Indole Alkaloid Formation and Storage in Cell Suspension Cultures of Catharanthus roseus

The localization and storage of alkaloids were investigated in a low producing cell suspension culture of CATHARANTHUS ROSEUS(L.) G. Don. (Apocynaceae). Fluorescence microscopy and electron microscopy indicate alkaloid accumulation to occur inside the vacuoles of particular cells. These alkaloid storage cells exhibit a vacuolar pH of 3, while "normal" cells of a suspension culture have a vacuolar pH of about 5. Alkaloids are taken up in their unprotonated forms, trapped by protonation inside the vacuole and are accumulated there. The differentiation of alkaloid storage cells depends both on the cell line and the growth conditions and seems to be a prerequisite for the accumulation of alkaloids in cell suspension cultures of CATHARANTHUS ROSEUS.

Cryopreservation of Digitalis lanata cell cultures

Suspension cultures of Digitalis lanata strain I were grown in a medium containing 3% mannitol. For cryopreservation cell suspensions were treated with a mixture of sucrose-glycerol (20%/20 V%), cooled slowly (about 1 degrees C/min) till -100 degrees C and then were transferred to liquid nitrogen. After storage in liquid nitrogen the cells were thawed rapidly in a water bath of 40 degrees C and spread on the surface of a solidified nutrient medium. After 7 days of regrowth the cells were suspended in liquid nutrient medium for further cultivation. About 50% of the cells survived freezing and thawing. However, also the apparently surviving cells showed signs of injury (membrane vesicles outside the plasmalemma, dilated ER cisternae and separation of the nuclear membranes). The cultures derived from the surviving cells had the same growth rate and biochemical activity relative to the transformation of cardenolides, e.g., digitoxin, as the parent cultures. The frequency distribution of the nuclear DNA content in the cell cultures was the same before and after cryopreservation. These results indicate that there is no selection of a special cell type during freezing and thawing.

Electron microscopic immunocytochemical localization of storage proteins in Vicia faba seeds

The main storage proteins legumin and vicilin were located by immuno-labeling with protein A-gold in formaldehyde fixed tissues of Vicia faba seeds at different developmental stages. Both proteins were found to be accumulated together in the same protein bodies. Besides these organelles only the rough endoplasmic reticulum (ER) is labeled in particular developmental stages of the cotyledons. A fraction of proteins accumulated in the vacuoles at earlier stages of development also represents storage proteins. Besides the formation of protein bodies by the ER a second route of origination from vacuoles is proposed for Vicia faba seeds at early developmental stages.

Changes in cytoplasmic ultrastructure during submerged cultivation of a peptide alkaloids-producing strain of Claviceps purpurea (Fr.) Tul

A strain of Claviceps purpurea, designated Pepty 695/S produces ergotoxine alkaloids under particular conditions of fermentation. The onset of alkaloid synthesis occurs around the second day of cultivation. Alkaloid formation is connected with morphological and ultrastructural changes. In the first 3-5 days of cultivation short thickened, septated hyphae, organized in plectenchymatic pellets as well as large single cells are formed. The hyphae are ultrastructurally characterized by increasing number of lipid droplets, deposits of glycogen and by extended ER membranes, which apparently may form numerous vesicles. The correlations between lipid and alkaloid synthesis are discussed.

Synthesis of ribosomal RNA in ribosome-deficient plastids of the mutant "albostrians" of Hordeum vulgare L

The nuclear gene-induced plastome mutant "albostrians" of Hordeum vulgare L. is characterized by a plastid ribosome-deficiency. This ribosome deficiency could be caused by the lack of or a defect in chloroplast RNA polymerase. However in our investigations we found an activity of chloroplast RNA polymerase in wild-type and mutant leaves of "albostrians" barley by (1) electron microscopic autoradio-graphy after in vivo labelling of RNA, (2) determination of RNA polymerase activity in isolated plastids, and (3) characterization of the newly synthesized RNA by electrophoresis in polyacrylamide gels. The genes of 23S and 16S rRNA are transcribed in mutant plastids and the RNAs are processed. From these results we conclude that the enzymes involved in transcription and processing of chloroplast rRNA are synthesized on cytoplasmic ribosomes and that the plastid ribosome deficiency in albostrians barley is probably not caused by a defective chloroplast DNA dependent RNA polymerase or by a mutation in the genes of 23S and 16S chloroplast rRNA.

An overview of neurogenic pulmonary edema

It is hoped that this presentation has increased the knowledge and understanding of the neurogenic pulmonary edema syndrome. Each of us should now be more aware of the potential for development of this complication in patients admitted with head trauma. Through increased awareness, knowledge, and understanding, we are better equipped to meet the challenge presented to us by these patients and to deliver the high-quality nursing care essential to their recovery.

[Optimized treatment planning in 60Co therapy: application of a schedule for irradiation of the lateral lymphatic areas of the neck by means of a programmable pocket computer (author's transl)]

The present program for irradiation of the lymphatics at the neck is yielding good results with reasonable expenditure. The shape of the neck can be shown not to influence the isodose curves. Thus, it is possible to use a programmable pocket computer for calculation of the irradiation. An appropriate scheme has been established.

Effect of gibberellic acid on the ion ratios in a dwarf maize mutant (Zea mays L. d1) : An electron microprobe study

The effect of gibberellic acid (GA3) on ion ratios in a dwarf maize mutant (Zea mays L. d1) exhibiting normal growth after hormone treatment has been investigated by electron microprobe analysis. Gibberellic-acid treatment increased the ion content in chloroplasts and vacuoles whereas no change of the ion content was found in the cytoplasm. The relation of these observations to the action of the hormone is discussed.

Early responses to gibberellic acid in a dwarf maize mutant (Zea mays L. d 1)

Early effects of gibberellic acid (GA3) (1-4 h treatment) on the ion ratios in a dwarf maize mutant (Zea mays L. d 1) showing normal growth after hormone treatment, have been investigated by electron microprobe analysis. GA3 exerts a different effect on the ion ratios in plastids, cytoplasm and vacuoles in short term experiments. The Cl content of chloroplasts and cytoplasm increases without a lag phase after GA3 treatment. The K content of plastids increases after a lag phase of 2 h, whereas in the cytoplasm an increase can be observed immediately after GA3 addition. The hormone has only little influence on the Ca content of the cell compartments investigated. Control experiments with water and the physiologically inactive GA3 methylester confirm the specifity of the short-term actions of GA3 on the ion ratios. The primary action of GA3 at the membrane level is discussed.

Valence Resonance States of N 2 -

Resonance valence excited states of N 2 - are calculated and used to interpret resonant excitation of the A and B states of N₂ by electron impact.