Detection and quantification of a mycorrhization helper bacterium and a mycorrhizal fungus in plant-soil microcosms at different levels of complexity

BACKGROUND: Host plant roots, mycorrhizal mycelium and microbes are important and potentially interacting factors shaping the performance of mycorrhization helper bacteria (MHB). We investigated the impact of a soil microbial community on the interaction between the extraradical mycelium of the ectomycorrhizal fungus Piloderma croceum and the MHB Streptomyces sp. AcH 505 in both the presence and the absence of pedunculate oak microcuttings. RESULTS: Specific primers were designed to target the internal transcribed spacer of the rDNA and an intergenic region between two protein encoding genes of P. croceum and the intergenic region between the gyrA and gyrB genes of AcH 505. These primers were used to perform real-time PCR with DNA extracted from soil samples. With a sensitivity of 10 genome copies and a linear range of 6 orders of magnitude, these real-time PCR assays enabled the quantification of purified DNA from P. croceum and AcH 505, respectively. In soil microcosms, the fungal PCR signal was not affected by AcH 505 in the absence of the host plant. However, the fungal signal became weaker in the presence of the plant. This decrease was only observed in microbial filtrate amended microcosms. In contrast, the PCR signal of AcH 505 increased in the presence of P. croceum. The increase was not significant in sterile microcosms that contained plant roots. CONCLUSIONS: Real-time quantitative PCR assays provide a method for directly detecting and quantifying MHB and mycorrhizal fungi in plant microcosms. Our study indicates that the presence of microorganisms and plant roots can both affect the nature of MHB-fungus interactions, and that mycorrhizal fungi may enhance MHB growth

Large scale transcriptome analysis reveals interplay between development of forest trees and a beneficial mycorrhiza helper bacterium

BACKGROUND: Pedunculate oak, Quercus robur is an abundant forest tree species that hosts a large and diverse community of beneficial ectomycorrhizal fungi (EMFs), whereby ectomycorrhiza (EM) formation is stimulated by mycorrhiza helper bacteria such as Streptomyces sp. AcH 505. Oaks typically grow rhythmically, with alternating root flushes (RFs) and shoot flushes (SFs). We explored the poorly understood mechanisms by which oaks integrate signals induced by their beneficial microbes and endogenous rhythmic growth at the level of gene expression. To this end, we compared transcript profiles of oak microcuttings at RF and SF during interactions with AcH 505 alone and in combination with the basidiomycetous EMF Piloderma croceum. RESULTS: The local root and distal leaf responses to the microorganisms differed substantially. More genes involved in the recognition of bacteria and fungi, defence and cell wall remodelling related transcription factors (TFs) were differentially expressed in the roots than in the leaves of oaks. In addition, interaction with AcH 505 and P. croceum affected the expression of a higher number of genes during SF than during RF, including AcH 505 elicited defence response, which was attenuated by co-inoculation with P. croceum in the roots during SF. Genes encoding leucine-rich receptor-like kinases (LRR-RLKs) and proteins (LRR-RLPs), LRR containing defence response regulators, TFs from bZIP, ERF and WRKY families, xyloglucan cell wall transglycolases/hydrolases and exordium proteins were differentially expressed in both roots and leaves of plants treated with AcH 505. Only few genes, including specific RLKs and TFs, were induced in both AcH 505 and co-inoculation treatments. CONCLUSION: Treatment with AcH 505 induces and maintains the expression levels of signalling genes encoding candidate receptor protein kinases and TFs and leads to differential expression of cell wall modification related genes in pedunculate oak microcuttings. Local gene expression response to AcH 505 alone and in combination with P. croceum are more pronounced when roots are in resting stages, possibly due to the fact that non growing roots re-direct their activity towards plant defence rather than growth. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12864-015-1856-y) contains supplementary material, which is available to authorized users

Metropolis versus necropolis: Polarity in the relationship between the city and the cemetery in history

The evolution of the city and the cemetery have always been running parallel in history, one couldn't exist without the other their relationship has always been strongly intertwined, yet strongly polarised. The aim of this report is to analyse key historical examples, relating to particular historical events, which in my opinion, may help to open - at least a partial view - on the evolution of the relationship between the city and the cemetery, affected by the shifting and changing balance of religious, political and socio-cultural components. In ancient times, the human body was taken as a reference to design the city first developing the metaphor of the city as a living organism - a metaphor which will be largely used through history, as will we see later. In the Greek and Roman cultures, the dead were not allowed to pollute the space of the living and the cemetery and the city were two separate entities. The advent of Christianity in Medieval times, saw the introduction of churchyards within the city walls, which also along with poor heath conditions of the then cities, facilitated the spread of epidemic diseases such as cholera. The Renaissance brought with it the desire to start afresh new cities and towns. The many projects of ideal cities left behind by architects such as Filarete or Scamozzi, were primarily concerned with the aesthetic and the security of the city rather than the real issues- health and hygiene and the spread epidemic diseases issues that finally urbanists had to address with the expansion of the cities due to the advent of the Industrial Revolution. Work forces during this particular historical moment moved from the countryside to city centres. The absence of any burial regulation and health issues urged the introduction of legislations which moved the cemeteries out of the city. In England, the Burial Act (which came to force in 1851) marked the introduction of suburban necropolises in the Victorian era, to resolve the issues of crowed inner city burial grounds, and guarantee city inhabitants a healthier life in the city centres. This also facilitated the condition for the development of a new strong architectural language specific to the cemetery in the Victorian era, which mostly came from cultures with strong past records of funerary traditions, like the Egyptians or the Romans. The new suburban necropolis in Victorian England, was the starting point of a new type of cemetery, which was also perceived as a public civic space, like a park. From now on we will see that the city and the cemetery will be almost completely separated: the city - growing into the metropolis, a complex, sometimes chaotic large urban development, and the cemetery - The Renaissance brought with it the desire to start afresh new cities and towns. The many projects of ideal cities left behind by architects such as Filarete or Scamozzi, were primarily concerned with the aesthetic and the security of the city rather than the real issues health and hygiene and the spread epidemic diseases issues that finally urbanists had to address with the expansion of the cities due to the advent of the Industrial Revolution. Work forces during this particular historical moment moved from the countryside to city centres. The absence of any burial regulation and health issues urged the introduction of legislations which moved the cemeteries out of the city. In England, the Burial Act (which came to force in 1851) marked the introduction of suburban necropolises in the Victorian era, to resolve the issues of crowed inner city burial grounds, and guarantee city inhabitants a healthier life in the city centres. This also facilitated the condition for the development of a new strong architectural language specific to the cemetery in the Victorian era, which mostly came from cultures with strong past records of funerary traditions, like the Egyptians or the Romans. The new suburban necropolis in Victorian England, was the starting point of a new type of cemetery, which was also perceived as a public civic space, like a park. From now on we will see that the city and the cemetery will be almost completely separated: the city - growing into the metropolis, a complex, sometimes chaotic large urban development, and the cemetery

Ectomycorrhizal fungus supports endogenous rhythmic growth and corresponding resource allocation in oak during various below- and aboveground biotic interactions

Endogenous rhythmic growth (ERG) is displayed by many tropical and some major temperate tree species and characterized by alternating root and shoot flushes (RF and SF). These flushes occur parallel to changes in biomass partitioning and in allocation of recently assimilated carbon and nitrogen. To address how biotic interactions interplay with ERG, we cross-compared the RF/SF shifts in oak microcuttings in the presence of pathogens, consumers and a mycorrhiza helper bacterium, without and with an ectomycorrhizal fungus (EMF), and present a synthesis of the observations. The typical increase in carbon allocation to sink leaves during SF did not occur in the presence of root or leaf pathogens, and the increase in nitrogen allocation to lateral roots during RF did not occur with the pathogens. The RF/SF shifts in resource allocation were mostly restored upon additional interaction with the EMF. Its presence led to increased resource allocation to principal roots during RF, also when the oaks were inoculated additionally with other interactors. The interactors affected the alternating, rhythmic growth and resource allocation shifts between shoots and roots. The restoring role of the EMF on RF/SF changes in parallel to the corresponding enhanced carbon and nitrogen allocation to sink tissues suggests that the EMF is supporting plants in maintaining the ERG

Differential transcriptional responses to Ebola and Marburg virus infection in bat and human cells

The unprecedented outbreak of Ebola in West Africa resulted in over 28,000 cases and 11,000 deaths, underlining the need for a better understanding of the biology of this highly pathogenic virus to develop specific counter strategies. Two filoviruses, the Ebola and Marburg viruses, result in a severe and often fatal infection in humans. However, bats are natural hosts and survive filovirus infections without obvious symptoms. The molecular basis of this striking difference in the response to filovirus infections is not well understood. We report a systematic overview of differentially expressed genes, activity motifs and pathways in human and bat cells infected with the Ebola and Marburg viruses, and we demonstrate that the replication of filoviruses is more rapid in human cells than in bat cells. We also found that the most strongly regulated genes upon filovirus infection are chemokine ligands and transcription factors. We observed a strong induction of the JAK/STAT pathway, of several genes encoding inhibitors of MAP kinases (DUSP genes) and of PPP1R15A, which is involved in ER stress-induced cell death. We used comparative transcriptomics to provide a data resource that can be used to identify cellular responses that might allow bats to survive filovirus infections.Additional co-authors: Andreas J. Gruber, Franziska Hufsky, Henrike Indrischek, Sabina Kanton, Jörg Linde, Nelly Mostajo, Roman Ochsenreiter, Konstantin Riege, Lorena Rivarola-Duarte, Abdullah H. Sahyoun, Sita J. Saunders, Stefan E. Seemann, Andrea Tanzer, Bertram Vogel, Michael T. Wolfinger, Rolf Backofen, Jan Gorodkin, Ivo Grosse, Ivo Hofacker, Steve Hoffmann, Christoph Kaleta, Peter F. Stadler, Stephan Becker, and Manja Marz

Cultural adaptation of internet- and mobile-based interventions for mental disorders: a systematic review

AbstractProviding accessible and effective healthcare solutions for people living in low- and middle-income countries, migrants, and indigenous people is central to reduce the global mental health treatment gap. Internet- and mobile-based interventions (IMI) are considered scalable psychological interventions to reduce the burden of mental disorders and are culturally adapted for implementation in these target groups. In October 2020, the databases PsycInfo, MEDLINE, Embase, Cochrane Central Register of Controlled Trials, and Web of Science were systematically searched for studies that culturally adapted IMI for mental disorders. Among 9438 screened records, we identified 55 eligible articles. We extracted 17 content, methodological, and procedural components of culturally adapting IMI, aiming to consider specific situations and perspectives of the target populations. Adherence and effectiveness of the adapted IMI seemed similar to the original IMI; yet, no included study conducted a direct comparison. The presented taxonomy of cultural adaptation of IMI for mental disorders provides a basis for future studies investigating the relevance and necessity of their cultural adaptation.PROSPERO registration number: CRD42019142320.</jats:p

Cultural adaptation of internet- and mobile-based interventions for mental disorders: a systematic review

Providing accessible and effective healthcare solutions for people living in low- and middle-income countries, migrants, and indigenous people is central to reduce the global mental health treatment gap. Internet- and mobile-based interventions (IMI) are considered scalable psychological interventions to reduce the burden of mental disorders and are culturally adapted for implementation in these target groups. In October 2020, the databases PsycInfo, MEDLINE, Embase, Cochrane Central Register of Controlled Trials, and Web of Science were systematically searched for studies that culturally adapted IMI for mental disorders. Among 9438 screened records, we identified 55 eligible articles. We extracted 17 content, methodological, and procedural components of culturally adapting IMI, aiming to consider specific situations and perspectives of the target populations. Adherence and effectiveness of the adapted IMI seemed similar to the original IMI; yet, no included study conducted a direct comparison. The presented taxonomy of cultural adaptation of IMI for mental disorders provides a basis for future studies investigating the relevance and necessity of their cultural adaptation.PROSPERO registration number: CRD42019142320

Oak displays common local but specific distant gene regulation responses to different mycorrhizal fungi

Abstract Background Associations of tree roots with diverse symbiotic mycorrhizal fungi have distinct effects on whole plant functioning. An untested explanation might be that such effect variability is associated with distinct impacts of different fungi on gene expression in local and distant plant organs. Using a large scale transcriptome sequencing approach, we compared the impact of three ectomycorrhizal (EMF) and one orchid mycorrhizal fungi (OMF) on gene regulation in colonized roots (local), non-colonized roots (short distance) and leaves (long distance) of the Quercus robur clone DF159 with reference to the recently published oak genome. Since different mycorrhizal fungi form symbiosis in a different time span and variable extents of apposition structure development, we sampled inoculated but non-mycorrhizal plants, for which however markedly symbiotic effects have been reported. Local root colonization by the fungi was assessed by fungal transcript analysis. Results The EMF induced marked and species specific effects on plant development in the analysed association stage, but the OMF did not. At local level, a common set of plant differentially expressed genes (DEG) was identified with similar patterns of responses to the three EMF, but not to the OMF. Most of these core DEG were down-regulated and correspond to already described but also new functions related to establishment of EMF symbiosis. Analysis of the fungal transcripts of two EMF in highly colonized roots also revealed onset of a symbiosis establishment. In contrast, in the OMF, the DEG were mainly related to plant defence. Already at short distances, high specificities in transcriptomic responses to the four fungi were detected, which were further enhanced at long distance in leaves, where almost no common DEG were found between the treatments. Notably, no correlation between phylogeny of the EMF and gene expression patterns was observed. Conclusions Use of clonal oaks allowed us to identify a core transcriptional program in roots colonized by three different EMF, supporting the existence of a common EMF symbiotic pathway. Conversely, the specific responses in non-colonized organs were more closely related to the specific impacts of the different of EMF on plant performance. </jats:sec

Streptomyces-Elicited Defence Response of Oak (Quercus robur) To Powdery Mildew Infection

Streptomyces can be favourable to plant growth in several ways. In their presence, the formation and functioning of mycorrhiza, a mutually beneficial plant-fungus symbiosis, may be promoted. In contrast, production of secondary metabolites can repress fungal growth at plant roots, thus preventing root colonisation. Most interestingly however, root colonisation with streptomycetes can trigger a response that is detectable in distal plant parts, i.e. in the leaves. Here we show that inoculation of roots of pedunculate oak (Quercus robur) with the Mycorrhiza Helper Bacterium Streptomyces sp. AcH 505 can be observed in oak leaves as a specific modulation of gene expression. Concomitantly, the plants’ defence response against the leaf pathogenic fungus Microsphaera alphitoides (oak powdery mildew) is increased, alleviating the detrimental effect of the fungal infection. Quercus robur clone DF159, the clonal tree model of the platform TrophinOak [1], was used to investigate how oak coordinates these biotrophic interactions.The analysis of gene expression patterns based on RNA-seq in the oak- Streptomyces AcH 505-powdery mildew interaction suggests that Streptomyces AcH 505 not only activates the jasmonic acid / ethylene dependent defence response, as it has previously been described in plant-bacterium interactions that result in increased resistance. Instead, Streptomyces AcH 505 also modulates salicylic acid and abscisic acid dependent signalling, even in the absence of the fungal pathogen. These signalling pathways may be activated as part of a direct defence against pathogen attack, suggesting that Streptomyces AcH 505 is perceived by the plant as a potential pathogen. This view was further substantiated following the comparison of gene expression patterns in single inoculations with powdery mildew and Streptomyces AcH 505, respectively. Here we were surprised to recognise that the systemic responses of oak to the fungus and to Streptomyces AcH 505 share patterns of gene expression [2]. This study provides novel insights into the molecular mechanisms of priming in plants for enhanced defence and may be instrumental in understanding actinobacteria elicited defence responses. In the case of Streptomyces AcH 505, priming acts in concert with proven antibiotics production and exudation of stimulators of mycorrhiza formation, and underlines the versatility of Streptomyces bacteria upon interactions with eukaryotes.References[1] Herrmann et al. Perspectives in Plant Ecology, Evolution and Systematics. 2016, 19:40-48[2] Kurth et al. Molecular Plant-Microbe Interactions. 2014, 27:891-90