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1.
PLoS One ; 19(2): e0290052, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38422016

RESUMO

Many commensal gut microbes are recognized for their potential to synthesize vitamin B12, offering a promising avenue to address deficiencies through probiotic supplementation. While bioinformatics tools aid in predicting B12 biosynthetic potential, empirical validation remains crucial to confirm production, identify cobalamin vitamers, and establish biosynthetic yields. This study investigates vitamin B12 production in three human colonic bacterial species: Anaerobutyricum hallii DSM 3353, Roseburia faecis DSM 16840, and Anaerostipes caccae DSM 14662, along with Propionibacterium freudenreichii DSM 4902 as a positive control. These strains were selected for their potential use as probiotics, based on speculated B12 production from prior bioinformatic analyses. Cultures were grown in M2GSC, chemically defined media (CDM), and Gorse extract medium (GEM). The composition of GEM was similar to CDM, except that the carbon and nitrogen sources were replaced with the protein-depleted liquid waste obtained after subjecting Gorse to a leaf protein extraction process. B12 yields were quantified using liquid chromatography with tandem mass spectrometry. The results suggested that the three butyrate-producing strains could indeed produce B12, although the yields were notably low and were detected only in the cell lysates. Furthermore, B12 production was higher in GEM compared to M2GSC medium. The positive control, P. freudenreichii DSM 4902 produced B12 at concentrations ranging from 7 ng mL-1 to 12 ng mL-1. Univariate-scaled Principal Component Analysis (PCA) of data from previous publications investigating B12 production in P. freudenreichii revealed that B12 yields diminished when the carbon source concentration was ≤30 g L-1. In conclusion, the protein-depleted wastes from the leaf protein extraction process from Gorse can be valorised as a viable substrate for culturing B12-producing colonic gut microbes. Furthermore, this is the first report attesting to the ability of A. hallii, R. faecis, and A. caccae to produce B12. However, these microbes seem unsuitable for industrial applications owing to low B12 yields.


Assuntos
Microbioma Gastrointestinal , Ulex , Humanos , Vitamina B 12 , Benzimidazóis , Carbono , Suplementos Nutricionais
2.
Mol Biol Rep ; 50(11): 9721-9729, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37814034

RESUMO

BACKGROUND: The genus Ulex is composed by 15 species distributed in Europe and Africa, but the majority of them are restricted to the Iberian Peninsula and Northwest Africa. Some of these species are common elements at the landscape level, and others contribute to global biodiversity as narrow endemics. Assayed nuclear and plastid Sanger-sequenced regions do not provide enough resolution to perform evolutionary studies on the genus, neither at the intraspecific population level nor at the interspecific phylogenetic level. Thus, we have developed and characterized a set of nuclear microsatellite loci in U. parviflorus to provide new highly polymorphic molecular markers for the genus Ulex. METHODS AND RESULTS: Genomic DNA enriched in microsatellite motifs using streptavidin-coated M-280 magnetic beads attached to 5'-biotinylated oligonucleotides was sequenced in a 454GS Junior System. After primer design, fluorescent-dyed amplicons were analyzed through capillary sequencing (ABI3730XL). Here we present twelve new high polimorphic SSRs markers developed in U. parviflorus specimens and tested in 120 individuals. The 12 SSR loci amplified a total of 152 alleles, and detected expected heterozygosities that ranged from 0.674 to 0.725 in the genotyped populations. Successful cross-species transferability of the 12 SSR loci to the rest of species included in the genus Ulex and three other representative Genisteae was achieved. CONCLUSIONS: The 12 novel proposed SSRs loci will contribute to perform evolutionary studies and genetic research on the genus Ulex and in other Genisteae.


Assuntos
Fabaceae , Ulex , Humanos , Ulex/genética , Filogenia , Repetições de Microssatélites/genética , Fabaceae/genética , Genótipo
3.
Molecules ; 28(1)2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36615543

RESUMO

The genus Ulex comprises thirteen accepted species of perennial shrubs in the family Fabaceae. In Galicia (Spain) many of these are considered spontaneous colonizing species, which are easy to establish and maintain. Among them, Ulex gallii Planch. is used in traditional medicine for the same anti-infective, hypotensive and diuretic purposes as Ulex europaeus L., which is the most studied species. Likewise, some studies have described the antitumoral properties of several species. However, there are few scientific studies that justify the use of Ulex gallii Planch. and nothing has been reported about its composition to date. In our study, the entire plant was extracted with methanol and the crude extract was subjected to liquid phase extraction with distinct solvents, yielding three fractions: hexane (H), dichloromethane (D) and methanol (M), which were subsequently fractionated. The dichloromethane (D5, D7 and D8) and methanol (M4) sub-fractions showed antiproliferative activity on A549 (lung cancer) and AGS (stomach cancer) cell lines, and caspase 3/7 activity assessment and DNA quantification were also performed. Targeted analysis via UHPLC-QToF, in combination with untargeted analysis via MS-Dial, MS-Finder and Global Natural Products Social Molecular Networking (GNPS), allowed us to tentatively identify different metabolites in these sub-fractions, mostly flavonoids, that might be involved in their antiproliferative activity.


Assuntos
Fabaceae , Plantas Medicinais , Plantas Medicinais/química , Ulex , Fabaceae/química , Metanol/química , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Espanha , Cloreto de Metileno , Compostos Fitoquímicos/farmacologia
4.
Nat Prod Res ; 37(5): 769-775, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35617490

RESUMO

Despite its worldwide relevance as an invasive plant, there are few studies on Ulex europaeus (gorse) and its allelopathic activity is almost unexplored. The allelochemical profile of gorse was analysed through methanolic extract of pods and roots, and its phytotoxic effects on Lactuca sativa germination. The methanolic extract of pods had no effect in germination, while extract of roots resulted in a U-shaped dose-response curve: reducing the germination at concentration 0.5 mg mL-1. GC-MS analysis detected compounds with proven antimicrobial and antioxidant activities in the pods and cytotoxic compounds in the roots, which could explain the bioassay results. The quinolizidine alkaloids (QAs) composition was evaluated to predict possible biological functions. It showed the presence of QAs in gorse that are absent in their native range, indicating broad defense strategies against bacteria, fungi, plants, and insects in the Chilean ecosystem. This could explain the superiority of gorse in the invaded areas.


Assuntos
Alcaloides , Ecossistema , Ulex/química , Chile , Feromônios/farmacologia , Plantas , Alcaloides/farmacologia , Extratos Vegetais/farmacologia , Alelopatia
5.
Cuad. Hosp. Clín ; 61(2): 17-22, dic. 2020. ilus.
Artigo em Espanhol | LILACS, LIBOCS | ID: biblio-1179063

RESUMO

Además del sistema ABO, los subgrupos del mismo revisten gran importancia en inmunohematología, Los subgrupos A difieren tanto en el número de sitios antigénicos como en la configuración del antígeno eritrocitario. Los principales, A1 y A2 se diferencian en que los eritrocitos A1 son aglutinados por el anticuerpo Anti-A1 humano o por la Lectina Anti-A1 (Dolichos biflorus), y los eritrocitos A2 son aglutinados por la Lectina Anti-H (Ulex europaeus). MATERIALES Y MÉTODOS: se realizó un estudio descriptivo, de Corte Transversal, Se analizó los registros tanto físico y electrónico del Banco de Sangre, se incluyeron todos los donadores efectivos, mismos que fueron tipificados por el laboratorio de inmunohematología en el periodo de mayo a julio del 2018. Método empleado, aglutinación en tubo y en micro placa. RESULTADOS: en un total de 1599 donantes, se determinó que el grupo O tiene mayor frecuencia con un 84% y el menos frecuente fue el AB con un 0,66%. Según el grupo sanguíneo A y AB tenemos las siguientes frecuencias: A1 que representa el (73.3%), A2 el (15.9%), Aint el (5.65%), A1 B el (3.60%) y A2 B el (1.55%). La importancia clínica se basa en que algunas personas del grupo A2 transfundidas con A1 , pueden producir Anti-A1 que es un anticuerpo natural irregular activo a 22 ºC, pero en ocasiones está activo a 37ºC causando una reacción transfusional extravascular, por lo que, si no se cuenta con eritrocitos A2 , se recomienda transfundir eritrocitos grupo O.


In addition to the ABO system, its subgroups review great importance in Immunohematology. Subgroups A differ both in the number of antigenic sites and in the configuration of the erythrocyte antigen. The main ones, A1 and A2 differ in that A1 erythrocytes are agglutinated by human Anti-A1 antibody or by Anti-A1 Lectin (Dolichos biflorus), and A2 erythrocytes are agglutinated by Anti-H Lectin (Ulex europaeus). MATERIALS AND METHODS: a descriptive, cross-sectional study was conducted. The physical and electronic records of the Blood Bank were analyzed, all effective donors were included, which were typified by the Immunohematology Laboratory in the period of May. to July 2018. Method used, agglutination in tube and in microplate. RESULTS: in a total of 1599 protocols, it was determined that group O has the highest frequency with 84% and the least frequent was the AB with 0.66%. According to blood group A and AB we have the following frequencies: A1 representing (73.3%), A2 (15.9%), Aint (5.65%), A1B (3.60%) and A2B (1.55%). The clinical importance is based on the fact that some people in group A2 transfused with A1, can produce Anti-A1 which is an irregular natural antibody active at 22 ° C but sometimes it is active at 37 °C causing an extravascular transfusion reaction, so if A2 erythrocytes are not available, it is recommended to transfuse group O erythrocytes.


Assuntos
Bancos de Sangue , Aglutinação , Eritrócitos , Registros , Ulex , Laboratórios
6.
N Z Med J ; 133(1524): 102-110, 2020 10 30.
Artigo em Inglês | MEDLINE | ID: mdl-33119573

RESUMO

Prior to colonisation, Maori had a well-developed holistic health system based on maintaining balance between people, place and spirit. The colonial imposition of British economic, religious, educational, legal, health and governance, through warfare, immigration, legislation and social coercion had a devastating effect on Maori health outcomes. With the release of the WAI 2575 Waitangi Tribunal report exposing the failings of our health system in relation to Maori health, the need to decolonise our health system becomes more pressing. A key difficulty in this work is the poverty of transformative language, concepts and frameworks in our workforce. This paper is the product of an anti-racism think tank that occurred in April 2019. While working through a system change analysis on our colonial health system, Maori and Tauiwi activists and scholars created an allegory-from gorse to ngahere. The allegory depicts the ongoing impact of the colonial health system as represented by gorse, and the possibilities of a decolonised health system represented by ngahere-a self-sustaining and flourishing native forest. Racism has a geographic specificity. The allegory we developed is a mechanism for conceptualising decolonisation for the context of Aotearoa. It serves to reinforce the different roles and responsibilities of the descendants of the colonisers and the colonised in the pursuit of decolonisation.


Assuntos
Colonialismo/história , Programas Nacionais de Saúde , Havaiano Nativo ou Outro Ilhéu do Pacífico , Ulex , Ecossistema , História do Século XIX , Humanos , Povos Indígenas/história , Havaiano Nativo ou Outro Ilhéu do Pacífico/história , Nova Zelândia
7.
J Exp Bot ; 71(12): 3725-3734, 2020 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-32185377

RESUMO

Many studies have investigated the effect of parasitic plants on their hosts; however, few have examined how parasite impact is affected by host size. In a glasshouse experiment, we investigated the impact of the Australian native hemiparasitic vine, Cassytha pubescens, on a major invasive shrub, Ulex europaeus, of different sizes. Infected plants had significantly lower total, shoot, and root biomass, but the parasite's impact was more severe on small than on large hosts. When infected, small but not large hosts had significantly lower nodule biomass. Irrespective of size, infection significantly decreased the host shoot/root ratio, pre-dawn and midday quantum yields, maximum electron transport rates, and carbon isotope composition, and the host nodule biomass per gram of root biomass significantly increased in response to infection. Infection did not affect host foliar nitrogen concentration or midday shoot water potential. Parasite biomass was significantly lower on small relative to large hosts, but was similar when expressed on a per gram of host total biomass basis. Parasite stem nitrogen, phosphorus, and potassium concentrations were significantly greater when C. pubescens was growing on small than on large hosts. Our results clearly show that C. pubescens strongly decreases performance of this major invasive shrub, especially when hosts are small. This suggests that C. pubescens could be used most effectively as a native biocontrol when deployed on smaller hosts.


Assuntos
Interações Hospedeiro-Parasita , Parasitos , Animais , Austrália , Biomassa , Ulex
8.
Molecules ; 24(24)2019 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-31835831

RESUMO

New herbicides based on natural products are claimed to address weed resistance and environmental concerns related to synthetic herbicides. In our previous studies, certain volatile organic compounds (VOCs) produced by Ulex europaeus and Cytisus scoparius were argued to be responsible for the phytotoxicity of both shrub species. Interactions among VOCs were hypothesized to explain the inconsistency between the effects of the identified pure compounds and those naturally emitted from fresh plant material. In this work, eugenol, verbenone, terpinen-4-ol, α-terpineol, and linalool were assayed as binary mixtures of Amaranthus retroflexus and Digitaria sanguinalis. Powerful synergistic inhibitory effects were revealed for germination and early growth. Only 3.1 ppm of verbenone was enough to inhibit A. retroflexus germination when paired to other VOCs. Eugenol was capable of exacerbating the effects of terpinen-4-ol on A. retroflexus, even though it was innocuous when acting alone at 12.5 ppm. The verbenone and linalool pair produced very significant synergistic effects in terms of D. sanguinalis germination. The synergistic effects were predominantly irreversible for D. sanguinalis, since seeds exposed to paired VOCs were unable to recover their germination capacity after removing the phytotoxins or produced damaged seedlings. Both shrub species have been revealed as sources of natural herbicide molecules, with promising synergistic modes of action that deserve to be studied in depth.


Assuntos
Cytisus/química , Herbicidas/farmacologia , Ulex/química , Compostos Orgânicos Voláteis/farmacologia , Monoterpenos Acíclicos/química , Monoterpenos Acíclicos/farmacologia , Amaranthus/efeitos dos fármacos , Amaranthus/crescimento & desenvolvimento , Monoterpenos Bicíclicos/química , Monoterpenos Bicíclicos/farmacologia , Digitaria/efeitos dos fármacos , Digitaria/crescimento & desenvolvimento , Sinergismo Farmacológico , Eugenol/química , Eugenol/farmacologia , Germinação/efeitos dos fármacos , Herbicidas/química , Extratos Vegetais/química , Compostos Orgânicos Voláteis/química
9.
J Environ Manage ; 229: 166-173, 2019 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-29934130

RESUMO

Species presently considered as invasive were often deliberately introduced. Which factors led them from being desired to being denounced and what trajectory did such a transition follow? Using the case of common gorse (Ulex europaeus) on Reunion Island, the aims of this study were first, to identify and describe the different status that were attributed to this species since its introduction; and second, to discern the factors that influenced their emergence and decline in the public sphere. Five types of status were identified for common gorse in Reunion (useful, nationalistic, indigenized, noxious weed, and invasive), each peaking at a certain time, and then reverting to a low-key presence. The emergence and dissemination of each status in the public sphere depends on how well the various narratives proposed about the plant by networks of legitimate actors match the socio-technical landscape, as well as on how these narratives appear within legal and institutional frameworks. In addition, translating a status into actions of management can bolster its trajectory in the public sphere. Lastly, the decline of a status can be explained by a gradual desynchronization between its cognitive, normative and/or instrumental dimensions and the local socio-technical landscape.


Assuntos
Espécies Introduzidas , Ulex , Reunião
10.
PLoS One ; 13(10): e0205997, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30372468

RESUMO

The phytotoxic potential of the legume shrubs Ulex europaeus L. (gorse) and Cytisus scoparius (L.) Link. (Scotch broom) is studied in this work for the first time. On the basis of their richness in active principles, the previous evidence of biological activity, and the abundance of biomass in their native range and invaded areas, a question arose: can U. europaeus and C. scoparius be considered as potential sources of natural herbicides for sustainable agriculture? By means of volatile bioassays, the flowering fresh plant material of both shrub species was shown to produce and emit volatile organic compounds (VOCs) able to inhibit the germination and/or early growth of two agricultural weeds: Amaranthus retroflexus and Digitaria sanguinalis. Novel complete VOCs profiles from the volatile extracts of the shrub species were obtained by GC and GC/MS. A total of 20 compounds were identified from U. europaeus flowering biomass, theaspirane and eugenol, among others, being described in gorse for the first instance. The chemical profile of C. scoparius yielded 28 compounds and was rich in oxygenated monoterpenes such as terpinen-4-ol, verbenol, α-terpineol, and verbenone, which were also identified in this species for the first time. Using dose-response bioassays with pure compounds, these VOCs were argued to be involved in the phytotoxicity observed for the plant materials, even at very low concentrations. The phytotoxic effects were predominantly irreversible, particularly for D. sanguinalis, since the seeds exposed to the VOCs produced damaged seedlings, were unable to recover germination capacity after removing the phytotoxin or, when recovered, produced unviable seedlings. Our results extend the interest of the abundant U. europaeus and C. scoparius for the obtention of natural products with bioherbicide potential, or to be used as allelopathic biomass in the development of new sustainable agricultural practices.


Assuntos
Cytisus/química , Herbicidas/toxicidade , Controle Biológico de Vetores , Ulex/química , Compostos Orgânicos Voláteis/toxicidade , Amaranthus/efeitos dos fármacos , Amaranthus/crescimento & desenvolvimento , Bioensaio , Biomassa , Digitaria/efeitos dos fármacos , Digitaria/crescimento & desenvolvimento , Flores/química , Germinação/efeitos dos fármacos , Plantas Daninhas/efeitos dos fármacos , Plantas Daninhas/crescimento & desenvolvimento , Análise de Regressão
11.
Nat Plants ; 4(6): 358-364, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29735984

RESUMO

We assessed the association between the natural environment and asthma in 49,956 New Zealand children born in 1998 and followed up until 2016 using routinely collected data. Children who lived in greener areas, as measured by the normalized difference vegetation index, were less likely to be asthmatic: a 1 s.d. increase in normalized difference vegetation index was associated with a 6.0% (95% CI 1.9-9.9%) lower risk of asthma. Vegetation diversity was also protective: a 1 s.d. increase in the number of natural land-cover types in a child's residential meshblock was associated with a 6.7% (95% CI 1.5-11.5%) lower risk. However, not all land-cover types were protective. A 1 s.d. increase in the area covered by gorse (Ulex europaeus) or exotic conifers, both non-native, low-biodiversity land-cover types, was associated with a 3.2% (95% CI 0.0-6.0%) and 4.2% (95% CI 0.9-7.5%) increased risk of asthma, respectively. The results suggest that exposure to greenness and vegetation diversity may be protective of asthma.


Assuntos
Asma/epidemiologia , Biodiversidade , Plantas , Adolescente , Poluição do Ar/efeitos adversos , Asma/etiologia , Criança , Pré-Escolar , Meio Ambiente , Feminino , Humanos , Lactente , Recém-Nascido , Espécies Introduzidas , Estudos Longitudinais , Masculino , Nova Zelândia/epidemiologia , Prevalência , Fatores de Risco , Traqueófitas , Ulex
12.
Math Biosci ; 297: 58-77, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29369788

RESUMO

The mathematical submodel ULEX is used to study the dynamic behavior of the green, floral and woody biomass of the main pyrophite shrub species, the gorse (Ulex parviflorus Pourret), and its relationship with other shrub species, typical of a Mediterranean ecosystem. The focus are the ecological conditions of post-fire stage growth, and its efficacy as a protective cover against erosion processes in the short, medium and long term, both in normal conditions and at the limits of desertification conditions. The model sets a target to observe the behavior and to anticipate and consequently intervene with adequate protection, restoration and management measures.


Assuntos
Biomassa , Conservação dos Recursos Naturais , Modelos Teóricos , Ulex , Incêndios Florestais , Região do Mediterrâneo , Espanha
13.
Animal ; 11(10): 1708-1717, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28264752

RESUMO

The number of horses in northern Spanish mountains has increased in recent decades, but little is known about their grazing behaviour, performance and potential for foal meat production. This research aimed to study the diet selection, liveweight (LW) changes and parasitic status of dry and lactating mares, and foals' LW gains, grazing on heathlands with different botanical composition. The experimental design consisted of three vegetation types: dominated by heather (Ericaceae) species (H), dominated by gorse (Ulex gallii; G) and co-dominated by gorse and heath-grasses (G-G), with four replicates per treatment (12 paddocks of 1.2 ha). The study lasted three grazing seasons (2010-12). Each year, 24 crossbred mature mares (310±52 kg LW) were used, managing one lactating mare with her foal plus one non-lactating mare per paddock from May to late summer or early autumn. In the case of H paddocks, animals had to be removed before (late August to early September) because of apparent loss of body condition. Animals were periodically weighed. Mares' diet composition was estimated using alkane markers, analysing the discrepancies in alkane concentrations between dietary plant components and faeces. Faecal samples were also analysed for gastrointestinal nematodes ova. Chemical composition of the main plant components (i.e. heather, gorse and grasses) revealed a low nutritive value, averaging 79, 115 and 113 g CP/kg dry matter (DM), respectively, that could restrict livestock performance. Mares initially selected gorse and grasses (0.47 and 0.40, respectively, in 2010), increasing heather consumption over time (from 0.13 in 2010 to 0.29 in 2012) as gorse availability decreased. The performance of both mares and foals was lower in H compared with G and G-G paddocks (-216 v. 347 g/day for mares, P<0.01; 278 v. 576 g/day for foals, P<0.05), whereas LW changes were more favourable in dry mares than in lactating ones (241 v. 78 g/day; P<0.05). Small strongyle (Cyathostominae) egg counts in mares' faeces increased across the grazing season with no differences between treatments. These results indicate that grazing by horses on gorse- and grass-gorse-dominated shrublands could be sustainable at least during part of the year (4 to 6 months). However, heather-dominated heathlands are not able to meet the nutritional needs of horses even for a short time (2 to 4 months). Nevertheless, the low nutritive quality of these vegetation communities, especially in autumn, requires animal access to other pastures with a higher nutritive value, or supplementary feeding, to enhance foals' growth and maintain sustainable grazing systems with productive herds.


Assuntos
Dieta/veterinária , Cavalos/fisiologia , Animais , Ericaceae , Fezes/parasitologia , Feminino , Cavalos/crescimento & desenvolvimento , Lactação , Valor Nutritivo , Poaceae , Ulex
14.
Environ Monit Assess ; 188(8): 495, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27473109

RESUMO

Ulex europaeus (gorse) is an invasive shrub deemed as one of the most invasive species in the world. U. europaeus is widely distributed in the south-central area of Chile, which is considered a world hotspot for biodiversity conservation. In addition to its negative effects on the biodiversity of natural ecosystems, U. europaeus is one of the most severe pests for agriculture and forestry. Despite its importance as an invasive species, U. europaeus has been little studied. Although information exists on the potential distribution of the species, the interaction of the invasion process with the spatial dynamic of the landscape and the landscape-scale factors that control the presence or absence of the species is still lacking. We studied the spatial and temporal dynamics of the landscape and how these relate to U. europaeus invasion in south-central Chile. We used supervised classification of satellite images to determine the spatial distribution of the species and other land covers for the years 1986 and 2003, analysing the transitions between the different land covers. We used logistic regression for modelling the increase, decrease and permanence of U. europaeus invasion considering landscape variables. Results showed that the species covers only around 1 % of the study area and showed a 42 % reduction in area for the studied period. However, U. europaeus was the cover type which presented the greatest dynamism in the landscape. We found a strong relationship between changes in land cover and the invasion process, especially connected with forest plantations of exotic species, which promotes the displacement of U. europaeus. The model of gorse cover increase presented the best performance, and the most important predictors were distance to seed source and landscape complexity index. Our model predicted high spread potential of U. europaeus in areas of high conservation value. We conclude that proper management for this invasive species must take into account the spatial dynamics of the landscape within the invaded area in order to address containment, control or mitigation of the invasion.


Assuntos
Conservação dos Recursos Naturais/métodos , Monitoramento Ambiental/métodos , Agricultura Florestal , Espécies Introduzidas , Ulex/crescimento & desenvolvimento , Agricultura , Biodiversidade , Chile , Ecossistema , Florestas , Modelos Teóricos
15.
Ann Bot ; 117(3): 521-31, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26832961

RESUMO

BACKGROUND AND AIMS: There have been very few studies investigating the influence of light on the effects of hemiparasitic plants on their hosts, despite the fact that hemiparasites are capable of photosynthesis but also access carbon (C) from their host. In this study we manipulated light availability to limit photosynthesis in an established hemiparasite and its hosts, and determined whether this affected the parasite's impact on growth and performance of two different hosts. We expected that limiting light and reducing autotrophic C gain in the parasite (and possibly increasing its heterotrophic C gain) would lead to an increased impact on host growth and/or host photosynthesis in plants grown in low (LL) relative to high light (HL). METHODS: The Australian native host Leptospermum myrsinoides and the introduced host Ulex europaeus were either infected or not infected with the native stem hemiparasite Cassytha pubescens and grown in either HL or LL. Photosynthetic performance, nitrogen status and growth of hosts and parasite were quantified. Host water potentials were also measured. KEY RESULTS: In situ midday electron transport rates (ETRs) of C. pubescens on both hosts were significantly lower in LL compared with HL, enabling us to investigate the impact of the reduced level of parasite autotrophy on growth of hosts. Despite the lower levels of photosynthesis in the parasite, the relative impact of infection on host biomass was the same in both LL and HL. In fact, biomass of L. myrsinoides was unaffected by infection in either HL or LL, while biomass of U. europaeus was negatively affected by infection in both treatments. This suggests that although photosynthesis of the parasite was lower in LL, there was no additional impact on host biomass in LL. In addition, light did not affect the amount of parasite biomass supported per unit host biomass in either host, although this parameter was slightly lower in LL than HL for U. europaeus (P = 0·073). We also found no significant enhancement of host photosynthesis in response to infection in either host, regardless of light treatment. CONCLUSIONS: Despite lower photosynthetic rates in LL, C. pubescens did not increase its dependency on host C to the point where it affected host growth or photosynthesis. The impact of C. pubescens on host growth would be similar in areas of high and low light availability in the field, but the introduced host is more negatively affected by infection.


Assuntos
Interações Hospedeiro-Parasita/efeitos da radiação , Espécies Introduzidas , Luz , Parasitos/fisiologia , Caules de Planta/parasitologia , Caules de Planta/efeitos da radiação , Análise de Variância , Animais , Biomassa , Transporte de Elétrons/efeitos da radiação , Leptospermum/parasitologia , Leptospermum/efeitos da radiação , Nitrogênio/metabolismo , Parasitos/crescimento & desenvolvimento , Parasitos/efeitos da radiação , Fotossíntese/efeitos da radiação , Brotos de Planta/fisiologia , Brotos de Planta/efeitos da radiação , Estômatos de Plantas/fisiologia , Estômatos de Plantas/efeitos da radiação , Ulex/parasitologia , Ulex/efeitos da radiação
16.
Int J Biometeorol ; 60(6): 813-25, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26449349

RESUMO

The application of spectral vegetation indices for the purpose of vegetation monitoring and modeling increased largely in recent years. Nonetheless, the interpretation of biophysical properties of vegetation through their spectral signature is still a challenging task. This is particularly true in Mediterranean oak forest characterized by a high spatial and temporal heterogeneity. In this study, the temporal dynamics of vegetation indices expected to be related with green biomass and photosynthetic efficiency were compared for the canopy of trees, the herbaceous layer, and two shrub species: cistus (Cistus salviifolius) and ulex (Ulex airensis). coexisting in a cork oak woodland. All indices were calculated from in situ measurements with a FieldSpec3 spectroradiometer (ASD Inc., Boulder, USA). Large differences emerged in the temporal trends and in the correlation between climate and vegetation indices. The relationship between spectral indices and temperature, radiation, and vapor pressure deficit for cork oak was opposite to that observed for the herbaceous layer and cistus. No correlation was observed between rainfall and vegetation indices in cork oak and ulex, but in the herbaceous layer and in the cistus, significant correlations were found. The analysis of spectral vegetation indices with fraction of absorbed PAR (fPAR) and quantum yield of chlorophyll fluorescence (ΔF/Fm') evidenced strongest relationships with the indices Normalized Difference Water Index (NDWI) and Photochemical Reflectance Index (PRI)512, respectively. Our results, while confirms the ability of spectral vegetation indices to represent temporal dynamics of biophysical properties of vegetation, evidence the importance to consider ecosystem composition for a correct ecological interpretation of results when the spatial resolution of observations includes different plant functional types.


Assuntos
Cistus , Quercus , Ulex , Clorofila/metabolismo , Ecossistema , Fluorescência , Florestas , Fotossíntese , Folhas de Planta/metabolismo , Portugal , Quercus/metabolismo , Radiometria , Chuva , Luz Solar , Temperatura
17.
J Exp Bot ; 67(5): 1567-75, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26703920

RESUMO

Environmental factors alter the impacts of parasitic plants on their hosts. However, there have been no controlled studies on how water availability modulates stem hemiparasites' effects on hosts. A glasshouse experiment was conducted to investigate the association between the Australian native stem hemiparasite Cassytha pubescens and the introduced host Ulex europaeus under high (HW) and low (LW) water supply. Cassytha pubescens had a significant, negative effect on the total biomass of U. europaeus, which was more severe in HW than LW. Regardless of watering treatment, infection significantly decreased shoot and root biomass, nodule biomass, nodule biomass per unit root biomass, F v/F m, and nitrogen concentration of U. europaeus. Host spine sodium concentration significantly increased in response to infection in LW but not HW conditions. Host water potential was significantly higher in HW than in LW, which may have allowed the parasite to maintain higher stomatal conductances in HW. In support of this, the δ(13)C of the parasite was significantly lower in HW than in LW (and significantly higher than the host). C. pubescens also had significantly higher F v/F m and 66% higher biomass per unit host in the HW compared with the LW treatment. The data suggest that the enhanced performance of C. pubescens in HW resulted in higher parasite growth rates and thus a larger demand for resources from the host, leading to poorer host performance in HW compared with LW. C. pubescens should more negatively affect U. europaeus growth under wet conditions rather than under dry conditions in the field.


Assuntos
Interações Hospedeiro-Parasita/fisiologia , Lauraceae/fisiologia , Parasitos/fisiologia , Ulex/parasitologia , Água/metabolismo , Análise de Variância , Animais , Biomassa , Isótopos de Carbono , Nitrogênio/metabolismo , Raízes de Plantas/parasitologia , Brotos de Planta/parasitologia , Sódio/metabolismo
18.
Proc Biol Sci ; 282(1814)2015 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-26336181

RESUMO

Interaction networks are widely used as tools to understand plant-pollinator communities, and to examine potential threats to plant diversity and food security if the ecosystem service provided by pollinating animals declines. However, most networks to date are based on recording visits to flowers, rather than recording clearly defined effective pollination events. Here we provide the first networks that explicitly incorporate measures of pollinator effectiveness (PE) from pollen deposition on stigmas per visit, and pollinator importance (PI) as the product of PE and visit frequency. These more informative networks, here produced for a low diversity heathland habitat, reveal that plant-pollinator interactions are more specialized than shown in most previous studies. At the studied site, the specialization index [Formula: see text] was lower for the visitation network than the PE network, which was in turn lower than [Formula: see text] for the PI network. Our study shows that collecting PE data is feasible for community-level studies in low diversity communities and that including information about PE can change the structure of interaction networks. This could have important consequences for our understanding of threats to pollination systems.


Assuntos
Abelhas/fisiologia , Dípteros/fisiologia , Ecossistema , Ericaceae/fisiologia , Flores/fisiologia , Polinização , Ulex/fisiologia , Animais , Coleta de Dados , Inglaterra , Pólen/fisiologia , Especificidade da Espécie
19.
PLoS One ; 10(9): e0137500, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26383627

RESUMO

Phenotypic plasticity may be advantageous for plants to be able to rapidly cope with new and changing environments associated with climate change or during biological invasions. This is especially true for perennial plants, as they may need a longer period to respond genetically to selective pressures than annuals, and also because they are more likely to experience environmental changes during their lifespan. However, few studies have explored the plasticity of the reproductive life history traits of woody perennial species. This study focuses on a woody shrub, Ulex europaeus (common gorse), and on the response of its reproductive traits to one important environmental factor, shading. The study was performed on clones originating from western France (within the native range of this invasive species) and grown for seven years. We compared traits of plants grown in a shade treatment (with two successive shade levels) vs. full natural light. The traits monitored included flowering onset, pod production and seed predation. All traits studied responded to shading, exhibiting various levels of plasticity. In particular, dense shade induced a radical but reversible decrease in flower and pod production, while moderate shade had little effect on reproductive traits. The magnitude of the response to dense shade depended on the genotype, showing a genetically based polymorphism of plasticity. The level of plasticity also showed substantial variations between years, and the effect of environmental variations was cumulative over time. This suggests that plasticity can influence the lifetime fitness of U. Europaeus and is involved in the capacity of the species to grow under contrasting environmental conditions.


Assuntos
Ulex/crescimento & desenvolvimento , Ulex/genética , Flores/genética , Flores/crescimento & desenvolvimento , Genótipo , Luz , Estações do Ano , Sementes/genética , Sementes/crescimento & desenvolvimento
20.
Animal ; 9(11): 1786-94, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26160068

RESUMO

Utilization of long-chain alcohols (LCOH) as diet composition markers in horses and cattle was assessed in a study conducted with 12 mature crossbreed mares (385±47 kg BW) and six adult non-lactating cows (499±36 kg BW) of Asturiana de los Valles breed. The LCOH data were combined with alkane and long-chain fatty acid (LCFA) data to test the applicability of combining these markers to estimate diet composition. Animals were randomly divided into groups of three animals and received a daily total amount of 1.0 kg dry matter/100 kg BW of diets composed of different proportions of ryegrass (Lolium perenne) and woody species (Ulex gallii and heather). Diet composition was estimated from even-chain LCOH (C(20)-OH to C(30)-OH) combined or not with alkane (C(25)-C(31) and C(33)) and/or LCFA (C(22)-FA to C(28)-FA, C(30)-FA, C(32)-FA and C(34)-FA) concentrations in diet components and faeces by least-squares procedures, using marker faecal concentrations uncorrected for incomplete faecal recovery (FR0) or corrected using mean recoveries across diets within animal species (FR1). Results showed large differences between plant species in their LCOH profiles, and that these markers offered additional discriminatory information to that provided by alkanes and LCFA. The LCOH markers were incompletely recovered in the faeces of both animal species. In cattle, LCOH FR tended to increase with carbon-chain length in a linear manner in both diets (P < 0.001), whereas in horses overall data showed a curvilinear relationship between these variables. Combination of LCOH, LCFA and alkanes resulted in more accurate diet estimates. Correction of faecal LCOH concentrations to incomplete FR led to more accurate diet composition estimates in both animal species. Results obtained in this study suggest the usefulness of LCOH markers combined with alkanes and LCFA to estimate diet composition of horses and cattle grazing mixed grassy-woody plant communities.


Assuntos
Álcoois/análise , Bovinos/fisiologia , Dieta/veterinária , Ácidos Graxos/análise , Cavalos/fisiologia , Alcanos/análise , Animais , Biomarcadores/análise , Ericaceae , Fezes , Feminino , Lactação , Lolium , Ulex
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