Taxus Cuspidata Research Articles

The Future Migration Direction of Deer and Japanese Yew Is Consistent Under Climate Change

Climate change is becoming an important driver of biodiversity loss by altering the habitat, distribution and interspecific relationships of species. Japanese yew (Taxus cuspidata) is a first class protected plant in China, which has important ecological significance and occupies a certain position in the feeding habit of wapiti (Cervus elaphus) and Siberian roe deer (Capreolus pygargus). Due to human and animal damage, the number of Japanese yew has gradually decreased. Therefore, understanding the potential distribution of Japanese yew and the suitable areas for deer to browse on it under climate change will help to further protect these three species in Northeast China, especially migrate to more suitable areas in different scenarios in the future. From July 2021 to July 2024, we collected the information of species distribution and the variables associated with the species’ ecological limits in Muling National Nature Reserve to cross-reflect the current and future distribution and feeding area of the two species to assess each other’s impacts with Maximum entropy model (MaxEnt). The results showed that under the SSP2-4.5 and SSP5-8.5 scenarios, feeding pressure, driest quarter precipitation (BIO17) and seasonal temperature variation coefficient (BIO4) were the main variables affecting the distribution of Japanese yew, and the driest quarter precipitation (BIO17) and annual precipitation (BIO12) were the main variables affecting wapiti and Siberian roe deer foraging them. Under SSP2-4.5 and SSP5-8.5 scenarios, the suitable area of Japanese yew and the feeding area of the two species of deer gradually decreased from 2041 to 2100. Compared with wapiti, Siberian roe deer has a greater impact on the distribution range of Japanese yew, and the suitable feeding area is wider. It is expected that the potential centroid of Japanese yew, wapiti and Siberian roe deer will migrate to higher latitudes in the future. These findings provide a scientific basis for the reserve to develop relevant measures and plans and effectively protect the three species.

Population structure and dynamic characteristics of Taxus cuspidata in Baishilazi National Nature Reserve, China

Taxus cuspidata is listed as a first-class national key protected plant in the northeast region, with scarce individuals in the wild and significant conservation value. We conducted a systematic field survey to explore the population structure and dynamic characteristics of T. cuspidata in the Baishilazi National Nature Reserve. A total of 313 T. cuspidata were recorded, displaying a spatially clustered distribution. Young individuals made up 33 % of the population, and the population's diameter class structure indicated a decreasing trend in population size. The population's survival curve closely resembled the Deevey-II type. These results suggest that the proportion of young individuals and strong potential for self-renewal. Geographic analysis revealed that north-facing slopes with moderate gradients were the primary habitat for T. cuspidata in the reserve. Interspecific analysis identified Acer ukurunduense and A. komarovii as the species with the highest interspecific associations with T. cuspidata. The population is projected to continue growing. The nature reserve is effectively fostering the natural renewal and recovery of T. cuspidata populations. These findings offer valuable insights for the conservation management of T. cuspidata in Baishilazi National Nature Reserve, supporting the sustainable development of endangered species populations.

Revisiting the early light-induced protein hypothesis in the sustained thermal dissipation mechanism in yew leaves.

Overwintering evergreen trees in boreal regions continuously convert absorbed light energy into heat through a process known as 'sustained thermal dissipation'. To better understand this mechanism, this study examined the alterations in the photosynthetic apparatus and transcriptomes of yew (Taxus cuspidata) leaves throughout the year, comparing sun-exposed and shaded leaves. The Y(II) parameter, conventionally used to estimate the quantum yield of photosystem II (PSII), suggests the occurrence of temperature-dependent thermal dissipation during winter. On the other hand, the levels of photosystem subunits, including the D1 subunit of the PSII reaction center, remain relatively stable year-round, suggesting that typical photoinhibition is unlikely to occur. Time-resolved chlorophyll fluorescence analysis revealed that heat dissipation at the PSII antenna is prominent in winter. Winter transcriptomes are notably characterized by a predominance of Elip transcripts encoding early light-induced protein (ELIP), which constitute 20% of the total transcripts, as deduced from RNA-seq analysis. Furthermore, ELIP protein concentration increases to nearly half that of the major light-harvesting complexes. The predicted structure of ELIP includes potential chlorophyll a and carotenoid binding sites. Considering a previous report showing ELIP's capacity for energy dissipation, these findings lead to a reevaluation of its significant role in sustained thermal dissipation.

Comparison of Foraging Strategies and Effects of the Wapiti and Siberian Roe Deer on Japanese Yew.

The foraging strategies of sympatric ungulates with similar ecological niches are important for understanding ecological niche differentiation, resource utilization, competition, and coexistence and for understanding the ecological impacts on plant communities in the ecosystem. The behavior of the wapiti (Cervus elaphus) and Siberian roe deer (Capreolus pygargus) foraging on Japanese yew (Taxus cuspidata) has affected its succession and renewal in the northeastern forests of China, which has become an urgent problem for the relevant departments. This study analyzed the foraging strategies of the wapiti and Siberian roe deer on Japanese yew from July 2021 to January 2024 using field investigations and infrared camera monitoring in the Muling National Nature Reserve, Heilongjiang Province, China. It was found that the wapiti and Siberian roe deer have different foraging strategies in terms of time, space, and behavior. Temporally, they both preferred to forage for the saplings of the Japanese yew during the winter season, the degree of overlap in foraging rhythms was medium (Dhat1 = 0.67), and the diurnal foraging activity index (D RAI) of the wapiti was larger than that of the Siberian roe deer. Spatially, the suitable foraging habitat of the Siberian roe deer was twice that of the wapiti, and their overlap was low in the location and direction of saplings and the distance of the seed tree. Behaviorally, the foraging intensity of the wapiti was high, and that of Siberian roe deer was low. Foraging reduced the average primary branch height, number of new branches, and length of lateral branches of saplings, and the influence of the wapiti was significantly greater than that of the Siberian roe deer. This study provides a scientific basis for solving the conservation and management problems of the deer animals foraging on Japanese yew and contributes to further understanding of the competition-coexistence mechanism of sympatric species.

Climate change vulnerability and conservation strategies for tertiary relict tree species: Insights from landscape genomics ofTaxus cuspidata.

The unprecedented habitat fragmentation or loss has threatened the existence of many species. Therefore, it is essential to understand whether and how these species can pace with the environmental changes. Recent advantages in landscape genomics enabled us to identify molecular signatures of adaptation and predict how populations will respond to changing environments, providing new insights into the conservation of species. Here, we investigated the pattern of neutral and putative adaptive genetic variation and its response to changing environments in a tertiary relict tree species, Taxus cuspidata Sieb. et Zucc, which is distributed in northeast China and adjacent regions. We investigated the pattern of genetic diversity and differentiation using restriction site-associated DNA sequencing (RAD-seq) and seven nuclear microsatellites (nSSRs) datasets. We further explored the endangered mechanism, predicted its vulnerability in the future, and provided guidelines for the conservation and management of this species. RAD-seq identified 16,087 single nucleotide polymorphisms (SNPs) in natural populations. Both the SNPs and nSSRs datasets showed high levels of genetic diversity and low genetic differentiation in T. cuspidata. Outlier detection by F ST outlier analysis and genotype-environment associations (GEAs) revealed 598 outlier SNPs as putative adaptive SNPs. Linear redundancy analysis (RDA) and nonlinear gradient forest (GF) showed that the contribution of climate to genetic variation was greater than that of geography, and precipitation played an important role in putative adaptive genetic variation. Furthermore, the genetic offset and risk of non-adaptedness (RONA) suggested that the species at the northeast edge may be more vulnerable in the future. These results suggest that although the species has maintained high current genetic diversity in the face of recent habitat loss and fragmentation, future climate change is likely to threaten the survival of the species. Temperature (Bio03) and precipitation (Prec05) variables can be potentially used as predictors of response of T. cuspidata under future climate. Together, this study provides a theoretical framework for conservation and management strategies for wildlife species in the context of future climate change.

Predicting the potential distribution of Taxus cuspidata in northeastern China based on the ensemble model

AbstractClimate change is poised to exert a significant impact on species distribution in the future, and Taxus cuspidata as an endangered species is no exception. Predicting the potential distribution of T. cuspidata is essential for decision‐makers to develop conservation policies and explicitly implement conservation measures. In this study, a combined model was employed to predict potentially suitable habitats for T. cuspidata based on extant data of T. cuspidata distributions in northeastern China. Our findings suggest that mean diurnal range (bio2) and isothermality (bio3) were identified as dominant factors influencing T. cuspidata distribution. Under future climate scenarios, suitable habitat areas increased only in the SSP126 scenario in the 2070s, declining in all other scenarios. In all climate scenarios, the centroid of suitable habitats ultimately shows a trend in northward movement. Decreases in suitable habitat predominantly occurred in Yanbian Korean Autonomous Prefecture, Baishan city, and Tonghua city. Overall, this study highlights a projected habitat reduction due to climate change. Recommendations entail the strategic establishment of nature reserves and the implementation of initiatives aimed at population replenishment.

Dynamic response of allelopathic potency of Taxus cuspidata Sieb. et Zucc. mediated by allelochemicals in Ficus carica Linn. root exudates

In a mixed forest, certain plants can release allelochemicals that exert allelopathic effects on neighboring plants, thereby facilitating interspecific coexistence of two species. Previous studies have demonstrated that allelochemicals released from Ficus carica Linn. roots in mixed forest of F. carica and Taxus cuspidata Sieb. et Zucc. has phase characteristics over time, which can improve the soil physicochemical properties, enzyme activity and microbial diversity, thus promoting the growth of T. cuspidata. Based on the irrigation of exogenous allelochemicals, changes in soil fertility (soil physical and chemical properties, soil enzyme activity and soil microelement content) were observed in response to variations in allelochemicals during five phases of irrigation: initial disturbance phase (0–2 d), physiological compensation phase (2–8 d), screening phase (8–16 d), restore phase (16–32 d) and maturity phase (32–64 d), which was consistent with the response of soil microorganisms. The allelopathic response of growth physiological indexes of T. cuspidata, however, exhibited a slight lag behind the soil fertility, with distinct phase characteristics becoming evident on the 4th day following irrigation of allelochemicals. The findings demonstrated that the allelochemicals released by the root of F. carica induced a synergistic effect on soil fertility and microorganisms, thereby facilitating the growth of T. cuspidata. This study provides a comprehensive elucidation of the phased dynamic response-based allelopathic mechanism employed by F. carica to enhance the growth of T. cuspidata, thus establishing a theoretical basis for optimizing forest cultivation through allelopathic pathways.

Japanese Yew (Taxus) poisoning of wild ungulates in Utah during the winter of 2022–2023

Taxus is a genus of coniferous shrubs and trees, commonly known as the yews, in the family Taxaceae. All species of yew contain taxine alkaloids, which are ascribed as the toxic principles. Anecdotally, free ranging ruminants such as antelope, deer, elk, and moose have been regarded as tolerant to yew. Herein several cases of intoxication of deer, elk, and moose by yew from the state of Utah in the winter of 2022–2023 are documented. Ingestion of yew was documented by three means among the poisoned cervids; plant fragments consistent with yew were visually observed in the rumen contents, chemical analysis, and subsequent detection of the taxines from rumen and liver contents, and identification of exact sequence variants identified as Taxus species from DNA metabarcoding. Undoubtedly, the record snowfall in Utah during the winter of 2022–2023 contributed to these poisonings.

Research on the Medicinal Chemistry and Pharmacology of Taxus × media.

Taxus × media, belonging to the genus Taxus of the Taxaceae family, is a unique hybrid plant derived from a natural crossbreeding between Taxus cuspidata and Taxus baccata. This distinctive hybrid variety inherits the superior traits of its parental species, exhibiting significant biological and medicinal values. This paper comprehensively analyzes Taxus × media from multiple dimensions, including its cultivation overview, chemical composition, and multifaceted applications in the medical field. In terms of chemical constituents, this study delves into the bioactive components abundant in Taxus × media and their pharmacological activities, highlighting the importance and value of these components, including paclitaxel, as the lead compounds in traditional medicine and modern drug development. Regarding its medicinal value, the article primarily discusses the potential applications of Taxus × media in combating tumors, antibacterial, anti-inflammatory, and antioxidant activities, and treating diabetes. By synthesizing clinical research and experimental data, the paper elucidates the potential and mechanisms of its primary active components in preventing and treating these diseases. In conclusion, Taxus × media demonstrates its unique value in biological research and tremendous potential in drug development.

Metabolomics analysis of different diameter classes of Taxus chinensis reveals that the resource allocation is related to carbon and nitrogen metabolism

Taxus chinensis (Taxus cuspidata Sieb. et Zucc.) is a traditional medicinal plant known for its anticancer substance paclitaxel, and its growth age is also an important factor affecting its medicinal value. However, how age affects the physiological and metabolic characteristics and active substances of T. chinensis is still unclear. In this study, carbon and nitrogen accumulation, contents of active substances and changes in primary metabolites in barks and annual leaves of T. chinensis of different diameter classes were investigated by using diameter classes instead of age. The results showed that leaves and barks of small diameter class (D1) had higher content of non-structural carbohydrates and C, which were effective in enhancing defense capacity, while N content was higher in medium (D2) and large diameter classes (D3). Active substances such as paclitaxel, baccatin III and cephalomannine also accumulated significantly in barks of large diameter classes. Moreover, 21 and 25 differential metabolites were identified in leaves and barks of different diameter classes, respectively. The differential metabolites were enhanced the TCA cycle and amino acid biosynthesis, accumulate metabolites such as organic acids, and promote the synthesis and accumulation of active substances such as paclitaxel in the medium and large diameter classes. These results revealed the carbon and nitrogen allocation mechanism of different diameter classes of T. chinensis, and its relationship with medicinal components, providing a guidance for the harvesting and utilization of wild T. chinensis.

Mass Spectrometry-Imaging Analysis of Active Ingredients in the Leaves of Taxus cuspidata.

Taxus cuspidata is an endangered evergreen conifer mainly found in Northeast Asia. In addition to the well-known taxanes, several active ingredients were detected in the leaves of T. cuspidata. However, the precise spatial distribution of active ingredients in the leaves of T. cuspidata is largely unknown. in the present study, timsTOF flex MALDI-2 analysis was used to uncover the accumulation pattern of active ingredients in T. cuspidata leaves. In total, 3084 ion features were obtained, of which 944 were annotated according to the mass spectrometry database. The principal component analysis separated all of the detected metabolites into four typical leaf tissues: mesophyll cells, upper epidermis, lower epidermis, and vascular bundle cells. Imaging analysis identified several leaf tissues that specifically accumulated active ingredients, providing theoretical support for studying the regulation mechanism of compound biosynthesis. Furthermore, the relative accumulation levels of each identified compound were analyzed. Two flavonoid compounds, ligustroflavone and Morin, were identified with high content through quantitative analysis of the ion intensity. our data provides fundamental information for the protective utilization of T. cuspidata.

СОВРЕМЕННОЕ СОСТОЯНИЕ РАСТИТЕЛЬНЫХ СООБЩЕСТВ ТЕРРИТОРИИ ОЗЕРА БОЛЬШОЕ ВАВАЙСКОЕ

This article analyzes the current state of plant communities on the territory of Lake Bolshoye Vavayskoye. The study covers the abundance, distribution and ecological relationships of the plant world.
 The article presents the results of field research conducted in different seasons of the year. The composition and structure of plant communities, as well as their functional characteristics, are described. Special attention is paid to the analysis of the impact of anthropogenic activities on the state of plant communities and their biodiversity.
 The study found that the plant communities of Lake Bolshoye Vavayskoye are characterized by a high level of biodiversity. In the studied phytocenoses (shrub larch with dwarf cedar, cedar dwarf lingonberry-ledum, lingonberry-lichen larch, fir-spruce moss, fir-spruce shrub, meadow, etc.) grow 283 species of vascular plants, which represent 18.03% of the total number of vascular plants o. Sakhalin, 5 rare plant species listed in the Red Books of the Russian Federation and the Sakhalin Region were also identified, such as Picea glehnii, Taxus cuspidata, Nuphar pumila, Nymphaea tetragona, Arália cordata. However, the study also showed that anthropogenic impact on the lake has a negative impact on the state of plant communities. In particular, signs of water pollution and deforestation have been identified, which leads to a decrease in biodiversity and deterioration of the environmental situation.
 The authors of the article draw attention to the importance of preserving this natural resource and its environmental sustainability, since in recent decades the territory has undergone anthropogenic impact. The study also highlights the importance of long-term monitoring and environmental control of the area to ensure the conservation of the lake's biodiversity and ecosystems for future generations. The results of the study may be useful for organizing nature conservation and developing an environmentally sustainable approach to the use of resources in the region.

Synthesis of magnetic bifunctional monomer molecularly imprinted polymers for highly selective separation of paclitaxel from Taxus cuspidata

Paclitaxel (PTX), an active anticancer compound derived from Taxus cuspidata, possesses considerable economic value. Given the abundance of structural analogs, the selective separation of PTX from T. cuspidata presents a formidable challenge. In this study, the bifunctional monomers magnetic molecular imprinted polymers (MMIPs) with multiple active sites were synthesized using Fe3O4 as the magnetic carrier, PTX as the template, 4-vinylpyridine (4-VP) and methacrylic acid (MAA) as the first-stage and the second-stage pre-assembly functional monomer, respectively. The results indicated that MMIPs exhibited excellent magnetic recovery capability and high adsorption capacity for PTX. Furthermore, the adsorption behaviors were more consistent with Langmuir isotherm model and pseudo-second-order kinetic model. The MMIPs possessed significantly higher selectivity for PTX than five structural analogs (Docetaxel, Baccatin III, 10-Deacetylbaccatin III, and Glucose) and recyclability for up to six cycles. Additionally, the adsorption mechanism analysis indicated that the excellent performance of MMIPs primarily arises from the multiple active binding sites involving hydrogen bonding and π-π stacking. Finally, MMIPs were used for PTX recognition and separation in T. cuspidata extracts. This study provides an efficient method and valuable theoretical basis for the highly selective separation of PTX from T. cuspidata.

Broad-leaved and mixed cooltemperate forests from the class Fagetea crenatae Miyawaki, Ohba et Murase 1964 on Kunashir Island (the Kurils archipelago)

This study presents the classification and description of three new associations of cool-temperate zonal forests of the vegetation class Fagetea crenatae Miyawaki, Ohba et Murase 1964 on Kunashir and Hokkaido islands. The Filipendulo camtschaticae–Aceretum mayrii ass. nov. encompasses broad-leaved forests in eutrophic moist ecotopes dominated by Acer mono subsp. mayrii. The Abieti sachalinensis–Quercetum crispulae ass. nov. represents zonal mixed forests dominated by Quercus mongolica var. crispula with an admixture of coniferous tree species Abies sachalinensis, Taxus cuspidata, and Picea jezoensis (the latter only on Kunashir Island, in forests of the subass. piceetosum jezoensis). The Hydrangeo paniculatae–Quercetum crispulae ass. nov. includes secondary species-poor forests dominated by Q. mongolica var. crispula, Betula ermanii, or B. pendula subsp. mandshurica. All associations feature a dense understory of dwarf bamboo species Sasa spp., with the densest tickets found in Hydrangeo paniculatae–Quercetum crispulae forests. We also validated the union Carpino cordatae–Quercion crispulae Takeda, Uemura et Nakanishi ex Korznikov, Dzizyurova et Petrenko all. nov. which represents the zonal cool-temperate broad-leaved and mixed forests in Hokkaido, Sakhalin, Iturup and Kunashir. Broad-leaved forests of Kunashir exhibit lower species diversity compared to Hokkaido, missing typical temperate tree species such as Acer palmatum, Carpinus cordata, and Tilia japonica.

Исследование химического состава и антибактериальной активности СО2 экстрактов Juniperus pseudosabina, Larix dahurica, Taxus cuspidata

Extracts of coniferous plants Juniperus pseudosabina, Larix dahurica, Taxus cuspidata were obtained by supercritical fluid extraction method. In the present study, it was found that polyphenols: isoflavonoids and flavonoids, and especially flavonoglycosides, which have P-vitamin activity, constitute the most extensive group of substances in the CO2 extracts of all three plants. The CO2 extract of Taxus cuspidata can be considered as a promising alternative to Taxus berry in the role of a source for the production of individual taxanes, such as paclitaxel and docetaxel. The presence of such groups of compounds as flavanoids, isoflavanoids in the composition of CO2 extracts increases their potential as sources of biologically active compounds suitable for use as components of biologically active and feed additives with immunomodeling antioxidant properties.

Transcriptomics and Physiological Analyses Reveal Changes in Paclitaxel Production and Physiological Properties in Taxus cuspidata Suspension Cells in Response to Elicitors.

In this research, the cell growth, physiological, and biochemical reactions, as well as the paclitaxel production, of Taxus cuspidata suspension cells after treatment with polyethylene glycol (PEG), cyclodextrin (CD), or salicylic acid (SA) (alone or in combination) were investigated. To reveal the paclitaxel synthesis mechanism of T. cuspidata suspension cells under elicitor treatment, the transcriptomics of the Control group and P + C + S group (PEG + CD + SA) were compared. The results show that there were no significant differences in cell biomass after 5 days of elicitor treatments. However, the content of hydrogen peroxide (H2O2) and malondialdehyde (MDA), and the activities of phenylalanine ammonia-lyase (PAL) and polyphenol oxidase (PPO) after elicitor combination treatments were decreased compared with the single-elicitor treatment. Meanwhile, the antioxidant enzyme activity (superoxide dismutase (SOD), catalase (CAT), and peroxidase (PO)) and the contents of soluble sugar and soluble protein were increased after combination elicitor treatments. Additionally, the paclitaxel yield after treatment with the combination of all three elicitors (P + C + S) was 6.02 times higher than that of the Control group, thus indicating that the combination elicitor treatments had a significant effect on paclitaxel production in T. cuspidata cell suspension culture. Transcriptomics analysis revealed 13,623 differentially expressed genes (DEGs) between the Control and P + C + S treatment groups. Both GO and KEGG analyses showed that the DEGs mainly affected metabolic processes. DEGs associated with antioxidant enzymes, paclitaxel biosynthesis enzymes, and transcription factors were identified. It can be hypothesized that the oxidative stress of suspension cells occurred with elicitor stimulation, thereby leading to a defense response and an up-regulation of the gene expression associated with antioxidant enzymes, paclitaxel synthesis enzymes, and paclitaxel synthesis transcription factors; this ultimately increased the production of paclitaxel.

Estimation of the Population Dynamics of Taxus cuspidata by Using a Static Life Table for Its Conservation

Taxus cuspidata is a rare and endangered plant species with an extremely small population which is endemic to China. This study focused on the natural T. cuspidata population in Jilin Province in China. Conventional population ecology survey methods were used to describe its population structure characteristics. Then, we chose diameter structure instead of temporal structure to establish a static population life table, draw a population survival curve, and quantify the future development trend by using population dynamic analysis and time sequence prediction. The results showed that: (1) the static life table suggested that the population of T. cuspidata was stable overall. The population survival curve tended to be Deevey Ⅱ, with a high early seedling mortality, and the later population growth tended to be stable; (2) the survival curve suggested that the population initially experienced higher mortality rates in the early stage. However, as time progressed and the population aged, the mortality rates decreased, resulting in a more stable population in the middle and late stages; (3) The diameter class structure of T. cuspidata was stable overall, and the dynamic indices showed that the population was fluctuating. The population was influenced by external disturbances and showed some resistance to human disturbance; (4) time sequence prediction analysis showed that the mortality rate of young individuals was high, natural renewal could be maintained, and the population size would remain at a certain amount in the future. The result shows that the Jilin region is a highly suitable area for the growth of Taxus cuspidata’s population in Northeast China. We recommend in situ conservation of remaining wild populations, relocation of germplasm resources, and reduction of human activities; these actions will be beneficial to Taxus cuspidata’s long-term survival.

Constraints on the maintenance of wild Taxus cuspidata populations based on regression conservation.

To clarify the key factors constraining the maintenance of wild Taxus cuspidata populations and to develop conservation strategies and technical links for current populations, we investigated the renewal status and distribution patterns of wild T. cuspidata populations in the main distribution areas of China. We analyzed the effects of stand factors and human disturbance on population renewal and maintenance. The results showed that the overall regeneration of wild T. cuspidata populations was poor. The basal diameter and height class structure of renewed individuals showed an unhealthy state. 19% of the area was well regenerated. There were three types of regeneration, including poor regeneration with few adult trees, poor regeneration with many adult trees, and good regeneration with few adult trees. The communities in which T. cuspidata was found could be classified into Abies nephrolepis + Tilia amurensis forest, spinney forest, and Picea jezoensis var. microsperma + A. nephrolepis forest. The renewal number of A. nephrolepis + T. amurensis forest was significantly higher than that of spinney forest. Increased stand density and moderate human disturbance contributed to the regeneration of T. cuspidata. The regenerating T. cuspidata seedlings increased significantly when stand density increased from low to medium. The number of regenerating populations in moderately disturbed habitats was significantly higher than those in lightly disturbed habitats. Human disturbance and habitat were currently critical constraints to maintaining and regenerating wild T. cuspidata populations. The conservation of T. cuspidata should consider current status of population regeneration in each habitat patch to develop corresponding in situ conservation and regression conservation measures and focus on the influence of critical factors such as disturbances and habitat conditions.

Alternaria alternata F3, a Novel Taxol-Producing Endophytic Fungus Isolated from the Fruits of Taxus cuspidata: Isolation, Characterization, Taxol Yield Improvement, and Antitumor Activity.

In this study, a novel taxol-producing endophytic fungus, strain F3, was isolated from the fruits of Taxus cuspidata and identified as Alternaria alternata according to its macroscopic and microscopic traits and sequence analysis of internal transcribed spacer (ITS). The presence of taxol was detected by thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC) and confirmed by ultra-high-performance liquid chromatography-electrospray coupled to tandem mass spectrometry (UPLC-ESI-MS/MS) and nuclear magnetic resonance (NMR). The fermentation parameters of strain F3 were then optimized for high taxol production. The maximum taxol yield of 195.4µg L-1 by A. alternata F3 was observed in 200-mL yeast peptone dextrose (YPD) broth, at an initial pH value of 6.0, supplemented with 0.1g L-1 sodium acetate, 0.25g L-1 salicylic acid, and 0.00125g L-1 silver nitrate and inoculum size 2%, and incubated at 28°C and 150rpm for 8days, which was 2.12-fold compared with the initial yield of taxol. Also, fungal taxol exhibited antitumor activity towards human lung carcinoma (A549) cell line and human cervical carcinoma (Hela) cell line with IC50 values of 3.98µgmL-1 and 0.35µgmL-1. Overall, this is the first report on taxol-producing endophytic fungus isolated from the fruits of Taxus. This study offers a novel source for the production of taxol for anticancer treatment.

Effects of Ficus carica L. Water Extract on Taxus cuspidata Sieb. et Zucc. Growth

Our research group successfully designed the F. carica and Taxus cuspidata Sieb. et Zucc mixed forest, and confirmed that their interspecific relationship was stable and F. carica has a promoting effect on neighboring T. cuspidata growth. However, the promoting mechanism has not been elucidated. In this study, F. carica was used as the donor plant and T. cuspidata was used as the recipient plant. T. cuspidata seedlings were irrigated with F. carica root extracts of different concentrations (10.0, 20.0, 40.0 g·L−1), and the plant height, base diameter, photosynthetic parameters, photosynthetic pigments, MDA contents, and antioxidant enzyme activities were measured. Soil physical and chemical properties, enzyme activities, and microbial diversity were measured. The results showed that the abundance of growth-promoting bacteria increased and the number of pathogenic bacteria decreased in the rhizosphere of T. cuspidata soil. It was speculated that the chemicals secreted by F. carica roots interacted with soil microorganisms of T. cuspidata soil after enrichment, changed soil microbial diversity, and indirectly promoted the growth of T. cuspidata. UPLC-QTOF-MS/MS was used to analyze F. carica root water extract and F. carica root exudates, respectively, and it was found that the main components were similar. Therefore, the promoting effect of F. carica on T. cuspidata is mainly caused by the accumulation of potential chemicals in F. carica root exudates in the soil through interaction with soil microorganisms. Furthermore, the allelopathic-promoting mechanism of F. carica on T. cuspidata was discussed from various aspects, to provide a theoretical basis for the protection, breeding, and sustainable management of T. cuspidata resources.