Cholinesterase activity in some species of theAllium genus

In partly purified protein complexes obtained from 22 species of theAllium genus and 6 cultivars ofAllium cepa the activity of cholinesterases was detected and measured using the method of Ellman et al. The degree of its inhibition with 10^-4 M neostigmine was also tested. It was found that the activity of cholinesterase differed in individual species up to two hundred times, while the differences in the inhibitory activity of 10^-4 M neostigmine occurred only in a few cases. Individual sections and cultivars could not be characterized on the basis of the differences in the activities of the cholinesterases. Of all the sections that ofPhyllodolon shows the highest average activity. In the case of the tested cultivars distinctly the lowest activity was observed in cv. Kastická. The values of the enzymatic activity measured by Ellman’s method in this plant material include the activity of specific and unspecific cholinesterases and the part uninhibitable by neostigmine.     

Developmental changes in gene expression during pollen differentiation and maturation inNicotiana tabacum L

Total and polysome-bound ribosomes and the uptake and incorporation of³H-uridine and¹⁴C-leucine were examined in dividing microspores and in pollen grains isolated from anthers of 6 different developmental stages. Direct evidence was obtained that the formation of cytoplasm of the vegetative cell following microspore division is related to a rapid activation of RNA and protein synthesis and of ribosomes in differentiating pollen. Total ribosomes associated with gametophytic programme rose about 10times and the process of differentiation was accompanied by a rapid increase in uptake capacity of pollen grains for both uridine and leucine. Pollen development after cytoplasm synthesis and starch deposition continued by pollen maturation, which was characterized by a decline in RNA synthesis, dissociation of polysomes and by a further rise of transport activity of pollen grain wall for exogenous substrates, indicating probable pollen adaptation for utilization of metabolites from the degenerating tapetal cytoplasm.     

The comparison of seed protein patterns within the genusArachis by polyacrylamide gel electrophoresis

The seed protein patterns of 12Arachis species were compared by polyacrylamide gel electrophoresis (PAGE), similarities between patterns were measured by the Jaccard index. Results obtained confirm the close relationships established between members of the genus on morphological grounds and support the more recent classification schemes.A. villosa andA. correntina could well be regarded as distinct species on grounds of protein differences whileA. macedoi andA. villosulicarpa (although members of the same section, Extranervosae) show considerable differentiation of their protein patterns. Surprisingly, the formA. ×batizogaea showed less similarity in protein pattern to those of its parental species than might have been expected. The principle value of seed protein pattern data appears to be in distinguishing species within sections.     

Translation of poly(U) on ribosomes from Streptomyces aureofaciens

Slowly cooled cells of Streptomyces aureofaciens contained mainly tight-couple ribosomes. Maximum rate of polyphenylalanine synthesis on ribosomes of S. aureofaciens was observed at 40°C, while cultures grew optimally at 28°C. Ribosomes of S. aureofaciens differed from those of E. coli in the amount of poly(U) required for maximum synthetic activity. The polyphenylalanine-synthesizing activity of E. coli ribosomes was about 3-times higher than that of S. aureofaciens ribosomes. The addition of protein S1 of E. coli or the homologous protein from S. aureofaciens had no stimulatory effect on the translation of poly(U). In order to localize alteration(s) of S. aureofaciens ribosomes in the elongation step of polypeptide synthesis we developed an in vitro system derived from purified elongation factors and ribosomal subunits. The enzymatic binding of Phe-tRNA to ribosomes of S. aureofaciens was significantly lower than the binding to ribosomes of E. coli. This alteration was mainly connected with the function of S. aureofaciens 50 S subunits. These subunits were not deficient in their ability to associate with 30 S subunits or with protein SL5 which is homologous to L7/L12 of E. coli.     

Steroid anaesthesia: alphadione depresses multiunit activity in the mesencephalic reticular formation

Cortical EEG and multiunit activity (MUA) of the mesencephalic reticular formation (MRF), area hypothalami anterior (AH) and the nucleus amygdalae basalis (AMY) were studied before and after different doses of alphadione (Althesin) and hexobarbitone (Evipan-Natrium) given to cats with chronically implanted electrodes. Non-anaesthetic doses of alphadione (0.15 ml/kg; 0.3 ml/kg; 0.6 ml/kg and 1.2 ml/kg i.p.) had sedative effects decreasing selectively the MUA in the MRF. In doses of 2.0 ml/kg, 2.4 ml/kg and 3.0 ml/kg i.p., alphadione induced anaesthesia which was associated with a rapid decrease of MUA in the MRF and by a gradual decrease of activity in the AH and AMY. The i.p. dose of 3.0 ml/kg abolished MUA responses of the reticular formation to acoustic, visual and somatic stimulation but failed to block responses to pain. Deep anaesthesia with lasting analgesia could be maintained by i.v. infusion (0.075 ml/kg/min). This procedure blocked the responsiveness to painful stimulation while pharyngeal and laryngeal reflexes were maintained. Hexobarbitone in a dose of 20.0 mg/kg i.p. did not produce anaesthesia in the cat. Administration of 40.0 mg/kg i.p. resulted in a rapid decrease of MUA in the MRF, AH and AMY, MUA responses to each stimulation were abolished and the pharyngeal reflex was blocked.     

Annotated chromosome counts of czechoslovak plants (31–60) (Materials for “Flóra ČSSR”—3)

Chromosome counts of the following 30 taxa (106 populations) are given:Betonica officinalis (2n=16);Bidens frondosus (2n=48);Calamagrostis arundinacea (2n=28+0–2B);Dianthus carthusianorum subsp.latifolius (2n=30);Festuca gigantea (2n=42, 42+2B);Hypericum perforatum (2n=32);Koeleria macrantha (2n=28);Kohlrauschia prolifera (2n=30);Lilium martagon (2n=24+0–2B);Melica ciliata (2n=18);Poa remota (2n=14);Ranunculus polyanthemos (2n=16);R. sardous subsp.sardous (2n=16);Roegneria canina (2n=28+0–1B);Rudbeckia laciniata (2n=76);Scabiosa canescens (2n=16);Serratula tinctoria (2n=22);Seseli elatum subsp.heterophyllum var.beckii (2n=18);S. hippomarathrum (2n=20);Thlaspicaerulescens caerulescens subsp.tatrense (2n=14);Trifolium alpestre (2n=16);T. avense (2n=14);T. medium (2n=79, 80+0–2B, 82);T. rubens (2n=16);Veronica officinalis subsp. alpestris (2n=36);Vincetoxicum hirundinaria (2n=22);Vulpia bromoides (2n=14);Zerna benekenii (2n=28)Z. monoclada (2n=28+0–8B);Z. ramosa (2n=42). Remarks on taxonomy, nomenclature and chorology for some of these taxa are given.     

Significance of various nitrogen sources for calcium deficient seedlings ofCucurbita pepo L.

The aim of the present investigation was to examine whether some of the growth defects of calcium-deficient pumpkin (Cucurbita pepo L.) seedlings are due to an incapability of the plants to assimilate nitrate nitrogen, such being the mechanism by which according to some of the previous authors growth defects in calcium deficient plants may be produced. The results of the present study, however, demonstrate that the accessibility of various possible products of nitrate reduction is not the limiting factor responsible for growth symptoms of calcium deficiency.