Uranium/cadmium (U/Cd) pollution poses a significant global environmental challenge, and phytoremediation offers a sustainable solution for heavy metal contamination. However, the mechanisms by which plants survive U/Cd stress remain unclear. Here, we conducted soil culture experiments of moso bamboo seedlings under U/Cd stress (U, Cd and U + Cd) to examine the effects of it on plant growth, mineral metabolism, and rhizosphere micro-environment. Our findings reveal that U/Cd stress inhibits seedling growth, enhances reactive oxygen species damage, and bolsters the antioxidant system. Additionally, Partial Least Squares Path Modeling (PLS-PM) was employed to uncover potential tolerance mechanisms in moso bamboo under U/Cd stress. U/Cd is mainly distributed in the root cell walls and also exists predominantly in the residual state within the roots. Correspondingly, U and Cd significantly disrupt mineral metabolism in plant. Metabolomic analyses indicate that U/ Cd markedly suppress amino acid metabolism pathways, while they stimulate carbon metabolism to mitigate toxicity. Furthermore, U/Cd stress disrupts the rhizosphere microbial community structure, and the competitive interaction of nitrogen functions exists between rhizosphere microorganism and bamboo roots. PLS-PM reveal the U/Cd stress impacts the interaction of the soil-rhizosphere-plant system. Together, these findings offer new insights into the response mechanism of bamboo plants to heavy metal stress, and provide a theoretical foundation for screening heavy metal tolerant plants and managing mining areas.

Zinc (Zn) is a vital micronutrient required for optimal plant growth and soil fertility. Its use in the form of nanoparticles (NPs) has gained significant attention in agricultural applications. Green synthesized Zn-based NPs offer an eco-friendly solution to several conventional problems in agriculture. Several plants, bacteria, fungi and yeast have shown significant potential in fabricating Zn NPs that can provide environmentally friendly solutions in agriculture and the approach is aligned with sustainable agricultural practices, reducing the dependency on harmful agrochemicals. Zn-based NPs act as plant growth promoters, enhance crop yield, promote resilience to abiotic stressors and are efficient crop protection agents. Their role as a smart delivery system, enabling targeted and controlled release of agrochemicals, further signifies their potential use in agriculture. Because agriculture requires repeated applications hence, the toxicological aspects of Zn NPs cannot be ignored. Zn NPs are reported to cause phytotoxicity, including root damage, physiological and biochemical disturbances, and genotoxic effects. Furthermore, exposure to Zn NPs poses risks to soil microbiota, and aquatic and terrestrial organisms potentially impacting the ecosystem. The green synthesis of Zn-based NPs has a promising aspect for advancing sustainable agriculture by reducing agrochemical use and improving crop productivity. Their diverse applications as plant growth promoters, crop protectants and smart delivery systems emphasize their potential. However, the toxicological aspects are essential to ensure the standardization of doses for their safe and effective use. Further research would help address such concerns and help in developing viable and eco-friendly solutions for modern agriculture. (c) 2025 Society of Chemical Industry.

Numerous specimens stored in natural history collections have been involuntarily preserved together with their associated microbiomes. We propose exploiting century-old soils occasionally found on the roots of herbarium plants to assess the diversity of ancient soil microbial communities originally associated with these plants. We extracted total DNA and sequenced libraries produced from rhizospheric soils and roots of four plants preserved in herbaria for more than 120 years in order to characterise the preservation and taxonomic diversity that can be recovered in such contexts. Extracted DNA displayed typical features of ancient DNA, with cytosine deamination at the ends of fragments predominantly shorter than 50 bp. When compared to extant microbiomes, herbarium microbial communities clustered with soil communities and were distinct from communities from other environments. Herbarium communities also displayed biodiversity features and assembly rules typical of soil and plant-associated ones. Soil communities were richer than root-associated ones with which they shared most taxa. Regarding community turnover, we detected collection site, soil versus root and plant species effects. Eukaryotic taxa that displayed a higher abundance in roots were mostly plant pathogens that were not identified among soil-enriched ones. Conservation of these biodiversity features and assembly rules in herbarium-associated microbial communities indicates that herbarium-extracted DNA might reflect the composition of the original plant-associated microbial communities and that preservation in herbaria seemingly did not dramatically alter these characteristics. Using this approach, it should be possible to investigate historical soils and herbarium plant roots to explore the diversity and temporal dynamics of soil microbial communities.

Global warming due to climate change has substantial impact on high-altitude permafrost affected soils. This raises a serious concern that the microbial degradation of sequestered carbon can result in alteration of the biogeochemical cycles. Therefore, the characterization of permafrost affected soil microbiomes, especially of unexplored high-altitude, low oxygen arid region, is important for predicting their response to climate change. This study presents the first report of the bacterial diversity of permafrost-affected soils in the Changthang region of Ladakh. The relationship between soil pH, organic carbon, electrical conductivity, and available micronutrients with the microbial diversity was investigated. Amplicon sequencing of permafrost affected soil samples from Jukti and Tsokar showed that Proteobacteria and Actinobacteria were the dominant phyla in all samples. The genera Brevitalea, Chthoniobacter, Sphingomonas, Hydrogenispora, Clostridium, Gaiella, Gemmatimonas were relatively abundant in the Jukti samples whereas the genera Thiocapsa, Actinotalea, Syntrophotalea, Antracticibcterium, Luteolibacter, Nitrospirillum dominated the Tsokar sample. Correlation analyses highlighted the influence of soil geochemical parameters on the bacterial community structure. PCoA analyses showed that the bacterial beta diversity varied significantly between the sampling locations (PERMANOVA test (F-value: 2.3316; R2 = 0.466, p = 0.001) and similar results were also obtained while comparing genus abundance data using the ANOSIM test (R = 0.345, p = 0.007).

Many studies have investigated the toxic effects of microplastics (MPs) ingested by aquatic animals, but the effects of MPs that adhere to the roots of macrophytes require further exploration. Thus, the present study investigated the dose-dependent toxic effects of adding 10-500 mg/kg of polycaprolactam microplastics (PCM) on allelopathic cyanobacterial inhibition by a wetland macrophyte due to the influence on rhizosphere bacteria in a pot trial. First, comparisons of sterilized and unsterilized Iris pseudacorus rhizosphere soil showed that the unsterilized soil could enhance the root activity and allelopathic inhibition of Microcystis aeruginosa cyanobacteria. Furthermore, adding 50-100 mg/kg PCM to the unsterilized soil significantly altered the abundances of many types of bacteria, and decreased the root activity and bacterial biodiversity in the rhizosphere. Importantly, PCM changed the secondary metabolites profile in the roots, as well as decreasing production of the allelochemical palmitic acid and the allelopathic potential of I. pseudacorus. Moreover, a dominant strain of functional bacterium AAP51 was identified as an allelopathic promoter, isolated, and successfully inoculated into the sterilized soil. The decomposition of PCM produced the toxic monomer caprolactam in the rhizosphere soil at an average rate of 0.067 mg/kgd under treatment with 50 mg/kg PCM. Toxicological testing showed that 5 mg/kg caprolactam inhibited the activities of the dominant bacteria and expression of the allelopathic gene FAD2 to weaken the allelopathic effect of I. pseudacorus. Thus, the findings obtained in this study indicate that PCM inhibited the allelopathic potential of the macrophyte due to the release of toxic caprolactam damaging bacteria in the rhizosphere. Consequently, it is necessary to remove MP pollutants from aquatic ecosystems in order to maintain the strong allelopathic potential of macrophytes and efficiently control cyanobacterial blooms.

Soil salinization has been the major form of soil degradation under the dual influence of climate change and high-intensity human activities, threatening global agricultural sustainability and food security. High salt concentrations induce osmotic imbalance, ion stress, oxidative damage, and other hazards to plants, resulting in retarded growth, reduced biomass, and even total crop failure. Halo-tolerant plant growth promoting rhizobacteria (HT-PGPR), as a widely distributed group of beneficial soil microorganisms, are emerging as a valuable biological tool for mitigating the toxic effects of high salt concentrations and improve plant growth while remediating degraded saline soil. Here, the current status, harm, and treatment measures of global soil salinization are summarized. The mechanism of salt tolerance and growth promotion induced by HT-PGPR are reviewed. We highlight that advances in multiomics technologies are helpful for exploring the genetic and molecular mechanisms of microbiota centered on HT-PGPR to address the issue of plant losses in saline soil. Future research is urgently needed to comprehensively and robustly determine the interaction mechanism between the root microbiome centered on HT-PGPR and salt-stressed plants via advanced means to maximize the efficacy of HT-PGPR as a microbial agent. Halo-tolerant plant growth promoting rhizobacteria (HT-PGPR) are a valuable biological tool for mitigating the toxic effects of high salt concentrations. And the microbiome centered on HT-PGPR is solutions for sustainable agriculture in saline soils.

A sustainable use of croplands should utilize beneficial services provided by their resident soil microbiome. To identify potentially adverse environmental effects on soil microbiomes in the future, a better understanding of their natural variability is fundamental. Here, we characterized the abundance and diversity of soil microbial communities over 2 years at two-week intervals on three neighboring fields at an operational farm in Northern Germany. Field soils differed in texture (clay, loam) and tillage (soil conservation vs. conventional). PCRamplicon analyses of soil DNA revealed distinct temporal variations of bacteria, archaea, fungi, and protists (Cercozoa and Endomyxa). Annual differences and seasonal effects on all microbial groups were detected. In addition to soil pH, prokaryotic communities varied with total soil C and N, but fungi with temperature and precipitation. The C/N ratio had contrasting effects on prokaryotic phyla and protistan classes, but all fungal phyla responded positively. Irrespective of the sampling date, prokaryotic and fungal but not protistan community compositions from the three soils were distinct. Compositional turnover rates were higher for fungi and protists than for prokaryotes and, for all, lower in clay. Conventional tillage had the strongest effect on protist diversity. In co-occurrence networks, most nodes were provided by prokaryotes, but highly connected nodes by predatory protists in the first, and by saprotrophic fungi in the second year. The temporal variation established here can provide insights of what is natural and thus below the limits of concern in detecting adverse effects on the soil microbiome.

Creeping perennial weeds are difficult to manage on organic farms in semi-arid regions of the northern Great Plains. Integrated weed management practices that combine biological, cultural, and mechanical controls can improve management of these weeds, but little is known about the soil microbial response to these practices. Our work investigated the soil microbiome response to contrasting, 4-year crop sequences with standard and reduced tillage. The crop sequences included a range of crop competition phases from high (three years of alfalfa, Medicago sativa L.) to low (two years of continuous fallow), within the longer 4-year period, with intermediate levels of crop competition between those two extremes. Soil samples were collected, and bacterial 16S and fungal ITS amplicon sequencing was performed. Differences in alpha diversity were not significant (p > 0.05) between tillage methods. Across all six locations, bacterial alpha diversity was negatively correlated with soil organic matter (R = -0.37, p < 0.001) while fungal alpha diversity was positively correlated (R = 0.17, p = 0.043). Bacterial community composition was not affected by crop sequence or tillage treatment. Fungal community composition was affected by crop sequence (p = 0.00163) and tillage (p = 0.02). The fungal genera Neosetophoma, Boeremia, and Paraphoma were 10 - 35-fold more abundant in continuous alfalfa compared to the mean abundance in the other crop sequences. Reduced tillage led to a 40% reduction in the fungal genus Fusarium, which contains many plant pathogen species. These results suggest that diversified crop sequences and altered tillage methods have minimal impact on bacterial communities, but fungal communities are sensitive to these management changes.

Disease-suppressive soils have been documented in many economically important crops, but not in turfgrass, one of the most intensively managed plant systems in the United States. Dollar spot, caused by the fungus Clarireedia jacksonii, is the most economically important disease of managed turfgrass and has historically been controlled through the intensive use of fungicides. However, previous anecdotal observations of lower dollar spot severity on golf courses with less intensive fungicide histories suggest that intensive fungicide usage may suppress microbial antagonism of pathogen activity. This study explored the suppressive activity of transplanted microbiomes against dollar spot from seven locations in the Midwestern U.S. and seven locations in the Northeastern U.S. with varying fungicide use histories. Creeping bentgrass was established in pots containing homogenized sterile potting mix and field soil and inoculated with C. jacksonii upon maturity. Bacterial and fungal communities of root-associated soil and phyllosphere were profiled with short-amplicon sequencing to investigate the microbial community associated with disease suppression. The results showed that plants grown in the transplanted soil microbiome collected from sites with lower fungicide intensities exhibited reduced disease severity. Plant growth-promot ing and pathogen-antagonistic microbes may be responsible for disease suppression, but further validation is required. Additional least squares regression analysis of the fungicides used at each location suggested that contact fungicides such as chlorotha lonil and fluazinam had a greater influence on the microbiome disease suppressive ness than penetrant fungicides. Potential organisms antagonistic to Clarireedia were identified in the subsequent amplicon sequencing analysis, but further characterization and validation are required.

Revalorized olive waste impacts root microbiome.Root microbiome modulates plant-induced defense.Insect's exudate simulates the pest attack.The objective of this study was to investigate the combined effect of soil amendments and pest attack on plant-induced defense and their impact on a biological control agent's behavior. The effects of olive mill wastes revalorized through vermicomposting on the aboveground tri-trophic interactions among olive trees (Olea europaea), the olive seed-feeder, Prays oleae, and its natural predator, Chrysoperla carnea, were evaluated. The findings demonstrate that soil nitrogen and organic carbon levels, in conjunction with fungal diversity and functionality within olive roots, exert a significant influence on the volatile compounds emitted by the plant under attack that are most appealing to C. carnea. Moreover, the attractiveness of aerial volatiles was found to correlate with soil organic carbon content and the taxonomic and functional diversity of both bacteria and fungi in the olive root system. It is worthy of note that three particular volatile compounds, namely 5-hepten-2-one-6-methyl, acetic acid and nonanal, were consistently observed to attract C. carnea. These findings highlight the potential of soil amendments to enhance biological control strategies. Future research should prioritise the validation the greenhouse findings through large-scale field trials and the assessment of the practical applications of soil amendments in pest management programmes.