Search Results (240)

Glycyrrhiza uralensis (G. uralensis), a leguminous plant, is an important medicinal and economic plant in saline–alkaline soils of arid regions in China. Its main bioactive components include liquiritin, glycyrrhizic acid, and flavonoids, which play significant roles in maintaining human health and preventing and adjuvantly treating related diseases. However, the cultivation of G. uralensis is easily restricted by adverse soil conditions in these regions, characterized by high salinity, high alkalinity, and nutrient deficiency. This study investigated the impacts of four multistrain microbial inoculants (Pa, Pb, Pc, Pd) on the growth performance and bioactive compound accumulation of G. uralensis in moderately saline–sodic soil. The aim was to screen the most beneficial inoculant from these strains, which were isolated from the rhizosphere of plants in moderately saline–alkaline soils of the Hexi Corridor and possess native advantages with excellent adaptability to arid environments. The results showed that inoculant Pc, comprising Pseudomonas silesiensis, Arthrobacter sp. GCG3, and Rhizobium sp. DG1, exhibited superior performance: it induced a 0.86-unit reduction in lateral root number relative to the control, while promoting significant increases in single-plant dry weight (101.70%), single-plant liquiritin (177.93%), single-plant glycyrrhizic acid (106.10%), and single-plant total flavonoids (107.64%). Application of the composite microbial inoculant Pc induced no significant changes in the pH and soluble salt content of G. uralensis rhizospheric soils. However, it promoted root utilization of soil organic matter and nitrate, while significantly increasing the contents of available potassium and available phosphorus in the rhizosphere. High-throughput sequencing revealed that Pc reorganized the rhizospheric microbial communities of G. uralensis, inducing pronounced shifts in the relative abundances of rhizospheric bacteria and fungi, leading to significant enrichment of target bacterial genera (Arthrobacter, Pseudomonas, Rhizobium), concomitant suppression of pathogenic fungi, and proliferation of beneficial fungi (Mortierella, Cladosporium). Correlation analyses showed that these microbial shifts were linked to improved plant nutrition and secondary metabolite biosynthesis. This study highlights Pc as a sustainable strategy to enhance G. uralensis yield and medicinal quality in saline–alkali ecosystems by mediating microbe–plant–nutrient interactions. Full article

In chili cultivation, obstacles to continuous cropping significantly compromise crop yield and soil health, whereas crop rotation can enhance the microbial environment of the soil and reduce disease incidence. However, its effects on the diversity of rhizosphere soil microbial communities are not clear. In this study, we analyzed the composition and characteristics of rhizosphere soil microbial communities under chili continuous cropping (CC) and chili–cotton crop rotation (CR) using high-throughput sequencing technology. CR treatment reduced the alpha diversity indices (including Chao1, Observed_species, and Shannon index) of bacterial communities and had less of an effect on fungal community diversity. Principal component analysis (PCA) revealed distinct compositional differences in bacterial and fungal communities between the treatments. Compared with CC, CR treatment has altered the structure of the soil microbial community. In terms of bacterial communities, the relative abundance of Firmicutes increased from 12.89% to 17.97%, while the Proteobacteria increased by 6.8%. At the genus level, CR treatment significantly enriched beneficial genera such as RB41 (8.19%), Lactobacillus (4.56%), and Bacillus (1.50%) (p < 0.05). In contrast, the relative abundances of Alternaria and Fusarium in the fungal community decreased by 6.62% and 5.34%, respectively (p < 0.05). Venn diagrams and linear discriminant effect size analysis (LEfSe) further indicated that CR facilitated the enrichment of beneficial bacteria, such as Bacillus, whereas CC favored enrichment of pathogens, such as Firmicutes. Fusarium solani MG6 and F. oxysporum LG2 are the primary chili root-rot pathogens. Optimal growth occurs at 25 °C, pH 6: after 5 days, MG6 colonies reach 6.42 ± 0.04 cm, and LG2 5.33 ± 0.02 cm, peaking in sporulation (p < 0.05). In addition, there are significant differences in the utilization spectra of carbon and nitrogen sources between the two strains of fungi, suggesting their different ecological adaptability. Integrated analyses revealed that CR enhanced soil health and reduced the root rot incidence by optimizing the structure of soil microbial communities, increasing the proportion of beneficial bacteria, and suppressing pathogens, providing a scientific basis for microbial-based soil management strategies in chili cultivation. Full article

The soil-borne fungal pathogen Verticillium dahliae causes devastating vascular wilt disease in numerous crops, including cotton. In this study, we reveal that VdSOX1, a highly conserved sarcosine oxidase gene, is significantly upregulated during host infection and plays a multifaceted role in fungal physiology and pathogenicity. Functional deletion of VdSOX1 leads to increased fungal virulence, accompanied by enhanced microsclerotia formation, elevated carbon source utilization, and pronounced upregulation of effector genes, including over 50 predicted secreted proteins genes. Moreover, the VdSOX1 knockout strains suppress the expression of key defense-related transcription factors in cotton, such as WRKY, MYB, AP2/ERF, and GRAS families, thereby impairing host immune responses. Transcriptomic analyses confirm that VdSOX1 orchestrates a broad metabolic reprogramming that links nutrient acquisition to immune evasion. Our findings identify VdSOX1 as a central regulator that promotes V. dahliae virulence by upregulating effector gene expression and suppressing host immune responses, offering novel insights into the molecular basis of host–pathogen interactions and highlighting potential targets for disease management. Full article

Soil bacteria drive biogeochemical cycles and influence disease suppression, playing pivotal roles in sustainable agriculture. Using Illumina MiSeq sequencing, we assessed how six ridge-furrow film mulching patterns affect soil bacterial diversity in a continuous potato system. The Shannon index showed significantly higher diversity in fully mulched treatments (T2–T3) versus controls (CK), suggesting mulching enhances microbial community richness. This result suggests that complete mulching combined with ridge planting (T2) may significantly enhance bacterial proliferation in soil. The bacterial communities were predominantly composed of Acidobacteria, Pseudomonadota, Bacteroidota, Chloroflexota, and Planctomycetota. Among these, Acidobacteria showed the highest abundance, with ridge planting patterns favoring greater Acidobacteria richness compared to furrow planting. In contrast, Pseudomonadota exhibited higher abundance under half-mulching conditions than under complete mulching. At class level, Acidobacteria and Proteobacteria emerged as the most abundant groups, with Proteobacteria constituting 22.6–35.7% of total microbial populations. Notably, Proteobacteria demonstrated particular dominance under the complete mulching with ridge planting pattern (T2). At the genus level, Subgroup_6_norank represented the most dominant taxon among the 439 identified bacterial genera, accounting for 14.0–20.2% of communities across all treatments, with half-mulching ridge planting (T4) showing the highest relative abundance. Our findings demonstrate that different ridge-furrow film mulching patterns significantly influence soil microbial diversity. While traditional non-mulched (CK) and mulched flat plots (T1) exhibited similar impacts on bacterial community structure, other treatments displayed distinct taxonomic profiles. Complete mulching patterns, particularly ridge planting (T2), appear most conducive to microbial development, suggesting their potential to enhance soil biogeochemical cycling in continuous cropping systems. These results provide valuable insights for optimizing mulching practices to improve soil health in agricultural ecosystems. Full article

Managing soil-borne pathogens and diseases in plants is particularly challenging because the pathogens that cause them can persist in the soil for extended periods, often resulting in repeated crop damage in affected areas. These destructive diseases compromise plant health by weakening the root systems, which makes the plants more susceptible to environmental stress and nutritional deficiencies. Every year in the United States, a whopping $9.6 million is allocated to reverse the harmful effects of pesticides on humans, plants, animals, and the environment. On the contrary, disease-suppressive soils offer an effective strategy for controlling pathogens while ensuring the least contamination of the environment. These soils can be managed by both conventional and advanced methods, such as reduced tillage, crop rotation, organic amendments, nanoparticles, omics approaches, and biofumigation. However, these soils can be local in nature, and their properties might be disrupted by common agricultural practices like tillage and agro-chemical application. This review synthesizes the concepts and mechanisms of disease suppression in soils and explores the ways that can be improved through the management of soil health for enhanced plant health and yield. Full article

Intercropping has been widely proven to boost agricultural yields and control diseases. This study examined the impact of sugarcane monoculture (SM) and sugarcane–pumpkin intercropping (IP) systems on soil physicochemical characteristics and microbial community dynamics. Compared to monoculture, intercropping significantly increased soil pH by 8.82% and total potassium (TK) by 17.92%, while reducing soil organic matter (SOM) by 25.56%. Bacterial communities under intercropping exhibited significantly higher alpha and beta diversity, whereas fungal community diversity remained unaffected. Notably, the relative abundances of certain taxa with known roles in plant growth promotion and pathogen suppression—such as Anaeromyxobacter, Nitrospira, and Massilia—were enriched. Canonical correlation analysis revealed that bacterial community composition was strongly associated with TK, while fungal community structure correlated with variations in soil available nitrogen (AN). These findings indicate that sugarcane–pumpkin intercropping reshapes soil microbial communities and contributes to some improvement in soil nutrient availability. Full article

Downy mildew, caused by Plasmopara viticola, is a major threat to grapevine (Vitis vinifera) cultivation in humid climates. Restrictions on synthetic pesticides and inconsistent efficacy of current biocontrol agents, especially under rainy conditions, complicate disease management. This study evaluated the potential of compost tea to suppress downy mildew in a two-year field experiment (2023 and 2024), combined with reduced synthetic fungicide applications. The study design compared two phytosanitary management strategies on a commercial vineyard: a conventional fungicide against a compost tea strategy supplemented with two cymoxanil applications. The experiment set up had three replicated blocks, each consisting of 100 plants for a total of 600 plants. Mechanistic insights were provided through controlled laboratory experiments involving pre- and post-infection leaf assays, vineyard bacteriome profiling, via 16S rRNA gene sequencing for bacterial communities, across vineyard compartments, i.e., bulk soil, rhizosphere, and phyllosphere, and grapevine metabolomic analysis by GC-MS analysis. Field trials demonstrated that compost tea combined with two fungicide applications effectively reduced disease severity, notably outperforming the fungicide alone in the particularly rainy year of 2023. Bacteriome analysis revealed that compost tea treatment enriched beneficial bacterial genera, including Pseudomonas, Sphingomonas, Enterobacter, Massilia, and Bacillus, known for their growth-promoting and biocontrol activity in the rhizosphere and phyllosphere. Laboratory assays on detached leaves further showed that compost tea alone could suppress both infection and sporulation of P. viticola. Metabolomic analysis highlighted the accumulation of compounds such as tartaric and shikimic acids in compost tea treated leaves, suggesting a potential role in induced resistance. The findings indicate that applying compost tea with reduced fungicide treatments represents a promising and sustainable strategy for managing grapevine downy mildew, even in challenging climates. Full article

Maize production in Fuxin City, Liaoning Province, China, is threatened by northern corn leaf blight (NCLB) and Fusarium stalk rot, with straw return under conservation tillage exacerbating the NCLB severity by 20% in local fields. This study evaluated the efficacy of combining difenoconazole, a commonly used fungicide, with a Trichoderma bioagent for disease control in straw-incorporated soils. Field trials in Fuxin showed that applying 300 g/ha difenoconazole with 1.5 L/ha Trichoderma fermentate achieved superior results: a 72.4% reduction in the NCLB disease index and a stalk rot incidence of only 0.61%. These outcomes significantly outperformed single-component treatments like difenoconazole alone (56.2% NCLB suppression) or other fungicides (e.g., carbendazim, triadimefon). The combined treatment also outperformed the single treatments with biocontrol agent (67.1% NCLB inhibition). The results highlight the synergistic potential of integrating chemical and biological agents to manage residue-borne diseases, offering a practical strategy for sustainable disease control in conservation agriculture systems with straw return in Liaoning, China. Full article

Utilizing environmentally friendly techniques for pathogen control in agriculture is a sustainable and eco-friendly approach to managing crop diseases. These techniques leverage the natural environment and ecosystem dynamics to reduce pathogen pressure, minimize the use of chemical inputs, and promote long-term agricultural productivity. Key strategies include crop rotation, intercropping, and maintaining biodiversity, all of which disrupt pathogen life cycles and enhance soil health. Biological control, such as introducing natural antagonists like beneficial fungi or bacteria, suppresses pathogen populations while promoting plant resilience. Additionally, practices such as mulching, soil solarization, and water management optimize environmental conditions to limit the development and spread of pathogens. These techniques also contribute to integrated pest management by providing sustainable, cost-effective solutions that reduce chemical dependency and mitigate climate change and other environmental impacts. This review discusses the importance of utilizing environmentally friendly techniques, highlighting their advantages, practical challenges, and limitations in different agro-ecological settings, and their role in advancing sustainable agriculture. Full article

Disease-suppressive soils confer fitness advantages to plants after a disease outbreak due to the subsequent assembly of protective microbiota in natural environments. However, the role of ecological effects on the assemblage of a protective soil microbiome is largely elusive. In this study, we investigated the composition of parasitic microbes and their relationships with soybean cyst nematodes in suppressive soil. The results showed that parasitic microbial assembly along soybean cyst nematodes was shaped predominantly by the density of soybean cyst nematodes. We also found soybean continuous cropping increased the number of parasitic microbes of soybean cyst nematodes with the order of Ss > Sr > Sc, while it decreased the population of soybean cyst nematodes, resulting in a natural decline in the number of soybean cyst nematodes. These findings indicate that the population of soybean cyst nematodes accumulated parasitic microorganisms against this soil-borne disease under soybean long-term continuous cropping. Moreover, the metabolic activity of cyst parasitic microbes was increased by two years of continuous cropping (Sc) of soybean, and total carbon and total nitrogen of soil were the main impact factors in this short-term continuous cropping for metabolic patterns of the cyst parasitic microbes. In summary, the results highlight that the interaction of plants and disease shape the soil microbiome, recruit a group of disease resistance-inducing microbes, and modulate their beneficial traits to protect the plant. Full article

American ginseng (AG) cultivation suffers from severe diseases, requiring heavy pesticide use. This study aimed to explore whether companion planting with maize (AG-maize) or Perilla frutescens (AG-perilla) could enhance AG growth and alter rhizosphere/root microbiomes in a root rot-infested field. Compared to monoculture (CK), companion planting significantly improved AG growth and survival rate at wither stage, with AG-maize showing the superior efficacy- increasing root length and fresh weight, and plant height by 39.04%, 46.10%, and 48.69%, respectively, while raising survival rate from 1.51% to 14.54%. Microbial analysis revealed that companion planting increased microbiome diversity and network complexity. At green fruit stage, AG-perilla increased rhizosphere fungal Chao1 index by 42.6%, while AG-maize and AG-perilla elevated endophytic fungal Shannon indices by 46.68% and 74.84%, respectively. At wither stage, AG-maize notably enriched beneficial microbes (e.g., soil Pseudomonas +108.49%, Bacillus +200.73%) while reducing pathogens (soil Fusarium −20.04%, root endophytic Alternaria −54.55%). Structural equation model indicated AG-maize improved AG survival via core species-driven antibiosis and nutrient regulation, with keystone species Lysobacter sp. RHLT3-4 and Verrucomicrobium sp. IMCC25902 significantly correlating with AG health. The AG-maize system fostered synergistic microbial networks, enriching beneficial taxa and suppressing pathogens. These findings provide a foundation for developing eco-friendly disease management and high-yield AG cultivation strategies. Full article

With continuous improvements in people’s environmental awareness, biological control agents have garnered considerable attention owing to their advantageous impacts on improving soil fertility and alleviating plant diseases. Bacillus subtilis (B. subtilis) B579, isolated from the rhizosphere soil of cucumber, has effectively suppressed the growth of pathogenic Fusarium oxysporum. Our study investigates the effects of B. subtilis B579 on the properties of the rhizosphere soil (its physicochemical properties and enzymatic activities) and microbial community of cucumber under Fusarium oxysporum infection. An amplicon sequencing analysis of the microorganisms in the rhizosphere soil was conducted, and the soil’s properties were measured. The findings demonstrated that B. subtilis B579 exhibited 73.68% efficacy in controlling cucumber Fusarium wilt disease. B579 pretreatment substantially increased the bacterial and fungi diversity and improved the soil’s physicochemical properties (pH level and OC, TN, TP, AK, and AP contents) and enzyme activities, especially those of urease and alkaline phosphatase, which exhibited significant increases of 77.22% and 64.77%, respectively, in comparison to those under the pathogen treatment. Furthermore, the utilization of B579 reduced the abundance of Fusarium while simultaneously increasing the abundance of beneficial groups, including the Bacillus, Paenibacillus, Sphingomonas, Pseudomonas, Microbacterium, Mortierella, and Trichoderma genera. The RDA showed that the abundance of Bacillus, Paenibacillus, Sphingomonas, and Mortierella in the rhizosphere showed positive correlations with most of the soil properties, whereas Fusarium abundance was negatively correlated with most of the soil’s properties. This study provides novel insights into the disease suppression mechanisms of Bacillus subtilis B579, laying the theoretical foundation for its development as a biocontrol agent. Full article

In recent years, there has been extensive documentation of pathogenic fungi infecting Morchella sextelata. However, investigations of microorganisms with antagonistic properties against these pathogens are limited. This study successfully isolated two isolates of the genus Streptomyces (F16 and F19) from the rhizosphere soil of M. sextelata fruiting bodies, both of which exhibit potent antagonistic activity against Pestalotiopsis trachicarpicola, the causative agent of M. sextelata wilt disease. Comprehensive characterization, including physiological–biochemical tests and 16S rDNA sequence analysis, led to the identification of these isolates as Streptomyces sp. F16 and Streptomyces sp. F19. Both isolates significantly inhibited P. trachicarpicola through multiple mechanisms. The volatile compounds produced by these isolates effectively suppressed the conidial germination of P. trachicarpicola in vitro. Furthermore, fermentation filtrates at various dilutions exhibited pronounced antifungal activity against conidial germination, with Streptomyces sp. F16 showing 66.93% inhibition at a 50× dilution and Streptomyces sp. F19 achieving 49.22% inhibition under identical conditions. Field experiments have demonstrated the practical applicability of these antagonists. The topical application of fermentation filtrates (diluted 50×) from both isolates significantly reduced the incidence and severity of disease in M. sextelata cultivation. Notably, the yield improvements were substantial: fields treated with Streptomyces sp. F16 produced 299.6 g/m², whereas those treated with Streptomyces sp. F19 yielded 277.65 g/m². These yields significantly surpassed those of both the untreated control group (231 g/m²) and the P. trachicarpicola-inoculated group (134.93 g/m²). These findings indicate that the two isolates not only effectively control P. trachicarpicola but also increase the yield of M. sextelata. Full article

Soil-borne fungal pathogens such as Sclerotium spp., Rhizoctonia spp., and Macrophomina spp. pose significant threats to global agriculture, with soybean crops among the most severely affected due to damping-off disease. These pathogens cause substantial yield losses, making their management a critical concern. In this study, we investigated the potential of Bacillus siamensis BCL, a novel Neotropical strain, as an eco-friendly solution for managing Sclerotium, Rhizoctonia, and Macrophomina species. The strain exhibited strong antifungal activity, significantly inhibiting fungal growth in vitro, with the greatest suppression observed against Macrophomina spp., reaching up to 81%. In vivo assays further confirmed the biocontrol potential of B. siamensis. When applied at 10⁶ colony-forming units (CFU)/mL, the strain reduced disease symptoms and improved plant growth parameters—including root length, shoot biomass, and leaf number—compared to untreated, infected controls. The protective effect varied by pathogen, with the most significant recovery in root length observed against Macrophomina spp. (85%) and Sclerotium spp. (78%). In preventive treatments, fermentation extracts of the B. siamensis strain suppressed disease progression, although they did not promote seedling growth. A genomic analysis of B. siamensis BCL revealed genes encoding antimicrobial secondary metabolites, including terpenes, fengycins, and surfactins. These findings highlight B. siamensis BCL as a promising candidate for sustainable crop protection and a valuable resource for developing novel antimicrobial strategies in agriculture. Full article

Ginger is an important spice crop in the north-eastern region of India. Rhizome rot, also called soft rot, is one of the most devastating diseases found in ginger that causes yield losses of up to 100% under favourable conditions. Initially, the disease symptoms appear as a light yellowing of the leaf tips that gradually spreads down to the leaf blade of lower leaves and the leaf sheath along the margin. Under favourable environmental conditions, the disease spreads rapidly, potentially causing significant crop damage. The pathogen can infect at any stage of crop growth, and under favourable environmental conditions, the disease spreads rapidly, failing the crop. Current research emphasises mitigating the losses caused by the devastating disease by using management strategies and biocontrol agents (BCAs). Results revealed that the average highest percent rhizome germination, lowest mean disease incidence, lowest mean disease severity index, lowest coefficient of disease index value, highest rhizome yield and benefit–cost ratio were recorded with Trichoderma harzianum (10 g/kg of rhizomes) + soil application of T. harzianum-enriched well-decomposed farm yard manure (3 kg of T. harzianum mixed with 100 kg FYM at 10–15 days before sowing) + soil drenching with T. harzianum at the rate 10 kg/ha, compared to the untreated control. Furthermore, soil chemical properties such as pH, electrical conductivity, soil organic carbon, total available nitrogen, total available phosphorus, and total available potassium play critical roles in rhizome rot disease severity. BCAs can suppress the phytopathogenic fungi and modulate different functions in plants. Full article