Micro- and nanoplastics (MNPs), pervasive environmental pollutants, contaminate water, soil, air, and the food chain and ultimately accumulate in living organisms. Macrophages are the main immune cells that gather around MNPs and engulf them through the process of phagocytosis. This internalization triggers M1 polarization and the secretion of inflammatory cytokines, including IL-1, IL-18, IL-12, TNF-alpha, and IFN-gamma. Furthermore, MNPs damage mitochondria and lysosomes, causing overactivation of iNOS and excessive production of ROS. This results in cellular stress and induce apoptosis, necroptosis, and, in some cases, metosis in macrophages. The internalization of MNPs also increases the expression of receptors, involving CD36, SR-A, LOX-1, and the macrophage receptor with a collagenous structure (MARCO) while decreasing ABCA-1 and ABCG-1. MNPs in adipose tissue macrophages trigger proinflammatory cytokine secretion, causing adipogenesis, lipid accumulation, insulin resistance, and the secretion of inflammatory cytokines in adipocytes. Various factors influence the rate of MNP internalization by macrophages, including size, charge, and concentration, which affect internalization through passive diffusion. Receptor-mediated phagocytosis of MNPs occurs directly via receptors like T-cell immunoglobulin and mucin domain containing 4 (TIM-4) and MARCO. The attachment of biomolecules, including proteins, antibodies, opsonins, or microbes to MNPs (forming corona structures) promotes indirect receptor-mediated endocytosis, as macrophages possess receptors like TLRs and Fc gamma RIII. MNPs also cause gut dysbiosis, a risk factor for proinflammatory microenvironment and M1 polarization. Here, we review the mechanisms and consequences of MNP macrophage exposure, which is linked to autoimmunity, inflammation, and cardiometabolic syndrome manifestations, including atherosclerosis and obesity, highlighting the immunotoxicity of MNPs.
Genera Pseudomonas and Xanthomonas include bacterial species that are etiological agents of several diseases of major vegetable crops, such as tomato, pepper, bean, cabbage and cauliflower. The bacterial pathogens of those genera may cause severe crop damage, leading to symptoms like leaf spots, wilting, blights, and rotting. These plant pathogens can affect propagation materials and spread rapidly through plant tissues, contaminated soils, or water sources, making them challenging to control using conventional chemical products alone. Biopesticides, such as essential oils (EOs), are nowadays studied, tested and formulated by employing nano- and micro-technologies as innovative biological control strategies to obtain more sustainable products using less heavy metal ions. Moreover, there is a growing interest in exploring new biological control agents (BCAs), such as antagonistic bacterial and fungal species or bacteriophages and understanding their ecology and biological mechanisms to control bacterial phytopathogens. These include direct competition for nutrients, production of antimicrobial compounds, quorum quenching and indirect induction of systemic resistance. Optimisation of the biocontrol potential goes through the development of nanoparticle-based formulations and new methods for field application, from foliar sprays to seed coatings and root inoculation, aimed to improve microbial stability, shelf life, controlled release and field performance. Overall, the use of biological control in horticultural crops is an area of research that continues to advance and shows promising potential. This review aims to provide an in-depth exploration of commercially accessible biocontrol solutions and innovative biocontrol strategies, with a specific focus on the management of bacterial diseases in vegetable crops caused by Pseudomonas and Xanthomonas species. In this article, we highlighted the advancements in the development and use of EOs and other BCAs, emphasizing their potential or shortcomings for sustainable disease management. Indeed, despite the reduced dependence on synthetic pesticides and enhanced crop productivity, variable regulatory frameworks, compatibility among different BCAs, and consistent performance under field conditions are among the current challenges to their commercialization and use. The review seeks to contribute valuable insights into the evolving landscape of biocontrol in vegetable crops and to provide guidance for more effective and eco-friendly solutions against plant bacterial diseases.
Since 1989, investigations into viral ecology have revealed how bacteriophages can influence microbial dynamics within ecosystems at global scales. Most of the information we know about temperate phages, which can integrate themselves into the host genome and remain dormant via a process called lysogeny, has come from research in aquatic ecosystems. Soil environments remain under-studied, and more research is necessary to fully understand the range of impacts phage infections have on the soil bacteria they infect. The aims of this study were to compare the efficacy of different prophage-inducing agents and to elucidate potential temporal trends in lysogeny within a soil bacterial community. In addition to mitomycin C and acyl-homoserine lactones, our results indicated that halosulfuron methyl herbicides may also be potent inducing agents. In optimizing chemical induction assays, we determined that taking steps to reduce background virus particles and starve cells was critical in obtaining consistent results. A clear seasonal trend in inducible lysogeny was observed in an Appalachian oak-hickory forest soil. The average monthly air temperature was negatively correlated with inducible fraction and burst size, supporting the idea that lysogeny provides a mechanism for phage persistence when temperatures are low and host metabolism is slower. Furthermore, the inducible fraction was negatively correlated with both soil bacterial and soil viral abundance, supporting the idea that lysogeny provides a mechanism for temperate phage persistence when host density is lower. The present study is the first of its kind to reveal clear seasonal trends in inducible lysogeny in any soil.IMPORTANCELysogeny is a relationship in which certain viruses that infect bacteria (phages) may exist within their bacterial host cell as a segment of nucleic acid. In this state, the phage genome is protected from environmental damage and retains the potential to generate progeny particles in the future. It is thought that lysogeny provides a mechanism for long-term persistence for phages when host density is low or hosts are starved-two conditions likely to be found in soils. In the present study, we provide the first known evidence for a seasonal trend in lysogeny in a forest soil. Based on clear relationships observed between lysogeny, temperature, and soil microbial abundance, we find support for previous hypotheses regarding the factors governing lysogeny. Lysogeny is a relationship in which certain viruses that infect bacteria (phages) may exist within their bacterial host cell as a segment of nucleic acid. In this state, the phage genome is protected from environmental damage and retains the potential to generate progeny particles in the future. It is thought that lysogeny provides a mechanism for long-term persistence for phages when host density is low or hosts are starved-two conditions likely to be found in soils. In the present study, we provide the first known evidence for a seasonal trend in lysogeny in a forest soil. Based on clear relationships observed between lysogeny, temperature, and soil microbial abundance, we find support for previous hypotheses regarding the factors governing lysogeny.
Permafrost stores approximately 50% of global soil carbon (C) in a frozen form; it is thawing rapidly under climate change, sand little is known about viral communities in these soils or their roles in C cycling. In permafrost soils, microorganisms contribute significantly to C cycling, and characterizing them has recently been shown to improve prediction of ecosystem function. In other ecosystems, viruses have broad ecosystem and community impacts ranging from host cell mortality and organic matter cycling to horizontal gene transfer and reprogramming of core microbial metabolisms. Here we developed an optimized protocol to extract viruses from three types of high organic matter peatland soils across a permafrost thaw gradient (palsa, moss-dominated bog, and sedge-dominated fen). Three separate experiments were used to evaluate the impact of chemical buffers, physical dispersion, storage conditions, and concentration and purification methods on viral yields. The most successful protocol, amended potassium citrate buffer with bead-beating or vortexing and BSA, yielded on average as much as 2-fold more virus-like particles (VLPs) g(-1) of soil than other methods tested. All method combinations yielded VLPs g(-1) of soil on the 108 order of magnitude across all three soil types. The different storage and concentration methods did not yield significantly more VLPs g(-1) of soil among the soil types. This research provides much-needed guidelines for resuspending viruses from soils, specifically carbon-rich soils, paving the way for incorporating viruses into soil ecology studies.