NMR based metabolomic comparison of the antitussive and expectorant effect of Farfarae Flos collected at different stages.

Farfarae Flos (FF) is widely used for the treatment of cough, bronchitis, and asthmatic disorders in the Traditional Chinese Medicine (TCM). According to the experience of TCM, only the flower bud can be used as herbal drug, and its medicinal quality becomes lower after blooming. However, the underlying scientific basis for this phenomenon is not fully understood. In this study, the chemical components and the bioactivities of the FF collected at three different development stages were compared systematically. NMR based fingerprint coupled with multivariate analysis showed that the flower buds differed greatly from the fully opened flower both on the secondary and primary metabolites, and the animal experiments showed that the fully opened flower exhibited no antitussive or expectorant effect. In addition, the endogenous metabolites correlated with the antitussive and expectorant effect of FF were also identified. These findings are useful for understanding the rationality of the traditional use of FF, and also suggested the components responsible for the antitussive and expectorant effect of FF.

[Tissue culture of callus and establishment of regeneration system of Tussilago farfara petiole].

Young petiole of Tussilago farfara was used as the material to investigate the plant growth regulators which could influence in vitro culture and plant regeneration and to establish rapid propagation technique. The ideal sterilization method was that young petiole of T. farfara was sterilized with 75% ethanol for 30 s, and then transferred to saturated bleaching power supernatant for 15 min. The suitable medium for callus induction was MS+6-BA 3.0 mg•L⁻¹+2,4-D 2.0 mg•L⁻¹ with 96.2% induction rate. The seedlings had better differentiation with 91% differentiation rate and 8.26 buds on the medium containing MS+ZT 2.0 mg•L⁻¹+NAA 0.3 mg•L⁻¹. The preferred enrichment medium of adventitious bud was MS+KT 1.0 mg•L⁻¹+IBA 0.3 mg•L⁻¹ with 11.81 enrichment times and 4.9 cm seedling height. The rooting medium included 1/2MS+IBA 0.2 mg•L⁻¹ with the average number of rooting was 5.86 and the rooting rate was above 95.22%. The container seedlings can grow well and the survival rate was more than 90% when they were transplanted on the medium added with river sand and organic fertilizer with the ratio of 3∶1. The field experiments indicated that significant differences in increment and yield of pollen grains among the tissue-culture, cultivation and wild type of T. farfara under the same cultivation conditions. The cultivated plants were relatively high on the increment and yield of pollen grains. The active ingredient content of the tissue culture and the wild materials was basically the same.

Metabolomic profiling of the antitussive and expectorant plant Tussilago farfara L. by nuclear magnetic resonance spectroscopy and multivariate data analysis.

This study aims to find metabolites responsible for antitussive and expectorant activities of Tussilago farfara L. by metabolomic approach. Different parts (roots, flower buds, and leaves) of the title plant were analyzed systematically. The in vivo study revealed that the leaves and flower buds had strong antitussive and expectorant effects. Then ¹H NMR spectrometry together with principal component analysis (PCA) and partial least squares discriminant (PLS-DA) analysis were used to investigate the compounds responsible for the bioactivities. PCA was used to find the differential metabolites, while PLS-DA confirmed a strong correlation between the observed effects and the metabolic profiles of the plant. The result revealed that chlorogenic acid, 3,5-dicaffeoylquinic acid, and rutin may be closely related with the antitussive and expectorant activities. The overall results of this study confirm the benefits of using metabolic profiling for screening active principles in medicinal plants.

[Metabolomic study of flower buds of Tussilago farfara in different development stages by GC-MS].

OBJECTIVE: Plant metabolomics combined with GC-MS was used to investigate metabolic fingerprinting of Tussilago farfara at different growth stages. METHOD: Dried Samples were extracted by two-phase solvent system to obtain polar and nonpolar parts, which were subjected to GC-MS analysis. Metabolites were identified by NIST data base search and comparison with the authentic standards. The data were introduced into SIMCA-P 11.0 software package for multivariate analysis after pretreatment. RESULT: Fifty-four metabolites were identified, including 35 polar metabolites and 19 nonpolar compounds. The score plot for PCA showed clear separation of the different development stages of flower buds of T. farfara, showing a trend of gradual change. Samples of October, November, December were in close proximity on the plot, indicating that the metabolome of these three periods was similar, samples from September (early development) and March (after flowering) were far away, showing big chemical differences. Content comparison results of some representative metabolites reveals that, the content of proline, lysine and linoleic acid increased gradually to the highest in the medium term, but sharply decreased to the lowest after flowering; the content of malic acid and citric acid were the lowest in the medium term; sucrose content decreased gradually, and then reached the lowest level after blooming. CONCLUSION: It is obvious that metabolites of the early development and flowering stage were quite different with those of the traditional harvest time, suggesting that they can not be used as traditional medicine. This study will provide a research basis for harvest time determination and bioactive compounds of T. farfara.

Influence of inflorescence size on sexual expression and female reproductive success in a monoecious species.

Sex allocation theory forecasts that larger plant size may modify the balance in fitness gain in both genders, leading to uneven optimal male and female allocation. This reasoning can be applied to flowers and inflorescences, because the increase in flower or inflorescence size can differentially benefit different gender functions, and thus favour preferential allocation to specific floral structures. We investigated how inflorescence size influenced sexual expression and female reproductive success in the monoecious Tussilago farfara, by measuring patterns of biomass, and N and P allocation. Inflorescences of T. farfara showed broad variation in sex expression and, according to expectations, allocation to different sexual structures showed an allometric pattern. Unexpectedly, two studied populations had a contrasting pattern of sex allocation with an increase in inflorescence size. In a shaded site, larger inflorescences were female-biased and had disproportionately more allocation to attraction structures; while in an open site, larger inflorescences were male-biased. Female reproductive success was higher in larger, showier inflorescences. Surprisingly, male flowers positively influenced female reproductive success. These allometric patterns were not easily interpretable as a result of pollen limitation when naïvely assuming an unequivocal relationship between structure and function for the inflorescence structures. In this and other Asteraceae, where inflorescences are the pollination unit, both male and female flowers can play a role in pollinator attraction.

The timing of life-history events in a changing climate.

Although empirical and theoretical studies suggest that climate influences the timing of life-history events in animals and plants, correlations between climate and the timing of events such as egg-laying, migration or flowering do not reveal the mechanisms by which natural selection operates on life-history events. We present a general autoregressive model of the timing of life-history events in relation to variation in global climate that, like autoregressive models of population dynamics, allows for a more mechanistic understanding of the roles of climate, resources and competition. We applied the model to data on 50 years of annual dates of first flowering by three species of plants in 26 populations covering 4 degrees of latitude in Norway. In agreement with earlier studies, plants in most populations and all three species bloomed earlier following warmer winters. Moreover, our model revealed that earlier blooming reflected increasing influences of resources and density-dependent population limitation under climatic warming. The insights available from the application of this model to phenological data in other taxa will contribute to our understanding of the roles of endogenous versus exogenous processes in the evolution of the timing of life-history events in a changing climate.