflorescence Development ◽  
Complete Cessation ◽  
Low Concentrations ◽  
High Concentrations

The effect of Ethrel on root formation in the blackcurrant (cv. Blacksmith) hardwood cuttings was investigated in five different periods of the year. Low concentrations of Ethrel (up to 250 ppm) stimulated rooting, whereas higher concentrations (above 250 ppm) had a harmful effect on root formation. It is suggested that ethylene can act as a rooting promoter (when low concentrations of Ethrel were used) or as rooting inhibitor (when Ethrel was used in high concentrations). Complete cessation of the inflorescence development was observed in cuttings treated with Ethrel at 100 ppm and higher concentrations.

scholarly journals Influence of Selected Antibiotics on the Tomato Regeneration in In Vitro Cultures

2019 ◽  
Vol 47 (3) ◽  
Author(s):  
Aneta GERSZBERG ◽  
Izabela GRZEGORCZYK-KAROLAK
Keyword(s):  
Antimicrobial Agents ◽  
Digital Object Identifier ◽  
Regeneration Ability ◽  
Indirect Organogenesis ◽  
Bud Formation ◽  
Putative Transformants ◽  
Low Concentrations ◽  
Plant Tissue Cultures ◽  
Tomato Cultivars

Generally, antimicrobial agents are frequently used in micropropagation techniques to obtain free elite clones or after genetic transformation to select putative transformants. Their successful application minimizes bacterial contamination however; they may be phytotoxic and may diversely affect the regeneration ability in plant tissue cultures. The objective of the current study was to estimate the effects of four antibiotics i.e. ampicillin, carbenicillin, cefotaxime and kanamycin on morphogenesis of three Polish tomato cultivars, cultured on MS medium with phytohormones. In this experiment the ability of tomato cotyledon explants to regenerate entire plants via indirect organogenesis was tested. Among four antibiotics tested, kanamycin was most harmful for the explants. This antibiotic, even at low doses (10-20 mg/L), inhibited tomato morphogenesis. On the other hand, the current study revealed significant influence of different concentrations of ampicillin, carbenicillin, cefotaxime on the frequency of bud formation. While the addition of cefotaxime at low concentration (100-200 mg/L) stimulated the bud formation, its increasing concentration adversely affected the organogenesis of tomato. The results clearly pointed out that carbenicillin and ampicillin at low concentrations (100-400 mg/L) were not only non-toxic, but they promoted bud regeneration. The obtained results show the crucial role not only of use of efficient antibiotics, but also of their proper doses in obtaining successful transformation and regeneration of tomato.   ********* In press - Online First. Article has been peer reviewed, accepted for publication and published online without pagination. It will receive pagination when the issue will be ready for publishing as a complete number (Volume 47, Issue 3, 2019). The article is searchable and citable by Digital Object Identifier (DOI). DOI link will become active after the article will be included in the complete issue. *********

Rapid Detection of Salmonella enteritidis in Pooled Liquid Egg Samples Using a Magnetic Bead-ELISA System

1995 ◽  
Vol 58 (9) ◽  
pp. 967-972 ◽  
Author(s):  
PETER S. HOLT ◽  
RICHARD K. GAST ◽  
CAM R. GREENE
Keyword(s):  
Salmonella Enteritidis ◽  
Magnetic Bead ◽  
Immunomagnetic Separation ◽  
Detection Methods ◽  
Enzyme Linked Immunosorbent Assay ◽  
Direct Plating ◽  
Elisa System ◽  
Low Concentrations ◽  
Standard Assay ◽  
Flagellar Proteins

An assay was developed to shorten the time necessary to detect Salmonella enteritidis (SE) in contaminated egg pools. The immunomagnetic separation (IMS)-based assay used the DynabeadsTM Anti-Salmonella, a magnetic bead with mouse anti-Salmonella antibodies affixed to the surface, to bind the SE in the egg pools. The bound SE were concentrated by a magnet and were detected via an enzyme-linked immunosorbent assay (ELISA) (IMS-ELISA) employing a monoclonal anti-SE flagellar proteins (flagellins) antibody. Following the ELISA, the beads were plated onto differential media (IMS-direct).The efficacy of the assay for detecting SE was compared with that of the standard assay, direct plating, in pooled egg samples spiked with low concentrations of SE and incubated at 37°C for 24 to 96 h. Conventional direct plating of egg samples required a total of 48 h before SE could be identified in egg pools, compared with 24 h for the IMS-ELISA. Plating of the beads (IMS-direct) to confirm the presence of SE required a further 24 h. The IMS-ELISA could detect SE at concentrations of 105 to 106 SE cells per ml, comparable to that shown previously for direct plating. The IMS-direct could detect SE at 104 SE cells per ml of egg pool. In egg pools initially contaminated with 10 SE cells per ml, the organism grew to levels by 24 h at 37°C where 100% of the pools were positive for SE by all three detection methods. In egg pools initially contaminated with 1 SE cell per ml, 61% of pools were detected by direct plating and IMS-ELISA and 72% were detected by IMS-direct. Similar detection frequencies were observed for a second SE isolate. The IMS-ELISA provides an SE detection rate comparable to direct plating but achieves the result 24 h sooner. The IMS-direct was the most sensitive means of detecting the SE.

scholarly journals Indole-3-Acetic Acid, Polyamines, and Phenols in Hardwood Cuttings of Recalcitrant-to-Root Wild Grapes Native to East Asia: Vitis davidii and Vitis kiusiana

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Shuji Shiozaki ◽  
Masahiro Makibuchi ◽  
Tsuneo Ogata
Keyword(s):  
Acetic Acid ◽  
East Asia ◽  
Root Formation ◽  
High Rate ◽  
Total Phenols ◽  
Endogenous Factors ◽  
Vitis Labruscana ◽  
Basal Portion ◽  
Vitis Davidii ◽  
Indole 3 Acetic Acid

Levels of indole-3-acetic acid (IAA), free, conjugated, and bound polyamines (PAs), and phenols were estimated in the basal portion of hardwood cuttings of Vitis davidii and V. kiusiana in relation to rooting and compared with Vitis labruscana Bailey cv. Campbell Early. A high rate of root formation was observed in ‘Campbell Early’ cuttings 60 days after planting. However, none of the V. davidii and V. kiusiana cuttings formed roots. An increase in IAA contents was observed in ‘Campbell Early’ cuttings, but not in V. davidii and V. kiusiana, 60 days after planting. The content of free, conjugated, and bound PAs was either constant or decreased in ‘Campbell Early’ cuttings during planting and was especially decreased in conjugated putrescine and spermidine. An increase in free and conjugated putrescine was observed after planting in V. kiusiana cuttings. In the cuttings of V. davidii, only bound spermine increased after planting. The content of total phenols, orthodiphenols, total catechins, and gallocatechin derivatives decreased after planting in ‘Campbell Early’ cuttings. Orthodiphenols and total catechin contents increased in the cuttings of V. kiusiana, and gallocatechin derivatives increased in V. davidii. The relationships between these endogenous factors and the recalcitrant-to-root features of V. davidii and V. kiusiana cuttings are discussed.

scholarly journals Paradoxical inhibition of rat glutathione transferase 4-4 by indomethacin explained by substrate-inhibitor-enzyme complexes in a random-order sequential mechanism

1988 ◽  
Vol 250 (3) ◽  
pp. 705-711 ◽  
Author(s):  
U H Danielson ◽  
B Mannervik
Keyword(s):  
Glutathione Transferase ◽  
Random Order ◽  
Competitive Inhibitor ◽  
Glutathione Transferases ◽  
Low Concentrations ◽  
Standard Assay ◽  
Sequential Mechanism ◽  
Substrate Inhibitor ◽  
Enzyme Complexes ◽  
Assay Conditions

Under standard assay conditions, with 1-chloro-2,4-dinitrobenzene (CDNB) as electrophilic substrate, rat glutathione transferase 4-4 is strongly inhibited (I50 = 1 microM) by indomethacin. No other glutathione transferase investigated is significantly inhibited by micromolar concentrations of indomethacin. Paradoxically, the strong inhibition of glutathione transferase 4-4 was dependent on high (millimolar) concentrations of CDNB; at low concentrations of this substrate or with other substrates the effect of indomethacin on the enzyme was similar to the moderate inhibition noted for other glutathione transferases. In general, the inhibition of glutathione transferases can be explained by a random-order sequential mechanism, in which indomethacin acts as a competitive inhibitor with respect to the electrophilic substrate. In the specific case of glutathione transferase 4-4 with CDNB as substrate, indomethacin binds to enzyme-CDNB and enzyme-CDNB-GSH complexes with an even greater affinity than to the corresponding complexes lacking CDNB. Under presumed physiological conditions with low concentrations of electrophilic substrates, indomethacin is not specific for glutathione transferase 4-4 and may inhibit all forms of glutathione transferase.

The relation between root hair infection by Rhizobium and nodulation in Trifolium and Vicia

1962 ◽  
Vol 156 (962) ◽  
pp. 122-137 ◽  
Keyword(s):  
Root Formation ◽  
Relative Rate ◽  
Lateral Roots ◽  
Root Hairs ◽  
Strain Differences ◽  
Nodule Formation ◽  
Low Concentrations ◽  
Rate Of Increase ◽  
Infection Threads ◽  
Root Hair Infection

The infection of the root hairs of young seedlings of twelve species of Trifolium and of Vicia hirsuta was examined. The amount of infection (numbers of hairs containing infection threads) at 2 weeks varied much between species of host and was less affected by bacterial strain ; host and strain differences were independent. In most hosts a high proportion of infections did not result in nodule formation. The relative rate of increase in numbers of infected hairs was constant before nodulation began. The duration of this pre-nodulation phase of exponential increase in infection, but not its rate, differed between species. Nodulation (and lateral root formation) caused an abrupt lowering of the initial rate of infection. Post-nodulation infection also increased exponentially. Low concentrations of nitrate nitrogen delayed nodulation and increased the number of hairs infected. Infected hairs were not randomly distributed along the root, infection beginning at a few well-separated points. Later infections occurred near these primary foci to give zones of infection which then spread up and down the root. The positions of nodules or lateral roots were not related to the primary foci of hair infection.

The effect of antibiotics on elongation and callus and bud formation from embryonic tissue of Piceaglauca

1989 ◽  
Vol 19 (10) ◽  
pp. 1343-1346 ◽  
Author(s):  
David D. Ellis ◽  
Wayne R. Lazaroff ◽  
Dane R. Roberts ◽  
Barry S. Flinn ◽  
David T. Webb
Keyword(s):  
Callus Formation ◽  
Marker Genes ◽  
Adventitious Bud ◽  
Seedling Mortality ◽  
Bud Formation ◽  
Low Concentrations ◽  
Adventitious Bud Formation ◽  
Effective Selection ◽  
Selection Of ◽  
Selection Of Transformants

Strategies for the selection of transformed cells and the counterselection (clearing) of Agrobacterium in genetic engineering requires a balance between the selection pressures and the normal morphogenetic response of transformed tissue. In this paper, we report the effect of antibiotics used for plant transformation studies on the elongation and induction of buds from embryos and the induction of callus from seedling tissue of Piceaglauca. Carbenicillin, ampicillin (500 and 750 μg/mL), and cefotaxime (250 and 500 μg/mL) are used to clear the invitro environment of bacteria and have little effect on the elongation or bud formation from P. glauca embryos. Concentrations of hygromycin greater than 1 μg/mL and kanamycin greater than 10 μg/mL inhibited elongation, whereas concentrations of kanamycin greater than 5 μg/mL totally inhibited adventitious bud formation, callus formation, and caused seedling mortality. At concentrations as low as 1 μg/mL, kanamycin decreased adventitious bud formation by greater than 50%. These results suggest that effective selection of transformants expressing marker genes can be performed using relatively low concentrations of kanamycin or hygromycin.

scholarly journals Direct Comparison of the Lowest Effect Concentrations of Mutagenic Reference Substances in Two Ames Test Formats

Toxics ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 152
Author(s):  
Bernhard Rainer ◽  
Elisabeth Pinter ◽  
Lukas Prielinger ◽  
Chiara Coppola ◽  
Maricel Marin-Kuan ◽  
...  
Keyword(s):  
Ames Test ◽  
Liver Homogenate ◽  
Correct Choice ◽  
Test Results ◽  
Low Concentrations ◽  
Standard Assay ◽  
High Concordance ◽  
Fit For Purpose ◽  
Assay Protocol ◽  
Mutagenic Compound

The Ames assay is the standard assay for identifying DNA-reactive genotoxic substances. Multiple formats are available and the correct choice of an assay protocol is essential for achieving optimal performance, including fit for purpose detection limits and required screening capacity. In the present study, a comparison of those parameters between two commonly used formats, the standard pre-incubation Ames test and the liquid-based Ames MPF™, was performed. For that purpose, twenty-one substances with various modes of action were chosen and tested for their lowest effect concentrations (LEC) with both tests. In addition, two sources of rat liver homogenate S9 fraction, Aroclor 1254-induced and phenobarbital/β-naphthoflavone induced, were compared in the Ames MPF™. Overall, the standard pre-incubation Ames and the Ames MPF™ assay showed high concordance (>90%) for mutagenic vs. non-mutagenic compound classification. The LEC values of the Ames MPF™ format were lower for 17 of the 21 of the selected test substances. The S9 source had no impact on the test results. This leads to the conclusion that the liquid-based Ames MPF™ assay format provides screening advantages when low concentrations are relevant, such as in the testing of complex mixtures.

scholarly journals The Interrelations Between Root Formation and Anthocyanin Synthesis in Red Maple Cuttings: Effects of Gibberellic Acid, Ccc, and 8-Azaguanine

1965 ◽  
Vol 18 (3) ◽  
pp. 699 ◽  
Author(s):  
EP Bachelard
Keyword(s):  
Gibberellic Acid ◽  
Root Formation ◽  
Anthocyanin Synthesis ◽  
Anthocyanin Content ◽  
Red Maple ◽  
Anthocyanin Formation ◽  
Low Concentrations ◽  
Rooting Of Cuttings

A relationship between anthocyanin content and root formation in red maple cuttings has been described earlier (Bachelard and Stowe 1962, 1963). Gibberellic acid inhibits rooting of cuttings, including those of red maple (Bachelard and Stowe 1963), and Furuya and Thimann (1964) have recently shown that anthocyanin synthesis in two species of Spirodela is inhibited by gibberellic acid, which in one of the species is active at extremely low concentrations. It was, therefore, of interest to study the effect of gibberellic acid on anthocyanin formation in the leaves of red maple cuttings.

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