In this study, the plantlet regeneration of
Panax vietnamensis
via somatic embryogenesis derived from hairy root callus was investigated. The results showed that the percentage of callus-induced ...hairy roots was 100% on SH medium supplemented with 0.5 mg/L NAA combined with 2.0 mg/L BA and 30 g/L sucrose after 6 weeks of culture. Callus was transferred to SH medium supplemented with 1.0 mg/L 2.4-D combined with 2.0 mg/L BA to induce somatic embryogenesis. The percentage of somatic embryogenesis callus was 100%, and the average number of embryos per sample was 63.7 embryos after 6 weeks of culture. The somatic embryos were then transferred to the plant growth regulators-free SH medium for the maturation. They developed progressively through the globular, heart, torpedo, cotyledon stages, and finally formed plantlets. PCR analysis revealed that plantlets derived from hairy roots retained the Ri T-DNA. The morphology of these plantlets were not different from the non-transformed plantlets as a control, but the root growth was better. Adding iron nanoparticles to the culture medium had improved the in vitro rhizome proliferation and growth of plantlets derived from hairy root, which supported plantlets survival when planted in the soil. This is the first report of transgenic plantlets regeneration from hairy roots in
P. vietnamensis
that shows the possibility of regenerating transgenic plantlets derived from hairy roots via somatic embryogenesis in high valuable medicinal plants.
Key Message
Plantlet regeneration of Panax vietnamensis via somatic embryogenesis derived from hairy root callus Iron nanoparticles in culture medium improved the in vitro rhizome proliferation and growth of plantlets.
Abstract
This work aimed at preparing and characterizing
TiO
2
nanotube supported hydrated ruthenium oxide catalysts. First of all, we succeeded in preparing
TiO
2
nanotube arrays by electrochemical ...anodization of titanium metal at 20 V for 8 h in a 1M
H
3
PO
4
+0.5
wt
% HF solution as evidenced from scanning electron microscopy (SEM) and x-ray photoelectron spectroscopy
(
XPS) results. The hydrated ruthenium oxide was then deposited onto
TiO
2
nanotubes by consecutive exchange of protons by
Ru
3+
ions, followed by formation of hydrated oxide during the alkali treatment. Further XPS measurements showed that the modified samples contain not only hydrated ruthenium oxide but also hydrated ruthenium species Ru(III)-OH.
In this study, the positive effect of AgNPs solution at the concentration of 2 mg/L on the in vitro shoot multiplication of Chrysanthemum was recored; this experiment was carried out to improve shoot ...quality and produce a large number of material sources for our experiments. Phytohormones are organic substances synthesized during plant metabolism. They have an obvious physiological effect on plant growth at very low concentrations. Phytohormones are found not only in higher plants but also in algae, bacteria and fungi related to plants. Previous studies have focused on determining which microorganisms can biosynthesize phytohormones and their effects on plant growth and development and stress tolerance under ex vitro conditions; however, few studies evaluate the effects of these compounds on in vitro plant growth. In this study, the effect of a phytohormone mixture (zeatin, IAA and GA
3
) produced by
Pseudomonas otitidis
YWY-9.1 on the growth and development of Chrysanthemum plantlets was determined for the first time. After 30 days of culture, physiological parameters such as plantlet height (6.17 cm), number of stem nodes (4.70 stem nodes/plantlet), number of leaves (10.33 leaves/plantlet), chlorophyll content (27.00 nmol/cm
2
), number of roots (4.67 roots/plantlet), root length (6.17 cm), fresh weight (6.17 mg) and dry weight (0.077 mg) of Chrysanthemum plants cultured on medium supplemented with 10 mL/L of phytohormones sterilized by filter was superior to that of the other treatments and the control. Besides, the content of endogenous hormones and antioxidant enzymes in Chrysanthemum plants grown on this medium is also more optimal. Furthermore, the plantlets derived from the medium containing phytohormones had better acclimatization and growth under ex vitro conditions than the control. However, when adding phytohormones at high concentration (15 mL/L), the growth and development parameters of Chrysanthemum was inhibited, reducing the quality of plantlets. Moreover, when adding phytohormones derived from microorganisms to the culture medium, a syringe filter should be used, avoiding sterilization at high temperature so as not to affect the phytohormone’s activity.
Key message
Supplementation of phytohormones produced by
Pseudomonas otitidis
YWY-9.1 in culture medium positively effects on growth and development of Chrysanthemum plantlets.
The spinel oxides NixZn1-xAl2O4/γ-Al2O3 (x = 0, 0.5, 1) were synthesized by hydrothermal method. Oxides obtained were characterized by XRD and SEM. The XRD result showed principal spinel phase over ...all samples. In addition, NiO phase appeared for two cases of x = 0.5 and 1. Using XRD results, the Rietveld Refinement method indicated that the sample ZnAl2O4/γ-Al2O3 consisted of wt 80% of ZnAl2O4 and 20% of γ-Al2O3 with crystal size of 60 nm and 40 nm, respectively. This one was in accordance with SEM image which showed quite uniform particles with the side from 50 to 80 nm. Catalytic activity was evaluated by methylation of toluene by methanol and dehydrogenation of ethylbenzene to styrene. For methylation reaction, the results showed high selectivity in xylene. In case of Ni0.5Zn0.5Al2O4/γ-Al2O3, at 400°C, the result showed the best toluene conversion of 25.46% and selectivity in xylene was 88.33%. In case of ethylbenzene dehydrogenation reaction, sample ZnAl2O4 synthesized by coprecipitation method used as a reference catalyst. We observed, after 180 min of time reaction, a double conversion of ethylbenzene on ZnAl2O4/γ-Al2O3 in comparison with ZnAl2O4 reference. In addition, working time of ZnAl2O4/γ-Al2O3 was longer than this one of ZnAl2O4 reference. DOI: 10.1380/ejssnt.2012.259
In this report, several series of AB2O4 (A = Zn2+ (Cu2+); B = Al3+, Cr3+) nanospinels were synthesized by hydrothermal method at different hydrothermal temperatures in autoclave. In this synthesis, ...the thermodifferential analysis method was used to find out the optimum temperature of calcinations for nanospinel phase formation. The structural, textural properties of the catalysts as-obtained were characterized by physical methods: DTA-TGA, XRD, TEM, BET. Their catalytic activity was measured by using oxidative dehydrogenation reaction of ethylbenzene to styrene at different temperatures. From experiment results obtained, it is observed that in the presence of the nanospinels catalysts, the catalytic activity and selectivity in styrene is high. DOI: 10.1380/ejssnt.2012.268
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