ABSTRACT
The seed-endophytic bacterial community is a potentially beneficial and heritable fraction of the plant microbiome. Its utilization as a sustainable crop improvement strategy could be especially valuable for species such as hemp, where production is being scaled up and new challenges will be faced in managing crop productivity and health. However, little is known about the makeup and variation of the hemp seed microbiome. This study profiled the endophytic bacterial communities harboured by 16 hemp cultivars sourced from commercial suppliers in Europe. A 16S rDNA amplicon sequencing approach identified 917 amplicon sequence variants across samples. Taxonomic classification of sequences revealed 4 phyla and 87 genera to be represented in the dataset. Several genera were widespread while some were specific to one or a few cultivars. Flavobacterium, Pseudomonas, and Pantoea were notable in their high overall abundance and prevalence, but community composition was variable and no one taxon was universally abundant, suggesting a high degree of flexibility in community assembly. Taxonomic composition and alpha diversity differed among cultivars, though further work is required to understand the relative influence of hemp genetic factors on community structure. The taxonomic profiles presented here can be used to inform further work investigating the functional characteristics and potential plant-growth-promoting traits of seed-borne bacteria in hemp.
Subject(s)
Bacteria , Cannabis , Endophytes , RNA, Ribosomal, 16S , Seeds , Cannabis/microbiology , Cannabis/genetics , Bacteria/classification , Bacteria/genetics , Bacteria/isolation & purification , Seeds/microbiology , Endophytes/genetics , Endophytes/classification , Endophytes/isolation & purification , RNA, Ribosomal, 16S/genetics , Microbiota , Phylogeny , Biodiversity , Europe , DNA, Bacterial/geneticsABSTRACT
Plant-associated microbes play vital roles in promoting plant growth and health, with plants secreting root exudates into the rhizosphere to attract beneficial microbes. Exudate composition defines the nature of microbial recruitment, with different plant species attracting distinct microbiota to enable optimal adaptation to the soil environment. To more closely examine the relationship between plant genotype and microbial recruitment, we analysed the rhizosphere microbiomes of landrace (Chevallier) and modern (NFC Tipple) barley (Hordeum vulgare) cultivars. Distinct differences were observed between the plant-associated microbiomes of the 2 cultivars, with the plant-growth promoting rhizobacterial genus Pseudomonas substantially more abundant in the Tipple rhizosphere. Striking differences were also observed between the phenotypes of recruited Pseudomonas populations, alongside distinct genotypic clustering by cultivar. Cultivar-driven Pseudomonas selection was driven by root exudate composition, with the greater abundance of hexose sugars secreted from Tipple roots attracting microbes better adapted to growth on these metabolites and vice versa. Cultivar-driven selection also operates at the molecular level, with both gene expression and the abundance of ecologically relevant loci differing between Tipple and Chevallier Pseudomonas isolates. Finally, cultivar-driven selection is important for plant health, with both cultivars showing a distinct preference for microbes selected by their genetic siblings in rhizosphere transplantation assays.
Subject(s)
Genotype , Hordeum , Microbiota , Plant Roots , Pseudomonas , Rhizosphere , Hordeum/microbiology , Hordeum/genetics , Hordeum/metabolism , Plant Roots/microbiology , Plant Roots/metabolism , Microbiota/physiology , Microbiota/genetics , Pseudomonas/genetics , Pseudomonas/metabolism , Pseudomonas/physiology , Soil Microbiology , Plant Exudates/metabolismABSTRACT
Heteroleptic metal-organic capsules, which incorporate more than one type of ligand, can provide enclosed, anisotropic interior cavities for binding low-symmetry molecules of biological and industrial importance. However, the selective self-assembly of a single mixed-ligand architecture, as opposed to the numerous other possible self-assembly outcomes, remains a challenge. Here, we develop a design strategy for the subcomponent self-assembly of heteroleptic metal-organic architectures with anisotropic internal void spaces. Zn6Tet3Tri2 triangular prismatic and Zn8Tet2Tet'4 tetragonal prismatic architectures were prepared through careful matching of the side lengths of the tritopic (Tri) or tetratopic (Tet, Tet') and panels.
ABSTRACT
OBJECTIVES: Limited evidence exists on the policies to increase self-isolation compliance, with no experimental evidence. This trial aimed to evaluate the effect of a home visiting intervention in the London Borough of Havering on compliance with self-isolation guidance, relative to positive COVID-19 cases who received no home visits. DESIGN: Mixed method evaluation involving a two-arm randomized controlled trial (RCT) with an implementation and process evaluation. METHODS: A total of 3878 cases who tested positive for COVID-19 were randomly allocated with equal probability to receive home visits from Havering outreach team staff (n = 1946) or to a control group (n = 1932) who did not receive home visits. Randomization was implemented through a spreadsheet consisting of random numbers generated online that was used to randomly allocate cases to treatment and control. Check-in calls were conducted by a separate blinded contact tracing team on day six of isolation to measure successful self-isolation compliance. The primary intention-to-treat (ITT) analysis was conducted on 3860 cases as 18 patients were excluded from analysis because of the missing outcome data. For the implementation and process evaluation, qualitative, semi-structured, one-to-one interviews were conducted with trial participants in the treatment arm of the RCT (n = 15) and stakeholders within the London Borough of Havering's Adult Social Care and Health Team (n = 8). Qualitative data was analysed thematically using a framework approach. RESULTS: Positive cases who were allocated to receive the home visiting intervention (n = 1933) were more likely to report successful self-isolation compared to those allocated to the control group (n = 1927), an effect that was statistically significant (odds ratio 1.204 [95% CI: 1.052, 1.377]; absolute probability difference: 4.1 percentage points [95% CI: 1.2-6.9]). The implementation and process evaluation found that a key driver of compliance was altruistic motivation based on its perceived importance for protecting the community with some participants also reporting the potential of being caught not complying as a driving factor. Participants also reported that the intervention helped them 'feel supported', provided them with information about practical and financial support, and clarified their understanding or increased their awareness of self-isolation and COVID-19 guidance. No harms were reported from this trial. The trial was registered at the ISRCTN registry, number ISRCTN10030612. CONCLUSIONS: A home-visiting intervention conducted between January and March 2022 increased the self-isolation compliance of positive COVID-19 cases allocated to receive home visits. The implementation and process evaluation highlighted that the intervention increased individuals' motivation to comply with guidance, and addressed some barriers associated with opportunity and capability to comply. This trial provides much-needed evidence to inform the policy and intervention design to support public health and social measures in future outbreak scenarios.
Subject(s)
COVID-19 , Adult , Humans , Patient Compliance , LondonABSTRACT
We derive design principles for the assembly of rectangular tetramines into Zn8 L6 pseudo-cubic coordination cages. Because of the rectangular, as opposed to square, geometry of the ligand panels, and the possibility of either Δ or Λ handedness of each metal center at the eight corners of the pseudo-cube, many different cage diastereomers are possible. Each of the six tetra-aniline subcomponents investigated in this work assembled with zinc(II) and 2-formylpyridine in acetonitrile into a single Zn8 L6 pseudo-cube diastereomer, however. Each product corresponded to one of four diastereomeric configurations, with T, Th , S6 or D3 symmetry. The preferred diastereomer for a given tetra-aniline subcomponent was shown to be dependent on its aspect ratio and conformational flexibility. Analysis of computationally modeled individual faces or whole pseudo-cubes provided insight as to why the observed diastereomers were favored.
ABSTRACT
The field of metallosupramolecular chemistry has advanced rapidly in recent years. Much work in this area has focused on the formation of hollow self-assembled metal-organic architectures and exploration of the applications of their confined nanospaces. These discrete, soluble structures incorporate metal ions as 'glue' to link organic ligands together into polyhedra.Most of the architectures employed thus far have been highly symmetrical, as these have been the easiest to prepare. Such high-symmetry structures contain pseudospherical cavities, and so typically bind roughly spherical guests. Biomolecules and high-value synthetic compounds are rarely isotropic, highly-symmetrical species. To bind, sense, separate, and transform such substrates, new, lower-symmetry, metal-organic cages are needed. Herein we summarize recent approaches, which taken together form the first draft of a handbook for the design of higher-complexity, lower-symmetry, self-assembled metal-organic architectures.
Subject(s)
Metals , Ligands , Metals/chemistryABSTRACT
Mastery imagery (i.e., images of being in control and coping in difficult situations) is used to regulate anxiety. The ability to image this content is associated with trait confidence and anxiety, but research examining mastery imagery ability's association with confidence and anxiety in response to a stressful event is scant. The present study examined whether trait mastery imagery ability mediated the relationship between confidence and anxiety, and the subsequent associations on performance in response to an acute psychological stress. Participants (N = 130; 55% male; M age = 19.94 years; SD = 1.07 years) completed assessments of mastery imagery ability and engaged in a standardized acute psychological stress task. Immediately prior to the task, confidence, cognitive and somatic anxiety intensity, and interpretation of anxiety symptoms regarding the task were assessed. Path analyses supported a model whereby mastery imagery ability mediated the relationship between confidence and cognitive and somatic anxiety interpretation. Greater mastery imagery ability and confidence were both directly associated with better performance on the stress task. Mastery imagery ability may help individuals experience more facilitative anxiety and perform better during stressful tasks. Improving mastery imagery ability by enhancing self-confidence may help individuals successfully cope with anxiety elicited during stressful situations.
ABSTRACT
Background: Acute psychological stress elicits increases in heart rate (HR) and anxiety. Theories propose associations between HR, perceived HR, and anxiety during stress. However, anxiety is often measured as a unidimensional construct which limits a comprehensive understanding of these relationships. Objectives: This research explored whether HR reactivity or perceived HR change was more closely associated with cognitive and somatic anxiety during acute psychological stress. Design: Two laboratory-based studies were conducted. Methods: In a single laboratory session, healthy male (N = 71; study 1) and female (N = 70; study 2) university students completed three laboratory psychological stress tasks (counterbalanced), each with a preceding baseline. Heart rate, perceived HR change, and cognitive and somatic anxiety intensity and interpretation of anxiety symptoms were assessed immediately following each task. Data were aggregated across tasks. Results: Actual HR change was unrelated to anxiety intensity, but was associated with more debilitative interpretations of anxiety (study 2). Perceptions of HR change were consistently associated with greater intensity of cognitive (study 1) and somatic (study 1 and 2) anxiety. Conclusions: Perceived HR rather than actual HR is more closely associated with anxiety intensity during psychological stress. The findings have implications for stress management and the clinical treatment of anxiety symptoms.
Subject(s)
Anxiety/physiopathology , Heart Rate , Psychological Distress , Anxiety/psychology , Competitive Behavior/physiology , Electrocardiography, Ambulatory , Female , Humans , Interoception , Male , Problem Solving/physiology , Stress, Psychological/physiopathology , Stress, Psychological/psychology , Young AdultABSTRACT
Crassulacean acid metabolism (CAM) is a specialized mode of photosynthesis that features nocturnal CO2 uptake, facilitates increased water-use efficiency (WUE), and enables CAM plants to inhabit water-limited environments such as semi-arid deserts or seasonally dry forests. Human population growth and global climate change now present challenges for agricultural production systems to increase food, feed, forage, fiber, and fuel production. One approach to meet these challenges is to increase reliance on CAM crops, such as Agave and Opuntia, for biomass production on semi-arid, abandoned, marginal, or degraded agricultural lands. Major research efforts are now underway to assess the productivity of CAM crop species and to harness the WUE of CAM by engineering this pathway into existing food, feed, and bioenergy crops. An improved understanding of CAM has potential for high returns on research investment. To exploit the potential of CAM crops and CAM bioengineering, it will be necessary to elucidate the evolution, genomic features, and regulatory mechanisms of CAM. Field trials and predictive models will be required to assess the productivity of CAM crops, while new synthetic biology approaches need to be developed for CAM engineering. Infrastructure will be needed for CAM model systems, field trials, mutant collections, and data management.