Glycerol and myo-inositol as carbon sources for the induction of xylogenesis in explants of Lactuca

1982 ◽  
Vol 60 (7) ◽  
pp. 1204-1206 ◽  
Author(s):  
L. W. Roberts ◽  
S. Baba
Keyword(s):  
Carbon Source ◽  
Lactuca Sativa ◽  
Secondary Wall ◽  
Carbon Sources ◽  
Tracheary Element ◽  
Tracheary Elements ◽  
Tracheary Element Differentiation ◽  
Cultural Conditions ◽  
Exogenous Carbon Source

Glycerol (2% w/v) and myo-inositol (2% w/v), respectively, functioned as the principal exogenous carbon source for the induction of tracheary element differentiation in cultured expiants of lettuce pith (Lactuca sativa cv. Romána). Although tracheary elements were first observed after 3 days on a xylogenic medium supplemented with either glucose (2% w/v) or myo-inositol (2% w/v), the induction of xylogenesis in explants cultured on a similar medium containing glycerol (2% w/v) required a minimum of 6 days. Tracheary elements formed in the presence of glycerol and myo-inositol, respectively, were characterized by various patterns of scalariform-reticulate secondary wall thickenings which were indistinguishable from tracheary elements produced under similar cultural conditions in the presence of glucose as the principal carbon source. This is the first report of a major exogenous carbon source other than a carbohydrate supporting the cytodifferentiation of tracheary elements under in vitro conditions.

Effect of carbon source on Phenobarbital metabolism by Rhizopus stolonifer

2010 ◽  
Vol 3 (2) ◽  
pp. 1022-1027
Author(s):  
Kavitha K ◽  
Asha S ◽  
Hima Bindu T.V.L ◽  
Vidyavathi M
Keyword(s):  
Carbon Source ◽  
High Performance ◽  
Carbon Sources ◽  
In Vitro Models ◽  
Rhizopus Stolonifer ◽  
Safety And Efficacy ◽  
Alternative Systems ◽  
Toxicological Studies ◽  
Microbial Model

The safety and efficacy of a drug is based on its metabolism or metabolite formed. The metabolism of drugs can be studied by different in vitro models, among which microbial model became popular. In the present study, eight microbes were screened for their ability to metabolize phenobarbital in a manner comparable to humans with a model to develop alternative systems to study human drug metabolism. Among the different microbes screened, a filamentous fungi Rhizopus stolonifer metabolized phenobarbital to its metabolite which is used for further pharmacological and toxicological studies. The transformation of phenobarbital was identified by high- performance liquid chromatography (HPLC). Interestingly, Rhizopus stolonifer sample showed an extra metabolite peak at 3.11min. compared to its controls. The influence of different carbon sources in media used for growth of fungus, on metabolite production was studied, to find its effect in production of metabolite as the carbon source may influence the growth of the cell.

scholarly journals Assessment of the Importance of Similarity in Carbon Source Utilization Profiles between the Biological Control Agent and the Pathogen in Biological Control of Bacterial Speck of Tomato

2002 ◽  
Vol 68 (9) ◽  
pp. 4383-4389 ◽  
Author(s):  
Pingsheng Ji ◽  
Mark Wilson
Keyword(s):  
Biological Control ◽  
Carbon Source ◽  
Disease Severity ◽  
Pseudomonas Syringae ◽  
Biological Control Agent ◽  
Carbon Sources ◽  
Control Agent ◽  
Carbon Source Utilization ◽  
Bacterial Speck

ABSTRACT Bacterial speck of tomato, caused by Pseudomonas syringae pv. tomato, was used to determine whether similarity in carbon source utilization between a preemptive biological control agent and the pathogen was significant in determining the ability of the bacterium to suppress disease. Similarity in carbon source utilization was quantified as the ratio of the number of tomato carbon sources utilized in vitro by the biological control agent to the number of tomato carbon sources utilized in vitro by the target pathogen (the niche overlap index [NOI]). Suppression of the disease was quantified as the percent reduction in disease severity compared to the pathogen-only control when nonpathogenic bacteria were applied to foliage 48 h prior to the pathogen. In the collection of 36 nonpathogenic bacterial strains, there was a significant (P < 0.01), but weak (r2 = 0.25), correlation between reduction in disease severity and similarity in carbon source utilization, suggesting that similarity in carbon source use was significant in determining ability to suppress disease. The relationship was investigated further using catabolic mutants of P. syringae strain TLP2, an effective biological control agent of speck. Catabolic mutants exhibited lower levels of similarity (NOI = 0.07 to 0.90) than did wild-type TLP2 (NOI = 0.93). With these catabolic mutants there was a significant (P < 0.01), and stronger (r2 = 0.42), correlation between reduction in disease severity and similarity in carbon source utilization. This suggests that similarity in carbon source utilization was a more important component of biological control ability for the catabolic mutants than for the nonpathogenic bacteria. Together, these studies indicate that suppression of bacterial speck of tomato was correlated with nutritional similarity between the pathogenic and nonpathogenic bacteria and suggest that preemptive utilization of carbon sources was probably involved in the biological control of the disease by both the naturally occurring nonpathogenic bacteria and the catabolic mutants.

scholarly journals Autolysis during In Vitro Tracheary Element Differentiation: Formation and Location of the Perforation

2000 ◽  
Vol 41 (11) ◽  
pp. 1267-1271 ◽  
Author(s):  
Jin Nakashima ◽  
Keiji Takabe ◽  
Minoru Fujita ◽  
Hiroo Fukuda
Keyword(s):  
Tracheary Element ◽  
Tracheary Element Differentiation

A Study of the Vascular Organization of Bamboos (Poaceae-Bambuseae) Using a Microcasting Method

IAWA Journal ◽  
1998 ◽  
Vol 19 (3) ◽  
pp. 265-278 ◽  
Author(s):  
Jean-Pierre André
Keyword(s):  
Tracheary Element ◽  
Vascular Structure ◽  
Tracheary Elements ◽  
Tracheary Element Differentiation ◽  
Bamboo Nodes ◽  
Intercalary Meristem ◽  
Anatomical Finding ◽  
The Continuum

A reliable and simple microcasting method is applied to the study of the vascular structure in bamboo nodes; it provides new insights into their complexity, revealing the exact arrangement of branched vessels and clustered tracheary elements. Axial differentiation gradients in the metaxylem cell files, probable relics of the intercalary meristem, can also be found using this method. This anatomical finding can be linked to arecent hypothesis on the continuum in the tracheary element differentiation.

Saccharomyces cerevisiae glucose signalling regulator Mth1p regulates the organellar Na+/H+ exchanger Nhx1p

2010 ◽  
Vol 432 (2) ◽  
pp. 343-352 ◽  
Author(s):  
Keiji Mitsui ◽  
Masafumi Matsushita ◽  
Hiroshi Kanazawa
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Carbon Source ◽  
Sole Carbon Source ◽  
Glucose Sensor ◽  
Ph Regulation ◽  
Gene Knockout ◽  
Carbon Sources ◽  
Acidic Ph ◽  
In Cells

Organelle-localized NHEs (Na+/H+ exchangers) are found in cells from yeast to humans and contribute to organellar pH regulation by exporting H+ from the lumen to the cytosol coupled to an H+ gradient established by vacuolar H+-ATPase. The mechanisms underlying the regulation of organellar NHEs are largely unknown. In the present study, a yeast two-hybrid assay identified Mth1p as a new binding protein for Nhx1p, an organellar NHE in Saccharomyces cerevisiae. It was shown by an in vitro pull-down assay that Mth1p bound to the hydrophilic C-terminal half of Nhx1p, especially to the central portion of this region. Mth1p is known to bind to the cytoplasmic domain of the glucose sensor Snf3p/Rgt2p and also functions as a negative transcriptional regulator. Mth1p was expressed in cells grown in a medium containing galactose, but was lost (possibly degraded) when cells were grown in medium containing glucose as the sole carbon source. Deletion of the MTH1 gene increased cell growth compared with the wild-type when cells were grown in a medium containing galactose and with hygromycin or at an acidic pH. This resistance to hygromycin or acidic conditions was not observed for cells grown with glucose as the sole carbon source. Gene knockout of NHX1 increased the sensitivity to hygromycin and acidic pH. The increased resistance to hygromycin was reproduced by truncation of the Mth1p-binding region in Nhx1p. These results implicate Mth1p as a novel regulator of Nhx1p that responds to specific extracellular carbon sources.

scholarly journals Aca1 and Aca2, ATF/CREB Activators in Saccharomyces cerevisiae, Are Important for Carbon Source Utilization but Not the Response to Stress

2000 ◽  
Vol 20 (12) ◽  
pp. 4340-4349 ◽  
Author(s):  
M. Adelaida Garcia-Gimeno ◽  
Kevin Struhl
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Carbon Source ◽  
Target Genes ◽  
Carbon Sources ◽  
Biological Functions ◽  
Carbon Source Utilization ◽  
The Family ◽  
Response To Stress

ABSTRACT In Saccharomyces cerevisiae, the family of ATF/CREB transcriptional regulators consists of a repressor, Acr1 (Sko1), and two activators, Aca1 and Aca2. The AP-1 factor Gen4 does not activate transcription through ATF/CREB sites in vivo even though it binds these sites in vitro. Unlike ATF/CREB activators in other species, Aca1- and Aca2-dependent transcription is not affected by protein kinase A or by stress, and Aca1 and Aca2 are not required for Hog1-dependent salt induction of transcription through an optimal ATF/CREB site. Aca2 is important for a variety of biological functions including growth on nonoptimal carbon sources, and Aca2-dependent activation is modestly regulated by carbon source. Strains lacking Aca1 are phenotypically normal, but overexpression of Aca1 suppresses some defects associated with the loss of Aca2, indicating a functional overlap between Aca1 and Aca2. Acr1 represses transcription both by recruiting the Cyc8-Tup1 corepressor and by directly competing with Aca1 and Aca2 for target sites. Acr1 does not fully account for osmotic regulation through ATF/CREB sites, and a novel Hog1-dependent activator(s) that is not a bZIP protein is required for ATF/CREB site activation in response to high salt. In addition, Acr1 does not affect a number of phenotypes that arise from loss of Aca2. Thus, members of the S. cerevisiae ATF/CREB family have overlapping, but distinct, biological functions and target genes.

scholarly journals First Report of Krymsk® 5 (cv. VSL 2) Cherry Rootstock In Vitro Propagation: Studying the Effect of Cytokinins, Auxins and Endogenous Sugars

2018 ◽  
Vol 47 (1) ◽  
pp. 152-161 ◽  
Author(s):  
Athanasios TSAFOUROS ◽  
Peter A. ROUSSOS
Keyword(s):  
Carbon Source ◽  
In Vitro Propagation ◽  
Carbon Sources ◽  
The Other ◽  
Mother Plant ◽  
Naphthaleneacetic Acid ◽  
Indolebutyric Acid ◽  
Synthetic Auxins ◽  
Number Of Shoots

Krymsk® 5 (VSL-2) is a semi-dwarf cherry rootstock adaptable to a range of climates. The present study aimed to establish the first efficient in vitro propagation protocol for this rootstock. Therefore, six cytokinines, four adenine type (6-benzyladenine, 2-isopentenyladenine, kinetin and meta-topolin) and two phenylureas (thidiazuron and forchlorfenuron) at three (2.4 μΜ, 4.8 μΜ and 9.6 μΜ) concentrations plus three (0.24 μΜ, 0.48 μΜ, 0.96 μΜ) for thidiazuron only were tested during the multiplication stage. 6-Benzyladenine was the most efficient cytokinin, based on the number of shoots produced (3.5 shoots at 9.6 μΜ) and the number of nodes per explant (10 nodes at 9.6 μΜ) whereas the other aromatic adenine tested, i.e. meta-topolin, presented the highest number of nodes per cm and node per shoot. During the rooting stage the synthetic auxins 1-naphthaleneacetic acid (1-NAA) and indolebutyric acid (IBA) were tested at concentrations of 0, 2.5, 5, 10 and 20 μΜ both separately and in all possible combinations. The percentage of successfully rooted explants reached 95% under the combination of 20 μΜ IBA plus 5 μΜ 1-NAA, whereas the highest number of roots recorded was 8.5 roots for the treatment 20 μΜ ΙΒΑ plus 2.5 μΜ 1-NAA. Furthermore, two different carbon sources were compared, the widely used sucrose and the endogenous sugar ratio of mother plant softwood shoot, sampled during late of May. Endogenous sugar ratio proved to be the preferable carbon source, since it increased the number of shoots produced and almost doubled the number of produced nodes per explant.

In vitro and transplantation experiments with germination of date embryos

1992 ◽  
Vol 70 (5) ◽  
pp. 965-974
Author(s):  
Darleen A. DeMason ◽  
Daniel Widney ◽  
James I. Stillman
Keyword(s):  
Carbon Source ◽  
Date Palm ◽  
Carbon Sources ◽  
Culture Conditions ◽  
Good Growth ◽  
Anatomical Features ◽  
Developmental Characteristics ◽  
Transplantation Experiments ◽  
Better Than

In vitro experiments with date palm embryos were designed to determine (i) which carbon sources support growth and (ii) what culture conditions promote haustorial growth and development. Date palm embryos were also transplanted into Washington filifera seeds to deterine whether any developmental characteristics were determined by the seed or endosperm. Date embryos did not grow on media containing starch or galactomannan any better than they do on medium lacking a carbon source. Good growth occurred on medium containing mannose, glucose, or sucrose as the carbon source. Embryos imbibed in the seed for 6 days grew better and produced larger haustoria than those imbibed 2 days, imbibed in water, imbibed in 3% mannose, or unimbibed. Date embryos imbibed in Washington seeds grew as well as those imbibed in date seeds. Optimum seedling and haustorium weights occurred at pH 7. The transembryonic seedlings germinated and grew normally but the shape of the haustorium was altered. Haustoria produced by in vitro grown seedlings exhibited many normal anatomical features, but haustoria from transembryonic seedlings exhibited more normal histological features. Results support the hypotheses that (i) date embryos do not possess the enzymes necessary to digest mannans and (ii) haustorium development is controlled by at least two steps, an initial inductive step that occurs by 6 days of imbibition and a further step that occurs later. We hypothesize that diffusable substances from the endosperm are responsible for controlling haustorium initiation and development. Key words: germination, embryo culture, palms, palm tissue culture, Arecaceae, haustorium.

scholarly journals Transcriptional Cross-Regulation of the Catechol and Protocatechuate Branches of the β-Ketoadipate Pathway Contributes to Carbon Source-Dependent Expression of the Acinetobacter sp. Strain ADP1 pobA Gene

2003 ◽  
Vol 69 (3) ◽  
pp. 1598-1606 ◽  
Author(s):  
Patricia C. Brzostowicz ◽  
Andrew B. Reams ◽  
Todd J. Clark ◽  
Ellen L. Neidle
Keyword(s):  
Carbon Source ◽  
Transcriptional Control ◽  
Direct Evidence ◽  
Carbon Sources ◽  
Exponential Growth Phase ◽  
Wild Type ◽  
Aromatic Substrates ◽  
Phase Complex ◽  
Source Preferences

ABSTRACT Transcriptional control of carbon source preferences by Acinetobacter sp. strain ADP1 was assessed with a pobA::lacZ fusion during growth on alternative substrates. The pobA-encoded enzyme catalyzes the first step in the degradation of 4-hydroxybenzoate, a compound consumed rapidly as a sole carbon source. If additional aromatic carbon sources are available, 4-hydroxybenzoate consumption is inhibited by unknown mechanisms. As reported here, during growth on aromatic substrates, pobA was not expressed despite the presence of 4-hydroxybenzoate, an inducer that normally causes the PobR regulator to activate pobA transcription. Growth on organic acids such as succinate, fumarate, and acetate allowed higher levels of pobA expression. In each case, pobA expression increased at the end of the exponential growth phase. Complex transcriptional regulation controlled 4-hydroxybenzoate catabolism in multisubstrate environments. Additional studies focused on the wild-type preference for benzoate consumption prior to 4-hydroxybenzoate consumption. These compounds are degraded via the catechol and protocatechuate branches of the β-ketoadipate pathway, respectively. Here, mutants were characterized that degraded benzoate and 4-hydroxybenzoate concurrently. These mutants lacked the BenM and CatM transcriptional regulators that normally activate genes for benzoate catabolism. A model is presented in which BenM and CatM prevent pobA expression indirectly during growth on benzoate. These regulators may affect pobA expression by lowering the PcaK-mediated uptake of 4-hydroxybenzoate. Consistent with this model, BenM and CatM bound in vitro to an operator-promoter fragment controlling the expression of several pca genes, including pcaK. These studies provide the first direct evidence of transcriptional cross-regulation between the distinct but analogous branches of the β-ketoadipate pathway.

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