Cooperative Interactions Between Bacillus and Lysobacter Enhance Consortium Stability and Fusarium Wilt Suppression in Cucumber.

The rhizosphere microbiome plays a pivotal role in plant health by mediating interactions between hosts, beneficial microbes, and pathogens. However, the ecological mechanisms underlying microbial consortia that suppress soil-borne diseases remain largely unexplored. In this study, we investigated how the biocontrol bacterium Bacillus velezensis SQR9 influences the assembly of the cucumber rhizosphere bacterial community in the presence of the pathogenic fungus Fusarium oxysporum f.

Bacterial social interactions in synthetic consortia enhance plant growth.

Plant growth-promoting rhizobacteria (PGPR) represent a sustainable method to improve crop productivity. Synthetic microbial consortia have emerged as a powerful tool for engineering rhizosphere microbiomes. However, designing functionally stable consortia remains challenging due to an insufficient understanding of bacterial social interactions.

Rhizosphere domestication enhances root colonization and plant growth promotion performance of SQR9.

The overuse of chemical fertilizers has caused severe soil degradation and environmental pollution, necessitating sustainable alternatives such as microbial fertilizers containing plant growth-promoting rhizobacteria (PGPR). However, application of laboratory-developed microbial inoculants usually reveals impaired performance, attributing to complicated field conditions including plant genotype, soil property, and interaction with indigenous microbiota. Currently, traditional microbial breeding methods such as random mutagenesis and genetic engineering, could not be so appropriate for screening agents with comprehensive phenotypes (e.

Presence of a biofilm beneficiary alters the evolutionary trajectory of a biofilm former.

Biofilm evolution is typically studied in monocultures or in communities displaying mutualistic or exploitative interactions. However, in communities with fluctuating interactions, the influence of biofilm-beneficiary bacteria on the evolution of biofilm-founder bacteria remains less understood. Biofilm-beneficiary bacteria cannot form robust biofilms independently but can incorporate into the biofilm of biofilm-formers, thereby gaining the ability to colonize given niche.

Narrow-spectrum resource-utilizing bacteria drive the stability of synthetic communities through enhancing metabolic interactions.

The importance of synthetic microbial communities in agriculture is increasingly recognized, yet methods for constructing targeted communities using existing microbial resources remain limited. Here, six plant-beneficial bacterial strains with distinct functions and rhizosphere resource utilization profiles are selected to construct stable, multifunctional communities for plant growth promotion. Metabolic modeling reveals that narrower resource utilization correlates with increased metabolic interaction potential and reduced metabolic resource overlap, contributing to greater community stability.

A rhizobacterium-secreted protein induces lateral root development through the IAA34-PUCHI pathway.

Lateral roots (LRs) can continuously forage water and nutrients from soil. In Arabidopsis thaliana, LR development depends on a canonical auxin signaling pathway involving the core transcription factors INDOLE-3-ACETIC ACIDs (IAAs) and AUXIN RESPONSE FACTORs (ARFs). In this study, we identified a protein, bacillolysin, secreted by the beneficial rhizobacterium Bacillus velezensis SQR9, that is able to stimulate LR formation of Arabidopsis.

A novel decomposer-exploiter interaction framework of plant residue microbial decomposition.

Background: Plant residue microbial decomposition, subject to significant environmental regulation, represents a crucial ecological process shaping and cycling the largest terrestrial soil organic carbon pool. However, the fundamental understanding of the functional dynamics and interactions between the principal participants, fungi and bacteria, in natural habitats remains limited.

Results: In this study, the evolution of fungal and bacterial communities and their functional interactions were elucidated during the degradation of complexity-gradient plant residues.

Substrate preference triggers metabolic patterns of indigenous microbiome during initial composting stages.

Composting organic waste is a sustainable recycling method in agricultural systems, yet the microbial preferences for different substrates and their influence on composting efficiency remain underexplored. Here, 210 datasets of published 16S ribosomal DNA amplicon sequences from straw and manure composts worldwide were analyzed, and a database of 278 bacterial isolates was compiled. Substrate-driven microbiome variations were most prominent during the initial composting stages.

Bridging the Gap: Biofilm-mediated establishment of on mycelia.

Bacterial-fungal interactions (BFIs) are important in ecosystem dynamics, especially within the soil rhizosphere. The bacterium SQR9 and the fungus NJAU 4742 have gathered considerable attention due to their roles in promoting plant growth and protecting their host against pathogens. In this study, we utilized these two model microorganisms to investigate BFIs.

Dissection of rhizosphere microbiome and exploiting strategies for sustainable agriculture.

The rhizosphere microbiome plays critical roles in plant growth and provides promising solutions for sustainable agriculture. While the rhizosphere microbiome frequently fluctuates with the soil environment, recent studies have demonstrated that a small proportion of the microbiome is consistently assembled in the rhizosphere of a specific plant genotype regardless of the soil condition, which is determined by host genetics. Based on these breakthroughs, which involved exploiting the plant-beneficial function of the rhizosphere microbiome, we propose to divide the rhizosphere microbiome into environment-dominated and plant genetic-dominated components based on their different assembly mechanisms.

Nonpathogenic Pseudomonas syringae derivatives and its metabolites trigger the plant "cry for help" response to assemble disease suppressing and growth promoting rhizomicrobiome.

Plants are capable of assembling beneficial rhizomicrobiomes through a "cry for help" mechanism upon pathogen infestation; however, it remains unknown whether we can use nonpathogenic strains to induce plants to assemble a rhizomicrobiome against pathogen invasion. Here, we used a series of derivatives of Pseudomonas syringae pv. tomato DC3000 to elicit different levels of the immune response to Arabidopsis and revealed that two nonpathogenic DC3000 derivatives induced the beneficial soil-borne legacy, demonstrating a similar "cry for help" triggering effect as the wild-type DC3000.

Metabolic interactions affect the biomass of synthetic bacterial biofilm communities.

Co-occurrence network analysis is an effective tool for predicting complex networks of microbial interactions in the natural environment. Using isolates from a rhizosphere, we constructed multi-species biofilm communities and investigated co-occurrence patterns between microbial species in genome-scale metabolic models and in vitro experiments. According to our results, metabolic exchanges and resource competition may partially explain the co-occurrence network analysis results found in synthetic bacterial biofilm communities.

Biocontrol mechanisms of Bacillus: Improving the efficiency of green agriculture.

Species of the genus Bacillus have been widely used for the biocontrol of plant diseases in the demand for sustainable agricultural development. New mechanisms underlying Bacillus biocontrol activity have been revealed with the development of microbiome and microbe-plant interaction research. In this review, we first briefly introduce the typical Bacillus biocontrol mechanisms, such as the production of antimicrobial compounds, competition for niches/nutrients, and induction of systemic resistance.

Listening to plant's Esperanto via root exudates: reprogramming the functional expression of plant growth-promoting rhizobacteria.

Rhizomicrobiome plays important roles in plant growth and health, contributing to the sustainable development of agriculture. Plants recruit and assemble the rhizomicrobiome to satisfy their functional requirements, which is widely recognized as the 'cry for help' theory, but the intrinsic mechanisms are still limited. In this study, we revealed a novel mechanism by which plants reprogram the functional expression of inhabited rhizobacteria, in addition to the de novo recruitment of soil microbes, to satisfy different functional requirements as plants grow.

Plant commensal type VII secretion system causes iron leakage from roots to promote colonization.

Competition for iron is an important factor for microbial niche establishment in the rhizosphere. Pathogenic and beneficial symbiotic bacteria use various secretion systems to interact with their hosts and acquire limited resources from the environment. Bacillus spp.

A toxin-mediated policing system in optimizes division of labor via penalizing cheater-like nonproducers.

Division of labor, where subpopulations perform complementary tasks simultaneously within an assembly, characterizes major evolutionary transitions of cooperation in certain cases. Currently, the mechanism and significance of mediating the interaction between different cell types during the division of labor, remain largely unknown. Here, we investigated the molecular mechanism and ecological function of a policing system for optimizing the division of labor in SQR9.

Chemical communication in plant-microbe beneficial interactions: a toolbox for precise management of beneficial microbes.

Harnessing the power of beneficial microbes in the rhizosphere to improve crop performance is a key goal of sustainable agriculture. However, the precise management of rhizosphere microbes for crop growth and health remains challenging because we lack a comprehensive understanding of the plant-rhizomicrobiome relationship. In this review, we discuss the latest research progress on root colonisation by representative beneficial microbes (e.

Sustained Inhibition of Maize Seed-Borne Fusarium Using a Bacillus-Dominated Rhizospheric Stable Core Microbiota with Unique Cooperative Patterns.

Seed-borne pathogens can inhabit the rhizosphere and infect the plant after germination. The rhizosphere microbiome plays critical roles in defending against seed-borne pathogens. However, the assembly of a core rhizosphere microbiome to suppress seed-borne pathogens is unknown.

Rhizosphere microbes enhance plant salt tolerance: Toward crop production in saline soil.

The world's population continues to increase and thus requires more food production to take place in nonarable land, such as saline soil; therefore, it is urgent to find solutions to enhance the salinity tolerance of crops. As the second genome of plants, the rhizosphere microbiome plays critical roles in plant fitness under stress conditions. Many beneficial microbes that help plants cope with salinity stress have been identified, highlighting their roles in mitigating salt stress-induced negative effects on plants.

Housekeeping gene gyrA, a potential molecular marker for Bacillus ecology study.

Bacillus is a genus of microorganisms (bacteria) and contains many important commercial species used in industry, agriculture and healthcare. Many different Bacilli are relatively well understood at the single-cell level; however, molecular tools that determine the diversity and ecology of Bacillus community are limited, which limits our understanding of how the Bacillus community works. In the present study, we investigated the potential of the housekeeping gene gyrA as a molecular marker for determining the diversity of Bacillus species.

Root-secreted bitter triterpene modulates the rhizosphere microbiota to improve plant fitness.

Underground microbial ecosystems have profound impacts on plant health. Recently, essential roles have been shown for plant specialized metabolites in shaping the rhizosphere microbiome. However, the potential mechanisms underlying the root-to-soil delivery of these metabolites remain to be elucidated.

Biosynthetic gene cluster profiling predicts the positive association between antagonism and phylogeny in Bacillus.

Understanding the driving forces and intrinsic mechanisms of microbial competition is a fundamental question in microbial ecology. Despite the well-established negative correlation between exploitation competition and phylogenetic distance, the process of interference competition that is exemplified by antagonism remains controversial. Here, we studied the genus Bacillus, a commonly recognized producer of multifarious antibiotics, to explore the role of phylogenetic patterns of biosynthetic gene clusters (BGCs) in mediating the relationship between antagonism and phylogeny.

Nitrogen fertilization modulates beneficial rhizosphere interactions through signaling effect of nitric oxide.

Chemical nitrogen (N) fertilization is customary for increasing N inputs in agroecosystems. The nutritional effects of N fertilization on plants and soil microbes have been well studied. However, the signaling effects of N fertilization on rhizosphere plant-microbe interactions and the following feedback to plant performance remain unknown.