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Simple Summary: This review highlights the intricate interactions between two major constituents of marine ecosystems: dinoflagellates and heterotrophic bacteria. Dinoflagellates typically associate with a diverse array of heterotrophic bacteria, which are not limited to but predominantly consist of phyla such as Alphaproteobacteria, Gammaproteobacteria, and the Cytophaga–Flavobacterium–Bacteroides group. These bacterial communities engage with dinoflagellates in a multifaceted manner, including nutrient exchange, the secretion of pathogenic substances, and involvement in the synthesis of chemical entities. Crucially, the process of horizontal gene transfer from bacteria is a significant force sculpting the genomic architecture of dinoflagellates. The objective of this review is to shed light on the dynamic interactions between dinoflagellates and their bacterial partners, examining the relationship through a physiological, ecological, and evolutionary perspective. Dinoflagellates and heterotrophic bacteria are two major micro-organism groups within marine ecosystems. Their coexistence has led to a co-evolutionary relationship characterized by intricate interactions that not only alter their individual behaviors but also exert a significant influence on the broader biogeochemical cycles. Our review commenced with an analysis of bacterial populations, both free-living and adherent to dinoflagellate surfaces. Members of Alphaproteobacteria, Gammaproteobacteria, and the Cytophaga–Flavobacterium–Bacteroides group are repeatedly found to be associated with dinoflagellates, with representation by relatively few genera, such as Methylophaga, Marinobacter, and Alteromonas. These bacterial taxa engage with dinoflagellates in a limited capacity, involving nutrient exchange, the secretion of pathogenic substances, or participation in chemical production. Furthermore, the genomic evolution of dinoflagellates has been profoundly impacted by the horizontal gene transfer from bacteria. The integration of bacterial genes into dinoflagellates has been instrumental in defining their biological characteristics and nutritional strategies. This review aims to elucidate the nuanced interactions between dinoflagellates and their associated bacteria, offering a detailed perspective on their complex relationship. [ABSTRACT FROM AUTHOR]

ABSTRACT Interactions between arbuscular mycorrhizal fungi (AMF), plants, and the soil microbial community have the potential to increase the availability and uptake of phosphorus (P) and nitrogen (N) in agricultural systems. Nutrient exchange between plant roots, AMF, and the adjacent soil microbes occurs at the interface between roots colonized by mycorrhizal fungi and soil, referred to as the mycorrhizosphere. Research on the P exchange focuses on plant–AMF or AMF–microbe interactions, lacking a holistic view of P exchange between the plants, AMF, and other microbes. Recently, N exchange at both interfaces revealed the synergistic role of AMF and bacterial community in N uptake by the host plant. Here, we highlight work carried out on each interface and build upon it by emphasizing research involving all members of the tripartite network. Both nutrient systems are challenging to study due to the complex chemical and biological nature of the mycorrhizosphere. We discuss some of the effective methods to identify important nutrient processes and the tripartite members involved in these processes. The extrapolation of in vitro studies into the field is often fraught with contradiction and noise. Therefore, we also suggest some approaches that can potentially bridge the gap between laboratory-generated data and their extrapolation to the field, improving the applicability and contextual relevance of data within the field of mycorrhizosphere interactions. Overall, we argue that the research community needs to adopt a holistic tripartite approach and that we have the means to increase the applicability and accuracy of in vitro data in the field.

Dinoflagellates and heterotrophic bacteria are two major micro-organism groups within marine ecosystems. Their coexistence has led to a co-evolutionary relationship characterized by intricate interactions that not only alter their individual behaviors but also exert a significant influence on the broader biogeochemical cycles. Our review commenced with an analysis of bacterial populations, both free-living and adherent to dinoflagellate surfaces. Members of Alphaproteobacteria, Gammaproteobacteria, and the Cytophaga–Flavobacterium–Bacteroides group are repeatedly found to be associated with dinoflagellates, with representation by relatively few genera, such as Methylophaga, Marinobacter, and Alteromonas. These bacterial taxa engage with dinoflagellates in a limited capacity, involving nutrient exchange, the secretion of pathogenic substances, or participation in chemical production. Furthermore, the genomic evolution of dinoflagellates has been profoundly impacted by the horizontal gene transfer from bacteria. The integration of bacterial genes into dinoflagellates has been instrumental in defining their biological characteristics and nutritional strategies. This review aims to elucidate the nuanced interactions between dinoflagellates and their associated bacteria, offering a detailed perspective on their complex relationship.

Symbiotic interactions occur in all domains of life, providing organisms with resources to adapt to new habitats. A prime example is the endosymbiosis between corals and photosynthetic dinoflagellates. Eukaryotic dinoflagellate symbionts reside inside coral cells and transfer essential nutrients to their hosts, driving the productivity of the most biodiverse marine ecosystem. Recent advances in molecular and genomic characterization have revealed symbiosis-specific genes and mechanisms shared among symbiotic cnidarians. In this review, we focus on the cellular and molecular processes that underpin the interaction between symbiont and host. We discuss symbiont acquisition via phagocytosis, modulation of host innate immunity, symbiont integration into host cell metabolism, and nutrient exchange as a fundamental aspect of stable symbiotic associations. We emphasize the importance of using model systems to dissect the cellular complexity of endosymbiosis, which ultimately serves as the basis for understanding its ecology and capacity to adapt in the face of climate change. [ABSTRACT FROM AUTHOR]

Phenological segregation among species in a community is assumed to promote coexistence, as using resources at different times reduces competition. However, other unexplored nonalternative mechanisms can also result in a similar outcome. This study first tests whether plants can redistribute nitrogen (N) among them based on their nutritional temporal demand (i.e. phenology). Field 15N labelling experiments showed that 15N is transferred between neighbour plants, mainly from low N‐demand (late flowering species, not reproducing yet) to high N‐demand plants (early flowering species, currently flowering‐fruiting). This can reduce species' dependence on pulses of water availability, and avoid soil N loss through leaching, having relevant implications in the structuring of plant communities and ecosystem functioning. Considering that species phenological segregation is a pervasive pattern in plant communities, this can be a so far unnoticed, but widely spread, ecological process that can predict N fluxes among species in natural communities, and therefore impact our current understanding of community ecology and ecosystem functioning. [ABSTRACT FROM AUTHOR]

Apicomplexan parasites that reside within a parasitophorous vacuole harbor a conserved pore-forming protein that enables small-molecule transfer across the parasitophorous vacuole membrane (PVM). In Plasmodium parasites that cause malaria, this nutrient pore is formed by EXP2 which can complement the function of GRA17, an orthologous protein in Toxoplasma gondii. EXP2, however, has an additional function in Plasmodium parasites, serving also as the pore-forming component of the protein export machinery PTEX. To examine how EXP2 can play this additional role, transgenes that encoded truncations of EXP2, GRA17, hybrid GRA17-EXP2, or EXP2 under the transcriptional control of different promoters were expressed in EXP2 knockdown parasites to determine which could complement EXP2 function. This revealed that EXP2 is a unique pore-forming protein, and its protein export role in P. falciparum cannot be complemented by T. gondii GRA17. This was despite the addition of the EXP2 assembly strand and part of the linker helix to GRA17, which are regions necessary for the interaction of EXP2 with the other core PTEX components. This indicates that the body region of EXP2 plays a critical role in PTEX assembly and/or that the absence of other T. gondii GRA proteins in P. falciparum leads to its reduced efficiency of insertion into the PVM and complementation potential. Altering the timing and abundance of EXP2 expression did not affect protein export but affected parasite viability, indicating that the unique transcriptional profile of EXP2 when compared to other PTEX components enables it to serve an additional role in nutrient exchange.

Over the last two decades, the rapidly expanding field of tumor metabolism has enhanced our knowledge of the impact of nutrient availability on metabolic reprogramming in cancer. Apart from established roles in cancer cells themselves, various nutrients, metabolic enzymes, and stress responses are key to the activities of tumor microenvironmental immune, fibroblastic, endothelial, and other cell types that support malignant transformation. In this article, we review our current understanding of how nutrient availability affects metabolic pathways and responses in both cancer and "stromal" cells, by dissecting major examples and their regulation of cellular activity. Understanding the relationship of nutrient availability to cellular behaviors in the tumor ecosystem will broaden the horizon of exploiting novel therapeutic vulnerabilities in cancer. [Display omitted] In this review, Lobel et al. summarize the current understanding of the metabolic requirements for the functions of multiple types of cells in the tumor microenvironment, including tumor, immune, stromal, and endothelial cells; as well as the metabolic interplay between these diverse cell types. [ABSTRACT FROM AUTHOR]

Abstract Background Symbionts provide a variety of reproductive, nutritional, and defensive resources to their hosts, but those resources can vary depending on symbiont community composition. As genetic techniques open our eyes to the breadth of symbiont diversity within myriad microbiomes, symbiosis research has begun to consider what ecological mechanisms affect the identity and relative abundance of symbiont species and how this community structure impacts resource exchange among partners. Here, we manipulated the in hospite density and relative ratio of two species of coral endosymbionts (Symbiodinium microadriaticum and Breviolum minutum) and used stable isotope enrichment to trace nutrient exchange with the host, Briareum asbestinum. Results The patterns of uptake and translocation of carbon and nitrogen varied with both density and ratio of symbionts. Once a density threshold was reached, carbon acquisition decreased with increasing proportions of S. microadriaticum. In hosts dominated by B. minutum, nitrogen uptake was density independent and intermediate. Conversely, for those corals dominated by S. microadriaticum, nitrogen uptake decreased as densities increased, and as a result, these hosts had the overall highest (at low density) and lowest (at high density) nitrogen enrichment. Conclusions Our findings show that the uptake and sharing of nutrients was strongly dependent on both the density of symbionts within the host, as well as which symbiont species was dominant. Together, these complex interactive effects suggest that host regulation and the repression of in hospite symbiont competition can ultimately lead to a more productive mutualism. Video Abstract

In forests, mycorrhizal fungi regulate carbon (C) and nitrogen (N) dynamics. We evaluated the interplay among ectomycorrhizas (ECM), ecosystem C fluxes, tree productivity, C and N exchange and isotopic fractionation along the soil‐ECM‐plant continuum in a Mediterranean beech forest. From bud break to leaf shedding, we monitored: net ecosystem exchange (NEE, a measure of the net exchange of C between an ecosystem and the atmosphere), leaf area index, stem growth, N concentration, δ13C and δ15N in rhizosphere soil, ectomycorrhizal fine root tips (ERT), ECM‐free fine root portions (NCR) and leaves. Seasonal changes in ERT relative biomass were strictly related to NEE and mimicked those detected in the radial growth. The analysis of δ13C in ERT, leaves and NCR highlighted the impact of canopy photosynthesis on ERT development and an asynchronous seasonal C allocation strategy between ERT and NCR at the root tips level. Concerning N, δ15N of leaves was negatively related to that of ERT and dependent on seasonal 15N differences between ERT and NCR. Our results unravel a synchronous C allocation towards ERT and tree stem driven by the increasing NEE in spring‐early summer. Moreover, they highlighted a phenology‐dependent 15N fractionation during N transfer from ECM to their hosts. This evidence, obtained in mature beech trees under natural conditions, may improve the knowledge of Mediterranean forests functionality. Summary Statement: The natural abundances of C and N stable isotopes along the soil‐ectomycorrhiza‐plant continuum in mature Fagus sylvatica trees revealed the key role of ectomycorrhizae in regulating source‐sink relationships and the close interchange between biogeochemical cycles in forest ecosystem. [ABSTRACT FROM AUTHOR]

Plant roots associate with diverse microbes (including bacteria, fungi, archaea, protists, and viruses) collectively called the root-associated microbiome. Among them, mycorrhizal fungi colonize host roots and improve their access to nutrients, usually phosphorus and nitrogen. In exchange, plants deliver photosynthetic carbon to the colonizing fungi. This nutrient exchange affects key soil processes, the carbon cycle, and plant health and therefore has a strong influence on the plant and microbe ecosystems. The framework of nutrient exchange and regulation between host plant and arbuscular mycorrhizal fungi has recently been established. The local and systemic regulation of mycorrhizal symbiosis by plant nutrient status and the autoregulation of mycorrhizae are strategies by which plants maintain a stabilizing free-market symbiosis. A better understanding of the synergistic effects between mycorrhizal fungi and mycorrhizosphere microorganisms is an essential precondition for their use as biofertilizers and bioprotectors for sustainable agriculture and forestry management. [ABSTRACT FROM AUTHOR]

Background: Symbionts provide a variety of reproductive, nutritional, and defensive resources to their hosts, but those resources can vary depending on symbiont community composition. As genetic techniques open our eyes to the breadth of symbiont diversity within myriad microbiomes, symbiosis research has begun to consider what ecological mechanisms affect the identity and relative abundance of symbiont species and how this community structure impacts resource exchange among partners. Here, we manipulated the in hospite density and relative ratio of two species of coral endosymbionts (Symbiodinium microadriaticum and Breviolum minutum) and used stable isotope enrichment to trace nutrient exchange with the host, Briareum asbestinum. Results: The patterns of uptake and translocation of carbon and nitrogen varied with both density and ratio of symbionts. Once a density threshold was reached, carbon acquisition decreased with increasing proportions of S. microadriaticum. In hosts dominated by B. minutum, nitrogen uptake was density independent and intermediate. Conversely, for those corals dominated by S. microadriaticum, nitrogen uptake decreased as densities increased, and as a result, these hosts had the overall highest (at low density) and lowest (at high density) nitrogen enrichment. Conclusions: Our findings show that the uptake and sharing of nutrients was strongly dependent on both the density of symbionts within the host, as well as which symbiont species was dominant. Together, these complex interactive effects suggest that host regulation and the repression of in hospite symbiont competition can ultimately lead to a more productive mutualism. 7h9js9xm2ik2K7FmJ48qFB Video Abstract [ABSTRACT FROM AUTHOR]

Diatom–diazotroph associations (DDAs) are one of the most important symbiotic dinitrogen (N2) fixing groups in the oligotrophic ocean. Despite their capability to fix N2, ammonium (NH4+) remains a key nitrogen (N) source for DDAs, and the effect of NH4+ on their metabolism remains elusive. Here, we developed a coarse-grained, cellular model of the DDA with NH4+ uptake and quantified how the level of extracellular NH4+ influences metabolism and nutrient exchange within the symbiosis. The model shows that, under a fixed growth rate, an increased NH4+ concentration may lower the required level of N2 fixation and photosynthesis, and decrease carbon (C) and N exchange. A low-NH4+ environment leads to more C and N in nutrient exchange and more fixed N2 to support a higher growth rate. With higher growth rates, nutrient exchange and metabolism increased. Our study shows a strong effect of NH4+ on metabolic processes within DDAs, and thus highlights the importance of in situ measurement of NH4+ concentrations. [ABSTRACT FROM AUTHOR]

Arbuscular mycorrhizal (AM) fungi form a root endosymbiosis with many agronomically important crop species. They enhance the ability of their host to obtain nutrients from the soil and increase the tolerance to biotic and abiotic stressors. However, AM fungal species can differ in the benefits they provide to their host plants. Here, we examined the putative molecular mechanisms involved in the regulation of the physiological response of Medicago truncatula to colonization by Rhizophagus irregularis or Glomus aggregatum, which have previously been characterized as high- and low-benefit AM fungal species, respectively. Colonization with R. irregularis led to greater growth and nutrient uptake than colonization with G. aggregatum. These benefits were linked to an elevated expression in the roots of strigolactone biosynthesis genes (NSP1, NSP2, CCD7, and MAX1a), mycorrhiza-induced phosphate (PT8), ammonium (AMT2;3), and nitrate (NPF4.12) transporters and the putative ammonium transporter NIP1;5. R. irregularis also stimulated the expression of photosynthesis-related genes in the shoot and the upregulation of the sugar transporters SWEET1.2, SWEET3.3, and SWEET 12 and the lipid biosynthesis gene RAM2 in the roots. In contrast, G. aggregatum induced the expression of biotic stress defense response genes in the shoots, and several genes associated with abiotic stress in the roots. This suggests that either the host perceives colonization by G. aggregatum as pathogen attack or that G. aggregatum can prime host defense responses. Our findings highlight molecular mechanisms that host plants may use to regulate their association with high- and low-benefit arbuscular mycorrhizal symbionts. [ABSTRACT FROM AUTHOR]

Interactions between arbuscular mycorrhizal fungi (AMF), plants, and the soil microbial community have the potential to increase the availability and uptake of phosphorus (P) and nitrogen (N) in agricultural systems. Nutrient exchange between plant roots, AMF, and the adjacent soil microbes occurs at the interface between roots colonized by mycorrhizal fungi and soil, referred to as the mycorrhizosphere. Research on the P exchange focuses on plant-AMF or AMF-microbe interactions, lacking a holistic view of P exchange between the plants, AMF, and other microbes. Recently, N exchange at both interfaces revealed the synergistic role of AMF and bacterial community in N uptake by the host plant. Here, we highlight work carried out on each interface and build upon it by emphasizing research involving all members of the tripartite network. Both nutrient systems are challenging to study due to the complex chemical and biological nature of the mycorrhizosphere. We discuss some of the effective methods to identify important nutrient processes and the tripartite members involved in these processes. The extrapolation of in vitro studies into the field is often fraught with contradiction and noise. Therefore, we also suggest some approaches that can potentially bridge the gap between laboratory-generated data and their extrapolation to the field, improving the applicability and contextual relevance of data within the field of mycorrhizosphere interactions. Overall, we argue that the research community needs to adopt a holistic tripartite approach and that we have the means to increase the applicability and accuracy of in vitro data in the field., Competing Interests: The authors declare no conflict of interest.

Summary: Mutualistic symbiotic associations between multicellular eukaryotes and their microbiota are driven by the exchange of nutrients in a quid pro quo manner. In the widespread arbuscular mycorrhizal (AM) symbiosis involving plant roots and Glomeromycotina fungi, the mycobiont is supplied with carbon through photosynthesis, which in return supplies the host plant with essential minerals such as phosphorus (P). Most terrestrial plants are largely dependent on AM fungi for nutrients, which raises the question of how plants that are unable to form a functional AM sustain their P nutrition. AM nonhost plants can form alternative, evolutionarily younger, mycorrhizal associations such as the ectomycorrhiza, ericoid and orchid mycorrhiza. However, it is unclear how plants such as the Brassicaceae species Arabidopsis thaliana, which do not form known mycorrhizal symbioses, have adapted to the loss of these essential mycorrhizal traits. Isotope tracing experiments with root‐colonizing fungi have revealed the existence of new 'mycorrhizal‐like' fungi capable of transferring nutrients such as nitrogen (N) and P to plants, including Brassicaceae. Here, we provide an overview of the biology of trophic relationships between roots and fungi and how these associations might support plant adaptation to climate change. [ABSTRACT FROM AUTHOR]

Laser microdissection (LMD) is a microscopy technique that, through the collection of specific cell-type populations from sections of heterogeneous tissues, allows the subsequent extraction of nucleic acids as well as primary and secondary metabolites. In plants, LMD was widely used to study cell-specific gene expression during symbiotic interactions with other organisms, including mycorrhizal fungi. In particular, LMD was extensively used to study cell-specificity in gene expression profiles in arbuscular mycorrhizal (AM) and orchid mycorrhizal (ORM) interactions. These earlier studies were mainly focused on the identification of functional markers in plant cells containing intracellular fungal structures, i.e. arbuscules, the typical structures in AM, and coils, typical of ORM. Several plant and fungal genes coding for nutrient transporters were identified in these cells thanks to LMD, suggesting that symbiotic nutrient exchange is cell specific. In the absence of a stable transformation protocol for the expression of tagged genes in the mycorrhizal fungal partner, LMD protocols represent a useful tool to study fungal gene expression in specific cell-type populations inside symbiotic plant tissues.

Diatom–diazotroph associations (DDAs) are one of the most important symbiotic dinitrogen (N2) fixing groups in the oligotrophic ocean. Despite their capability to fix N2, ammonium (NH4+) remains a key nitrogen (N) source for DDAs, and the effect of NH4+ on their metabolism remains elusive. Here, we developed a coarse-grained, cellular model of the DDA with NH4+ uptake and quantified how the level of extracellular NH4+ influences metabolism and nutrient exchange within the symbiosis. The model shows that, under a fixed growth rate, an increased NH4+ concentration may lower the required level of N2 fixation and photosynthesis, and decrease carbon (C) and N exchange. A low-NH4+ environment leads to more C and N in nutrient exchange and more fixed N2 to support a higher growth rate. With higher growth rates, nutrient exchange and metabolism increased. Our study shows a strong effect of NH4+ on metabolic processes within DDAs, and thus highlights the importance of in situ measurement of NH4+ concentrations.

Dryland communities may mitigate the loss of limited resources by exchanging nutrients through subterranean fungal connections, termed fungal loops. In arid grasslands, fungal loops can influence community composition and primary productivity, yet their ecological significance across dryland systems remains unexplored. We investigated the functional role of fungal loops in nutrient translocation in a North American shrubland ecosystem.We traced the movement of 15N from moss‐dominated biocrusts to the dominant xeric shrub Larrea tridentata, and the movement of 13C from L. tridentata to biocrusts in plots established in situ in the Sonoran Desert. Measurements occurred at three time points spanning 1 week following a simulated 2.5 mm rainfall event, and at distances up to 1 m from tracer application. We also used ITS sequencing to investigate changes in fungal community composition in soils over the 1‐week period.We discovered movement of 15N from biocrusts into L. tridentata foliage as well as 15N movement to other spatially isolated moss‐dominated biocrust patches, yet this movement did not occur until 4–6 days post‐rainfall, when significantly higher δ15N was observed in L. tridentata and biocrusts compared to previous days. We did not observe consistent patterns of 13C movement from L. tridentata into neighbouring shrubs or biocrusts, suggesting differential environmental drivers for carbon movement in this system. Fungal communities exhibited a decrease in alpha diversity on the last day of the study, indicative of a delayed community response to rainfall concomitant with nutrient translocation. Fungal endophyte orders Pleosporales and Pezizales dominated all plot soils, and order Pleosporales was significantly more abundant in 15N enriched plots, suggesting that dark septate endophytic fungi were involved in nitrogen translocation. The delay in nutrient translocation may reflect a rainfall‐triggered rebuilding of mycelial networks between community members following drought.Synthesis. Our results point to fungal‐mediated nutrient exchange pathways in a previously uninvestigated vegetation type, shrublands, where nutrients are translocated between moss‐dominated biocrusts and nearby shrubs. We provide the first evidence that nutrient transfer may be delayed up to 6 days following rainfall, consistent with pulse‐dynamic responses in drylands, and that moss‐dominated biocrusts play a role in fungal loops. [ABSTRACT FROM AUTHOR]

The focus on adopting practices that ensure long-term food production while minimizing environmental impacts has gained considerable prominence in sustainable agriculture. To achieve sustainable agricultural practices, plants must interact with the soil microbiome in a complex manner, which includes arbuscular mycorrhizae (AM) fungi and phosphate-solubilizing microorganisms (PSMs). In fostering plant health and resilience, these microorganisms play an important role. The improved nutrient absorption facilitated by AMF is instrumental in promoting plant growth, development, and resistance to various environmental stresses. PSMs play a similarly significant role in this intricate interdependence, if not more so. The low solubility of phosphorus in soil makes it inaccessible to plants, a fundamental element in plant physiology. These insoluble phosphorus compounds are converted to readily available forms for plant uptake by PSMs, which secrete specific enzymes, primarily phosphatases. PSMs contribute to plant health in more ways than just phosphorus solubilization; they produce growth stimulants and create a robust environment, enhancing plant health overall. Ultimately, AM fungi and PSMs have a vital role to play in agriculture. According to this assessment, there is a need to address existing knowledge gaps and actively promote the comprehensive integration of these microorganisms into modern agricultural practices. To ensure a well-rounded perspective and successful implementation of these practices, it is critical to acknowledge potential challenges, such as education, technical expertise, regulatory hurdles, cost-effectiveness, and scaling up. [Display omitted] • Emphasizes the need for practices that ensure long-term food production with minimal environmental impact. • Highlights the complex interactions between plants and soil microbiome • Points out the broader benefits of these microorganisms on soil quality, water retention, and ecosystem health. • Explores the potential of AM fungi and PSMs as sustainable substitutes for chemical fertilizers. • Recognizes the need for more research on soil microorganisms, emphasizing challenges in education, expertise, and scalability [ABSTRACT FROM AUTHOR]

[Display omitted] • Desmodesmus sp. to A. pulmonis coculture optimizes to DBP removal efficiency. • Excellent, 93 % DBP removal recorded at 1:1 coculture, pH-6, L:D-12:12, 120 rpm speed. • High protein & sugar: 107.67 & 39.78 mg/L were observed with DBP. • The degradation 81% played the key role in coculture system. A green approach of Desmodesmus sp. to Achromobacter pulmonis (1:1) coculture ratios was optimized to improve the removal efficiency of dibutyl phthalate (DBP) from simulated wastewater. High DBP resistance bacterial strains and microalgae was optimized from plastic contaminated water and acclimation process respectively. The influence of various factors on DBP removal performance was comprehensively investigated. Highest DBP removal 93 % was recorded, when the ratios algae-bacteria 1:1, with sodium acetate, pH-6, shaking speed-120 rpm and lighting periods L:D-12:12. Enough nutrient (TN/TP/TOC) availability and higher protein-108 mg/L and sugar-40 mg/L were observed in presences of 50 mg/L DBP. The degradation and sorption were calculated 81,12; 27,39 & 43,12 % in algae-bacteria, only algae and only bacteria system respectively. The degradation kinetics t 1/2 3.74,22.15,12.86 days were evaluated, confirming that algae-bacteria effectively degrade the DBP. This outcome leading to promote a green sustainable approach to remove the emerging contamination from wastewater. [ABSTRACT FROM AUTHOR]

Abstract Traditionally, the most popular sentences used to describe the arbuscular mycorrhizal symbiosis sound like: “AM fungi form one of the most widespread root symbioses, associating with 80% of land plants. In this symbiosis, the fungus provides the plant host with mineral nutrients, especially phosphate, receiving in turn carbohydrates.” In the last years, the mycorrhiza research field has witnessed a big step forward in the knowledge of the physiology and the mechanisms governing this important symbiosis, that helped plants colonizing the lands more than 400 MYA. The huge expansion of the -omics studies produced the first results on the fungal side, with genomes and transcriptomes of AM fungi being published. In parallel, the need for more sustainable agricultural practices has boosted the research in the field of the plant symbioses, with the final aim of improving plant productivity employing symbiotic microbes as bioinoculants. Beside all the other (positive) effects that mycorrhizal fungi exert on plants, the nutrient exchange is considered as the keystone, and the core mechanism governing this symbiosis. This review will focus on the molecular determinants underneath this exchange, both on the fungal and the plant side. Coming back to the sentence that claims this symbiosis as based on phosphate provided to the plant in return to carbohydrate, we will find that some concepts of this view still stand, while some others have been partly revolutionized.

Apicomplexan parasites that reside within a parasitophorous vacuole harbor a conserved pore-forming protein that enables small-molecule transfer across the parasitophorous vacuole membrane (PVM). In Plasmodium parasites that cause malaria, this nutrient pore is formed by EXP2 which can complement the function of GRA17, an orthologous protein in Toxoplasma gondii. EXP2, however, has an additional function in Plasmodium parasites, serving also as the pore-forming component of the protein export machinery PTEX. To examine how EXP2 can play this additional role, transgenes that encoded truncations of EXP2, GRA17, hybrid GRA17-EXP2, or EXP2 under the transcriptional control of different promoters were expressed in EXP2 knockdown parasites to determine which could complement EXP2 function. This revealed that EXP2 is a unique pore-forming protein, and its protein export role in P. falciparum cannot be complemented by T. gondii GRA17. This was despite the addition of the EXP2 assembly strand and part of the linker helix to GRA17, which are regions necessary for the interaction of EXP2 with the other core PTEX components. This indicates that the body region of EXP2 plays a critical role in PTEX assembly and/or that the absence of other T. gondii GRA proteins in P. falciparum leads to its reduced efficiency of insertion into the PVM and complementation potential. Altering the timing and abundance of EXP2 expression did not affect protein export but affected parasite viability, indicating that the unique transcriptional profile of EXP2 when compared to other PTEX components enables it to serve an additional role in nutrient exchange., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2024 Pitman, Counihan, Modak, Chowdury, Gilson, Webb and de Koning-Ward.)

Arbuscular mycorrhizal fungi (AMF) contribute predominantly to soil organic matter by creating a sink demand for plant C and distributing to below-ground hyphal biomass. The extra-radical hyphae along with glomalin-related soil protein significantly influence the soil carbon dynamics through their larger extent and turnover period need to discuss. The role of AMF is largely overlooked in terrestrial C cycling and climate change models despite their greater involvement in net primary productivity augmentation and further accumulation of this additional photosynthetic fixed C in the soil. However, this buffering mechanism against elevated CO2 condition to sequester extra C by AMF can be described only after considering their potential interaction with other microbes and associated mineral nutrients such as nitrogen cycling. In this article, we try to review the potential of AMF in C sequestration paving the way towards a better understanding of possible AMF mechanism by which C balance between biosphere and atmosphere can be moved forward in more positive direction. [ABSTRACT FROM AUTHOR]

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The mutualistic symbiosis between plants and arbuscular mycorrhizal (AM) fungi is based on a balanced nutrient exchange between both partners, with the plant achieving improved nutrition and stress tolerance. The symbiosis is finely-tuned according to plant's needs and surrounding conditions, usually through phytohormonal signaling. Thus, environmental conditions or stress factors modulating phytohormone signaling may influence the symbiosis. This study compares the colonization abilities of 2 AM fungal species, Funneliformis mosseae and Rhizophagus irregularis , independently or in combination, in tomato plants subjected to different stress conditions. These included salt stress and systemic defense activation by aboveground application of the defense-related hormones methyl jasmonate, abscisic acid and salicylic acid. The results show that root colonization by the two fungal species differs depending on the stress treatment. Nutrient and transcriptional analyses revealed that changes in colonization correlated with differential regulation of nutrient exchange, plant defensive responses, and symbiosis regulatory genes. Specifically, under salt stress R. irregularis colonization decreased , while F. mosseae colonization was promoted. These differential regulation of colonization under stress positively correlated with changes in the functionality of the symbiosis. Overall, the results support that the benefits provided by each AM fungi influence carbon reward and determines the control of root colonization by the host plant. • Tomato plants differentially regulate mycorrhizal colonization under stress. • Changes in colonization levels depend on the fungal genotype and the stress faced. • Colonization levels are adjusted according to symbiotic efficiency of the interaction. • The regulation depends on nutrient exchange, plant defenses and autoregulation. [ABSTRACT FROM AUTHOR]

A thorough understanding of the services provided by microorganisms to the agricultural ecosystem is integral to understanding how management systems can improve or deteriorate soil health and production over the long term. Yet it is hampered by the difficulty in measuring the intersection of plant, microbe, and environment, in no small part because of the situational specificity to some plant-microbial interactions, related to soil moisture, nutrient content, climate, and local diversity. Despite this, perspective on soil microbiota in agricultural settings can inform management practices to improve the sustainability of agricultural production.

Summary: Mutually beneficial resource exchange is fundamental to global biogeochemical cycles and plant and animal nutrition. However, there is inherent potential conflict in mutualisms, as each organism benefits more when the exchange ratio ('price') minimizes its own costs and maximizes its benefits. Understanding the bargaining power that each partner has in these interactions is key to our ability to predict the exchange ratio and therefore the functionality of the cell, organism, community and ecosystem.We tested whether partners have symmetrical ('fair') or asymmetrical ('unfair') bargaining power in a legume–rhizobia nitrogen‐fixing symbiosis using measurements of carbon and nitrogen dynamics in a mathematical modeling framework derived from economic theory.A model of symmetric bargaining power was not consistent with our data. Instead, our data indicate that the growth benefit to the plant (Medicago truncatula) has greater weight in determining trade dynamics than the benefit to the bacteria. Quantitative estimates of the relative power of the plant revealed that the plant's influence rises as soil nitrogen availability decreases and trade benefits to both partners increase.Our finding that M. truncatula legumes have more bargaining power than their rhizobial partner at lower nitrogen availabilities highlights the importance of context‐dependence for the evolution of mutualism with increasing nutrient deposition. [ABSTRACT FROM AUTHOR]

Mycorrhizas play an important role in plant growth and development. In mycorrhizal symbioses, fungi supply soil mineral nutrients, such as nitrogen and phosphorus, to their host plants in exchange for carbon resources. Plants gain as much as 80% of mineral nutrient requirements from mycorrhizal fungi, which form associations with the roots of over 90% of all plant species. Orchid seeds lack endosperms and contain very limited storage reserves. Therefore, the symbiosis with mycorrhizal fungi that form endomycorrhizas is essential for orchid seed germination and protocorm development under natural conditions. The rapid advancement of next-generation sequencing contributes to identifying the orchid and fungal genes involved in the orchid mycorrhizal symbiosis and unraveling the molecular mechanisms regulating the symbiosis. We aim to update and summarize the current understanding of the mechanisms on orchid-fungus symbiosis, and the main focus will be on the nutrient exchange between orchids and their fungal partners. [ABSTRACT FROM AUTHOR]

Abstract Tight metabolic control of type-1 diabetes is essential during gestation, but it could be crucial during the periconception period. Feto-placental consequences of maternal type-1 diabetes around the time of conception need to be explored. Using a rabbit model, type-1 diabetes was induced by alloxan 7 days before mating. Glycemia was maintained at 15–20 mmol/L with exogenous insulin injections to prevent ketoacidosis. At 4 days post-conception (dpc), embryos were collected from diabetic (D) or normoglycemic control (C) dams, respectively, and transferred into non-diabetic recipients. At 28dpc, D- and C-feto-placental units were collected for biometry, placental analyses and lipid profiles. D-fetuses were growth-retarded, hyperglycemic and dyslipidemic compared to C-fetuses. The efficiency of D-placentas was associated with an increased gene expression related to nutrient supply and lipid metabolism whereas volume density of fetal vessels decreased. Fetal plasma, placental and fetal liver membranes had specific fatty acid signatures depending on embryonic origin. Tissues from D-fetuses contained more omega-6 polyunsaturated fatty acids. The concentrations of docosahexaenoic acid decreased while linoleic acid increased in the heart of D-fetuses. This study demonstrates that a short exposure to maternal type-1 diabetes in the periconception window, until the blastocyst stage, is able to irreversibly malprogram the feto-placental phenotype, through precocious and persistent structural and molecular adaptations of placenta. Graphical abstract Image 1 Highlights • Pre-gestational diabetes in periconception prior implantation, induced persistent embryonic adaptations throughout gestation. • Embryo transfer into normoglycemic recipient mothers cannot erase effects of early embryonic programming. • Periconceptional diabetes altered placental transporters, leading to fetal hyperglycemia and dyslipidemia but hypotrophy. • The periconceptional maternal diabetes induced a fatty acid specific signature in glucose-sensitive feto-placental tissues. [ABSTRACT FROM AUTHOR]

Arbuscular mycorrhizal fungi colonize the roots of most plants, forming a near-ubiquitous symbiosis 1 that is typically characterized by the bi-directional exchange of fungal-acquired nutrients for plant-fixed carbon. 2 Mycorrhizal fungi can form below-ground networks 3,4,5,6 with potential to facilitate the movement of carbon, nutrients, and defense signals across plant communities. 7,8,9 The importance of neighbors in mediating carbon-for-nutrient exchange between mycorrhizal fungi and their plant hosts remains equivocal, particularly when other competing pressures for plant resources are present. We manipulated carbon source and sink strengths of neighboring pairs of host plants through exposure to aphids and tracked the movement of carbon and nutrients through mycorrhizal fungal networks with isotope tracers. When carbon sink strengths of both neighboring plants were increased by aphid herbivory, plant carbon supply to extraradical mycorrhizal fungal hyphae was reduced, but mycorrhizal phosphorus supply to both plants was maintained, albeit variably, across treatments. However, when the sink strength of only one plant in a pair was increased, carbon supply to mycorrhizal fungi was restored. Our results show that loss of carbon inputs into mycorrhizal fungal hyphae from one plant may be ameliorated through inputs of a neighbor, demonstrating the responsiveness and resilience of mycorrhizal plant communities to biological stressors. Furthermore, our results indicate that mycorrhizal nutrient exchange dynamics are better understood as community-wide interactions between multiple players rather than as strict exchanges between individual plants and their symbionts, suggesting that mycorrhizal C-for-nutrient exchange is likely based more on unequal terms of trade than the "fair trade" model for symbiosis. [Display omitted] • We assessed neighbors' impact on mycorrhizal function in plant-aphid interactions • When both plants were aphid infested, carbon supply to mycorrhizal fungi decreased • If only one plant was infested, carbon supply was partially restored • Mycorrhizal nutrient exchanges are better understood as community-wide interactions Durant et al. show that mycorrhizal nutrient exchange involves community-wide interactions between multiple players. Loss of carbon inputs into mycorrhizal fungi caused by aphid herbivory of one plant can be compensated for by aphid-free neighbors, demonstrating the responsiveness and resilience of mycorrhizal plant communities to biological stressors. [ABSTRACT FROM AUTHOR]

Mycorrhizas play an important role in plant growth and development. In mycorrhizal symbioses, fungi supply soil mineral nutrients, such as nitrogen and phosphorus, to their host plants in exchange for carbon resources. Plants gain as much as 80% of mineral nutrient requirements from mycorrhizal fungi, which form associations with the roots of over 90% of all plant species. Orchid seeds lack endosperms and contain very limited storage reserves. Therefore, the symbiosis with mycorrhizal fungi that form endomycorrhizas is essential for orchid seed germination and protocorm development under natural conditions. The rapid advancement of next-generation sequencing contributes to identifying the orchid and fungal genes involved in the orchid mycorrhizal symbiosis and unraveling the molecular mechanisms regulating the symbiosis. We aim to update and summarize the current understanding of the mechanisms on orchid-fungus symbiosis, and the main focus will be on the nutrient exchange between orchids and their fungal partners.

Most land plants form symbiotic associations with arbuscular mycorrhizal (AM) fungi. These are the most common and widespread terrestrial plant symbioses, which have a global impact on plant mineral nutrition. The establishment of AM symbiosis involves recognition of the two partners and bidirectional transport of different mineral and carbon nutrients through the symbiotic interfaces within the host root cells. Intriguingly, recent discoveries have highlighted that lipids are transferred from the plant host to AM fungus as a major carbon source. In this review, we discuss the transporter-mediated transfer of carbon, nitrogen, phosphate, potassium and sulfate, and present hypotheses pertaining to the potential regulatory mechanisms of nutrient exchange in AM symbiosis. Current challenges and future perspectives on AM symbiosis research are also discussed. [ABSTRACT FROM AUTHOR]

Long-term field observations of nitrogen [N] and phosphorus [P] concentrations were used to construct nutrient budgets for the western Dutch Wadden Sea between 1976 and 2012. Nutrients come into the western Dutch Wadden Sea via river runoff, through exchange with the coastal zone of the North Sea, neighbouring tidal basins and through atmospheric deposition (for N). The highest concentrations in phosphorus and nitrogen were observed in the mid-1980s. Improved phosphorus removal at waste water treatment plants, management of fertilization in agriculture and removal of phosphates from detergents led to reduced riverine nutrient inputs and, consequently, reduced nutrient concentrations in the Wadden Sea. The budgets suggest that the period of the initial net import of phosphorus and nitrogen switched to a net export in 1981 for nitrogen and in 1992 for phosphorus. Such different behaviour in nutrient budgets during the rise and fall of external nutrient concentrations may be the result of different sediment-water exchange dynamics for P and N. It is hypothesized that during the period of increasing eutrophication (1976–1981) P, and to a lesser degree N, were stored in sediments as organic and inorganic nutrients. In the following period (1981–1992) external nutrient concentrations (especially in the North Sea) decreased, but P concentrations in the Wadden Sea remained high due to prolonged sediment release, whilst denitrification removed substantial amounts of N. From 1992 onwards, P and N budgets were closed by net loss, most probably because P stores were then depleted and denitrification continued. Under the present conditions (lower rates of sediment import and depleted P stores), nutrient concentrations in this area are expected to be more strongly influenced by wind-driven exchange with the North Sea and precipitation-driven discharge from Lake IJssel. This implies that the consequences of climate change will be more important, than during the 1970s and 1980s. [ABSTRACT FROM AUTHOR]