Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 15.072
Filtrar
1.
Zhongguo Zhong Yao Za Zhi ; 45(19): 4792-4797, 2020 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-33164447

RESUMO

"Shengdeng" is a traditional Tibetan medicine, which has many synonyms. It is complex in origin and serious in mi-xing. In order to clarify the origin of "Shengdeng" and its medicinal use, this paper makes a textual research on the name, variety and efficacy of "Shengdeng" by consulting Tibetan medicine classics such as The Four Medical Trantras and Jingzhu Materia Medica, combined with modern literature of Tibetan medicine. It is clear that the synonyms, primitive species, mainstream varieties and functions of Tibetan medicine "Shengdeng". The collation and analysis of the literature shows that "Shengdeng" has effects of treating rheumatism, drying "Huangshui", detumescence and relieving pain, and is mainly used for the treatment of rheumatoid arthritis in Tibetan medicine. Its original varieties include 14 species of plants belonging to 6 families: Spicaceae, Rhamnaceae, Cephalotaxus, Leguminosae, Hematoxylaceae and Taxaceae. Combined with the collection of legal standards at all levels, the distribution of resources and the application of clinical prescriptions, it is considered that the mainstream species of "Shengdeng" are Rhamnella gilgitica, Xanthoceras sorbifolia, Rhamnus parvifolia. As a substitute, Acacia catechu is also widely used in clinic. The literature review and variety textual research on Tibetan medicine "Shengdeng" is helpful to improve the safety, effectiveness and quality controllability of its clinical application, and provide scientific basis for its further standard setting, pharmacodynamics research, new drug development and so on.


Assuntos
Fabaceae , Plantas Medicinais , Rhamnaceae , Dessecação , Medicina Tradicional Tibetana
2.
Zootaxa ; 4778(2): zootaxa.4778.2.1, 2020 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-33055819

RESUMO

Osmia (Hemiosmia), O. (Tergosmia) and O. (Erythrosmia) are three related Palaearctic osmiine bee subgenera (Megachilidae, Megachilinae, Osmiini) comprising eight, seven and four species, respectively. Analysis of female pollen loads and field observations revealed that the species of both O. (Hemiosmia) and O. (Tergosmia) have a distinct or even exclusive preference for Fabaceae as pollen hosts. Species of O. (Erythrosmia) also collect pollen on Fabaceae, but additionally frequently visit nototribic flowers of Lamiaceae and Antirrhineae (Plantaginaceae), which they exploit by rubbing a specialized facial pilosity over the raised anthers. The representatives of O. (Hemiosmia) and the basal members of O. (Tergosmia) build their brood cells in self-excavated burrows in the ground, whereas the more derived O. (Tergosmia) species as well as the O. (Erythrosmia) species place them in preexisting cavities above-ground, which are empty snail shells hidden under prominences of rocks or under stones in the latter subgenus. In O. (Hemiosmia) and O. (Tergosmia), the brood cells are entirely constructed from foreign material and either consist of chewed leaves ("leaf pulp") in the former subgenus or are distinctly three-layered with a thin layer of mud sandwiched between two layers of large pieces of petals in the latter subgenus. In O. (Erythrosmia), the brood cells within the shell whorls are delimited by one-layered partitions of leaf pulp and the nests are closed by a barricade of densely packed small particles followed by a double wall of leaf pulp at the shell opening. The taxonomic revision of the three subgenera revealed the existence of an undescribed species, O. (Hemiosmia) spinicoxa spec. nov., which occurs in southwestern Morocco. The subgenus O. (Ozbekosmia) Zanden, 1994 syn. nov. is newly put into synonymy with O. (Tergosmia) Warncke, 1988. Osmia (Tergosmia) rhodoensis arquata Warncke, 1988 syn. nov. and O. (Tergosmia) tergestensis ononidis Ferton, 1897 syn. nov. are no longer accepted as valid subspecies of O. (Tergosmia) rhodoensis (Zanden, 1983) and O. (Tergosmia) tergestensis Ducke, 1897, respectively. Identification keys for all species of the three subgenera are given.


Assuntos
Abelhas , Fabaceae , Comportamento de Nidação , Animais , Feminino , Flores , Pólen
3.
Zootaxa ; 4786(3): zootaxa.4786.3.1, 2020 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-33056470

RESUMO

Twelve new species in a new genus, Geelus gen.n. are described, 10 species from a confined area in the north- and south-western parts of South Africa and two from Namibia. The genus has been recorded from 35 plant species in 18 families, with one species Geelus dundraad collected on Rooibos Tea, Aspalathus linearis (Fabaceae), which is indigenous to South Africa and cultivated commercially. The 12 new species are Geelus driehoekdraad sp.n., G. drietanddraad sp.n., G. dundraad sp.n., G. haakdraad sp.n., G. kinkeldraad sp.n., G. lemdraad sp.n., G. nektanddraad sp.n., G. platdraad sp.n., G. slangdraad sp.n., G. stompdraad sp.n., G. viertanddraad and G. vurkdraad sp.n. This new genus is allied to the Bonaspeiini, in the Deltocephalinae based on the broad lorum, apically expanded clypellus, dorsal side of the pygofer deeply and broadly incised, large sclerotized segment X, smooth merging of face and crown and Y-shaped connective with short stem. A MaxEnt distribution model based on 19 bioclimatic variables confirmed that the South African species occur within a confined region in the south-western parts of southern Africa.


Assuntos
Fabaceae , Hemípteros , África Austral , Animais
4.
Plant Genome ; 13(1): e20000, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-33016628

RESUMO

Soybean breeding relies on the use of wild (Glycine soja Sieb. and Zucc.) and domesticated [Glycine max (L.) Merr.] germplasm for trait improvement. Soybeans are self-pollinating and accessions can be maintained as pure lines, however within-accession genetic variation has been observed in previous studies of some landraces and elite cultivars. The objective of this study was to characterize within-line variation in the accessions housed in the USDA Soybean Germplasm Collection. This collection includes over 20,000 accessions, each previously genotyped using the SoySNP50K Chip. Each SoySNP50K genotype was developed by pooling approximately three individuals per accession. Therefore, clusters of SNPs called as heterozygous within an accession can be inferred to represent putative regions of heterogeneity between the three individuals sampled. In this study, we found high-probability intervals of heterogeneity in 4% of the collection, representing 870 accessions. Heterogeneous loci were found on every chromosome and, collectively, covered 98.4% of the soybean genome and 99% of the gene models. Sanger sequencing confirmed regions of genomic heterogeneity among a subset of ten accessions. This dataset provides useful information and considerations for users of crop germplasm seed banks. Furthermore, the heterogeneous accessions and/or loci represent a unique genetic resource that is immediately available for forward and reverse genetics studies.


Assuntos
Fabaceae , Soja , Genoma de Planta , Genótipo , Humanos , Soja/genética , Estados Unidos , United States Department of Agriculture
5.
An Acad Bras Cienc ; 92(suppl 2): e20181172, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33053068

RESUMO

To study the ontogeny of the extrafloral nectaries present in the inflorescences of Vigna luteola (Jacq.) Benth (Leguminosae, Phaseolinae), the location, morphology, anatomy of the earliest stages, histology of the definitive structures and ultrastructure of the secretory stage were analyzed. The extrafloral nectaries at different developmental stages were examined with light microscopy and scanning electron microscopy. The secretory stage was also examined with transmission electron microscopy. The racemose inflorescence of V. luteola has six nodes. At each node, a short globose secondary axis bears two flowers and one to three extrafloral nectaries. Each extrafloral nectary originates from the abscission of a flower bud and is formed by two differentiated zones: a ring of epidermal cells surrounding a group of longitudinally enlarged papillose central cells, both with underlying secretory parenchyma. The primary secretory tissue consists of the central cells, while the ring contributes to secretion to a lesser degree. Secretion is granulocrine, by means of exocytotic vesicles and plasmalemma invaginations. Four developmental stages succeed; the third one being the secretory. The extrafloral nectaries activity period starts when the flowers of the same secondary axis open and ceases before fruit development.


Assuntos
Fabaceae , Vigna , Diferenciação Celular , Flores , Néctar de Plantas
6.
Phytochemistry ; 179: 112496, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33070076

RESUMO

Elicited soybean (Glycine max (L.) Merrill, Leguminosae) seedlings can produce prenylated isoflavonoids from different subclasses, namely pterocarpans (glyceollins), isoflavones and coumestans. These prenylated isoflavonoids serve as defence compounds and can possess antimicrobial activity. Recently, we showed that priming with reactive oxygen species (ROS) specifically stimulated the production of glyceollins in Rhizopus spp.-elicited soybean seedlings (ROS + R). In this study, we achieved diversification of the inducible subclasses of prenylated isoflavonoids in soybean, by additional stimulation of two prenylated isoflavones and one prenylated coumestan. This was achieved by using a combination of the relatively long-lived ROS representative, H2O2, with AgNO3 prior to microbial elicitation. Microbial elicitation was performed with a live preparation of either a phytopathogenic fungus, Rhizopus spp. or a symbiotic bacterium, Bacillus subtilis. B. subtilis induced 30% more prenylated isoflavones than Rhizopus spp. in (H2O2 + AgNO3)-treated seedlings, without significantly compromising the total levels of glyceollins, compared to (ROS + R)-treated seedlings. The most abundant prenylated isoflavone induced was 6-prenyl daidzein, which constituted 60% of the total isoflavones. The prenylated coumestan, phaseol, was also induced in the (H2O2 + AgNO3)-treated and microbially elicited seedlings. Based on previously developed quantitative structure-activity relationship (QSAR) models, 6-prenyl daidzein and phaseol were predicted to be promising antibacterials. Overall, we show that treatment with H2O2 and AgNO3 prior to microbial elicitation leads to the production of promising antibacterial isoflavonoids from different subclasses. Extracts rich in prenylated isoflavonoids may potentially be applied as natural antimicrobial agents.


Assuntos
Fabaceae , Isoflavonas , Antibacterianos/farmacologia , Peróxido de Hidrogênio , Isoflavonas/farmacologia , Plântula , Soja
7.
Proc Natl Acad Sci U S A ; 117(38): 23823-23834, 2020 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-32900931

RESUMO

By analyzing successive lifestyle stages of a model Rhizobium-legume symbiosis using mariner-based transposon insertion sequencing (INSeq), we have defined the genes required for rhizosphere growth, root colonization, bacterial infection, N2-fixing bacteroids, and release from legume (pea) nodules. While only 27 genes are annotated as nif and fix in Rhizobium leguminosarum, we show 603 genetic regions (593 genes, 5 transfer RNAs, and 5 RNA features) are required for the competitive ability to nodulate pea and fix N2 Of these, 146 are common to rhizosphere growth through to bacteroids. This large number of genes, defined as rhizosphere-progressive, highlights how critical successful competition in the rhizosphere is to subsequent infection and nodulation. As expected, there is also a large group (211) specific for nodule bacteria and bacteroid function. Nodule infection and bacteroid formation require genes for motility, cell envelope restructuring, nodulation signaling, N2 fixation, and metabolic adaptation. Metabolic adaptation includes urea, erythritol and aldehyde metabolism, glycogen synthesis, dicarboxylate metabolism, and glutamine synthesis (GlnII). There are 17 separate lifestyle adaptations specific to rhizosphere growth and 23 to root colonization, distinct from infection and nodule formation. These results dramatically highlight the importance of competition at multiple stages of a Rhizobium-legume symbiosis.


Assuntos
Rhizobium leguminosarum , Rizosfera , Simbiose/genética , Fabaceae/microbiologia , Genes Bacterianos/genética , Fixação de Nitrogênio/genética , Rhizobium leguminosarum/genética , Rhizobium leguminosarum/fisiologia , Nódulos Radiculares de Plantas/genética , Nódulos Radiculares de Plantas/microbiologia
8.
PLoS One ; 15(9): e0239011, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32915885

RESUMO

Exotic ambrosia beetles are increasing in Europe due to global trade and global warming. Among these xylomycetophagous insects, Xylosandrus compactus (Eichhoff) (Coleoptera: Curculionidae) is a serious threat for several Mediterranean host plants. Carob trees growing in Sicily (Italy) have been extensively attacked by beetles leading to rapid tree decline. Although X. compactus has been found in Europe for several years, most aspects of its ecology are still unknown. We thus studied the population structure and dynamics of X. compactus, together with its twig size preference during a sampling of infested carob trees in south east Sicily. In addition, fungi associated with insects or galleries were isolated and characterized. The results showed that, in this newly-colonized environment and host plant, adult X. compactus overwinters inside twigs and starts to fly and reproduce in mid spring, completing five generations before overwintering in late fall. The mean diameter of carob twigs infested by the beetle varied significantly over the seasons, with the insect tending to infest larger twigs as season progresses. The mean number of adults/gallery was 19.21, ranging from 6 to 28. The minimum temperature significantly affected the overwintering adult mortality. Ambrosiella xylebori and Fusarium solani were the main symbionts associated with the pest in this study. Acremonium sp. was instead recorded for the first time in Europe inside X. compactus galleries. Several other fungi species were also found for the first time in association with X. compactus. Our findings provide useful insights into the sustainable management of this noxious pest.


Assuntos
Gorgulhos/microbiologia , Gorgulhos/patogenicidade , Animais , Ascomicetos/isolamento & purificação , Ascomicetos/fisiologia , Ecossistema , Fabaceae/parasitologia , Fusarium/isolamento & purificação , Fusarium/fisiologia , Interações Hospedeiro-Parasita , Doenças das Plantas/parasitologia , Dinâmica Populacional , Estações do Ano , Sicília , Simbiose , Árvores/parasitologia
9.
Science ; 369(6504): 620-621, 2020 08 07.
Artigo em Inglês | MEDLINE | ID: mdl-32764052
10.
Ecotoxicol Environ Saf ; 204: 111098, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32798749

RESUMO

Cadmium (Cd) is a detrimental element that can be toxic to plants. The physiological and biochemical responses of plants to Cd stress have been extensively studied, but the molecular mechanisms remain unclear. The present study showed that Cd severely inhibited the growth of roots and shoots and reduced plant biomass of mung bean seedlings. To further investigate the gene profiles and molecular processes in response Cd stress, transcriptome analyses of mung bean roots exposed to 100 µM Cd for 1, 5, and 9 days were performed. Cd treatment significantly decreased global gene expression levels at 5 and 9 d compared with the control. A total of 6737, 10279, and 9672 differentially expressed genes (DEGs) were identified in the 1-, 5-, and 9-day Cd-treated root tissues compared with the controls, respectively. Based on the analysis of DEG function annotation and enrichment, a pattern of mung bean roots response to Cd stress was proposed. The processes detoxification and antioxidative defense were involved in the early response of mung bean roots to Cd. Cd stress downregulated the expressions of a series of genes involved in cell wall biosynthesis, cell division, DNA replication and repair, and photosynthesis, while genes involved in signal transduction and regulation, transporters, secondary metabolisms, defense systems, and mitochondrial processes were upregulated in response to Cd, which might be contributed to the improvement of plant tolerance. Our results provide some novel insights into the molecular processes for growth and adaption of mung bean roots in response to Cd and many candidate genes for further biotechnological manipulations to improve plant tolerance to heavy metals.


Assuntos
Cádmio/toxicidade , Poluentes do Solo/toxicidade , Aclimatação , Adaptação Fisiológica , Antioxidantes/metabolismo , Cádmio/metabolismo , Poluição Ambiental , Fabaceae/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Metais Pesados/metabolismo , Raízes de Plantas/metabolismo , Plântula/metabolismo , Poluentes do Solo/metabolismo , Transcriptoma , Vigna/metabolismo
11.
An Acad Bras Cienc ; 92(2): e20181115, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32785425

RESUMO

We surveyed 58 scientific articles published between 1987 and 2018 to evaluate the representative nature of the Fabaceae as hosts of insect galls in Brazil, and to gain a better understanding of the interactions between gall-inducing insects and plants and the evolutionary ecology of those insects and their plant hosts. A total of 438 gall morphotypes were reported as being generated by gall-inducing insects on 178 Fabaceae host species belonging to five subfamilies Caesalpinioideae (22 genera and 79 spp.), Cercidoideae (1 genus and 11 spp.), Detarioideae (6 genera and 17 spp.), Dialioideae (2 genera and 2 spp.), and Papilionoideae (26 genera and 69 spp.). The plant host genera demonstrating the greatest richness of gall-inducing insects were Inga, Bauhinia, and Copaifera; the super-host species were Copaifera langsdorffii, Bauhinia brevipes, and Copaifera sabulicola. Most of the galls were observed on leaves; they were mostly globoid, green, glabrous, isolated, and unilocular. The principal gall inducers belonged to Cecidomyiidae; the associated fauna was represented by Collembola, Coleoptera, Diptera, Formicidae, Hemiptera, Hymenoptera, Lepidoptera, Pseudoscorpionida, and Thysanoptera. Fabaceae are the principal super-hosts of galls and one of the most diverse families of angiosperms in Brazil, aggregating evidences for the hypotheses of floristic richness and taxon size.


Assuntos
Fabaceae , Animais , Brasil , Interações Hospedeiro-Parasita , Insetos , Tumores de Planta
12.
Toxicon ; 186: 182-190, 2020 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-32822735

RESUMO

Snakebites produce several toxic effects in victims, such as hemorrhage, tissue necrosis, hemostatic, renal, or cardiotoxic alterations, inflammation, and death. To counteract these symptoms, antivenom is the official treatment. Although such therapy prevents death, it does not efficiently neutralize necrosis or other local effects, leading to amputation or morbidities of the affected limb. Therefore, the search for better and more efficient therapies deserves attention; further, plants have been used to ameliorate a number of diseases and medical conditions, including snakebites, for many years. Thus, the aim of this work was to evaluate the antivenom effect of the crude extract, fractions (aqueous and diethyl acetate), and subfractions derived from the aqueous fraction (P1, P2, P3, and P4) of the plant Stryphnodendron adstringens against in vitro (coagulation and proteolytic) and in vivo (edema, hemorrhage, and myotoxic) activities caused by Bothrops jararacussu venom. Overall, all extracts inhibited the toxic effect of B. jararacussu venom, but with different potencies, regardless of whether plant samples were incubated together with venom or injected before or after venom injection into animals; the crude extract and aqueous fraction were found to be the most effective. Indeed, phytochemical and mass spectrometry analysis of S. adstringens samples revealed the presence of flavonols, tannins, and saponins. In conclusion, the plant S. adstringens may represent a promising natural source of molecules to treat the toxic effects associated with envenomation by B. jararacussu snakebites.


Assuntos
Bothrops , Venenos de Crotalídeos/toxicidade , Fabaceae , Extratos Vegetais/farmacologia , Substâncias Protetoras/farmacologia , Animais , Antivenenos , Edema , Hemorragia , Mordeduras de Serpentes
13.
Cell Rep ; 32(6): 108016, 2020 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-32755598

RESUMO

The influenza virus hemagglutinin (HA) and coronavirus spike (S) protein mediate virus entry. HA and S proteins are heavily glycosylated, making them potential targets for carbohydrate binding agents such as lectins. Here, we show that the lectin FRIL, isolated from hyacinth beans (Lablab purpureus), has anti-influenza and anti-SARS-CoV-2 activity. FRIL can neutralize 11 representative human and avian influenza strains at low nanomolar concentrations, and intranasal administration of FRIL is protective against lethal H1N1 infection in mice. FRIL binds preferentially to complex-type N-glycans and neutralizes viruses that possess complex-type N-glycans on their envelopes. As a homotetramer, FRIL is capable of aggregating influenza particles through multivalent binding and trapping influenza virions in cytoplasmic late endosomes, preventing their nuclear entry. Remarkably, FRIL also effectively neutralizes SARS-CoV-2, preventing viral protein production and cytopathic effect in host cells. These findings suggest a potential application of FRIL for the prevention and/or treatment of influenza and COVID-19.


Assuntos
Antivirais/uso terapêutico , Infecções por Coronavirus/tratamento farmacológico , Fabaceae/química , Infecções por Orthomyxoviridae/tratamento farmacológico , Lectinas de Plantas/uso terapêutico , Pneumonia Viral/tratamento farmacológico , Células A549 , Administração Intranasal , Animais , Antivirais/administração & dosagem , Antivirais/farmacologia , Betacoronavirus/efeitos dos fármacos , Embrião de Galinha , Chlorocebus aethiops , Cães , Feminino , Humanos , Vírus da Influenza A Subtipo H1N1/efeitos dos fármacos , Células Madin Darby de Rim Canino , Camundongos , Camundongos Endogâmicos BALB C , Pandemias , Lectinas de Plantas/administração & dosagem , Lectinas de Plantas/farmacologia , Ligação Proteica , Células Vero , Proteínas do Envelope Viral/metabolismo
14.
Sci Total Environ ; 743: 140771, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32673921

RESUMO

Overseeding legumes in natural grasslands coupled with phosphorous fertilization are management practices oriented to increase forage production and quality, and to restore nutrient losses generated by livestock. Several studies show increases in forage due to this practice, but less is known about impacts on soil fertility and carbon sequestration. The objective of this study was to evaluate under real farm conditions changes in root C and N stocks and soil organic carbon (SOC) and nitrogen (SON) stocks in two different soil pools, the particulate organic matter (POM) and the mineral associated organic matter (MAOM), after the introduction in natural grasslands of a legume species, Lotus subbiflorus cv. "El Rincón", accompanied with phosphorous fertilization. We also evaluated changes in the natural abundance of 15N and 13C in soils and roots to understand changes in N fixation and species composition. We selected 12 adjacent paddocks of natural grasslands (NG) and natural grasslands overseeded with legumes and fertilized with phosphorous (NGLP) located in commercial farms in Uruguay. We found that overseeding legumes increased root C and N stocks and SOC and SON stocks in some farms but decreased them in others. On average, no significant differences arose between NGLP and NG paddocks in total stocks of 0-30 cm depth. However, higher C stocks were observed in POM of NGLP paddocks in 0-5 cm layer and lower contents in 5-10 cm layer indicating a change in the vertical distribution of C in POM. Changes in δ15N suggest that atmospheric N is being fixed by legumes in NGLP paddocks, but not translated into more N or C stocks in the MAOM fraction, probably due to high N losses promoted by cattle grazing. Our work suggests that carbon sequestration can be achieved after legumes introduction in grazed natural grasslands but will depend on grazing management practices.


Assuntos
Fabaceae , Solo , Animais , Biomassa , Carbono/análise , Bovinos , Fazendas , Pradaria , Nitrogênio/análise , Uruguai
15.
Sci Total Environ ; 744: 140612, 2020 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-32711302

RESUMO

Increased nitrogen (N) deposition can affect ecosystem processes and thus influence plant eco-physiological processes in grasslands. However, how N deposition affects eco-physiological processes of leguminous and non-leguminous forbs in alpine grasslands is understudied. A long-term field experiment using a range of simulated N deposition rates (0, 8, 24, 40, 56, and 72 kg N ha-1 year-1) was established to examine the effects of N deposition on various eco-physiological parameters in leguminous and non-leguminous forbs in an alpine meadow of the Qinghai-Tibetan Plateau. We found that the responses of leguminous and non-leguminous forbs to simulated N deposition varied. Net photosynthetic rate of leguminous and non-leguminous forbs exhibited different response patterns, but chronic increases in simulated N deposition rates may lead to negative effects in both functional groups. Neither functional group responded differently in aboveground biomass under the highest N addition level (72 kg N ha-1 year-1) compared to the control. Differences in aboveground biomass of leguminous forbs were observed at intermediate N levels. Short-term simulated N deposition significantly promoted N uptake of both functional groups. In leguminous forbs, simulated N deposition affected net photosynthetic rates (PN) and aboveground biomass (AGB) mainly via stomatal conductance (gs), water use efficiency (WUE), and plant N uptake. In non-leguminous forbs, simulated N deposition affected PN and AGB mainly through WUE and plant N uptake. Our findings suggest that leguminous and non-leguminous forbs have differential response mechanisms to N deposition, and compared with non-leguminous forbs, leguminous forbs are more sensitive to continuing increased N deposition. The obvious decline trend in photosynthetic capacity in leguminous forbs is likely to exacerbate the already divergent ecological processes between leguminous and non-leguminous forbs. More importantly, these changes are likely to alter the future composition, function, and stability of alpine meadow ecosystems.


Assuntos
Fabaceae , Fenômenos Fisiológicos , Biomassa , Ecossistema , Pradaria , Solo , Tibet
16.
Int J Syst Evol Microbiol ; 70(8): 4623-4636, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32667875

RESUMO

The genus Bradyrhizobium is considered as the probable ancestor lineage of all rhizobia, broadly spread in a variety of ecosystems and with remarkable diversity. A polyphasic study was performed to characterize and clarify the taxonomic position of eight bradyrhizobial strains isolated from indigenous legumes to Western Australia. As expected for the genus, the 16S rRNA gene sequences were highly conserved, but the results of multilocus sequence analysis with four housekeeping genes (dnaK, glnII, gyrB and recA) confirmed three new distinct clades including the following strains: (1) WSM 1744T, WSM 1736 and WSM 1737; (2) WSM 1791T and WSM 1742; and (3) WSM 1741T, WSM 1735 and WSM 1790. The highest ANI values of the three groups in relation to the closest type strains were 92.4, 92.3 and 93.3 %, respectively, below the threshold of species circumscription. The digital DNA-DNA hybridization analysis also confirmed new species descriptions, with less than 52 % relatedness with the closest type strains. The phylogeny of the symbiotic gene nodC clustered the eight strains into the symbiovar retamae, together with seven Bradyrhizobium type strains, sharing from 94.2-98.1 % nucleotide identity (NI), and less than 88.7 % NI with other related strains and symbiovars. Morpho-physiological, phylogenetics, genomic and symbiotic traits were determined for the new groups and our data support the description of three new species, Bradyrhizobium archetypum sp. nov., Bradyrhizobium australiense sp. nov. and Bradyrhizobium murdochi sp. nov., with WSM 1744T (=CNPSo 4013T=LMG 31646T), WSM 1791T (=CNPSo 4014T=LMG 31647T) and WSM 1741T (=CNPSo 4020T=LMG 31651T) designated as type strains, respectively.


Assuntos
Bradyrhizobium/classificação , Fabaceae/microbiologia , Filogenia , Nódulos Radiculares de Plantas/microbiologia , Técnicas de Tipagem Bacteriana , Composição de Bases , Bradyrhizobium/isolamento & purificação , DNA Bacteriano/genética , Genes Bacterianos , Tipagem de Sequências Multilocus , Fixação de Nitrogênio , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Austrália Ocidental
17.
PLoS One ; 15(6): e0234769, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32603370

RESUMO

Understanding the mechanisms governing complex traits variation is a requirement for efficient crop improvement. In this study, the molecular characterization, marker-trait associations and the possibility for genomic selection in a collection of 281 Kersting's groundnut accessions were carried out. The diversity panel was phenotyped using an Alpha lattice design with two replicates in two contrasting environments. Accessions were genotyped using genotyping by sequencing technology. Genome-wide association analyses were performed between single nucleotide polymorphism markers and yield-related traits across tested environments. SNP markers were used to calculate the observed (Ho) and expected heterozygosity (He), and the total gene diversity (Ht). Genetic differentiation among accessions across ecological regions of origin was analysed. Our results revealed 493 quality SNPs of which 113 had a minor allele frequency>0.05, a total gene diversity of 0.43 and average Ho and He values of 0.04 and 0.22, respectively. Four clusters, highly differentiated by seed coat colour (Fst = 0.79), were identified. The population structure analysis showed two subpopulations with high differentiation across ecological regions (Fst = 0.37). The GWAS revealed 10 significant marker-trait associations, of which six SNPs were consistent across environments. The genomic selection through cross-validation showed moderate to high prediction accuracies for leaflet length, seed dimension traits, 100 seed weight, days to 50% flowering and days to maturity. This demonstrates the existence of genetic variability within Kersting's groundnut and shows the potential for the improvement of the species. The findings also provide a first insight into the phenotype-to-genotype relationships in Kersting's groundnut, using SNP markers.


Assuntos
Fabaceae/genética , Genômica , Polimorfismo de Nucleotídeo Único , Seleção Genética , África Ocidental , Evolução Molecular , Fenótipo
18.
Phytochemistry ; 177: 112423, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32688268

RESUMO

The US Southwest plant Dalea parryi (Fabaceae) was investigated as part of an ongoing study of the potential of plant compounds for anthelmintic activity to the human pathogenic hookworm Ancylostoma ceylanicum. This has resulted in the isolation of three previously undescribed isoflavonoid metabolites, denoted parryans A-C, a chalcone, six pterocarpans, and three known compounds from the roots of D. parryi. Parryans A and B express a rarely-seen O-prenyl substituent. Structures of the previously undescribed compounds were established using 1D and 2D NMR spectroscopy and mass spectrometry. The relative and absolute configurations of the undescribed stereoisomers were assigned using chemical shift and coupling constant data and comparisons of specific rotations to published data. The most active of the isolated compounds only expressed a 17% reduction in survival of A. ceylanicum adult hookworm in an ex vivo assay at 50 µg/mL after 5 days exposure. Toxicity, ranging from 47 to 93% reduction in survival of mammalian splenocytes was expressed by four of the compounds.


Assuntos
Anti-Helmínticos , Fabaceae , Adulto , Ancylostoma , Ancylostomatoidea , Animais , Humanos , Raízes de Plantas
19.
Environ Entomol ; 49(4): 876-885, 2020 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-32623469

RESUMO

A number of soybean varieties traditionally bred for resistance to various soybean arthropod pests have been identified as resistant to Megacopta cribraria (F.) (Hemiptera: Plataspidae). However, the mechanisms of host-plant resistance (HPR) in this system are not understood. The goal of this study was to identify the mechanisms of resistance by examining the role of plant volatile organic compounds (VOCs) and free amino acids (FAAs) among 16 soybean varieties. Choice and no-choice cage experiments identified several soybean varieties that demonstrated antixenosis as well as antibiosis. However, resistance varied over time in certain soybean varieties, such as N02-7002 and PI567352B. Mean nymph number from choice experiments had positive correlations with the FAAs asparagine, tryptophan, alanine, phenylanaline, and serine; negative correlation with leucine and threonine. Four plant volatiles, hexanal, 2-pentylfuran, beta-cyclocitral, and cis-9-hexadecenal, were positively correlated with subsequent nymph development, whereas n-hexadecenoic acid was negatively correlated with nymph number only, in adult choice cage experiments. This study contributes to understanding the mechanisms of HPR through associations with plant VOCs and FAAs in relation to M. cribraria development and provides useful knowledge for developing soybean varieties for M. cribraria management.


Assuntos
Fabaceae , Hemípteros , Heterópteros , Compostos Orgânicos Voláteis , Animais , Ninfa , Soja
20.
Arch Microbiol ; 202(9): 2533-2542, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32656677

RESUMO

The aim of this study was to evaluate the phytochemical constituents, antioxidant, antifungal, and anti-virulence activities of traditionally used Mezoneuron benthamianum leaves. Extracts were prepared using acetone and methanol, and the preliminary phytochemical screening was performed. The antioxidant activity was studied using the DPPH method. Anti-Candida albicans activity was established and the effect on the germ tube and phospholipase production, as well as on the host cell adherence was assessed. The extracts showed the presence of anthraquinones, cardiac glycosides, flavonoids, reducing sugars, saponins, steroids, tannins, and terpenoids. Gallic acid and trans-resveratrol were among the predominant phytochemicals found in M. benthamianum. The crude extracts presented significantly higher antioxidant activity than the ascorbic acid standard. At 0.39 mg/mL, acetone extract inhibited the growth of Candida albicans. At lower concentrations (200-50 µg/mL), it significantly inhibited the adherence ability (up to 51%), formation of hyphae (up to 65%), and the production of phospholipase. In conclusion, at high concentrations, M. benthamianum kills C. albicans, and at lower concentrations, it can inhibit the virulence properties of this pathogen. This study on crude extract validates the traditional use of this plant. However, further research is required to establish the anti-virulence activity of the two compounds and their therapeutic potential.


Assuntos
Candida albicans/efeitos dos fármacos , Adesão Celular/efeitos dos fármacos , Fabaceae/química , Regulação Fúngica da Expressão Gênica/efeitos dos fármacos , Hifas/efeitos dos fármacos , Extratos Vegetais/farmacologia , Antifúngicos/farmacologia , Antioxidantes/análise , Fosfolipases/genética , Fosfolipases/metabolismo , Extratos Vegetais/química , Folhas de Planta/química , Taninos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA