The effect of maleic hydrazide and exogenous DNA on chromosomes ofVicia faba

The mitotic activity of merstematic cells ofVicia faba, the frequency of chromosomal abnormalities and their interchromosomal distribution are evaluated in dependence on the concentration of maleic hydrazide (MH) and on the recovery period. The influence of exogenous DNA of different genetic origin on the course of repair of primary root cells damaged by MH was also studied. Isologous DNA which exhibited a strong repair effect in authors' previous experiments was quite ineffective in the case of maleic hydrazide. Heterologous DNA, on the other hand, had to some extent a parallel effect with MH in breaking down the structural integrity of chromosomes and increased the frequency of aberrations induced by maleic hydrazide in meristematic cells ofVicia faba.     

Ethylene-enhanced ethylene oxidation inVicia faba

The alkene oxygenase (AO) of fababean (Vicia faba L.) converts ethylene to ethylene oxide. Treatment of fababeans with 10μl/liter ethylene increases the activity of this enzyme within 2 hours of ethylene treatment. Though other alkenes were taken up by fababean seedlings, ethylene was the most active in inducing AO activity. The ability of ethylene to increase AO was blocked 60% by cycloheximide, an inhibitor of protein synthesis, and 35% by AgNO₃, an inhibitor of ethylene action.     

The influence of exogenous DNA of different origin on the mitosis and chromosomes of irradiated meristematic cells ofVicia faba

In this paper we compare the influence of heterologous and isologous DNA on the radiation damage repair of primary root meristematic cells ofVicia faba. Roots, irradiated by exposure of 150 r were cultivated at different time intervals either in tap water, or in a solution of heterologous or isologous DNA. In comparing mitotic activity of meristematic cells it was found that both types of DNA studied enhance the recovery of irradiated cells. The frequency of postmetaphase chromosomal aberrations of irradiated cells was influenced also by post-irradiation action of exogenous DNA. While heterologous DNA exhibited synergical effect with radiation in the sense that it increased the post-irradiation incidence of aberrations in all time intervals studied, isologous DNA had a strong repair effect—the application caused a significant decrease of the percentage of post-metaphase aberrations. Both kinds of DNA caused changes in the relation of chromosome to chromatid aberrations; a higher percentage of chromatid aberrations was registered. The study of the distribution of aberrations between large and small chromosomes ofVicia faba showed that the post-irradiation application of heterologous DNA increases damage of small chromosomes while isologous DNA caused an increased repair ability in this chromosomal group.     

Effect of the herbicide terbutryn on meiosis,yield and mitotic chromosomes in C2 plants ofVicia faba L.

The herbicide terbutryn induced up to 11.3 % chromosomal abnormalities in cells undergoing meiosis inVicia faba. The mean number of pods/plant and the mean number of seeds/pod were considerably reduced, but the average seed dry mass was not or was only slightly affected by this herbicide. In C₂ plants chromosomal abnormalities were observed in few but significant numbers of cells.     

Contribution to the study on the reparative effect of exogenous DNA in the irradiated meristem ofVicia faba

The present report is focused on the study of participation of exogenous DNA in the process of postirradiation reparation of meristematic cells ofVicia faba primary roots. It is aimed at comparison of the positive reparative effect of isologous DNA with postirradiation action of heterologous DNA in its native, thermally denatured and DNAase-degraded forms, or DNA degraded by ultrasound, and with the effect of other biologically important macromolecules (RNA, histone, heparin, and dextran sulphate). For this purpose, the roots ofVicia faba irradiated by 150 r exposure were cultivated in solutions containing the above substances for an appropriate time interval. In squash slides both mitotic activity of the investigated cell population and frequency of postmetaphase chromosomal aberrations induced by radiation were evaluated. It was shown that a stimulation of cell division and reparation of chromosome damages were supported exclusively by isologous DNA. On the contrary, exogenously applied heterologous DNA increased postirradiation frequency of aberrations; maintenance of native structure of applied DNA was an essential condition for the above effect. Other macromolecules investigated on the course of postirradiation reparation ofVicia faba meristematic cells were without effect.     

Production of plant growth substances by rhizosphere mycoflora of broad bean and cotton

The culture filtrates of the rhizosphere fungi of broad bean (Vicia faba L.) and cotton (Gossypium barbadense L.) were analysed for the presence of plant growth substances of auxin and gibberellins nature. Bioassay test and chromatographic analysis indicated that these fungi, each synthesized different auxins in their culture medium. These auxins were indole compounds. Similarly the rhizosphere fungi produced in their culture medium some gibberellins and gibberellin-like substances.     

Comparison of the effects of radiation and deoxyribonucleic acids on the mitosis in roots ofVicia faba

Differences as well as similarities in the action of ionizing radiation and deoxyribonucleic acids from various sources on mitosis in root cells ofVicia faba were established. The time course of occurrence of aberrations were examined. Whereas in irradiated broad beant the maximum percentage of aberrations was observed immediately after irradiation, the aps plication of non-isologous DNA was followed by maximum aberrations after 8–16 hours. As all the time-intervals studied, an incraasad number of aberrations was found during metaphase-as compared with anaphases, both after irradiation and after application of DNA. A comparison of isologous, homologous and heterologous DNA as inductors of chromosomal aberrations supported our previous findings and showed that the efficiency of DNA depends on the genetic difference between donor and acceptor. During a study of distribution of aberrations between large and small chromosomes of meristematic cells ofVicia faba, at various time-intervals it was obsarved that after irradiation the distribution of aberrations between individual chromosomes is proportional to their total length, whereas the effect of heterologous DNA is mostly in the damage to small chromosomes. It was also found that aftar irradiation mostly chromatid aberrations are formed at shorter time-intervals and only later chromosomal aberrations will appear. On the other hand, heterologous DNA brings about in all time-intervals a predominance of chromatid aberrations.     

Comparative electrophoretical analysis of plasmid-like mitochondrial DNAs in Vicia faba and in some other legumes

Minicircular DNAs found in mitochondria of 6-d-old etiolated seedlings of Vicia faba L. were also present in mitochondria isolated from cell suspension cultures and from green leaves of this plant. These results support the suggestion that the plasmid-like molecules found in mitochondria of V. faba are an essential component of the mitochondrial genome. The minicircular DNAs were, apparently, peculiar for the species V. faba since they were found in all three cultivars of this species which were studied. The distribution pattern of plasmid-like DNAs in Vicia villosa L. was completely different and mitochondria from Medicago sativa L. also contained specific minicircular DNAs. Thus, minicircular DNAs are typical for the mitochondrial genomes of several legumes and different plant species have their specific mitochondrial plasmid-like DNAs     

Effects of podophyllin and 8-hydroxyquinoline on meiosis

The induced meiotic abnormalities as a result of sprayingVicia faba plants with aqueous saturated solutions of podophyllin and 8-hydroxyquinoline were studied. The 2 drugs induced the same types of abnormalities including lagging chromosomes, stickiness, and bridges. The main difference between the 2 agents was the induction of polyploid P.M.Cs. by 8-hydroxyquinoline.     

Histogenesis and localization of non-specific esterase in root tip

A procedure was developed for satisfactory freeze-sectioning of root tips. The use of Ca formol-fixed material kept and frozen in Holt's syrup is recommended. The existence and different localization of 2 fractions of non—specific esterase was verified in root tips ofVicia faba. The same results were revealed in fixed and unfixed material. The dynamics ofin situ reaction was followed with respect to optimal incubation time. The results with substrates of different chain length support the existence of 2 fraction of the studied enzyme, none of which, concerning substrate specificity, is a lipase. It follows from the present studies inVicia faba and other species (Cucurbita pepo, Lupinus albus, Pisum sativum Zea mays), that non-specific esterase localization is not directly given by histogenesis.     

Glucose-6-phosphate dehydrogenase isoenzymes in root growth zones ofVicia faba

The specific activity of glucose-6-phosphate dehydrogenase (G-6-PD) in growth zones ofVicia faba roots is increasing with cell maturation and differentiation. Changes in the total activity of G-6-PD are not associated with a change in the number of G-6-PD isoenzymes. Five G-6-PD isoenzymes were found in all root growth zones. Some differences were found in the activity of individual isoenzymes.     

Effects of the insecticide pyrethroid ii in the ames test,and onhordeum vulgare andvicia faba

The insecticide pyrethroid II, representing synthetic pyrethroids of the second generation, was not found to be mutagenic inSalmonella typhimurium strains TA1535, TA100, TA1538, TA98 and TA97. High concentrations of the tested insecticide inhibited the germination and length of roots of germinating seeds, the height of plants cultivatedin vitro, and slightly increased the frequency of aberrant anaphases and telophase in root-tips ofVicia faba andHordeum vulgare.     

Participation of exogenous DNA in the repair processes of meristematicVicia faba cells injured by monofunctional alkylating agens ethylmethane sulphonate

The effect of exogenous DNA of syngeneic origin on the course of reparation of meristematic cells ofVicia faba primary roots followed after treatment with monofunctional alkylating agent, ethyl methanesulphonate (EMS), was tested. Time course of alternations in mitotic activity of investigated cellular population and the dynamics of formation of postmetaphase chromosomal aberrations was evaluated. A reparation of damaged cells was significantly supported by syngeneic DNA; its application induced an increased incidence of cellular division already in the early intervals of the repair which was accompanied by concomitant decrease of microscopically detectable rupture in the chromosomes. The study performed on the localization of induced damages occurring in metaphase chromosomes pointed out an increased sensitivity of small chromosomes ofVicia faba to EMS. Similarly, a reparative action of syngeneic DNA was exhibited by significant decrease of aberrations frequency, predominantly in the same chromosomal group. Per cent representation of individual types, not affected by the action of syngeneic DNA, was established by detailed classification of induced aberrations. In both cases, isochromatide breaks were found of greatest predominance.     

Isoenzymes of lactate dehydrogenase in the root growth zones ofVicia faba L.

The present studies of the LDH isoenzymes have been made as a part of our studies on the respiration systems of the roots ofVicia faba. All the root zones had 5 LDH isoenzymes and 2 antibands, but there were differences in their relative quantity. Cathodic isoenzymes (LDH₅, LDH₄) prevailed in the meristematic zone, whereas the anodic ones (LDH₁) prevailed in the others. The different enzyme activity in individual zones is probably connected with the transition of the anaerobic metabolism in the meristem to the aerobic one in the differentiating parts of the root.     

Chromosome aberrations caused by the effect of ultrasound in the meristematic cells ofvicia faba

In our present work the formation of chromosome aberrations has been studied in dependence on the tima interval between sonication and fixation of the primary root tips of Vicia faba. Maximum occurrence of aberrations was recorded immediately after sonication. The results of our experiments pointed to the fact that the frequency of the induced changes was independent on the sonic waves intensity within the range of 0-2—3-0 W/cm² and on ultrasond treatment duration within the range of 1—20 min. Studies of the distribution of chromosome abnormalities caused by ultrasound between the large and small chromosomes of theVicia faba meristematic cells in various time intervals showed that the frequency of the aberrations in both chromosome groups was proportional to its total metaphase lengths. Analysis of the type of aberrations observed in various time intervals after sonication indicated the simultaneous formation of chromosome and chromatide abnormalities.     

Maintenance of plant cell membrane integrity and function by the immobilisation of protoplasts in alginate matrices

Isolated protoplasts (Vicia faba) suspended in a mannitol solution over a time period of about 10 d undergo a process of aging characterised by increased ethane formation, decrease in oxygen evolution and CO₂ uptake, pigment degradation and a change in certain enzyme activities (ribulose-1,5-bisphosphate carboxylase and protease). The technique of immobilisation of protoplasts in a cross-linked alginate matrix offers a way to delay the appearance of the indicators mentioned. Various possible mechanisms for the increased stability of protoplasts are discussed.     

The effect of CCC on the levels of endogenous indole-3-acetic acid,abscisic acid,gibberellins and cytokinins inVicia faba plants

Vicia faba plants cv. ‘Erfordia’ were treated with single application of CCC at 250 mg l^?1, 7 days before extraction. Such a concentration resulted in a 10.4, 14, 5 and 3.3 fold, respectively, increase in the levels of endogenous IAA, ABA, gibberellins and cytokinins relative to the controls. The results obtained indicate that a single application of CCC at a low concentration was sufficient to enhance the endogenous growth hormones in the treated plants. The results were obtained using GLC analyses for IAA, ABA and cytokinins, and the lettuce hypocotyl and soybean callus bioassay for gibberellins and cytokinins, respectively.     

The localization and the isoenzymes of α- and β-Galactosidases in root tips

The localization was studied of α- and β-galactosidases in frozen sections of Ca-formol fixed root tips using simultaneous azocoupling reaction. In all species studied (Allium cepa,Cucurbita maxima, Lupinus albus, Pisum sativum, Vicia faba, Zea mays) positive results were obtained, the localization being ubiquitous (according to localization typology given here). InVicia faba andZea mays the isoenzymes of α- and β-galactosidases were revealed by means of acrylamide gel electrophoresis, using authors’ modification of Reisfeld method, in whole root tips, particular growth zones and separately in cortex and central cylinder. No differences were observed comparing stele and cortex. Whereas characteristic isoenzyme patterns were found in individual growth zones in maize, no differences appeared in broad bean. A comparison was made of thein situ localization and of the isoenzyme patterns of α- and β-galactosidases with α- and β-glucosidases. In the case of galactosidases, positive results appear with both α- and β-galactoside. The rising of pH to neutrality leads to considerable decrease in the activity of both galactosidases.     

Cytogenetic effect of radiation products of cytosine: Parabanic and oxaluric acids

The two final products of radiolytic degradation of cytosinei.e. parabanic and oxaluric acids were investigated as regards their cytogenetic effects. Broad bean (Vicia faba L.) root meristem was used as experimental material. While the oxaluric acid was not able to induce chromosomal aberrations to a greater extent, the parabanic acid acts as a clastogenic compound. When applied on a resting broad bean root meristem at concentration from 10^-3 to 10^-2 M it induces chromosome and chromatid aberrations, especially breakages. Their frequency reaches 9–12% at the highest tested concentration. The same concentrations of the parabanic acid increases mitotic index of the first cell generation of primary root.     

Contribution to the estimation of malic dehydrogenase isoenzymes in the root growth zones ofVicia faba L.

Highly active NAD-MDH (E.C.1.1.1.37) and low activity of NADP-MDH (E.C.1.1.1.40) were found inVicia faba roots. The NAD-MDH activity is associated with 6 to 12 isoenzymes. The number of isoenzymes is dependent on the extraction (use of Triton X-100etc.) and detection procudures (presence of KCN, phenazine methosulphate). The meristematic zone does not contain one isoenzyme (X) which is present in the other two zones. The meristematic zone, elongation zone and zone with the beginning differentiation differ in their activity of individual isoenzymes.