Carotenoid Distribution in Living Cells of Haematococcus pluvialis (Chlorophyceae)

Haematococcus pluvialis is a freshwater unicellular green microalga belonging to the class Chlorophyceae and is of commercial interest for its ability to accumulate massive amounts of the red ketocarotenoid astaxanthin (3,3′-dihydroxy-β,β-carotene-4,4′-dione). Using confocal Raman microscopy and multivariate analysis, we demonstrate the ability to spectrally resolve resonance–enhanced Raman signatures associated with astaxanthin and β-carotene along with chlorophyll fluorescence. By mathematically isolating these spectral signatures, in turn, it is possible to locate these species independent of each other in living cells of H. pluvialis in various stages of the life cycle. Chlorophyll emission was found only in the chloroplast whereas astaxanthin was identified within globular and punctate regions of the cytoplasmic space. Moreover, we found evidence for β-carotene to be co-located with both the chloroplast and astaxanthin in the cytosol. These observations imply that β-carotene is a precursor for astaxanthin and the synthesis of astaxanthin occurs outside the chloroplast. Our work demonstrates the broad utility of confocal Raman microscopy to resolve spectral signatures of highly similar chromophores in living cells

Pharmazeutisch biologische Untersuchungen der Gattung Harpagophytum (Bruch.) DC ex Meissn.

Comparing the analytical results of the constituants of naturally growing roots and callus of Harpagophytum procumbens, it could be demonstrated that both, the products of the primary and the secondary metabolism, showed important differences. Harpagosid which is present in significant amounts in the roots and tubers of the fresh plants, was shown to be completely absent in the callus. Stachyose the main reserve carbohydrate again was only produced in minor amounts. Fructose was the predominant sugar in the callus cells

Fructan Synthesis in Tissue Cultures of Symphytum officinale

Tissue cultures originating from different organs i.e. leaves, leaf-stalks, ovaries, anthers, and roots of Symphytum officinale were initiated under various growth conditions and subcultured several times to give the first callus generation. From all these calli, whole plants could be regenerated which again were used for the preparation of tissue cultures resulting in the formation of the second callus generation. The different calli and the regenerated plants were analyzed with respect to the fructan-synthesizing capacity. Only calli derived from the leaves of the original plant synthesized fructan whereas calli derived from ovaries, anthers, and roots, which are known to contain large amounts of fructan, were not capable of synthesizing fructan. The regenerated plants obtained from the first callus generation showed ability for fructan synthesis only if the originating callus synthesized fructan. The calli of the second generation, which were prepared from fructan-containing leaves and roots of regenerated plants, showed the capacity for fructan formation. The calli of the second generation obtained from leaves and roots of regenerated, fructan-free plants were not able to synthesize this specific reserve polysaccharide. From these data it can be concluded that the calli of the first generation prepared from roots, ovaries, and anthers have lost their ability for fructan synthesis. Calli initiated from leaves and leaf-stalks preserved the capacity for fructan formation even after many calli generations and regeneration to entire plants. Different phytohormones used in the tissue cultures had only a slight effect upon the fructan formation. An influence of light on fructan synthesis could not be detected