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Background: A growing body of evidence demonstrates that host-associated microbial communities of plant leaf surfaces (i.e. the phyllosphere) can influence host functional traits. However, it remains unclear whether host selection is a universal driver of phyllosphere community assembly. We targeted mānuka (Leptospermum scoparium) and three neighbouring non-mānuka plant species along an 1800-m transect in a New Zealand native bush to conduct a hypothesis-driven investigation of the relative influence of host species identity and stochastic dispersal on the composition of natural phyllosphere bacterial communities. Results: We detected significant correlations between host species identity and mānuka phyllosphere communities that are consistent with a dominant role of host selection in the assembly of the mānuka phyllosphere microbiome. In contrast, the phyllosphere community compositions of neighbouring, ecologically similar native plants were highly variable, suggesting that stochastic processes, such as dispersal, had a stronger influence on the phyllosphere microbiomes of those non-mānuka plants compared to the phyllosphere microbiome of mānuka. Furthermore, the distribution of phyllosphere taxa among plant species was congruent with a scenario in which microorganisms had dispersed from mānuka to non-mānuka phyllosphere microbiomes. Conclusions: We conclude that host selection of phyllosphere communities is not and should not be presumed to be a universal trait across plant species. The specificity of the mānuka phyllosphere microbiome suggests the presence of functionally significant bacteria that are under direct, possibly chemically mediated, selection by the host. Furthermore, we propose that phyllosphere microbiomes under strong host selection, such as that of mānuka, may act as a source of microorganisms for the phyllosphere microbiomes of neighbouring plants. 2ZqHFcd3Z-Di37dyajupxd Video Abstract [ABSTRACT FROM AUTHOR]

Continuous monocultures alter the composition and function of root-associated microbiota, and thus compromise crop health and productivity. In comparison, little is known about how leaf-associated microbiota respond to continuous monocultures. Here, we profiled root and leaf-associated microbiota of peanut plants under monocropping and rotation conditions. Additionally, their protective effects against root pathogen Fusarium oxysporum and leaf pathogen Alternaria alstroemeriae were evaluated. We found that monocropping increased root and leaf disease severity. Meanwhile, the peanut growth and productivity were inhibited by monocropping. Microbiota analysis revealed that monocropping reduced rhizosphere microbial population and diversity, while increased leaf epiphytic microbial population and did not influence leaf epiphytic microbial diversity. Cropping conditions had a greater impact on the microbiota composition of leaf epiphytes than that of the rhizosphere. Moreover, in vitro and in vivo experiments, combined with correlation analyses showed that monocropping weakened the antagonistic activity of rhizosphere microbiota against F. oxysporum and root rot disease. This effect may be associated with the depletion of Bacillus sp. and Sphingomonas sp.. By contrast, leaf epiphytic microbiota under monocropping exhibited greater inhibition of A. alstroemeriae growth and leaf spot control. Together, our results demonstrated a differential response pattern of root and leaf-associated microbiota to continuous monocultures. [ABSTRACT FROM AUTHOR]

Background: Pseudomonas syringae pv. tagetis (Pstag) causes apical chlorosis on sunflower and various other plants of the Asteraceae family. Whole genome sequencing of Pstag strain EB037 and transposon-mutant derivatives, no longer capable of causing apical chlorosis, was conducted to improve understanding of the molecular basis of disease caused by this pathogen. Results: A tripartite pathogenicity island (TPI) for a Type III secretion system (T3SS) with the complete hrp-hrc gene cluster and conserved effector locus was detected in the Pstag genome. The exchange effector region of the TPI contained genes potentially functioning in detoxification of the environment as well as two integrases, but no previously described T3SS effector homologues. In all, the Pstag EB037 genome contained homologues for at least 44 T3SS effectors with 30 having known functions. Plasmids similar with pTagA and pTagB of P. syringae pv. tagetis ICMP 4091 were also identified in the Pstag genome. The pTagA-like plasmid contained a complete Type IV secretion system (T4SS) with associated putative killer protein. Mutational analysis using transposon insertions within genes functioning in the T3SS and T4SS confirmed the role of both secretion systems and these plasmids in apical chlorosis. Transposon mutagenesis identified an additional 22 genes in loci, including two more plasmid-bound loci, involved in apical chlorosis on sunflower; some with known importance in other plant or animal pathosystems. Conclusions: Apical chlorosis disease caused by Pstag EB037 is the result of a complex set of mechanisms. This study identified a TPI and homologues for at least 44 T3SS effectors, 30 of which with known functions in disease, and another 20 genes in loci correlated with apical chlorosis on sunflower. Two plasmids were detected that were correlated with apical chlorosis disease, one of which contained a complete T4SS that was correlated with disease. To our knowledge, we provide the first direct evidence for a T4SS functioning in disease by a pathogenic P. syringae strain. [ABSTRACT FROM AUTHOR]

Recently, the incidence rate and mortality of various acute or chronic vascular occlusive diseases have increased yearly. As one of the most effective measures to treat them, vascular stents have been widely studied by researchers, and presently, the most commonly used is a drug-eluting stent, which reduces the process of rapid endothelialization because the drug is not selective. Fortunately, with the discovery and exploration of micro–nanostructures that can regulate cells selectively, reducing the incidence of "intravascular restenosis" and achieving rapid endothelialization simultaneously are possible through a special structure that cannot only improve endothelial cells (ECs), but also inhibit smooth muscle cells (SMCs). Therefore, this paper mainly introduces the preparation methods of micro–nanostructures used in the past, as well as the detection methods of EC and SMC. Then, the various functions of different dimensional structures for different cells are summarized and analyzed. Finally, the application of micro–nanostructure in future stent materials is summarized and proposed. [ABSTRACT FROM AUTHOR]

Background: Postharvest lemons are affected by several fungal infections, and as alternatives to chemical fungicides for combating these infections, different microbial biocontrol agents have been studied, with the Clavispora lusitaniae 146 strain standing out. Although strain 146 has proven to be an effective agent, the influence of a microbial biological control agent on the postharvest lemon microbiome has not been studied until now. Thus, this study aimed to evaluate how the epiphytic microbiome of postharvest lemons is affected by the application of the biocontrol yeast C. lusitaniae 146. Results: In terms of bacterial composition, the most abundant genera were Sphingomonas, Pelomonas, and Bacillus and no significant differences in the composition were detected between the treated and control samples. Among fungi, Clavispora was predominant not only in the treated samples but also in the control, and statistics indicated differences, suggesting its significant role in modulating the epiphytic community composition of lemon. Understanding fruit microbiomes is vital for effective disease control, and this study provides insights into the microbial composition of the surface of lemon and the role of C. lusitaniae 146. [ABSTRACT FROM AUTHOR]

Background: Fusarium head blight (FHB) is a major disease affecting cereal crops including wheat, barley, rye, oats and maize. Its predominant causal agent is the ascomycete fungus Fusarium graminearum, which infects the spikes and thereby reduces grain yield and quality. The frequency and severity of FHB epidemics has increased in recent years, threatening global food security. Spray-induced gene silencing (SIGS) is an alternative technique for tackling this devastating disease through foliar spraying with exogenous double-stranded RNA (dsRNA) to silence specific pathogen genes via RNA interference. This has the advantage of avoiding transgenic approaches, but several aspects of the technology require further development to make it a viable field-level management tool. One such existing knowledge gap is how dsRNA spraying affects the microbiota of the host plants. Results: We found that the diversity, structure and composition of the bacterial microbiota are subject to changes depending on dsRNA targeted and host studied, while the fungal microbiota in the phyllosphere remained relatively unchanged upon spraying with dsRNA. Analyses of fungal co-occurrence patterns also showed that F. graminearum established itself among the fungal communities through negative interactions with neighbouring fungi. Through these analyses, we have also found bacterial and fungal genera ubiquitous in the phyllosphere, irrespective of dsRNA treatment. These results suggest that although rarer and less abundant microbial species change upon dsRNA spray, the ubiquitous bacterial and fungal components of the phyllosphere in wheat and barley remain unchanged. Conclusion: We show for the first time the effects of exogenous dsRNA spraying on bacterial and fungal communities in the wheat and barley phyllospheres using a high-throughput amplicon sequencing approach. The results obtained further validate the safety and target-specificity of SIGS and emphasize its potential as an environmentally friendly option for managing Fusarium head blight in wheat and barley. [ABSTRACT FROM AUTHOR]

Leaf endospheres harbor diverse bacterial communities, comprising generalists and specialists, that profoundly affect ecosystem functions. However, the ecological dynamics of generalist and specialist leaf-endophytic bacteria and their responses to climate change remain poorly understood. We investigated the diversity and environmental responses of generalist and specialist bacteria within the leaf endosphere of mangroves across China. Our findings show a predominance of specialists in the mangrove leaf endosphere. Temperature is the key factor driving community dissimilarity in both groups, yet it negatively influences the alpha diversity. Soil nutritional factors, particularly phosphate for generalists and total organic carbon for specialists are critical in shaping the functional profiles. Interestingly, temperature has a limited impact on functional profiles. Stochastic processes govern community assembly in both bacterial groups, altering the β-nearest taxon indices as temperatures increase. Our findings indicate that the halophytic leaf endosphere favors microbial niche specialization, due to its unique microenvironment and discrete niches, showing thermal sensitivity in terms of the microbial community profile. This study provides insights into niche differentiation and environmental adaptation mechanisms of leaf endophytic microbes in woody halophytes in response to environmental perturbations. Thermal sensitivity of mangrove leaf endosphere microbiome reveals distinct niche adaptations in generalist and specialist bacteria. Specialists dominate, while temperature significantly drives diversity, impacting mangrove ecosystem resilience. [ABSTRACT FROM AUTHOR]

Microbial utilization of methanol for valorization is an effective way to advance green bio-manufacturing technology. Although synthetic methylotrophs have been developed, strategies to enhance their cell growth rate and internal regulatory mechanism remain underexplored. In this study, we design a synthetic methanol assimilation (SMA) pathway containing only six enzymes linked to central carbon metabolism, which does not require energy and carbon emissions. Through rational design and laboratory evolution, E. coli harboring with the SMA pathway is converted into a synthetic methylotroph. By self-adjusting the expression of TOPAI (topoisomerase I inhibitor) to alleviate transcriptional-replication conflicts (TRCs), the doubling time of methylotrophic E. coli is reduced to 4.5 h, approaching that of natural methylotrophs. This work has the potential to overcome the growth limitation of C1-assimilating microbes and advance the development of a circular carbon economy. Slow growth rate of synthetic methylotrophs affects methanol valorization. Here, the strains self-adjust expression of topoisomerase I inhibitor to alleviate transcription-replication conflicts in synthetic methylotrophic E. coli and reduce its doubling time to that of natural methylotrophs. [ABSTRACT FROM AUTHOR]

Cotton (Gossypium spp.) is grown worldwide owing to the vast economic value of its natural fiber. However, the widespread and destructive soilborne pathogen, Verticillium dahliae, causes Verticillium wilt, leading to severe yield losses and reduced fiber quality of cotton. The ability of V. dahliae to perceive and infect cotton determines the outcome of their interactions. V. dahliae employs diverse defense mechanisms to evade or suppress plant immunity, ultimately establishing a proliferation niche. Evading plant immunity by suppressing host recognition or successive immune signaling is a successful infection strategy employed by various microbial pathogens, posing a significant challenge to effectively utilizing host hereditary resistance genes in sustainable disease management. This review focused on summarizing "effectors" and the molecular mechanisms of various effectors on cotton and the corresponding defense mechanisms in the plants. Furthermore, it highlighted the potential of effectors for engineering resistance cotton plants against Verticillium wilt, aiming to provide a reference for the creation of cotton disease-resistant germplasm resources by host genome editing and other methods. [ABSTRACT FROM AUTHOR]

Background: Pollen is a crucial source of nutrients and energy for pollinators. It also provides a unique habitat and resource for microbiota. Previous research on the microbiome of pollen has largely focused on angiosperm systems, with limited research into coniferous gymnosperms. This study characterises the pollen microbiome and metabolome associated with one of the world's most widely grown tree species, Pinus radiata. Trees were sampled from locations across Canterbury, New Zealand. Repeated collections were undertaken in 2020 and 2021. Results: Metabolomic analysis revealed the main compounds present on P. radiata pollen to be amino acids (principally proline), and carbohydrates (fructose, glucose, and sucrose). Although phenolic compounds such as ρ-coumaric acid and catechin, and terpenoids such as dehydroabietic acid, were present at low concentrations, their strong bioactive natures mean they may be important in ecological filtering of microbiome communities on pollen. The P. radiata pollen microbiome was richer in fungal taxa compared with bacteria, which differs from many angiosperm species. Geographic range and annual variation were evaluated as drivers of microbiome assembly. Neither sampling location (geographic range) nor annual variation significantly influenced the fungal community which exhibited remarkable conservation across samples. However, some bacterial taxa exhibited sensitivity to geographic distances and yearly variations, suggesting a secondary role of these factors for some taxa. A core microbiome was identified in P. radiata pollen, characterized by a consistent presence of specific fungal and bacterial taxa across samples. While the dominant phyla, Proteobacteria and Ascomycota, align with findings from other pollen microbiome studies, unique core members were unidentified at genus level. Conclusion: This tree species-specific microbiome assembly emphasizes the crucial role of the host plant in shaping the pollen microbiome. These findings contribute to a deeper understanding of pollen microbiomes in gymnosperms, shedding light on the need to look further at their ecological and functional roles. [ABSTRACT FROM AUTHOR]

Background: The application of beneficial microbes in agriculture is gaining increasing attention as a means to reduce reliance on chemical fertilizers. This approach can potentially mitigate negative impacts on soil, animal, and human health, as well as decrease climate-changing factors. Among these microbes, yeast has been the least explored, particularly within the phyllosphere compartment. This study addresses this knowledge gap by investigating the potential of phyllosphere yeast to improve rice yield while reducing fertilizer dosage. Results: From fifty-two rice yeast phyllosphere isolates, we identified three yeast strains—Rhodotorula paludigena Y1, Pseudozyma sp. Y71, and Cryptococcus sp. Y72—that could thrive at 36 °C and possessed significant multifarious plant growth-promoting traits, enhancing rice root and shoot length upon seed inoculation. These three strains demonstrated favorable compatibility, leading to the creation of a yeast consortium. We assessed the combined effect of foliar application of this yeast consortium and individual strains with two distinct recommended doses of chemical fertilizers (RDCFs) (75 and 100%), as well as RDCFs alone (75 and 100%), in rice maintained in pot-culture and field experiments. The pot-culture experiment investigated the leaf microbial community, plant biochemicals, root and shoot length during the stem elongation, flowering, and dough phases, and yield-related parameters at harvest. The field experiment determined the actual yield. Integrated results from both experiments revealed that the yeast consortium with 75% RDCFs was more effective than the yeast consortium with 100% RDCFs, single strain applications with RDCFs (75 and 100%), and RDCFs alone (75 and 100%). Additionally, this treatment improved leaf metabolite levels compared to control rice plants. Conclusions: Overall, a 25% reduction in soil chemical fertilizers combined with yeast consortium foliar application improved rice growth, biochemicals, and yield. This study also advances the field of phyllosphere yeast research in agriculture. [ABSTRACT FROM AUTHOR]

Background: Mangrove plants growing in the high salt environment of coastal intertidal zones colonize a variety of microorganisms in the phyllosphere, which have potential salt-tolerant and growth-promoting effects. However, the characteristics of microbial communities in the phyllosphere of mangrove species with and without salt glands and the differences between them remain unknown, and the exploration and the agricultural utilization of functional microbial resources from the leaves of mangrove plants are insufficient. Results: In this study, we examined six typical mangrove species to unravel the differences in the diversity and structure of phyllosphere microbial communities between mangrove species with or without salt glands. Our results showed that a combination of salt-tolerant growth-promoting strains of Pantoea stewartii A and Bacillus marisflavi Y25 (A + Y25) was constructed from the phyllosphere of mangrove plants, which demonstrated an ability to modulate osmotic substances in rice and regulate the expression of salt-resistance-associated genes. Further metagenomic analysis revealed that exogenous inoculation with A + Y25 increased the rice rhizosphere's specific microbial taxon Chloroflexi, thereby elevating microbial community quorum sensing and ultimately enhancing ionic balance and overall microbial community function to aid salt resistance in rice. Conclusions: This study advances our understanding of the mutualistic and symbiotic relationships between mangrove species and their phyllosphere microbial communities. It offers a paradigm for exploring agricultural beneficial microbial resources from mangrove leaves and providing the potential for applying the salt-tolerant bacterial consortium to enhance crop adaptability in saline–alkaline land. -b8tYoWqwFfV9a2SY3Js-8 Video Abstract The sources of the photos used in this figure are provided below: Avicennia marina: https://guru.sanook.com/6011/ Acanthus ilicifolius: https://tracuuduoclieu.vn/acanthus-ilicifolius-l.html Aegiceras corniculatum: https://apps.lucidcentral.org/plants%5fse%5fnsw/text/entities/aegiceras%5fcorniculatum.html Sonneratia apetala: http://www.fpcn.net/a/shuishengzhiwu/20131109/Sonneratia%5fapetala.html Excoecaria agallocha: https://efloraofindia.com/2011/03/01/excoecaria-agallocha/ Kandelia candel: https://www.szhb.org/6539.html Background photo: https://www.discovery.com/nature/the-world-is-waking-up-to-the-importance-of-mangroves [ABSTRACT FROM AUTHOR]

Ecological restoration and environmental risk control on bauxite residue disposal areas have received persistent attention worldwide as it concerns the sustainable development of global alumina enterprises. Currently, microbially driven ecological restoration has been regarded as a promising way in consideration of its cost effectiveness, lower risks, and durability. However, the extremely degraded environment (e.g., high alkalinity, poor physical structure, and low organic carbon content) poses significant challenges for the activity and effectiveness of functional microorganisms involved in bioremediation. Moreover, the specific mechanisms of functional microorganisms, including alkaline regulation, stable aggregate formation, organic carbon accumulation, and plant growth promotion, in the soil-formation and revegetation process are not well understood, hindering the widespread application of microbially driven ecological restoration strategies in large-scale bauxite residue disposal. To date, these strategies have not been demonstrated in a large scale. To address these gaps, this review focuses on the microbial properties of bauxite residue disposal areas and the limiting factors of microbial functions. Furthermore, considering the differences between bauxite residue and natural soils, the roles of microorganisms in alkaline stabilization, aggregate formation, and organic carbon accumulation in bauxite residue during the soil-formation process are explored. Meanwhile, the microbially driven ecological restoration on bauxite residue disposal areas, including plant growth capacity and restoration process regulation, are discussed. Lastly, future research directions for understanding microbially driven soil-formation processes and ecological restoration on bauxite residue disposal areas are envisaged. This review provides new insights into the driving mechanisms of microorganisms on the soil formation of bauxite residue, offering a theoretical foundation and practical guidance for ecological restoration on bauxite residue disposal areas. [ABSTRACT FROM AUTHOR]

Salt stress is a global environmental problem, which affects various biochemical and physiological processes in plants and significantly decreases the quantity and quality of the yield. NaCl is the main driver of NaCl-mediated effects because the accumulation of sodium ions (Na+) in plant tissues disrupts the homeostasis of other ions and may lead to secondary stresses. Two-component signalling (TCS) is an evolutionally conserved histidine-kinase based system utilised by many organisms to react to inner and environmental stimuli and stresses. In this review, we focus on the effect of NaCl on histidine-kinase based two-component signalling systems (TCS) in bacteria and its advanced form multi-step phosphorely (MSP) engaged in cytokinin signalling in plants. Further, we discuss available data on the sodium-sensing approach employed by bacteria and plants, current limitations, and future prospects in this area. Also, based on the analysed experimental and evolutional data, we suggested some potential directions for the future investigation of the salt-sensing mechanisms in plants. [ABSTRACT FROM AUTHOR]

During a series of sampling conducted in Nobaria, El-Beheira, Egypt in 2022 and 2023, defoliation disorders were identified in tomato fields. Three soil samples were collected and subjected to fungal isolation and identification. Molecular analysis revealed the presence of three fungal species, namely Fusarium verticillioides, Fusarium proliferatum and Alternaria tenuissima, with their Genbank accession numbers being OP889680, OP889682 and OP886855, respectively. The efficacy of an effective microorganism (EM) product as an antifungal agent was screened and its bioactive substances were analyzed. The bioactive substances in the EM product included antioxidant compounds, such as phenolics (58 mg/mL) and tannins (17 mg/mL), which contributed to total antioxidant activity of 73% as measured by FRP, PMA and DPPH assays. The EM product was tested for its antifungal activity against the three isolated fungal pathogens. The sensitivity of A. tenuissima, F. verticillioides and F. proliferatum was assessed by measuring the colony growth when exposed to the EM product. It showed concentration-dependent growth inhibition, completely stopping growth at 7% concentration, with inhibition percentages of 93, 100 and 100% for each pathogen. Gene expression in treated fungi was studied, revealing down-regulation of the chitinase gene in F. verticillioides, F. proliferatum and A. tenuissima, compared to controls. Up-regulation of PR4 and PR5 genes was noted in F. verticillioides, while a significant up-regulation of peroxidase and PPO genes was observed in A. tenuissima. This suggests the EM product holds promise as a fungicide alternative. [ABSTRACT FROM AUTHOR]

Synthetic microbial community has widely concerned in the fields of agriculture, food and environment over the past few years. However, there is little consensus on the method to synthetic microbial community from construction to functional verification. Here, we review the concept, characteristics, history and applications of synthetic microbial community, summarizing several methods for synthetic microbial community construction, such as isolation culture, core microbiome mining, automated design, and gene editing. In addition, we also systematically summarized the design concepts, technological thresholds, and applicable scenarios of various construction methods, and highlighted their advantages and limitations. Ultimately, this review provides four efficient, detailed, easy-to-understand and -follow steps for synthetic microbial community construction, with major implications for agricultural practices, food production, and environmental governance. [ABSTRACT FROM AUTHOR]

The complexity of plant traits and involvement of a number of genes, decreasing progress in the genetic engineering and the molecular breeding mainly hinders the quest to enhance the drought resistance in crops. A viable short-term solution could be the Chemical priming but its high cost and potential environmental risks, like altering the fertility of soil and affecting the ecosystems, limits the widespread adoption of it in natural farming. To sustainably and efficiently enhancing the crop resilience to drought, there is a potential need of innovative techniques. Due to the unique physicochemical properties of nanomaterials, the nanotechnology presents a promising avenue. These nano-materials can potentially improve the efficiency of water use, uptake of nutrients and tolerance of stress in plants. For instance, the nanoparticles can be efficiently used in delivering the nutrients and water more effectively to roots of plant, can reduce loss of water by forming protective coatings on leaf surfaces and by enhancing photosynthesis efficiency under stressful conditions. Moreover, nanomaterials can be engineered in a specific way to release beneficial compounds in a controlled manner, which minimizes the environmental impacts and maximizes the plant uptake. In parallel, harnessing the capabilities of plant microbiomes offers an environmentally friendly approach. Microbiomes, present abundant in natural ecosystems, exhibit high metabolic flexibility and physiological tolerance, contributing significantly to the availability of nutrients and stress mitigation in the plants. They achieve this through processes such as nitrogen fixation, solubilization of various minerals and production of beneficial compounds like exopolysaccharides and hormones. Leveraging microbiomes in agriculture could enhance crop resilience to drought while promoting the sustainable farming practices. Looking forward, integrating nanotechnology with microbiome-based approaches holds promise for synergistically enhancing crop drought resistance. By combining precise nutrient delivery and stress tolerance support from microbiomes, this integrated strategy could offer a robust solution to the challenges posed by drought in agriculture. Embracing these advancements represents a forward-looking approach towards sustainable food production in a changing climate landscape. [ABSTRACT FROM AUTHOR]

Background: The extensive use of antibiotics in the global livestock industry in recent decades has accelerated the accumulation and dissemination of antibiotic-resistance genes (ARGs) within terrestrial ecosystems. This occurs due to the limited absorption of most antibiotics, leading to their release into the environment through feces and urine. This poses a significant threat to both the environment and human health. However, the response of antibiotic-resistant microorganisms and their ARGs in grasslands to prolonged grazing, as well as the primary microbial taxa driving the ARG distribution, remain poorly understood, especially within various microhabitats. In this study, we characterized ARGs in the phyllosphere, litter, and soil after decades of livestock grazing in a meadow steppe. We particularly focused on identifying the major members of the microbial community influencing ARGs and the distinction between microbial generalists and specialists. Results: Our findings indicate that a core set of ARGs accounted for 90% of the abundance in this plant-soil ecosystem. While the soil exhibited the highest ARG abundance, the phyllosphere, and litter displayed higher ARG diversity and diverse distribution patterns after overgrazing. Grazing increased ARG abundance by elevating the proportion of core ARGs and suppressing stochastic ARGs in the phyllosphere and litter, while it had little effect on the ARGs in the soil. Additionally, microbial generalist abundance increased, but specialist abundance decreased in the phyllosphere and litter, with no effect in the soil, under grazed conditions. Ultimately, microbial microhabitats and grazing influenced ARG community characteristics through direct (i.e., feces and other exogenous ARG input) and indirect (i.e., trampling and selective feeding) effects on nutrient availability, microbial community composition, and mobile genetic elements. The generalist community, with its broad ecological niches and phylogenetic composition, made the most significant contribution to the ARG characteristics. Conclusions: This study underscores the impact of environmental disturbances on the distributional patterns of ARGs in ecosystems, mediated by the regulation of microbial generalized species. These insights enhance our understanding of microbial control over ARGs and facilitate predictions regarding the dynamics and risk of ARGs in diverse ecological niches subjected to anthropogenic disturbances. 7ey-7_XWoViaAbs3ZbZRu7 Video Abstract [ABSTRACT FROM AUTHOR]

Endosymbioses have profoundly impacted the evolution of life and continue to shape the ecology of a wide range of species. They give rise to new combinations of biochemical capabilities that promote innovation and diversification1,2. Despite the many examples of known endosymbioses across the tree of life, their de novo emergence is rare and challenging to uncover in retrospect3–5. Here we implant bacteria into the filamentous fungus Rhizopus microsporus to follow the fate of artificially induced endosymbioses. Whereas Escherichia coli implanted into the cytosol induced septum formation, effectively halting endosymbiogenesis, Mycetohabitans rhizoxinica was transmitted vertically to the progeny at a low frequency. Continuous positive selection on endosymbiosis mitigated initial fitness constraints by several orders of magnitude upon adaptive evolution. Phenotypic changes were underscored by the accumulation of mutations in the host as the system stabilized. The bacterium produced rhizoxin congeners in its new host, demonstrating the transfer of a metabolic function through induced endosymbiosis. Single-cell implantation thus provides a powerful experimental approach to study critical events at the onset of endosymbiogenesis and opens opportunities for synthetic approaches towards designing endosymbioses with desired traits. A study presents an approach to establish and track a new endosymbiotic partnership by implanting bacteria in a non-host fungus and shows that stable inheritance of the implanted bacteria is possible with positive selection. [ABSTRACT FROM AUTHOR]

Local adaptation has been a central theme of eco-evolutionary research for decades. It is generally assumed that plant pathogens are locally adapted due to their standing interactions with biotic and abiotic factors in the ecosystem. Effectors, secreted small proteins encoded by pathogens, play critical roles in host–pathogen interactions, by activating host genotype-specific resistance, suppressing plant immunity, and playing other functions. In this study, we investigated the potential involvement of RXLR effector genes in ecological adaptation by examining the simple sequence repeat (SSR), virulence, and effector profiles in Phytophthora infestans isolates collected from two geographic regions differing in ecological environments. Genotypic analyses with SSR markers and virulence assays showed that the pathogen from the two regions shared genetic background but differed in virulence spectrums. High-throughput sequencing and expression analysis of 24 selected P. infestans isolates further showed variations in the RXLR effector repertoire, ranging from 536 to 548 for each isolate and the expression of effector genes was highly associated with the accumulation of homologous sRNA. Regional specific alleles were detected at 94 RXLR effector genes, and a specific accumulation of homologous 25–26 nt sRNAs was found at 67 RXLR effector genes. Two of the regional specific RXLR effector genes were confirmed to be virulence factors. Taken together, these results suggest that genomic and epigenetic variations in RXLR effector genes contribute significantly to the ecological adaptation of P. infestans populations and that regional specific effector genes will help to understand the adaptive landscape of pathogens and efficient use of host resistance genes. [ABSTRACT FROM AUTHOR]

Background: Tobacco production faces ongoing challenges due to soil degradation, leading to a persistent decline in yield. Plant growth-promoting fungi (PGPF) have been recognized as an environmentally friendly agricultural strategy. However, many commercial PGPF products exhibit instability due to insufficient environmental compatibility. Results: In this study, Penicillium sp. PQxj3 was isolated and assessed for its potential to enhance tobacco productivity under field conditions. The results demonstrated that Penicillium sp. PQxj3 treatment significantly promoted the tobacco growth and improved the crop yield. The height of tobacco in Penicillium sp. PQxj3 treatment group significantly increased by 50.19% and 24.05% compared with CK at exuberant and maturity period (P < 0.05). The average yield of tobacco significantly increased by 36.16% compared to CK (P < 0.05). Fungal microbiome analysis revealed that phylogenetically similar probiotic taxa were recruited by Penicillium sp. PQxj3 and reassembled tobacco rhizosphere fungal microbiome. The key chemical indicators of tobacco such as alkaloid, total sugar, and phosphorus were significantly enhanced in Penicillium sp. PQxj3 treatment. The recruited probiotic taxa (Penicillium brasilianum, Penicillium simplicissimum, Penicillium macrosclerotiorum and Penicillium senticosum) were significantly associated with alkaloid, total sugar etc. (P < 0.05), which were identified as the key drivers for improving the chemical components of tobacco. Transcriptome analysis indicated that Penicillium sp. PQxj3 promoted up-regulation of key functional genes involved in alkaloid, indoleacetic, and gibberellin biosynthesis pathways. Conclusion: In summary, this study assessed the biopromotion mechanism of PGPF Penicillium sp. PQxj3 linking chemical traits, rhizosphere fungal microbiome, and transcriptome profiling. The findings provide a fundamental basis and a sustainable solution for developing fungal fertilizers to enhance agricultural sustainability. [ABSTRACT FROM AUTHOR]

With global climate change, ecosystems are affected, some of which are more vulnerable than others, such as alpine ecosystems. Microbes play an important role in environmental change in global ecosystems. Plants and microbes are tightly associated, and symbiotic or commensal microorganisms are crucial for plants to respond to stress, particularly for alpine plants. The current study of alpine and subalpine plant microbiome only stays at the community structure scale, but its ecological function and mechanism to help plants to adapt to the harsh environments have not received enough attention. Therefore, it is essential to systematically understand the structure, functions and mechanisms of the microbial community of alpine and subalpine plants, which will be helpful for the conservation of alpine and subalpine plants using synthetic microbial communities in the future. This review mainly summarizes the research progress of the alpine plant microbiome and its mediating mechanism of plant cold adaptation from the following three perspectives: (1) Microbiome community structure and their unique taxa of alpine and subalpine plants; (2) The role of alpine and subalpine plant microbiome in plant adaptation to cold stress; (3) Mechanisms by which the microbiome of alpine and subalpine plants promotes plant adaptation to low-temperature environments. Finally, we also discussed the future application of high-throughput technologies in the development of microbial communities for alpine and subalpine plants. The existing knowledge could improve our understanding of the important role of microbes in plant adaptation to harsh environments. In addition, perspective further studies on microbes' function confirmation and microbial manipulations in microbiome engineering were also discussed. [ABSTRACT FROM AUTHOR]

Plants and microorganisms have been co-evolving and interacting for billions of years. Prior researchers have explored the plant's immune system responses and interaction with diverse microbes, but several ambiguities need further explanation. This review provides insight into mechanisms underlying plant–microbe interaction and knowledge dearth domains, along with possibilities to use beneficial microbes to improve plant growth, disease resistance, nutritional value, and productivity. Microorganisms in the phyllosphere and the rhizosphere could be beneficial or pathogenic. Host plants use their innate immune system and the antagonistic competence of plant-growth-promoting microbes against pathogens. The innate immune system of plants has two paramount protection forms involving different types of immune receptors, which assist in recognizing non-self-components. The first group of receptors is membrane-resident pattern recognition receptors (PRRs), which are responsible for sensing microbe-associated molecular patterns (MAMPs) and damage-associated molecular patterns (DAMPs). The second group consists of intracellular immune sensors, specifically resistance (R) proteins, astute in recognizing the structure or function of strain-specific pathogen effectors injected into host plant cells. Plants activate their pattern-triggered immunity (PTI) and effector-triggered immunity (ETI) defense mechanisms to counter the infection. Plants benefit from certain microbes by promoting their growth, disease resistance, and resilience under various stress conditions in exchange for shelter and nutrients. [ABSTRACT FROM AUTHOR]

Methylobacterium sp. XJLW converts formaldehyde into methanol and formic acid via a Cannizzaro reaction in response to environmental formaldehyde stress. Methanol is further assimilated without formaldehyde or formic acid formation, whereas formic acid accumulates without undergoing further metabolism. Synthetic biology-based biotransformation of methanol to generate additional products can potentially achieve carbon neutrality. However, practical applications are hampered by limitations such as formaldehyde tolerance. In this study, we aimed to explore the specific mechanism of strain XJLW in response to formaldehyde stress. Thus, a transcriptomic analysis of XJLW under formaldehyde treatment was performed, revealing changes in the expression of specific genes related to one-carbon metabolism. Central metabolic genes were downregulated, whereas metabolic bypass genes were upregulated to maintain methanol assimilation in XJLW's response to formaldehyde treatment. In total, 100 genes potentially related to methyl transfer were identified. The function of only one gene, RS27765, was similar to that of glyA, which encodes a methyltransferase involved in one-carbon metabolism. The double-mutant strain, lacking RS27765 and glyA, lost its ability to grow in methanol, whereas the single-mutant strain, lacking only one of these genes, still grew in methanol. Co-expression of RS27765 and RS31205 (YscQ/HrcQ type III secretion apparatus protein) enabled Escherichia coli BL21 (DE3) to effectively degrade methanol. Using protein sequence analysis and molecular docking, we proposed a model wherein RS27765 is necessary for cell growth by using methanol generated via formaldehyde cannizzaro reaction. This process enables direct assimilation of methanol without producing formaldehyde and formic acid as intermediate metabolites. The RS27765 gene cluster, in conjunction with metabolic bypass genes, constitutes a novel auxiliary pathway facilitating formaldehyde stress tolerance in the strain. [ABSTRACT FROM AUTHOR]

Candida auris is an emerging nosocomial fungal pathogen associated with life-threatening invasive disease due to its persistent colonization, high level of transmissibility and multi-drug resistance. Aggregative and non-aggregative growth phenotypes for C. auris strains with different biofilm forming abilities, drug susceptibilities and virulence characteristics have been described. Using comprehensive transcriptional analysis we identified key cell surface adhesins that were highly upregulated in the aggregative phenotype during in vitro and in vivo grown biofilms using a mouse model of catheter infection. Phenotypic and functional evaluations of generated null mutants demonstrated crucial roles for the adhesins Als4112 and Scf1 in mediating cell-cell adherence, coaggregation and biofilm formation. While individual mutants were largely non-aggregative, in combination cells were able to co-adhere and aggregate, as directly demonstrated by measuring cell adhesion forces using single-cell atomic force spectroscopy. This co-adherence indicates their role as complementary adhesins, which despite their limited similarity, may function redundantly to promote cell-cell interaction and biofilm formation. Functional diversity of cell wall proteins may be a form of regulation that provides the aggregative phenotype of C. auris with flexibility and rapid adaptation to the environment, potentially impacting persistence and virulence. Here, Wang et al show that Candida auris cell wall adhesins function redundantly to promote cell-cell interaction and biofilm formation as a form of regulation and potential adaption to the environment. [ABSTRACT FROM AUTHOR]

Background: The symbiosis between arbuscular mycorrhizal fungi (AMF) and plants often stimulates plant growth, increases agricultural yield, reduces costs, thereby providing significant economic benefits. AMF can also benefit plants through affecting the rhizosphere microbial community, but the underlying mechanisms remain unclear. Using Rhizophagus intraradices as a model AMF species, we assessed how AMF influences the bacterial composition and functional diversity through 16 S rRNA gene sequencing and non-targeted metabolomics analysis in the rhizosphere of aluminum-sensitive soybean that were inoculated with pathogenic fungus Nigrospora oryzae and phosphorus-solubilizing fungus Talaromyces verruculosus in an acidic soil. Results: The inoculation of R. intraradices, N. oryzae and T. verruculosus didn't have a significant influence on the levels of soil C, N, and P, or various plant characteristics such as seed weight, crude fat and protein content. However, their inoculation affected the structure, function and nutrient dynamics of the resident bacterial community. The co-inoculation of T. verruculosus and R. intraradices increased the relative abundance of Pseudomonas psychrotolerans, which was capable of N-fixing and was related to cry-for-help theory (plants signal for beneficial microbes when under stress), within the rhizosphere. R. intraradices increased the expression of metabolic pathways associated with the synthesis of unsaturated fatty acids, which was known to enhance plant resistance under adverse environmental conditions. The inoculation of N. oryzae stimulated the stress response inside the soil environment by enriching the polyene macrolide antifungal antibiotic-producing bacterial genus Streptomyces in the root endosphere and upregulating two antibacterial activity metabolic pathways associated with steroid biosynthesis pathways in the rhizosphere. Although inoculation of pathogenic fungus N. oryzae enriched Bradyrhizobium and increased soil urease activity, it had no significant effects on biomass and N content of soybean. Lastly, the host niches exhibited differences in the composition of the bacterial community, with most N-fixing bacteria accumulating in the endosphere and Rhizobium vallis only detected in the endosphere. Conclusions: Our findings demonstrate that intricate interactions between AMF, associated core fungi, and the soybean root-associated ecological niches co-mediate the regulation of soybean growth, the dynamics of rhizosphere soil nutrients, and the composition, function, and metabolisms of the root-associated microbiome in an acidic soil. Highlights: AMF R. intraradices improved soybean stress resistance by recruiting specific PGPR and upregulating plant resistance promotion metabolic pathway. The pathogenic fungus N. oryzae stimulated the stress response by enriching the antifungal antibiotic production bacteria and upregulating the antibacterial reaction-associated metabolic pathways. The utility evaluation of some microbial agents on host plants should consider their potential impact on Olsen-P content in acidic soils with limited P availability. The sampling compartments (i.e., host niches of the soybean rhizosphere) exerted greater influence on the assembly and shift of the bacterial community than the application of microbial agents. [ABSTRACT FROM AUTHOR]

Background: While substantial research has explored rhizosphere and phyllosphere microbiomes, knowledge on flower microbiome, particularly in wild plants remains limited. This study explores into the diversity, abundance, and composition of bacterial and fungal communities on leaves and flowers of wild flowering plants in their natural alpine habitat, considering the influence of environmental factors. Methods: We investigated 50 wild flowering plants representing 22 families across seven locations in Austria. Sampling sites encompassed varied soil types (carbonate/silicate) and altitudes (450–2760 m). Amplicon sequencing to characterize bacterial and fungal communities and quantitative PCR to assess microbial abundance was applied, and the influence of biotic and abiotic factors assessed. Results: Our study revealed distinct bacterial and fungal communities on leaves and flowers, with higher diversity and richness on leaves (228 fungal and 91 bacterial ASVs) than on flowers (163 fungal and 55 bacterial ASVs). In addition, Gammaproteobacteria on flowers and Alphaproteobacteria on leaves suggests niche specialization for plant compartments. Location significantly shaped both community composition and fungal diversity on both plant parts. Notably, soil type influenced community composition but not diversity. Altitude was associated with increased fungal species diversity on leaves and flowers. Furthermore, significant effects of plant family identity emerged within a subset of seven families, impacting bacterial and fungal abundance, fungal Shannon diversity, and bacterial species richness, particularly on flowers. Conclusion: This study provides novel insights into the specific microbiome of wild flowering plants, highlighting adaptations to local environments and plant–microbe coevolution. The observed specificity indicates a potential role in plant health and resilience, which is crucial for predicting how microbiomes respond to changing environments, ultimately aiding in the conservation of natural ecosystems facing climate change pressures. [ABSTRACT FROM AUTHOR]

Bitter gourd wilt, a severe vascular disease triggered by the soilborne pathogen Fusarium oxysporum f. sp. momordicae (FOM), markedly constrains bitter gourd yield. In this study, a novel strain BF19 of Brevibacillus brevis was isolated and identified, exhibiting strong antimicrobial activity against FOM through in vivo and in vitro experiments. To comprehensively assess the biocontrol potential of strain BF19, we conducted phenotypic, phylogenetic, and comparative genomics analyses. Phenotypic analysis revealed that BF19 exhibited 53.33% biocontrol efficacy and significantly increased the average plant height, root fresh weight, and dry weight. Whole-genome sequencing and comparative genomic analysis revealed numerous potential genes associated with biocontrol mechanisms in BF19. Importantly, the integration of metabolic cluster prediction with liquid chromatography‒tandem mass spectrometry (LC‒MS/MS) revealed the presence of a macrobrevin antibiotic, a product of polyketide synthases (PKSs), predominantly in BF19 fermentation products. The effectiveness of the Br. brevis strain BF19 and its crude extract against bitter gourd wilt has also been confirmed. This study provides a genetic framework for future investigations on PKSs and establishes a scientific basis for optimizing field applications of microbial biopesticides derived from Br. brevis BF19. [ABSTRACT FROM AUTHOR]

Background : Nematodes are the most abundant metazoans in marine sediments, many of which are bacterivores; however, how habitat bacteria affect physiological outcomes in marine nematodes remains largely unknown. Results: Here, we used a Litoditis marina inbred line to assess how native bacteria modulate host nematode physiology. We characterized seasonal dynamic bacterial compositions in L. marina habitats and examined the impacts of 448 habitat bacteria isolates on L. marina development, then focused on HQbiome with 73 native bacteria, of which we generated 72 whole genomes sequences. Unexpectedly, we found that the effects of marine native bacteria on the development of L. marina and its terrestrial relative Caenorhabditis elegans were significantly positively correlated. Next, we reconstructed bacterial metabolic networks and identified several bacterial metabolic pathways positively correlated with L. marina development (e.g., ubiquinol and heme b biosynthesis), while pyridoxal 5'-phosphate biosynthesis pathway was negatively associated. Through single metabolite supplementation, we verified CoQ10, heme b, acetyl-CoA, and acetaldehyde promoted L. marina development, while vitamin B6 attenuated growth. Notably, we found that only four development correlated metabolic pathways were shared between L. marina and C. elegans. Furthermore, we identified two bacterial metabolic pathways correlated with L. marina lifespan, while a distinct one in C. elegans. Strikingly, we found that glycerol supplementation significantly extended L. marina but not C. elegans longevity. Moreover, we comparatively demonstrated the distinct gut microbiota characteristics and their effects on L. marina and C. elegans physiology. Conclusions: Given that both bacteria and marine nematodes are dominant taxa in sedimentary ecosystems, the resource presented here will provide novel insights to identify mechanisms underpinning how habitat bacteria affect nematode biology in a more natural context. Our integrative approach will provide a microbe–nematodes framework for microbiome mediated effects on host animal fitness. [ABSTRACT FROM AUTHOR]

Background: Indonesia is a country that uses half or more aquatic foods as protein intake. The increased production in aquaculture industries might cause several problems, such as bacterial disease resulting in mass mortality and economic losses. Antibiotics are no longer effective because aquaculture pathogens can form biofilm. Biofilm is a microbial community that aggregates and firmly attaches to living or non-living surfaces. Biofilm formation can be caused by environmental stress, the presence of antibiotics, and limited nutrients. Therefore, it is important to explore antibiofilm to inhibit biofilm formation and/or eradicate mature biofilm. Phyllosphere bacteria can produce bioactive compounds for antimicrobial, antibiofilm, and anti-quorum sensing. Three aquaculture pathogens were used in this study, such as Aeromonas hydrophila, Streptococcus agalactiae, and Vibrio harveyi. Results: Pseudomonas fluorescens JB3B and Morganella morganii JB8F extracts could disrupt single and multi-species biofilms. Both extracts could inhibit single biofilm formation from one to seven days of incubation time. We confirmed the destruction activity on multi-species biofilm using light microscope and scanning electron microscope. Using GC-MS analysis, indole was the most active fraction of the P. fluorescens JB3B extracts and octacosane from the M. morganii JB8F extract. We also conducted a toxicity test using brine shrimp lethality assay on P. fluorescens JB3B and M. morganii JB8F extracts. P. fluorescens JB3B, M. morganii JB8F, and a mixture of both extracts were confirmed non-toxic according to the LC50 value of the brine shrimp lethality test. Conclusions: P. fluorescens JB3B and M. morganii JB8F phyllosphere extracts had antibiofilm activity to inhibit single biofilm and disrupt single and multi-species biofilm of aquaculture pathogens. Both extracts could inhibit single species biofilm until seven days of incubation. Bioactive compounds that might contribute to antibiofilm properties were found in both extracts, such as indole and phenol. P. fluorescens JB3B, M. morganii JB8F extracts, and mixture of both extracts were non-toxic against Artemia salina. [ABSTRACT FROM AUTHOR]

Aims: The accumulation of organic acids in soil can trigger autotoxicity, resulting in the continuous cropping obstacles (CCOs) for Panax notoginseng under conventional management systems. However, limited information is available about the threshold value of organic acids representing the CCOs in the soil of P. notoginseng from the forest understorey. Methods: In this study, mixed organic acids at different concentrations were exogenously applied to simulate the P. notoginseng CCO. The plant growth, edaphic factors, soil extracellular enzyme activity, and bacterial/fungal abundances and diversity in the rhizospheric soil were assessed in the P. notoginseng from the forest understorey. Results: High concentrations (>150 mg/kg) rather than low concentrations (<150 mg/kg) of organic acid decreased the dry and fresh weight of plants (1.99%-1.98%), edaphic properties (2.75%-1.03%) and soil extracellular enzyme activities (3.38%-1.05%). Under high organic acid concentrations, the fungal abundance increased by 2.37%, whereas the bacterial abundance decreased by 4.56%. Moreover, the abundance of Pseudomonadales, Xanthomonadales, and Ilyonectria as pathogenic bacteria tended to increase. Compared to bacteria, the fungal community structure varied significantly, and the fungal core flora was more abundant. The SEM results showed that the direct and indirect factors affecting the α-diversity in the rhizosphere of P. notoginseng were increased under the high organic acid concentrations. Conclusion: Organic acid concentrations greater than 150 mg/kg in P. notoginseng soils are detrimental to the relationships among plant growth, soil environment, and microbiomes, which implies the occurrence of the CCOs in P. notoginseng; and therefore, we recommend that P. notoginseng should not be planted again. [ABSTRACT FROM AUTHOR]

Phyllosphere microorganisms execute important ecological functions including supporting host plant growth, enhancing host resistance to abiotic stresses, and promoting plant diversity. How leaf developmental stages affect plant-microbiome interactions and phyllosphere microbial community assembly and diversity is poorly understood. In this study, we utilized amplicon sequencing of 16S rRNA and ITS genes to investigate the composition and diversity of microbial communities across different leaf developmental stages of rubber trees. Our findings reveal that endophytic microbial communities, particularly bacterial communities, are more influenced by leaf senescence than by epiphytic communities. The high abundance of metabolism genes in the endosphere of yellow leaves contributes to the degradation and nutrient relocation processes. Nutrient loss leads to a higher abundance of α-Proteobacteria (r-selected microorganisms) in the yellow leaf endosphere, thereby promoting stochastic community assembly. As leaves age, the proportion of microorganisms entering the inner layer of leaves increases, consequently enhancing the diversity of microorganisms in the inner layer of leaves. These results offer insights into the mechanisms governing community assembly and diversity of leaf bacteria and fungi, thereby advancing our understanding of the evolving functions of microbial communities during leaf senescence in general, and for an important tropical crop species in particular. Leaf senescence has significant impacts on the composition, diversity, assembly, and functions of phyllosphere microbiomes, especially impacting endophytic bacterial communities. [ABSTRACT FROM AUTHOR]

Background: Trees are associated with a broad range of microorganisms colonising the diverse tissues of their host. However, the early dynamics of the microbiota assembly microbiota from the root to shoot axis and how it is linked to root exudates and metabolite contents of tissues remain unclear. Here, we characterised how fungal and bacterial communities are altering root exudates as well as root and shoot metabolomes in parallel with their establishment in poplar cuttings (Populus tremula x tremuloides clone T89) over 30 days of growth. Sterile poplar cuttings were planted in natural or gamma irradiated soils. Bulk and rhizospheric soils, root and shoot tissues were collected from day 1 to day 30 to track the dynamic changes of fungal and bacterial communities in the different habitats by DNA metabarcoding. Root exudates and root and shoot metabolites were analysed in parallel by gas chromatography-mass spectrometry. Results: Our study reveals that microbial colonisation triggered rapid and substantial alterations in both the composition and quantity of root exudates, with over 70 metabolites exclusively identified in remarkably high abundances in the absence of microorganisms. Noteworthy among these were lipid-related metabolites and defence compounds. The microbial colonisation of both roots and shoots exhibited a similar dynamic response, initially involving saprophytic microorganisms and later transitioning to endophytes and symbionts. Key constituents of the shoot microbiota were also discernible at earlier time points in the rhizosphere and roots, indicating that the soil constituted a primary source for shoot microbiota. Furthermore, the microbial colonisation of belowground and aerial compartments induced a reconfiguration of plant metabolism. Specifically, microbial colonisation predominantly instigated alterations in primary metabolism in roots, while in shoots, it primarily influenced defence metabolism. Conclusions: This study highlighted the profound impact of microbial interactions on metabolic pathways of plants, shedding light on the intricate interplay between plants and their associated microbial communities. 2SWtA3_gUD-Xt4Z7N25436 Video Abstract [ABSTRACT FROM AUTHOR]

Background: Plants have evolved various defense mechanisms against insect herbivores, including the formation of physical barriers, the synthesis of toxic metabolites, and the activation of phytohormone responses. Although plant-associated microbiota influence plant growth and health, whether they play a role in plant defense against insect pests in natural ecosystems is unknown. Results: Here, we show that leaves of beetle-damaged weeping willow (Salix babylonica) trees are more resistant to the leaf beetle Plagiodera versicolora (Coleoptera) than those of undamaged leaves. Bacterial community transplantation experiments demonstrated that plant-associated microbiota from the beetle-damaged willow contribute to the resistance of the beetle-damaged willow to P. versicolora. Analysis of the composition and abundance of the microbiome revealed that Pseudomonas spp. is significantly enriched in the phyllosphere, roots, and rhizosphere soil of beetle-damaged willows relative to undamaged willows. From a total of 49 Pseudomonas strains isolated from willows and rhizosphere soil, we identified seven novel Pseudomonas strains that are toxic to P. versicolora. Moreover, re-inoculation of a synthetic microbial community (SynCom) with these Pseudomonas strains enhances willow resistance to P. versicolora. Conclusions: Collectively, our data reveal that willows can exploit specific entomopathogenic bacteria to enhance defense against P. versicolora, suggesting that there is a complex interplay among plants, insects, and plant-associated microbiota in natural ecosystems. 5putw3esi-W9k4EYdexs12 Video Abstract [ABSTRACT FROM AUTHOR]

Plant growth regulators (PGRs) are well known for their ability to improve plants' tolerance to heavy metals. However, in these treatments, the contribution of native rhizobacteria on heightened tolerance to heavy metals is usually not considered, and thus PGR ability is overestimated. In this study, using duckweed Spirodela polyrhiza as indicating plant and according to the responses of it grown under nonsterile and sterile conditions, native rhizobacteria were able to cooperate with PGRs and thereby improved duckweed's tolerance to Cd stress. All the randomly selected bacterial isolates and salicylic acid exerted synergistic effects that improved Cd tolerance, suggesting that active rhizobacteria are not necessarily plant growth-promoting rhizobacteria (PGPRs). Comparative physiological and transcriptomic analyses showed that the cooperation between the native bacterium Pseudomonas and salicylic acid can greatly reduce Cd accumulation and decrease oxidative stress, thus lowering the requirement of antioxidant defense in duckweed; moreover, the synthesis of flavonoids that facilitates reactive oxygen species scavenging in duckweed was significantly induced. This study recommends that the contribution of native rhizobacteria on improved plant tolerance to heavy metals should be considered when applying PGRs. [ABSTRACT FROM AUTHOR]

Nanopore sequencing technology has enabled the rapid, on-site taxonomic identification of samples from anything and anywhere. However, sequencing errors, inadequate databases, as well as the need for bioinformatic expertise and powerful computing resources, have hampered the widespread use of the technology for pathogen identification in the agricultural sector. Here we present RAPiD, a lightweight and accurate real-time taxonomic profiling pipeline. Compared to other metagenomic profilers, RAPiD had a higher classification precision achieved through the use of a curated, non-redundant database of common agricultural pathogens and extensive quality filtering of alignments. On a fungal, bacterial and mixed mock community RAPiD was the only pipeline to detect all members of the communities. We also present a protocol for in-field sample processing enabling pathogen identification from plant sample to sequence within 3 h using low-cost equipment. With sequencing costs continuing to decrease and more high-quality reference genomes becoming available, nanopore sequencing provides a viable method for rapid and accurate pathogen identification in the field. A web implementation of the RAPiD pipeline for real-time analysis is available at https://agrifuture.senckenberg.de. [ABSTRACT FROM AUTHOR]

The interactions of microorganisms among themselves and with their multicellular host take place at the microscale, forming complex networks and spatial patterns. Existing technology does not allow the simultaneous investigation of spatial interactions between a host and the multitude of its colonizing microorganisms, which limits our understanding of host–microorganism interactions within a plant or animal tissue. Here we present spatial metatranscriptomics (SmT), a sequencing-based approach that leverages 16S/18S/ITS/poly-d(T) multimodal arrays for simultaneous host transcriptome- and microbiome-wide characterization of tissues at 55-µm resolution. We showcase SmT in outdoor-grown Arabidopsis thaliana leaves as a model system, and find tissue-scale bacterial and fungal hotspots. By network analysis, we study inter- and intrakingdom spatial interactions among microorganisms, as well as the host response to microbial hotspots. SmT provides an approach for answering fundamental questions on host–microbiome interplay. Interactions among plant hosts, bacteria and fungi are measured at high spatial resolution. [ABSTRACT FROM AUTHOR]

When a pathogen invades a plant, it encounters a diverse microbiota with some members contributing to the health and growth of the plant host. So far, the relevance of interactions between pathogens and the plant microbiota are poorly understood; however, new lines of evidence suggest that pathogens play an important role in shaping the microbiome of their host during invasion. This review aims to summarize recent findings that document changes in microbial community composition during the invasion of filamentous pathogens in plant tissues. We explore the known mechanisms of interaction between plant pathogens and the host microbiota that underlie these changes, particularly the pathogen-encoded traits that are produced to target specific microbes. Moreover, we discuss the limitations of current strategies and shed light on new perspectives to study the complex interaction networks between filamentous pathogens and the plant microbiome. [ABSTRACT FROM AUTHOR]