Arbuscular mycorrhizal symbiosis regulates physiology and performance of Digitaria eriantha plants subjected to abiotic stresses by modulating antioxidant and jasmonate levels.

This study evaluates antioxidant responses and jasmonate regulation in Digitaria eriantha cv. Sudafricana plants inoculated (AM) and non-inoculated (non-AM) with Rhizophagus irregularis and subjected to drought, cold, or salinity. Stomatal conductance, photosynthetic efficiency, biomass production, hydrogen peroxide accumulation, lipid peroxidation, antioxidants enzymes activities, and jasmonate levels were determined. Stomatal conductance and photosynthetic efficiency decreased in AM and non-AM plants under all stress conditions. However, AM plants subjected to drought, salinity, or non-stress conditions showed significantly higher stomatal conductance values. AM plants subjected to drought or non-stress conditions increased their shoot/root biomass ratios, whereas salinity and cold caused a decrease in these ratios. Hydrogen peroxide accumulation, which was high in non-AM plant roots under all treatments, increased significantly in non-AM plant shoots under cold stress and in AM plants under non-stress and drought conditions. Lipid peroxidation increased in the roots of all plants under drought conditions. In shoots, although lipid peroxidation decreased in AM plants under non-stress and cold conditions, it increased under drought and salinity. AM plants consistently showed high catalase (CAT) and ascorbate peroxidase (APX) activity under all treatments. By contrast, the glutathione reductase (GR) and superoxide dismutase (SOD) activity of AM roots was lower than that of non-AM plants and increased in shoots. The endogenous levels of cis-12-oxophytodienoc acid (OPDA), jasmonic acid (JA), and 12-OH-JA showed a significant increase in AM plants as compared to non-AM plants. 11-OH-JA content only increased in AM plants subjected to drought. Results show that D. eriantha is sensitive to drought, salinity, and cold stresses and that inoculation with AM fungi regulates its physiology and performance under such conditions, with antioxidants and jasmonates being involved in this process.

Combined analysis of copy number alterations by single-nucleotide polymorphism array and MYC status in non-metastatic breast cancer patients: comparison according to the circulating tumor cell status.

Recent technological advances have made it possible to detect circulating tumor cells (CTCs) as a prognostic marker in operable breast cancer patients. Whether the presence of CTCs in cancer patients correlates with molecular alterations in the primary tumor has not been widely explored. We identified 14 primary breast cancer specimens with known CTC status, in order to evaluate the presence of differential genetic aberrations by using SNP array assay. There was a global increase of altered genome, CNA, and copy-neutral loss of heterozygosity (cn-LOH) observed in the CTC-positive (CTC(+)) versus CTC-negative (CTC(-)) cases. As the preliminary results showed a higher proportion of copy number alteration (CNA) at 8q24 (MYC loci) and the available evidence supporting the role of MYC in the processes cancer metastases is conflicting, MYC status was determined in tissue microarray sections in a larger series of patients (n = 49) with known CTC status using FISH. MYC was altered in 62% (16/26) CTC(+) patients and in 43% (6/14) CTC(-) patients (p = 0.25). Based on the observation in our study, future studies involving a larger number of patients should be performed in order to definitively define if this correlation exists.

Fluorescent carbon nanoparticles synthesized from bovine serum albumin nanoparticles.

Fluorescent carbon based-nanoparticles are one of the emerging nanomaterials. Their preparation is relatively simple, rapid and inexpensive, and they are less toxic compared with metal and semiconductor nanoparticles. Here, we report a simple and reliable method to prepare water-soluble fluorescent carbon nanoparticles (FC-NPs) from nanoparticles made from a protein, bovine serum albumin. The obtained mean size of our carbon nanoparticles is between 3.8 and 3.4 nm, and they exhibit its maximum fluorescence emission at 424 and 408 nm respectively (with a reasonable QY of 16.5%) due to the presence of functional groups (NH, NH2, COOH and OH) that contain O and N; the presence of these functional groups was confirmed by FTIR and XPS analysis. The photoluminescent decay lifetime was modeled by a two exponential fit which indicates a contribution from both core and surface states. Also, the preliminary results showed that FC-NPs had a good interaction with HeLa and normal oral epithelial cells; nanoparticles were permeable at the cell membrane and went to the cytosol, and even to the nucleus, in less than 30 min, the fluorescence images of our preliminary results did not show any apparent toxic damage in any of the cell lines.

Metabolite profiling of polyphenols in peels of Citrus limetta Risso by combination of preparative high-speed countercurrent chromatography and LC-ESI-MS/MS.

The polar constituents of peels from Citrus limetta variety Risso (Rutaceae) were investigated by a combination of two complementary chromatographic techniques consisting of preparative high-speed countercurrent chromatography (HSCCC), and off-line LC-ESI-MS/MS analysis to design a two-dimensional metabolite profile. Countercurrent chromatography (CCC) using solely immiscible solvent systems allowed the fractionation of principal components and an enrichment of minor concentrated metabolites from a crude polar solvent partition of C. limetta peels for subsequent structural identification by LC-ESI-MS/MS analysis. The combination of two very different chromatographic techniques resulted in lower detection limits for electrospray mass-spectrometry and revealed eighty-five compounds, including three abscisic acid derivatives, five limonoid glycosides, twenty-six dihydro-cinnamic and cinnamic acid glycosides, eleven flavanone glycosides, seven flavone glycosides, seventeen flavonol glycosides, including limocitrol and limocitrin derivatives. As a chemocharacteristic for C. limetta metabolites, many of the detected structures were linked to single and multiple 3-hydroxy-3-methyl-glutaryl (HMG) substitutions. C. limetta peels are a by-product of juice production, and not only the antioxidant fractions but also some of the fortified compounds could be used for food and pharmaceutical purposes.