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Fomesafen, a long-lived protoporphyrinogen-oxidase inhibitor, specially developed for post-emergence control of broad-leaf weeds, is used widely in soybean fields in northern China (Dayan and Duke, 2010). The impact of fomesafen on microbial communities in rhizosphere soils, however, is unknown. In this study we examined fomesafen degradation as well as its effects in the rhizosphere of soybean plants grown in a greenhouse. Fomesafen had shorter half-life in rhizosphere soil than previously reported for bulk soil from the same location (87 vs 120 days). The enzyme activity of soil extracts and the microbial community composition of 16S rRNA genes (16S) amplified from soil DNA were also investigated. Although not immediately apparent, both the high (37.5 mg kg−1) and low (18.75 mg kg−1) doses of fomesafen significantly decreased urease and invertase activities in the rhizosphere soil from days 30 and 45 respectively until the end of the experiment (90 days). Analysis of 16S amplicons demonstrated that fomesafen had a dose dependent effect, decreasing alpha diversity and altering beta diversity. Significant phylum level decreases were observed in five of the ten phyla that were most abundant in the control. Proteobacteria was the only phylum whose relative abundance increased in the presence of fomesafen, driven by increases in the genera Methylophilacaea, Dyella, and Sphingomonas. The functional implications of changes in 16S abundance as predicted using PICRUSt suggested that fomesafen enriched for enzymes involved in xenobiotic metabolism and detoxification (cytochrome P450s and glutathione metabolism). Our data suggest that, despite being degraded more rapidly in the rhizosphere than in bulk soil, fomesafen had long-lasting functional impacts on the soil microbial community. Image 1 • The activities of urease and invertase were affected by fomesafen. • Fomesafen significantly decreased bacterial richness and diversity. • Only Proteobacteria increased in response to fomesafen treatment. • Sphingomonas , Methylophilaceae and Dyella were enriched by fomesafen treatment. [ABSTRACT FROM AUTHOR]

There is a knowledge gap in the interaction between the effects of herbicide thiencarbazone-methyl·isoxaflutole on soil microflora and environmental parameters, which leads to a lack of measures in mitigating damage to bacterial communities from the herbicide use. The impacts of thiencarbazone-methyl·isoxaflutole and soil parameters on the diversity, structure and functions of soil bacterial communities were clarified, and the effects and potential mitigation mechanisms of nitrapyrin and modified attapulgite with bacterial function intervention on bacterial communities were explored through incubation and field experiments. The results showed that as thiencarbazone-methyl·isoxaflutole application increased, the stress on soil bacterial community structure and diversity also increased. The relative abundance of bacteria including Aridibacter and GP7 and functional annotations including "nitrate_reduction" were significantly negatively correlated with thiencarbazone-methyl·isoxaflutole residues in soils. The remarkable toxic effects on the Adhaeribacter bacteria were detected at the recommended dose of thiencarbazone-methyl·isoxaflutole application. The residue of isoxaflutole (one of the effective ingredients of thiencarbazone-methyl·isoxaflutole) directly and more strongly affected the diversity of soil bacterial communities than thiencarbazone-methyl. Increasing soil pH was recognised as an important factor in improving the diversity and structure of soil microflora based on the results of the Mantel test and canonical correspondence analysis. Supplemental use of nitrapyrin or modified attapulgite was found to increase soil pH, and further improve the expression of "manganese oxidation" function annotation. This contributed to the increased bacterial diversity (Shannon index). Therefore, the disturbance of soil microflora caused by thiencarbazone-methyl·isoxaflutole application can be mitigated by the use of nitrapyrin and modified attapulgite through raising soil pH. [Display omitted] • TMI directly affected soil microflora negatively even at the recommended dosage. • Toxic effects on bacterial structure were detected, especially Adhaeribacter bacteria. • Increased soil pH stimulated the "manganese oxidation" and further improved diversity. • Use of nitrapyrin and modified attapulgite can improve microflora by raising soil pH. [ABSTRACT FROM AUTHOR]

Intestinal inflammation, such as ulcerative colitis (UC), is a condition in which there is chronic or recurring inflammation of the gastrointestinal tract. Designing safe, effective, and multifunctional nanomedicines is one of the current difficulties in the treatment of UC. Here we developed a delivery nanosystem based on metal polyphenol network/cerium oxide artificial enzymes (MPN@CeOx) to manage UC and evaluate the severity of inflammation by MRI/CT imaging. MPN@CeOx was engineered by Fe3+ and epigallocatechin gallate (EGCG) wrapped around CeOx. Increased levels of oxidative stress in the inflammatory lesion facilitated the release of Fe3+ and EGCG from MPN and liberated CeOx. EGCG with anti-oxidative and anti-inflammatory effects plus CeOx with superoxide dismutase (SOD)-like activity effectively scavenged reactive oxygen species (ROS) and reduced pro-inflammatory cytokines to protect cells from oxidative damage. In addition, H 2 O 2 -responsive releasing of Fe3+ at the site of inflammation and Ce elements in CeOx enable MRI/CT imaging of UC. In mice colitis models, oral administration of enteric-coated MPN@CeOx alleviated intestinal inflammation and intestinal barrier dysfunction. RNA sequencing analysis revealed that MPN@CeOx ameliorated UC symptoms mainly through inflammation-related signaling pathways. MPN@CeOx with multilevel inflammation management and multimodal imaging capabilities represents an innovative diagnosis and treatment approach for UC. [Display omitted] • Metal polyphenol network-wrapped cerium oxide nanozymes (MPN@CeOx) efficiently scavenge reactive oxygen species (ROS). • MPN@CeOx preferentially accumulates at the site of intestinal inflammation to enable MRI/CT imaging of UC. • MPN@CeOx alleviates inflammation and intestinal barrier dysfunction via multiple inflammation-related signaling pathways. [ABSTRACT FROM AUTHOR]