Influence of location and fertilization on antioxidant acitivity in highbush blueberries (Vaccinium corymbosum L.)

Highbush blueberry cultivars ‘Bluecrop’ and ‘Reka’ were growing in two variants of mulching and fertilizing systems on formerly used farmland. Fruits were harvested at two picking dates and analyzed for their content of phenolic compounds and antioxidant activity. These data were compared with samples of two forest soil locations from the Brandenburg region (Beelitz and Klaistow). The results showed significant differences between cultivars, both harvest times and different locations. The variations in fertilization and ground cover (with or without mulch) showed significant differences. Moreover, it is demonstrated that without ground cover and commercial fertilization higher contents of total phenolic compounds and an increase in antioxidant activity tendentiously occurred. This result paralleled the decline in vegetative growth and was associated with drought stress

UV-B induced changes of phenol composition and antioxidant activity in black currant fruit (Ribes nigrum L.)

Information on UV-B elicitor mediated changes on phenolic composition and antioxidant activity of black currant (Ribes nigrum L.) are scanty. In the present study physiological ripe black currant fruits were harvested and exposed to UV-B radiation with different exposure and adaptation times. The influence of UV-B on phenolic profile and quantitative composition as well as on the corresponding antioxidant activity was investigated. Antioxidant activity was screened with electron spin resonance spectrometry (ESR), while phenolic compound composition was conducted by HPLC analysis. Total phenol content and phenolic composition (flavonols, anthocyanins, hydroxycinnamic and hydroxybenzoic acids) increased to a large extent during UV-B treatment, irrespective of the adaptation time. Anthocyanins are concluded to absorb UV radiation within a short time, meanwhile flavonols and phenolic acids are assumed to have an impact on antioxidant protection of UV-B mediated tissue damage. Moreover, antioxidant activity significantly correlated with different phenolic compounds and increased to a similar extent by UV-B exposure

Cryptic speciation in pan-tropical sea urchins: a case study of an edge-of-range population of Tripneustes from the Kermadec Islands

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Technical Aspects for the Evaluation of Circulating Nucleic Acids (CNAs): Circulating Tumor DNA (ctDNA) and Circulating MicroRNAs

Circulating nucleic acids (CNAs), for example, circulating tumor DNA (ctDNA) and circulating microRNA (miRNA), represent promising biomarkers in several diseases including cancer. They can be isolated from many body fluids, such as blood, saliva, and urine. Also ascites, cerebrospinal fluids, and pleural effusion may be considered as a source of CNAs, but with several and intrinsic limitations. Therefore, blood withdrawal represents one of the best sources for CNAs due to the very simple and minimally invasive way of sampling. Moreover, it can be repeated at different time points, giving the opportunity for a real-time monitoring of the disease

Efficient preparation of Arabidopsis pollen tubes for ultrastructural analysis using chemical and cryo-fixation

The pollen tube (PT) serves as a model system for investigating plant cell growth and morphogenesis. Ultrastructural studies are indispensable to complement data from physiological and genetic analyses, yet an effective method is lacking for PTs of the model plant Arabidopsis thaliana. Methods: Here, we present reliable approaches for ultrastructural studies of Arabidopsis PTs, as well as an efficient technique for immunogold detection of cell wall epitopes. Using different fixation and embedding strategies, we show the amount of PT ultrastructural details that can be obtained by the different methods. Results: Dozens of cross-sections can be obtained simultaneously by the approach, which facilitates and shortens the time for evaluation. In addition to in vitro-grown PTs, our study follows the route of PTs from germination, growth along the pistil, to the penetration of the dense stylar tissue, which requires considerable mechanical forces. To this end, PTs have different strategies from growing between cells but also between the protoplast and the cell wall and even within each other, where they share a partly common cell wall. The separation of PT cell walls in an outer and an inner layer reported for many plant species is less clear in Arabidopsis PTs, where these cell wall substructures are connected by a distinct transition zone. Conclusions: The major advancement of this method is the effective production of a large number of longitudinal and cross-sections that permits obtaining a detailed and representative picture of pollen tube structures in an unprecedented way. This is particularly important when comparing PTs of wild type and mutants to identify even subtle alterations in cytoarchitecture. Arabidopsis is an excellent plant for genetic manipulation, yet the PTs, several-times smaller compared to tobacco or lily, represent a technical challenge. This study reveals a method to overcome this problem and make Arabidopsis PTs more amenable to a combination of genetic and ultrastructural analyses

Identification of Mouse Serum miRNA Endogenous References by Global Gene Expression Profiles

MicroRNAs (miRNAs) are recently discovered small non-coding RNAs and can serve as serum biomarkers for disease diagnosis and prognoses. Lack of reliable serum miRNA endogenous references for normalization in miRNA gene expression makes single miRNA assays inaccurate. Using TaqMan® real-time PCR miRNA arrays with a global gene expression normalization strategy, we have analyzed serum miRNA expression profiles of 20 female mice of NOD/ShiLtJ (n = 8), NOR/LtJ (n = 6), and C57BL/6J (n = 6) at different ages and disease conditions. We identified five miRNAs, miR-146a, miR-16, miR-195, miR-30e and miR-744, to be stably expressed in all strains, which could serve as mouse serum miRNA endogenous references for single assay experiments