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1.
Genes (Basel) ; 12(2)2021 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-33557242

RESUMO

The Taxodium hybrid 'Zhongshanshan 406' (T. hybrid 'Zhongshanshan 406') [Taxodium mucronatum Tenore × Taxodium distichum (L.). Rich] has an outstanding advantage in flooding tolerance and thus has been widely used in wetland afforestation in China. Alcohol dehydrogenase genes (ADHs) played key roles in ethanol metabolism to maintain energy supply for plants in low-oxygen conditions. Two ADH genes were isolated and characterized-ThADH1 and ThADH4 (GenBank ID: AWL83216 and AWL83217-basing on the transcriptome data of T. hybrid 'Zhongshanshan 406' grown under waterlogging stress. Then the functions of these two genes were investigated through transient expression and overexpression. The results showed that the ThADH1 and ThADH4 proteins both fall under ADH III subfamily. ThADH1 was localized in the cytoplasm and nucleus, whereas ThADH4 was only localized in the cytoplasm. The expression of the two genes was stimulated by waterlogging and the expression level in roots was significantly higher than those in stems and leaves. The respective overexpression of ThADH1 and ThADH4 in Populus caused the opposite phenotype, while waterlogging tolerance of the two transgenic Populus significantly improved. Collectively, these results indicated that genes ThADH1 and ThADH4 were involved in the tolerance and adaptation to anaerobic conditions in T. hybrid 'Zhongshanshan 406'.


Assuntos
Álcool Desidrogenase/genética , Estresse Fisiológico/genética , Taxodium/genética , Transcriptoma/genética , Adaptação Fisiológica/genética , Inundações , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Proteínas de Plantas , Raízes de Plantas , Plântula/genética , Plântula/crescimento & desenvolvimento , Taxodium/crescimento & desenvolvimento , Água/efeitos adversos
2.
Sci Total Environ ; 759: 143484, 2021 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-33203558

RESUMO

Changing environments of temperature, precipitation and moisture availability can affect vegetation in ecosystems, by affecting regeneration from the seed bank. Our objective was to explore the responses of soil seed bank germination to climate-related environments along geographic gradients. We collected seed banks in baldcypress (Taxodium distichum) swamps along the Mississippi River and the Gulf of Mexico Coast in the United States, which have distinct temperature and/or precipitation gradients, and germinated them in a greenhouse. The frequency, richness and seed density of species germinated from the seed bank were compared between various geographic locations, experimental water regimes (saturated, flooded) and wetland types (tidal, non-tidal and inland swamps). We also analyzed the relationship of seed density to the environment by using a Non-metric Multi-dimensional Scaling (NMDS) model. Sixty-one species germinated from the seed bank, differing in pattern by geographic location, experimental water regime and wetland type. The foundation species (i.e., T. distichum and Cephalanthus occidentalis) germinated with a niche affinity for the northern part of the latitudinal gradient (Tennessee and Illinois) and these species may shift northward with climate change. Some species had higher seed density in the locations that were subject to more persistent drought conditions (e.g., Texas) including Cyperus rotundus and Gratiola virginiana, indicating that these species may be better adapted to sites with high temperature and low precipitation. In contrast, certain species including Saururus cernuus and Ludwigia palustris were present throughout the range of these gradients, and so may be more resilient to any future climate shifts. We found that the regeneration potential of baldcypress swamps might be altered by changes in local and climate environment because of nuances of responses of seed banks to climates along latitudinal and longitudinal gradients. Our study can help predict vegetation regeneration potential to climate change environments depending on the ability of these species to disperse and maintain seed banks.


Assuntos
Banco de Sementes , Taxodium , Ecossistema , Germinação , Golfo do México , Illinois , Mississippi , Sementes , Solo , Tennessee , Texas , Áreas Alagadas
3.
Chem Commun (Camb) ; 56(22): 3329-3332, 2020 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-32083260

RESUMO

Taxodisones A and B, C30-terpenes with an unprecedented tetracyclo[12.4.0.0.2,709,14]octodecane core, were isolated from the seeds of Taxodium distichum. Their structures, including their configurations, were unambiguously determined. Their biomimetic synthesis suggests that they stem from diterpenes and monoterpenes, and not from squalene or oxidosqualene. In addition, their bioactivities were also evaluated.


Assuntos
Diterpenos/química , Taxodium/química , Biomimética , Catálise , Complexos de Coordenação/química , Cristalografia por Raios X , Reação de Cicloadição , Diterpenos/metabolismo , Érbio/química , Conformação Molecular , Sementes/química , Sementes/metabolismo , Taxodium/metabolismo , Terpenos/química , Terpenos/metabolismo
4.
BMC Genomics ; 21(1): 114, 2020 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-32005143

RESUMO

BACKGROUND: Chloroplast (cp) genome information would facilitate the development and utilization of Taxodium resources. However, cp genome characteristics of Taxodium were poorly understood. RESULTS: We determined the complete cp genome sequences of T. distichum, T. mucronatum, and T. ascendens. The cp genomes are 131,947 bp to 132,613 bp in length, encode 120 genes with the same order, and lack typical inverted repeat (IR) regions. The longest small IR, a 282 bp trnQ-containing IR, were involved in the formation of isomers. Comparative analysis of the 3 cp genomes showed that 91.57% of the indels resulted in the periodic variation of tandem repeat (TR) motifs and 72.46% single nucleotide polymorphisms (SNPs) located closely to TRs, suggesting a relationship between TRs and mutational dynamics. Eleven hypervariable regions were identified as candidates for DNA barcode development. Hypothetical cp open reading frame 1(Ycf1) was the only one gene that has an indel in coding DNA sequence, and the indel is composed of a long TR. When extended to cupressophytes, ycf1 genes have undergone a universal insertion of TRs accompanied by extreme length expansion. Meanwhile, ycf1 also located in rearrangement endpoints of cupressophyte cp genomes. All these characteristics highlight the important role of repeats in the evolution of cp genomes. CONCLUSIONS: This study added new evidence for the role of repeats in the dynamics mechanism of cp genome mutation and rearrangement. Moreover, the information of TRs and hypervariable regions would provide reliable molecular resources for future research focusing on the infrageneric taxa identification, phylogenetic resolution, population structure and biodiversity for the genus Taxodium and Cupressophytes.


Assuntos
Cloroplastos/genética , Análise de Sequência de DNA/métodos , Taxodium/classificação , Evolução Molecular , Variação Genética , Tamanho do Genoma , Genoma de Cloroplastos , Sequenciamento de Nucleotídeos em Larga Escala , Filogenia , Taxodium/genética
5.
PLoS One ; 15(1): e0226998, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31899783

RESUMO

A common idea in the discussion of soil carbon processes is that litter decomposition rates and soil carbon stocks are inversely related. To test this overall hypothesis, simultaneous studies were conducted of the relationship of environmental gradients to leaf and wood decomposition, buried cloth decomposition and percent soil organic matter in Taxodium distichum swamps across the Mississippi River Alluvial Valley (MRAV) and northern Gulf of Mexico (GOM) of the US. Decomposition of leaf tissue was 6.2 to 10.9 times faster than wood tissue. Both precipitation and flooding gradients were negatively related to leaf and wood litter decomposition rates based on models developed using Stepwise General Model Selection (MRAV vs. GOM, respectively). Cotton cloth should not be used as a proxy for plant litter without prior testing because cloth responded differently than plant litter to regional environmental gradients in T. distichum swamps. The overall hypothesis was supported in the MRAV because environments with higher precipitation (climate normal) had lower rates of decomposition and higher percent soil organic matter. In the MRAV, higher levels of percent soil organic matter were related to increased 30-year climate normals (30 year averages of precipitation and air temperature comprising southward increasing PrinComp1). Soil organic carbon % in inland vs. coastal T. distichum forests of the MRAV were comparable (range = 1.5% to 26.9% vs. 9.8 to 31.5%, respectively). GOM swamps had lower rates of litter decomposition in more flooded environments. Woody T. distichum detritus had a half-life of up to 300 years in the MRAV, which points to its likely role in the maintenance of inland "teal" soil organic carbon. This unique study can contribute to the discussion of approaches to maintain environments conducive to soil carbon stock maximization.


Assuntos
Florestas , Substâncias Húmicas/análise , Folhas de Planta/química , Solo/química , Áreas Alagadas , Carbono/análise , Clima , Inundações , Chuva , Sudeste dos Estados Unidos , Taxodium , Temperatura , Estados Unidos
6.
Molecules ; 24(17)2019 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-31438610

RESUMO

The resins bled from stems and in seed cones and leaves of Cryptomeria japonica, Glyptostrobus pensilis, Taxodium distichum, and T. mucronatum were characterized to provide an overview of their major natural product compositions. The total solvent extract solutions were analyzed as the free and derivatized products by gas chromatography-mass spectrometry to identify the compounds, which comprised minor mono- and sesquiterpenoids, and dominant di- and triterpenoids, plus aliphatic lipids (e.g., n-nonacosan-10-ol). Ferruginol, 7α-p-cymenylferruginol, and chamaecydin were the major characteristic markers for the Taxodioideae conifer subfamily. The mass spectrometric data can aid polar compound elucidation in environmental, geological, archeological, forensic and pharmaceutical studies.


Assuntos
Cupressaceae/química , Cromatografia Gasosa-Espectrometria de Massas/métodos , Taxodium/química , Terpenos/análise
7.
Int J Mol Sci ; 20(5)2019 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-30862088

RESUMO

Adventitious root (AR) formation from cuttings is the primary manner for the commercial vegetative propagation of trees. Cuttings is also the main method for the vegetative reproduction of Taxodium 'Zhongshanshan', while knowledge of the molecular mechanisms regulating the processes is limited. Here, we used mRNA sequencing and an isobaric tag for relative and absolute quantitation-based quantitative proteomic (iTRAQ) analysis to measure changes in gene and protein expression levels during AR formation in Taxodium 'Zhongshanshan'. Three comparison groups were established to represent the three developmental stages in the AR formation process. At the transcript level, 4743 genes showed an expression difference in the comparison groups as detected by RNA sequencing. At the protein level, 4005 proteins differed in their relative abundance levels, as indicated by the quantitative proteomic analysis. A comparison of the transcriptome and proteome data revealed regulatory aspects of metabolism during AR formation and development. In summary, hormonal signal transduction is different at different developmental stages during AR formation. Other factors related to carbohydrate and energy metabolism and protein degradation and some transcription factor activity levels, were also correlated with AR formation. Studying the identified genes and proteins will provide further insights into the molecular mechanisms controlling AR formation.


Assuntos
Perfilação da Expressão Gênica , Raízes de Plantas/genética , Raízes de Plantas/metabolismo , Proteoma , Proteômica , Taxodium/genética , Taxodium/metabolismo , Transcriptoma , Biologia Computacional/métodos , Perfilação da Expressão Gênica/métodos , Regulação da Expressão Gênica de Plantas , Anotação de Sequência Molecular , Fenótipo , Reguladores de Crescimento de Plantas/metabolismo , Proteômica/métodos , Reação em Cadeia da Polimerase em Tempo Real , Transdução de Sinais
8.
Sci Total Environ ; 658: 1514-1522, 2019 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-30678009

RESUMO

Changes in global precipitation patterns would make wet regions more humid and extreme precipitation events occur frequently, followed by widespread flooding. Riparian forests are more capable of withstanding floods than inland forests because they are frequently exposed to short-term flooding events. Although many previous studies have investigated the soil water dynamics of terrestrial forests, little is known about how the soil water of riparian forests responds to different amounts of rainfall and which factors mainly regulate the soil water-holding capacity. Here, we employed stable hydrogen isotope to explore the contribution of different magnitudes of rainfall (7.9, 18.6 and 34.1 mm) to the soil water in two types of riparian forests (pure vs. mixed stand of Populus deltoides) in the middle-lower reaches of the Yangtze River, China. We further used structure equation modelling to determine the relative importance of soil properties and vegetation biomass in affecting the contribution of different magnitudes of rainfall to soil water. Our results revealed that there was no significant difference between these two stand types in the contributions of light and moderate rainfall to soil water, while the contribution of heavy rainfall to soil water (CHRSW) in mixed stand was significantly higher than that in pure stand (74.3% vs. 62.9%), suggesting that mixed stand soil has higher water-holding capacity than pure stand soil. Furthermore, soil properties were the best predictor affecting CHRSW, which explained 68% and 59% of the variation in the CHRSW on the 1st and 8th days after rainfall, respectively. Moreover, the root biomass could indirectly affect the CHRSW. Overall, mixed stand soil had a greater capacity in intercepting and storing rainwater than pure stand soil, implying that the mixed stand plantation, rather than the pure stand, should be recommended in riparian forest restoration projects that aim to improve their capacity for alleviating floods.


Assuntos
Biomassa , Biota , Florestas , Água Subterrânea/análise , Chuva , Árvores , China , Liquidambar/fisiologia , Populus/fisiologia , Solo/química , Taxodium/fisiologia , Árvores/fisiologia
9.
BMC Plant Biol ; 18(1): 263, 2018 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-30382825

RESUMO

BACKGROUND: 'Zhongshanshan' is the general designation for the superior interspecific hybrid clones of Taxodium species, which is widely grown for economic and ecological purposes in southern China. Growth is the priority objective in 'Zhongshanshan' tree improvement. A high-density linkage map is vital to efficiently identify key quantitative trait loci (QTLs) that affect growth. RESULTS: In total, 403.16 Gb of data, containing 2016,336 paired-end reads, was obtained after preprocessing. The average sequencing depth was 28.49 in T. distichum var. distichum, 25.18 in T. mucronatum, and 11.12 in each progeny. In total, 524,662 high-quality SLAFs were detected, of which 249,619 were polymorphic, and 6166 of the polymorphic markers met the requirements for use in constructing a genetic map. The final map harbored 6156 SLAF markers on 11 linkage groups, and was 1137.86 cM in length, with an average distance of 0.18 cM between adjacent markers. Separate QTL analyses of traits in different years by CIM detected 7 QTLs. While combining multiple-year data, 13 QTLs were detected by ICIM. 5 QTLs were repeatedly detected by the two methods, and among them, 3 significant QTLs (q6-2, q4-2 and q2-1) were detected in at least two traits. Bioinformatic analysis discoveried a gene annotated as a leucine-rich repeat receptor-like kinase gene within q4-2. CONCLUSIONS: This map is the most saturated one constructed in a Taxodiaceae species to date, and would provide useful information for future comparative mapping, genome assembly, and marker-assisted selection.


Assuntos
Locos de Características Quantitativas , Taxodium/crescimento & desenvolvimento , Taxodium/genética , Cruzamentos Genéticos , Marcadores Genéticos , Genoma de Planta , Plântula/genética
10.
Plant Cell Rep ; 37(11): 1547-1555, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30056500

RESUMO

KEY MESSAGE: The T.118 and T.406 seedlings showed strong adaptability under Cd concentrations ≤ 50 µM. The mechanisms of photoprotection in T.118 and T.406 differed in high-Cd concentrations. To explore the physiological response characteristics of Taxodium hybrids to cadmium (Cd) stress and provide basis for screening of Cd-tolerant species, the hydroponic cultivation of T.118 and T.406 seedlings was conducted to demonstrate the effects of Cd stress on seedling growth, antioxidant system, and chlorophyll fluorescence parameters. After 35 days of Cd stress at a concentration ≤ 50 µM, the dry weight biomass of the two clones did not significantly differ from that of the control. T.406 exhibited a significant increase in POD activity compared to T.118 and maintained high SOD activity after exposure to high concentrations of Cd, whereas MDA levels showed little changes. Under low-Cd stress, chlorophyll content and fluorescence parameters remained stable, especially for T.406. Under high-Cd concentration stress, the above parameters were lower than the control, with a more significant decrease in T.118 than in T.406. The non-photochemical quenching coefficient (NPQ) of both clones increased with increasing Cd concentration. T.118 showed a greater increase than T.406, particularly under high-Cd concentration stress. The T.118 and T.406 seedlings adapted to low-Cd concentration stress by enhancing their antioxidant enzyme activity to maintain the balance of reactive oxygen metabolism and reduce cellular damage. The photochemical activity of mesophyll cells remained high to maintain photosynthetic capacity and normal seedling growth. T.406 showed stronger resistance to Cd than T.118. T.406 prevented photodamage by promoting the photochemical utilization of the excitation energy and maintaining a strong antioxidant stress ability. Enhancement of heat dissipation capability may be the main photoprotection mechanism of T.118.


Assuntos
Antioxidantes/metabolismo , Cádmio/toxicidade , Fotossíntese/efeitos dos fármacos , Taxodium/efeitos dos fármacos , Biomassa , Clorofila/metabolismo , Fluorescência , Hidroponia , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Plântula/fisiologia , Estresse Fisiológico , Taxodium/crescimento & desenvolvimento , Taxodium/fisiologia
11.
Biochem Pharmacol ; 154: 357-372, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29859988

RESUMO

Chronic myeloid leukemia (CML) and acute lymphoblastic leukemia (ALL) are hematopoietic malignancies caused by the constitutive activation of BCR-ABL tyrosine kinase. Although direct BCR-ABL inhibitors, such as imatinib, were initially successful in the treatment of leukemia, many patients developed drug resistance over time due to the gatekeeper mutation of BCR-ABL T315I. In the present study, we found that taxodione, a quinone methide diterpene isolated from Taxodium distichum, significantly induced apoptosis in human myelogenous leukemia-derived K562 cells, which were transformed by BCR-ABL. Taxodione reduced the activities of mitochondrial respiratory chain (MRC) complexes III and V, which appeared to induce the production of reactive oxygen species (ROS). N-acetylcysteine (NAC), an antioxidant agent, canceled taxodione-induced ROS production, reductions in MRC activities, particularly complex V, and apoptotic cell death. Furthermore, in K562 cells treated with taxodione, BCR-ABL and its major signaling molecules, such as STAT5 and Akt were sequestered in mitochondrial fraction, and their localization changes decrease their abilities to stimulate cell proliferation, suggesting that these actions seem to be a mechanism how taxodione functions as an anti-tumor drug. Strikingly, NAC canceled these taxodione-caused anti-cancer effects. Taxodione induced apoptosis in transformed Ba/F3 cells induced not only by BCR-ABL, but also T315I-mutated BCR-ABL through the generation of ROS. Collectively, the present results suggest that in the treatment of leukemia, taxodione has potential as a compound with high efficacy to overcome BCR-ABL T315I mutation-mediated resistance in leukemia cells.


Assuntos
Apoptose/efeitos dos fármacos , Diterpenos/farmacologia , Proteínas de Fusão bcr-abl/metabolismo , Extratos Vegetais/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Taxodium , Apoptose/fisiologia , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Diterpenos/isolamento & purificação , Relação Dose-Resposta a Droga , Humanos , Células K562 , Extratos Vegetais/isolamento & purificação
12.
Environ Sci Pollut Res Int ; 25(23): 23261-23275, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29869211

RESUMO

In order to understand the effect of submergence on nutrient release of the reforested tree leaves and assess the environmental risk of leaf decomposition under submergence, the mass loss and nutrient release rates of three reforestation tree species, Taxodium ascendens Brongn, Taxodium distichum (L.) Rich., and Salix matsudana Koidz., at different elevation in the hydro-fluctuation zone of the Three Gorges Dam Reservoir (TGDR) region were tested in situ. Results showed that the initial macroelement contents of the leaves of the three tree species varied among different elevations due to different submergence stresses. All foliar mass loss rates of the three tree species at 165 m a.s.l. were significantly higher than that at 175 m a.s.l. (except that of S. matsudana at 165 m a.s.l.), after 179 days of incubation commenced September 20. After 138 days of incubation commenced October 5, the foliar mass loss rates of the three tree species at 170 m a.s.l. were significantly higher than that at 175 m a.s.l. Moreover, the leaf mass loss rates of S. matsudana were higher than the other two species when compared at the same elevation of the same incubation period. In addition, foliar release rates of N and Ca in T. ascendens, C, N, and Ca in T. distichum as well as Ca in S. matsudana at 165 m a.s.l. after 179 days of incubation and at 170 m a.s.l. after 138 days of incubation were significantly higher than that at 175 m a.s.l., respectively. Leaf mass loss rates of T. ascendens were significantly correlated with its initial leaf K, Ca, and Mg contents. In contrast, leaf mass loss rates of T. distichum had significant correlations with the initial leaf P and K contents, as well as C/P and N/P ratios. However, the mass loss rates of S. matsudana significantly correlated with initial leaf N, P, and Ca contents and C/N, C/P, and N/P ratios. Foliar nutrient release rates, especially the foliar release of C, N, and P of the three tree species, had significant correlations with initial leaf C/P and N/P ratios. Our results suggested that submergence facilitated the decomposition and nutrient release rates of the leaves of the three woody species, especially the broad leaves of S. matsudana, which may potentially cause secondary pollution to the water body of the TGDR. Thus, we suggested that a sustainable harvest of leaves of the reforested forest stands prior to submergence should be considered in the hydro-fluctuation zone so as to protect the water quality of the TGDR.


Assuntos
Folhas de Planta/metabolismo , Salix/metabolismo , Taxodium/metabolismo , Árvores , China , Inundações , Florestas , Nitrogênio/análise , Nutrientes/análise , Folhas de Planta/química , Salix/química , Taxodium/química
13.
Environ Sci Pollut Res Int ; 25(24): 23748-23763, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29876849

RESUMO

As one of the most active components in soil, bacteria can affect soil physicochemical properties, its biological characteristics, and even its quality and health. We characterized dynamics of the soil bacterial diversity in planted (with Taxodium distichum) and unplanted soil in the riparian zone of the Three Gorges Dam Reservoir (TGDR), in southwestern China, in order to accurately quantify the changes in long-term soil bacterial community structure after revegetation. Measurements were taken annually in situ in the TGDR over the course of 5 years, from 2012 to 2016. Soil chemical properties and bacterial diversity were analyzed in both the planted and unplanted soil. After revegetation, the soil chemical properties in planted soil were significantly different than in unplanted soil. The effects of treatment, time, and the interaction of both time and treatment had significant impacts on most diversity indices. Specifically, the bacterial community diversity indices in planted soil were significantly higher and more stable than that in unplanted soil. The correlation analyses indicated that the diversity indices correlated with the pH value, organic matter, and soil available nutrients. After revegetation in the riparian zone of the TGDR, the soil quality and health is closely related to the observed bacterial diversity, and a higher bacterial diversity avails the maintenance of soil functionality. Thus, more reforestation should be carried out in the riparian zone of the TGDR, so as to effectively mitigate the negative ecological impacts of the dam. Vegetating the reservoir banks with Taxodium distichum proved successful, but planting mixed stands of native tree species could promote even higher riparian soil biodiversity and improved levels of ecosystem functioning within the TGDR.


Assuntos
Conservação dos Recursos Naturais , Microbiologia do Solo , Taxodium , Bactérias/classificação , Bactérias/isolamento & purificação , Biodiversidade , China , Solo/química , Árvores , Abastecimento de Água
14.
Biomed Pharmacother ; 96: 1199-1208, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29239817

RESUMO

Extracts and components of Taxodium ascendens Brongn, an excellent afforestation tree, have exhibited several activities, including antibacterial activity and inhibitory activity on carbonic anhydrase II. However, the anti-hepatocellular carcinoma (anti-HCC) activity of extracts from the leaves of T. ascendens (TALE) remains unclear. In the present study, six diterpenoid compounds were isolated from a TALE extract. Here, the pro-apoptotic activities and the molecular mechanisms of TALE and the compounds 1-6 on HepG2 and Hep3B HCC cells were evaluated. Results show that the TALE and compounds 1-6 were able to induce apoptosis in the HepG2 and Hep3B HCC cells, particularly ferruginol (3). Mechanistically, the application of TALE and ferruginol (3) resulted in a significant decrease in mitochondria membrane potential, which was coupled with an increase in the Bax/Bcl-2 ratio and caspase-3/-9 activity. In vivo experiments showed that oral administration of TALE inhibited the proliferation of transplanted H22 cells in Kunming mice. However, TALE toxicity in KM mice was undetectable. The study provides strong evidence for the anti-HCC capacity of TALE.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Diterpenos/farmacologia , Mitocôndrias/efeitos dos fármacos , Taxodium/química , Animais , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Feminino , Células Hep G2 , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/metabolismo , Masculino , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos , Mitocôndrias/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto/métodos , Proteína X Associada a bcl-2/metabolismo
16.
Org Lett ; 19(3): 556-559, 2017 02 03.
Artigo em Inglês | MEDLINE | ID: mdl-28094965

RESUMO

Two dimeric diterpenoids, taxodikaloids A (1) and B (2), have been identified from the seeds of Taxodium ascendens. The diterpenoid structures were established on the basis of comprehensive spectroscopic analysis, and the absolute configuration of taxodikaloid A (1) was further confirmed by single-crystal X-ray diffraction. Both structures feature an unprecedented oxazoline ring linkage connecting two abietane diterpenoid monomers. A plausible biosynthetic pathway for compounds 1 and 2 is proposed. Both compounds show potential neuroprotective activity against Aß25-35-induced damage in SH-SY5Y cells.


Assuntos
Taxodium/química , Abietanos , Diterpenos , Estrutura Molecular
17.
Am J Bot ; 103(11): 1937-1949, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27849160

RESUMO

PREMISE OF THE STUDY: Studies of natural genetic variation can elucidate the genetic basis of phenotypic variation and the past population structure of species. Our study species, Taxodium distichum, is a unique conifer that inhabits the flood plains and swamps of North America. Morphological and ecological differences in two varieties, T. distichum var. distichum (bald cypress) and T. distichum var. imbricarium (pond cypress), are well known, but little is known about the level of genetic differentiation between the varieties and the demographic history of local populations. METHODS: We analyzed nucleotide polymorphisms at 47 nuclear loci from 96 individuals collected from the Mississippi River Alluvial Valley (MRAV), and Gulf Coastal populations in Texas, Louisiana, and Florida using high-throughput DNA sequencing. Standard population genetic statistics were calculated, and demographic parameters were estimated using a composite-likelihood approach. KEY RESULTS: Taxodium distichum in North America can be divided into at least three genetic groups, bald cypress in the MRAV and Texas, bald cypress in Florida, and pond cypress in Florida. The levels of genetic differentiation among the groups were low but significant. Several loci showed the signatures of positive selection, which might be responsible for local adaptation or varietal differentiation. CONCLUSIONS: Bald cypress was genetically differentiated into two geographical groups, and the boundary was located between the MRAV and Florida. This differentiation could be explained by population expansion from east to west. Despite the overlap of the two varieties' ranges, they were genetically differentiated in Florida. The estimated demographic parameters suggested that pond cypress split from bald cypress during the late Miocene.


Assuntos
Variação Genética , Taxodium/genética , Demografia , Florida , Geografia , Sequenciamento de Nucleotídeos em Larga Escala , Funções Verossimilhança , Louisiana , Mississippi , Polimorfismo Genético , Análise de Sequência de DNA , Taxodium/fisiologia , Texas , Árvores
18.
Sci Rep ; 6: 36015, 2016 10 31.
Artigo em Inglês | MEDLINE | ID: mdl-27796330

RESUMO

Influenza virus remains an emerging virus and causes pandemics with high levels of fatality. After screening different plant extracts with potential anti-influenza activity, a water extract of Taxodium distichum stems (TDSWex) showed excellent activity against influenza viruses. The EC50 of TDSWex was 0.051 ± 0.024 mg/mL against influenza virus A/WSN/33. TDSWex had excellent antiviral efficacy against various strains of human influenza A and B viruses, particularly oseltamivir-resistant clinical isolates and a swine-origin influenza strain. We observed that the synthesis of viral RNA and protein were inhibited in the presence of TDSWex. The results of the time-of-addition assay suggested that TDSWex inhibited viral entry and budding. In the hemagglutination inhibition assay, TDSWex inhibited the hemagglutination of red blood cells, implying that the extract targeted hemagglutin-related functions such as viral entry. In the attachment and penetration assay, TDSWex showed antiviral activity with EC50s of 0.045 ± 0.026 and 0.012 ± 0.003 mg/mL, respectively. In addition, TDSWex blocked neuraminidase activity. We conclude that TDSWex has bimodal activities against both hemagglutinin and neuraminidase during viral replication.


Assuntos
Hemaglutininas/metabolismo , Neuraminidase/metabolismo , Orthomyxoviridae/metabolismo , Extratos Vegetais/metabolismo , Taxodium/química , Animais , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Cães , Hemaglutininas/química , Humanos , Células Madin Darby de Rim Canino , Microscopia de Fluorescência , Neuraminidase/antagonistas & inibidores , Orthomyxoviridae/enzimologia , Extratos Vegetais/química , Extratos Vegetais/toxicidade , RNA Viral/química , RNA Viral/metabolismo , Taxodium/metabolismo , Proteínas Virais/metabolismo , Internalização do Vírus/efeitos dos fármacos , Liberação de Vírus/efeitos dos fármacos
19.
PLoS One ; 11(9): e0162867, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27618547

RESUMO

Responses of bald cypress (Taxodium distichum) and pond cypress (Taxodium ascendens) saplings in photosynthesis and growth to long-term periodic submergence in situ in the hydro-fluctuation zone of the Three Gorges Dam Reservoir (TGDR) were studied. Water treatments of periodic deep submergence (DS) and moderate submergence (MS) in situ were imposed on 2-year-old bald cypress and pond cypress saplings. The effects of periodic submergence on photosynthesis and growth were investigated after 3 years (i.e. 3 cycles) compared to a control (i.e. shallow submergence, abbreviated as SS). Results showed that pond cypress had no significant change in net photosynthetic rate (Pn) in response to periodic moderate and deep submergence in contrast to a significant decrease in Pn of bald cypress under both submergence treatments, when compared to that of SS. Ratios of Chlorophyll a/b and Chlorophylls/Carotenoid of pond cypress were significantly increased in periodic moderate submergence and deep submergence, while bald cypress showed no significant change. Diameter at breast height (DBH) and tree height of both species were significantly reduced along with submergence depth. Relative diameter and height growth rates of the two species were also reduced under deeper submergence. Moreover, bald cypress displayed higher relative diameter growth rate than pond cypress under deep submergence mainly attributed to higher productivity of the larger crown area of bald cypress. When subjected to deep subergence, both species showed significant reduction in primary branch number, while in moderate submergence, bald cypress but not pond cypress showed significant reduction in primary branch number. These results indicate that both bald cypress and pond cypress are suitbale candidates for reforestation in the TGDR region thanks to their submergence tolerance characteristics, but bald cypress can grow better than pond cypress under deep submergence overall.


Assuntos
Fotossíntese , Taxodium/fisiologia , China , Especificidade da Espécie , Taxodium/classificação , Taxodium/crescimento & desenvolvimento
20.
Parasit Vectors ; 9(1): 312, 2016 05 31.
Artigo em Inglês | MEDLINE | ID: mdl-27245322

RESUMO

BACKGROUND: Lymphatic filariasis caused by Wuchereria bancrofti, Brugia malayi and B. timori, is a debilitating disease with an adverse social and economic impact. The infection remains unabated in spite of treatment with existing antifilarial drugs diethylcarbamazine (DEC) and ivermectin which are chiefly microfilaricides. There is therefore, need for macrofilaricides, embryostatic agents and better microfilaricides. In the present study we explored the antifilarial potential of crude extract and its molecular fractions of the plant Taxodium distichum using in vitro assay systems and rodent models of B. malayi infection. METHODS: Ethanolic extract (A001) of aerial parts of T. distichum was solvent fractionated and sub-fractionated. Four molecules, 3-Acetoxylabda-8(20), 13-diene-15-oic acid (K001), Beta-sitosterol (K002), labda-8(20),13-diene-15-oic acid (K003) and Metasequoic acid A (K004) were isolated from the fractions and their structure determined by spectroscopic analysis. The extract, subfractions and molecules were evaluated for antifilarial activity against B. malayi by 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide (MTT) reduction and motility assays in vitro and in two animal models, Meriones unguiculatus and Mastomys coucha, harbouring B. malayi infection. RESULTS: A001 was effective in killing microfilariae (mf) and adult worms in vitro. The diterpenoid K003 produced 100 % reduction in motility of both mf and adult worms and > 80 % inhibition in MTT reduction potential of adult female worms. In B. malayi-M. unguiculatus model, A001 killed all the adult worms in > 80 % of infected animals. K003 was embryostatic (> 95 %) in this model. In the B. malayi-M. coucha model, K003 killed ~54 % of adult worms (macrofilaricidal activity) and rendered > 36 % female worms sterile; it also stopped any further rise in microfilaraemia after day 42 post-initiation of treatment. CONCLUSION: Ethanolic extract of aerial parts of the plant T. distichum possesses potent antifilarial activity and the active principle was localised to K003 which showed significant macrofilaricidal activity and late suppression of peripheral microfilaraemia and some embryostatic activity. These findings indicate that labdane diterpenoid molecule(s) may provide valuable leads for design and development of new macrofilaricidal agent(s). To the best of our knowledge, this is the first report on antifilarial efficacy of products from the plant T. distichum.


Assuntos
Brugia Malayi/efeitos dos fármacos , Diterpenos/farmacologia , Filariose Linfática/tratamento farmacológico , Filaricidas/farmacologia , Extratos Vegetais/farmacologia , Taxodium/química , Animais , Brugia Malayi/citologia , Dietilcarbamazina/uso terapêutico , Modelos Animais de Doenças , Diterpenos/química , Diterpenos/isolamento & purificação , Feminino , Filaricidas/química , Filaricidas/isolamento & purificação , Gerbillinae , Humanos , Ivermectina/uso terapêutico , Masculino , Microfilárias , Murinae , Componentes Aéreos da Planta/química , Extratos Vegetais/química
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