Transcriptome and metabolite profiling reveals the effects of Funneliformis mosseae on the roots of continuously cropped soybeans.

BACKGROUND: Arbuscular mycorrhizal fungi are the most widely distributed mycorrhizal fungi, which can form mycorrhizal symbionts with plant roots and enhance plant stress resistance by regulating host metabolic activities. In this paper, the RNA sequencing and ultra-performance liquid chromatography (UPLC) coupled with tandem mass spectrometry (MS/MS) technologies were used to study the transcriptome and metabolite profiles of the roots of continuously cropped soybeans that were infected with F. mosseae and F. oxysporum. The objective was to explore the effects of F. mosseae treatment on soybean root rot infected with F. oxysporum. RESULTS: According to the transcriptome profiles, 24,285 differentially expressed genes (DEGs) were identified, and the expression of genes encoding phenylalanine ammonia lyase (PAL), trans-cinnamate monooxygenase (CYP73A), cinnamyl-CoA reductase (CCR), chalcone isomerase (CHI) and coffee-coenzyme o-methyltransferase were upregulated after being infected with F. oxysporum; these changes were key to the induction of the soybean's defence response. The metabolite results showed that daidzein and 7,4-dihydroxy, 6-methoxy isoflavone (glycine), which are involved in the isoflavone metabolic pathway, were upregulated after the roots were inoculated with F. mosseae. In addition, a substantial alteration in the abundance of amino acids, phenolic and terpene metabolites all led to the synthesis of defence compounds. An integrated analysis of the metabolic and transcriptomic data revealed that substantial alterations in the abundance of most of the intermediate metabolites and enzymes changed substantially under pathogen infection. These changes included the isoflavonoid biosynthesis pathway, which suggests that isoflavonoid biosynthesis plays an important role in the soybean root response. CONCLUSION: The results showed that F. mosseae could alleviate the root rot caused by continuous cropping. The increased activity of some disease-resistant genes and disease-resistant metabolites may partly account for the ability of the plants to resist diseases. This study provides new insights into the molecular mechanism by which AMF alleviates soybean root rot, which is important in agriculture.

Transcriptomic and Proteomic Analysis Revealed the Effect of Funneliformis mosseae in Soybean Roots Differential Expression Genes and Proteins.

Glycine max is easily infected with root rot in continuous cropping systems, which can severely affect crop yield. Arbuscular mycorrhizal fungi (AMF) can reduce the incidence of root rot and increase plant height and biomass indices. However, the molecular changes that occur during soybean symbiosis with AMF remain largely unknown. To better understand the molecular mechanism underlying soybean symbiosis with AMF, we performed transcriptomic and proteomic analyses to explore the changes in protein expression during a high-incidence period (79 days) in asymbiotic and symbiotic plants and to identify the key proteins that regulate the mechanism of soybean symbiosis with AMF. A total of 10 104 genes were identified in the CK-vs-F comparison, and 11 562 genes were significantly differentially expressed in the AF group compared with the F group. A total of 9488 proteins were identified, with 256 differentially expressed proteins (DEPs) in the CK-vs-F comparison and 651 DEPs in the F-vs-AF comparison. Key pathways and DEPs were found to be involved in processes associated with "phenylalanine metabolism", "plant hormone signal transduction", "plant-pathogen interaction", and "metabolic pathways". The expression of phenylalanine ammonia-lyase (PAL), calcium-dependent protein kinase (CPK), and other defense-related proteins was upregulated by Funneliformis mosseae, indicating that inoculation promotes the development of soybean and increases disease resistance. Our results suggest that symbiosis promotes the growth and development of soybean and increases disease resistance. This study provides new insight into the molecular basis of the mechanism by which AMF affect plant disease resistance.

iTRAQ Proteomic Analysis of Continuously Cropped Soybean Root Inoculated With Funneliformis mosseae.

Soybean (Glycine max) is susceptible to root rot when subjected to continuous cropping, and this disease can seriously diminish the crop yield. Proteomics analyses can show the difference of protein expression in different treatment samples. Herein, isobaric tag for relative and absolute quantitation (iTRAQ) labeling and liquid chromatography-tandem mass spectrometry (LC-MS/MS) were employed for proteomic analysis of continuously cropped soybean inoculated with the arbuscular mycorrhizal fungus (AMF) Funneliformis mosseae. The AMF can reduce the incidence of root rot and increase plant height, biomass index in 1, 2, and 4 year of continuous cropping. Differential expression of proteins in soybean roots was determined following 1 year of continuous cropping. A total of 131 differentially expressed proteins (DEPs) were identified in F. mosseae-treated samples, of which 49 and 82 were up- and down-regulated, respectively. The DEPs were annotated with 117 gene ontology (GO) terms, with 48 involved in biological processes, 31 linked to molecular functions, and 39 associated with cell components. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis mapped the DEPs to 113 mainly metabolic pathways including oxidative phosphorylation, glycolysis, and amino acid metabolism. Expression of glucan 1,3-beta-glucosidase, chalcone isomerase, calcium-dependent phospholipid binding and other defense-related proteins was up-regulated by F. mosseae, suggesting inoculation promotes the growth and development of soybean and increases disease resistance. The findings provide an experimental basis for further research on the molecular mechanisms of AMF in resolving problems associated with continuous soybean cropping.

Effects of Funneliformis mosseae on Root Metabolites and Rhizosphere Soil Properties to Continuously-Cropped Soybean in the Potted-Experiments.

Continuous cropping in soybean is increasingly practiced in Heilongjiang Province, leading to substantial yield reductions and quality degradation. Arbuscular mycorrhizal fungi (AMF) are soil microorganisms that form mutualistic interactions with plant roots and can restore the plant rhizosphere microenvironment. In this study, two soybean lines (HN48 and HN66) were chosen as experimental materials, which were planted in different years of continuous cropping soybean soils and were inoculated or not with Funneliformis mosseae in potted-experiments. Ultimately, analysis of root tissue metabolome and root exudates, soil physicochemical properties, plant biomass, as well as rhizosphere soil properties in different experimental treatments, inoculated or not with F. mosseae, was performed. Experimental results showed that: (a) The disease index of soybean root rot was significantly lower in the treatment group than in the control group, and there were differences in disease index and the resistance effect of F. mosseae between the two cultivars; (b) compared with the control, the root tissue metabolome and root exudates remained unchanged, but there were changes in the relative amounts in the treatment group, and the abundant metabolites differed by soybean cultivar; (c) soybean biomass was significantly higher in the treatment group than in the control group, and the effect of F. mosseae on biomass differed with respect to the soybean cultivar; and (d) there were differences in the physiochemical indexes of soybean rhizosphere soil between the treatment and control groups, and the repairing effect of F. mosseae differed between the two cultivars. Therefore, F. mosseae can increase the biomass of continuously cropped soybean, improve the physicochemical properties of the rhizosphere soil, regulate the root metabolite profiles, and alleviate barriers to continuous cropping in potted-experiments of soybean.

Reversible switching of magnetic states by electric fields in nitrogenized-divacancies graphene decorated by tungsten atoms.

Magnetic graphene-based materials have shown great potential for developing high-performance electronic devices at sub-nanometer such as spintronic data storage units. However, a significant reduction of power consumption and great improvement of structural stability are needed before they can be used for actual applications. Based on the first-principles calculations, here we demonstrate that the interaction between tungsten atoms and nitrogenized-divacancies (NDVs) in the hybrid W@NDV-graphene can lead to high stability and large magnetic anisotropy energy (MAE). More importantly, reversible switching between different magnetic states can be implemented by tuning the MAE under different electric fields, and very low energy is consumed during the switching. Such controllable switching of magnetic states is ascribed to the competition between the tensile stain and orbital magnetic anisotropy, which originates from the change in the occupation number of W-5d orbitals under the electric fields. Our results provide a promising avenue for developing high-density magnetic storage units or multi-state logical switching devices with ultralow power at sub-nanometer.

miR­494 is an independent prognostic factor and promotes cell migration and invasion in colorectal cancer by directly targeting PTEN.

Accumulating evidence has shown that micro-RNAs (miRNAs) are involved in multiple processes in cancer development and progression. Upregulation of miRNA-494 (miR-494) has been identified as an oncogenic miRNA and is associated with poor prognosis in several types of human cancer. However, the specific function of miR-494 in colorectal cancer remains unclear. In this study we found that the expression of miR-494 in colorectal cancer tissues and cell lines was much higher than in normal control tissues and cells, respectively. In addition, upregulation of miR-494 more frequently occurred in tissue specimens with adverse clinical stage and the presence of distant metastasis. Moreover, multivariate survival analyses demonstrated that overexpression of miR-494 is an independent prognostic factor for both progression-free and overall survival. In addition miR-494 promoted invasion and migration in colorectal cancer cells, and miR-494 directly inhibited the phosphatase and tensin homolog deleted on chromosome 10 (PTEN) expression by targeting its 3'-untranslated region (3'-UTR). Moreover, PTEN is down regulated and inversely correlated with miR-494 expression in tissues. Thus, for the first time, we provided convincing evidence that upregulation of miR-494 was associated with tumor aggressiveness and tumor metastasis and promoted cell migration and invasion by targeting PTEN gene in colorectal cancer, and miR-494 is an independent prognostic marker for colorectal cancer patients.

Angiotensin II receptor type 1 blockers suppress the cell proliferation effects of angiotensin II in breast cancer cells by inhibiting AT1R signaling.

Chronic stress and a high-fat diet are well-documented risk factors associated with the renin-angiotensin system in the development of breast cancer. The angiotensin II type 1 receptor (AT1R) is a novel component of the renin-angiotensin system. Several recent studies have focused on the function of AT1R in cell proliferation during cancer development. Thus, we hypothesized that angiotensin II (Ang Ⅱ) can promote proliferation of breast cancer via activated AT1R; the activation of AT1R may play an important role in promoting breast cancer growth, and AT1R blocker (ARB) may suppress the promotional effect on proliferation by antagonizing AT1R. The expression level of AT1R was found to be significantly upregulated in breast cancer cells by immunohistochemistry, but no correlation between AT1R expression and ER/PR/Her-2 expression was observed. The AT1R(+)-MCF-7 cell line exhibited high expression of AT1R protein, and we generated the AT1R(-)-MCF-7 cell line using RNA interference. ARBs, and in particular irbesartan, effectively inhibited the effects of Ang II on cell proliferation, cell cycle development and downstream AT1R signaling events, including the activation of the Ras-Raf-MAPK pathway and the transcription factors NF-κB and CREB. Irbesartan also significantly altered p53, PCNA and cyclin D1 expression, which was also influenced by activated AT1R in AT1R(+)-MCF-7 cells. These results suggest that ARBs may be useful as a novel preventive and therapeutic strategy for treating breast cancer.

[Role of oxidative stress and thioredoxin in gastric cancer].

OBJECTIVE: To explore the role of oxidative stress and the antioxidant protein thioredoxin in the tumorigenesis and progression of gastric cancer. METHODS: The plasma levels of adenosine deaminase (ADA), glutathione peroxidase (GPX), superoxide dismutase (SOD), and advanced oxidation protein products (AOPP) were determined by colorimetry, and the plasma levels of thioredoxin were determined by enzyme-linked immunosorbent assay (ELISA) in 48 gastric cancer patients and 30 healthy subjects. RT-PCR assay was employed to examine the expression levels of thioredoxin mRNA in the tissue samples of the patients. RESULTS: Compared with the healthy controls, patients with gastric cancer had significantly increased plasma levels of ADA and AOPP (P<0.05), decreased plasma GPX level (P<0.05), and similar plasma SOD levels. The plasma levels of thioredoxin were significantly higher in patients with gastric cancer than in the healthy controls (P<0.05). Thioredoxin levels was not associated with gender, age, degree of tumor cell differentiation, invasion depth, or lymph node metastasis (P>0.05), but was correlated to distant tumor metastasis (P<0.05). The expression of Trx mRNA was significantly higher in gastric carcinoma than in normal gastric tissue (P<0.05). CONCLUSION: Gastric cancer patients have high levels of oxidative stress and thioredoxin expression, and the latter is related to distant metastasis of the tumor.