Imaging Mass Spectrometry: Hype or Hope?

Imaging mass spectrometry is currently receiving a significant amount of attention in the mass spectrometric community. It offers the potential of direct examination of biomolecular patterns from cells and tissue. This makes it a seemingly ideal tool for biomedical diagnostics and molecular histology. It is able to generate beautiful molecular images from a large variety of surfaces, ranging from cancer tissue sections to polished cross sections from old-master paintings. What are the parameters that define and control the implications, challenges, opportunities, and (im)possibilities associated with the application of imaging MS to biomedical tissue studies. Is this just another technological hype or does it really offer the hope to gain new insights in molecular processes in living tissue? In this critical insight this question is addressed through the discussion of a number of aspects of MS imaging technology and sample preparation that strongly determine the outcome of imaging MS experiments

Phytic acid and phosphorus concentrations in seeds of wheat cultivars grown with and without zinc fertilization

WOS: 000173749600009Seeds of twenty wheat cultivars grown with (+Zn = 23 kg Zn ha(-1)) and without zinc (Zn) fertilization in a Zn-deficient calcareous soil in Central Anatolia were analyzed for the levels of Zn, phosphorus (P), phytic acid, and phytase activity. Additionally, seeds of four wheat cultivars grown on 55 different locations in Turkey were also analyzed for Zn, P, and phytic acid. In the field experiment with 20 wheat cultivars, seed Zn concentrations showed a range between 7 to 11 mg kg(-1) under Zn-deficient and 14 to 23 mg kg(-1) under Zn-added conditions. Zinc fertilization reduced seed concentrations of P and phytic acid of all cultivars. On average, the reductions caused by Zn fertilization were from 3.9 to 3.5 mg g(-1) for P and from 10.7 to 9.1 mg g(-1) for phytic acid. Irrespective of Zn fertilization, seed phytic acid concentrations showed a large genotypic variation, i.e., from 7 to 12 mg g I with Zn fertilization and 8 to 13 mg g I at nil Zn treatment. As a result of decreases in phytic acid and increases in Zn concentrations by Zn fertilization, phytic acid to Zn molar ratios in seeds of cultivars markedly decreased. On average for ail cultivars, phytic acid to Zn molar ratios decreased from 126 to 56 with Zn fertilization. Seed phytase activity of cultivars was not consistently influenced by varied Zn supply. However, on average for 20 cultivars, Zn fertilization tended to decrease phytase activity. In seeds of four wheat cultivars collected from 55 locations, the concentrations of Zn, P, and phytic acid ranged from 8 to 34 mg kg(-1), 2.1 to 4.9 mg g(-1), and 5.8 to 14.3 mg kg(-1), respectively. Results obtained in the present study indicate that seed Zn concentrations of wheat cultivars grown in different locations of Turkey, especially under Zn-deficient conditions, are very low. Considering very high phytic acid: Zn molar ratios it can be suggested that bioavailability of Zn would be very low for humans