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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]

Tomato (Solanum lycopersicum L.) production is constantly threatened by several fungal pathogens, such as Alternaria solani, the causal agent of early blight disease. In this study, a greenhouse experiment was set up to evaluate the biocontrol ability of arbuscular mycorrhizal fungi (AMF) against A. solani in the presence of reduced doses of fungicides (i.e., captan and copper oxychloride). Disease severity, plant growth traits, chlorophyll and phosphorus content, phenolic compounds, and antioxidant activity were assessed. The effects of fungicide dose on AMF were investigated by root colonization, spore density, and mycorrhizal dependence evaluation. AMF-inoculated and fungicide-treated plants reduced disease severity compared to fungicide-treated and non-mycorrhizal plants, in most cases, regardless of the fungicide dose. AMF improved plant growth, especially when combined with copper oxychloride. However, plant fresh weight decreased in plants treated with the lowest dose of captan (25 g 100 L−1). Overall, AMF colonization decreased in plants with high fungicide doses, while the leaf color parameters did not show differences between treatments. The results suggest reducing the fungicide dose using AMF is possible, particularly for copper oxychloride. Further studies will be required to confirm these data. This integrated approach could offer a sustainable alternative to decrease the use of chemical control. [ABSTRACT FROM AUTHOR]

Sustainable alternatives are essential to improving agriculture production to meet the growing world's critical demands. Cyanobacteria and microalgae are considered renewable resources with a wide range of potential uses in the agricultural sector. We aimed to isolate cyanobacteria and microalgae from the mud of a carbon dioxide-rich sulfur pond and to investigate their plant growth-promoting (PGP) and soil bio-consolidating ability. Mud samples were subjected to DNA extraction and 16S rRNA gene sequencing to characterize the prokaryotic community. Phototrophic culturable microbiota was isolated and evaluated for different PGP properties. The most relevant isolates were combined in a consortium and used for in vitro bioconsolidation activity. In a greenhouse experiment, the isolates were evaluated for their ability to promote salinity stress tolerance in sunflower plants. Metabarcoding results showed that most Amplicon Sequence Variants (ASV) were associated with Actinobacteriota (35%), Proteobacteria (19%), and Acidobacteriota (11%) at the phylum level and Unknown (32%) and uncultured (31%) lineages at the genus level. The culture-dependent method yielded eight isolates associated with cyanobacteria and microalgae genera. The isolates obtained showed interesting PGP activities. Isolates C1, C2, and M1 were selected based on phosphate solubilization (85.6 µg PO43- mL-1 on average), indoles (C1 and M1 0.54 µg mL-1 IAA equivalents on average), and ACC deaminase activity (C2 and M1 6.00 µmol α-KB mg proteins-1 h-1). The consortium efficiently consolidated sand particles in the presence of calcium carbonate by forming activities biomineralized aggregates. In planta results showed positive effects of the consortium on Helianthus annuus L., plant growth under normal conditions and salt stress. The positive effects on soil and plants indicated their effectiveness as bioconsolidants and biostimulant agents. Our findings highlight the interesting potential of cyanobacteria and microalgae applications in sustainable agriculture. [ABSTRACT FROM AUTHOR]

With the expansion of the green products market and the worldwide policies and strategies directed toward a green revolution and ecological transition, the demand for innovative approaches is always on the rise. Among the sustainable agricultural approaches, microbial-based products are emerging over time as effective and feasible alternatives to agrochemicals. However, the production, formulation, and commercialization of some products can be challenging. Among the main challenges are the industrial production processes that ensure the quality of the product and its cost on the market. In the context of a circular economy, solid-state fermentation (SSF) might represent a smart approach to obtaining valuable products from waste and by-products. SSF enables the growth of various microorganisms on solid surfaces in the absence or near absence of free-flowing water. It is a valuable and practical method and is used in the food, pharmaceutical, energy, and chemical industries. Nevertheless, the application of this technology in the production of formulations useful in agriculture is still limited. This review summarizes the literature dealing with SSF agricultural applications and the future perspective of its use in sustainable agriculture. The survey showed good potential for SSF to produce biostimulants and biopesticides useful in agriculture. [ABSTRACT FROM AUTHOR]