Isolation and characterization of Paenibacillus peoriae JC-3jx from Dendrobium nobile.

Dendrobium is a rich source of high-value natural components. Endophytic fungi are well studied, yet bacteria research is limited. In this study, endophytic bacteria from Dendrobium nobile were isolated using an improved method, showing inhibition of pathogens and growth promotion. JC-3jx, identified as Paenibacillus peoriae, exhibited significant inhibitory activity against tested fungi and bacteria, including Escherichia coli. JC-3jx also promoted corn seed rooting and Dendrobium growth, highlighting its excellent biocontrol and growth-promoting potential.

Understanding the metabolism of the novel plant antiviral agent dufulin by different positional 14C labeling in cherry radishes.

Dufulin is a new type of plant antiviral agent. However, its metabolism in plants, which is very important for environmental risk assessment, is still unclear. In this study, we used 14C markers at different positions and high-performance liquid chromatography-quadrupole time-of-flight-mass spectrometry (HPLC-QTOF-MS) to qualitatively and quantitatively analyze dufulin metabolites in cherry radish. By combining ion pairs with unique abundance ratios, we clarified the metabolite structures, inferred the metabolic pathway of dufulin, and clarified the criteria for residues. The extractable residue of dufulin from cherry radish stem and leaf tissues was above 98 % and that in the succulent root was above 87 %. In the stem and leaf tissues and succulent root, dufulin underwent both phase I and phase II metabolism, and four metabolites were produced, including a conjugate of glucose malonate and hydroxylated dufulin, which was confirmed by comparison with a standard. However, the proportions and concentrations of the four metabolites did not meet the residue criteria, so only the dufulin precursor compound was included as a residue. This study provides reliable data for evaluating the impacts of dufulin on the environment and human health and for objectively examining the safety of dufulin.

Directed Self-Assembly of Heterologously Expressed Hagfish EsTKα and EsTKγ for Functional Hydrogel.

Hagfish slime proteins have long been considered useful due to their potential applications in novel green, environmental, and functional bionic materials. The two main component proteins in the slime thread of hagfish, (opt)EsTKα and (opt)EsTKγ, were used as raw materials. However, the methods available to assemble these two proteins are time- and labor-intensive. The conditions affecting protein self-assembly, such as the pH of the assembly buffer, protein concentration, and the protein addition ratio, were the subject of the present research. Through a series of tests, the self-assembly results of a variety of assembly conditions were explored. Finally, a simplified protein self-assembly method was identified that allows for simple, direct assembly of the two proteins directly. This method does not require protein purification. Under the optimal assembly conditions obtained by exploration, a new gel material was synthesized from the hagfish protein through self-assembly of the (opt)EsTKα and (opt)EsTKγ. This assembly method has the benefits of being a simple, time-saving, and efficient. The self-assembled protein gel products were verified by SDS polyacrylamide gel electrophoresis (SDS-PAGE) and contained (opt)EsTKα and (opt)EsTKγ proteins. Scanning electron microscopy (SEM) was used to investigate the self-assembled protein gel after freeze-drying, and it was observed that the self-assembled protein formed a dense, three-dimensional porous network structure, meaning that it had good water retention. Evaluation of the gel with atomic force microscopy (AFM) indicated that the surface of the protein fiber skeleton show the network-like structure and relatively smooth. Characterization by circular dichroism (CD) and Fourier transform infrared spectroscopy (FT-IR) demonstrated that the two proteins were successfully assembled, and that the assembled protein had a secondary structure dominated by α-helices. The rheological properties of the self-assembled products were tested to confirm that they were indeed hydrogel property.

Nonstereoselective behavior of novel chiral organophosphorus pesticide Dufulin in cherry radish by different absorption methods.

Dufulin is a biologically derived antiviral agent chemically synthesized by α-phosphoramidate in sheep and is effective against viral diseases in plants such as tobacco, rice, cucumber and tomato. However, the environmental behaviors and fate of Dufulin under different cultivation systems remain unknown. This study investigates the absorption, translocation and accumulation of 14C-Dufulin stereoisomers introduced by pesticide leaf daubing and by mixing the pesticide with soil in different tissues of cherry radish. We particularly focused on whether the behaviors of Dufulin enantiomers in plants were stereoselective. In the leaf uptake experiments, S-Dufulin and R-Dufulin were transported both up and down, while more than 93% of the pesticide remained in the labeled leaves. During the radicular absorption experiments, both enantiomers of Dufulin were taken up by radish roots and moved to the upper part of the plant, while less than 0.2% Dufulin was absorbed from the soil. Hence, it was easier for Dufulin to enter plants through the leaf surface than through the roots. However, we found in this trial that the stereoisomers of Dufulin underwent nonstereoselective absorption and translocation, which implies that rac-Dufulin and its metabolites should be a major research priority. Overall, our results provide a relatively accurate prediction of the risk assessment of Dufulin, which will help guide its rational use in the environment as well as ensure eco-environmental safety and human health.

Diverse positional 14C labeling-assisted metabolic analysis of pesticides in rats: The case of vanisulfane, a novel vanillin-derived pesticide.

Information on pesticide metabolites is crucial for accurate environmental risk assessment. However, identifying the various metabolites of a novel pesticide is challenging since the potential metabolic pathways are unknown. In this study, we coupled diverse positional 14C labeling with high-resolution mass spectrometry to quantitatively and qualitatively study pesticide metabolism in rats. With the unique M/(M + 2) ratios derived from 14C, precursor compounds of metabolites could be better distinguished from impurity ions. Additionally, the use of diverse 14C labeling positions is a powerful tool to elucidate the complete metabolic fate of novel contaminants. Vanisulfane is a novel vanillin-derived antiviral agent with encouraging prospects for the efficient control of cucumber mosaic virus in China, but its metabolic pathways in mammals are still poorly understood. Thus, the metabolism of vanisulfane was studied in rats of both sexes by this strategy. The results showed that phase I and phase II metabolism occurred in both sexes. The former included mainly oxidation reactions, and the latter involved binding reactions that formed glucuronide, sulfate and amino acid conjugates. Sex-related differences were observed in the experiment, with earlier appearance of downstream metabolites and a preference for sulfate conjugate formation in males compared to females. This research facilitates the risk evaluation of vanisulfane, and offers an effective framework for screening unknown pesticide metabolic pathways, which could be applied to establish the metabolic profiles of other novel contaminants with limited information.

Sex-related deposition and metabolism of vanisulfane, a novel vanillin-derived pesticide, in rats and its hepatotoxic and gonadal effects.

A series of vanillin derivatives have recently been synthesized as effective candidate antiviral agents, with vanisulfane exhibiting pronounced curative and protective activities against cucumber mosaic virus and potato virus Y. However, research on some new pesticides usually ignores their various metabolites and sex-related toxicity. Assisted by 14C labeling, a trial was conducted to investigate the tissue distribution, excretion, and metabolism of vanisulfane in male and female rats for the first time. The results showed that 83.30-87.51% of applied 14C activity was excreted in urine and feces within 24 h of oral administration, and 14C was most abundant in the liver and kidney in both sexes. Interestingly, sex differences were observed in the experiment, with lower body clearance in males than in females 24 h after treatment and preferences for biliary and renal excretion of the pesticide in male and female rats, respectively. A high degradation rate was found for vanisulfane in the plasma; thus, the metabolites of vanisulfane were investigated using liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-QTOF-MS) combined with 14C labeling. One glucuronic acid conjugate and two oxidation metabolites were detected, supporting the monitoring of vanisulfane in vivo. Additionally, rats exposed to vanisulfane exhibited hepatic steatosis in both sexes, along with mild gonadal effects in males. This research offers an effective method for conducting environmental behavioral research and provides new insights for evaluating the potential risks of novel pesticides in mammals from a sex perspective.

Translocation and metabolism of the chiral neonicotinoid cycloxaprid in oilseed rape (Brassica napus L.).

Neonicotinoids have been banned in some countries because of increased nontarget resistance and ecological toxicity. Cycloxaprid is a potentially promising substitute, but its metabolism in plants is still poorly understood. The study aims to clarify the translocation of cycloxaprid, identify its metabolites, propose possible metabolic pathways and compare differences between enantiomers in oilseed rape via 14C tracing technology and HPLC-QTOF-MS. The results showed that most cycloxaprid remained in the treated leaves, and only a small amount translocated to the anthers. Seven metabolites were identified, and the possible metabolic pathway was divided into two phases. Phase Ⅰ metabolism included two metabolites obtained via cleavage of the oxa-bridged seven-membered ring. Phase II metabolism was responsible for glucose conjugate formation. The possible metabolic pathways revealed that the proportion of phase I metabolites gradually decreased over time, and the phase II metabolites transformed from monosaccharide and disaccharide conjugates to trisaccharide and tetrasaccharide conjugates. The levels of metabolites were significantly different between the enantiomers. In particular, the main metabolite was M4, which has confirmed biological toxicity. M2 was the only metabolite detected in rapeseed. The results will promote the scientific application of cycloxaprid in agriculture and could have implications for assessing environmental risk.

Corrigendum: Using Integrative Analysis of DNA Methylation and Gene Expression Data in Multiple Tissue Types to Prioritize Candidate Genes for Drug Development in Obesity.

[This corrects the article DOI: 10.3389/fgene.2018.00663.].

Using Integrative Analysis of DNA Methylation and Gene Expression Data in Multiple Tissue Types to Prioritize Candidate Genes for Drug Development in Obesity.

Obesity has become a major public health issue which is caused by a combination of genetic and environmental factors. Genome-wide DNA methylation studies have identified that DNA methylation at Cytosine-phosphate-Guanine (CpG) sites are associated with obesity. However, subsequent functional validation of the results from these studies has been challenging given the high number of reported associations. In this study, we applied an integrative analysis approach, aiming to prioritize the drug development candidate genes from many associated CpGs. Association data was collected from previous genome-wide DNA methylation studies and combined using a sample-size-weighted strategy. Gene expression data in adipose tissues and enriched pathways of the affiliated genes were overlapped, to shortlist the associated CpGs. The CpGs with the most overlapping evidence were indicated as the most appropriate CpGs for future studies. Our results revealed that 119 CpGs were associated with obesity (p ≤ 1.03 × 10-7). Of the affiliated genes, SOCS3 was the only gene involved in all enriched pathways and was differentially expressed in both visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT). In conclusion, our integrative analysis is an effective approach in highlighting the DNA methylation with the highest drug development relevance. SOCS3 may serve as a target for drug development of obesity and its complications.