Phytophthora sojae effector PsAvh113 associates with the soybean transcription factor GmDPB to inhibit catalase-mediated immunity.

Phytophthora species are the most destructive plant pathogens worldwide and the main threat to agricultural and natural ecosystems; however, their pathogenic mechanism remains largely unknown. Here, we show that Avh113 effector is required for the virulence of Phytophthora sojae and is important for development of Phytophthora root and stem rot (PRSR) in soybean (Glycine max). Ectopic expression of PsAvh113 enhanced viral and Phytophthora infection in Nicotiana benthamiana. PsAvh113 directly associated with the soybean transcription factor GmDPB, inducing its degradation by the 26S proteasome. The internal repeat 2 (IR2) motif of PsAvh113 was important for its virulence and interaction with GmDPB, while silencing and overexpression of GmDPB in soybean hairy roots altered the resistance to P. sojae. Upon binding to GmDPB, PsAvh113 decreased the transcription of the downstream gene GmCAT1, which acts as a positive regulator of plant immunity. Furthermore, we revealed that PsAvh113 suppressed the GmCAT1-induced cell death by associating with GmDPB, thereby enhancing plant susceptibility to Phytophthora. Together, our findings reveal a vital role of PsAvh113 in inducing PRSR in soybean and offer a novel insight into the interplay between defence and counter-defence during the P. sojae infection of soybean.

Preparation of Rubra (Paeonia lactiflora Pall.) extract and studies in activity and skin penetration.

The inhibition rate of tyrosinase activity was used to determine extraction solvent of Paeoniae Radix Rubra extract (PRRE), which was established quality control standards by HPLC and verified the antioxidant activity. Ternary phase diagram was used to screen the best formulation of PRRE nanoemulsion, the skin permeability of PRRE and nanoemulsion were compared. The results show that 70% ethanol as the extraction solvent were highest (88.89%) and the contents of catechin (CC) and paeoniflorin (PF) in PRRE were 0.145 ± 0.0006 µg/mg and 21.783 ± 0.0247 µg/mg, respectively. The inhibition rate of PRRE on pyrogallol autoxidation was 6.94% ± 0.53%. The optimal formulation is Isopropyl myristate (IPM) as oil phase, Ethoxylated hydrogenated castor oil (RH40) as emulsifier, glycerine as coemulsifier, Km 3:1. The skin penetration of CC in PRRE nanoemulsion (0.79 ± 0.04 µg·cm-2) was significantly higher than that PRRE (0.17 ± 0.09 µg·cm-2) after 12 h.

CircHIRA sponges miR-196b-5p to promote porcine early embryonic development.

Circular RNA (circRNA) is abundantly expressed in preimplantation embryos and embryonic stem cells in mice and humans. However, its function and mechanism in early development of mammalian embryos remain unclear. Here, we showed that circHIRA mediated miR-196b-5p to regulate porcine early embryonic development. We verified the circular feature of circHIRA by sanger sequencing, and proved the authenticity of circHIRA by enzyme digestion test. HIRA and circHIRA were expressed in porcine early embryos, and its expression levels significantly increased from 8-cell stage onwards and reached the maximum at the blastocyst stage. Functional studies revealed that circHIRA knockdown not only significantly reduced the developmental efficiency of embryos from 8-cell stage to blastocyst stage, but also impaired the blastocyst quality. Mechanistically, integrated analysis of miRNA prediction and gene expression showed that circHIRA knockdown significantly increased the expression of miR-196b-5p in porcine early embryos. Furthermore, miR-196b-5p inhibitor injection could rescue the early development of circHIRA knockdown embryos. Taken together, the findings reveal that circHIRA regulates porcine early embryonic development via inhibiting the expression of miR-196b-5p.

Involvement of METTL3-mediated m6A methylation in the early development of porcine cloned embryos.

METTL3-mediated N6-methyladenosine (m6A) modification is critical for gametogenesis and early embryonic development. However, the function of METTL3-mediated m6A modification in the early development of somatic nuclear transfer embryos (SCNT) remains unclear. Here, we found that METTL3 mRNA and protein levels exhibit dynamic changes during the early development of porcine SCNT embryos. The levels of METTL3 mRNA and protein in SCNT embryos at specific developmental stages differ from those in parthenogenetic activation (PA) counterparts. SiRNA injection effectively reduced the levels of METTL3 mRNA and protein in 4-cell embryos and blastocysts. METTL3 knockdown significantly reduced the cleavage and blastocyst rates of SCNT embryos. METTL3 knockdown significantly reduced the number of total cells and trophectoderm (TE) cells in the resulting blastocysts and perturbed cell lineage allocation. In addition, METTL3 knockdown reduced the levels of m6A modification in 4-cell embryos and blastocysts. Importantly, METTL3 knockdown decreased the expression levels of CDX2, GATA3, NANOG and YAP, and increased the expression levels of SOX2 and OCT4. Taken together, these results demonstrate that METTL3-mediated m6A modification regulates early development and lineage differentiation of porcine SCNT embryos.

[Effect of osthol on apoptosis and bone resorption of osteoclasts cultured in vitro].

This study is to investigate the effect of osthol on osteoclasts' activity, bone resorption as well as apoptosis in vitro, and explore the mechanism of osthol in preventing osteoporosis. Osteoclasts were separated from long-limb bones of new born rabbits, cultured in 24-well plate with glass slices and bone slices, and treated by 1 x 10(-5) mol x L(-1) osthol. Osteoclasts were identified by observing live cells with phase contrast microscope, HE staining, TRAP staining and toluidine blue staining of bone resorption pits. The numbers of bone resorption pits were counted as well as the surface area of bone resorption on bone slice. Osteoclasts were stained with acridine orange to detect the cell apoptosis. The ratio of apoptotic osteoclasts was observed under fluorescence microscope. The gene expression of RANKL, OPG, TRAP and p-JNK1/2 protein expression were examined using real time PCR and Western blotting, respectively. Comparing with the control group without osthol, the rates of apoptotic osteoclasts increased obviously and the number and area of bone resorption pits decreased evidently with 1 x 10(-5) mol x L(-1) osthol. There is significant difference between control group and experiment group treated by 1 x 10(-5) mol x L(-1) osthol. Therefore, the osthol through RANK+RANKL/TRAF6/Mkk/JNK signal pathway inhibits the osteoclasts activity, enhances osteoclasts apoptotic and inhibits the bone resorption.

[Effect of sinusoidal electricity magnetic fields on the proliferation and differentiation of osteoblasts in vitro].

OBJECTIVE: To investigate the effect of sinusoidal electricity magnetic fields (SEMFs) on the proliferation and differentiation of osteoblasts in vitro. METHODS: Calvarial osteoblasts of newborn rats were isolated by enzyme digestion and randomly divided into 3 groups after subculture. Two groups of cells were exposed to 50 Hz 1.8 mT SEMFs for 30 min/d in parallel and vertical, respectively. Those without SEMFs exposure served as control. The cells were observed under the contrast phase microscope each day. After 48 h, cell proliferation was assayed by MTT method. The alkaline phasphatase (ALP) activities and calcium contents were measured after 3, 6, 9, and 12 days. The ALP positive colonies were histochemically stained after 10 days and the calcified nodules were stained by Alizarin Bordeaux after 12 days. Expressions of ALP, bone morphogenetic protein-2 (BMP-2) and Osterix (OSX) mRNA were measured at 0 h, 24 h, 48 h and 96 h. RESULTS: The cells exposed to the SEMFs were arranged in spiral appearance after 3 days. Compared with control, SEMFs inhibited cell proliferation (P < 0.01 or P < 0.05), but enhanced the maturation and mineralization of the osteoblasts. The results showed that SEMFs improved ALP activities, promoted calcium contents, increased calcified nodulues numbers, boosted expressions of ALP, BMP-2 and OSX mRNA. SEMFs with magnetic lines of force in parallel has stronger activities than those in vertical. CONCLUSION: The SEMFs at 1.8 mT and 50 Hz inhibit the proliferation of osteoblasts, but enhance the maturation and mineralization of osteoblasts.

[Study on estrogenic effect of genistein and apigenin in vitro].

OBJECTIVE: To detect the estrogenic activity of genistein and apigenin with ER-positive cell line MCF-7 human breast cancer cells. METHOD: MTT method was adopted to study the impact of genistein and apigenin on MCF-7 proliferation in vitro. Real-time RT-PCR method was used to detect their impact on ERalpha, ERbeta, PR and PS2 mRNA expression levels. RESULT: Genistein and apigenin promoted the proliferation of MCF-7. Genistein 1 x 10(-10) mol x L(-1) group showed a significant increase in the expression of ERa mRNA levels or a 17. 76 times more than the control group and a 1.75 times more than the E2 group. Apigenin notably promoted the PR mRNA expression or a 4. 57 times more than the control group and a 1.11 times more than the E2 group. Both of them had different effect in promoting ERalpha, ERbeta, PR or PS2 mRNA. CONCLUSION: Both genistein and apigenin have a strong estrogen-like effect. Although they have different effect in promoting estrogenic response genes (such as ERa, ERbeta, PR and PS2 mRNA), genistein shows a stronger activity than apigenin. It also suggests that the signaling pathways of phytoestrogens showing estrogen-like effect are not completely identical with estrogen pathways. The B-cycle position of flavonoids is one of the key sites to estrogen-like activity, and isoflavones (cycle B on site 3) show stronger estrogen-like activity than flavones (B-cycle lies in site 2).

Responses of germination strategy of Agriophyllum squarrosum to rainfall pattern in the Tengger desert.

Agriophyllum squarrosum (L.) Moq. (Chenopodiaceae) is an annual pioneer psammophyte that is strictly distributed along desert margins. However, little is known about how this species adapts to shifting dunes. In this study, seeds bank was selected and germination behaviors of A. squarrosum were tested in laboratory. In addition, the effects of rainfall patterns on population dynamics were observed in field at the southeastern edge of the Tengger Desert. Soil seed bank density was significantly different in different depth of sand dunes. Under adequate water in Petri dishes, seeds began to germinate in less than 3 h and the germination peak was reached in seven days after watering. It showed that there is no innate dormancy of A. squarrosum. The buried experiments showed that the germination percentage decreased with increasing buried depth, and deeply buried seeds (10 cm) remained ungerminated. Population dynamics in different rainfall pattern of three years in field showed that germination, survival and deaths of A. squarrosum were extremely sensitive to rainfall variation. Our results suggest that precipitation is the key factor in determining population of A. squarrosum. The germination strategy of A. squarrosum ensures the efficiency use of unpredicted and scarce precipitation. The high disturbance of moving sand endowed persistence seed bank of A. squarrosum, which is essential for population continuation, avoiding population extinction under unpredicted precipitation.

Effects of Different Land Use Types and Soil Depths on Soil Mineral Elements, Soil Enzyme Activity, and Fungal Community in Karst Area of Southwest China.

The current research was aimed to study the effects of different land use types (LUT) and soil depth (SD) on soil enzyme activity, metal content, and soil fungi in the karst area. Soil samples with depths of 0-20 cm and 20-40 cm were collected from different land types, including grassland, forest, Zanthoxylum planispinum land, Hylocereus spp. land and Zea mays land. The metal content and enzyme activity of the samples were determined, and the soil fungi were sequenced. The results showed that LUT had a significant effect on the contents of soil K, Mg, Fe, Cu and Cr; LUT and SD significantly affected the activities of invertase, urease, alkaline phosphatase and catalase. In addition, Shannon and Chao1 index of soil fungal community was affected by different land use types and soil depths. Ascomycota, Basidiomycota and Mortierellomycota were the dominant phyla at 0-20 cm and 20-40 cm soil depths in five different land types. Land use led to significant changes in soil fungal structure, while soil depth had no significant effect on soil fungal structure, probably because the small-scale environmental changes in karst areas were not the dominant factor in changing the structure of fungal communities. Additionally, metal element content and enzyme activity were related to different soil fungal communities. In conclusion, soil mineral elements content, enzyme activity, and soil fungal community in the karst area were strongly affected by land use types and soil depths. This study provides a theoretical basis for rational land use and ecological restoration in karst areas.

Sinusoidal electromagnetic field stimulates rat osteoblast differentiation and maturation via activation of NO-cGMP-PKG pathway.

Nitric oxide (NO) is an important intracellular and intercellular messenger, critically affecting bone metabolism. The purpose of this research is to investigate whether the effect of sinusoidal electromagnetic field (SEMF) on the differentiation and maturation of osteoblasts is mediated by the NO-cGMP-PKG signal pathway. We examined the impact of SEMF on nitric oxide synthase (NOS) activity, and found that L-NAME, nitric oxide synthase's inhibitor, prevents SEMF-mediated increase in NOS activity and NO levels. We showed that an inhibitor of soluble guanylyl cyclase (ODQ) blocks the increase in cGMP levels triggered by exposure to SEMF. The inhibitor PDE5, which hydrolyzes 3',5'-cyclic-GMP to 5'-GMP, prevents the SEMF's stimulation of PKG activity. We also blocked the NO-cGMP-PKG pathway to determine whether the maturation and mineralization of osteoblasts, stimulated by SEMF, would be inhibited. This was evaluated by measuring alkaline phosphatase (ALP) activity, osterix gene expression and mineralized bone modulus. After treatment with SEMF, the NOS activity increases in comparison with the control group (P<0.01), reaching the highest level after 0.5h. Osterix gene expression, ALP activity and mineralized bone nodules in the SEMF experimental group also increase significantly. However, these effects are partially blocked in the L-NAME treated cultures. Surprisingly, all the osteogenic markers in the SEMF+L-NAME group were slightly higher than in the control culture, but lower than in the cells exposed to SEMF only. We conclude that the NO-cGMP-PKG signal pathway is activated by SEMF treatment, the stimulatory effect of SEMF on the differentiation and mineralization of osteoblasts is attenuated when the pathway is blocked.

[Effects of icariin on the proliferation, differentiation and maturation of rat calvarial osteoblasts in vitro].

OBJECTIVE: To investigate the effects of icariin on the proliferation, differentiation and maturation of rat calvarial osteoblasts (ROB). METHODS: Segregated neonatal SD rat skull,enzyme digestion to obtain ROB. The culture medium was replaced every three days. Serial subcultivation proceeded when cells covered with 80% culture dish. Icariin was added into the culture at 1 x 10(-4), 1 x 10(-5), 1 x 10(-6), 1 x 10(-7) mol/L respectively. MTT method was adopted in proliferation analysis. The activity of ALP was assayed after 9 days' induced. Optimal concentration icariin was added into the medium, then the osteogenic differentiation markers including mineralized bone nodules, CFU-F(ALP) were compared between the icariin-added group and the control. Total RNA was isolated and the gene expressions of Runx-2 and Osterix were investigated by Real Time RT-PCR. Total protein was also isolated and the secretion of collagen I was examined by Western-blot. RESULTS: The ROB proliferation was inhibited by icariin in a dose-dependent manner. But it evidently led to osteogenic process and maturation. 1 x 10(-5) mol/L was the best concentration. Icariin improved the secretion of collagen I, CFU-F(ALP) amounts and mineralized nodules significantly. It also enhanced the mRNA level of Runx-2 and Osterix. CONCLUSION: The icariin with final concentration of 1 x 10(-5) mol/L can enhance the osteogenic differentiation and maturation of ROB significantly, suggesting that icariin has the activity of inducing bone formation, it has the potential to be developed into a new drug of anti-osteoporosis.

Vegetation richness, species identity and soil nutrients drive the shifts in soil bacterial communities during restoration process.

Soil bacteria play an essential role in functioning of ecosystems and maintaining of biogeochemical cycles. However, little is known about changes in the compositions and functional groups of soil bacterial communities during different restoration stages. The influences of aboveground vegetation and belowground soil properties on soil bacterial communities were also unclear during this process. Here we sequenced the soil bacterial communities in different stages of sand fixation. Sand fixation increased the diversity of the bacterial communities, among which the populations of Actinobacteria, Acidobacteria and Gemmatimonadetes changed significantly. The function prediction showed sand fixation increased Gram-positive and aerobic bacteria. Bacterial structure is significantly correlated with plant richness, coverage and biomass. In particular, we found species identity was an important determinant in structuring bacterial composition. Soil properties were all significantly correlated with soil bacterial community richness and diversity. Fusobacteria was strongly positively correlated with sand, Chloroflexi with total N and Gemmatimonadetes with SOM and total C. It suggested that soil nutrients (TC, TN and SOM) have large consequences for soil bacterial community dissimilarities. These results indicated that vegetation richness, especially species identity, together with improvement in soil nutrients, play key roles in driving the shifts in soil microbial community structure and function during restoration process.

Effects of 1.5 and 4.3 GHz microwave radiation on cognitive function and hippocampal tissue structure in Wistar rats.

Previous studies have shown that single-frequency microwave radiation can lead to cognitive decline in rats. However, few studies have focused on the combined effects of irradiation with different frequencies of microwaves. Our research aimed to investigate the effects of 1.5 GHz and 4.3 GHz microwave radiation, singly and in combination, on cognitive function and hippocampal tissue structure in rats. A total of 140 male Wistar rats were randomly divided into 4 groups: the S group (sham radiation group), L10 group (10 mW/cm2 1.5 GHz group), C10 group (10 mW/cm2 4.3 GHz band group) and LC10 group (10 mW/cm2 1.5 and 4.3 GHz multi-frequency radiation group). For 1-28 days after microwave radiation, we analyzed the average escape latency for the Morris water maze task, electroencephalograms, change in hippocampal tissue structure and ultrastructure, content of the Nissl body in the hippocampus, and activities of lactate dehydrogenase and succinate dehydrogenase. Compared to the S group, all exposure groups showed varying degrees of learning and memory decline and hippocampal structural damage. The results showed that 1.5 GHz and 4.3 GHz microwave radiation was able to induce cognitive impairment and hippocampal tissue damage in rats and combined radiation with both frequencies caused more serious injuries, but none of these damaging effects varied with microwave frequency.

Effects of 50 Hz sinusoidal electromagnetic fields of different intensities on proliferation, differentiation and mineralization potentials of rat osteoblasts.

Electromagnetic fields (EMFs) have been used clinically to slow down osteoporosis and promote fracture healing for many years. However, the underlying action mechanisms and optimal parameters of the EMF applications are unclear. In this study, we investigated the effects of treatment for different durations with 50 Hz sinusoidal electromagnetic fields (SEMFs) at different intensities on proliferation, differentiation and mineralization potentials of rat osteoblasts. Osteoblasts isolated from neonatal rats were treated with SEMFs (50 Hz at 0.9 mT-4.8 mT, 0.3 mT interval, 30 min/day up to 15 days). Compared to untreated control, SEMFs inhibited osteoblast proliferation (after 3 days' treatment) but increased alkaline phosphatase (ALP) activity (after treatment for 9 days) from 0.9 mT to 1.8 mT, declined from 1.8 mT until 3.0 mT, and then increased again from 3.0 mT to 3.6 mT and decreased once again from 3.6 mT to 4.8 mT. Numbers of colonies stained positive for ALP after 8 days and mineralized nodules stained by Alizarin red after 10 days showed the same bimodal tendency as with the ALP activity, with two peaks at 1.8 mT and 3.6 mT. SEMFs also bimodally increased Runx-2, Col1α2 and Bmp-2 mRNA expression levels in osteoblasts at 12, 24 and 96 h after exposure. The results indicated that while exposure to 50 Hz SEMFs inhibits the osteoblast proliferation, it significantly promotes differentiation and mineralization potentials of osteoblasts in an intensity-dependent manner with peak activity at 1.8 mT and 3.6 mT.