Screening of compounds for antimutagenic properties towards dimethylnitrosamine-induced mutagenicity inArabidopsis thaliana

T. Gichner, J. Velemínský, F. Pospíšil

Biologia plantarum 27:417-423, 1985 | DOI: 10.1007/BF02894710

The inhibitor of microsomal monooxygenase activities 9-hydroxyellipticine markedly inhibited the frequency of embryonic and chlorophyll mutations induced by the metabolism-requiring mutagen dimethylnitrosamine (DMN) in a higher plantArabidopsis thaliana, but had no effect on the frequency of mutations induced by the direct-acting mutagen N-methyl-N-nitrosourea (MNU). The presence of thiol containing compounds thiourea and cysteine before and during DMN or MNU treatment resulted in a decline of mutation frequency as compared to treatment with either nitroso compound alone. In contrast, the mutagenicity of DMN and. MNU was not altered in the presence...

Reevaluation of the "in vitro" and "in vivo" methods of nitrate reductase determination in pea roots

J. Sahulka

Biologia plantarum 27:424, 1985 | DOI: 10.1007/BF02894711

Nitrate consumption, nitrite production and nitrite loss were followed in the"in vitro" nitrate reductase (NR) assay mixtures with pea root extracts, and nitrite production in the "in vitro" NR assay was compared with anaerobic nitrite production in the "in vivo" assay with pea root segments. NR activity could not be reliably determined on the basis of nitrate consumption using three methods of NO₃-determination (salicylate, cadmium, enzymatic). NR activity based on nitrite determination was slightly underestimated due to nitrite loss (less than 10% with pea root extracts) in the assay mixture. Nitrite production in...

Effect of gibberellic acid on organogenesis in buckwheat tissue culture

Veroslava Srejović, Mirjana Nešković

Biologia plantarum 27:432, 1985 | DOI: 10.1007/BF02894712

Buckwheat cotyledons were induced to form callus tissuein vitro, in which shoots or roots could be regenerated, by changing the hormonal composition of the medium. The effect of gibberellic acid (GA₃) was studied in these processes. Addition of GA₃ to cell division medium during the first 5 days after inoculation did not interfere either with the induction of cell division, or with the subsequent organogenesis. However, GA₃ had a very pronounced effect on organogenesis when added immediately upon the transfer of expiants to organ induction medium. While root initiation was accelerated and root number increased,...

Book reviews

P. Urbánek, J. Velemínský

Biologia plantarum 27:437, 1985 | DOI: 10.1007/BF02894713

Protein changes during pollen development inNicotiana tabacum L.

V. Žárský, Věra Čapková, Eva Hrabětová, J. Tupý

Biologia plantarum 27:438, 1985 | DOI: 10.1007/BF02894714

Developmental variations in the amount and SDS-PAGE pattern of soluble proteins and of those. bound to heavy cell structures were examined during transition of the dividing microspore into mature pollen in tobacco cultivars Samsun and White Burley. Both protein fractions exhibited an initial rapid rise associated with young pollen grain filling with cytoplasm and a slight decrease during pollen maturation after starch deposition. These changes were more marked in the soluble fraction and the total protein content at its maximum was more than three times higher than at the stage of microspore mitosis. Most of about 70 distinct polypeptides detected...

The effect of nitrite on glutamine synthetase level in isolatedPisutn sativutn L. roots

M. Vágner, F. Pospíšil, J. Sahulka

Biologia plantarum 27:445, 1985 | DOI: 10.1007/BF02894715

Exposure of isolated pea roots to 0.5 and 2.0 mM nitrite resulted in a temporary decrease in glutamine synthetase (GS) level. The GS level decrease was preceded by a temporary increase in NO₂- content: nitrite content maximum was observed after 6 h exposure, GS level was depressed most after 12 h. At this time, GS level also significantly decreased by 0.3 and 0.4 mM NO₂-, but the effect of these concentrations was only slight and not significant after 18 h exposure. By contrast, GS level in roots precultivated for 24 h in solutions containing 2 mM NO₂- did not fully recover even after further 24 h cultivation in nutrient...

Effect of media pH on nitrate uptake, dry matter production and nitrogen accumulation by corn (Zea mays L.) seedlings grown in solution culture

Raghuveer Polisetty, R. H. Hageman

Biologia plantarum 27:451, 1985 | DOI: 10.1007/BF02894716

Experiments were conducted (a) to identify optimum media pH for nitrate uptake by intact corn (Zed ways L. cv. XL-81) plants grown under solution culture conditions, (b) to understand the effect of media pH on growth, nitrate uptake, water use and nitrogen accumulation. pH was maintained using carboxy cation exchange resin IRC-50. Plantswere grown in 15mM NO₃-N per litre and nitrate depleted from nutrient solution over a period of time was measured. Dry matter accumulation by the plants decreased progressively with increased pH. However, the decrease was significant only at pH 7.0 and 8.0. Data on water use showed results similar...

Exogenously supplied amino acids and water deficits inZea mays cultivars

P. S. Thakur, V. K. Rai

Biologia plantarum 27:458, 1985 | DOI: 10.1007/BF02894717

Wilting of maize seedlings was significantly delayed in the presence of amino acids supplied in the ambient medium along with different levels of osmotic stress. Water saturation deficit (WSD) values at all stress levels were lower in the presence of exogenous amino acids, however, the effect was much clearer in resistant cv. Ageti-76 as compared to susceptible cv. Vijay under similar conditions. The effectiveness of proline in the external medium was in no way better than other amino acidse.g. serine, asparagine, alanine and cystine.

Book reviews

Jarmila Solárová, M. Kamínek, T. Gichner, J. Velemínský, Jana Pospíšilová, Z. Šesták, Frideta Seidlova, Kateřina Pánková, Libuše Pavlová, J. Šatava, Jiřina Slavíková, B. Slavík

Biologia plantarum 27:468-476, 1985 | DOI: 10.1007/BF02894721

Cell wall disintegration consistently found in tissues of reversion diseased red currant cv. Heinemann's rote spätlesse

J. Polák, M. Jokes, Marie Ulrychová

Biologia plantarum 27:462-464, 1985 | DOI: 10.1007/BF02894718

Black currant reversion disease causes serious problems in some cultivars of black and red currant. Investigating ultrathin sections prepared from overground parts of diseased red currant plants cv. Heinemann's rote spätlesse, we observed consistently local cell wall disintegration of tracheids in vascular bundles. We have observed these changes in red currant plants showing reversion symptoms during the vegetation period from March to June. The observed phenomenoni.e. cell wall disintegration of tracheids might be utilized as an auxiliary diagnostic criterion m ident ification of red currant reversion disease in the cultivar Heinemann.

Crown gall tumors inCentaurium

Jana Dusbábková, J. Nečásek, K. Pešina

Biologia plantarum 27:465-467, 1985 | DOI: 10.1007/BF02894720

Agrobacterium tumefaciens C58M (a nopaline strain) was used for induction of crown gall tumors inCentaurium umbellatum Gilib. The formation of tumors is very rare. After elimination of bacteria the tumor tissues grow in the light on R3B medium without growth regulators. They are positive in nopaline synthase.

Ninetieth birthday of Academician Silvestr Prát

Vladimír Rypáček

Biologia plantarum 27:477-478, 1985 | DOI: 10.1007/BF02894722

Prof. RNDr. Vladimír Rypáček, DrSc. *October 10, 1910

Bohdan Slavík

Biologia plantarum 27:479-480, 1985 | DOI: 10.1007/BF02894723

Stratification of tropical forests as seen in leaf structure (tasks for vegetation science vol. 6)

Ingrid Tichá

Biologia plantarum 27:464, 1985 | DOI: 10.1007/BF02894719

Erratum

Kveta Vacková, Archana Mehta, M. Kutácek

Biologia plantarum 27:i, 1985 | DOI: 10.1007/BF02894724