Cerium improves the physiology and medicinal components of Dendrobium nobile Lindl. under copper stress.

Heavy metal stress affects the quality of medicinal plants, and rare earth elements can effectively alleviate heavy metal stress. In this paper, we investigated the effects of rare earth element cerium (0, 5, 10, 20, 40, 80, and 160 mg/L) on the physiological and medicinal components of Dendrobium nobile Lindl. under copper (200 mg/L) stress. The results revealed that cerium (Ce) had a good alleviating effect on copper (Cu) stress, low concentrations of Ce (10-20 mg/L) significantly improved the resistance and medicinal qualities of the plant such as polysaccharide, polyphenol and flavonoid, it also increased the content of photosynthetic pigment, proline, soluble sugar and soluble protein of D. nobile Lindl., effectively balance the osmotic pressure and the generation and removal of reactive oxygen species in the plant, thereby the toxic effect of copper on D. nobile Lindl. is alleviated. From the point of view of the treatment time when the optimal relieving concentration appeared, the optimal concentration for relieving antioxidant enzyme activity all appeared at the treatment time of 10 d, the optimum concentrations of other indicators all appeared at the treatment time of 15 d. Overall, this study suggests that the optimum level of Ce (10-20 mg/L) might be promising for alleviating the adverse impacts of copper stress and promoting the accumulation of medicinal components in D. nobile Lindl.

A New Dual-peak Fluorescent Probe for Water Content Detection Made From Taxus.

In this paper, the leaves of Taxus were used as the sole carbon source, and two kinds of carbon dots blue and red, with different properties, were synthesized by the hydrothermal method under different conditions. The red carbon dots were quenched in the water, and the blue carbon dots had stable fluorescence properties in water environment. The bimodal fluorescence probe formed by mixing could accurately and stably measure the water content in ethanol, which was in the range of 82.5%-100%, is highly correlated with the fluorescence intensity ratio (I481/I678) of mixed carbon dots under 390 nm excitation light, with R2 = 0.995 and the detection limit as low as 0.31%. The experimental materials are environmentally friendly, low in cost, and simple to operate, as well as the water content measured by proportional fluorescence has high accuracy, which provides a new method for measuring moisture in ethanol.

Zinc affects the physiology and medicinal components of Dendrobium nobile Lindl.

The growth of Dendrobium nobile is often influenced by zinc. Here, D. nobile was regularly sprayed with different concentrations (0, 50, 100, 200, 400, 800, 1000, 2000 µmol L-1) of zinc to study its effect on the growth and biosynthesis of medicinal components. Samples were taken at 0, 7, 14, and 21 days to detect physiological and medicinal components. The results showed that the net photosynthetic rate, transpiration rate, stomatal conductance, and Chl A and Chl B levels of leaves first increased and then decreased as the concentration of zinc increased. At 400 µmol L-1 concentration, these parameters reached their maximum values. Thus, a certain dose of zinc could promote the photosynthesis of D. nobile. There was an obvious increase in the synthesis of superoxide dismutase (SOD), while the content of ascorbate peroxidase and ascorbic acid (AsA) were the highest after treatment with 400 µmol L-1 zinc. Maximum levels of polysaccharides and polyphenols were observed on day 7 and 14, respectively, at a zinc concentration of 400 µmol L-1. These results suggest that exogenous zinc may promote the accumulation of medicinal components in D. nobile. It was also found that polysaccharides could combine well with zinc to form a polysaccharide-zinc chelate and transform inorganic zinc into organic form, which is stored in the form of polysaccharide-Zn and is known to reduce the damage induced by Zn stress.

Novel method for improving ardicrenin content in hairy roots of Ardisia crenata Sims plants.

To develop an alternative medicine related with taxol/camptothecin, a hairy roots induction system for measuring triterpenoid saponin ardicrenin was established. In the current study, mature and healthy seeds of Ardisia crenata plants were selected for obtaining aseptic seedlings. Two Agrobacterium rhizogenes strains ATCC 15834 and A4 were used to infect aseptic euphylla for inducing hairy roots of A. crenata plants. For the best combination of seeds germination, a Murashige-Skoog medium containing 1.0 mg L-1 6-benzylaminopurine and 1.0 mg L-1 naphthalene acetic acid was made, which reached a rate of 92.4 %. Results showed that ATCC 15834 and A4 both induced hairy roots of A. crenata for improving ardicrenin production. The PCR analysis demonstrated that ATCC 15834 and A4 Ri plasmid T-DNA had been successfully transferred and integrated into the genome of leaf cell nuclei, however the Vir region was not. Further, ardicrenin content in hairy roots ACHR 15834 8.2 %) induced by ATCC 15834 was quantified by the RP-HPLC, which was also 1.8-, 2.7-, 9.4- and 2.6-fold greater than those of ACHR 4 induced by A4 (4.5 %), ACR C formed by tissue culture (3.1 %), euphylla (0.8 %) and NR C formed nature (3.2 %), respectively. Taken together, hairy root lines of A. crenata obtained were able to express naturally more ardicrenin than natural plants.

Effects of non-thermal plasma treatment on the polysaccharide from Dendrobium nobile Lindl. And its immune activities in vitro.

In order to improve the hydrophilicity and immune activity of the polysaccharide from Dendrobium nobile Lindl., non-thermal plasma was used to treat the polysaccharide. It was found that the hydrophilicity of the polysaccharide plasma-treated was significantly enhanced. Infrared spectra showed that the content of OH in the molecule increased significantly, and the monosaccharide ring changed from ß-pyran sugar to ß-furan sugar. The detection of SEM, AFM and TEM showed that the degree of cross-linking of surface molecules increased, and the arrangement of the polysaccharide was more compact and orderly. In vitro cell tests showed that the polysaccharide plasma-treated significantly improve the phagocytosis ability of RAW264.7, and promote the secretion of cytokines TNF-α, IL-6, IL-1. However, the cell proliferation test indicated that the polysaccharide did not increase the concentration of cytokines by promoting cell proliferation. RT-PCR showed that the polysaccharide plasma-treated could promote the expression of IL-1ß at the transcriptional level. These results showed that non-thermal plasma treatment can effectively enhance the hydrophilicity of the polysaccharide and enhance its immune activity in vitro. Therefore, it can be inferred that the non-thermal plasma technology can be applied to the modification of active polysaccharides and will promote active polysaccharides to work better.

[Tissue culture and plant regeneration of Ardisia crenata].

OBJECTIVE: Our research studied the fast-breeding technology of Ardisia crenata sims by using tissue culture and provided the scientific foundation for industry production. METHOD: The effects of axillary buds and plant regeneration of different basic medium, hormones and additives on induction and multiplication were studied. RESULT: The best culture medium for the induction of axillary buds, which took the stems of A. crenate were as explants, was MS + 6-BA 0.5 mg x L(-1) + NAA 0.1 mg x L(-1), and the best medium for multiplication was MS + 6-BA 2.0 mg x L(-1) + NAA 0.1 mg x L(-1) + KT 0.5 mg x L(-1), the best medium for roots generation was 1/2MS + IBA 0.2 mg x L(-1). We also found that the roots'generation, roots rate and mean number of roots can be promoted by adding 0.2% Ac, and the most suitable ground substance was river sand-perlite-vermiculite (1:1:1) or perlite-vermiculite (1:1). With axillary buds and plant regeneration methode, more than 80% A. crenata sims could be regenerated integratedly. CONCLUSION: A. crenata sims can be regenerated integratedly and breeded fast by using axillary bud proliferation technology.