Studies on protein and RJVA syntheses in activated and temperature-blocked seeds ofAgrostemma githago: the influence of benzylaminopurine

M. Hecker

Biologia plantarum 19:2-9, 1977 | DOI: 10.1007/BF02922478

Embryos ofAgrostemma githago seeds blocked by higher temperature are suitable objects for the study of the regulation of gen expression independent of transeriptional processes. Germination of afterripened seeds can be prevented by imbibing at 30°C, whereas at 20°C germination will be completed after 30 h of soaking (BORRISS 1956). In temperature-blocked embryos RNA is synthesized with undiminished intensity, whereas DNA and protein syntheses are remarkably reduced. Equal amounts of poly(A)-RNA (probably mRNA), enriched by affinity chromatography on oligo(dT)-ceIlulose columns, are detected in blocked and activated embryos.
We suggest that...

Physiological mechanisms of frost tolerance: Possible role of protein in plant adaptation to cold

Alina Kacperska-Palacz, Ewa Dlugokecka, Jolanta Breitenwald, Barbara Wciślińska

Biologia plantarum 19:10-17, 1977 | DOI: 10.1007/BF02922479

Studies performed on winter rape plants(Brassica nnpus var.oleifera, cv. 'Gór-czański') revealed that cold treatment affected the cell membranes and led to the temporary increase in electrolytic leakage from a tissue. This was followed by the marked decrease of the electrolytic leakage in the course of hardening. Changes in membrane properties were accompanied by the promotion of soluble protein accumulation. Inhibition of protein accumulation by the cycloheximide treatment brought about wilting of plants under cold conditions. Possible role of soluble protein in protection of cells against secondary water stress caused by the coldinduced...

Physiological mechanisms of frost tolerance: subcellular localization and some physical-chemical properties of protein fractions accumulated under cold treatment

Alina Kacperska-Palacz, Maria Jasińska, Elůbieta Anna Sobczyk, Barbara Wciślińska

Biologia plantarum 19:18-26, 1977 | DOI: 10.1007/BF02922480

Two soluble protein fractions were found to increase under cold treatment in winter rape plants. They were the proteins of low molecular weight, impoverished in proline and methionine residues and localized in the citosol subcellular fractions. They seem to be linked in "situ" with the hydrophobic compounds of cytoplasm. Owing to those properties, they seem to be more resistant against salt-induced aggregation which may occur at freezing or at A01GP096.

Book Review

T. Gichneb

Biologia plantarum 19:26, 1977 | DOI: 10.1007/BF02922481

Effect of Light on Peroxidases and on Phesiolle Content in Cichorium intybus L. Leaf Tissues Cultured in vitro.

B. Legeand

Biologia plantarum 19:27-33, 1977 | DOI: 10.1007/BF02922482

Three days" illumination of tissues cultured previously in darkness decreases their peroxidase activity and increases their content in phenolic compounds; conversely, when tissues cultured under continuous illumination are placed in darkness for three days, their peroxidase activity increases and their content in phenolic compounds decreases. There is an inverse relationship between the quantity of phenol compound and peroxidase activity. The isoperoxidase pattern is the same in both illuminated and not illuminated tissues.

Changes in endogenous level of auxins and cytokinins in axillary buds ofpisutn sativum L. in relation to apical dominance

M. Jablanović, Mibjana Nešković

Biologia plantarum 19:34-39, 1977 | DOI: 10.1007/BF02922483

Decapitation of the stem in one-week-old pea seedlings below the first node causes a rapid outgrowth of the two cotyledonary buds. One of them soon becomes dominant, while the other one is inhibited, but can be released from inhibition by cutting off the dominant bud. The level of endogenous auxins and cytokinins was determined in dominant and inhibited buds, as well as in released buds at different time intervals after deinhibition. It was found that the inhibited buds contained very little acidic, ether soluble auxins, a high level of tryptophan and also a high level of cytokinins, in comparison with dominant buds. When the inhibited buda were released...

An attempt to lteplare vernalization hy application of gibberellic acid in biennial hyoscyamus niger L.

Catherine Mugnibr

Biologia plantarum 19:40-47, 1977 | DOI: 10.1007/BF02922484

Applications of various amounts of GA₃ onto the shoot apex of biennial rosette-plantHyoscyamus niger L., exposed to long days and non vernalized, caused internodes formation and stem elongation. The stem length was proportional to the amount of GA₃ applied. Number and length of developed internodes and the whole length of the shoot were maximal in plants treated with a greater amount of GA₃. In the end, stem elongation stopped and plants formed perchedrosettes without flowering. Hence, gibberellic acid participates in mechanisms of flowering only by indirect effect on stem elongation and not directly on flower...

Book Review

Ingrid Tichá

Biologia plantarum 19:47, 1977 | DOI: 10.1007/BF02922485

Nuclear behaviour in callus cells: Morphology and division

H. Kallak, L. Yarvekylg

Biologia plantarum 19:48-52, 1977 | DOI: 10.1007/BF02922486

The cells of some pea, tobacco and haplopappus callus strains reveal considerable variability in nuclear morphology (polymorphous nuclei, differences in nucleolar size and number, enlarged chromocentres) and chromosome counts. The specific features in the nuclear morphology of callus cells are related with some pecularities in the reproduction activity of these cells (amplification, amitosis, fragmentation, various deviations from normal mitosis) under cultural conditions including both the definite action of the culture system and the absence of the regulatory control by the intact organism.

Activity of mitochondria isolated and purified from dwarf and tall, light-grown pea seedlings

G. F. Israelstam, K. Fukumoto

Biologia plantarum 19:53-58, 1977 | DOI: 10.1007/BF02922487

Mitochondria from dwarf and tall light-grown peas have been separated from contaminating chloroplasts and other organelles on discontinuous sucrose gradients. A comparison between activities of the mitochondria from the two cultivars of light-grown pea seedlings was made. It was observed that both respiratory control (R.C.) indices and phosphate to oxygen (P : O) ratios were superior in mitochondria from the tall cultivar than the dwarf cultivar. The results are discussed in relation to energy status and possible gibberellic acid content in the two cultivars.

Leaf conductance and gas exchange through adaxial and abaxial surfaces in water stressed primary bean leaves

Jarmila Solárová, J. Václavík, Jana Pospíšilová

Biologia plantarum 19:59-64, 1977 | DOI: 10.1007/BF02922488

Epidermal conductances for water vapour transfer(gep), water vapour efflux(E), and net photosynthetic CO² uptake (P _N ) through adaxial and abaxial leaf surfaces were estimated, simultaneously during the development of water stress in primary leaves ofPhaseolus vulgaris L. Hydration level was characterized by water saturation deficit (ΔW _sat ), water potential (Τ _w ), osmotic potential (Τ₈) and pressure potential (Τ_p). The conductance of the abaxial epidermis was consistently greater than that of the adaxial...

Stabilization of virus particles from the mosaic diseasedfreesia by phenylmethylsulfonylfluoride during purification and storage

M. Čech, Věra Mokrá, Hana Branišová

Biologia plantarum 19:65-70, 1977 | DOI: 10.1007/BF02922489

Threadlike particles from mosaic freesia aggregate during and shortly after the purification which is followed by full degradation into insoluble amorphous precipitate. This irreversible process is caused predominantly by host plant proteases. Such degradation can be completely inhibited if the virus complex is purified and stored in the presence of 0.1 mM phenyl-methylsulfonylfluoride. A modified purification method which gives a higher yield and the virua preparation of greater purity is described.

Book Reviews

J. Šatava, Ingrid Tichá, Z. Šesták, Eva Klozová, I. Šetlík, J. Tupý, Jana Pospišilová, Jarmila Solárová, Frideta Seidlová, Danuše Hodáňová, M. Kamínek, B. Slavík

Biologia plantarum 19:70-80, 1977 | DOI: 10.1007/BF02922490