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1.
J Environ Manage ; 322: 116045, 2022 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-36067662

RESUMEN

Integrated management of biodiversity and ecosystem services (ES) in heterogeneous landscapes requires considering the potential trade-offs between conflicting objectives. The UNESCO's Biosphere Reserve zoning scheme is a suitable context to address these trade-offs by considering multiple management zones that aim to minimise conflicts between management objectives. Moreover, in Mediterranean ecosystems, management and planning also needs to consider drivers of landscape dynamics such as wildfires and traditional farming and forestry practices that have historically shaped landscapes and the biodiversity they host. In this study, we applied a conservation planning approach to prioritise the allocation of management zones under future landscape and climate scenarios. We tested different landscape management scenarios reflecting the outcomes of climate-smart and fire-smart policies. We projected the expected landscape dynamics and associated changes on the distribution of 207 vertebrate species, 4 ES and fire hazard under each scenario. We used Marxan with Zones to allocate three management zones, replicating the Biosphere Reserves zoning scheme ("Core area", "Buffer zone" and "Transition area") to address the various management objectives within the Biosphere Reserve. Our results show that to promote ES supply and biodiversity conservation, while also minimising fire hazard, the reserve will need to: i) Redefine its zoning, especially regarding Core Areas, which need a considerable expansion to help mitigate changes in biodiversity and accommodate ES supply under expected changes in climate and species distribution. ii) Revisit current management policies that will result in encroached landscapes prone to high intensity, uncontrollable wildfires with the potential to heavily damage ecosystems and compromise the supply of ES. Our results support that both climate- and fire-smart policies in the Meseta Ibérica can help develop multifunctional landscapes that help mitigate and adapt to climate change and ensure the best possible maintenance of biodiversity and ES supply under uncertain future climate conditions.


Asunto(s)
Ecosistema , Incendios , Biodiversidad , Cambio Climático , Conservación de los Recursos Naturales/métodos , Objetivos
2.
Arch Microbiol ; 203(7): 3869-3882, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34013419

RESUMEN

Strains of Bacillus thuringiensis (Bt) are commonly commercialized as bioinoculants for insect pest control, but their benefits go beyond their insecticidal property: they can act as plant growth-promoters. Auxins play a major role in the plant growth promotion. However, the mechanism of auxin production by the Bacilli group, and more specifically by Bt strains, is unclear. In previous work, the plant growth-promoting rhizobacterium (PGPR) B. thuringiensis strain RZ2MS9 increased the corn roots. This drew our attention to the strain's auxin production trait, earlier detected in vitro. Here, we demonstrate that in its genome, RZ2MS9 harbours the complete set of genes required in two pathways that are used for Indole acetic acid (IAA) production. We also detected that the strain produces almost five times more IAA during the stationary phase. The bacterial application increased the shoot dry weight of the Micro-Tom (MT) tomato by 24%. The application also modified MT root architecture, with an increase of 26% in the average lateral root length and inhibition of the axial root. At the cellular level, RZ2MS9-treated MT plants presented elongated root cortical cells with intensified mitotic activity. Altogether, these are the best characterized auxin-associated phenotypes. Besides that, no growth alteration was detected in the auxin-insensitive diageotropic (dgt) plants either with or without the RZ2MS9 inoculation. Our results suggest that auxins play an important role in the ability of B. thuringiensis RZ2MS9 to promote MT growth and provide a better understanding of the auxin production mechanism by a Bt strain.


Asunto(s)
Bacillus thuringiensis , Ácidos Indolacéticos , Solanum lycopersicum , Bacillus thuringiensis/fisiología , Ácidos Indolacéticos/metabolismo , Solanum lycopersicum/crecimiento & desarrollo , Solanum lycopersicum/microbiología , Raíces de Plantas/crecimiento & desarrollo , Raíces de Plantas/microbiología
3.
Mol Breed ; 41(10): 63, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37309313

RESUMEN

Exploring the symbiosis between plants and plant growth-promoting bacteria (PGPB) is a new challenge for sustainable agriculture. Even though many works have reported the beneficial effects of PGPB in increasing plant resilience for several stresses, its potential is not yet widely explored. One of the many reasons is the differential symbiosis performance depending on the host genotype. This opens doors to plant breeding programs to explore the genetic variability and develop new cultivars with higher responses to PGPB interaction and, therefore, have higher resilience to stress. Hence, we aimed to study the genetic architecture of the symbiosis between PGPB and tropical maize germplasm, using a public association panel and its impact on plant resilience. Our findings reveal that the synthetic PGPB population can modulate and impact root architecture traits and improve resilience to nitrogen stress, and 37 regions were significant for controlling the symbiosis between PGPB and tropical maize. In addition, we found two overlapping SNPs in the GWAS analysis indicating strong candidates for further investigations. Furthermore, genomic prediction analysis with genomic relationship matrix computed using only significant SNPs obtained from GWAS analysis substantially increased the predictive ability for several traits endorsing the importance of these genomic regions for the response of PGPB. Finally, the public tropical panel reveals a significant genetic variability to the symbiosis with the PGPB and can be a source of alleles to improve plant resilience. Supplementary Information: The online version contains supplementary material available at 10.1007/s11032-021-01257-6.

4.
Adv Mind Body Med ; 35(3): 10-19, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34237025

RESUMEN

CONTEXT: Students are vulnerable to developing anxiety, a psychiatric disorder closely related to emotional stress, when systematically stressed by classes, homework, and evaluations. Qigong integrates physical, respiratory, and mental exercises, inducing vegetative biofeedback with significant effects on physiological regulation. OBJECTIVE: The current study aimed to assess the potential effects of specific Qigong exercises on students' anxiety levels and evaluate the feasibility of practical integration in a daily school context. DESIGN: The research team developed a randomized controlled trial. SETTING: This study was performed in Cedros and Horizonte private schools located in Vila Nova de Gaia in Portugal. PARTICIPANTS: Participants were 104 high-school students at the schools. INTERVENTION: Participants were randomly divided into three groups: (1) an intervention group, the Qigong (QG) group (n = 34), which performed Qigong exercises; (2) a control group, the TV documentary (TVD) group (n = 34), which watched a TV documentary; and (3) a second control group, the typical school duties (TSD) group (n = 36), which performed regular school duties. OUTCOME MEASURES: Anxiety levels were assessed through a psychological test, the State-Trait Anxiety Inventory (STAI) and salivary cortisol tests. RESULTS: Psychological and biochemical variables assessed at baseline and postintervention showed a greater decrease in anxiety levels in the QG group than in the other two groups. CONCLUSIONS: Qigong seems to be an efficient tool to reduce anxiety and control the stress of high-school students.


Asunto(s)
Qigong , Adolescente , Ansiedad/terapia , Humanos , Portugal , Instituciones Académicas , Estudiantes
7.
J Basic Microbiol ; 60(4): 380-385, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-31898333

RESUMEN

Aspergillus nidulans is a fungal model organism extensively used in genetic approaches. It may reproduce sexually and asexually, with a well-defined parasexual cycle. The current paper demonstrates that the limitation of nitrogen source facilitates the production of A. nidulans's nonmeiotic recombinants directly from heterokaryons, without the recovery of the diploid phase. Heterokaryons formed between master strains were inoculated in sodium nitrate-low (basal medium [BM]) and sodium nitrate-rich media (minimal medium [MM]). All mitotic segregants produced by the heterokaryons were tested for their mitotic stability in the presence of benomyl, the haploidizing agent. Only mitotically stable haploid segregants were selected for subsequent analysis. Phenotypic analyses of such haploids favored the characterization of nonmeiotic recombinants. As the number of such recombinants was higher in BM than in MM, nitrogen limitation may have facilitated the isolation of nonmeiotic recombinants from heterokaryons by stimulating nuclear fusion still inside the heterokaryotic mycelium as a survival strategy.


Asunto(s)
Aspergillus nidulans/genética , Mitosis , Nitrógeno/química , Recombinación Genética , Benomilo/química , Medios de Cultivo/química , Diploidia , Haploidia , Nitratos/química
8.
Arch Microbiol ; 201(8): 1061-1073, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31123792

RESUMEN

Plants are colonized by diverse microorganisms that can substantially impact their health and growth. Understanding bacterial diversity and the relationships between bacteria and phytopathogens may be key to finding effective biocontrol agents. We evaluated the bacterial community associated with anthracnose symptomatic and asymptomatic leaves of guarana, a typical tropical crop. Bacterial communities were assessed through culture-independent techniques based on extensive 16S rRNA sequencing, and cultured bacterial strains were evaluated for their ability to inhibit the growth of Colletotrichum sp. as well as for enzyme and siderophore production. The culture-independent method revealed that Proteobacteria was the most abundant phylum, but many sequences were unclassified. The emergence of anthracnose disease did not significantly affect the bacterial community, but the abundance of the genera Acinetobacter, Pseudomonas and Klebsiella were significantly higher in the symptomatic leaves. In vitro growth of Colletotrichum sp. was inhibited by 11.38% of the cultured bacterial strains, and bacteria with the highest inhibition rates were isolated from symptomatic leaves, while asymptomatic leaves hosted significantly more bacteria that produced amylase and polygalacturonase. The bacterial isolate Bacillus sp. EpD2-5 demonstrated the highest inhibition rate against Colletotrichum sp., whereas the isolates EpD2-12 and FD5-12 from the same genus also had high inhibition rates. These isolates were also able to produce several hydrolytic enzymes and siderophores, indicating that they may be good candidates for the biocontrol of anthracnose. Our work demonstrated the importance of using a polyphasic approach to study microbial communities from plant diseases, and future work should focus on elucidating the roles of culture-independent bacterial communities in guarana anthracnose disease.


Asunto(s)
Antibiosis/fisiología , Agentes de Control Biológico/aislamiento & purificación , Colletotrichum/crecimiento & desarrollo , Paullinia/microbiología , Proteobacteria/aislamiento & purificación , Acinetobacter/clasificación , Acinetobacter/genética , Acinetobacter/aislamiento & purificación , Amilasas/metabolismo , Antracosis/microbiología , Bacillus/clasificación , Bacillus/genética , Bacillus/aislamiento & purificación , Klebsiella/clasificación , Klebsiella/genética , Klebsiella/aislamiento & purificación , Microbiota , Enfermedades de las Plantas/microbiología , Hojas de la Planta/microbiología , Poligalacturonasa/metabolismo , Proteobacteria/clasificación , Proteobacteria/genética , Pseudomonas/clasificación , Pseudomonas/genética , Pseudomonas/aislamiento & purificación , ARN Ribosómico 16S/genética , Bosque Lluvioso , Sideróforos/metabolismo
9.
Indian J Microbiol ; 59(2): 217-224, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-31031437

RESUMEN

Fungus-caused diseases are among the greatest losses in grapevine culture. Biological control of pathogens by endophytes may be used to decrease fungicide application rates and environmental impacts. Previously, Diaporthe sp. B46-64 and C27-07 were highlighted as antagonists of grapevine phytopathogens. Herein, molecular multigene (ITS-TUB-TEF1) identification and phylogenetic analysis allowed the identification of these endophytes as belonging to Diaporthe schini species. Agrobacterium tumefaciens-mediated transformation was employed for obtaining 14 stable and traceable gfp- or DsRed-expressing transformants, with high transformation efficiency: 96% for the pFAT-GFP plasmid and 98% for pCAM-DsRed plasmid. Transformants were resistant to hygromycin B with gene hph confirmed by polymerase chain reaction and proved to be mitotically stable, expressing the fluorescent phenotype, with morphological differences in the colonies when compared with wild strains. In vitro antagonism tests revealed an increased antagonistic activity of some transformant strains. The current genetic transformation of D. schini mediated by A. tumefaciens proved to be an efficient technique within the randomized insertion of reporter genes for the monitoring of the strain in the environment.

10.
Microb Pathog ; 121: 106-109, 2018 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-29777829

RESUMEN

The clonal Eucalyptus plants are commonly obtained by vegetative propagation under a protected environment. This system improves the Botrytis cinerea and Calonectria spp infection on the young eucalypts plantings, resulting gray mold and cutting rot respectively. Currently, the unique available control method is based on chemicals. As alternative, novel methods to manage plant diseases, endophytic microorganisms could be an interesting alternative. Thus, we aimed to evaluate endophytic Bacillus isolated from eucalypts as a biocontrol agent against Botrytis cinerea and Calonectria gracilis, important fungal pathogens in the greenhouse, using clonal plantlets of E. urograndis. Eight endophytic strains of Bacillus, previously described as eucalyptus growth promoters, were evaluated in vitro and in vivo against Botrytis cinerea and Calonectria gracilis. The diffusible metabolites assay showed the potential of endophytic Bacillus to decrease the growth of both pathogens. Differences in the susceptibility of the pathogens to bacterial volatile metabolites were observed, B. cinerea showed more susceptible than Calonectria gracilis. In vivo assays, Bacillus amyloliquefaciens EUCB 10 demonstrated better overall reductions in these diseases. Based on the results obtained from the in vitro and in vivo analyses, we suggest that the endophytic B. amyloliquefaciens strain EUCB 10 constitutes a promising biocontrol agent against B. cinerea and Calonectria gracilis. Furthermore, this is the first reporting of B. amyloliquefaciens previously describe as plant growth promoter and also as potential control agent of B. cinerea and Calonectria gracilis to eucalyptus.


Asunto(s)
Bacillus , Agentes de Control Biológico , Botrytis/crecimiento & desarrollo , Eucalyptus/microbiología , Hypocreales/crecimiento & desarrollo , Bioensayo , Enfermedades de las Plantas/microbiología , Compuestos Orgánicos Volátiles/química
11.
Curr Microbiol ; 75(5): 588-596, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29299623

RESUMEN

Endophytes are fungi and bacteria that inhabit plant tissues without causing disease. Endophytes have characteristics that are important for the health of the plant and have been isolated from several plants of economic and medicinal interest but rarely from ornamental plants. The current study isolates and identifies endophytic fungi from the leaves of Pachystachys lutea and evaluates the antagonistic activity of these endophytes as well as cellulase production by the endophytes. Fungi were isolated by fragmentation from surface-disinfected leaves and were identified by the sequencing of the ITS gene and the genes coding for EF 1-α and ß-tubulin followed by multilocus sequence analysis. Molecular taxonomic analysis revealed that 78% of the identified fungi belonged to the genus Diaporthe. We also identified strains belonging to the genera Colletotrichum, Phyllosticta, Xylaria, Nemania, and Alternaria. Most of the strains tested were able to inhibit the growth of pathogenic fungi, especially PL09 (Diaporthe sp.), which inhibited the growth of Colletotrichum sp., and PL03 (Diaporthe sp.), which inhibited the growth of Fusarium oxysporum. The production of cellulase ranged from 0.87 to 1.60 µmol/min. Foliar endophytic fungal isolates from P. lutea showed promising results for the in vitro control of plant pathogens and for cellulase production. This paper is the first report on culturable endophytic fungi isolated from the ornamental plant P. lutea.


Asunto(s)
Endófitos/aislamiento & purificación , Endófitos/fisiología , Hongos/aislamiento & purificación , Hongos/fisiología , Magnoliopsida/microbiología , Enfermedades de las Plantas/prevención & control , Antibiosis , Colletotrichum/fisiología , Endófitos/clasificación , Endófitos/genética , Hongos/clasificación , Hongos/genética , Fusarium/fisiología , Magnoliopsida/crecimiento & desarrollo , Filogenia , Enfermedades de las Plantas/microbiología , Hojas de la Planta/microbiología
12.
World J Microbiol Biotechnol ; 34(4): 56, 2018 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-29594576

RESUMEN

Plant leaves (phyllosphere) have a great potential for colonization and microbial growth, consisting of a dynamic environment in which several factors can interfere with the microbial population structure. The use of genetically modified (GM) plants has introduced several traits in agriculture, such as the improvement of plant drought tolerance, as observed in the AtAREB1 transcription factor overexpression in soybean (Glycine max L. Merrill). The present study aimed at investigating the taxonomic and functional profile of the leaf microbial community of bacteria found in GM (drought-tolerant event 1Ea2939) and conventional (BR 16) soybean plants. Bacterial DNA was extracted from leaf samples collected from each genotype and used for microbial diversity and richness analysis through the MiSeq Illumina platform. Functional prediction was performed using the PICRUSt tool and the STAMP v 2.1.3 software. The obtainment of the GM event 1Ea2939 showed minimum effects on the microbial community and in the potential for chemical-genetic communication, i.e. in the potential for symbiotic and/or mutualistic interaction between plants and their natural microbiota.


Asunto(s)
Proteínas de Arabidopsis/genética , Bacterias/clasificación , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/genética , Endófitos/clasificación , Glycine max/genética , Glycine max/microbiología , Microbiota , Hojas de la Planta/microbiología , Plantas Modificadas Genéticamente/genética , Arabidopsis/genética , Bacterias/genética , Bacterias/aislamiento & purificación , Biodiversidad , ADN Bacteriano/genética , Sequías , Endófitos/genética , Endófitos/aislamiento & purificación , Fabaceae/genética , Fabaceae/microbiología , Microbiota/genética , Filogenia , ARN Ribosómico 16S/genética , Microbiología del Suelo
13.
Arch Virol ; 162(11): 3535-3539, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-28808809

RESUMEN

The present report describes a case of splenic rupture due to dengue, a rare complication of dengue that should be considered in any patient with suspected dengue disease who started with left upper quadrant abdominal pain and hypotension. The pathophysiology of this entity is not yet well elucidated, but one of the theories present in the literature is that it is due to a depletion of coagulation factors and platelets leading to intra-splenic hemorrhage and rupture. The RT-PCR technique detected serotype 1 and histopathological studies of the spleen revealed significant atrophy of lymphoid follicles and extensive hemorrhage areas. Besides histopathological observations, virus replication was investigated by detection of dengue antigens, especially the non-structural 3 protein (NS3) in endothelial cells and splenic macrophages. This important complication has serious clinical repercussions and high mortality, due to the diagnostic difficulty and many factors that usually confuse or delay its diagnosis. Therefore, it is of the utmost importance to recognize their manifestations and their management to try to best minimize their consequences and mortality.


Asunto(s)
Dengue/complicaciones , Rotura del Bazo/etiología , Replicación Viral/fisiología , Humanos , Masculino , Rotura del Bazo/patología , Rotura del Bazo/cirugía , Adulto Joven
14.
J Oral Maxillofac Surg ; 75(4): 701-708, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-27816732

RESUMEN

PURPOSE: To determine whether gastric aspiration performed after orthognathic surgery, in conjunction with a prophylactic protocol, could prevent postoperative nausea and vomiting (PONV). PATIENTS AND METHODS: Twenty-four consecutive patients treated at a single academic institution were included in this double-blinded randomized control trial and were divided into control (n = 12) and study (n = 12) groups. Patients underwent orthognathic surgery, and the same anesthetic protocol was used for the 2 groups. The only difference between groups was the performance of gastric aspiration in the study group. Patients were observed during the first postoperative day, and information concerning PONV was collected and statistically analyzed. RESULTS: The 2 groups were similar in age, gender, and medical history. There was no statistically relevant difference between the control and study groups in the overall incidence of PONV (33.3 vs 33.3%). However, there was a significant correlation between the presence of PONV after turbinectomy (P = .011) and patient dissatisfaction (P = .049). CONCLUSION: The results of this study could not associate the performance of gastric aspiration with a decrease in the incidence of PONV after orthognathic surgery.


Asunto(s)
Procedimientos Quirúrgicos Ortognáticos , Náusea y Vómito Posoperatorios/prevención & control , Estómago , Succión/métodos , Adolescente , Adulto , Método Doble Ciego , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Resultado del Tratamiento
15.
Environ Monit Assess ; 189(2): 88, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-28144871

RESUMEN

The current study investigates the potential for discolouration and degradation of Reactive Blue 19 and Reactive Black 5 textile dyes by endophytic fungi Phlebia sp. and Paecilomyces formosus as well as the potential cytotoxicity of products or by-products generated by the treatments in fish erythrocytes. It was observed at 30 days that both endophytes showed biodegradation activity with 0.1 g mL-1 of dyes. P. formosus showed highest extracellular and intracellular protein content levels after the 15th day, and Phlebia sp. stands out for production of extracellular laccase, indicating that this enzyme may be associated with the decolouration capacity. The dyes showed toxic effects in fishes at 0.01 g mL-1 concentration, resulting in the appearance of micronuclei in erythrocyte cells. When degraded dyes treated by endophytes were tested, the frequency of micronuclei reduced approximately 20%, indicating the effectiveness of these endophytic in the treatment of textile dyes with less environmental impact, thus indicating a potential for application of these fungi in bioremediation process.


Asunto(s)
Basidiomycota/metabolismo , Biodegradación Ambiental , Colorantes/metabolismo , Monitoreo del Ambiente , Paecilomyces/metabolismo , Animales , Antraquinonas/efectos adversos , Antraquinonas/metabolismo , Colorantes/efectos adversos , Endófitos/metabolismo , Eritrocitos/efectos de los fármacos , Peces , Proteínas Fúngicas/metabolismo , Lacasa/metabolismo , Pruebas de Micronúcleos/veterinaria , Naftalenosulfonatos/efectos adversos , Naftalenosulfonatos/metabolismo , Industria Textil , Eliminación de Residuos Líquidos
16.
Microb Pathog ; 98: 16-22, 2016 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-27343372

RESUMEN

Guarana (Paullinia cupana var. sorbilis) is a plant from the Amazonas region with socio-economic importance. However, guarana production has been increasingly affected by unfavorable conditions resulting from anthracnose, caused by the Colletotrichum fungal genus, which primarily affects mainly the Amazonas region. The aim of the present study was to isolate bacterial endophytes from the seeds of guarana plants obtained from Amazonas region and the Northeast state of Bahia, a region where this disease is not a problem for guarana plantations. The number of bacterial Colony Forming Units (CFU/g seeds) was 2.4 × 10(4) from the Bahia and 2.9 × 10(4) from the Amazonas region. One hundred and two isolated bacteria were evaluated in vitro against the phytopathogenic strain Colletotrichum gloeosporioides L1. These isolates were also analyzed for the enzymatic production of amylase, cellulase, protease, pectinase, lipase and esterase. Approximately 15% of isolates, showing high antagonistic activity, and the production of at least one enzyme were identified through the partial sequencing of 16S rDNA. The genus Bacillus was the most frequently observed, followed by Paenibacillus, Ochrobactrum, Microbacterium and Stenotrophomonas. Proteolytic activity was observed in 24 isolates followed by amylolytic, pectinolytic and cellulolytic activities. No esterase and lipase production was detected. Most of the isolates, showing antagonistic effects against C. gloeosporioides and high enzymatic activities, were isolated from the anthracnose-affected region. A biocontrol method using the endophytes from guarana seeds could be applied in the future, as these bacteria are vertically transferred to guarana seedlings.


Asunto(s)
Antibiosis , Bacterias/clasificación , Bacterias/aislamiento & purificación , Colletotrichum/crecimiento & desarrollo , Endófitos/clasificación , Endófitos/aislamiento & purificación , Paullinia/microbiología , Bacterias/genética , Carga Bacteriana , Biodiversidad , Brasil , Análisis por Conglomerados , Recuento de Colonia Microbiana , ADN Bacteriano/química , ADN Bacteriano/genética , ADN Ribosómico/química , ADN Ribosómico/genética , Endófitos/genética , Endófitos/fisiología , Enzimas/análisis , Control Biológico de Vectores/métodos , Filogenia , Enfermedades de las Plantas/prevención & control , ARN Ribosómico 16S/genética , Semillas/microbiología , Análisis de Secuencia de ADN
17.
Genet Mol Biol ; 39(4): 476-491, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27727362

RESUMEN

The bacterium Xylella fastidiosa is the causal agent of citrus variegated chlorosis (CVC) and has been associated with important losses in commercial orchards of all sweet orange [Citrus sinensis (L.)] cultivars. The development of this disease depends on the environmental conditions, including the endophytic microbial community associated with the host plant. Previous studies have shown that X. fastidiosa interacts with the endophytic community in xylem vessels as well as in the insect vector, resulting in a lower bacterial population and reduced CVC symptoms. The citrus endophytic bacterium Methylobacterium mesophilicum can trigger X. fastidiosa response in vitro, which results in reduced growth and induction of genes associated with energy production, stress, transport, and motility, indicating that X. fastidiosa has an adaptive response to M. mesophilicum. Although this response may result in reduced CVC symptoms, the colonization rate of the endophytic bacteria should be considered in studies that intend to use this endophyte to suppress CVC disease. Symbiotic control is a new strategy that uses symbiotic endophytes as biological control agents to antagonize or displace pathogens. Candidate endophytes for symbiotic control of CVC must occupy the xylem of host plants and attach to the precibarium of sharpshooter insects to access the pathogen. In the present review, we focus on interactions between endophytic bacteria from sweet orange plants and X. fastidiosa, especially those that may be candidates for control of CVC.

18.
Angew Chem Int Ed Engl ; 55(25): 7142-7, 2016 06 13.
Artículo en Inglés | MEDLINE | ID: mdl-27151516

RESUMEN

The intermittent nature of the sunlight and its increasing contribution to electricity generation is fostering the energy storage research. Direct solar charging of an auspicious type of redox flow battery could make solar energy directly and efficiently dispatchable. The first solar aqueous alkaline redox flow battery using low cost and environmentally safe materials is demonstrated. The electrolytes consist of the redox couples ferrocyanide and anthraquinone-2,7-disulphonate in sodium hydroxide solution, yielding a standard cell potential of 0.74 V. Photovoltage enhancement strategies are demonstrated for the ferrocyanide-hematite junction by employing an annealing treatment and growing a layer of a conductive polyaniline polymer on the electrode surface, which decreases electron-hole recombination.

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