The Experts below are selected from a list of 618 Experts worldwide ranked by ideXlab platform
Praveen K. Saxena - One of the best experts on this subject based on the ideXlab platform.
-
Induction of high-frequency somatic embryogenesis in geranium (Pelargonium x hortorum Bailey cv Ringo Rose) cotyledonary cultures
Plant Cell Reports, 1996Co-Authors: B. N. S. Murthy, R. P. Singh, Praveen K. SaxenaAbstract:The cv Ringo Rose of hybrid seed geranium ( Pelargonium x hortorum Bailey), previously shown to be recalcitrant in culture, produced somatic embryos when cotyledonary explants were cultured on regeneration medium containing thidiazuron (TDZ), Forchlorfenuron (CPPU), or a combination of indole-3-acetic acid and N^6 benzylaminopurine (IAA+BAP). Amendment of the basal medium with TDZ (0.5 μM) was the most effective treatment. Addition of amino acids to the medium promoted the growth of somatic embryos. Retention of the proximal region of the cotyledon was crucial for regeneration, but the removal of the distal 1/3 to 1/2 cotyledon had no significant effect on somatic embryogenesis. Cotyledonary explants formed somatic embryos in higher frequency and much earlier than hypocotyl explants cultured on the same medium. The somatic embryos induced on cotyledonary explants were germinated on basal medium. More than 70% of the somatic embryos were converted into plants and transferred to soil
-
Somatic embryogenesis in peanut (Arachis hypogaea L.): stimulation of direct differentiation of somatic embryos by Forchlorfenuron (CPPU)
Plant Cell Reports, 1994Co-Authors: B. N. S. Murthy, Praveen K. SaxenaAbstract:The ability of Forchlorfenuron (CPPU), a substituted phenylurea compound, for inducing somatic embryogenesis in peanut ( Arachis hypogaea L.) seedlings has been demonstrated. CPPU promoted somatic embryogenesis at a range of concentrations in all three peanut cultivars tested. Embryogenic response was dependent on applied CPPU concentrations. Exposure of seedlings for only two days to CPPU induced somatic embryogenesis, but the most effective treatment was to induce seed germination on media supplemented with either 2.5 or 4.0 μM CPPU and to maintain the seedlings on the same medium. Number of somatic embryos and the frequency of embryogenesis was higher for younger seedlings (up to 9 days), regardless of the CPPU concentrations and seedlings older than 21 days failed to produce somatic embryos. Removal of cotyledons from the seeds drastically reduced the embryogenic potential of the seedlings. Somatic embryos developed into whole plants following their separation and subculture on a medium lacking growth regulators. The induction of somatic embryos using CPPU as a sole growth regulator may provide a useful system to study the role of this compound in plant morphogenesis.
B. N. S. Murthy - One of the best experts on this subject based on the ideXlab platform.
-
Induction of high-frequency somatic embryogenesis in geranium (Pelargonium x hortorum Bailey cv Ringo Rose) cotyledonary cultures
Plant Cell Reports, 1996Co-Authors: B. N. S. Murthy, R. P. Singh, Praveen K. SaxenaAbstract:The cv Ringo Rose of hybrid seed geranium ( Pelargonium x hortorum Bailey), previously shown to be recalcitrant in culture, produced somatic embryos when cotyledonary explants were cultured on regeneration medium containing thidiazuron (TDZ), Forchlorfenuron (CPPU), or a combination of indole-3-acetic acid and N^6 benzylaminopurine (IAA+BAP). Amendment of the basal medium with TDZ (0.5 μM) was the most effective treatment. Addition of amino acids to the medium promoted the growth of somatic embryos. Retention of the proximal region of the cotyledon was crucial for regeneration, but the removal of the distal 1/3 to 1/2 cotyledon had no significant effect on somatic embryogenesis. Cotyledonary explants formed somatic embryos in higher frequency and much earlier than hypocotyl explants cultured on the same medium. The somatic embryos induced on cotyledonary explants were germinated on basal medium. More than 70% of the somatic embryos were converted into plants and transferred to soil
-
Somatic embryogenesis in peanut (Arachis hypogaea L.): stimulation of direct differentiation of somatic embryos by Forchlorfenuron (CPPU)
Plant Cell Reports, 1994Co-Authors: B. N. S. Murthy, Praveen K. SaxenaAbstract:The ability of Forchlorfenuron (CPPU), a substituted phenylurea compound, for inducing somatic embryogenesis in peanut ( Arachis hypogaea L.) seedlings has been demonstrated. CPPU promoted somatic embryogenesis at a range of concentrations in all three peanut cultivars tested. Embryogenic response was dependent on applied CPPU concentrations. Exposure of seedlings for only two days to CPPU induced somatic embryogenesis, but the most effective treatment was to induce seed germination on media supplemented with either 2.5 or 4.0 μM CPPU and to maintain the seedlings on the same medium. Number of somatic embryos and the frequency of embryogenesis was higher for younger seedlings (up to 9 days), regardless of the CPPU concentrations and seedlings older than 21 days failed to produce somatic embryos. Removal of cotyledons from the seeds drastically reduced the embryogenic potential of the seedlings. Somatic embryos developed into whole plants following their separation and subculture on a medium lacking growth regulators. The induction of somatic embryos using CPPU as a sole growth regulator may provide a useful system to study the role of this compound in plant morphogenesis.
Biao Yang - One of the best experts on this subject based on the ideXlab platform.
-
Discriminating Forchlorfenuron-treated kiwifruits using a portable spectrometer and Vis/NIR diffuse transmittance spectroscopy technology
Analytical Methods, 2020Co-Authors: Qianqian Li, Weiqiang Li, Biao YangAbstract:To explore the feasibility of low-cost miniaturized spectrometers in discriminating Forchlorfenuron treated kiwifruits, a visible and near infrared (Vis/NIR) diffuse transmittance spectroscopy system was constructed by using a miniaturized charge coupled device (CCD) spectrometer in the wavelength range of 400–1100 nm and a self-developed optical fiber probe. Two hundred and forty spectra were acquired from two positions about 180° apart around the equatorial position of 120 ‘Xuxiang’ kiwifruits (including 60 Forchlorfenuron-treated kiwifruits and 60 untreated kiwifruits). The spectra in the range of 500–950 nm including 2386 wavelengths were used in this study. The successive projections algorithm (SPA) was used to select effective wavelengths (EWs). Support vector machine (SVM), extreme learning machine (ELM), and partial least squares discriminant analysis (PLS-DA) modeling methods were used to build discrimination models. 40 EWs were selected from 2386 full wavelengths by using the SPA. The average accuracy rates of each developed model were higher than 98.1% and 88.8% for the calibration set and prediction set, respectively. ELM models achieved better calibration and prediction performance than SVM and PLS-DA models. The SPA-ELM model, whose discrimination accuracy rate was 100% for the calibration set and 95.0% for the prediction set, was the best model for the discrimination of Forchlorfenuron-treated kiwifruits from untreated ones. This research indicates that portable detectors with high accuracy in discriminating Forchlorfenuron-treated kiwifruits could be developed by using cheap and miniaturized CCD spectrometers.
-
discriminating Forchlorfenuron treated kiwifruits using a portable spectrometer and vis nir diffuse transmittance spectroscopy technology
Analytical Methods, 2017Co-Authors: Qianqian Li, Weiqiang Li, Biao YangAbstract:To explore the feasibility of low-cost miniaturized spectrometers in discriminating Forchlorfenuron treated kiwifruits, a visible and near infrared (Vis/NIR) diffuse transmittance spectroscopy system was constructed by using a miniaturized charge coupled device (CCD) spectrometer in the wavelength range of 400–1100 nm and a self-developed optical fiber probe. Two hundred and forty spectra were acquired from two positions about 180° apart around the equatorial position of 120 ‘Xuxiang’ kiwifruits (including 60 Forchlorfenuron-treated kiwifruits and 60 untreated kiwifruits). The spectra in the range of 500–950 nm including 2386 wavelengths were used in this study. The successive projections algorithm (SPA) was used to select effective wavelengths (EWs). Support vector machine (SVM), extreme learning machine (ELM), and partial least squares discriminant analysis (PLS-DA) modeling methods were used to build discrimination models. 40 EWs were selected from 2386 full wavelengths by using the SPA. The average accuracy rates of each developed model were higher than 98.1% and 88.8% for the calibration set and prediction set, respectively. ELM models achieved better calibration and prediction performance than SVM and PLS-DA models. The SPA-ELM model, whose discrimination accuracy rate was 100% for the calibration set and 95.0% for the prediction set, was the best model for the discrimination of Forchlorfenuron-treated kiwifruits from untreated ones. This research indicates that portable detectors with high accuracy in discriminating Forchlorfenuron-treated kiwifruits could be developed by using cheap and miniaturized CCD spectrometers.
Amnon Lichter - One of the best experts on this subject based on the ideXlab platform.
-
effect of the cytokinin Forchlorfenuron on tannin content of thompson seedless table grapes
American Journal of Enology and Viticulture, 2014Co-Authors: Itay Maoz, Askin Bahar, Tatiana Kaplunov, Yochanan Zutchi, Avinoam Daus, Susan Lurie, Amnon LichterAbstract:The cytokinin-like compound Forchlorfenuron (CPPU) is commonly applied in many vineyards worldwide to achieve optimal berry size. It was noticed that berries treated by CPPU may be more astringent and it was therefore hypothesized that CPPU-treated berries produce more tannins or delay tannin decomposition during ripening. CPPU was applied to Thompson Seedless grapes (Vitis vinifera L.) after fruit set in three different vineyards and over three seasons. As previously reported, CPPU affected berry size and delayed maturation. Application of CPPU at 6 mm berry diameter (early treatment) had greater influence on increasing berry size, while application at 10 mm berry diameter (late treatment) had greater influence on delaying berry maturation. Berry ripening was also measured by following changes in berry autofluorescence, and it was shown that CPPU caused higher chlorophyll-related autofluorescence throughout the ripening period. The CPPU treatments consistently elevated the level of condensed tannins with up to a four-fold increase as measured by the protein precipitation assay and total phenol content. The level of total tannins in either control or CPPU-treated fruit did not seem to decrease during ripening. These results were in agreement with a sensory assessment in which CPPU-treated berries were more astringent than untreated berries. As reported here for the first time, the fact that CPPU can increase the level of tannins in Thompson Seedless must be taken into account from the perspective of berry taste.
-
Effect of the Cytokinin Forchlorfenuron on Tannin Content of Thompson Seedless Table Grapes
American Journal of Enology and Viticulture, 2014Co-Authors: Itay Maoz, Askin Bahar, Tatiana Kaplunov, Yochanan Zutchi, Avinoam Daus, Susan Lurie, Amnon LichterAbstract:The cytokinin-like compound CPPU is commonly applied in many vineyards worldwide in order to achieve optimal berry size. It was noticed that berries treated by CPPU may be more astringent and it was therefore hypothesized that CPPU-treated berries produce more tannins or delay tannin decomposition during ripening. CPPU was applied to Thompson Seedless grapes (Vitis vinifera L.) after fruit set in three different vineyards and over three seasons. As previously reported CPPU affected berry size and delayed maturation. Application of CPPU at berry diameter of 6 mm (early treatment) had more influence on increasing berry size, while treatment at 10 mm berry diameter (late treatment) had greater effect on delaying berry maturation. Berry ripening was also measured by following changes in berry auto fluorescence and it was shown that CPPU caused higher chlorophyll-related autofluorescence throughout the ripening period. The CPPU treatments consistently elevated the level of condensed tannins with up to 4-fold increase as measured by the protein precipitation assay and total phenol content. Interestingly, the level of total tannins in either control or CPPU-treated fruit did not seem to decrease during ripening. These results were in agreement with the sensory analysis in which CPPU-treated berries were more astringent than untreated berries. As reported here for the first time, the fact that CPPU can increase the level of tannins in Thompson Seedless, and possibly in other grape cultivars, must be taken into account from the perspective of berry taste.
Antonio Abadfuentes - One of the best experts on this subject based on the ideXlab platform.
-
development and validation of a direct competitive monoclonal antibody based immunoassay for the sensitive and selective analysis of the phytoregulator Forchlorfenuron
Analytical and Bioanalytical Chemistry, 2012Co-Authors: Celia Suarezpantaleon, Josep V. Mercader, Consuelo Agulló, Francesc A Esteveturrillas, Antonio Abadsomovilla, Antonio AbadfuentesAbstract:Forchlorfenuron is a synthetic phytohormone with cytokinin-like activity used worldwide as a plant growth regulator to increase fruit size in a number of crops, mostly in kiwifruit and grape vines. A monoclonal antibody-based enzyme-linked immunosorbent assay (ELISA) for the determination of Forchlorfenuron has been characterized and optimized. The selected immunoreagents afforded a highly selective assay with a limit of detection of 10 ng L−1 in buffer. This direct competitive ELISA was validated in terms of trueness, precision, and robustness using both commercial juice and whole fruit samples. Recoveries from fortified kiwifruit juices and white and red musts were between 97 % and 131 %, with relative standard deviations below 16 %. When homogenized whole fruits were analysed after acetonitrile extraction, recoveries between 96 % and 113 % were found, with a limit of quantification of 5 μg kg−1. The proposed immunoassay was validated by comparison with a reference chromatographic method using fruits from in-field treated grape and kiwifruit vines. Linear regression analysis of ELISA and HPLC–UV determinations showed an excellent correlation (r2 = 0.998), whereas analysis of the slope (0.99 ± 0.01) and of the intercept (−1 ± 3) clearly proved that the developed competitive immunoassay provided results that were statistically comparable to those obtained by the instrumental method for the analysis of Forchlorfenuron in fruits at trace levels.
-
Forchlorfenuron mimicking haptens from immunogen design to antibody characterization by hierarchical clustering analysis
Organic and Biomolecular Chemistry, 2011Co-Authors: Celia Suarezpantaleon, Josep V. Mercader, Consuelo Agulló, Antonio Abadsomovilla, Antonio AbadfuentesAbstract:To obtain highly-specific and selective Forchlorfenuron binders, a collection of functionalized derivatives with different spacer arm locations and lengths was prepared. By immunization with target-mimicking haptens, a large battery of monoclonal and polyclonal antibodies against this synthetic cell regulator was produced and exhaustively characterized in two immunoassay formats using homologous and heterologous conjugates. Antibodies with IC50 values lower than 0.3 nM were successfully raised from the prepared immunogens, thus evidencing the efficacy of the explored strategies. In order to identify significant epitopes in the antibody–antigen interaction, a series of new chemical Forchlorfenuron analogues, with slight modifications at both rings of the target molecule, were synthesized and evaluated in competitive assays. As a novel approach in hapten recognition studies, data processing was performed by computational classification methods based on hierarchical clustering. This strategy was shown to be highly valuable for a straightforward profiling of antibodies according to analogue recognition patterns. A relationship could be established between the antigen binding properties of antibodies and the structure of the immunogen. Whereas antibodies with equivalent affinities had been obtained from all of the derivatives, their specificity was found to be largely influenced by the differential exposition of the molecule to the immune system.
-
hapten synthesis and polyclonal antibody based immunoassay development for the analysis of Forchlorfenuron in kiwifruit
Journal of Agricultural and Food Chemistry, 2010Co-Authors: Celia Suarezpantaleon, Josep V. Mercader, Consuelo Agulló, Antonio Abadsomovilla, Antonio AbadfuentesAbstract:High-affinity polyclonal antibodies directed against the synthetic cytokinin Forchlorfenuron (CPPU) were produced from three immunizing haptens with equivalent spacer arms located at different positions. A competitive immunoassay was developed with a limit of detection in buffer of 12.42 ± 3.06 ng/L. In addition, the ability of the produced antibodies to recognize a set of synthetic CPPU analogues was studied. It was evidenced that the linker position had a strong impact on the specificity of the generated polyclonals, which were more sensitive to changes at moieties of the target analyte located furthest from the derivatization site of the immunogen. Finally, matrix effects of gold and green kiwifruit over assay parameters were evaluated. Excellent recoveries and low coefficients of variation were found with just a 100-fold dilution of the sample in buffer, hence indicating the effectiveness of the developed immunoassay as an analytical tool for monitoring this agrochemical in kiwifruit samples.
-
production and characterization of monoclonal and polyclonal antibodies to Forchlorfenuron
Journal of Agricultural and Food Chemistry, 2008Co-Authors: Celia Suarezpantaleon, Josep V. Mercader, Consuelo Agulló, Antonio Abadsomovilla, Antonio AbadfuentesAbstract:The development of immunoassays for the detection of the plant growth regulator Forchlorfenuron (CPPU) is described. To achieve that purpose, a set of CPPU derivatives has been obtained by the previous synthesis of the adequate p-aminophenyl alkanoic acid. Protein conjugates of these compounds have been used as immunogens to produce rabbit polyclonal antibodies and a collection of mouse monoclonal antibodies. Additionally, a battery of structural analogues of the target analyte has been synthesized and used for the characterization of antibody binding. This strategy has demonstrated that most antibodies followed Landsteiner’s principle, although some monoclonal antibodies showing important deviations from this behavior have also been found. Finally, different assay formats have been developed with a variety of antibodies and conjugates, and a rapid procedure has been optimized for the indirect ELISA format using monoclonal and polyclonal antibodies. In the indirect competitive ELISA, assay IC50 values for...