25 research outputs found
Masterplan para UNIMAK y Estrategias para la ciudad de Makeni
El proyecto se desarrolla en tres escalas. Por un lado están las propuestas a nivel ciudad muy relacionadas con la siguiente escala, la de la universidad, y por último hay una escala de detalle, tanto para ciudad como para universidad. Se plantea la creación de unos nodos interconectados por los corredores verdes de la ciudad que den servicios básicos a la ciudad tales gestión de residuos, equipamientos públicos, puntos de agua, saneamiento...
Plant cell wall‐mediated immunity: cell wall changes trigger disease resistance responses
[EN] Plants have evolved a repertoire of monitoring systems to sense plant morphogenesis and to face environmental
changes and threats caused by different attackers. These systems integrate different signals into
overreaching triggering pathways which coordinate developmental and defence-associated responses. The
plant cell wall, a dynamic and complex structure surrounding every plant cell, has emerged recently as an
essential component of plant monitoring systems, thus expanding its function as a passive defensive barrier.
Plants have a dedicated mechanism for maintaining cell wall integrity (CWI) which comprises a diverse
set of plasma membrane-resident sensors and pattern recognition receptors (PRRs). The PRRs perceive
plant-derived ligands, such as peptides or wall glycans, known as damage-associated molecular patterns
(DAMPs). These DAMPs function as ‘danger’ alert signals activating DAMP-triggered immunity (DTI), which
shares signalling components and responses with the immune pathways triggered by non-self microbeassociated
molecular patterns that mediate disease resistance. Alteration of CWI by impairment of the
expression or activity of proteins involved in cell wall biosynthesis and/or remodelling, as occurs in some
plant cell wall mutants, or by wall damage due to colonization by pathogens/pests, activates specific defensive
and growth responses. Our current understanding of how these alterations of CWI are perceived by the
wall monitoring systems is scarce and few plant sensors/PRRs and DAMPs have been characterized. The
identification of these CWI sensors and PRR–DAMP pairs will help us to understand the immune functions
of the wall monitoring system, and might allow the breeding of crop varieties and the design of agricultural
strategies that would enhance crop disease resistance.S
Arabinoxylan-Oligosaccharides Act as Damage Associated Molecular Patterns in Plants Regulating Disease Resistance
[EN] Immune responses in plants can be triggered by damage/microbe-associated molecular
patterns (DAMPs/MAMPs) upon recognition by plant pattern recognition receptors
(PRRs). DAMPs are signaling molecules synthesized by plants or released from host
cellular structures (e.g., plant cell walls) upon pathogen infection or wounding. Despite the
hypothesized important role of plant cell wall-derived DAMPs in plant-pathogen
interactions, a very limited number of these DAMPs are well characterized. Recent work
demonstrated that pectin-enriched cell wall fractions extracted from the cell wall mutant
impaired in Arabidopsis Response Regulator 6 (arr6), that showed altered disease
resistance to several pathogens, triggered more intense immune responses than those
activated by similar cell wall fractions from wild-type plants. It was hypothesized that arr6
cell wall fractions could be differentially enriched in DAMPs. In this work, we describe the
characterization of the previous immune-active fractions of arr6 showing the highest
triggering capacities upon further fractionation by chromatographic means. These
analyses pointed to a role of pentose-based oligosaccharides triggering plant immune
responses. The characterization of several pentose-based oligosaccharide structures
revealed that b-1,4-xylooligosaccharides of specific degrees of polymerization and
carrying arabinose decorations are sensed as DAMPs by plants. Moreover, the
pentasaccharide 33-a-L-arabinofuranosyl-xylotetraose (XA3XX) was found as a highly
active DAMP structure triggering strong immune responses in Arabidopsis thaliana and
enhancing crop disease resistance.SIThis work was supported by grants IND2017/BIO-7800 of the Comunidad de Madrid Regional Government.This work has been also financially supported by the “Severo Ochoa Programme for Centres of Excellence in R&D” from the Agencia Estatal de Investigación of Spain (grant SEV-2016- 0672 (2017-2021) to the CBGP). In the frame of this program HM was supported with a postdoctoral fellow. DR was the recipient of an Industrial PhD Fellow (IND2017/BIO-7800) and IH was the recipient of an PhD FPU fellow from the Spanish Ministry of Education (FPU16/07118). FP thanks the Max Planck Society and the German Research Foundation (DFG, Emmy Noether program PF850/1-1 to FP) for financial support
Non‐branched β‐1,3‐glucan oligosaccharides trigger immune responses in Arabidopsis
[EN] Fungal cell walls, which are essential for environmental adaptation and host colonization by the fungus,
have been evolutionarily selected by plants and animals as a source of microbe-associated molecular patterns
(MAMPs) that, upon recognition by host pattern recognition receptors (PRRs), trigger immune
responses conferring disease resistance. Chito-oligosaccharides [b-1,4-N-acetylglucosamine oligomers,
(GlcNAc)n] are the only glycosidic structures from fungal walls that have been well-demonstrated to function
as MAMPs in plants. Perception of (GlcNAc)4–8 by Arabidopsis involves CERK1, LYK4 and LYK5, three of
the eight members of the LysM PRR family. We found that a glucan-enriched wall fraction from the pathogenic
fungus Plectosphaerella cucumerina which was devoid of GlcNAc activated immune responses in Arabidopsis
wild-type plants but not in the cerk1 mutant. Using this differential response, we identified the
non-branched 1,3-b-D-(Glc) hexasaccharide as a major fungal MAMP. Recognition of 1,3-b-D-(Glc)6 was
impaired in cerk1 but not in mutants defective in either each of the LysM PRR family members or in the
PRR-co-receptor BAK1. Transcriptomic analyses of Arabidopsis plants treated with 1,3-b-D-(Glc)6 further
demonstrated that this fungal MAMP triggers the expression of immunity-associated genes. In silico docking
analyses with molecular mechanics and solvation energy calculations corroborated that CERK1 can bind
1,3-b-D-(Glc)6 at effective concentrations similar to those of (GlcNAc)4. These data support that plants, like
animals, have selected as MAMPs the linear 1,3-b-D-glucans present in the walls of fungi and oomycetes.
Our data also suggest that CERK1 functions as an immune co-receptor for linear 1,3-b-D-glucans in a similar
way to its proposed function in the recognition of fungal chito-oligosaccharides and bacterial peptidoglycan
MAMPs.S
Arabidopsiscell wall composition determines disease resistance specificity and fitness
[EN] Plant cell walls are complex structures subject to dynamic remodeling
in response to developmental and environmental cues and
play essential functions in disease resistance responses. We tested
the specific contribution of plant cell walls to immunity by
determining the susceptibility of a set of Arabidopsis cell wall mutants
(cwm) to pathogens with different parasitic styles: a vascular
bacterium, a necrotrophic fungus, and a biotrophic oomycete. Remarkably,
most cwm mutants tested (29/34; 85.3%) showed alterations
in their resistance responses to at least one of these
pathogens in comparison to wild-type plants, illustrating the relevance
of wall composition in determining disease-resistance phenotypes.
We found that the enhanced resistance of cwm plants to
the necrotrophic and vascular pathogens negatively impacted
cwm fitness traits, such as biomass and seed yield. Enhanced resistance
of cwm plants is not only mediated by canonical immune
pathways, like those modulated by phytohormones or microbeassociated
molecular patterns, which are not deregulated in the
cwm tested. Pectin-enriched wall fractions isolated from cwm
plants triggered immune responses in wild-type plants, suggesting
that wall-mediated defensive pathways might contribute to cwm
resistance. Cell walls of cwm plants show a high diversity of composition
alterations as revealed by glycome profiling that detect
specific wall carbohydrate moieties. Mathematical analysis of glycome
profiling data identified correlations between the amounts of
specific wall carbohydrate moieties and disease resistance phenotypes
of cwm plants. These data support the relevant and specific
function of plant wall composition in plant immune response modulation
and in balancing disease resistance/development trade-offs.SIThis work has been also financially supported by the Severo Ochoa Program for Centers of Excellence in R&D from the Agencia Estatal de Investigación of Spain (Grant SEV-2016-0672 (2017-2021) to the Centro de Biotecnología y Genómica de Plantas). In the frame of this program, H.M. was a postdoctoral fellow. H.M. was also supported by an Individual Fellowship grant (SignWALLINg-624721) from the European Union. E.M. was a Juan de la Cierva Postdoctoral Fellow from MINECO, and L.B. was a Formacion Personal Investigador fellow of MICIU. The generation of the CCRC-series of plant cell glycan-directed monoclonal antibodies used in this work was supported by the US NSF (DBI-0421683 and IOS 0923992) to M.G.H
Signwalling: signals derived from arabiopsis cell wall activate specific resistance to pathogens
The cell wall is a dynamic structure that regulates both constitutive and inducible plant defence responses. Different molecules o DAMPs (damage-associated molecular patterns) can be released from plant cell walls upon pathogen infection or wounding and can trigger immune responses. To further characterize the function of cell wall on the regulation of these immune responses, we have performed a biased resistance screening of putative/well-characterized primary/secondary Arabidopsis thaliana cell wall mutants (cwm). In this screening we have identified more than 20 cwm mutants with altered susceptibility/resistance to at least one of the following pathogens: the necrotrophic fungi Plectosphaerella cucumerina, the vascular bacterium Ralstonia solanacearum, the biotrophic oomycete Hyaloperonospora arabidopsidis and the powdery mildew fungus Erisyphe cruciferarum. We found that cell wall extracts from some of these cwm plants contain novel DAMPs that activate immune responses and conferred enhanced resistance to particular pathogens when they were applied to wild-type plants. Using glycomic profiling we have performed an initial characterization of the active carbohydrate structures present in these cwm wall fractions, and we have determined the signalling pathways regulated by thesse fractions. . The data generated with this collection of wall mutants support the existence of specific correlations between cell wall structure/composition, resistance to particular type of pathogens and plant fitness. Remarkably, we have identified specific cwm mutations that uncoupled resistance to pathogens from plant trade-offs, further indicating the plasticity of wall structures in the regulation of plant immune responses
Healthcare workers hospitalized due to COVID-19 have no higher risk of death than general population. Data from the Spanish SEMI-COVID-19 Registry
Aim To determine whether healthcare workers (HCW) hospitalized in Spain due to COVID-19 have a worse prognosis than non-healthcare workers (NHCW). Methods Observational cohort study based on the SEMI-COVID-19 Registry, a nationwide registry that collects sociodemographic, clinical, laboratory, and treatment data on patients hospitalised with COVID-19 in Spain. Patients aged 20-65 years were selected. A multivariate logistic regression model was performed to identify factors associated with mortality. Results As of 22 May 2020, 4393 patients were included, of whom 419 (9.5%) were HCW. Median (interquartile range) age of HCW was 52 (15) years and 62.4% were women. Prevalence of comorbidities and severe radiological findings upon admission were less frequent in HCW. There were no difference in need of respiratory support and admission to intensive care unit, but occurrence of sepsis and in-hospital mortality was lower in HCW (1.7% vs. 3.9%; p = 0.024 and 0.7% vs. 4.8%; p<0.001 respectively). Age, male sex and comorbidity, were independently associated with higher in-hospital mortality and healthcare working with lower mortality (OR 0.211, 95%CI 0.067-0.667, p = 0.008). 30-days survival was higher in HCW (0.968 vs. 0.851 p<0.001). Conclusions Hospitalized COVID-19 HCW had fewer comorbidities and a better prognosis than NHCW. Our results suggest that professional exposure to COVID-19 in HCW does not carry more clinical severity nor mortality
Plant Biology: Plants Turn Down the Volume to Respond to Cell Swelling.
Turgor manipulation to induce plant cell swelling is one of the classic experiments undertaken in biology courses in schools and at universities. However, only now do we start to understand the molecular mechanisms responsible for detecting plant cell swelling
The role of mechanoperception in plant cell wall integrity maintenance
The plant cell walls surrounding all plant cells are highly dynamic structures, which change their composition and organization in response to chemical and physical stimuli originating both in the environment and in plants themselves. They are intricately involved in all interactions between plants and their environment while also providing adaptive structural support during plant growth and development. A key mechanism contributing to these adaptive changes is the cell wall integrity (CWI) maintenance mechanism. It monitors and maintains the functional integrity of cell walls by initiating adaptive changes in cellular and cell wall metabolism. Despite its importance, both our understanding of its mode of action and knowledge regarding the molecular components that form it are limited. Intriguingly, the available evidence implicates mechanosensing in the mechanism. Here, we provide an overview of the knowledge available regarding the molecular mechanisms involved in and discuss how mechanoperception and signal transduction may contribute to plant CWI maintenance
The interplay between cell wall integrity and cell cycle progression in plants
Plant cell walls are dynamic structures that play crucial roles in growth, development, and stress responses. Despite our growing understanding of cell wall biology, the connections between cell wall integrity (CWI) and cell cycle progression in plants remain poorly understood. This review aims to explore the intricate relationship between CWI and cell cycle progression in plants, drawing insights from studies in yeast and mammals. We provide an overview of the plant cell cycle, highlight the role of endoreplication in cell wall composition, and discuss recent findings on the molecular mechanisms linking CWI perception to cell wall biosynthesis and gene expression regulation. Furthermore, we address future perspectives and unanswered questions in the field, such as the identification of specific CWI sensing mechanisms and the role of CWI maintenance in the growth-defense trade-off. Elucidating these connections could have significant implications for crop improvement and sustainable agriculture