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Many popular ornamental shrubs are not only beautiful but also toxic when ingested in sufficient quantities. Common toxic landscaping shrubs in North America include yew (Taxus spp), oleander (Nerium oleander), and rhododendrons and azaleas (Rhododendron spp). Horses are often exposed when plant trimmings are placed within reach or discarded in pastures. Occasionally clippings or fallen leaves contaminate hay. Some plants are unpalatable unless dried and mixed with hay or lawn clippings but others are ingested more readily. In many cases, disease can be severe and treatment unrewarding; therefore, client education is critical to preventing serious and potentially fatal poisonings.
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Jardines , Enfermedades de los Caballos , Humanos , Animales , Caballos , Enfermedades de los Caballos/inducido químicamente , Plantas Tóxicas , América del NorteRESUMEN
INTRODUCTION: English yew is an evergreen conifer frequently planted in household gardens and, when ingested in large doses, results in severe cardiotoxicity characterized by difficult to control ventricular arrhythmias with high rates of mortality. CASE REPORT: A previously healthy teenage female presented as an out-of-hospital cardiac arrest with refractory ventricular arrhythmias and severe biventricular dysfunction. Due to rapid deterioration in her clinical status, she was cannulated onto venoarterial extracorporeal membrane oxygenation (ECMO) which resulted in rapid normalization of her rhythm and ventricular function. DISCUSSION: Our case highlights the importance of keeping a broad differential diagnosis when considering etiologies of ventricular arrhythmias in the pediatric population. The final diagnosis was not made until after discharge and implantable cardiac defibrillator (ICD) placement. CONCLUSION: The delayed diagnosis of this intentional English yew ingestion ultimately resulted subsequent ICD removal. Early ECMO activation in cases of English yew toxicity can be essential for patient survival.
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Although seed quality and quantity, as well as reproductive performance are important life history stages of plants, little is known about the reproductive responses of trees to environmental changes such as increased anthropogenic deposition of nitrogen (N) and phosphorus (P). Dioecious plants are good models with which to test the environmental impact on female or male reproductive responses individually. We analysed effects of different long-term nutritional availability on the reproductive performance of two dioecious species (Taxus baccata L. and Juniperus communis L.) characterised by different life histories. By using pot experiments with vegetatively propagated plants grown in different fertilisation conditions, we observed an increase in plant growth and strobili production but a decrease in seed efficiency. Seeds produced by fertilised plants had greater seed mass. Fertiliser addition did not change C or N content nor the C/N ratio of T. baccata seeds, but increased N content and the N/P ratio; however, it did lower the C/N ratio in J. communis. Fertilisation did not change the metabolite profile in T. baccata but 18 metabolites were changed in J. communis. The study revealed new links between species life history, environmental changes, and reproduction. The findings imply that future environmental conditions may alter both seed productivity, and quality, as well as plant reproductive behaviour.
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Juniperus , Semillas , Ambiente , Fertilización , Plantas , Reproducción/fisiologíaRESUMEN
We present the case of a 46-year-old male who developed refractory bradycardia with cardiogenic shock after attempting suicide by ingestion of yew leaves. Due to delayed availability of the Digoxin immune fab, a va-ECMO was established to maintain sufficient circulation. Administration of the digoxin fab resulted in recovery of spontaneous circulation. Continuous venovenous hemodiafiltration with hemoadsorption and albumin dialysis were initiated with the intention to remove immune fab-toxin complexes and as organ support in acute kidney and liver failure. Within 5 days the patient was successfully weaned from ECMO, liver support and renal replacement and discharged without physical sequelae.
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Oxigenación por Membrana Extracorpórea , Taxus , Albúminas , Oxigenación por Membrana Extracorpórea/métodos , Humanos , Fragmentos Fab de Inmunoglobulinas , Masculino , Persona de Mediana Edad , Hojas de la Planta , Diálisis Renal , Choque Cardiogénico/terapia , Ideación SuicidaRESUMEN
Yew plants (Taxus species) represent a genus of plants known to be highly toxic, though lethal intoxication is rare. The majority of deaths in yew berry poisonings occur due to its cardiotoxic effect, mediated through generation of a number of fatal tachy- and brady-arrhythmias. However, there are no guidelines on the most effective management in these cases, and interventions vary greatly between published reports. Here we report a case of a 20-year-old female who presented with refractory lethal arrythmia and shock refractory to conventional therapy. She presented to the emergency department and promptly required airway management and hemodynamic support necessitating intensive care unit management. She received many antiarrhythmics, digoxin immune Fab, lipid emulsification, and eventually transvenous pacemaker insertion for overdrive pacing. Despite our interventions, our patient ultimately died after a decision to withdraw care. We also reviewed 43 reports of yew poisoning cases described in the literature. We discuss the most common strategies used to treat such patients including gastric decontamination, antiarrhythmics, electrical pacing, extracorporeal life support and other therapies. We need better understanding of this condition, to identify which therapies offer maximal benefit and to optimize outcomes for this rare but often devastating toxidrome.
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Arritmias Cardíacas/inducido químicamente , Frutas/envenenamiento , Choque Cardiogénico/inducido químicamente , Suicidio , Taxus/envenenamiento , Arritmias Cardíacas/diagnóstico , Cardiotoxicidad , Resultado Fatal , Femenino , Humanos , Choque Cardiogénico/diagnóstico , Adulto JovenRESUMEN
The Hyrcanian Forest region is rich in relict species, and endemic and endangered species. Although there are concerns about climate change, its influence on tree species in the Hyrcanian forests in the north of Iran is still unidentified. Taxus baccata is among the few conifer species found in the region, and the present study aims to evaluate the potential impact of climate change on the distribution of T. baccata. For this purpose, we used ensemble species distribution modeling with ten algorithms and based on two geographic extents (global and regional) and climate data for different climate change scenarios. For the regional extent, we calibrated the models in Hyrcanian forests including the three provinces in the north of Iran. For the global extent, we calibrated the models on the whole range distribution of T. baccata. In both cases, we applied the models to predict the distribution of T. baccata in northern Iran under current, 2050, and 2070 climates. In regional extent modeling, precipitation of coldest quarter and in global extent modeling temperature seasonality emerged as the most important variables. Present environmental suitability estimates indicated that the suitable area for T. baccata in Hyrcanian forests is 5.89 × 103 km2 (regional modeling) to 9.74 × 103 km2 (global modeling). The modeling suggests that climate change under representative concentration pathways (RCP) 8.5 is likely to lead to strong suitability reductions in the region, with just between 0.63 × 103 km2 (regional modeling) and 0.57 × 103 km2 (global modeling) suitable area in 2070. Hence, T. baccata risks losing most currently suitable areas in the Hyrcanian forests under climate change. The results of the present study suggest there should be focus on conservation of areas predicted to remain suitable through near-future climate change and provide an estimate of the availability of suitable areas for the regeneration of T. baccata and its use in reforestation.
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Taxus , Animales , Cambio Climático , Ecosistema , Bosques , Irán , ÁrbolesRESUMEN
OBJECTIVES: Yew plant materials contain highly toxic taxine alkaloids. Serious ingestions can result in life-threatening toxicity. The purpose of this article is to summarize the literature on the treatment of acute yew poisoning. DATA SOURCES: PubMed (January 1946 to November 2017) was searched using the search terms "taxus/po". EMBASE (1980 to November 2017) was searched using the search terms "taxus/to" and "yew.mp." Web of Science (1945 to November 2017) was searched using the text words taxus, taxine, and yew. STUDY SELECTION AND DATA EXTRACTION: Available English language articles involving case reports, epidemiology, treatment, and outcomes were included. DATA SYNTHESIS: Although not uncommon, unintentional yew poisoning rarely results in significant morbidity or mortality. A total of 26 case reports of yew poisoning were evaluated along with 4 case series articles (totaling 22 additional cases). Only 4 of the 48 total cases (8%) were accidental poisonings, the rest being deliberate ingestions. In 20 patients (42%), it resulted in fatalities. Severe, acute yew poisoning results in symptomatology largely resistant to pharmacotherapy intervention. CONCLUSIONS: Most nonintentional ingestions of yew plant constituents are asymptomatic and require little intervention. Severe poisoning can result in life-threatening cardiac toxicity and require aggressive supportive care. Therapeutic interventions, such as sodium bicarbonate, digoxin immune fab, and hemodialysis that have been utilized in case studies and case series in the literature have little proven benefit. Extracorporeal life support should be considered in severe yew poisoning.
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Intoxicación por Plantas/terapia , Taxus/envenenamiento , Animales , Oxigenación por Membrana Extracorpórea , HumanosRESUMEN
Yew leaves poisoning is a rare life-threatening intoxication, whose diagnosis can be difficult. Initial symptoms are nausea, vomiting, abdominal pain, dizziness, tachycardia, muscle weakness, confusion, beginning within 1 hr from ingestion and followed by bradycardia, ventricular arrhythmias, ventricular fibrillation, severe hypotension, and death. Taxine-derived alkaloids are responsible for the toxicity of the yew leaves, blocking sodium and calcium channels, and causing conduction abnormalities. Because of lack of a specific antidote and limited efficacy of common antiarrhythmic drugs, prompt diagnosis, detoxification measures, and immediate hemodynamic support (also with transvenous cardiac stimulation) are essential.
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Arritmias Cardíacas/inducido químicamente , Cephalotaxus/envenenamiento , Electrocardiografía/métodos , Paro Cardíaco/inducido químicamente , Extractos Vegetales/envenenamiento , Hojas de la Planta/envenenamiento , Agonistas alfa-Adrenérgicos/uso terapéutico , Adulto , Anciano , Amiodarona/uso terapéutico , Antiarrítmicos/uso terapéutico , Arritmias Cardíacas/terapia , Reanimación Cardiopulmonar , Carbón Orgánico/uso terapéutico , Femenino , Lavado Gástrico , Paro Cardíaco/terapia , Humanos , Sulfato de Magnesio/uso terapéutico , Masculino , Persona de Mediana Edad , Norepinefrina/uso terapéutico , Marcapaso Artificial , Bicarbonato de Sodio/uso terapéutico , Resultado del TratamientoRESUMEN
INTRODUCTION: Yew plants are evergreen shrubs which are widely spread throughout the northern hemisphere. Taxane alkaloid derivatives, mainly taxine B, represent the main toxins of Taxus baccata and are highly cardiotoxic. Due to the lack of randomized clinical trials, case reports on accidental or suicidal yew intoxications build the only source of knowledge of clinical treatment options. CASE REPORT: We report the case of a suicidal yew ingestion admitted to our hospital under prolonged cardiopulmonary resuscitation due to pulseless electrical activity. Extra-corporeal life support (ECLS) was established to maintain adequate organ perfusion. Repeated administration of digoxin-specific Fab antibody fragments, which cross-react with taxine, was associated with an immediate conversion from asystole to broad-complex bradycardia and a gradual normalization of the electrocardiogram (ECG). This was paralleled by a recovery of the cardiac function and weaning from the ECLS. The taxine metabolite 3,5-dimethoxyphenol could be detected by mass spectrometry before but not after the first Fab-fragment treatment. In contrast, the total amount of taxine (including the neutralized, Fab fragment-bound fraction) was increased after each Fab fragment administration, suggesting an accumulation of neutralized, since antibody-bound taxine in the blood by anti-digoxin Fab fragments. DISCUSSION: In conclusion, the successful clinical course of this case suggests a benefit of an early anti-digoxin Fab-fragment administration for the treatment of yew intoxication.
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Arritmias Cardíacas/inducido químicamente , Oxigenación por Membrana Extracorpórea/métodos , Fragmentos Fab de Inmunoglobulinas/uso terapéutico , Extractos Vegetales/envenenamiento , Taxus/envenenamiento , Lesión Renal Aguda/inducido químicamente , Arritmias Cardíacas/fisiopatología , Electrocardiografía , Femenino , Humanos , Espectrometría de Masas , Pancreatectomía , Hojas de la Planta/envenenamiento , Diálisis Renal , Esplenectomía , Intento de Suicidio , Resultado del Tratamiento , Adulto JovenRESUMEN
INTRODUCTION: European yew (Taxus baccata) is a plant known to man for centuries as it produces many interesting and important metabolites. These chemical compounds were repeatedly analysed by various analytical techniques, but none of the methods used so far allowed the localisation of the chemical compounds within the tissue and also correlation between plant morphology and its biochemistry. OBJECTIVE: Visualisation of the spatial distribution of yew metabolites with nanoparticle-based mass spectrometry imaging. METHODOLOGY: Compounds occurring on cross-section of a one-year yew sprig has been transferred to gold nanoparticle-enhanced target (AuNPET) by imprinting. The imprint was then subjected to mass spectrometry imaging analysis. RESULTS: Nanoparticle-enhanced mass spectrometry imaging made it possible to study the distribution of selected compounds in the European yew tissue, including taxanes - terpene alkaloids characteristic for the Taxus genus. Results prove that aspartate, taxinine M, baccatin IV and taxine B are located mainly in the cortex. Taxuspine W was located in the vascular tissue. Maleate was found to be located mainly in the phloem tissue. In contrast, the proton adduct of chlorophyll b was found in the external layer of twigs. CONCLUSION: The results presented a high correlation between the location of compounds and the morphology of the plant, thus giving the opportunity to see the selected details of chemical structure of the analysed tissue for the first time. Copyright © 2017 John Wiley & Sons, Ltd.
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Nanopartículas , Extractos Vegetales/análisis , Taxoides/análisis , Taxus/química , Oro , Espectrometría de MasasRESUMEN
Paclitaxel, a rare diterpene extracted from the bark of Chinese yew (Taxus chinensis), is renowned for its anti-cancer activity and serves as a primary drug for treating cancers. Due to the exceptionally low content of paclitaxel in the bark, a semi-synthetic method that depletes Chinese yew resources is used in the production of paclitaxel, which, however, fails to meet the escalating clinical demand. In recent years, researchers have achieved significant progress in heterologous biosynthesis and metabolic engineering for the production of paclitaxel. This article comprehensively reviews the advancements in paclitaxel production, encompassing chemical synthesis, heterologous biosynthesis, and cell engineering. It provides an in-depth introduction to the biosynthetic pathway and transcriptional regulation mechanisms of paclitaxel, aiming to provide a valuable reference for further research on paclitaxel biosynthesis.
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Paclitaxel , Paclitaxel/biosíntesis , Ingeniería Metabólica/métodos , Taxus/genética , Taxus/metabolismo , Antineoplásicos Fitogénicos/biosíntesis , Antineoplásicos Fitogénicos/farmacología , Transcripción Genética , Vías Biosintéticas/genéticaRESUMEN
Maire yew (Taxus mairei), an evergreen conifer, has high ornamental and medicinal value. The arils of this species has three different colors. However, the variation mechanisms of arils color formation remains unclear. Here, the gene expression and metabolite concentration were profiled for red (RTM), yellow (YTM), and purple (PTM) arils in different developmental stages. A total of 266 flavonoids and 35 carotenoids were identified. The predominant pigments identified in YTM were epiafzelechin, lutein, and ß-Cryptoxanthin, while malvidin-3,5-di-O-glucoside and apigenin played crucial roles in PTM. And significant differential expression was observed among the HCT, DFR, LAR, ANS, crtB, NCED, and CCoAOMT genes across different color arils. During the maturation of yellow arils, the upregulation of HCT was strongly correlated with the accumulation of epiafzelechin. The diminished expression of DFR, LAR, and ANS seemed to inhibit the production of delphinidin-3-O-rutinoside. The decrease in crtB expression and concurrent increase in NCED expression potentially regulate the heightened accumulation of lutein. Meanwhile, the accumulation of ß-cryptoxanthin appeared seemed to be positively influenced by NCED. As aril turning purple, the decreased expression of CCoAOMT seemed to facilitate the synthesis of apigenin. The substantial upregulation of DFR promoted the production of malvidin-3,5-di-O-glucoside. Additionally, the overexpression of MYBs may plays the important role in regulating the formation of different colored arils. In total, 14 genes were selected for qRT-PCR validation, the results indicated the reliability of the transcriptome sequences data. Our findings could provide valuable insight into the molecular breeding, development, and application of Maire yew resources.
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The cool temperate origin of gymnosperm Taxus species in East Asia is specifically diverse and widespread. Certain lineages have managed to extend their distribution further south to subtropical and tropical islands such as Taiwan and the Philippines. To address questions including whether these insular lineages, recently identified as T. phytonii, have become genetically distinct from each other and from their continental relatives, and when and how they colonized their residing islands, we sampled over 11 populations, covering 179 Taxus individuals from Taiwan and the Philippines. Using four cpDNA and one nuclear marker, we showed in population genetic and genealogical analyses that the two insular lineages were genetically distinct from each other and also from other continental Taxus and that they represented each other's closest relative. Estimated with the coalescent-based multi-type tree (MTT) analyses, we inferred an origin of Taiwanese T. phytonii more ancient than 2.49 Mya and that of Philippine T. phytonii more ancient than 1.08 Mya. In addition, the divergence demographic history revealed by both MTT and isolation with migration (IM) analyses indicated the presence of recent post-split migrations from a continental taxon, T. mairei, to Taiwanese T. phytonii, as well as from Taiwanese T. phytonii to Philippine T. phytonii. Overall, this study suggests Taiwan as a stepping stone through which the temperate-origin yew trees can extend their distributions to tropical regions such as the Philippines.
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A series of new taxanes, 1-93, have been isolated, together with 37 known taxoids including Taxol(®) (paclitaxel) and cephalomannine, from the Canadian yew, Taxus canadensis (Taxaceae) in the past 30 years. These new taxoids possess various skeletons containing 5/7/6, 6/10/6, 6/5/5/6, 6/8/6, and 6/12 ring systems and six new taxanes with four novel skeletons, i.e., a taxane with a 6/6/8/6 ring system, a taxane with a [3.3.3] propellane skeleton, three taxanes with [3.3.3] [3.4.5] dipropellane sytems, as well as a novel taxane with a unique 5/5/4/6/6/6 hexacyclic skeleton, containing a unique [3.3.2] propellane, were isolated for the first time from natural sources. It should be emphasized that 13-acetyl-9-dihydrobaccatin III, a very useful starting material for the semisynthesis of Taxol(®) and Taxotere(®) , represents the most abundant taxane in the needles of this yew tree. These findings establish the above mentioned yew tree as significantly different from the remaining species. On the other hand, some chemical modifications on the taxanes isolated from this plant were carried out.
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Extractos Vegetales/química , Taxus/química , Supervivencia Celular/efectos de los fármacos , Resistencia a Antineoplásicos/efectos de los fármacos , Humanos , Isomerismo , Células MCF-7 , Conformación Molecular , Taxoides/química , Taxoides/aislamiento & purificación , Taxoides/toxicidad , Taxus/metabolismoRESUMEN
In order to understand the adaptative changes of the Japanese yew (Taxus cuspidate L.) to high light conditions, this study investigated gas-exchange, chlorophyll fluorescence, chlorophyll, and the impact of epicuticular wax on the gas-exchange and photoinhibition of Japanese yew seedlings and saplings. The chlorophyll content per unit area and photosynthetic rate in seedling leaves were significantly lower than in sapling leaves. When leaves from seedlings and saplings were exposed to 1,200 µmol·m-2·s-1 photon flux density (PFD) for 2 h, seedling leaves exhibited a greater down-regulation of maximum quantum yield (Fv/Fm) and actual photosystem II efficiency ( Φ PSII). Non-photochemical quenching (NPQ) and high energy quenching (qE) in sapling leaves were much higher than in seedling leaves when both were exposed to 1,200 µmol·m-2·s-1 PFD for 2 h. At a low level of O2, the photorespiration rate (Pr) and the ratio of photorespiration/gross photosynthetic rate (Pr/Pg) in seedling leaves were lower than in sapling leaves when both were exposed to 1,200 µmol·m-2·s-1 PFD, but this difference did not reach statistical significance (P < 0.05). Compared with sapling leaves, seedling leaves exhibited lower levels of xanthophyll pool. Epicuticular wax content on seedling leaves was significantly lower than on sapling leaves. The results of this study showed that wax coverage on the leaf surface decreased the photosynthetic rate in sapling leaves as a consequence of decreased stomatal conductance. Epicuticular wax is related to tree age and photoinhibition prevention in the Japanese yew. It is possible that lower photosynthetic rate, lower NPQ depending on the xanthophyll cycle, and lower deposition of epicuticular wax results in seedling plants that are not adapted to high light conditions.
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Plantones , Taxus , Humanos , Clorofila/fisiología , Fotosíntesis/fisiología , Plantones/metabolismo , Taxus/metabolismo , Xantófilas/metabolismoRESUMEN
OBJECTIVE: Presentations of Taxus baccata (yew) poisoning can range between asymptomatic cases and life-threatening cardiotoxicity - depending on the amount ingested. This study aimed to describe emergency department (ED) presentations after yew exposure, and covers their clinical presentation, diagnostic and specific treatment, to contribute to optimising intreatment and prophylaxis. METHODS: Retrospective observational study of cases (≥ 16 years of age) presenting at the ED of the University Hospital of Bern, Switzerland, from 1 May 2012 to 31 May 2020 following reported yew exposure. Cases were retrieved from the electronic patient database using full-text terms. RESULTS: During the study period, 55 presentations (11 patients) of the 350,381 ED attendances were included. All patients were female and the median age on first presentation was 22 years (range 16-48). All 10 patients with intentional intake had previous diagnoses of psychiatric disorders. Commonly reported symptoms on presentation were gastrointestinal disturbances (31 presentations, 56%), neurological (six presentations, 11%) and subjective cardiovascular symptoms (five presentations, 9%). The most frequent clinical findings on presentation were tachycardia (15 presentations, 27%) and hypotension (11 presentations, 20%). In 52 presentations (95%), gastroscopic extraction of the leaves was performed, activated charcoal was administered in 25 cases (45%), and there were no fatalities. In the majority of the cases (40, 73%), the patient was admitted to psychiatric care and in 10 (18%) the patient was discharged home. CONCLUSION: ED presentations after yew exposure appear to be rare, but potentially life-threatening and commonly observed in this study in young female patients with underlying psychiatric diseases. In this case series, gastroscopic extraction and activated charcoal application were commonly performed and there were no fatalities.
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Trastornos Mentales , Taxus , Humanos , Femenino , Adolescente , Adulto Joven , Adulto , Persona de Mediana Edad , Masculino , Carbón Orgánico , Servicio de Urgencia en Hospital , Ingestión de AlimentosRESUMEN
In an adolescent patient with severe yew intoxication and consecutive cardiac arrest, non-responsive to conventional resuscitation necessitating extracorporeal life support, Levosimendan has been implemented in the early acute phase of hemodynamic stabilization, without obvious side effects. However, the additive value of this treatment in severe yew intoxication remains speculative.
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The effect of key ecological and anthropic factors on the recruitment of the common yew (Taxus baccata L.) in Sardinia (Italy) has been analyzed. After bibliographic and cartographic research, followed by field surveys, we found 232 sites where yew grows in Sardinia (as opposed to 69 previously reported in the literature). Among them, we selected 40 sites, located in 14 different mountain chains, characterized by a number of individuals ranging from 11 to 836 adult yews with an average diameter at breast height (DBH) from 13 to 130 cm. By means of generalized linear modeling, we investigated and weighted the effect of ecological, structural, and anthropic factors on the amount of T. baccata recruitment. Our analyses showed that stand recruitment was positively correlated to shrub cover and soil moisture. In particular, shrub cover had a stronger effect, clearly showing that a thicker shrub layer, both bushy and/or spiny, corresponded to a higher number of yew seedlings and saplings. Secondarily, moister sites had a higher number of seedlings and saplings, showing that habitat suitability improved with higher humidity. On the contrary, recruitment was negatively correlated to browsing (both from livestock and wild animals). Our data confirm that the presence of a protective layer of shrubs is a crucial factor for seedling and sapling survival, mostly in relation to protection from summer drought and the browsing of large herbivores. Finally, guidelines for the conservation and restoration of T. baccata communities, referred to as the EU priority habitat 9580* (Mediterranean Taxus baccata woods), have been outlined.
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5-aminolevulinic acid (ALA) is a novel regulator that can promote plant growth, nitrogen uptake, and abiotic stress tolerance. Its underlying mechanisms, however, have not been fully investigated. In this study, the effects of ALA on morphology, photosynthesis, antioxidant systems, and secondary metabolites in two cultivars of 5-year-old Chinese yew (Taxus chinensis) seedlings, 'Taihang' and 'Fujian', were examined under shade stress (30% light for 30 days) using different doses of ALA (0, 30, and 60 mg/L). The findings from our study show that shade stress significantly reduced plant height, stem thickness, and crown width and increased malondialdehyde (MDA) levels. However, the application of 30 mg/L ALA effectively mitigated these effects, which further induced the activity of antioxidant enzymes under shade stress, resulting in the activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) being increased by 10%, 16.4%, and 42.1%, and 19.8%, 20.1%, and 42% in 'Taihang' and 'Fujian', respectively. It also promoted their role in the absorption, conversion, and efficient use of light energy. Additionally, the use of 30 mg/L ALA caused a significant increase in the concentration of secondary metabolites, including polysaccharide (PC), carotenoid (CR), and flavonoids (FA), with increases of up to 46.1%, 13.4%, and 35.6% and 33.5%, 7.5%, and 57.5% in both yew cultivars, respectively, contributing to nutrient uptake. With ALA treatment, the yew seedlings showed higher chlorophyll (total chlorophyll, chlorophyll a and b) levels and photosynthesis rates than the seedlings that received the shade treatment alone. To conclude, the application of 30 mg/L ALA alleviated shade stress in yew seedlings by maintaining redox balance, protecting the photorespiratory system, and increasing organic metabolites, thus increasing the number of new branches and shoots and significantly promoting the growth of the seedlings. Spraying with ALA may be a sustainable strategy to improve the shade-resistant defense system of yew. As these findings increase our understanding of this shade stress response, they may have considerable implications for the domestication and cultivation of yew.
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The active, poisonous constituents in Taxus baccata, the yew plants, are taxine alkaloids whose main action is suggested to be a block of calcium and sodium channels. The main alkaloids are taxine B (30%) and taxine A (1.3%). Symptoms can include bradycardia, bradypnea, diastolic, and cardiac standstill. The current investigation reports the analytical toxicology of human blood and urine to confirm a suspected ingestion of yew needles. This includes the qualitative detection of several yew ingredients, including the main alkaloids, the validated quantification of 3,5-dimethoxyphenol, and the discussion of suitable analytical targets. After analyzing human specimens and yew needle extracts using the developed procedures, the five alkaloids 1-deotaxine B, taxicatin, taxine A, taxine B, and taxine I could be detected and tentatively identified. Finally, taxine A and B can be recommended as analytical targets besides 3,5-dimethoxyphenol.