Cytogenetic characterization and genome size of the medicinal plant Catharanthus roseus (L.) G. Don

The genome size and organization of the important medicinal plant Catharanthus roseus is shown to correspond to 1C = 0.76 pg (~738 Mbps) and 2n = 16 chromosomes. The data provide a sound basis for future studies including cytogenetic mapping, genomics and breeding

An epifluorescent attachment improves whole-plant digital photography of Arabidopsis thaliana expressing red-shifted green fluorescent protein

Filter cubes made with machine-vision dichroic filters and illuminated with a royal blue light emitting diode can be used to produce an epifluorescent digital camera attachment that improves whole organism green fluorescent protein (GFP) photography. Mean pixel intensity responds linearly to purified GFP titration

Application of synchrotron-radiation-induced TXRF-XANES for arsenic speciation in cucumber (Cucumis sativus L.) xylem sap

Synchrotron-radiation-induced total reflection x-ray fluorescence (SR-TXRF) analysis was used for x-ray absorption near edge structure (XANES) measurements for the speciation of arsenic in cucumber (Cucumis sativus L.) xylem sap. The objective of the presented work was to exploit the advantages of the TXRF geometry for XANES analysis. Measurements were accomplished at the bending magnet beamline L of HASYLAB, Hamburg, Germany, using a Si(111) double crystal monochromator and a silicon drift detector (SDD). Experiments were performed by growing cucumber plants in hydroponics containing arsenite [As(III)] or arsenate [As(V)] in order to identify the arsenic species of the collected xylem saps by K-edge SR-TXRF XANES. Cucumber xylem saps, as well as nutrient solutions containing arsenic in the two above-mentioned species, were analyzed and compared with arsenate and arsenite standard solutions. Arsenic speciation in xylem sap down to 30 ng/ml (30 ppb) was achieved, and no alteration of the oxidation state was observed during the measurements. Analysis of xylem saps showed that As(V) taken up from the nutrient solution was reduced to As(III). As(III) contained in the nutrient solutions was found to be partially oxidized to As(V). These results confirmed the preliminary measurements obtained with flow injection analysis (FIA) and high-performance liquid chromatography-high resolution inductively coupled plasma mass spectrometry (HPLC-HR-ICP-MS) and showed the competitive capability of SR-TXRFXANES analysis for this application