BackgroundPlant phenology has crucial biological, physical, and chemical effects on the biosphere. Phenological drivers have largely been studied, but the role of plant microbiota, particularly rhizosphere microbiota, has not been considered.ResultsWe discovered that rhizosphere microbial communities could modulate the timing of flowering of Arabidopsis thaliana. Rhizosphere microorganisms that increased and prolonged N bioavailability by nitrification delayed flowering by converting tryptophan to the phytohormone indole acetic acid (IAA), thus downregulating genes that trigger flowering, and stimulating further plant growth. The addition of IAA to hydroponic cultures confirmed this metabolic network.ConclusionsWe document a novel metabolic network in which soil microbiota influenced plant flowering time, thus shedding light on the key role of soil microbiota on plant functioning. This opens up multiple opportunities for application, from helping to mitigate some of the effects of climate change and environmental stress on plants (e.g. abnormal temperature variation, drought, salinity) to manipulating plant characteristics using microbial inocula to increase crop potential.Electronic supplementary materialThe online version of this article (10.1186/s40168-018-0615-0) contains supplementary material, which is available to authorized users.
Antibiotic resistance genes (ARGs) have accelerated microbial threats to human health in the last decade. Many genes can confer resistance, but evaluating the relative health risks of ARGs is complex. Factors such as the abundance, propensity for lateral transmission and ability of ARGs to be expressed in pathogens are all important. Here, an analysis at the metagenomic level from various habitats (6 types of habitats, 4572 samples) detects 2561 ARGs that collectively conferred resistance to 24 classes of antibiotics. We quantitatively evaluate the health risk to humans, defined as the risk that ARGs will confound the clinical treatment for pathogens, of these 2561 ARGs by integrating human accessibility, mobility, pathogenicity and clinical availability. Our results demonstrate that 23.78% of the ARGs pose a health risk, especially those which confer multidrug resistance. We also calculate the antibiotic resistance risks of all samples in four main habitats, and with machine learning, successfully map the antibiotic resistance threats in global marine habitats with over 75% accuracy. Our novel method for quantitatively surveilling the health risk of ARGs will help to manage one of the most important threats to human and animal health.
Microorganisms
colonizing the plant rhizosphere provide a number
of beneficial functions for their host. Although an increasing number
of investigations clarified the great functional capabilities of rhizosphere
microbial communities, the understanding of the precise mechanisms
underlying the impact of rhizosphere microbiome assemblies is still
limited. Also, not much is known about the various beneficial functions
of the rhizosphere microbiome. In this review, we summarize the current
knowledge of biotic and abiotic factors that shape the rhizosphere
microbiome as well as the rhizosphere microbiome traits that are beneficial
to plants growth and disease-resistance. We give particular emphasis
on the impact of plant root metabolites on rhizosphere microbiome
assemblies and on how the microbiome contributes to plant growth,
yield, and disease-resistance. Finally, we introduce a new perspective
and a novel method showing how a synthetic microbial community construction
provides an effective approach to unravel the plant–microbes
and microbes–microbes interplays.
Development of advanced wound dressing materials with rapid healing rates is in urgent demand for wound cares. A suitable microenvironment will promote cell proliferation and migration, which benefits to early wound healing and prevents inflammations and scars. In this work, N-carboxymethyl chitosan- and alginate-based hydrogels are prepared via both electrostatic interaction and divalent chelation with epidermal growth factor (EGF) payload to promote the cell proliferation and wound healing. The dual-crosslinked hydrogels are investigated in terms of rheology, water retention ability, and the release rate of EGF. Moreover, such amorphous hydrogel can promote cell proliferation and accelerate wound healing. The present study demonstrates that dual-crosslinked polysaccharide hydrogels are promising in wound care management.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.