Effects of shell sand burial on seedling emergence, growth and stoichiometry of Periploca sepium Bunge.

BACKGROUND: Sand burial plays an irreplaceable and unique role in the growth and distribution of vegetation on the Shell Dike Island in the Yellow River Delta. There are still some unknown on the effects of sand burial on the morphology, biomass, and especially the stoichiometry of Periploca sepium, as well as the relationship between these factors. RESULTS: Shell sand burial depth had a significant influence on seedling emergence, growth, and biomass of P. sepium. Shallow sand burial shortened the emergence time and improved the emergence rate, morphological and biomass of P. sepium compared to deep burial and the control. Burial depth significantly affected the nitrogen (N) and phosphorus (P) contents of the leaves. With deep burial, the carbon/nitrogen (C/N) and carbon/phosphorus (C/P) ratios decreased firstly and then increased with depth, while the nitrogen/phosphorus ratio (N/P) presented the contrary trend. Correlation analysis showed that the stoichiometry of N/P was positively correlated to morphology and biomass of P. sepium at different burial depths. Structural equation model analysis revealed that N was the largest contributor to P. sepium biomass. CONCLUSIONS: Optimal burial depth is beneficial to the seedling emergence, growth and nutritional accumulation of P. sepium. Stoichiometry has an important influence on the morphological formation and biomass accumulation.

[Quality assessment of Periplocae Cortex from different habitats by UPLC fingerprint and quantitative analysis].

Ultra performance liquid chromatography (UPLC) was employed for simultaneous determination of three components and fingerprint analysis of Periplocae Cortex with gradient elution of mehtanol and water containing 0.1% phosphoric acid as mobile phase. Three components including chlorogenic acid, 4-methoxysalicylaldehyde and periplocoside were well separated under the analytical condition. Seventeen peaks were selected as the common peaks of 30 batches of Periplocae Cortex. The results showed that there is a significant difference in contents of periplocoside between the samples collected from Henan and Shanxi province. Based on the results of three components quantification and fingerprint analysis, hierarchical clustering analysis ( HCA) and principle component analysis (PCA) were used to further prove the differences between two group samples, and the results indicated that quality of Periplocae Cortex from Shanxi was more stable than that from Henan. The established UPLC fingerprint and quantitative analysis methods could be used efficiently in the quality control of Periplocae Cortex, and this study might contribute to the reasonable clinical application.

[Study on tissue culture and plant regeneration of the stem-tips and buds of Periploca forrestii].

OBJECTIVE: To establish the rapid propagation systems of the stem-tips and buds of Periploca forrestii. METHODS: Inserted the stem-tips and buds of Periploca forrestii into MS medium with different concentrations of 6-BA, NAA and 2.4-D and induced them growing into complete plants. RESULTS AND CONCLUSION: The optimal culture medium for bud induction is MS + 6-BA 1.0 mg/L + NAA 0.3 mg/L and the bud induction rate can reach 86.29%. The optimal culture medium for stem-tips induction is MS +6-BA 2.0 mg/L + NAA 0.5 mg/L and the bud induction rate can reach 86.29%. The optimal culture medium for bud multiplication is MS + 6-BA 2.0 mg/L + NAA 0.1 mg/L and the multiplication coefficient can reach 2.10. The best rooting medium is 1/2 MS + IBA 0.5 mg/L and the rooting rate is 53.33%.

[Affect of Ag+ and La3+ elicitors on growth and accumulation of adventitious roots of Periploca sepium].

OBJECTIVE: To study the characteristics of the growth and periplocin accumulation of the adventitious roots of Periploca sepium, and on this basis, study the effect of Ag+ and La3+ elicitors on the growth and periplocin accumulation of the adventitious roots. METHOD: The adventitious roots were sampled every four days, and the dry weight and the contents of the periplocin were measured. The curves of the growth and periplocin accumulation of the roots were plotted. The Ag+ and La3+ elicitors with different concentrations were added to the medium when the adventitious roots grew in the stable phase to study the optimal concentration which was good to synthesize the periplocin. Besides, the optimal concentration of Ag+ and La3+ elicitors was added to the different growth phases to study the effect of the elicitors on the growth and periplocin synthesis of adventitious roots. RESULT: The characteristics of the growth of adventitious roots of P. sepium showed a typical growth S-Curve, which displayed a half-coupling relationship with the metabolism of periplocin. The optimal concentrations of Ag+ and La3+ elicitors were both 0.05 mmol L(-1). Besides, it was the best period for the Ag+ and La3+ elicitors to elicit the synthesis of periplocin when in the terminally exponential phase. CONCLUSION: The growth of adventitious roots and the accumulation of periplocin show a half-coupling relationship. Besides, the concentration and additive time of Ag and La3+ elicitors obviously influences the growth of adventitious roots and synthesis of periplocin.

[Cutting propagation of Periploca forrestii and dynamic analyses of physiological and biochemical characteristitics related to adventitious roots formation].

OBJECTIVE: To study the effects of different auxcin regulators on rooting of Periplocaforrestii cuttings as well as dynamic change rules of endogenous plant hormones and oxidases related to adventitious root formation. METHODS: Cuttings propagation characters of Periploca forrestii were investigated and compared with different concentration treatments of indolebutyric acid (IBA), Rooting Powder No. 1 (ABT1) and naphthylacetic acid (NAA). The dynamic changes of contents of endogenous hormones including indole acetic acid (IAA), abscisic acid (ABA), zeatin ribosides (ZRs) as well as the activities of indoleacetic acid oxidase( IAAO), polyphenol oxidase (PPO), peroxidase (POD) were tested. RESULTS: Rooting percentage of cutting with 150 mg/L IBA, 150 mg/L ABT1 treatment and NAA treatment were 80% ,70% and 68% respectively, rooting percentage of cuttings of the control was 23% only. The adventitious rooting displayed three distinct phases i. e. root-inducing, root-formating and root-elongating phases. During root-inducing phase the contents of IAA, ABA and ZRs decreased,whereas IAAO activity kept at a higher level. The IAA content reached the peak and PPO activity increased obviously during root-formating phase, while activities of IAAO, POD and contents of ABA, ZRs declined to minimum. During root-elongating phase contents of IAA, ABA, ZRs were much steadfast and activities of PPO, IAAO, POD were increased. After that, the activities of the three oxidases decreased slowly. 150 mg/L IBA treatment increased the content of IAA and PPO activity in cuttings during rooting,while the opposite result occurred in contents of ZRs, ABA and the activities of IAAO, POD. CONCLUSION: The dynamic changes of endogenous hormones (IAA, ABA, ZRs) contents and IAAO, PPO, POD activities are tightly related to the rooting process of cuttings in Periploca forrestii.

[Induction of Periploca sepium in vitro plantlet and studies on dynamic accumulation of periplocin].

OBJECTIVE: To analyze the content of periplocin in different part of the Periploca sepium in vitro plantlet and study its dynamic variation during the process of differentiation. METHOD: The seeds were generated seedling under aseptic condition, and the cut hypocotyl was induced to form the callus and adventitious buds on the MS culture medium with the hormone of IBA 0.1 mg x L(-1) + BA 1 mg x L(-1). The seedling was cut down when the buds grew up to 3 cm and then the root was cultured in the 1/2 MS culture medium with the hormone of IBA 0.5 mg x L(-1) to form intact plantlet. Different parts of it were collected and the content of periplocin was measured during the process of differentiation. RESULT: The contents of periplocin varied widely in different parts during the process of differentiation, with the highest in the roots and then callus, stem and leaf of intact plantlet, stem and leaf of plantlet without root from high to low. CONCLUSION: The periplocin of the secondary metabolite is more likely to be produced and accumulated in root and callus. Periplocin in stem and leaf is probably transported by conducting tissue.