Bacterial wilt disease caused by Ralstonia solanacearum is a widespread, severe plant disease. Tomato (Solanum lycopersicum), one of the most important vegetable crops worldwide, is particularly susceptible to this disease. Biological control offers numerous advantages, making it a highly favorable approach for managing bacterial wilt. In this study, the results demonstrate that treatment with the biological control strain Bacillus subtilis R31 significantly reduced the incidence of tomato bacterial wilt. In addition, R31 directly inhibits the growth of R. solanacearum, and lipopeptides play an important role in this effect. The results also show that R31 can stably colonize the rhizosphere soil and root tissues of tomato plants for a long time, reduce the R. solanacearum population in the rhizosphere soil, and alter the microbial community that interacts with R. solanacearum. This study provides an important theoretical basis for elucidating the mechanism of B. subtilis as a biological control agent against bacterial wilt and lays the foundation for the optimization and promotion of other agents such as R31.

Aborycin is a ribosomally synthesized member of the type I lasso peptide natural products. In the present study, aborycin was isolated and identified from the deep-sea-derived microbe Streptomyces sp. SCSIO ZS0098. The aborycin biosynthetic gene cluster (abo) was identified on the basis of genome sequence analyses and then heterologously expressed in Streptomyces coelicolor M1152 to effectively produce aborycin. Aborycin generated in this fashion exhibited moderate antibacterial activity against 13 Staphylococcus aureus strains from various sources with minimum inhibitory concentrations MICs = 8.0~128 µg/mL, against Enterococcus faecalis ATCC 29212 with an MIC = 8.0 µg/mL, and against Bacillus thuringiensis with MIC = 2.0 µg/mL. Additionally, aborycin displayed potent antibacterial activity (MIC = 0.5 µg/mL) against the poultry pathogen Enterococcus gallinarum 5F52C. The reported abo cluster clearly has the potential to provide a means of expanding the repertoire of anti-infective type I lasso peptides.

Four metabolites (1–4), including a new macrolide, O-demethylated-zeaenol (2), and three known compounds, zeaenol (1), adenosine (3), and ergosta-5,7,22-trien-3b-ol (4) were isolated and purified from Curvularia crepinii QTYC-1, a fungus residing in the gut of Pantala flavescens. The structures of isolated compounds were identified on the basis of extensive spectroscopic analysis and by comparison of the corresponding data with those reported in the literature previously. The new compound 2 showed good phytotoxic activity against Echinochloa crusgalli with an IC₅₀ value of less than 5 µg/mL, which was comparable to that of positive 2,4-dichlorophenoxyacetic acid (2,4-D). Compound 1 exhibited moderate herbicidal activity against E. crusgalli with an IC₅₀ value of 28.8 μg/mL. Furthermore, the new metabolite 2 was found to possess moderate antifungal activity against Valsa mali at the concentration of 100 µg/mL, with the inhibition rate of 50%. These results suggest that the new macrolide 2 and the known compound 1 have potential to be used as biocontrol agents in agriculture.

Continuous cropping of bananas leads to Fusarium wilt, affecting crop health, yet employing biocontrol bacteria to modulate rhizosphere microbial communities may offer effective disease suppression. This study revealed the secondary succession characteristics of rhizosphere microbiota in banana fields after more than 5‐year continuous cropping and assessed the suppressive effects induced by biocontrol strain Bacillus subtilis R31. Through high‐throughput sequencing, we observed a convergent enrichment of core bacterial genera Burkholderia ‐ Dyella and Arthrobacter ‐ Ralstonia in naturally suppressive and R31‐treated suppressive soils, indicating broad‐spectrum disease‐suppressive soil traits induced by R31. R31 significantly enhanced associations between Streptomyces and the rhizosphere core community while weakening Burkholderia 's linkage with membrane transport and energy metabolism pathways; moreover, it strengthened positive correlations between Rhizobium and terpenoid and polyketide metabolism ( r = 0.65, p < 0.01). Culture‐dependent assays showed that among 46 isolates from root and rhizosphere, those with high activities of indole‐3‐acetic acid, protease, cellulase, chitinase, and β ‐1,3‐glucanase exhibited pronounced antagonistic activities against Fusarium oxysporum . Although R31 was undetectable in the rhizosphere in the second year, its modulation of rhizosphere function persisted, displaying a “legacy effect” consistent with the priority effects theory, whereby early colonizing beneficial communities resist subsequent pathogen invasions. R31 induced functional bacteria colonization in nascent banana root hair tissues, establishing new microbiome patterns that contributed to long‐term disease suppression. Pot experiments further indicated that endophytic bacteria within roots exhibited stronger Fusarium wilt control than rhizosphere isolates. However, single‐strain treatments frequently led to sheath rot co‐infection, suggesting that synergistic actions of multiple strains might be more effective for disease suppression. This study highlighted R31's potential to sustainably modulate the rhizosphere microbiome, enhance enzyme activity, and promote beneficial bacteria colonization, laying the groundwork for constructing efficient synthetic bacterial communities for biocontrol.