Transcriptomic and metabolomic perspectives for the growth of alfalfa (Medicago sativa L.) seedlings with the effect of vanadium exposure.

Hitherto, the effect of vanadium on higher plant growth remains an open topic. Therefore, nontargeted metabolomic and RNA-Seq profiling were implemented to unravel the possible alteration in alfalfa seedlings subjected to 0.1 mg L-1 (B group) and 0.5 mg L-1 (C group) pentavalent vanadium [(V(V)] versus control (A group) in this study. Results revealed that vanadium exposure significantly altered some pivotal transcripts and metabolites. The number of differentially expressed genes (DEGs) markedly up- and down-regulated was 21 and 23 in B_vs_A, 27 and 33 in C_vs_A, and 24 and 43 in C_vs_B, respectively. The number for significantly up- and down-regulated differential metabolites was 17 and 15 in B_vs_A, 43 and 20 in C_vs_A, and 24 and 16 in C_vs_B, respectively. Metabolomics and transcriptomics co-analysis characterized three significantly enriched metabolic pathways in C_vs_A comparing group, viz., α-linolenic acid metabolism, flavonoid biosynthesis, and phenylpropanoid biosynthesis, from which some differentially expressed genes and differential metabolites participated. The metabolite of traumatic acid in α-linolenic acid metabolism and apigenin in flavonoid biosynthesis were markedly upregulated, while phenylalanine in phenylpropanoid biosynthesis was remarkably downregulated. The genes of allene oxide cyclase (AOC) and acetyl-CoA acyltransferase (fadA) in α-linolenic acid metabolism, and chalcone synthase (CHS), flavonoid 3'-monooxygenase (CYP75B1), and flavonol synthase (FLS) in flavonoid biosynthesis, and caffeoyl-CoA O-methyltransferase (CCoAOMT) in phenylpropanoid biosynthesis were significantly downregulated. While shikimate O-hydroxycinnamoyltransferase (HCT) in flavanoid and phenylpropanoid biosynthesis were conspicuously upregulated. Briefly, vanadium exposure induces a readjustment yielding in metabolite and the correlative synthetic precursors (transcripts/unigenes) in some branched metabolic pathways. This study provides a practical and in-depth perspective from transcriptomics and metabolomics in investigating the effects conferred by vanadium on plant growth and development.

Interaction behaviors of Cr(VI) at biotite-water interface in the presence of HA: Batch, XRD and XPS investigations.

The interaction behaviors of heavy metals and micaceous minerals are extremely important to understand the environmental behaviors of heavy metals. In this work, the interaction behaviors of Cr(VI) and biotite in the presence and absence of HA were studied combining batch and spectroscopic approaches. Batch experiments showed that biotite had the ability to remove Cr(VI) from the water and the removal markedly increased with decreasing pH. However, sorption of total Cr onto biotite increased with increasing pH (2.0-4.0), whilst quickly decreased above pH âˆ¼ 4.0. It was worth noting that redox process of Cr(VI) to Cr(III), caused by structural Fe(II) on biotite, was another important factor for the high removal of Cr(VI) in a pH range of 2.0-4.0. Ionic strength also influenced Cr(VI) removal that Cr(VI) removal became higher with increasing ion strength. The presence of HA did not show obvious macroscopic effect on Cr(VI) removal, however, HA could cover biotite surface, and promote the sorption of total Cr onto biotite and attenuate the reduction effect caused by Fe(II) on biotite. Spectroscopic approaches, like FT-IR, XRD and XPS further confirmed the existence of Cr(III) on biotite interacting with Cr(VI) and the reduction of Cr(VI) to Cr(III) was drove by the Fe(II) dissolving from biotite to Fe(III). Further, sorption effect and reduction effect competitively contributed to the Cr(VI) removal by biotite, and reduction effect played a more important role at lower pH.

Effect of vanadium on Lactuca sativa L. growth and associated health risk for human due to consumption of the vegetable.

Elevated vanadium in the environment adversely affects organisms, including plants, animals, and humans. Plants act as the main conduit for environmental vanadium to enter the food chain, and simultaneously their growth response characteristics reflect vanadium toxicity efficacy for plants. The aim of the present study is to investigate lettuce (Lactuca sativa L.) growth involving morphological change, physiological adjustment, vanadium accumulation under vanadium stress, and the potential health risk (expressed as health risk index (HRI)) of adults and children who consume it. Lettuce was grown in nutrient solution with 0, 0.1, 0.5, 2.0, and 4.0 mg L-1 of pentavalent vanadium [V(V)]. Results showed that 0.1 mg L-1 V did not significantly affect lettuce growth versus control, and marked depression arose at ≥ 0.5 mg L-1 V. Foliar proline increased rapidly at ≥ 0.5 mg L-1 V. No striking change emerged in leaf cell membrane permeability at all treatments. V(V) and total vanadium concentration in plant tissues were ordered as root > stem > leaf, while tetravalent vanadium [V(IV)] was leaf > root > stem. No health risk (HRI < 1) exists for adults and children who consume lettuce at control treatment. However, the health risk occurs (HRI ˃ 1) when they both ingest the seedlings exposed to ≥ 0.1 mg L-1 V, and the risk overall markedly increases with increasing vanadium. Therefore, enough attention needs to be paid to the human health associated with the ingestion of vegetables like lettuce grown in substrata contaminated by vanadium.

A comparative study of peroxydisulfate and peroxymonosulfate activation by a transition metal-H2O2 system.

In this study, the impacts of common activation methods, namely heating, the addition of zero-valent metals (Cu, Fe, Al, Co, and Ni) and the addition of H2O2, on peroxydisulfate (PS) and peroxymonsulfate (PMS) activation were investigated. Rhodamine B (Rhb, 50 mg/L) was chosen as the substrate to be tested. Results showed that the efficiency of PMS was higher than that of PS under the same heat activation conditions. Cu, Fe, and Ni activated PS, while Co exhibited detrimental effects; Among them, Cu was the best. Co was the best activator among the investigated metals for PMS. Additionally, the use of H2O2 achieved a higher removal of Rhb in the PS/Cu system but inhibited the PMS/Co system. Three common anions (SO42-, Cl-, NO3-) that exist in the Yellow River were investigated. Cl- was found to accelerate Rhb degradation, while SO42- and NO3- slowed Rhb degradation. Toxicity experiment results showed that the addition of H2O2 promoted the transformation of Cu (0) to Cu2+ and Co (0) to Co2+, which was dangerous for seed germination. Graphical abstract.

Growth responses, accumulation, translocation and distribution of vanadium in tobacco and its potential in phytoremediation.

The metal tolerance mechanism of plants is of great importance to explore the plant-based clean-up of environmental substrata contaminated by heavy metals. Indoor experiment of tobacco (Nicotiana tabacum L.) seedlings growing hydroponically in nutrient solution containing 0, 0.1, 0.5, 2.0, and 4.0 mg L-1 V was conducted. The results indicated that plant overall growth performance was significantly affected at ≥ 2.0 mg L-1 V. Oxidative stress degree as indicated by foliar O2-· and H2O2 content intensified markedly at ≥ 0.5 mg L-1 V treatments. In response, the plant activated its enzyme and non-enzyme protecting mechanism to cope with oxidative stress inflicted by vanadium. The activities of antioxidant enzymes, including SOD, POD, CAT, APX, and the concentration of non-enzyme antioxidants, e.g., AsA and GSH were all conspicuously (p < 0.5 or p < 0.1) enhanced at ≥ 0.5 mg L-1 V treatments. Vanadium accumulated in leaves, stems, and roots increased with increasing vanadium level. The majority of the absorbed vanadium retained in plant root, and minor portions were transferred to aerial parts. Vanadium concentration in plant tissues ordered as root ˃ stem ˃ leaf. Translocation factors (TF) in vanadium-treated tobaccos (TF « 1) were significantly lower than that of control (TF ˃ 1). In conclusion, although vanadium at ≥ 2.0 mg L-1 inhibited plant growth, tobacco exhibited a relatively good vanadium tolerance through self-adaptive regulation and has the potential as a phytostabilizer in decontaminating the environment contaminated by vanadium.

The Downregulation of lncRNA pgm5-as1 Inhibits the Proliferation and Metastasis Via Increasing miR-484 Expression in Colorectal Cancer.

Background: Bioinformatics showed that long non-coding RNA (lncRNA) pgm5-as1 was regulated in patients with colorectal cancer (CRC), and miR-484 was also regulated in CRC. We aimed at determining the modulatory pathway of lncRNA pgm5-as1 in CRC cells, and whether miR-484 was involved in the pathway. Materials and Methods: The target gene of pgm5-as1 was predicted by bioinformatics and verified by dual luciferase assay. Transcription levels of pgm5-as1 and miR-484 were determined by quantitative real-time polymerase chain reaction. Viability, migration rate, invasion, and growth of SW480 and HCT116 cells were determined by Cell Counting Kit-8 (CCK-8), wound healing assay, transwell, and colony formation assay, respectively. Results: pgm5-as1 was upregulated in CRC tissues and cell lines; however, its downregulation contributed to the decreasing of cell viability, growth, migration, and invasion of SW480 and HCT116 cells. Moreover, miR-484 was predicted as the target of pgm5-as1, and the downregulation of pgm5-as1 partially restored the elevated cell viability, growth, migration, and invasion that were induced by the inhibition of miR-484 expression in SW480 and HCT116 cells. Conclusions: The loss of miR-484 expression in CRC might be involved in the promotion and metastasis of CRC, which may be caused by the overexpression of pgm5-as1. Hence, the downregulation of pgm5-as1 could be a therapeutic target in the prevention or intervention of CRC.

Trichoderma viride involvement in the sorption of Pb(II) on muscovite, biotite and phlogopite: Batch and spectroscopic studies.

In this study, batch and spectroscopic approaches were used to explore the sorption of Pb(II) on micas (i.e., muscovite, biotite and phlogopite) in the presence of Trichoderma viride (T. viride). Batch sorption showed that ion exchange, outer-sphere complexes (OSCs) and inner-sphere complexes (ISCs) contributed to Pb(II) sorption on biotite and phlogopite in the pH range of 2.0-7.4, whereas the ISCs were predominant for Pb(II) sorption on muscovite. X-ray diffraction and Fourier transform infrared (FT-IR) analyses have confirmed the changes of structure and surface properties of micas after co-culturing with T. viride, which could improve the sorption capacity of micas to Pb(II). Scanning electron microscopy revealed the bio-mineralization of Pb(II) on T. viride and mica-T. viride composites forming lead phosphates. Furthermore, FT-IR analysis showed that the groups of Si-OH, Al-OH from micas, and carboxyl, phosphate and amino groups from T. viride were synergistically contributing to Pb(II) sorption on mica-T. viride composite. X-ray photoelectron spectroscopy further confirmed that both OSCs and ISCs formed for Pb(II) sorption on micas; however, in the case of mica-T. viride composites, the synergistic effects of T. viride and micas were contributing to Pb(II) sorption through forming the ISCs and biomineralization.

Photocatalytic degradation of reactive red 141 in the presence of Cr(VI) using TiO2 nanotubes.

TiO2 nanotubes were prepared by hydrothermal process, then characterized using Brunauer-Emmett-Teller (BET), transmission electron microscopy (TEM), X-ray diffraction (XRD) and UV-Visible spectroscopy measurements. The photodegradation performance assessment of Reactive Red 141 (RR141) with near visible light irradiation (lambda = 380 nm) was carried out under different catalyst doses, dye concentrations, pH and initial Cr(VI) concentrations by TiO2 powder and nanotubes. The results showed that the specific surface area of TiO2 nanotubes were 152 m2 g(-1), about three times larger than that of TiO2 powder which was roughly 51 m2 g(-1). The TiO2 nanotubes did not affect the lattice structure of the TiO2. The adsorption amount increases as the dosage and RR141 concentration increases. However, the decolonization efficiency decreased with increasing initial RR141 concentration. Results also showed that an acidic solution is more favorable for photocatalytic degradation of RR141. On the other hand, Cr(VI) can be adsorbed on the surface of TiO2 nanotubes to affect the decolonization efficiency of RR141.