The Effect of Several Protein Amino Acids and Some Inorganic Nitrogen Sources on the Growth of Sphagnum nemoreum

The nitrogen metabolism of a bog moss, Sphagnum nemoreum Scop., has been studied in aseptic cultures. The effect of several protein amino acids, especially those found in peat, has been investigated. NH₄NO₃ (1.25 mM) was the best nitrogen source but NH₄⁺ ions were more effectively utilized than NO₃⁻ ions when given as the only nitrogen source. Some of the amino acids (2.5 mM) allowed fairly satisfactory growth (arginine and alanine) when given as the only nitrogen source, but some of them were not utilized at all (leucine, lysine, isoleucine and methionine). Given at low concentrations (0.001 and 0.25 mM) together with NH₄NO₃ (2.5 mM), most of the protein amino acids failed to reveal any growth-promoting or -inhibiting effect. Only lysine (0.25 mM) clearly inhibited growth under these conditions. The nitrogen metabolism of Sphagnum nemoreum seems to be rather flexible and this species is more tolerant of organic nitrogen, especially hydroxyproline, than the higher plants.     

The Conditions promoting Anthocyanin-formation in Sphagnum nemoreum Scop.

Abstract

Gymnostomum calcareum Nees &; Hornsch., G. viridulum Brid. and G. mosis (Lor.) Jur &; Milde are recognized as distinct species on the basis of their morphology and from culture studies. The best distinguishing characters are the elongated leaves of G. calcareum, the biseriate axillary and protonema-gemmae of G. viridulum,and the bistratose regions near the leaf margins, and nerve 50 μm wide, in G. mosis. Sporophytes are unknown in G. mosis. G. calcareum has a world-wide distribution, G. viridulum occurs in southern Europe, north Africa and the Middle East, and G. mosis seems to be confined to the Middle East.     

Effect of Humic Substances on the Growth of Microalgal Cultures

Treatment with humic substances (preparation Biomin) considerably increased viability of algae during long storage (6 months) in collection. The effect was greater with green algae (Scenedesmus and Chlorella) than with blue-green algae (Nostoc and Anabaena). In intensive cultures, lower Biomin concentrations (1–10 mg/l) increased the biomass production, protein, chlorophyll and carotenoid content, as well as -esterase and glutamate dehydrogenase activities, whereas the lipid and carbohydrate content was higher at 100 mg/l Biomin. A high Biomin concentration (1 g/l) exerted an inhibition. Biomin supply to the cultures in outdoor installation of Shetlik type was associated with a moderate stimulation of algal biomass accumulation. It was concluded that Biomin might be helpful in the improvement of algal viability and growth.__________From Fiziologiya Rastenii, Vol. 52, No. 3, 2005, pp. 463–466.Original English Text Copyright © 2005 by Pouneva.This article was submitted by the author in English.     

Effect of Various Elicitors on Lignan Biosynthesis in Callus Cultures of Linum austriacum

Effects of elicitors (mannan, -1,3-glucan, and ancymidol) on the activity of several key enzymes participating in lignan biosynthesis were studied in Linum austriacum L. cell cultures. The activities of L-phenylalanine ammonia-lyase, polyphenoloxydase, tyrosine ammonia-lyase, soluble phenoloxidase, and membrane-bound and soluble oxidases were assayed. The elicitors under study affected various steps in the metabolic pathway of lignan biosynthesis. Elevated enzyme activity accompanied an elicitor-enhanced synthesis of podophyllotoxins and peltatins.     

Effect of Shaking on the Growth of Diluted Cultures of Tetrahymena

ABSTRACT. Cultures of Tetrahymena pyriformis, T. thermophila and T. pigmentosa have been studied with regard to growth rates in shaken and unshaken flasks. In the standard medium, a minimum doubling time of 170 min was obtained for T. pyriformis at 28° C in the unshaken cultures. If the depth of the medium was less than 1 cm, the gyratoric shaking increased the doubling time to 340 min. The effect of shaking could be reduced by the addition of dextrane. Cells subjected to shaking were observed in different media and at different growth temperatures. If cultures were inoculated with 10⁴ cell·ml⁻¹ or more, the effect of shaking was absent. However, with inoculates of 10³ or 10² cell·ml⁻¹, the doubling times for T. pyriformis increased to 240 and 275 min, respectively. Periods of 2 min shaking followed by rest for 60 min could not induce an effect.     

The Effect of Various Aliphatic Aldehydes and Related Compounds on the Growth of Dipodascus aggregatus

The growth of Dipodascus aggregatus in cultures inoculated with cells from the acceleration phase of growth was stimulated by the saturated and unbranched aliphatic C(3) C(4) , and C(6) to C(11) aldehydes (80 μM]. Nonanal was most active in stimulating growth. The C(12) aldehyde inhibited growth. The C(5) , aldehyde generally inhibited growth. - Nonan did not affect growth. 2-Nonanone and 5-nonanone promoted growth insignificantly. - In cultures inoculated with cells from the exponential phase growth was unaffected or even inhibited by all the aldehydes tested. The C(4) , C(5) , C(10) , and C(11) aldehydes inhibited growth to a larger extent than nonanal.     

The Effect of Growth Hormones on Cell Division and Expansion in Liquid Suspension Cultures of Acer pseudoplatanus

The effects on cell division and cell size of indole-3-aceticacid (IAA), gibberellic acid (GA), and kinetin were studiedin liquid suspension cultures of cambial cells derived fromAcer pseudoplatanus. It was shown that all three hormones promotecell division and that the effects of both GA and kinetin areadditive to those of IAA, but the effects of GA and kinetintogether are not additive. Treatment with IAA resulted in anincrease of mean cell size (indicating that cell expansion ispromoted), but after GA or kinetin treatment the mean cell sizewas smaller, indicating that little cell expansion had takenplace after each division. The results are discussed in relationto previous work on the effects of hormones in the intact cambiumand to current theories on the interactions of growth hormones.     

The Effect of Various Media on the Growth Responses of Different Clones of Carrot Explants

The induction of growth in otherwise quiescent tissue explantedfrom carrot root has been investigated with reference to theeffects of different kinds of growth-promoting substances addedas supplements to a basal medium, singly and in combination.The effects of these media upon different clones of carrot explantsare described. The idiosyncrasies of different clones of explantswere detected by their responses measured by the incidence ofcell division, the extent of cell enlargement, and by theirnucleic acid content. The basal medium which contains salts,sugar, and vitamins supported only a minimal amount of growth;the basal medium supplemented with casein hydrolysate and coconutmilk (10 per cent by volume) supported the highest level ofgrowth obtained in any of the treatments tried. The active componentsof the coconut milk (AF_cm) when refined required the furtherparticipation of either indole-3yl-acetic acid (IAA) or inositol,and were further stimulated by casein hydrolysate (CH). Thusthe over-all stimulus of the coconut milk comprised two parts—nowrecognized as growth-promoting systems I and II, respectively.The effects of System I were mediated by appropriate combinationsof inositol and the corresponding active growth-promoting factors(AF₁) which were, in turn, represented by a purified factorpreviously isolated from Aesculus (AF₂). System I induced bothcell division and cell enlargement in balance, whereas SystemII stimulated internal cell division more than cell enlargement.The effects of System II were mediated by appropriate combinationsof IAA and active growth-promoting factors (AF₂), which wererepresented by the substance zeatin. The maximum growth of anygiven clone of carrot explants isolated from a given carrotroot was only supported by exogenous requirements, over andabove a basal nutrient medium, which meet its specific endogenouslimitations. The paper shows how these limitations may be diagnosed,and discusses the over-all growth stimulus due to coconut milkin terms of the partial responses elicited by the known componentsof Systems I and II.     

Experimental and Analytical Studies of Pteridophytes: XVII. The Effect of Various Physiologically Active Substances on the Development of Marsilea in Sterile Culture

A technique for growing Marsilea aseptically is described. Theeffects of varying concentrations of indoleacetic acid, a-napthaleneaceticacid, and 2, 4-dichlorophenoxyacetic acid have been studied—theyresemble in general those reported for other plants. Additionsof adenine, guanine, or uracil have no observed effects. The effects of departures from complete nutrition and of additionsof growth-promoting substances are described and discussed inrelation to observed changes in leaf morphology.     

Effects of Various Phytoimmunocorrectors on Fruit and Soft Fruit Cultures

Catalase activity and induction of delayed chlorophyll fluorescence were shown to be the markers of the plant native state. The dependence of reaction of the plant to exogenous elicitors, stimulators or inhibitors of the defense system, on the age, cultivar and/or species was found. Prolonged effect of the treatment with phytoimmunocorrectors was observed. The necessity of careful choice of elicitors depending on the plant state was shown.     

不同剂量的LED红光直接照射对人肝癌细胞HepG2生长特性的影响

采用发光二极管(light-emitting diode,LED)对人肝癌细胞株HepG2进行不同时间的照射,研究了LED直接照射对肿瘤细胞牛长特性的影响.实验采用功率密度为7.23 mW/cm2、中心波长为(650±10)nm的红色LED对人肝癌细胞株HepG2进行不同时间的照射,采用MTT法用酶标仪测试了实验处理后肿瘤细胞的吸光值,采用光学显微镜对细胞进行形态学分析,用PI荧光染色法对细胞的生长特性进行了分析.实验结果表明,小于18 min的低强度红色LED照射呵以促进肿瘤细胞的增殖,而大于35 min的低强度红色LED照射可以抑制肿瘤细胞生长.采用合适剂量的低强度红色LED照射肿瘤细胞可以抑制肿瘤细胞的生长,这对LED直接照射治疗肿瘤疾病有一定的指导意义.     

The Effect of Various Culture Media on the Formation of Embryo-like Structures in Cultures Derived from Explants Taken from Mature Larix decidua

The effect of various collection dates and nine different culture media on the formation of ‘embryo-like structures’ (ELS) in cultures derived from explants taken from a 42-year-old Larix decidua tree was studied. The best medium was AFC, a medium low in NH₄⁻, NO₃ ⁺, Mg²⁺ and SO₄²⁻ but high in PO₄³⁻ compared with the concentration of these elements in the other media. On AFC, ELS production reached a peak with collections made in late summer during the period when needle primordia are being initiated. For the other media, collection date had a lesser effect on ELS initiation.