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The current study examines the desiccation-resistant Ramlibacter tataouinensis TTB310 T 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. The optimized medium produced significant quantities of exopolysaccharide in a single growth phase, since the production of exopolysaccharide took place during the division of the cysts. The exopolysaccharide layer was extracted from the cysts using a modified trichloroacetic acid method. The biochemical characterization of purified exopolysaccharide was performed by gas chromatography, ultrahigh-resolution mass spectrometry, nuclear magnetic resonance, and Fourier-transform infrared spectrometry. The repeating unit of exopolysaccharide was a decasaccharide consisting of ribose, glucose, rhamnose, galactose, mannose, and glucuronic acid with the ratio 3:2:2:1:1:1, and additional substituents such as acetyl, succinyl, and methyl moieties were also observed as a part of the exopolysaccharide structure. This study contributes to a fundamental understanding of the novel structural features of exopolysaccharide from a dividing form of cysts, and, further, results can be used to study its rheological properties for various industrial applications.

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. Aim of this study is to analyse the soil-to-plant transfer of some of these chemical elements and to shed light on their uptake pathways. For this purpose, the geological site of Jas Roux (France) was chosen as this alpine site is naturally rich in critical and potentially toxic elements such as As, Sb, Ba and Tl, but nevertheless is host to a high diversity of plants. Elemental concentrations were analysed in the topsoil and in 12 selected alpine plant species sampled in situ. Statistical tools were used to detect species dependent characteristics in elemental uptake. Our analyses revealed accumulation of rare earth elements by Saxifraga paniculata, selective oxyanion absorption by Hippocrepis comosa, accumulation of Tl by Biscutella laevigata and Galium corrudifolium and an exclusion strategy in Juniperus communis. These findings advance our understanding of the environmental behaviour of critical metals and metalloids such as V, As, Y, Sb, Ce, Ba and Tl and might bare valuable information for phytoremediation applications., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Two-component systems (TCSs) are ubiquitous signaling pathways, typically comprising a sensory histidine kinase (HK) and a response regulator, which communicate via intermolecular kinase-to-receiver domain phosphotransfer. Hybrid HKs constitute non-canonical TCS signaling pathways, with transmitter and receiver domains within a single protein communicating via intramolecular phosphotransfer. Here, we report how evolutionary relationships between hybrid HKs can be used as predictors of potential intermolecular and intramolecular interactions ('phylogenetic promiscuity'). We used domain-swap genes chimeras to investigate the specificity of phosphotransfer within hybrid HKs of the GacS-GacA multikinase network of Pseudomonas brassicacearum. The receiver domain of GacS was replaced with those from nine donor hybrid HKs. Three chimeras with receivers from other hybrid HKs demonstrated correct functioning through complementation of a gacS mutant, which was dependent on strains having a functional gacA. Formation of functional chimeras was predictable on the basis of evolutionary heritage, and raises the possibility that HKs sharing a common ancestor with GacS might remain components of the contemporary GacS network. The results also demonstrate that understanding the evolutionary heritage of signaling domains in sophisticated networks allows their rational rewiring by simple domain transplantation, with implications for the creation of designer networks and inference of functional interactions.

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. Seed nano-priming is an efficient process that can change seed metabolism and signaling pathways, affecting not only germination and seedling establishment but also the entire plant lifecycle. Studies have shown various benefits of using seed nano-priming, such as improved plant growth and development, increased productivity, and a better nutritional quality of food. Nano-priming modulates biochemical pathways and the balance between reactive oxygen species and plant growth hormones, resulting in the promotion of stress and diseases resistance outcoming in the reduction of pesticides and fertilizers. The present review provides an overview of advances in the field, showing the challenges and possibilities concerning the use of nanotechnology in seed nano-priming, as a contribution to sustainable agricultural practices.

Soil salinization, extreme climate conditions, and phytopathogens are abiotic and biotic stressors that remarkably reduce agricultural productivity. Recently, nanomaterials have gained attention as effective agents for agricultural applications to mitigate such stresses. This review aims to critically appraise the available literature on interactions involving nanomaterials, plants, and microorganisms. This review explores the role of nanomaterials in enhancing plant growth and mitigating biotic and abiotic stresses. These materials can be synthesized by microbes, plants, and algae, and they can be applied as fertilizers and stress amelioration agents. Nanomaterials facilitate nutrient uptake, improve water retention, and enhance the efficiency of active ingredient delivery. Nanomaterials strengthen plant antioxidant systems, regulate photosynthesis, and stabilize hormonal pathways. Concurrently, their antimicrobial and protective properties provide resilience against biotic stressors, including pathogens and pests, by promoting plant immune responses and optimizing microbial-plant symbiosis. The synergistic interactions of nanomaterials with beneficial microorganisms optimize plant growth under stress conditions. These materials also serve as carriers of nutrients, growth regulators, and pesticides, thus acting like "smart fertilizers. While nanotechnology offers great promise, addressing potential environmental and ecotoxicological risks associated with their use is necessary. This review outlines pathways for leveraging nanotechnology to achieve resilient, sustainable, and climate-smart agricultural systems by integrating molecular insights and practical applications. [ABSTRACT FROM AUTHOR]

Nitric oxide (NO) is a multifunctional signaling molecule in plants, playing key roles in germination, microbial symbiosis, and nodule formation. However, its instability requires innovative approaches, such as using nanoencapsulated NO donors, to prolong its effects. This study evaluated the impact of treating soybean (Glycine max) seeds with the NO donor S-nitrosoglutathione (GSNO), encapsulated in polymeric nanoparticles, on the germination, nodulation, and plant growth. Seeds were treated with free GSNO, chitosan nanoparticles with/without NO (NP CS-GSNO/NP CS-GSH, where GSH is glutathione, the NO donor precursor), and alginate nanoparticles with/without NO (NP Al-GSNO/NP Al-GSH). Chitosan nanoparticles (positive zeta potential) were smaller and released NO faster compared with alginate nanoparticles (negative zeta potential). The seed treatment with NP CS-GSNO (1 mM, related to GSNO concentration) significantly improved germination percentage, root length, number of secondary roots, and dry root mass of soybean compared with the control. Conversely, NP CS-GSH resulted in decreased root and shoot length. NP Al-GSNO enhanced shoot dry mass and increased the number of secondary roots by approximately threefold at the highest concentrations. NP CS-GSNO, NP Al-GSNO, and NP Al-GSH increased S-nitrosothiol levels in the roots by approximately fourfold compared with the control. However, NP CS-GSNO was the only treatment that increased the nodule dry mass of soybean plants. Therefore, our results indicate the potential of chitosan nanoparticles to improve the application of NO donors in soybean seeds. [ABSTRACT FROM AUTHOR]

Legumes play a pivotal role in addressing global challenges of food and nutrition security by offering a sustainable source of protein and bioactive compounds. The capacity of legumes to establish symbiotic relationships with rhizobia bacteria enables biological nitrogen fixation (BNF), reducing the dependence on chemical fertilizers while enhancing soil health. However, the efficiency of this symbiosis is significantly influenced by environmental factors, such as soil acidity, salinity, temperature, moisture content, light intensity, and nutrient availability. These factors affect key processes, including rhizobia survival, nodule formation, and nitrogenase activity, ultimately determining the growth and productivity of legumes. This review summarizes current knowledge on legume-rhizobia interactions under varying abiotic conditions. It highlights the impact of salinity and acidity in limiting nodule development, soil temperature in regulating microbial community dynamics, and moisture availability in modulating metabolic and hormonal responses during drought and waterlogging. Moreover, the role of essential nutrients, including nitrogen, phosphorus, potassium, and trace elements such as iron, molybdenum, and boron, in optimizing symbiosis is critically analyzed. [ABSTRACT FROM AUTHOR]

Background: As an important prokaryotic model organism, Bacillus subtilis has been widely used in the industrial production of a variety of target products. The efficient secretion of target products has always been the main purpose of industrial microbial technology. The modification of gene regulatory networks is an important technical means to construct a factory of microbial cells that efficiently secretes target products. However, the regulatory network of the efficient expression of foreign genes in B. subtilis has not been studied at the translation level. Results: In this study, Ribo-seq and RNA-seq technology were used to study the changes in differentially expressed genes during the efficient secretion of the protease PB92 by B. subtilis WB600, and the results revealed the gene regulatory network related to efficient secretion of foreign protein. The results revealed that the correlation between the differentially expressed genes of B. subtilis at the transcription and translation levels was only 0.5354. Forty-one common (transcription and translation) and 436 unique (translation) key differential gene sets that may be related to the efficient secretion of foreign proteins were revealed. KEGG enrichment analysis of these key gene sets revealed that they were involved mainly in the cell motility and central metabolic regulatory network of B. subtilis. Conclusion: Our study provides important guidance for the construction of cell factories and metabolic networks for the efficient secretion of target products by B. subtilis. [ABSTRACT FROM AUTHOR]

Pogostemon cablin (Patchouli), an essential medicinal plant in the Lamiaceae family, faces significant challenges under continuous cropping (CC) obstacles. This study examined the rhizospheric soil bacterial communities of patchouli under four different CC years, zero (CK), one (T1), two (T2), and three (T3) years through high-throughput 16S rRNA gene amplicon sequencing. Results showed long-term CC led to significant soil properties and enzyme activity shifts. Key parameters such as soil pH and total potassium (TK) decreased, while ammonium nitrogen (NH4+–N), soil organic carbon (SOC), nitrate nitrogen (NO3−–N), available potassium (AK), available phosphorus (AP), total nitrogen (TN), and total phosphorus (TP) increased over the cropping years. Enzyme activities, including ß-glucosidase (ß-GC), polyphenol oxidase (PPO), catalase (CAT), N-acetyl-β-D-glucosaminidase (NAG), and leucine aminopeptidase (LAP), were notably affected. The CC altered the bacterial community structure and composition, reducing the relative abundance of Proteobacteria, Firmicutes, Actinobacteria, and Planctomycetota over time. These findings highlight the impact of CC on patchouli rhizosphere bacteria, providing insights for improved soil management and fertilization strategies in CC systems. [ABSTRACT FROM AUTHOR]

Plant growth-promoting rhizobacteria (PGPR) are beneficial bacteria that play a crucial role in sustainable agriculture by enhancing plant growth through various mechanisms. This review examines the contributions of PGPR in improving nutrient availability, producing phytohormones, providing biocontrol against pathogens, and enhancing abiotic stress tolerance. By reducing the necessity for chemical fertilizers and pesticides, PGPR mitigate environmental impacts, enhance soil health, and support long-term agricultural productivity. However, challenges such as inconsistent performance across various soils, regulatory barriers, and limited farmer awareness, hinder their widespread adoption. Recent advancements in nano-encapsulation technology, genetic engineering, and bioinformatics, present promising solutions for overcoming these obstacles and enhancing PGPR efficacy. The incorporation of PGPR into biofertilizers, biopesticides, and integrated plant management (IPM) offers a sustainable resolution to global agricultural challenges. This review addresses the current state of PGPR research, applications, and future directions for optimizing their use in promoting sustainable agriculture. [ABSTRACT FROM AUTHOR]

Nanoparticles of silicon (Si) and titanium (Ti), typically considered non-essential elements, show promise in enhancing fertilizer efficiency and crop performance. This study aimed to synthesize these nanoparticles and evaluate their potential as seed treatments for maize. Using the sol-gel method, Si and Ti nanoparticles were produced and extensively characterized through techniques like X-ray diffractometry, transmission electron microscopy, surface area analysis, and Fourier-transform infrared spectroscopy. Their effects on maize were assessed in a randomized experiment with a 2 × 5 factorial design, testing two sources (microparticles and nanoparticles) of Si and Ti at concentrations ranging from 0 to 160 mg L−1. SiO2 and TiO2 nanoparticles, with particle sizes below 50 nm and specific surface areas of 282.3 and 134.8 m2 g−1, respectively, were utilized. Mathematical models did not adequately explain variations in germination rate, abnormal seedlings, non-viable seeds, or biometric parameters in response to these nanoparticles. However, concentrations of 20 or 40 mg L−1 of Si and Ti nanoparticles notably improved maize germination rates, reduced abnormalities and non-viability in seedlings, and enhanced overall plant biometrics. These findings underscore the potential of SiO2 and TiO2 nanoparticles to enhance maize seed germination and growth metrics. [ABSTRACT FROM AUTHOR]

Seed priming is a state-of-the-art, low-cost, and environment-friendly strategy to improve seed germination, seed vigor, abiotic and biotic stress tolerance, and the yield of field and horticultural crops. Seed priming involves imbibing the seeds in a priming solution under a desired set of environmental conditions for a period followed by drying before the radicle protrusion. Several seed priming approaches including hydropriming, osmopriming, bio-priming, hormonal priming, nutrient priming, nanoparticle priming, and electropriming can be effectively employed under different environmental conditions to improve crop growth and stress resilience. Seed priming is known to trigger enzymatic, hormonal, physiological, transcriptomic, metabolomic, and proteomic regulations in seed embryos during seed germination and plant growth, which leads to faster and synchronized seed germination and higher abiotic and biotic stress tolerance in crop plants. Furthermore, seed priming can induce cross-tolerance between abiotic and biotic stressors and induce stress memory for higher resilience of the next generation to environmental stresses. The present review paper discusses the applications of seed priming in biotic and abiotic stress tolerance and the underlying abiotic and biotic stress tolerance physiological, biochemical, and molecular mechanisms of seed priming. Furthermore, we discuss the current challenges/bottlenecks in the widespread application of seed priming in crop production. [ABSTRACT FROM AUTHOR]

Metal-based nanoparticles (MNPs) are increasingly prevalent in the environment due to both natural processes and human activities, leading to direct interactions with plants through soil, water, and air exposure that can have beneficial and detrimental effects on plant growth and health. Understanding the uptake, translocation, and transformation of MNPs in plants is crucial for assessing environmental risks and leveraging nanotechnology in agriculture. However, accurate analysis of MNPs in plant tissues poses significant challenges due to complex plant matrices and the dynamic nature of nanoparticles. This short review summarizes recent advances in analytical methods for determining MNP–plant interactions, focusing on pre-processing and quantitative nanoparticle analysis. It highlights the importance of selecting appropriate extraction and analytical techniques to preserve nanoparticle integrity and accurate quantification. Additionally, recent advances in mass spectrometry, microscopy, and other spectroscopic techniques that improve the characterization of MNPs within plant systems are discussed. Future perspectives highlight the need to develop real-time in situ monitoring techniques and sensitive tools for characterizing nanoparticle biotransformation. [ABSTRACT FROM AUTHOR]

Silver nanoparticles are one of the most commonly used forms of silver (Ag) in nanotechnology applications due to their antibacterial properties and electrical and thermal resistance. The increasing production and use of products containing nanoparticles has led to their release into and contamination of soil and water. This review summarizes the literature on the fate, behavior (adsorption/desorption, precipitation/oxidative dissolution, transformation), and transport/mobility of Ag forms in soils (Ag+ ions and Ag nanoparticles—AgNPs). The behavior of Ag+/AgNPs in soil is a complex process. It depends on many factors, including the characteristics of the Ag forms (ions, nanoparticle size, ligand type used for coating, surface charge, initial Ag concentration), the soil properties (organic matter and clay mineral content, textural properties, point of zero charge, cation exchange capacity, surface functional groups), and the solute properties (pH–Eh, ionic strength, cation type, oxygen content). The binding of Ag+ and AgNPs is significantly positively correlated with Al/Fe/Mn oxide and SOM content and depends on the surface charge of the minerals and CEC, which controls adsorption processes. Very important parameters to consider are the pH and Eh of the solution, which determine the durability of the ligands, the aggregation rate and the oxidation process of AgNPs, as well as the presence of sulfide and chloride and the Cl/Ag ratio, which determine the stability/mobility of Ag. Since AgNPs can be oxidized to Ag+ ions during their life cycle, it is necessary to consider the behavior of both forms of Ag in soils. Understanding the transport and behavior of Ag in soil is essential for the environmental risk assessment and management of wastes containing Ag. [ABSTRACT FROM AUTHOR]

The P2CS database (http://www.p2cs.org/) is a comprehensive resource for the analysis of Prokaryotic Two-Component Systems (TCSs). TCSs are comprised of a receptor histidine kinase (HK) and a partner response regulator (RR) and control important prokaryotic behaviors. The latest incarnation of P2CS includes 164,651 TCS proteins, from 2758 sequenced prokaryotic genomes. Several important new features have been added to P2CS since it was last described. Users can search P2CS via BLAST, adding hits to their cart, and homologous proteins can be aligned using MUSCLE and viewed using Jalview within P2CS. P2CS also provides phylogenetic trees based on the conserved signaling domains of the RRs and HKs from entire genomes. HK and RR trees are annotated with gene organization and domain architecture, providing insights into the evolutionary origin of the contemporary gene set. The majority of TCSs are encoded by adjacent HK and RR genes, however, 'orphan' unpaired TCS genes are also abundant and identifying their partner proteins is challenging. P2CS now provides paired HK and RR trees with proteins from the same genetic locus indicated. This allows the appraisal of evolutionary relationships across entire TCSs and in some cases the identification of candidate partners for orphan TCS proteins., (© The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.)

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 (1.5 mg/L). Physico-chemical as well as microbiological parameters took two weeks to equilibrate. These parameters were found to be reproducible across the 9-mesocosm setup over a 45-day period of time. Recovery mass balances of 115 ± 18% and 60 ± 30% of the Ce were obtained for the pulse dosing and the chronic dosing, respectively. This demonstrated the relevance of our experimental approach that allows for adequately monitoring the fate and impact of a given nanomaterial.

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. Root border cells are cells that originate from root caps and are released individually into the rhizosphere. Root tips of Arabidopsis (Arabidopsis thaliana) and flax (Linum usitatissimum) release cells known as "border-like cells." Whereas root border cells of pea (Pisum sativum) are clearly involved in defense against fungal pathogens, the function of border-like cells remains to be established. In this study, we have investigated the responses of root border-like cells of Arabidopsis and flax to flagellin22 and peptidoglycan. We found that both MAMPs triggered a rapid oxidative burst in root border-like cells of both species. The production of reactive oxygen species was accompanied by modifications in the cell wall distribution of extensin epitopes. Extensins are hydroxyproline-rich glycoproteins that can be cross linked by hydrogen peroxide to enhance the mechanical strength of the cell wall. In addition, both MAMPs also caused deposition of callose, a well-known marker of MAMP-elicited defense. Furthermore, flagellin22 induced the overexpression of genes involved in the plant immune response in root border-like cells of Arabidopsis. Our findings demonstrate that root border-like cells of flax and Arabidopsis are able to perceive an elicitation and activate defense responses. We also show that cell wall extensin is involved in the innate immunity response of root border-like cells.

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. We report here the first genome sequence of this species.

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. Adsorption isotherms show that the EPS of R. alamii binds cadmium in competition with calcium. A metabonomics approach based on ion cyclotron resonance Fourier transform mass spectrometry has showed that cadmium alters mainly the bacterial metabolism in pathways implying sugars, purine, phosphate, calcium signalling and cell respiration. We determined the influence of EPS on the bacterium response to cadmium, using a mutant of R. alamii impaired in EPS production (MSΔGT). Cadmium dose-dependent effects on the bacterial growth were not significantly different between the R. alamii wild type (wt) and MSΔGT strains. Although cadmium did not modify the quantity of EPS isolated from R. alamii, it triggered the formation of biofilm vs planktonic cells, both by R. alamii wt and by MSΔGT. Thus, it appears that cadmium toxicity could be managed by switching to a biofilm way of life, rather than producing EPS. We conclude that modulations of the bacterial metabolism and switching to biofilms prevails in the adaptation of R. alamii to cadmium. These results are original with regard to the conventional role attributed to EPS in a biofilm matrix, and the bacterial response to cadmium.

Background: Changes in precipitation alter soil moisture, thereby affecting the aboveground and belowground ecological processes. However, it remains unclear whether plant root systems alter these effects through rhizospheric processes. In this study, a precipitation control experiment was conducted in the alpine grassland of northern Tibet to simulate precipitation changes with a 50% decrease and 50% increase in precipitation. Nutrient and microbial biomass, root traits, and survival strategies in the rhizosphere and bulk soils of the dominant plant, Stipa purpurea, were analyzed for alterations under precipitation changes. Results: Increased precipitation (IP) significantly decreased the rhizosphere soil total phosphorus and bulk soil ammonium nitrogen and increased the rhizosphere soil total potassium. Decreasing precipitation (DP) significantly increased the rhizosphere soil total potassium and decreased the bulk soil total potassium. DP significantly reduced microbial biomass carbon, nitrogen and phosphorus in rhizosphere soil, while IP significantly increased the bulk soil MBC:MBP, soil C:P imbalance, and soil N:P imbalance. Along the PC1 axis, where the contribution of the traits was relatively large, it was possible to define the root economic spectrum. The root system of Stipa purpurea from the DP treatment was distributed on the conservative side of the economic spectrum, whereas that from the control and IP treatments were clustered on the acquisition side. Conclusions: Increasing and decreasing precipitation mainly affected the contents of total phosphorus and total potassium in rhizosphere soil and the contents of ammonium nitrogen and total potassium in bulk soil of Stipa purpurea. The microbial biomass carbon, nitrogen and phosphorus were mainly affected by a decrease in precipitation. Decreasing precipitation significantly reduced microbial biomass carbon, nitrogen and phosphorus, but the rhizosphere MBC:MBN, MBC:MBP and MBN:MBP remained stable under the change of precipitation. Increasing precipitation exacerbated the C:P imbalance and N:P imbalance in bulk soil, and increased the demand for phosphorus by bulk microorganisms. Increased precipitation promoted root access to resources. The root system of Stipa purpurea in the context of precipitation changes was driven by rhizosphere nutrients and bulk microorganisms. This study is important for revealing plant–microbe–soil interactions in terrestrial ecosystems. [ABSTRACT FROM AUTHOR]

This review explores the intricate relationship between plants and bacterial endophytes, revealing their multifaceted roles in promoting plant growth, resilience, and defense mechanisms. By selectively shaping their microbiome, plants harness diverse endophytic bacterial strains to enhance nutrient absorption, regulate hormones, mitigate damage, and contribute to overall plant health. The review underscores the potential of bacterial endophytes in self-sustaining agricultural systems, offering solutions to reduce reliance on fertilizers and pesticides. Additionally, the review highlights the importance of endophytes in enhancing plant tolerance to various environmental stresses, such as drought, salinity, extreme temperatures, and heavy metal toxicity. The review emphasizes the significance of understanding and harnessing the mutualistic relationship between plants and endophytes for maximizing agricultural yields and promoting sustainable farming practices. [ABSTRACT FROM AUTHOR]

Background: Pecan [Carya illinoinensis (Wangenh.) Koch] is a widely cultivated dried fruit and woody oil tree with high economic value. Continuous sole planting of pecan caused some land to lie idle and deterioration of soil conditions. Tree and medicinal crops intercropping represents an environmental-friendly and economically feasible solution to these issues. Thus, we aimed to explore the underlying mechanism by which intercropping improved soil condition by regulating the interactions of the soil microbiome and metabolome. In this study, pecans were intercropped with medicinal crops caper spurge and honeysuckle on a tree farm in China. A combined analysis of soil microbiomes and metabolomes was performed to discover the effects of intercropping on bulk and rhizosphere soils. Results: The results showed that intercropping improved the edaphic properties of bulk soil and promoted the growth of pecan and caper spurge. Intercropping also significantly altered the structures of both bacterial and fungal communities in bulk soil, stabilised the enrichment of nitrogen-cyclic bacteria, for instance, Bacillus, and decreased the relative abundances of plant–pathogenic fungi, for instance, Fusarium. In addition, the result of metabolomic analysis showed that intercropping promoted the synthesis of functional compounds, such as trehalose and ethanolamine, which enhanced plant disease resistance in bulk soils. Moreover, the co-occurrence networks of microbiomes and metabolomes of bulk soils revealed that Bacillus was significantly correlated with Fusarium, Alternaria, and trehalose under intercropping patterns. Furthermore, analysis of microbiomes and metabolomes in the rhizosphere soil of caper spurge and honeysuckle revealed that Penicillium and Rhizomicrobium were significantly increased by intercropping and showed more dynamic connections with other genera and metabolites compared with single planting. Conclusions: Overall, intercropping pecans with caper spurge and honeysuckle can improve soil conditions and promote plant growth through microbiological and metabolomics integrated analyses. This study provides valuable information and theoretical basis for optimizing land resource utilisation and improving soil conditions in tree fields like pecan fields via intercropping, thereby reducing production losses and ensuring economic benefits. [ABSTRACT FROM AUTHOR]

Plant root border cells (RBCs) prevent the colonization of plant growth‐promoting rhizobacteria (PGPR) at the root tip, rendering the PGPR unable to effectively control pathogens infecting the root tip. In this study, we engineered four strains of Pseudomonas sp. UW4, a typical PGPR strain, each carrying an enhanced green fluorescent protein (EGFP)‐expressing plasmid. The UW4E strain harboured only the plasmid, whereas the UW4E‐flg22 strain expressed a secreted EGFP‐Flg22 fusion protein, the UW4E‐Flg(flg22) strain expressed a non‐secreted Flg22, and the UW4E‐flg22‐D strain expressed a secreted Flg22‐DNase fusion protein. UW4E‐flg22 and UW4E‐flg22‐D, which secreted Flg22, induced an immune response in wheat RBCs and colonized wheat root tips, whereas the other strains, which did not secrete Flg22, failed to elicit this response and did not colonize wheat root tips. The immune response revealed that wheat RBCs synthesized mucilage, extracellular DNA, and reactive oxygen species. Furthermore, the Flg22‐secreting strains showed a 33.8%–93.8% higher colonization of wheat root tips and reduced the root rot incidence caused by Rhizoctonia solani and Fusarium pseudograminearum by 24.6%–35.7% compared to the non‐Flg22‐secreting strains in pot trials. There was a negative correlation between the incidence of wheat root rot and colonization of wheat root tips by these strains. In contrast, wheat root length and dry weight were positively correlated with the colonization of wheat root tips by these strains. These results demonstrate that engineered secretion of Flg22 by PGPR is an effective strategy for controlling root rot and improving plant growth. [ABSTRACT FROM AUTHOR]

Breed selection alters the coevolution of plant–microbiome associations that have developed over long periods of natural evolution. We investigated the effects of breed selection on the rhizosphere microbiomes and metabolites of hybrid parents (I101 and 84K) and their offspring (Q1–Q5) using metagenomics and untargeted metabolomics. Rhizosphere archaeal, bacterial and fungal community β-diversity significantly differed among hybrid parents and offspring, but only the dominant bacterial phyla and bacterial community α-diversity revealed significant differences. Approximately 5.49%, 14.90% and 7.86% of the archaeal, bacterial and fungal species significantly differed among the poplar hybrid parents and offspring. Rhizosphere microbial functional genes and metabolites were both clustered into the following three groups: I101 and 84K; Q2 and Q4; and Q1, Q3 and Q5. Compared with the hybrid parents, 15 phytochemical compounds were enriched in the hybrid offspring and explained 7.15%, 18.24% and 6.68% of the total variation in the archaeal, bacterial and fungal community compositions, respectively. Rhizosphere metabolites significantly affected the bacterial community, rather than the archaeal and fungal communities. Our observations suggested that poplar breed selection imposed greater selection pressure on the rhizosphere bacterial community, which was mainly driven by metabolites. [ABSTRACT FROM AUTHOR]

Currently, the problem of heavy metal pollution in China is becoming increasingly serious, which poses grave threats to the environment and human health. Owing to the non-biodegradability and toxicity of heavy metals, a more sustainable and ecological approach to remediate heavy metal pollution has always been a focus of attention for environmental researchers. In recent years, many scientists have found that phytoremediation aided by endophytes has high potential to remediate heavy metals owing to its low cost, effectiveness, environmental friendliness, and sustainability compared with physical and chemical methods. Indeed, the mechanism of interaction between endophytes, plants, and heavy metals in the soil is pivotal for plants to tolerate metal toxicity and thrive. In this review, we focus on the mechanism of how endophytic bacteria resist heavy metals, and the direct and indirect mechanisms employed by endophytic bacteria to promote the growth of plants and enhance phytoextraction and phytostabilization. Moreover, we also discuss the application of combinations of endophytic bacteria and plants that have been used to remediate heavy metal pollution. Finally, it is pointed out that although there have been many studies on phytoremediation systems that have been assisted by endophytes, large-scale field trials are important to deliver "real" results to evaluate and improve phytoremediation assisted with microorganisms in polluted natural environments. [ABSTRACT FROM AUTHOR]

Currently, one of the main challenges is the mitigation of the effects of climate change on the agricultural sector. Conventional agriculture, with the intensive use of herbicides and pesticides to control weeds and pests, and the improper use of mineral fertilizers, contributes to climate change by causing increased greenhouse gases and groundwater pollution. Therefore, more innovative technologies must be used to overcome these problems. One possible solution is nanotechnology, which has the potential to revolutionize the conventional agricultural system. Active nanoparticles can be used both as a direct source of micronutrients and as a delivery platform for bioactive agrochemicals to improve crop growth, yield, and quality. The use of nanoparticle formulations, including nano-pesticides, nano-herbicides, nano-fertilizers, and nano-emulsions, has been extensively studied to improve crop health and shelf-life of agricultural products. Comprehensive knowledge of the interactions between plants and nanoparticles opens up new opportunities to improve cropping practices through the enhancement of properties such as disease resistance, crop yield, and nutrient use. The main objective of this review is to analyze the main effects of climate change on conventional agricultural practices, such as the use of pesticides, herbicides, and fertilizers. It also focuses on how the introduction of nanoparticles into conventional practices can improve the efficiency of chemical pest control and crop nutrition. Finally, this review examines in depth the last 10 years (2014–2024) of scientific literature regarding the use of nanoparticles in agriculture to mitigate the effects of climate change. [ABSTRACT FROM AUTHOR]

The pursuit of sustainable agriculture has become imperative in addressing global food security challenges while minimizing environmental impacts. Recent innovations in nanotechnology have given rise to a promising solution: nanofertilizers. Research reveals that these nanofertilizers can significantly enhance nutrient use efficiency, reducing environmental consequences, and advancing the cause of cleaner production. With potential increases of up to 30% in nutrient use efficiency and 20% in crop yields compared to traditional fertilizers, nanofertilizers demonstrate the capability to substitute up to 50% of conventional fertilizers, thereby diminishing their ecological footprint. This review paper explores the emerging trends and advancements in the field of nanofertilizers and their potential to revolutionize modern agriculture. We delve into the fundamental concepts of nanofertilizers, including their unique characteristics and controlled-release mechanisms. We analysed the impact of nanofertilizers on crop productivity, quality, and growth through the lens of research findings and case studies. While acknowledging the substantial potential of nanofertilizers, we also address environmental and safety considerations, emphasizing the importance of responsible deployment. In an era prioritizing environmental concerns, nanofertilizers offer a promising solution to meet growing food demands while protecting ecosystems.Highlights: Nanofertilizers enhance nutrient use efficiency, reducing environmental pollution from conventional fertilizers. Controlled release properties of nanofertilizers align nutrient availability with plant growth, boosting productivity. Nanofertilizers support sustainable agriculture, addressing global challenges like food security and soil health. [ABSTRACT FROM AUTHOR]

Nano-priming is a relatively new seed treatment technique using metal and metal oxide nanoparticles (NPs), and such application of NPs may support the plants' immunity. Recently we have shown that the that biologically synthesized silver nanoparticles (bio-AgNPs) used as short-term foliar treatment protect pea seedlings against D. pinodes and F. avenaceum. In the present study, the protection of peas against both fungal pathogens via seed priming with bio-AgNPs was analyzed. Moreover, the changes in the polar metabolic profiles of the seedlings caused by priming and infection were also compared. Seed priming with bio-AgNPs at concentrations of 50 and 100 mg/L considerably reduced the symptoms and infection levels of both pathogens by over 70% and 90% for F. avenaceum and D. pinodes, respectively. Pathogens infection and nano-priming affected the metabolic profile of pea seedlings. The major changes in the primary metabolism were observed among carbohydrates and amino acids. In turn, this may result in changes in the expression and accumulation of secondary metabolites. Therefore, further investigation of the effect of nano-priming should focus on the changes in the secondary metabolism. [ABSTRACT FROM AUTHOR]

Introduction: The rhizosphere is the zone of soil surrounding plant roots that is directly influenced by root exudates released by the plant, which select soil microorganisms. The resulting rhizosphere microbiota plays a key role in plant health and development by enhancing its nutrition or immune response and protecting it from biotic or abiotic stresses. In particular, plant growth-promoting rhizobacteria (PGPR) are beneficial members of this microbiota that represent a great hope for agroecology, since they could be used as bioinoculants for sustainable crop production. Therefore, it is necessary to decipher the molecular dialog between roots and PGPR in order to promote the establishment of bioinoculants in the rhizosphere, which is required for their beneficial functions. Methods: Here, the ability of root exudates from rapeseed (Brassica napus), pea (Pisum sativum), and ryegrass (Lolium perenne) to attract and feed three PGPR (Bacillus subtilis, Pseudomonas fluorescens, and Azospirillum brasilense) was measured and compared, as these responses are directly involved in the establishment of the rhizosphere microbiota. Results: Our results showed that root exudates differentially attracted and fed the three PGPR. For all beneficial bacteria, rapeseed exudates were the most attractive and induced the fastest growth, while pea exudates allowed the highest biomass production. The performance of ryegrass exudates was generally lower, and variable responses were observed between bacteria. In addition, P. fluorescens and A. brasilense appeared to respond more efficiently to root exudates than B. subtilis. Finally, we proposed to evaluate the compatibility of each plant–PGPR couple by assigning them a “love match” score, which reflects the ability of root exudates to enhance bacterial rhizocompetence. Discussion: Taken together, our results provide new insights into the specific selection of PGPR by the plant through their root exudates and may help to select the most effective exudates to promote bioinoculant establishment in the rhizosphere. [ABSTRACT FROM AUTHOR]

Introduction: Root exudates act as the "language" of plant-soil communication, facilitating crucial interactions, information exchange, and energy transfer between plants and soil. The interactions facilitated by root exudates between plants and microorganisms in the rhizosphere are crucial for nutrient uptake and stress resilience in plants. However, the mechanism underlying the interaction between root exudates and rhizosphere microorganisms in desert plants under drought conditions remains unclear, especially among closely related species. Methods: To reveal the ecological strategies employed by the genus Haloxylon in different habitats. Using DNA extraction and sequencing and UPLC-Q-Tof/MS methods, we studied root exudates and soil microorganisms from two closely related species, Haloxylon ammodendron (HA) and Haloxylon persicum (HP), to assess differences in their root exudates, soil microbial composition, and interactions. Results: Significant differences were found in soil properties and root traits between the two species, among which soil water content (SWC) and soil organic carbon (SOC) in rhizosphere and bulk soils (P < 0.05). While the metabolite classification of root exudates was similar, their components varied, with terpenoids being the main differential metabolites. Soil microbial structure and diversity also exhibited significant differences, with distinct key species in the network and differential functional processes mainly related to nitrogen and carbon cycles. Strong correlations were observed between root exudatemediated root traits, soil microorganisms, and soil properties, although the complex interactions differed between the two closely relative species. The primary metabolites found in the network of HA include sugars and fatty acids, while HP relies on secondary metabolites, steroids and terpenoids. Discussion: These findings suggest that root exudates are key in shaping rhizosphere microbial communities, increasing microbial functionality, fostering symbiotic relationships with hosts, and bolstering the resilience of plants to environmental stress. [ABSTRACT FROM AUTHOR]

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Microplastic contamination in terrestrial environments has risen significantly, far exceeding levels in marine environments. This shift underscores the concerning prevalence of microplastics (MPs) in sewage sludge and soil, raising environmental apprehensions. Microplastics from various sources accumulate in sewage systems, consequently, sewage sludge and soil have transformed into primary reservoirs of microplastic pollutants, capable of infiltrating aquatic ecosystems. While using sludge to enrich soil provides nutrients, it simultaneously introduces substantial microplastic content, posing environmental hazards. These microplastics can accumulate in the soil, altering its properties and potentially polluting deeper soil layers and groundwater, compounding environmental risks. This review scrutinizes the abundance, types, and shapes of microplastics in sewage sludge and soil, evaluating their impacts and suggesting future research directions. Statistical analysis reveals higher microplastic concentrations in sludge (271 Particles/kg dry weight) than in soil (34.6 Particles/kg). Strong correlations between microplastic concentrations in soil and sludge (R2 = 0.95) underscore the significant influence of sludge application on soil ecosystems. The p-value of 0.0001 indicates a significant correlation between MP amounts in soil and sludge, while the p-value of 0.47 suggests no significant association between MP concentrations in wastewater and sludge. Research confirms that microplastics influence sludge properties, microbial communities, and soil characteristics, contingent on microplastic attributes and soil conditions. Predominantly, microplastic shapes found in sludge and soil are fibers and fragments, often linked to agricultural fertilizer use. Microplastics detrimentally affect soil bulk density and aggregate stability, impairing soil structure and surface. Furthermore, their presence alters pollutant transport behavior in soil, emphasizing the imperative to investigate microplastics' effects and transport mechanisms for mitigating environmental and health risks. [ABSTRACT FROM AUTHOR]

In light of the growing plastic waste problem worldwide, including in agriculture, this study focuses on the usefulness of both conventional, non-degradable plastics and environmentally friendly bioplastics in the agricultural sector. Although conventional plastic products are still essential in modern, even ecological agriculture, the increasing contamination by these materials, especially in a fragmented form, highlights the urgent need to search for alternative, easily biodegradable materials that could replace the non-degradable ones. According to the literature, polymers are widely used in agriculture for the preparation of agrochemicals (mostly fertilizers) with prolonged release. They also play a role as functional polymers against pests, serve as very useful super absorbents of water to improve crop health under drought conditions, and are commonly used as mulching films, membranes, mats, non-woven fabrics, protective nets, seed coatings, agrochemical packaging, or greenhouse coverings. This widespread application leads to the uncontrolled contamination of soil with disintegrated polymeric materials. Therefore, this study highlights the possible applications of bio-based materials as alternatives to conventional polyolefins or other environmentally persistent polymers. Bio-based polymers align with the strategy of innovative agricultural advancements, leading to more productive farming by reducing plastic contamination and adverse ecotoxicological impacts on aquatic and terrestrial organisms. On the other hand, advanced polymer membranes act as catching agents for agrochemicals, protecting against environmental intoxication. The global versatility of polymer applications in agriculture will not permit the elimination of already existing technologies involving polymers in the near future. However, in line with ecological trends in modern agriculture, more "green" polymers should be employed in this sector. Moreover, we highlight that more comprehensive legislative work on these aspects should be undertaken at the European Union level to guarantee environmental and climate protection. From the EU legislation point of view, the implementation of a unified, legally binding system on applications of bio-based, biodegradable, and compostable plastics should be a priority to be addressed. In this respect, the EU already demonstrates an initial action plan. Unfortunately, these are still projected directions for future EU policy, which require in-depth analysis. [ABSTRACT FROM AUTHOR]

Agriculture plays a fundamental role in ensuring global food security, yet plant diseases remain a significant threat to crop production. Traditional methods to manage plant diseases have been extensively used, but they face significant drawbacks, such as environmental pollution, health risks and pathogen resistance. Similarly, biopesticides are eco-friendly, but are limited by their specificity and stability issues. This has led to the exploration of novel biotechnological approaches, such as the development of synthetic proteins, which aim to mitigate these drawbacks by offering more targeted and sustainable solutions. Similarly, recent advances in genome editing techniques—such as meganucleases (MegNs), zinc finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs) and clustered regularly interspaced short palindromic repeats (CRISPR)—are precise approaches in disease management, but are limited by technical challenges and regulatory concerns. In this realm, nanotechnology has emerged as a promising frontier that offers novel solutions for plant disease management. This review examines the role of nanoparticles (NPs), including organic NPs, inorganic NPs, polymeric NPs and carbon NPs, in enhancing disease resistance and improving pesticide delivery, and gives an overview of the current state of nanotechnology in managing plant diseases, including its advantages, practical applications and obstacles that must be overcome to fully harness its potential. By understanding these aspects, we can better appreciate the transformative impact of nanotechnology on modern agriculture and can develop sustainable and effective strategies to mitigate plant diseases, ensuring enhanced agricultural productivity. [ABSTRACT FROM AUTHOR]

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. The secretion of cell wall molecules including pectic polysaccharides and arabinogalactan-proteins (AGPs) was examined also using immunofluorescence microscopy and a set of anticarbohydrate antibodies. We show that root tips of Arabidopsis seedlings released cell layers in an organized pattern that differs from the rather randomly dispersed release observed in other plant species studied to date. Therefore, we termed such cells border-like cells (BLC). Electron microscopical results revealed that BLC are rich in mitochondria, Golgi stacks, and Golgi-derived vesicles, suggesting that these cells are actively engaged in secretion of materials to their cell walls. Immunocytochemical data demonstrated that pectins as well as AGPs are among secreted material as revealed by the high level of expression of AGP-epitopes. In particular, the JIM13-AGP epitope was found exclusively associated with BLC and peripheral cells in the root cap region. In addition, we investigated the function of BLC and root cap cell AGPs in the interaction with rhizobacteria using AGP-disrupting agents and a strain of Rhizobium sp. expressing a green fluorescent protein. Our findings demonstrate that alteration of AGPs significantly inhibits the attachment of the bacteria to the surface of BLC and root tip.

The clearance from blood circulation of fluorinated liposomes made with perfluoroalkylated phosphatidylcholines was investigated in mice using liposome-entrapped 5(6)-carboxyfluorescein. The presence of a fluorinated core inside the membrane strongly retards their blood clearance. The fluorinated vesicles showed circulation half-lives of up to 8.6 h, which are 6-13 and 3-6 times larger than those of similarly sized conventional distearoylphosphatidylcholine and distearoylphosphatidylcholine/cholesterol liposomes, respectively. Their blood clearance was similar to that of some polyethylene glycol (PEG)-labelled 'stealth' liposomes and was dose-independent in a 3.3-330 mumol/kg body weight dose range.

Investigating the quantity and spatiotemporal dynamics of metabolite release from plant roots is essential if we are to understand the ecological significance of root exudates in the rhizosphere; however, this is difficult to quantify. In the present study, we quantified in situ root exudation rates during three incubation periods (0-24, 24-48, and 48-72 h) and fine roots within four diameter ranges (<0.8, 0.8-1.0, 1.0-1.2, and 1.2-2.0 mm), and also measured nine morphological traits in the fine roots of Pinus massoniana. Higher root carbon (C) exudation rates were detected during the 0-24 h period. During the 0-24 h and 24-48 h periods, nitrogen (N) uptake rates were higher than N exudation rates, while during the 48-72 h period, N exudation rates exceeded uptake rates. As C exudation increased during 0-48h incubation period, the uptake of N tended to level out. We concluded that the 24-48 h incubation period was the most suitable for capturing root exudates from P. massoniana. The exudation of C from the roots was positively associated with root mass, length, surface area, volume, the number of root tips, and the root tissue density, when incubated for 0-24 h and 24-48 h. Furthermore, length-specific C exudation rates, along with N exudation and uptake rates, all increased as the diameter of the fine roots increased. The release of root exudates could be efficiently predicted by the fine root morphological traits, although the accuracy of prediction depended on the incubation period. Higher values for fine root morphological traits were generally indicative of higher nutrient requirements and tissue investment, as well as higher C exudation rates. [ABSTRACT FROM AUTHOR]

Seeds, considered as the foundation of agriculture, are invaded by a broad spectrum of seed-borne pathogens. The current study aimed to control seed-borne fungal pathogens of wheat, Aspergillus flavus and A. niger, by using Ag+ nanochitosan (Ag-NC) for nano-priming of seeds and enhancing seed quality. Nanochitosan (NC) and Ag-NC were synthesized using the gelation method and characterized by UV–vis spectrophotometry, FESEM, EDXS, and HRTEM. NC and Ag-NC showed irregular surface topography with an average particle size of 275 and 325 nm, respectively. Antifungal activity of both the nanoparticles at 0.1, 0.2, 0.3, 0.4, and 0.5 mg/mL revealed that Ag-NC at 0.5 mg/mL has completely terminated the mycelial growth of both pathogens. Malonaldehyde content increased to 77.77% in A. flavus and 82.66% in A. niger when exposed to 0.5 mg/mL Ag-NC. High-intensity fluorescence due to oxidative stress was observed in Ag-NC-treated pathogens. Ultra-structural changes in Ag-NC treated pathogenic spores under SEM displayed pronounced membrane damages. Wheat seeds were nano-primed with NC and Ag-NC at 0.5 mg/mL, and fungal load was examined to evaluate the mitigation of pathogenic stress and its effect on seedling growth promotion activity. Ag-NC priming reduced the fungal load and allowed successful seed germination. Ag-NC priming increased the albumin, gliadin, gluten, and glutenin content along with total phenol, reducing sugar and starch levels. Ag-NC priming increased the overall protein levels traced through SDS-PAGE. Seed priming with Ag-NC promotes seed germination, mean germination time, stress tolerance index, vigour, etc. NC and Ag-NC at 0.5 mg/mL showed no cytotoxic effect on the Human Embryonic Kidney (HEK293) cell line that ensures the nanoparticles are non-toxic. Thus, the synthesized nanoparticles exhibit a dual role in antifungal activity and plant growth promotion. [ABSTRACT FROM AUTHOR]

Nickel (Ni) is an essential micronutrient for plants, responsible for metabolizing urea nitrogen (urea-N) by urease and mitigating abiotic and oxidative stresses through the glyoxalase (Gly) and glutathione (GSH) cycles. However, excess Ni is toxic to flora at >100 mg kg−1, except for hyperaccumulators that tolerate >1000 mg kg−1 Ni. This review discusses the benefits of Ni nutrient management for soil fertility, improving food security, and minimizing adverse environmental impacts from urea overapplication. Many farming soils are Ni deficient, suggesting that applying 0.05–5 kg ha−1 of Ni improves yield and urea-N use efficiency. Applied foliar and soil Ni fertilizers decrease biotic stresses primarily by control of fungal diseases. The bioavailability of Ni is the limiting factor for urease synthesis in plants, animal guts, and the soil microbiome. Improved urease activity in plants and subsequently through feed in livestock guts reduces the release of nitrous oxide and nitrite pollutants. Fertilizer Ni applied to crops is dispersed in vegetative tissue since Ni is highly mobile in plants and is not accumulated in fruit or leafy tissues to cause health concerns for consumers. New methods for micronutrient delivery, including rhizophagy, recycled struvite, and nanoparticle fertilizers, can improve Ni bioavailability in farming systems. [ABSTRACT FROM AUTHOR]

The jalapeño pepper is a vegetable of great economic importance worldwide. However, low germination efficiency, weak seedlings, and a high mortality rate during transplant compromise the viability and sustainability of the crop. An innovative solution is the nanopriming technique, an emerging and novel technology, which involves the imbibition of seeds for a specific period using mineral nanoparticles. The addition of micronutrients such as zinc and molybdenum has been used in seed germination and early seedling development due to their crucial roles. The aim of this study was to evaluate the effectiveness of using zinc–molybdenum nanopriming in jalapeño pepper on germination and early growth. The results showed that applying nanopriming (124–10 mg L−1 of zinc–molybdenum) promotes the effectiveness on the imbibition and germination of jalapeño pepper seeds, resulting in heavier seeds with a better initial absorption. This method not only improves germination rates and seedling vigor, but also points towards more sustainable and efficient agriculture. Building on these findings, the zinc–molybdenum nanopriming method could potentially transform jalapeño pepper cultivation by enhancing seed quality and resilience. Nanopriming could help increase crop yields and minimize reliance on chemical inputs, such as fertilizers and pesticides, which might reduce production costs and environmental impact. [ABSTRACT FROM AUTHOR]

In a scenario of accelerated global climate change, the continuous growth of the world population, and the excessive use of chemical fertiliser, the search for sustainable alternatives for agricultural production is crucial. The present study was conducted to evaluate the plant growth-promoting (PGP) characteristics of two yeast strains, Candida guilliermondii and Rhodotorula mucilaginosa, and the physicochemical characteristics of nanometric capsules and iron oxide nanoparticles (Fe2O3-NPs) for the formulation of nanobiofertilisers. The physiological and productive effects were evaluated in a greenhouse assay using lettuce plants. The results showed that C. guilliermondii exhibited higher tricalcium phosphate solubilisation capacity, and R. mucilaginosa had a greater indole-3-acetic acid (IAA) content. The encapsulation of C. guilliermondii in sodium alginate capsules significantly improved the growth, stomatal conductance, and photosynthetic rate of the lettuce plants. Physicochemical characterisation of the Fe2O3-NPs revealed a particle size of 304.1 nm and a negative Z-potential, which indicated their stability and suitability for agricultural applications. The incorporation of Fe2O3-NPs into the capsules was confirmed by SEM-EDX analysis, which showed the presence of Fe as the main element. In summary, this study highlights the potential of nanobiofertilisers containing yeast strains encapsulated in sodium alginate with Fe2O3-NPs to improve plant growth and photosynthetic efficiency as a path toward more sustainable agriculture. [ABSTRACT FROM AUTHOR]

The functioning of living organisms in nature is possible only due to active interaction with microbiota. It is typical for phytobionts, the microbial cenosis of which is even more diverse. Plants contribute to the spread of microorganisms in the rhizosphere by releasing root exudates. The chemical composition of these exudates varies in different plant species and depends on the significant number of factors that affect their growth and development. The components of the plant root exudates stimulate expansion in the rhizosphere of microorganisms, useful for the plant growth. This microbiota improves the mineral life of plants considerably, stimulating their growth with biologically active compounds, increasing the availability of a number of microelements for them, protecting the growth of plants from phytopathogens and phytophages. It provides significant stimulation for the growth and development of phytobionts. It has been shown that microbial groups in the rhizosphere can induce some changes in the composition of plant root exudates. [ABSTRACT FROM AUTHOR]

Trees that are categorised by their light requirements have similarities in their growth strategies and adaptation mechanisms. We aimed to understand the complex responses of elevated air humidity on whole tree fine root carbon (C) exudation (ExC) and respiration rate, morphology, and functional distribution in species with different light requirements. Three light-demanding (LD) species, Populus Ã--wettsteinii, Betula pendula, and Pinus sylvestris, and two shade-tolerant species, Picea abies and Tilia cordata saplings were grown in growth chambers under moderate and elevated air relative humidity (eRH) at two different inorganic nitrogen sources with constant air temperature and light availability. The proportion of assimilated carbon released by ExC, and respiration decreased at eRH; up to about 3 and 27%, respectively. There was an indication of a trade-off between fine root released C and biomass allocation. The elevated air humidity changed the tree biomass allocation and fine root morphology, and the responses were species-specific. The specific fine root area and absorptive root proportion were positively related to canopy net photosynthesis and leaf nitrogen concentration across tree species. The variation in ExC was explained by the trees' light-use strategy (p < 0.05), showing higher exudation rates in LD species. The LD species had a higher proportion of pioneer root tips, which related to the enhanced ExC. Our findings highlight the significant role of fine root functional distribution and morphological adaptation in determining rhizosphere C fluxes in changing environmental conditions such as the predicted increase of air humidity in higher latitudes. [ABSTRACT FROM AUTHOR]