Shoot Organogenesis and Plant Regeneration from Leaf Explants of Lysionotus serratus D. Don

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Qiansheng Li

2013-01-01

Full Text Available The gesneriaceous perennial plant, Lysionotus serratus, has been used in traditional Chinese medicine. It also has a great development potential as an ornamental plant with its attractive foliage and beautiful flowers. An efficient propagation and regeneration system via direct shoot organogenesis from leaf explant was established in this study. High active cytokinin (6-benzyladenine (BA or thidiazuron (TDZ was effective for direct organogenesis of initial induction. Murashige and Skoog (MS growth media containing 0.5 mg L−1 BA alone or with combination of 0.1 mg L−1  α-Naphthaleneacetic acid (NAA were the most effective for shoot proliferation. High BA concentration (1.0 mg L−1 in the media caused high percentage of vitrified shoots though they introduced high shoot proliferation rate. Histological observation indicated that adventitious shoot regeneration on the medium containing 0.5 mg L−1 BA alone occurred directly from leaf epidermal cells without callus formation. Regenerated shoots rooted well on medium containing half-strength MS medium with 0.5 mg L−1 indole-3-butyric acid (IBA and indole-3-acetic acid (IAA, and the plantlets successfully acclimatized and grew vigorously in the greenhouse with a 94.2% and 92.1% survival rate.

Genotype dependent callus induction and shoot regeneration in ...

African Journals Online (AJOL)

SERVER

2007-07-04

Jul 4, 2007 ... tems have been used for improvement of sunflower, but these techniques are mainly limited by the tissue culture response of commercial varieties (Nestares et al., 2002). In sunflower, reports on shoot regeneration from hypocotyls, cotyledons, leaves and meristematic tissues of young plantlets are available ...

Shoot regeneration from cotyledonary leaf explants of jatropha curcas: A biodiesel plant

KAUST Repository

Kumar, Nitish Chandramohana

2010-03-07

A simple, high frequency, and reproducible method for plant regeneration through direct organogenesis from cotyledonary leaf explants of Jatropha curcas was developed using Murashige and Skoog (MS) medium supplemented with different concentrations of thidiazuron (TDZ) or 6-benzyl aminopurine (BAP). Medium containing TDZ has greater influence on regeneration as compared to BAP. The induced shoot buds were transferred to MS medium containing 10 lM kinetin (Kn), 4.5 lM BAP, and 5.5 lM a-naphthaleneacetic acid (NAA) for shoot proliferation. The proliferated shoots could be elongated on MS medium supplemented with different concentrations and combinations of BAP, indole-3-acetic acid (IAA), NAA, and indole-3-butyric acid (IBA). MS medium with 2.25 lM BAP and 8.5 lM IAA was found to be the best combination for shoot elongation. However, significant differences in plant regeneration and shoot elongation were observed among the genotypes studied. Rooting was achieved when the basal cut end of elongated shoots were dipped in half strength MS liquid medium containing dif- ferent concentrations and combinations of IBA, IAA, and NAA for 4 days, followed by transfer to growth regulators free half strength MS medium supplemented 0.25 mg l-1 activated charcoal. Elongated shoot treated with 15 lM IBA, 5.7 lM IAA, and 11 lM NAA resulted in highest percent rooting. The rooted plants could be established in soil with more than 90% survival rate. The method developed may be useful in improvement of J. curcas through genetic modification. © Franciszek Górski Institute of Plant Physiology, Polish Academy of Sciences, Kraków 2010.

Shoot regeneration from cotyledonary leaf explants of jatropha curcas: A biodiesel plant

KAUST Repository

Kumar, Nitish Chandramohana; Vijay Anand, K. G.; Reddy, Muppala P.

2010-01-01

A simple, high frequency, and reproducible method for plant regeneration through direct organogenesis from cotyledonary leaf explants of Jatropha curcas was developed using Murashige and Skoog (MS) medium supplemented with different concentrations of thidiazuron (TDZ) or 6-benzyl aminopurine (BAP). Medium containing TDZ has greater influence on regeneration as compared to BAP. The induced shoot buds were transferred to MS medium containing 10 lM kinetin (Kn), 4.5 lM BAP, and 5.5 lM a-naphthaleneacetic acid (NAA) for shoot proliferation. The proliferated shoots could be elongated on MS medium supplemented with different concentrations and combinations of BAP, indole-3-acetic acid (IAA), NAA, and indole-3-butyric acid (IBA). MS medium with 2.25 lM BAP and 8.5 lM IAA was found to be the best combination for shoot elongation. However, significant differences in plant regeneration and shoot elongation were observed among the genotypes studied. Rooting was achieved when the basal cut end of elongated shoots were dipped in half strength MS liquid medium containing dif- ferent concentrations and combinations of IBA, IAA, and NAA for 4 days, followed by transfer to growth regulators free half strength MS medium supplemented 0.25 mg l-1 activated charcoal. Elongated shoot treated with 15 lM IBA, 5.7 lM IAA, and 11 lM NAA resulted in highest percent rooting. The rooted plants could be established in soil with more than 90% survival rate. The method developed may be useful in improvement of J. curcas through genetic modification. © Franciszek Górski Institute of Plant Physiology, Polish Academy of Sciences, Kraków 2010.

An Integrated Strategy to Identify Key Genes in Almond Adventitious Shoot Regeneration

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Plant genetic transformation usually depends on efficient adventitious regeneration systems. In almond (Prunus dulcis Mill.), regeneration of transgenic adventitious shoots was achieved but with low efficiency. Histological studies identified two main stages of organogenesis in almond explants that ...

Adventitious shoot regeneration from leaf explants of the valuable ...

African Journals Online (AJOL)

The objective of this study was to develop an efficient protocol for adventitious shoot regeneration for Plectranthus barbatus Andrews using leaf explants. The explants were cultured on MS (Murashige and Skoog, 1962) medium containing various concentration of kinetin (KN), 6-benzylaminopurine (BAP) and thidiazuron ...

Adventitious shoot regeneration from leaf explants of the valuable ...

African Journals Online (AJOL)

Jane

2011-08-10

Aug 10, 2011 ... 2Department of Plant Biology and Plant Biotechnology, St. Joseph's College, Tiruchirappalli – 620 002, South India. Accepted 28 March, 2011 .... Effect of cytokinins (KN and BAP) alone or in combination with NAA on direct shoot bud regeneration from leaf explants of P. barbatus. Plant growth regulator ...

Assessment of silver nitrate on callus induction and in vitro shoot regeneration in tomato (solanum lycopersicum mill.)

International Nuclear Information System (INIS)

Shah, S.H.; Ali, S.; Jan, S.A.

2014-01-01

In vitro morphogenesis is greatly influenced by a gaseous plant growth regulator (ethylene). The effect of silver nitrate (AgNO/sub 3/) and different plant growth regulators were assessed on callus induction, In vitro shoot regeneration and multiple primordial shoots per explant in tomato. The maximum callus induction frequency was recorded culturing hypocotyls, while In vitro shoot regeneration frequency and the number of primordial shoots per explant were significantly higher when leaf discs were used as explants. The callus induction frequency was improved by the supplementation of 10-15 mg/l AgNO/sub 3/ in MS basal media along with 2.0 mg/l IAA, 2.5 mg/l BAP and yielded the highest callus induction frequency (91.33%) in cv. Rio Grande, followed by Roma (88.33%) and Moneymaker (82.66%). Similarly, the highest In vitro shoot regeneration frequency (96.66, 92.66 and 90%) was recorded in Rio Grande, Roma and Moneymaker on MS media fortified with 0.1 mg/l IAA, 1.0 mg/l ZEA and 2.0 mg/l BAP along with 8-10 mg/l AgNO/sub 3/. AgNO/sub 3/ also had promotive effect on induction of multiple shoots per explant. These findings indicate that ethylene is linked with the suppression of In vitro morphogenesis in tomato and AgNO3 interacts with ethylene and enhances callus induction and In vitro shoot regeneration in tomato. (author)

Detection of sodium azide-induced mutagenicity in the regenerated shoots of artemisia annual L., using internal transcribed spacer (its) sequences of nrDNA

International Nuclear Information System (INIS)

Al-Qurainy, F.; Al-Hemaidi, F.M.; Khan, S.; Ali, M.A.; Tarroum, M.; Ashraf, M.

2011-01-01

Sodium azide (NaN/sub 3/) is a well known chemical mutagen which can effectively cause point mutation in plant genome. The mutagenicity by this potential mutagen was assessed in the regenerated mutant shoots of Artemisia annua using internal transcribed spacer (ITS) sequences of n rDNA. Insertions and/or deletions were detected in n rDNA-ITS sequences of all mutant shoots and compared with control ones using the ClustalX program. The regenerated shoots TS1 and TS2 had deleted bases, whereas TS3, TS4 and TS5 had insertions, because NaN/sub 3/ replaced the cytosine (C) by thymine (T) (C - T) (shoots; TS1 and TS4) and thymine (T) replaced by guanine (G) (T - G) (shoot; TS5), respectively. Artemisinin content was also measured in the regenerated six-week-old shoots of A. annua. All regenerated shoots had enhanced level of this compound as compared to that in the controls, being highest in the regenerated shoot TS3. (author)

Stable transformation via particle bombardment in two different soybean regeneration systems.

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Sato, S; Newell, C; Kolacz, K; Tredo, L; Finer, J; Hinchee, M

1993-05-01

The Biolistics(®) particle delivery system for the transformation of soybean (Glycine max L. Merr.) was evaluated in two different regeneration systems. The first system was multiple shoot proliferation from shoot tips obtained from immature zygotic embryos of the cultivar Williams 82, and the second was somatic embryogenesis from a long term proliferative suspension culture of the cultivar Fayette. Bombardment of shoot tips with tungsten particles, coated with precipitated DNA containing the gene for β-glucuronidase (GUS), produced GUS-positive sectors in 30% of the regenerated shoots. However, none of the regenerants which developed into plants continued to produce GUS positive tissue. Bombardment of embryogenic suspension cultures produced GUS positive globular somatic embryos which proliferated into GUS positive somatic embryos and plants. An average of 4 independent transgenic lines were generated per bombarded flask of an embryogenic suspension. Particle bombardment delivered particles into the first two cell layers of either shoot tips or somatic embryos. Histological analysis indicated that shoot organogenesis appeared to involve more than the first two superficial cell layers of a shoot tip, while somatic embryo proliferation occurred from the first cell layer of existing somatic embryos. The different transformation results obtained with these two systems appeared to be directly related to differences in the cell types which were responsible for regeneration and their accessibility to particle penetration.

In vitro shoot regeneration and microcorm development in crocus vernus (l.) hill

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Sivanesan, I.

2014-01-01

An efficient method has been developed for In vitro regeneration of shoot and microcorm from corm explants of Crocus vernus. Corms were cut into 0.5-1.0 cm long segments and cultured on the SH medium supplemented with 0.5, 1.0, 2.0, or 4.0 mg L-1 2-isopentyl adenine (2-iP), N6-benzyladenine (BA), and N6-furfuryladenine (kinetin, Kin) alone or combination with 0.5 or 1.0 mg L-1 alpha-naphthalene acetic acid (NAA) for shoot regeneration. Of the three cytokinins tested, BA was found to be the most effective cytokinin for shoot formation. The number of shoots induced per explant was more when BA was combined with 0.5 mg L-1 NAA than with 1.0 mg L-1 NAA. The greatest percentage of shoot induction (97.2) with the mean number of 11.8 shoots per explant was obtained when the SH medium was supplemented with 2.0 mg L-1 BA and 0.5 mg L-1 NAA. The frequency of microcorm induction was significantly affected by the concentrations of sucrose.The greatest number of 6.1 microcorms per explant was obtained when the SH medium was supplemented with 2.0 mg L-1 BA, 0.5 mg L-1 NAA and 6.0% sucrose. The microcorms formed In vitro developed daughter corms when they were cultured on this medium. Microcorms were separated from the culture and planted out in acclimatization boxes containing a commercial medium. About 85% of corms developed shoot and root after 30 days. This protocol could be utilized for genetic transformation and mass clonal propagation of C. (author)

Plant regeneration from protoplasts ofVicia narbonensis via somatic embryogenesis and shoot organogenesis.

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Tegeder, M; Kohn, H; Nibbe, M; Schieder, O; Pickardt, T

1996-11-01

Protoplasts ofVicia narbonensis isolated from epicotyls and shoot tips of etiolated seedlings were embedded in 1.4% sodium-alginate at a final density of 2.5×10(5) protoplasts/ml and cultivated in Kao and Michayluk-medium containing 0.5 mg/I of each of 2,4- dichlorophenoxyacetic acid, naphthylacetic acid and 6 -benzylaminopurine. A division frequency of 36% and a plating efficiency of 0.40-0.5% were obtained. Six weeks after embedding, protoplast-derived calluses were transferred onto gelrite-solidified Murashige and Skoog-media containing various growth regulators. Regeneration of plants was achieved via two morphologically distinguishable pathways. A two step protocol (initially on medium with a high auxin concentration followed by a culture phase with lowered auxin amount) was used to regenerate somatic embryos, whereas cultivation on medium containing thidiazuron and naphthylacetic acid resulted in shoot morphogenesis. Mature plants were recovered from both somatic embryos as well as from thidiazuron-induced shoots.

Cytokinin induced shoot regeneration and flowering of Scoparia dulcis L. (Scrophulariaceae)-an ethnomedicinal herb.

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Premkumar, G; Sankaranarayanan, R; Jeeva, S; Rajarathinam, K

2011-06-01

To develop an improved protocol for micropropagation of ethnomedicinally important Scoparia dulcis (S. dulcis) L. Explants were inoculated on MS basal medium supplemented with kinetin and 6-benzylaminopurine for shoot bud induction. To enhance the shoot induction, various auxins like 3-indoleacetic acid or 3-indolebutyric acid or α-naphthylacetic acid were tested along with 2.32 M KI and 4.44 µM BAP. The regenerated shoots were rooted in half strength MS medium supplemented with various concentrations of IAA, IBA or NAA. After roots were developed, the plantlets were transplanted to pots filled with vermiculate and sand and kept in growth chamber with 70%-80% humidity under 16 h photoperiod. After acclimatization, the plantlets were transferred to the garden and survival percentage was calculated. Data were statistically analyzed and means were compared using Duncan's multiple range test (Pdulcis. Shoot induction on young leaf explants was most successful in MS medium supplemented with combination of two cytokinins (2.32 µM KI and 4.44 µM BAP) 2.85 µM IAA, 10% CM and 1 483.79 µM adenine sulfate. A single young leaf explant was capable of producing 59 shoots after 13 days of culture. Flower was induced in medium supplemented with combination of KI and BAP. Cytokinins are the key factor to induce the direct shoot regeneration and flowering of S. dulcis.

Effects of gamma-rays irradiation in seed of mungbean (vigna radiata (L.) wilczek) composition of media on shoot regeneration of explants from node of cotyledon

International Nuclear Information System (INIS)

Hutabarat, Dameria; H, Soeranto

1998-01-01

Study the effects of gamma-rays irradiation and composition and media on shoot regeneration of explants from node of cotyledon of mungbean. Wallet variety have been conducted. The explants derived of irradiated seeds of 10-20 Gy of gamma rays were planted in the 0.7% agar solution. One day after planting in the agar media the embryo axis of germinate seed were removed and the node of cotyledon were cultured in the regeneration media as examples. The results shown that shoot regeneration was influenced by media composition and the doses of gamma rays irradiation in seed. In the MURASHIGE and SKOOG medium which contain of BAP or 2-iP or Kinetin with 3 ppm concentrate respectively the explants could produced 100% of shoots. However, the highest. number of produced shoot (3 shoots) was showed in the medium which contained of BAP. The medium with I ppm concentrate od BAP could produced 100% shoot regeneration and the maximum number of shoots (4 shoots) per explant was showed in with 5 ppm. concentrate of BAP. The effectivity off BAP for shoot regeneration by enrichment of 12 ppm Ag 2 SO 4 in the media. Irradiation of 10-20 Gy gamma rays on seeds of mungbean walet variety could improved shoot regeneration of explants from node cotyledon. (author)

The effect of sodium hypochlorite solutions on in vitro seedling growth and shoot regeneration of flax (Linum usitatissimum)

Science.gov (United States)

Yildiz, Mustafa; Er, Celâl

2002-04-01

The aim of this study was to determine the effect of concentration (40, 60, and 80%) and temperature (0, 10, 20, and 30°C) of sodium hypochlorite (NaOCl) solutions on seed germination, in vitro viability and growth of flax seedlings and regeneration capacity of hypocotyl explants. Results showed that seed germination, seedling growth and shoot regeneration were negatively affected by increasing concentration and temperature of disinfectant. The best results in seedling growth and shoot regeneration were obtained when 40% disinfectant concentration at 10°C was used.

Transcriptomic and Hormonal Analyses Reveal that YUC-Mediated Auxin Biogenesis Is Involved in Shoot Regeneration from Rhizome in Cymbidium.

Science.gov (United States)

Liu, Yang; Zhang, Hai-Liang; Guo, He-Rong; Xie, Li; Zeng, Rui-Zhen; Zhang, Xiang-Qian; Zhang, Zhi-Sheng

2017-01-01

Cymbidium , one of the most important orchid genera in horticulture, can be classified into epiphytic and terrestrial species. Generally, epiphytic Cymbidium seedlings can be easily propagated by tissue culture, but terrestrial seedlings are difficult to propagate. To date, the molecular mechanisms underlying the differences in the ease with which terrestrial and epiphytic cymbidiums can be propagated are largely unknown. Using RNA-sequencing, quantitative reverse transcription PCR and enzyme-linked immunosorbent assay, Cymbidium 'Xiaofeng' (CXF), which can be efficiently micropropagated, and terrestrial Cymbidium sinense 'Qijianbaimo' (CSQ), which has a low regeneration ability, were used to explore the molecular mechanisms underlying the micropropagation ability of Cymbidium species. To this end, 447 million clean short reads were generated, and 31,264 annotated unigenes were obtained from 10 cDNA libraries. A total of 1,290 differentially expressed genes (DEGs) were identified between CXF and CSQ during shoot induction. Gene ontology (GO) enrichment analysis indicated that the DEGs were significantly enriched in auxin pathway-related GO terms. Further analysis demonstrated that YUC and GH3 family genes, which play crucial roles in the regulation of auxin/IAA (indole-3-acetic acid) metabolism, acted quickly in response to shoot induction culture in vitro and were closely correlated with variation in shoot regeneration between CXF and CSQ. In addition, the study showed that IAA accumulated rapidly and significantly during shoot induction in CXF compared to that in CSQ; in contrast, no significant changes in other hormones were observed between CXF and CSQ. Furthermore, shoot regeneration in CXF was inhibited by a yucasin-auxin biosynthesis inhibitor, indicating that increased IAA level is required for high-frequency shoot regeneration in CXF. In conclusion, our study revealed that YUC-mediated auxin biogenesis is involved in shoot regeneration from rhizome in

Transcriptomic and Hormonal Analyses Reveal that YUC-Mediated Auxin Biogenesis Is Involved in Shoot Regeneration from Rhizome in Cymbidium

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Yang Liu

2017-10-01

Full Text Available Cymbidium, one of the most important orchid genera in horticulture, can be classified into epiphytic and terrestrial species. Generally, epiphytic Cymbidium seedlings can be easily propagated by tissue culture, but terrestrial seedlings are difficult to propagate. To date, the molecular mechanisms underlying the differences in the ease with which terrestrial and epiphytic cymbidiums can be propagated are largely unknown. Using RNA-sequencing, quantitative reverse transcription PCR and enzyme-linked immunosorbent assay, Cymbidium ‘Xiaofeng’ (CXF, which can be efficiently micropropagated, and terrestrial Cymbidium sinense ‘Qijianbaimo’ (CSQ, which has a low regeneration ability, were used to explore the molecular mechanisms underlying the micropropagation ability of Cymbidium species. To this end, 447 million clean short reads were generated, and 31,264 annotated unigenes were obtained from 10 cDNA libraries. A total of 1,290 differentially expressed genes (DEGs were identified between CXF and CSQ during shoot induction. Gene ontology (GO enrichment analysis indicated that the DEGs were significantly enriched in auxin pathway-related GO terms. Further analysis demonstrated that YUC and GH3 family genes, which play crucial roles in the regulation of auxin/IAA (indole-3-acetic acid metabolism, acted quickly in response to shoot induction culture in vitro and were closely correlated with variation in shoot regeneration between CXF and CSQ. In addition, the study showed that IAA accumulated rapidly and significantly during shoot induction in CXF compared to that in CSQ; in contrast, no significant changes in other hormones were observed between CXF and CSQ. Furthermore, shoot regeneration in CXF was inhibited by a yucasin-auxin biosynthesis inhibitor, indicating that increased IAA level is required for high-frequency shoot regeneration in CXF. In conclusion, our study revealed that YUC-mediated auxin biogenesis is involved in shoot

Agrobacterium-mediated transformation and direct shoot regeneration in Iranian tomato (Solanum lycopersicum L.) cultivar Falat- CH

International Nuclear Information System (INIS)

Kauser, N.; Khan, S.

2016-01-01

Falat CH is an important commercial tomato cultivar being used in Iran. In this article an optimized protocol with increased transformation and regeneration rate for this tomato variety is reported. Several explants including cotyledon, leaf and hypocotyl were evaluated for direct shoot formation and the effect of various combinations of BAP, Zeatin, IAA and IBA were studied. It is the first report on two cytokinins BAP and Zeatin in various combinations to evaluate the synergetic effect of cytokinins on direct shoot regeneration. The synergetic combination of 1.5mg/l BAP, 0.5 mg/l Zeatin and 0.2 mg/l IAA was considered as the best treatment which resulted in higher plant regeneration rates from all of the explants over previous reported methods. Using the best regeneration treatment obtained, the HBsAg gene was transferred into the tomato explants using Agrobacterium mediated transformation technique Percent of the putative transgenic plants regenerated was 68%. PCR of putative transformed plants showed that 87.1% of regenerated plants amplified nptII and HBsAg gene when specifically designed primers were used giving a final transformation rate of 34.85%. (author)

Shoot regeneration of callus culture from irradiated sheed of piper nigrum L by gamma rays

International Nuclear Information System (INIS)

Ishak; Hutabarat, D.

1988-01-01

Shoot regeneration was obtained from callus that induced by irradiated seed with 25 and 50 Gy of gamma-rays and then on M.S. medium containing NAA 1 ppm and 2-ip 0.5 ppm. Irradiated seed with a dose of 25 Gy produced normal root and failed to produce shoot, but rice callus. Irradiated seed with a dose of 50 Gy pruduce callus only. Shoot differentiation occured after the callus were cultured on M.S., medium containing 2-ip 1 ppm and Kinetin 2.5 ppm. (authors). 9 refs, 3 figs

Effects of thidiazuron and paclobutrazol on regeneration potential of tulip flower stalk explants in vitro and subsequent shoot multiplication

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Małgorzata Podwyszyńska

2011-01-01

Full Text Available The effects of TDZ and paclobutrazol on the primary regeneration on tulip flower stalk explants of six cultivars and subsequent shoot multiplication were examined. Explants, flower stalk slices, were excised from cooled and subsequently forced bulbs. The explants were incubated for two months in darkness on medium containing NAA and cytokinins, 2iP and BAP, as control, or TDZ (0.5-4 mg l-1 and paclobutrazol (0.05-0.4 mg l-1. Then, the regenerating explants were subcultured on medium with TDZ and NAA applied at low concentrations. Different regeneration capabilities were found depending on cultivar and growth regulators. The percentage of explants forming leaf-like structures ranged, on the control medium, from 80% in 'Blue Parrot' and 'Prominence' to below 30% in 'Apeldoorn' and 'Mirjoran'. TDZ, applied at optimum for each cultivar concentration, greatly increased the regeneration potential up to 70-100%. Paclobutrazol, added to the TDZ-containing medium, significantly enhanced the response of explants, resulting in high numbers of leaf-like structures formed per explant (13.7-22.8. The structures developed gradually into characteristic forms: the growing up cotyledonary leaf, the probable root primordium formed at its base, the growing downwards stolon and the shoot meristem developed finely on its tip. It is suggested that such primary regeneration may have a nature of somatic embryogenesis. Then, the adventitious shoots developed and formed clusters, which were divided into 2-3 smaller ones every two months. The growth regulators, used at initial stage, markedly influenced subsequent shoot multiplication. Thus, the most intensive shoot formation was noted with TDZ at concentrations of 0.5-2 mg l-1 and paclobutrazol of 0.05-0.1 mg l-1.

Effects of GhWUS from upland cotton (Gossypium hirsutum L.) on somatic embryogenesis and shoot regeneration.

Science.gov (United States)

Xiao, Yanqing; Chen, Yanli; Ding, Yanpeng; Wu, Jie; Wang, Peng; Yu, Ya; Wei, Xi; Wang, Ye; Zhang, Chaojun; Li, Fuguang; Ge, Xiaoyang

2018-05-01

The WUSCHEL (WUS) gene encodes a plant-specific homeodomain-containing transcriptional regulator, which plays important roles during embryogenesis, as well as in the formation of shoot and flower meristems. Here, we isolated two homologues of Arabidopsis thaliana WUS (AtWUS), GhWUS1a_At and GhWUS1b_At, from upland cotton (Gossypium hirsutum). Domain analysis suggested that the two putative GhWUS proteins contained a highly conserved DNA-binding HOX domain and a WUS-box. Expression profile analysis showed that GhWUSs were predominantly expressed during the embryoid stage. Ectopic expression of GhWUSs in Arabidopsis could induce somatic embryo and shoot formation from seedling root tips. Furthermore, in the absence of exogenous hormone, overexpression of GhWUSs in Arabidopsis could promote shoot regeneration from excised roots, and in the presence of exogenous auxin, excised roots expressing GhWUS could be induced to produce somatic embryo. In addition, expression of the chimeric GhWUS repressor in cotton callus inhibited embryogenic callus formation. Our results show that GhWUS is an important regulator of somatic embryogenesis and shoot regeneration. Copyright © 2018 Elsevier B.V. All rights reserved.

The effect of tomato juices and bean sprout extracts on vitro shoot regeneration of Physalis angulata L.

Science.gov (United States)

Mastuti, Retno; Munawarti, Aminatun; Rosyidah, Mufidatur

2017-11-01

Physalis angulata L. (Ciplukan) which belongs to Solanaceae is an important medicinal plant. In vitro culture medium contains carbon source, inorganic substance, vitamins, and plant growth regulators. However, organic growth supplements have frequently been added to improve regeneration capability of explants. This study was conducted to observe the effect of tomato juices and extract bean sprout on shoot regeneration and multiplication of in vitro nodal explants. The explants were cultured on MS basal medium + 6-benzyl amino purine (BAP) 2 mg/L + indole-3-acetic acid (IAA) 0.05 mg/L with and without organic supplements. Tomato juices (T) 5, 7.5 and 10% or bean sprout extract (B) 1.25, 2.5, and 3.75% were added as natural organic supplements. Almost all explants have produced shoots one week after culture. After six weeks of culture maximum shoot number (12.5±3.9) was produced in medium MS + T5 while maximum shoot length (10.7 ± 0.7 cm) was obtained in medium MS + T 7.5. Medium T tends to produce more shoots than the medium B and medium control. This result indicates the potential of natural organic supplements for supporting Ciplukan propagation through in vitro culture.

In vtro adventitious shoot regeneration from cotyledon explant of brassica oleracea subsp. Italica and brassica oleracea subsp. capitata using tdz and naa

International Nuclear Information System (INIS)

Salim, S.; Rashid, A.

2014-01-01

Broccoli(Brassica oleracea subsp. italica) cv. Green Dragon King and cabbage (Brassica oleracea subsp. capitata) cv. Gianty are important vegetable crops grown in Cameron Highlands, Malaysia. The cotyledons of both cultivars were used as explant source for in vitro shoot regeneration. The objective of this research was to examine the influence of the growth regulators thidiazuron (TDZ) and naphthaleneacetic acid (NAA) on adventitious shoot formation in these cultivars. This system of adventitious shoot regeneration from cotyledon explants could be useful as a tool for genetic transformation of the subspecies. Cotyledon explants of both cultivars excised from 5-day-old in vitro germinated seedlings were placed on shoot induction medium containing basal salts of Murashige and Skoog (MS) and various concentrations of TDZ and NAA. The highest percentage of cotyledon explant of broccoli cv. Green Dragon King producing shoot (76.66%) and the highest mean number of shoots produced per explant (0.9) were obtained on 0.1 mg/l TDZ with 0.1 mg/l NAA. Meanwhile, the highest percentage of cotyledon explant of cabbage cv. Gianty producing shoots (86.67%) and highest number of shoots produced per explant (1.1) were recorded on 0.5 mg/l TDZ with 0.1 mg/l NAA. Therefore, 0.1 mg/l TDZ with 0.1 mg/l NAA and 0.5 mg/l TDZ with 0.1mg/l NAA are the recommended combinations for adventitious shoot regeneration from cotyledonary explants of broccoli cv. Dragon King and cabbage cv. Gianty respectively. (author)

Regeneration of multiple shoots from transgenic potato events facilitates the recovery of phenotypically normal lines: assessing a cry9Aa2 gene conferring insect resistance

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Jacobs Jeanne ME

2011-10-01

Full Text Available Abstract Background The recovery of high performing transgenic lines in clonal crops is limited by the occurrence of somaclonal variation during the tissue culture phase of transformation. This is usually circumvented by developing large populations of transgenic lines, each derived from the first shoot to regenerate from each transformation event. This study investigates a new strategy of assessing multiple shoots independently regenerated from different transformed cell colonies of potato (Solanum tuberosum L.. Results A modified cry9Aa2 gene, under the transcriptional control of the CaMV 35S promoter, was transformed into four potato cultivars using Agrobacterium-mediated gene transfer using a nptII gene conferring kanamycin resistance as a selectable marker gene. Following gene transfer, 291 transgenic lines were grown in greenhouse experiments to assess somaclonal variation and resistance to potato tuber moth (PTM, Phthorimaea operculella (Zeller. Independently regenerated lines were recovered from many transformed cell colonies and Southern analysis confirmed whether they were derived from the same transformed cell. Multiple lines regenerated from the same transformed cell exhibited a similar response to PTM, but frequently exhibited a markedly different spectrum of somaclonal variation. Conclusions A new strategy for the genetic improvement of clonal crops involves the regeneration and evaluation of multiple shoots from each transformation event to facilitate the recovery of phenotypically normal transgenic lines. Most importantly, regenerated lines exhibiting the phenotypic appearance most similar to the parental cultivar are not necessarily derived from the first shoot regenerated from a transformed cell colony, but can frequently be a later regeneration event.

Effects of ion beam irradiation on adventitious shoot regeneration from in vitro leaf explants of Septennial ionahta

International Nuclear Information System (INIS)

Zhou, L.B.; Li, W.J.; Ma, S.; Dong, X.C.; Yu, L.X.; Li, Q.; Zhou, G.M.; Gao, Q.X.

2006-01-01

The effects of 960 MeV carbon ion beam and 8 MeV X-ray irradiation on adventitious shoots from in vitro leaf explants of two different Saintpaulia ionahta (Mauve and Indikon) cultivars were studied with regard to tissue increase, shoots differentiation and morphology changes in the shoots. The experimental results showed that the survival fraction of shoot formation for the Mauve and Indikon irradiated with the carbon ion beam at 20 Gy were 0.715 and 0.600, respectively, while those for both the cultivars exposed to the X-ray irradiation at the same dose were 1.000. Relative biological effectiveness (RBE) of Mauve with respect to X-ray was about two. Secondly, the percentage of regenerating explants with malformed shoots in all Mauve regenerating explants irradiated with carbon ion beam at 20 Gy accounted for 49.6%, while that irradiated with the same dose of X-ray irradiation was only 4.7%; as for Saintpaulia ionahta Indikon irradiated with 20 Gy carbon ion beam, the percentage was 43.3%, which was higher than that of X-ray irradiation. Last, many chlorophyll deficient and other varieties of mutants were obtained in this study. Based on the results above, it can be concluded that the effect of mutation induction by carbon ion beam irradiation on the leaf explants of Saintpaulia ionahta is better than that by X-ray irradiation; and the optimal mutagenic dose varies from 20 Gy to 25 Gy for carbon ion beam irradiation

Effects of N6-benzylaminopurine and Indole Acetic Acid on In Vitro Shoot Multiplication, Nodule-like Meristem Proliferation and Plant Regeneration of Malaysian Bananas (Musa spp.)

Science.gov (United States)

Sipen, Philip; Davey, Michael R

2012-01-01

Different concentrations of N6-benzylaminopurine (BAP) and indole acetic acid (IAA) in Murashige and Skoog based medium were assessed for their effects on shoot multiplication, nodule-like meristem proliferation and plant regeneration of the Malaysian banana cultivars Pisang Mas, Pisang Nangka, Pisang Berangan and Pisang Awak. BAP at 1–14 mg L−1 with or without 0.2 mg L−1 IAA, or BAP at 7–14 mg L−1 with the same concentration of IAA, was evaluated for shoot multiplication from shoot tips and the proliferation of nodule-like meristems from scalps, respectively. Plant regeneration from scalps was assessed using 1 mg L−1 BAP and 0.2 mg L−1 IAA separately, or a combination of these two growth regulators. Data on shoot multiplication, the proliferation of nodule-like meristems with associated plant regeneration were recorded after 30 days of culture. A maximum of 5 shoots per original shoot tip was achieved on medium supplemented with BAP at 5 mg L−1 (Pisang Nangka), 6 mg L−1 (Pisang Mas and Pisang Berangan), or 7 mg L−1 (Pisang Awak), with 0.2 mg L−1 IAA. BAP at 11 mg L−1 with 0.2 mg L−1 IAA induced the most highly proliferating nodule-like meristems in the four banana cultivars. Plant regeneration from scalps was optimum in all cases on medium containing 1 mg L−1 BAP and 0.2 mg L−1 IAA. This is the first report on the successful induction of highly proliferating nodule-like meristems and plant regeneration from scalps of the Malaysian banana cultivars Pisang Mas, Pisang Nangka, Pisang Berangan and Pisang Awak. PMID:24575235

Field evaluation of regenerated plants by somatic embryogenesis from shoots apexes of axillary buds in ´Navolean’ (Musa spp., AAB.

Directory of Open Access Journals (Sweden)

Jorge López

2005-04-01

Full Text Available The use of shoots apexes from axilary buds for callus induction with embryogenic structures in plantain ‘Navolean’ (Group AAB permitted to develop a plant regeneration method through out somatic embryogenesis. In order to know the phenotypic variants that may be produced with the previously mentioned method , 1000 plants were planted in field conditions in comparison to those coming from somatic embryos obtained from multibuds as initial explants and organogenesis-derived plants (shoot tipsand conventionally derived plants (corms, during two growing cycles. The main morphological characters and yield components were evaluated. The total frequency of somaclonal variation during the first growing cycle in plants coming from somatic embryos obtained from shoots apexes from axilary buds as initial explants were 1.1%, and 8,6% in regenerated plants from somatic embryos obtained from multi-buds as initial explants. Later, in this same growing cycle, plants regenerated from somatic embryos (both sources showed a similar performance between them and they were significantly superior in all evaluated variants in comparison to corm-derived plants. In the second growing cycle, significant differences were not observed in yield components of suckers from evaluated plants, in spite of the propagation method used. With regard to somaclonal variation, the best performance was obtained with shoots apexes from axilary buds as explants. Finally, the feasibility of using the new method was shown. Key words: embryogenic cell suspensions, somaclonal variation

An efficient in vitro shoot regeneration from leaf petiolar explants and ex vitro rooting of Bixa orellana L.- A dye yielding plant.

Science.gov (United States)

Mohammed, Arifullah; Chiruvella, Kishore K; Namsa, Nima D; Ghanta, Rama Gopal

2015-07-01

Bixa orellana L. (Bixaceae) is a multipurpose tree grown for the production of commercially important dyes. In the present study, an efficient, reproducible protocol was developed for direct plant regeneration from in vitro derived petiole explants of Bixa orellana L. Murashige and Skoog medium (MS) supplemented with 2-isopentenyl adenine (9.8 μM) and naphthalene acetic acid (10.7 μM) was found to be optimum for production of high frequency of shoot organogenesis. Subculturing of the shoots onto the fresh MS medium containing similar concentrations of 2-iP (9.8 μM) and NAA (10.7 μM) produced elongated shoots. Elongated shoots when placed onto MS medium supplemented with 1.7 μM indole-3-acetic acid and 14.7 μM 2-iP produced optimal rooting. Rooted plantlets were acclimatized and transplanted to the field successfully. Histological investigation revealed the origin of shoot primordia, from sub-epidermal cells of petiole explants. The regeneration protocol developed in this study can be useful for mass in vitro propagation and effective genetic transformation of commercially important edible dye yielding tree species.

In Vitro Regeneration of Shoots From Nodal Explants of Dendrobium Chrysotoxum Lindl

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Kaur Saranjeet

2017-06-01

Full Text Available Transverse sections (2 mm thickness of stem-nodes from in vitro raised seedlings had morphogenic potential on semisolid and liquid Murashige and Skoog medium supplemented with cytokinins N6-benzyladenine (BA 4.44 μM, furfurylaminopurine (KIN 4.65 μM and auxin α-naphthalene acetic acid (NAA 5.37 μM individually and in combinations. The regeneration response was influenced by both the type of growth regulator and physical state of the medium. The explants produced either shoot buds on cytokinincontaining media or protocorm-like bodies (PLBs on NAA containing media both solid and liquid. More neo-formations were produced on liquid media, especially those containing only NAA. They were formed at nodal and inter-nodal regions. The secondary buds were produced on the surface of primary PLBs. The plantlets were developed on MS medium containing banana homogenate 50 g·dm-3. The current study is the first ever report on successful regeneration of Dendrobium chrysotoxum from stem-node segments.

Effect of lanthanum on rooting of in vitro regenerated shoots of Saussurea involucrata Kar. et Kir.

Science.gov (United States)

Guo, Bin; Xu, Ling-Ling; Guan, Zhen-Jun; Wei, Ya-Hui

2012-06-01

In present study, the effect of lanthanum (La) on the rooting of regenerated shoots of Saussurea involucrata Kar. et Kir was analyzed. Rooting occurred from regenerated shoots inoculated on a medium supplemented with La, the plant rooting hormone indole-3-acetic acid (IAA), or both La and IAA together. The highest rooting efficiency (96%), root number/shoot (8.5), and root length (63 mm) were recorded in shoots cultured on medium containing 2.5 μM IAA combined with 100 μM La(3+). In order to elucidate the mechanism of rooting enhancement by La, we examined dynamic changes in antioxidant enzyme activities in plant tissue over time in culture. We found that the activities of peroxidase (POX) and superoxide dismutase (SOD) were significantly higher in plant tissue cultured in IAA plus La than in La or IAA alone. At the same time, the highest H(2)O(2) content was detected in plant tissue in the presence of 2.5 μM IAA plus 100 μM La(3+). In light of these data and previous results, we speculate that La enhanced IAA-induced rooting by acting as a mild abiotic stress to stimulate POX and SOD activities in plant cells. Then, IAA reacted with oxygen and POX to form the ternary complex enzyme-IAA-O(2) that dissociated into IAA radicals and O(2)(-). Subsequently, IAA-induced O(2)(-) readily converted to hydroxyl radical (HO·) via SOD-catalyzed dismutation. Finally, cell wall loosening and cell elongation occurred as a consequence of HO-dependent scission of wall components, leading to root growth. The treatment of IAA combined with La resulted in the highest plantlet survival (80%) compared to single treatments with IAA or La alone. These data suggest that rare earth elements enhance root morphogenesis and the growth of S. involucrata.

Vegetative regeneration

Science.gov (United States)

George A. Schier; John R. Jones; Robert P. Winokur

1985-01-01

Aspen is noted for its ability to regenerate vegetatively by adventitious shoots or suckers that arise on its long lateral roots. It also produces sprouts from stumps and root collars; but they are not common. In a survey of regeneration after clearcutting mature aspen in Utah. Baker (1918b) found that 92% of the shoots originated from roots, 7% from root collars, and...

thidiazuron improves adventitious bud and shoot regeneration

African Journals Online (AJOL)

Prof. Adipala Ekwamu

Induction of adventitious buds and shoots from intact leaves and stem internode segments of two recalcitrant. Ugandan sweetpotato (Ipomoea batatas L.) cultivars was investigated in vitro on Murashige and Skoog (MS) medium, supplemented with 3 different levels (0.5, 2.0 and 4.0 µM) of Thidiazuron (TDZ). Shoots were.

Multiple shoot regeneration of cotton (Gossypium hirsutum L.) via ...

African Journals Online (AJOL)

user

2011-03-14

Mar 14, 2011 ... Induction of multiple shoots of cotton (Gossypium hirsutum L.) plant in two commercial varieties (Sahel and Varamin) using shoot apex was done. Explants were isolated from 3 - 4 days old seedlings, then they were cultured on a shoot induction media, modified MS nutrient agar with combinations: 1- ...

Isatin as an auxin source favoring floral and vegetative shoot regeneration from calli produced by thin layer explants of tomato pedicel

Science.gov (United States)

Applewhite, P. B.; K-Sawhney, R.; Galston, A. W.

1994-01-01

Thin layer explants taken from the pedicels and peduncles of flowering tomato plants yielded calli with great organogenetic potential. Of the 15 cultivars tested, 7 regenerated roots, shoots and eventually entire fruit-bearing plants. Calli grown on modified Murashige-Skoog medium responded to varied auxins and cytokinins with different morphogenetic patterns. Thus, naphthaleneacetic acid yielded root-producing calli, while the auxin precursor isatin (indole 2,3-dione) caused the production of calli with vegetative and floral shoots, rarely yielding roots. This may be related to isatin's slow, steady conversion to an active auxin (Plant Physiol 41:1485-1488, 1966) in contrast with naphthaleneacetic acid's immediate presentation of a high level of active auxin. The highest incidence of vegetative shoot (100%) and flower (50%) formation was obtained with 10 micromoles isatin and 3 micromoles zeatin. A few of the flowers developed into ripe fruits. The high frequency of induction of vegetative shoots and flowers before roots with isatin suggests its utility in micropropagation from plant tissue cultures.

Plants Regeneration Derived From Various on Peanut on Mutant Lines

International Nuclear Information System (INIS)

Dewi, Kumala; Masrizal; Mugiono

1998-01-01

The study of calli, greenspot formation and shoot regeneration on peanut mutant lines has ben conducted by MS media. Three explants derived from shoot tips, embryo and seeding root of two mutant lines a/20/3 and D/25/3/2 were used in this experiment. the explants were cultured on modified MS media enriched by vitamins, growth regulation, amino acids for fourth teen calli were transferred on regeneration media. The ability of calli formation and plant regeneration of each explant and genotypes of plants was varied. Greenspot and shoot formation were observed seventh days after the calli transferred on regeneration media. It is shown that the ability of calli, greenspot and shoot formation of each explants and genotypes was varied. the high ability of calli, greenspot and shoot formation were found in explant derived from shoot tip and embryo. Seedling root explant has lower ability in calli formation, while greenspot and shoot was formatted. The ability of calli, greenspot and shoot formation on A/20/3 mutant line was better than D/25/3/2 mutant line. (author)

Cell fate regulation in the shoot meristem.

Science.gov (United States)

Laux, T; Mayer, K F

1998-04-01

The shoot meristem is a proliferative centre containing pluripotent stem cells that are the ultimate source of all cells and organs continuously added to the growing shoot. The progeny of the stem cells have two developmental options, either to renew the stem cell population or to leave the meristem and to differentiate, possibly according to signals from more mature tissue. The destiny of each cell depends on its position within the dynamic shoot meristem. Genetic data suggest a simple model in which graded positional information is provided by antagonistic gene functions and is interpreted by genes which regulate cell fate.

Shoot and root morphogenesis from Eucalyptus grandis x urophylla ...

African Journals Online (AJOL)

Eucalyptus grandis x urophylla plantlets were regenerated via indirect organogenesis. Histological assessment of their development focused on identifying the calli, the differentiation of shoots from the calli and the shoot-root junction from the nascent shoots. Vascular tissue formation within the callus preceded that of ...

Shoot organogenesis in oleaster (Elaeagnus angustifolia L.)

African Journals Online (AJOL)

STORAGESEVER

2009-02-04

Feb 4, 2009 ... Regenerated plantlets were acclimatized and successfully transplanted to soil. Key words: shoot organogenesis, callus, ... saline and alkaline soils (Economou and Maloupa, 1995). Its fruits have been used as a .... cally inert compounds as reported by Kaminek (1992). Direct shoot organogenesis without ...

Improved recovery of cryotherapy-treated shoot tips following thermotherapy of in vitro-grown stock shoots of raspberry (Rubus idaeus L.).

Science.gov (United States)

Wang, Qiaochun; Valkonen, Jari P T

2009-01-01

Raspberry bushy dwarf virus (RBDV) can be efficiently eradicated from raspberry plants (Rubus idaeus) by a procedure combining thermotherapy and cryotherapy. However, the bottleneck of this procedure is that, following thermotherapy, cryopreserved shoot tips become chlorotic during regrowth and eventually die after several subcultures. In addition, survival of heat-treated stock shoots and recovery of cryopreserved shoot tips following thermotherapy are low. The present study focused towards improving regrowth of cryopreserved raspberry shoot tips following thermotherapy. Results showed that preconditioning stock shoots with salicylic acid (SA; 0.01-0.1 mM) markedly increased survival of stock shoots after 4 weeks of thermotherapy. Regrowth of cryopreserved shoot tips following thermotherapy was also significantly enhanced when SA (0.05-0.1 mM) was used for preconditioning stock shoots. Addition of either Fe-ethylenediaminetetracetic acid (Fe-EDTA, 50 mg per L) or Fe-ethylenediaminedi(o)hydroxyphenylacetic acid (Fe-EDDHA, 50 mg per L) to post-culture medium strongly promoted regrowth and totally prevented chlorosis of shoots regenerated from cryopreserved shoot tips following thermotherapy. Using the parameters optimized in the present study, about 80 percent survival of heat-treated stock shoots and about 33 percent regrowth of cryopreserved shoot tips following thermotherapy were obtained. Morphology of plants regenerated from cryopreserved shoot tips following thermotherapy was identical to that of control plants, based on observations of leaf shape and size, internode length and plant height. Optimization of the thermotherapy procedure followed by cryotherapy will facilitate the wider application of this technique to eliminate viruses which can invade meristems.

Plant regeneration of bananas Ambon kuning and Barangan mutant lines were carried out by using female organ and shoot-tip as explants source

International Nuclear Information System (INIS)

Dewi, Azri K; Ishak

1998-01-01

Plant regeneration of bananas Ambon Kuning and Barangan mutant lines were carried out by using female organ and shoot-tip as explants source. Female organ was taken from heart of banana stem, while shoot-tip taken from sucker in banana plantation at Pasar Jumat, Jakarta. Those explants were cultured on MS medium containing 3 mg/l BAP, 0.5 mg/l IAA and supplemented by 100 tyrosin and 80 mg/l adenin hemisulphate. Observation showed that 180 and 42 buds were obtained from JBR 02 mutant lines respectively, while 84 and 79 buds for JAK 01 and JAK 02 respectively. The highest shoot formation was 1.013 shoots were obtained from BRC variety and lowest one was JBR 01 mutant line. statistical data analysis indicated that shoot formation between BRC variety and another mutant lines were significant difference using LSD test at level 0.05. Plantlet formation derived from female organ as well as shoot-tip showed that BRC variety produced number of plantlets per bottle was higher that another one. (author)

In-vitro morphogenesis of corn (Zea mays L.) : I. Differentiation of multiple shoot clumps and somatic embryos from shoot tips.

Science.gov (United States)

Zhong, H; Srinivasan, C; Sticklen, M B

1992-07-01

In-vitro methods have been developed to regenerate clumps of multiple shoots and somatic embryos at high frequency from shoot tips of aseptically-grown seedlings as well as from shoot apices of precociously-germinated immature zygotic embryos of corn (Zea mays L.). About 500 shoots were produced from a shoot tip after eight weeks of culture (primary culture and one subculture of four weeks) in darkness on Murashige and Skoog basal medium (MS) supplemented with 500 mg/L casein hydrolysate (CH) and 9 μM N(6)-benzyladenine (BA). In this medium, shoots formed in shoot tips as tightly packed "multiple shoot clumps" (MSC), which were composed of some axillary shoots and many adventitious shoots. When the shoot tips were cultured on MS medium containing 500 mg/L CH, 9 μM BA and 2.25 μM 2,4-dichlorophenoxyacetic acid (2,4-D), most of the shoots in the clumps were adventitious in origin. Similar shoot tips cultured on MS medium containing 500 mg/L CH, 4.5 μM BA and 2.25 μM 2,4-D regenerated many somatic embryos within eight weeks of culture. Somatic embryos were produced either directly from the shoot apical meristems or from calli derived from the shoots apices. Both the MSC and the embryos produced normal shoots on MS medium containing 2.25 μM BA and 1.8 μM indole-3-butyric acid (IBA). These shoots were rooted on MS medium containing 3.6 μM IBA, and fertile corn plants were grown in the greenhouse. The sweet-corn genotype, Honey N Pearl, was used for the experiments described above, but shoot-tip cultures from all of 19 other corn genotypes tested also formed MSC on MS medium containing 500 mg/L CH and 9 μM BA.

In Vitro Regeneration of Endangered Medicinal Plant Heliotropium kotschyi (Ramram).

Science.gov (United States)

Sadeq, Manal Ahmed; Pathak, Malabika Roy; Salih, Ahmed Ali; Abido, Mohammed; Abahussain, Asma

2016-01-01

Heliotropium kotschyi (Ramram) is an important endangered medicinal plant distributed in the Kingdom of Bahrain. Plant tissue culture technique is applied for ex situ conservation study. Nodal stem segments are cultured in modified MS media supplemented with various combination and concentration of plant growth regulators (PGRs). Plants are regenerated via shoot organogenesis from the nodal meristems. Plants are regenerated in three different steps: initial shoot development, shoot multiplication, and rooting. After 4 weeks of culture, 100 % explants respond to shoot initiation on the medium containing 8.88 μM BAP and 5.71 μM IAA. The highest frequency of shoot regeneration is observed in the same media after second subculture of shoots. The highest rooting frequency is observed in the presence of 2.85 μM IAA. After root development, the plantlets are transferred to pots filled with soil and 60 % of plants survived after 45 days. This plant regeneration protocol is of great value for rapid desert plant propagation program.

Regeneration in Jatropha curcas: Factors affecting the efficiency of in vitro regeneration

KAUST Repository

Sharma, Sweta K.; Kumar, Nitish Chandramohana; Reddy, Muppala P.

2011-01-01

Factors influencing in vitro regeneration through direct shoot bud induction from hypocotyl explants of Jatropha curcas were studied in the present investigation. Regeneration in J. curcas was found to be genotype dependent and out of four toxic and one non-toxic genotype studied, non-toxic was least responsive. The best results irrespective of genotype were obtained on the medium containing 0.5mgL-1 TDZ (Thidiazuron) and in vitro hypocotyl explants were observed to have higher regeneration efficiency as compared to ex vitro explant in both toxic and non-toxic genotypes. Adventitious shoot buds could be induced from the distal end of explants in all the genotypes. The number of shoot buds formed and not the number of explants responding to TDZ treatment were significantly affected by the position of the explant on the seedling axis. Explants from younger seedlings (≤15 days) were still juvenile and formed callus easily, whereas the regeneration response declined with increase in age of seedlings after 30 days. Transient reduction of Ca2+ concentrations to 0.22gL-1 in the germination medium increased the number of responding explants.Induced shoot buds, upon transfer to MS medium containing 2mgL-1 Kn (Kinetin) and 1mgL-1 BAP (6-benzylamino purine) elongated. These elongated shoots were further proliferated on MS medium supplemented with 1.5mgL-1 IAA (indole-3-acetic acid) and 0.5mgL-1 BAP and 3.01-3.91cm elongation was achieved after 6 weeks. No genotype specific variance in shoot elongation was observed among the toxic genotypes except the CSMCRI-JC2, which showed reduced response. And for proliferation among the toxic genotypes, CSMCRI-JC4 showed highest number of shoots formed. Among the rest, no significant differences were observed. The elongated shoot could be rooted by pulse treatment on half-strength MS medium supplemented with 2% sucrose, 3mgL-1 IBA (indole-3-butyric acid), 1mgL-1 IAA, 1mgL-1 NAA (α-naphthalene acetic acid) and subsequent transfer on 0

Regeneration in Jatropha curcas: Factors affecting the efficiency of in vitro regeneration

KAUST Repository

Sharma, Sweta K.

2011-07-01

Factors influencing in vitro regeneration through direct shoot bud induction from hypocotyl explants of Jatropha curcas were studied in the present investigation. Regeneration in J. curcas was found to be genotype dependent and out of four toxic and one non-toxic genotype studied, non-toxic was least responsive. The best results irrespective of genotype were obtained on the medium containing 0.5mgL-1 TDZ (Thidiazuron) and in vitro hypocotyl explants were observed to have higher regeneration efficiency as compared to ex vitro explant in both toxic and non-toxic genotypes. Adventitious shoot buds could be induced from the distal end of explants in all the genotypes. The number of shoot buds formed and not the number of explants responding to TDZ treatment were significantly affected by the position of the explant on the seedling axis. Explants from younger seedlings (≤15 days) were still juvenile and formed callus easily, whereas the regeneration response declined with increase in age of seedlings after 30 days. Transient reduction of Ca2+ concentrations to 0.22gL-1 in the germination medium increased the number of responding explants.Induced shoot buds, upon transfer to MS medium containing 2mgL-1 Kn (Kinetin) and 1mgL-1 BAP (6-benzylamino purine) elongated. These elongated shoots were further proliferated on MS medium supplemented with 1.5mgL-1 IAA (indole-3-acetic acid) and 0.5mgL-1 BAP and 3.01-3.91cm elongation was achieved after 6 weeks. No genotype specific variance in shoot elongation was observed among the toxic genotypes except the CSMCRI-JC2, which showed reduced response. And for proliferation among the toxic genotypes, CSMCRI-JC4 showed highest number of shoots formed. Among the rest, no significant differences were observed. The elongated shoot could be rooted by pulse treatment on half-strength MS medium supplemented with 2% sucrose, 3mgL-1 IBA (indole-3-butyric acid), 1mgL-1 IAA, 1mgL-1 NAA (α-naphthalene acetic acid) and subsequent transfer on 0

Plant regeneration protocol of Andrographis paniculata (Burm. f ...

African Journals Online (AJOL)

Plant regeneration protocol of Andrographis paniculata (Burm. f.) - an important medicinal plant. ... Inclusion of 1.0 mg/l 1-naphthalene acetic acid (NAA) in the culture medium along with BA + Ads promoted a higher rate of shoot bud regeneration. Maximum mean number of shoot bud per explant (28.6) was achieved on the ...

Characterization of the early proliferative response of the rodent bladder to subtotal cystectomy: a unique model of mammalian organ regeneration.

Directory of Open Access Journals (Sweden)

Charles C Peyton

Full Text Available Subtotal cystectomy (STC; surgical removal of ∼75% of the rat urinary bladder elicits a robust proliferative response resulting in complete structural and functional bladder regeneration within 8-weeks. The goal of these studies was to characterize the early cellular response that mediates this regenerative phenomenon, which is unique among mammalian organ systems. STC was performed on eighteen 12-week-old female Fischer F344 rats. At 1, 3, 5 and 7-days post-STC, the bladder was harvested 2-hours after intraperitoneal injection of bromodeoxyuridine (BrdU. Fluorescent BrdU labeling was quantified in cells within the urothelium, lamina propria (LP, muscularis propria (MP and serosa. Cell location was confirmed with fluorescently co-labeled cytokeratin, vimentin or smooth muscle actin (SMA, to identify urothelial, interstitial and smooth muscle cells, respectively. Expression of sonic hedgehog (Shh, Gli-1 and bone morphogenic factor-4 (BMP-4 were evaluated with immunochemistry. Three non-operated rats injected with BrdU served as controls. Less than 1% of cells in the bladder wall were labeled with BrdU in control bladders, but this percentage significantly increased by 5-8-fold at all time points post-STC. The spatiotemporal characteristics of the proliferative response were defined by a significantly higher percentage of BrdU-labeled cells within the urothelium at 1-day than in the MP and LP. A time-dependent shift at 3 and 5-days post-STC revealed significantly fewer BrdU-labeled cells in the MP than LP or urothelium. By 7-days the percentage of BrdU-labeled cells was similar among urothelium, LP and MP. STC also caused an increase in immunostaining for Shh, Gli-1 and BMP-4. In summary, the early stages of functional bladder regeneration are characterized by time-dependent changes in the location of the proliferating cell population, and expression of several evolutionarily conserved developmental signaling proteins. This report extends

A rapid and efficient in vitro regeneration system for lettuce (Lactuca sativa L.).

Science.gov (United States)

Armas, Isabel; Pogrebnyak, Natalia; Raskin, Ilya

2017-01-01

Successful biotechnological improvement of crop plants requires a reliable and efficient in vitro regeneration system. Lettuce ( Lactuca sativa L.), one the most important vegetable crops worldwide, is strongly genotype-dependent in terms of regeneration capacity, limiting the potential for biotechnological improvement of cultivars which show recalcitrance under currently available protocols. The effect of different nutrient sources, plant hormone combinations and activated charcoal supplementation on shoot induction efficiency was evaluated on the cultivar 'RSL NFR', which had previously shown poor regeneration efficiency. Multiple shoot organogenesis from cotyledon explants was recorded at the highest frequency and speed on Murashige and Skoog regeneration medium supplemented with 200 mg/l of activated charcoal, 3% sucrose, 10 mg/l benzylaminopurine and 0.5 mg/l naphthaleneacetic acid, which induced shoots through direct regeneration in 90.8 ± 7.9% of explants. High shoot induction efficiency was also observed, albeit not quantified, when using this medium on some other cultivars. This activated charcoal-containing regeneration medium might offer a rapid and efficient option for direct shoot induction in some lettuce genotypes that do not respond well to common lettuce regeneration protocols. This is also the first report of the effect of activated charcoal in lettuce tissue culture.

Direct adventitious shoot bud formation on hypocotyls explants in Millettia pinnata (L.) Panigrahi- a biodiesel producing medicinal tree species

OpenAIRE

Nagar, Durga Singh; Jha, Suman Kumar; Jani, Jigar

2015-01-01

A reproducible protocol developed for in vitro regeneration of Milletia pinnata using hypocotyl segments. Multiple shoots were induced from hypocotyl explants through direct adventitious shoot bud regeneration. The proximal end of hypocotyls was responsive for shoot bud induction. Silver nitrate and adenine sulphate had a positive effect on shoot bud induction and elongation. The maximum response and number of shoot bud produced in media supplemented with 8.88 μM BAP with 108.6 μM adenine sul...

Direct shoot organogenesis of Digitalis trojana Ivan., an endemic ...

African Journals Online (AJOL)

STORAGESEVER

2010-03-15

Mar 15, 2010 ... An efficient protocol for in vitro propagation of Digitalis trojana Ivan. was developed via adventitious shoot regeneration. Leaf explants were cultured on MS which were supplemented with different concentrations of NAA (0.1, 0.5, 1.0 mg/ml) and BAP (0.1, 0.5, 1.0, 3.0, 5.0 mg/ml) for shoot formation.

Optimization of soybean (glycine max L.) regeneration for korean cultivars

International Nuclear Information System (INIS)

Phat, P.; Rehman, S. U.; Ju, H. J.; Jung, H. I.

2015-01-01

Tissue culture could provide key insights into the development of transgenic plants, production of good cultivars and secondary metabolites, conservation of endangered plants, and safeguarding of germplasms. In this study, the effects of shoot induction media, explants, cultivars, and phytohormone concentrations on the regeneration efficiency of Korean soybean cultivars were evaluated. Restricted dormancy and poor germination may affect regeneration, depending on the type of germination medium or initiation of phytohormone treatment. Therefore, we analyzed the effects of different germination media containing plant growth regulators, i.e. 6-benzyladenine (BAP), gibberellic acid 3 (GA /sub 3/), and naphthalene acetic acid (NAA), prior to investigating the influences of explant types, media with or without vitamins, cultivars, and different phytohormones (BAP and GA3). A high frequency of germination was observed in Murashige and Skooge (MS) medium with vitamins supplemented with 1 mg L /sup -1/ BAP and 0.25 mg L /sup -1/ GA /sub 3/. Cotyledonary node explants and Gamborg B5 with vitamins supplemented with 1 mg L /sup -1/ BAP and 0.17 mg L /sup -1/ GA /sub 3/ in callus induction medium (CIM) and 1 mg L /sup -1/ BAP in shoot induction medium (SIM) were found to be the most efficient conditions for induction of soybean regeneration, both in callus development and shoot regeneration. Two Korean soybean cultivars, cv. Daepung and Nampung, showed similar development of shoot regeneration efficiency, but significantly different shoot induction times. Therefore, the protocol reported here may be used for further development of regeneration efficiency and can be employed for efficient transformation in soybeans. (author)

Agrobacterium-mediated transformation of cotton (Gossypium hirsutum) shoot apex with a fungal phytase gene improves phosphorus acquisition.

Science.gov (United States)

Ma, Zhiying; Liu, Jianfeng; Wang, Xingfen

2013-01-01

Cotton is an important world economic crop plant. It is considered that cotton is recalcitrant to in vitro proliferation. Somatic embryogenesis and plant regeneration has been successful by using hypocotyl, whereas it is highly genotype dependent. Here, a genotype-independent cotton regeneration protocol from shoot apices is presented. Shoot apices from 3- to 5-day-old seedlings of cotton are infected with an Agrobacterium strain, EHA105, carrying the binary vector pC-KSA contained phytase gene (phyA) and the marker gene neomycin phosphotransferase (NPTII), and directly regenerated as shoots in vitro. Rooted shoots can be obtained within 6-8 weeks. Plants that survived by leaf painting kanamycin (kan) were -further analyzed by DNA and RNA blottings. The transgenic plants with increased the phosphorus (P) acquisition efficiency were obtained following the transformation method.

A new approach for in vitro regeneration of tomato plants devoid of exogenous plant growth hormones.

Science.gov (United States)

Plana, Dagmara; Fuentes, Alejandro; Alvarez, Marta; Lara, Regla M; Alvarez, Félix; Pujol, Merardo

2006-10-01

Many available methodologies for in vitro regeneration of commercial tomato varieties promote not only the production of normal shoots but also individual leaves, shoots without apical meristems and vitrified structures. All these abnormal formations influence and diminish the regeneration efficiency. At the basis of this phenomenon lies callus development. We optimized an alternative procedure by which the regeneration occurs without abnormal shoot formation. The portion including the proximal part of hypocotyls and the radicle was cultured on medium consisting of Murashige and Skoog salts, 4 mg/L thiamine, 100 mg/L mio-inositol and 3% sucrose. After two-three weeks, 60% explants showed adventitious shoot formation. No changes in the morphological characteristics of regenerated plants and fruits were observed as compared with parents. Karyotypic analysis of regenerated plants showed no variations in chromosome number. The optimized procedure offers the advantage of tomato plant regeneration avoiding callus formation, which enables normal plant recovery with an efficiency ranging from 1.45 +/- 0.05 to 2.57 +/- 0.06 shoots per explant in Campbell-28, Amalia, Lignon, and Floradel cultivars.

Improving adventitious shoot regeneration from cultured leaf ...

African Journals Online (AJOL)

The effect of various concentrations of thidiazuron (TDZ) with or without 2.7 μM of α-naphthalene acetic acid (NAA) on adventitious shoot formation of two Petunia hybrida cultivars was studied. Seeds from 'Daddy Blue' and 'Dreams White' cultivars were germinated in vitro. Expanded leaves from both seedlings and ...

An evaluation of a new approach to the regeneration of Helichrysum italicum (Roth) G. Don, and the molecular characterization of the variation among sets of differently derived regenerants.

Science.gov (United States)

Perrini, Rosaria; Alba, Vittorio; Ruta, Claudia; Morone-Fortunato, Irene; Blanco, Antonio; Montemurro, Cinzia

2009-01-01

A protocol for the induction of regeneration from leaves of Helichrysum italicum was established. Calli were found to form on the basal medium only when it was supplemented with thidiazuron (TDZ) alone or in combination with naphthalene acetic acid (NAA), with a percentage ranking of at least 80%. The hormone-free medium showed the highest percentage of shoot regeneration (62%) even though no callus formed. AFLP markers were employed to verify tissue culture-induced variation in the regenerated plantlets obtained by direct shoot regeneration or the indirect shoot regeneration process (callus formation). Seven out of the eleven AFLP primer pairs yielded polymorphic patterns. The average number of fragments per primer pair was 64.1. Singletons were represented by 12 (2.7%) fragments. Student's T-test was performed both on the average number of shared fragments and on the nucleotide diversity, and no significant statistical difference was observed between the two regeneration treatments.

Plant regeneration from cotyledons of mature soybean (Glycine max L.) Wilis cultivar using gamma rays

International Nuclear Information System (INIS)

Hutabarat, D.; Ratna, R.

1999-01-01

Soybean Wilis cultivar was efficiently regenerated in vitro via somatic embryogenesis. Cotyledonary explants were excised from mature germinating seeds. Seeds were germinated on agar solution and on B5 medium enriched with 5 ppm BA, 0.25 ppm BA, 0.25 ppm IBA and 500 ppm casein hydrolyzate. Cotyledonary nodes from both germinating seeds were excised and cultured on B5 medium enriched with 5 ppm BA, 0.25 ppm IBA and 500 ppm casein hydrolyzate. Age of seedlings had a remarkable influence on shoot regeneration. Cotyledon from seeds germinated on agar solution with light gave better result in shoot regeneration compare with those germinated in darkness. The highest number of regenerants per explants (5 shoots) was produced by cotyledon from seeds germinated on B5 medium enriched with 5 ppm IBA and 500 ppm casein hydrolyzate in darkness. The seeds of soybean were exposed to gamma-rays doses 10 Gy then germinated on B5 medium enriched with 5 ppm BA, 0.25 ppm IBA and 500 ppm casein hydrolyzate did not improve the number of plant regeneration. Only 5-day-old seedlings from seeds were exposed to gamma-rays dose 30 Gy could improve the number of shoot regeneration, one of the cotyledonary node treated produced 21 regeneration shoots

Spine micromorphology of normal and hyperhydric Mammillaria gracilis Pfeiff. (Cactaceae) shoots.

Science.gov (United States)

Peharec, P; Posilović, H; Balen, B; Krsnik-Rasol, M

2010-07-01

Artificial conditions of tissue culture affect growth and physiology of crassulacean acid metabolism plants which often results in formation of hyperhydric shoots. In in vitro conditions Mammillaria gracilis Pfeiff. (Cactaceae) growth switches from organized to unorganized way, producing a habituated organogenic callus which simultaneously regenerates morphologically normal as well as altered hyperhydric shoots. In this study, influence of tissue culture conditions on morphology of cactus spines of normal and hyperhydric shoots was investigated. Spines of pot-grown Mammillaria plants and of in vitro regenerated shoots were examined with stereo microscope and scanning electron microscope. The pot-grown plants had 16-17 spines per areole. In vitro grown normal shoots, even though they kept typical shoot morphology, had lower number of spines (11-12) and altered spine morphology. This difference was even more pronounced in spine number (six to seven) and morphology of the hyperhydric shoots. Scanning electron microscopy analysis revealed remarkable differences in micromorphology of spine surface between pot-grown and in vitro grown shoots. Spines of in vitro grown normal shoots showed numerous long trichomes, which were more elongated on spines of the hyperhydric shoots; the corresponding structures on spine surface of pot-grown plants were noticed only as small protrusions. Scanning electron microscopy morphometric studies showed that the spines of pot-grown plants were significantly longer compared to the spines of shoots grown in tissue culture. Moreover, transverse section shape varies from elliptical in pot-grown plants to circular in normal and hyperhydric shoots grown in vitro. Cluster and correspondence analyses performed on the scanning electron microscope obtained results suggest great variability among spines of pot-grown plants. Spines of in vitro grown normal and hyperhydric shoots showed low level of morphological variation among themselves despite the

Regeneración de brotes adventicios en hojas de guayaba (Psidium guajava L. cultivadas in vitro Adventitious shoot regeneration from in vitro cultured leaves of guava (Psidium guava L.

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Trujillo Sánchez Reinaldo

2004-12-01

Full Text Available La regeneración de brotes adventicios es una etapa clave para la aplicación de las técnicas de ingeniería gené­tica. El presente trabajo tuvo como objetivo el desarrollo de un procedimiento para la regeneración de brotes por organogénesis a partir de hojas de microesquejes o brotes de guayaba (Psidium guajava L. cultivados in vi­tro. Para ello se estudiaron algunos de los principales factores que afectan la regeneración de brotes, tales como la concentración de reguladores del crecimiento (citoquinina, el estado fisiológico del explante y la he­rida. En todos los experimentos se utilizaron como explantes hojas de vitroplantas de guayaba de la variedad Enana Roja Cubana EEA18-40 de diferentes subcultivos. El mejor resultado se alcanzó con una concentración de 0,75 mg/L de 6-bencilaminopurina como suplemento hormonal del medio MS. Se comprobó que para las hojas provenientes de microesquejes con mayor número de subcultivo y tomadas de la parte inferior de los brotes, el potencial morfogenético disminuye significativamente (p60% y el mayor número de brotes por explante promedio (>3 se alcanzó al realizar varias heridas en forma de punteaduras en el nervio central de las hojas. Este protocolo de regeneración constituye una importante herramienta que puede ser empleada para futuros estudios de transformación genética en esta especie. Palabras clave: cultivo de tejidos, explantes de hoja, reguladores de crecimiento, organogénesis, guayaba.Adventitious regeneration is a key step in the application of genetic engineering to the breeding programs of plants. In this work a method for adventitious shoot regeneration from leaves of micropropagated guava shoots has been developed and some of main factors to affect the shoot regeneration like, concentration of plant growth regulators (citoquinine, physiological state of explants and the wound are studied. Leaves from guava in vitro cultured of variety Cuban Red Dwarf 18-40 was used

Studies on Callus Induction and Regeneration of Medicinal Plant Chicory (Cichorium intybus L. from Leaf and Petiole Explants

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H. Hadizadeh

2016-07-01

Full Text Available Introduction: Chicory (Cichorium intybus L. belongs to Asteraceae family is commonly known as witloof chicory. The leaves and the roots of this medicinal plant are edible and commonly used as salad. Some varieties are also cultivated as coffee substitute after roasting the roots. All parts of the plant contain these volatile oils, with the majority of the toxic components concentrated in the plant's root. In folk medicine, the plant is used for the treatment of diarrhea, spleen enlargement, fever, and vomiting. Antihepatotoxic activity on damaged rat’s liver sections and anti-bacterial activity of this crop has been recently reported. In vitro regeneration from leaf explants with various hormonal combinations has been reported previously. Moreover, in vitro regeneration of Chicory from cotyledon explants using different combinations of plant growth regulators has been studied. Also, a protocol for the regeneration of plantlets from leaf and petiole explants of witloof chicory has been developed. The aim of the present investigation was optimization of callus induction and shoot regeneration from leaf and petiole tissues of Chicory (Esfahan genotype. Materials and Methods: In this investigation, Esfahan genotype was used for callus induction and direct shoot regeneration. Seeds were first washed with running tap water for 30 min then seeds were surface sterilized by dipping in 70% ethanol for 90 s and rinsed with sterile distilled water, followed by immersing in 5% sodium hypochlorite solution for 25 min and thereafter rinsed for 30 min with sterile distilled water. The basal medium used in this investigation was MS. For shoot regeneration, leaf and petiole explants (5 mm segments were excised from 4-week-old sterile seedlings and cultured on MS medium containing different combinations of NAA / BA and KIN / BA in two separate experiments. Experiments were performed factorial based on completely randomized design. Cultures were incubated at 25�

High Frequency Multiple Shoot Induction of Curculigo orchioides Gaertn.: Shoot Tip V/S Rhizome Disc

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K. S. Nagesh

2008-09-01

Full Text Available Curculigo orchioides Gaertn. is an endangered medicinal plant with anticancer properties. The rhizome and tuberous roots of the plant have been used extensively in India in indigenous medicine. Due to its multiple uses, the demand for Curculigo orchioides is constantly on the rise; however, the supply is rather erratic and inadequate. Destructive harvesting, combined with habitat destruction in the form of deforestation has aggravated the problem. The plant is now considered ‘endangered’ in its natural habitat. Therefore, the need for conservation of this plant is crucial. Here, we describe a successful protocol for multiple shoot induction of C. orchioides using shoot tip and rhizome disc. We find that proximal rhizome discs are optimal for high frequency shoot bud formation than shoot tip and distal rhizome disc. We observed a synergistic effect between 6-benzylaminopurine (BAP and kinetin (KN (each at 1 mg/L on the regeneration of shoot buds from proximal rhizome disc than shoot tip explant. Optimum root induction was achieved on half-strength MS liquid medium supplemented with 1 mg/L of indole-3-butyric acid (IBA. The in vitro raised plantlets were acclimatized in green house and successfully transplanted to natural condition with 90% survival.

In vitro shoot multiplication and conservation of Caralluma ...

African Journals Online (AJOL)

Jane

2011-03-30

Burm. f.) Merrill. In Vitro Cell Deve. Biol. Plant. 41: 124-128. Thomas TD, Shankar S (2009). Multiple shoot induction and callus regeneration in Sarcostemma brevistigma Wight & Arnott, a rare medicinal plant. Plant Biotechnol.

Plant regeneration through organogenesis and shoot proliferation in ...

African Journals Online (AJOL)

STORAGESEVER

2008-10-20

Oct 20, 2008 ... Effect of 2,4-D, NAA and BA (in MS medium) on Trichodesma indicum callus induction and shoot .... Structure/activity relationships of the fenotoxic potentcies of sixteen pyrrolizidine ... In vitro propagation of Cordia verbe- ...

Shoot regeneration of limau purut (citrus hystrix) using shoot tip: assessment of calcium gluconate and silver nitrate in overcoming premature leaf senescence

International Nuclear Information System (INIS)

Eng, W.H.; Aziz, M.A.; Sinniah, U.R.

2014-01-01

This study was carried out to establish an optimum In vitro shoot multiplication system using shoot tip explants derived from 7 week-old seedlings of Citrus hystrix. In the first experiment, shoot tips were cultured on Murashige and Skoog (MS) medium supplemented with 0-13.33 mu M 6-benzylaminopurine (BAP) for 8 weeks. Shoot tips cultured on 2.22 mu M BAP produced the highest mean number of shoots (3.42 shoots) but the shoots had low number of leaves (1.14 leaves) due to the occurrence of premature leaf senescence and callus formation. Meanwhile, the medium devoid of BAP produced the lowest mean number of shoots (1.50 shoots) but highest mean number of leaves (5.41 leaves) indicating that BAP was likely responsible for the premature leaf senescence. In order to overcome the occurrence of premature leaf senescence on medium with BAP, a second experiment was carried out whereby shoot tips were cultured on medium containing 2.22 micro M BAP fortified with 2.00, 4.00 and 6.00 mM calcium gluconate (Ca-glu) and a control treatment with 2.22 mu M BAP. The shoot and leaf numbers were increased with the addition of 4.00 and 6.00 mM Ca-glu. The presence of Ca-glu reduced premature leaf senescence and callus formation to some extent. In the third experiment, the addition of silver nitrate (AgNO/sub 3/) at 10-80 micro M in media with 2.22 micro M BAP and 2.22 micro M BAP + 4 mM Ca-glu could totally overcome premature leaf senescence and callus formation. Media supplemented with 2.22 mirco M BAP + 4 mM Ca-glu + 20 micro M AgNOsub 3/ significantly induced among the highest mean number of shoots and highest mean number of leaves per shoot. (author)

An efficient protocol for regeneration and transformation of Symphyotrichum novi-belgii

DEFF Research Database (Denmark)

Mørk, Eline Kirk; Henriksen, Karin; Brinch-Pedersen, Henrik

2012-01-01

) fusion gene, and an enhanced green fluorescent protein gene. Pre-cultured hypocotyl explants were transformed in the presence of 100 μM acetosyringone using 90 s sonication plus 10 min vacuum-infiltration. Kanamycin at 20 mg l−1 was used for selecting transformed cells. Adventitious shoots regenerated......II genes in GUS-positive shoots were confirmed by PCR and copy number of the nptII gene in PCR-positive shoots was determined by Southern blotting. Three transgenic plantlets were acclimatized to the greenhouse. This transformation and regeneration system using hypocotyls provides a foundation...

Development of Sirococcus shoot blight following thinning in western hemlock regeneration.

Science.gov (United States)

Charles G. Shaw; Thomas H. Laurent; Spencer. Israelson

1981-01-01

Shoot mortality from Sirococcus strobilinus Preuss. and other causes was recorded by crown position from April 1978 through October 1979 in younggrowth western hemlock (Tsuga heterophylla (Raf.) Sarg.) crop trees released in a 1977 thinning at Thomas Bay, Alaska. All study trees contained some infected shoots, but no terminal...

Regeneration efficiency based on genotype, culture condition and growth regulators of eggplant (Solanum melongena L.

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Md Abdul Muktadir

2016-01-01

Full Text Available Several experiments were carried out to establish an efficient regenerating protocol for cultivated eggplant varieties. Among the five varieties cultured on Murashige and Skoog (MS medium with free plant growth regulator (PGR, Nayantara performed better considering the number of shoots/explant (2.48. Considering explant types and culture conditions, better performance was observed (3.68 shoots/explant when seed germination in the dark was proceeded by bottom hypocotyl segments cultured under dark conditions. A higher rate of shoot regeneration was observed in Nayantara when cultured in Zeatin Riboside (ZR and Thidizuron (TDZ supplemented MS medium. The highest number of shoots per explant was produced on MS medium supplemented with 2.0 mg/L ZR and 0.1 mg/L indole acetic acid (6.65 shoots/explant. Proliferation and elongation of the regenerated shoots were obtained in the MS medium with free PGR. The best rooting performance was observed in MS medium supplemented with 2.0 mg/L indole butyric acid. Plantlets with well developed roots and shoots were successfully transferred to soil.

Direct adventitious shoot bud formation on hypocotyls explants in Millettia pinnata (L.) Panigrahi- a biodiesel producing medicinal tree species.

Science.gov (United States)

Nagar, Durga Singh; Jha, Suman Kumar; Jani, Jigar

2015-04-01

A reproducible protocol developed for in vitro regeneration of Milletia pinnata using hypocotyl segments. Multiple shoots were induced from hypocotyl explants through direct adventitious shoot bud regeneration. The proximal end of hypocotyls was responsive for shoot bud induction. Silver nitrate and adenine sulphate had a positive effect on shoot bud induction and elongation. The maximum response and number of shoot bud produced in media supplemented with 8.88 μM BAP with 108.6 μM adenine sulphate and 11.84 μM silver nitrate. Elongated shoots were harvested and successful rooting of microshoots achieved on MS media supplemented with 9.84 μM IBA, with 81.1 % rooting. Remaining shoot buds sub-cultured for further multiplication and elongation. Each subculture produced eight to nine elongated microshoots up to four subcultures. The rooted microshoots were successfully hardened and transferred to field.

Plant Regeneration Through Tissue Culture Of Pear Millet ...

African Journals Online (AJOL)

1. 1. 2,5), MS(5) and N6(1.100.25) culture media, calli embryogenic potential and fertile plants regeneration were conserved for more than 12 months. Characteristics of regenerated plants were similar to control. It appears that dissected shoot ...

Auxin-cytokinin synergism in vitro for producing genetically stable plants of Ruta graveolens using shoot tip meristems

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Mohammad Faisal

2018-02-01

Full Text Available An efficient micropropagation protocol was developed for Ruta graveolens Linn. using shoot tip meristems derived from a 4-month-old field grown plant. In vitro shoot regeneration and proliferation was accomplished on Murashige and Skoogs (MS semi-solid medium in addition to different doses of cytokinins viz.6- benzyl adenine (BA, Kinetin (Kn or 2-isopetynyl adenine (2iP, singly or in combination with auxins viz. indole-3-acetic acid (IAA, indole-3-butyric acid (IBA or α-naphthalene acetic acid (NAA. Highest regeneration frequency (27.6% was obtained on (MS medium composed of BA (10 µM with maximum number (9.4 of shoots and 4.3 cm shoot length after 4 weeks of incubation. Among various combinations tried best regeneration frequency (71% of multiple shoot formation with highest number (12.6 of shoots per shoot tip explants were achieved in MS medium augmented with a combination BA (10.0 µM and NAA (2.5 µM after 4 weeks of incubation. The optimum frequency (97% of rhizogenesis was achieved on half-strength MS medium having 0.5 µM IBA after 4 weeks of incubation. Tissue culture raised plantlets with 5–7 fully opened leaves with healthy root system were successfully acclimatized off in Soilrite™ with 80% survival rate followed by transportation to normal soil under natural light. Genetic stability among in vitro raised progeny was evaluated by ISSR and RAPD markers. The entire banding pattern revealed from in vitro regenerated plants was monomorphic to the donor. The present protocol provides an alternative option for commercial propagation and fruitful setting up of genetically uniform progeny for sustainable utilization and germplasm preservation.

Optimization of Protocols for In Vitro Regeneration of Sugarcane (Saccharum officinarum

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Shakra Jamil

2017-01-01

Full Text Available Sugarcane contributes 60–70% of annual sugar production in the world. Somaclonal variation has potential to enhance genetic variation present within a species. Present study was done to optimize an in vitro propagation protocol for sugarcane. The experiments included four varieties, 9 callus induction media, 27 regeneration media, and 9 root induction media under two-factor factorial CRD. Data were recorded on callus induction, embryogenic callus formation, shoot elongation (cm, root induction, and plant regeneration. Statistically significant differences existed between genotypes and treatments for callus induction (%, embryogenic callus formation (%, shoot elongation (cm, root induction, and plant regeneration (%. All parameters showed dependency on genotypes, culture media, and their interaction. Highest callus induction (95% embryogenic callus formation (95% was observed in callus induction media 5. Highest plantlet regeneration (98.9% capacity was observed in regeneration media 11 whereas maximum shoot elongation (12.13 cm and root induction (8.32 were observed in rooting media 4. G1 showed best response for all traits and vice versa for G4. Hence it was concluded that G1, callus induction media 5, regeneration media 11, and rooting media 4 are the best conditions for in vitro propagation of sugarcane.

Heritability of regeneration in tissue cultures of sweet potato (Ipomoea batatas L.).

Science.gov (United States)

Templeton-Somers, K M; Collins, W W

1986-03-01

A population of open-pollinated progeny from 12 parents, and the 12 parents, was surveyed for in vitro growth and regeneration characteristics. Four different tissue culture procedures involving different media and the use of different explants to initiate the cultures were used. Petiole explants from young leaves were used as explants for initiation of callus cultures. These were evaluated for callus growth rate, friability, and callus color and texture, before transferring to each of three different regeneration media for evaluation of morphogenetic potential. Small shoot tips also were used to initiate callus cultures, which were evaluated for the same growth characteristics and transferred to growth-regulator free regeneration media. Regeneration occurred through root or shoot regeneration or through embryogenesis. Tissue culture treatment effects, as well as genotypic effects, were highly significant in determining: the types of callus produced, callus growth rates, color and texture on the two types of media used for the second and third subcultures. The family x treatment interaction was generally not statistically significant, affecting only callus color. Estimates of narrow sense heritability for callus growth rate in both the second and third subcultures were high enough (0.35 and 0.63, respectively) for the evaluation of parental lines for selection procedures. These characteristics were also the only early culture callus traits that were consistently correlated with later morphogenesis of the cultures. They were negatively correlated with root or shoot regeneration. The occurence of somatic embryogenesis was not correlated with early callus growth characteristics. Genetic and treatment effects were highly significant in the evaluation of morphogenetic potential, through root or shoot regeneration, or through embryogenesis. Regeneration of all types was of low frequency for all procedures, expressed in ≦ 11% of the cultures of the total population.

Efficient genetic transformation of Lotus corniculatus L. using a direct shoot regeneration protocol, stepwise hygromycin B selection, and a super-binary Agrobacterium tumefaciens vector

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Nikolić Radomirka

2007-01-01

Full Text Available Cotyledons from 6-day-old Lotus corniculatus cv. Bokor seedlings, transversally cut into two halves, were capa­ble of regenerating buds without intervening callus formation. The explants were co-cultivated with the Agrobacterium tumefaciens LBA4404/pTOK233 superbinary vector carrying the uidA-intron gene and the genes hpt and nptII. They were cultured for 14 days on a regeneration medium, then subjected to a stepwise hygromycin B selection procedure consisting of gradually increasing antibiotic concentrations (5-15 mg L-1 over 21 weeks. Transformed shoots were obtained within 5 months after co-cultivation. Out of 124 initially co-cultivated explants, 52 (42% plants survived hygromycin B selection. The presence of transgenes in regenerated plants was verified by β-glucuronidase histochemical assays and PCR analysis for the presence of uidA gene sequences. Hygromycin B-resistant and PCR-positive T0 plants were cultured in the greenhouse to produce flowers and seeds. The obtained data demonstrate that the reported transformation protocol could be useful for introducing agriculturally important genes into the new L. corniculatus cultivar Bokor.

High frequency plant regeneration from shoot tip explants of ...

African Journals Online (AJOL)

USER

2010-08-02

Aug 2, 2010 ... 16/8-h (light/dark) photoperiod provided by cool white fluorescent light. Multiple .... formation from shoot tip explant of C. colocynthis on MS-medium. S. No. .... micropropagation of Musa sapientum L. (Cavendish Dwarf). Afr. J.

Antioxidant potential in regenerated tissues of medicinally important atropa accuminata

International Nuclear Information System (INIS)

Khan, F. A.; Abbasi, B. H.; Shinwari, Z. K.; Shah, S. H.

2017-01-01

Due to random exploitation from natural resources, an efficient regeneration system of medicinally important but rare plant species, Atropa acuminata for conservation was inevitable. Leaf explants were incubated on MS medium with different level of various plant growth regulators (PGRs) alone and in combination for callus induction and induced organogenesis. After 4 weeks of culture, callus induction was recorded with the highest frequency with 1.0 mg/l thidiazuron (TDZ) supplement. After 5 weeks of subsequent sub-culturing, optimum shoot induction frequency of 89% was achieved with 1.0 mg/l TDZ and 1.0 mg/l a-naphthaleneacetic acid (NAA) supplement. Highest number of shoots/explant (8.2) were recorded on MS medium with 2.0 mg/l 6-benzyladenine (BA)+1.0 mg/l NAA supplement. Shoots in elongation medium was recorded 5.8 cm long in two medium i.e., 1.0 mg/l TDZ supplement and 1.0 mg/l TDZ+1.0 mg/l NAA supplement. Successful In vitro rooting was induced on MS medium with all applied level of indole butyric acid (IBA). The regenerated shoots with well developed roots were successfully acclimatized in sterilized soil and transferred to greenhouse conditions. Furthermore higher activity for detoxifying DPPH free radical was shown by regenerated shoots in this medicinally important plant species. (author)

PLETHORA genes control regeneration by a two-step mechanism

NARCIS (Netherlands)

Kareem, Abdul; Durgaprasad, Kavya; Sugimoto, Kaoru; Du, Yujuan; Pulianmackal, Ajai J.; Trivedi, Zankhana B.; Abhayadev, Pazhoor V.; Pinon, Violaine; Meyerowitz, Elliot M.; Scheres, Ben; Prasad, Kalika

2015-01-01

Summary Regeneration, a remarkable example of developmental plasticity displayed by both plants and animals, involves successive developmental events driven in response to environmental cues. Despite decades of study on the ability of the plant tissues to regenerate a complete fertile shoot

Regeneration and genetic transformation of cowpea (Vigna unguiculata Walp.)

Energy Technology Data Exchange (ETDEWEB)

Filippone, E; Colucci, G; Ciardi, F; Monti, L [Department of Agronomy and Plant Genetics, Univ. of Naples Federico 11, Portici (Italy)

1997-07-01

Regeneration of cowpea (Vigna unguiculata Walp.) was achieved through massive bud formation induced in apical and lateral meristems by the herbicide Thidiazuron (TDZ). The effect of TDZ (5, 10, or 20 {mu}M) was tested in vitro on four different cowpea genotypes. Thidiazuron, even at the highest concentration, had no effect on seed germination. After one month of culture, multiple bud cluster formation was observed in all genotypes tested; about 80% of shoot apices regenerated multiple buds, whilst only 34% of cotyledonary nodes behaved in the same way. Histology of regenerating multiple bud clusters revealed that regeneration initiated from pre-existing meristems in the apex and cotyledonary node. Thidiazuron at 10 {mu}M appeared to be the best concentration to produce clusters with high number of buds, ranging from 5 to 10. Shoot elongation occurred only on MS medium without TDZ. On the same medium, 75% of elongated shoots rooted. For genetic transformation of cowpea, a direct DNA transfer methods in plants under in vivo conditions was tested by electroporation of plasmid DNA into the nodal meristematic cells. Some transformed plants were obtained, and produced T{sub 1} transformed progenies; their transgenic nature was confirmed by Southern analysis. (author). 21 refs, 2 figs, 3 tabs.

Regeneration and genetic transformation of cowpea (Vigna unguiculata Walp.)

International Nuclear Information System (INIS)

Filippone, E.; Colucci, G.; Ciardi, F.; Monti, L.

1997-01-01

Regeneration of cowpea (Vigna unguiculata Walp.) was achieved through massive bud formation induced in apical and lateral meristems by the herbicide Thidiazuron (TDZ). The effect of TDZ (5, 10, or 20 μM) was tested in vitro on four different cowpea genotypes. Thidiazuron, even at the highest concentration, had no effect on seed germination. After one month of culture, multiple bud cluster formation was observed in all genotypes tested; about 80% of shoot apices regenerated multiple buds, whilst only 34% of cotyledonary nodes behaved in the same way. Histology of regenerating multiple bud clusters revealed that regeneration initiated from pre-existing meristems in the apex and cotyledonary node. Thidiazuron at 10 μM appeared to be the best concentration to produce clusters with high number of buds, ranging from 5 to 10. Shoot elongation occurred only on MS medium without TDZ. On the same medium, 75% of elongated shoots rooted. For genetic transformation of cowpea, a direct DNA transfer methods in plants under in vivo conditions was tested by electroporation of plasmid DNA into the nodal meristematic cells. Some transformed plants were obtained, and produced T 1 transformed progenies; their transgenic nature was confirmed by Southern analysis. (author). 21 refs, 2 figs, 3 tabs

Regeneration and acclimatization of salt-tolerant arachis hypogaea plants through tissue culture

International Nuclear Information System (INIS)

Ghauri, E.G.

2006-01-01

Excised embryos of Arachis hypogaea were cultured on Murashige and Skoog's medium (MS medium) supplemented with different combinations of growth hormones. The highest frequency of callus proliferation (80%) was recorded on MS medium mixed with 1.0 mg/1 of 2,4-D and 0.5 mg/1 of BAP. These cultures were treated with 0.65 mg/l of trans-4-hydroxy-L-proline (HyP) a:1d various concentrations (0.1-0.5%) of NaCl. In all cases the presence of salt reduced the fresh mass of callus. Shoot regeneration in the cultures took place when transferred to MS medium supplemented with 1.0 mg/1 of kinetin (Kin) and 0.5 mg/1 of 6-benzyl aminopurine (BAP). Percentage of shoot regeneration decreased with the increase of NaCl (0.1- 0.5%) in the shoot regeneration medium. Root formation in these cultures took place when the cultures were nurtured on MS medium free of growth hormones. Regeneration, hardening and acclimatization of the salt tolerant plants was conducted. (author)

Genetic stability among date palm plantlets regenerated from petiole ...

African Journals Online (AJOL)

The regeneration capacity between the shoot tip and petiole explants that excised from two date palm (Phoenix dactylifera L.) cutivar namely Unknown and Ferhi was compared. It was noted that the shoot tip explants started to swill after several subculture when placed on Murashige and Skoog (MS) medium supplemented ...

A fasciclin-like arabinogalactan-protein (FLA mutant of Arabidopsis thaliana, fla1, shows defects in shoot regeneration.

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Kim L Johnson

Full Text Available BACKGROUND: The fasciclin-like arabinogalactan-proteins (FLAs are an enigmatic class of 21 members within the larger family of arabinogalactan-proteins (AGPs in Arabidopsis thaliana. Located at the cell surface, in the cell wall/plasma membrane, they are implicated in many developmental roles yet their function remains largely undefined. Fasciclin (FAS domains are putative cell-adhesion domains found in extracellular matrix proteins of organisms from all kingdoms, but the juxtaposition of FAS domains with highly glycosylated AGP domains is unique to plants. Recent studies have started to elucidate the role of FLAs in Arabidopsis development. FLAs containing a single FAS domain are important for the integrity and elasticity of the plant cell wall matrix (FLA11 and FLA12 and FLA3 is involved in microspore development. FLA4/SOS5 with two FAS domains and two AGP domains has a role in maintaining proper cell expansion under salt stressed conditions. The role of other FLAs remains to be uncovered. METHOD/PRINCIPAL FINDINGS: Here we describe the characterisation of a T-DNA insertion mutant in the FLA1 gene (At5g55730. Under standard growth conditions fla1-1 mutants have no obvious phenotype. Based on gene expression studies, a putative role for FLA1 in callus induction was investigated and revealed that fla1-1 has a reduced ability to regenerate shoots in an in vitro shoot-induction assay. Analysis of FLA1p:GUS reporter lines show that FLA1 is expressed in several tissues including stomata, trichomes, the vasculature of leaves, the primary root tip and in lateral roots near the junction of the primary root. CONCLUSION: The results of the developmental expression of FLA1 and characterisation of the fla1 mutant support a role for FLA1 in the early events of lateral root development and shoot development in tissue culture, prior to cell-type specification.

Organ and plantlet regeneration of Menyanthes trifoliata through tissue culture

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Urszula Adamczyk-Rogozińska

2014-01-01

Full Text Available The conditions for the regeneration of plants through organogenesis from callus tissues of Menyanthes trifoliata are described. The shoot multiplication rate was affected by basal culture media, the type and concentration of cytokinin and subculture number. The best response was obtained when caulogenic calli were cultured on the modified Schenk and Hildebrandt medium (SH-M containing indole-3-acetic acid (IAA 0,5 mg/l and 6-benzyladenine (BA 1 mg/l or zeatin (2 mg/l. Under these conditions ca 7 shoots (mostly 1 cm or more in length per culture in the 5th and 6th passages could be developed. In older cultures (after 11-12 passages there was a trend for more numerous but shorter shoot formation. All regenerated shoots could be rooted on the SH-M medium supplemented with 0.5 mg/l IAA within 6 weeks; 80% of in vitro rooted plantlets survived their transfer to soil.

The muscle stem cell niche : regulation of satellite cells during regeneration

NARCIS (Netherlands)

Boonen, K.J.M.; Post, M.J.

2008-01-01

Satellite cells are considered to be adult skeletal muscle stem cells. Their ability to regenerate large muscle defects is highly dependent on their specific niche. When these cells are cultured in vitro, the loss of this niche leads to a loss of proliferative capacity and defective regeneration

Rapid plant regeneration of chrysanthemum (Chrysanthemum ...

African Journals Online (AJOL)

STORAGESEVER

2009-05-04

May 4, 2009 ... demand for chrysanthemum, it has become one of the first commercial targets for ... frequency of multiple shoot regeneration response was. 95 and 91%, for nodal ..... Dordrecht, The Netherlands, pp. 91-101. Prasad RN ...

Regeneration and growth rates of allofragments in four common stream plants

DEFF Research Database (Denmark)

Riis, Tenna; Madsen, Tom Vindbæk; Sennels, R. S. H.

2009-01-01

perfoliatus L. and Ranunculus baudotii x pseudofluitans. The objectives of this study were to determine (1) if shoots with an apical tip have higher regeneration (growth of new shoots and rhizomes from allofragments) and colonisation (root attachment in sediment) abilities and higher relative growth rates...

In vitro plant regeneration of Albizia lebbeck (L. from seed explants

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S. Perveen

2013-07-01

Full Text Available Objectives: An efficient and reproducible regeneration protocol for rapid multiplication of Albizia lebbeck (L. was developed by using intact seed explants.Methods: Murashige and Skoog's (MS medium supplemented with different hormones (BA, Kn, GA3 and TDZ was used for the induction of multiple shoots from the seed explants. Ex-vitro rooting was performed by using pulse treatment method in auxins (IBA and NAA and the complete plantlets were transferred to the field.Results: High frequency direct shoot induction was found in aseptic seed cultures of A. lebbeck on Murashige and Skoog medium supplemented with 5.0 µM TDZ (Thiadiazuron. Seeds were germinated after 7 days of culture and induced maximum 8 shoots from the region adjacent to the apex of the primary shoot of the seedling upto 25 days of incubation. Proliferating shoot cultures with increased shoot length was established by sub-culture of excised sprouting epicotyls on MS medium supplied with reduced concentrations of TDZ. Maximum shoot regeneration frequency (76 % with  highest number of shoots (21 and shoot length (5.1 cm per sprouting epicotyl was observed in the MS medium supplemented with 0.5 µM TDZ after 8 weeks of culture. Different concentrations of Indole-3-butyric acid (IBA and α-naphthalene acetic acid (NAA were tested to determine the optimal conditions for ex-vitro rooting of the microshoots. The best treatment for maximum ex-vitro root induction frequency (81 % was accomplished with IBA (250 µM pulse treatment given to the basal end of the microshoots for 30 min followed by their transfer in plastic cups containing soilrite and eventually established in normal garden soil + soilrite (1:1 with 78 % survival rate. In addition, histological study was undertaken to gain a better understanding of the regenerated shoots from the epicotyl region.Conclusion: The findings will be fruitful in getting a time saving and cost effective protocol for the in vitro propagation of Albizia

Evaluation of the tolerance to Finale® in the germination and regeneration of Cuban rice varieties (IACuba-17 and IACuba-19

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Daymí Abreu

2005-01-01

Full Text Available Selection agent used during the shoot selection has an important role on the transgenic plant generation efficiency. In this work, the tolerance to the herbicide Finale® in two Cuban rice cultivars, IACuba17 and IACuba-19 was evaluated, and determined that 10 days exposure to 5 and 10 mg.l-1 of Finale® were enough to avoid seedlings of IAC-17 and IAC-19, respectively. Cultivated calluses (0, 2, 4 and 6 days in the absence of Finale®in the regeneration medium were used to evaluate the minimal concentration of Finale®that totally inhibits shoot regeneration. Pre-induced calluses cultured during two days and 3 mg.l-1 of Finale® in the regeneration medium was the most efficient combination to select shoots during the generation of transgenic plants resistant to the herbicide. Our shoot selection procedure reduces to 3 weeks the time to obtain shoots during the generation of transgenic rice plants. Key words: germination, mature seeds, Oryza, phosphinothricin, regeneration, selection markers

Genotype dependent callus induction and shoot regeneration in ...

African Journals Online (AJOL)

This study aims to observe the effect of genotype, hormone and culture conditions on sunflower (Helianthus annuus L.) callus induction and indirect plant regeneration. Calli were obtained from hypocotyl and cotyledon explants of five different sunflower genotypes; Trakya 80, Trakya 129, Trakya 259, Trakya 2098 and ...

Cryopreservation of in vitro grown shoot tips and apical meristems of the forage legume Arachis pintoi.

Science.gov (United States)

Rey, Hebe Y; Faloci, Mirta; Medina, Ricardo; Dolce, Natalia; Mroginski, Luis; Engelmann, Florent

2009-01-01

A cryopreservation protocol using the encapsulation-dehydration procedure was established for shoot tips (2-3 mm in length) and meristems (0.3-0.5 mm) sampled from in vitro plantlets of diploid and triploid cytotypes of Arachis pintoi. The optimal protocol was the following: after dissection, explants were precultured for 24 h on establishment medium (EM), encapsulated in calcium alginate beads and pretreated in liquid EM medium with daily increasing sucrose concentration (0.5, 0.75, 1.0 M) and desiccated to 22-23 percent moisture content (fresh weight basis). Explants were frozen using slow cooling (1 C per min from 25C to -30C followed by direct immersion in liquid nitrogen), thawed rapidly and post-cultured in liquid EM medium enriched with daily decreasing sucrose concentrations (0.75, 0.50, 0.1 M). Explants were then transferred to solid EM medium in order to achieve shoot regeneration, then on Murashige and Skoog medium supplemented with 0.05 microM naphthalene acetic acid to induce rooting of shoots. With this procedure, 53 percent and 56 percent of cryopreserved shoot tips of the diploid and triploid cytotypes, respectively, survived and formed plants. However, only 16 percent of cryopreserved meristems of both cytotypes regenerated plants. Using ten isozyme systems and seven RAPD profiles, no modification induced by cryopreservation could be detected in plantlets regenerated from cryopreserved material.

Expression and localization of regenerating gene I in a rat liver regeneration model

International Nuclear Information System (INIS)

Wang Jingshu; Koyota, Souichi; Zhou, Xiaoping; Ueno, Yasuharu; Ma Li; Kawagoe, Masami; Koizumi, Yukio; Okamoto, Hiroshi; Sugiyama, Toshihiro

2009-01-01

Regenerating gene (Reg) I has been identified as a regenerative/proliferative factor for pancreatic islet cells. We examined Reg I expression in the regenerating liver of a rat model that had been administered 2-acetylaminofluorene and treated with 70% partial hepatectomy (2-AAF/PH model), where hepatocyte and cholangiocyte proliferation was suppressed and the hepatic stem cells and/or hepatic progenitor cells were activated. In a detailed time course study of activation of hepatic stem cells in the 2-AAF/PH model, utilizing immunofluorescence staining with antibodies of Reg I and other cell-type-specific markers, we found that Reg I-expressing cells are present in the bile ductules and increased during regeneration. Reg I-expressing cells were colocalized with CK19, OV6, and AFP. These results demonstrate that Reg I is significantly upregulated in the liver of the 2-AAF/PH rat model, accompanied by the formation of bile ductules during liver regeneration.

Regeneration of Pelargonium in vitro

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Agnieszka Wojtania

2013-12-01

Full Text Available Pelargonium sp. has been a subject of numerous studies to deterimine the effec tiveness of in vitro techniques to produce a large number of pathogen-free plants. Regeneration of pelargonium plants from the different initial explants as well via organogenesis as via somatic embryogenesis has been obtained. The most effective adventitious shoot formation has been achieved from shoot tips and axillary buds using cytokinin or cytokinin/auxin combinations. Leaf explants, whose general have lower organogenic potency, regenerate better in the presence of thidiazuron. This growth regulator stimulate the somatic embryos production from hypocotyl and cotyledone explants too. The main problem in tissue culture propagation of Pelargonium has been the high tendency to formation of vigorously growing callus with low organogenic potency and rapid senescence of cultures. Moreover, the significant differen ces in requirements to the medium composition (minerals, organic compounds and growth regulators between Pelargonium cultivars has been observed. This makes difficult to develop an universaI method of Pelargonium micropropagation.

Optimization of in vitro regeneration and Agrobacterium tumefaciens-mediated transformation with heat-resistant cDNA in Brassica oleracea subsp. italica cv. Green Marvel.

Science.gov (United States)

Ravanfar, Seyed Ali; Aziz, Maheran Abdul; Saud, Halimi Mohd; Abdullah, Janna Ong

2015-11-01

An efficient system for shoot regeneration and Agrobacterium tumefaciens-mediated transformation of Brassica oleracea cv. Green Marvel cultivar is described. This study focuses on developing shoot regeneration from hypocotyl explants of broccoli cv. Green Marvel using thidiazuron (TDZ), zeatin, and kinetin, the optimization of factors affecting Agrobacterium-mediated transformation of the hypocotyl explants with heat-resistant cDNA, followed by the confirmation of transgenicity of the regenerants. High shoot regeneration was observed in 0.05-0.1 mg dm(-3) TDZ. TDZ at 0.1 mg dm(-3) produced among the highest percentage of shoot regeneration (96.67 %) and mean number of shoot formation (6.17). The highest percentage (13.33 %) and mean number (0.17) of putative transformant production were on hypocotyl explants subjected to preculture on shoot regeneration medium (SRM) with 200 µM acetosyringone. On optimization of bacterial density and inoculation time, the highest percentage and mean number of putative transformant production were on hypocotyl explants inoculated with a bacterial dilution of 1:5 for 30 min. Polymerase chain reaction (PCR) assay indicated a transformation efficiency of 8.33 %. The luciferase assay showed stable integration of the Arabidopsis thaliana HSP101 (AtHSP101) cDNA in the transgenic broccoli regenerants. Three out of five transgenic lines confirmed through PCR showed positive hybridization bands of the AtHSP101 cDNA through Southern blot analysis. The presence of AtHSP101 transcripts in the three transgenic broccoli lines indicated by reverse transcription-PCR (RT-PCR) confirmed the expression of the gene. In conclusion, an improved regeneration system has been established from hypocotyl explants of broccoli followed by successful transformation with AtHSP101 for resistance to high temperature.

Response of Syngonium podophyllum L. ‘White Butterfly’ shoot cultures to alternative media additives and gelling agents, and flow cytometric analysis of regenerants

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JAIME A. TEIXEIRA DA SILVA

2015-05-01

Full Text Available Abstract. Teixeira da Silva JA. 2015. Response of Syngonium podophyllum L. ‘White Butterfly’ shoot cultures to alternative media additives and gelling agents, and flow cytometric analysis of regenerants. Nusantara Bioscience 7: 26-32. Syngonium podophyllum L. (arrowhead vine is a popular leafy indoor pot plant whose tissue culture has been established, primarily through in vitro shoot culture, but several interesting aspects have not yet been explored. In this study, cv. ‘White Butterfly’ was used to investigate the response of shoot formation to alternative gelling agents and media additives. Gellan gum (Gelrite® at 2 g/L resulted in greater leaf production, plantlet fresh weight and higher chlorophyll content (SPAD value than all other gelling agents tested, including agar, Bacto agar, phytagel, oatmeal agar, potato dextrose agar, barley starch and corn starch, when on a basal Hyponex® (NPK = 6.5: 6: 19; 3 g/L medium. Several alternative liquid medium additives tested (low and full fat milk, Coca-Cola®, coffee, Japanese green, Oolong and Darjeeling teas negatively impacted plant growth, stunted roots and decreased chlorophyll content (SPAD value of leaves. Plant growth on medium with refined sucrose or table sugar responded similarly. Poor growth was observed when crude extract from a high rebaudioside-containing stevia (Stevia rebaudiana Bertoni line - an artificial sweetener - was used. Leaf tissue from the control did not show any endopolyploidy but low levels of endopolyploidy (8C were detected in some treatments.

Assessment of the potentiality of TDZ on multiple shoot induction in Bauhinia tomentosa L., a woody legume.

Science.gov (United States)

Naz, Ruphi; Anis, M; Aref, I M

2012-12-01

An efficient and reproducible protocol for in vitro multiplication of Bauhinia tomentosa L. was developed. Multiple shoots were regenerated from cotyledonary node and stem nodal segments excised from in vitro raised seedlings on Murashige and Skoog (MS) medium supplemented with different concentrations (0.1, 0.3, 0.5, 0.8 and 1.0 μM) of thidiazuron (TDZ). The maximum response (62.6%) was recorded on MS medium amended with 0.8 μM TDZ. A long exposure to TDZ for 8 weeks showed abnormalities such as fasciation and compact shoots formation. To avoid adverse effects of prolonged exposure to TDZ in long-term establishment, the culture were transferred to TDZ free MS medium for further multiplication and elongation. The highest number of shoots and shoot length were recorded at the end of fourth subculture passage. Ex vitro rooting was achieved when the basal cut end of regenerated shoots were dipped in 200 μM indole-3-butyric acid (IBA) for half an hour followed by their transplantation in plastic pots filled with sterile Soilrite™ where 60% plantlets grew well and all expressed normal development.

IN VITRO REGENERATION OF LOURO-PARDO (Cordia trichotoma (Vellozo Arrabida ex Steudel

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Nilton César Mantovani

2010-08-01

Full Text Available This study was carried out aiming at evaluating the in vitro regeneration of louro-pardo (Cordia trichotoma (Vellozo Arrabida ex Steudel. Nodal segments were desinfested and innoculated in two basal media: WPM (Wood Plant Médium, 1981 and MS (Murashige & Skoog, 1962 supplemented with BAP (6-Benzylaminopurine, TDZ (Thidiazuron, NAA (Naphthaleneacetic Acid, GA3 (Gibberellic Acid, IBA (Indole-3-Butyric Acid and  A.C. (Activated Charcoal in different combinations and concentrations for each developmental step. The regeneration rate and the shoot elongation were higher in the WPM medium containing 0,1 mg.l-1 of BAP and GA3. The rooting of regenerated shoots was observed in IBA (0,5 mg.l-1 and Ativated Charcoal (1,5 g.l-1.

Influence of calcium content of tissue on hyperhydricity and shoot-tip necrosis of in vitro regenerated shoots of Lavandula angustifolia Mill.

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Marília Pereira Machado

2014-10-01

Full Text Available In the present study, the effects of two CaCl2.2H2O levels (440 and 1320 mg L-1 and two subcultures were evaluated on in vitro shoots of Lavandula angustifolia cv. Provence Blue. Ca2+ content of the apical, middle and basal portion of shoots was determined. Increasing CaCl2.2H2O level in the culture medium increased tissue Ca2+ content and decreased hyperhydricity. Shoot-tip necrosis also decreased with 1320 mg L-1 CaCl2.2H2O, but it did not occur in the second subculture. The middle and basal portion had higher Ca2+ content than apical portion. In non-hyperhydric tissues, there were smaller and more juxtaposed cells. Scanning electron microscopy of the leaves demonstrated that trichomes from in vitro leaf surface occurred in smaller quantities.

In vitro propagation of Cymbidium goeringii Reichenbach fil. through direct adventitious shoot regeneration.

Science.gov (United States)

Park, Han Yong; Kang, Kyung Won; Kim, Doo Hwan; Sivanesan, Iyyakkannu

2018-03-01

The influence of 2,4-dichlorophenoxyacetic acid (2,4-D), benzyladenine (BA), and thidiazuron (TDZ) on direct rhizome induction and shoot formation from rhizome explants of Cymbidium goeringii was explored. Rhizome segments obtained from in vitro seed cultures of C. goeringii were placed on Murashige and Skoog (MS) medium incorporated with 5, 10, 20, or 40 µM 2,4-D and 1, 2, 4, or 8 µM BA or TDZ alone or in combination with 20 µM 2,4-D. The explants developed only rhizomes on MS medium with or without 2,4-D. The highest percent of rhizome formation (100%) was obtained on MS medium incorporated with 20 μM of 2,4-D. The morphology and number of rhizomes varied with the level of 2,4-D in the medium. Direct adventitious shoot formation was achieved on medium incorporated with BA or TDZ. The adventitious shoots produced per explant significantly increased with the supplementation of 2,4-D to cytokinin-containing medium. The highest mean of 21.8 ± 1.8 shoot buds per rhizome segment was obtained in medium fortified with 20 μM 2,4-D and 2 μM TDZ. The greatest percent of root induction (100%) and the mean of 5.3 ± 1.1 roots per shoot were achieved on ½ MS medium incorporated with 2 μM of α-naphthaleneacetic acid. About 97% of the in vitro-produced plantlets acclimatized in the greenhouse. An efficient in vitro propagation protocol was thus developed for C. goeringii using rhizome explants.

Matriptase zymogen supports epithelial development, homeostasis and regeneration

DEFF Research Database (Denmark)

Friis, Stine; Tadeo, Daniel; Le-Gall, Sylvain M.

2017-01-01

Background Matriptase is a membrane serine protease essential for epithelial development, homeostasis, and regeneration, as well as a central orchestrator of pathogenic pericellular signaling in the context of inflammatory and proliferative diseases. Matriptase is an unusual protease in that its...... previously reported for transgenic mice mis-expressing wildtype epidermal matriptase. Equally surprising, mice engineered to express only zymogen-locked endogenous matriptase, unlike matriptase null mice, were viable, developed epithelial barrier function, and regenerated the injured epithelium. Compatible...

Alginate-encapsulation of shoot tips of jojoba [Simmondsia chinensis (Link) Schneider] for germplasm exchange and distribution.

Science.gov (United States)

Kumar, Sunil; Rai, Manoj K; Singh, Narender; Mangal, Manisha

2010-12-01

Shoot tips excised from in vitro proliferated shoots derived from nodal explants of jojoba [Simmondsia chinensis (Link) Schneider] were encapsulated in calcium alginate beads for germplasm exchange and distribution. A gelling matrix of 3 % sodium alginate and 100 mM calcium chloride was found most suitable for formation of ideal calcium alginate beads. Best response for shoot sprouting from encapsulated shoot tips was recorded on 0.8 % agar-solidified full-strength MS medium. Rooting was induced upon transfer of sprouted shoots to 0.8 % agar-solidified MS medium containing 1 mg l(-1) IBA. About 70 % of encapsulated shoot tips were rooted and converted into plantlets. Plants regenerated from encapsulated shoot tips were acclimatized successfully. The present encapsulation approach could also be applied as an alternative method of propagation of desirable elite genotype of jojoba.

In vitro shoot regeneration of fenugreek (Trigonella foenum-graecum ...

African Journals Online (AJOL)

Jane

2010-10-18

Oct 18, 2010 ... sprouts are good source of protein, mineral and vitamin C. (Khan et al. ... hypocotyl explants were isolated from 8 - 10 days old germinated seedlings and ..... TJV (1993). Transformation and regeneration of two cultivars of pea.

TDZ-Induced Plant Regeneration in Jatropha curcas: A Promising Biofuel Plant

KAUST Repository

Kumar, Nitish

2018-03-23

In recent years, Jatropha curcas has pronounced attention due to its capacity of production of biodiesel. Uniform large-scale propagation of J. curcas is one of the significant keys that will eventually decide victory. Direct regeneration is one of the methods which help in the production of uniform and homogenous plant, and TDZ plays an important role in the production of plantlets by direct organogenesis in several number of plant species including J. curcas. Measuring the economical importance of J. curcas and the role of TDZ in shoot regeneration, the present book chapter briefly reviews the impact of TDZ on shoot bud induction from various explants of J. curcas.

TDZ-Induced Plant Regeneration in Jatropha curcas: A Promising Biofuel Plant

KAUST Repository

Kumar, Nitish; Bhatt, Vacha D.; Mastan, Shaik G.; Reddy, Muppala P.

2018-01-01

In recent years, Jatropha curcas has pronounced attention due to its capacity of production of biodiesel. Uniform large-scale propagation of J. curcas is one of the significant keys that will eventually decide victory. Direct regeneration is one of the methods which help in the production of uniform and homogenous plant, and TDZ plays an important role in the production of plantlets by direct organogenesis in several number of plant species including J. curcas. Measuring the economical importance of J. curcas and the role of TDZ in shoot regeneration, the present book chapter briefly reviews the impact of TDZ on shoot bud induction from various explants of J. curcas.

Epithelial regeneration of transposed intestine after high doses of X irradiation

Energy Technology Data Exchange (ETDEWEB)

Both, N.J. de; Vermey, M [Erasmus Universiteit, Rotterdam (Netherlands)

1976-01-01

The regeneration capacities of normal and transposed small bowel epithelium were compared in rats after applying high doses of x irradiation. It has been shown that the potency of the mucosa to regenerate was much higher than assumed and that the mucosa could regenerate after single doses varying from 2000 to 5000 R. Even in the villus epithelium and in flat epithelium covering infiltrates of the lamina propria cells survived, which were still able to resume proliferative activity several days after irradiation.

Epithelial regeneration of transposed intestine after high doses of X-irradiation

International Nuclear Information System (INIS)

Both, N.J. de; Vermey, M.

1976-01-01

The regeneration capacities of normal and transposed small bowel epithelium were compared in rats after applying high doses of X-irradiation. It has been shown that the potency of the mucosa to regenerate was much higher than assumed and that the mucosa could regenerate after single doses varying from 2000 to 5000 R. Even in the villus epithelium and in flat epithelium covering infiltrates of the lamina propria cells survived, which were still able to resume proliferative activity several days after irradiation. (author)

Evaluation of the capacity for direct regeneration of maize inbreds of the Lancaster selection group

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K. V. Derkach

2013-11-01

Full Text Available In connection with the necessity of bringing elite maize inbreds of the Lancaster germplasm group, which have potential for cultivation in Ukraine, into the system of genetic tranformation, the aim of this investigation is to identify the ability of maize inbreds of this group to regenerate by direct organogenesis and to determine the optimal mineral basis for their nutritional environment using segments of the node area of shoots. As explantats we used sterile 4-day old seedlings of 4 maize inbreds of Lancaster germplasm and model inbred Chi31 exotic germplasm. The seedlings were obtained by germination of sterile seeds in Petri dishes between two layers of moist sterile filter paper at a temperature of 27 ºC in dark conditions. A single 1 cmlong segment was cut from each from each seedling, running from 0.5 cmbefore the node to 0.5 cmafter the node. A cut was made in each segment of the node in order to create a wounded surface. Explantats were planted in a nutrient environment with mineral bases of MS or N6, modified by the addition of 10 mg/l silver nitrate, 100 mg/l casein hydrolyzate, 690 mg/l L-proline, 30 g/l sucrose, 1.0 mg/l 2,4-dychlorphenoksiacetic acid and 0,1 mg/l abscisic acid. Cultivation was carried out at 25–27 ºC in the light. Direct hemogenesis in this environment on the 14th day of cultivation in vitro reached 100% for each line. This meant that all researched lines of Lancaster germplasm and the model line showed a high capacity for direct regeneration through direct hemogenesis, which does not depend on the composition of the mineral content of their nutritional environment. Callus formation was observed in all genotypes on the 14th day of cultivation in vitro and the extent of its formation increased during the following month of cultivation. The callus formation was observed only at the site of the wounded surface. The calluses were transparent. Although green areas appeared in these calluses, they were

Direct regeneration and efficient in vitro root development studies in lentil (lens culinaris medik)

International Nuclear Information System (INIS)

Sultana, T.; Majeed, N.; Naqvi, S.

2016-01-01

Lentil is a self-pollinating annual crop with increasing demand all over the world due to its high protein content and easy digestibility. However, like many other crops lentil too needs improvement for which conventional as well as biotechnological tools are to be employed. This study was aimed at development of tissue culture protocol especially targeting improved root development to ensure their establishment in soil in order to use their potential towards genetic manipulation. Two Pakistani lentil cultivars, Masoor-2002 and Manshera-89 were used to obtain cotyledonary nodes, epicotyl and hypocotyl explants. The explants were cultured on shoot regeneration medium containing different concentration of kinetin, BAP and tyrosine with the addition of GA3, with or without charcoal for shoot development. Masoor-2002, showed the highest frequency of shoot development on MS medium containing 5.5 mg/L tyrosine, 0.25 mg/L kinetin, 1.0 mg/L BAP, 0.1 mg/L GA3, using cotyledonary node as explant. The addition of 2 g/L of charcoal in shoot medium resulted in healthier plants, but the number of shoots were reduced. Regarding the effect of age of explants on regeneration frequency, cotyledonary nodes of age 4-6 days had higher regeneration potential. Well-developed shoots were shifted to rooting medium containing different concentration of auxin with or without charcoal. Healthier and more roots were observed on medium containing 4 mg/L IAA with addition of 2 g/L charcoal. Plants were better established (70% survival) in a soil mix containing perlite, vermiculite and peat moss in 1:1:1 ratio. (author)

Genotype, explant, medium, light and radiation effects on the in vitro plant regeneration in alfalfa (Medicago Sativa L.)

International Nuclear Information System (INIS)

El-Fiki, A.A.; Abdel-Hameed, A.A.M.; Sayed, A.I.H.

2005-01-01

The relative importance of genotype, explants, radiation, medium and light and their interactions for in vitro plant regeneration via somatic embryogenesis in alfalfa (Medicago sativa L.) has been studied. Shoot and leaf explants of two commercially grown Egyptian cultivars, Al-Wadi Al-Gadid and Siwa Tarkibi, were used in the study. The effect of gamma radiation doses 40, 80, 120 and 160 Gy were negative on plant regeneration, in spite of increase with some treatments. The best results of plant regeneration were obtained with dose 40 Gy with control light regime (16 h) on MS + 0.5 mg NAA + 1.5 mg BAP in both shoot and leaf explants of cv. Al-Wadi. The shoot explant of cv. Siwa was sensitive for gamma radiation dose 40 Gy while affirmative effect was obtained in leaf explant on MS + 1.0 mg NAA + 0.5 mg BAP with control light regime. However, dose 80 Gy showed the best results on MS + 0.5 mg NAA + 0.5 mg BAP in shoot and leaf explants of both cultivars, with control light regime in shoot explant and dark/light (DL) and dark/dark (DD) in leaf explant of cv. Al-Wadi, while with light/dark (LD) in shoot explant and control light regime in leaf explant of cv. Siwa. On the other hand, the highest plant regeneration ratio observed with dose 120 Gy were on 1.5 mg NAA + 0.5 mg BAP with control light regime in shoot and leaf explants of cv. Al-Wadi but on 0.5 mg NAA + 0.5 mg BAP with control and dark/light (DL) light regime in shoot and leaf explants of cv. Siwa. Whereas, the radiation dose 160 Gy showed severe effect on plant regeneration in both cultivars but highest percentage was observed on MS + 0.5 mg NAA + 0.5 mg BAP with dark/light (DL) in shoot explant, MS + 0.5 mg NAA + 1.5 mg BAP with control light regime in leaf explant of cv. Al-Wadi, MS + 0.5 mg NAA + 1.5 mg BAP in shoot explant and MS + 0.5 mg NAA + 0.5 mg BAP in leaf explant with dark/light (DL) in cv. Siwa. However, the effects of the same doses on callus growth showed that the highest callus weight was

Effect of 60Co γ-rays irradiation on plant regeneration from callus of sea dallisgrass (paspalum vaginatum Sw.)

International Nuclear Information System (INIS)

Ye Xiaoqing; She Jianming; Wang Songfeng; Zhang Xu; Liang Liufang; Dong Mingqiang; Wu Yingying

2010-01-01

The pellet embryonic calli of Paspalum vagiantum Sw. cv. Adalay were used for 60 Co γ-rays irradiation. In the callus subculture medium with 2, 4-D 2.0 mg /L and BAP 0.05 mg /L, calli were irradiated at the dose rate 1 Gy /min of 60 Co γ-rays. Results showed that the rate of shoot regeneration was from 94% to 85% when calli irradiated with 20 ∼ 50 Gy; the rate of shoot regeneration was from 76% to 30%, and the rate of plant regeneration was from 44.5% to 8.7% between 60 ∼ 80 Gy. By 60 Gy of 60 Co γ-rays irradiation, the rate of shoot regeneration was about 76% in the differentiation medium with BAP 2.0 mg /L, and the relative rate of plant regeneration was 44.5% in the rooting medium with NAA 0.5 mg /L. The result of sequence-related amplified polymorphism (SRAP) markers analysis showed that the specific SRAP markers were associated with the somatic mutants. The mutation technique of 60 Co γ-rays has been established in the somatic cell of Paspalum vaginatum Sw. (authors)

Thidiazuron enhanced regeneration and silymarin content in silybum marianum

International Nuclear Information System (INIS)

Khan, M.A.; Abbasi, B.H.; Shinwari, Z.K.

2014-01-01

Silybum marianum, of family Asteraceae is renowned for production of biologically important silymarin, which has shown multi-dimensional medicinal properties. It has a high protective role against jaundice and hepatitis C worldwide. We hereby established a feasible and efficient method for indirect regeneration of S. marianum for production of consistent plantlets. Calli were induced from leaf explants of seed-derived plantlets on Murashige and Skoog (MS) medium supplemented with several concentrations of different plant growth regulators (PGRs). Highest callogenic response (89%) was recorded for 4.4 meu M Thidiazuron (TDZ) in combination with 6.6 meu M Kinetin (Kn). Subsequent sub-culturing of callus after 4 weeks of culture, on medium with similar compositions of PGRs induced shoot organogenesis. Highest shoot induction frequency (86%) with maximum mean multiple shoots (26 shoots per explant) were recorded for 11meu M TDZ after 4 weeks of transfer. Longest shoots (4.1 cm) were recorded for MS medium augmented with 6.6 meu M TDZ and 4.4 meu M naphthalene acetic acid (NAA). Furthermore, rooted plantlets were developed on MS medium containing different concentrations of indole acetic acid (IAA). Silymarin was determined by High performance liquid chromatography (HPLC) and 8.47 mg/g DW silymarin was detected in the regenerated plantlets. This study contributes to a better understanding of the different mechanisms involved in morphogenesis and production of biologically active principle in Silybum marianum. (author)

In Vitro Regeneration of Foxtail Millet (Setaria italica (L. Beauv. cv. Buru Hotong

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Iriawati

2017-09-01

Full Text Available In vitro regeneration of foxtail millet (Setaria italica (L. Beauv. was done using basal shoot explants of 10-day old seedlings. Explants were cultured in MS basal medium supplemented with 2,4-dichlorophenoxyacetic acid (2,4-D, kinetin, 6-benzylaminopurine (BAP and 1.5 ppm NiSO4. Shoot multiplication and root induction were done in Murashige and Skoog (MS basal media. Plantlets were then acclimatized in rice husk charcoal, cocopeat, or mixed media. Results showed that MS basal medium containing 0.5 ppm kinetin, 2 ppm BAP, and 0.1 ppm 2,4-D was the optimal medium for shoot induction, in which 60% of explants developed direct shoot organogenesis. In addition, callus was optimally formed in MS medium supplemented by 1 ppm kinetin, 1 ppm BAP, and 0.5 ppm 2,4-D. Regenerated shoots spontaneously developed roots after being transferred into MS basal media without growth regulator. During acclimatization, the highest survival rate of plantlets (47% was obtained in rice husk charcoal. The developed method could be useful towards improvement of this species using in vitro tissue culture techniques.

Callus induction and plant regeneration of Ulex europaeus

OpenAIRE

Ramírez,Ingrid; Dorta,Fernando; Cuadros-Inostroza,Álvaro; Peña-Cortés,Hugo

2012-01-01

A callus induction and plant regeneration protocol was developed from leaf and thorn explants for the plant Ulex europaeus. Explants were incubated on 2% sucrose half-strength Murashige and Skoog Medium (MS) with various combinations of plant growth regulators and antioxidants. The best frequency of callus and shoot formation was obtained with 2,4-dichlorophenoxyacetic acid (2,4-D) 1 mg/l x kinetin (Kin) 0.2 mg/l (DK Medium; callus induction) and zeatin (Z) 1 mg/l (DK medium; shoot induction)...

Efficient plant regeneration of bittersweet (Solanum dulcamara L., a medicinal plant

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Arzu Ucar Turker

2011-01-01

Full Text Available Solanum dulcamara L. (bittersweet is a medicinal plant that has been used to treat skin diseases, warts, tumors, felons, arthritis, rheumatism, bronchial congestion, heart ailments, ulcerative colitis, eye inflammations, jaundice and pneumonia. A reliable in vitro culture protocol for bittersweet was established. Explants (leaf and petiole segments were cultured on Murashige and Skoog minimal organics (MSMO medium with various plant growth regulator combinations. Leaf explants formed more shoots than petiole explants. Plant regeneration was observed through indirect organogenesis with both explants. Best shoot proliferation was obtained from leaf explants with 3 mg/l BA (benzyladenine and 0.5 mg/l IAA (indole-3-acetic acid. Regenerated shoots were transferred to rooting media containing different levels of IAA (indole-3-acetic acid, IBA (indole-3-butyric acid, NAA (naphthalene acetic acid or 2,4-D (2,4 dichlorophenoxyacetic acid. Most shoots developed roots on medium with 0.5 mg/l IBA. Rooted explants were transferred to vermiculate in Magenta containers for acclimatization and after 2 weeks, they were planted in plastic pots containing potting soil and maintained in the plant growth room.

Improved regeneration and transformation protocols for three strawberry cultivars

Science.gov (United States)

Zakaria, Hossam; Hussein, Gihan M; Abdel-Hadi, Abdel-Hadi A; Abdallah, Naglaa A

2014-01-01

Strawberry (Fragaria × ananassa) is an economically important soft fruit crop with polyploid genome which makes the breeding of new cultivars difficult. Simple and efficient method for transformation and regeneration is required for cultivars improvement in strawberry. In the present study, adventitious shoot regeneration has been investigated in three cultivated strawberry plants, i.e., Festival, Sweet Charly and Florida via direct organogenesis using the in vitro juvenile leaves as explants. Explants were collected after sub-culturing on a propagation medium composed of MS supplemented with 0.5 mg/l BA; 0.1 mg/l GA3 and 0.1 mg/l IBA. To select the suitable organogenesis, the explants of the three cultivars were cultured on MS medium supplemented with different concentrations of TDZ (1, 2, 3, and 4 mg/l), then incubated at a temperature of 22 °C ± 2. Medium containing 2 mg/l TDZ revealed the best regeneration efficiency with the three cultivars (72% for Festival, and 73% for Sweet Charly and Florida). After 4 weeks, the produced shoots were cultured on MS medium with different concentrations of BA and Kin to enhance shoot elongation. Results showed that the medium containing 1.5 mg/l BA and 0.5 mg/l Kin revealed highest elongation efficiency (88% and 94%) for Festival and Sweet Charly, respectively. On the other hand, medium containing 1.5 mg/l BA and 0.1 mg/l Kin showed highest elongation efficiency (90%) in Florida. Elongated shoots were successfully rooted on MS medium containing 1.5 mg/l NAA. Furthermore, transformation of the two cultivars, Festival and Sweet Charly, has been established via Agrobacterium strain LBA44404 containing the plasmid pISV2678 with gus-intron and bar genes. Three days post co-cultivation, GUS activity was screening using the histochemical assay. The results showed 16% and 18% of the tested plant materials has changed into blue color for Festival and Sweet Charly, respectively. Out of 120 explants only 13 shoots were developed on

Establishment of an efficient plant regeneration culture protocol and achievement of successful genetic transformation in Jatropha curcas L.

Science.gov (United States)

Liu, Ying; Liu, Guoxuan; Yang, Yali; Niu, Sufang; Yang, Fuguang; Yang, Shaoxia; Tang, Jianian; Chen, Jianping

2017-12-01

An efficient and reproducible protocol is described for shoot-bud regeneration and Agrobacterium tumefaciens-mediated genetic transformation of J. curcas. Treating the explants with high concentrations (5-120 mg/L) of TDZ for short durations (5-80 min) before inoculation culture increased significantly the regeneration frequency and improved the quality of the regenerated buds. The highest shoot-buds induction rate (87.35%) was achieved when petiole explants were treated with 20 mg/L TDZ solution for 20 min and inoculated on hormone-free MS medium for 30 days. Regenerated shoots of 0.5 cm or a little longer were isolated and grafted to seedling stocks of the same species, and then the grafted plantlets were planted on half-strength MS medium containing 0.1 mg/L IBA and 2 mg/L sodium nitroprusside (SNP). This grafting strategy was found to be very effective, to obtain that healthy grafted plantlets ready for acclimatization within 20 days. By the above mentioned protocol and with general Agrobacterium - mediated genetic transformation methods only 65 days were needed to obtain intact transgenic plants.

The influence of different hormone concentration and combination on callus induction and regeneration of Rauwolfia serpentina L. Benth.

Science.gov (United States)

Salma, U; Rahman, M S M; Islam, S; Haque, N; Jubair, T A; Haque, A K M F; Mukti, I J

2008-06-15

The influence of media composition on callus induction and subsequent regeneration of Rauwolfia serpentina L. Benth has been studied. High frequency (96.43%) callus induction was obtained when nodal segments from in vitro raised shoots were cultured on MS medium supplemented with 0.5 mg L(-1) BA and 2.0 mg L(-1) NAA. The callus differentiated into adventitious shoots when it was subcultured on MS medium supplemented with 2.0 mg L(-1) BA with 0.2 mg L(-1) NAA. Regenerated shoots were best rooted on half-strength MS medium with 1.0 mg L(-1) each of IBA and IAA.

Thidiazuron: A potent cytokinin for efficient plant regeneration in Himalayan poplar (Populus ciliata Wall. using leaf explants

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Gaurav Aggarwal

2012-11-01

Full Text Available Populus species are important resource for certain branches of industry and have special roles for scientific study on biological and agricultural systems. The present investigation was undertaken with an objective of enhancing the frequency of plant regeneration in Himalayan poplar (Populus ciliata Wall.. The effect of Thiadizuron (TDZ alone and in combination with adenine and α-Naphthalene acetic acid (NAA were studied on the regeneration potential of leaf explants. A high efficiency of shoot regeneration was observed in leaf (80.00% explants on MS basal medium supplemented with 0.024 mg/l TDZ and 79.7 mg/l adenine. Elongation and multiplication of shoots were obtained on Murashige and Skoog (MS basal medium, containing 0.5 mg/l 6. Benzyl aminopurine (BAP + 0.2mg/l Indole 3-acetic acid (IAA + 0.3 mg/l Gibberellic acid (GA3. High frequency root regeneration from in vitro developed shoots was observed on MS basal medium supplemented with 0.10 mg/l Indole 3-butyric acid(IBA. Maximum of the in vitro rooted plantlets were well accomplished to the mixture of sand: soil (1:1 and exhibited similar morphology with the field plants. A high efficiency plant regeneration protocol has been developedfrom leaf explants in Himalayan poplar (Populus ciliata Wall..

In vitro plant regeneration from leaf explants of Solanum pimpinellifolium L.

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Shirley Valderrama-Alfaro

2011-01-01

Full Text Available Tomato is a species of agricultural importance. Besides, it is a source of vitamins, minerals and antioxidant compounds. Therefore it is essential to obtain varieties resistant to diseases. Solanum pimpinellifolium L. ‘Tomatillo wild’, one of the wild relatives of tomato, is considered multipurpose reservoir of genes. This characteristic must be exploited. In vitro plantlets from leaves of ‘wild tomatillo’ were regenerated with this objective. A system for in vitro germination of seeds obtained from ex vitro sources was created. The use of seed allowed obtaining adequate seedlings in a short time to start regeneration. Thein vitro response of explants was evaluated in four treatments. The Murashige and Skoog (MS basal culture medium supplemented with a-naphthaleneacetic acid (NAA and 6-benzyl aminopurine (BAP was used in different combinations. The higher percentage (30% of shoot induction was achieved with 0.1 mg l1 NAA / 1 mg l1 BAP. The presence of callus and roots was observed after seven days of culture in the combination treatment with 1 mg l1 NAA / 0.1 mg l1 BAP. Callus showed 1 or 2 adventitious shoots per explant after 30 days of culture and 3 to 6 shoots after seventy days. Furthermore, the presence of fully formed adventitious plantlets (shoot and root was observed after the fifth week of culture. Therefore, the best combination for in vitro regeneration is NAA 0.1 mg l1 / 1 mg l1 BAP. Keywords: auxin, cytokinins, indirect organogenesis

Acetylcholine suppresses shoot formation and callusing in leaf explants of in vitro raised seedlings of tomato, Lycopersicon esculentum Miller var. Pusa Ruby.

Science.gov (United States)

Bamel, Kiran; Gupta, Rajendra; Gupta, Shirish C

2016-06-02

We present experimental evidence to show that acetylcholine (ACh) causes decrease in shoot formation in leaf explants of tomato (Lycopersicon esculentum Miller var Pusa Ruby) when cultured on shoot regeneration medium. The optimum response was obtained at 10(-4) M ACh-enriched medium. ACh also causes decrease in percentage of cultures forming callus and reduces the callus mass. Inhibitors of enzymatic hydrolysis of ACh, neostigmine and physostigmine, also suppresses callogenesis and caulogenesis. On the other hand, the breakdown products of Ach, choline and acetate, do not alter the morphogenic response induced on the shoot regeneration medium. Neostigmine showed optimal reduction in shoot formation at 10(-5) M. The explants cultured on neostigmine augmented medium showed decline in the activity of ACh hydrolyzing enzyme acetylcholinesterase. ACh and neostigmine added together showed marked reduction in callus mass. These results strongly support the role of ACh as a natural regulator of morphogenesis in tomato plants.

Acetylcholine suppresses shoot formation and callusing in leaf explants of in vitro raised seedlings of tomato, Lycopersicon esculentum Miller var. Pusa Ruby

Science.gov (United States)

Bamel, Kiran; Gupta, Rajendra; Gupta, Shirish C.

2016-01-01

ABSTRACT We present experimental evidence to show that acetylcholine (ACh) causes decrease in shoot formation in leaf explants of tomato (Lycopersicon esculentum Miller var Pusa Ruby) when cultured on shoot regeneration medium. The optimum response was obtained at 10−4 M ACh-enriched medium. ACh also causes decrease in percentage of cultures forming callus and reduces the callus mass. Inhibitors of enzymatic hydrolysis of ACh, neostigmine and physostigmine, also suppresses callogenesis and caulogenesis. On the other hand, the breakdown products of Ach, choline and acetate, do not alter the morphogenic response induced on the shoot regeneration medium. Neostigmine showed optimal reduction in shoot formation at 10−5 M. The explants cultured on neostigmine augmented medium showed decline in the activity of ACh hydrolyzing enzyme acetylcholinesterase. ACh and neostigmine added together showed marked reduction in callus mass. These results strongly support the role of ACh as a natural regulator of morphogenesis in tomato plants. PMID:27348536

Plant regeneration of natural tetraploid Trifolium  Hum pratense L

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HATICE ÇÖLGEÇEN

2008-01-01

Full Text Available The regeneration of natural tetraploid T. pratense, originated from Erzurum-Turkey, is reported in this study. This plant has low seed setting and hard seed problems due to polyploidy. Hypocotyl, cotyledon, apical meristems, epicotyl and young primary leaves were inoculated on MS and PC-L2 media containing different concentrations of BAP and NAA as growth regulators. The best shoot formation has been observed on explants initiated from apical meristem placed on PC-L2 medium that includes 2 mg dm-3 BAP and 1 mg dm-3 NAA. 94.4% of the shoots originated from calli were rooted on PC-L2 medium with 1 mg dm-3 NAA. In vitro organogénesis has been accomplished in the natural tetraploid T. pratense regenerated plants successively transferred to the field

Development of an Efficient Regeneration and Transformation Method for Nicothiana tabacum L. through the Optimization of Growth Regulators and Sucrose Concentration

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maria Beihaghi

2018-03-01

Full Text Available Introduction: Plant tissue culture is a collection of techniques used to maintain or grow plant cells, tissues or organs under sterile conditions on a nutrient culture medium of known composition and widely used to produce clones of a plant in a method known as micropropagation. Plant research often involves growing new plants in a controlled environment. These may be plants that we have genetically altered in some way or may be plants of which we need many copies all exactly alike. These things can be accomplished through tissue culture of small tissue pieces from the plant of interest. These small pieces may come from a single mother plant or they may be the result of genetic transformation of single plant cells which are then encouraged to grow and to ultimately develop into a whole plant. Tissue culture techniques are often used for commercial production of plants as well as for plant research. Tobacco (Nicotiana tabacum L. is one of the most important model plants used in the physiologic, genetic and tissue culture studies. The manipulation of tobacco genetic structure requires an efficient technique of gene transferring and regeneration. Whereas, the tobacco plant is a very effective bioreactor in the production of recombinant proteins, in this research we optimized the best tissue culture system and also, genetic transformation process of this plant. Materials and Methods: Our plant tissue culture protocols, Include helpful information for Murashige and Skoog media, plant growth regulators, plant growth hormones, plant transformation systems, and other products for plant tissue culture. For this purpose, different concentrations of sucrose and 4 combinations of growth regulators (BAP and NAA on callus induction, direct shoot regeneration and rooting were examined in a factorial experiment based on completely randomized design with 3 replications. The sensitivity of tobacco explants to kanamycin was examined through the cultivation of them

Cell walls as a stage for intercellular communication regulating shoot meristem development

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Toshiaki eTameshige

2015-05-01

Full Text Available Aboveground organs of plants are ultimately derived/generated from the shoot apical meristem (SAM, which is the proliferative tissue located at the apex of the stem. The SAM contains a population of stem cells that provide new cells for organ/tissue formation. The SAM is composed of distinct cell layers and zones with different properties. Primordia of lateral organs develop at the periphery of the SAM. The shoot apex is a dynamic and complex tissue, and as such intercellular communications among cells, layers and zones play significant roles in the coordination of cell proliferation, growth and differentiation to achieve elaborate morphogenesis. Recent findings have highlighted the importance of a number of singling molecules acting in the cell wall space for the intercellular communication, including classic phytohormones and secretory peptides. Moreover, accumulating evidences reveal that cell wall properties and their modifying enzymes modulate hormone actions. In this review, we overview how behaviors of singling molecules and changes of cell wall properties are integrated for the shoot meristem regulation.

Transplantation of Expanded Fetal Intestinal Progenitors Contributes to Colon Regeneration after Injury

DEFF Research Database (Denmark)

Fordham, Robert P; Yui, Shiro; Hannan, Nicholas R F

2013-01-01

Regeneration and homeostasis in the adult intestinal epithelium is driven by proliferative resident stem cells, whose functional properties during organismal development are largely unknown. Here, we show that human and mouse fetal intestine contains proliferative, immature progenitors, which can...... be expanded in vitro as Fetal Enterospheres (FEnS). A highly similar progenitor population can be established during intestinal differentiation of human induced pluripotent stem cells. Established cultures of mouse fetal intestinal progenitors express lower levels of Lgr5 than mature progenitors and propagate...... in the presence of the Wnt antagonist Dkk1, and new cultures can be induced to form mature intestinal organoids by exposure to Wnt3a. Following transplantation in a colonic injury model, FEnS contribute to regeneration of colonic epithelium by forming epithelial crypt-like structures expressing region...

Plants regeneration from African cowpea variety (Vigna unguiculata ...

African Journals Online (AJOL)

STORAGESEVER

2008-08-18

Aug 18, 2008 ... Vigna unguiculata (L.) Walp. plant was efficiently regenerated from cotyledonary node explants. The shoots multiplication rate was ... Africa, insect pests are often responsible for 100% losses of cowpea yields (Singh and .... 26 days after acclimatization first flower buds were observed; thus plants were ...

Plant regeneration of Erigeron breviscapus (vant.) Hand. Mazz. and its chromatographic fingerprint analysis for quality control.

Science.gov (United States)

Liu, Chun-Zhao; Gao, Min; Guo, Bin

2008-01-01

An efficient micropropagation system for Erigeron breviscapus (vant.) Hand. Mazz., an important medicinal plant for heart disease, has been developed. Shoot organogenesis occurred from E. breviscapus leaf explants inoculated on a medium supplemented with a combination of plant growth regulators. On average, 17 shoots per leaf explant were produced after 30 days when they were cultured on MS basal salts and vitamin medium containing 5 microM 6-benzylaminopurine (BAP) and 5 microM 1-naphthaleneacetic acid (NAA). All the regenerated shoots formed complete plantlets on a medium containing 2.5-10 microM indole-3-butyric acid (IBA) within 30 days, and 80.2% of the regenerated plantlets survived and grew vigorously in field conditions. Based on the variation in common peaks and the produced amount of the most important bioactive component, scutellarin, a high performance liquid chromatography (HPLC) fingerprinting system was developed for quality control of these micropropagated plants. Chemical constituents in E. breviscapus micropropagated plants varied during plant development from regeneration to maturation, the latter of which showed the most similar phytochemical profile in comparison with mother plants. The regeneration protocol and HPLC fingerprint analysis developed here provided a new approach to quality control of micropropagated plants producing secondary metabolites with significant implications for germplasm conservation.

In vitro regeneration of Turkish dwarf chickling (Lathyrus cicera L ...

African Journals Online (AJOL)

STORAGESEVER

2008-06-17

Jun 17, 2008 ... Key words: Immature zygotic embryos, dwarf chickling, Lathyrus cicera L., axillary shoot regeneration, ... are widely used as animal feed in green and dry form or ..... Hanbury CD, White CL, Mullan BP, Siddique KHM (2000).

Micropropagation of chokeberry by in vitro axillary shoot proliferation.

Science.gov (United States)

Litwińczuk, Wojciech

2013-01-01

The black chokeberry-aronia (Aronia melanocarpa Elliot) is a shrub native to North America although nowadays well known in Eastern Europe. The fruits are regarded as the richest source of antioxidant phytonutrients among fruit crops and vegetables. Chokeberries can be easily propagated by seeds but this method is not recommended. Micropropagation is far more efficient than other conventional cloning methods like layering or softwood cuttings. Aronia clones are propagated in vitro through four- or three-stage method based on subculturing of shoot explants. The double diluted MS or full strength MS medium with elevated 50% Ca(2+) and Mg(2+) content are used in the initiation and proliferation chokeberry in vitro cultures, respectively. They are supplemented with 0.5-1.0 mg LBA, and 0.05 mg LIBA. The double-phase medium is recommended in the last passage before shoot rooting. The regenerated shoots could be rooted both in vitro on double diluted MS with 0.05 mg L(-1) IBA or in vivo in peat and perlite substrate and subsequently grown in the greenhouse.

Establishment of plant regeneration system from anther culture of ...

African Journals Online (AJOL)

ajl yemi

2011-11-28

Nov 28, 2011 ... Plant regeneration of Tagetes patula was achieved from anther explants via adventitious shoot differentiation from callus. The effects of genotype, temperature pretreatment, plant growth regulators, light regimes and sucrose concentration were studied. Eight of ten genotypes tested were successfully.

In-vitro regeneration of castor bean (ricinus communis, L) and physic nut (jatropha curcas, L.)

International Nuclear Information System (INIS)

Afful, N. T.

2008-06-01

Investigations were conducted on in vitro regeneration of physic nut (Jatropha curcas, 1.) and castor bean (Ricinus communis, 1.) using zygotic embryo culture, shoot tip and meristem culture as well as somatic embryogenesis. Zygotic embryos from different stages of fruit maturity cultured on Murashige and Skoog (MS) medium supplemented with benzylaminopurine (BAP), kinetin and 2-isopentyl (2iP) produced vigorous seedlings with roots. However the optimal concentration of cytokinin for seedling development depended on the type cytokinin as well as the maturity stage of the fruit. Embryos from yellow fruits of Jatropha had the highest germination (100%) on an MS medium supplemented with 0.5 mg/L kinetin or 1 mg/L BAP while in Ricinus embryos from black fruits had the highest percentage germination (97%) on an MS medium modified with I mg/L 2iP or 0.5 or I mg/L BAP. Decrease in embryo viability especially in Jatropha as the seed matured may be due to high oil content in matured (black) fruit. Oil content in both Jatropha and Ricinus increased as the fruit matured from green to black and this may have effect on germination of zygotic embryos. In vitro culture response of shoot tip or meristem was significantly influenced by the concentration of growth regulators in the culture medium as well as the plant species. In both plant species, 2iP resulted in highest percentage shoot regeneration. The optimal concentration of 2iP was 0.5 mg/L for Ricinus shoot tip and 1.5 or 2.0 mg/L for Jatropha, indicating genotypic difference between the species. However excessive callus formation and browning in Ricinus led to the loss of all the regenerants. Shoot regeneration from meristem explants was also influenced by growth regulators with 2iP again being the best. Cultures of cotyledon and leaf lobe explants on MS medium supplemented with 2, 4-D and picloram resulted in callus induction with the exception of cotyledons obtained from black fruits. However transfer of calli onto fresh

In vitro somatic embryogenesis and plant regeneration of cassava.

Science.gov (United States)

Szabados, L; Hoyos, R; Roca, W

1987-06-01

An efficient and reproducible plant regeneration system, initiated in somatic tissues, has been devised for cassava (Manihot esculenta Crantz). Somatic embryogenesis has been induced from shoot tips and immature leaves of in vitro shoot cultures of 15 cassava genotypes. Somatic embryos developed directly on the explants when cultured on a medium containing 4-16 mg/l 2,4-D. Differences were observed with respect to the embryogenic capacity of the explants of different varieties. Secondary embryogenesis has been induced by subculture on solid or liquid induction medium. Long term cultures were established and maintained for up to 18 months by repeated subculture of the proliferating somatic embryos. Plantlets developed from primary and secondary embryos in the presence of 0.1 mg/l BAP, 1mg/l GA3, and 0.01 mg/l 2,4-D. Regenerated plants were transferred to the field, and were grown to maturity.

Optimization of Callus Induction and Regeneration in Two Fenugreek Landraces as a Medicinal Plant during in vitro Condition

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Hasan Hasani Jifroudi

2017-10-01

Full Text Available Introduction: Fenugreek (Trigonella foenum- graecum is a medicinal plant extensively distributed in most regions of the world. Fenugreek is an annual plant from the family of papilionaceae, leguminosae. Fenugreek leaves and seeds have been used extensively to prepare extracts and powders for medicinal uses. Its root, leaf and seed contain a number of important medicinal compounds such as polysaccharide, galactomannan, different saponins such as diosgenin, yamogenin, mucilage, volatile oil and alkaloids such as choline and trigonelline. Plant tissue culture is fundamental to most aspects of biotechnology of plants. Establishment of an efficient callus induction and direct regeneration protocol is an essential prerequisite in harnessing the advantage of cell and tissue culture for genetic improvement. For the successful application of the tissue culture technique in plant breeding, callus induction and plant regeneration potential of each plant must be determined. The present study was performed in order to determine the optimum concentration of plant growth regulators (IBA + TDZ for producing of in vitro plantlet using cotyledon and hypocotyl as an explant for two different Iranian genotypes (Ardestani and Neyshabouri. Materials and Methods: In this investigation, Ardestani and Neyshabouri genotypes were used for callus induction and direct shoot regeneration. The medium used in this investigation was MS (Murashige and Skoog basal medium. Then seeds were germinated on MS medium. For callus induction and direct shoot regeneration, cotyledon and hypocotyl explants were excised from 8-day-old sterile seedlings and cultured on MS medium containing various concentrations of IBA and TDZ. In this experiment, two combinations (TDZ + IBA were used. In the first composition, IBA had four levels (0, 0.1, 0.3, 0.5 mg l-1 and TDZ had five levels (0, 0.2, 0.4, 0.6, 0.8 mg l-1 and in the second composition, IBA had four levels (0, 0.05, 0.1, 0.15 mg l-1 and TDZ

Myocardial Polyploidization Creates a Barrier to Heart Regeneration in Zebrafish.

Science.gov (United States)

González-Rosa, Juan Manuel; Sharpe, Michka; Field, Dorothy; Soonpaa, Mark H; Field, Loren J; Burns, Caroline E; Burns, C Geoffrey

2018-02-26

Correlative evidence suggests that polyploidization of heart muscle, which occurs naturally in post-natal mammals, creates a barrier to heart regeneration. Here, we move beyond a correlation by demonstrating that experimental polyploidization of zebrafish cardiomyocytes is sufficient to suppress their proliferative potential during regeneration. Initially, we determined that zebrafish myocardium becomes susceptible to polyploidization upon transient cytokinesis inhibition mediated by dominant-negative Ect2. Using a transgenic strategy, we generated adult animals containing mosaic hearts composed of differentially labeled diploid and polyploid-enriched cardiomyocyte populations. Diploid cardiomyocytes outcompeted their polyploid neighbors in producing regenerated heart muscle. Moreover, hearts composed of equivalent proportions of diploid and polyploid cardiomyocytes failed to regenerate altogether, demonstrating that a critical percentage of diploid cardiomyocytes is required to achieve heart regeneration. Our data identify cardiomyocyte polyploidization as a barrier to heart regeneration and suggest that mobilizing rare diploid cardiomyocytes in the human heart will improve its regenerative capacity. Copyright © 2018 Elsevier Inc. All rights reserved.

Plant regeneration of Brassica oleracea subsp. italica (Broccoli) CV ...

African Journals Online (AJOL)

STORAGESEVER

2009-06-03

Jun 3, 2009 ... Department of Agriculture Technology, Faculty of Agriculture, Universiti Putra Malaysia, 43400 Serdang, Selangor Darul. Ehsan, Malaysia. Accepted 20 March, 2009. Hypocotyls and shoot tips were used as explants in in vitro plant regeneration of broccoli (Brassica oleracea subsp.italica) cv. Green Marvel.

Interactions of phytochromes A, B1 and B2 in light-induced competence for adventitious shoot formation in hypocotyl of tomato (Solanum lycopersicum L.).

Science.gov (United States)

Lercari, B; Bertram, L

2004-02-01

The interactions of phytochrome A (phyA), phytochrome B1 (phyB1) and phytochrome B2 (phyB2) in light-dependent shoot regeneration from the hypocotyl of tomato was analysed using all eight possible homozygous allelic combinations of the null mutants. The donor plants were pre-grown either in the dark or under red or far-red light for 8 days after sowing; thereafter hypocotyl segments (apical, middle and basal portions) were transferred onto hormone-free medium for culture under different light qualities. Etiolated apical segments cultured in vitro under white light showed a very high frequency of regeneration for all of the genotypes tested besides phyB1phyB2, phyAphyB1 and phyAphyB1phyB2 mutants. Evidence is provided of a specific interference of phyB2 with phyA-mediated HIR to far-red and blue light in etiolated explants. Pre-treatment of donor plants by growth under red light enhanced the competence of phyB1phyB2, phyAphyB1 and phyAphyB1phyB2 mutants for shoot regeneration, whereas pre-irradiation with far-red light enhanced the frequency of regeneration only in the phyAphyB1 mutant. Multiple phytochromes are involved in red light- and far-red light-dependent acquisition of competence for shoot regeneration. The position of the segments along the hypocotyl influenced the role of the various phytochromes and the interactions between them. The culture of competent hypocotyl segments under red, far-red or blue light reduced the frequency of explants forming shoots compared to those cultured under white light, with different genotypes having different response patterns.

In vitro plant regeneration from Narbon Vetch (Vicia narbonensis L ...

African Journals Online (AJOL)

STORAGESEVER

2008-07-18

Jul 18, 2008 ... regeneration from cotyledonary node explants obtained from, in vitro raised seeds of 4 - 5 and 14 - 15 days old .... shoots in Vicia faba using different concentrations of. BAP-TDZ. ... feed legume crop for dry areas in west Asia.

Monochromic radiation through light-emitting diode (LED positively augments in vitro shoot regeneration in Orchid (Dendrobium sonia

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Vandita Billore

2017-07-01

Full Text Available Monochromatic lights emitted by light-emitting diodes (LEDs have generated great interest for efficient and controlled growth in vitro, especially of plants which are endangered or require specific intensity and wavelength of light. In the present study, we have evaluated the effect of monochromatic LEDs on in vitro morphogenesis: growth, proliferation of shoot cultures, and rooting of Dendrobium sonia. Different light sources viz. white LEDs (W, blue LEDs (B, yellow LEDs (Y and red LEDs (R were tested under photoperiod of 16 h of exposure and 8 h of dark. The frequency of morphogenesis depended on the wavelength of the applied monochromatic light. Higher wavelength monochromatic light (yellow light was observed to induce higher shoot proliferation (98%, early PLB (protocorm-like bodies formation, differentiation into green buds and shoot initiation as compared to red, blue and white light treatments. Yellow light also yielded higher number of shoots per explants (29 shoots/explant than red, blue and white light treatments. The results suggest that the monochromatic light sources stimulate morphogenic effects on in vitro culture of Dendrobium sonia, and that yellow light treatment can be used to enhance the efficiency of micropropagation.

Robust regeneration protocol for the Agrobacterium tumefaciens mediated transformation of Solanum tuberosum

International Nuclear Information System (INIS)

Abbasi, A.; Bilal, M.; Hussain, J.; Shah, M. M.; Hassan, A.

2016-01-01

Plant genetic transformation requires robust regeneration system. Plant growth regulators (PGRs) such as cytokinins (CKs) play a pivotal role in organogenesis; however, CKs are the most expensive PGRs. In the current study, an efficient yet economical protocol for regeneration of potato plant was developed. Stem inter-nodal and leaf explants were cultured on different regeneration media supplemented with varying concentration of different CKs such as kinetin and zeatin. Murashige- Skoog media added with zeatin (1, 1.5 mg/L) was designated as RZ1, RZ1.5, respectively or kinetin (1.5, 2 mg/L) was designated as RK1.5 and RK2, respectively, however, concentrations of other hormones such as NAA (1-Naphthaleneacetic acid) and GA3 (Gibberellic acid A3) were kept same. RZ1 and RZ1.5 gave significantly better Results as compared to RK-type media in all aspects studied such as callus initiation, days to first shoot emergence, number of shoots per explants. RZ1 medium was then selected as regeneration media for Agrobacterium-mediated transformation of potato plants with cyanobacterial phosphoenol pyruvate carboxylase gene, which provided multiple putative transformants on selection media. The transformants were further confirmed through PCR. The current protocol is found to be cost effective and efficient for the regeneration of Solanum tuberosum and can be successfully implied for the Agrobacterium-mediated transformation. (author)

Establishment of an Efficient and Reproducible Regeneration System for Potato Cultivars Grown in Pakistan

International Nuclear Information System (INIS)

Iqbal, A.; Rizwan, A.; Mukhtar, Z.; Mansoor, S.; Asad, S.; Khalid, Z. M.

2016-01-01

The present study was carried out to assess the effect of growth regulators in three different combinations on mass propagation of currently grown three potato cultivars cv. Desiree, Kuroda and Cardinal. Varietal response on In vitro regeneration under different hormonal combinations. For callus induction, internodes of potato cultivars were cultured on modified Murashige and Skoog (MS) medium, added with different growth hormonal combinations. Callusing frequency for all these treatments and cultivars were recorded and in callus induction medium (CIM1) explants showed significantly higher callus formation as compared to two other combinations. For shoot induction, calli were cultured on Murashige and Skoog (MS) modified medium, supplemented with different hormonal combinations. Shoot induction medium (SIM3) gave best shoot induction frequency as compared to other media combinations. On the same media, an average number of shoots per explant were obtained for cultivar Desiree which is significantly different from the other two media combinations. Overall, the In vitro regeneration and multiplication potential was highest in the variety Cardinal followed by Kuroda and Desiree. The interaction between different hormonal combinations and varietal response for all the parameters showed significant differences. (author)

Micropropagation of nucellar embryos and their histological comparative study for regeneration ability with other explants of kinnow mandarin (Citrus reticulata Blanco)

International Nuclear Information System (INIS)

Kazmi, S.K.; Khan, S.; Kabir, N.

2018-01-01

Polyembryony is the most beneficial and distinct character in citrus seeds. This characteristic can be beneficial in citrus improvement programs. Nucellar embryos developed from nucellar wall in citrus seeds along with zygotic embryo are found to have high plants regeneration ability in comparison to zygotic embryos. Under In vitro culture conditions, nucellar embryos were detected and multiplied on MT media with 0.5ml of coconut water along with 50g/L sucrose. These nucellar embryonic tissues were also regenerated on MT media upplemented with 0.5 mg/L BAP and 0.5 mg/L kinetin. Many shoots were regenerated from nucellar embryonic tissue; these shoots were rooted on MT media supplemented with IBA 0.5mg/L and NAA 0.1 mg/L in addition to activated charcoal 0.5gm/L. The resulting plantlets were acclimatized in the green house. After micropropagation, histological studies of nucellar embryonic tissues were carried out under fluorescence microscope to examine their high regeneration ability in comparison with usual plant parts, like seeds, shoots as well as with tissue culture stages including embryogenic and non-embryogenic callus. It was found that nucellar embryos have more regeneration ability as compared to usual plant parts and other tissue culture stages. (author)

Plant regeneration from petiole segments of some species in tissue culture

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Krystyna Klimaszewska

2013-12-01

Full Text Available The regeneration ability of 21 plant species belonging to 14 families was tested. The method of tissue culture in vitro was applied, on basic MS medium with an addition of growth regulators from the auxin and cytokinin groups. From among the investigated plant groups Peperomia scandens and Caladium × hortulanum were capable of plant regeneration, Passiilora coerulea regenerated shoots, Hedera helix, Begonia glabra, Coleus blumei, Fuchsia hybrida, Passiflora suberosa and Peperomia eburnea formed callus and roots, Kalanchoe blossfeldiana, Pelargonium grandiflorum, P. peltatum, P. radula, Coleus shirensis and Magnolia soulangeana produced callus, Philodendron scandens, Rhododendron smirnovii, Hibiscus rosa-sinensis, Coprosma baueri, Cestrum purpureum and Solanum rantonnetii did not exhibit any regeneration reactions.

In vitro regeneration of five wheat genotypes from immature zygotic embryos

International Nuclear Information System (INIS)

Khokhar, M.I.; Iqbal, M.Z.

2016-01-01

This study examined the ability to induce callus from immature zygotic embryos of five wheat genotypes (Lu 26, WH 543, Zamindar 80, BT-002 and Seher-06) in response to 2, 4 and 6 mg/L of 2,4-dichlorophenoxy acetic acid (2,4-D). Callus induction was most effective (41% averaged across the 5 genotypes) in the presence of 2 mg/L 2,4-D. Callus induction was highest in Lu 26 (34%) followed by WH 543 (33%). Highest percentage shoot formation (33%) from callus was possible on Murashige and Skoog (1962) medium containing 300 mg casein hydrolysate. BT-002 responded best to shoot formation (26%) followed by WH 543 (24%). Under these optimal conditions, callus could form within 7.4 days and shoots within 20.87 days (fastest growth averaged across the 5 genotypes). Zamindar-80 responded best by taking fewest days to initiate callus formation (7.88 days) while Lu 26 took the least amount of time to form shoots (23.25 days). This study provides a rapid and efficient, as well as cultivar-independent protocol for the indirect formation of shoots from callus, the first such report for WH 543, Zamindar 80, BT-002 and Seher-06. This protocol may be a useful protocol for transgenic wheat plants that are derived from the genetic transformation of callus, either by particle bombardment or Agrobacterium-mediated transformation, to produce, for example, insect- or herbicide-resistant plants, since a rapid and effective regeneration protocol is an essential first step for the successful regeneration of transgenic plants. (author)

Plant regeneration of non-toxic Jatropha curcas—impacts of plant growth regulators, source and type of explants

KAUST Repository

Kumar, Nitish

2011-01-28

Jatropha curcas is an oil bearing species with multiple uses and considerable economic potential as a biofuel plant, however, oil and deoiled cake are toxic. A non-toxic variety of J. curcas is reported from Mexico. The present investigation explores the effects of different plant growth regulators (PGRs) viz. 6-benzyl aminopurine (BAP) or thidiazuron (TDZ) individually and in combination with indole-3-butyric acid (IBA), on regeneration from in vitro and field-grown mature leaf explants, in vitro and glasshouse-grown seedlings cotyledonary leaf explants of non-toxic J. curcas. In all the tested parameters maximum regeneration efficiency (81.07%) and the number of shoot buds per explants (20.17) was observed on 9.08 μM TDZ containing Murashige and Skoog’s (MS) medium from in vitro cotyledonary leaf explants. The regenerated shoot buds were transferred to MS medium containing 10 μM kinetin (Kn), 4.5 μM BAP and 5.5 μM α-naphthaleneacetic acid (NAA) for shoot proliferation. The proliferated shoots could be elongated on MS medium supplemented with 2.25 μM BAP and 8.5 μM IAA. Rooting was achieved when the basal cut end of elongated shoots were dipped in half strength MS liquid medium containing different concentrations and combinations of IBA, IAA and NAA for four days followed by transfer to growth regulators free half strength MS medium supplemented 0.25 mg/l activated charcoal. The rooted plants could be established in soil with more than 90% survival rate.

Plant regeneration of non-toxic Jatropha curcas—impacts of plant growth regulators, source and type of explants

KAUST Repository

Kumar, Nitish; Vijay Anand, K. G.; Reddy, Muppala P.

2011-01-01

Jatropha curcas is an oil bearing species with multiple uses and considerable economic potential as a biofuel plant, however, oil and deoiled cake are toxic. A non-toxic variety of J. curcas is reported from Mexico. The present investigation explores the effects of different plant growth regulators (PGRs) viz. 6-benzyl aminopurine (BAP) or thidiazuron (TDZ) individually and in combination with indole-3-butyric acid (IBA), on regeneration from in vitro and field-grown mature leaf explants, in vitro and glasshouse-grown seedlings cotyledonary leaf explants of non-toxic J. curcas. In all the tested parameters maximum regeneration efficiency (81.07%) and the number of shoot buds per explants (20.17) was observed on 9.08 μM TDZ containing Murashige and Skoog’s (MS) medium from in vitro cotyledonary leaf explants. The regenerated shoot buds were transferred to MS medium containing 10 μM kinetin (Kn), 4.5 μM BAP and 5.5 μM α-naphthaleneacetic acid (NAA) for shoot proliferation. The proliferated shoots could be elongated on MS medium supplemented with 2.25 μM BAP and 8.5 μM IAA. Rooting was achieved when the basal cut end of elongated shoots were dipped in half strength MS liquid medium containing different concentrations and combinations of IBA, IAA and NAA for four days followed by transfer to growth regulators free half strength MS medium supplemented 0.25 mg/l activated charcoal. The rooted plants could be established in soil with more than 90% survival rate.

Regeneration and molecular analysis of date palm ( Phoenix ...

African Journals Online (AJOL)

Clonal plants of date palm (Poenix dactylifera L.) were regenerated from juvenile leaves on regimes consisting of the use of 2,4-D. Success depended on the concentrations of 2,4-D tested. The cultures produced adventitious shoot buds directly at the basal part of leaves as well as excessive calli. Somaclonal variation in ...

A filter paper-based liquid culture system for citrus shoot organogenesis - a mixture-amount experiment

Science.gov (United States)

The objective of this study was to determine the effects of a static liquid culture system on shoot regeneration from citrus epicotyl explants. Two citrus types were used, Carrizo citrange and Ridge Pineapple sweet orange. A liquid culture system comprised of a Petri dish, cellulose filter paper dis...

Factors affecting in vitro plant regeneration of the critically endangered Mediterranean knapweed ( Centaurea tchihatcheffii Fisch et. Mey)

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Ozel, Cigdem Alev; Khawar, Khalid Mahmood; Mirici, Semra; Ozcan, Sebahattin; Arslan, Orhan

2006-10-01

Habitat destruction has resulted in the extinction of many plant species from the earth, and many more face extinction. Likely, the annual endemic Mediterranean knapweed ( Centaurea tchihatcheffii) growing in the Golbasi district of Ankara, Turkey is facing extinction and needs urgent conservation. Plant tissue culture, a potentially useful technique for ex situ multiplication, was used for the restoration of this ill-fated plant through seed germination, micropropagation from stem nodes, and adventitious shoot regeneration from immature zygotic embryos. The seeds were highly dormant and very difficult to germinate. No results were obtained from the micropropagation of stem nodes. However, immature zygotic embryos showed the highest adventitious shoot regeneration on Murashige and Skoog (MS) medium, containing 1 mg l-1 kinetin and 0.25 mg l-1 NAA. Regenerated shoots were best rooted on MS medium containing 1 mg l-1 IBA and transferred to the greenhouse for flowering and seed set. As such, the present work is the first record of in vitro propagation of critically endangered C. tchihatcheffii, using immature zygotic embryos, and is a step forward towards conservation of this indigenous species.

An Efficient In Vitro Regeneration System for Ornamental Ginger (Hedychium spp.)

Science.gov (United States)

An improved and efficient regeneration protocol was established for Hedychium via somatic embryogenesis. The plant material used consisted of 11 species and 9 cultivars of Hedychium. The explants consisted of young leaves taken from lateral or terminal shoots of mature greenhouse grown plants. These...

Effects of gibberellin mutations on in vitro shoot bud regeneration of ...

African Journals Online (AJOL)

hormone in regulating plant growth and development. It is interesting to know the effects of gibberellin and its signalling pathway on plant regeneration. In this report Arabidopsis thaliana landsberg (wild type), ga1-3 (gibberellin biosynthesis deficiency mutant), gai (gibberellin insensitive mutant), penta mutant (lacking GA1, ...

Micropropagation and validation of genetic and biochemical fidelity among regenerants of Nothapodytes nimmoniana (Graham) Mabb. employing ISSR markers and HPLC.

Science.gov (United States)

Prakash, Lokesh; Middha, Sushil Kumar; Mohanty, Sudipta Kumar; Swamy, Mallappa Kumara

2016-12-01

An in vitro protocol has been established for clonal propagation of Nothapodytes nimmoniana which is an important source of Camptothecin (CPT). Elite source was identified based on the chemical potency to accumulate the optimum level of CPT. Different types and concentrations of plant growth regulators were used to study their effect on inducing multiple shoots from the explants regenerated from embryos of N. nimmoniana. Of these, a combination of N6-benzyladenine (0.2 mg L -1 ) and Indole-3-butyric acid (IBA) (0.1 mg L -1 ) proved optimum for differentiating multiple shoots in 90.6 % of the cultures with an average of 10.24 shoots per explant obtained within 8 weeks of inoculation. Nearly, 92 % of the excised in vitro shoots rooted on half strength Murashige and Skoog (MS) medium containing 0.05 % activated charcoal, supplemented with 1-naphthaleneacetic acid and IBA at 0.1 mg L -1 each. The micropropagated plants were evaluated for their genetic fidelity by employing inter simple sequence repeats (ISSR) markers. Ten individuals, randomly chosen from a population of 145 regenerants, were compared with the donor plant. The regenerated plants were also evaluated for their chemical potency using high-performance liquid chromatography (HPLC) analysis of CPT content. The true-to-type nature of the micropropagated plants was confirmed based on their monomorphic banding profiles with that of the mother plants using ISSR markers. Besides, HPLC evaluation of the CPT content confirmed the existence of chemical uniformity among the regenerated plants and the elite mother plant.

Arabidopsis brassinosteroid biosynthetic mutant dwarf7-1 exhibits slower rates of cell division and shoot induction

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Schulz Burkhard

2010-12-01

Full Text Available Abstract Background Plant growth depends on both cell division and cell expansion. Plant hormones, including brassinosteroids (BRs, are central to the control of these two cellular processes. Despite clear evidence that BRs regulate cell elongation, their roles in cell division have remained elusive. Results Here, we report results emphasizing the importance of BRs in cell division. An Arabidopsis BR biosynthetic mutant, dwarf7-1, displayed various characteristics attributable to slower cell division rates. We found that the DWARF4 gene which encodes for an enzyme catalyzing a rate-determining step in the BR biosynthetic pathways, is highly expressed in the actively dividing callus, suggesting that BR biosynthesis is necessary for dividing cells. Furthermore, dwf7-1 showed noticeably slower rates of callus growth and shoot induction relative to wild-type control. Flow cytometric analyses of the nuclei derived from either calli or intact roots revealed that the cell division index, which was represented as the ratio of cells at the G2/M vs. G1 phases, was smaller in dwf7-1 plants. Finally, we found that the expression levels of the genes involved in cell division and shoot induction, such as PROLIFERATING CELL NUCLEAR ANTIGEN2 (PCNA2 and ENHANCER OF SHOOT REGENERATION2 (ESR2, were also lower in dwf7-1 as compared with wild type. Conclusions Taken together, results of callus induction, shoot regeneration, flow cytometry, and semi-quantitative RT-PCR analysis suggest that BRs play important roles in both cell division and cell differentiation in Arabidopsis.

In vitro regeneration of a common medicinal plant, Ocimum sanctum ...

African Journals Online (AJOL)

Embracing micro-propagation method for large scale production of plantlets and also for protection of appropriate germplasm is a prerequisite that needs to be undertaken in order to develop a rapid in vitro regeneration protocol for Ocimum sanctum L. Shoot tips as well as nodal segments were subjected to numerous ...

Adenosine signaling promotes regeneration of pancreatic β-cells in vivo

Science.gov (United States)

Andersson, Olov; Adams, Bruce A.; Yoo, Daniel; Ellis, Gregory C.; Gut, Philipp; Anderson, Ryan M.; German, Michael S.; Stainier, Didier Y. R.

2012-01-01

Diabetes can be controlled with insulin injections, but a curative approach that restores the number of insulin-producing β-cells is still needed. Using a zebrafish model of diabetes, we screened ~7000 small molecules to identify enhancers of β-cell regeneration. The compounds we identified converge on the adenosine signaling pathway and include exogenous agonists and compounds that inhibit degradation of endogenously produced adenosine. The most potent enhancer of β-cell regeneration was the adenosine agonist 5′-N-Ethylcarboxamidoadenosine (NECA), which acting through the adenosine receptor A2aa increased β-cell proliferation and accelerated restoration of normoglycemia in zebrafish. Despite markedly stimulating β-cell proliferation during regeneration, NECA had only a modest effect during development. The proliferative and glucose-lowering effect of NECA was confirmed in diabetic mice, suggesting an evolutionarily conserved role for adenosine in β-cell regeneration. With this whole-organism screen, we identified components of the adenosine pathway that could be therapeutically targeted for the treatment of diabetes. PMID:22608007

C4 photosynthesis in Euphorbia degeneri and E. remyi: a comparison of photosynthetic carbon metabolism in leaves, callus cultures and regenerated plants

International Nuclear Information System (INIS)

Ruzin, S.E.

1984-04-01

Based on analysis of 14 CO 2 fixation kinetics and assays of enzymes related to C 4 metabolism (NAD-ME, NADP-ME, NAD-MDH, NADP-MDH, AST, ALT), leaves and regenerated plants of Euphorbia degeneri exhibit a modified NADP-ME-type photosynthesis. Apparently, both aspartate and malate are used for transport of CO 2 to bundle sheath cells. Callus grown on either non-shoot-forming or shoot-forming media fixes CO 2 into RPP-cycle intermediates and sucrose, as well as malate and aspartate. 14 CO 2 pulse/chase kinetics show no significant loss of label from C 4 acids throughout a one minute chase. Analysis of PEPCase revealed the presence of 2 isoenzymes in both leaf and regenerated plant tissues (K/sub m/ [PEP] = 0.080 and 0.550) but only one isoenzyme in callus (K/sub m/ = 0.100). It appears that C 4 photosynthesis does not occur in callus derived from this C 4 dicot but is regenerated concomitant with shoot regeneration, and β-carboxylation of PEP in callus, mediated by the low K/sub m/ isoenzyme of PEPCase, produces C 4 acids that are not involved in the CO 2 shuttle mechanism characteristic of C 4 photosynthesis. 161 references, 19 figures, 12 tables

Characterization of somatic embryogenesis initiated from the Arabidopsis shoot apex.

Science.gov (United States)

Kadokura, Satoshi; Sugimoto, Kaoru; Tarr, Paul; Suzuki, Takamasa; Matsunaga, Sachihiro

2018-04-28

Somatic embryogenesis is one of the best examples of the remarkable developmental plasticity of plants, in which committed somatic cells can dedifferentiate and acquire the ability to form an embryo and regenerate an entire plant. In Arabidopsis thaliana, the shoot apices of young seedlings have been reported as an alternative tissue source for somatic embryos (SEs) besides the widely studied zygotic embryos taken from siliques. Although SE induction from shoots demonstrates the plasticity of plants more clearly than the embryo-to-embryo induction system, the underlying developmental and molecular mechanisms involved are unknown. Here we characterized SE formation from shoot apex explants by establishing a system for time-lapse observation of explants during SE induction. We also established a method to distinguish SE-forming and non-SE-forming explants prior to anatomical SE formation, enabling us to identify distinct transcriptome profiles of these two explants at SE initiation. We show that embryonic fate commitment takes place at day 3 of SE induction and the SE arises directly, not through callus formation, from the base of leaf primordia just beside the shoot apical meristem (SAM), where auxin accumulates and shoot-root polarity is formed. The expression domain of a couple of key developmental genes for the SAM transiently expands at this stage. Our data demonstrate that SE-forming and non-SE-forming explants share mostly the same transcripts except for a limited number of embryonic genes and root genes that might trigger the SE-initiation program. Thus, SE-forming explants possess a mixed identity (SAM, root and embryo) at the time of SE specification. Copyright © 2018. Published by Elsevier Inc.

Localization of QTLs for in vitro plant regeneration in tomato.

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Trujillo-Moya, Carlos; Gisbert, Carmina; Vilanova, Santiago; Nuez, Fernando

2011-10-20

Low regeneration ability limits biotechnological breeding approaches. The influence of genotype in the regeneration response is high in both tomato and other important crops. Despite the various studies that have been carried out on regeneration genetics, little is known about the key genes involved in this process. The aim of this study was to localize the genetic factors affecting regeneration in tomato. We developed two mapping populations (F2 and BC1) derived from a previously selected tomato cultivar (cv. Anl27) with low regeneration ability and a high regeneration accession of the wild species Solanum pennellii (PE-47). The phenotypic assay indicated dominance for bud induction and additive effects for both the percentage of explants with shoots and the number of regenerated shoots per explant. Two linkage maps were developed and six QTLs were identified on five chromosomes (1, 3, 4, 7 and 8) in the BC1 population by means of the Interval Mapping and restricted Multiple QTL Mapping methods. These QTLs came from S. pennellii, with the exception of the minor QTL located on chromosome 8, which was provided by cv. Anl27. The main QTLs correspond to those detected on chromosomes 1 and 7. In the F2 population, a QTL on chromosome 7 was identified on a similar region as that detected in the BC1 population. Marker segregation distortion was observed in this population in those areas where the QTLs of BC1 were detected. Furthermore, we located two tomato candidate genes using a marker linked to the high regeneration gene: Rg-2 (a putative allele of Rg-1) and LESK1, which encodes a serine/threonine kinase and was proposed as a marker for regeneration competence. As a result, we located a putative allele of Rg-2 in the QTL detected on chromosome 3 that we named Rg-3. LESK1, which is also situated on chromosome 3, is outside Rg-3. In a preliminary exploration of the detected QTL peaks, we found several genes that may be related to regeneration. In this study we have

Localization of QTLs for in vitro plant regeneration in tomato

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Nuez Fernando

2011-10-01

Full Text Available Abstract Background Low regeneration ability limits biotechnological breeding approaches. The influence of genotype in the regeneration response is high in both tomato and other important crops. Despite the various studies that have been carried out on regeneration genetics, little is known about the key genes involved in this process. The aim of this study was to localize the genetic factors affecting regeneration in tomato. Results We developed two mapping populations (F2 and BC1 derived from a previously selected tomato cultivar (cv. Anl27 with low regeneration ability and a high regeneration accession of the wild species Solanum pennellii (PE-47. The phenotypic assay indicated dominance for bud induction and additive effects for both the percentage of explants with shoots and the number of regenerated shoots per explant. Two linkage maps were developed and six QTLs were identified on five chromosomes (1, 3, 4, 7 and 8 in the BC1 population by means of the Interval Mapping and restricted Multiple QTL Mapping methods. These QTLs came from S. pennellii, with the exception of the minor QTL located on chromosome 8, which was provided by cv. Anl27. The main QTLs correspond to those detected on chromosomes 1 and 7. In the F2 population, a QTL on chromosome 7 was identified on a similar region as that detected in the BC1 population. Marker segregation distortion was observed in this population in those areas where the QTLs of BC1 were detected. Furthermore, we located two tomato candidate genes using a marker linked to the high regeneration gene: Rg-2 (a putative allele of Rg-1 and LESK1, which encodes a serine/threonine kinase and was proposed as a marker for regeneration competence. As a result, we located a putative allele of Rg-2 in the QTL detected on chromosome 3 that we named Rg-3. LESK1, which is also situated on chromosome 3, is outside Rg-3. In a preliminary exploration of the detected QTL peaks, we found several genes that may be related

A valued Indian medicinal plant – Begonia malabarica Lam. : Successful plant regeneration through various explants and field performance

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Sevanan Rajeshkumar

2009-05-01

Full Text Available A cost-effective and efficient protocol has been described in the present work for large-scale and rapid in vitro propagation of a valuable medicinal herb Begonia malabarica Lam. (Begoniaceae by shoot auxillary-bud proliferation and organogenesis on MS medium supplemented with 6-benzylaminopurine (BA; 0.0-8.8 mg/l and indole-3-acetic acid (IAA; 0.0-2.88 mg/l at different concentrations, either alone or in combinations. Initiation of callus formation from the base of the leaf lamina was observed on MS supplemented with BA, IAA and adenine sulphate. Root induction on shoots was achieved on full strength MS with IAA/ indole-3-butyric acid (IBA at different concentrations. MS medium with 4.4 mg/l BA and 1.4 mg/l IAA elicited the maximum number of shoots (10 multiple shoots from nodal explants. Leaf-based callus differentiated into more than 28 shoots on MS with 150 mg/l adenine sulphate. The regenerated shoots were rooted on MS with 1.2 mg/l IBA within ten days. Almost 95% of the rooted shoots survived hardening when transferred to the field. The regenerated plants did not show any morphological change and variation in levels of secondary metabolites when compared with the mother stock. Thus, a reproduction of B. malabarica was established through nodal and leaf explants. This protocol can be exploited for conservation and commercial propagation of this medical plant in the Indian subcontinent and might be useful for genetic improvement programs.

Proliferative activity of elastin-like-peptides depends on charge and phase transition.

Science.gov (United States)

Yuan, Yuan; Koria, Piyush

2016-03-01

Elastin-like-peptides (ELPs) are stimulus-responsive protein-based polymers and are attractive biomaterials due to their biocompatibility and unique properties. This study shows that in addition to their physical properties, ELPs have biological activities that are conducive to tissue regeneration. Specifically, we found that ELPs induce fibroblast proliferation via cell surface heparan sulfate proteoglycans (HSPG). Furthermore, our data suggests that ELP based materials with differential proliferative potential can be designed by controlling the interaction of ELPs with HSPGs by incorporating either hydrophobic or positively charged residues within the ELP sequence. Fibroblast proliferation is important for granulation tissue formation which is important in chronic wounds as well as in healing of other tissues. The customizable biological activity of ELPs coupled with their unique physical properties will enable us to design novel, sustainable and cost effective therapies for different tissue regeneration applications. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 697-706, 2016. © 2015 Wiley Periodicals, Inc.

A novel life cycle arising from leaf segments in plants regenerated from horseradish hairy roots.

Science.gov (United States)

Mano, Y; Matsuhashi, M

1995-03-01

Horseradish (Armoracia rusticana) hairy root clones were established from hairy roots which were transformed with the Ri plasmid in Agrobacterium rhizogenes 15834. The transformed plants, which were regenerated from hairy root clones, had thicker roots with extensive lateral branches and thicker stems, and grew faster compared with non-transformed horseradish plants. Small sections of leaves of the transformed plants generated adventitious roots in phytohormone-free G (modified Gamborg's) medium. Root proliferation was followed by adventitious shoot formation and plant regeneration. Approximately twenty plants were regenerated per square centimeter of leaf. The transformed plants were easily transferable from sterile conditions to soil. When leaf segments of the transformed plants were cultured in a liquid fertilizer under non-sterile conditions, adventitious roots were generated at the cut ends of the leaves. Adventitious shoots were generated at the boundary between the leaf and the adventitious roots and developed into complete plants. This novel life cycle arising from leaf segments is a unique property of the transformed plants derived from hairy root clones.

[Effect of dibunol liniment on posttraumatic skin regeneration in mice].

Science.gov (United States)

Krutova, T V; Efimov, E A; Korman, D B

1984-10-01

The effect of dibunol liniment (5-50 mg/kg) on excised mouse skin was studied. The liniment caused complete skin regeneration with hair and gland formation in the majority of treated mice. Application of the liniment led to a considerable increase in proliferative activity of skin epithelial cells and inhibition of wound area reduction within the first day of healing as compared with controls.

Effect of nickel on regeneration in Jatropha curcas L. and assessment of genotoxicity using RAPD markers

KAUST Repository

Sarkar, Tanmoy

2010-07-08

The aim of the present study was to determine the effect of nickel on shoot regeneration in tissue culture as well as to identify polymorphisms induced in leaf explants exposed to nickel through random amplified polymorphic DNA (RAPD). In vitro leaf explants of Jatropha curcas were grown in nickel amended Murashige and Skoog (MS) medium at four different concentrations (0, 0.01, 0.1, 1 mM) for 3 weeks. Percent regeneration, number of shoots produced and genotoxic effects were evaluated by RAPD using leaf explants obtained from the first three treatments following 5 weeks of their subsequent subculture in metal free MS medium. Percent regeneration decreased with increase in addition of nickel to the medium up to 14 days from 42.31% in control to zero in 1.0 mM. The number of shoot buds scored after 5 weeks was higher in control as compared to all other treatments except in one of the metal free subculture medium wherein the shoot number was higher in 0.01 mM treatment (mean = 7.80) than control (mean = 7.60). RAPD analysis produced only 5 polymorphic bands (3.225%) out of a total of 155 bands from 18 selected primers. Only three primers OPK-19, OPP-2, OPN-08 produced polymorphic bands. The dendrogram showed three groups A, B, and C. Group A samples showed 100% genetic similarity within them. Samples between groups B and C were more genetically distant from each other as compared to samples between groups A and B as well as groups A and C. Cluster analysis based on RAPD data correlated with treatments. © 2010 Springer Science+Business Media, LLC.

Hair cell regeneration in the avian auditory epithelium.

Science.gov (United States)

Stone, Jennifer S; Cotanche, Douglas A

2007-01-01

Regeneration of sensory hair cells in the mature avian inner ear was first described just over 20 years ago. Since then, it has been shown that many other non-mammalian species either continually produce new hair cells or regenerate them in response to trauma. However, mammals exhibit limited hair cell regeneration, particularly in the auditory epithelium. In birds and other non-mammals, regenerated hair cells arise from adjacent non-sensory (supporting) cells. Hair cell regeneration was initially described as a proliferative response whereby supporting cells re-enter the mitotic cycle, forming daughter cells that differentiate into either hair cells or supporting cells and thereby restore cytoarchitecture and function in the sensory epithelium. However, further analyses of the avian auditory epithelium (and amphibian vestibular epithelium) revealed a second regenerative mechanism, direct transdifferentiation, during which supporting cells change their gene expression and convert into hair cells without dividing. In the chicken auditory epithelium, these two distinct mechanisms show unique spatial and temporal patterns, suggesting they are differentially regulated. Current efforts are aimed at identifying signals that maintain supporting cells in a quiescent state or direct them to undergo direct transdifferentiation or cell division. Here, we review current knowledge about supporting cell properties and discuss candidate signaling molecules for regulating supporting cell behavior, in quiescence and after damage. While significant advances have been made in understanding regeneration in non-mammals over the last 20 years, we have yet to determine why the mammalian auditory epithelium lacks the ability to regenerate hair cells spontaneously and whether it is even capable of significant regeneration under additional circumstances. The continued study of mechanisms controlling regeneration in the avian auditory epithelium may lead to strategies for inducing

In vitro regeneration of Basella alba L

Science.gov (United States)

Edney, Norris Allen; Rizvi, Muhammad A.; Rizvi, Narjis F.

1989-01-01

Basella alba L. is a tropical vine used as a vegetable in some Asian and African countries. It has potential as a nontraditional crop for small family farms. A short day plant, it blooms during the fall, provided the temperatures are mild. In the southeastern U.S., the short days of fall are associated with subfreezing temperatures, and plants are killed before blooming. Attempts were made to regenerate the plant using tissue culture techniques. Several trials were conducted with different media, hormones, and explants. It was found that nodal segments on Gamborg medium regenerated shoots. Interaction studies of auxins and cytokinins indicated that its endogeneous auxin content might be high because callus proliferated in almost all treatments and roots initiated even when the medium was not supplemented with an auxin.

In-vitro regeneration of sugarcane (saccharum officinarum L.)

International Nuclear Information System (INIS)

Azu, E.

2009-01-01

Sugarcane (Saccharum officinarum L.) cultivars Barbados 46 (B46), Natal Coimbatore 339 (NC0339), Ragna, local sugarcane cultivar (LSC) and Kenana (Kn) series sourced from Kyebi, Akorley, Subriso, Jejeti and the University of Ghana Agriculture Research Station, Kpong, were evaluated for sterilisation, multiplication and rooting. An efficient double sterilisation protocol was achieved by immersing axillary buds pre-treated with Goldazim (active ingredient carbendazim) in 0.2% mercuric chloride for 7 minutes followed by 0.1 % mercuric chloride for 3 minutes. At this optimal sterilisation regime, 70% of the cultured buds were decontaminated. However, post sterilisation survival required the incorporation of 0.002g/L and 0.001g/L of amphotericin Band cefotaxime respectively in the culture medium indicating that the contaminants were endophytic. Evaluation for multiple shoot induction was conducted using Murashige and Skoog (1962) basal salts (MS) medium supplemented with 25g/L sucrose, 2mg/L IAA, 2mg/L GA 3 , 3g/L activated charcoal and varying concentrations (mg/L) of BAP or kinetin. The response of the cultivars to shoot induction varied with Ragna producing the highest number of shoots (2.17) on 5mg/L BAP indicating genotypic differences. Naphthalene acetic acid (NAA) at a concentration of 5mg/L induced the highest frequency (65%) of roots in all the cultivars tested. Post-flask acclimatization and survival of plantlets was high and independent of the age at which regenerated plantlets were transferred to the plant barn for weaning. This procedure could therefore be useful for regenerating sugarcane plantlets as well as provide target tissues for genetic transformation studies (au).

The effects of gamma-ray irradiation to strawberry (Fragaria x ananassa Duch.) calli on shoot regeneration, achene formation and morphological variations of regenerants

International Nuclear Information System (INIS)

Kasumi, Masakazu

2002-01-01

Strawberry (Fragaria x ananassa 'Nyoho') calli, derived from anthers, were irradiated with gamma -ray at dosages from 100 to 1,600 Gy (10 Gy · hr - 1) and their effects on callus growth, plant regeneration, and somaclonal variation were analyzed. The growth of callus and percentage of plant regeneration from the callus were reduced slightly at dosages less than 200 Gy, moderately at 400 Gy, and markedly above 800 Gy. Fruit growth associated with seed fertility (>50 % ) was morphologically normal at less than 100 Gy, whereas achene formation was significantly inhibited above 200 Gy. The percentages of morphological variation in regenerants formed from the irradiated callus were:13.7 (no irradiation), 18.6 (100 Gy), 66.0 (200 Gy), 75.7 (400 Gy), and 97.0 (800 Gy). Furthermore, higher dosages yielded wider variations, e.g., thick and small leaf, light leaf color, white flesh, and long fruit. In some regenerants, more than one morphological aberrations developed, some of which were transmissible to daughter plants. These results revealed that the irradiating strawberry callus with gamma - ray resulted in a higher degree and wider spectrum of somaclonal variation than did simple callus culture. (author)

Understanding Liver Regeneration: From Mechanisms to Regenerative Medicine.

Science.gov (United States)

Gilgenkrantz, Hélène; Collin de l'Hortet, Alexandra

2018-04-16

Liver regeneration is a complex and unique process. When two-thirds of a mouse liver is removed, the remaining liver recovers its initial weight in approximately 10 days. The understanding of the mechanisms responsible for liver regeneration may help patients needing large liver resections or transplantation and may be applied to the field of regenerative medicine. All differentiated hepatocytes are capable of self-renewal, but different subpopulations of hepatocytes seem to have distinct proliferative abilities. In the setting of chronic liver diseases, a ductular reaction ensues in which liver progenitor cells (LPCs) proliferate in the periportal region. Although these LPCs have the capacity to differentiate into hepatocytes and biliary cells in vitro, their ability to participate in liver regeneration is far from clear. Their expansion has even been associated with increased fibrosis and poorer prognosis in chronic liver diseases. Controversies also remain on their origin: lineage studies in experimental mouse models of chronic injury have recently suggested that these LPCs originate from hepatocyte dedifferentiation, whereas in other situations, they seem to come from cholangiocytes. This review summarizes data published in the past 5 years in the liver regeneration field, discusses the mechanisms leading to regeneration disruption in chronic liver disorders, and addresses the potential use of novel approaches for regenerative medicine. Copyright © 2018 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

C/sub 4/ photosynthesis in Euphorbia degeneri and E. remyi: a comparison of photosynthetic carbon metabolism in leaves, callus cultures and regenerated plants

Energy Technology Data Exchange (ETDEWEB)

Ruzin, S.E.

1984-04-01

Based on analysis of /sup 14/CO/sub 2/ fixation kinetics and assays of enzymes related to C/sub 4/ metabolism (NAD-ME, NADP-ME, NAD-MDH, NADP-MDH, AST, ALT), leaves and regenerated plants of Euphorbia degeneri exhibit a modified NADP-ME-type photosynthesis. Apparently, both aspartate and malate are used for transport of CO/sub 2/ to bundle sheath cells. Callus grown on either non-shoot-forming or shoot-forming media fixes CO/sub 2/ into RPP-cycle intermediates and sucrose, as well as malate and aspartate. /sup 14/CO/sub 2/ pulse/chase kinetics show no significant loss of label from C/sub 4/ acids throughout a one minute chase. Analysis of PEPCase revealed the presence of 2 isoenzymes in both leaf and regenerated plant tissues (K/sub m/ (PEP) = 0.080 and 0.550) but only one isoenzyme in callus (K/sub m/ = 0.100). It appears that C/sub 4/ photosynthesis does not occur in callus derived from this C/sub 4/ dicot but is regenerated concomitant with shoot regeneration, and ..beta..-carboxylation of PEP in callus, mediated by the low K/sub m/ isoenzyme of PEPCase, produces C/sub 4/ acids that are not involved in the CO/sub 2/ shuttle mechanism characteristic of C/sub 4/ photosynthesis. 161 references, 19 figures, 12 tables.

High Frequency Plant Regeneration System from Transverse Thin Cell Layer Section of In vitro Derived ‘Nadia’ Ginger Microrhizome

Directory of Open Access Journals (Sweden)

Dikash Singh THINGBAIJAM

2014-03-01

Full Text Available An efficient and reproducible procedure is outlined for rapid in vitro multiplication of Zingiber officinale var. ‘Nadia’ through high frequency shoot proliferation from transverse thin cell layer (tTCL sections of in vitro derived microrhizome. In vitro derived microrhizome of size 500 μm in thickness was used as initial explants for induction of somatic embryos. Among the different phytohormones tested, tTCL explants shows maximum calli proliferation in medium containing 2 mg/L 2,4-Dichlorophenoxyacetic acid (88.30±0.11%. Reduced concentration of 2,4 Dichlorophenoxyacetic acid was supplemented with different cytokinins for regeneration of callus. Among the different medium tested, optimum redifferentiation of somatic embryos were observed in medium containing 0.2 mg/L 2,4 Dichlorophenoxyacetic acid and 6.0 mg/L BAP (141.08±0.25. Clump of regenerated plantlets were further subculture and transfer into microrhizome inducing medium containing high sucrose concentration (8%. Plantlets with well developed microrhizome were successfully acclimatized and eventually transferred to the field. The application of studying embryo section for regeneration of plants might be useful alternative to ginger improvement programme. Histological analysis showed formation of somatic embryos and regenerated adventitious shoot.

RAPD analysis of mutants obtained by ion beam irradiation to hinoki cypress shoot primordia

International Nuclear Information System (INIS)

Ishii, K.; Yamada, Y.; Hase, Y.; Shikazono, N.; Tanaka, A.

2003-01-01

Mutants were induced by irradiation of the shoot primordia of Hinoki cypress with 50 MeV 4 He 2+ heavy ion beam. Fresh shoot primordia on the CD medium in the plastic Petri dish (35 x 10 mm) were irradiated. Xanta mutants were induced from 38 to 266 Gy irradiation. Waxy mutants were induced from 76 to 266 Gy irradiation. Xanta, waxy and control type of regenerated Hinoki cypress in vitro were checked for their DNA level difference using RAPD analysis. Among 81 primers used, 23 primers produced the 68 bands. Among them stable 44 bands produced by 15 primers were compared between mutants and control plant. So far, there is no variation among the RAPD analysis band patterns of those mutants. Bigger test size may detect the gene variation specific for mutants

Improved efficiency of plant regeneration from protoplasts of eggplant Solanum melongena L.

Science.gov (United States)

Guri, A; Izhar, S

1984-12-01

Eggplant (Solanum melongena L.) mesophyll protoplasts were obtained from in vitro growing plants of line 410 and cv. 'Classic'. Relatively high (15%) plating efficiency was achieved using petri dishes with alternate quadrants containing reservoir medium (R medium + 1% activated charcoal) and culture medium. Shoot regeneration occurred within 6 weeks following initiation of protoplast culture.

β-catenin/Wnt signaling controls progenitor fate in the developing and regenerating zebrafish retina

Directory of Open Access Journals (Sweden)

Meyers Jason R

2012-08-01

Full Text Available Abstract Background The zebrafish retina maintains two populations of stem cells: first, the germinal zone or ciliary marginal zone (CMZ contains multipotent retinal progenitors that add cells to the retinal periphery as the fish continue to grow; second, radial glia (Müller cells occasionally divide asymmetrically to generate committed progenitors that differentiate into rod photoreceptors, which are added interstitially throughout the retina with growth. Retinal injury stimulates Müller glia to dedifferentiate, re-enter the cell cycle, and generate multipotent retinal progenitors similar to those in the CMZ to replace missing neurons. The specific signals that maintain these two distinct populations of endogenous retinal stem cells are not understood. Results We used genetic and pharmacological manipulation of the β-catenin/Wnt signaling pathway to show that it is required to maintain proliferation in the CMZ and that hyperstimulation of β-catenin/Wnt signaling inhibits normal retinal differentiation and expands the population of proliferative retinal progenitors. To test whether similar effects occur during regeneration, we developed a method for making rapid, selective photoreceptor ablations in larval zebrafish with intense light. We found that dephosphorylated β-catenin accumulates in Müller glia as they re-enter the cell cycle following injury, but not in Müller glia that remain quiescent. Activation of Wnt signaling is required for regenerative proliferation, and hyperstimulation results in loss of Müller glia from the INL as all proliferative cells move into the ONL. Conclusions β-catenin/Wnt signaling is thus required for the maintenance of retinal progenitors during both initial development and lesion-induced regeneration, and is sufficient to prevent differentiation of those progenitors and maintain them in a proliferative state. This suggests that the β-catenin/Wnt cascade is part of the shared molecular circuitry that

Serum Proteases Potentiate BMP-Induced Cell Cycle Re-entry of Dedifferentiating Muscle Cells during Newt Limb Regeneration

NARCIS (Netherlands)

Wagner, Ines; Wang, Heng; Weissert, Philipp M.; Straube, Werner L.; Shevchenko, Anna; Gentzel, Marc; Brito, Goncalo; Tazaki, Akira; Oliveira, Catarina; Sugiura, Takuji; Shevchenko, Andrej; Simon, Andras; Drechsel, David N.; Tanaka, Elly M.

2017-01-01

Limb amputation in the newt induces myofibers to dedifferentiate and re-enter the cell cycle to generate proliferative myogenic precursors in the regeneration blastema. Here we show that bone morphogenetic proteins (BMPs) and mature BMPs that have been further cleaved by serum proteases induce cell

Regeneration of three sweet potato (Ipomea batatas (L.)) accessions via meristem, Nodal and callus induction

International Nuclear Information System (INIS)

Addae-Frimpomaah, F.

2012-11-01

In vitro regeneration of three sweet potato accessions UE007, UK-BNARI and SA-BNARI using meristem, nodal cuttings or callus induction was studied. Meristematic explants cultured on Murashige and Skoog (1962) basal medium supplemented with low concentration of benzylaminopurine (BAP) or kinetin resulted in callus with or without shoot development which delayed shoot emergence. The degree of callus development increased as the concentration of the cytokinin in the culture medium increased. Although, callus development was comparatively lower on kinetin amended medium than BAP amended medium, Murashige and Skoog medium supplemented with 0.25mg/1BAP had the highest shoot induction (80%). For further differentiation of callus or shoots into distinct stem and leaves, the culture were transferred into fresh MS medium supplemented with 0.25mg/1 BAP, 0.1 mg/1 NAA and 0.1 mg/1 Gibberellic acid (GA 3 . To overcome the delay in shoot initiation using meristem culture, nodal cuttings of sweet potato were used as explants and cultured on MS medium amended with 0.3 - 0.9mg/1 BAP. All explants cultured on 0.3 or 0.6mg/1 BAP developed shoots. Furthermore, liquid MS medium amended with 0.25mg/1 BAP, 0.1mg/I NAA, and 0.1mg/1 GA 3 also enhanced early shoot development from nodal cutting explants compared to solid culture. Post flask acclimatisation of meristem or nodal cutting-derived plantlets showed that meristem derived plantlets were better acclimatised than nodal cutting plants due to vigorous root development leading to higher percentage survival in pots and subsequent tuber production. Callusogenesis was achieved when leaf lobe explants were cultured on CLC/ Ipomoea medium supplemented with 1.0 - 4.0mg/1 2,4-D with 4.0mg/1 2,4-D being the optimal concentration. However, the calli were non-embryogenic and therefore could not produce embryos when transferred to 0.1mg/1 BAP amended medium but rather produced either single or multiple shoots. The highest percentage shoot (83

In vitro regeneration of Drosera burmannii Vahl.: a carnivorous plant of north-east India.

Science.gov (United States)

Yanthan, J Sureni; Kehie, Mechuselie; Kumaria, Suman; Tandon, Pramod

2017-06-01

An efficient in vitro regeneration protocol has been developed from shoot tips of Drosera burmannii Vahl., a carnivorous plant of north-east India. Various plant growth regulators were used to study their efficacy in the induction of multiple shoots and roots. Of the various treatments, the maximum number of shoots (28.8 ± 1.5) and roots (9.7 ± 0.6) was observed in one-fourth strength standard medium (MS with 50 mg/l citric acid and 10 mg/l ascorbic acid) supplemented with 4 mg/l 6-benzylaminopurine (BAP) and 4 mg/l α-naphthalene acetic acid (NAA) followed by 26.8 ± 1.4 shoots in one-fourth strength SM fortified with 4 mg/l kinetin (KN) and 4 mg/l NAA. The well-developed plantlets with shoots and roots were potted in small plastic glasses filled with a mixture of sand and farmyard manure (3:1); these plantlets when transferred to a glasshouse for hardening and acclimatization showed 90% survival.

Sirococcus Shoot Blight

Science.gov (United States)

Thomas H. Nicholls; Kathryn Robbins

1984-01-01

Sirococcus shoot blight, caused by the fungus Sirococcus strobilinus Preuss, affects conifers in the Northern United States and southern Canada. The fungus infects the new shoots; diseased seedlings and saplings are especially affected. In the United States, sirococcus shoot blight has become increasingly widespread since the early 1970's. When favorable...

In vitro regeneration from petiole explants of non-toxic Jatropha curcas

KAUST Repository

Kumar, Nitish

2011-01-01

Jatropha curcas, a multipurpose shrub has acquired significant economic potential as biodiesel plant. The seeds or pressed cake is toxic due to the presence of toxic substances and is not useful as food/fodder despite having the best protein composition. A simple, efficient, and reproducible method for plant regeneration through direct organogenesis from petiole explants of non-toxic J. curcas was developed using Murashige and Skoog (MS) medium supplemented with different concentrations of thidiazuron (TDZ). The best induction of shoot buds (57.61%), and number of shoot buds (4.98) per explant were obtained when in vitro petiole explants were placed horizontally on MS medium supplemented with 2.27 mu M TDZ. The Induced shoot buds were transferred to MS medium containing 10 mu M kinetin (Kn), 4.5 mu M 6-benzyl aminopurine (BA), and 5.5 mu M alpha-naphthaleneacetic acid (NAA) for shoot proliferation and subsequent elongation was achieved on MS medium supplemented with 2.25 mu M BA and 8.5 mu M IAA. The elongated shoots could be rooted on half-strength MS medium with 15 mu M IBA, 11.4 mu M IAA and 5.5 mu M NAA with more than 90% survival rate. (C) 2010 Elsevier B.V. All rights reserved.

PERBANDINGAN JUMP SHOOT DENGAN AWALAN DAN TANPA AWALAN TERHADAP PENINGKATAN KETEPATAN SHOOTING DALAM PERMAINAN BOLABASKET

OpenAIRE

I Gusti Ngurah Agung Cahya Prananta; N. Adiputra; I P G Adiatmika

2015-01-01

The effectiveness of  jump-shoot technique step jump shoot and still jump shoot in a game is still questionable,  because many different assumptions arise. One opinion stated that step jump shoot was more effective and the other stated that and still jump shoot was more efective. Therefore it is necessary to do research on the analysis of the results of step jump shoot and and still jump shoot to improve the accuracy of shooting in a basketball. The experimental research had been conducted on...

Lack of a differential radiation response for proliferative and non-proliferative rat thyroid cells (FRTL-5) in vitro

International Nuclear Information System (INIS)

Brosing, J.W.; Giese, W.L.; Mulcahy, R.T.

1989-01-01

FRTL-5 rat thyroid epithelial cells maintain normal thyroid function and morphology in vitro, exhibit an absolute requirement for thyroid stimulating hormone (TSH) for proliferation and display radiation dose response characteristics indistinguishable from those of rat thyroid epithelial cells in vivo. In TSH-free medium cells remain in a non-proliferative, yet viable, state for prolonged periods of time and respond to TSH re-stimulation by a return to exponential growth. Flow cytometric analysis using two-step acridine orange (AO) staining revealed an accumulation of cells in the G1 phase of the cell cycle accompanied by a pronounced reduction in red fluorescence (indicative of RNA content) in FRTL-5 cells cultured in the absence of TSH. The response of proliferative and non-proliferative FRTL-5 cells to single dose, split dose and fractionated radiation was compared to determine whether proliferative status was an important response determinant. The response of FRTL-5 cells was not influenced by proliferative status at the time of irradiation. Additionally, dose response was not altered by variable (12 hr-8 days) non-proliferative intervals before or after irradiation. As revealed by split dose experiments, the rate and extent of sublethal damage repair was likewise similar for proliferative and non-proliferative cells. Multifraction experiments employing three fractions separated by 6 hr intervals indicate that non-proliferative FRTL-5 cells completely repair sublethal damage between fractions. These results indicate that the radiation response of FRTL-5 cells is not influenced by the proliferative status of the cells prior to or post-irradiation

Neuregulin-1 signaling is essential for nerve-dependent axolotl limb regeneration.

Science.gov (United States)

Farkas, Johanna E; Freitas, Polina D; Bryant, Donald M; Whited, Jessica L; Monaghan, James R

2016-08-01

The Mexican axolotl (Ambystoma mexicanum) is capable of fully regenerating amputated limbs, but denervation of the limb inhibits the formation of the post-injury proliferative mass called the blastema. The molecular basis behind this phenomenon remains poorly understood, but previous studies have suggested that nerves support regeneration via the secretion of essential growth-promoting factors. An essential nerve-derived factor must be found in the blastema, capable of rescuing regeneration in denervated limbs, and its inhibition must prevent regeneration. Here, we show that the neuronally secreted protein Neuregulin-1 (NRG1) fulfills all these criteria in the axolotl. Immunohistochemistry and in situ hybridization of NRG1 and its active receptor ErbB2 revealed that they are expressed in regenerating blastemas but lost upon denervation. NRG1 was localized to the wound epithelium prior to blastema formation and was later strongly expressed in proliferating blastemal cells. Supplementation by implantation of NRG1-soaked beads rescued regeneration to digits in denervated limbs, and pharmacological inhibition of NRG1 signaling reduced cell proliferation, blocked blastema formation and induced aberrant collagen deposition in fully innervated limbs. Taken together, our results show that nerve-dependent NRG1/ErbB2 signaling promotes blastemal proliferation in the regenerating limb and may play an essential role in blastema formation, thus providing insight into the longstanding question of why nerves are required for axolotl limb regeneration. © 2016. Published by The Company of Biologists Ltd.

Branch architecture in Ginkgo biloba: wood anatomy and long shoot-short shoot interactions.

Science.gov (United States)

Little, Stefan A; Jacobs, Brooke; McKechnie, Steven J; Cooper, Ranessa L; Christianson, Michael L; Jernstedt, Judith A

2013-10-01

Ginkgo, centrally placed in seed plant phylogeny, is considered important in many phylogenetic and evolutionary studies. Shoot dimorphism of Ginkgo has been long noted, but no work has yet been done to evaluate the relationships between overall branch architecture and wood ring characters, shoot growth, and environmental conditions. • Branches, sampled from similar canopy heights, were mapped with the age of each long shoot segment determined by counting annual leaf-scar series on its short shoots. Transverse sections were made for each long shoot segment and an adjacent short shoot; wood ring thickness, number of rings, and number of tracheids/ring were determined. Using branch maps, we identified wood rings for each long shoot segment to year and developmental context of each year (distal short shoot growth only vs. at least one distal long shoot). Climate data were also analyzed in conjunction with developmental context. • Significantly thicker wood rings occur in years with distal long shoot development. The likelihood that a branch produced long shoots in a given year was lower with higher maximum annual temperature. Annual maximum temperature was negatively correlated with ring thickness in microsporangiate trees only. Annual minimum temperatures were correlated differently with ring thickness of megasporangiate and microsporangiate trees, depending on the developmental context. There were no significant effects associated with precipitation. • Overall, developmental context alone predicts wood ring thickness about as well as models that include temperature. This suggests that although climatic factors may be strongly correlated with wood ring data among many gymnosperm taxa, at least for Ginkgo, correlations with climate data are primarily due to changes in proportions of shoot developmental types (LS vs. SS) across branches.

High Frequency Plant Regeneration System from Transverse Thin Cell Layer Section of In vitro Derived ‘Nadia’ Ginger Microrhizome

Directory of Open Access Journals (Sweden)

Dikash Singh THINGBAIJAM

2014-03-01

Full Text Available An efficient and reproducible procedure is outlined for rapid in vitro multiplication of Zingiber officinale var. ‘Nadia’ through high frequency shoot proliferation from transverse thin cell layer (tTCL sections of in vitro derived microrhizome. In vitro derived microrhizome of size 500 μm in thickness was used as initial explants for induction of somatic embryos. Among the different phytohormones tested, tTCL explants shows maximum calli proliferation in medium containing 2 mg/L 2,4-Dichlorophenoxyacetic acid (88.30±0.11%. Reduced concentration of 2,4 Dichlorophenoxyacetic acid was supplemented with different cytokinins for regeneration of callus. Among the different medium tested, optimum redifferentiation of somatic embryos were observed in medium containing 0.2 mg/L 2,4 Dichlorophenoxyacetic acid and 6.0 mg/L BAP (141.08±0.25. Clump of regenerated plantlets were further subculture and transfer into microrhizome inducing medium containing high sucrose concentration (8%. Plantlets with well developed microrhizome were successfully acclimatized and eventually transferred to the field. The application of studying embryo section for regeneration of plants might be useful alternative to ginger improvement programme. Histological analysis showed formation of somatic embryos and regenerated adventitious shoot.

Rosette growth of shoots in chrysanthemum (Dendranthema grandiflora Tzvelev) as a result of in vitro propagation of plants and gamma irradiation used for mutation induction

International Nuclear Information System (INIS)

Jerzy, M.; Zalewska, M.; Lema, J.

1999-01-01

Rosette growth of chrysanthemum shoots in 'Mrs. R.C. Puling' was observed after in vitro propagation with explants obtained from vernalised and non-vernalised stock plants. The phenomenon was also observed as a result of the exposure of leaf explants to gamma radiation used for in vitro regeneration of plants in mutation induction. The higher the irradiation dose, the more considerable the rosette growth. Following the 4th pinching of shoot tips, only elongating growth of plants was observed

Callus induction and plant regeneration from different explant types of Miscanthus x ogiformis Honda 'Giganteus'

DEFF Research Database (Denmark)

Holme, Inger Bæksted; Petersen, Karen Koefoed

1996-01-01

. The explants were cultured on urashige and Skoog medium supplemented with 4.5, 13.6, 22.6 or 31.7 μM 2,4-dichlorophenoxyacetic acid. Three types of callus were formed but only one was embryogenic and regenerated plants. Callus induction and formation of embryogenic callus depended on the type and developmental......-propagated shoots and older leaves of greenhouse-grown plants. Immature inflorescences smaller than 2.5 cm produced a higher percentage of embryogenic callus than larger more mature inflorescences. Embryogenic callus derived from immature inflorescences had the highest regeneration capacity. Differences in 2......,4-dichlorophenoxyacetic acid concentrations had no significant effect on callus induction, embryogenic callus formation and plant regeneration....

Which stem parts of Slender speedwell (Veronica filiformis) are the most successful in plant regeneration?

Czech Academy of Sciences Publication Activity Database

Šerá, Božena

2012-01-01

Roč. 67, č. 1 (2012), s. 110-115 ISSN 0006-3088 R&D Projects: GA MŠk OC10032 Institutional research plan: CEZ:AV0Z60870520 Keywords : clonal * invasive species * regeneration * shoot * stem * terminal * vegetative reproduciton Subject RIV: EF - Botanics Impact factor: 0.506, year: 2012

Rapid in vitro propagation system through shoot tip cultures of Vitex trifolia L.-an important multipurpose plant of the Pacific traditional Medicine.

Science.gov (United States)

Ahmed, Rafique; Anis, Mohammad

2014-07-01

A rapid and efficient plant propagation system through shoot tip explants was established in Vitex trifolia L., a medicinally important plant belonging to the family Verbenaceae. Multiple shoots were induced directly on Murashige and Skoog (MS) medium consisting of different cytokinins, 6-benzyladenine (BA), kinetin (Kin) and 2-isopentenyl adenine (2-iP), BA at an optimal concentration of 5.0 μM was most effective in inducing multiple shoots where 90 % explants responded with an average shoot number (4.4±0.1) and shoot length (2.0±0.1 cm) after 6 weeks of culture. Inclusion of NAA in the culture medium along with the optimum concentration of BA promoted a higher rate of shoot multiplication and length of the shoot, where 19.2±0.3 well-grown healthy shoots with an average shoot length of 4.4±0.1 cm were obtained on completion of 12 weeks culture period. Ex vitro rooting was achieved best directly in soilrite when basal portion of the shoots were treated with 500 μM indole-3-butyric acid for 15 min which was the most effective in inducing roots, as 95 % of the microshoots produced roots. Plantlets went through a hardening phase in a controlled plant growth chamber, prior to ex-vitro transfer. Micropropagated plants grew well, attained maturity and flowered with 92 % survival rate. The results of this study provide the first report on in vitro plant regeneration of Vitex trifolia L. using shoot tip explants.

Making sense of Wnt signaling – linking hair cell regeneration to development

Directory of Open Access Journals (Sweden)

Lina eJansson

2015-03-01

Full Text Available Wnt signaling is a highly conserved pathway crucial for development and homeostasis of multicellular organisms. Secreted Wnt ligands bind Frizzled receptors to regulate diverse processes such as axis patterning, cell division, and cell fate specification. They also serve to govern self-renewal of somatic stem cells in several adult tissues. The complexity of the pathway can be attributed to the myriad of Wnt and Frizzled combinations as well as its diverse context-dependent functions. In the developing mouse inner ear, Wnt signaling plays diverse roles, including specification of the otic placode and patterning of the otic vesicle. At later stages, its activity governs sensory hair cell specification, cell cycle regulation, and hair cell orientation. In regenerating sensory organs from non-mammalian species, Wnt signaling can also regulate the extent of proliferative hair cell regeneration. This review describes the current knowledge of the roles of Wnt signaling and Wnt-responsive cells in hair cell development and regeneration. We also discuss possible future directions and the potential application and limitation of Wnt signaling in augmenting hair cell regeneration.

PERBANDINGAN JUMP SHOOT DENGAN AWALAN DAN TANPA AWALAN TERHADAP PENINGKATAN KETEPATAN SHOOTING DALAM PERMAINAN BOLABASKET

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I Gusti Ngurah Agung Cahya Prananta

2015-01-01

Full Text Available The effectiveness of  jump-shoot technique step jump shoot and still jump shoot in a game is still questionable,  because many different assumptions arise. One opinion stated that step jump shoot was more effective and the other stated that and still jump shoot was more efective. Therefore it is necessary to do research on the analysis of the results of step jump shoot and and still jump shoot to improve the accuracy of shooting in a basketball. The experimental research had been conducted on 20samples of people whowere selected randomly from the men's basketball club of the Faculty of Physical Educationand Health of Teacher Training Institute PGRI Bali. Samples were divided into two groups each  consisting of 10 people. Group I was given training step  jump shoot four sets of 10 reps  and Group II training still jump shoot four sets of 10 reps. The data before and after treatment were tested by SPSS computer program. The data were normally distributed and homogeneous so further tested using pairedt-test to compare the average values?? before and after training between each group, while the independent t-test was used to determine differences in mean values?? between the two groups. Paired t-test resulted the obtained data were significantly increased in both treatment groups p=0,001 in Group I and p=0,000 in Group II (p <0.05. Results of independent t-test found that both groups before training did not differ significantly p=0,926 (p>0.05 and after training both groups equally improve the accuracy of shooting because p=0,133 (p>0.05. It was concluded that botht raining improved the shooting accuracy and there was no difference between the effect of step jumps hoot and still jump shoot toward the shooting accuracy. It was suggested to improve the shooting accuracy in basketball used step jump shoot training and still jump shoot training four sets of 10 reps with a training frequency of 4 times a week for 6 weeks

Development of an efficient regeneration protocol for three genotypes of brassica juncea

International Nuclear Information System (INIS)

Bano, R.; Khan, M.H.; Rashid, H.

2010-01-01

Two phytohormones, auxins (Naphthalene acetic acid and Indole acetic acid) and cytokinins (Benzyl aminopurine and Kinetin) with concentrations were used to develop an efficient regeneration protocol for 3 genotypes of Brassica juncea (UCD-635, RL-18 and NIFA RAYE). The explants were cultured on MS-medium supplemented with BAP 1.0 mgL/sup -1//NAA 0.1 mgL-1, BAP 2.0 mg L/sup -1//NAA 0.2 mg L/sup -1/, BAP 3.0 mgL/sup -1/ NAA 0.3 mg L-1 and Kinetin 1.0 mg L/sup -1/ IAA 0.1 mg L/sup -1/, Kinetin 2.0 mg L/sup -1//IAA 0.2 mg L/sup -1/, Kinetin 3.0mg L-1/IAA 0.3 mg L/sup -1/. Maximum callus production (65.55) was observed on MS medium containing with BAP 2.0 mgL-1/NAA 0.2 mg L/sup -1/. Maximum shooting (22.31) was observed BAP 3.0 mg L/sup -1//NAA 0.3 mg L/sup -1/ and KIN 3.0 mg L-1/IAA 0.3 mg L/sup -1/. Regeneration efficiency was found maximum (7.13) with BAP 3.0 mg L/sup -1//NAA 0.3 mg L/sup -1/. The three genotypes were found significantly different at p greater or equal to 0.05 in shoots production and regeneration efficiency. (author)

Clonal fidelity of chrysanthemum regenerated from long term cultures

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Jevremović Slađana

2006-01-01

Full Text Available Morphological characteristics of flowers of long term regenerated chrysanthemum, cv. "White Spider", after ten years of micropropagation are investigated. Shoot cultures are established and maintained more than ten years by stem segment culture on MS medium supplemented with BAP and NAA (1.0, 0.1 mgL-1, respectively. Rooting of shoots (100 % has done on MS medium without hormones and it was very successful after ten years, as well as, after two or eight years of micropropagation. Acclimation of rooted chrysanthemum plantlets at greenhouse conditions was excellent and after appropriate photoperiod "in vitro" plants flowered 90.3 % and have the same flower color, shape and size as mother plants. Flower color changes of "in vitro" plants are observed during another flowering cycle one year after acclimatization. Observed variations of chrysanthemum flowers could be attributed to epigenetic factors.

Resposta à regeneração e crescimento de brotos in vitro de Kielmeyera coriacea quando influenciado por diferentes concentrações dos sais e de sacarose In vitro regeneration and growth response of Kielmeyera coriacea shoots when affected by salts and sucrose concentrations

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José Eduardo Brasil Pereira Pinto

1996-04-01

Full Text Available Avaliaram-se diferentes concentrações de sacarose e sais do MS (MURASHIGE & SKOOG, J 962 na regeneração e crescimento de brotos de Kielmeyera coriacea in vitro. A redução e o aumento da quantidade de sacarose partindo de 30 e 45g/L, respectivamente, causou um decréscimo no número total de brotos. O uso integral ou da metade das concentrações dos sais do MS proporcionou maiores taxas de multiplicação. A maior porcentagem de brotos com mais de 1,0cm de comprimento pôde ser obtida empregando-se 30 g/l de sacarose associado a concentração 1/1 do MS. A porcentagem média de brotos decresceu linearmente com a diluição salina.Trials were carried out to test sucrose and salt concentrations added to growth medium on regeneration and growth response of Kielmeyera coriacea shoots. The reduction and increase of sucrose of 30 and 45g/l, rerspectively, caused a decrease in total number of shoots. A higher shoots percentage of with more than 1.0cm, occurred on media with 30g/L of sucrose. The use of total force (1/1 and half strength (1/2 of MS salt proportioned a higher shoot ratio and growth.

Understory Structure and Vascular Plant Diversity in Naturally Regenerated Deciduous Forests and Spruce Plantations on Similar Clear-Cuts: Implications for Forest Regeneration Strategy Selection

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ZhiQiang Fang

2014-04-01

Full Text Available The active effect of natural regeneration on understory vegetation and diversity on clear-cut forestlands, in contrast to conifer reforestation, is still controversial. Here we investigated differences in understory vegetation by comparing naturally regenerated deciduous forests (NR and reforested spruce plantations (SP aged 20–40 years on 12 similar clear-cuts of subalpine old-growth spruce-fir forests from the eastern Tibetan Plateau. We found that 283 of the 334 vascular plant species recorded were present in NR plots, while only 264 species occurred in SP plots. This was consistent with richer species, higher cover, and stem (or shoot density of tree seedlings, shrubs, and ferns in the NR plots than in the SP plots. Moreover, understory plant diversity was limited under dense canopy cover, which occurred more frequently in the SP plots. Our findings implied that natural deciduous tree regeneration could better preserve understory vegetation and biodiversity than spruce reforestation after clear-cutting. This result further informed practices to reduce tree canopy cover for spruce plantations or to integrate natural regeneration and reforestation for clear-cuts in order to promote understory vegetation and species diversity conservation.

Effect of gamma irradiation on Callus formation and regeneration of wheat immature embryos

International Nuclear Information System (INIS)

Saleh, O.M.

2007-01-01

Four Egyptian bread wheat cultivars; G164, G168, SK61 and Sids1, were tested for their response to six gamma irradiation treatments; 1, 2, 3 Gy (as low doses) and 10, 20, 30 Gy (as high doses) in addition to 0 Gy (as a control) in terms of callus formation and regeneration of immature embryos. Low doses of gamma irradiations ( 1, 2 and 3 Gy) showed favourable effects on both traits; number of regenerated calli and number of shoots per callus comparing with the control (0 Gy), while high doses; 10, 20 and 30 Gy, had the worst effect comparing with the control (0 Gy). G164 cultivar was shown to get the best response in terms of callus formation and regeneration when exposed to low doses of gamma irradiation. In conclusion, gamma irradiation can serve in increasing regeneration efficiency of Egyptian bread wheat cells when used in low doses

Proliferative retinopathy predicts nephropathy

DEFF Research Database (Denmark)

Karlberg, Charlotte; Falk, Christine; Green, Anders

2012-01-01

We wanted to examine proliferative retinopathy as a marker of incident nephropathy in a 25-year follow-up study of a population-based cohort of Danish type 1 diabetic patients and to examine cross-sectional associations between nephropathy and retinopathy in long-term surviving patients of the same...... cohort. All type 1 diabetic patients from Fyn County, Denmark, were identified as of 1 July 1973. One hundred and eighty four patients were examined in 1981-1982 (baseline) and in 2007-2008 (follow-up). The level of retinopathy was graded by ophthalmoscopy at baseline and nine-field digital colour fundus...... and proliferative retinopathy, respectively. In conclusion, proliferative retinopathy is an independent marker of long-term nephropathy in type 1 diabetes. Upcoming studies should examine whether these microvascular complications are also causally linked in type 1 diabetes....

Influence of gamma ray treatment on in vitro regenerated plants of Atropa Belladonna L

International Nuclear Information System (INIS)

Toth, E.; Onisei, T.; Amariei, D.

1994-01-01

Regenerated plants were obtained through callus organogenesis after gamma ray treatment with 1 to 9 Krad doses. Vigorous shoots were regenerated on MS (1962) medium supplemented with 2 mg/l 6-benzylaminopurine. Shoot growth was inhibited with increasing irradiation doses. At 2 Krad dose root Primordia were observed after 18 days while 32 days were necessary to produce roots at 7-9 Krad. As compared to the control, the survival percent during acclimatization was 80 to 85% at 2-3 Krad, 65-70% at 4-6 Krad and 60-62% at 7-9 Krad. Approximately 330 plants were transferred to field conditions. Morphological and biochemical parameters were measured and the data were statistically processed. Plant height was negatively influenced by higher doses of irradiation. A chlorophyll deficient plant arose from the 6 Krad treatment which showed a different pattern of isoperoxidase and isoesterase as compared to the control. A yellow-flower mutant was obtained from the 3 Krad treatment and is assumed to be Atropa belladonna var. Flava Pater. (author)

Non-Proliferative Diabetic Retinopathy Vision Simulator

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... Oncology Oculoplastics/Orbit Refractive Management/Intervention Retina/Vitreous Uveitis Focus On Pediatric Ophthalmology ... Retinopathy Diagnosis Diabetic Retinopathy Treatment Proliferative Diabetic Retinopathy Vision Simulator Non-Proliferative Diabetic ...

Slow-cycling stem cells in hydra contribute to head regeneration

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Niraimathi Govindasamy

2014-11-01

Full Text Available Adult stem cells face the challenge of maintaining tissue homeostasis by self-renewal while maintaining their proliferation potential over the lifetime of an organism. Continuous proliferation can cause genotoxic/metabolic stress that can compromise the genomic integrity of stem cells. To prevent stem cell exhaustion, highly proliferative adult tissues maintain a pool of quiescent stem cells that divide only in response to injury and thus remain protected from genotoxic stress. Hydra is a remarkable organism with highly proliferative stem cells and ability to regenerate at whole animal level. Intriguingly, hydra does not display consequences of high proliferation, such as senescence or tumour formation. In this study, we investigate if hydra harbours a pool of slow-cycling stem cells that could help prevent undesirable consequences of continuous proliferation. Hydra were pulsed with the thymidine analogue 5-ethynyl-2′-deoxyuridine (EdU and then chased in the absence of EdU to monitor the presence of EdU-retaining cells. A significant number of undifferentiated cells of all three lineages in hydra retained EdU for about 8–10 cell cycles, indicating that these cells did not enter cell cycle. These label-retaining cells were resistant to hydroxyurea treatment and were predominantly in the G2 phase of cell cycle. Most significantly, similar to mammalian quiescent stem cells, these cells rapidly entered cell division during head regeneration. This study shows for the first time that, contrary to current beliefs, cells in hydra display heterogeneity in their cell cycle potential and the slow-cycling cells in this population enter cell cycle during head regeneration. These results suggest an early evolution of slow-cycling stem cells in multicellular animals.

Development of efficient plant regeneration and transformation system for impatiens using Agrobacterium tumefaciens and multiple bud cultures as explants.

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Dan, Yinghui; Baxter, Aaron; Zhang, Song; Pantazis, Christopher J; Veilleux, Richard E

2010-08-09

Impatiens (Impatiens walleriana) is a top selling floriculture crop. The potential for genetic transformation of Impatiens to introduce novel flower colors or virus resistance has been limited by its general recalcitrance to tissue culture and transformation manipulations. We have established a regeneration and transformation system for Impatiens that provides new alternatives to genetic improvement of this crop. In a first step towards the development of transgenic INSV-resistant Impatiens, we developed an efficient plant regeneration system using hypocotyl segments containing cotyledonary nodes as explants. With this regeneration system, 80% of explants produced an average of 32.3 elongated shoots per initial explant plated, with up to 167 elongated shoots produced per explant. Rooting efficiency was high, and 100% of shoots produced roots within 12 days under optimal conditions, allowing plant regeneration within approximately 8 weeks. Using this regeneration system, we developed an efficient Agrobacterium-mediated Impatiens transformation method using in vitro multiple bud cultures as explants and a binary plasmid (pHB2892) bearing gfp and nptII genes. Transgenic Impatiens plants, with a frequency up to 58.9%, were obtained within 12 to 16 weeks from inoculation to transfer of transgenic plants to soil. Transgenic plants were confirmed by Southern blot, phenotypic assays and T1 segregation analysis. Transgene expression was observed in leaves, stems, roots, flowers, and fruit. The transgenic plants were fertile and phenotypically normal. We report the development of a simple and efficient Agrobacterium-mediated transformation system for Impatiens. To the best of our knowledge, there have been no reports of Agrobacterium-mediated transformation of Impatiens with experimental evidence of stable integration of T-DNA and of Agrobacterium-mediated transformation method for plants using in vitro maintained multiple bud cultures as explants. This transformation system

Development of Efficient Plant Regeneration and Transformation System for Impatiens Using Agrobacterium tumefaciens and Multiple Bud Cultures as Explants

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Dan Yinghui

2010-08-01

Full Text Available Abstract Background Impatiens (Impatiens walleriana is a top selling floriculture crop. The potential for genetic transformation of Impatiens to introduce novel flower colors or virus resistance has been limited by its general recalcitrance to tissue culture and transformation manipulations. We have established a regeneration and transformation system for Impatiens that provides new alternatives to genetic improvement of this crop. Results In a first step towards the development of transgenic INSV-resistant Impatiens, we developed an efficient plant regeneration system using hypocotyl segments containing cotyledonary nodes as explants. With this regeneration system, 80% of explants produced an average of 32.3 elongated shoots per initial explant plated, with up to 167 elongated shoots produced per explant. Rooting efficiency was high, and 100% of shoots produced roots within 12 days under optimal conditions, allowing plant regeneration within approximately 8 weeks. Using this regeneration system, we developed an efficient Agrobacterium-mediated Impatiens transformation method using in vitro multiple bud cultures as explants and a binary plasmid (pHB2892 bearing gfp and nptII genes. Transgenic Impatiens plants, with a frequency up to 58.9%, were obtained within 12 to 16 weeks from inoculation to transfer of transgenic plants to soil. Transgenic plants were confirmed by Southern blot, phenotypic assays and T1 segregation analysis. Transgene expression was observed in leaves, stems, roots, flowers, and fruit. The transgenic plants were fertile and phenotypically normal. Conclusion We report the development of a simple and efficient Agrobacterium-mediated transformation system for Impatiens. To the best of our knowledge, there have been no reports of Agrobacterium-mediated transformation of Impatiens with experimental evidence of stable integration of T-DNA and of Agrobacterium-mediated transformation method for plants using in vitro maintained

Photosynthesis of a scots pine shoot: the effect of shoot inclination on the photosynthetic response of a shoot subjected to direct radiation

International Nuclear Information System (INIS)

Oker-Blom, P.; Kellomaki, S.; Smolander, H.

1983-01-01

A set of photosynthetic responses of a Scots pine (Pinus sylvestris L.) shoot to light was derived from the shoot geometry and the photosynthetic response of a single needle. Computations showed that the shape of the photosynthesis light-curves varies substantially depending on the direction of radiation relative to the shoot position. Differences in the initial and maximum rates of photosynthesis were due to changes in the effective projection area and the irradiated fraction of the shoot, respectively

Zinc tolerance and accumulation in stable cell suspension cultures and in vitro regenerated plants of the emerging model plant Arabidopsis halleri (Brassicaceae).

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Vera-Estrella, Rosario; Miranda-Vergara, Maria Cristina; Barkla, Bronwyn J

2009-03-01

Arabidopsis halleri is increasingly employed as a model plant for studying heavy metal hyperaccumulation. With the aim of providing valuable tools for studies on cellular physiology and molecular biology of metal tolerance and transport, this study reports the development of successful and highly efficient methods for the in vitro regeneration of A. halleri plants and production of stable cell suspension lines. Plants were regenerated from leaf explants of A. halleri via a three-step procedure: callus induction, somatic embryogenesis and shoot development. Efficiency of callus proliferation and regeneration depended on the initial callus induction media and was optimal in the presence of 1 mg L(-1) 2,4-dichlorophenoxyacetic acid, and 0.05 mg L(-1) benzylaminopurine. Subsequent shoot and root regeneration from callus initiated under these conditions reached levels of 100% efficiency. High friability of the callus supported the development of cell suspension cultures with minimal cellular aggregates. Characterization of regenerated plants and cell cultures determined that they maintained not only the zinc tolerance and requirement of the whole plant but also the ability to accumulate zinc; with plants accumulating up to 50.0 micromoles zinc g(-1) FW, and cell suspension cultures 30.9 micromoles zinc g(-1) DW. Together this work will provide the experimental basis for furthering our knowledge of A. halleri as a model heavy metal hyperaccumulating plant.

Shoot differentiation from protocorm callus cultures of Vanilla planifolia (Orchidaceae): proteomic and metabolic responses at early stage.

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Palama, Tony L; Menard, Patrice; Fock, Isabelle; Choi, Young H; Bourdon, Emmanuel; Govinden-Soulange, Joyce; Bahut, Muriel; Payet, Bertrand; Verpoorte, Robert; Kodja, Hippolyte

2010-05-05

Vanilla planifolia is an important Orchid commercially cultivated for the production of natural vanilla flavour. Vanilla plants are conventionally propagated by stem cuttings and thus causing injury to the mother plants. Regeneration and in vitro mass multiplication are proposed as an alternative to minimize damage to mother plants. Because mass production of V. planifolia through indirect shoot differentiation from callus culture is rare and may be a successful use of in vitro techniques for producing somaclonal variants, we have established a novel protocol for the regeneration of vanilla plants and investigated the initial biochemical and molecular mechanisms that trigger shoot organogenesis from embryogenic/organogenic callus. For embryogenic callus induction, seeds obtained from 7-month-old green pods of V. planifolia were inoculated on MS basal medium (BM) containing TDZ (0.5 mg l(-1)). Germination of unorganized mass callus such as protocorm -like structure (PLS) arising from each seed has been observed. The primary embryogenic calli have been formed after transferring on BM containing IAA (0.5 mg l(-1)) and TDZ (0.5 mg l(-1)). These calli were maintained by subculturing on BM containing IAA (0.5 mg l(-1)) and TDZ (0.3 mg l(-1)) during 6 months and formed embryogenic/organogenic calli. Histological analysis showed that shoot organogenesis was induced between 15 and 20 days after embryogenic/organogenic calli were transferred onto MS basal medium with NAA (0.5 mg l(-1)). By associating proteomics and metabolomics analyses, the biochemical and molecular markers responsible for shoot induction have been studied in 15-day-old calli at the stage where no differentiating part was visible on organogenic calli. Two-dimensional electrophoresis followed by matrix-assisted laser desorption ionization time-of-flight-tandem mass spectrometry (MALDI-TOF-TOF-MS) analysis revealed that 15 protein spots are significantly expressed (P tissue culture, phenolic compounds such

School Shootings and Student Performance

OpenAIRE

Panu Poutvaara; Olli Ropponen

2010-01-01

In this paper, we study how high school students reacted to the shocking news of a school shooting. The shooting coincided with national high-school matriculation exams. As there were exams both before and after the shooting, we can use a difference-in-differences analysis to uncover how the school shooting affected the test scores compared to previous years. We find that the average performance of young men declined due to the school shooting, whereas we do not observe a similar pattern for ...

Regeneration of Centella asiatica plants from non-embryogenic cell lines and evaluation of antibacterial and antifungal properties of regenerated calli and plants

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Habib Darima

2011-10-01

Full Text Available Abstract Background The threatened plant Centella asiatica L. is traditionallyused for a number of remedies. In vitro plant propagation and enhanced metabolite production of active metabolites through biotechnological approaches has gained attention in recent years. Results Present study reveals that 6-benzyladenine (BA either alone or in combination with 1-naphthalene acetic acid (NAA supplemented in Murashige and Skoog (MS medium at different concentrations produced good quality callus from leaf explants of C. asiatica. The calli produced on different plant growth regulators at different concentrations were mostly embryogenic and green. Highest shoot regeneration efficiency; 10 shoots per callus explant, from non-embryogenic callus was observed on 4.42 μM BA with 5.37 μM NAA. Best rooting response was observed at 5.37 and 10.74 μM NAA with 20 average number of roots per explant. Calli and regenerated plants extracts inhibited bacterial growth with mean zone of inhibition 9-13 mm diameter when tested against six bacterial strains using agar well diffusion method. Agar tube dilution method for antifungal assay showed 3.2-76% growth inhibition of Mucor species, Aspergillus fumigatus and Fusarium moliniformes. Conclusions The present investigation reveals that non-embryogenic callus can be turned into embryos and plantlets if cultured on appropriate medium. Furthermore, callus from leaf explant of C. asiatica can be a good source for production of antimicrobial compounds through bioreactor.

In vitro plant regeneration of Spartina argentinensis Parodi

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Mirian Susana Bueno

2012-07-01

; in vitro; organogénesis; variación somaclonal. Abstract: Spartina argentinensis Parodi is the dominant species of the temporally-flooded halophyte communities of the Santa Fe Province, Argentina. It occupies around 20,000 km2 and it is mainly used as low-cost impute forage for cattle production. The objective of this work was to develop a simple method for in vitro plant regeneration of S. argentinensis that could be used for fundamental and applied research. Leaf-basal segments from both young and mature plants, roots tips and immature inflorescences were used as explants. Culture media for calli, shoot, and root induction consisted of Murashige & Skoog salts supplemented with different plant growth regulators (2,4-D; BAP or ANA. Most of the explants (with the exception of root tips showed cell proliferation and calli formation after 30 days of culture. However, only immature inflorescences responded to shoot and root induction when calli were incubated on MS salts plus 2,4_D and BAP (0.1 and 0.01 mg.L-1, respectively, transferred to shoot inductionmedia (MS salts plus BAP, 0.5 mg.L-1 and then to root induction media (MS slts plus NAA 0.5 mg.L-1. Regenerated plants were evaluated for morphological abnormalities and lignin content. Historical analysis of regenerating calli showed that shoots and roots originated via organogenesis. A low proportion of regenerated plants resulted with deficiency in chlorophyll (albino plants and other morphological abnormalities. Interestingly, significant variations in the lignin content were detected between regenerated plants. The protocol described in this work could be used ordinarily for S. argentinensis in vitro plant regeneration and selecting somaclonal variants for breeding purposes. Key words: Spartina argentinensis; in vitro; organogenesis; somaclonal variation.

Shoot differentiation from protocorm callus cultures of Vanilla planifolia (Orchidaceae: proteomic and metabolic responses at early stage

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Payet Bertrand

2010-05-01

Full Text Available Abstract Background Vanilla planifolia is an important Orchid commercially cultivated for the production of natural vanilla flavour. Vanilla plants are conventionally propagated by stem cuttings and thus causing injury to the mother plants. Regeneration and in vitro mass multiplication are proposed as an alternative to minimize damage to mother plants. Because mass production of V. planifolia through indirect shoot differentiation from callus culture is rare and may be a successful use of in vitro techniques for producing somaclonal variants, we have established a novel protocol for the regeneration of vanilla plants and investigated the initial biochemical and molecular mechanisms that trigger shoot organogenesis from embryogenic/organogenic callus. Results For embryogenic callus induction, seeds obtained from 7-month-old green pods of V. planifolia were inoculated on MS basal medium (BM containing TDZ (0.5 mg l-1. Germination of unorganized mass callus such as protocorm -like structure (PLS arising from each seed has been observed. The primary embryogenic calli have been formed after transferring on BM containing IAA (0.5 mg l-1 and TDZ (0.5 mg l-1. These calli were maintained by subculturing on BM containing IAA (0.5 mg l-1 and TDZ (0.3 mg l-1 during 6 months and formed embryogenic/organogenic calli. Histological analysis showed that shoot organogenesis was induced between 15 and 20 days after embryogenic/organogenic calli were transferred onto MS basal medium with NAA (0.5 mg l-1. By associating proteomics and metabolomics analyses, the biochemical and molecular markers responsible for shoot induction have been studied in 15-day-old calli at the stage where no differentiating part was visible on organogenic calli. Two-dimensional electrophoresis followed by matrix-assisted laser desorption ionization time-of-flight-tandem mass spectrometry (MALDI-TOF-TOF-MS analysis revealed that 15 protein spots are significantly expressed (P Conclusion The

Establishment of the regeneration system for Vicia faba L.

Science.gov (United States)

Bahgat, Shimaa; Shabban, Omer A; El-Shihy, Osama; Lightfoot, David A; El-Shemy, Hany A

2009-01-01

A reliable regeneration system for faba bean has been difficult to establish and therefore, the genetic improvement of Vicia faba L. was delayed. The paper describes a method of somatic embryo induction in callus of V. faba. Two Egyptian faba bean cultivars 'Giza 2' and '24 Hyto' were used. Callus was induced from epicotyls and shoot tips cultured on MS or Gamborg medium supplemented with 3% sucrose and 0.025% (w/v) for each of ascorbic and citric acid, 0.8% agar and different concentrations of 10 mg/l BAP, 0.5 mg/l of each NAA and 2,4-dichlorophenoxyacetic acid (M1) and 1 mg/l BAP and 0.5 mg/l NAA (M2) . The media with BAP, NAA and 2,4-D were optimal for embryogenic callus induction. Somatic embryos developed after transfer of the callus to 1/2 B5 medium with no plant growth regulators. There were various stages of somatic embryo development present including globular, heart-shaped, torpedo, and cotyledonary stages. Embryos developed into plantlets and plants were regenerated. RAPD analyses were performed to investigate the genetic stability of the regenerated plants obtained from different treatments and different explants. The cultivar Giza 2 exhibited more genetic stability than cultivar 24 Hyto. In conclusion, a regeneration system was established suitable for both gene transformation and the isolation of somaclonal mutants. The regeneration system will be used in order to improve the nutritional value of faba bean.

dlx and sp6-9 Control optic cup regeneration in a prototypic eye.

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Sylvain W Lapan

2011-08-01

Full Text Available Optic cups are a structural feature of diverse eyes, from simple pit eyes to camera eyes of vertebrates and cephalopods. We used the planarian prototypic eye as a model to study the genetic control of optic cup formation and regeneration. We identified two genes encoding transcription factors, sp6-9 and dlx, that were expressed in the eye specifically in the optic cup and not the photoreceptor neurons. RNAi of these genes prevented formation of visible optic cups during regeneration. Planarian regeneration requires an adult proliferative cell population with stem cell-like properties called the neoblasts. We found that optic cup formation occurred only after migration of progressively differentiating progenitor cells from the neoblast population. The eye regeneration defect caused by dlx and sp6-9 RNAi can be explained by a failure to generate these early optic cup progenitors. Dlx and Sp6-9 genes function as a module during the development of diverse animal appendages, including vertebrate and insect limbs. Our work reveals a novel function for this gene pair in the development of a fundamental eye component, and it utilizes these genes to demonstrate a mechanism for total organ regeneration in which extensive cell movement separates new cell specification from organ morphogenesis.

Impact of cycling cells and cell cycle regulation on Hydra regeneration.

Science.gov (United States)

Buzgariu, Wanda; Wenger, Yvan; Tcaciuc, Nina; Catunda-Lemos, Ana-Paula; Galliot, Brigitte

2018-01-15

Hydra tissues are made from three distinct populations of stem cells that continuously cycle and pause in G2 instead of G1. To characterize the role of cell proliferation after mid-gastric bisection, we have (i) used flow cytometry and classical markers to monitor cell cycle modulations, (ii) quantified the transcriptomic regulations of 202 genes associated with cell proliferation during head and foot regeneration, and (iii) compared the impact of anti-proliferative treatments on regeneration efficiency. We confirm two previously reported events: an early mitotic wave in head-regenerating tips, when few cell cycle genes are up-regulated, and an early-late wave of proliferation on the second day, preceded by the up-regulation of 17 cell cycle genes. These regulations appear more intense after mid-gastric bisection than after decapitation, suggesting a position-dependent regulation of cell proliferation during head regeneration. Hydroxyurea, which blocks S-phase progression, delays head regeneration when applied before but not after bisection. This result is consistent with the fact that the Hydra central region is enriched in G2-paused adult stem cells, poised to divide upon injury, thus forming a necessary constitutive pro-blastema. However a prolonged exposure to hydroxyurea does not block regeneration as cells can differentiate apical structures without traversing S-phase, and also escape in few days the hydroxyurea-induced S-phase blockade. Thus Hydra head regeneration, which is a fast event, is highly plastic, relying on large stocks of adult stem cells paused in G2 at amputation time, which immediately divide to proliferate and/or differentiate apical structures even when S-phase is blocked. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Improvement of efficient in vitro regeneration potential of mature callus induced from Malaysian upland rice seed (Oryza sativa cv. Panderas).

Science.gov (United States)

Mohd Din, Abd Rahman Jabir; Iliyas Ahmad, Fauziah; Wagiran, Alina; Abd Samad, Azman; Rahmat, Zaidah; Sarmidi, Mohamad Roji

2016-01-01

A new and rapid protocol for optimum callus production and complete plant regeneration has been assessed in Malaysian upland rice (Oryza sativa) cv. Panderas. The effect of plant growth regulator (PGR) on the regeneration frequency of Malaysian upland rice (cv. Panderas) was investigated. Mature seeds were used as a starting material for callus induction experiment using various concentrations of 2,4-D and NAA. Optimal callus induction frequency at 90% was obtained on MS media containing 2,4-D (3 mg L(-1)) and NAA (2 mg L(-1)) after 6 weeks while no significant difference was seen on tryptophan and glutamine parameters. Embryogenic callus was recorded as compact, globular and light yellowish in color. The embryogenic callus morphology was further confirmed with scanning electron microscopy (SEM) analysis. For regeneration, induced calli were treated with various concentrations of Kin (0.5-1.5 mg L(-1)), BAP, NAA and 0.5 mg L(-1) of TDZ. The result showed that the maximum regeneration frequency (100%) was achieved on MS medium containing BAP (0.5 mg L(-1)), Kin (1.5 mg L(-1)), NAA (0.5 mg L(-1)) and TDZ (0.5 mg L(-1)) within four weeks. Developed shoots were successfully rooted on half strength MS free hormone medium and later transferred into a pot containing soil for acclimatization. This cutting-edge finding is unique over the other existing publishable data due to the good regeneration response by producing a large number of shoots.

Violence and school shootings.

Science.gov (United States)

Flannery, Daniel J; Modzeleski, William; Kretschmar, Jeff M

2013-01-01

Multiple-homicide school shootings are rare events, but when they happen they significantly impact individuals, the school and the community. We focus on multiple-homicide incidents and identified mental health issues of shooters. To date, studies of school shootings have concluded that no reliable profile of a shooter exists, so risk should be assessed using comprehensive threat assessment protocols. Existing studies primarily utilize retrospective case histories or media accounts. The field requires more empirical and systematic research on all types of school shootings including single victim incidents, those that result in injury but not death and those that are successfully averted. We discuss current policies and practices related to school shootings and the role of mental health professionals in assessing risk and supporting surviving victims.

PEMBELAJARAN LAY UP SHOOT MENGGUNAKAN MEDIA AUDIO VISUAL BASIC LAY UP SHOOT UNTUK MENINGKATKAN HASILBELAJAR LAY UP SHOOT PADA SISWA KELAS VIIIA SMP KANISIUS PATI TAHUN 2013/2014

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Frendy Nurochwan Febryanto

2015-01-01

Full Text Available The purpose of this study was to determine the learning lay up shoot using basic audiovisual media shoot lay ups can improve learning outcomes shoot lay ups in class VIIIA Starch Canisius junior year 2013/2014 . This study uses Classroom Action Research ( CAR. The technique of collecting data through observation and assessment of learning outcomes shoot basketball lay up. Data analysis techniques used in this research is descriptive . At the end of the first cycle activity of teachers in teaching basic techniques lay up shoot using audio-visual media reaches 76.19%, whereas at the end of the first cycle of student activity during the learning process lay up shoot using audio-visualmediareaches78.57%. At the end of the second cycle of activity of teachers in teaching basic techniques lay up shoot using audio-visual media reaches 85.71%, whereas at the end of the second cycle of activity of students during the learning process lay up shoot using audio-visual media reaches 92.86%. Based on the results of the study it can be concluded that learning the lay-up shoot using basic audiovisual media shoot lay ups can improve student learning outcomes at Canisius junior class VIIIA Pati year 2013/2014.

Adolescent mass shootings: developmental considerations in light of the Sandy Hook shooting.

Science.gov (United States)

Rice, Timothy R; Hoffman, Leon

2015-05-01

Adolescent mass shootings are a special subset of mass killings, which continue despite significant preventative public health efforts. It is often held that these individuals have few salient warning signs that could have been identified. This piece proposes that mass shootings committed by adolescent and post-adolescent young males must be understood from a developmental perspective. The hypothesis proposed in this paper is that such killings occur as the result of the adolescent's frustrated effort to progress along normative development. The goal of normative separation from maternal figures by the boy is presented as a potential risk factor when this goal is thwarted. Childhood case material from the perpetrator of a recent adolescent mass shooting, the Sandy Hook shooting, is discussed as an illustration of this hypothesis. Implications for public health measures and for individualized treatment are presented and developed.

Micropropagation and validation of genetic and biochemical fidelity amongst regenerants of Cassia angustifolia Vahl employing RAPD marker and HPLC.

Science.gov (United States)

Chetri, Siva K; Sardar, Pratima Rani; Agrawal, Veena

2014-10-01

In vitro protocol has been established for clonal propagation of Cassia angustifolia Vahl which is an important source of anticancerous bioactive compounds, sennoside A and B. Nodal explants excised from field raised elite plant (showing optimum level of sennoside A and B) of C. angustifolia when reared on Murashige and Skoog's medium augmented with different cytokinins, viz. N(6)-benzyladenine (BA), N(6)-(2-isopentenyl) adenine (2iP) and 6-furfuryl aminopurine (Kn) differentiated multiple shoots in their axils. Of the three cytokinins, BA at 5 μM proved optimum for differentiating multiple shoots in 95 % cultures with an average of 9.14 shoots per explant within 8 weeks of culture. Nearly, 95 % of the excised in vitro shoots rooted on half strength MS medium supplemented with 10 μM indole-3-butyric acid (IBA). The phenotypically similar micropropagated plants were evaluated for their genetic fidelity employing random amplified polymorphic DNA (RAPD) markers. Eleven individuals, randomly chosen amongst a population of 120 regenerants were compared with the donor plant. A total of 36 scorable bands, ranging in size from 100 to 1,000 bp were generated amongst them by the RAPD primers. All banding profiles from micropropagated plants were monomorphic and similar to those of mother plant proving their true to the type nature. Besides, high performance liquid chromatography evaluation of the sennoside A and B content amongst leaves of the mature regenerants and the elite mother plant too revealed consistency in their content.

Benign Proliferative Breast Lesions and Risk of Cancer

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Serap Erel

2010-06-01

Full Text Available Benign breast lesions (BBL includes a wide variety of histologic entities, which have been broadly classified into non-proliferative lesions, proliferative lesions without atypia, and hyperplasia with atypia. With the increased use of mammography, more benign lesions are being detected, and in order to estimate the risk of breast cancer for specific histologic categories is of great importance to guide clinical management. Women with proliferative lesions without atypia are at slightly increased risk of subsequent breast cancer, whereas women with proliferative lesions with atypia have a higher risk. The risk is 1.5- 2-fold in women with proliferative lesions without atypia, 4-5-fold in women with proliferative lesions with atypia, and 8-10 fold in women with ductal carcinoma in situ. Age at diagnosis of BBL, menopausal status, family history of breast cancer in a first-degree relative, and time since BBL diagnosis on risk of breast cancer are important for risk evaluation. [Archives Medical Review Journal 2010; 19(3.000: 155-167

In vitro regeneration of solanum aethiopicum L. (scarlet eggplant), an african vegetable crop with potential ornamental value

Science.gov (United States)

Successful in vitro regeneration of plantlets was obtained from shoot tips of five Solanum aethiopicum (African eggplants) accessions evaluated in two media, M1 and M2. The M1 medium consisted of Murashige and Skoog (MS) basal salt mixture supplemented with 20 g/L sucrose, 0.75 g/L MgCl2, and 2 g/L ...

Preculturing effect of thidiazuron on in vitro shoot multiplication and micropropagation round in Capparis decidua (Forsk.) an important multipurpose plant.

Science.gov (United States)

Bukhari, Najat A W; Siddique, Iram; Perveen, Kahkashan

2016-09-01

An efficient protocol was developed for clonal multiplication of an important shrub: Capparis decidua (Forsk.) Edgew, through in vitro shoot induction and multiplication from nodal explants. Pretreatment of nodal explants in a liquid Murashige and Skoog (MS) medium augmented with various thidiazuron (TDZ) concentrations at relatively high levels (5-100 μM) for different time duration (4, 8, 12 and 16 d), proved a significant approach for in vitro shoot production. After an initial exposure time to TDZ, nodal explants were inoculated onto a MS basal medium devoid of TDZ for further induction and proliferation. The highest regeneration rate (85%), average number of shoots/explant (8.7 ± 0.22) and maximum shoot length (3.9 ± 0.33 cm) were obtained from the nodal explants exposed to 50 μM TDZ for 8 d. The nodal explants excised from the proliferated cultures of TDZ (50 μM) for 8 d were used as explants and showed an enhancement rate after next three round of in vitro propagation. Best results for rooting was obtained by ex vitro treatment of shoots with 200 μM indole-3-butyric acid (IBA) for 20 min. as it produced an average of 5.7 ± 0.41 roots per microshoot with 4.4 ± 0.39 cm root length in 84% shoots. Different planting substrates was tested for maximum survival of hardening off micropropagated plantlets and soilrite proved most effective than others as 97.1 ± 7.21 plantlets survived. All micropropagated plants grew well in natural conditions and showed similar morphology to the mother plant.

Regeneration and vegetative propagation of Sphagnum palustre as factor of population stability

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Dygna Sobotka

2015-01-01

Full Text Available The stability of the Sphagnum palustre populations on the meadows of the Kampinos National Park situated north-west of Warsaw was investigated in the period 1971-1974. Laboratory cultures were also started to establish the regenerative ability of various gametophyte parts of Sphagnum: the main stem, branches, leaves and spore germination. The green stems and apical branches of the plants showed the highest regeneration ability. Brown stems and white branches developed less intensively. Leaves showed no tendency to develop into new plants. Gametophores were found to form quicker and more effectively by way of regeneration than from spores. In natural conditions more intensive growth of branchings (new shoots from the apical and green parts of Sphagnum was also observed, whereas the brown parts did not exhibit this ability.

Current perspectives on shoot branching regulation

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Cunquan YUAN,Lin XI,Yaping KOU,Yu ZHAO,Liangjun ZHAO

2015-03-01

Full Text Available Shoot branching is regulated by the complex interactions among hormones, development, and environmental factors. Recent studies into the regulatory mecha-nisms of shoot branching have focused on strigolactones, which is a new area of investigation in shoot branching regulation. Elucidation of the function of the D53 gene has allowed exploration of detailed mechanisms of action of strigolactones in regulating shoot branching. In addition, the recent discovery that sucrose is key for axillary bud release has challenged the established auxin theory, in which auxin is the principal agent in the control of apical dominance. These developments increase our understan-ding of branching control and indicate that regulation of shoot branching involves a complex network. Here, we first summarize advances in the systematic regulatory network of plant shoot branching based on current information. Then we describe recent developments in the synthesis and signal transduction of strigolactones. Based on these considerations, we further summarize the plant shoot branching regulatory network, including long distance systemic signals and local gene activity mediated by strigolactones following perception of external envi-ronmental signals, such as shading, in order to provide a comprehensive overview of plant shoot branching.

CXC chemokines function as a rheostat for hepatocyte proliferation and liver regeneration.

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Gregory C Wilson

Full Text Available Our previous in vitro studies have demonstrated dose-dependent effects of CXCR2 ligands on hepatocyte cell death and proliferation. In the current study, we sought to determine if CXCR2 ligand concentration is responsible for the divergent effects of these mediators on liver regeneration after ischemia/reperfusion injury and partial hepatectomy.Murine models of partial ischemia/reperfusion injury and hepatectomy were used to study the effect of CXCR2 ligands on liver regeneration.We found that hepatic expression of the CXCR2 ligands, macrophage inflammatory protein-2 (MIP-2 and keratinocyte-derived chemokine (KC, was significantly increased after both I/R injury and partial hepatectomy. However, expression of these ligands after I/R injury was 30-100-fold greater than after hepatectomy. Interestingly, the same pattern of expression was found in ischemic versus non-ischemic liver lobes following I/R injury with expression significantly greater in the ischemic liver lobes. In both systems, lower ligand expression was associated with increased hepatocyte proliferation and liver regeneration in a CXCR2-dependent fashion. To confirm that these effects were related to ligand concentration, we administered exogenous MIP-2 and KC to mice undergoing partial hepatectomy. Mice received a "high" dose that replicated serum levels found after I/R injury and a "low" dose that was similar to that found after hepatectomy. Mice receiving the "high" dose had reduced levels of hepatocyte proliferation and regeneration whereas the "low" dose promoted hepatocyte proliferation and regeneration.Together, these data demonstrate that concentrations of CXC chemokines regulate the hepatic proliferative response and subsequent liver regeneration.

Inhibition of H3K27me3 Histone Demethylase Activity Prevents the Proliferative Regeneration of Zebrafish Lateral Line Neuromasts

Science.gov (United States)

Bao, Beier; He, Yingzi; Tang, Dongmei; Li, Wenyan; Li, Huawei

2017-01-01

The H3K27 demethylases are involved in a variety of biological processes, including cell differentiation, proliferation, and cell death by regulating transcriptional activity. However, the function of H3K27 demethylation in the field of hearing research is poorly understood. Here, we investigated the role of H3K27me3 histone demethylase activity in hair cell regeneration using an in vivo animal model. Our data showed that pharmacologic inhibition of H3K27 demethylase activity with the specific small-molecule inhibitor GSK-J4 decreased the number of regenerated hair cells in response to neomycin damage. Furthermore, inhibition of H3K27me3 histone demethylase activity dramatically suppressed cell proliferation and activated caspase-3 levels in the regenerating neuromasts of the zebrafish lateral line. GSK-J4 administration also increased the expression of p21 and p27 in neuromast cells and inhibited the ERK signaling pathway. Collectively, our findings indicate that H3K27me3 demethylation is a key epigenetic regulator in the process of hair cell regeneration in zebrafish and suggest that H3K27me3 histone demethylase activity might be a novel therapeutic target for the treatment of hearing loss. PMID:28348517

Transformation and regeneration of the holoparasitic plant Phelipanche aegyptiaca

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Fernández-Aparicio Mónica

2011-11-01

Full Text Available Abstract Background Transformation and subsequent regeneration of holoparasitic plants has never been reported, in part due to challenges in developing transformation protocols, but also because regeneration of obligate parasites is difficult since their survival depends completely on successful haustorium penetration of a host and the formation of vascular connections. The recent completion of a massive transcriptome sequencing project (the Parasitic Plant Genome Project will fuel the use of genomic tools for studies on parasitic plants. A reliable system for holoparasite transformation is needed to realize the full value of this resource for reverse genetics and functional genomics studies. Results Here we demonstrate that transformation of Phelipanche aegyptiaca is achieved by infection of 3 month-old in vitro grown P. aegyptiaca calli with Agrobacterium rhizogenes harboring the yellow fluorescent protein (YFP. Four months later, YFP-positive regenerated calli were inoculated onto tomato plants growing in a minirhizotron system. Eight days after inoculation, transgenic parasite tissue formed lateral haustoria that penetrated the host and could be visualized under UV illumination through intact host root tissue. YFP-positive shoot buds were observed one month after inoculation. Conclusions This work constitutes a breakthrough in holoparasitic plant research methods. The method described here is a robust system for transformation and regeneration of a holoparasitic plant and will facilitate research on unique parasitic plant capabilities such as host plant recognition, haustorial formation, penetration and vascular connection.

Linking ontogeny and tissue regeneration: a study on tissue damage and wound healing in carp in connection to the developmental stage

DEFF Research Database (Denmark)

Nielsen, Michael Engelbrecht; Schmidt, Jacob; Ingerslev, Hans-Christian

regeneration since its genome is well-described and it is easy visually to follow the wound healing. In this study, carps were physically damaged in the musculature using sterile needles at day 10, 16, 24, 47 and 94 post hatch. Muscle tissue samples were subsequently taken at day 1, 3 and 7 post damage...... healing and tissue regeneration, the developmental stage of the individual may influence the immune reaction initiated following damage and thus the proliferative responses, which usually cross-talk with the immune system. Common carp (Cyprinus carpio) is an excellent fish specie to study tissue...

Shooting mechanisms in nature

NARCIS (Netherlands)

Sakes, Aimée; Wiel, van der Marleen; Henselmans, Paul W.J.; Leeuwen, van Johan L.; Dodou, Dimitra; Breedveld, Paul

2016-01-01

Background In nature, shooting mechanisms are used for a variety of purposes, including prey capture, defense, and reproduction. This review offers insight into the working principles of shooting mechanisms in fungi, plants, and animals in the light of the specific functional demands that these

Visual selection and maintenance of the cell lines with high plant regeneration ability and low ploidy level in Dianthus acicularis by monitoring with flow cytometry analysis.

Science.gov (United States)

Shiba, Tomonori; Mii, Masahiro

2005-12-01

Efficient plant regeneration system from cell suspension cultures was established in D. acicularis (2n=90) by monitoring ploidy level and visual selection of the cultures. The ploidy level of the cell cultures closely related to the shoot regeneration ability. The cell lines comprising original ploidy levels (2C+4C cells corresponding to DNA contents of G1 and G2 cells of diploid plant, respectively) showed high regeneration ability, whereas those containing the cells with 8C or higher DNA C-values showed low or no regeneration ability. The highly regenerable cell lines thus selected consisted of compact cell clumps with yellowish color and relatively moderate growth, suggesting that it is possible to select visually the highly regenerable cell lines with the original ploidy level. All the regenerated plantlets from the highly regenerable cell cultures exhibited normal phenotypes and no variations in ploidy level were observed by flow cytometry (FCM) analysis.

Expression of Msx-2 during development, regeneration, and wound healing in axolotl limbs.

Science.gov (United States)

Carlson, M R; Bryant, S V; Gardiner, D M

1998-12-15

Msx genes are transcription factors that are expressed during embryogenesis of developing appendages in regions of epithelial-mesenchymal interactions. Various lines of evidence indicate that these genes function to maintain embryonic tissues in an undifferentiated, proliferative state. We have identified the axolotl homolog of Msx-2, and investigated its expression during limb development, limb regeneration, and wound healing. As in limb buds of higher vertebrates, axolotl Msx-2 is expressed in the apical epidermis and mesenchyme; however, its expression domain is more extensive, reflecting the broader region of the apical epidermal cap in amphibians. Msx-2 expression is downregulated at late stages of limb development, but is reexpressed within one hour after limb amputation. Msx-2 is also reexpressed during wound healing, and may be essential in the early stages of initiation of the limb regeneration cascade.

1. modification of the proliferative capacity of transplanted bone marrow colony forming units by changes in the host environment

International Nuclear Information System (INIS)

Beran, M.; Tribukait, B.

1974-01-01

Regulation of the proliferation of transplanted colony forming units (CFUs) was investigated in lethally irradiated mice, pretreated by methods known to accelerate hemopoietic recovery after sublethal irradiation. Prospective recipients were exposed to either hypoxia, vinblastine or priming irradiation and at different intervals thereafter lethally irradiated and transplanted with bone marrow. Repopulation of CFUs was determined by counting the number of splenic colonies in primary recipients or by retransplantation. Regeneration of grafted CFUs was greatly accelerated and their self-renewal capacity increased in mice grafted within 2 days after hypoxia. Also the number of splenic colonies formed by grafted syngeneic CFUs as well as by C57B1 parent CFUs growing in BC3F1 hosts was significantly increased. The effect was not dependent on the seeding efficiency of CFUs and apparently resulted from hypoxia induced changes in the hosts' physiological environment. Proliferative capacity of grafted CFUs increased remarkably in hosts receiving vinblastine 2 or 4 days prior to irradiation. Priming irradiation given 6 days before main irradiation accelerated, given 2 days before impaired regeneration of CFUs. The increased rate of regeneration was not related to the cellularity of hemopoietic organs at the time of transplantation. The growth of CFUs in diffusion chambers implanted into posthypoxic mice was only slightly improved which does indicate that the accelerated regeneration of CFUs in posthypoxic mice is mainly due to the changes in the hemopoietic microenvironment. A short conditioning of transplanted CFUs by host factor(s) was sufficient to improve regeneration. The results might suggest that the speed of hemopoietic regeneration depends on the number of CFUs being induced to proliferate shortly after irradiation, rather than on the absolute numbers of CFUs available to the organism. (author)

Proliferative lifespan is conserved after nuclear transfer.

Science.gov (United States)

Clark, A John; Ferrier, Patricia; Aslam, Samena; Burl, Sarah; Denning, Chris; Wylie, Diana; Ross, Arlene; de Sousa, Paul; Wilmut, Ian; Cui, Wei

2003-06-01

Cultured primary cells exhibit a finite proliferative lifespan, termed the Hayflick limit. Cloning by nuclear transfer can reverse this cellular ageing process and can be accomplished with cultured cells nearing senescence. Here we describe nuclear transfer experiments in which donor cell lines at different ages and with different proliferative capacities were used to clone foetuses and animals from which new primary cell lines were generated. The rederived lines had the same proliferative capacity and rate of telomere shortening as the donor cell lines, suggesting that these are innate, genetically determined, properties that are conserved by nuclear transfer.

Mass shooting and mass media : does media coverage of mass shootings inspire copycat crimes?

OpenAIRE

Mesoudi, A.

2013-01-01

In December 2012, twenty elementary school children and six adult staff members were shot and killed by a single individual at a school in Connecticut. Although this horrific event was met with widespread shock, Americans are sadly all too familiar with such mass shootings. From Columbine in 1999, to Virginia Tech in 2007, to the Colorado cinema shootings earlier in 2012, mass shootings seem to occur with alarming regularity. And although they appear to afflict the United States more than mos...

Effect of antioxidants and associate changes in antioxidant enzymes in controlling browning and necrosis of proliferating shoots of elite Jatropha curcas L

International Nuclear Information System (INIS)

Misra, Pratibha; Toppo, Dibya D.; Gupta, Neha; Chakrabarty, Debasis; Tuli, Rakesh

2010-01-01

A high yielding elite plant of Jatropha curcas was established under aseptic condition from field-grown nodal explants. Shoots were proliferated in MS medium supplemented with 0.5 mg dm -3 benzyladenine and 0.1 mg dm -3 indolebutyric acid along with 10 mg dm -3 adenine sulphate and a combination of 15 mg dm -3 each of L-glutamine and L-arginine. However, within 15-20 d of culture incubation, tissue browning/necrosis leading to poor plant regeneration in vitro was observed. A set of different antioxidants, namely, reduced glutathione, ascorbic acid, tocopherol and cysteine were used in the medium individually and in combination to solve the problem of tissue browning and necrosis. The addition of antioxidants proved beneficial for the growth of the shoots. The optimum medium comprised of 25 mg dm -3 reduced glutathione and 10 mg dm -3 ascorbic acid, where proliferating shoots having highest leaf canopy area, remained fresh, green and regenerative up to 40 d of culture incubation without any subculture. The activities of antioxidant enzymes, such as superoxide dismutase was higher in control shoots, indicating that tissue browning/necrosis was associated with oxidative stress which was further supported by higher contents of H 2 O 2 and phenolics in control shoots compared to the other treatments. Similarly glutathione reductase, ascorbate peroxidase and guiacol peroxidase was higher in treated shoots than control indicating that these shoots have developed antioxidant enzymatic protective system which determine the ability to survive in oxidative stress and up regulation of these enzymes would help to reduce the built up of reactive oxygen species.

Regeneration Responses to Management for Old-Growth Characteristics in Northern Hardwood-Conifer Forests

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Aviva J. Gottesman

2017-02-01

Full Text Available Successful tree regeneration is essential for sustainable forest management, yet it can be limited by the interaction of harvesting effects and multiple ecological drivers. In northern hardwood forests, for example, there is uncertainty whether low-intensity selection harvesting techniques will result in adequate and desirable regeneration. Our research is part of a long-term study that tests the hypothesis that a silvicultural approach called “structural complexity enhancement” (SCE can accelerate the development of late-successional forest structure and functions. Our objective is to understand the regeneration dynamics following three uneven-aged forestry treatments with high levels of retention: single-tree selection, group selection, and SCE. Regeneration density and diversity can be limited by differing treatment effects on or interactions among light availability, competitive environment, substrate, and herbivory. To explore these relationships, manipulations and controls were replicated across 2 ha treatment units at two Vermont sites. Forest inventory data were collected pre-harvest and periodically over 13 years post-harvest. We used mixed effects models with repeated measures to evaluate the effect of treatment on seedling and sapling density and diversity (Shannon–Weiner H’. The treatments were all successful in recruiting a sapling class with significantly greater sapling densities compared to the controls. However, undesirable and prolific beech (Fagus americana sprouting dominates some patches in the understory of all the treatments, creating a high degree of spatial variability in the competitive environment for regeneration. Multivariate analyses suggest that while treatment had a dominant effect, other factors were influential in driving regeneration responses. These results indicate variants of uneven-aged systems that retain or enhance elements of stand structural complexity—including old-growth characteristics�

In vitro Embryogenesis Derived from Shoot Tips in Mass Propagation of Two Selected-Clones of Phalaenopsis

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Budi WINARTO

2016-09-01

Full Text Available Phalaenopsis is of high economic value and market demand in Indonesia; however, orchid products are mostly imported from other countries. ‘Kristina Dwi’ (KD 69.274 and ‘Dedeh’ (D 802.28 are two selected clones with high potential utilized and developed commercially. To support their commercialization, a reliable in vitro propagation protocol is essential.  In the current study, an in vitro mass propagation protocol for KD 69.274 and D 802.28 clones was successfully established using shoot tips as explant sources. A high number of embryos, up to 8.2 embryos per explant, with 58.5% explant regeneration, and 3.5 regenerated-explants in average were regenerated from shoot tips of KD 69.274 clone cultured on  half-strength Murashige and Skoog (MS medium, with full strength micro, Fe-chellate and vitamin containing 0.5 mg/L thidiazuruon (TDZ and 0.25 mg/L N6-benzyladenine (BA. The initial embryos were proliferated by culturing embryos individually on half-strength MS medium with 0.13 mg/L TDZ and 0.25 mg/L BA and resulted in high embryo regeneration up to 91.4%, with 10.2 embryos per explant and no embryo browning. The embryos were multiplied under periodical subcultures of 3 months each, resulting in gradual increasing number of embryos from the first subculture till the fifth subculture, with 23.6 embryos produced, then declined afterward. The embryos were easily germinated on half-strength MS medium with full strength of vitamin and hormone free, with 73.9% embryo germination and 14.9 germinated embryos. Healthy plantlets were stimulated on the same medium with 2 g/L activated charcoal (AC and successfully acclimatized on Cycas rumphii bulk, with 88.3% survival plantlets. Finally, it can be summarized that a new in vitro mass propagation protocol, as new alternative choice for Phalaenopsis propagation, was successfully established.

Cell proliferation is necessary for the regeneration of oral structures in the anthozoan cnidarian Nematostella vectensis

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Passamaneck Yale J

2012-12-01

Full Text Available Abstract Background The contribution of cell proliferation to regeneration varies greatly between different metazoan models. Planarians rely on pluripotent neoblasts and amphibian limb regeneration depends upon formation of a proliferative blastema, while regeneration in Hydra can occur in the absence of cell proliferation. Recently, the cnidarian Nematostella vectensis has shown potential as a model for studies of regeneration because of the ability to conduct comparative studies of patterning during embryonic development, asexual reproduction, and regeneration. The present study investigates the pattern of cell proliferation during the regeneration of oral structures and the role of cell proliferation in this process. Results In intact polyps, cell proliferation is observed in both ectodermal and endodermal tissues throughout the entire oral-aboral axis, including in the tentacles and physa. Following bisection, there is initially little change in proliferation at the wound site of the aboral fragment, however, beginning 18 to 24 hours after amputation there is a dramatic increase in cell proliferation at the wound site in the aboral fragment. This elevated level of proliferation is maintained throughout the course or regeneration of oral structures, including the tentacles, the mouth, and the pharynx. Treatments with the cell proliferation inhibitors hydroxyurea and nocodazole demonstrate that cell proliferation is indispensable for the regeneration of oral structures. Although inhibition of regeneration by nocodazole was generally irreversible, secondary amputation reinitiates cell proliferation and regeneration. Conclusions The study has found that high levels of cell proliferation characterize the regeneration of oral structures in Nematostella, and that this cell proliferation is necessary for the proper progression of regeneration. Thus, while cell proliferation contributes to regeneration of oral structures in both Nematostella and

Somatic embryogenesis and plant regeneration in Carica papaya L. tissue culture derived from root explants.

Science.gov (United States)

Chen, M H; Wang, P J; Maeda, E

1987-10-01

The regeneration potential of shoot tip, stem, leaf, cotyledon and root explants of two papaya cultivars (Carica papaya cv. 'Solo' and cv. 'Sunrise') were studed. Callus induction of these two cultivars of papaya showed that the shoot tips and stems are most suitable for forming callus, while leaves, cotyledons and roots are comparatively difficult to induce callus. Callus induction also varied with the varities. Somatic embryogenesis was obtained from 3-month-old root cultures. A medium containing half strength of MS inorganic salts, 160 mg/l adenine sulfate, 1.0 mg/1 NAA, 0.5 mg/1 kinetin and 1.0 mg/1 GA3 was optimal for embryogenesis. The callus maintained high regenerative capacity after two years of culture on this medium. Plants derived from somatic embryos were obtained under green-house conditions.

Tissue culture regeneration and radiation induced mutagenesis in banana

International Nuclear Information System (INIS)

Kulkarni, V.M.; Ganapathi, T.R.

2009-01-01

Radiation induced mutagenesis is an important tool for banana genetic improvement. At BARC, protocols for shoo-tip multiplication of commercial banana varieties have been developed and transferred to user agencies for commercial production. Excellent embryogenic cell suspensions were established in banana cvs. Rasthali and Rajeli, and were maintained at low temperatures for long-term storage. Normal plantlets were successfully regenerated from these cell suspensions. The cell suspensions and shoot-tip cultures were gamma-irradiated for mutagenesis. The mutagenized populations were field screened and a few interesting mutants have been isolated. The existence of genetic variation was confirmed using DNA markers. Further evaluation of these mutants is in progress. (author)

Proteome analysis of a hepatocyte-specific BIRC5 (survivin)-knockout mouse model during liver regeneration.

Science.gov (United States)

Bracht, Thilo; Hagemann, Sascha; Loscha, Marius; Megger, Dominik A; Padden, Juliet; Eisenacher, Martin; Kuhlmann, Katja; Meyer, Helmut E; Baba, Hideo A; Sitek, Barbara

2014-06-06

The Baculoviral IAP repeat-containing protein 5 (BIRC5), also known as inhibitor of apoptosis protein survivin, is a member of the chromosomal passenger complex and a key player in mitosis. To investigate the function of BIRC5 in liver regeneration, we analyzed a hepatocyte-specific BIRC5-knockout mouse model using a quantitative label-free proteomics approach. Here, we present the analyses of the proteome changes in hepatocyte-specific BIRC5-knockout mice compared to wildtype mice, as well as proteome changes during liver regeneration induced by partial hepatectomy in wildtype mice and mice lacking hepatic BIRC5, respectively. The BIRC5-knockout mice showed an extensive overexpression of proteins related to cellular maintenance, organization and protein synthesis. Key regulators of cell growth, transcription and translation MTOR and STAT1/STAT2 were found to be overexpressed. During liver regeneration proteome changes representing a response to the mitotic stimulus were detected in wildtype mice. Mainly proteins corresponding to proliferation, cell cycle and cytokinesis were up-regulated. The hepatocyte-specific BIRC5-knockout mice showed impaired liver regeneration, which had severe consequences on the proteome level. However, several proteins with function in mitosis were found to be up-regulated upon the proliferative stimulus. Our results show that the E3 ubiquitin-protein ligase UHRF1 is strongly up-regulated during liver regeneration independently of BIRC5.

Chimeric autologous/allogeneic constructs for skin regeneration.

Science.gov (United States)

Rasmussen, Cathy Ann; Tam, Joshua; Steiglitz, Barry M; Bauer, Rebecca L; Peters, Noel R; Wang, Ying; Anderson, R Rox; Allen-Hoffmann, B Lynn

2014-08-01

The ideal treatment for severe cutaneous injuries would eliminate the need for autografts and promote fully functional, aesthetically pleasing autologous skin regeneration. NIKS progenitor cell-based skin tissues have been developed to promote healing by providing barrier function and delivering wound healing factors. Independently, a device has recently been created to "copy" skin by harvesting full-thickness microscopic tissue columns (MTCs) in lieu of autografts traditionally harvested as sheets. We evaluated the feasibility of combining these two technologies by embedding MTCs in NIKS-based skin tissues to generate chimeric autologous/allogeneic constructs. Chimeric constructs have the potential to provide immediate wound coverage, eliminate painful donor site wounds, and promote restoration of a pigmented skin tissue possessing hair follicles, sweat glands, and sebaceous glands. After MTC insertion, chimeric constructs and controls were reintroduced into air-interface culture and maintained in vitro for several weeks. Tissue viability, proliferative capacity, and morphology were evaluated after long-term culture. Our results confirmed successful MTC insertion and integration, and demonstrated the feasibility of generating chimeric autologous/allogeneic constructs that preserved the viability, proliferative capacity, and structure of autologous pigmented skin. These feasibility studies established the proof-of-principle necessary to further develop chimeric autologous/allogeneic constructs for the treatment of complex skin defects. Reprint & Copyright © 2014 Association of Military Surgeons of the U.S.

The Binomial Distribution in Shooting

Science.gov (United States)

Chalikias, Miltiadis S.

2009-01-01

The binomial distribution is used to predict the winner of the 49th International Shooting Sport Federation World Championship in double trap shooting held in 2006 in Zagreb, Croatia. The outcome of the competition was definitely unexpected.

Connective Tissue Fibroblast Properties Are Position-Dependent during Mouse Digit Tip Regeneration

Science.gov (United States)

Wu, Yuanyuan; Wang, Karen; Karapetyan, Adrine; Fernando, Warnakulusuriya Akash; Simkin, Jennifer; Han, Manjong; Rugg, Elizabeth L.; Muneoka, Ken

2013-01-01

A key factor that contributes to the regenerative ability of regeneration-competent animals such as the salamander is their use of innate positional cues that guide the regeneration process. The limbs of mammals has severe regenerative limitations, however the distal most portion of the terminal phalange is regeneration competent. This regenerative ability of the adult mouse digit is level dependent: amputation through the distal half of the terminal phalanx (P3) leads to successful regeneration, whereas amputation through a more proximal location, e.g. the subterminal phalangeal element (P2), fails to regenerate. Do the connective tissue cells of the mammalian digit play a role similar to that of the salamander limb in controlling the regenerative response? To begin to address this question, we isolated and cultured cells of the connective tissue surrounding the phalangeal bones of regeneration competent (P3) and incompetent (P2) levels. Despite their close proximity and localization, these cells show very distinctive profiles when characterized in vitro and in vivo. In vitro studies comparing their proliferation and position-specific interactions reveal that cells isolated from the P3 and P2 are both capable of organizing and differentiating epithelial progenitors, but with different outcomes. The difference in interactions are further characterized with three-dimension cultures, in which P3 regenerative cells are shown to lack a contractile response that is seen in other fibroblast cultures, including the P2 cultures. In in vivo engraftment studies, the difference between these two cell lines is made more apparent. While both P2 and P3 cells participated in the regeneration of the terminal phalanx, their survival and proliferative indices were distinct, thus suggesting a key difference in their ability to interact within a regeneration permissive environment. These studies are the first to demonstrate distinct positional characteristics of connective tissue

Connective tissue fibroblast properties are position-dependent during mouse digit tip regeneration.

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Yuanyuan Wu

Full Text Available A key factor that contributes to the regenerative ability of regeneration-competent animals such as the salamander is their use of innate positional cues that guide the regeneration process. The limbs of mammals has severe regenerative limitations, however the distal most portion of the terminal phalange is regeneration competent. This regenerative ability of the adult mouse digit is level dependent: amputation through the distal half of the terminal phalanx (P3 leads to successful regeneration, whereas amputation through a more proximal location, e.g. the subterminal phalangeal element (P2, fails to regenerate. Do the connective tissue cells of the mammalian digit play a role similar to that of the salamander limb in controlling the regenerative response? To begin to address this question, we isolated and cultured cells of the connective tissue surrounding the phalangeal bones of regeneration competent (P3 and incompetent (P2 levels. Despite their close proximity and localization, these cells show very distinctive profiles when characterized in vitro and in vivo. In vitro studies comparing their proliferation and position-specific interactions reveal that cells isolated from the P3 and P2 are both capable of organizing and differentiating epithelial progenitors, but with different outcomes. The difference in interactions are further characterized with three-dimension cultures, in which P3 regenerative cells are shown to lack a contractile response that is seen in other fibroblast cultures, including the P2 cultures. In in vivo engraftment studies, the difference between these two cell lines is made more apparent. While both P2 and P3 cells participated in the regeneration of the terminal phalanx, their survival and proliferative indices were distinct, thus suggesting a key difference in their ability to interact within a regeneration permissive environment. These studies are the first to demonstrate distinct positional characteristics of

DNA Methylation and Methylation Polymorphism in Genetically Stable In vitro Regenerates of Jatropha curcas L. Using Methylation-Sensitive AFLP Markers.

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Rathore, Mangal S; Jha, Bhavanath

2016-03-01

The present investigation aimed to evaluate the degree and pattern of DNA methylation using methylation-sensitive AFLP (MS-AFLP) markers in genetically stable in vitro regenerates of Jatropha curcas L.. The genetically stable in vitro regenerates were raised through direct organogenesis via enhanced axillary shoot bud proliferation (Protocol-1) and in vitro-derived leaf regeneration (Protocol-2). Ten selective combinations of MS-AFLP primers produced 462 and 477 MS-AFLP bands in Protocol-1 (P-1) and Protocol-2 (P-2) regenerates, respectively. In P-1 regenerates, 15.8-31.17 % DNA was found methylated with an average of 25.24 %. In P-2 regenerates, 15.93-32.7 % DNA was found methylated with an average of 24.11 %. Using MS-AFLP in P-1 and P-2 regenerates, 11.52-25.53 % and 13.33-25.47 % polymorphism in methylated DNA was reported, respectively. Compared to the mother plant, P-1 regenerates showed hyper-methylation while P-2 showed hypo-methylation. The results clearly indicated alternation in degree and pattern of DNA methylation; hence, epigenetic instability in the genetically stable in vitro regenerates of J. curcas, developed so far using two different regeneration systems and explants of two different origins. The homologous nucleotide fragments in genomes of P-1 and P-2 regenerates showing methylation re-patterning might be involved in immediate adaptive responses and developmental processes through differential regulation of transcriptome under in vitro conditions.

Effects of NAA and BAP, double-layered media, and light distance on in vitro regeneration of Nelumbo nucifera Gaertn. (lotus), an aquatic edible plant.

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Mahmad, Noraini; Taha, Rosna Mat; Othman, Rashidi; Saleh, Azani; Hasbullah, Nor Azlina; Elias, Hashimah

2014-01-01

In vitro direct regeneration of Nelumbo nucifera Gaertn. was successfully achieved from immature explants (yellow plumule) cultured on a solid MS media supplemented with combinations of 0.5 mg/L BAP and 1.5 mg/L NAA which resulted in 16.00 ± 0.30 number of shoots per explant and exhibited a new characteristic of layered multiple shoots, while normal roots formed on the solid MS basal media. The double-layered media gave the highest number of shoots per explant with a ratio of 2 : 1 (liquid to solid) with a mean number of 16.67 ± 0.23 shoots per explant with the formation of primary and secondary roots from immature explants. In the study involving light distance, the tallest shoot (16.67 ± 0.23 mm) obtained from the immature explants was at a light distance of 200 mm from the source of inflorescent light (1000 lux). The plantlets were successfully acclimatized in clay loam soil after 8 months being maintained under in vitro conditions.

Germination and plantlet regeneration of encapsulated microshoots of aromatic rice (Oryza sativa L. Cv. MRQ 74).

Science.gov (United States)

Taha, Rosna Mat; Saleh, Azani; Mahmad, Noraini; Hasbullah, Nor Azlina; Mohajer, Sadegh

2012-01-01

Plant tissues such as somatic embryos, apical shoot tips, axillary shoot buds, embryogenic calli, and protocom-like bodies are potential micropropagules that have been considered for creating synthetic seeds. In the present study, 3-5 mm microshoots of Oryza sativa L. Cv. MRQ 74 were used as explant sources for obtaining synthetic seeds. Microshoots were induced from stem explants on Murashige and Skoog (MS) medium supplemented with 1.5 mg/L benzylaminopurine (BAP). They were encapsulated in 3% (w/v) sodium alginate, 3% sucrose, 0.1 mg/L BAP, and 0.1 mg/L α-Naphthalene acetic acid (NAA). Germination and plantlet regeneration of the encapsulated seeds were tested by culturing them on various germination media. The effect of storage period (15-30 days) was also investigated. The maximum germination and plantlet regeneration (100.0%) were recorded on MS media containing 3% sucrose and 0.8% agar with and without 0.1 mg/L BAP. However, a low germination rate (6.67%) was obtained using top soil as a sowing substrate. The germination rate of the encapsulated microshoots decreased from 93.33% to 3.33% after 30 days of storage at 4°C in the dark. Therefore, further research is being done to improve the germination rate of the synthetic seeds.

Date of shoot collection, genotype, and original shoot position affect early rooting of dormant hardwood cuttings of Populus

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R. S., Jr. Zalesny; A.H. Wiese

2006-01-01

Identifying superior combinations among date of dormant- season shoot collection, genotype, and original shoot position can increase the rooting potential of Populus cuttings. Thus, the objectives of our study were to: 1) evaluate variation among clones in early rooting from hardwood cuttings processed every three weeks from shoots collected...

Optimization of culture conditions (sucrose, pH, and photoperiod) for in vitro regeneration and early detection of somaclonal variation in ginger lime (Citrus assamensis).

Science.gov (United States)

Yaacob, Jamilah Syafawati; Mahmad, Noraini; Mat Taha, Rosna; Mohamed, Normadiha; Mad Yussof, Anis Idayu; Saleh, Azani

2014-01-01

Various explants (stem, leaf, and root) of Citrus assamensis were cultured on MS media supplemented with various combinations and concentrations (0.5-2.0 mg L(-1)) of NAA and BAP. Optimum shoot and root regeneration were obtained from stem cultures supplemented with 1.5 mg L(-1) NAA and 2.0 mg L(-1) BAP, respectively. Explant type affects the success of tissue culture of this species, whereby stem explants were observed to be the most responsive. Addition of 30 gL(-1) sucrose and pH of 5.8 was most optimum for in vitro regeneration of this species. Photoperiod of 16 hours of light and 8 hours of darkness was most optimum for shoot regeneration, but photoperiod of 24 hours of darkness was beneficial for production of callus. The morphology (macro and micro) and anatomy of in vivo and in vitro/ex vitro Citrus assamensis were also observed to elucidate any irregularities (or somaclonal variation) that may arise due to tissue culture protocols. Several minor micromorphological and anatomical differences were observed, possibly due to stress of tissue culture, but in vitro plantlets are expected to revert back to normal phenotype following full adaptation to the natural environment.

Lifespan extension by preserving proliferative homeostasis in Drosophila.

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Benoît Biteau

2010-10-01

Full Text Available Regenerative processes are critical to maintain tissue homeostasis in high-turnover tissues. At the same time, proliferation of stem and progenitor cells has to be carefully controlled to prevent hyper-proliferative diseases. Mechanisms that ensure this balance, thus promoting proliferative homeostasis, are expected to be critical for longevity in metazoans. The intestinal epithelium of Drosophila provides an accessible model in which to test this prediction. In aging flies, the intestinal epithelium degenerates due to over-proliferation of intestinal stem cells (ISCs and mis-differentiation of ISC daughter cells, resulting in intestinal dysplasia. Here we show that conditions that impair tissue renewal lead to lifespan shortening, whereas genetic manipulations that improve proliferative homeostasis extend lifespan. These include reduced Insulin/IGF or Jun-N-terminal Kinase (JNK signaling activities, as well as over-expression of stress-protective genes in somatic stem cell lineages. Interestingly, proliferative activity in aging intestinal epithelia correlates with longevity over a range of genotypes, with maximal lifespan when intestinal proliferation is reduced but not completely inhibited. Our results highlight the importance of the balance between regenerative processes and strategies to prevent hyperproliferative disorders and demonstrate that promoting proliferative homeostasis in aging metazoans is a viable strategy to extend lifespan.

Mechanism of impaired regeneration of fatty liver in mouse partial hepatectomy model.

Science.gov (United States)

Murata, Hiroshi; Yagi, Takahito; Iwagaki, Hiromi; Ogino, Tetsuya; Sadamori, Hiroshi; Matsukawa, Hiroyoshi; Umeda, Yuzoh; Haga, Sanae; Takaka, Noriaki; Ozaki, Michitaka

2007-12-01

The mechanism of injury in steatotic liver under pathological conditions been extensively examined. However, the mechanism of an impaired regeneration is still not well understood. The aim of this study was to analyze the mechanism of impaired regeneration of steatotic liver after partial hepatectomy (PH). db/db fatty mice and lean littermates were used for the experiments. Following 70% PH, the survival rate and recovery of liver mass were examined. Liver tissue was histologically examined and analyzed by western blotting and RT-PCR. Of 35 db/db mice, 25 died within 48 h of PH, while all of the control mice survived. Liver regeneration of surviving db/db mice was largely impaired. In db/db mice, mitosis of hepatocytes after PH was disturbed, even though proliferating cell nuclear antigen (PCNA) expression (G1 to S phase marker) in hepatocytes was equally observed in both mice groups. Interestingly, phosphorylation of Cdc2 in db/db mice was suppressed by reduced expression of Wee1 and Myt1, which phosphorylate Cdc2 in S to G2 phase. In steatotic liver, cell-cycle-related proliferative disorders occurred at mid-S phase after PCNA expression. Reduced expression of Wee1 and Myt1 kinases may therefore maintain Cdc2 in an unphosphorylated state and block cell cycle progression in mid-S phase. These kinases may be critical factors involved in the impaired liver regeneration in fatty liver.

Scar-free wound healing and regeneration following tail loss in the leopard gecko, Eublepharis macularius.

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Delorme, Stephanie Lynn; Lungu, Ilinca Mihaela; Vickaryous, Matthew Kenneth

2012-10-01

Many lizards are able to undergo scar-free wound healing and regeneration following loss of the tail. In most instances, lizard tail loss is facilitated by autotomy, an evolved mechanism that permits the tail to be self-detached at pre-existing fracture planes. However, it has also been reported that the tail can regenerate following surgical amputation outside the fracture plane. In this study, we used the leopard gecko, Eublepharis macularius, to investigate and compare wound healing and regeneration following autotomy at a fracture plane and amputation outside the fracture plane. Both forms of tail loss undergo a nearly identical sequence of events leading to scar-free wound healing and regeneration. Early wound healing is characterized by transient myofibroblasts and the formation of a highly proliferative wound epithelium immunoreactive for the wound keratin marker WE6. The new tail forms from what is commonly referred to as a blastema, a mass of proliferating mesenchymal-like cells. Blastema cells express the protease matrix metalloproteinase-9. Apoptosis (demonstrated by activated caspase 3 immunostaining) is largely restricted to isolated cells of the original and regenerating tail tissues, although cell death also occurs within dermal structures at the original-regenerated tissue interface and among clusters of newly formed myocytes. Furthermore, the autotomized tail is unique in demonstrating apoptosis among cells adjacent to the fracture planes. Unlike mammals, transforming growth factor-β3 is not involved in wound healing. We demonstrate that scar-free wound healing and regeneration are intrinsic properties of the tail, unrelated to the location or mode of tail detachment. Copyright © 2012 Wiley Periodicals, Inc.

Training visual control in wheelchair basketball shooting

NARCIS (Netherlands)

Oudejans, R.R.D.; Heubers, S.; Ruitenbeek, J-R.J.A.C.; Janssen, T.W.J.

2012-01-01

We examined the effects of visual control training on expert wheelchair basketball shooting, a skill more difficult than in regular basketball, as players shoot from a seated position to the same rim height. The training consisted of shooting with a visual constraint that forced participants to use

Putrescine treatment reverses α-tocopherol-induced desynchronization of polyamine and retinoid metabolism during rat liver regeneration

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Lourdes Sánchez-Sevilla

2016-10-01

Full Text Available Abstract Background The pre-treatment with α-tocopherol inhibits progression of rat liver proliferation induced by partial hepatectomy (PH, by decreasing and/or desynchronizing cyclin D1 expression and activation into the nucleus, activation and nuclear translocation of STAT-1 and -3 proteins and altering retinoid metabolism. Interactions between retinoic acid and polyamines have been reported in the PH-induced rat liver regeneration. Therefore, we evaluated the effect of low dosage of α-tocopherol on PH-induced changes in polyamine metabolism. Methods This study evaluated the participation of polyamine synthesis and metabolism during α-tocopherol-induced inhibition of rat liver regeneration. In PH-rats (Wistar treated with α-tocopherol and putrescine, parameters indicative of cell proliferation, lipid peroxidation, ornithine decarboxylase expression (ODC, and polyamine levels, were determined. Results Pre-treatment with α-tocopherol to PH-animals exerted an antioxidant effect, shifting earlier the increased ODC activity and expression, temporally affecting polyamine synthesis and ornithine metabolism. Whereas administration of putrescine induced minor changes in PH-rats, the concomitant treatment actually counteracted most of adverse actions exerted by α-tocopherol on the remnant liver, restituting its proliferative potential, without changing its antioxidant effect. Putrescine administration to these rats was also associated with lower ODC expression and activity in the proliferating liver, but the temporally shifting in the amount of liver polyamines induced by α-tocopherol, was also “synchronized” by the putrescine administration. The latter is supported by the fact that a close relationship was observed between fluctuations of polyamines and retinoids. Conclusions Putrescine counteracted most adverse actions exerted by α-tocopherol on rat liver regeneration, restoring liver proliferative potential and restituting the decreased

Plant regeneration from organ culture in white Guinea Yam

Energy Technology Data Exchange (ETDEWEB)

Nwachukwu, E C; Mbanaso, E N.A. [National Root Crops Research Inst., Umudike, Umuahia, Abia State (Nigeria); Sonnino, A [Centro Recerche Energia, ENEA, Rome (Italy)

1997-07-01

Explants from leaves, leaf segments, petioles and internodal stem of in vitro grown seedlings of white guinea yam, Dioscorea rotundata Poir, cv. `Obiaoturugo` were cultured on defined media. NAA at concentrations of 0.5-1.0 mg/1 induced shoot regeneration from petiolar and inter-nodal stem pieces, and rooting occurred with little or no callusing from whole leaves or leaf segments. With concentration of 3.0-10.0 m/1 NAA, explants from petioles, inter-nodal stem, whole leaves and leaf segments formed callus which produced roots. These explants developed plantlets when subcultured on MS medium supplemented with 2.0 mg/1 BAP and 0.1 mg/1 NAA. (author). 11 refs, 1 tab.

Plant regeneration from organ culture in white Guinea Yam

International Nuclear Information System (INIS)

Nwachukwu, E.C.; Mbanaso, E.N.A.; Sonnino, A.

1997-01-01

Explants from leaves, leaf segments, petioles and internodal stem of in vitro grown seedlings of white guinea yam, Dioscorea rotundata Poir, cv. 'Obiaoturugo' were cultured on defined media. NAA at concentrations of 0.5-1.0 mg/1 induced shoot regeneration from petiolar and inter-nodal stem pieces, and rooting occurred with little or no callusing from whole leaves or leaf segments. With concentration of 3.0-10.0 m/1 NAA, explants from petioles, inter-nodal stem, whole leaves and leaf segments formed callus which produced roots. These explants developed plantlets when subcultured on MS medium supplemented with 2.0 mg/1 BAP and 0.1 mg/1 NAA. (author). 11 refs, 1 tab

Rampage shootings: an historical, empirical, and theoretical overview.

Science.gov (United States)

Rocque, Michael; Duwe, Grant

2018-02-01

Rampage shootings is a relatively new term to describe a phenomenon that has a long history. Rampage shootings are mass shootings (generally defined as involving four or more victims), taking place in a public location, with victims chosen randomly or for symbolic purposes. These shootings are isolated events, meaning they are not connected to another criminal act (such as robbery or terrorism). Research suggests that rampage shootings are not a new phenomenon, but have occurred throughout the US since the early 1900s. There is some evidence of an increase in recent years, but definitional differences across studies and data sources make interpreting trends somewhat tenuous. Theories regarding the perpetration of rampage shootings center on masculinity, mental illness, and contagion effects. Policies aimed at preventing rampage shootings remain somewhat controversial and not well-tested in the literature. Copyright © 2017 Elsevier Ltd. All rights reserved.

Modeling shoot-tip temperature in the greenhouse environment

International Nuclear Information System (INIS)

Faust, J.E.; Heins, R.D.

1998-01-01

An energy-balance model is described that predicts vinca (Catharanthus roseus L.) shoot-tip temperature using four environmental measurements: solar radiation and dry bulb, wet bulb, and glazing material temperature. The time and magnitude of the differences between shoot-tip and air temperature were determined in greenhouses maintained at air temperatures of 15, 20, 25, 30, or 35 °C. At night, shoot-tip temperature was always below air temperature. Shoot-tip temperature decreased from 0.5 to 5 °C below air temperature as greenhouse glass temperature decreased from 2 to 15 °C below air temperature. During the photoperiod under low vapor-pressure deficit (VPD) and low air temperature, shoot-tip temperature increased ≈4 °C as solar radiation increased from 0 to 600 W·m -2 . Under high VPD and high air temperature, shoot-tip temperature initially decreased 1 to 2 °C at sunrise, then increased later in the morning as solar radiation increased. The model predicted shoot-tip temperatures within ±1 °C of 81% of the observed 1-hour average shoot-tip temperatures. The model was used to simulate shoot-tip temperatures under different VPD, solar radiation, and air temperatures. Since the rate of leaf and flower development are influenced by the temperature of the meristematic tissues, a model of shoot-tip temperature will be a valuable tool to predict plant development in greenhouses and to control the greenhouse environment based on a plant temperature setpoint. (author)

The study of ascorbate peroxidase, catalase and peroxidase during in vitro regeneration of Argyrolobium roseum.

Science.gov (United States)

Habib, Darima; Chaudhary, Muhammad Fayyaz; Zia, Muhammad

2014-01-01

Here, we demonstrate the micropropagation protocol of Argyrolobium roseum (Camb.), an endangered herb exhibiting anti-diabetic and immune-suppressant properties, and antioxidant enzymes pattern is evaluated. Maximum callogenic response (60 %) was observed from leaf explant at 1.0 mg L(-1) 1-nephthalene acetic acid (NAA) and 0.5 mg L(-1) 6-benzyl aminopurine (BA) in Murashige and Skoog (MS) medium using hypocotyl and root explants (48 % each). Addition of AgNO3 and PVP in the culture medium led to an increase in callogenic response up to 86 % from leaf explant and 72 % from hypocotyl and root explants. The best shooting response was observed in the presence of NAA, while maximum shoot length and number of shoots were achieved based on BA-supplemented MS medium. The regenerated shoots were rooted and successfully acclimatized under greenhouse conditions. Catalase and peroxidase enzymes showed ascending pattern during in vitro plant development from seed while ascorbate peroxidase showed descending pattern. Totally reverse response of these enzymes was observed during callus induction from three different explants. During shoot induction, catalase and peroxidase increased at high rate while there was a mild reduction in ascorbate peroxidase activity. Catalase and peroxidase continuously increased; on the other hand, ascorbate peroxidase activity decreased during root development and acclimatization states. The protocol described here can be employed for the mass propagation and genetic transformation of this rare herb. This study also highlights the importance and role of ascorbate peroxidase, catalase, and peroxidase in the establishment of A. roseum in vitro culture through callogenesis and organogenesis.

Training Visual Control in Wheelchair Basketball Shooting

Science.gov (United States)

Oudejans, Raoul R. D.; Heubers, Sjoerd; Ruitenbeek, Jean-Rene J. A. C.; Janssen, Thomas W. J.

2012-01-01

We examined the effects of visual control training on expert wheelchair basketball shooting, a skill more difficult than in regular basketball, as players shoot from a seated position to the same rim height. The training consisted of shooting with a visual constraint that forced participants to use target information as late as possible.…

Radiosensitivity of in vitro Cultured Banana Shoot-Tips

International Nuclear Information System (INIS)

Elagamawy, M.R.

2002-01-01

Longitudinally dissected shoot apices of Grand Nain, Williams and Maghrabi banana cultivars were exposed to gamma irradiation with Cobalt 60 source at the doses of 0, 20, 40 and 60 Gy and immediately placed into proliferation medium. A number of micropropagation cycles after irradiation were necessary up to M1 V2 to M1 V4 stage to let mutated sectors developing into non-chimeric shoots. Radiosensitivity was evaluated by the rate of shoot proliferation and by the shoot fresh weight increase. Increasing gamma doses caused reduction in survival rates and average number of shoots. Grand Nain exhibited the highest multiplication- rate (3.1). The lower dose (20 Gy) enhanced shoot multiplication ratio specially in Williams and Maghrabi, which however decreased with increased doses. The doses of 20-40 Gy yielded Ld50, with sensible degree of shoot multiplication, which occurred hardly ever beyond 40 Gy. The dose of 60 Gy resulted 80% lethal shoot growth. Linear decrease in fresh weight was observed in post-irradiation recovery, notably in the Maghrabi. In contradictory vulnerable damage was observed in Williams which showed the highest fresh weight value. Shoot proliferation appeared generally on the surface of the corm. Root formation was observed without additional hormone. The roots were dark colored and was decreased with the increased of dosage

DIAGNOSTIC CRITERIA FOR PROLIFERATIVE THYROID LESIONS IN BONY FISHES

Science.gov (United States)

Thyroid proliferative lesions are rather common in bony fishes but disagreement exists in the fish pathology community concerning diagnostic criteria for hyperplastic versus neoplastic lesions. To simplify the diagnosis of proliferative thyroid lesions and to reduce confusion reg...

Proliferation zones in the axolotl brain and regeneration of the telencephalon

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Maden Malcolm

2013-01-01

Full Text Available Abstract Background Although the brains of lower vertebrates are known to exhibit somewhat limited regeneration after incisional or stab wounds, the Urodele brain exhibits extensive regeneration after massive tissue removal. Discovering whether and how neural progenitor cells that reside in the ventricular zones of Urodeles proliferate to mediate tissue repair in response to injury may produce novel leads for regenerative strategies. Here we show that endogenous neural progenitor cells resident to the ventricular zone of Urodeles spontaneously proliferate, producing progeny that migrate throughout the telencephalon before terminally differentiating into neurons. These progenitor cells appear to be responsible for telencephalon regeneration after tissue removal and their activity may be up-regulated by injury through an olfactory cue. Results There is extensive proliferation of endogenous neural progenitor cells throughout the ventricular zone of the adult axolotl brain. The highest levels are observed in the telencephalon, especially the dorsolateral aspect, and cerebellum. Lower levels are observed in the mesencephalon and rhombencephalon. New cells produced in the ventricular zone migrate laterally, dorsally and ventrally into the surrounding neuronal layer. After migrating from the ventricular zone, the new cells primarily express markers of neuronal differentiative fates. Large-scale telencephalic tissue removal stimulates progenitor cell proliferation in the ventricular zone of the damaged region, followed by proliferation in the tissue that surrounds the healing edges of the wound until the telencephalon has completed regeneration. The proliferative stimulus appears to reside in the olfactory system, because telencephalic regeneration does not occur in the brains of olfactory bulbectomized animals in which the damaged neural tissue simply heals over. Conclusion There is a continual generation of neuronal cells from neural progenitor cells

Mesenchymal stem cells in cartilage regeneration.

Science.gov (United States)

Savkovic, Vuk; Li, Hanluo; Seon, Jong-Keun; Hacker, Michael; Franz, Sandra; Simon, Jan-Christoph

2014-01-01

Articular cartilage provides life-long weight-bearing and mechanical lubrication with extraordinary biomechanical performance and simple structure. However, articular cartilage is apparently vulnerable to multifactorial damage and insufficient to self-repair, isolated in articular capsule without nerves or blood vessels. Osteoarthritis (OA) is known as a degenerative articular cartilage deficiency progressively affecting large proportion of the world population, and restoration of hyaline cartilage is clinical challenge to repair articular cartilage lesion and recreate normal functionality over long period. Mesenchymal stem cells (MSC) are highly proliferative and multipotent somatic cells that are able to differentiate mesoderm-derived cells including chondrocytes and osteoblasts. Continuous endeavors in basic research and preclinical trial have achieved promising outcomes in cartilage regeneration using MSCs. This review focuses on rationale and technologies of MSC-based hyaline cartilage repair involving tissue engineering, 3D biomaterials and growth factors. By comparing conventional treatment and current research progress, we describe insights of advantage and challenge in translation and application of MSC-based chondrogenesis for OA treatment.

De novo regeneration of Scrophularia yoshimurae Yamazaki (Scrophulariaceae) and quantitative analysis of harpagoside, an iridoid glucoside, formed in aerial and underground parts of in vitro propagated and wild plants by HPLC.

Science.gov (United States)

Sagare, A P; Kuo, C L; Chueh, F S; Tsay, H S

2001-11-01

A protocol for de novo regeneration and rapid micropropagation of Scrophularia yoshimurae (Scrophulariaceae) has been developed. Multiple shoot development was achieved by culturing the shoot-tip, leaf-base, stem-node and stem-internode explants on Murashige and Skoog (MS) medium supplemented with 4.44 microM N6-benzyladenine (BA) and 1.07 microM alpha-naphthaleneacetic acid (NAA). Stem-node and shoot-tip explants showed the highest response (100%) followed by stem-internode (74.4%) and leaf-base (7.7%) explants. The shoots were multiplied by subculturing on the same medium used for shoot induction. Shoots were rooted on growth regulator-free MS basal medium and the plantlets were transplanted to soil and acclimatized in the growth chamber. The content of harpagoside, a quantitatively predominant iridoid glycoside, in different plant material was determined by high performance liquid chromatography (HPLC). The analysis revealed that the content of harpagoside in the aerial and underground parts of S. yoshimurae was significantly higher than the marketed crude drug (underground parts of Scrophularia ningpoensis).

Germination and Plantlet Regeneration of Encapsulated Microshoots of Aromatic Rice (Oryza sativa L. Cv. MRQ 74

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Rosna Mat Taha

2012-01-01

Full Text Available Plant tissues such as somatic embryos, apical shoot tips, axillary shoot buds, embryogenic calli, and protocom-like bodies are potential micropropagules that have been considered for creating synthetic seeds. In the present study, 3–5 mm microshoots of Oryza sativa L. Cv. MRQ 74 were used as explant sources for obtaining synthetic seeds. Microshoots were induced from stem explants on Murashige and Skoog (MS medium supplemented with 1.5 mg/L benzylaminopurine (BAP. They were encapsulated in 3% (w/v sodium alginate, 3% sucrose, 0.1 mg/L BAP, and 0.1 mg/L α-Naphthalene acetic acid (NAA. Germination and plantlet regeneration of the encapsulated seeds were tested by culturing them on various germination media. The effect of storage period (15–30 days was also investigated. The maximum germination and plantlet regeneration (100.0% were recorded on MS media containing 3% sucrose and 0.8% agar with and without 0.1 mg/L BAP. However, a low germination rate (6.67% was obtained using top soil as a sowing substrate. The germination rate of the encapsulated microshoots decreased from 93.33% to 3.33% after 30 days of storage at 4°C in the dark. Therefore, further research is being done to improve the germination rate of the synthetic seeds.

Proliferative and non-proliferative lesions of the rat and mouse integument.

Science.gov (United States)

Mecklenburg, Lars; Kusewitt, Donna; Kolly, Carine; Treumann, Silke; Adams, E Terence; Diegel, Kelly; Yamate, Jyoji; Kaufmann, Wolfgang; Müller, Susanne; Danilenko, Dimitry; Bradley, Alys

2013-01-01

The INHAND (International Harmonization of Nomenclature and Diagnostic Criteria for Lesions in Rats and Mice) project is a joint initiative of the societies of toxicological pathology from Europe (ESTP), Great Britain (BSTP), Japan (JSTP) and North America (STP). Its aim is to develop an internationally-accepted nomenclature for proliferative and non-proliferative lesions in laboratory rodents. A widely accepted international harmonization of nomenclature in laboratory animals will decrease confusion among regulatory and scientific research organizations in different countries and will provide a common language to increase and enrich international exchanges of information among toxicologists and pathologists. The purpose of this publication is to provide a standardized nomenclature for classifying microscopical lesions observed in the integument of laboratory rats and mice. Example colour images are provided for most lesions. The standardized nomenclature presented in this document and additional colour images are also available electronically at http://www.goreni.org. The nomenclature presented herein is based on histopathology databases from government, academia, and industrial laboratories throughout the world, and covers lesions that develop spontaneously as well as those induced by exposure to various test materials. (DOI: 10.1293/tox.26.27S; J Toxicol Pathol 2013; 26: 27S-57S).

A School Shooting Plot Foiled

Science.gov (United States)

Swezey, James A.; Thorp, Kimberly A.

2010-01-01

Dinkes, Cataldi, and Lin-Kelly (2007) claims that 78% of public schools reported one or more violent incidents during the 2005/2006 school year. School shootings are a rare but real threat on school campuses. Shootings at private schools are even less frequent with only a few recorded examples in the United States. This case study examines how a…

Proliferative capacity of murine hematopoietic stem cells

International Nuclear Information System (INIS)

Hellman, S.; Botnick, L.E.; Hannon, E.C.; Vigneulle, R.M.

1978-01-01

The present study demonstrates a decrease in self-renewal capacity with serial transfer of murine hematopoietic stem cells. Production of differentiated cell progeny is maintained longer than stem cell self-renewal. In normal animals the capacity for self-renewal is not decreased with increasing donor age. The stem cell compartment in normal animals, both young and old, appears to be proliferatively quiescent. After apparent recovery from the alkylating agent busulfan, the probability of stem cell self-renewal is decreased, there is a permanent defect in the capacity of the bone marrow for serial transplantation, and the stem cells are proliferatively active. These findings support a model of the hematopoietic stem cell compartment as a continuum of cells with decreasing capacities for self-renewal, increasing likelihood for differentiation, and increasing proliferative activity. Cells progress in the continuum in one direction and such progression is not reversible

Mass Shootings, Mental Illness, and Gun Control.

Science.gov (United States)

Philpott-Jones, Sean

2018-03-01

In the wake of the Stoneman Douglas School shooting, Republican and Democratic leaders-like the American electorate they represent-remain sharply divided in their responses to gun violence. They are united in their condemnation of these mass shootings, but they disagree about whether stricter or looser gun control laws are the answer. Those on the right side of the political aisle suggest that the issue is one of mental illness rather than gun control. Conversely, those who are more liberal or progressive in their political learnings are quick to condemn attempts to reframe the issue of mass shootings as a mental health problem. Both sides are wrong. Mass shootings are indeed partially a mental health problem, albeit one poorly addressed by our current laws and policies. But the solution to mass shootings also needs to consider strategies that may reduce gun violence in general. © 2018 The Hastings Center.

SHOOT2.0: An indirect grid shooting package for optimal control problems, with switching handling and embedded continuation

OpenAIRE

Martinon , Pierre; Gergaud , Joseph

2010-01-01

The SHOOT2.0 package implements an indirect shooting method for optimal control problems. It is specifically designed to handle control discontinuities, with an automatic switching detection that requires no assumptions concerning the number of switchings. Special care is also devoted to the computation of the Jacobian matrix of the shooting function, using the variational system instead of classical finite differences. The package also features an embedded continuation method and an automati...

Arabidopsis CDS blastp result: AK241762 [KOME

Lifescience Database Archive (English)

Full Text Available ctor, putative / enhancer of shoot regeneration (ESR1) similar to gb|D38124 EREBP-3 from Nicotiana tabacum a...nd contains PF|00847 AP2 domain; identical to cDNA enhancer of shoot regeneration ESR1 GI:18028939, enhancer of shoot regeneration ESR1 [Arabidopsis thaliana] GI:18028940 9e-17 ...

Arabidopsis CDS blastp result: AK242393 [KOME

Lifescience Database Archive (English)

Full Text Available ctor, putative / enhancer of shoot regeneration (ESR1) similar to gb|D38124 EREBP-3 from Nicotiana tabacum a...nd contains PF|00847 AP2 domain; identical to cDNA enhancer of shoot regeneration ESR1 GI:18028939, enhancer of shoot regeneration ESR1 [Arabidopsis thaliana] GI:18028940 3e-13 ...

Arabidopsis CDS blastp result: AK242986 [KOME

Lifescience Database Archive (English)

Full Text Available ctor, putative / enhancer of shoot regeneration (ESR1) similar to gb|D38124 EREBP-3 from Nicotiana tabacum a...nd contains PF|00847 AP2 domain; identical to cDNA enhancer of shoot regeneration ESR1 GI:18028939, enhancer of shoot regeneration ESR1 [Arabidopsis thaliana] GI:18028940 1e-13 ...

Arabidopsis CDS blastp result: AK241281 [KOME

Lifescience Database Archive (English)

Full Text Available ctor, putative / enhancer of shoot regeneration (ESR1) similar to gb|D38124 EREBP-3 from Nicotiana tabacum a...nd contains PF|00847 AP2 domain; identical to cDNA enhancer of shoot regeneration ESR1 GI:18028939, enhancer of shoot regeneration ESR1 [Arabidopsis thaliana] GI:18028940 1e-12 ...

In vitro regeneration of cocona (Solanum sessiliflorum, Solanaceae) cultivars for commercial production.

Science.gov (United States)

Schuelter, A R; Grunvald, A K; Amaral, A T; da Luz, C L; Luz, C L; Gonçalves, L M; Stefanello, S; Scapim, C A

2009-08-11

Cocona (Solanum sessiliflorum Dunal) is a solanaceous shrub native to the Amazon region that produces an edible fruit. This species has numerous advantages, particularly a high nutritional value and productivity. However, due to irregular germination and rapid loss of seed viability, there are few plantations for production on a large scale. Development of alternative propagation strategies is essential for the production of homogeneous seedlings of genotypes with superior agronomic performance. We developed techniques for in vitro regeneration of the cocona varieties Santa Luzia and Thaís for large-scale production of healthy plantlets. Twenty days after seeding, seedling segments germinated in vitro were used as explant sources. Three successive experiments were performed: one to test the effect of the explant source and combinations of two growth regulators, auxin (indole acetic acid, IAA) and kinetin (KIN), on the morphogenetic response; another to investigate the effect of the combination of growth regulators on the morphogenetic response of hypocotyl segments, and another to evaluate how sucrose concentration affects the development of adventitious shoots. The best shoot induction was obtained using hypocotyl segments and stem apices, while rhizogenesis was greatest in leaves with a petiole. The number of adventitious shoots per explant on hypocotyl segments increased with 10 and 20 mg/L KIN, combined with 0.02 mg/L IAA in the variety Santa Luzia. Sucrose combined with these growth regulator levels increased the average number of calli; these were optimally produced when 45 g/L sucrose and 0.01 mg/L IAA + 20 mg/L KIN were applied. Only sucrose concentration influenced shoot proliferation in the two S. sessiliflorum varieties, with a maximum at 17.5 g/L.

The Ror1 receptor tyrosine kinase plays a critical role in regulating satellite cell proliferation during regeneration of injured muscle.

Science.gov (United States)

Kamizaki, Koki; Doi, Ryosuke; Hayashi, Makoto; Saji, Takeshi; Kanagawa, Motoi; Toda, Tatsushi; Fukada, So-Ichiro; Ho, Hsin-Yi Henry; Greenberg, Michael Eldon; Endo, Mitsuharu; Minami, Yasuhiro

2017-09-22

The Ror family receptor tyrosine kinases, Ror1 and Ror2, play important roles in regulating developmental morphogenesis and tissue- and organogenesis, but their roles in tissue regeneration in adult animals remain largely unknown. In this study, we examined the expression and function of Ror1 and Ror2 during skeletal muscle regeneration. Using an in vivo skeletal muscle injury model, we show that expression of Ror1 and Ror2 in skeletal muscles is induced transiently by the inflammatory cytokines, TNF-α and IL-1β, after injury and that inhibition of TNF-α and IL-1β by neutralizing antibodies suppresses expression of Ror1 and Ror2 in injured muscles. Importantly, expression of Ror1 , but not Ror2 , was induced primarily in Pax7-positive satellite cells (SCs) after muscle injury, and administration of neutralizing antibodies decreased the proportion of Pax7-positive proliferative SCs after muscle injury. We also found that stimulation of a mouse myogenic cell line, C2C12 cells, with TNF-α or IL-1β induced expression of Ror1 via NF-κB activation and that suppressed expression of Ror1 inhibited their proliferative responses in SCs. Intriguingly, SC-specific depletion of Ror1 decreased the number of Pax7-positive SCs after muscle injury. Collectively, these findings indicate for the first time that Ror1 has a critical role in regulating SC proliferation during skeletal muscle regeneration. We conclude that Ror1 might be a suitable target in the development of diagnostic and therapeutic approaches to manage muscular disorders. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

[Induction and in vitro culture of hairy roots of Dianthus caryophyllus and its plant regeneration].

Science.gov (United States)

Shi, Heping; Zhu, Yuanfeng; Wang, Bei; Sun, Jiangbing; Huang, Shengqin

2014-11-01

To use Agrobacterium rhizogenes-induced hairy roots to create new germplasm of Dianthus caryophyllus, we transformed D. caryophyllus with A. rhizogenes by leaf disc for plant regeneration from hairy roots. The white hairy roots could be induced from the basal surface of leaf explants of D. caryophyllus 12 days after inoculation with A. rhizogenes ATCC15834. The percentage of the rooting leaf explants was about 90% 21 days after inoculation. The hairy roots could grow rapidly and autonomously in liquid or solid phytohormone-free MS medium. The transformation was confirmed by PCR amplification of rol gene of Ri plasmid and silica gel thin-layer chromatography of opines from D. caryophyllus hairy roots. Hairy roots could form light green callus after cultured on MS+6-BA 1.0-3.0 mg/L + NAA 0.1-0.2 mg/L for 15 days. The optimum medium for adventitious shoots formation was MS + 6-BA 2.0 mg/L + NAA 0.02 mg/L, where the rate of adventitious shoot induction was 100% after cultured for 6 weeks. The mean number of adventitious shoot per callus was 30-40. The adventitious shoots can form roots when cultured on phytohormone-free 1/2 MS or 1/2 MS +0.5 mg/L NAA for 10 days. When the rooted plantlets transplanted in the substrate mixed with perlite sand and peat (volume ratio of 1:2), the survival rate was above 95%.

School shootings: law enforcement and school district networking

OpenAIRE

Topadzhikyan, Tigran

2013-01-01

CHDS State/Local School shootings have happened in the past and will happen again. The history of school shootings prompts all stakeholders to look at ways to prevent them from happening, and if they do happen, to be resilient. Change is needed in the prevention of school shootings. The case studies of Virginia Tech, Sandy Hook, E. O. Green Junior High, and Beslan school shootings reveal that the lack of information sharing and lack of communication were flaws; and the incidents might have...

Endothelin-1 is associated with fibrosis in proliferative diabetic retinopathy membranes.

Science.gov (United States)

Chang, William; Lajko, Michelle; Fawzi, Amani A

2018-01-01

To characterize the relationship between endothelin-1 and fibrosis in epiretinal membranes in proliferative diabetic retinopathy and explore the role of endothelial-mesenchymal transition in these membranes. Membranes were obtained from eyes undergoing pars plana vitrectomy for complicated proliferative diabetic retinopathy or idiopathic epiretinal membrane. Through standard immunohistochemical techniques, we labeled membranes to explore the distribution of endothelin-1 and endothelin receptor B, comparing proliferative diabetic retinopathy and idiopathic epiretinal membranes. In addition, membranes were also labeled with markers for fibroblasts, endothelial, and glial cells and studied with confocal laser scanning microscopy. The intensity of endothelin-1 labeling was quantified using standard image analysis software. Fourteen membranes were included in the analysis, nine from eyes with proliferative diabetic retinopathy and five idiopathic membranes. Flatmount diabetic membranes showed co-localization of endothelin-1 with S100A4 and CD31. Immunohistochemistry and quantitative analysis of cross-sectional membranes showed significantly higher endothelin-1 labeling in proliferative diabetic retinopathy membranes compared to idiopathic membranes (pmembranes showed more elements staining positive for S100A4 compared to idiopathic membranes. Epiretinal membrane formation in proliferative diabetic retinopathy involves higher tissue levels of endothelin-1 and fibroblastic activity. Furthermore, endothelin-1, endothelial and fibroblastic staining appear to be correlated, suggestive of endothelial-to-mesenchymal transition in proliferative diabetic retinopathy.

Shooting Mechanisms in Nature: A Systematic Review.

Directory of Open Access Journals (Sweden)

Aimée Sakes

Full Text Available In nature, shooting mechanisms are used for a variety of purposes, including prey capture, defense, and reproduction. This review offers insight into the working principles of shooting mechanisms in fungi, plants, and animals in the light of the specific functional demands that these mechanisms fulfill.We systematically searched the literature using Scopus and Web of Knowledge to retrieve articles about solid projectiles that either are produced in the body of the organism or belong to the body and undergo a ballistic phase. The shooting mechanisms were categorized based on the energy management prior to and during shooting.Shooting mechanisms were identified with projectile masses ranging from 1·10-9 mg in spores of the fungal phyla Ascomycota and Zygomycota to approximately 10,300 mg for the ballistic tongue of the toad Bufo alvarius. The energy for shooting is generated through osmosis in fungi, plants, and animals or muscle contraction in animals. Osmosis can be induced by water condensation on the system (in fungi, or water absorption in the system (reaching critical pressures up to 15.4 atmospheres; observed in fungi, plants, and animals, or water evaporation from the system (reaching up to -197 atmospheres; observed in plants and fungi. The generated energy is stored as elastic (potential energy in cell walls in fungi and plants and in elastic structures in animals, with two exceptions: (1 in the momentum catapult of Basidiomycota the energy is stored in a stalk (hilum by compression of the spore and droplets and (2 in Sphagnum energy is mainly stored in compressed air. Finally, the stored energy is transformed into kinetic energy of the projectile using a catapult mechanism delivering up to 4,137 J/kg in the osmotic shooting mechanism in cnidarians and 1,269 J/kg in the muscle-powered appendage strike of the mantis shrimp Odontodactylus scyllarus. The launch accelerations range from 6.6g in the frog Rana pipiens to 5,413,000g in

Sound propagation from a semi-open shooting range

NARCIS (Netherlands)

Eerden, F.J.M. van der; Berg, F. van den

2011-01-01

Semi-open shooting ranges, in contrast to a fully open shooting range, are often used in the densely populated area of the Netherlands. The Ministry of Defense operates a number of these ranges. In these shooting ranges above the line of fire a number of screens are situated for safety precautions

Water Status Related Root-to-Shoot Communication Regulates the Chilling Tolerance of Shoot in Cucumber (Cucumis sativus L.) Plants.

Science.gov (United States)

Zhang, Zi-Shan; Liu, Mei-Jun; Gao, Hui-Yuan; Jin, Li-Qiao; Li, Yu-Ting; Li, Qing-Ming; Ai, Xi-Zhen

2015-10-16

Although root-to-shoot communication has been intensively investigated in plants under drought, few studies have examined root-to-shoot communication under chilling. Here we explored whether root-to-shoot communication contributes to the chilling-light tolerance of cucumber shoots and clarified the key signal involves in this communication. After leaf discs chilling-light treatment, the photoinhibitions of Photosystem I (PSI) and Photosystem II (PSII) were similar in leaf discs of two cucumber varieties (JY-3 and JC-4). When the whole plants, including roots, were chilled under light, the photosynthetic performances in JC-4 leaves decreased more seriously than that in JY-3 leaves. However, when the water status of leaves was maintained by warming roots or floating the attached leaves on water, the PSII activity and amount of PSI in the leaves of the two varieties were similar after chilling-light treatment. In addition, the differences of PSII activities and amount of PSI between the two varieties under whole plant chilling-light treatment were independent of ABA pretreatment. Above results indicate that (1) the better water status in leaves under chilling contributes to the higher chilling tolerance of JY-3; (2) the water status, rather than an ABA signal, dominates root-to-shoot communication under chilling and the chilling tolerance of cucumber shoot.

Differentiation of shoot elements from the rachis of Secale cereale L.

Directory of Open Access Journals (Sweden)

Jan J. Rybczyński

2014-01-01

Full Text Available In vitro culture of young Secale cereale spikes is described with special attention given to changes in development of the rachis. 7 mm explants were cultivated on a modified M u r a s h i g e and S k o o g (1962 medium (MS supplemented with 2,4-D (dichlorophenoxyacetic acid, NAA (α-naph-thaleneacetic acid, IAA (β-indoleacetic acid, 2,4,5-T (trichlorophenoxyacetic acid, and ZEA (zeatin, KIN (kinetin, BAP (6-benzylaminopurine, IPA (izopentenyladenine or 2 iP in numerous combinations and concentrations. Rachises differentiated branches with node construction in the presence of synthetic auxin. Rhizogenesis of explants was stimulated by 2,4-D and 2,4,5-T. 2,4,5-T + IPA appeared to be the best combination for callus regeneration. Many meristematic centres were found previously and combinations of NAA + KIN stimulated direct, whereas 2,4-D + ZEA indirect, differentiation of shoot elements. Development was observed from plantlets to flowering plants.

Mechanisms mediating the trophic effect of nerves during vertebrate limb regeneration

International Nuclear Information System (INIS)

Munaim, S.I.

1986-01-01

Salamanders regenerate their appendages after amputation and nerves are required for this process. Experiments were designed to test the idea that one way nerves could affect blastema cell proliferation is by influencing the metabolism of extracellular matrix (ECM) components and to identify neurotrophic factors which promote blastema cell mitosis. Temporal and spatial differences of glycosaminoglycans (GAGs) synthesis is innervated and denervated limbs were examined. Hyaluronic acid (HA) was found to be the major GAG produced during the proliferative period and chondroitin sulfate during differentiation. Denervation reduced synthesis of both these components by half. Dorsal root ganglia and fibroblast growth factor (FGF), a brain-derived mitogen, similarly doubled GAG synthesis in cultured blastemas, the FGF-effect being primarily on HA production. Histochemical and autoradiographical results confirmed the biochemical data. Autoradiography of the limb tissue showed heaviest labeling of the ECM with 3 H-acetate in areas which also stained most intensely with the dye, carbocyanine DBTC. Denervation reduced the staining and the radioactive labeling. These data indicate that nerves affect synthesis and accumulation of GAGs in the regenerating limb, which may be one way blastema cell proliferation is promoted

Effect of Plant Growth Regulators on a Shoot and Root Formation from the Leaf and Flower Culture of a Standard-type Chrysanthemum 'Jinba'

International Nuclear Information System (INIS)

Lee, J.S.; Lee, G.J.; Chung, S.J.; Kim, J.B.; Kim, D.S.; Kang, S.Y.

2008-01-01

In this study we investigated the conditions of a higher frequency for regenerated plants from different explants of a standard-type chrysanthemum 'Jinba'. In vitro culture was initiated on an MS medium containing 3% sucrose, 0.8% agar, and 5 μM benzyl adenine (BA) with naphthalene acetic acid (NAA) by using surface-sterilized leaf and flower tissues from greenhouse-grown plants. Direct shoot regeneration from the leaf and flower explants was obtained 21 to 28 days after the initial culture. Among the seven combinations of the growth regulators used for the culture, the most efficient condition for the shoot and root formation from the leaf tissue was obtained when the MS basic medium was supplemented with 0.5 mg L-¹ BA and 1.0 mg L-¹ NAA, and 0.1 mg L-¹ BA and 0.5 mg L-¹ NAA, while the culture using floret tissues was most efficient on the medium supplemented with 0.5 mg L-¹ BA and 0.5 mg L-¹ NAA, and 0.1 mg L-¹ BA and 1.0 mg L-¹ NAA. These results will provide valuable information to help set up an efficient system for a tissue culture of chrysanthemum cv. Jinba to improve one or some of its negative traits in combination with a radiation mutagenesis approach

Characteristics of schools in which fatal shootings occur.

Science.gov (United States)

de Apodaca, Roberto Flores; Brighton, Lauren M; Perkins, Ashley N; Jackson, Kiana N; Steege, Jessica R

2012-04-01

School-based violence, and fatal school shootings in particular, have gained increased attention in the media and psychological literature. Most reports have focused on the characteristics of perpetrators, but there is a growing awareness that school-related factors may also influence the occurrence of fatal school shootings. The current study examined several key characteristics of all schools where random (38) and targeted (96) fatal shootings occurred in the United States between 1966 and 2009. These were compared with a group (138) of schools randomly selected to represent the population of all schools in the United States. The size of a school's enrollment, urban or suburban locale, public funding, and predominantly non-white enrollment were positively associated with fatal shootings. Universities and colleges were disproportionately associated with random shootings and high schools with targeted ones. It was proposed that characteristics of schools that allow feelings of anonymity or alienation among students may help create environmental conditions associated with fatal school shootings. Implications for future research and interventions are considered.

Atypical proliferative myositis: original MR description with pathologic correlation: Case report

Energy Technology Data Exchange (ETDEWEB)

Jarraya, Mohamed; Guermazi, Ali [Boston University School of Medicine, Department of Radiology, Musculoskeletal Section, Boston, MA (United States); Parva, Pedram [VA Boston Healthcare System, Boston, MA (United States); Stone, Michael [Stamford Hospital, Department of Surgery, Stamford, CT (United States); Klein, Michael J. [Hospital for Special Surgery, Department of Pathology and Laboratory Medicine, New York, NY (United States)

2014-08-15

Proliferative myositis (PM) along with proliferative fasciitis and nodular fasciitis are a group of pseudosarcomatous myofibroblastic proliferations. Although the histologic presentation of each is almost identical, the magnetic resonance imaging (MRI) appearance of proliferative myositis is closer to that of inflammatory myopathies. We report a case of PM in which the imaging and histologic features combine typical findings of PM with unusual imaging features, suggesting of reactive (or nodular) fasciitis. (orig.)

Atypical proliferative myositis: original MR description with pathologic correlation: Case report

International Nuclear Information System (INIS)

Jarraya, Mohamed; Guermazi, Ali; Parva, Pedram; Stone, Michael; Klein, Michael J.

2014-01-01

Proliferative myositis (PM) along with proliferative fasciitis and nodular fasciitis are a group of pseudosarcomatous myofibroblastic proliferations. Although the histologic presentation of each is almost identical, the magnetic resonance imaging (MRI) appearance of proliferative myositis is closer to that of inflammatory myopathies. We report a case of PM in which the imaging and histologic features combine typical findings of PM with unusual imaging features, suggesting of reactive (or nodular) fasciitis. (orig.)

An improved protocol for efficient transformation and regeneration of diverse indica rice cultivars

Directory of Open Access Journals (Sweden)

Sahoo Khirod K

2011-12-01

Full Text Available Abstract Background Rice genome sequencing projects have generated remarkable amount of information about genes and genome architecture having tremendous potential to be utilized in both basic and applied research. Success in transgenics is paving the way for preparing a road map of functional genomics which is expected to correlate action of a gene to a trait in cellular and organismal context. However, the lack of a simple and efficient method for transformation and regeneration is a major constraint for such studies in this important cereal crop. Results In the present study, we have developed an easy, rapid and highly efficient transformation and regeneration protocol using mature seeds as explants and found its successful applicability to a choice of elite indica rice genotypes. We have optimized various steps of transformation and standardized different components of the regeneration medium including growth hormones and the gelling agent. The modified regeneration medium triggers production of large number of shoots from smaller number of calli and promotes their faster growth, hence significantly advantageous over the existing protocols where the regeneration step requires maximum time. Using this protocol, significantly higher transformation efficiency (up to 46% and regeneration frequency (up to 92% for the untransformed calli and 59% for the transformed calli were achieved for the four tested cultivars. We have used this protocol to produce hundreds of independent transgenic lines of different indica rice genotypes. Upon maturity, these transgenic lines were fertile thereby indicating that faster regeneration during tissue culture did not affect their reproductive potential. Conclusions This speedy, yet less labor-intensive, protocol overcomes major limitations associated with genetic manipulation in rice. Moreover, our protocol uses mature seeds as the explant, which can easily be obtained in quantity throughout the year and kept

Dilong: Role in Peripheral Nerve Regeneration

Directory of Open Access Journals (Sweden)

Yung-Ming Chang

2011-01-01

Full Text Available Dilong, also known as earthworm, has been widely used in traditional Chinese medicine (TCM for thousands of years. Schwann cell migration and proliferation are critical for the regeneration of injured nerves and Schwann cells provide an essentially supportive role for neuron regeneration. However, the molecular mechanisms of migration and proliferation induced by dilongs in Schwann cells remain unclear. Here, we discuss the molecular mechanisms that includes (i migration signaling, MAPKs (mitogen-activated protein kinases, mediated PAs and MMP2/9 pathway; (ii survival and proliferative signaling, IGF-I (insulin-like growth factor-I-mediated PI3K/Akt pathways and (iii cell cycle regulation. Dilong stimulate RSC96 cell proliferation and migration. It can induce phosphorylation of ERK1/2 and p38, but not JNK, and activate the downstream signaling expression of PAs (plasminogen activators and MMPs (matrix metalloproteinases in a time-dependent manner. In addition, Dilong stimulated ERK1/2 and p38 phosphorylation was attenuated by pretreatment with chemical inhibitors (U0126 and SB203580, and small interfering ERK1/2 and p38 RNA, resulting in migration and uPA-related signal pathway inhibition. Dilong also induces the phosphorylation of IGF-I-mediated PI3K/Akt pathway, activates protein expression of PCNA (proliferating cell nuclear antigen and cell cycle regulatory proteins (cyclin D1, cyclin E and cyclin A in a time-dependent manner. In addition, it accelerates G1-phase progression with earlier S-phase entry and significant numbers of cells entered the S-phase. The siRNA-mediated knockdown of PI3K that significantly reduces PI3K protein expression levels, resulting in Bcl2 survival factor reduction, revealing a marked blockage of G1 to S transition in proliferating cells. These results reveal the unknown RSC96 cell migration and proliferation mechanism induced by dilong, which find use as a new medicine for nerve regeneration.

The Level of Vision Necessary for Competitive Performance in Rifle Shooting: Setting the Standards for Paralympic Shooting with Vision Impairment.

Science.gov (United States)

Allen, Peter M; Latham, Keziah; Mann, David L; Ravensbergen, Rianne H J C; Myint, Joy

2016-01-01

The aim of this study was to investigate the level of vision impairment (VI) that would reduce performance in shooting; to guide development of entry criteria to visually impaired (VI) shooting. Nineteen international-level shooters without VI took part in the study. Participants shot an air rifle, while standing, toward a regulation target placed at the end of a 10 m shooting range. Cambridge simulation glasses were used to simulate six different levels of VI. Visual acuity (VA) and contrast sensitivity (CS) were assessed along with shooting performance in each of seven conditions of simulated impairment and compared to that with habitual vision. Shooting performance was evaluated by calculating each individual's average score in every level of simulated VI and normalizing this score by expressing it as a percentage of the baseline performance achieved with habitual vision. Receiver Operating Characteristic curves were constructed to evaluate the ability of different VA and CS cut-off criteria to appropriately classify these athletes as achieving 'expected' or 'below expected' shooting results based on their performance with different levels of VA and CS. Shooting performance remained relatively unaffected by mild decreases in VA and CS, but quickly deteriorated with more moderate losses. The ability of visual function measurements to classify shooting performance was good, with 78% of performances appropriately classified using a cut-off of 0.53 logMAR and 74% appropriately classified using a cut-off of 0.83 logCS. The current inclusion criteria for VI shooting (1.0 logMAR) is conservative, maximizing the chance of including only those with an impairment that does impact performance, but potentially excluding some who do have a genuine impairment in the sport. A lower level of impairment would include more athletes who do have a genuine impairment but would potentially include those who do not actually have an impairment that impacts performance in the sport. An

Correlation between proliferative activity and cellular thickness of human mesenchymal stem cells

International Nuclear Information System (INIS)

Katsube, Yoshihiro; Hirose, Motohiro; Nakamura, Chikashi; Ohgushi, Hajime

2008-01-01

A cell's shape is known to be related to its proliferative activity. In particular, large and flat mammalian adult stem cells seem to show slow proliferation, however using quantitative analysis to prove the phenomenon is difficult. We measured the proliferation and cellular thickness of human mesenchymal stem cells (MSCs) by atomic force microscopy and found that MSCs with high proliferative activity were thick while those with low proliferative activity were thin, even though these MSCs were early passage cells. Further, low proliferative MSCs contained many senescence-associated β-galactosidase positive cells together with high senescence-associated gene expression. These findings suggest that the measurement of cellular thickness is useful for estimating the proliferative activity of human MSCs and is expected to be a practical tool for MSC applications in regenerative medicine

Immunohistochemical analyses of cell cycle progression and gene expression of biliary epithelial cells during liver regeneration after partial hepatectomy of the mouse.

Science.gov (United States)

Fukuda, Tatsuya; Fukuchi, Tomokazu; Yagi, Shinomi; Shiojiri, Nobuyoshi

2016-05-20

The liver has a remarkable regeneration capacity, and, after surgical removal of its mass, the remaining tissue undergoes rapid regeneration through compensatory growth of its constituent cells. Although hepatocytes synchronously proliferate under the control of various signaling molecules from neighboring cells, there have been few detailed analyses on how biliary cells regenerate for their cell population after liver resection. The present study was undertaken to clarify how biliary cells regenerate after partial hepatectomy of mice through extensive analyses of their cell cycle progression and gene expression using immunohistochemical and RT-PCR techniques. When expression of PCNA, Ki67 antigen, topoisomerase IIα and phosphorylated histone H3, which are cell cycle markers, was immunohistochemically examined during liver regeneration, hepatocytes had a peak of the S phase and M phase at 48-72 h after resection. By contrast, biliary epithelial cells had much lower proliferative activity than that of hepatocytes, and their peak of the S phase was delayed. Mitotic figures were rarely detectable in biliary cells. RT-PCR analyses of gene expression of biliary markers such as Spp1 (osteopontin), Epcam and Hnf1b demonstrated that they were upregulated during liver regeneration. Periportal hepatocytes expressed some of biliary markers, including Spp1 mRNA and protein. Some periportal hepatocytes had downregulated expression of HNF4α and HNF1α. Gene expression of Notch signaling molecules responsible for cell fate decision of hepatoblasts to biliary cells during development was upregulated during liver regeneration. Notch signaling may be involved in biliary regeneration.

In vitro propagation of olive (Olea europaea L.) by nodal segmentation of elongated shoots.

Science.gov (United States)

Lambardi, Maurizio; Ozudogru, Elif Aylin; Roncasaglia, Romano

2013-01-01

Olive (Olea europaea L.), long-living, ever-green fruit tree of the Old World, has been part of a traditional landscape in the Mediterranean area for centuries. Both the fruits consumed after processing and the oil extracted from the fruits are among the main components of the Mediterranean diet, widely used for salads and cooking, as well as for preserving other food. Documentations show that the ancient use of this beautiful tree also includes lamp fuel production, wool treatment, soap production, medicine, and cosmetics. However, unlike the majority of the fruit species, olive propagation is still a laborious practice. As regards traditional propagation, rooting of cuttings and grafting stem segments onto rootstocks are possible, former being achieved only when the cuttings are collected in specific periods (spring or beginning of autumn), and latter only when skilled grafters are available. In both the cases, performance of the cultivars varies considerably. The regeneration of whole plants from ovules, on the other hand, is used only occasionally. Micropropagation of olive is not easy mainly due to explant oxidation, difficulties in explant disinfection, and labor-oriented establishment of in vitro shoot cultures. However today, the progress in micropropagation technology has made available the complete protocols for several Mediterranean cultivars. This chapter describes a micropropagation protocol based on the segmentation of nodal segments obtained from elongated shoots.

Proliferative changes in nonpalpable breast lesions detected by mammography

International Nuclear Information System (INIS)

Vega, A.; Delgado, A.; Ortega, E.; Garijo, F.; Mosquera, J.; Sogo, C.; Alvarez, A.

2000-01-01

To analyze retrospectively the radiological findings in nonpalpable breast lesions detected by mammography that lead to the performance of surgical biopsy, resulting in a histological diagnosis of proliferative breast disease with and without atypia. From two Spanish hospitals, 421 women with 429 biopsies indicative of the presence of proliferative breast disease with and without atypia were selected out of a total of 1252 surgical biopsies in nonpalpable lesions that proved to be benign. Age, personal and familial history of breast cancer, reason for requesting the mammography and radiological findings that had indicated the need for surgical biopsy were recorded for each patient. The diagnosis was proliferative breast disease (epithelial hyperplasia) in 347 women with 354 biopsies and atypical hyperplasia in the remaining 74 women with 75 biopsies, representing 28% and 6%, respectively, of the 1252 biopsies of lesions found to be benign. In 221 of the 354 cases of epithelial hyperplasia (62%) and 45 of the 75 cases of atypical hyperplasia (60%), the presence of calcifications was the most common radiological findings leading to biopsy (p<0.05). Parenchymal distortion, with or without calcifications, was the second most common radiological sign. The histological study revealed a close relationship between these proliferative events and radial scars. Calcifications are the radiological finding that most frequently indicate the need for surgical biopsy in nonpalpable lesions that results in a diagnosis of proliferative breast disease with and without atypia. (Author) 12 refs

Root~Shoot Growth Interactions of Sorghmn (Sorghwn Bicolor L ...

African Journals Online (AJOL)

growth. Studies on root-shoot intera'ctions in relation to mechanical impedance have only investigated the effect on shoots of ... growth regulators that may be responsible. Studies of root-shoot ... of germinating seeds to MI leaving roots in rela-.

High frequency plant regeneration from leaf explants derived callus of evening primrose (oenothera biennis)

International Nuclear Information System (INIS)

Ghauri, E.G.; Shafi, N.; Ghani, S.; Fatima, A.

2008-01-01

The seeds of Evening primrose were aseptically grown and leaf explants were used for establishment of callus culture. The Excellent growth in callus biomass was achieved on MS medium supplemented with 2, 4, -D and TDZ. For optimal growth of bud and shoot regeneration, fortification of IAA along with TDZ, or BAP was found to be essential. Rooting (70%) could be inducted on hormone free MS-medium. This percentage improved to 98 when NAA was added to the medium. The plantlets thus obtained were transferred to the field successfully after passing through the process of hardening. (author)

Protocol optimization for in vitro shoot multiplication of Jackfruit ...

African Journals Online (AJOL)

Jemal

2017-01-11

Jan 11, 2017 ... Protocol optimization for in vitro shoot multiplication of ... shoot length and leaf number, whereby 2 mg/L BAP alone was found to be the best with a mean shoot .... Analysis of variance showed that the interaction between.

In vitro propagation of lnula royleana DC

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Anna Stojakowska

2011-01-01

Full Text Available A micropropagation method, through axillary shoot proliferation, was elaborated for Inula royleana DC. (Asteraceae, a medicinal plant native of Himalaya. Primary explants (cotyledonary node explants and secondary explants (node explants of in vitro regenerated shoots of the plant, inoculated on MS medium supplemented with 0.1 μM NAA and 5.0 μM kinetin, regenerated 3.4 ± 1.2 and 5.1 ± 1.9 axillary shoots per explant, respectively. The regenerated shoots were easily rooting and adapting to growth in soil.

Differential expression of myogenic regulatory genes and Msx-1 during dedifferentiation and redifferentiation of regenerating amphibian limbs.

Science.gov (United States)

Simon, H G; Nelson, C; Goff, D; Laufer, E; Morgan, B A; Tabin, C

1995-01-01

An amputated limb of an adult urodele amphibian is capable of undergoing regeneration. The new structures form from an undifferentiated mass of cells called the regenerative blastema. The cells of the blastema are believed to derive from differentiated tissues of the adult limb. However, the exact source of these cells and the process by which they undergo dedifferentiation are poorly understood. In order to elucidate the molecular and cellular basis for dedifferentiation we isolated a number of genes which are potential regulators of the process. These include Msx-1, which is believed to support the undifferentiated and proliferative state of cells in the embryonic limb bud; and two members of the myogenic regulatory gene family, MRF-4 and Myf-5, which are expressed in differentiated muscle and regulate muscle-specific gene activity. As anticipated, we find that Msx-1 is strongly up-regulated during the initiation of regeneration. It remains expressed throughout regeneration but is not found in the fully regenerated limb. The myogenic gene MRF-4 has the reverse expression pattern. It is expressed in adult limb muscle, is rapidly shut off in early regenerative blastemas, and is only reexpressed at the completion of regeneration. These kinetics are paralleled by those of a muscle-specific Myosin gene. In contrast Myf-5, a second member of the myogenic gene family, continues to be expressed throughout the regenerative process. Thus, MRF-4 and Myf-5 are likely to play distinct roles during regeneration. MRF-4 may directly regulate muscle phenotype and as such its repression may be a key event in dedifferentiation.(ABSTRACT TRUNCATED AT 250 WORDS)

Micropropagation of Asparagus by in vitro shoot culture.

Science.gov (United States)

Stajner, Nataša

2013-01-01

Asparagus officinalis is most extensively studied species within the genus Asparagus, which is well known as garden asparagus. This species is dioecious with unisexual flowers, which means that generative propagation gives roughly equal number of male and female plants. Male plants are high yielders and preferred commercially over female plants. Tissue culture techniques could efficiently promote vegetative propagation of male plants and pave the way for efficient plant breeding.This chapter describes an efficient micropropagation protocol for developing rapid growing in vitro Asparagus shoot cultures. The source of explants, inoculation, and shoot proliferation, followed by shoot propagation, rooting, and acclimatization is described. The optimal medium for Asparagus micropropagation described in this chapter is composed of MS macro- and microelements and a combination of auxins and cytokinins. Plant growth regulators NAA, kinetin, and BA were used in various concentrations. Three different media representing the whole micropropagation protocol of Asparagus are described; medium for shoot initiation, medium for shoot multiplication, and medium for root formation. By in vitro propagation of Asparagus, root initiation is difficult, but can be promoted by adding growth retardant ancymidol which also greatly promotes shoot development and suppresses callus formation.

Genetic stability and phytochemical analysis of the in vitro regenerated plants of Dendrobium nobile Lindl., an endangered medicinal orchid

Science.gov (United States)

Bhattacharyya, Paromik; Kumaria, Suman; Diengdoh, Reemavareen; Tandon, Pramod

2014-01-01

An efficient genetically stable regeneration protocol with increased phytochemical production has been established for Dendrobium nobile, a highly prized orchid for its economic and medicinal importance. Protocorm like bodies (PLBs) were induced from the pseudostem segments using thidiazuron (TDZ; 1.5 mg/l), by-passing the conventional auxin–cytokinin complement approach for plant regeneration. Although, PLB induction was observed at higher concentrations of TDZ, plantlet regeneration from those PLBs was affected adversely. The best rooting (5.41 roots/shoot) was achieved in MS medium with 1.5 mg/l TDZ and 0.25% activated charcoal. Plantlets were successfully transferred to a greenhouse with a survival rate of 84.3%, exhibiting normal development. Genetic stability of the regenerated plants was investigated using randomly amplified polymorphic DNA (RAPD) and start codon targeted (SCoT) polymorphism markers which detected 97% of genetic fidelity among the regenerants. The PIC values of RAPD and SCoT primers were recorded to be 0.92 and 0.76 and their Rp values ranged between 3.66 and 10, and 4 and 12 respectively. The amplification products of the regenerated plants showed similar banding patterns to that of the mother plant thus demonstrating the homogeneity of the micropropagated plants. A comparative phytochemical analysis among the mother and the micropropagated plants showed a higher yield of secondary metabolites. The regeneration protocol developed in this study provides a basis for ex-situ germplasm conservation and also harnesses the various secondary metabolite compounds of medicinal importance present in D. nobile. PMID:25606433

Mass propagation of shoots of Stevia rebaudiana using a large scale bioreactor.

Science.gov (United States)

Akita, M; Shigeoka, T; Koizumi, Y; Kawamura, M

1994-01-01

A procedure for the mass propagation of multiple shoots of Stevia rebaudiana is described. Isolated shoot primordia were used as the inoculum to obtain clusters of shoot primordia. Such clusters were grown in a 500 liter bioreactor to obtain shoots. A total of 64.6 Kg of shoots were propagated from 460 g of the inoculated shoot primordia. These shoots were easily acclimatized in soil.

Enhanced in vitro multiple shoot induction in elite Pakistani guava ...

African Journals Online (AJOL)

Elite guava (Psidium guajava L.) strains of cv. Safeda were explored in vitro for multiple shoot induction. Shoot induction was enhanced up to 83% with 3.5 to 4.25 shoots per single node cutting and shoot tip explants, respectively, using higher levels of benzyl amino purine (BAP) in Murashige and Skoog (MS) medium.

Exposure to lead in South African shooting ranges

International Nuclear Information System (INIS)

Mathee, Angela; Jager, Pieter de; Naidoo, Shan; Naicker, Nisha

2017-01-01

Introduction: Lead exposure in shooting ranges has been under scrutiny for decades, but no information in this regard is available in respect of African settings, and in South Africa specifically. The aim of this study was to determine the blood lead levels in the users of randomly selected private shooting ranges in South Africa's Gauteng province. Methods: An analytical cross sectional study was conducted, with participants recruited from four randomly selected shooting ranges and three archery ranges as a comparator group. Results: A total of 118 (87 shooters and 31 archers) were included in the analysis. Shooters had significantly higher blood lead levels (BLL) compared to archers with 36/85 (42.4%) of shooters versus 2/34 (5.9%) of archers found to have a BLL ≥10 μg/dl (p<0.001). Conclusion: Shooting ranges may constitute an import site of elevated exposure to lead. Improved ventilation, low levels of awareness of lead hazards, poor housekeeping, and inadequate personal hygiene facilities and practices at South African shooting ranges need urgent attention. - Highlights: • This is the first study, to our knowledge, of lead exposure in shooting ranges in an African setting. • This study indicates highly elevated lead exposure amongst the users of certain private shooting ranges in South Africa. • Lead exposure may be a serious, yet under-studied, source of adult lead exposure in South Africa, and possibly elsewhere on the African continent.

Exposure to lead in South African shooting ranges

Energy Technology Data Exchange (ETDEWEB)

Mathee, Angela [South African Medical Research Council, Environment & Health Research Unit, PO Box 87373, Houghton 2041 (South Africa); University of the Witwatersrand (School of Public Health), PO Box Wits, Johannesburg 2050 (South Africa); University of Johannesburg (Environmental Health Department, Faculty of Health Sciences), PO Box 524, Auckland Park, Johannesburg 2006 (South Africa); Jager, Pieter de [University of the Witwatersrand (School of Public Health), PO Box Wits, Johannesburg 2050 (South Africa); National Health Laboratory Service (Epidemiology and Surveillance Unit, National Institute for Occupational Health), PO Box 4788, Johannesburg 2000 (South Africa); Naidoo, Shan [University of the Witwatersrand (School of Public Health), PO Box Wits, Johannesburg 2050 (South Africa); Naicker, Nisha [South African Medical Research Council, Environment & Health Research Unit, PO Box 87373, Houghton 2041 (South Africa); University of the Witwatersrand, School of Public Health, PO Box Wits, Johannesburg 2050 (South Africa); University of Johannesburg, Environmental Health Department, Faculty of Health Sciences, PO Box 524, Auckland Park, Johannesburg 2006 (South Africa)

2017-02-15

Introduction: Lead exposure in shooting ranges has been under scrutiny for decades, but no information in this regard is available in respect of African settings, and in South Africa specifically. The aim of this study was to determine the blood lead levels in the users of randomly selected private shooting ranges in South Africa's Gauteng province. Methods: An analytical cross sectional study was conducted, with participants recruited from four randomly selected shooting ranges and three archery ranges as a comparator group. Results: A total of 118 (87 shooters and 31 archers) were included in the analysis. Shooters had significantly higher blood lead levels (BLL) compared to archers with 36/85 (42.4%) of shooters versus 2/34 (5.9%) of archers found to have a BLL ≥10 μg/dl (p<0.001). Conclusion: Shooting ranges may constitute an import site of elevated exposure to lead. Improved ventilation, low levels of awareness of lead hazards, poor housekeeping, and inadequate personal hygiene facilities and practices at South African shooting ranges need urgent attention. - Highlights: • This is the first study, to our knowledge, of lead exposure in shooting ranges in an African setting. • This study indicates highly elevated lead exposure amongst the users of certain private shooting ranges in South Africa. • Lead exposure may be a serious, yet under-studied, source of adult lead exposure in South Africa, and possibly elsewhere on the African continent.

Shoot growth of Merlot and Cabernet Sauvignon grapevine varieties

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Marcelo Borghezan

2012-02-01

Full Text Available The objective of this work was to evaluate shoot growth of the grapevine varieties Merlot and Cabernet Sauvignon, during 2006/2007, and Cabernet Sauvignon, during 2008/2009, in São Joaquim, SC, Brazil. The experiment was carried out in a commercial vineyard trained on a vertical trellis system. The shoots of the central part of the plants were selected, and the lengths from the base to the apex of 20 shoots per cultivar were evaluated. In 2006/2007, monitoring began at pruning, on 9/15/2006, and ended on 2/6/2007, totalizing 144 days of evaluation. During the 2008/2009 cycle, phenology and shoot growth for 'Cabernet Sauvignon' were assessed from grape development (1/13/2009 (pea-sized grapes until shoot vegetative growth had ceased. Budburst occurred in the second half of September, and shoot-growth cessation occurred during ripening. Higher growth rates (about 4 cm per day were observed in pre- and post-flowering, followed by reduction due to the competition for photosynthates for the formation of flowers and bunches. Temperature and photoperiod induce grapevine shoots to cease growth in the highland regions of Santa Catarina State, Brazil.

The Level of Vision Necessary for Competitive Performance in Rifle Shooting: Setting the Standards for Paralympic Shooting With Vision Impairment

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Peter M Allen

2016-11-01

Full Text Available The aim of this study was to investigate the level of vision impairment that would reduce performance in shooting; to guide development of entry criteria to visually impaired (VI shooting. Nineteen international-level shooters without vision impairment took part in the study. Participants shot an air rifle, while standing, towards a regulation target placed at the end of a 10m shooting range. Cambridge simulation glasses were used to simulate six different levels of vision impairment. Visual acuity (VA and contrast sensitivity (CS were assessed along with shooting performance in each of seven conditions of simulated impairment and compared to that with habitual vision. Shooting performance was evaluated by calculating each individual’s average score in every level of simulated vision impairment and normalising this score by expressing it as a percentage of the baseline performance achieved with habitual vision. Receiver Operating Characteristic (ROC curves were constructed to evaluate the ability of different VA and CS cut-off criteria to appropriately classify these athletes as achieving ‘expected’ or ‘below expected’ shooting results based on their performance with different levels of VA and CS. Shooting performance remained relatively unaffected by mild decreases in VA and CS, but quickly deteriorated with more moderate losses. The ability of visual function measurements to classify shooting performance was good, with 78% of performances appropriately classified using a cut-off of 0.53 logMAR and 74% appropriately classified using a cut-off of 0.83 logCS. The current inclusion criteria for VI shooting (1.0 logMAR is conservative, maximising the chance of including only those with an impairment that does impact performance, but potentially excluding some who do have a genuine impairment in the sport. A lower level of impairment would include more athletes who do have a genuine impairment but would potentially include those who do not

Arabidopsis CDS blastp result: AK119645 [KOME

Lifescience Database Archive (English)

Full Text Available PF|00847 AP2 domain; identical to cDNA enhancer of shoot regeneration ESR1 GI:18028939, enhancer of shoot regeneration ESR1 [Arabidopsis thaliana] GI:18028940 1e-10 ... ...ve / enhancer of shoot regeneration (ESR1) similar to gb|D38124 EREBP-3 from Nicotiana tabacum and contains ...AK119645 002-130-G05 At1g12980.1 AP2 domain-containing transcription factor, putati

IN VITRO REGENERATION OF THREE CHRYSANTHEMUM (Dendrathema grandiflora VARIETIES “VIA” ORGANOGENESIS AND SOMATIC EMBRYOGENESIS

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Elizabeth Hodson de Jaramillo

2008-09-01

Full Text Available Chrysanthemum (Dendrathema grandiflora has a high demand in the Colombian and international cut flower markets.Since commercial production of this ornamental species is strongly affected by fungal diseases such as chrysanthemumwhite rust (Puccinia horiana, high doses of fungicides are being used posing increased environmental and commercialcosts. Assessment of in vitro regeneration systems from leaf discs was a first step in developing a plant genetic transformationprotocol to obtain fungi-resistant plants. Leaf discs of White Albatross, Yellow Albatross, and Escapade varieties wereestablished in vitro on MS medium supplemented with NAA (0 - 4.83 μM and BAP (0 - 13.32 μM alone and incombination. Leaf discs were also cultured on MumB medium containing 2,4-D (0 - 4.52 μM for 7, 14, and 21 days priorto their transferral to a 2,4-D free MumB medium. Regenerated shoots were individualized, rooted, and hardened. Resultsshow that MS with 4.83 μM NAA + 4.44 μM BAP and 4.83 μM NAA + 13.32 μM BAP induce organogenesis, and MumBwith 2.26 μM 2,4-D induces somatic embryogenesis on all three varieties, with exposition periods to 2,4-D of 14 days forWhite Albatross and 21 days for Yellow Albatross and Escapade. Shoot development from somatic embryos was observedin the three varieties when cultured on a 2,4-D free MumB medium. Spontaneous rooting was recorded in 85% of the shootsthus facilitating hardening and successful transfer to soil.

Structure–Function Relationships in Highly Modified Shoots of Cactaceae

Science.gov (United States)

MAUSETH, JAMES D.

2006-01-01

• Background and Aims Cacti are extremely diverse structurally and ecologically, and so modified as to be intimidating to many biologists. Yet all have the same organization as most dicots, none differs fundamentally from Arabidopsis or other model plants. This review explains cactus shoot structure, discusses relationships between structure, ecology, development and evolution, and indicates areas where research on cacti is necessary to test general theories of morphogenesis. • Scope Cactus leaves are diverse; all cacti have foliage leaves; many intermediate stages in evolutionary reduction of leaves are still present; floral shoots often have large, complex leaves whereas vegetative shoots have microscopic leaves. Spines are modified bud scales, some secrete sugar as extra-floral nectaries. Many cacti have juvenile/adult phases in which the flowering adult phase (a cephalium) differs greatly from the juvenile; in some, one side of a shoot becomes adult, all other sides continue to grow as the juvenile phase. Flowers are inverted: the exterior of a cactus ‘flower’ is a hollow vegetative shoot with internodes, nodes, leaves and spines, whereas floral organs occur inside, with petals physically above stamens. Many cacti have cortical bundles vascularizing the cortex, however broad it evolves to be, thus keeping surface tissues alive. Great width results in great weight of weak parenchymatous shoots, correlated with reduced branching. Reduced numbers of shoot apices is compensated by great increases in number of meristematic cells within individual SAMs. Ribs and tubercles allow shoots to swell without tearing during wet seasons. Shoot epidermis and cortex cells live and function for decades then convert to cork cambium. Many modifications permit water storage within cactus wood itself, adjacent to vessels. PMID:16820405

Structure-function relationships in highly modified shoots of cactaceae.

Science.gov (United States)

Mauseth, James D

2006-11-01

Cacti are extremely diverse structurally and ecologically, and so modified as to be intimidating to many biologists. Yet all have the same organization as most dicots, none differs fundamentally from Arabidopsis or other model plants. This review explains cactus shoot structure, discusses relationships between structure, ecology, development and evolution, and indicates areas where research on cacti is necessary to test general theories of morphogenesis. Cactus leaves are diverse; all cacti have foliage leaves; many intermediate stages in evolutionary reduction of leaves are still present; floral shoots often have large, complex leaves whereas vegetative shoots have microscopic leaves. Spines are modified bud scales, some secrete sugar as extra-floral nectaries. Many cacti have juvenile/adult phases in which the flowering adult phase (a cephalium) differs greatly from the juvenile; in some, one side of a shoot becomes adult, all other sides continue to grow as the juvenile phase. Flowers are inverted: the exterior of a cactus 'flower' is a hollow vegetative shoot with internodes, nodes, leaves and spines, whereas floral organs occur inside, with petals physically above stamens. Many cacti have cortical bundles vascularizing the cortex, however broad it evolves to be, thus keeping surface tissues alive. Great width results in great weight of weak parenchymatous shoots, correlated with reduced branching. Reduced numbers of shoot apices is compensated by great increases in number of meristematic cells within individual SAMs. Ribs and tubercles allow shoots to swell without tearing during wet seasons. Shoot epidermis and cortex cells live and function for decades then convert to cork cambium. Many modifications permit water storage within cactus wood itself, adjacent to vessels.

Millet's Shooting Stars

Science.gov (United States)

Beech, M.

1988-12-01

In this essay two paintings by the French artist Jean-Francois Millet are described. These paintings, Les Etoiles Filantes and Nuit Etoilée are particularly interesting since they demonstrate the rare artistic employment of the shooting-star image and metaphor.

Production of polyploids from cultured shoot tips of Eucalyptus ...

African Journals Online (AJOL)

Polyploids from cultured shoot tips of Eucalyptus globulus were produced by treatment with colchicine. Results showed that the combination of 0.5% colchicine and treating multiple shoot clumps for 4 days was the most appropriate conditions for E. globulus polyploidy induction and the effect of the use of multiple shoot ...

Metabolic changes associated with shoot formation in tobacco callus cultures

Energy Technology Data Exchange (ETDEWEB)

Grady, K.L.

1982-08-01

Callus tissue derived from Nicotiana tabacum L. stem pith parenchyma cells was grown either on medium which maintains the callus in an undifferentiated state, or on medium which induces the formation of shoots. Two complementary types of studies were performed with the goal of establishing metabolic markers for the initiation of shoot formation: one designed to characterize the flow of radioactive sucrose into various metabolic pools, and one which allowed measurement of intermediary metabolite concentrations. In the former, callus tissue was incubated in (U-/sup 14/C)sucrose for periods up to one hour, and patterns of metabolite labelling in tissue grown on shoot-forming and non-shoot-forming media were compared. In the latter studies, tissue was grown for an entire subculture period on non-shoot-forming medium labelled with (U-/sup 14/C)sucrose, then subcultured to labelled non-shoot-forming or shoot-forming media, and sampled at intervals during the first week of growth. 189 references.

Metabolic changes associated with shoot formation in tobacco callus cultures

International Nuclear Information System (INIS)

Grady, K.L.

1982-08-01

Callus tissue derived from Nicotiana tabacum L. stem pith parenchyma cells was grown either on medium which maintains the callus in an undifferentiated state, or on medium which induces the formation of shoots. Two complementary types of studies were performed with the goal of establishing metabolic markers for the initiation of shoot formation: one designed to characterize the flow of radioactive sucrose into various metabolic pools, and one which allowed measurement of intermediary metabolite concentrations. In the former, callus tissue was incubated in [U- 14 C]sucrose for periods up to one hour, and patterns of metabolite labelling in tissue grown on shoot-forming and non-shoot-forming media were compared. In the latter studies, tissue was grown for an entire subculture period on non-shoot-forming medium labelled with [U- 14 C]sucrose, then subcultured to labelled non-shoot-forming or shoot-forming media, and sampled at intervals during the first week of growth. 189 references

Shooting mechanisms in Nature : A systematic review

NARCIS (Netherlands)

Sakes, A.; van der Wiel, M.; Henselmans, P.W.J.; van Leeuwen, J.L.; Dodou, D.; Breedveld, P.

2016-01-01

Background
In nature, shooting mechanisms are used for a variety of purposes, including prey capture, defense, and reproduction. This review offers insight into the working principles of shooting mechanisms in fungi, plants, and animals in the light of the specific functional demands that these

Successful micropropagation of the cadmium hyperaccumulator Viola baoshanensis (Violaceae).

Science.gov (United States)

Li, Jin-Tian; Deng, Dong-Mei; Peng, Guang-Tian; Deng, Jin-Chuan; Zhang, Jun; Liao, Bin

2010-01-01

Viola baoshanensis is one of the most rare cadmium (Cd) hyperaccumulators, however, it is hard to propagate. Micropropagation has been applied to solve the problems with propagation of a few heavy metal hyperaccumulators. Therefore there is a high likelihood that micropropagation may offer a suitable method for large-scale propagation of V. baoshanensis To test this hypothesis, three types of explants were used for shoot regeneration and various combinations of four plant growth regulators were used to improve shoot regeneration efficiency from leaflet of V. baoshanensis. Best shoot regeneration efficiency was obtained by incubating leaflet in a 1/2 MS medium supplemented with 2.5 oM BA + 2.5 microM IBA, therein shoot regeneration rate was 70.9% and the number of shoots formation per explant was 22.4. Rooting was achieved from almost all regenerated shoot growing on 1/2 MS medium without plant growth regulator. Micropropagated seedlings were acclimatized under greenhouse conditions and 95% of them survived and showed no visible morphological variation compared to their donor plant. Furthermore, there were no significant differences between regenerated and seed-germinated V. baoshanensis in Cd tolerance and accumulation. These results suggested that an efficient and rapid micropropogation system was successfully developed for V. baoshanensis.

Proliferative and inflammatory factors in the vitreous of patients with proliferative diabetic retinopathy

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V V Chernykh

2015-01-01

Full Text Available Purpose: The purpose was to measure the concentrations of various cytokines and growth factors (including vascular endothelial growth factor [VEGF] and pigment epithelium-derived factor [PEDF] in the vitreous of patients with proliferative diabetic retinopathy (PDR and to investigate interaction between inflammatory and proliferative factors in the genesis of PDR. Materials and Methods : Vitreous samples from 32 eyes with PDR and 25 eyes without diabetes mellitus and signs of DR (control were collected. Vitreous concentrations of VEGF, PEDF, monocyte chemotactic protein-1 (MCP-1, interleukin-4 (IL-4, IL-6, IL-8, IL-10, IL-17A, and secretory immunoglobulin A (sIgA were simultaneously measured using enzyme-linked immunoassay. Results : Vitreous levels of VEGF, PEDF, IL-17A, IL-6, IL-8, IL-4, and sIgA were significantly (Π < 0.05 higher in eyes with PDR compared to control. The concentration of VEGF was more than 17-times higher than in control, and the concentration of PEDF was not changed oppositely and was also higher (1.45-times compared to control, that may indicate disturbances of compensatory mechanisms in angiogenesis regulation in PDR. Significant (Π < 0.05 positive correlations were observed between vitreous concentrations of VEGF and IL-17ΐ (r = 0.45, VEGF and IL-8 (r = 0.48, VEGF and IL-4 (r = 0.51, PEDF and IL-17ΐ (r = 0.48, PEDF and IL-8 (r = 0.59, MCP-1 and PEDF (r = 0.72, MCP-1 and IL-8 (r0 = 0.45, IL-4 and IL-17ΐ (r = 0.65, IL-4 and IL-8 (r = 0.71, IL-8 and IL-17ΐ (r = 0.59. Conclusions: Significantly raised levels of inflammatory and proliferative factors and numerous positive correlations between them may demonstrate a significant role of activation of vascular proliferation and local inflammation in the pathogenesis of PDR.

Bilateral proliferative retinopathy in B-cell acute lymphoblastic leukemia

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Devesh Kumawat

2018-01-01

Full Text Available A 4-year-old child with B-cell acute lymphoblastic leukemia presented with vitreous hemorrhage due to proliferative retinopathy in both eyes. Pars plana vitrectomy was performed in both eyes to clear nonresolving vitreous hemorrhage after systemic stabilization. Visual recovery was limited by the disc drag in the right eye and subfoveal exudation in the left eye. Etiopathogenesis and management of proliferative retinopathy in acute leukemias are discussed.

Radiographing roots and shoots

International Nuclear Information System (INIS)

Shariffah Noor Khamseah Al Idid

1985-01-01

The effect of seed orientation on germination time and on shoot and root growth patterns is studied. Neutron radiography is used to observe the development of 4 types of plants, maize, greenpea, soya bean and padi. These plants were grown in varying orientations; sand sizes, sand thicknesses, and level of water content. Radiography of the seeds and plants were obtained for time exposure ranging from 3-12 hours and at reactor thermal power level, ranging from 500-750 kilowatts. Results obtained showed that seeds planted in varying orientations need different length of time for shoot emergence. Neutron radiography is now developed to other areas of non-industrial applications in Malaysia. (A.J.)

Plant regeneration from leaf protoplasts of Solanum torvum.

Science.gov (United States)

Guri, A; Volokita, M; Sink, K C

1987-07-01

A protocol to obtain regenerated plants from protoplasts of Solanum torvum Sw a wild species of eggplant resistant to Verticillium wilt is reported. Leaf protoplasts were enzymatically isolated from six-week old seedlings grown in a controlled environment chamber. Protoplasts were plated on modified KM medium (0.4 M glucose)+(mg/l): 1.0 p-chlorophenoxyacetic acid (CPA)+1.0 naphthaleneacetic acid (NAA)+0.5 6-benzylaminopurine (BAP) and 0.02 abscisic acid (ABA). The protoplast density was 5×10(4) per ml with 5 ml placed in each of two quadrants in X-dishes (100×15 mm). The reservoir medium was modified KM+(mg/l): 0.1 NAA+0.5 BAP+0.1 M sucrose+0.1 M mannitol+0.6% washed agar+1% activated charcoal. Dishes were initially placed in the dark at 27°C. Protoplast division was initiated in 1-2 weeks and 4 weeks later p-calli were 1-3 mm. Plating efficiency was 11% when measured at 3 weeks. Six-week old p-calli were transferred individually onto Whatman No. 1 filter paper layered on modified KM (0.15 M sucrose)+mg/l: 2.0 indoleacetic acid (IAA)+2.0 zeatin+0.5% washed agar for 2 weeks. Subsequently, shoots occurred within 4 weeks at 70% efficiency on MS+30 g/l sucrose+2 mg/l zeatin. Shoots were rooted on half strength MS+10 g/l sucrose.

Accuracy of Skill Performance in the Basketball Free Throw Shooting

Directory of Open Access Journals (Sweden)

Igawa Shoji

2011-12-01

Full Text Available The purpose of this study were to investigates how timing of shot of skilled player and assess performance accuracy of free throw shooting. Ten college students participated in this study (5 skilled players, and 5 naïve participants aged 18-23 years. They performed free throw shooting at 10 times. Shooting seen was recorded three cameras and analyzed shooting successful rate, off-target distance (the distance between the basketball through point and the center of the goal and shot timing. Shot timing was not significant difference. Shooting successful rate of skilled players was higher than unskilled players. Offtarget distance of skilled players was significant smaller than naive player. Consequently, skilled player is possible to aim at the center of the goal and shooting near the center of goal.

Journalism and School Shootings in Finland 2007 -2008

OpenAIRE

Raittila, Pentti; Koljonen, Kari; Väliverronen, Jari

2010-01-01

Two school shootings in Finland (Jokela in 2007 and Kauhajoki in 2008) resulted in the death of 20 people, and they shook not only the foundations of Finnish society but also of the profession that reported about the tragedies. This report is based on research conducted on school shootings at the University of Tampere Journalism Research and Development Centre between 2008 and 2009. The analysis concentrates on both the journalistic texts published on the shootings and journalists' actions...

Defense.gov Special Report: Fort Hood Shooting

Science.gov (United States)

identify possible insider threats, Army Secretary John M. McHugh told lawmakers. Story Obama: Soldiers ," Army Secretary John M. McHugh told lawmakers. Story President Praises Swift Response to Fort Hood Remarks on Fort Hood Shooting at White House McHugh, Odierno Address Fort Hood Shooting Before Congress

Lead pollution of shooting range soils | Sehube | South African ...

African Journals Online (AJOL)

Atotal of eight military shooting ranges were used for this study. Soil samples were collected at each of the eight shooting ranges at the berm, target line, 50 and 100 m from berm. In all of the shooting ranges investigated the highest total lead (Pb) concentrations were found in the bermsoils. Elevated Pb concentrations of 38 ...

Contagion in Mass Killings and School Shootings.

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Sherry Towers

Full Text Available Several past studies have found that media reports of suicides and homicides appear to subsequently increase the incidence of similar events in the community, apparently due to the coverage planting the seeds of ideation in at-risk individuals to commit similar acts.Here we explore whether or not contagion is evident in more high-profile incidents, such as school shootings and mass killings (incidents with four or more people killed. We fit a contagion model to recent data sets related to such incidents in the US, with terms that take into account the fact that a school shooting or mass murder may temporarily increase the probability of a similar event in the immediate future, by assuming an exponential decay in contagiousness after an event.We find significant evidence that mass killings involving firearms are incented by similar events in the immediate past. On average, this temporary increase in probability lasts 13 days, and each incident incites at least 0.30 new incidents (p = 0.0015. We also find significant evidence of contagion in school shootings, for which an incident is contagious for an average of 13 days, and incites an average of at least 0.22 new incidents (p = 0.0001. All p-values are assessed based on a likelihood ratio test comparing the likelihood of a contagion model to that of a null model with no contagion. On average, mass killings involving firearms occur approximately every two weeks in the US, while school shootings occur on average monthly. We find that state prevalence of firearm ownership is significantly associated with the state incidence of mass killings with firearms, school shootings, and mass shootings.

Contagion in Mass Killings and School Shootings.

Science.gov (United States)

Towers, Sherry; Gomez-Lievano, Andres; Khan, Maryam; Mubayi, Anuj; Castillo-Chavez, Carlos

2015-01-01

Several past studies have found that media reports of suicides and homicides appear to subsequently increase the incidence of similar events in the community, apparently due to the coverage planting the seeds of ideation in at-risk individuals to commit similar acts. Here we explore whether or not contagion is evident in more high-profile incidents, such as school shootings and mass killings (incidents with four or more people killed). We fit a contagion model to recent data sets related to such incidents in the US, with terms that take into account the fact that a school shooting or mass murder may temporarily increase the probability of a similar event in the immediate future, by assuming an exponential decay in contagiousness after an event. We find significant evidence that mass killings involving firearms are incented by similar events in the immediate past. On average, this temporary increase in probability lasts 13 days, and each incident incites at least 0.30 new incidents (p = 0.0015). We also find significant evidence of contagion in school shootings, for which an incident is contagious for an average of 13 days, and incites an average of at least 0.22 new incidents (p = 0.0001). All p-values are assessed based on a likelihood ratio test comparing the likelihood of a contagion model to that of a null model with no contagion. On average, mass killings involving firearms occur approximately every two weeks in the US, while school shootings occur on average monthly. We find that state prevalence of firearm ownership is significantly associated with the state incidence of mass killings with firearms, school shootings, and mass shootings.

The effect of triacontanol on shoot multiplication and production of antioxidant compounds in shoot cultures of Salvia officinalis L.

Directory of Open Access Journals (Sweden)

Izabela Grzegorczyk

2011-01-01

Full Text Available This report describes the effect of triacontanol on shoot multiplication and production of antioxidant compounds (carnosic acid, carnosol and rosmarinic acid in S. officinalis cultures grown on MS basal medium (agar solidified medium supplemented with 0.1 mg l-1 IAA, 0.45 mg l-1 BAP. It was found that shoot proliferation significantly increased when triacontanol at concentrations of 5, 10 or 20 µg l-1 was added to the medium. HPLC analysis of acetone and methanolic extracts of sage shoots showed that the production of diterpenoids, carnosic acid/carnosol ratio, as well as, contents of rosmarinic acid were also affected by the treatment with triacontanol. The highest stimulation effect of triacontanol was observed on the production of carnosol, where the treatment with 20 µg l l-1 increased the content of this diterpenoid 4.5-fold compared to that in the control (sage shoots growing on MS basal medium, only.

Australian Mass Shootings: An Analysis of Incidents and Offenders.

Science.gov (United States)

McPhedran, Samara

2017-06-01

Mass shooting events are relatively underresearched, and most study comes from the United States. Despite significant international interest, little is known about other countries' experiences of these events. The current study examines Australian mass shooting incidents and offenders, with emphasis on mental illness, life strains, and offenders' life histories. Australia had 14 mass shootings between 1964 and 2014. Most offenders experienced acute life stressors and/or chronic strains leading up to the event; however, diagnosed mental illness was less commonly documented. These observations provide new information about mass shooting incidents and offenders, and can help to inform international policy development.

Shooting stars

International Nuclear Information System (INIS)

Maurette, M.; Hammer, C.

1985-01-01

A shooting star passage -even a star shower- can be sometimes easily seen during moonless black night. They represent the partial volatilization in earth atmosphere of meteorites or micrometeorites reduced in cosmic dusts. Everywhere on earth, these star dusts are searched to be gathered. This research made one year ago on the Greenland ice-cap is this article object; orbit gathering projects are also presented [fr

School shootings during 2013-2015 in the USA.

Science.gov (United States)

Kalesan, Bindu; Lagast, Kinan; Villarreal, Marcos; Pino, Elizabeth; Fagan, Jeffrey; Galea, Sandro

2017-10-01

Data on the factors associated with school shootings in the USA are limited. The public conversation has often suggested several factors that may be linked to these events, however with little empirical support. Aiming to fill this gap, we describe the characteristics of school shooting incidents in the USA between 2013 and 2015 and explore whether four factors that represent domains of firearm policy, educational policy and epidemiological risk factors for intentional firearm injuries-background check (BC) policies, per capita mental health expenditures (MHE), K-12 education expenditure (KEE) and urbanicity-were associated with school shootings during this period. We searched LexisNexis, a newspaper and broadcast media databases for school shooting incidents from 1 January 2013 to 31 December 2015. Presence of BC laws was extracted from legal information in LexisNexis. State-level covariates of per capita MHE (2013), KEE (2013) and urbanicity (2010) rates were obtained from publicly available data sources. We used negative binomial regression models accounting for clustering by state to explore unadjusted associations between the BC laws, state-level covariates and school shootings to report IRR and 95% CI. We documented 154 school shootings (35, 55 and 64 each year). In unadjusted models, BC for firearm purchase (IRR=0.55, 95% CI 0.39 to 0.76), ammunition purchase (IRR=0.11, 95% CI 0.05 to 0.27), log per capita MHE (IRR=0.58, 95% CI 0.37 to 0.90), log per-capita KEE (IRR=0.09, 9% CI 0.02 to 0.29) and urbanicity (IRR=0.97, 95% CI 0.96 to 0.99) were associated with school shooting. School shootings are less likely in states with BC laws, higher MHE and KEE, and with greater per cent urban population. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Evaluación y selección de un protocolo para la regeneración in vitro de la variedad de tomate Unapal-Arreboles Evaluation and selection of a protocol for in vitro regeneration of tomato variety Unapal-Arreboles

Directory of Open Access Journals (Sweden)

Hernando Ramírez

2009-01-01

Full Text Available Se compararon tres medios de cultivo para seleccionar el apropiado para la regeneración in vitro de la variedad de tomate UNAPAL-Arreboles. Se evaluó la producción de callos/explante, brotes/explante y plántulas /explante. El análisis de varianza y la prueba de Duncan permitieron concluir que el medio M3 presentó los mejores promedios para las variables evaluadas.The main objective of this research was to carried out the comparison of three culture medium of major use for in vitro regeneration of tomato, to select the more appropriate medium for in vitro regeneration of tomato, variety UNAPAL-Arreboles. The analysis of variance and media comparison was made based on the callus, shoots and plantlets production. The highest efficiency of callus, shoots and plantlets production was obtained with the M3 media.

Wide variety of flower-color and -shape mutants regenerated from leaf cultures irradiated with ion beams

International Nuclear Information System (INIS)

Okamura, M.; Yasuno, N.; Ohtsuka, M.; Tanaka, A.; Shikazono, N.; Hase, Y.

2003-01-01

The efficiency of ion-beam irradiation combined with tissue culture in obtaining floral mutants was investigated and compared with those of gamma rays and X-rays in carnation. Leaf segments of carnation plants in vitro were irradiated with the 220 MeV carbon ions, and cultured till the shoot regenerated. The carbon ion had the highest effect in reducing the regeneration frequency, and the RBE value with respect to gamma-rays was four. The higher mutation frequency and the wider mutation spectrum were obtained in plants irradiated with the carbon ions than low LET radiations. Three new carnation varieties developed by ion-beam irradiation were applied for the registration of the Japanese Ministry of Agriculture, Forestry and Fisheries. The results indicate that ion beam irradiation could induce wide variety of flower-color and -shape mutants, and that the combined method of ion-beam irradiation with tissue culture is useful to obtain the commercial varieties in a short time

The Mental Health Consequences of Mass Shootings.

Science.gov (United States)

Lowe, Sarah R; Galea, Sandro

2017-01-01

Mass shooting episodes have increased over recent decades and received substantial media coverage. Despite the potentially widespread and increasing mental health impact of mass shootings, no efforts to our knowledge have been made to review the empirical literature on this topic. We identified 49 peer-reviewed articles, comprised of 27 independent samples in the aftermath of 15 mass shooting incidents. Based on our review, we concluded that mass shootings are associated with a variety of adverse psychological outcomes in survivors and members of affected communities. Less is known about the psychological effects of mass shootings on indirectly exposed populations; however, there is evidence that such events lead to at least short-term increases in fears and declines in perceived safety. A variety of risk factors for adverse psychological outcomes have been identified, including demographic and pre-incident characteristics (e.g., female gender and pre-incident psychological symptoms), event exposure (e.g., greater proximity to the attack and acquaintance with the deceased), and fewer psychosocial resources (e.g., emotion regulation difficulties and lower social support). Further research that draws on pre-incident and longitudinal data will yield important insights into the processes that exacerbate or sustain post-incident psychological symptoms over time and provide important information for crisis preparedness and post-incident mental health interventions. © The Author(s) 2015.

Wnt/β-Catenin Signaling Defines Organizing Centers that Orchestrate Growth and Differentiation of the Regenerating Zebrafish Caudal Fin

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Daniel Wehner

2014-02-01

Full Text Available Zebrafish regenerate their fins via the formation of a population of progenitor cells, the blastema. Wnt/β-catenin signaling is essential for blastemal cell proliferation and patterning of the overlying epidermis. Yet, we find that β-catenin signaling is neither active in the epidermis nor the majority of the proliferative blastemal cells. Rather, tissue-specific pathway interference indicates that Wnt signaling in the nonproliferative distal blastema is required for cell proliferation in the proximal blastema, and signaling in cells lining the osteoblasts directs osteoblast differentiation. Thus, Wnt signaling regulates epidermal patterning, blastemal cell proliferation, and osteoblast maturation indirectly via secondary signals. Gene expression profiling, chromatin immunoprecipitation, and functional rescue experiments suggest that Wnt/β-catenin signaling acts through Fgf and Bmp signaling to control epidermal patterning, whereas retinoic acid and Hedgehog signals mediate its effects on blastemal cell proliferation. We propose that Wnt signaling orchestrates fin regeneration by defining organizing centers that instruct cellular behaviors of adjacent tissues.

Mass Shootings: The Role of the Media in Promoting Generalized Imitation.

Science.gov (United States)

Meindl, James N; Ivy, Jonathan W

2017-03-01

Mass shootings are a particular problem in the United States, with one mass shooting occurring approximately every 12.5 days. Recently a "contagion" effect has been suggested wherein the occurrence of one mass shooting increases the likelihood of another mass shooting occurring in the near future. Although contagion is a convenient metaphor used to describe the temporal spread of a behavior, it does not explain how the behavior spreads. Generalized imitation is proposed as a better model to explain how one person's behavior can influence another person to engage in similar behavior. Here we provide an overview of generalized imitation and discuss how the way in which the media report a mass shooting can increase the likelihood of another shooting event. Also, we propose media reporting guidelines to minimize imitation and further decrease the likelihood of a mass shooting.

Effect of different intervals of x-ray split doses on shoot production of in vitro derived explants of Gerbera jamesonii Bolus

Energy Technology Data Exchange (ETDEWEB)

Walther, F; Sauer, A [Federal Research Centre for Horticultural Plant Breeding, Ahrensburg (Germany)

1990-01-01

Full text: Linearity between rising x-ray doses and mutation rate is limited by the simultaneously increasing radiation damage; induced chromosome aberrations eliminate valuable factor mutations. The application of fractionated doses provides the opportunity for repair of a distinct portion of damage. The dose of 30 Gy was fractionated into two identical parts. The periods for repair were 0.5 to 48 hs. The absolute and cumulative number of post-irradiation regenerated axillary shoots on 4 subsequent dates of cutoff were used as parameters to estimate radiosensitivity. From an economical point of view the interval of 4 hs between two dose fractions may be recommended for practice. (author)

Planarian regeneration under micro- and hyper-gravity simulated contexts

Science.gov (United States)

Auletta, Gennaro; Van Loon, ing.. Jack J. W. A.; Adell, Teresa; Salo, Emili

Planarians are non-parasitic flatworms of the Turbellaria class, some of which show the striking ability to regenerate any part of their body, even the head, in few days. Planarians are common to many parts of the world, living in both saltwater and freshwater, as well as in terrestrial areas. Due to their plasticity Planarians have been a classical model for the study of the mechanisms of regeneration. Currently, their cheap and easy maintenance, as well as the establishment of robust genetic tools, have converted them into an essential system in the field of stem cells and regenerative medicine. The aim of our project is to study the effect that micro- and hyper- gravity could exert during the process of planarians regeneration. The reason for planarians extreme regenerative capability is the maintenance until adulthood of a population of totipotent stem cells as well as the continuous activation of the cell-cell communication molecular pathways. Our prediction is that the alteration of the forces could affect planarians regeneration at different levels: 1) To regenerate, planarians must activate both proliferative and apoptotic responses, in order to create new tissue and to remodel the pre-existing one, respectively. Both cellular processes have been reported to be altered in several models under differential gravitational forces; 2) In planarians, the main intercellular signalling pathways (Wnt, TGFb, BMP, Hh, EGF) must control the process of differentiation and determination of each cell. For instances, it has been demonstrated that the differential activity of the wnt/beta-catenin pathway specifies the posterior (tail) versus the anterior (head) identity. Those pathways rely on the distance that secreted molecules (morphogens) are able to reach. Either this mechanism consist in a passive diffusion or an active transport through phyllopodia, it could sense the magnitude of the gravitational force; 3) The epidermis of planarians is covered by cilia, which beat

Effects of calcium gluconate and ascorbic acid on controlling shoot ...

African Journals Online (AJOL)

In vitro shoot necrosis is a quite widespread disorder affecting raspberry micropropagation. This study was conducted to investigate effects of calcium gluconate and ascorbic acid on shoot necrosis and dieback of raspberry shoots during micropropagation. Nodal segments of primocane-fruiting raspberry cultivars 'Allgold', ...

Tragedy and the Meaning of School Shootings

Science.gov (United States)

Warnick, Bryan R.; Johnson, Benjamin A.; Rocha, Samuel

2010-01-01

School shootings are traumatic events that cause a community to question itself, its values, and its educational systems. In this article Bryan Warnick, Benjamin Johnson, and Samuel Rocha explore the meanings of school shootings by examining three recent books on school violence. Topics that grow out of these books include (1) how school shootings…

Cryogenic regenerators

International Nuclear Information System (INIS)

Kush, P.; Joshi, S.C.; Thirumaleshwar, M.

1986-01-01

Importance of regenerators in cryogenic refrigerators is highlighted. Design aspects of regenerator are reviewed and the factors involved in the selection of regenerator material are enumerated. Various methods used to calculate the heat transfer coefficient and regenerator effectiveness are mentioned. Variation of effectiveness with various parameters is calculated by a computer programme using the ideal, Ackermann and Tipler formulae. Results are presented in graphical form. Listing of the computer programme is given in the Appendix. (author)

Distributed trouble-shooting

NARCIS (Netherlands)

Post, W.M.; Bogaard, S.A.A. van den; Rasker, P.C.

2004-01-01

When knowledge, required for trouble-shooting at sea, can be supplied real-time but from a distance, problems, such as with the limited availability of specialists, and the high costs of maintenance, may be tackled. Unclear is, however, how this redistribution of knowledge will work in practice. We

Firearm Legislation and Fatal Police Shootings in the United States.

Science.gov (United States)

Kivisto, Aaron J; Ray, Bradley; Phalen, Peter L

2017-07-01

To examine whether stricter firearm legislation is associated with rates of fatal police shootings. We used a cross-sectional, state-level design to evaluate the effect of state-level firearm legislation on rates of fatal police shootings from January 1, 2015, through October 31, 2016. We measured state-level variation in firearm laws with legislative scorecards from the Brady Center, and for fatal police shootings we used The Counted, an online database maintained by The Guardian. State-level firearm legislation was significantly associated with lower rates of fatal police shootings (incidence rate ratio = 0.961; 95% confidence interval = 0.939, 0.984). When we controlled for sociodemographic factors, states in the top quartile of legislative strength had a 51% lower incidence rate than did states in the lowest quartile. Laws aimed at strengthening background checks, promoting safe storage, and reducing gun trafficking were associated with fewer fatal police shootings. Legislative restrictions on firearms are associated with reductions in fatal police shootings. Public Health Implications. Although further research is necessary to determine causality and potential mechanisms, firearm legislation is a potential policy solution for reducing fatal police shootings in the United States.

The correlation of the radiocaesium concentration of new shoots harvested in 2012 and old leaves, and new shoots harvested in 2011 grown in Kanagawa prefecture

International Nuclear Information System (INIS)

Shiraki, Yoshiya; Takeda, Hajime; Okamoto, Tamotsu; Kita, Nobuhiro

2013-01-01

We conducted this study to analyze the correlation between 137 Cs concentration of new shoots harvested in the first crop of tea in 2012, and new shoots harvested in the shuto-bancha in 2011 and old leaves harvested at the same time respectively. In the first crop of tea in 2012, the 137 Cs concentration of new shoots was related to that of old leaves, and the correlation of the coefficient was 0.663(p 137 Cs concentration(new shoots/old leaves) was related to the days until harvest of the first crop of tea in 2012, and the correlation coefficient was -0.771(p 137 Cs concentration was derived from the dilution effect due to growth and development of tea plants. Regression analysis was performed to forecast the 137 Cs concentration of the new shoots in the first crop of tea. The 137 Cs concentration of new shoots in the harvested first crop of tea(Y) was related to the 137 Cs concentration of old leaves harvested the previous winter(X). The correlation of the coefficient was 0.783(p 137 Cs concentration of new shoots of the first crop of tea in 2012 decreased about 1/6 to 1/25 compared with that of new shoots of the first crop of tea in 2011. (author)

Standard effective doses for proliferative tumours

International Nuclear Information System (INIS)

Jones, L.C.; Hoban, P.

1999-01-01

This study was undertaken to investigate the treatment schedules used clinically for highly proliferative tumours, particularly with reference to the effects of fraction size, fraction number and treatment duration. The linear quadratic model (with time component) is used here to compare non-standard treatment regimens (e.g. accelerated and hyperfractionated schedules), currently the focus of randomized trials, with each other and some common 'standard regimens'. To ensure easy interpretation of results, two parameters known as proliferative standard effective dose one (PSED 1 ) and proliferative standard effective dose two (PSED 2 ) have been calculated for each regimen. Graphs of PSED 1 and PSED 2 versus potential doubling time (T p ) have been generated for a range of fractionation regimens which are currently under trial in various randomized studies. From these graphs it can be seen that the highly accelerated schedules (such as CHART) only show advantages for tumours with very short potential doubling times. Calculations for most of the schedules considered showed at least equivalent tumour control expected for the trial schedule compared with the control arm used and these values agree quite well with clinical results. These calculations are in good agreement with clinical results available at present. The greater the PSED 1 or PSED 2 for the schedule considered the greater the tumour control, which can be expected. However, as has been seen with clinical trials, this higher cell kill also results in higher acute effects which have proved too great for some accelerated schedules to continue. (author)

The Level of Vision Necessary for Competitive Performance in Rifle Shooting: Setting the Standards for Paralympic Shooting with Vision Impairment

NARCIS (Netherlands)

Allen, P.M.; Latham, K.; Mann, D.L.; Ravensbergen, H.J.C.; Myint, J.

2016-01-01

The aim of this study was to investigate the level of vision impairment (VI) that would reduce performance in shooting; to guide development of entry criteria to visually impaired (VI) shooting. Nineteen international-level shooters without VI took part in the study. Participants shot an air rifle,

Genetically induced cell death in bulge stem cells reveals their redundancy for hair and epidermal regeneration.

Science.gov (United States)

Driskell, Iwona; Oeztuerk-Winder, Feride; Humphreys, Peter; Frye, Michaela

2015-03-01

Adult mammalian epidermis contains multiple stem cell populations in which quiescent and more proliferative stem and progenitor populations coexist. However, the precise interrelation of these populations in homeostasis remains unclear. Here, we blocked the contribution of quiescent keratin 19 (K19)-expressing bulge stem cells to hair follicle formation through genetic ablation of the essential histone methyltransferase Setd8 that is required for the maintenance of adult skin. Deletion of Setd8 eliminated the contribution of bulge cells to hair follicle regeneration through inhibition of cell division and induction of cell death, but the growth and morphology of hair follicles were unaffected. Furthermore, ablation of Setd8 in the hair follicle bulge blocked the contribution of K19-postive stem cells to wounded epidermis, but the wound healing process was unaltered. Our data indicate that quiescent bulge stem cells are dispensable for hair follicle regeneration and epidermal injury in the short term and support the hypothesis that quiescent and cycling stem cell populations are equipotent. © 2014 AlphaMed Press.

 Age-related changes of skeletal muscles: physiology, pathology and regeneration

Directory of Open Access Journals (Sweden)

Aleksandra Ławniczak

2012-06-01

Full Text Available  This review provides a short presentation of the aging-related changes of human skeletal muscles. The aging process is associated with the loss of skeletal muscle mass (sarcopenia and strength. This results from fibre atrophy and apoptosis, decreased regeneration capacity, mitochondrial dysfunction, gradual reduction of the number of spinal cord motor neurons, and local and systemic metabolic and hormonal alterations. The latter involve age-related decrease of the expression and activity of some mitochondrial and cytoplasmic enzymes, triacylglycerols and lipofuscin accumulation inside muscle fibres, increased proteolytic activity, insulin resistance and decreased serum growth hormone and IGF-1 concentrations. Aging of the skeletal muscles is also associated with a decreased number of satellite cells and their proliferative activity. The age-related reduction of skeletal muscle mass and function may be partially prevented by dietary restriction and systematic physical exercises.

Ferns: the missing link in shoot evolution and development

Directory of Open Access Journals (Sweden)

Andrew Robert George Plackett

2015-11-01

Full Text Available Shoot development in land plants is a remarkably complex process that gives rise to an extreme diversity of forms. Our current understanding of shoot developmental mechanisms comes almost entirely from studies of angiosperms (flowering plants, the most recently diverged plant lineage. Shoot development in angiosperms is based around a layered multicellular apical meristem that produces lateral organs and/or secondary meristems from populations of founder cells at its periphery. In contrast, non-seed plant shoots develop from either single apical initials or from a small population of morphologically distinct apical cells. Although developmental and molecular information is becoming available for non-flowering plants, such as the model moss Physcomitrella patens, making valid comparisons between highly divergent lineages is extremely challenging. As sister group to the seed plants, the monilophytes (ferns and relatives represent an excellent phylogenetic midpoint of comparison for unlocking the evolution of shoot developmental mechanisms, and recent technical advances have finally made transgenic analysis possible in the emerging model fern Ceratopteris richardii. This review compares and contrasts our current understanding of shoot development in different land plant lineages with the aim of highlighting the potential role that the fern C. richardii could play in shedding light on the evolution of underlying genetic regulatory mechanisms.

Resynthesized Brassica juncea lines with novel organellar genome ...

Indian Academy of Sciences (India)

To obtain shoot cultures, shoot apices were ... and culture, plant regeneration and hardening etc. are as described ... Hence two other media were tested for plant regeneration. .... genomes exert a strong influence on reorganization of nuclear.

Mental illness, mass shootings, and the politics of American firearms.

Science.gov (United States)

Metzl, Jonathan M; MacLeish, Kenneth T

2015-02-01

Four assumptions frequently arise in the aftermath of mass shootings in the United States: (1) that mental illness causes gun violence, (2) that psychiatric diagnosis can predict gun crime, (3) that shootings represent the deranged acts of mentally ill loners, and (4) that gun control "won't prevent" another Newtown (Connecticut school mass shooting). Each of these statements is certainly true in particular instances. Yet, as we show, notions of mental illness that emerge in relation to mass shootings frequently reflect larger cultural stereotypes and anxieties about matters such as race/ethnicity, social class, and politics. These issues become obscured when mass shootings come to stand in for all gun crime, and when "mentally ill" ceases to be a medical designation and becomes a sign of violent threat.

Multiple vantage points on the mental health effects of mass shootings.

Science.gov (United States)

Shultz, James M; Thoresen, Siri; Flynn, Brian W; Muschert, Glenn W; Shaw, Jon A; Espinel, Zelde; Walter, Frank G; Gaither, Joshua B; Garcia-Barcena, Yanira; O'Keefe, Kaitlin; Cohen, Alyssa M

2014-09-01

The phenomenon of mass shootings has emerged over the past 50 years. A high proportion of rampage shootings have occurred in the United States, and secondarily, in European nations with otherwise low firearm homicide rates; yet, paradoxically, shooting massacres are not prominent in the Latin American nations with the highest firearm homicide rates in the world. A review of the scientific literature from 2010 to early 2014 reveals that, at the individual level, mental health effects include psychological distress and clinically significant elevations in posttraumatic stress, depression, and anxiety symptoms in relation to the degree of physical exposure and social proximity to the shooting incident. Psychological repercussions extend to the surrounding affected community. In the aftermath of the deadliest mass shooting on record, Norway has been in the vanguard of intervention research focusing on rapid delivery of psychological support and services to survivors of the "Oslo Terror." Grounded on a detailed review of the clinical literature on the mental health effects of mass shootings, this paper also incorporates wide-ranging co-author expertise to delineate: 1) the patterning of mass shootings within the international context of firearm homicides, 2) the effects of shooting rampages on children and adolescents, 3) the psychological effects for wounded victims and the emergency healthcare personnel who care for them, 4) the disaster behavioral health considerations for preparedness and response, and 5) the media "framing" of mass shooting incidents in relation to the portrayal of mental health themes.

In vitro mass propagation of Salvia canariensis by axillary shoots

Directory of Open Access Journals (Sweden)

Sebastiana Mederos Molina

2014-01-01

Full Text Available During the establishment of shoots of Salvia canariensis L., five environmental factor treatments were applied. For each axillary node two shoots grew well when explants were incubated at continued ligth for 15 days followed by 16 hrs photoperiod by 30 days. Shoots multiplication was improved on a modified Murashige and Skoog (MS (1962 medium - MS + 825 mg/l NH4NO3 - supplemented with 10-7 M BA and 10-7 M NAA. The shoots produced well developed root systems within three weeks after transfer to the same culture medium supplemented with 5x 10-7 M NAA.

Proliferative glomerulonephritis and primary antiphospholipid syndrome

International Nuclear Information System (INIS)

Abdalla, H. Abdalla; Kfoury, Hala K.; Al-Khader, Abdulla A.; Al-Suleiman, M.

2006-01-01

Little is known regarding the association of primary antiphospholipid syndrome (APLS) and proliferative glomerulonephiritis (GN). We describe a biopsy-documented case with primary APLS and proliferative (GN) with no evidence of thrombotic microangiopathy (TMA), and in the absence of other manifestations of systematic lupus erythematosus (SLE). She presented initially with left popliteal deep venous thrombosis and nephrotic syndrome. Her first pregnancy at the age of 26 years resulted in the intra-uterine fetal death at term. Two subsequent pregnancies ended up with miscarriages at 3 and 4 months of gestation. Urinalysis revealed glomerular red blood cells of 1.0000.000/ml and granular cast; proteinuria of 13.4grams/24 hours, which was non-selective; hemoglobin 12 gm/dl, normal white blood cell and platelets; serum albumin 2.6gm/dl; anti-nuclear antibody (ANA) and anti DNA were negative and complement levels normal. Lupus anticoagulant was positive leading to a diagnosis of primary APLS. The biopsy findings were consistent with membranoproliferative GN. She continued to have steroid-resistant proteinuria, but stable renal function after a 12-year follow up period. She had 2 pregnancies during this period and was delivered at term using caesarian section. She received heparin during the pregnancies. Later she developed hypertension easily controlled by atenolol. This case provides evidence that primary APLS can be associated with proliferative GN due to immune deposits and not only TMA as previously reported, and in the complete absence of SLE. Performing more renal biopsies in this group of patients may disclose a greater prevalence of proleferative GN and may help in devising a rationale for treatment. (author)

The Relationship between Proliferative Scars and Endothelial Function in Surgically Revascularized Patients

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Murat Ziyrek

2015-12-01

Full Text Available Background: Proliferative scars are benign fibrotic proliferations which demonstrate abnormal wound healing in response to skin injuries. As postulated in the “response to injury hypothesis”, atherosclerosis is also triggered by an endothelial injury. Keloid and atherosclerotic processes have many pathophysiological and cytological features in common. Aims: In this study, we investigated the relationship between proliferative scars and endothelial function in surgically revascularized patients. We aimed to test the hypothesis that atherosclerosis is a wound healing abnormality. Study Design: Cross-sectional study. Methods: Consecutive patients who were admitted to the cardiology outpatient clinic with a history of coronary artery bypass grafting operation were evaluated. Thirty-three patients with proliferative scars at the median sternotomy site formed the keloid group, and 36 age- and sex-matched patients with no proliferative scar at the median sternotomy site formed the control group. Endothelial function was evaluated by flow-mediated vasodilatation of the brachial artery via ultrasonograhic examination. Results: There is no signicant difference according to the demographic data, biochemical parameters, clinical parameters and number of grafts between keloid and control groups. Endothelial-dependent vasodilatory response was lower in the keloid group than the control group (9.30±3.5 and 18.68±8.2, respectively; p=0.001. Conclusion: This study showed that endothalial dysfunction, which is strongly correlated with atherosclerosis, was more prominent in patients with proliferative scars. As proliferative scars and atherosclerosis have many features in common, we might conclude that atherosclerosis is a wound healing abnormality.

Shoot Differentiation in Callus Cultures of Datura Innoxia

DEFF Research Database (Denmark)

Engvild, Kjeld Christensen

1973-01-01

promoted shoot differentiation. Gibberellic acid inhibited shoot formation weakly, but inhibited proper leaf blade formation. Root differentiation was rare. The callus cultures of Datura innoxia grew rapidly (100-fold in 4 weeks) on a slightly modified Murashige and Skoog medium (0.5 mg/l thiamin · HCl, p...

Handgun Acquisitions in California After Two Mass Shootings.

Science.gov (United States)

Studdert, David M; Zhang, Yifan; Rodden, Jonathan A; Hyndman, Rob J; Wintemute, Garen J

2017-05-16

Mass shootings are common in the United States. They are the most visible form of firearm violence. Their effect on personal decisions to purchase firearms is not well-understood. To determine changes in handgun acquisition patterns after the mass shootings in Newtown, Connecticut, in 2012 and San Bernardino, California, in 2015. Time-series analysis using seasonal autoregressive integrated moving-average (SARIMA) models. California. Adults who acquired handguns between 2007 and 2016. Excess handgun acquisitions (defined as the difference between actual and expected acquisitions) in the 6-week and 12-week periods after each shooting, overall and within subgroups of acquirers. In the 6 weeks after the Newtown and San Bernardino shootings, there were 25 705 (95% prediction interval, 17 411 to 32 788) and 27 413 (prediction interval, 15 188 to 37 734) excess acquisitions, respectively, representing increases of 53% (95% CI, 30% to 80%) and 41% (CI, 19% to 68%) over expected volume. Large increases in acquisitions occurred among white and Hispanic persons, but not among black persons, and among persons with no record of having previously acquired a handgun. After the San Bernardino shootings, acquisition rates increased by 85% among residents of that city and adjacent neighborhoods, compared with 35% elsewhere in California. The data relate to handguns in 1 state. The statistical analysis cannot establish causality. Large increases in handgun acquisitions occurred after these 2 mass shootings. The spikes were short-lived and accounted for less than 10% of annual handgun acquisitions statewide. Further research should examine whether repeated shocks of this kind lead to substantial increases in the prevalence of firearm ownership. None.

Depletion of resident macrophages does not alter sensory regeneration in the avian cochlea.

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Mark E Warchol

Full Text Available Macrophages are the primary effector cells of the innate immune system and are also activated in response to tissue injury. The avian cochlea contains a population of resident macrophages, but the precise function of those cells is not known. The present study characterized the behavior of cochlear macrophages after aminoglycoside ototoxicity and also examined the possible role of macrophages in sensory regeneration. We found that the undamaged chick cochlea contains a large resting population of macrophages that reside in the hyaline cell region, immediately outside the abneural (inferior border of the sensory epithelium. Following ototoxic injury, macrophages appear to migrate out of the hyaline cell region and towards the basilar membrane, congregating immediately below the lesioned sensory epithelium. In order to determine whether recruited macrophages contribute to the regeneration of sensory receptors, we quantified supporting cell proliferation and hair cell recovery after the elimination of most resident macrophages via application of liposomally-encapsulated clodronate. Examination of macrophage-depleted specimens at two days following ototoxic injury revealed no deficits in hair cell clearance, when compared to normal controls. In addition, we found that elimination of macrophages did not affect either regenerative proliferation of supporting cells or the production of replacement hair cells. However, we did find that macrophage-depleted cochleae contained reduced numbers of proliferative mesothelial cells below the basilar membrane. Our data suggest that macrophages are not required for normal debris clearance and regeneration, but that they may play a role in the maintenance of the basilar membrane.

Biolistic transformation of Carrizo citrange (Citrus sinensis Osb. × Poncirus trifoliata L. Raf.).

Science.gov (United States)

Wu, Hao; Acanda, Yosvanis; Jia, Hongge; Wang, Nian; Zale, Janice

2016-09-01

The development of transgenic citrus plants by the biolistic method. A protocol for the biolistic transformation of epicotyl explants and transgenic shoot regeneration of immature citrange rootstock, cv. Carrizo (Citrus sinensis Osb. × Poncirus trifoliata L. Raf.) and plant regeneration is described. Immature epicotyl explants were bombarded with a vector containing the nptII selectable marker and the gfp reporter. The number of independent, stably transformed tissues/total number of explants, recorded by monitoring GFP fluorescence 4 weeks after bombardment was substantial at 18.4 %, and some fluorescing tissues regenerated into shoots. Fluorescing GFP, putative transgenic shoots were micro-grafted onto immature Carrizo rootstocks in vitro, confirmed by PCR amplification of nptII and gfp coding regions, followed by secondary grafting onto older rootstocks grown in soil. Southern blot analysis indicated that all the fluorescing shoots were transgenic. Multiple and single copies of nptII integrations were confirmed in five regenerated transgenic lines. There is potential to develop a higher throughput biolistics transformation system by optimizing the tissue culture medium to improve shoot regeneration and narrowing the window for plant sampling. This system will be appropriate for transformation with minimal cassettes.

PROSPECTIVE STUDY OF HISTOLOGICAL PROLIFERATIVE CHANGES IN ADJACENT AREAS OF BREAST CANCER

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Rema Nair Sarkar

2016-11-01

Full Text Available BACKGROUND Breast cancer remains a global health problem with an increasing incidence. Proliferative breast diseases are recognised as one of the risk factors in the development of carcinoma. This study was undertaken to know the frequency of proliferative lesions and other lesions in association with breast carcinomas in mastectomy specimens. MATERIALS AND METHODS 100 cases of excised carcinoma breast sent to the Department of Pathology for a three-year period at tertiary care centre was thoroughly examined and changes adjacent to the tumour was recorded and tissue was subjected for histopathological examination and results tabulated. RESULTS Infiltrating duct cell carcinoma, Not Otherwise Specified (NOS type was present in 89% of cases. Among the associated lesions, nonproliferative lesions constituted 16%, proliferative breast disease without atypia 29%, proliferative breast disease with atypia 10% and others 45%. Fibrocystic disease constituted 14% of cases, epithelial hyperplasia 15%, sclerosing adenosis 12% and atypical ductal hyperplasia in 10% of cases. Other types of associated lesions were duct carcinoma in situ in 4 cases. CONCLUSION Proliferative lesions adjacent to carcinoma breast were seen in 39% of cases. Fibrocystic disease, epithelial hyperplasia, sclerosing adenosis and atypical ductal hyperplasia being the commonest lesions adjacent to carcinoma breast in the present study.

The Effect of High School Shootings on Schools and Student Performance

OpenAIRE

Louis-Philippe Beland; Dongwoo Kim

2015-01-01

We analyze how fatal shootings in high schools affect schools and students using data from shooting databases, school report cards, and the Common Core of Data. We examine schools’ test scores, enrollment, and number of teachers, as well as graduation, attendance, and suspension rates at schools that experienced a shooting, employing a difference-in-differences strategy that uses other high schools in the same district as the comparison group. Our findings suggest that homicidal shootings s...

Methodology of shooting training using modern IT techniques

Science.gov (United States)

Gudzbeler, Grzegorz; Struniawski, Jarosław

2017-08-01

Mastering, improvement, shaping and preservation of skills of safe, efficient and effective use of the firearm requires the use of relevant methodology of conducting the shooting training. However reality of police trainings does not usually allow for intensive training shooting with the use of ammunition. An alternative solution is the use of modern training technologies. Example of this is the "Virtual system of improvement tactics of intervention services responsible for security and shooting training." Introduction of stimulator to police trainings will enable complete stuff preparation to achieve its tasks, creating potential of knowledge and experience in many areas, far exceeding the capabilities of conventional training.

[Genetic regulation of plant shoot stem cells].

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Al'bert, E V; Ezhova, T A

2013-02-01

This article describes the main features of plant stem cells and summarizes the results of studies of the genetic control of stem cell maintenance in the apical meristem of the shoot. It is demonstrated that the WUS-CLV gene system plays a key role in the maintenance of shoot apical stem cells and the formation of adventitious buds and somatic embryos. Unconventional concepts of plant stem cells are considered.

THE PRELIMINARY STUDIES ON THE INFLUENCE OF SHOOTING RANGES ON ENVIRONMENT

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Karolina Wodnik

2017-08-01

Full Text Available The aim of the study was to assess the impact of the shooting activity on the environment. The studies were conducted in the area of the sports shooting range. The invertebrates assemblages were identified to the family level as well as morphospecies. The second method do not require the proficiency in identification. The following indices of the biodiversity were used for the assessment of the impact of sports shooting ranges: Simpson, Shannon-Wiener, Margalef, Berger-Parker and Menhinick. A decreased biodiversity was observed at two studied sites comparing to the reference site what proves the influence of shooting activity on the biodiversity and suggest disturbance of the ecosystem integrity because of shooting activity.

The use of analogy in pro-life argumentation

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Simona Mazilu

2012-11-01

Full Text Available The paper is concerned with how analogy is strategically used in pro-life argumentation on abortion. Pragma-dialectics (van Eemeren and Grootendorst 1992 offers a set of critical questions by means of which I will evaluate the use of the argumentation based on a relation of analogy in terms of dialectical soundness. Examining various pro-life texts, I have noticed that the analogies employed remain unexplained. Therefore, despite the apparent similarities between abortion and the German holocaust or slavery, for instance, there are essential differences which are not mentioned. I claim that these analogies mainly have a rhetorical function, to operate what has been called by Micheli (2007: 960 “a transfer of emotional consensus”.

The cancer paradigms of mammalian regeneration: can mammals regenerate as amphibians?

Science.gov (United States)

Sarig, Rachel; Tzahor, Eldad

2017-04-01

Regeneration in mammals is restricted to distinct tissues and occurs mainly by expansion and maturation of resident stem cells. During regeneration, even subtle mutations in the proliferating cells may cause a detrimental effect by eliciting abnormal differentiation or malignant transformation. Indeed, cancer in mammals has been shown to arise through deregulation of stem cells maturation, which often leads to a differentiation block and cell transformation. In contrast, lower organisms such as amphibians retain a remarkable regenerative capacity in various organs, which occurs via de- and re-differentiation of mature cells. Interestingly, regenerating amphibian cells are highly resistant to oncogenic transformation. Therapeutic approaches to improve mammalian regeneration mainly include stem-cell transplantations; but, these have proved unsuccessful in non-regenerating organs such as the heart. A recently developed approach is to induce de-differentiation of mature cardiomyocytes using factors that trigger their re-entry into the cell cycle. This novel approach raises numerous questions regarding the balance between transformation and regeneration induced by de-differentiation of mature mammalian somatic cells. Can this balance be controlled artificially? Do de-differentiated cells acquire the protection mechanisms seen in regenerating cells of lower organisms? Is this model unique to the cardiac tissue, which rarely develops tumors? This review describes regeneration processes in both mammals and lower organisms and, particularly, the ability of regenerating cells to avoid transformation. By comparing the characteristics of mammalian embryonic and somatic cells, we discuss therapeutic strategies of using various cell populations for regeneration. Finally, we describe a novel cardiac regeneration approach and its implications for regenerative medicine. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email

Shoot growth of Merlot and Cabernet Sauvignon grapevine varieties

OpenAIRE

Marcelo Borghezan; Olavo Gavioli; Hamilton Justino Vieira; Aparecido Lima da Silva

2012-01-01

The objective of this work was to evaluate shoot growth of the grapevine varieties Merlot and Cabernet Sauvignon, during 2006/2007, and Cabernet Sauvignon, during 2008/2009, in São Joaquim, SC, Brazil. The experiment was carried out in a commercial vineyard trained on a vertical trellis system. The shoots of the central part of the plants were selected, and the lengths from the base to the apex of 20 shoots per cultivar were evaluated. In 2006/2007, monitoring began at pruning, on 9/15/2006, ...

Effect of cadmium pretreatment on liver regeneration after partial hepatectomy in rats

International Nuclear Information System (INIS)

Margeli, A.; Theocharis, S.; Skaltsas, S.; Skopelitou, A.; Kittas, C.; Mykoniatis, M.; Varonos, D.

1994-01-01

In this study we examined the effect of cadmium pretreatment, administered 24 h before partial hepatectomy, on the liver regenerative process in rats, at different time intervals. The rate of 3 H thymidine incorporation into hepatic DNA and the activity of the enzyme thymidine kinase were used as indices of liver proliferative capacity. Thymidine kinase, the rate-determining enzyme of DNA biosynthesis, was suppressed during the first hours following partial hepatectomy in the liver of cadmium pretreated animals. DNA biosynthesis was also strongly decreased in cadmium pretreated animals, by delaying the first peak of liver regeneration, compared with the partially hepatectomized ones. Biochemical parameters, mitotic index and proliferating cell nuclear antigen staining were also coestimated. The above data suggest that cadmium pretreatment suppressed the hepatic regenerative process, probably due to the inhibition of thymidine kinase. (orig./MG)

Treatment and prevention of porcine proliferative enteropathy with oral tiamulin.

Science.gov (United States)

McOrist, S; Smith, S H; Shearn, M F; Carr, M M; Miller, D J

The effect of an oral treatment or prevention programme, incorporating the antibiotic tiamulin, on the development of proliferative enteropathy in experimentally challenged pigs was studied. Twenty weaner pigs were challenged orally with a virulent inoculum of Lawsonia intracellularis strain LR189/5/83, a British isolate of the causative agent of porcine proliferative enteropathy, and seven control pigs were dosed with a buffer solution. Seven of the 20 challenged pigs were left untreated; they gained less weight than the controls and three of them developed mild to moderate diarrhoea two weeks after the challenge. All seven developed lesions, six visible grossly, of proliferative enteropathy, and numerous intracellular L intracellularis were detected in sections of the intestines examined three weeks after the challenge. To test a 'prevention' dosing strategy for tiamulin, six of the challenged pigs were dosed orally with 50 ppm tiamulin, incorporated in a 2 per cent stabilised premix, given from two days before the challenge until they were euthanased. To test a 'treatment' strategy, the remaining group of seven challenged pigs were dosed orally with 150 ppm tiamulin given in the premix from seven days after challenge until they were euthanased. All the control pigs and the 13 pigs treated with tiamulin, either before or after challenge, remained clinically normal and had no specific lesions of proliferative enteropathy in sections of the intestines examined post mortem.

Comparative proteomics reveals the physiological differences between winter tender shoots and spring tender shoots of a novel tea (Camellia sinensis L.) cultivar evergrowing in winter.

Science.gov (United States)

Liu, Shengjie; Gao, Jiadong; Chen, Zhongjian; Qiao, Xiaoyan; Huang, Hualin; Cui, Baiyuan; Zhu, Qingfeng; Dai, Zhangyan; Wu, Hualing; Pan, Yayan; Yang, Chengwei; Liu, Jun

2017-11-20

A recently discovered tea [Camellia sinensis (L.) O. Kuntze] cultivar can generate tender shoots in winter. We performed comparative proteomics to analyze the differentially accumulated proteins between winter and spring tender shoots of this clonal cultivar to reveal the physiological basis of its evergrowing character during winter. We extracted proteins from the winter and spring tender shoots (newly formed two leaves and a bud) of the evergrowing tea cultivar "Dongcha11" respectively. Thirty-three differentially accumulated high-confidence proteins were identified by matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF / TOF MS). Among these, 24 proteins had increased abundance while nine showed were decreased abundance in winter tender shoots as compared with the spring tender shoots. We categorized the differentially accumulated proteins into eight critical biological processes based on protein function annotation including photosynthesis, cell structure, protein synthesis & destination, transporters, metabolism of sugars and polysaccharides, secondary metabolism, disease/defense and proteins with unknown functions. Proteins with increased abundance in winter tender shoots were mainly related to the processes of photosynthesis, cytoskeleton and protein synthesis, whereas those with decreased abundance were correlated to metabolism and the secondary metabolism of polyphenolic flavonoids. Biochemical analysis showed that the total contents of soluble sugar and amino acid were higher in winter tender shoots while tea polyphenols were lower as compared with spring tender shoots. Our study suggested that the simultaneous increase in the abundance of photosynthesis-related proteins rubisco, plastocyanin, and ATP synthase delta chain, metabolism-related proteins eIF4 and protease subunits, and the cytoskeleton-structure associated proteins phosphatidylinositol transfer protein and profilin may be because of the adaptation of the

Estrogen signaling in the proliferative endometrium: implications in endometriosis

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Rita de Cássia Pereira da Costa e Silva

2016-02-01

Full Text Available SUMMARY Even though the physiological role of estrogen in the female reproductive cycle and endometrial proliferative phase is well established, the signaling pathways by which estrogen exerts its action in the endometrial tissue are still little known. In this regard, advancements in cell culture techniques and maintenance of endometrial cells in cultures enabled the discovery of new signaling mechanisms activated by estrogen in the normal endometrium and in endometriosis. This review aims to present the recent findings in the genomic and non-genomic estrogen signaling pathways in the proliferative human endometrium specifically associated with the pathogenesis and development of endometriosis.

Bringing sexy back: reclaiming the body aesthetic via self-shooting

DEFF Research Database (Denmark)

Tiidenberg, Katrin

2014-01-01

’s ‘technologies of the self’ to analyze self-shooting (taking photos of one-self). Constricting societal norms of sexuality, body shape and body practices influence how my participants (N=20, 10 female, 9 male, 1 transgender, ages 21 - 51, average age 34) live their embodied and sexual lives. Through self-shooting...... and by negotiating the community specific issues of control, power and the gaze, they are able to construct a new, empowered, embodied identity for themselves. I look at self-shooting and selfie-blogging as a practice of reclaiming control over one’s embodied self AND over the body-aesthetic, thus appropriating what...... is and is not ‘sexy’. The NSFW self-shooting community offers a safe space otherwise so hard to find within the body/sexuality-normative mainstream culture. This makes self-shooting a collective therapeutic activity. In their self-images participants construct themselves as ‘beautiful’, ‘sexy’, ‘devious’, ‘more than...

Administration of multipotent mesenchymal stromal cells restores liver regeneration and improves liver function in obese mice with hepatic steatosis after partial hepatectomy.

Science.gov (United States)

Ezquer, Fernando; Bahamonde, Javiera; Huang, Ya-Lin; Ezquer, Marcelo

2017-01-28

The liver has the remarkable capacity to regenerate in order to compensate for lost or damaged hepatic tissue. However, pre-existing pathological abnormalities, such as hepatic steatosis (HS), inhibits the endogenous regenerative process, becoming an obstacle for liver surgery and living donor transplantation. Recent evidence indicates that multipotent mesenchymal stromal cells (MSCs) administration can improve hepatic function and increase the potential for liver regeneration in patients with liver damage. Since HS is the most common form of chronic hepatic illness, in this study we evaluated the role of MSCs in liver regeneration in an animal model of severe HS with impaired liver regeneration. C57BL/6 mice were fed with a regular diet (normal mice) or with a high-fat diet (obese mice) to induce HS. After 30 weeks of diet exposure, 70% hepatectomy (Hpx) was performed and normal and obese mice were divided into two groups that received 5 × 10 5 MSCs or vehicle via the tail vein immediately after Hpx. We confirmed a significant inhibition of hepatic regeneration when liver steatosis was present, while the hepatic regenerative response was promoted by infusion of MSCs. Specifically, MSC administration improved the hepatocyte proliferative response, PCNA-labeling index, DNA synthesis, liver function, and also reduced the number of apoptotic hepatocytes. These effects may be associated to the paracrine secretion of trophic factors by MSCs and the hepatic upregulation of key cytokines and growth factors relevant for cell proliferation, which ultimately improves the survival rate of the mice. MSCs represent a promising therapeutic strategy to improve liver regeneration in patients with HS as well as for increasing the number of donor organs available for transplantation.

The Effect of High School Shootings on Schools and Student Performance

Science.gov (United States)

Beland, Louis-Philippe; Kim, Dongwoo

2016-01-01

We analyze how fatal shootings in high schools affect schools and students using data from shooting databases, school report cards, and the Common Core of Data. We examine schools' test scores, enrollment, number of teachers, graduation, attendance, and suspension rates at schools that experienced a shooting, employing a difference-in-differences…

Hydrolyzable tannins of tamaricaceous plants. IV: Micropropagation and ellagitannin production in shoot cultures of Tamarix tetrandra.

Science.gov (United States)

Orabi, Mohamed A A; Taniguchi, Shoko; Terabayashi, Susumu; Hatano, Tsutomu

2011-11-01

Shoot cultures of Tamarix tetrandra on Linsmaier-Skoog (LS) agar medium with 30 g l(-1) sucrose, 2.13 mg l(-1) indoleacetic acid and 2.25 mg l(-1) benzyl adenine produced ellagitannins found in intact plants of the Tamaricaceae. This was demonstrated by the isolation of 14 monomeric-tetrameric ellagitannins from the aq. Me2CO extract of the cultured tissues. This is the first report on the production of ellagitannin tetramers by plant tissue culture. The effects of light and certain medium constituents on tissue growth and ellagitannin production were examined. The contents of representative tannins of different types [i.e., tellimagrandin II (monomer), hirtellin A (linear GOG-type dimer), hirtellin B (hellinoyl-type dimer), hirtellin C (macrocyclic-type dimer), and hirtellin T1 (linear GOG-type trimer)] in the resultant tissues in response to these factors were estimated by HPLC, and the optimal condition for production of these tannins were established. Shoots cultured on LS hormone-free medium promoted root development, and regenerated plants could adapt to ordinary soil and climate. Acclimatized and intact T. tetrandra plants that were collected in November and May, respectively, demonstrated seasonal differences in individual ellagitannin contents. HPLC comparison of individual ellagitannin contents in different plant materials (i.e., leaves, stems, and roots) of intact T. tetrandra plants is also reported. The results are discussed with respect to cellular deposition and biosynthetic relationship of tannins. Copyright © 2011 Elsevier Ltd. All rights reserved.

Regeneration

Science.gov (United States)

George A. Schier; Wayne D. Shepperd; John R. Jones

1985-01-01

There are basically two approaches to regenerating aspen stands-sexual reproduction using seed, or vegetative regeneration by root suckering. In the West, root suckering is the most practical method. The advantage of having an existing, well established root system capable of producing numerous root suckers easily outweighs natural or artificial reforestation in the...

Loss of PACS-2 delays regeneration in DSS-induced colitis but does not affect the ApcMin model of colorectal cancer

DEFF Research Database (Denmark)

Dombernowsky, Sarah L.; Schwarz, Jeanette; Samsøe-Petersen, Jacob

2017-01-01

in these processes. Specifically, we analyzed the role of Pacs2- deficiency in a DSS-induced colitis model as well as in the genetic ApcMin colon cancer model. We now report that loss of PACS-2 delays tissue regeneration after colonic injury with little effect on key inflammatory parameters. We did however...... not observe any apparent effects on tumor formation driven by excessive proliferative signaling downstream from APC-deficiency. Our findings reveal that the role of PACS- 2 in regulating ADAM17-mediated shedding is not an obligate requirement for the epithelium to respond to the strong inflammatory...

Proliferative myositis: a case report

International Nuclear Information System (INIS)

Kim, Young Sook; Jeon, Ho Jong

2002-01-01

We report a case of proliferative myositis arising in the pectoralis major muscle of a 59-year-old man who presented with palpable mass. The initial clinical impression was a malignant tumor. Ultrasonography revealed the lesion as a spindle-shaped hypoechoic mass, and MR imaging of the left pectoralis major muscle showed hypointensity at T1-weighted imaging, hyperintensity at T2-weighted imaging, and strong enhancement at contrast-enhanced T1-weighted imaging

Proliferative myositis: a case report

Energy Technology Data Exchange (ETDEWEB)

Kim, Young Sook; Jeon, Ho Jong [Chosun University College of Medicine, Gwangju (Korea, Republic of)

2002-09-01

We report a case of proliferative myositis arising in the pectoralis major muscle of a 59-year-old man who presented with palpable mass. The initial clinical impression was a malignant tumor. Ultrasonography revealed the lesion as a spindle-shaped hypoechoic mass, and MR imaging of the left pectoralis major muscle showed hypointensity at T1-weighted imaging, hyperintensity at T2-weighted imaging, and strong enhancement at contrast-enhanced T1-weighted imaging.

In vitro shoot multiplication of Ziziphus spina-christi by shoot tip culture

African Journals Online (AJOL)

USER

2010-02-08

Feb 8, 2010 ... Key words: Clonal propagation, cidir, shoot tip culture, Ziziphus spina-christi (L.) Desf. INTRODUCTION. Ziziphus spina-christi (L.) Desf., locally known as cidir, is a multipurpose tree species belonging to the botanical family Rhamnaceae. It is an important cultivated tree and one of the few truly native tree ...

The high frequency of variegated forms after in vitro mutagenesis in Saintpaulia ionantha Wendl.

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Marek Gaj

2014-01-01

Full Text Available The leaf-explants of Saintpaulia ionantha Wendl. var.'miniature' were treated by different doses of MNH and cultured on shoot regeneration medium. A strong toxic effect of some MNH doses on explant survival during the first two subcultures was noticed. The explants surviving treatment regenerated shoots with the efficiency comparable to the control. The high number of shoots regenerated from mutagenised leaves showed chlorophyll chimerism (so-called variegated forms. The use of 5 mM MNH for 1.5 or 2 h was found very effective, as 100% of survived explants regenerated variegated shoots. Besides hundreds of variegated forms also leaf-shape and flower-colour variants were observed in MNH-treated culture. Somaclonal variation was not observed in the control culture. The results indicate the great efficiency of in vitro applied MNH for in-duction of morphological variants of Saintpaulia, and especially variegated forms.

Ship and Shoot

Science.gov (United States)

Woods, Ron

2012-01-01

Ron Woods shared incredibly valuable insights gained during his 28 years at the Kennedy Space Center (KSC) packaging Flight Crew Equipment for shuttle and ISS missions. In particular, Woods shared anecdotes and photos from various processing events. The moral of these stories and the main focus of this discussion were the additional processing efforts and effects related to a "ship-and-shoot" philosophy toward flight hardware.

In vitro propagation, encapsulation, and genetic fidelity analysis of Terminalia arjuna: a cardioprotective medicinal tree.

Science.gov (United States)

Gupta, Amit K; Harish; Rai, Manoj K; Phulwaria, Mahendra; Agarwal, Tanvi; Shekhawat, N S

2014-07-01

The present study described an improved and reproducible in vitro regeneration system for Terminalia arjuna using nodal segment explants obtained from a mature plant. Shoot tips excised from in vitro proliferated shoots were encapsulated in 3 % sodium alginate and 100 mM CaCl2[Symbol: see text]2H2O for the development of synthetic seeds which may be applicable in short-term storage and germplasm exchange of elite genotype. Shoot multiplication was significantly influenced by a number of factors, namely types and concentrations of plant growth regulators, medium composition, repeated transfer of mother explants, subculturing of in vitro regenerated shoot clumps, agar concentrations, and temperature. Maximum numbers of shoots (16.50 ± 3.67) were observed on modified Murashige and Skoog (MMS) medium containing 0.5 mg l(-1) of benzylaminopurine (BAP) and 0.1 mg l(-1) of naphthalene acetic acid (NAA). To shortening the regeneration pathway, rooting of micropropagated shoots under in vitro condition was excluded and an experiment on ex vitro rooting was conducted and it was observed that the highest percentage of shoots rooted ex vitro when treated with indole-3-butyric acid (IBA, 250 mg l(-1)) + 2-naphthoxy acetic acid (NOA, 250 mg l(-1)) for 5 min. The well-developed ex vitro rooted shoots were acclimatized successfully in soilrite under greenhouse conditions with 80 % survival of plants. Randomly amplified polymorphic DNA (RAPD) analysis confirmed that all the regenerated plants were genetically identical to the mother plant, suggesting the absence of detectable genetic variation in the regenerated plantlets. To the best of our knowledge, this is the first report on synthetic seed production as well as ex vitro rooting and genetic fidelity assessment of micropropagated shoots of T. arjuna.

Disentangling the intertwined genetic bases of root and shoot growth in Arabidopsis.

Directory of Open Access Journals (Sweden)

Marie Bouteillé

Full Text Available Root growth and architecture are major components of plant nutrient and water use efficiencies and these traits are the matter of extensive genetic analysis in several crop species. Because root growth relies on exported assimilate from the shoot, and changes in assimilate supply are known to alter root architecture, we hypothesized (i that the genetic bases of root growth could be intertwined with the genetic bases of shoot growth and (ii that the link could be either positive, with alleles favouring shoot growth also favouring root growth, or negative, because of competition for assimilates. We tested these hypotheses using a quantitative genetics approach in the model species Arabidopsis thaliana and the Bay-0 × Shahdara recombinant inbred lines population. In accordance with our hypothesis, root and shoot growth traits were strongly correlated and most root growth quantitative trait loci (QTLs colocalized with shoot growth QTLs with positive alleles originating from either the same or the opposite parent. In order to identify regions that could be responsible for root growth independently of the shoot, we generated new variables either based on root to shoot ratios, residuals of root to shoot correlations or coordinates of principal component analysis. These variables showed high heritability allowing genetic analysis. They essentially all yielded similar results pointing towards two regions involved in the root--shoot balance. Using Heterogeneous Inbred Families (a kind of near-isogenic lines, we validated part of the QTLs present in these two regions for different traits. Our study thus highlights the difficulty of disentangling intertwined genetic bases of root and shoot growth and shows that this difficulty can be overcome by using simple statistical tools.

Differential TOR activation and cell proliferation in Arabidopsis root and shoot apexes.

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Li, Xiaojuan; Cai, Wenguo; Liu, Yanlin; Li, Hui; Fu, Liwen; Liu, Zengyu; Xu, Lin; Liu, Hongtao; Xu, Tongda; Xiong, Yan

2017-03-07

The developmental plasticity of plants relies on the remarkable ability of the meristems to integrate nutrient and energy availability with environmental signals. Meristems in root and shoot apexes share highly similar molecular players but are spatially separated by soil. Whether and how these two meristematic tissues have differential activation requirements for local nutrient, hormone, and environmental cues (e.g., light) remain enigmatic in photosynthetic plants. Here, we report that the activation of root and shoot apexes relies on distinct glucose and light signals. Glucose energy signaling is sufficient to activate target of rapamycin (TOR) kinase in root apexes. In contrast, both the glucose and light signals are required for TOR activation in shoot apexes. Strikingly, exogenously applied auxin is able to replace light to activate TOR in shoot apexes and promote true leaf development. A relatively low concentration of auxin in the shoot and high concentration of auxin in the root might be responsible for this distinctive light requirement in root and shoot apexes, because light is required to promote auxin biosynthesis in the shoot. Furthermore, we reveal that the small GTPase Rho-related protein 2 (ROP2) transduces light-auxin signal to activate TOR by direct interaction, which, in turn, promotes transcription factors E2Fa,b for activating cell cycle genes in shoot apexes. Consistently, constitutively activated ROP2 plants stimulate TOR in the shoot apex and cause true leaf development even without light. Together, our findings establish a pivotal hub role of TOR signaling in integrating different environmental signals to regulate distinct developmental transition and growth in the shoot and root.

Shoot regeneration and plantlet formation by cascade huckleberry, mountain huckleberry, and in oval-leaf bilberry on a zeatin-containing nutrient medium

Science.gov (United States)

A plant regeneration protocol was developed for Cascade huckleberry (Vaccinium deliciosum Piper), mountain huckleberry (V. membranaceum Douglas ex Hooker) and for oval-leaf bilberry (V. ovalifolium Smith) clones. The effects of zeatin concentrations (0, 4.6, 9.1 and 13.7 µM) and explant type (leaf a...

Desulfurization sorbent regeneration

Science.gov (United States)

Jalan, V.M.; Frost, D.G.

1982-07-07

A spent solid sorbent resulting from the removal of hydrogen sulfide from a fuel gas flow is regenerated with a steam-air mixture. The mixture of steam and air may also include additional nitrogen or carbon dioxide. The gas mixture contacts the spent sorbent containing metal sulfide at a temperature above 500/sup 0/C to regenerate the sulfide to metal oxide or carbonate. Various metal species including the period four transition metals and the lanthanides are suitable sorbents that may be regenerated by this method. In addition, the introduction of carbon dioxide gas permits carbonates such as those of strontium, barium and calcium to be regenerated. The steam permits regeneration of spent sorbent without formation of metal sulfate. Moreover, the regeneration will proceed with low oxygen concentrations and will occur without the increase in temperature to minimize the risk of sintering and densification of the sorbent. This method may be used for high-temperature fuel cells.

Proliferative activity as a prognostic factor of a human tumor radiation reactions

International Nuclear Information System (INIS)

Karakulov, R.K.; Pelevina, I.I.

1986-01-01

The following questions are considered: 1) whether cell proliferation initial parameters can serve for predicting the tumor radial reaction; 2) whether proliferative activity change can be a criterion for estimating the treatment efficiency; 3) acquisition of data on biological peculiarities of different types of tumors. Connection between proliferative activity drop and clinical reaction under tumor radiotherapy is ascertained

Evaluation of VEGF gene polymorphisms and proliferative diabetic retinopathy in Mexican population.

Science.gov (United States)

Gonzalez-Salinas, Roberto; Garcia-Gutierrez, Maria C; Garcia-Aguirre, Gerardo; Morales-Canton, Virgilio; Velez-Montoya, Raul; Soberon-Ventura, Vidal R; Gonzalez, Victoria; Lechuga, Rodrigo; Garcia-Solis, Pablo; Garcia-Gutierrez, David G; Garcia-Solis, Marco Vinicio; Saenz de Viteri, Manuel; Solis-S, Juan C

2017-01-01

To assess if the included vascular endothelial growth factor (VEGF) polymorphisms rs3025035, rs3025021 and rs2010963 are associated to proliferative retinopathy in a Mexican population with type 2 diabetes mellitus (T2DM). A case-control study was conducted in adult individuals with T2DM associated to proliferative retinopathy or non-proliferative retinopathy from Oct. 2014 to Jun. 2015 from the Retina Department of the Asociation to Prevent Blindness in Mexico. The selected patients were adults with a diagnosis of T2DM ≥5y. All subjects had a comprehensive ocular examination and the classification of the retinopathy severity was made considering the Early Treatment Diabetic Retinopathy Study (ETDRS) standardization protocols. Genomic DNA was extracted from whole fresh blood. All samples were genotyped by qPCR for selected VEGF polymorphisms. Hardy-Weinberg equilibrium was calculated by comparing Chi-square values between the expected and the observed values for genotype counts. In total 142 individuals were enrolled, 71 individuals with T2DM and associated proliferative retinopathy and 71 individuals with non-proliferative retinopathy. One-sided Fisher's exact test was performed for rs3025021 [OR (95% CI)=0.44(0.08-2.2); P =0.25] and rs2010963 [OR (95% CI)=0.63(0.25-1.6); P =0.23]. The minor allelic frequencies obtained were 26% for rs3025021, 10% for rs3025035 and 61% for rs2010963. The pairwise linkage disequilibrium between the three SNP was assessed, and was as follows: rs3025021 vs rs3025035: D'=1.0, r 2 =0.1043, P ≤0.0001; rs3025021 vs rs2010963: D'=0.442, r 2 =0.0446, P =0.149; rs3025035 vs rs2010963: D'=0.505, r 2 =0.0214, P =0.142. This is the first analysis involving VEGF polymorphisms and proliferative diabetic retinopathy in a Mexican population. A major finding of the present study is that none of the polymorphisms studied was significantly associated with proliferative retinopathy. Based on these results, we can infer that different populations

Arabidopsis CDS blastp result: AK101133 [KOME

Lifescience Database Archive (English)

Full Text Available F|00847 AP2 domain; identical to cDNA enhancer of shoot regeneration ESR1 GI:18028939, enhancer of shoot regeneration ESR1 [Arabidopsis thaliana] GI:18028940 1e-10 ... ...eneration (ESR1) similar to gb|D38124 EREBP-3 from Nicotiana tabacum and contains P...AK101133 J033026F23 At1g12980.1 AP2 domain-containing transcription factor, putative / enhancer of shoot reg

3,3'-Diindolylmethane, a cruciferous vegetable derived synthetic anti-proliferative compound in thyroid disease

International Nuclear Information System (INIS)

Tadi, Kiranmayi; Chang Yushan; Ashok, Badithe T.; Chen, Yuangen; Moscatello, Augustine; Schaefer, Steven D.; Schantz, Stimsom P.; Policastro, Anthony J.; Geliebter, Jan; Tiwari, Raj K.

2005-01-01

Considerable epidemiological evidence exists to link thyroid disease with differing patterns of dietary consumption, in particular, cruciferous vegetables. We have been studying the anti-thyroid cancer (TCa) activity of indole-3-carbinol (I3C) found in cruciferous vegetables and its acid catalyzed dimer, 3,3'-diindolylmethane (DIM). There are no studies as yet to elucidate the effect of these compounds on the altered proliferative patterns in goiter or thyroid neoplasia. In this study, we tested the anti-proliferative effects of I3C and DIM on four different thyroid cancer cell lines representative of papillary (B-CPAP and 8505-C) and follicular carcinoma of the thyroid (CGTH-W-1 and ML-1), and primary human goiter cells. Cell survival and IC 50 values for I3C and DIM were calculated by the XTT assay and cell cycle distribution analysis was done by flow cytometry. DIM was found to be a better anti-proliferative agent than I3C in both papillary and follicular TCa resulting in a greater cytotoxic effect at a concentration over three fold lower than predicted by the molar ratio of DIM and I3C. The anti-proliferative activity of DIM in follicular TCa was mediated by a G1 arrest followed by induction of apoptosis. DIM also inhibited the growth of primary goiter cells by 70% compared to untreated controls. Contrary to traditional belief that cruciferous vegetables are 'goitrogenic,' DIM has anti-proliferative effects in glandular thyroid proliferative disease. Our preclinical studies provide a strong rationale for the clinical exploration of DIM as an adjuvant to surgery in thyroid proliferative disease

Structuring agreements for seismic group shoots

International Nuclear Information System (INIS)

Keeping, C.E.

1999-01-01

Sigma Explorations Inc. sells licenses to use Sigma owned seismic data. The company participates with exploration and production companies in the joint acquisition of semi-private participation surveys. This paper discusses three major types of seismic group shoots and the essential elements of the agreements that govern or should govern them. They are: (1) exploration and production company joint ventures, (2) publicly offered spec shoots, and (3) semi-private participation surveys. The key issue with the exploration and production company joint ventures is that the companies are owners of the seismic data in proportion to their contribution towards the cost of the program. Their use of the data should be restricted to those situations permitted by the other owners. These are not often well documented, and there is much concern in the industry as a result. The key issue with publicly offered spec shoots is that the seismic company ultimately owns the data and the client exploration and production company is a licensee and must behave as such. In most such cases the rights and responsibilities are well documented in formal agreements that are signed in advance of the program's beginning date

Regeneration performance of CO2-rich solvents by using membrane vacuum regeneration technology: Relationships between absorbent structure and regeneration efficiency

International Nuclear Information System (INIS)

Yan, Shuiping; Fang, Mengxiang; Wang, Zhen; Luo, Zhongyang

2012-01-01

Highlights: ► MVR may be viable to successfully use less valuable heat to replace high grade steam. ► Increasing OH and amine groups will increase the regeneration efficiency. ► Absorbents with a four carbon chain length will be more attractive to MVR. ► Amino acid salts will be more appropriate for MVR. ► HRM conducted at ambient pressure and low temperature is inferior to MVR. -- Abstract: In order to give a better understanding for the selection of suitable absorbents for the novel membrane vacuum regeneration technology (MVR) which has the potential to reduce CO 2 energy requirement by utilizing the waste heat or low-grade energy, an experimental study to determine the relationships between chemical structure and vacuum regeneration behavior of CO 2 absorbents at 70 °C and 10 kPa was performed. Eleven typical absorbents with different functional groups in their chemical structures were investigated in terms of vacuum regeneration efficiencies. Results showed that the regeneration efficiency decreased with an increase of number of activated hydrogen atom in amine group and decreased with the number of hydroxyl group. Especially, more attention should be paid to these alkanolamines with one hydrogen atom in amine group and two or more hydroxyl groups in the structures due to their better comprehensive performance in regeneration, absorbent loss and CO 2 absorption aspects. Increasing the carbon chain length and amine groups in the absorbent structure contributed to the improvement of regeneration performance and reduction of absorbent volatile loss. These absorbents with a four carbon chain length bonded at amine group might be more attractive to MVR. Furthermore, polyamines were superior to monoamines in terms of higher regeneration efficiencies and lower absorbent losses. Additionally, the individual effects of the potassium carboxylate group and hydroxymethylene group were also compared in this study. Results showed that amino acid salts were more

In vitro propagation of chungah (caralluma tuberculata n.e. brown)

International Nuclear Information System (INIS)

Rehman, R.

2014-01-01

In vitro propagation of Caralluma tuberculata (Chungah) was developed from shoot tip and meristem explants. C. tuberculata is an imperative medicinal plant comprising antidiabetic and anticancer properties. The explants were inoculated on Murashige and Skoog (MS) medium containing different plant growth regulators. Presence of BA or Kin alone in the MS medium did not favor regeneration of shoot from both explants. However, addition of 2,4-dichlorophenoxy acetic acid (2,4-D), gibberellic acid (GA3) and thidiazuron (TDZ) along with 6-benzyl amino purine (BA) or kinetin (Kin) in the medium exhibited significant percentage response, number of shoots per explant and shoot length. Maximum shooting response (53.3+-5.77% from meristem and shoot tip explants each) with highest number of shoots per explant (5.33+-2.08 and 5.6+-2.52 from meristem and shoot tip explants, respectively) were observed at 13.32 micro mol BA along with 2.26 micro mol 2,4-D, 2.89 micro mol GA3 and 9.08*10-3 micro mol TDZ. Replacing BA with kin showed less shoot regeneration response and number of shoots per explant, however, shoots length markedly increased in the presence of Kin. The regenerated plants were successfully rooted and acclimatized in ex vitro condition. The protocol described here can be used for fast multiplication of this endangered herb and genetic transformation. (author)

Vitreous vascular endothelial growth factor concentrations in proliferative diabetic retinopathy versus proliferative vitreoretinopathy.

Science.gov (United States)

Citirik, Mehmet; Kabatas, Emrah Utku; Batman, Cosar; Akin, Kadir Okhan; Kabatas, Naciye

2012-01-01

To assess vitreous vascular endothelial growth factor (VEGF) concentrations in proliferative diabetic retinopathy (PDR) in comparison to proliferative vitreoretinopathy (PVR). Vitreous samples were collected from 69 eyes of 69 patients with traumatic lens dislocation (n = 10), grade B PVR with rhegmatogenous retinal detachment (n = 13), grade C PVR with rhegmatogenous retinal detachment (n = 14), PDR with vitreous hemorrhage (n = 18), and PDR with vitreous hemorrhage and tractional retinal detachment (n = 14). Vitreous fluid samples were obtained at vitrectomy, and the levels of VEGF were measured by enzyme-linked immunosorbent assay. The mean vitreous level of VEGF was 15.14 ± 5.22 pg/ml in eyes with grade B PVR, 99.15 ± 38.58 pg/ml in eyes with grade C PVR, 4,534.01 ± 1,193.28 pg/ml in eyes with vitreous hemorrhage secondary to PDR, 5,157.29 ± 969.44 pg/ml in eyes with vitreous hemorrhage and tractional retinal detachment secondary to PDR, and 16.19 ± 5.76 pg/ml in eyes of the control group with traumatic lens dislocation. Vitreous VEGF concentrations were significantly higher in the patients with grade C PVR, PDR with vitreous hemorrhage and PDR with vitreous hemorrhage and tractional retinal detachment in comparison to the control patients (p < 0.05). A significant alteration was not observed in patients with grade B PVR (p = 0.55). Vitreous VEGF concentrations are increased in PDR and grade C PVR. The high VEGF concentrations could suggest a possible effect of VEGF on advanced PVR. Copyright © 2011 S. Karger AG, Basel.

Water relations, gas exchange and growth of dominant and suppressed shoots of Arbutus unedo L.

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Castell, C; Terradas, J

1995-06-01

Basal shoots produced by Arbutus unedo L. after cutting at ground level vary in size and growth rate, and are classified accordingly as dominant or suppressed. The suppressed shoots eventually cease growth and die. In this study, we investigated the role of light and water in the competition among shoots of A. unedo. Dominant and suppressed shoots of A. unedo showed similar leaf water potentials and tissue water relations over the year, suggesting that water status is not responsible for the lack of flushing in suppressed shoots. Although suppressed shoots did not flush under low light, they showed many characteristics of shade-tolerant plants. Leaves of suppressed shoots had lower leaf conductance and light-saturated photosynthetic rate, and higher specific leaf area than leaves of dominant shoots. We conclude that light was the main resource determining competition among shoots and the death of suppressed shoots.

In Vitro Propagation of Sambong (Blumea balsamifera Linn.).

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Soriano, Thelma L; Cangao, Evangelina C

2016-01-01

Terminal shoot tips of sambong (Blumea balsamifera Linn.) are cultured to initiate and regenerate shoots on Murashige and Skoog (MS) medium containing 1.0 mg/L benzyl adenine (BA). After 1 month, shoots, usually 4.5 cm long are separated and subcultured for multiplication. Regenerated shoots, about 6 cm long are rooted on MS medium supplemented with 1.0 mg/L naphthalene acetic acid (NAA). Exposure of shoots to high humidity for the first 2 weeks and equal proportion (1:1:1) of sterile sand, compost, and coir dust as potting mix favors the development of whole sambong plants. Young shoots from in vitro-derived sambong plants could also be used for propagation.

Shear stress upregulates regeneration-related immediate early genes in liver progenitors in 3D ECM-like microenvironments.

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Nishii, Kenichiro; Brodin, Erik; Renshaw, Taylor; Weesner, Rachael; Moran, Emma; Soker, Shay; Sparks, Jessica L

2018-05-01

The role of fluid stresses in activating the hepatic stem/progenitor cell regenerative response is not well understood. This study hypothesized that immediate early genes (IEGs) with known links to liver regeneration will be upregulated in liver progenitor cells (LPCs) exposed to in vitro shear stresses on the order of those produced from elevated interstitial flow after partial hepatectomy. The objectives were: (1) to develop a shear flow chamber for application of fluid stress to LPCs in 3D culture; and (2) to determine the effects of fluid stress on IEG expression in LPCs. Two hours of shear stress exposure at ∼4 dyn/cm 2 was applied to LPCs embedded individually or as 3D spheroids within a hyaluronic acid/collagen I hydrogel. Results were compared against static controls. Quantitative reverse transcriptase polymerase chain reaction was used to evaluate the effect of experimental treatments on gene expression. Twenty-nine genes were analyzed, including IEGs and other genes linked to liver regeneration. Four IEGs (CFOS, IP10, MKP1, ALB) and three other regeneration-related genes (WNT, VEGF, EpCAM) were significantly upregulated in LPCs in response to fluid mechanical stress. LPCs maintained an early to intermediate stage of differentiation in spheroid culture in the absence of the hydrogel, and addition of the gel initiated cholangiocyte differentiation programs which were abrogated by the onset of flow. Collectively the flow-upregulated genes fit the pattern of an LPC-mediated proliferative/regenerative response. These results suggest that fluid stresses are potentially important regulators of the LPC-mediated regeneration response in liver. © 2017 Wiley Periodicals, Inc.

Hospital-based shootings in the United States: 2000 to 2011.

Science.gov (United States)

Kelen, Gabor D; Catlett, Christina L; Kubit, Joshua G; Hsieh, Yu-Hsiang

2012-12-01

Workplace violence in health care settings is a frequent occurrence. Emergency departments (EDs) are considered particularly vulnerable. Gunfire in hospitals is of particular concern; however, information about such workplace violence is limited. Therefore, we characterize US hospital-based shootings from 2000 to 2011. Using LexisNexis, Google, Netscape, PubMed, and ScienceDirect, we searched reports for acute care hospital shooting events in the United States for 2000 through 2011. All hospital-based shootings with at least 1 injured victim were analyzed. Of 9,360 search "hits," 154 hospital-related shootings were identified, 91 (59%) inside the hospital and 63 (41%) outside on hospital grounds. Shootings occurred in 40 states, with 235 injured or dead victims. Perpetrators were overwhelmingly men (91%) but represented all adult age groups. The ED environs were the most common site (29%), followed by the parking lot (23%) and patient rooms (19%). Most events involved a determined shooter with a strong motive as defined by grudge (27%), suicide (21%), "euthanizing" an ill relative (14%), and prisoner escape (11%). Ambient society violence (9%) and mentally unstable patients (4%) were comparatively infrequent. The most common victim was the perpetrator (45%). Hospital employees composed 20% of victims; physician (3%) and nurse (5%) victims were relatively infrequent. Event characteristics that distinguished the ED from other sites included younger perpetrator, more likely in custody, and unlikely to have a personal relationship with the victim (ill relative, grudge, coworker). In 23% of shootings within the ED, the weapon was a security officer's gun taken by the perpetrator. Case fatality inside the hospital was much lower in the ED setting (19%) than other sites (73%). Although it is likely that not every hospital-based shooting was identified, such events are relatively rare compared with other forms of workplace violence. The unpredictable nature of this type of

Study on Effect of Type of Explant and Hormone on Callus Induction and Regeneration in Saffron (Crocus sativus L.

Directory of Open Access Journals (Sweden)

Mohsen Sajjadi

2015-10-01

Full Text Available Saffron (Crocus sativus L. is one of the medicinal plants that contain active components and medicinal materials. Tissue culture of saffron can improve the quality and quantity of the saffron product, increase its export and the farmers’ income. In this study, 36 different types of hormone combinations in the dark and 9 different treatments of hormone combinations in cold (4°C, using different saffron explants (bulb, leaf, scales around leaf and distal parts of the leaf were studied in tissue culture. To investigate the growth of corms, the callus formation and the regeneration rate, three replications for each treatment were used and the length of shoot (cm, the callus formation percentage and the regeneration percentage were measured and statistical analysis was performed. Among the types of explants, only explants from bulbs produced the callus on MS medium containing 2 mg.l-1 BAP and 1 mg.l-1 IBA in both the dark and cold conditions. The highest percentage of regeneration was obtained in MS medium with hormonal composition of 0.3 mg.l-1 TDZ, 1 mg.l-1 BAP, 2 mg.l-1 IBA and 0.01 mg.l-1 GA3 in the cold conditions.

Model Persamaan Massa Karbon Akar Pohon dan Root-Shoot Ratio Massa Karbon (Equation Models of Tree Root Carbon Mass and Root-Shoot Carbon Mass Ratio

Directory of Open Access Journals (Sweden)

Elias .

2011-03-01

Full Text Available The case study was conducted in the area of Acacia mangium plantation at BKPH Parung Panjang, KPH Bogor. The objective of the study was to formulate equation models of tree root carbon mass and root to shoot carbon mass ratio of the plantation. It was found that carbon content in the parts of tree biomass (stems, branches, twigs, leaves, and roots was different, in which the highest and the lowest carbon content was in the main stem of the tree and in the leaves, respectively. The main stem and leaves of tree accounted for 70% of tree biomass. The root-shoot ratio of root biomass to tree biomass above the ground and the root-shoot ratio of root biomass to main stem biomass was 0.1443 and 0.25771, respectively, in which 75% of tree carbon mass was in the main stem and roots of tree. It was also found that the root-shoot ratio of root carbon mass to tree carbon mass above the ground and the root-shoot ratio of root carbon mass to tree main stem carbon mass was 0.1442 and 0.2034, respectively. All allometric equation models of tree root carbon mass of A. mangium have a high goodness-of-fit as indicated by its high adjusted R2.Keywords: Acacia mangium, allometric, root-shoot ratio, biomass, carbon mass

Correlation of arbuscular mycorrhizal colonization with plant growth, nodulation, and shoot npk in legumes

International Nuclear Information System (INIS)

Javaid, A.; Anjum, T.; Shah, M.H.M.

2007-01-01

Correlation of arbuscular mycorrhizal colonization with different root and shoot growth, nodulation and shoot NPK parameters was studied in three legumes viz. Trifolium alexandrianum, Medicago polymorpha and Melilotus parviflora. The three test legume species showed different patterns of root and shoot growth, nodulation, mycorrhizal colonization and shoot N, P and K content. Different mycorrhizal structures viz. mycelium, arbuscules and vesicles showed different patters of correlation with different studied parameters. Mycelial infection showed an insignificantly positive correlation with root and shoot dry biomass and total root length. Maximum root length was however, negatively associated with mycelial infection. Both arbuscular and vesicular infections were negatively correlated with shoot dry biomass and different parameters of root growth. The association between arbuscular infection and maximum root length was significant. All the three mycorrhizal structures showed a positive correlation with number and biomass of nodules. The association between arbuscular infection and nodule number was significant. Mycelial infection was positively correlated with percentage and total shoot N and P. Similarly percentage N was also positively correlated with arbuscular and vesicular infections. By contrast, total shoot N showed a negative association with arbuscular as well as vesicular infections. Similarly both percentage and total shoot P were negatively correlated with arbuscular and vesicular infections. All the associations between mycorrhizal parameters and shoot K were negative except between vesicular infection and shoot %K. (author)

Mass shootings: a meta-analysis of the dose-response relationship.

Science.gov (United States)

Wilson, Laura C

2014-12-01

A meta-analysis was conducted to examine the dose-response theory as it relates to posttraumatic stress symptoms (PTSSs) following mass shootings. It was hypothesized that greater exposure to a mass shooting would be associated with greater PTSSs. Trauma exposure in the current study was broadly defined as the extent to which a person experienced or learned about a mass shooting. The meta-analysis identified 11 qualifying studies that included 13 independent effect sizes from a total of 8,047 participants. The overall weighted mean effect size, based on a random effects model, was r = .19, p shooting on the relationship between exposure and PTSSs. Because so few studies satisfied the inclusion criteria, the present study also documents that this area of the literature is underresearched. Copyright © 2014 International Society for Traumatic Stress Studies.

Youth Responses to School Shootings: A Reviw

DEFF Research Database (Denmark)

Travers, Áine

2018-01-01

PURPOSE OF REVIEW:This paper aims to synthesize research relating to youth responses to school shootings between 2014 and 2017. The main questions it addresses are how such events impact young people psychologically, and what risk or protective factors may contribute to different trajectories...... of recovery? RECENT FINDINGS:Recent research suggests that most young people exposed to school shootings demonstrate resilience, exhibiting no long-term dysfunction. However, a minority will experience severe and chronic symptoms. The likelihood of experiencing clinically significant reactions is influenced...

Morphogenetic Potential of Tomato (Lycopersicon esculentum cv. ‘Arka Ahuti’ to Plant Growth Regulators

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Kanakapura K. NAMITHA

2013-05-01

Full Text Available A highly reproducible in vitro regeneration method for tomato (Lycopersicon esculentum Mill. cultivar ‘Arka Ahuti’ was established by using hypocotyl, leaf and cotyledon explants from in vitro raised seedlings on Murashige and Skoog medium supplemented with different concentrations and combinations of hormones 6-Benzylamino purine (2 to 4 mg/L and Indole-3-acetic acid (0.1 to 1 mg/L. The medium supplemented with 2 mg/L 6-benzylamino purine and 0.1 mg/L indole-3-acetic acid was found to be the best for inducing direct shoot regeneration and multiple shoots per explant from hypocotyl explants. Callus induction was observed in all the explants and regeneration of shoots was also promoted by all these combinations. Shoots were transferred to the elongation medium which also induced 100% rooting. After hardening, plants were transferred to soil. Thus, a tissue culture base line was established for ‘Arka Ahuti’ cultivar of tomato for obtaining direct regeneration using hypocotyl, leaf and cotyledon as explants.

Proliferative diabetic retinopathy is associated with microalbuminuria in patients with type 2 diabetes

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M.C. Boelter

2006-08-01

Full Text Available Diabetic retinopathy is one of the leading causes of blindness in working-age individuals. Diabetic patients with proteinuria or those on dialysis usually present severe forms of diabetic retinopathy, but the association of diabetic retinopathy with early stages of diabetic nephropathy has not been entirely established. A cross-sectional study was conducted on 1214 type 2 diabetic patients to determine whether microalbuminuria is associated with proliferative diabetic retinopathy in these patients. Patients were evaluated by direct and indirect ophthalmoscopy and grouped according to the presence or absence of proliferative diabetic retinopathy. The agreement of diabetic retinopathy classification performed by ophthalmoscopy and by stereoscopic color fundus photographs was 95.1% (kappa = 0.735; P < 0.001. Demographic information, smoking history, anthropometric and blood pressure measurements, glycemic and lipid profile, and urinary albumin were evaluated. On multiple regression analysis, diabetic nephropathy (OR = 5.18, 95% CI = 2.91-9.22, P < 0.001, insulin use (OR = 2.52, 95% CI = 1.47-4.31, P = 0.001 and diabetes duration (OR = 1.04, 95% CI = 1.01-1.07, P = 0.011 were positively associated with proliferative diabetic retinopathy, and body mass index (OR = 0.90, 95% CI = 0.86-0.96, P < 0.001 was negatively associated with it. When patients with macroalbuminuria and on dialysis were excluded, microalbuminuria (OR = 3.3, 95% CI = 1.56-6.98, P = 0.002 remained associated with proliferative diabetic retinopathy. Therefore, type 2 diabetic patients with proliferative diabetic retinopathy more often presented renal involvement, including urinary albumin excretion within the microalbuminuria range. Therefore, all patients with proliferative diabetic retinopathy should undergo an evaluation of renal function including urinary albumin measurements.

Complement components of nerve regeneration conditioned fluid influence the microenvironment of nerve regeneration

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Guang-shuai Li

2016-01-01

Full Text Available Nerve regeneration conditioned fluid is secreted by nerve stumps inside a nerve regeneration chamber. A better understanding of the proteinogram of nerve regeneration conditioned fluid can provide evidence for studying the role of the microenvironment in peripheral nerve regeneration. In this study, we used cylindrical silicone tubes as the nerve regeneration chamber model for the repair of injured rat sciatic nerve. Isobaric tags for relative and absolute quantitation proteomics technology and western blot analysis confirmed that there were more than 10 complement components (complement factor I, C1q-A, C1q-B, C2, C3, C4, C5, C7, C8ß and complement factor D in the nerve regeneration conditioned fluid and each varied at different time points. These findings suggest that all these complement components have a functional role in nerve regeneration.

Germination, seedling growth and relative water content of shoot in ...

African Journals Online (AJOL)

STORAGESEVER

2008-08-18

Aug 18, 2008 ... (mg), root : shoot length (R:S) ratio, and relative water content of shoot (RWC, %) were investigated in this study. The results ... seedlings may provide an advantage by allowing access ... Residual chlorine was eliminated by.

An Analysis of US School Shooting Data (1840-2015)

Science.gov (United States)

Paradice, David

2017-01-01

This paper describes the construction and descriptive analysis of a data set of United States school shooting events. Three hundred forty-three shooting events are included, spanning 175 years of United States educational history. All levels of US educational institution are included. Events are included when a firearm is discharged, regardless of…

Revisiting the Virginia Tech Shootings: An Ecological Systems Analysis

Science.gov (United States)

Hong, Jun Sung; Cho, Hyunkag; Lee, Alvin Shiulain

2010-01-01

School shooting cases since the late 1990s have prompted school officials and legislators to develop and implement programs and measures that would prevent violence in school. Despite the number of explanations by the media, politicians, organizations, and researchers about the etiology of school shootings, we are not united in our understanding…

Proliferative response of the murine esophageal epithelium to radiation: Modification by food consumption patterns

International Nuclear Information System (INIS)

Burholt, D.R.

1985-01-01

The single layer of proliferative epithelial cells of the murine esophagus undergoes a sequence of damage and recovery following cytotoxic insult. The modification of both damage and proliferative recovery by the alteration of animal eating patterns was investigated following thoracic field irradiation through the determination of /sup 3/H-TdR incorporation into the esophagus along with selective counting of labeled nuclei and mitotic figures. Initial radiation-induced damage, as determined by /sup 3/H-TdR incorporation suppression and mitotic delay, is under normal conditions dependent on the time of day of treatment. This circadian sensitivity may be altered by changing the eating pattern of the animal. The proliferative recovery following single dose irradiation is also dependent on food consumption patterns: fasting immediately following treatment and then refeeding 2 days later results in a more rapid proliferative recovery than observed under control eating conditions, while reduced food consumption during the period of proliferative hyperplasia reduces the extent of recovery. During multifraction radiation schedules both the damage produced by a subsequent dose and recovery capacity are influenced by the food consumption pattern between fractions

The effect of time constraints and running phases on combined event pistol shooting performance.

Science.gov (United States)

Dadswell, Clare; Payton, Carl; Holmes, Paul; Burden, Adrian

2016-01-01

The combined event is a crucial aspect of the modern pentathlon competition, but little is known about how shooting performance changes through the event. This study aimed to identify (i) how performance-related variables changed within each shooting series and (ii) how performance-related variables changed between each shooting series. Seventeen modern pentathletes completed combined event trials. An optoelectronic shooting system recorded score and pistol movement, and force platforms recorded centre of pressure movement 1 s prior to every shot. Heart rate and blood lactate values were recorded throughout the event. Whilst heart rate and blood lactate significantly increased between series (P  0.05). Thus, combined event shooting performance following each running phase appears similar to shooting performance following only 20 m of running. This finding has potential implications for the way in which modern pentathletes train for combined event shooting, and highlights the need for modern pentathletes to establish new methods with which to enhance shooting accuracy.

The differential proliferative ability of satellite cells in Lantang and Landrace pigs.

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Xiu-qi Wang

Full Text Available Here, for the first time, we evaluate the hypothesis that the proliferative abilities of satellite cells (SCs isolated from Lantang (indigenous Chinese pigs and Landrace pigs, which differ in muscle characteristics, are different. SCs were isolated from the longissimus dorsi muscle of neonatal Lantang and Landrace pigs. Proliferative ability was estimated by the count and proliferative activity of viable cells using a hemocytometer and MTT assay at different time points after seeding, respectively. Cell cycle information was detected by flow cytometry. Results showed that there was a greater (P<0.05 number of SCs in Lantang pigs compared with Landrace pigs after 72 h of culture. The percentage of cell population in S phase and G(2/M phases in Lantang pigs were higher (P<0.05, while in G(0/G(1 phase was lower (P<0.05 in comparison with the Landrace pigs. The mRNA abundances of MyoD, Myf5, myogenin and Pax7 in SCs from Lantang pigs were higher (P<0.05, while those of myostatin, Smad3 and genes in the mammalian target of rapamycin (mTOR pathway (with the exception of 4EBP1 were lower (P<0.05 than the Landrace pigs. Protein levels of MyoD, myogenin, myostatin, S6K, phosphorylated mTOR and phosphorylated eIF4E were consistent with the corresponding mRNA abundance. Collectively, these findings suggested that SCs in the two breeds present different proliferative abilities, and the proliferative potential of SCs in Lantang pigs is higher than in Landrace pigs.

Agrobacterium-mediated genetic transformation and regeneration of transgenic plants using leaf midribs as explants in ramie [Boehmeria nivea (L.) Gaud].

Science.gov (United States)

An, Xia; Wang, Bo; Liu, Lijun; Jiang, Hui; Chen, Jie; Ye, Shengtuo; Chen, Leiyu; Guo, Pingan; Huang, Xing; Peng, Dingxiang

2014-05-01

In this study, leaf midribs, the elite explants, were used for the first time to develop an efficient regeneration and transformation protocol for ramie [Boehmeria nivea (L.) Gaud.] via Agrobacterium-mediated genetic transformation. Sensitivity of leaf midribs regeneration to kanamycin was evaluated, which showed that 40 mg l(-1) was the optimal concentration needed to create the necessary selection pressure. Factors affecting the ramie transformation efficiency were evaluated, including leaf age, Agrobacterium concentration, length of infection time for the Agrobacterium solution, acetosyringone concentration in the co-cultivation medium, and the co-cultivation period. The midrib explants from 40-day-old in vitro shoots, an Agrobacterium concentration at OD600 of 0.6, 10-min immersion in the bacteria solution, an acetosyringone concentration of 50 mg l(-1) in the co-cultivation medium and a 3-day co-cultivation period produced the highest efficiencies of regeneration and transformation. In this study, the average transformation rate was 23.25%. Polymerase chain reactions using GUS and NPTII gene-specific primers, Southern blot and histochemical GUS staining analyses further confirmed that the transgene was integrated into the ramie genome and expressed in the transgenic ramie. The establishment of this system of Agrobacterium-mediated genetic transformation and regeneration of transgenic plants will be used not only to introduce genes of interest into the ramie genome for the purpose of trait improvement, but also as a common means of testing gene function by enhancing or inhibiting the expression of target genes.

The development of proliferative verrucous leukoplakia in oral lichen planus. A preliminary study

Science.gov (United States)

Llorente-Pendás, Santiago; González-Garcia, Manuel; García-Martín, José-Manuel

2016-01-01

Background Was to describe 14 cases of a proliferative verrucous leukoplakia as a clinical evolution of oral lichen planus. Material and Methods The clinical and histopathological characteristics of 14 cases of OLP that progress towards a plaque-like and verrucous form were indicated, with monitoring over a period of six to 24.3 years. Results The female/male ratio was 11/3, (78.6 and 21.4%). The mean age when the first biopsy was undertaken was 56.4 years old. None of the patients smoked during the study. As bilateral reticular was clinically diagnostic criterion, the second most frequent clinical form was the plaque form (n=10; 71.4%), followed by the atrophic (n=6; 42.8%), and erosive forms (n=4; 28.5%). Clinically it spread towards attached gingival mucosa and the hard palate. In the histopathologic study, there were a predominance of hyperkeratosis and verrucous epithelial hyperplasia. Three of the cases progressed to a squamous cell carcinoma, and one patient developed two verrucous carcinoma. Conclusions Further research is needed to demonstrate if proliferative multifocal oral lichen planus and proliferative multifocal oral leukoplakia are the same disorder but have different behaviour of malignancy for reasons of origin. Key words:Oral lichen planus, proliferative verrucous oral leukoplakia, malignant oral lichen planus, multifocal verrucous oral lichen planus, proliferative verrucous oral lichen planus. PMID:27031060

GPU based numerical simulation of core shooting process

Directory of Open Access Journals (Sweden)

Yi-zhong Zhang

2017-11-01

Full Text Available Core shooting process is the most widely used technique to make sand cores and it plays an important role in the quality of sand cores. Although numerical simulation can hopefully optimize the core shooting process, research on numerical simulation of the core shooting process is very limited. Based on a two-fluid model (TFM and a kinetic-friction constitutive correlation, a program for 3D numerical simulation of the core shooting process has been developed and achieved good agreements with in-situ experiments. To match the needs of engineering applications, a graphics processing unit (GPU has also been used to improve the calculation efficiency. The parallel algorithm based on the Compute Unified Device Architecture (CUDA platform can significantly decrease computing time by multi-threaded GPU. In this work, the program accelerated by CUDA parallelization method was developed and the accuracy of the calculations was ensured by comparing with in-situ experimental results photographed by a high-speed camera. The design and optimization of the parallel algorithm were discussed. The simulation result of a sand core test-piece indicated the improvement of the calculation efficiency by GPU. The developed program has also been validated by in-situ experiments with a transparent core-box, a high-speed camera, and a pressure measuring system. The computing time of the parallel program was reduced by nearly 95% while the simulation result was still quite consistent with experimental data. The GPU parallelization method can successfully solve the problem of low computational efficiency of the 3D sand shooting simulation program, and thus the developed GPU program is appropriate for engineering applications.

Atypical hyperplasia, proliferative fibrocystic change, and exogenous hormone use.

Science.gov (United States)

Zera, R T; Danielson, D; Van Camp, J M; Schmidt-Steinbrunn, B; Hong, J; McCoy, M; Anderson, W R; Linzie, B M; Rodriguez, J L

2001-10-01

The association between breast cancer development and exogenous hormone use (EHU) is suggested by indirect clinical evidence. We undertook this study to better define the relationship that EHU has with proliferative fibrocystic change (PFC) and atypical hyperplasia (AH). Women diagnosed with AH without associated carcinoma from January 1990 to December 1999 were compared with control subjects who underwent breast biopsy procedures during the same interval and who were diagnosed with either a proliferative fibrocystic change (PFC) or a nonproliferative fibrocystic change (NPFC). EHU was defined as the use of estrogen or progesterone taken together or separately within 3 months of biopsy. EHU was significantly higher in patients with AH compared with women with NPFC (P =.01). This observation was also significant if all proliferative change (both AH and PFC) was compared with NPFC (P =.03); it was not significant when PFC alone was compared with NPFC. No significant difference in EHU was demonstrated between women with AH and those with PFC. There is strong association between AH and EHU. These results support the theory that a continuum exists between hyperplasia and carcinoma and that EHU may influence the transition from one to the other in an undefined subset of women. We encourage our patients with AH to discontinue EHU.

Micropropagation of Plantago asiatica L. through culture of shoot-tips

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Joanna Makowczyńska

2011-01-01

Full Text Available Shoot-tip multiplication of the medicinal species - Plantago asiatica was carried on MS medium with IAA and BAP or kinetin. Best results in micropropagation were achieved by adding 0.1 mg/dm3 IAA and 1 mg/dm3 BAP. After 6 weeks shoots were transferred to MS medium for rooting. The resulting plantlets were transferred after 8 weeks into pots and after a period of adaptation into the ground (field culture. The species Plantago asiatica was propagated in vitro by shoot-tip multiplication for the first time.

Lippia dulcis shoot cultures as a source of the sweet sesquiterpene hernandulcin.

Science.gov (United States)

Sauerwein, M; Flores, H E; Yamazaki, T; Shimomura, K

1991-04-01

The axenic shoot culture of Lippia dulcis Trev., Verbenaceae, was established on hormone-free Murashige-Skoog solid medium containing 3% sucrose. Shoots were cultured in various liquid or solid media. Woody Plant liquid medium was best for shoot multiplication, but the production of hernandulcin was relatively low. The highest hernandulcin content (2.9% dry wt) was obtained after 28 days of culture on Murashige-Skoog solid medium containing 2% sucrose. The addition of chitosan to the culture media enhanced the growth of shoots as well as the production of hernandulcin, especially with the liquid medium.

The effects of increased phosphorus application on shoot dry matter ...

African Journals Online (AJOL)

The effects of increased phosphorus application on shoot dry matter, shoot P and Zn concentrations in wheat ( Triticum durum L.) and maize ( Zea mays L.)wheat ( Triticum durum L.) and maize ( Zea mays L.) grown in a calcareous soil.

Variation in shoot tolerance mechanisms not related to ion toxicity in barley

KAUST Repository

Tilbrook, Joanne

2017-09-27

Soil salinity can severely reduce crop growth and yield. Many studies have investigated salinity tolerance mechanisms in cereals using phenotypes that are relatively easy to measure. The majority of these studies measured the accumulation of shoot Na+ and the effect this has on plant growth. However, plant growth is reduced immediately after exposure to NaCl before Na+ accumulates to toxic concentrations in the shoot. In this study, nondestructive and destructive measurements are used to evaluate the responses of 24 predominately Australian barley (Hordeum vulgare L.) lines at 0, 150 and 250mMNaCl. Considerable variation for shoot tolerance mechanisms not related to ion toxicity (shoot ion-independent tolerance) was found, withsome lines being able to maintain substantial growth rates under salt stress, whereas others stopped growing. Hordeum vulgare spp. spontaneum accessions and barley landraces predominantly had the best shoot ion independent tolerance, although two commercial cultivars, Fathom and Skiff, also had high tolerance. The tolerance of cv. Fathom may be caused by a recent introgression from H. vulgare L. spp. spontaneum. This study shows that the most salt-tolerant barley lines are those that contain both shoot ion-independent tolerance and the ability to exclude Na+ from the shoot (and thus maintain high K+: Na+ ratios).

Variation in shoot tolerance mechanisms not related to ion toxicity in barley

KAUST Repository

Tilbrook, Joanne; Schilling, Rhiannon K.; Berger, Bettina; Garcia, Alexandre F.; Trittermann, Christine; Coventry, Stewart; Rabie, Huwaida; Brien, Chris; Nguyen, Martin; Tester, Mark A.; Roy, Stuart J.

2017-01-01

Soil salinity can severely reduce crop growth and yield. Many studies have investigated salinity tolerance mechanisms in cereals using phenotypes that are relatively easy to measure. The majority of these studies measured the accumulation of shoot Na+ and the effect this has on plant growth. However, plant growth is reduced immediately after exposure to NaCl before Na+ accumulates to toxic concentrations in the shoot. In this study, nondestructive and destructive measurements are used to evaluate the responses of 24 predominately Australian barley (Hordeum vulgare L.) lines at 0, 150 and 250mMNaCl. Considerable variation for shoot tolerance mechanisms not related to ion toxicity (shoot ion-independent tolerance) was found, withsome lines being able to maintain substantial growth rates under salt stress, whereas others stopped growing. Hordeum vulgare spp. spontaneum accessions and barley landraces predominantly had the best shoot ion independent tolerance, although two commercial cultivars, Fathom and Skiff, also had high tolerance. The tolerance of cv. Fathom may be caused by a recent introgression from H. vulgare L. spp. spontaneum. This study shows that the most salt-tolerant barley lines are those that contain both shoot ion-independent tolerance and the ability to exclude Na+ from the shoot (and thus maintain high K+: Na+ ratios).

Different proliferative capacity of lung fibroblasts obtained from control subjects and patients with emphysema

NARCIS (Netherlands)

Noordhoek, JA; Postma, DS; Chong, LL; Vos, JTWM; Kauffman, HF; Timens, W; van Straaten, JFM

2003-01-01

To characterize the possible role of a dysregulated proliferative capacity of pulmonary fibroblasts in insufficient tissue repair in lungs from patients with pulmonary emphysema, the authors undertook in vitro proliferative studies with pulmonary fibroblasts obtained from lung tissue of patients

Liver regeneration

NARCIS (Netherlands)

Chamuleau, R. A.; Bosman, D. K.

1988-01-01

Despite great advances in analysing hemodynamic, morphological and biochemical changes during the process of liver regeneration, the exact (patho)physiological mechanism is still unknown. A short survey of literature is given of the kinetics of liver regeneration and the significance of different

Stable transformation of sunflower (Helianthus annuus L.) using a non-meristematic regeneration protocol and green fluorescent protein as a vital marker.

Science.gov (United States)

Müller, A; Iser, M; Hess, D

2001-10-01

Stable transformation of sunflower was achieved using a non-meristematic hypocotyl explant regeneration protocol of public inbred HA300B. Uniformly transformed shoots were obtained after co-cultivation with Agrobacterium tumefaciens carrying a gfp (green fluorescent protein) gene containing an intron that blocks expression of gfp in Agrobacterium. Easily detectable, bright green fluorescence of transformed tissues was used to establish an optimal regeneration and transformation procedure. By Southern blot analysis, integration of the gfp and nptll genes was confirmed. Stable transformation efficiency was 0.1%. From 68 T1 plants analyzed, 17 showed transmission of transgene DNA and 15 of them contained the intact gfp gene. Expression of gfp was detected in 10 T1 plants carrying the intact gfp gene using a fluorimetric assay or western blot analysis. Expression of the nptll gene was confirmed in 13 T1 plants. The transformation system enables the rapid transfer of agronomically important genes.

EPICORMIC SHOOTS INDUCTION AND ROOTING CUTTINGS OF Calophyllum brasiliense

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Dagma Kratz

2016-12-01

Full Text Available Calophyllum brasiliense is present in a wide natural distribution range in Brazil and its monopodial growth, with a rectilinear stem and a moderately dense timber has attracted the attention from the logging industry in recent decades. In the meantime, the lack of efficient rescue and vegetative propagation methods of adult plants has been a narrowing condition for the selection of superior genotypes in breeding programs of the species. Therefore, we evaluate epicormic shoots induction methods and the rooting cuttings of 14 year-old Calophyllum brasiliense trees. From this scope, three methods of epicormic shoots induction were evaluated: coppicing, girdling and partial girdling. We evaluate the number of produced sprouts and the percentage of sprouted trees at 06, 12 and 15 months’ after the experiment installation. Results have indicated the feasibility of Calophyllum brasiliense vegetative rescue by cuttings method using epicormic shoots induced by coppicing and girdling. In contrast, partial girdling was not effective in epicormic shoots emission. Concerning adventitious roots, the sprouting technique had no influence in the rooting of cuttings, showing variation among the different stock plants.

How to talk (and not to talk) about school shootings

OpenAIRE

Scheper-Hughes, N

2018-01-01

© RAI 2018 In this guest editorial, the author addresses the latest school shootings at the Marjory Stoneman Douglas High School in Parkland, Florida. This event is weighed up against reports written by prominent academics, including anthropologists, during previous school shootings.

School Shootings Stun Reservation

Science.gov (United States)

Borja, Rhea R.; Cavanagh, Sean

2005-01-01

This article deals with the impact brought by the school shootings at Red Lake Indian Reservation in Minnesota to the school community. A deeply troubled 16-year-old student shot and killed seven other people and himself at a high school. The nation's deadliest school attack since the 1999 slayings at Colorado's suburban Columbine High School took…

Effect of arbuscular mycorrhizal fungi and multi-combination of bioinoculants on regenerated seedlings of cotton

International Nuclear Information System (INIS)

Pindi, P.K.; Sultana, T.

2014-01-01

Effect of arbuscular mycorrhizal fungi and multi-combination of bioinoculants on regenerated seedlings of cotton Cotton, referred as 'The white gold' is an important commercial crop in India and stands third in the world by means of area of cultivation. Cotton plant regeneration from callus by somatic embryogenesis and its efficiency has been improved significantly in recent times. Our primary investigation was on regenerative studies and multiple shoot induction system focusing mainly on meristematic tissues like seedling cotyledonary nodal explants in RAH-9750 cotton cultivar. An attempt has been made to improve the rate of surveillance and growth of regenerated cotton seedlings by bio-inoculant (mainly AMF) treatment under greenhouse conditions. Out of a total seven pure cultures of AMF fungi, R1-R2 have shown maximum mycorrhizal colonization with RAH-9750 (R) and was identified as Glomus mosseae. This variety was also tested with three different bioinoculants i.e., Rhizobium sp. RHPU-7, Azospirillum sp. PPK-27, Bacillus sp. PU-1, apart from AMF R1-R2 in different combinations. The cotton seedlings have shown the best results in single, dual, triple and multiple combinations i.e R+R1-R2, R+R1-R2+Rhizobium, R+R1-R2+Rhizobium+Azospirillum and R+R1-R2+Rhizobium+Azospirillum+Bacillus respectively. The growth of cotton plants (RAH-9750) generated from meristematic tissue culture was found to be increasing significantly when compared with the normal seeds. Similar results were noticed when the same experiment was subjected to the different soil types of Mahabubnagar district. The investigation clearly infers that better yield of cotton RAH-9750 (R) could be achieved by treating the regenerated cotton seedlings with bioinoculants in different combination in various soil types of Mahabubnagar district. (author)

Violent mass shootings in Sweden from 1960 to 1995: profiles, patterns, and motives.

Science.gov (United States)

Lindquist, O; Lidberg, L

1998-03-01