Root and leaves growth differentially respond to soil mineral content and microbiota

Plants integrate complex regulatory networks to ensure the adaptative growth of roots and leaves. These networks combine internal signals and external cues, such as nutrient availability and plant-colonising microorganisms – plant microbiota. The extent to how microbial communities, nutrient availability and internal signalling are coordinated to ensure adaptative growth of plant organs remains poorly understood. To study root and leaf responses to the different environmental cues, we planted four maise genotypes in three selected soils with different mineral nutrient contents and bacterial compositions. While root growth of the different genotypes was not affected by soil variability, leaves differentially integrated the soil effect. To understand the factors modulating the development of individual leaves, we investigated their mineral nutrient content and microbiome composition. We demonstrated that the soil effect on leaf development results from changes in the concentration of individual mineral elements impacting distinct leaf-associated bacterial communities

Sculpting the soil microbiota

Soil is a living ecosystem, the health of which depends on fine interactions among its abiotic and biotic components. These form a delicate equilibrium maintained through a multilayer network that absorbs certain perturbations and guarantees soil functioning. Deciphering the principles governing the interactions within soils is of critical importance for their management and conservation. Here, we focus on soil microbiota and discuss the complexity of interactions that impact the composition and function of soil microbiota and their interaction with plants. We discuss how physical aspects of soils influence microbiota composition and how microbiota–plant interactions support plant growth and responses to nutrient deficiencies. We predict that understanding the principles determining the configuration and functioning of soil microbiota will contribute to the design of microbiota-based strategies to preserve natural resources and develop more environmentally friendly agricultural practices

Understand the Potential Role of Aureobasidium pullulans, a Resident Microorganism From Grapevine, to Prevent the Infection Caused by Diplodia seriata

Grapevine trunk diseases (GTDs) are one of the major concern amongst grapevine diseases, responsible for the decline of vineyards and for several economical losses. Since grapevine is naturally colonized by resident microorganisms such as Aureobasidium pullulans, the present challenge is to understand their biocontrol potential and how such microorganisms can be successfully integrated in the control of GTDs. In this context, the first priority consists to exploit the plant-beneficial-phytopathogen interactions in plant model systems, to identify the most prevalent equilibrium limiting expression of GTDs. In the current study, we deep characterized the interaction of a resident and abundant microorganism from grapevine – Aureobasidium pullulans strain Fito_F278 – against D. seriata F98.1, a Botryosphaeria dieback agent, and with plant (cv Chardonnay). Results revealed that A. pullulans strain Fito_F278 was able to reduce significantly the mycelium growth of D. seriata F98.1 at 33.41 ± 0.55%, under in vitro conditions, though this reduction is possibly dependent on a direct interaction between strain Fito_F278 and pathogen. Furthermore, strain Fito_F278 was able to promote an induction of some plant defense responses in cutting plants, 1 week after the D. seriata F98.1 infection. Results evidenced that strain Fito_F278 colonized efficiently grapevine at both epiphyte and endophyte level, could persist on plant roots for long-periods (up to 2 months after its inoculation) and grow at different pH and high salinity conditions. Moreover, a significant decrease of the microbial load from soil and rhizosphere was observed in plants treated with the strain Fito_F278, suggesting its competitivity potential in a microbial ecosystem. Altogether, the present study gives the first insights about the interaction of A. pullulans strain Fito_F278, a resident microorganism, with grapevine, its potential role against a Botryosphaeria dieback agent, and highlights its importance to toward more resilient grapevine

Limit of viability of extremely preterm infants treated at a university hospital / Limite de viabilidade de prematuros extremos atendidos em um hospital universitário

Objective: to describe the profile of newborns with extreme prematurity and to identify factors associated with mortality according to gestational age and their limit of viability. Method: a retrospective observational study, with a quantitative approach, carried out in a university hospital in the state of Minas Gerais, developed from August 2021 to January 2022. The sample consisted of 39 records of live-born extreme preterm infants. Descriptive analysis of quantitative variables was performed using measures such as mean, standard deviation and minimum and maximum values. Categorical variables were described from their absolute and percentage frequency distributions. Results: most pregnant women are young-adult women, who underwent prenatal care and cesarean delivery. Of the preterm infants, the male sex prevails, with a gestational age of 25 weeks, most of whom died at a gestational age of 23 and 24 weeks. Conclusion: the limit of viability in this service is at a gestational age equal to or greater than 25 weeks.Objetivo: describir el perfil de los recién nacidos con prematuridad extrema e identificar los factores asociados a la mortalidad según la edad gestacional y su límite de viabilidad. Método: estudio observacional retrospectivo, con abordaje cuantitativo, realizado en un hospital universitario del estado de Minas Gerais, desarrollado entre agosto de 2021 y enero de 2022. La muestra estuvo compuesta por 39 prontuarios de prematuros extremos nacidos vivos. El análisis descriptivo de las variables cuantitativas se realizó utilizando medidas como la media, la desviación estándar y los valores mínimo y máximo. Las variables categóricas se describieron a partir de sus distribuciones de frecuencia absoluta y porcentual. Resultados: la mayoría de las gestantes son mujeres adultas jóvenes, que realizaron control prenatal y parto por cesárea. De los prematuros prevalece el sexo masculino, con una edad gestacional de 25 semanas, la mayoría de los cuales fallecieron a las 23 y 24 semanas de edad gestacional. Conclusión: el límite de viabilidad en este servicio es a una edad gestacional igual o mayor a 25 semanas.Objetivo: descrever o perfil de recém-nascidos com prematuridade extrema e identificar fatores associados a mortalidade segundo idade gestacional e o limite de viabilidade destes. Método: estudo observacional retrospectivo, com abordagem quantitativa, realizado em um hospital universitário do estado de Minas Gerais, desenvolvido de agosto de 2021 a janeiro de 2022. A amostra foi composta por 39 prontuários de prematuros extremos nascidos vivos. Foi realizada a análise descritiva das variáveis quantitativas usando medidas como média, desvio-padrão e valores mínimo e máximo. As variáveis categóricas foram descritas a partir de suas distribuições de frequência absoluta e percentual. Resultados: a maioria das gestantes são mulheres adultos-jovens, realizaram pré-natal e parto cesárea. Dos prematuros prevalece sexo masculino, idade gestacional de 25 semanas, evoluíram para óbito a maioria destes com idade gestacional de 23 e 24 semanas. Conclusão: o limite de viabilidade nesse serviço situa-se em uma idade gestacional igual ou maior que 25 semanas. 

Direct inhibition of phosphate transport by immune signaling in Arabidopsis

Soil availability of inorganic ortho-phosphate (PO 4 3−, P i) is a key determinant of plant growth and fitness. 1 Plants regulate the capacity of their roots to take up inorganic phosphate by adapting the abundance of H +-coupled phosphate transporters of the PHOSPHATE TRANSPORTER 1 (PHT1) family 2 at the plasma membrane (PM) through transcriptional and post-translational changes driven by the genetic network of the phosphate starvation response (PSR). 3–8 Increasing evidence also shows that plants integrate immune responses to alleviate phosphate starvation stress through the association with beneficial microbes. 9–11 Whether and how such phosphate transport is regulated upon activation of immune responses is yet uncharacterized. To address this question, we first developed quantitative assays based on changes in the electrical PM potential to measure active P i transport in roots in real time. By inserting micro-electrodes into bulging root hairs, we were able to determine key characteristics of phosphate transport in intact Arabidopsis thaliana (hereafter Arabidopsis) seedlings. The fast P i-induced depolarization observed was dependent on the activity of the major phosphate transporter PHT1;4. Notably, we observed that this PHT1;4-mediated phosphate uptake is repressed upon activation of pattern-triggered immunity. This inhibition depended on the receptor-like cytoplasmic kinases BOTRYTIS-INDUCED KINASE 1 (BIK1) and PBS1-LIKE KINASE 1 (PBL1), which both phosphorylated PHT1;4. As a corollary to this negative regulation of phosphate transport by immune signaling, we found that PHT1;4-mediated phosphate uptake normally negatively regulates anti-bacterial immunity in roots. Collectively, our results reveal a mechanism linking plant immunity and phosphate homeostasis, with BIK1/PBL1 providing a molecular integration point between these two important pathways

Dysfunctional purinergic signaling correlates with disease severity in COVID-19 patients

Ectonucleotidases modulate inflammatory responses by balancing extracellular ATP and adenosine (ADO) and might be involved in COVID-19 immunopathogenesis. Here, we explored the contribution of extracellular nucleotide metabolism to COVID-19 severity in mild and severe cases of the disease. We verified that the gene expression of ectonucleotidases is reduced in the whole blood of patients with COVID-19 and is negatively correlated to levels of CRP, an inflammatory marker of disease severity. In line with these findings, COVID-19 patients present higher ATP levels in plasma and reduced levels of ADO when compared to healthy controls. Cell type-specific analysis revealed higher frequencies of CD39+ T cells in severely ill patients, while CD4+ and CD8+ expressing CD73 are reduced in this same group. The frequency of B cells CD39+CD73+ is also decreased during acute COVID-19. Interestingly, B cells from COVID-19 patients showed a reduced capacity to hydrolyze ATP into ADP and ADO. Furthermore, impaired expression of ADO receptors and a compromised activation of its signaling pathway is observed in COVID-19 patients. The presence of ADO in vitro, however, suppressed inflammatory responses triggered in patients’ cells. In summary, our findings support the idea that alterations in the metabolism of extracellular purines contribute to immune dysregulation during COVID-19, possibly favoring disease severity, and suggest that ADO may be a therapeutic approach for the disease

Coordination between microbiota and root endodermis supports plant mineral nutrient homeostasis

Copyright © 2021, American Association for the Advancement of Science. Plant roots and animal guts have evolved specialized cell layers to control mineral nutrient homeostasis. These layers must tolerate the resident microbiota while keeping homeostatic integrity. Whether and how the root diffusion barriers in the endodermis, which are critical for the mineral nutrient balance of plants, coordinate with the microbiota is unknown. We demonstrate that genes controlling endodermal function in the model plant Arabidopsis thaliana contribute to the plant microbiome assembly. We characterized a regulatory mechanism of endodermal differentiation driven by the microbiota with profound effects on nutrient homeostasis. Furthermore, we demonstrate that this mechanism is linked to the microbiota's capacity to repress responses to the phytohormone abscisic acid in the root. Our findings establish the endodermis as a regulatory hub coordinating microbiota assembly and homeostatic mechanisms

Soroprevalência da anemia infecciosa eqüina, da arterite viral dos eqüinos e do aborto viral eqüino no município de Uruará, PA, Brasil

Os vírus da anemia infecciosa eqüina (VAIE), da arterite viral dos eqüinos (VAVE) e do aborto viral eqüino (Herpesvírus eqüino tipo 1, HVE-1) são agentes causadores de enfermidades nos eqüídeos que podem causar graves prejuízos econômicos. O objetivo do presente trabalho foi estimar a soroprevalência de anticorpos contra os vírus VAIE, VAVE e HVE-1, utilizando como unidades de análise os eqüídeos e as propriedades rurais do tipo familiar do município de Uruará, PA. Os anticorpos contra o VAIE foram pesquisados pela prova de imunodifusão em gel de ágar e os anticorpos contra o VAVE e o HVE-1 pela prova de soroneutralização. O tamanho da amostra foi estimado a partir de um total de 2069 propriedades, caracterizadas por agricultura familiar e ausência de vacinações contra o VAVE e o HVE-1. Foi adotado um nível de confiança de 90%, com uma precisão de 15% e prevalência estimada de 50%. As seguintes prevalências de animais soro reatores para os diferentes vírus foram observadas: VAIE: 17,71% (IC 10,67 - 26,83%); HVE-1: 17,71% (IC 10,67 - 26,83%) e VAVE: 0,00% (IC 0,00 - 3,77%). As seguintes prevalências de propriedades com pelo menos um animal soro reator para os diferentes vírus foram observadas: VAIE: 53% (IC 38,12 - 68,12%); HVE-1: 40.62% (IC 25.96 - 56.65%) e VAVE: 0% (IC 0 - 6.94%).Equine infection anemia virus (EIAV), Equine arteritis virus (EAV) and Equine herpesvirus 1 (EHV 1) are the causal agents of diseases which may bring economical losses. The aim o of this study was to estimate the prevalence of herds and animals infected with EIA, EAV and EHV in Uruará municipal district, Pará State-Brazil. Antibodies against EIAV were detected by the immunodiffusion test and those against EAV and HEV-1 by the serum neutralization test. Sample size was estimated from 2069 holder farms that raised Equidae and did not vaccinate against EAV and EHV. A 90% confidence level was adopted with 15% precision and 50% estimated prevalence. The herd was considered positive when it had at least one positive animal. The following prevalence of serum reactors animals were observed: VAIE: 17,71% (IC 10,67 - 26,83%), HVE-1: 17,71% (IC 10,67 - 26,83%) and VAVE: 0,00% (IC 0,00 - 3,77%). The following prevalence of positive herds were observed: VAIE: 53% (IC 38,12 - 68,12%), HVE-1: 40.62% (IC 25.96 - 56.65%) and VAVE: 0% (IC 0 - 6.94%)