The behaviour of residues of tebuconazole, prochloraz, and abamectin in rehmannia during rehmannia decoction processing was systemically assessed. The pesticides were determined by ultra-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS) after each processing step including washing, steaming and drying, carbonising, and boiling. Results showed that the pesticide residues significantly decreased after the steps of washing, carbonising, and boiling. Washing reduced pesticide residues by 41.2%–60.0%; carbonising reduced pesticides by 27.1%–71.1% in both prepared rehmannia and unprepared rehmannia. After boiling, the concentrations of tebuconazole and prochloraz were 0.0002–0.0022 mg kg⁻¹ in decoctions. Abamectin was not detected in rehmannia after carbonising, and it was not detected in decoctions either. The processing factors (PFs) were less than 1 during food processing, indicating that the full set of processing can reduce the residues of tebuconazole, prochloraz, and abamectin in rehmannia decoction.

Rehmannia glutinosa, a valuable medicinal plant, is threatened by ring rot, a condition that greatly affects its yield and quality. Interactions between plant and the rhizosphere soil microbiome in the context of pathogen invasion are generally more specific, with recruitment of specialized microbes potentially antagonistic to a certain pathogen. Isolation of microorganisms from rhizosphere soil of healthy and ring rot-infected R. glutinosa was carried out to screen antifungal microbes. A strain designated RerS4 isolated from ring rot-infected R. glutinosa rhizosphere soil with strong antifungal activities was selected for further study. RerS4 was taxonomically characterized as the genus Streptomyces according to its morphology and 16S rRNA sequences that were most closely related to Streptomyces racemochromogenes NRRL B-5430^T (99.72%) and Streptomyces polychromogenes NBRC 13072^T (99.72%). A new lipopeptide isolated from RerS4 showed restrained proliferation, but was devoid of significant antibacterial and antioxidant activity with minimum inhibitory concentration (MIC) values of 20.3 ± 2.5 and 70.8 ± 3.7 μg/mL and half-maximal inhibitory concentration (IC₅₀) values of 23.3 ± 0.8 and 58.8 ± 2.9 μg/mL, respectively. In addition, we report the complete genome sequence of Streptomyces sp. RerS4, which consists of a 7,301,482 bp linear chromosome and a 242,139 bp plasmid. Genome analysis revealed that Streptomyces sp. RerS4 contained 25 biosynthetic gene clusters (BGCs) for secondary metabolites, among which 68% had low similarities with known BGCs, leading us to believe that Streptomyces sp. RerS4 could produce valuable bioactive compounds.

Introduction: Bacterial communities are important for soil functions, but the effect of clomazone on network complexity, composition, and stability is not well studied.Method: In this study, two agricultural soils were used to test the impact of clomazone on bacterial communities, and the two soils were treated with three concentrations of clomazone (0, 0.8, 8, and 80 mg kg¹) in an incubator.Results and discussion: Bacterial network nodes, links, and average degrees were all decreased by 9–384, 648–829, and 0.703–2.429, respectively. Based on keystone nodes, the topological roles of the nodes were also influenced by clomazone. Bacterial network composition was also impacted based on the analysis of similarity (ANOSIM) and network dissimilarity. Compared with control and clomazone treatments in both soils, the ANOSIM between control and all clomazone treatments was higher than 0.6, network dissimilarities were 0.97–0.98, shared nodes were 131–260, and shared links were 12–100. The bacterial network stability was decreased by clomazone, with decreased robustness by 0.01–0.016 and increased vulnerability by 0.00023–0.00147 in both soils. There were fewer bacterial network modules preserved after clomazone treatment, and the bacterial network community functions were also impacted in both soils. Based on these results, soil bacterial species connections, modularization, and network stability were significantly impacted by clomazone.

Introduction: The composition and stability of soil fungal network are important for soil function, but the effect of trifluralin on network complexity and stability is not well understood.Methods: In this study, two agricultural soils were used to test the impact of trifluralin on a fungal network. The two soils were treated with trifluralin (0, 0.84, 8.4, and 84 mg kg⁻¹) and kept in artificial weather boxes.Results and discussion: Under the impact of trifluralin, the fungal network nodes, edges, and average degrees were increased by 6–45, 134–392, and 0.169–1.468 in the two soils, respectively; however, the average path length was decreased by 0.304–0.70 in both soils. The keystone nodes were also changed in trifluralin treatments in the two soils. In the two soils, trifluralin treatments shared 219–285 nodes and 16–27 links with control treatments, and the network dissimilarity was 0.98–0.99. These results indicated that fungal network composition was significantly influenced. After trifluralin treatment, fungal network stability was increased. Specifically, the network robustness was increased by trifluralin with 0.002–0.009, and vulnerability was decreased by trifluralin with 0.0001–0.00032 in the two soils. Fungal network community functions were also impacted by trifluralin in both soils. Trifluralin significantly impacts the fungal network.