Physical conditions of propagation media and their influence on the rooting of cuttings

Summary The formation and subsequent growth of roots by cuttings of poinsettia, hydrangea, rose and azalea in various propagation media, Jiffy-7, Jiffy-9 and Grodan under different conditions of aeration was investigated. The interrelationships of the effects of air content of the media, temperature and light intensity on the rooting of poinsettia cuttings was also studied.With low air contents (0 cm moisture tension) in the propagation media the formation and growth of roots was strongly inhibited. The rooting performance of rose appeared to be less affected by the poor aeration. Increasing air content improved rooting but best results were obtained at moisture tensions of 4 to 8 cm. Rooting seems to be better correlated with oxygen diffusion rate (ODR) than with air content.For poinsettia cuttings the optimum temperature for rooting was 24 to 28°C. At low temperatures rooting was delayed while at higher temperatures it was almost completely inhibited. Callus formation increased with temperature but decreased with increasing moisture tension. Conditions which induced large callus formation inhibited root formation.High light intensity during rooting reduced overall rooting performance and the inhibition was most pronounced in conjunction with high moisture tensions.Report No. 255.     

Na+, Cl− cotransport in Ehrlich ascites tumor cells activated during volume regulation (regulatory volume increase)

Ehrlich ascites cells were preincubated in hypotonic medium with subsequent restoration of tonicity. After the initial osmotic shrinkage the cells recovered their volume within 5 min with an associated KCl uptake. The volume recovery was inhibited when NO-3 was substituted for Cl-, and when Na+ was replaced by K+, or by choline (at 5 mM external K+). The volume recovery was strongly inhibited by furosemide and bumetanide, but essentially unaffected by DIDS. The net uptake of Cl- was much larger than the value predicted from the conductive Cl- permeability. The undirectional 36Cl flux, which was insensitive to bumetanide under steady-state conditions, was substantially increased during regulatory volume increase, and showed a large bumetanide-sensitive component. During volume recovery the Cl- flux ratio (influx/efflux) for the bumetanide-sensitive component was estimated at 1.85, compatible with a coupled uptake of Na+ and Cl-, or with an uptake via a K+,Na+,2Cl- cotransport system. The latter possibility is unlikely, however, because a net uptake of KCl was found even at low external K+, and because no K+ uptake was found in ouabain-poisoned cells. In the presence of ouabain a bumetanide-sensitive uptake during volume recovery of Na+ and Cl- in nearly equimolar amounts was demonstrated. It is proposed that the primary process during the regulatory volume increase is an activation of an otherwise quiescent, bumetanide-sensitive Na+,Cl- cotransport system with subsequent replacement of Na+ by K+ via the Na+/K+ pump, stimulated by the Na+ influx through the Na+,Cl- cotransport system.     

Central innervation of the pineal organ of the Mongolian gerbil

Nerve fibers connecting the brain with the pineal gland of the Mongolian gerbil (central pinealopetal fibers) were investigated by means of light and electron microscopy. Several myelinated fibers penetrate from the brain into the deep pineal gland, extend further into the pineal stalk and continue to the superficial portion of the pineal gland. In the centripetal direction these fibers were traced to the stria medullaris and to the habenular nuclei, where they turned laterad and then occupied a position immediately ventral to the optic tract. As shown in electron micrographs, lesions of the habenular area led to degeneration of myelinated fibers and nerve boutons in the deep pineal gland, the pineal stalk and the superficial pineal gland. Only boutons containing clear transmitter vesicles (devoid of a dense core) were observed to degenerate after the habenular lesions. On the other hand, removal of the superior cervical ganglia resulted in degeneration of boutons containing small (40 to 60 nm in diameter) dense-core vesicles. Several of the nerve fibers that penetrate into the deep pineal directly from the brain (central fibers) exhibited a positive reaction for acetylcholinesterase (AChE). AChE-positive perikarya were located in the projections of the stria medullaris, the lateral portions of the deep pineal, the area of the posterior commissure, and the periventricular gray of the mesencephalon. Such perikarya were found neither in the pineal stalk nor in the superficial pineal gland. These results present anatomical evidence that the pineal organ of the Mongolian gerbil receives multiple nervous inputs mediated by peripheral autonomic (i.e., sympathetic) nerve fibers, on the one hand, and by central fibers, on the other.     

A histochemically demonstrable thiaminepyrophosphatase activity in the sinusoidal endothelium of the liver

Summary A new histochemically demonstrable thiaminepyrophosphatase activity in liver tissue is described. It appears to be localized solely to the cytosomes of the sinusoidal endothelium. The activity, which requires high concentration of lead ion for its demonstration, has a high degree of substrate specificity. It resists formaldehyde fixation, ethanol and many inhibitors. The optimum pH is at pH 6.This study was supported in part by a grant from the Swedish Medical Research Council.     

A comparison between histochemically demonstrable Golgi-associated and bile canalicular TDP-ase activity in liver

Summary Histochemically demonstrable Golgi-associated TDP-ase activity in liver cells from cat, chicken, rat and frog has been investigated.This activity is highly substrate-specific, insensitive to aldehyde fixation, ethanol, acetate, lead and most enzyme inhibitors. It is stimulated by divalent manganese, calcium, magnesium and cobalt and optimum pH is at pH 6 to 7.The characteristics are identical for all four species but significant differences exist at a comparison with bile canalicular activity, Golgi-associated activity in other cells and biochemical findings.This study was supported in part by a grant from the Swedish Medical Research Council.     

Serum Enzyme Activity of Newborn Calves,Pigs, and Lambs

Serum activities of aspartate aminotransferase (AspAT = GOT), alanine aminotransferase (AlAT = GPT), and total lactate dehydrogenase (LDH) have been investigated in newborn calves, pigs, and lambs. In the two latter species the LDH isoenzyme distribution in serum was also studied. Blood samples were taken at frequent intervals from birth to 48–72 hrs. post partum. Calves and pigs were born with very low serum enzyme values, whereas lambs showed a picture more similar to what has been reported in human infants. In all species a marked temporary enzyme increase occurred during the first 24–48 hrs. This elevation was found not to be due to colostrum feeding, since a parallel increase was found in starved animals. Possible regulating mechanisms are discussed. The LDH isoenzyme pattern proved to be more stable than total LDH in the early post-natal period. The percentage isoenzyme distribution, however, showed characteristic differences from that found in adult animals of the same species.     

Carotenoids of Thiorhodaceae

Summary The isolation, morphology and growth chracteristics of pure cultures of a Thiothece, Lamprocystis and Thiodictyon strain are described.Their carotenoid composition is reported. The Thiothece strain produced in addition to okenone (1), several related ketocarotenoids, among which a demethylated okenone (6) was identified by a small scale total synthesis. Thiodictyon and Lamprocystis produced carotenoids of the rhodopinal (previously warmingone) series, the latter organism contained as major carotenoids a lycopenol (4), not previously found in Nature, and a cross-conjugated lycopenal (2), previously called anhydro-warmingone.Part 7. Acta chem. scand. 21, 2185 (1967).     

The Light Requirement for Different Steps in the Development of Chloroplasts in Excised Wheat Roots

For the formation of chloroplasts in excised wheat roots blue light is necessary, but red light enhances the blue light effect. Intensity-response relationships and action spectra have been determined for the specific blue light effect as well as for the effect of red light when given before or after blue light. The longest wave length giving a blue light effect is about 500 nm. The spectrum shows a peak at about 450 nm, and a considerable effect extends down to 368 nm, the shortest wave length tested. The photoreceptor mechanism for the “blue reaction” is thought to be related to that of certain phototropisms and chloroplast movements, and to that involved in carotenoid synthesis in certain fungi. The active pigment is thought to be either a carotenoid or a flavoprotein, probably the latter. The effect of red light shows similar action spectra whether the red light is given before or after the blue, and they are consistent with protochlorophyll absorption. However, much less light is needed to produce a detectable response when the red light is given before the blue light than after. Because of the similarity of the spectra phytochrome may also be involved in the response to red light when given before blue. Far-red reversal has not been tested. The results are discussed in relation to the development of chloroplasts in leaves.