Encapsulated plant growth regulators and associative microorganisms: Nature-based solutions to mitigate the effects of climate change on plants.

Over the past decades, the atmospheric CO concentration and global average temperature have been increasing, and this trend is projected to soon become more severe. This scenario of climate change intensifies abiotic stress factors (such as drought, flooding, salinity, and ultraviolet radiation) that threaten forest and associated ecosystems as well as crop production. These factors can negatively affect plant growth and development with a consequent reduction in plant biomass accumulation and yield, in addition to increasing plant susceptibility to biotic stresses.

Production and Characterization of a Novel Exopolysaccharide from .

The current study examines the desiccation-resistant TTB310 as a model organism for the production of novel exopolysaccharides and their structural features. This bacterium is able to produce dividing forms of cysts which synthesize cell-bound exopolysaccharide. Initial experiments were conducted on the enrichment of cyst biomass for exopolysaccharide production under batch-fed conditions in a pilot-scale bioreactor, with lactate as the source of carbon and energy.

Bacterial Metabolites and Particle Size Determine Cerium Oxide Nanomaterial Biotransformation.

Soil is a major receptor of manufactured nanomaterials (NMs) following unintentional releases or intentional uses. Ceria NMs have been shown to undergo biotransformation in plant and soil organisms with a partial Ce(IV) reduction into Ce(III), but the influence of environmentally widespread soil bacteria is poorly understood. We used high-energy resolution fluorescence-detected X-ray absorption spectroscopy (HERFD-XAS) with an unprecedented detection limit to assess Ce speciation in a model soil bacterium () exposed to CeO NMs of different sizes and shapes.

Aquatic Mesocosm Strategies for the Environmental Fate and Risk Assessment of Engineered Nanomaterials.

In the past decade, mesocosms have emerged as a useful tool for the environmental study of engineered nanomaterials (ENMs) as they can mimic the relevant exposure scenario of contamination. Herein, we analyzed the scientific outcomes of aquatic mesocosm experiments, with regard to their designs, the ENMs tested, and the end points investigated. Several mesocosm designs were consistently applied in the past decade to virtually mimic various contamination scenarios with regard to ecosystem setting as well as ENMs class, dose, and dosing.

Uptake patterns of critical metals in alpine plant species growing in an unimpaired natural site.

The range of metals used for industrial purposes - electrical engineering, solar panels, batteries - has increased substantially over the last twenty years. Some of these emerging metals are the subject of geopolitical conflict and are considered critical as their unique properties make them irreplaceable. Many of these elements are poorly studied and their biogeochemical cycles still raise many questions.

Nanotechnology Potential in Seed Priming for Sustainable Agriculture.

Our agriculture is threatened by climate change and the depletion of resources and biodiversity. A new agriculture revolution is needed in order to increase the production of crops and ensure the quality and safety of food, in a sustainable way. Nanotechnology can contribute to the sustainability of agriculture.

Evidence that Soil Properties and Organic Coating Drive the Phytoavailability of Cerium Oxide Nanoparticles.

The ISO-standardized RHIZOtest is used here for the first time to decipher how plant species, soil properties, and physical-chemical properties of the nanoparticles and their transformation regulate the phytoavailability of nanoparticles. Two plants, tomato and fescue, were exposed to two soils with contrasted properties: a sandy soil poor in organic matter and a clay soil rich in organic matter, both contaminated with 1, 15, and 50 mg·kg of dissolved Ce(SO), bare and citrate-coated CeO nanoparticles. All the results demonstrate that two antagonistic soil properties controlled Ce uptake.

Nanoparticle Uptake in Plants: Gold Nanomaterial Localized in Roots of Arabidopsis thaliana by X-ray Computed Nanotomography and Hyperspectral Imaging.

Terrestrial plants can internalize and translocate nanoparticles (NPs). However, direct evidence for the processes driving the NP uptake and distribution in plants is scarce at the cellular level. Here, NP-root interactions were investigated after 10 days of exposure of Arabidopsis thaliana to 10 mg·L of negatively or positively charged gold NPs (∼12 nm) in gels.

Halotolerant bioanodes: The applied potential modulates the electrochemical characteristics, the biofilm structure and the ratio of the two dominant genera.

The development of economically-efficient microbial electrochemical technologies remains hindered by the low ionic conductivity of the culture media used as the electrolyte. To overcome this drawback, halotolerant bioanodes were designed with salt marsh sediment used as the inoculum in electrolytes containing NaCl at 30 or 45g/L (ionic conductivity 7.0 or 10.

Remote Biodegradation of Ge-Imogolite Nanotubes Controlled by the Iron Homeostasis of Pseudomonas brassicacearum.

The toxicity of high-aspect-ratio nanomaterials (HARNs) is often associated with oxidative stress. The essential nutrient Fe may also be responsible of oxidative stress through the production of reactive oxygen species. In the present study, it has been examined to what extent adding Fenton reaction promoting Fe impacted the toxicity of an alumino-germanate model HARN.

Design Defines the Effects of Nanoceria at a Low Dose on Soil Microbiota and the Potentiation of Impacts by the Canola Plant.

Soils act as nanoceria sinks via agricultural spreading and surface waters. Canola plants were grown for one month in soil spiked with nanoceria (1 mg·kg(-1)). To define the role of nanomaterials design on environmental impacts, we studied nanoceria with different sizes (3.

Fate of Ag-NPs in Sewage Sludge after Application on Agricultural Soils.

The objective of this work was to investigate the fate of silver nanoparticles (Ag-NPs) in a sludge-amended soil cultivated with monocot (Wheat) and dicot (Rape) crop species. A pot experiment was performed with sludges produced in a pilot wastewater treatment plant containing realistic Ag concentrations (18 and 400 mg kg(-1), 14 mg kg(-1) for the control). Investigations focused on the highest dose treatment.

P2CS: updates of the prokaryotic two-component systems database.

The P2CS database (http://www.p2cs.org/) is a comprehensive resource for the analysis of Prokaryotic Two-Component Systems (TCSs).

Transfer, transformation, and impacts of ceria nanomaterials in aquatic mesocosms simulating a pond ecosystem.

Mesocosms are an invaluable tool for addressing the complex issue of exposure during nanoecotoxicological testing. This experimental strategy was used to take into account parameters as the interactions between the NPs and naturally occurring (in)organic colloids (heteroaggregation), or the flux between compartments of the ecosystems (aqueous phase, sediments, biota) when assessing the impacts of CeO2 NPs in aquatic ecosystems. In this study, we determine the transfer, redox transformation, and impacts of 1 mg L(-1) of bare and citrate coated CeO2-NPs toward an ecologically relevant organism (snail, Planorbarius corneus) exposed 4 weeks in a complex experimental system mimicking a pond ecosystem.

An adaptable mesocosm platform for performing integrated assessments of nanomaterial risk in complex environmental systems.

Physical-chemists, (micro)biologists, and ecologists need to conduct meaningful experiments to study the environmental risk of engineered nanomaterials with access to relevant mechanistic data across several spatial and temporal scales. Indoor aquatic mesocosms (60L) that can be tailored to virtually mimic any ecosystem appear as a particularly well-suited device. Here, this concept is illustrated by a pilot study aimed at assessing the distribution of a CeO₂-based nanomaterial within our system at low concentration (1.

Transformation of pristine and citrate-functionalized CeO2 nanoparticles in a laboratory-scale activated sludge reactor.

Engineered nanomaterials (ENMs) are used to enhance the properties of many manufactured products and technologies. Increased use of ENMs will inevitably lead to their release into the environment. An important route of exposure is through the waste stream, where ENMs will enter wastewater treatment plants (WWTPs), undergo transformations, and be discharged with treated effluent or biosolids.

Aged TiO2-based nanocomposite used in sunscreens produces singlet oxygen under long-wave UV and sensitizes Escherichia coli to cadmium.

TiO2-based nanocomposite (NC) are widely used as invisible UV protectant in cosmetics. These nanomaterials (NMs) end in the environment as altered materials. We have investigated the properties of T-Lite SF, a TiO2-NC used as sunscreen, after weathering in water and under light.

Deciphering the responses of root border-like cells of Arabidopsis and flax to pathogen-derived elicitors.

Plant pathogens including fungi and bacteria cause many of the most serious crop diseases. The plant innate immune response is triggered upon recognition of microbe-associated molecular patterns (MAMPs) such as flagellin22 and peptidoglycan. To date, very little is known of MAMP-mediated responses in roots.

Modulation of metabolism and switching to biofilm prevail over exopolysaccharide production in the response of Rhizobium alamii to cadmium.

Heavy metals such as cadmium (Cd(2+)) affect microbial metabolic processes. Consequently, bacteria adapt by adjusting their cellular machinery. We have investigated the dose-dependent growth effects of Cd(2+) on Rhizobium alamii, an exopolysaccharide (EPS)-producing bacterium that forms a biofilm on plant roots.

Complete genome sequence of a beneficial plant root-associated bacterium, Pseudomonas brassicacearum.

To shed light on the genetic equipment of the beneficial plant-associated bacterium Pseudomonas brassicacearum, we sequenced the whole genome of the strain NFM421. Its genome consists of one chromosome equipped with a repertoire of factors beneficial for plant growth. In addition, a complete type III secretion system and two complete type VI secretion systems were identified.

Rhizobium alamii sp. nov., an exopolysaccharide-producing species isolated from legume and non-legume rhizospheres.

A group of exopolysaccharide-producing bacteria was isolated from the root environment of Arabidopsis thaliana. The genetic diversity revealed by REP-PCR fingerprinting indicated that the isolates correspond to different strains. 16S rRNA gene sequence analysis showed that the isolates are closely related to the strains Rhizobium sp.

The exopolysaccharide of Rhizobium sp. YAS34 is not necessary for biofilm formation on Arabidopsis thaliana and Brassica napus roots but contributes to root colonization.

Microbial exopolysaccharides (EPSs) play key roles in plant-microbe interactions, such as biofilm formation on plant roots and legume nodulation by rhizobia. Here, we focused on the function of an EPS produced by Rhizobium sp. YAS34 in the colonization and biofilm formation on non-legume plant roots (Arabidopsis thaliana and Brassica napus).

Root border-like cells of Arabidopsis. Microscopical characterization and role in the interaction with rhizobacteria.

Plant roots of many species produce thousands of cells that are released daily into the rhizosphere. These cells are commonly termed border cells because of their major role in constituting a biotic boundary layer between the root surface and the soil. In this study, we investigated the occurrence and ultrastructure of such cells in Arabidopsis (Arabidopsis thaliana) using light and electron microscopy coupled to high-pressure freezing.

Measurement of the 13C/12C ratio of soil-plant individual sugars by gas chromatography/combustion/isotope-ratio mass spectrometry of silylated derivatives.

Carbohydrate is an important pool in the terrestrial carbon cycle. The potential offered by natural and artificial 13C-labelling techniques should therefore be applied to the investigation of the dynamics of individual sugars in soils. For this reason, we evaluated the method of 13C sugar analysis by gas chromatography/combustion/isotope-ratio mass spectrometry (GC/C/IRMS) after hydrolysis and direct trimethylsilylation.