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31.
Chlorella fusca can utilize the following substances as sole sulfur sources for growth: C1 to C8 n-alkane-1-sulfonates, linear alkylbenzenes sulfonates (LAS), -sulfonated fatty acid esters, polyethylene glycol sulfate and alkylsulfates. Good sulfur sources are alkylsulfonic acids, which are comparable to sulfate. Ethanesulfonic acid was used for comparison of the growth on sulfate and on a sulfonic acid, because best growth was achieved on this C2-sulfonic acid.Growth data of Chlorella on the enviromental important detergents linear alkylbenzene sulfonic acids, -sulfonated fatty acid methylester, Texapon and Sulfopon are presented. So far only microorganisms have been discussed as a source for degradation of sulfonic acids and detergents. It is suggested that green algae could be of similar importance for the biodegradation of these compounds.Abbreviations LAS Linear alkylbenzene sulfonate - ES -sulfonated fatty acid methylester - DTE dithiocrythritol  相似文献   
32.
697 children with concomitant strabism, all patients who were seen in the Ophthalmalogical university hospital and outpatient service of the Charité, Berlin, during a certain period, have been examined together with their parents and siblings. In a second series, 3398 12-years old school children (born 1953) from three urban districts of Berlin were examined at the occasion of a vaccination term, and 179 children with strabism were ascertained. Probands as well as their parents and siblings were examined thoroughly according to the criteria of strabism diagnostics. Incidence of squinting among siblings was increased markedly when compared with the population frequency, but did not reach the expectations under rthe assumption of a single, monomeric mode of inheritance. Admixture of phenocopies or new mutants could be excluded. Twin investigations (12 monocygotic and 27 dicygotic pairs) showed a manifestation rate of 94,1% in monocygotic pairs, corresponding to a 3 1/2 times higher concordance in monocygotic as compared with dicygotic twins. From the results discussed, a multifactorial genetic system in combination with a threshold effect seems to be the most likely genetic interpretation. An analysis of pedigrees shows that slight sensoric as well as motoric anomalies might combine in different and continuously varying quantities, contributing to the syndrom of concomitant strabism.  相似文献   
33.
Susanne Daniel  Wolfgang Barz 《Planta》1990,182(2):270-278
Cell-suspension cultures of two chickpea (Cicer arietinum L.) cultivars, resistant (ILC 3279) and susceptible (ILC 1929) to the fungus Ascochyta rabiei (Pass.) Lab., showed differential accumulation of the phytoalexins medicarpin and maackiain, and transient induction of related enzyme activities after application of an A. rabiei-derived elicitor. The chalcone-synthase (CHS) activity (EC 2.3.1.74) which is involved in the first part of phytoalexin biosynthesis exhibited a maximum 8–12 h after elicitation in the cells of both cultivars. Concomitant with the fivefold-higher phytoalexin accumulation, CHS activity increased twofold in the cells of the resistant cultivar. The maximum of the elicitor-induced CHS-mRNA activity was determined 4 h after onset of induction in the cultures of both cultivars, although in cells of cultivar ILC 3279 this mRNA activity was induced at a level twofold higher than that in cells of the susceptible race ILC 1929. Investigations of CHS isoenzymes by two-dimensional gel electrophoresis of immunoprecipitated in-vitro-translated protein indicated the presence of five proteins. In the cells of both cultivars only two of the isoenzymes were induced after elicitor treatment. Analysis of the total in-vitro-translated proteins by two-dimensional gel electrophoresis showed that the constitutively expressed patterns of mRNA activities in the cell cultures of the two cultivars were identical. After elicitation, considerably more translatable mRNAs were induced in the cells of cultivar ILC 3279. The few induced proteins, and their respective mRNA activities, which could be detected in the cells of the susceptible cultivar, all existed in the cells of the resistant cultivar, too. One highly induced protein (Mr 18 kDa) found in the cells of cultivar ILC 3279 reached its maximum mRNA activity 6 h after elicitor application. The amount of this protein was hardly increased in the cells of the susceptible cultivar. This protein appears to be excreted from the cells into the growth medium.Abbreviations CHS chalcone synthase - IEF isoelectric focussing - ILC international legume chickpea - PR-protein pathogenesis-related protein - SDS-PAGE sodium dodecyl sulfate-polyacrylamide gel electrophoresis Financial support by Deutsche Forschungsgemeinschaft and Fonds der Chemischen Industrie is gratefully acknowledged. The authors thank Dr. K. Hahlbrock (Max-Planck-Institut für Züchtungsforschung, Köln, FRG) for provision of antisera and the International Centre for Agricultural Research in the Dry Areas (Aleppo, Syria) for plant material.  相似文献   
34.
Opioid receptors of NG 108-15 cell membranes are distributed in two membrane fractions sedimenting at 20,000 g (P2) and 200,000 g(P3). The number of receptors is identical in P2 and P3, but in P2 all sites are present in one high-affinity state (2 nM), whereas in P3 60% of these receptors display lower affinity (150 nM). Upon addition of GTP or pretreatment with pertussis toxin, 80% of the sites exist in low affinity in both P2 and P3. Therefore, the effect of GTP and pertussis toxin on agonist binding appears to be smaller in P2 than in P3. In contrast, sodium inhibits agonist binding in P2 and P3 to the same extent and with identical potency. Opioid-mediated stimulation of GTPase is much greater in P2 than in P3, whereas inhibition of adenylate cyclase does not differ in the two fractions. Using site-specific antibodies and pertussis toxin-catalyzed ADP-ribosylation, we found that the amount of G proteins in P3 is only 30-50% of that in P2. Treatment of intact cells with the hydrophilic protein-modifying agent sulfosuccinimido-biotin results in biotinylation of proteins from both fractions and in a similar reduction of opioid binding in P2 and P3. Likewise, exposure of intact cells to the alkylating opioid antagonist, chlornaltrexamine, produces identical degrees of receptor inactivation in P2 and P3. The rate of in vivo pertussis toxin-mediated modification of G proteins is not different in the two fractions.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
35.
Insect-plant interactions have played a prominent role in investigating phylogenetic constraints in the evolution of ecological traits. The patterns of host association among specialized insects have often been described as highly conservative, yet not all specialized herbivorous insect lineages display the same degree of fidelity to their host plants. In this paper, we present an estimate of the evolutionary history of the leaf beetle genus Oreina. This genus displays an amazing flexibility in several aspects of its ecology and life history: (1) host plant switches in Oreina occurred between plant families or distantly related tribes within families and thereby to more distantly related plants than in several model systems that have contributed to the idea of parallel cladogenesis; (2) all species of the genus are chemically defended, but within the genus a transition between autogenous production of defensive toxins and sequestration of secondary plant compounds has occurred; and (3) reproductive strategies in the genus range from oviparity to viviparity including all intermediates that could allow the gradual evolution of viviparity. Cladistic analysis of 18 allozyme loci found two most parsimonious trees that differ only in the branching of one species. According to this phylogeny estimate, Oreina species were originally associated with Asteraceae, with an inclusion of Apiaceae in the diet of one oligophagous species and an independent switch to Apiaceae in a derived clade. The original mode of defense appears to be the autogenous production of cardenolides as previously postulated; the additional sequestration of pyrrolizidine alkaloids could have either originated at the base of the genus or have arisen three times independently in all species that switched to plants containing these compounds. Viviparity apparently evolved twice in the genus, once without matrotrophy, through a retention of the eggs inside the female's oviducts, and once in combination with matrotrophy. We hypothesize that the combination of autogenous defense and a life history that involves mobile externally feeding larvae allowed these beetles to switch host plants more readily than has been reported for highly conservative systems.  相似文献   
36.
Pituitary adenylate cyclase-activating polypeptide (PACAP) and helospectin are two vasoactive intestinal polypeptide (VIP)-related neuropeptides that have recently been demonstrated in the mammalian gut; the aim of this study was to reveal their occurrence and localisation in the gastrointestinal tract, swimbladder, urinary bladder and the vagal innervation of the gut of teleosts, using immunohistochemical methods on whole-mounts and sections of these tissues from the Atlantic cod, Gadus morhua and the rainbow trout, Oncorhynchus mykiss. Both PACAP-like and helospectin-like peptides were present in the gut wall of the two species. Immunoreactive nerve fibres were found in all layers but were most frequent in the myenteric plexus and along the circular muscle fibres. Immunoreactivity was also demonstrated in nerves innervating the swimbladder wall, the urinary bladder and blood vessels to the gut. Immunoreactive nerve cell bodies were found in the myenteric plexus of the gut and in the muscularis mucosae of the swimbladder. In the vagus nerve, non-immunoreactive nerve cells were surrounded by PACAP-immunoreactive fibres. Double staining revealed the coexistence of PACAP-like and helospectin-like peptides with VIP in all visualized nerve fibres and in some endocrine cells. It is concluded that PACAP-like and helospectin-like peptides coexist with VIP in nerves innervating the gut of two teleost species. The distribution suggests that both PACAP and helospectin, like VIP, are involved in the control of gut motility and secretion.  相似文献   
37.
Spinach plants were grown in bowls of aerated nutrient solutionin a controlled environment chamber for 24 h, and harvestedevery 3·5-5 h to record their growth, nitrate and wateruptake, and plant nitrate concentration. Twelve such experimentsare described, either with a 14/10 h dark/light regime, or continuouslight or darkness. The irradiance was either 110, 320, or 510µmol m-2 s-1 (PPFD). All these regimes began at the endof the light period of a 14/10 h dark/light regime (510 µmolm-2 s-1) lasting approximately 2 weeks. Nitrate uptake rate per g of dry weight of plant continued almostunabated at about 17 µmol h-1 through the initial 14-hdark period, and then fell away sharply if the light was notrestored, but increased slightly when it was. With continuouslight at 510 µmol m-2 s-1, uptake rate rose steadily forthe first 24 h of light, and then fell sharply for about 6 h.Shoot nitrate concentration increased about three-fold in thedark phase, and declined in the light at a rate which was positivelyrelated to the irradiance. Root nitrate concentration was severaltimes higher than that of the shoot: its diurnal change wassmaller (relative to the mean) than that of the shoot. Nitratereduction occurred to a small extent in the dark, and increasedrapidly as soon as the lights came on, to remain at a roughlyconstant rate (related to the irradiance) throughout the lightphase. Dry matter increase in the light was related to irradiance,but with little increase above 320 µmol m-2 s-1. Respiratoryweight loss in the dark was not detectable. Rate of fresh weightincrease was approximately constant throughout light and darkperiods. The results compare quite well with the predictions of a simplesimulation model, based on the pump/leak principle.Copyright1994, 1999 Academic Press Spinacia oleracea, nitrate, uptake, reduction, influx, efflux, diurnal, regulation, model, simulation  相似文献   
38.
In lyophilized needles of Norway spruce ( Picea abies [L.] Karsten) and starting from bud break, we determined enzyme activities (sucrose phosphate synthase [SPS; EC 2.4,1.14]. sucrose synthase [SS; EC 2.4,1.13]. acid invertase [AI; EC 3.2,1.26]) and intermediates (starch, sucrose, glucose, fructose; fructose 6-phosphate, fructose 2.6-bisphosphate [F26BP]) of carbohydrate metabolism together with needle weight, shoot length, chlorophyll and protein. For up to 110 days after bud break, samples were taken twice a week from about 25-year-old trees under field conditions. At least three periods can be distinguished during needle maturation. During the first period (up to 45 days after bud break) Al showed the highest extractable activity. This coincided with very high levels of F26BP (up to 11 pmol [mg dry weight]−1) and a transient increase of starch in parallel to a decrease of sucrose. The interval between 45 and 70 days after bud break was characterized by high SS activity (ratio of fructose/glucose >1), much decreased levels of F26BP (down to below 1 pmol [mg dry weight]−1), and a pronounced increase in the dry weight/fresh weight ratio. In parallel, starch declined and soluble carbohydrates increased. Finally, needle maturation was characterized by decreasing SS and continuously increasing SPS activities, so that the ratio of SPS/SS increased more than 6-fold. AI. however, did not decline with maturation. Changes in pool sizes of metabolites and enzyme activities (AI. SPS) are consistent with current concepts on sink/source transition. SS is obviously important with regard to the synthesis of structural polysaccharides.  相似文献   
39.
Studied with the fluorochrome 3,3-dihexyloxacarbocyanine iodide [(DIOC6(3)], the dynamic system of the endoplasmic reticulum (ER) in epidermal cells of onion bulb scales consists of long, tubular strands moving together with organelles in the deeper cytoplasm, and of a less mobile network composed of tubular and lamellar elements at the cell periphery. Treatment with the sulfhydryl-reagent N-ethylmaleimide (NEM) inhibited organelle and ER movement, and caused the fusion of ER-tubules into flat sheets. Fixed, long, tubular ER strands were formed by lowering the cytosolic pH of NEM-treated cells. Both these observations indicate the involvement of myosin in the dynamics of organelles and ER. Using a monoclonal antibody against murine skeletal muscle myosin (known to cross-react with plant myosin; Tang et al. 1989, J. Cell Sci. 92: 569–574), myosin was identified by immunofluorescence microscopy. Mapping the distribution of myosin, actin filaments, ER, and organelles in different phases of recovery after centrifugation of epidermal cells, co-localization of myosin with ER and organelles but not with actin filaments was observed, supporting the hypothesis that a membrane bound motor protein exists in onion epidermal cells, which translocates organelles and the endoplasmic reticulum along actin filaments.  相似文献   
40.
The effects of the acylcyclohexanedione-type growth retardant prohexadione calcium on seedling growth and endogenous levels of immunoreactive phytohormone-like substances in shoots of wheat ( Triticum aestivum L. cv. Kanzler) and oilseed rape ( Brassica napus L. ssp. napus cv. Lirajet) were studied. After treatment of seedlings with increasing retardant concentrations in hydroponics, plant height and fresh weight of shoots were reduced by up to 40%. Concomitantly, the amount of immunoreactive gibberellins decreased, on a fresh weight basis, when compared with levels in the shoots of control plants. In contrast, the levels of abscisic acid and dihydrozeatin riboside and isopentenyladenosine-type cytokinins were considerably elevated by the growth retardant. The content of 3-indoleacetic acid decreased slightly. These results suggest that, in addition to its effect on gibberellin content, prohexadione calcium also influences the levels of endogenous abscisic acid and cytokinins.  相似文献   
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