Diversity and function of rhizosphere microorganisms between wild and cultivated medicinal plant Glycyrrhiza uralensis Fisch under different soil conditions.

Glycyrrhiza uralensis Fisch is a widely cultivated traditional Chinese medicine plant. In the present study, culture-independent microbial diversity analysis and functional prediction of rhizosphere microbes associated with wild and cultivated G. uralensis Fisch plant (collected from two locations) were carried. Soil physicochemical parameters were tested to assess their impact on microbial communities. A total of 4428 OTUs belonging to 41 bacterial phyla were identified. In general, cultivated sample sites were dominated by Actinobacteria whereas wild sample sites were dominated by Proteobacteria. The alpha diversity analysis showed the observed species number was higher in cultivated soil samples when compared with wild soil samples. In beta diversity analysis, it was noticed that the weighted-unifrac distance of two cultivated samples was closer although the samples were collected from different regions. Functional annotation based on PICRUST and FAPROTAX showed that the nitrogen metabolism pathway such as nitrate reduction, nitrogen fixation, nitrite ammonification, and nitrite respiration were more abundant in rhizosphere microorganisms of wild G. uralensis Fisch. These results also correlate in redundancy analysis results which show correlation between NO3--N and wild samples, which indicated that nitrogen nutrition conditions might be related to the quality of G. uralensis Fisch.

Succession of endophytic fungi and arbuscular mycorrhizal fungi associated with the growth of plant and their correlation with secondary metabolites in the roots of plants.

BACKGROUND: To decipher the root and microbial interaction, secondary metabolite accumulation in roots and the microbial community's succession model during the plant's growth period demands an in-depth investigation. However, till now, no comprehensive study is available on the succession of endophytic fungi and arbuscular mycorrhizal fungi (AMF) with roots of medicinal licorice plants and the effects of endophytic fungi and AMF on the secondary metabolite accumulation in licorice plant's root. RESULTS: In the current study, interaction between root and microbes in 1-3 years old medicinal licorice plant's root and rhizospheric soil was investigated. Secondary metabolites content in licorice root was determined using high-performance liquid chromatography (HPLC). The composition and diversity of endophytic and AMF in the root and soil were deciphered using high-throughput sequencing technology. During the plant's growth period, as compared to AMF, time and species significantly affected the diversity and richness of endophytic fungi, such as Ascomycota, Basidiomycota, Fusarium, Cladosporium, Sarocladium. The growth period also influenced the AMF diversity, evident by the significant increase in the relative abundance of Glomus and the significant decrease in the relative abundance of Diversispora. It indicated a different succession pattern between the endophytic fungal and AMF communities. Meanwhile, distance-based redundancy analysis and Mantel tests revealed root's water content and secondary metabolites (glycyrrhizic acid, liquiritin, and total flavonoids), which conferred endophytic fungi and AMF diversity. Additionally, plant growth significantly altered soil's physicochemical properties, which influenced the distribution of endophytic fungal and AMF communities. CONCLUSIONS: This study indicated a different succession pattern between the endophytic fungal and AMF communities. During the plant's growth period, the contents of three secondary metabolites in roots increased per year, which contributed to the overall differences in composition and distribution of endophytic fungal and AMF communities. The endophytic fungal communities were more sensitive to secondary metabolites than AMF communities. The current study provides novel insights into the interaction between rhizospheric microbes and root exudates.

Two responses to MeJA induction of R2R3-MYB transcription factors regulate flavonoid accumulation in Glycyrrhiza uralensis Fisch.

Flavonoids are key components of licorice plant that directly affect its medicinal quality. Importantly, the MYB family of transcription factors serves to regulate the synthesis of flavonoids in plants. The MYB transcription factors represent one of the largest families of transcription factors in plants and play important roles in the process of plant growth and development. MYB gene expression is induced by a number of plant hormones, including the lipid-based hormone jasmonate (JA). Methyl jasmonate (MeJA) is an endogenous plant growth regulator that can induce the JA signaling pathway, which functions to regulate the synthesis of secondary metabolites, including flavonoids. In this study, MeJA was added to licorice cell suspensions, and RNA-seq analysis was performed to identify the differentially expressed genes. As a result, the MYB transcription factors GlMYB4 and GlMYB88 were demonstrated to respond significantly to MeJA induction. Subsequently, the GlMYB4 and GlMYB88 protein were shown to localize to the cell nucleus, and it was verified that GlMYB4 and GlMYB88 could positively regulate the synthesis of flavonoids in licorice cells. Overall, this research helps illustrate the molecular regulation of licorice flavonoid biosynthesis induced by MeJA.

The intervention effect of licorice in d-galactose induced aging rats by regulating the taurine metabolic pathway.

Licorice, an edible and officinal plant material, has attracted considerable attention for its wide range of pharmacological activities. Our previous study showed that licorice can ameliorate cognitive damage and improve oxidative stress and apoptosis in aging rats induced by d-galactose (d-gal). In this study, in order to further explore the changes of the metabolic profile during the aging process and the antiaging mechanism of licorice, the 1H NMR-based metabolomics approach was used to analyze serum and urine samples and identify a potential biomarker in d-gal induced aging rats. The results revealed that the taurine metabolic pathway was significantly correlated with the ageing process in d-gal induced rats. Furthermore, the taurine contents were significantly decreased in both the serum and urine samples of aging rats compared with the controls. At the same time, the levels of cysteine dioxygenase type I (CDO1), cysteine sulfinic acid decarboxylase (CSAD) and glutamate decarboxylase type I (GAD1), which are the key enzymes affecting the synthesis reactions, were decreased in aging rats compared with the controls. After licorice administration, the levels of taurine, CDO1 and CSAD were all significantly increased. These findings firstly demonstrated that the regulation of the taurine metabolic pathway is involved in the anti-aging effect of licorice in d-gal induced aging rats.

[Effects of different concentrations of nitrogen,phosphorus and potash on Glycyrrhiza uralensis and its relationship with soil element content].

With annual Glycyrrhiza uralensis seedlings as experimental material, using "3414" optimal regression design and applied fertilizer, through the sampling of G. uralensis at harvest, root fresh weight and content of active components were measured in Lanzhou, Bayan Nur city, Chifeng, Jiuquan. Combined with NPK content in soil, potted experiments were used to study the effects of different nitrogen and phosphorus ratios on the dry matter accumulation and accumulation of active components of G. uralensis. The results reported as follows: the optimum fertilizer treatment in Lanzhou, Bayan Nur city, Chifeng, Jiuquan was N1P2K1,N2P2K1,N1P1K2 and N2P1K2, respectively. The efforts of single fertilizer on the fresh root weight acted as parabolic type.There was no significant effect of fertilizer treatment on the accumulation of active components of G. uralensis. Furthermore, in terms of nitrogen and phosphorus, the type of fertilizers that restricted the growth of the region was the type of elements with lower content in the soil. The optimal fertilizer usage was in inverse proportion to content of elements in soil. When the content of phosphorus in soil was low, nitrogen fertilizer and potash fertilizer showed positive interaction with phosphorus fertilizer, whereas, they showed negative interaction.

Arbuscular mycorrhiza facilitates the accumulation of glycyrrhizin and liquiritin in Glycyrrhiza uralensis under drought stress.

Liquorice (Glycyrrhiza uralensis) is an important medicinal plant for which there is a huge market demand. It has been reported that arbuscular mycorrhizal (AM) symbiosis and drought stress can stimulate the accumulation of the active ingredients, glycyrrhizin and liquiritin, in liquorice plants, but the potential interactions of AM symbiosis and drought stress remain largely unknown. In the present work, we investigated mycorrhizal effects on plant growth and accumulation of glycyrrhizin and liquiritin in liquorice plants under different water regimes. The results indicated that AM plants generally exhibited better growth and physiological status including stomatal conductance, photosynthesis rate, and water use efficiency compared with non-AM plants. AM inoculation up-regulated the expression of an aquaporin gene PIP and decreased root abscisic acid (ABA) concentrations under drought stress. In general, AM plants displayed lower root carbon (C) and nitrogen (N) concentrations, higher phosphorus (P) concentrations, and therefore, lower C:P and N:P ratios but higher C:N ratio than non-AM plants. On the other hand, AM inoculation increased root glycyrrhizin and liquiritin concentrations, and the mycorrhizal effects were more pronounced under moderate drought stress than under well-watered condition or severe drought stress for glycyrrhizin accumulation. The accumulation of glycyrrhizin and liquiritin in AM plants was consistent with the C:N ratio changes in support of the carbon-nutrient balance hypothesis. Moreover, the glycyrrhizin accumulation was positively correlated with the expression of glycyrrhizin biosynthesis genes SQS1, ß-AS, CYP88D6, and CYP72A154. By contrast, no significant interaction of AM inoculation with water treatment was observed for liquiritin accumulation, while we similarly observed a positive correlation between liquiritin accumulation and the expression of a liquiritin biosynthesis gene CHS. These results suggested that AM inoculation in combination with proper water management potentially could improve glycyrrhizin and liquiritin accumulation in liquorice roots and may be practiced to promote liquorice cultivation.

Effect of Abscisic Acid on Accumulation of Five Active Components in Root of Glycyrrhiza uralensis.

Licorice is one of the most generally used herbal medicines in the world; however, wild licorice resources have decreased drastically. Cultivated Glycyrrhiza uralensis Fischer are the main source of licorice at present, but the content of main active components in cultivated G. uralensis are lower than in wild G. uralensis. Therefore, the production of high-quality cultivated G. uralensis is an urgent issue for the research and production fields. In this study, the content of five active components and seven endogenous phytohormones in cultivated G. uralensis (two-year-old) were determined by high-performance liquid chromatography (HPLC) and enzyme-linked immunosorbent assay (ELISA), respectively. Furthermore, different concentrations (25-200 mg/L) of exogenous abscisic acid (ABA) were sprayed on the leaves of G. uralensis in the fast growing period. Results showed that ABA, zeatin riboside (ZR), and dihydrozeatin riboside (DHZR) had strong correlation with active components. In addition, the content of five active components increased remarkably after ABA treatment. Our results indicate that ABA is significantly related to the accumulation of active components in G. uralensis, and the application of exogenous ABA at the proper concentration is able to promote the accumulation of main components in G. uralensis.

Silicon alleviates salt and drought stress of Glycyrrhiza uralensis seedling by altering antioxidant metabolism and osmotic adjustment.

This study was conducted to determine effect and mechanism of exogenous silicon (Si) on salt and drought tolerance of Glycyrrhiza uralensis seedling by focusing on the pathways of antioxidant defense and osmotic adjustment. Seedling growth, lipid peroxidation, antioxidant metabolism, osmolytes concentration and Si content of G. uralensis seedlings were analyzed under control, salt and drought stress [100 mM NaCl with 0, 10 and 20% of PEG-6000 (Polyethylene glycol-6000)] with or without 1 mM Si. Si addition markedly affected the G. uralensis growth in a combined dose of NaCl and PEG dependent manner. In brief, Si addition improved germination rate, germination index, seedling vitality index and biomass under control and NaCl; Si also increased radicle length under control, NaCl and NaCl-10% PEG, decreased radicle length, seedling vitality index and germination parameters under NaCl-20% PEG. The salt and drought stress-induced-oxidative stress was modulated by Si application. Generally, Si application increased catalase (CAT) activity under control and NaCl-10% PEG, ascorbate peroxidase (APX) activity under all treatments and glutathione (GSH) content under salt combined drought stress as compared with non-Si treatments, which resisted to the increase of superoxide radicals and hydrogen peroxide caused by salt and drought stress and further decreased membrane permeability and malondialdehyde (MDA) concentration. Si application also increased proline concentration under NaCl and NaCl-20% PEG, but decreased it under NaCl-10% PEG, indicating proline play an important role in G. uralensis seedling response to osmotic stress. In conclusion, Si could ameliorate adverse effects of salt and drought stress on G. uralensis likely by reducing oxidative stress and osmotic stress, and the oxidative stress was regulated through enhancing of antioxidants (mainly CAT, APX and GSH) and osmotic stress was regulated by proline.

Assessment of genetic fidelity and composition: Mixed elicitors enhance triterpenoid and flavonoid biosynthesis of Glycyrrhiza uralensis Fisch. tissue cultures.

Glycyrrhiza uralensis has acquired significant importance due to its medicinal properties and health function. In this study, the quality of G. uralensis adventitious roots was evaluated in terms of genetic stability, active compounds, and anti-inflammatory activity. Monomorphic banding pattern obtained from the mother plant and tissue cultures of G. uralensis with randomly amplified polymorphic DNA markers confirmed the genetic stability of adventitious roots. Neoliquiritin (neoisoliquiritin), ononin, liquiritin, and glycyrrhizic acid were identified from G. uralensis adventitious roots on the basis of high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry analysis. This study also revealed that adventitious roots possessed a better anti-inflammatory effect than native roots. To increase the contents of G. uralensis active components, elicitors were used in the adventitious roots culture. The combination of methyl jasmonate and phenylalanine synergistically stimulated the accumulation of glycyrrhetinic acid (0.22 mg/g) and total flavonoid (5.43 mg/g) compared with single treatment. In conclusion, G. uralensis adventitious roots can be an exploitable system for the production of licorice.

A synergistic interaction between salt-tolerant Pseudomonas and Mesorhizobium strains improves growth and symbiotic performance of liquorice (Glycyrrhiza uralensis Fish.) under salt stress.

Chinese liquorice (Glycyrrhiza uralensis Fish.) is a salt-tolerant medicinal legume that could be utilized for bioremediation of salt-affected soils. We studied whether co-inoculation of the symbiotic Mesorhizobium sp. strain NWXJ19 or NWXJ31 with the plant growth-promoting Pseudomonas extremorientalis TSAU20 could restore growth, nodulation, and shoot/root nitrogen contents of salt-stressed G. uralensis, which was grown in potting soil and irrigated with 0, 50, and 75 mM NaCl solutions under greenhouse conditions. Irrigation with NaCl solutions clearly retarded the growth of uninoculated liquorice, and the higher the NaCl concentration (75 and 100 mM NaCl), the more adverse is the effect. The two Mesorhizobium strains, added either alone or in combination with P. extremorientalis TSAU20, responded differently to the salt levels used. The strain NWXJ19 was a good symbiont for plants irrigated with 50 mM NaCl, whereas the strain NWXJ31 was more efficient for plants irrigated with water or 75 mM NaCl solution. P. extremorientalis TSAU20 combined with single Mesorhizobium strains alleviated the salt stress of liquorice plants and improved yield and nodule numbers significantly in comparison with single-strain-inoculated liquorice. Both salt stress and inoculation raised the nitrogen content of shoots and roots. The nitrogen contents were at their highest, i.e., 30 and 35 % greater compared to non-stressed uninoculated plants, when plants were inoculated with P. extremorientalis TSAU20 and Mesorhizobium sp. NWXJ31 as well as irrigated with 75 mM NaCl solution. From this study, we conclude that dual inoculation with plant growth-promoting rhizobacteria could be a new approach to improve the tolerance of G. uralensis to salt stress, thereby improving its suitability for the remediation of saline lands.

[Production regionalization study of Glycyrrhiza uralensis].

The distribution information of Glycyrrhiza uralensis was collected by interview investigation and field survey, and 46 related environmental factors were collected, some kinds of functional chemical constituents of G.uralensis were analyzed. Integrated climate, topography and other related ecological factors, the habitat suitability study was conducted based on Arc geographic information system(ArcGIS),and maximum entropy model. The AUC of ROC curve was both above 0.95, indicating that the predictive results with the maximum model were highly precise. The results showed that 5 major ecological factors have obvious influence on ecology suitability distributions of G. uralensis, including July average temperature, soil sub category, Dec precipitation, vegetation types and standard deviation of seasonal variation in temperature, et al. It is suitable for the living habits of the G. uralensis, adequate light, low rainfall, summer heat and large temperature difference between day and night, which is suitable for distribution in the northern temperate plains and mountains. In addition, the ecological suitability regionalization based on the chemical constituents of G.uralensis also provides a new suitable distribution area other than the traditional distribution area, which provides a scientific basis for the reasonable introduction of G.uralensis.

[Effect of exogenous brassinolide on morphological characters and contents of seven chemical constituents of Glycyrrhiza uralensis].

The transplants of the two-year-old Glycyrrhiza uralensis were subjected to four concentration of brassinolide (BR 0.1, 0.4, 0.7, 1.0 mg•L⁻¹) in July. The morphological characters ( plant height, stem diameter, nodes number, internode length and root length , root thick, root fresh weight and root dry weight ) were measured and seven kinds of chemical constituents (glycyrrhizic acid, liquiritin, isoliquiritin, liquiritigenin, isoliquiritigenin, liquiritin apioside, isoliquiritin apioside) were determined by HPLC with the aim of increasing sinter output and improving quality of G. uralensis. Then the long-term dynamic changes of these morphological characters and chemical compositions' content were analyzed. The results showed that morphological characters of plant height, stem diameter, root length , root thick, root fresh weight and root dry weight increased remarkably with the 0.7 mg•L⁻¹ BR stimulating 2 months later,the increase rates were： 15.09%,6.15%,16.52%,8.46%,21.90%,29.41%, respectively. The content of glycyrrhizic acid, liquiritin, isoliquiritin, liquiritigenin, liquiritin apioside, isoliquiritin apioside were increased 20.16%,45.31%,53.56%,27.66%,23.54%,8.46% with the 0.7 mg•L⁻¹ BR stimulating 2 months later. The best effects were achieved in 2 months after brassinolide stimulating. The conclusions prove that morphological characters and the main chemical constituents accumulation of G. uralensis could be effected by exogenous BR stimulation in certain case.

[Effects of abscisic acid on chemical components content and color of Glycyrrhiza uralensis].

An experiment was conducted using cultivated Glycyrrhiza uralensis in age of one year to study the effects of abscisic acid (ABA) on chemical components content and color of G. uralensis. By using different concentrations of ABA spraying on leaves, the change of the chemical component content was analyzed within 45 d after ABA stimulation, and the effects on quality were studied combined with colorimetric analysis data. It turned out that in some sense the content of glycyrrhizic acid and liquiritin had increased within 45 d, especially for liquiritin. After high concentrations of ABA (3.96 mg · L(-1)) stimulating, the content of glycyrrhizic acid rose 52% while liquiritin up 392% within 30 d. Then they both showed a decline in the content of glycyrrhizic acid and liquiritin on 45 d. Color index values of a* and b* were all significantly higher than that of the control group within 45 d, which meant the color of powders turned toward red and yellow. The conclusion was that ABA (3.96 mg · L(-1)) stimulating could not only improve the quality in the traditional sense through the color of G. uralensis, but also in the modern sense by improving the content of glycyrrhizic acid and liquiritin.

[The Indigenization of Licorice and Its Meaning During the Early Days of the Joseon Dynasty].

This article explores the indigenization of licorice(Glycyrrhiza uralensis Fisch.) which was the most important medicine of the Oriental Medicine. There are a lot of records on licorice even before the Joseon Dynasty. The licorice had been used mainly in stomach related diseases such as food poisoning or indigestion. But the licorice was an imported medicine until the early days of the Joseon Dynasty. As the Joseon Dynasty began, the licorice production became necessary with the investigation and obtaining the herbs. And a large amount of licorice was needed when the epidemics outbroke under the reign of King Sejong(). In particular, the licorice had been essential in treating the diseases of the Cold Damage which was focused in the Joseon Dynasty. That was why King Sejong ordered to plant the licorice in the Chollado province and Hamgildo province in 1448. But the licorice cultivation was not easy for two reasons. First, it was difficult to find the proper soil for proper soil for planting. Second, the people didn't actively grow the licorice, because they had to devote the licorice as the tax when the indigenization of licorice was succeeded. King Sejo() and King Seongjong() encouraged the people to plant the licorice. The recognition that the licorice is essential in pediatric diseases such as smallpox got stronger then before. Finally the indigenization of licorice was completed under the reign of King Seongjong. According to the Dongguknyeojiseungnam(), edited in 1481, and Shinjeungdongguknyeojiseungnam( ), edited in 1530, the licorice was planted in seven districts. With the success of the indigenization of licorice, the approach of the people to the Oriental Medicine treatment had became much easier.

[Effect of five fungicides on growth of Glycyrrhiza uralensis and efficiency of mycorrhizal symbiosis].

In order to obtain the fungicides with minimal impact on efficiency of mycorrhizal symbiosis, the effect of five fungicides including polyoxins, jinggangmycins, thiophanate methylate, chlorothalonil and carbendazim on the growth of medicinal plant and efficiency of mycorrhizal symbiosis were studied. Pot cultured Glycyrrhiza uralensis was treated with different fungicides with the concentration that commonly used in the field. 60 d after treated with fungicides, infection rate, infection density, biomass indexes, photosyn- thetic index and the content of active component were measured. Experimental results showed that carbendazim had the strongest inhibition on mycorrhizal symbiosis effect. Carbendazim significantly inhibited the mycorrhizal infection rate, significantly suppressed the actual photosynthetic efficiency of G. uralensis and the most indicators of biomass. Polyoxins showed the lowest inhibiting affection. Polyoxins had no significant effect on mycorrhizal infection rate, the actual photosynthetic efficiency of G. uralensis and the most indicators of biomass. The other three fungicides also had an inhibitory effect on efficiency of mycorrhizal symbiosis, and the inhibition degrees were all between polyoxins's and carbendazim's. The author considered that fungicide's inhibition degree on mycorrhizal effect might be related with the species of fungicides, so the author suggested that the farmer should try to choose bio-fungicides like polyoxins.

The Indigenization of Licorice and Its Meaning During the Early Days of the Joseon Dynasty / 의사학

This article explores the indigenization of licorice(Glycyrrhiza uralensis Fisch.) which was the most important medicine of the Oriental Medicine. There are a lot of records on licorice even before the Joseon Dynasty. The licorice had been used mainly in stomach related diseases such as food poisoning or indigestion. But the licorice was an imported medicine until the early days of the Joseon Dynasty. As the Joseon Dynasty began, the licorice production became necessary with the investigation and obtaining the herbs. And a large amount of licorice was needed when the epidemics outbroke under the reign of King Sejong. In particular, the licorice had been essential in treating the diseases of the Cold Damage which was focused in the Joseon Dynasty. That was why King Sejong ordered to plant the licorice in the Chollado province and Hamgildo province in 1448. But the licorice cultivation was not easy for two reasons. First, it was difficult to find the proper soil for proper soil for planting. Second, the people didn't actively grow the licorice, because they had to devote the licorice as the tax when the indigenization of licorice was succeeded. King Sejo and King Seongjong encouraged the people to plant the licorice. The recognition that the licorice is essential in pediatric diseases such as smallpox got stronger then before. Finally the indigenization of licorice was completed under the reign of King Seongjong. According to the Dongguknyeojiseungnam, edited in 1481, and Shinjeungdongguknyeojiseungnam, edited in 1530, the licorice was planted in seven districts. With the success of the indigenization of licorice, the approach of the people to the Oriental Medicine treatment had became much easier.

[Wild-tending techniques study on Glycyrrhiza uralensis--effect of irrigation and rhizome length on survival ratio, yield and quality].

This research aimed at studying the effects of irrigation and rhizome length on the survival of ratio, yield and quality of Glycyrrhiza uralensis in wild tending condition. Employed the split-block design to carry out the field experiment, sampled with the quadrat method to measured the relative growth indexes and to estimate the yield, used the HPLC (high performance liquid chromatog- raphy ) method to measure the glycyrrhizin in the rhizome and adventitious root of the G. uralensis in this study. The quantity of the adventitious roots and the survival ratio were increased significantly as the length of the rhizome increased (P < 0.01), but the length of the rhizome had no remarkable effect on the content of glycyrrhizin. The average content of the glycyrrhizin in the adventitious root and rhizome could reach 3.03% and 2.12% after 3-year wild tending, respectively, and this results indicated that the quality of the glycyrrhiza using this method was much better than that from cultured glycyrrhiza with the reproducing method of seeding. so using the rhizome as reproductive material to produce the glycyrrhiza under the wild tending condition could get the high quality glycyrrhiza quick- ly and steadily, this phenomenon could be explained by the Hypothesis of synthetic inertia of the medicinal components from the wild material of G. uralensis. But the maximum yield with this method was just more than 945 kg x hm(-2) in this study. So the further work of how to increase the yield in the practical application with the method found in this study need to be done in the next research.

[Effect of nitrogen supply on biomass accumulating and root respiration dynamic changing of Glycyrrhiza uralensis].

This paper aimed to study the effect nitrogen supplying on biomass accumulation and root respiration dynamic change of Glycyrrhiza uralensis and reveal the metabolic pathway of root respiration impact the biomass accumulating of G. uralensis. Six groups of one-year-old G. uralensis were fertilized with total nutrition containing various nitrogen concentration (0, 0.5, 1, 2, 4, 8 mmol x L(-1)) every week. At the end of every month, from June to October, the volume respiration rate and biomass of different classes of root samples were determined, and the correlation between root respiration and biomass was analyzed. The results indicated a negative correlation between volume respiration rate and biomass, nitrogen supply significantly affected both root respiration and biomass of G. uralensis by reducing root respiration and increasing root biomass. Under 8 mmol x L(-1) nitrogen supplying, there existed the optimal inhibition of root respiration, which has increased biomass of G. uralensis.

Distribution patterns of the contents of five active components in taproot and stolon of Glycyrrhiza uralensis.

Wild or cultivated Glycyrrhiza uralensis FISCHER (G. uralensis) are the main source of licorice, and they contain the similar compounds, such as the triterpenoid saponins and flavonoids, but above two kinds of the components contents are low level in the cultivated licorice. To produce the high quality cultivated licorices, researchers studied the affecting factors about the compounds producing in the plant of licorice, and then found that the growth years, genetic differences and water deficit are all the important factors. In this paper, we found that there were different distribution patterns of the main five active components (FAC) including glycyrrhizin, liquiritin, isoliquiritin, liquiritigenin and isoliquiritigenin in the taproot and stolon of G. uralensis and maybe they are also important influence factors to the FAC contents of the licorices. In wild G. uralensis, the contents of FAC tended to be lower in the younger parts of the stolon, and in the cultivated G. uralensis taproot, the contents of glycyrrhizin, liquiritin and isoliquiritin tended to increase from top to end, contrary to the contents of liquiritigenin and isoliquiritigenin, which increased first and then decreased. Our results will contribute to the analyses of factors which influence the quality of licorice, and provide some reference for cultivating high quality licorices for herbal medicine.

Aim for production of Glycyrrhizae Radix in Japan (3): development of a new licorice cultivar.

The development of cultivars is indispensable for the establishment of a method aimed at producing licorice in Japan. The cultivar should have the following attributes: (1) the underground parts should grow vigorously; (2) the glycyrrhizin (GL) content must be 2.5 % or greater; and (3) the architecture of the aerial parts should be erect. A new cultivar suitable for the domestic production of licorice was developed by crossbreeding between strain A-19 (with a high GL content) as the mother and strain G-6 (with vigorous growth) as the father. After 2 years of cultivation, strain C-2 exhibited vigorous growth; the fresh weight and stem diameter were 148.8 g and 0.89 mm, respectively. Moreover, the dry-weight GL and total flavonoid contents of the new cultivar (strain C-2) from cultured plants were 3.61 and 1.365 %, respectively.