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Background and aims: Nitrogen (N) deposition and native allelopathic plants may affect seed germination and growth of species through their effects on soil microbes and soil nutrient availability. However, our understanding of the interactions between N addition and allelopathic plants on the regeneration of alpine grasslands remains limited. Methods: Here, we investigated the effects of N addition and the presence of the allelopathic plant Ligularia virgaurea (Maxim.) Mattf. on seed germination, survival, and growth of native herbaceous species (Elymus nutans, Delphinium kamaonense and Tibetia himalaica) on the Qinghai-Tibet Plateau. We used piecewise structural equation modelling to assess both the direct effects of N addition, allelopathic plants, and their interactions and indirect effects mediated by soil properties, soil microbial richness and diversity, and soil enzyme activity. Results: We found that (1) L. virgaurea directly increased seed germination and early plant survival, and reduced plant root-to-shoot ratio; N addition directly increased early plant survival and biomass, (2) L. virgaurea indirectly increased plant biomass via bacterial richness, (3) N addition offsets the increase in seed germination promoted by the presence of L. virgaurea via soil acid phosphatase. Conclusion: Our study suggests the importance of direct and indirect roles of allelopathic plants, N addition and their interaction on seed germination, survival and plant growth. Our results highlight the need to consider the interactions between environmental and biological factors as well as their direct and indirect effects to obtain reliable predictions and mechanistic understanding of the response of alpine plants to future climate change. [ABSTRACT FROM AUTHOR]

Ligularia virgaurea is one of the original plants of the Tibetan medicine “Rixiao” for the treatment of clearing heat and removing yellow water. In order to study the chemical constituents and anti-inflammatory activity of L. virgaurea, the compounds were separated by silica gel, Sephadex LH-20 gel, ODS gel column chromatography and other column chromatography technologies. The structures of all isolates were identified by spectroscopic methods (NMR and HR-ESI-MS). Their inhibitory activity of the compounds on nitric oxide (NO) was determined by lipopolysaccharide (LPS)-induced RAW264.7 cell model. The results were as follows: (1) Twenty-one compounds were separated and identified from petroleum ether and n-butanol extracts of L. virgaurea, including spiroeuryolide (1), cacalol acetate (2), oplopenone (3), 8-ethyl-palmosalide A (4), 1-hydroxy-3,7-dimethyl-2-(pent-3-enyl)benzofuran (5), syringaresinol-O-β-D-glucopyranoside (6), pinoresinol-O-β-D-glucopyranoside (7), isoeucommin A (8), eucommin A (9), 6,7-dimethoxycoumarin (10), ferulic acid (11), ethyl caffeate (12), methyl caffeate (13), methyl ferulate (14), ethyl ferulate (15), caffeic acid (16), 2-［(2′E)-3′,7′-dimethyl-2′,6′-octadienyl］-4-methoxy-6-methylphenol (17), 2,8-dimethyl-6-methoxy-2-(4′-methylpent-3′-enyl)-chromene (18), β-sitosterol (19), dodecyl(Z)-9-hexadecenoate (20) and hexacosanal (21). Compounds 1-4, 6, 11-16, 18, 20, 21 were isolated from the whole herbs of L. virgaurea for the first time. (2) The anti-inflammatory activity in vitro showed that compounds 1-3, 6, 11-16, 17, 19 could significantly inhibited releases of NO at concentration ranging from 1.56 to 50.00 μmol·L-1(P

Ligularia virgaurea is one of the original plants of the Tibetan medicine “Rixiao” for the treatment of clearing heat and removing yellow water. In order to study the chemical constituents and anti-inflammatory activity of L. virgaurea, the compounds were separated by silica gel, Sephadex LH-20 gel, ODS gel column chromatography and other column chromatography technologies. The structures of all isolates were identified by spectroscopic methods(NMR and HR-ESI-MS). Their inhibitory activity of the compounds on nitric oxide(NO)was determined by lipopolysaccharide(LPS)-induced RAW264.7 cell model. The results were as follows:(1)Twenty-one compounds were separated and identified from petroleum ether and n-butanol extracts of L. virgaurea, including spiroeuryolide(1), cacalol acetate(2), oplopenone(3), 8-ethyl-palmosalide A(4), 1-hydroxy-3,7-dimethyl-2-(pent-3-enyl)benzofuran(5), syringaresinol-O-β-D-glucopyranoside(6), pinoresinol-O-β-D-glucopyranoside(7), isoeucommin A(8), eucommin A(9), 6,7-dimethoxycoumarin(10), ferulic acid(11), ethyl caffeate(12), methyl caffeate(13), methyl ferulate(14), ethyl ferulate(15), caffeic acid(16), 2-[(2'E)-3',7'-dimethyl-2',6'-octadienyl]-4-methoxy-6-methylphenol(17), 2,8-dimethyl-6-methoxy-2-(4'-methylpent-3'-enyl)-chromene(18), β-sitosterol(19), dodecyl(Z)-9-hexadecenoate(20)and hexacosanal(21). Compounds 1-4, 6, 11-16, 18, 20, 21 were isolated from the whole herbs of L. virgaurea for the first time.(2)The anti-inflammatory activity in vitro showed that compounds 1-3, 6, 11-16, 17, 19 could significantly inhibited releases of NO at concentration ranging from 1.56 to 50.00 μmol·L-1(P<0.05 or P<0.01), Compound 5 had no inhibitory effect on the release of NO at a concentration of 50.00 μmol·L-1, but it could inhibit releases of NO at concentrations of 12.50, 25.00 μmol·L-1(P<0.05). This finding enriches the chemical constituent and biological activity research of L. virgaurea and provides a certain theoretical reference for the future development and utilization of its anti-inflammatory activity. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Applied Ecology / Yingyong Shengtai Xuebao is the property of Chinese Journal of Applied Ecology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Ligularia virgaurea and Ligularia sagitta are two species of poisonous plants with strong invasiveness in natural grasslands in China that have caused considerable harm to animal husbandry and the ecological environment. However, little is known about their suitable habitats and the key environmental factors affecting their distribution. Although some studies have reported the distributions of poisonous plants on the Qinghai–Tibet Plateau (QTP) and predicted their potential distributions at local scales in some regions under climate change, there have been few studies on the widespread distributions of L. virgaurea and L. sagitta. In this study, we recorded 276 and 118 occurrence points of L. virgaurea and L. sagitta on the QTP using GPS, and then used the MaxEnt model to predict the distribution of suitable habitats. Results showed that (1) under current climate conditions, L. virgaurea and L. sagitta are mainly distributed in southern Gansu, eastern Qinghai, northwestern Sichuan, eastern Tibet, and southwestern Yunnan, accounting for approximately 34.9% and 39.8% of the total area of the QTP, respectively; (2) the main environmental variables affecting the distribution of suitable habitats for L. virgaurea and L. sagitta are the Human Footprint Index (52.8%, 42.2%), elevation (11%, 4.4%), soil total nitrogen (18.9%, 4.2%), and precipitation seasonality (5.1%, 7.3%); and (3) in the future, in the 2050s and 2070s, the area of habitat of intermediate suitability for L. virgaurea will spread considerably in northwest Sichuan, while that of high suitability for L. sagitta will spread to eastern Tibet and western Sichuan. [ABSTRACT FROM AUTHOR]

Copyright of Acta Prataculturae Sinica is the property of Acta Prataculturae Sinica Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Ligularia virgaurea (Asteraceae) is an indicator species of alpine meadow degradation. Here, the complete chloroplast genome of L. virgaurea was studied. The chloroplast genome of L. virgaurea is 151,185 bp in length. It has a typical quadripartite structure, containing a large single copy region of 83,369 bp, a small single copy region of 18,156 bp, and a pair of inverted repeated regions of 24,830 bp. A total of 132 functional genes were annotated, including eight rRNA genes, 37 tRNA genes, and 87 protein-coding genes. In the neighbour-joining phylogenetic tree based on chloroplast genome, the genus Ligularia clustered together, while L. virgaurea has a slightly more distant relationship with other Ligularia species.

Abstract Secobakkane B (C-6/C-7 cleaved secobakkane type aldehyde), secovirgaurenols B and C (C-8/C-9 cleaved secoeremophilane type), a 1β,10β-epoxyfuranoeremophilane, two 1β,10β-epoxyeremophilanolides, and fukinospirolide C (bakkane-type lactone), as well as 33 known compounds were isolated from three samples of Ligularia virgaurea collected in China. Two of the three analyzed samples were grouped in the neoadenostylone (N) type, and the rest, a mixture of the 6-hydroxyeuryopsyn (H) and cacalol (C) types, out of five chemotypes found in this species. Graphical abstract Image 1 [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Applied Ecology / Yingyong Shengtai Xuebao is the property of Chinese Journal of Applied Ecology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To understand the formation process of typical poisonous plant degraded grassland, we studied the cha-racteristics of vegetation and soil during the gradual expansion of Ligularia virgaurea into the native grassland of Qinghai-Tibet Plateau. The results showed that population density, plant height, coverage, and biomass of L. virgaurea increased during the formation of L. virgaurea degraded grassland. In comparison with native grassland, the degraded grassland had higher total aboveground biomass (113.9%), soil total nitrogen concentration (61.0%), NH 4 + -N (77.9%), organic carbon concentration (45.3%), available phosphorus concentration (78.8%) as well as soil microbial biomass carbon (42.1%) and nitrogen (47.4%), but lower NO 3 - -N (40.1%) and species richness (28.5%) and aboveground biomass (45.7%) of other species beyond L. virgaurea . The extremely strong abilities of interspecific inhibition and morphological plasticity of L. virgaurea , as well as efficient nutrient accumulation and utilization were the keys to its successful expansion, which facilitated the formation of typical L. virgaurea degraded grassland.

Ligularia virgaurea and Ligularia sagitta are two species of poisonous plants with strong invasiveness in natural grasslands in China that have caused considerable harm to animal husbandry and the ecological environment. However, little is known about their suitable habitats and the key environmental factors affecting their distribution. Although some studies have reported the distributions of poisonous plants on the Qinghai-Tibet Plateau (QTP) and predicted their potential distributions at local scales in some regions under climate change, there have been few studies on the widespread distributions of L. virgaurea and L. sagitta . In this study, we recorded 276 and 118 occurrence points of L. virgaurea and L. sagitta on the QTP using GPS, and then used the MaxEnt model to predict the distribution of suitable habitats. Results showed that (1) under current climate conditions, L. virgaurea and L. sagitta are mainly distributed in southern Gansu, eastern Qinghai, northwestern Sichuan, eastern Tibet, and southwestern Yunnan, accounting for approximately 34.9% and 39.8% of the total area of the QTP, respectively; (2) the main environmental variables affecting the distribution of suitable habitats for L. virgaurea and L. sagitta are the Human Footprint Index (52.8%, 42.2%), elevation (11%, 4.4%), soil total nitrogen (18.9%, 4.2%), and precipitation seasonality (5.1%, 7.3%); and (3) in the future, in the 2050s and 2070s, the area of habitat of intermediate suitability for L. virgaurea will spread considerably in northwest Sichuan, while that of high suitability for L. sagitta will spread to eastern Tibet and western Sichuan., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Dong, Hua, Hua, Ye, Bao, Cai, Cai, Zhao, Chu and Tang.)

Further chemical investigation of two Ligularia virgaurea samples collected in China resulted in the isolation of 21 new compounds, two of which were bakkane-type sesquiterpenoids bearing an anhydride-type ring C, which was a previously unknown partial structure. These samples belonged to the V-type (the major component was virgaurenone) among the five chemotypes found in this species. [ABSTRACT FROM AUTHOR]

The aim of the present study was to investigate the acaricidal activity of Ligularia virgaurea. An extract was prepared by refluxing with ethanol and steam distillation, and its toxic effect was tested in vitro against Sarcoptes scabiei. The data from the toxicity tests were analyzed using a complementary log-log (CLL) model. The ethanol extract exhibited strong acaricidal activity against these mites; at a concentration of 2 g/ml it killed all S. scabiei within 2 h and at 1 g/ml it killed all S. scabiei within 6 h. Similarly, 2, 1, 0.5 and 0.25 g/ml concentrations of the extract had strong toxicity against S. scabiei, with median lethal time (LT50) values of 0.716, 1.741, 2.968 and 4.838 h, respectively. The median lethal concentration (LC50) values were 1.388, 0.624, 0.310 and 0.213 g/ml for Scabies mite in 1, 2, 4 and 6 h, respectively. The results indicate that the L. virgaurea extract has strong acaricidal activity and may be exploited as a novel treatment for the effective control of acariasis in animals. [ABSTRACT FROM AUTHOR]

A new eremophilane norsesquiterpenoid (1), together with a known eremophilane sesquiterpenoid (2), was isolated from the leaves ofLigularia virgaurea. The structure of1was elucidated by a combination of spectroscopic analysis (IR, 1D NMR, 2D NMR, and HR-ESI-MS), and its absolute configuration was determined by a single-crystal X-ray diffraction experiment (with copper radiation). The known compound2was identified by comparison of its physical and spectral data with those reported in the literature. Compound1was assayed for its cytotoxic activities against human cervical carcinoma cell (HeLa) and human small cell lung cancer cell (NCI-446) lines. [ABSTRACT FROM AUTHOR]

Abstract: Four new compounds, rearranged noreremophilan-8,6-olide, rearranged dinoreremophilanone, epoxy γ-lactone, and 2α-hydroxyermophil-11-en-9-one, along with eremophilenolides related to ligularol and other known terpenoids, were isolated from Ligularia virgaurea (ligularol type) collected from the northern Sichuan Province of China. Three of the new compounds had degraded and unique structures. The absolute configuration of 2α-hydroxyermophil-11-en-9-one was determined on the basis of density functional theory calculation. The back octant rule cannot be applied to this compound because of the contribution of the hydroxy group to the front octant. [Copyright &y& Elsevier]

Abstract: Root chemicals and DNA sequences were analyzed for Ligularia virgaurea collected in the northern Sichuan Province and adjacent areas of China. Thirty-eight samples were found to contain five chemotypes, two known and three new ones. From samples of the new chemotypes, 13 new compounds were isolated, including 3 sesquiterpene dimers and some rearranged eremophilanes. The DNA sequences suggested that the chemotype differentiation had a genetic origin. [Copyright &y& Elsevier]

Studies of diclinous species have showed that floral sex allocation and female reproductive success were quite variable within inflorescences. However, little attention has been paid to gynomonoecious species, in which individuals produce both female and bisexual flowers. The purpose of this study was to investigate the variations in reproductive patterns at different capitulum positions within racemiform synflorescence in Ligularia virgaurea, and to determine selective mechanisms of variations in reproductive patterns. We conducted observational and experimental studies in natural populations of the gynomonoecious composite L. virgaurea. Floral sex allocation, seed production and pre-dispersal seed predation were quantified in the field. The results showed several patterns of variation from top to bottom capitula, including an increase in bisexual flowers and flower number per capitulum, but a decrease in seed set and size. Removing earlier capitula during bud stage did not change floral sex allocation in later capitula. And no effect was found on seed set under supplemental pollination. Thus, although it has been reported many times in previous studies, the variation of floral sex allocation in L. virgaurea may not result from architectural effect or mating environment, and the variation of seed production could not be fully explained by pollination success. Additionally, our results showed that L. virgaurea was susceptible to high levels of bisexual biased predation, which was greater for top capitula. We therefore suggest that these variations may help to enhance reproductive success of L. virgaurea in the face of bisexual-biased seed predation. [ABSTRACT FROM AUTHOR]

In order to investigate the function of arbuscular mycorrhizae in Tibetan Plateau Alpine meadow ecosystems, experiments were carried out to evaluate the influence of arbuscular mycorrhizal (AM) fungi on inter-specific competition between the poisonous plant, Ligularia virgaurea, and the grazing grass, Elymus nutans, at different relative densities. Our results showed that the biomass of L. virgaurea significantly declined in AM treatments while the biomass of E. nutans increased in our inter-specific competition system. Relative yields and root/shoot ratios of these two species indicated that AM fungi had a significant influence on the growth of L. virgaurea and E. nutans. This implies that arbuscular mycorrhiza do not benefit both plant species equally but rather contribute to the growth of E. nutans more than L. virgaurea. We thus provide evidence that AM fungi could regulate plant interactions and influence the plant community structure in the Tibetan Plateau Alpine meadow ecosystem. [ABSTRACT FROM AUTHOR]

llelopathy is an important process in plant communities, but the role of seed allelopathy in natural ecosystems remains poorly understood. In the present study, we examined the potential allelopathic effects of Ligularia virgaurea (a dominant species in degraded Tibetan grasslands) seeds on the germination of four native grass species ( Festuca sinensis, Agrostis gigantean, Bromus inermis, and Elymus nutans). The results showed that L. virgaurea seeds can have potential allelopathic effects on seed germination, mean time to germination and root growth rates of native grass species. We further demonstrate that these effects are driven by a water-soluble seed leachate. Species with smaller seeds were generally more sensitive than larger seeded species. The results suggest that seed-to-seed allelopathic potential may be an important mechanism driving the dominance of L. virgaurea in degraded alpine grasslands on the Tibetan Plateau. Further studies are required to demonstrate effects of seed-to-seed potential allelopathy in a field setting. [ABSTRACT FROM AUTHOR]

Ligularia virgaurea is widely distributed in the alpine meadows of the eastern Qinghai-Tibet plateau. We studied the effects of temperature and seed storage length on seed germination in a laboratory experiment, the effects of seed mass and light intensity on seed emergence in a pot experiment, and the effect of meadow disturbance intensity on seed emergence in a field experiment. Our results showed that seeds of L. virgaurea germinated well under a wide range of temperatures. Germination percentage decreased with increased seed storage length. When seeds were stored for either 6 or 12 months the germination percentage increased with decreasing temperature. The emergence percentage of large seeds was higher than that of small seeds. Seedling survival of large seeds was greater than that of small seeds in 75% and 50% of natural irradiance. Large seeds of L. virgaurea were more successful colonizers in the alpine meadows. Seeds of L. virgaurea germinated in both disturbed meadows and non-disturbed meadows, but seed emergence and seedling establishment were higher in the disturbed meadows, that is, disturbance could facilitate the recruitment and establishment of L. virgaurea. [ABSTRACT FROM AUTHOR]

Ligularia virgaurea is a perennial herb that is widely distributed in the alpine meadow on the eastern Qinghai-Tibet plateau. We investigated the patterns of growth and reproduction of L. virgaurea under two contrasting levels of light conditions for two continuous growing seasons. Our results showed that the light effects on the maximum relative growth rate, the shoot weight ratio and the root weight ratio differed between the two growing seasons. L. virgaurea reproduced initially through rhizome in the second growing season, rather than sexual reproduction. The proportion of genets with clonal reproduction decreased under shaded conditions. A minimum genet size should be attained for clonal reproduction to begin under the shaded conditions. There was a positive linear relationship between clonal reproduction and genet size. Light level affected the allocation of total biomass to clonal structures, with less allocation under the full natural irradiance than under the shaded conditions. There seemed to be a trade-off between vegetative growth and clonal reproduction under the full natural irradiance, in terms of smaller relative growth rates of genets with clonal reproduction than those without clonal reproduction. L. virgaurea emphasized clonal reproduction under the full natural irradiance, while the plant emphasized vegetative growth under the shaded conditions. [ABSTRACT FROM AUTHOR]

Ligularia virgaurea (Asteraceae) is an indicator species of alpine meadow degradation. Here, the complete chloroplast genome of L. virgaurea was studied. The chloroplast genome of L. virgaurea is 151,185 bp in length. It has a typical quadripartite structure, containing a large single copy region of 83,369 bp, a small single copy region of 18,156 bp, and a pair of inverted repeated regions of 24,830 bp. A total of 132 functional genes were annotated, including eight rRNA genes, 37 tRNA genes, and 87 protein-coding genes. In the neighbour-joining phylogenetic tree based on chloroplast genome, the genus Ligularia clustered together, while L. virgaurea has a slightly more distant relationship with other Ligularia species. [ABSTRACT FROM AUTHOR]

Abstract: Chemical constituents of root extract and the nucleotide sequences of the atpB–rbcL intergenic region and the internal transcribed spacers (ITSs) of the ribosomal RNA gene were studied for Ligularia virgaurea var. virgaurea collected in southwestern Sichuan Province of China. Eleven samples were collected. Four of them were found to contain four new furanoeremophilanes, virgaurenones A–D, as well as a new eremophilanolide, virgaurenolide A. The other samples contained different furanoeremophilanes and their derivatives including nor-type of compounds, two of which were new. Diversity was found to be present in the nucleotide sequences as well. The chemical composition was found to be correlated with the ITS variation but not with the geographic distribution of the samples. [Copyright &y& Elsevier]