Search

Forest ecosystems worldwide currently face worrying episodes of forest decline, which have boosted weakening and mortality of the trees. In the Mediterranean region, especially in the southeast Iberian Peninsula, Pinus sylvestris forests are severely affected by this phenomenon, and it has been commonly attributed to drought events. Remarkably, the role of root microbiota on pine decline has been overlooked and remains unclear. We therefore used metabarcoding to identify the belowground microbial communities of decline-affected and unaffected pine trees. Taxonomic composition of bacterial and fungal rhizosphere communities, and fungal populations dwelling in root endosphere showed different profiles depending on the health status of the trees. The root endosphere of asymptomatic trees was as strongly dominated by 'Candidatus Phytoplasma pini' as the root of decline-affected pines, accounting for >99 % of the total bacterial sequences in some samples. Notwithstanding, the titer of this phytopathogen was four-fold higher in symptomatic trees than in symptomless ones. Furthermore, the microbiota inhabiting the root endosphere of decline-affected trees assembled into a less complex and more modularized network. Thus, the observed changes in the microbial communities could be a cause or a consequence of forest decline phenomenon. Moreover, 'Ca. Phytoplasma pini' is positively correlated to Pinus sylvestris decline events, either as the primary cause of pine decline or as an opportunistic pathogen exacerbating the process once the tree has been weaken by other factors.

[EN] This paper aims to analyse the level of commitment with the SDGs of large Spanish companies based on the information published in their Non-Financial Statements and their letters from the chairman. To achieve this objective and identify potential explanatory factors, a balanced sample of 58 Spanish companies, 29 listed and 29 unlisted, in 2019 has been used. The results of this study evidence: i) the greater commitment with the SDGs of companies which are exposed in the stock markets and those which are larger; ii) the relevance of the diversity into the boards of directors, in order to integrate the largest and the widest number of interests as well as those values and principles which are intrinsically associated to women directors; and iii) the greater emphasis on those SDGs related to well-known issues by these organizations, thanks to their greater experience in non-financial reporting, publishing documents such as corporate social responsibility or sustainability reports., [ES] El presente trabajo tiene como principal objetivo evaluar el nivel de compromiso con los Objetivos de Desarrollo Sostenible (ODS) de las grandes empresas españolas a partir de la información contenida en sus Estados de Información No Financiera (EINF) y las cartas de sus presidentes e identificar los posibles factores explicativos asociados a la propia organización. Para ello se ha contado con una muestra equilibrada de 58 compañías españolas, 29 cotizadas y 29 no cotizadas, en el ejercicio 2019. Los resultados obtenidos ponen de relieve: i) la mayor preocupación que despiertan los ODS entre las empresas expuestas en los mercados bursátiles y aquellas que son de mayor tamaño; ii) la importancia de contar con consejos de administración diversos, que integren el mayor número de intereses posibles así como aquellos valores y principios que se atribuyen de forma intrínseca a las mujeres; y iii) el mayor énfasis en aquellos ODS relacionados con aquellas temáticas ya conocidas por este tipo de organizaciones, gracias a su mayor experiencia en el reporting no financiero, publicando documentos como los informes de responsabilidad social corporativa o las memorias de sostenibilidad.

Background: The complex and co-evolved interplay between plants and their microbiota is crucial for the health and fitness of the plant holobiont. However, the microbiota of the seeds is still relatively unexplored and no studies have been conducted with olive trees so far. In this study, we aimed to characterize the bacterial, fungal and archaeal communities present in seeds of ten olive genotypes growing in the same orchard through amplicon sequencing to test whether the olive genotype is a major driver in shaping the seed microbial community, and to identify the origin of the latter. Therefore, we have developed a methodology for obtaining samples from the olive seed’s endosphere under sterile conditions. Results: A diverse microbiota was uncovered in olive seeds, the plant genotype being an important factor influencing the structure and composition of the microbial communities. The most abundant bacterial phylum was Actinobacteria, accounting for an average relative abundance of 41%. At genus level, Streptomyces stood out because of its potential influence on community structure. Within the fungal community, Basidiomycota and Ascomycota were the most abundant phyla, including the genera Malassezia, Cladosporium, and Mycosphaerella. The shared microbiome was composed of four bacterial (Stenotrophomonas, Streptomyces, Promicromonospora and Acidipropionibacterium) and three fungal (Malassezia, Cladosporium and Mycosphaerella) genera. Furthermore, a comparison between findings obtained here and earlier results from the root endosphere of the same trees indicated that genera such as Streptomyces and Malassezia were present in both olive compartments. Conclusions: This study provides the first insights into the composition of the olive seed microbiota. The highly abundant fungal genus Malassezia and the bacterial genus Streptomyces reflect a unique signature of the olive seed microbiota. The genotype clearly shaped the composition of the seed’s microbial community, al

Verticillium wilt of olive (VWO), caused by Verticillium dahliae, is a major concern in many olive-growing countries. An efficient VWO control measure is the use of tolerant/resistant cultivars. Low information is available about olive secondary metabolites and its relationship with VWO tolerance. In this study, a comprehensive metabolic profiling of the roots of six olive cultivars differing in their level of tolerance/susceptibility to VWO was addressed. Potential changes in the metabolite profiles due to the presence of the pathogen were also assessed. A strong relationship between the quantitative basal composition of the root secondary metabolic profile and VWO tolerance/susceptibility of olive varieties was found. Tolerant cultivars showed higher content of secoiridoids, while the susceptible ones presented greater amounts of verbascoside and methoxypinoresinol glucoside. The presence of V. dahliae only caused few significant variations mostly restricted to the earliest times after inoculation. Thus, a rapid activation of biochemical-based root defense mechanisms was observed. Key policy highlights Quantitative differences of secondary metabolites in roots contribute to explain the tolerance/susceptibility of olive cultivars to Verticillium dahliae. Higher basal content of secoiridoids correlate with tolerance, while greater concentration of verbascoside and methoxypinoresinol glucoside seem to be linked to susceptibility. Few alterations are observed in the olive root metabolic profiles in the presence of the pathogen. Changes in the root metabolic profile occur at early times after pathogen inoculation which suggests a rapid activation of a biochemical-based defense response against V. dahliae. Quantitative differences of secondary metabolites in roots contribute to explain the tolerance/susceptibility of olive cultivars to Verticillium dahliae. Higher basal content of secoiridoids correlate with tolerance, while greater concentration of verbascoside and met

Verticillium wilt of olive (VWO), caused by the soil borne fungus Verticillium dahliae, is one of the most relevant diseases affecting this crop worldwide. One of the best VWO management strategies is the use of tolerant cultivars. Scarce information is available about physiological and structural responses in the leaves of olive cultivars displaying different levels of tolerance to VWO. To identify links between this phenotype and variations in functional characteristics of the leaves, this study examined the structural and physiological traits and the correlations among them in different olive varieties. This evaluation was conducted in the presence/absence of V. dahliae. On the one hand, no leaf trait but the area was related to VWO tolerance in the absence of the pathogen. On the other hand, after inoculation, susceptible cultivars showed lower leaf area and higher leaf mass per area and dry matter content. Furthermore, at the physiological level, these plants showed severe symptoms resembling water stress. Analyzing the relationships among physiological and structural traits revealed differences between tolerant and susceptible cultivars both in the absence and in the presence of V. dahliae. These results showed that olive leaves of VWO-tolerant and VWO-susceptible cultivars adopt different strategies to cope with the pathogen.

Background: Verticillium wilt of olive (VWO), caused by Verticillium dahliae Kleb, is one of the most threatening diseases affecting olive cultivation. An integrated disease management strategy is recommended for the effective control of VWO. Within this framework, the use of biological control agents (BCAs) is a sustainable and environmentally friendly approach. No studies are available on the impact that the introduction of BCAs has on the resident microbiota of olive roots. Pseudomonas simiae PICF7 and Paenibacillus polymyxa PIC73 are two BCAs effective against VWO. We examined the effects of the introduction of these BCAs on the structure, composition and co-occurrence networks of the olive (cv. Picual) root-associated microbial communities. The consequences of the subsequent inoculation with V. dahliae on BCA-treated plants were also assessed. Results: Inoculation with any of the BCAs did not produce significant changes in the structure or the taxonomic composition of the ‘Picual’ root-associated microbiota. However, significant and distinctive alterations were observed in the topologies of the co-occurrence networks. The introduction of PIC73 provoked a diminution of positive interactions within the ‘Picual’ microbial community; instead, PICF7 inoculation increased the microbiota’s compartmentalization. Upon pathogen inoculation, the network of PIC73-treated plants decreased the number of interactions and showed a switch of keystone species, including taxa belonging to minor abundant phyla (Chloroflexi and Planctomycetes). Conversely, the inoculation of V. dahliae in PICF7-treated plants significantly increased the complexity of the network and the number of links among their modules, suggestive of a more stable network. No changes in their keystone taxa were detected. Conclusion: The absence of significant modifications on the structure and composition of the ‘Picual’ belowground microbiota due to the introduction of the tested BCAs underlines the low/null en

Verticillium wilt of olive (VWO), caused by Verticillium dahliae, is a major concern in many olive-growing countries. An efficient VWO control measure is the use of tolerant/resistant cultivars. Low information is available about olive secondary metabolites and its relationship with VWO tolerance. In this study, a comprehensive metabolic profiling of the roots of six olive cultivars differing in their level of tolerance/susceptibility to VWO was addressed. Potential changes in the metabolite profiles due to the presence of the pathogen were also assessed. A strong relationship between the quantitative basal composition of the root secondary metabolic profile and VWO tolerance/susceptibility of olive varieties was found. Tolerant cultivars showed higher content of secoiridoids, while the susceptible ones presented greater amounts of verbascoside and methoxypinoresinol glucoside. The presence of V. dahliae only caused few significant variations mostly restricted to the earliest times after inoculation. Thus, a rapid activation of biochemical-based root defense mechanisms was observed.

Nowadays, Ni@C nanostructured materials are attracting a great deal of attention due to their multiple catalytic or magnetic functionalities. In this article we report on the investigation of the correlation between the microstructure and magnetic properties of Ni nanoparticles embedded in a carbon matrix. The samples were obtained following a two-step procedure that ensures protection against nanoparticle oxidation, and was carried out in the following way: (i) the synthesis of a nickel-imidazole-based metal-organic framework (MOF) by a simple method in an aqueous medium at moderate temperature (95 °C); and (ii) carbonization of the MOF at different temperatures between 400 and 600 °C to obtain a carbon-supported hybrid material, containing Ni nanoparticles with an “artichoke-like” morphology, where a Ni-FCC core is surrounded by “bracts” of Ni-HCP and Ni3C. The average size of the nanoparticle slightly changes from 7 to 10 nm as the carbonization temperature is increased, but the Ni-FCC core diameter ranges from 3 to around 6 nm. We show how the information obtained on the evolution of the magnetic behaviour with carbonization temperature, using X-ray diffraction and electron microscopy, complements each other by providing consistent structural and magnetic characteristics of the investigated Ni@C nanoparticles. In fact, this joint analysis allows us to explain the formation and transformation of different Ni-based crystalline phases along the synthesis process, including Ni3C and Ni with both hexagonal and cubic crystalline structures. The amount of conventional Ni-FCC is below 10 wt% for the sample treated at 400 °C and it can reach up to 50 wt% for that treated at 600 °C. Finally, based on our current findings we propose an explanation for understanding the magnetic properties of Ni@C, in which the Ni-FCC core spins mainly govern the magnetic coupling of the whole system.

Soil health and root-associated microbiome are interconnected factors involved in plant health. The use of manure amendment on agricultural fields exerts a direct benefit on soil nutrient content and water retention, among others. However, little is known about the impact of manure amendment on the root-associated microbiome, particularly in woody species. In this study, we aimed to evaluate the effects of ovine manure on the microbial communities of the olive rhizosphere and root endosphere. Two adjacent orchards subjected to conventional (CM) and organic (OM) management were selected. We used metabarcoding sequencing to assess the bacterial and fungal communities. Our results point out a clear effect of manure amendment on the microbial community. Fungal richness and diversity were increased in the rhizosphere. The fungal biomass in the rhizosphere was more than doubled, ranging from 1.72 × 10 ± 1.62 × 10 (CM) to 4.54 × 10 ± 8.07 × 10 (OM) copies of the 18 S rRNA gene g soil. Soil nutrient content was also enhanced in the OM orchard. Specifically, oxidable organic matter, total nitrogen, nitrate, phosphorous, potassium and sulfate concentrations were significantly increased in the OM orchard. Moreover, we predicted a higher abundance of bacteria in OM with metabolic functions involved in pollutant degradation and defence against pathogens. Lastly, microbial co-occurrence network showed more positive interactions, complexity and shorter geodesic distance in the OM orchard. According to our results, manure amendment on olive orchards represents a promising tool for positively modulating the microbial community in direct contact with the plant.

The holobiont concept has revolutionized our understanding of plant-associated microbiomes and their significance for the development, fitness, growth and resilience of their host plants. The olive tree holds an iconic status within the Mediterranean Basin. Innovative changes introduced in olive cropping systems, driven by the increasing demand of its derived products, are not only modifying the traditional landscape of this relevant commodity but may also imply that either traditional or emerging stresses can affect it in ways yet to be thoroughly investigated. Incomplete information is currently available about the impact of abiotic and biotic pressures on the olive holobiont, what includes the specific features of its associated microbiome in relation to the host’s structural, chemical, genetic and physiological traits. This comprehensive review consolidates the existing knowledge about stress factors affecting olive cultivation and compiles the information available of the microbiota associated with different olive tissues and organs. We aim to offer, based on the existing evidence, an insightful perspective of diverse stressing factors that may disturb the structure, composition and network interactions of the olive-associated microbial communities, underscoring the importance to adopt a more holistic methodology. The identification of knowledge gaps emphasizes the need for multilevel research approaches and to consider the holobiont conceptual framework in future investigations. By doing so, more powerful tools to promote olive’s health, productivity and resilience can be envisaged. These tools may assist in the designing of more sustainable agronomic practices and novel breeding strategies to effectively face evolving environmental challenges and the growing demand of high quality food products.

We consider a real discrete pricing problem in network revenue management for FlixBus. We improve the company's current pricing policy by an intermediate optimization step using booking limits from standard deterministic linear programs. We pay special attention to computational efficiency. FlixBus' strategic decision to allow for low-cost refunds might encourage large group bookings early in the booking process. In this context, we discuss counter-intuitive findings comparing booking limits with static bid price policies. We investigate the theoretical question whether the standard deterministic linear program for network revenue management does provide an upper bound on the optimal expected revenue if customer's willingness to pay varies over time.

La búsqueda de la innovación constante, el “reinventarse o morir”, resumen a grandes rasgos el espíritu de todo emprendedor a la hora de impulsar su Startup. Estos emprendedores tendrán que aprovechar las oportunidades que les brindan las nuevas tecnologías para conseguir alcanzar esa idea innovadora de negocio. Con la realización de este trabajo se pretende dar una visión de algunos de los aspectos más relevantes del ecosistema Startup. El trabajo de investigación consta de tres partes: Una primera parte introductoria donde el lector sabrá cuáles van a ser las líneas generales del trabajo, dándole una pequeña visión acerca de lo que es el emprendimiento. Trataremos de dar una justificación del porqué de la elección de este tema y la metodología que hemos seguido para la elaboración de todos los puntos. En la segunda parte, comenzamos con una aproximación al origen de las Startups y continuaremos con la definición y principales características de este tipo de empresas que la hacen tan innovadoras y diferenciadoras del resto. Conocer cómo las fases por las que pasan a lo largo de su ciclo de vida y los métodos de financiación que van utilizando o necesitando, resultará imprescindible para entender mucho mejor su comportamiento y necesidades. Se destacan algunos de los principales sectores en los que operan, ya que, a la hora de pensar en el emprendimiento, será importante saber cuáles están en expansión. A través del estudio del ecosistema Startup en nuestro país, con una pequeña aportación acerca de cómo es el empleo en esta tipología de empresas, se pretende dar una visión general de cómo se encuentra en nuestro país el avance indiscutible de estas empresas. Por último, hemos considerado importante aportar un estudio acerca del uso de la metodología Lean Startup como elemento clave para tener los conocimientos necesarios para emprender. En la tercera parte, terminaremos con las conclusiones a las que hemos llegado con la realización de este trabajo., Grado en Administración y Dirección de Empresas

La búsqueda de la innovación constante, el “reinventarse o morir”, resumen a grandes rasgos el espíritu de todo emprendedor a la hora de impulsar su Startup. Estos emprendedores tendrán que aprovechar las oportunidades que les brindan las nuevas tecnologías para conseguir alcanzar esa idea innovadora de negocio. Con la realización de este trabajo se pretende dar una visión de algunos de los aspectos más relevantes del ecosistema Startup. El trabajo de investigación consta de tres partes: Una primera parte introductoria donde el lector sabrá cuáles van a ser las líneas generales del trabajo, dándole una pequeña visión acerca de lo que es el emprendimiento. Trataremos de dar una justificación del porqué de la elección de este tema y la metodología que hemos seguido para la elaboración de todos los puntos. En la segunda parte, comenzamos con una aproximación al origen de las Startups y continuaremos con la definición y principales características de este tipo de empresas que la hacen tan innovadoras y diferenciadoras del resto. Conocer cómo las fases por las que pasan a lo largo de su ciclo de vida y los métodos de financiación que van utilizando o necesitando, resultará imprescindible para entender mucho mejor su comportamiento y necesidades. Se destacan algunos de los principales sectores en los que operan, ya que, a la hora de pensar en el emprendimiento, será importante saber cuáles están en expansión. A través del estudio del ecosistema Startup en nuestro país, con una pequeña aportación acerca de cómo es el empleo en esta tipología de empresas, se pretende dar una visión general de cómo se encuentra en nuestro país el avance indiscutible de estas empresas. Por último, hemos considerado importante aportar un estudio acerca del uso de la metodología Lean Startup como elemento clave para tener los conocimientos necesarios para emprender. En la tercera parte, terminaremos con las conclusiones a las que hemos llegado con la realización de este trabajo., Grado en Administración y Dirección de Empresas

La búsqueda de la innovación constante, el “reinventarse o morir”, resumen a grandes rasgos el espíritu de todo emprendedor a la hora de impulsar su Startup. Estos emprendedores tendrán que aprovechar las oportunidades que les brindan las nuevas tecnologías para conseguir alcanzar esa idea innovadora de negocio. Con la realización de este trabajo se pretende dar una visión de algunos de los aspectos más relevantes del ecosistema Startup. El trabajo de investigación consta de tres partes: Una primera parte introductoria donde el lector sabrá cuáles van a ser las líneas generales del trabajo, dándole una pequeña visión acerca de lo que es el emprendimiento. Trataremos de dar una justificación del porqué de la elección de este tema y la metodología que hemos seguido para la elaboración de todos los puntos. En la segunda parte, comenzamos con una aproximación al origen de las Startups y continuaremos con la definición y principales características de este tipo de empresas que la hacen tan innovadoras y diferenciadoras del resto. Conocer cómo las fases por las que pasan a lo largo de su ciclo de vida y los métodos de financiación que van utilizando o necesitando, resultará imprescindible para entender mucho mejor su comportamiento y necesidades. Se destacan algunos de los principales sectores en los que operan, ya que, a la hora de pensar en el emprendimiento, será importante saber cuáles están en expansión. A través del estudio del ecosistema Startup en nuestro país, con una pequeña aportación acerca de cómo es el empleo en esta tipología de empresas, se pretende dar una visión general de cómo se encuentra en nuestro país el avance indiscutible de estas empresas. Por último, hemos considerado importante aportar un estudio acerca del uso de la metodología Lean Startup como elemento clave para tener los conocimientos necesarios para emprender. En la tercera parte, terminaremos con las conclusiones a las que hemos llegado con la realización de este trabajo., Grado en Administración y Dirección de Empresas

La búsqueda de la innovación constante, el “reinventarse o morir”, resumen a grandes rasgos el espíritu de todo emprendedor a la hora de impulsar su Startup. Estos emprendedores tendrán que aprovechar las oportunidades que les brindan las nuevas tecnologías para conseguir alcanzar esa idea innovadora de negocio. Con la realización de este trabajo se pretende dar una visión de algunos de los aspectos más relevantes del ecosistema Startup. El trabajo de investigación consta de tres partes: Una primera parte introductoria donde el lector sabrá cuáles van a ser las líneas generales del trabajo, dándole una pequeña visión acerca de lo que es el emprendimiento. Trataremos de dar una justificación del porqué de la elección de este tema y la metodología que hemos seguido para la elaboración de todos los puntos. En la segunda parte, comenzamos con una aproximación al origen de las Startups y continuaremos con la definición y principales características de este tipo de empresas que la hacen tan innovadoras y diferenciadoras del resto. Conocer cómo las fases por las que pasan a lo largo de su ciclo de vida y los métodos de financiación que van utilizando o necesitando, resultará imprescindible para entender mucho mejor su comportamiento y necesidades. Se destacan algunos de los principales sectores en los que operan, ya que, a la hora de pensar en el emprendimiento, será importante saber cuáles están en expansión. A través del estudio del ecosistema Startup en nuestro país, con una pequeña aportación acerca de cómo es el empleo en esta tipología de empresas, se pretende dar una visión general de cómo se encuentra en nuestro país el avance indiscutible de estas empresas. Por último, hemos considerado importante aportar un estudio acerca del uso de la metodología Lean Startup como elemento clave para tener los conocimientos necesarios para emprender. En la tercera parte, terminaremos con las conclusiones a las que hemos llegado con la realización de este trabajo., Grado en Administración y Dirección de Empresas

The impact of the versatile biocontrol and plant-growth-promoting rhizobacteria Pseudomonas simiae PICF7 on the banana holobiont under controlled conditions was investigated. We examine the fate of this biological control agent (BCA) upon introduction in the soil, the effect on the banana root microbiota, and the influence on specific host genetic defense responses. While the presence of strain PICF7 significantly altered neither the composition nor the structure of the root microbiota, a significant shift in microbial community interactions through co-occurrence network analysis was observed. Despite the fact that PICF7 did not constitute a keystone, the topology of this network was significantly modified—the BCA being identified as a constituent of one of the main network modules in bacterized plants. Gene expression analysis showed the early suppression of several systemic acquired resistance and induced systemic resistance (ISR) markers. This outcome occurred at the time in which the highest relative abundance of PICF7 was detected. The absence of major and permanent changes on the banana holobiont upon PICF7 introduction poses advantages regarding the use of this beneficial rhizobacteria under field conditions. Indeed a BCA able to control the target pathogen while altering as little as possible the natural host-associated microbiome should be a requisite when developing effective bio-inoculants.

Fusarium oxysporum f. sp. cubense (Foc) tropical race 4 (TR4) is threatening banana production because of its increasing spread. Biological control approaches have been widely studied and constitute interesting complementary measures to integrated disease management strategies. They have been based mainly on the use of single biological control agents (BCAs). In this study, we moved a step forward by designing a synthetic microbial community (SynCom) for the control of Fusarium wilt of banana (FWB). Ninety-six isolates of Pseudomonas spp., Bacillus spp., Streptomyces spp., and Trichoderma spp. were obtained from the banana rhizosphere and selected in vitro for the antagonism against Foc TR4. In pot experiments, a large community such as SynCom 1.0 (44 isolates with moderate to high antagonistic activity) or a small one such as SynCom 1.1 (seven highly effective isolates) provided similar disease control (35% symptom severity reduction). An in vitro study of the interactions among SynCom 1.1 isolates and between them and Foc revealed that beneficial microorganisms not only antagonized the pathogen but also some of the SynCom constituents. Furthermore, Foc defended itself by antagonizing the beneficial microbes. We also demonstrated that fusaric acid, known as one of the secondary metabolites of Fusarium species, might be involved in such an interaction. With this knowledge, SynCom 1.2 was then designed with three isolates: Pseudomonas chlororaphis subsp. piscium PS5, Bacillus velezensis BN8.2, and Trichoderma virens T2C1.4. A non-simultaneous soil application of these isolates (to diminish cross-inhibition) delayed FWB progress over time, with significant reductions in incidence and severity. SynCom 1.2 also performed better than two commercial BCAs, BioPak® and T-Gro. Eventually, SynCom 1.2 isolates were characterized for several biocontrol traits and their genome was sequenced. Our data showed that assembling a SynCom for biocontrol is not an easy task. The mere mi

The impact of the versatile biocontrol and plant-growth-promoting rhizobacteria Pseudomonas simiae PICF7 on the banana holobiont under controlled conditions was investigated. We examine the fate of this biological control agent (BCA) upon introduction in the soil, the effect on the banana root microbiota, and the influence on specific host genetic defense responses. While the presence of strain PICF7 significantly altered neither the composition nor the structure of the root microbiota, a significant shift in microbial community interactions through co-occurrence network analysis was observed. Despite the fact that PICF7 did not constitute a keystone, the topology of this network was significantly modified—the BCA being identified as a constituent of one of the main network modules in bacterized plants. Gene expression analysis showed the early suppression of several systemic acquired resistance and induced systemic resistance (ISR) markers. This outcome occurred at the time in which the highest relative abundance of PICF7 was detected. The absence of major and permanent changes on the banana holobiont upon PICF7 introduction poses advantages regarding the use of this beneficial rhizobacteria under field conditions. Indeed a BCA able to control the target pathogen while altering as little as possible the natural host-associated microbiome should be a requisite when developing effective bio-inoculants.

The impact of the versatile biocontrol and plant-growth-promoting rhizobacteria Pseudomonas simiae PICF7 on the banana holobiont under controlled conditions was investigated. We examine the fate of this biological control agent (BCA) upon introduction in the soil, the effect on the banana root microbiota, and the influence on specific host genetic defense responses. While the presence of strain PICF7 significantly altered neither the composition nor the structure of the root microbiota, a significant shift in microbial community interactions through co-occurrence network analysis was observed. Despite the fact that PICF7 did not constitute a keystone, the topology of this network was significantly modified—the BCA being identified as a constituent of one of the main network modules in bacterized plants. Gene expression analysis showed the early suppression of several systemic acquired resistance and induced systemic resistance (ISR) markers. This outcome occurred at the time in which the highest relative abundance of PICF7 was detected. The absence of major and permanent changes on the banana holobiont upon PICF7 introduction poses advantages regarding the use of this beneficial rhizobacteria under field conditions. Indeed a BCA able to control the target pathogen while altering as little as possible the natural host-associated microbiome should be a requisite when developing effective bio-inoculants.

Fusarium oxysporum f. sp. cubense (Foc) tropical race 4 (TR4) is threatening banana production because of its increasing spread. Biological control approaches have been widely studied and constitute interesting complementary measures to integrated disease management strategies. They have been based mainly on the use of single biological control agents (BCAs). In this study, we moved a step forward by designing a synthetic microbial community (SynCom) for the control of Fusarium wilt of banana (FWB). Ninety-six isolates of Pseudomonas spp., Bacillus spp., Streptomyces spp., and Trichoderma spp. were obtained from the banana rhizosphere and selected in vitro for the antagonism against Foc TR4. In pot experiments, a large community such as SynCom 1.0 (44 isolates with moderate to high antagonistic activity) or a small one such as SynCom 1.1 (seven highly effective isolates) provided similar disease control (35% symptom severity reduction). An in vitro study of the interactions among SynCom 1.1 isolates and between them and Foc revealed that beneficial microorganisms not only antagonized the pathogen but also some of the SynCom constituents. Furthermore, Foc defended itself by antagonizing the beneficial microbes. We also demonstrated that fusaric acid, known as one of the secondary metabolites of Fusarium species, might be involved in such an interaction. With this knowledge, SynCom 1.2 was then designed with three isolates: Pseudomonas chlororaphis subsp. piscium PS5, Bacillus velezensis BN8.2, and Trichoderma virens T2C1.4. A non-simultaneous soil application of these isolates (to diminish cross-inhibition) delayed FWB progress over time, with significant reductions in incidence and severity. SynCom 1.2 also performed better than two commercial BCAs, BioPak® and T-Gro. Eventually, SynCom 1.2 isolates were characterized for several biocontrol traits and their genome was sequenced. Our data showed that assembling a SynCom for biocontrol is not an easy task. The mere mi

The aim of this study was to figure out the influence of manure amendment on the radicular (rhizosphere and root endosphere) microbial communities from olive trees. For this purpose, two adjacent olive orchards with different soil managements were surveyed: i) traditional management (TM) and ii) with manure amendment (MA). TM orchard was subjected to common agriculture procedures (including herbicides, mechanical plough and pesticides treatments), while MA cultivar did not receive any herbicides treatment, but a manure amendment was applied to the soil. For each orchard, 12 replicates (trees) were considered for analysis, all of them belonging to Picual variety. From each replicate and microhabitat, both bacterial and fungal communities were studied with the use of amplicon sequencing (pairedend 2x300-bp [PE 300] with the Illumina MiSeq platform). Raw reads were processed following our own tutorial, recently published in GitHub (https://nuriamw.github.io/micro4all/) and also available as an R package (micro4all). This tutorial includes analysis for ASV inferring with DADA2, ¿ and ß-diversity (index calculation, graphical representation and statistical analysis), differential abundance analysis with ANCOM-BC and taxonomical profiling (plots and tables). Moreover, microbial ecological networks were also studied with MENAP online tool. Our results showed that a higher fungal diversity was found in MA rhizosphere. However, no statistically significant differences were found for bacterial community at rhizosphere level, neither for fungal or bacterial endosphere community. Interestingly, community structure (ß-diversity) seemed to differ for both microhabitats (rhizosphere and root endosphere) and kingdoms (bacteria and fungi). Furthermore, network analysis showed that in both compartments TM microbial communities had closer interactions (i.e., a shorter geodesic distance) as well as a greater percentage of positive links. Regarding taxonomical profiles, it should be hig

Bulk Cr2O3 is an antiferromagnetic (AFM) oxide that exhibits the magnetoelectric effect at room temperature, with neither spontaneous magnetization nor net electric polarization. These physical properties stem from a subtle competition between exchange and crystal field interactions. In this article, we exploit the symmetry breaking at the surface of Cr2O3 nanoparticles for unbalancing this delicate physical equilibrium. The emerging weak ferromagnetic signal we observe persists up to near room temperature (≈ 270 K) at which the antiferromagnetic order disappears. In addition, an exchange-bias effect, that rapidly decreases on heating from low temperature up to 30 K, is resistant to thermal disorder above 200 K. Our findings point to the possible formation of an entangled core/shell magnetic structure, where pinned uncompensated spins at the shell are randomly distributed in a low-temperature spin-glass ordering, with low net magnetic moment and an ordering temperature governed by the AFM Néel temperature.

The impact of the versatile biocontrol and plant-growth-promoting rhizobacteria Pseudomonas simiae PICF7 on the banana holobiont under controlled conditions was investigated. We examine the fate of this biological control agent (BCA) upon introduction in the soil, the effect on the banana root microbiota, and the influence on specific host genetic defense responses. While the presence of strain PICF7 significantly altered neither the composition nor the structure of the root microbiota, a significant shift in microbial community interactions through co-occurrence network analysis was observed. Despite the fact that PICF7 did not constitute a keystone, the topology of this network was significantly modified—the BCA being identified as a constituent of one of the main network modules in bacterized plants. Gene expression analysis showed the early suppression of several systemic acquired resistance and induced systemic resistance (ISR) markers. This outcome occurred at the time in which the highest relative abundance of PICF7 was detected. The absence of major and permanent changes on the banana holobiont upon PICF7 introduction poses advantages regarding the use of this beneficial rhizobacteria under field conditions. Indeed a BCA able to control the target pathogen while altering as little as possible the natural host-associated microbiome should be a requisite when developing effective bio-inoculants.

The production of volatile organic compounds (VOCs) represents a promising strategy of plant-beneficial bacteria to control soil-borne phytopathogens. Pseudomonas sp. PICF6 and Pseudomonas simiae PICF7 are two indigenous inhabitants of olive roots displaying effective biological control against Verticillium dahliae. Additionally, strain PICF7 is able to promote the growth of barley and Arabidopsis thaliana, VOCs being involved in the growth of the latter species. In this study, the antagonistic capacity of these endophytic bacteria against relevant phytopathogens (Verticillium spp., Rhizoctonia solani, Sclerotinia sclerotiorum and Fusarium oxysporum f.sp. lycopersici) was assessed. Under in vitro conditions, PICF6 and PICF7 were only able to antagonize representative isolates of V. dahliae and V. longisporum. Remarkably, both strains produced an impressive portfolio of up to twenty VOCs, that included compounds with reported antifungal (e.g., 1-undecene, (methyldisulfanyl) methane and 1-decene) or plant growth promoting (e.g., tridecane, 1-decene) activities. Moreover, their volatilomes differed strongly in the absence and presence of V. dahliae. For example, when co incubated with the defoliating pathotype of V. dahliae, the antifungal compound 4-methyl-2,6-bis(2-methyl-2-propanyl)phenol was produced. Results suggest that volatiles emitted by these endophytes may differ in their modes of action, and that potential benefits for the host needs further investigation in planta.

Fusarium oxysporum f. sp. cubense (Foc) tropical race 4 (TR4) is threatening banana production because of its increasing spread. Biological control approaches have been widely studied and constitute interesting complementary measures to integrated disease management strategies. They have been based mainly on the use of single biological control agents (BCAs). In this study, we moved a step forward by designing a synthetic microbial community (SynCom) for the control of Fusarium wilt of banana (FWB). Ninety-six isolates of Pseudomonas spp., Bacillus spp., Streptomyces spp., and Trichoderma spp. were obtained from the banana rhizosphere and selected in vitro for the antagonism against Foc TR4. In pot experiments, a large community such as SynCom 1.0 (44 isolates with moderate to high antagonistic activity) or a small one such as SynCom 1.1 (seven highly effective isolates) provided similar disease control (35% symptom severity reduction). An in vitro study of the interactions among SynCom 1.1 isolates and between them and Foc revealed that beneficial microorganisms not only antagonized the pathogen but also some of the SynCom constituents. Furthermore, Foc defended itself by antagonizing the beneficial microbes. We also demonstrated that fusaric acid, known as one of the secondary metabolites of Fusarium species, might be involved in such an interaction. With this knowledge, SynCom 1.2 was then designed with three isolates: Pseudomonas chlororaphis subsp. piscium PS5, Bacillus velezensis BN8.2, and Trichoderma virens T2C1.4. A non-simultaneous soil application of these isolates (to diminish cross-inhibition) delayed FWB progress over time, with significant reductions in incidence and severity. SynCom 1.2 also performed better than two commercial BCAs, BioPak® and T-Gro. Eventually, SynCom 1.2 isolates were characterized for several biocontrol traits and their genome was sequenced. Our data showed that assembling a SynCom for biocontrol is not an easy task. The mere mi

Fusarium oxysporum f. sp. cubense (Foc) tropical race 4 (TR4) is threatening banana production because of its increasing spread. Biological control approaches have been widely studied and constitute interesting complementary measures to integrated disease management strategies. They have been based mainly on the use of single biological control agents (BCAs). In this study, we moved a step forward by designing a synthetic microbial community (SynCom) for the control of Fusarium wilt of banana (FWB). Ninety-six isolates of Pseudomonas spp., Bacillus spp., Streptomyces spp., and Trichoderma spp. were obtained from the banana rhizosphere and selected in vitro for the antagonism against Foc TR4. In pot experiments, a large community such as SynCom 1.0 (44 isolates with moderate to high antagonistic activity) or a small one such as SynCom 1.1 (seven highly effective isolates) provided similar disease control (35% symptom severity reduction). An in vitro study of the interactions among SynCom 1.1 isolates and between them and Foc revealed that beneficial microorganisms not only antagonized the pathogen but also some of the SynCom constituents. Furthermore, Foc defended itself by antagonizing the beneficial microbes. We also demonstrated that fusaric acid, known as one of the secondary metabolites of Fusarium species, might be involved in such an interaction. With this knowledge, SynCom 1.2 was then designed with three isolates: Pseudomonas chlororaphis subsp. piscium PS5, Bacillus velezensis BN8.2, and Trichoderma virens T2C1.4. A non-simultaneous soil application of these isolates (to diminish cross-inhibition) delayed FWB progress over time, with significant reductions in incidence and severity. SynCom 1.2 also performed better than two commercial BCAs, BioPak® and T-Gro. Eventually, SynCom 1.2 isolates were characterized for several biocontrol traits and their genome was sequenced. Our data showed that assembling a SynCom for biocontrol is not an easy task. The mere mi

Pseudomonas simiae PICF7 is an indigenous inhabitant of the olive ( Olea europaea L.) rhizosphere/root endosphere and an effective biocontrol agent against Verticillium wilt of olive (VWO), caused by the soil-borne fungus Verticillium dahliae. This study aimed to evaluate the potential involvement of selected phenotypes of strain PICF7 in root colonization ability and VWO biocontrol. Therefore, a random transposon-insertion mutant bank of P. simiae PICF7 was screened for the loss of phenotypes likely involved in rhizosphere/soil persistence (copper resistance), root colonization (biofilm formation) and plant growth promotion (phytase activity). Transposon insertions in genes putatively coding for the transcriptional regulator CusR or the chemotaxis protein CheV were found to affect copper resistance, whereas an insertion in fleQ gene putatively encoding a flagellar regulatory protein hampered the ability to form a biofilm. However, these mutants displayed the same antagonistic effect against V. dahliae as the parental strain. Remarkably, two mutants impaired in biofilm formation were never found inside olive roots, whereas their ability to colonize the root exterior and to control VWO remained unaffected. Endophytic colonization of olive roots was unaltered in mutants impaired in copper resistance and phytase production. Results demonstrated that the phenotypes studied were irrelevant for VWO biocontrol.

Within the wave energy community, hydrodynamic coefficients obtained from boundary element methods (BEMs) are commonly used to predict the behaviour of wave energy converters (WECs) in response to incident waves. A number of commercially-available BEM solvers exist, with a number of open-source alternatives also available. While open-source solvers have an obvious cost advantage compared to their commercial counterparts, the results from such solvers are often susceptible to so-called ‘irregular frequencies’, which arise from ill-conditioning in boundary integral problems, and result in large under or over-estimation of hydrodynamic parameters at certain excitation frequencies. Furthermore, while commercial solvers may employ techniques to suppress the effects of irregular frequencies, such solvers may, under certain circumstances, exhibit other problems in the hydrodynamic results produced. For example, the results obtained for the added mass at high frequencies, and the infinite frequency added mass for a water column, may be incorrect. The current work first focusses on an approach to remove the effects of irregular frequencies from the results obtained for the radiation damping of a particular WEC geometry. The use of radiation damping results to obtain values for the added mass, through the use of the Ogilvie relations, is then considered. The technique described herein has been implemented in BEMRosetta, an open-source tool which allows a user to view the results from various BEM solvers, as well as converting input files between solvers. The results presented in this paper have been obtained using the BEMRosetta implementation.

Within the wave energy community, hydrodynamic coefficients obtained from boundary element methods (BEMs) are commonly used to predict the behaviour of wave energy converters (WECs) in response to incident waves. A number of commercially-available BEM solvers exist, with a number of open-source alternatives also available. While open-source solvers have an obvious cost advantage compared to their commercial counterparts, the results from such solvers are often susceptible to so-called ‘irregular frequencies’, which arise from ill-conditioning in boundary integral problems, and result in large under or over-estimation of hydrodynamic parameters at certain excitation frequencies. Furthermore, while commercial solvers may employ techniques to suppress the effects of irregular frequencies, such solvers may, under certain circumstances, exhibit other problems in the hydrodynamic results produced. For example, the results obtained for the added mass at high frequencies, and the infinite frequency added mass for a water column, may be incorrect. The current work first focusses on an approach to remove the effects of irregular frequencies from the results obtained for the radiation damping of a particular WEC geometry. The use of radiation damping results to obtain values for the added mass, through the use of the Ogilvie relations, is then considered. The technique described herein has been implemented in BEMRosetta, an open-source tool which allows a user to view the results from various BEM solvers, as well as converting input files between solvers. The results presented in this paper have been obtained using the BEMRosetta implementation.

COVID-19 infection produces multiple clinical manifestations, among which headache has been frequently observed. We report the case of a 30-year-old patient with COVID-19 infection 2 months ago who consults at pain specialist for headache of moderate intensity, throbbing, with a sensation of hyperalgesia, burning and heat, a sensation of currents, in the parietal and occipital region bilateral, persistent, that does not improve with usual analgesics. After ruling out space-occupying lesions, neurovascular and rheumatological alterations; with a single significant history of viral infection, chronic craniofacial atypical headache was considered as a sequel to COVID-19. We invite the scientific community to continue etiological research in this area after the increasing appearance of post-COVID syndrome with extrapulmonary manifestations, such as neurological complications., La infección por COVID-19 produce múltiples manifestaciones clínicas, dentro de las cuales se ha observado con frecuencia la cefalea. Se reporta el caso de una paciente de 30 años con infección por COVID-19 hace 2 meses quien consulta a especialista de dolor por cefalea de intensidad moderada, pulsátil, con sensación de hiperalgesia, ardor y calor, corrientazos, en región parietal y occipital bilaterales, persistente que no mejora con analgésicos habituales. Tras descartarse lesiones ocupantes de espacio, alteraciones neurovasculares y reumatológicas; con antecedente de importancia infección viral se consideró cefalea atípica crónica cráneo–facial, como secuela del COVID-19. Se invita a la comunidad científica a continuar la investigación etiológica en esta área tras la creciente aparición de síndrome post COVID con manifestaciones extrapulmonares, como lo son las complicaciones neurológicas.

La verticilosis del olivo, causada por el hongo Verticillium dahliae Kleb, es considerada como una de las enfermedades más relevantes que afectan a un cultivo de tanta importancia como es el del olivo. Una de las principales técnicas de los agricultores frente a esta plaga es reemplazar los árboles enfermos por árboles de una variedad tolerante a dicha enfermedad: Frantoio. Sin embargo, aunque existen estudios que ahondan en aspectos transcriptómicos, histológicos y bioquímicos subyacentes a esta tolerancia, poco se sabe sobre la influencia del microbioma de la raíz, a pesar de que es bien conocido el papel que juega la especie vegetal, e incluso la variedad, en el ensamblaje de las comunidades microbianas asociadas a la planta. Más allá de esto, el manejo agrícola es un elemento de gran influencia en el desarrollo de la enfermedad y en la salud del árbol y el equilibrio del suelo en general. A pesar de esto, existen escasos estudios que indaguen sobre el efecto del manejo agrícola en comunidades microbianas asociadas a leñosas. Así, se plantearon dos comparaciones en este estudio: (i) Analizar la posible variación de las comunidades microbianas de suelo suelto y rizosférico de olivares en comparación a sistemas sin manejo agrícola, en concreto, bosques autóctonos de encinas que se encuentren rodeando al olivar objeto de estudio (ii) Testar la hipótesis de una posible diferencia en las comunidades microbianas de dos variedades de olivar presentes en el mismo cultivar, pero con susceptibilidades a la verticilosis diferentes (Frantoio, tolerante; Picual, sensible). Estos objetivos se abordaron con el uso de técnicas de secuenciación masiva, mediante la secuenciación de regiones específicas del gen 16S rARN para identificación bacteriana y del ITS2 (espacio intergénico del operón ribosomal) para hongos. Como resultados destacables, hay que resaltar que no se pudo observar la presencia de efecto rizosférico en el suelo sometido a manejo agrícola, mientras que este estab

Verticillium wilt of olive (VWO), caused by the fungus Verticillium dahliae Kleb., together with drought and salinity are considered serious (a)biotic constraints affecting olive cultivation worldwide. Different microorganisms have been identified as effective biocontrol agents (BCA) against V. dahliae and/or as useful tools to alleviate these stresses. A collection of olive beneficial rhizobacteria was screened, including the effective BCA against VWO Pseudomonas simiae PICF7 and Pseudomonas sp. PICF6, to assess them as protectants towards abiotic stresses. In this study, we pursued a double goal: i) on the one hand, to evaluate the potential involvement of selected phenotypes of strain PICF7 in root colonization and VWO biocontrol, and ii) on the other hand, to assess whether olive beneficial rhizobacteria can be used as protective agents to alleviate drought and salt stresses. For the latter objective we aimed to identify 1-aminocyclopropane-1-carboxylic acid deaminase (ACD) producers and tested the hypothesis that ACD producers lessen the effects of these abiotic stresses. A random transposon-insertion mutant bank of PICF7 was screened for the loss of phenotypes likely involved in rhizosphere/soil persistence (copper resistance), root colonization (biofilm formation) and plant growth promotion (phytase activity). Transposon insertions in genes putatively coding for the transcriptional regulator CusR or the chemotaxis protein CheV were found to affect copper resistance, whereas an insertion in the fleQ gene putatively encoding a flagellar regulatory protein hampered the ability to form a biofilm. However, these mutants displayed the same antagonistic effect against V. dahliae as the parental strain. Endophytic colonization of olive roots was only altered in mutants impaired in biofilm formation since they were never found inside olive roots. This rhizobacteria collection was in vitro screened for ACD activity. Strain PICF6 displayed this phenotype while PICF7 was

In their natural environment, plants live in close interaction with complex populations of microorganisms, including rhizobacteria species commonly referred to as ‘Plant Growth Promoting Rhizobacteria’ (PGPR). A growing body of evidence demonstrates the importance of sugar transport in plant pathogen resistance and in plant-microorganism mutualistic symbioses. Using an in vitro experimental system, including the model plant species Arabidopsis thaliana, two PGPR strains (Pseudomonas simiae PICF7 and Burkholderia phytofirmans PsJN) and a non-PGPR strain (Escherichia coli), we conducted a comprehensive set of phenotypic and gene expression analyses to explore the role and regulation of sugar transporter genes in plant-PGPR interactions. In physical contact with the seedling roots, or solely via the emission of bacterial volatile compounds, the two PGPR strains tested improved the growth and development of the Arabidopsis seedlings and altered the expression of several plant sugar transporter genes. Our results also revealed both conserved and strain-specific transcriptional regulation mechanisms.

La Verticilosis está causada por el hongo del suelo Verticillium dahliae y es uno de los principales problemas que afecta al cultivo del olivo. Se trata de una enfermedad de muy difícil control por lo que la aplicación de una estrategia de manejo integrado es la recomendación más eficaz para confrontarla. Uno de las medidas más eficaces dentro de dicha estrategia es el uso de cultivares resistentes/tolerantes. Por ello, la búsqueda de características funcionales que puedan vincularse a cultivares/genotipos que presentan tolerancia al patógeno constituye una interesante aproximación en programas de evaluación y mejora frente a la Verticilosis. Actualmente no se dispone de información sobre una posible relación entre tolerancia a esta enfermedad y rasgos funcionales en olivo. En este trabajo se analizaron 25 rasgos funcionales de hoja, tallo, raíz y planta entera en 6 variedades de olivos que presentan diferentes niveles de tolerancia a V. dahliae. Los resultados obtenidos mostraron que las variedades tolerantes presentaban mayor área de las hojas y contenido de materia seca (en hojas, tallos y planta entera), así como mayor fracción de tallo y menor de hojas. Las diferencias más significativas se identificaron en la arquitectura del sistema radicular, tanto en el caso de raíces finas como en las gruesas, especialmente en longitud, área, diámetro y contenido de lignina.

[Background] Olive orchards are threatened by a wide range of pathogens. Of these, Verticillium dahliae has been in the spotlight for its high incidence, the difficulty to control it and the few cultivars that has increased tolerance to the pathogen. Disease resistance not only depends on detection of pathogen invasion and induction of responses by the plant, but also on barriers to avoid the invasion and active resistance mechanisms constitutively expressed in the absence of the pathogen. In a previous work we found that two healthy non-infected plants from cultivars that differ in V. dahliae resistance such as ‘Frantoio’ (resistant) and ‘Picual’ (susceptible) had a different root morphology and gene expression pattern. In this work, we have addressed the issue of basal differences in the roots between Resistant and Susceptible cultivars., [Results] The gene expression pattern of roots from 29 olive cultivars with different degree of resistance/susceptibility to V. dahliae was analyzed by RNA-Seq. However, only the Highly Resistant and Extremely Susceptible cultivars showed significant differences in gene expression among various groups of cultivars. A set of 421 genes showing an inverse differential expression level between the Highly Resistant to Extremely Susceptible cultivars was found and analyzed. The main differences involved higher expression of a series of transcription factors and genes involved in processes of molecules importation to nucleus, plant defense genes and lower expression of root growth and development genes in Highly Resistant cultivars, while a reverse pattern in Moderately Susceptible and more pronounced in Extremely Susceptible cultivars were observed., [Conclusion] According to the different gene expression patterns, it seems that the roots of the Extremely Susceptible cultivars focus more on growth and development, while some other functions, such as defense against pathogens, have a higher expression level in roots of Highly Resistant cultivars. Therefore, it seems that there are constitutive differences in the roots between Resistant and Susceptible cultivars, and that susceptible roots seem to provide a more suitable environment for the pathogen than the resistant ones.

El hierro (Fe) es un micronutriente esencial para las plantas. En suelos calizos se encuentra en su forma oxidada (Fe 3+), presentando baja solubilidad y disponibilidad para las plantas. Bajo deficiencia de Fe, las plantas dicotiledóneas inducen diversas respuestas fisiológicas y morfológicas en sus raíces para facilitar así su captación y paliar los efectos que produce su deficiencia. Existen evidencias de que determinados microorganismos rizosféricos, como los que provocan la Respuesta Sistémica Inducida (ISR), pueden facilitar la nutrición férrica de las plantas. El objetivo de este trabajo ha sido, por una parte, estudiar el efecto de la cepa no patogénica de Fusarium oxysporum (FO12), posiblemente inductora de ISR, sobre el crecimiento y clorosis de plantas de tomate (Solanum lycopersicum Mill.), y sobre la colonización de raíces de pepino (Cucumis sativus L.). Por otra parte, estudiar el efecto de determinadas levaduras (Debaryomyces hansenii, Saccharomyces cerevisiae y Hansenula polymorpha) sobre diversas respuestas a la deficiencia de Fe en plantas de pepino. Los experimentos con tomate se han desarrollado en suelo calizo y los de pepino en cultivo hidropónico. Los resultados obtenidos con FO12 han mostrado su capacidad para colonizar endofiticamente las raíces de pepino y su efecto promotor del crecimiento, la concentración de clorofila y de Fe (en hojas) en plantas de tomate. Las diferentes levaduras utilizadas han causado inducción de la capacidad reductora de Fe 3+, de la acidificación de la rizosfera, y de la proliferación de pelos radicales en la zona subapical de las raíces de pepino. Estos resultados sugieren que, tanto FO12 como las diferentes levaduras utilizadas, tienen potencial como biofertilizantes de Fe.

Verticillium wilt of olive (VWO), caused by the soil-borne pathogen Verticillium dahliae, is considered one of the most important diseases affecting this tree crop. One of the best VWO management measures is the use of tolerant cultivars. Remarkably, no information is available about olive functional traits and their potential relationship with tolerance to V. dahliae. Twenty-five selected functional traits (for leaf, stem, root and whole plant) were evaluated in six olive varieties differing in their VWO tolerance level to identify possible links between this phenotype and functional traits’ variation. High intervarietal diversity was found among cultivars and several functional traits were related with VWO tolerance. Tolerant varieties showed higher leaf area, dry matter content (leaf, stem and plant) and mass fraction for stems, but lower for leaves. Significant differences were also detected for root functional traits, tolerant cultivars displaying larger fine root diameter and lignin content but smaller specific length and area of thick and fine roots. Correlations were found among functional traits both within varieties and between levels of tolerance/susceptibility to VWO. Associations were observed between biomass allocation, dry matter content and VWO tolerance. The most relevant difference between tolerant and susceptible cultivars was related to root system architecture.

This study aimed to disentangle the structure, composition, and co-occurrence relation-ships of the banana (cv. Dwarf Cavendish) root endophytome comparing two phenological plant stages: mother plants and suckers. Moreover, a collection of culturable root endophytes (>1000) was also generated from Canary Islands. In vitro antagonism assays against Fusarium oxysporum f.sp. cubense (Foc) races STR4 and TR4 enabled the identification and characterization of potential biocontrol agents (BCA). Eventually, three of them were selected and evaluated against Fusarium wilt of banana (FWB) together with the well-known BCA Pseudomonas simiae PICF7 under controlled conditions. Culturable and non-culturable (high-throughput sequencing) approaches provided concordant information and showed low microbial diversity within the banana root en-dosphere. Pseudomonas appeared as the dominant genus and seemed to play an important role in the banana root endophytic microbiome according to co-occurrence networks. Fungal communities were dominated by the genera Ophioceras, Cyphellophora, Plecosphaerella, and Fusarium. Overall, significant differences were found between mother plants and suckers, suggesting that the phe-nological stage determines the recruitment and organization of the endophytic microbiome. While selected native banana endophytes showed clear antagonism against Foc strains, their biocontrol performance against FWB did not improve the outcome observed for a non-indigenous reference BCA (strain PICF7).

The connection between olive genetic responses to environmental and agro-climatic conditions and the composition, structure and functioning of host-associated, belowground microbiota has never been studied under the holobiont conceptual framework. Two groups of cultivars growing under the same environmental, pedological and agronomic conditions, and showing highest (AH) and lowest (AL) Actinophytocola relative abundances, were earlier identified. We aimed now to: i) compare the root transcriptome profiles of these two groups harboring significantly different relative abundances in the above-mentioned bacterial genus; ii) examine their rhizosphere and root-endosphere microbiota co-occurrence networks; and iii) connect the root host transcriptome pattern to the composition of the root microbial communities by correlation and co-occurrence network analyses. Significant differences in olive gene expression were found between the two groups. Co-occurrence networks of the root endosphere microbiota were clearly different as well. Pearson's correlation analysis enabled a first portray of the interaction occurring between the root host transcriptome and the endophytic community. To further identify keystone operational taxonomic units (OTUs) and genes, subsequent co-occurrence network analysis showed significant interactions between 32 differentially expressed genes (DEGs) and 19 OTUs. Overall, negative correlation was detected between all upregulated genes in the AH group and all OTUs except of Actinophytocola. While two groups of olive cultivars grown under the same conditions showed significantly different microbial profiles, the most remarkable finding was to unveil a strong correlation between these profiles and the differential gene expression pattern of each group. In conclusion, this study shows a holistic view of the plant-microbiome communication.

Reseña de la obra 'Las respuestas del Derecho a las crisis de salud pública' (2020) de Elena Atienza Macías y Juan Francisco Rodríguez Ayuso (dirs.).

La generalización del corso, de la esclavitud y de las conversiones al Islam hace que la literatura en la Edad Moderna experimente un renovado interés por los temas de moros y turcos, moda que también afectará a las relaciones de sucesos, que buscan informar, entretener y conmover a su público creando así una literatura popular y propagandística en el Estado Moderno. Esta literatura favorecerá el proceso de confesionalización en torno a un ideal político-religioso en el enfrentamiento entre la Monarquía Hispánica y sus enemigos musulmanes. En las relaciones de sucesos de la época se nos presentan todo tipo de conversiones, sin embargo, el objeto de este trabajo son las relaciones que versan sobre conversiones de personajes femeninos, puesto que la imagen de la mujer en las relaciones de sucesos ha sido poco estudiada. Las obras seleccionadas son once relaciones de sucesos, cuyas fechas de edición abarcan desde 1584 a 1761, aunque se desconoce el año de edición de dos de ellas. El corpus analizado se ha dividido en dos bloques diferenciados por el motivo de la conversión: el amor o un milagro