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Margrethe Serek - One of the best experts on this subject based on the ideXlab platform.

  • Improved leaf and flower longevity by expressing the etr1-1 allele in Pelargonium Zonale under control of FBP1 and SAG12 promoters
    Plant Growth Regulation, 2018
    Co-Authors: Christian Gehl, David Wamhoff, Frank Schaarschmidt, Margrethe Serek
    Abstract:

    The ethylene receptor etr1-1 (ETHYLENE RESPONSE 1) mutant gene from Arabidopsis thaliana , with its expression under the control of either the Petunia floral binding protein FBP1 promoter or the Arabidopsis senescence-specific SAG12 gene promoter, was introduced into Pelargonium Zonale cv. ‘Katinka’. The heterologous expression of these transgenes and the response of flowers and leaves to exogenous ethylene were then studied. Transgenic etr1-1 lines grown in the greenhouse did not differ morphologically or physiologically from nontransformed plants nor was the rooting ability of cuttings affected. Reverse transcription (RT)-PCR revealed that transcripts from an FBP1 promoter were present from green tissue to the roots, whereas the SAG12 promoter was only active in processes associated with aging or senescence of flower petals and leaves. The sensitivity to ethylene exposure was markedly reduced by using both promoter constructs. Flower petals from nontransformed controls were fully senescent 4 days after ethylene exposure, while more than 90% of the flower petals from FBP1-promoter lines and over 50% of the flower petals from SAG12-promoter lines remained unchanged, without showing any signs of wilting or any response to ethylene. However, ethylene sensitivity of leaves was only delayed in the best lines but not suppressed through etr1-1 expression. Foliage displayed less intense leaf yellowing and wilting, which were similar for both promoter variants compared to wild type controls.

  • AGROBACTERIUM-MEDIATED TRANSFORMATION OF Pelargonium (Pelargonium Zonale HYBRIDS AND Pelargonium PELTATUM HYBRIDS)
    Acta Horticulturae, 2006
    Co-Authors: Traud Winkelmann, K. Kaviani, Margrethe Serek
    Abstract:

    [...] The attempts of this investigation were to use a system for plant regeneration from explants of in vitro grown and greenhouse-grown plants for genetic transformation of important commercial Pelargonium Zonale hybrid and P. peltatum hybrid cultivars. To this aim, petiole explants were cultured on modified MS medium containing 10 μM TDZ. In eight out of sixteen tested cultivars, shoot regeneration has been obtained using explants from greenhouse-grown plants. Explants from in vitro plantlets regenerated shoots in nine out of twelve investigated cultivars. For selection of transgenic cells carrying the pat gene, a concentration of 2.5 μM glufosinate (syn. phosphinothricin) was shown to be appropriate. [...]

  • Development of a shoot regeneration protocol for genetic transformation in Pelargonium Zonale and Pelargonium peltatum hybrids
    Plant Cell Tissue and Organ Culture, 2005
    Co-Authors: Traud Winkelmann, K. Kaviani, Margrethe Serek
    Abstract:

    The attempts of this investigation were to develop a system for plant regeneration from explants of adult plants and its use for genetic transformation of important commercial Pelargonium Zonale hybrid and P. peltatum hybrid cultivars. To this aim, leaf blade and petiole explants of eight cultivars were cultured on modified MS (Murashige and Skoog, 1962) medium with two concentrations of TDZ, BA, and zeatin (5 and 20 μ M). Petiole explants showed a higher regeneration response than leaf blade explants and TDZ was the most effective cytokinin. Petioles of 16 cultivars were incubated on medium containing 5, 10, 15, and 20 μ M TDZ, respectively, in order to identify the most effective TDZ concentration. For the majority of genotypes 10 μ M TDZ resulted in the best regeneration response. Cefotaxim at 500 mg l ^−1 had no effect on shoot regeneration and did not show interaction with glufosinate. For selection of transgenic cells, a concentration of 2.5 μ M glufosinate was shown to be appropriate. LBA4404 and EHA101 Agrobacterium strains carrying pIBGUS vector with pat gene as selectable marker gene and GUS gene as reporter gene were compared in transformation studies. With regard to GUS expression in petiole explants 16 days after coculture, better results were obtained with EHA 101 than with LBA 4404.

  • Inhibitors of ethylene action affect final quality and rooting of cuttings before and after storage
    Hortscience, 1998
    Co-Authors: Margrethe Serek, Adam Prabucki, Edward C. Sisler, Arne Skytt Andersen
    Abstract:

    Vegetative cuttings of three species, Dendranthema grandiflorum (Ramat.) Kitamura, Pelargonium Zonale L., and Hibiscus rosa-sinensis L., were treated with 1-MCP or STS to determine the effect of inhibition of the action of ethylene on quality and rooting ability both without and with storage. Storage decreased quality of Pelargonium and Hibiscus cuttings, causing leaf yellowing and chlorophyll degradation. No leaf yellowing was detected in Dendranthema cuttings, regardless of treatment. Storage inhibited rooting of the cuttings, particularly in Pelargonium, where rooting was halved. Chemical inhibition of ethylene action retarded storage-induced leaf yellowing, but also reduced rooting ability both in fresh and stored cuttings. Chemical names used: 1-methylcyclopropene (1-MCP); silver thiosulfate (STS).

Luis Hernandez - One of the best experts on this subject based on the ideXlab platform.

  • topical hemostatic effect of a common ornamental plant the geraniaceae Pelargonium Zonale
    The Journal of Clinical Pharmacology, 2003
    Co-Authors: Ximena Paez, Luis Hernandez
    Abstract:

    Geranium has been traditionally used as a local hemostatic medicine in some Andean regions, but this effect has not been tested in controlled experiments. In the present report, the leaves of a geraniaceae (Pelargonium Zonale) were tested on a bleeding rat model. The bleeding time was 50% shorter in the geranium leaf juice treatment group (18.10 ± 2.03 min) and 80% shorter in the geranium crushed-leaf group (7.10 ± 0.88 min) than in the control (nontreatment) group (37.6 ± 3.04 min), p < 0.0001. Bleeding time with guava (Psidium guajava) crushed leaves (39.90 ± 1.54 min) was not different from the control group. A proved hemostatic agent, gelatin sponge, had a similar effect as geranium juice (16.7 ± 3.32 min) in the same animal model. A buffer solution at pH 3 (the same pH as the geranium leaf extract) did not have any hemostatic effect, and the bleeding time (39.3 ± 2.71 min) was not different from the control group. The dilution 1:4 geranium leaf juice at pH 3 (25.6 ± 3.08 min) or pH 5 (28.8 ± 3.98 min) still had a statistically significant hemostatic effect. The results confirm the hemostatic effect of P. Zonale leaves and show that it is similar (geranium leaf juice) or better (crushed geranium leaves) than the hemostatic effect of a commercial hemostatic sponge. It seems that the hemostasis caused by P. Zonale extract leaves is not due to its low pH. The potential benefits as a new, inexpensive, safe, and easily available natural topical hemostatic agent are discussed.

Monika Tkalec - One of the best experts on this subject based on the ideXlab platform.

  • tehnologija uzgoja presadnica rosa canina l i Pelargonium Zonale l u kulturi tkiva i njihova adaptacija u razlicitim supstratima
    Poljoprivreda, 2017
    Co-Authors: Monika Tkalec
    Abstract:

    Cilj rada bio je utvrditi mogucnost dobivanja sadnog materijala Rosa canina L. i Pelargonium Zonale L. u kulturi tkiva te pogodnost alternativnih kom

  • TEHNOLOGIJA UZGOJA PRESADNICA Rosa canina L. I Pelargonium Zonale L. U KULTURI TKIVA I NJIHOVA ADAPTACIJA U RAZLIČITIM SUPSTRATIMA
    Faculty of Agriculture in Osijek, 2017
    Co-Authors: Monika Tkalec
    Abstract:

    Cilj rada bio je utvrditi mogućnost dobivanja sadnoga materijala Rosa canina L. i Pelargonium Zonale L. u kulturi tkiva te pogodnost alternativnih komponenti i njihovih mješavina kao supstrata za adaptaciju proizvedenih in vitro presadnica navedenih cvjetnih vrsta. U istraživanju analizirano je četiri alternativne komponente (ljuske od kakaovca (A), vrbina kora (B), supstrat nastao nakon proizvodnje šampinjona (C), piljevina (D)) te šest njihovih mješavina za uzgoj cvjetnih presadnica. Kao kontrolni supstrat analizirani su Klasman Potgrond P (za divlju ružu) (E) i Balkon – blumenerde (za pelargoniju) (F). Statističkom obradom podataka, utvrđene su značajne razlike između svih tretmana (supstrata) i njihovih analiziranih svojstava. Prosječan postotak adaptiranih presadnica u svim istraživanim supstratima iznosio je 54,68% za divlju ružu te 99,68% za pelargoniju. Najveće vrijednosti morfoloških pokazatelja divlje ruže utvrđene su na mješavini supstrata M2 (30% A + 20% B + 40% C + 10% D), gdje je zabilježen najveći broj izboja, broj listova, svježa nadzemna masa, ukupna svježa masa presadnice te odnos mase nadzemnoga dijela i korijena u svježem i suhome stanju. Kemijski sastav presadnica divlje ruže varirao je među tretmanima, no najviši sadržaj većine makro i mikroelemenata utvrđen je na presadnicama uzgajanim na supstratu od piljevine (D) te kontrolnome supstratu (E). Kod pelargonije, najveće vrijednosti gotovo svih morfoloških pokazatelja zabilježene su, također, na mješavinama supstrata M4 (18% A + 22% B + 40% C + 20% D) i M6 (18% A + 42% B + 20% C + 20% D). Nadalje, dok su najveće vrijednosti morfoloških pokazatelja utvrđene na presadnicama pelargonija uzgajanim na mješavinama, najviši sadržaj mikro i makroelemenata utvrđen je u presadnicama uzgajanim na alternativnim komponentama

  • THE TECHNOLOGY OF GROWING Rosa canina L. AND Pelargonium Zonale L. SEEDLINGS IN TISSUE CULTURE AND THEIR ADAPTATION IN DIFFERENT SUBSTRATES
    Faculty of Agriculture in Osijek, 2017
    Co-Authors: Monika Tkalec
    Abstract:

    The aim of this study was to establish the possibility of growing Rosa canina L. and Pelargonium Zonale L. in tissue culture and suitability of alternative components and their mixtures as a substrate for adaptation of in vitro seedlings of these floral species. In this research, four alternative components (cocoa shell (A), willow bark (B), spent mushroom substrate (C), sawdust (D)) and six of their mixtures were analysed. Klasman Potgrond P (for wild rose) and Balkon – blumenerde (for Pelargonium) were analysed as a control substrate. Statistical analysis has revealed significant differences between all the treatments (substrates) and their analysed properties. An average percentage of adapted seedlings in all of the substrates was 54.68% for wild rose, and 99.68% for Pelargonium. The largest values of morphological properties for the wild rose were determined on an M2 (30% A + 20% B + 40% C + 10% D) substrate mixture, where the greatest number of shoots, leaf number, fresh overground mass, total fresh mass of seedling and the ratio of fresh and dry overground mass and root were recorded. Chemical composition of wild rose seedlings varied among the treatments, but the highest content of macro and micro elements was determined in the seedlings grown on sawdust (D) and control substrate (E). The largest values of almost all morphological properties of Pelargonium were also recorded on substrate mixtures M4 (18% A + 22% B + 40% C + 20% D) and M6 (18% A + 42% B + 20% C + 20% D). Furthermore, while the largest morphological properties of Pelargonium seedlings were recorded in the mixtures, the highest content of macro and micro elements determined in the seedlings was on those grown on alternative components, especially in the seedlings grown on a willow bark substrate

Ximena Paez - One of the best experts on this subject based on the ideXlab platform.

  • topical hemostatic effect of a common ornamental plant the geraniaceae Pelargonium Zonale
    The Journal of Clinical Pharmacology, 2003
    Co-Authors: Ximena Paez, Luis Hernandez
    Abstract:

    Geranium has been traditionally used as a local hemostatic medicine in some Andean regions, but this effect has not been tested in controlled experiments. In the present report, the leaves of a geraniaceae (Pelargonium Zonale) were tested on a bleeding rat model. The bleeding time was 50% shorter in the geranium leaf juice treatment group (18.10 ± 2.03 min) and 80% shorter in the geranium crushed-leaf group (7.10 ± 0.88 min) than in the control (nontreatment) group (37.6 ± 3.04 min), p < 0.0001. Bleeding time with guava (Psidium guajava) crushed leaves (39.90 ± 1.54 min) was not different from the control group. A proved hemostatic agent, gelatin sponge, had a similar effect as geranium juice (16.7 ± 3.32 min) in the same animal model. A buffer solution at pH 3 (the same pH as the geranium leaf extract) did not have any hemostatic effect, and the bleeding time (39.3 ± 2.71 min) was not different from the control group. The dilution 1:4 geranium leaf juice at pH 3 (25.6 ± 3.08 min) or pH 5 (28.8 ± 3.98 min) still had a statistically significant hemostatic effect. The results confirm the hemostatic effect of P. Zonale leaves and show that it is similar (geranium leaf juice) or better (crushed geranium leaves) than the hemostatic effect of a commercial hemostatic sponge. It seems that the hemostasis caused by P. Zonale extract leaves is not due to its low pH. The potential benefits as a new, inexpensive, safe, and easily available natural topical hemostatic agent are discussed.

Marija Vidović - One of the best experts on this subject based on the ideXlab platform.

  • Antioxidative response in variegated Pelargonium Zonale leaves and generation of extracellular H2O2 in (peri)vascular tissue induced by sunlight and paraquat.
    Journal of plant physiology, 2016
    Co-Authors: Marija Vidović, Filis Morina, Ljiljana Prokić, Sonja Milić-komić, Bojana Živanović, Sonja Veljović Jovanović
    Abstract:

    Abstract In this study we exposed variegated leaves of Pelargonium Zonale to strong sunlight (>1100 μmol m −2  s −1 of photosynthetically active radiation) with and without paraquat (Pq), with the aim to elucidate the mechanisms of H 2 O 2 regulation in green and white tissues with respect to the photosynthetically-dependent generation of reactive oxygen species (ROS). Sunlight induced marked accumulation of H 2 O 2 in the apoplast of vascular and (peri)vascular tissues only in green sectors. This effect was enhanced by the addition of Pq. In the presence of diphenyl iodide, an NADPH oxidase inhibitor, H 2 O 2 accumulation was abolished. Distinct light-induced responses were observed: in photosynthetic cells, sunlight rapidly provoked ascorbate (Asc) biosynthesis and an increase of glutathione reductase (GR) and catalase activities, while in non-photosynthetic cells, early up-regulation of soluble ascorbate peroxidase, dehydroascorbate reductase (DHAR) and GR activities was observed. Paraquat addition stimulated DHAR and GR activities in green sectors, while in white sectors activities of monodehydroascorbate reductase, DHAR and class III peroxidases, as well as Asc content rapidly increased. Differential antioxidative responses in the two tissues in the frame of their contrasting metabolisms, and the possible role of (peri)vascular H 2 O 2 in signaling were discussed.

  • Comparison of Photoacoustic Signals in Photosynthetic and Nonphotosynthetic Leaf Tissues of Variegated Pelargonium Zonale
    International Journal of Thermophysics, 2016
    Co-Authors: Sonja Veljovic-jovanovic, Marija Vidović, Filis Morina, Lj. Prokic, Dragan M. Todorovic
    Abstract:

    Green-white variegated leaves of Pelargonium Zonale were studied using the photoacoustic method. Our aim was to characterize photosynthetically active green tissue and nonphotosynthetically active white tissue by the photoacoustic amplitude signals. We observed lower stomatal conductance and higher leaf temperature in white tissue than in green tissue. Besides these thermal differences, significantly higher absorbance in green tissue was based on chlorophyll and carotenoids which were absent in white tissue. However, optical properties of epidermal layers of both tissues were equal. The photoacoustic amplitude of white tissue was over four times higher compared to green tissue, which was correlated with lower stomatal conductance. In addition, at frequencies >700 Hz, the significant differences between the photoacoustic signals of green and white tissue were obtained. We identified the photoacoustic signal deriving from photosynthetic oxygen evolution in green tissue, using high intensity of red light modulated at 10 Hz. Moreover, the photoacoustic amplitude of green tissue increased progressively with time which corresponded to the period of induction of photosynthetic oxygen evolution. For the first time, very high frequencies (1 kHz to 5 kHz) were applied on leaf material.

  • Characterisation of antioxidants in photosynthetic and non‐photosynthetic leaf tissues of variegated Pelargonium Zonale plants
    Plant biology (Stuttgart Germany), 2016
    Co-Authors: Marija Vidović, Filis Morina, Lj. Prokic, S. Milić‐komić, Ana Vuleta, Bernd Zechmann, S. Veljović Jovanović
    Abstract:

    Hydrogen peroxide is an important signalling molecule, involved in regulation of numerous metabolic processes in plants. The most important sources of H2 O2 in photosynthetically active cells are chloroplasts and peroxisomes. Here we employed variegated Pelargonium Zonale to characterise and compare enzymatic and non-enzymatic components of the antioxidative system in autotrophic and heterotrophic leaf tissues at (sub)cellular level under optimal growth conditions. The results revealed that both leaf tissues had specific strategies to regulate H2 O2 levels. In photosynthetic cells, the redox regulatory system was based on ascorbate, and on the activities of thylakoid-bound ascorbate peroxidase (tAPX) and catalase. In this leaf tissue, ascorbate was predominantly localised in the nucleus, peroxisomes, plastids and mitochondria. On the other hand, non-photosynthetic cells contained higher glutathione content, mostly located in mitochondria. The enzymatic antioxidative system in non-photosynthetic cells relied on the ascorbate-glutathione cycle and both Mn and Cu/Zn superoxide dismutase. Interestingly, higher content of ascorbate and glutathione, and higher activities of APX in the cytosol of non-photosynthetic leaf cells compared to the photosynthetic ones, suggest the importance of this compartment in H2 O2 regulation. Together, these results imply different regulation of processes linked with H2 O2 signalling at subcellular level. Thus, we propose green-white variegated leaves as an excellent system for examination of redox signal transduction and redox communication between two cell types, autotrophic and heterotrophic, within the same organ.

  • Carbon allocation from source to sink leaf tissue in relation to flavonoid biosynthesis in variegated Pelargonium Zonale under UV-B radiation and high PAR intensity
    Plant physiology and biochemistry : PPB, 2015
    Co-Authors: Marija Vidović, Filis Morina, Bernd Zechmann, Sonja Milić, Andreas Albert, Tomislav Tosti, J. B. Winkler, Sonja Veljović Jovanović
    Abstract:

    Abstract We studied the specific effects of high photosynthetically active radiation (PAR, 400–700 nm) and ecologically relevant UV-B radiation (0.90 W m −2 ) on antioxidative and phenolic metabolism by exploiting the green-white leaf variegation of Pelargonium Zonale plants. This is a suitable model system for examining “source-sink” interactions within the same leaf. High PAR intensity (1350 μmol m −2  s −1 ) and UV-B radiation induced different responses in green and white leaf sectors. High PAR intensity had a greater influence on green tissue, triggering the accumulation of phenylpropanoids and flavonoids with strong antioxidative function. Induced phenolics, together with ascorbate, ascorbate peroxidase (APX, EC 1.11.1.11) and catalase (CAT, EC 1.11.1.6) provided efficient defense against potential oxidative pressure. UV-B-induced up-regulation of non-phenolic H 2 O 2 scavengers in green leaf sectors was greater than high PAR-induced changes, indicating a UV-B role in antioxidative defense under light excess; on the contrary, minimal effects were observed in white tissue. However, UV-B radiation had greater influence on phenolics in white leaf sections compared to green ones, inducing accumulation of phenolic glycosides whose function was UV-B screening rather than antioxidative. By stimulation of starch and sucrose breakdown and carbon allocation in the form of soluble sugars from “source” (green) tissue to “sink” (white) tissue, UV-B radiation compensated the absence of photosynthetic activity and phenylpropanoid and flavonoid biosynthesis in white sectors.