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A staggering diversity of endophytic fungi associate with healthy plants in nature, but it is usually unclear whether these represent stochastic encounters or provide host fitness benefits. Although most characterized species of the fungal genus Colletotrichum are destructive pathogens, we show here that C. tofieldiae (Ct) is an endemic endophyte in natural Arabidopsis thaliana populations in central Spain. Colonization by Ct initiates in roots but can also spread systemically into shoots. Ct transfers the macronutrient phosphorus to shoots, promotes plant growth, and increases fertility only under phosphorus-deficient conditions, a nutrient status that might have facilitated the transition from pathogenic to beneficial lifestyles. The host's phosphate starvation response (PSR) system controls Ct root colonization and is needed for plant growth promotion (PGP). PGP also requires PEN2-dependent indole glucosinolate metabolism, a component of innate immune responses, indicating a functional link between innate immunity and the PSR system during beneficial interactions with Ct.
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Arabidopsis/microbiología , Colletotrichum/aislamiento & purificación , Fosfatos/metabolismo , Arabidopsis/crecimiento & desarrollo , Arabidopsis/fisiología , Proteínas de Arabidopsis/metabolismo , Colletotrichum/fisiología , Endófitos , Proteínas de Transporte de Fosfato/metabolismo , Raíces de Plantas/crecimiento & desarrollo , Raíces de Plantas/metabolismo , Raíces de Plantas/microbiología , España , SimbiosisRESUMEN
Plants respond to phosphorus (P) limitation through an array of morphological, physiological and metabolic changes which are part of the phosphate (Pi) starvation response (PSR). This response influences the establishment of the arbuscular mycorrhizal (AM) symbiosis in most land plants. It is, however, unknown to what extent available P and the PSR redefine plant interactions with the fungal microbiota in soil. Using amplicon sequencing of the fungal taxonomic marker ITS2, we examined the changes in root-associated fungal communities in the AM nonhost species Arabidopsis thaliana in response to soil amendment with P and to genetic perturbations in the plant PSR. We observed robust shifts in root-associated fungal communities of P-replete plants in comparison with their P-deprived counterparts, while bulk soil communities remained unaltered. Moreover, plants carrying mutations in the phosphate signaling network genes, phr1, phl1 and pho2, exhibited similarly altered root fungal communities characterized by the depletion of the chytridiomycete taxon Olpidium brassicae specifically under P-replete conditions. This study highlights the nutritional status and the underlying nutrient signaling network of an AM nonhost plant as previously unrecognized factors influencing the assembly of the plant fungal microbiota in response to P in nonsterile soil.
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Arabidopsis/microbiología , Micobioma , Fósforo/farmacología , Suelo/química , Arabidopsis/efectos de los fármacos , Micobioma/efectos de los fármacos , Micobioma/genética , Fosfatos/farmacología , Raíces de Plantas/microbiología , RizosferaRESUMEN
A key feature of arbuscular mycorrhizal symbiosis is improved phosphorus nutrition of the host plant via the mycorrhizal pathway, i.e., the fungal uptake of Pi from the soil and its release from arbuscules within root cells. Efficient transport of Pi from the fungus to plant cells is thought to require a proton gradient across the periarbuscular membrane (PAM) that separates fungal arbuscules from the host cell cytoplasm. Previous studies showed that the H+-ATPase gene HA1 is expressed specifically in arbuscule-containing root cells of Medicago truncatula. We isolated a ha1-2 mutant of M. truncatula and found it to be impaired in the development of arbuscules but not in root colonization by Rhizophagus irregularis hyphae. Artificial microRNA silencing of HA1 recapitulated this phenotype, resulting in small and truncated arbuscules. Unlike the wild type, the ha1-2 mutant failed to show a positive growth response to mycorrhizal colonization under Pi-limiting conditions. Uptake experiments confirmed that ha1-2 mutants are unable to take up phosphate via the mycorrhizal pathway. Increased pH in the apoplast of abnormal arbuscule-containing cells of the ha1-2 mutant compared with the wild type suggests that HA1 is crucial for building a proton gradient across the PAM and therefore is indispensible for the transfer of Pi from the fungus to the plant.
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Interaction of plant roots with arbuscular mycorrhizal fungi (AMF) is a complex trait resulting in cooperative interactions among the two symbionts including bidirectional exchange of resources. To study arbuscular mycorrhizal symbiosis (AMS) trait variation in the model plant Lotus japonicus, we performed an integrated multi-omics analysis with a focus on plant and fungal phospholipid (PL) metabolism and biological significance of lysophosphatidylcholine (LPC). Our results support the role of LPC as a bioactive compound eliciting cellular and molecular response mechanisms in Lotus. Evidence is provided for large interspecific chemical diversity of LPC species among mycorrhizae with related AMF species. Lipid, gene expression and elemental profiling emphasize the Lotus-Glomus intraradices interaction as distinct from other arbuscular mycorrhizal (AM) interactions. In G. intraradices, genes involved in fatty acid (FA) elongation and biosynthesis of unsaturated FAs were enhanced, while in Lotus, FA synthesis genes were up-regulated during AMS. Furthermore, FAS protein localization to mitochondria suggests FA biosynthesis and elongation may also occur in AMF. Our results suggest the existence of interspecific partitioning of PL resources for generation of LPC and novel candidate bioactive PLs in the Lotus-G. intraradices symbiosis. Moreover, the data advocate research with phylogenetically diverse Glomeromycota species for a broader understanding of the molecular underpinnings of AMS.
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Glomeromycota/fisiología , Glicerofosfolípidos/metabolismo , Lotus/microbiología , Lisofosfatidilcolinas/metabolismo , Metabolómica/métodos , Micorrizas/fisiología , Proteómica/métodos , Simbiosis , Vías Biosintéticas/efectos de los fármacos , Vías Biosintéticas/genética , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Glomeromycota/efectos de los fármacos , Metabolismo de los Lípidos/efectos de los fármacos , Metabolismo de los Lípidos/genética , Lotus/citología , Lotus/efectos de los fármacos , Modelos Biológicos , Micorrizas/efectos de los fármacos , Fosfatos/farmacología , Carácter Cuantitativo Heredable , ARN Mensajero/genética , ARN Mensajero/metabolismo , Análisis de Secuencia de ARN , Fracciones Subcelulares/metabolismo , Simbiosis/efectos de los fármacos , Simbiosis/genética , Factores de Tiempo , Transcripción Genética/efectos de los fármacos , Transcriptoma/efectos de los fármacos , Transcriptoma/genéticaRESUMEN
Most terrestrial plants benefit from the symbiosis with arbuscular mycorrhizal fungi (AMF) mainly under nutrient-limited conditions. Here the crop plant Zea mays was grown with and without AMF in a bi-compartmented system separating plant and phosphate (Pi) source by a hyphae-permeable membrane. Thus, Pi was preferentially taken up via the mycorrhizal Pi uptake pathway while other nutrients were ubiquitously available. To study systemic effects of mycorrhizal Pi uptake on leaf status, leaves of these plants that display an increased biomass in the presence of AMF were subjected to simultaneous ionomic, transcriptomic and metabolomic analyses. We observed robust changes of the leaf elemental composition, that is, increase of P, S and Zn and decrease of Mn, Co and Li concentration in mycorrhizal plants. Although changes in anthocyanin and lipid metabolism point to an improved P status, a global increase in C versus N metabolism highlights the redistribution of metabolic pools including carbohydrates and amino acids. Strikingly, an induction of systemic defence gene expression and concomitant accumulation of secondary metabolites such as the terpenoids alpha- and beta-amyrin suggest priming of mycorrhizal maize leaves as a mycorrhiza-specific response. This work emphasizes the importance of AM symbiosis for the physiological status of plant leaves and could lead to strategies for optimized breeding of crop species with high growth potential.
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Micorrizas/metabolismo , Simbiosis , Zea mays/metabolismo , Antocianinas/metabolismo , Biomasa , Carbono/metabolismo , Perfilación de la Expresión Génica , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Metabolismo de los Lípidos/efectos de los fármacos , Metabolismo de los Lípidos/genética , Metaboloma/efectos de los fármacos , Metaboloma/genética , Análisis Multivariante , Micorrizas/efectos de los fármacos , Nitrógeno/metabolismo , Fenotipo , Fosfatos/metabolismo , Fotosíntesis/efectos de los fármacos , Fotosíntesis/genética , Hojas de la Planta/efectos de los fármacos , Hojas de la Planta/genética , Hojas de la Planta/metabolismo , Análisis de Componente Principal , Simbiosis/efectos de los fármacos , Simbiosis/genética , Transcripción Genética/efectos de los fármacos , Zea mays/efectos de los fármacos , Zea mays/genética , Zea mays/crecimiento & desarrolloRESUMEN
Background: The coronavirus disease 2019 (COVID-19) pandemic had challenged health systems worldwide, including those in low- and middle-income countries (LMICs). Aside from measures to control the pandemic, efforts were made to continue the provision and use of essential services. At that time, information was not organised and readily available to guide country-level decision-making. This review aims to summarise evaluated interventions to maintain essential services for maternal, newborn, child, and adolescent health in response to COVID-19 in LMICs, in order to learn from the interventions and facilitate their use in the next disruption. Methods: We conducted a scoping review by Embase, MEDLINE, and Global Health for literature published between 1 January 2020 and 26 December 2022, without restrictions for language. We extracted information about the setting, population targeted, service type, intervention, and evaluation from the included studies and summarised it both quantitatively and narratively. Results: We retrieved 11 395 unique references and included 30 studies describing 32 evaluated interventions. Most interventions (84%) were implemented in 2020, with a median duration of five months (interquartile range (IQR) = 3-8), and were conducted in Africa (34%) or Southeast Asia (31%). Interventions focussed on maintaining services for maternal and newborn health (56%) or children and adolescents (56%) were most common. Interventions aimed to address problems related to access (94%), fear (31%), health workers shortage (25%), and vulnerability (22%). Types of interventions included telehealth (69%), protocols/guidelines to adapt care provision (56%), and health education (40%); a few entailed health worker training (16%). The described interventions were mostly led by the public (56%) or non-profit (34%) sectors. Methodologies of their evaluations were heterogeneous; the majority used quantitative methods, had a prospective research design, and used output- and outcome-based indicators. Conclusions: In this review, we identified an important and growing body of evidence of evaluated interventions to maintain essential services for maternal, newborn, child, and adolescent health during COVID-19 in LMICs. To improve preparedness and responsiveness for future disruptions, managers for decision-makers in LMICs could benefit from up-to-date inventories describing implemented interventions and evaluations to facilitate evidence-based implementation of strategies, as well as tools for conducting optimal quality operational and implementation research during disruptions (e.g. rapid ethical approvals, access to routine data).
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COVID-19 , Países en Desarrollo , Humanos , COVID-19/epidemiología , COVID-19/prevención & control , Adolescente , Niño , Recién Nacido , Femenino , Salud del Adolescente , Salud Infantil , EmbarazoRESUMEN
INTRODUCTION: Widespread vaccination against COVID-19 is one of the most effective ways to control, and ideally, end the global COVID-19 pandemic. Vaccine hesitancy and vaccine rates vary widely across countries and populations and are influenced by complex sociocultural, political, economic and psychological factors. Community engagement is an integral strategy within immunisation campaigns and has been shown to improve vaccine acceptance. As evidence on community engagement to support COVID-19 vaccine uptake is emerging and constantly changing, research that lessens the knowledge-to-practice gap by providing regular and up-to-date evidence on current best-practice is essential. METHODS AND ANALYSIS: A living systematic review will be conducted which includes an initial systematic review and bimonthly review updates. Searching and screening for the review and subsequent updates will be done in four streams: a systematic search of six databases, grey literature review, preprint review and citizen sourcing. The screening will be done by a minimum of two reviewers at title/abstract and full-text in Covidence, a systematic review management software. Data will be extracted across predefined fields in an excel spreadsheet that includes information about article characteristics, context and population, community engagement approaches, and outcomes. Synthesis will occur using the convergent integrated approach. We will explore the potential to quantitatively synthesise primary outcomes depending on heterogeneity of the studies. ETHICS AND DISSEMINATION: The initial review and subsequent bimonthly searches and their results will be disseminated transparently via open-access methods. Quarterly briefs will be shared on the reviews' social media platforms and across other interested networks and repositories. A dedicated web link will be created on the Community Health-Community of Practice site for sharing findings and obtaining feedback. A mailing list will be developed and interested parties can subscribe for updates. PROSPERO REGISTRATION NUMBER: CRD42022301996.
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COVID-19 , Envío de Mensajes de Texto , COVID-19/epidemiología , COVID-19/prevención & control , Vacunas contra la COVID-19 , Humanos , Pandemias/prevención & control , Proyectos de Investigación , Revisiones Sistemáticas como Asunto , VacunaciónRESUMEN
Plant roots are colonized by microorganisms from the surrounding soil that belong to different kingdoms and form a multikingdom microbial community called the root microbiota. Despite their importance for plant growth, the relationship between soil management, the root microbiota, and plant performance remains unknown. Here, we characterize the maize root-associated bacterial, fungal, and oomycetal communities during the vegetative and reproductive growth stages of four maize inbred lines and the pht1;6 phosphate transporter mutant. These plants were grown in two long-term experimental fields under four contrasting soil managements, including phosphate-deficient and -sufficient conditions. We showed that the maize root-associated microbiota is influenced by soil management and changes during host growth stages. We identified stable bacterial and fungal root-associated taxa that persist throughout the host life cycle. These taxa were accompanied by dynamic members that covary with changes in root metabolites. We observed an inverse stable-to-dynamic ratio between root-associated bacterial and fungal communities. We also found a host footprint on the soil biota, characterized by a convergence between soil, rhizosphere, and root bacterial communities during reproductive maize growth. Our study reveals the spatiotemporal dynamics of the maize root-associated microbiota and suggests that the fungal assemblage is less responsive to changes in root metabolites than the bacterial community. IMPORTANCE Plant roots are inhabited by microbial communities called the root microbiota, which supports plant growth and health. We show in a maize field study that the root microbiota consists of stable and dynamic members. The dynamics of the microbial community appear to be driven by changes in the metabolic state of the roots over the life cycle of maize.
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Microbiota , Zea mays , Bacterias , Hongos/genética , Raíces de Plantas/microbiología , Plantas , Suelo , Microbiología del Suelo , Zea mays/microbiologíaRESUMEN
Rapid population growth and increasing demand for food, feed, and bioenergy in these times of unprecedented climate change require breeding for increased biomass production on the world's croplands. To accelerate breeding programs, knowledge of the relationship between biomass features and underlying gene networks is needed to guide future breeding efforts. To this end, large-scale multiomics datasets were created with genetically diverse maize lines, all grown in long-term organic and conventional cropping systems. Analysis of the datasets, integrated using regression modeling and network analysis revealed key metabolites, elements, gene transcripts, and gene networks, whose contents during vegetative growth substantially influence the build-up of plant biomass in the reproductive phase. We found that S and P content in the source leaf and P content in the root during the vegetative stage contributed the most to predicting plant performance at the reproductive stage. In agreement with the Gene Ontology enrichment analysis, the cis-motifs and identified transcription factors associated with upregulated genes under phosphate deficiency showed great diversity in the molecular response to phosphate deficiency in selected lines. Furthermore, our data demonstrate that genotype-dependent uptake, assimilation, and allocation of essential nutrient elements (especially C and N) during vegetative growth under phosphate starvation plays an important role in determining plant biomass by controlling root traits related to nutrient uptake. These integrative multiomics results revealed key factors underlying maize productivity and open new opportunities for efficient, rapid, and cost-effective plant breeding to increase biomass yield of the cereal crop maize under adverse environmental factors.
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Globally, there is growing awareness of the important contributions men can make as key stakeholders in maternal and newborn health (MNH), and increased investment in interventions designed to influence men's engagement to improve MNH outcomes. Interventions typically target men, women, couples or health providers, yet how these stakeholders perceive and experience interventions is not well understood and the fact that women may experience these interventions as disempowering has been identified as a major concern. This review aims to synthesise how women, men, and providers perceive and experience interventions designed to influence men's engagement in MNH, in order to identify perceived benefits and risks of participating in interventions, and other key factors affecting uptake of and adherence to interventions. We conducted a qualitative evidence synthesis based on a systematic search of the literature, analysing a purposive sample of 66 out of 144 included studies to enable rich synthesis. Women, men and providers report that interventions enable more and better care for women, newborns and men, and strengthen family relationships between the newborn, father and mother. At the same time, stakeholders report that poorly designed or implemented interventions carry risks of harm, including constraining some women's access to MNH services and compounding negative impacts of existing gender inequalities. Limited health system capacity to deliver men-friendly MNH services, and pervasive gender inequality, can limit the accessibility and acceptability of interventions. Sociodemographic factors, household needs, and peer networks can influence how men choose to support MNH, and may affect demand for and adherence to interventions. Overall, perceived benefits of interventions designed to influence men's engagement in MNH are compelling, reported risks of harm are likely manageable through careful implementation, and there is clear evidence of demand from women and men, and some providers, for increased opportunities and support for men to engage in MNH.
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Salud del Lactante , Servicios de Salud Materna , Familia , Femenino , Humanos , Recién Nacido , Masculino , Salud Materna , Embarazo , Factores SociodemográficosRESUMEN
Maize, a main crop worldwide, establishes a mutualistic symbiosis with arbuscular mycorrhizal (AM) fungi providing nutrients to the roots from soil volumes which are normally not in reach of the non-colonized root. The mycorrhizal phosphate uptake pathway (MPU) spans from extraradical hyphae to root cortex cells housing fungal arbuscules and promotes the supply of phosphate to the mycorrhizal host in exchange for photosynthetic carbon. This symbiotic association with the mycobiont has been shown to affect plant host nutritional status and growth performance. However, whether and how the MPU affects the root microbial community associated with mycorrhizal hosts in association with neighboring plants, remains to be demonstrated. Here the maize germinal Mu transposon insertion mutant pht1;6, defective in mycorrhiza-specific Pi transporter PHT1;6 gene, and wild type B73 (wt) plants were grown in mono- and mixed culture and examined under greenhouse and field conditions. Disruption of the MPU in pht1;6 resulted in strongly diminished growth performance, in reduced P allocation to photosynthetic source leaves, and in imbalances in leaf elemental composition beyond P. At the microbial community level a loss of MPU activity had a minor effect on the root-associated fungal microbiome which was almost fully restricted to AM fungi of the Glomeromycotina. Moreover, while wt grew better in presence of pht1;6, pht1;6 accumulated little biomass irrespective of whether it was grown in mono- or mixed culture and despite of an enhanced fungal colonization of its roots in co-culture with wt. This suggested that a functional MPU is prerequisite to maintain maize growth and that neighboring plants competed for AM fungal Pi in low P soil. Thus future strategies towards improving yield in maize populations on soils with low inputs of P fertilizer could be realized by enhancing MPU at the individual plant level while leaving the root-associated fungal community largely unaffected.
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Micorrizas/metabolismo , Fosfatos/metabolismo , Zea mays/microbiología , Zea mays/fisiología , Biomasa , Mutación con Pérdida de Función , Hojas de la Planta/crecimiento & desarrollo , Hojas de la Planta/fisiología , Plantas Modificadas Genéticamente , Suelo/química , Simbiosis/fisiología , Zea mays/genética , Zea mays/crecimiento & desarrolloRESUMEN
Drosophila provides a powerful experimental system to analyze gene functions in a multi-cellular organism. Here we describe an in vivo method that interferes with the integrity of selected proteins through site-specific cleavage in Drosophila. The technique is based on the highly specific seven-amino-acid recognition site of the tobacco etch virus (TEV) protease. We established transgenic fly lines that direct TEV protease expression in various tissues without affecting fly viability. The insertion of the TEV protease recognition site in defined positions of target proteins mediates their sequence-specific cleavage after controlled TEV protease expression in the fly. Thereby, this technique is a powerful tool that allows the in vivo manipulation of selected proteins in a time- and tissue-specific manner.
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Animales Modificados Genéticamente/metabolismo , Proteínas de Drosophila/fisiología , Drosophila/genética , Drosophila/metabolismo , Endopeptidasas/genética , Ingeniería de Proteínas/métodos , AnimalesRESUMEN
Maize (Zea mays) is the most widely grown crop species in the world and a classical model organism for plant research. The completion of a high-quality reference genome sequence and the advent of high-throughput sequencing have greatly empowered re-sequencing studies in maize. In this study, plants of maize inbred line B73 descended from two different sets of seed material grown for several generations either in the field or in the greenhouse were found to show a different growth phenotype and ionome under phosphate starvation conditions and moreover a different responsiveness towards mycorrhizal fungi of the species Glomus intraradices (syn: Rhizophagus irregularis). Whole genome re-sequencing of individuals from both sets and comparison to the B73 reference sequence revealed three cryptic introgressions on chromosomes 1, 5 and 10 in the line grown in the greenhouse summing up to a total of 5,257 single-nucleotide polymorphisms (SNPs). Transcriptome sequencing of three individuals from each set lent further support to the location of the introgression intervals and confirmed them to be fixed in all sequenced individuals. Moreover, we identified >120 genes differentially expressed between the two B73 lines. We thus have found a nearly-isogenic line (NIL) of maize inbred line B73 that is characterized by an altered growth phenotype under phosphate starvation conditions and an improved responsiveness towards symbiosis with mycorrhizal fungi. Through next-generation sequencing of the genomes and transcriptomes we were able to delineate exact introgression intervals. Putative de novo mutations appeared approximately uniformly distributed along the ten maize chromosomes mainly representing G:C -> A:T transitions. The plant material described in this study will be a valuable tool both for functional studies of genes differentially expressed in both B73 lines and for research on growth behavior especially in response to symbiosis between maize and mycorrhizal fungi.
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Cromosomas de las Plantas/genética , Genoma de Planta , Secuenciación de Nucleótidos de Alto Rendimiento , Zea mays/genética , Mapeo Cromosómico , Regulación de la Expresión Génica de las Plantas , Genómica , Repeticiones de Microsatélite/genética , Micorrizas/genética , Micorrizas/patogenicidad , Fenotipo , Polimorfismo de Nucleótido Simple , Zea mays/microbiologíaRESUMEN
Arbuscular mycorrhizal fungi (AMF) form a mutually beneficial symbiosis with plant roots providing predominantly phosphorus in the form of orthophosphate (Pi) in exchange for plant carbohydrates on low P soils. The goal of this work was to generate molecular-genetic evidence in support of a major impact of the mycorrhizal Pi uptake (MPU) pathway on the productivity of the major crop plant maize under field and controlled conditions. Here we show, that a loss-of-function mutation in the mycorrhiza-specific Pi transporter gene Pht1;6 correlates with a dramatic reduction of above-ground biomass and cob production in agro-ecosystems with low P soils. In parallel mutant pht1;6 plants exhibited an altered fingerprint of chemical elements in shoots dependent on soil P availability. In controlled environments mycorrhiza development was impaired in mutant plants when grown alone. The presence of neighboring mycorrhizal nurse plants enhanced the reduced mycorrhiza formation in pht1;6 roots. Uptake of (33)P-labeled orthophosphate via the MPU pathway was strongly impaired in colonized mutant plants. Moreover, repression of the MPU pathway resulted in a redirection of Pi to neighboring plants. In line with previous results, our data highlight the relevance of the MPU pathway in Pi allocation within plant communities and in particular the role of Pht1;6 for the establishment of symbiotic Pi uptake and for maize productivity and nutritional value in low-input agricultural systems. In a first attempt to identify cellular pathways which are affected by Pht1;6 activity, gene expression profiling via RNA-Seq was performed and revealed a set of maize genes involved in cellular signaling which exhibited differential regulation in mycorrhizal pht1;6 and control plants. The RNA data provided support for the hypothesis that fungal supply of Pi and/or Pi transport across Pht1;6 affects cell wall biosynthesis and hormone metabolism in colonized root cells.
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Development of the ectodermally derived Drosophila tracheal system is based on branch outgrowth and fusion that interconnect metamerically arranged tracheal subunits into a highly stereotyped three-dimensional tubular structure. Recent studies have revealed that this process involves a specialized cell type of mesodermal origin, termed bridge-cell. Single bridge-cells are located between adjacent tracheal subunits and serve as guiding posts for the outgrowing dorsal trunk branches. We show that bridge-cell-approaching tracheal cells form filopodia-like cell extensions, which attach to the bridge-cell surface and are essential for the tracheal subunit interconnection. The results of both dominant-negative and gain-of-function experiments suggest that the formation of cell extensions require Cdc42-mediated Drosophila fibroblast growth factor activity.