Potato () is considered one of the most widely consumed crops worldwide, due to its high yield and nutritional profile, climate change-related environmental threats and increasing food demand. This scenario highlights the need of sustainable agricultural practices to enhance potato productivity, while preserving and maintaining soil health. Plant growth-promoting bacteria (PGPB) stimulate crop production through biofertilization mechanisms with low environmental impact.
View Article and Find Full Text PDFRising atmospheric carbon dioxide concentrations (CO) and atmospheric nitrogen (N) deposition have contrasting effects on ectomycorrhizal (EM) and arbuscular mycorrhizal (AM) symbioses, potentially mediating forest responses to environmental change. In this study, we evaluated the cumulative effects of historical environmental change on N concentrations and δN values in AM plants, EM plants, EM fungi, and saprotrophic fungi using herbarium specimens collected in Minnesota, USA from 1871 to 2016. To better understand mycorrhizal mediation of foliar δN, we also analyzed a subset of previously published foliar δN values from across the United States to parse the effects of N deposition and CO rise.
View Article and Find Full Text PDFThe few studies that compared direct oral anticoagulants (DOAC) vs. warfarin in the setting of advanced renal insufficiency have focused on patients with atrial fibrillation. The purpose of this observational, matched, cohort study of patients was to assess the effectiveness and safety of DOAC vs.
View Article and Find Full Text PDFIntroductionCerebral venous sinus thrombosis (CVST) is a rare neurovascular emergency that has been observed following COVID-19 infection, as well as following the use of non-mRNA COVID-19 vaccines. Case PresentationThe authors report a case of CVST in a 67-year-old woman, unvaccinated for COVID-19, who presented with acute otitis externa. It remains unclear whether the CVST was a following COVID-19 infection complication, otogenic CVST, or a combination of both.
View Article and Find Full Text PDFStrain OCN044 was isolated from the homogenised tissue and mucus of an apparently healthy Acropora cytherea coral fragment collected from the western reef terrace of Palmyra Atoll in the Northern Line Islands and was taxonomically evaluated with a polyphasic approach. The morphological and chemotaxonomic properties are consistent with characteristics of the genus Vibrio: Gram-stain-negative rods, oxidase- and catalase-positive, and motile by means of a polar flagellum. Strain OCN044 can be differentiated as a novel subspecies based on 21 differences among chemotaxonomic features (e.
View Article and Find Full Text PDFImproving biological nitrogen fixation (BNF) in cereal crops is a long-sought objective; however, no successful modification of cereal crops showing increased BNF has been reported. Here, we described a novel approach in which rice plants were modified to increase the production of compounds that stimulated biofilm formation in soil diazotrophic bacteria, promoted bacterial colonization of plant tissues and improved BNF with increased grain yield at limiting soil nitrogen contents. We first used a chemical screening to identify plant-produced compounds that induced biofilm formation in nitrogen-fixing bacteria and demonstrated that apigenin and other flavones induced BNF.
View Article and Find Full Text PDFIt is commonly assumed that microbial communities are structured by "bottom-up" ecological forces, although few experimental manipulations have rigorously tested the mechanisms by which resources structure soil communities. We investigated how plant substrate availability might structure fungal communities and belowground processes along an experimental plant richness gradient in a grassland ecosystem. We hypothesized that variation in total plant-derived substrate inputs, plant functional group diversity, as well as the relative abundance of C grasses and legumes would modulate fungal α- and β-diversity and their rates of soil carbon (C) and nitrogen (N) cycling.
View Article and Find Full Text PDFForaging intensity of large herbivores may exert an indirect top-down ecological force on soil microbial communities via changes in plant litter inputs. We investigated the responses of the soil microbial community to elk (Cervus elaphus) winter range occupancy across a long-term foraging exclusion experiment in the sagebrush steppe of the North American Rocky Mountains, combining phylogenetic analysis of fungi and bacteria with shotgun metagenomics and extracellular enzyme assays. Winter foraging intensity was associated with reduced bacterial richness and increasingly distinct bacterial communities.
View Article and Find Full Text PDFLitter decomposition is an enzymatically-complex process that is mediated by a diverse assemblage of saprophytic microorganisms. It is a globally important biogeochemical process that can be suppressed by anthropogenic N deposition. In a northern hardwood forest ecosystem located in Michigan, USA, 20 years of experimentally increased atmospheric N deposition has reduced forest floor decay and increased soil C storage.
View Article and Find Full Text PDFAlthough we understand the ecological processes eliciting changes in plant community composition during secondary succession, we do not understand whether co-occurring changes in plant detritus shape saprotrophic microbial communities in soil. In this study, we investigated soil microbial composition and function across an old-field chronosequence ranging from 16 to 86 years following agricultural abandonment, as well as three forests representing potential late-successional ecosystems. Fungal and bacterial community composition was quantified from ribosomal DNA, and insight into the functional potential of the microbial community to decay plant litter was gained from shotgun metagenomics and extracellular enzyme assays.
View Article and Find Full Text PDFSaprotrophic microbial communities in soil are primarily structured by the availability of growth-limiting resources (i.e., plant detritus), a bottom-up ecological force.
View Article and Find Full Text PDFPriority effects are an important ecological force shaping biotic communities and ecosystem processes, in which the establishment of early colonists alters the colonization success of later-arriving organisms via competitive exclusion and habitat modification. However, we do not understand which biotic and abiotic conditions lead to strong priority effects and lasting historical contingencies. Using saprotrophic fungi in a model leaf decomposition system, we investigated whether compositional and functional consequences of initial colonization were dependent on initial colonizer traits, resource availability or a combination thereof.
View Article and Find Full Text PDFThe synthesis, computer modeling, and biological activity of an octawalled molecular umbrella short interfacing RNA (siRNA) conjugate is described. This molecular umbrella-siRNA conjugate exhibited mRNA knockdown activity in vitro in the absence of a transfection reagent. Evaluation of this molecular umbrella conjugate in vivo, using the rat eye via intravitreal injection, resulted in sequence specific mRNA knockdown in the retina with no obvious signs of toxicity, as judged by ophthalmic examination.
View Article and Find Full Text PDFMicrobial communities in soil mediate biogeochemical processes; however, understanding forces shaping their composition and function remains a gap in our ecological knowledge. We investigated phylogenetic turnover and functional gene composition of saprotrophic fungi along a 4000-year glacial chronosequence. A direct relationship between β-diversity and geographic distance, a proxy for time since deglaciation, indicated that dispersal limitation shapes saprotrophic fungal communities.
View Article and Find Full Text PDFA strategy was developed to extend the lifetime of an peptide-based substrate for Abl kinase in the cytosolic environment. Small β-turn structures were added to the peptide's N-terminus to block entry into peptidase catalytic sites. The influence of the size of the β-turn and two covalent cross-linking strategies on the rate of hydrolysis was assessed.
View Article and Find Full Text PDFPEGylated phospholipids are commonly used to increase the blood-circulation time of liposomes by providing a steric barrier around them. This paper documents a fundamentally new property of these lipids-an ability to stimulate the release of cholesterol from phospholipid membranes. Evidence for such stimulation has been obtained by measuring the transport of dehydroergosterol (DHE), a fluorescent simulant of cholesterol, from donor liposomes made from 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)-2000 (DSPE-PEG(2000)), and DHE to acceptor liposomes made from POPC, 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoglycerol (POPG), and cholesterol.
View Article and Find Full Text PDFA series of diwalled and tetrawalled molecular umbrellas have been synthesized using cholic acid, spermidine, and lysine as starting materials. Coupling of these molecular umbrellas to an octaarginine peptide afforded agents that were capable of promoting the transport of small interfering RNA to HeLa cells, as judged by the knockdown of enhanced green fluorescent protein expression. The efficiency of this knockdown was found to increase with an increasing number of facially amphiphilic walls present, and also when a cleavable disulfide linker was replaced with a noncleavable, maleimido moiety; i.
View Article and Find Full Text PDFDesigning receptors that bind RNA is a challenging endeavor because of the unique and sometimes complex structure of RNA. However these structural features provide regions for ligands to bind using different types of interactions. To increase specificity and binding affinity to RNA, divalent systems have been designed which incorporate more than one binding motif into one molecule.
View Article and Find Full Text PDFTo investigate the effect of peptide secondary structure on proteolytic resistance, we have synthesized a series of peptides based on a well-folded beta-hairpin, WKWK. Mutations were made within the peptide which either decreased or increased the propensity to form beta-hairpin structures and one scrambled sequence was used as an unstructured control. The peptides were incubated with three different enzymes, alpha-chymotrypsin, trypsin, and pronase E, which represented both specific and non-specific proteases.
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