Rhizosphere microbial characteristics of pioneer plant Oxyria sinensis Hemsl. in abandoned Pb-Zn mining area

Oxyria sinensis has the characteristics of drought resistance, barren resistance, pollution resistance and clonal reproduction, and has the potential to be developed as a restoration plant (pioneer plant) for vegetation restoration and heavy metal pollution control in mining wasteland. In this study, the rhizosphere microbial communities of the pioneer plant O. sinensis growing in a lead-zinc mine wasteland and the rhizosphere microbial communities of O. sinensis growing in adjacent non-mining areas were studied by field investigation. There were significant differences in the composition of microbial communities between the rhizosphere soil of O. sinensis and the bare soil. There were significant differences in the composition of soil microbial communities between the non-mining area control and the lead-zinc mine wasteland. Compared with the non-mining area control, the rhizosphere soil of O. sinensis in the lead-zinc mine wasteland had a unique microbial community. The dominant bacteria were Nitrospirae, Chloroflexi, Proteobacteria, Actinobacteria, Ascomycota and Kickxellomycota. Further gene function prediction showed that the metabolic pathway sequences related to heavy metal ion transport, heavy metal resistance and repair in the rhizosphere soil of O. sinensis were more abundant than those in the control. The dominant ecological functional groups of fungi in the rhizosphere soil of O. sinensis were saprophytic flora and pathological flora. Plenodomus, Surfurifusis, Sphingomonas, Filobasidium and Articulospora were enriched in the rhizosphere soil of O. sinensis in the abandoned land of lead-zinc mining area, and had high tolerance to heavy metals in the soil, indicating that O. sinensis can recruit heavy metal-tolerant microbial groups to promote its survival and adaptation in the abandoned land of the mining area

AOB Nitrosospira cluster 3a.2 (D11) dominates N2O emissions in fertilised agricultural soils.

CRediT authorship contribution statement Na Deng: Writing – review & editing, Methodology, Investigation, Data curation. Cecile Gubry-Rangin: Writing – review & editing, Methodology, Conceptualization. Xiao-Tong Song: Writing – review & editing, Methodology, Data curation. Xiao-Tang Ju: Writing – review & editing, Conceptualization. Si-Yi Liu: Methodology, Data curation. Ju-Pei Shen: Writing – review & editing, Data curation. Hong-jie Di: Writing – review & editing. Li-Li Han: Writing – review & editing, Methodology. Li-Mei Zhang: Writing – review & editing, Methodology, Data curation, Conceptualization.Peer reviewe

Nurse role and mechanism of Coriaria nepalensis in abandoned land of Pb-Zn mining area

Mining activities, while providing a huge material base for human society, have also caused great damage to the ecosystem. A large amount of mine waste is in urgent need of treatment and remediation. Phytoremediation, as a green and low-cost way of mine site restoration, has been researched by a large number of scholars. Ecological restoration, as a suitable alternative to phytoremediation, has also received extensive attention from scholars too. Field survey revealed that a native plant, Coriaria nepalensis, adapted to the abandoned sites of Pb-Zn mines for its adaptability to pollution and extreme habitats and its improvement of the surrounding microenvironment, with its formation of plant communities may contribute to the natural recovery of the abandoned sites of mines. For this reason, the present study was conducted on the nurse plant, C. nepalensis, which was naturally colonized in the abandoned land of the Pb-Zn mine in Mine Town, Huize County. The specific results of the study are as follows: Coriaria nepalensis promotes the stabilization of the soil structure under the canopy, and the local resources of the soil increase and the “fertilizer island” effect appears: (1) Improvement of physical properties: Compared with the herbaceous sample, the soil bulk density of the Coriaria nepalensis is significantly lower than that of the herbaceous sample. (2) Improve soil nutrition: the organic matter, total nitrogen and total phosphorus contents of the inter-root soil of the Coriaria nepalensis in large multi-diversity sites were higher than those of the herbaceous sample sites. (3) Reducing the toxicity of soil heavy metals to plants: although the total amount of heavy metals and the effective state of the Coriaria nepalensis were significantly higher than that of the herbaceous samples, the diversity and biomass of the plants under the Coriaria nepalensis were not affected, but were higher instead, which indicated that the Coriaria nepalensis mitigated the stress and toxicity of the heavy metals to the plants under the canopy, and allowed the plants to colonize and grow under the canopy. (4) Coriaria nepalensis in Pb-Zn mine abandoned sites can regulating soil microbial community structure, thus enabling plant community succession in degraded environments. Ascomycetes, Mycobacteriophages, Ascomycetes, and Stramenophages with higher abundance. (5) Coriaria nepalensis microbial community structure and increases the abundance of functions associated with nitrogen cycling and stress tolerance. There were higher abundances of bacterial functions related to nitrogen fixation, nitrate reduction, nitrogen respiration, nitrate respiration; and higher abundances of stress-tolerant, parthenogenetic anaerobic, biofilm-forming, aerobic, mobile protozoa-containing, and Gram-negative bacteria in the Coriaria nepalensis. In sum: C. nepalensis can have a nurse effect on its sub-canopy plants by improving microhabitat soil properties and regulating soil microbial community structure in abandoned sites of Pb-Zn mines, thus enabling plant community succession in degraded environments

Effect of potassium fertilization on storage root number, yield, and appearance quality of sweet potato (Ipomoea batatas L.)

Increasing storage root number is a pivotal approach to enhance both storage root (SR) yield and appearance quality of sweet potato. Here, 2-year field experiments were conducted to investigate the effect of 0 (K0), 120 (K1), 240 (K2), and 360 (K3) kg ha−1 potassium fertilizer (K2O) on lignin metabolism, root growth, storage root yield, and uniformity. The results demonstrated that potassium (K) application led to a decrease in the activities of key enzymes involved in lignin biosynthesis, including phenylalanine deaminase (PAL), 4-coumarate coenzyme A ligase (4-CL), cinnamic acid dehydrogenase (CAD), polyphenol oxidase (PPO), and peroxidase (POD). This resulted in a significant reduction in lignin and G-type lignin contents in potential SRs compared to K0 treatment within 10–30 days after planting (DAP). BJ553 exhibited a significant decrease in PAL activity, as well as lignin and G-type contents at 10 DAP, whereas YS25 showed delayed effects until 20 DAP. However, the number and distribution of secondary xylem conduits as well as the mid-column diameter area in roots were increased in K2 treatment. Interestingly, K2 treatment exhibited significantly larger potential SR diameter than other treatments at 15, 20, and 25 DAP. At harvest, K2 treatment increased the SR number, the single SR weight, and overall yield greatly compared with K0 treatment, with an average increase of 19.12%, 16.54%, and 16.92% respectively. The increase of SR number in BJ553 was higher than that of YS25. Furthermore, K2 treatment exhibited the lowest coefficient of variation for both SR length and diameter, indicating a higher yield of middle-sized SRs. In general, appropriate potassium application could effectively suppress lignin biosynthesis, leading to a reduction in the degree of pericycle lignification in potential SRs. This promotes an increase in the number of storage roots and ultimately enhances both yield and appearance quality of sweet potato. The effect of potassium fertilizer on lignin metabolism in BJ553 roots was earlier and resulted in a greater increase in the SR number compared to YS25

Non-canonical Notch Signaling Regulates Actin Remodeling in Cell Migration by Activating PI3K/AKT/Cdc42 Pathway

Tumor cell migration is a critical step in cancer metastasis. Over-activated Notch pathway can promote the migration of cancer cells, especially in the breast cancer. However, the underlying mechanism of non-canonical Notch signaling in modulating the migration has not yet been clearly characterized. Here we demonstrated that DAPT, a gamma secretase inhibitor, inhibited protrusion formation and cell motility, and then reduced the migration of triple-negative breast cancer cells, through increasing the activity of Cdc42 by non-canonical Notch pathway. Phosphorylation of AKT on S473 was surprisingly increased when Notch signaling was inhibited by DAPT. Inhibition of PI3K and AKT by LY294002 and MK2206, respectively, or knockdown of AKT expression by siRNA blocked DAPT-induced activation of Cdc42. Moreover, immunofluorescence staining further showed that DAPT treatment reduced the formation of lamellipodia and induced actin cytoskeleton remodeling. Taken together, these results indicated that DAPT inhibited Notch signaling and consequently activated PI3K/AKT/Cdc42 signaling by non-canonical pathway, facilitated the formation of filopodia and inhibited the assembly of lamellipodia, and finally resulted in the decrease of migration activity of breast cancer cells

Neuroprotectants attenuate hypobaric hypoxia-induced brain injuries in cynomolgus monkeys

Hypobaric hypoxia (HH) exposure can cause serious brain injury as well as life-threatening cerebral edema in severe cases. Previous studies on the mechanisms of HH-induced brain injury have been conducted primarily using non-primate animal models that are genetically distant to humans, thus hindering the development of disease treatment. Here, we report that cynomolgus monkeys (Macaca fascicularis) exposed to acute HH developed human-like HH syndrome involving severe brain injury and abnormal behavior. Transcriptome profiling of white blood cells and brain tissue from monkeys exposed to increasing altitude revealed the central role of the HIF-1 and other novel signaling pathways, such as the vitamin D receptor (VDR) signaling pathway, in co-regulating HH-induced inflammation processes. We also observed profound transcriptomic alterations in brains after exposure to acute HH, including the activation of angiogenesis and impairment of aerobic respiration and protein folding processes, which likely underlie the pathological effects of HH-induced brain injury. Administration of progesterone (PROG) and steroid neuroprotectant 5α-androst-3β,5,6β-triol (TRIOL) significantly attenuated brain injuries and rescued the transcriptomic changes induced by acute HH. Functional investigation of the affected genes suggested that these two neuroprotectants protect the brain by targeting different pathways, with PROG enhancing erythropoiesis and TRIOL suppressing glutamate-induced excitotoxicity. Thus, this study advances our understanding of the pathology induced by acute HH and provides potential compounds for the development of neuroprotectant drugs for therapeutic treatment

Radiofrequency Catheter Ablation of Supraventricular Tachycardia in Patients With Pulmonary Hypertension: Feasibility and Long-Term Outcome

BackgroundSupraventricular tachycardia (SVT) occurs commonly and is strongly correlated with clinical deterioration in patients with pulmonary hypertension (PH). This study aimed to investigate the feasibility and long-term outcome of radiofrequency catheter ablation (RFCA) in PH patients with SVT.Materials and MethodsConsecutive PH patients with SVT who were scheduled to undergo electrophysiological study and RFCA between September 2010 and July 2019 were included. The acute results and long-term success of RFCA were assessed after the procedure.ResultsIn total, 71 PH patients with 76 episodes of SVT were analyzed. Cavotricuspid isthmus-dependent atrial flutter (n = 33, 43.5%) was the most common SVT type, followed by atrioventricular nodal reentrant tachycardia (n = 16, 21.1%). Of the 71 patients, 60 (84.5%) underwent successful electrophysiological study and were subsequently treated by RFCA. Among them, acute sinus rhythm was restored in 54 (90.0%) patients, and procedure-related complications were observed in 4 (6.7%) patients. Univariate logistic regression analysis showed that cavotricuspid isthmus-independent atrial flutter [odds ratio (OR) 25.00, 95% confidence interval (CI) 3.45–180.98, p = 0.001] and wider pulmonary artery diameter (OR 1.19, 95% CI 1.03–1.38; p = 0.016) were associated with RFCA failure. During a median follow-up of 36 (range, 3–108) months, 7 patients with atrial flutter experienced recurrence, yielding a 78.3% 3-year success rate for RFCA treatment.ConclusionThe findings suggest that RFCA of SVT in PH patients is feasible and has a good long-term success rate. Cavotricuspid isthmus-independent atrial flutter and a wider PAD could increase the risk for ablation failure

Mass spectrometry-based metabolomics:a guide for annotation, quantification and best reporting practices

Mass spectrometry-based metabolomics approaches can enable detection and quantification of many thousands of metabolite features simultaneously. However, compound identification and reliable quantification are greatly complicated owing to the chemical complexity and dynamic range of the metabolome. Simultaneous quantification of many metabolites within complex mixtures can additionally be complicated by ion suppression, fragmentation and the presence of isomers. Here we present guidelines covering sample preparation, replication and randomization, quantification, recovery and recombination, ion suppression and peak misidentification, as a means to enable high-quality reporting of liquid chromatography– and gas chromatography–mass spectrometry-based metabolomics-derived data.</p