Tunable polarization properties of charge, spin, and valley in Janus VSiGeZ4 (Z = N, P, As) monolayers.

Polarization, as an important characterization of the symmetry breaking systems, has attracted tremendous attention in two-dimensional (2D) materials. Due to their significant symmetry breaking, Janus 2D ferrovalley materials provide a desirable platform to investigate the charge, spin, and valley polarization, as well as their coupling effects. Herein, using first-principles calculations, the polarization properties of charge, spin, and valley in Janus VSiGeZ4 (Z = N, P, and As) monolayers are systematically studied. The mirror symmetry breaking leads to a non-zero dipole moment and surface work function difference, indicating the presence of out-of-plane charge polarization. Magnetic properties calculations demonstrate that VSiGeN4 is a 2D-XY magnet with a Berezinskii-Kosterlitz-Thouless temperature of 342 K, while VSiGeP4 and VSiGeAs4 have an out-of-plane magnetization with a Curie temperature below room temperature. The magnetization can be rotated by applying biaxial strain, allowing manipulation of the spin polarization via nonmagnetic means. The spontaneous valley polarization is predicted to be 46, 49, and 70 meV for VSiGeN4, VSiGeP4, and VSiGeAs4, respectively, whose physical origin can be elucidated by employing the model analysis. In particular, the biaxial strain can induce the valley polarization switching from the valence (conduction) band to conduction (valence) band, but it hardly changes the valley polarization strength. Meanwhile, the valley extremum is transformed from the K' (K) to K (K') points. The present work not only provides an underlying insight into the polarization properties of Janus VSiGeZ4 but also offers a class of promising materials for spintronic and valleytronic devices.

Tuning of the electronic and photocatalytic properties of Janus WSiGeZ4 (Z = N, P, and As) monolayers via strain engineering.

Recently, MA2Z4 materials have received tremendous attention due to their amazing electronic, spintronic, and optoelectronic properties. In this work, we propose a class of 2D Janus materials WSiGeZ4 (Z = N, P, and As). It was found that their electronic and photocatalytic properties are sensitive to the change of the Z element. Biaxial strain results in an indirect-direct band gap transition in WSiGeN4 and a semiconductor-metal transition in WSiGeP4 and WSiGeAs4. Comprehensive studies demonstrate that these transitions as well as valley-contrasting physics are closely related to the crystal field induced orbital distribution. By taking into account several features of the excellent photocatalysts reported for water splitting, we predict three promising photocatalytic materials WSi2N4, WGe2N4, and WSiGeN4. Their optical and photocatalytic properties can be well modulated by applying biaxial strain. Our work not only provides a class of potential electronic and optoelectronic materials but also enriches the study of Janus MA2Z4 materials.

Strain-dependent optical properties of the novel monolayer group-IV dichalcogenides SiS2semiconductor: a first-principles study.

We studied the structural, electronic, and optical characters of SiS2, a new type of group IV-VI two-dimensional semiconductor, in this article. We focused on monolayer SiS2and its characteristic changes when different strains are applied on it. Results reveal that the monolayer SiS2is dynamically stable when no strain is applied. In terms of electronic properties, it remains a semiconductor under applied strain within the range from -10% to 10%. Besides, its indirect band-gap is altered regularly after applying a strain, whereas different strains lead to various changing trends. As for its optical properties, it exhibits remarkable transparency for infrared and most visible light. Its main absorption and reflection regions lie in the blue and ultraviolet areas. The applied uniaxial strain causes its different optical properties along the armchair direction and zigzag direction. Moreover, the tensile strain could tune its optical properties more effectively than the compressive strain. When different strains are applied, the major changes are in blue and ultraviolet regions, but only minor changes can be found in infrared and visible regions. So its optical properties reveal good stability in infrared and visible regions. Therefore, SiS2has a promising prospect in nano-electronic and nano-photoelectric devices.

Strain-tunable electronic and optical properties of novel anisotropic green phosphorene: a first-principles study.

The effect of in-layer strain on the optical and electrical properties of monolayer green phosphorene, a new anisotropic two-dimensional (2D) material, has been systematically studied. The studied strain includes in-layer uniaxial strain and biaxial strain. Green phosphorene can be viewed as a combination of black and blue phosphorene segments in regular order. We adopt the HSE06 method to correct the calculated results. The results reveal that, firstly, strain-free monolayer green phosphorene is a stable direct band gap 2D semiconductor with the anisotropic optical property. The transmittance of infrared and visible light along the zigzag direction is better than that along the armchair direction. However, the transmittance of the UV-light along the armchair direction is better than that along the zigzag direction. Secondly, the optical properties, such as the absorption coefficient and reflectivity, along armchair and zigzag direction respond very differently to the various applied strains. As for the electronic properties, the band gap exhibits different changing trends by applying either in-layer biaxial strain or uniaxial strain in different directions. Besides, the near-band-edge electronic orbitals exhibit different bond nature in different directions. These results suggest that green phosphorene shows strong anisotropy in electronic and optical properties. By calculating and comparing the energies of near-band-edge states after applying different strains on green phosphorene, the reason for the anisotropy of the new 2D material is analyzed. This study implies that the electronic and optical properties of green phosphorene, a stable direct band gap anisotropic semiconductor, could be efficiently tuned by in-layer biaxial or uniaxial strain. Therefore, green phosphorene can be used in linear polarizers and other anisotropic photoelectric devices.

Topologically nontrivial phase and tunable Rashba effect in half-oxidized bismuthene.

Bismuth based (Bi-based) materials exhibit promising potential for the study of two-dimensional (2D) topological insulators or quantum spin Hall (QSH) insulators due to their intrinsic strong spin-orbit coupling (SOC). Herein, we theoretically propose a new inversion-asymmetry topological phase with tunable Rashba effect in a 2D bismuthene monolayer, which is driven by the sublattices half-oxidation (SHO). The nontrivial topology is identified by the SHO induced p-p band inversion at the Γ point, the Z2 topological number, and the metallic edge states. Interestingly, the SOC opens a band gap as large as 0.26 eV at Γ, which is twice as large as that of the freestanding bismuthene monolayer, revealing a predominant contribution of the orbital filtering effect. Inversion-symmetry breaking leads to a substantial Rashba constant of 11.5 eV Å near the valence band top, which is about twice as large as that of the freestanding bismuthene monolayer due to the SHO effect. In particular, the topological insulator-to-topological semimetal phase-transition and the tunable Rashba effect were achieved by exerting a moderate strain. We demonstrate that 3% stretching is the most desirable strain to obtain superior properties. Hexagonal boron nitrogen (h-BN) is proposed to serve as a suitable substrate for SHO-Bi in practical applications. Our findings not only provide a new route to engineering a 2D inversion-asymmetry topological insulator but also represent a significant advance in the exploration of 2D Bi-based topological materials.

Dietary supplementation of Streptococcus faecalis benefits the feed utilization, antioxidant capability, innate immunity, and disease resistance of blunt snout bream (Megalobrama amblycephala).

This study aimed to investigate the effects of Streptococcus faecalis on the growth performance, intestinal histology, antioxidant capability, innate immunity, and disease resistance of blunt snout bream Megalobrama amblycephala. Fish were fed five experimental diets containing 0 (SF0, control), 1 × 105 (SF1), 1 × 106 (SF2), 1 × 107 (SF3), and 1 × 108 cfu/g (SF4) of Streptococcus faecalis, respectively, for 10 weeks. After the feeding trial, fish were challenged by Aeromonas hydrophila with the cumulative mortality recorded during a period of 96 h. The results showed that WG and FI of fish both showed no significant difference (P > 0.05) among all the treatments. However, the FCR was significantly (P < 0.05) affected by Streptococcus faecalis levels with the lowest value observed in the SF2 group, whereas the opposite was true for intestinal microvillus length (P < 0.05). Dietary supplementation of 1 × 106 cfu/g Streptococcus faecalis significantly (P < 0.05) increased the hepatic activities of SOD, CAT, and GPx; plasma activities of LZM, MPO, ACP, and AKP; and the levels of C3, C4, and IgM of fish, compared with the control group. Similar results were also observed in the tissue expressions of Leap-I, Leap-II, muc2, and muc5b (P < 0.05), whereas the opposite was true for liver MDA contents and plasma NO levels (P < 0.05). At 96 h after challenge, the cumulative mortality of the control was significantly (P < 0.05) higher than that of the SF2 group, but it showed no statistical difference (P > 0.05) with that of the other treatments. These results indicated that dietary supplementation of 1 × 106 cfu/g Streptococcus faecalis could not only improve the feed utilization of blunt snout bream but also enhance its antioxidant capability, innate immunity, and disease resistance.

Electronic and magnetic properties of 3D transition-metal atom adsorbed arsenene.

To utilize arsenene as the electronic and spintronic material, it is important to enrich its electronic properties and induce useful magnetic properties in it. In this paper, we theoretically studied the electronic and magnetic properties of arsenene functionalized by 3D transition-metal (TM) atoms (TM@As). Although pristine arsenene is a nonmagnetic material, the dilute magnetism can be produced upon TM atoms chemisorption, where the magnetism mainly originates from TM adatoms. We find that the magnetic properties can be tuned by a moderate external strain. The chemisorption of 3D TM atoms also enriches the electronic properties of arsenene, such as metallic, half-metallic, and semiconducting features. Interestingly, we can classify the semiconducting feature into three types according to the band-gap contribution of spin channels. On the other hand, the chemisorption properties can be modified by introducing monovacancy defect in arsenene. Present results suggest that TM-adsorbed arsenene may be a promising candidate for electronic and spintronic applications.

Dual Heterogeneous Catalyst Pd-Au@Mn(II)-MOF for One-Pot Tandem Synthesis of Imines from Alcohols and Amines.

A new Mn(II) metal-organic framework (MOF) 1 was synthesized by the combination of 4,4,4-trifluoro-1-(4-(pyridin-4-yl)phenyl)butane-1,3-dione (L) and Mn(OAc)2 in solution. 1 features a threefold-interpenetrating NbO net containing honeycomb-like channels, in which the opposite Mn(II)···Mn(II) distance is 23.5075(10) Å. Furthermore, 1 can be an ideal platform to support Pd-Au bimetallic alloy nanoparticles to generate a composite catalytic system of Pd-Au@Mn(II)-MOF (2). 2 can be a highly active bifunctional heterogeneous catalyst for the one-pot tandem synthesis of imines from benzyl alcohols and anilines and from benzyl alcohols and benzylamines.

Tuning the electronic properties of bilayer group-IV monochalcogenides by stacking order, strain and an electric field: a computational study.

As the isoelectronic counterpart of phosphorene, monolayer group IV-VI binary MX (M = Ge, Sn; X = Se, S) compounds have drawn considerable attention in recent years. In this paper, we construct four high-symmetry stacking models for bilayer MX to tune their electronic properties. We systematically explore the dynamical and thermal stabilities of all bilayer MX. It is found that five of them are possible at room temperature. Then, we perform first-principles calculations to study how the bilayer structure affects their electronic properties. The results demonstrate that the electronic properties of MX materials can be modulated by forming bilayer structures. Their bandgap can be tuned over a wide range from 0.789 to 1.617 eV, and an indirect-to-direct transition occurs in three cases. Considering the flexibility of bilayer MX, we utilize in-plane uniaxial tensile strain to adjust their band structures and achieve much more indirect-to-direct bandgap transitions. The realization of direct bandgaps will be helpful for their application in next-generation high-efficiency modern nano-optoelectronic and photovoltaic devices. We also study the responses of different bilayer MX to an external vertical electric field. It is found that their bandgaps decrease rapidly with the increase of the electric field.

Au@Cu(II)-MOF: Highly Efficient Bifunctional Heterogeneous Catalyst for Successive Oxidation-Condensation Reactions.

A new composite Au@Cu(II)-MOF catalyst has been synthesized via solution impregnation and full characterized by HRTEM, SEM-EDS, XRD, gas adsorption-desorption, XPS, and ICP analysis. It has been shown here that the Cu(II)-framework can be a useful platform to stabilize and support gold nanoparticles (Au NPs). The obtained Au@Cu(II)-MOF exhibits a bifunctional catalytic behavior and is able to promote selective aerobic benzyl alcohol oxidation-Knoevenagel condensation in a stepwise way.

Pd@Cu(II)-MOF-Catalyzed Aerobic Oxidation of Benzylic Alcohols in Air with High Conversion and Selectivity.

A new 3D porous Cu(II)-MOF (1) was synthesized based on a ditopic pyridyl substituted diketonate ligand and Cu(OAc)2 in solution, and it features a 3D NbO motif which is determined by the X-ray crystallography. Furthermore, the Pd NPs-loaded hybrid material Pd@Cu(II)-MOF (2) was prepared based on 1 via solution impregnation, and its structure was confirmed by HRTEM, SEM, XRPD, gas adsorption-desorption, and ICP measurement. 2 exhibits excellent catalytic activity (conversion, 93% to >99%) and selectivity (>99% to benzaldehydes) for various benzyl alcohol substrates (benzyl alcohol and its derivatives with electron-withdrawing and electron-donating groups) oxidation reactions in air. In addition, 2 is a typical heterogeneous catalyst, which was confirmed by hot solution leaching experiment, and it can be recycled at least six times without significant loss of its catalytic activity and selectivity.

Defect effects on the electronic, valley, and magnetic properties of the two-dimensional ferrovalley material VSi2N4.

Due to their novel spin and valley properties, two-dimensional (2D) ferrovalley materials are expected to be promising candidates for next-generation spintronic and valleytronic devices. However, they are subject to various defects in practical applications. Therefore, the electronic, valley, and magnetic properties may be modified in the presence of the defects. In this work, utilizing first-principles calculations, we systematically studied the effects of defects on the electronic, valley, and magnetic properties of the 2D ferrovalley material VSi2N4. It has been found that C doping, O doping, and N vacancies result in the half-metallic feature, Si vacancies result in the metallic feature, and V vacancies result in a bipolar gapless semiconductor. These defect-induced electronic properties can be effectively tuned by changing defect concentration and layer thickness. Since the impurity bands do not affect the K and K' valleys, valley polarization is well maintained in O-doped and N-defective systems. Importantly, these defects play a crucial role in modifying the magnetic properties of the pristine VSi2N4, especially the magnitude of local magnetic moments and the magnetic anisotropy energy. Detailed analysis of the density of states demonstrates that the variations of the total magnetic moment and magnetic anisotropy energy with biaxial strain are determined by the electronic states near the Fermi level rather than the type of defect, which provides a new understanding of the effects of defects on the magnetic properties of 2D materials. Moreover, the layer thickness can affect the magnetic coupling between defects and surrounding V atoms. Our results offer insight into the electronic, valley, and magnetic properties of VSi2N4 in the presence of various point defects.

Halogenated aromatic pollutants in routine animal-derived food of south China: Occurrence, sources, and dietary intake risks.

Halogenated aromatic pollutants (HAPs) including polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs), polychlorinated biphenyls (PCBs), polybrominated dibenzo-p-dioxins/furans (PBDD/Fs), and polybrominated diphenyl ethers (PBDEs) exhibit diverse toxicities and bio-accumulation in animals, thereby imposing risks on human via animal-derived food (ADF) consumption. Here we examined these HAPs in routine ADFs from South China and observed that PBDEs and PCBs showed statistically higher concentrations than PCDD/Fs and PBDD/Fs. PCDD/Fs and PCBs in these ADFs were mainly from the polluted feed and habitat of animals, except PCDD/Fs in egg, which additionally underwent selective biotransformation/progeny transfer after the maternal intake of PCDD/F-polluted stuff. PBDEs and PBDD/Fs were mostly derived from the extensive use of deca-BDE and their polluted environments. Significant interspecific differences were mainly observed for DL-PCBs and partly for PBDD/Fs and PBDEs, which might be caused by their distinct transferability/biodegradability in animals and the different living habit and habitat of animals. The dietary intake doses (DIDs) of these HAPs via ADF consumption were all highest for toddlers, then teenagers and adults. Milk, egg, and fish contributed most to the DIDs and risks for toddlers and teenagers, which results of several cities exceeded the recommended thresholds and illustrated noteworthy risks. Pork, fish, and egg were the top three risk contributors for adults, which carcinogenic and non-carcinogenic risks were both acceptable. Notably, PBDD/Fs showed the lowest concentrations but highest contributions to the total risks of these HAPs, thereby meriting continuous attention.

Exploration in the Mechanism of Ginsenoside Rg5 for the Treatment of Osteosarcoma by Network Pharmacology and Molecular Docking.

OBJECTIVE: Osteosarcoma is a primary malignancy originating from mesenchymal tissue characterized by rapid growth, early metastasis and poor prognosis. Ginsenoside Rg5 (G-Rg5) is a minor ginsenoside extracted from Panax ginseng C.A. Meyer which has been discovered to possess anti-tumor properties. The objective of current study was to explore the mechanism of G-Rg5 in the treatment of osteosarcoma by network pharmacology and molecular docking technology. METHODS: Pharmmapper, SwissTargetPrediction and similarity ensemble approach databases were used to obtain the pharmacological targets of G-Rg5. Related genes of osteosarcoma were searched for in the GeneCards, OMIM and DrugBank databases. The targets of G-Rg5 and the related genes of osteosarcoma were intersected to obtain the potential target genes of G-Rg5 in the treatment of osteosarccoma. The STRING database and Cytoscape 3.8.2 software were used to construct the protein-protein interaction (PPI) network, and the Database for Annotation, Visualization and Integrated Discovery (DAVID) platform was used to perform gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses. AutoDock vina software was used to perform molecular docking between G-Rg5 and hub targets. The hub genes were imported into the Kaplan-Meier Plotter online database for survival analysis. RESULTS: A total of 61 overlapping targets were obtained. The related signaling pathways mainly included PI3K-Akt signaling pathway, Proteoglycans in cancer, Lipid and atherosclerosis and Kaposi sarcoma-associated herpesvirus infection. Six hub targets including PIK3CA, SRC, TP53, MAPK1, EGFR, and VEGFA were obtained through PPI network and targets-pathways network analyses. The results of molecular docking showed that the binding energies were all less than -7 kcal/mol. And the results of survival analysis showed TP53 and VEGFA affect the prognosis of sarcoma patients. CONCLUSION: This study explored the possible mechanism of G-Rg5 in the treatment of osteosarcoma using network pharmacology method, suggesting that G-Rg5 has the characteristics of multi-targets and multi-pathways in the treatment of osteosarcoma, which lays a foundation for the follow-up experimental and clinical researches on the therapeutic effects of G-Rg5 on osteosarcoma.

Occurrence and carcinogenic potential of airborne PBDD/Fs and PCDD/Fs around a large-scale municipal solid waste incinerator: A long-term passive air sampling study.

Municipal solid waste incinerator (MSWI) not only is deemed one of the uppermost sources of polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs), but also produces substantial amount of polybrominated dibenzo-p-dioxins/furans (PBDD/Fs) owing to the existence of brominated flame retardants (BFRs) in the waste. So far, however, PBDD/Fs in the vicinal environments of MSWI and their associated risks remain rarely studied. Based on a one-year passive air sampling (PAS) scheme, we investigated airborne PBDD/Fs and PCDD/Fs around a large-scale MSWI that has been operated for multi-years. Both the concentrations of PBDD/Fs and PCDD/Fs showed spatially decreasing trends with the distance away from the MSWI, confirming the influence of the MSWI on the dioxin levels in its ambient air. But its influence on PBDD/Fs was less because PBDD/Fs exhibit lower volatility and therefore lower gaseous concentrations than PCDD/Fs. Compared to the existing global data of airborne PCDD/Fs and PBDD/Fs, our data of the MSWI vicinity were at medium levels, despite PAS samples only represent the concentrations of gaseous dioxins in theory. The seasonal data suggest that meteorological conditions exerted apparent influences over the concentrations and sources of airborne dioxins around the MSWI. As for PCDD/Fs, the MSWI was diagnosed as their uppermost source, followed by local traffic and volatilization/deposition. Whereas the top three PBDD/F sources were related to PBDEs, bromophenol/bromobenzene, and traffic vehicles, respectively. The bioassay-derived TEQs based on the aryl hydrocarbon receptor activation of airborne dioxins around the MSWI were one or two orders of magnitudes higher than their concentration-based TEQs, and the corresponding carcinogenic risks at some MSWI-vicinal sites exceeded the acceptable threshold proposed by the U. S. EPA (10-6 âˆ¼ 10-4) and deserve continuous attention.

Organophosphate esters (OPEs) in a heavily polluted river in South China: Occurrence, spatiotemporal trends, sources, and phase distribution.

In the past decade, organophosphate esters (OPEs) undergo rapid increase in production and use. Meanwhile, owing to their additive property, OPEs exhibit liability to escape from related products and therefore ubiquity in various environments. Moreover, numerous researches verify their bioavailability and negative effects on biota and human, hence their occurrence and associated risks have caught much concern, particularly those in aquatic systems. So far, however, OPEs in water are generally investigated as a whole, their phase distribution and behavior in waterbodies are incompletely characterized. We examined 25 OPEs in water (including dissolved and particulate phases), sediment, and sediment core samples from the Lian River, which flows through the Guiyu e-waste recycling zone and Shantou specific economic zone in South China. Compared to most global waterbodies, the Lian River showed high or ultrahigh OPE levels in both water and sediments, particularly in the reaches surrounded by e-waste recycling and plastic-related industries, which were the top two greatest OPE sources. Non-industrial and agriculture-related anthropogenic activities also contributed OPEs. Sediment core data suggested that OPEs have been present in waters in Guiyu since the 1960s and showed a temporal trend consistent with the local waste-recycling business. The phase distribution of OPEs in the Lian River was significantly correlated with their hydrophobicity and solubility. Owing to their wide range of physicochemical properties, OPE congeners showed significant percentage differences in the Lian River water and sediments. Generally, OPEs in water reflect their dynamic real-time inputs, while those in sediment signify their accumulative deposition, which is another cause of their phase distribution disparities in the Lian River. The physicochemical parameters of OPEs first imposed negative and then positive influences on their dissolved phase-sediment distribution, indicating the involvement of both the adsorption of dissolved OPEs and the deposition of particle-bound OPEs.

Pharmacological Effects of Resveratrol in Intervertebral Disc Degeneration: A Literature Review.

Intervertebral disc degeneration (IDD) is a high incidence disease of musculoskeletal system that often leads to stenosis, instability, pain and even deformity of the spinal segments. IDD is an important cause of discogenic lower back pain and often leads to large economic burden to families and society. Currently, the treatment of IDD is aimed at alleviating symptoms rather than blocking or reversing pathological progression of the damaged intervertebral disc. Resveratrol (RSV) is a polyphenol phytoalexin first extracted from the Veratrum grandiflflorum O. Loes and can be found in various plants and red wine. Owing to the in-depth study of pharmacological mechanisms, the therapeutic potential of RSV in various diseases such as osteoarthritis, neurodegenerative diseases, cardiovascular diseases and diabetes have attracted the attention of many researchers. RSV has anti-apoptotic, anti-senescent, anti-inflammatory, anti-oxidative, and anabolic activities, which can prevent further degeneration of intervertebral disc cells and enhance their regeneration. With high safety and various biological functions, RSV might be a promising candidate for the treatment of IDD. This review summarizes the biological functions of RSV in the treatment of IDD and to facilitate further research.

Insight into the pharmacological effects of andrographolide in musculoskeletal disorders.

Andrographis paniculata (A. paniculata) is a traditional herbal medicine that has been widely used in Asian countries for hundreds of years. Andrographolide (AG) is a diterpene lactone extracted from A. paniculata. Owing to the in-depth study of pharmacological mechanisms, the therapeutic potential of AG, including its anti-inflammatory, anti-tumor, and immunoregulatory attributes, has attracted the attention of many researchers. Studies testing the therapeutic effects of AG have demonstrated desirable results in the treatment of a variety of clinical diseases. With high safety and various biological functions, AG might be a promising candidate for the treatment of musculoskeletal disorders. Here, we review all available literatures to summarize the pharmacological effects of AG and facilitate further researches on musculoskeletal diseases.

Arbuscular mycorrhizal fungi and phosphorus supply accelerate main medicinal component production of Polygonum cuspidatum.

The medicinal plant Polygonum cuspidatum Sieb. Et Zucc is rich in stilbenes (e.g., polygonin and resveratrol) and anthraquinones (e.g., emodin) for the therapy of human diseases, while how to increase the growth and medicinal composition concentrations of P. cuspidatum has become an urgent issue. The aim of the present study was to evaluate the effects of inoculation with an arbuscular mycorrhizal (AM) fungus, Funneliformis mosseae, on plant growth, phosphorus (P) acquisition, medicinal component concentrations, and expressions of resveratrol synthesis-associated enzyme genes of P. cuspidatum at two P levels (0 M and 0.2 M). P supply (0.2 M) stimulated root AM fungal colonization rate. F. mosseae inoculation significantly improved growth performance (height, diameter, and biomass) and root morphology (diameter, length, and projected area), irrespectively of substrate P levels. P supply and F. mosseae distinctly increased soil acid and neutral phosphatase activities, as well as root P concentrations. P supply increased root physcion and resveratrol concentrations in inoculated and uninoculated plants, along with up-regulated expressions of PcCHS1, PcCRS1, PcRS11, and PcSTS. AM plants represented significantly higher root aloe-emodin, chrysophanol, emodin, physcion, polydatin, and resveratrol concentrations than non-AM plants irrespective of P levels, coupled with up-regulated expressions of PcCHS1, PcCHS2, PcRS11, PcRS, and PcSTS. It is concluded that 0.2 M P supply and F. mosseae inoculation promoted chrysophanol, physcion, polydatin, and resveratrol concentrations of P. cuspidatum, with the increase in resveratrol associated with up-regulated expressions of related genes.

Mycorrhizal Effects on Growth and Expressions of Stress-Responsive Genes (aquaporins and SOSs) of Tomato under Salt Stress.

Environmentally friendly arbuscular mycorrhizal fungi (AMF) in the soil can alleviate host damage from abiotic stresses, but the underlying mechanisms are unclear. The objective of this study was to analyze the effects of an arbuscular mycorrhizal fungus, Paraglomus occultum, on plant growth, nitrogen balance index, and expressions of salt overly sensitive genes (SOSs), plasma membrane intrinsic protein genes (PIPs), and tonoplast intrinsic protein genes (TIPs) in leaves of tomato (Solanum lycopersicum L. var. Huapiqiu) seedlings grown in 0 and 150 mM NaCl stress. NaCl stress severely inhibited plant growth, but P. occultum inoculation significantly improved plant growth. NaCl stress also suppressed the chlorophyll index, accompanied by an increase in the flavonoid index, whereas inoculation with AMF significantly promoted the chlorophyll index as well as reduced the flavonoid index under NaCl conditions, thus leading to an increase in the nitrogen balance index in inoculated plants. NaCl stress regulated the expression of SlPIP1 and SlPIP2 genes in leaves, and five SlPIPs genes were up-regulated after P. occultum colonization under NaCl stress, along with the down-regulation of only SlPIP1;2. Both NaCl stress and P. occultum inoculation induced diverse expression patterns in SlTIPs, coupled with a greater number of up-regulated TIPs in inoculated versus uninoculated plants under NaCl stress. NaCl stress up-regulated SlSOS2 expressions of mycorrhizal and non-mycorrhizal plants, while P. occultum significantly up-regulated SlSOS1 expressions by 1.13- and 0.45-fold under non-NaCl and NaCl conditions, respectively. It was concluded that P. occultum inoculation enhanced the salt tolerance of the tomato, associated with the nutrient status and stress-responsive gene (aquaporins and SOS1) expressions.