Marcela Gubišová, Jozef Gubiš and Alžbeta Žofajová
The effect of plant propagation method on growth parameters and the yield of above-ground biomass in two species of gigantic grasses were measured during three growing seasons. Plants were multiplied in explant culture and through traditional methods – by rhizome segments (Miscanthus × giganteus) or by stem cuttings (Arundo donax). In the case of M. × giganteus, in vitro-multiplied plants produced more shoots with significantly lower diameter, but the differences in the number of shoots, plant height and the yield of dry biomass were not statistically significant. Different results were observed for A. donax, where in vitro-multiplied plants showed significantly weaker results in all parameters, with the exception of the number of shoots in the first measured season. In both the species, there was observed the strong effect of the year. While in M. × giganteus the yield of dry biomass gradually decreased during the measured years, it increased in the case of giant reed.
Optimization of Barley Mature Embryo Regeneration and Comparison with Immature Embryos of Local Cultivars
Regeneration ability of plant cells or tissues in explant culture is one of the key factors affecting success of genetic transformation. In experiments, the effect of explant type (whole embryo, scutellum embryonic axis, meristematic/central zone of embryonic axis) and plant growth regulators (BAP or TDZ) on mature embryo regeneration was determined. Explant type significantly affected regeneration efficiency. While no regenerants were observed using mature scutella, whole embryos or embryonic axes produced the highest number of regenerants. Using embryonic axes with discarded apical and basal parts, regeneration efficiency dramatically decreased. No statistical differences in regeneration were observed between BAP and TDZ added to the regeneration medium in concentration 0.1 or 1 mg l-1. At last, regeneration ability of mature embryos of nine Slovak spring barley cultivars (Donaris, Ezer, Levan, Ludan, Nitran, Pribina Sladar, Orbit, Pax) and Golden Promise as a model cultivar was examined and compared with regeneration ability of immature embryos which have been usually used for genetic transformation of barley. Although the regeneration from mature embryos was very weak, the same cultivars Golden Promise, Pribina and Levan showed the best regeneration ability by using both, immature and mature embryos. On the other hand cultivars Ezer and Pax belonged to the weakest ones in both experiments.
Zuzana Dürešová, Anna Šuňovská, Miroslav Horník, Martin Pipíška, Marcela Gubišová, Jozef Gubiš and Juraj Lesný
The aim of the present work was to compare the accumulation and translocation of Cd and Zn in plants of tobacco (Nicotiana tabacum L.), celery (Apium graveolens L.), maize (Zea mays L.), giant reed (Arundo donax L.), and alpine pennycress (Noccaea caerulescens L.) under conditions of short-term hydroponic experiments using nutrient solutions spiked with radionuclides 109Cd or 65Zn, and direct gamma-spectrometry. It was found that the time-course of metals accumulation in studied plants was not different in terms of target metal, but it was significantly different on the level of plant species. The highest values of Cd accumulation showed plants of giant reed, whereby the accumulation decreased in the order: giant reed > tobacco > alpine pennycress >> maize and celery. On the basis of concentration ratios (CR) [Me]shoot / [Me]root calculation for both metals, it was found that Cd and Zn were in prevailing part accumulated in the root tissues and only partially accumulated in the shoots, where the amount of accumulated Cd and Zn increased from the oldest developed leaves to the youngest developed leaves. The CR values corresponding to these facts were calculated in the range 0.06 – 0.27 for Cd and for Zn 0.06 – 0.48. In terms of plant species, the CR values obtained for Cd decreased in the order: maize > celery > tobacco and giant reed > alpine pennycress. The similarity between studied objects – individual plant species on the basis of the obtained variables defining Cd or Zn accumulation at different conditions of the experiments as well as the relationships between obtained variables and conditions of the experiments were subjected to multivariate analysis method – cluster analysis (CA). According to the findings and this analysis, it can be expected that plants of tobacco and giant reed will dispose with similar characteristics as plants of alpine pennycress, which are classified as Zn/Cd hyperaccumulators, in terms of Cd or Zn accumulation and other positive parameters for their utilization in phytoremediation processes and techniques.
Martin Sák, Ivana Dokupilová, Daniel Mihálik, Jana Lakatošová, Marcela Gubišová and Ján Kraic
The in vitro cell cultures of Vitis vinifera L. cv. St. Laurent were treated with two elicitors - synthetic methyl jasmonate and natural, prepared from grapevine plant infected with the Phaeomoniella chlamydospora, the agent causing the Esca disease of grapevine. Efficiency of phenolic compounds production after elicitation of cell culture was analysed immediately after treatment (15 min, 30 min, 60 min) and later (after 24, 48, and 72 hours). The cell growth and content of phenolic compounds (+)-catechin, (-)-epicatechin, p-coumaric acid, syringaldehyde, rutin, vanillic acid, and trans-resveratrol were analysed in cultivated cells as well as in cultivation medium. Pch-treatment increased production of total polyphenols the most significantly 15 min after the elicitation and in optimal time was 2.86 times higher than in nonelicited culture and 1.44 times higher than in MeJa induced cell culture.
Katarína Ondreičková, Mária Babulicová, Daniel Mihálik, Marcela Gubišová and Jozef Gubiš
Terminal restriction fragment length polymorphism was used to determine the bacterial community diversity in crop rotations with different proportion of cereals (40%, 60% and 80%) and various fertilisation treatments (F1 - mineral fertiliser amendment + the application of organic fertiliser Veget® and F2 - mineral fertilisation) sampled on two dates (July and October 2012). No statistically significant differences in the number of terminal restriction fragments were detected by Fisher´s least significant difference between two types of fertilisation or among samples with different proportion of cereals. In contrast, statistically significant differences were detected between samples collected in July and October, when in October there was a 43.5% reduction in the number of bacterial species in comparison with July. Principal component analysis as well as cluster analysis showed that a higher similarity in composition of bacterial communities was present among all soil samples collected in July and two samples collected in October. Other samples collected in October were separated from each other. The results of this study demonstrated that bacteria abundance and community composition were not affected by the proportion of cereals and fertiliser used.
Lenka Klčová, Katarína Ondreičková, Daniel Mihálik and Marcela Gubišová
Wheat is one of three most important cereals worldwide. Its production rises every year. There is a possibility to improve quantitative and qualitative parameters by biolistic method of transformation. The process of introduction of desired gene into the wheat genome and plant regeneration is affected by many factors. To identify the suitable conditions, selection system, the influence of donor, plant environment and the regeneration capacity of wheat genotypes were tested. The scutella of immature embryos served as the initial explants. Plant regeneration was achieved by 6 out of 11 genotypes tested. The highest values were reached by the cultivar Ilias. The effect of donor, plant environment was evaluated by two genotypes. Plants from growth chamber appeared to be better source of explants compared to plants grown in the natural conditions. The selection system was optimized as follows: regeneration medium in the dark and subsequently in photoperiod conditions (DR) with 5 mg/l of phosphinotricin (PPT), shoot induction medium (DS) with 7 mg/l of PPT.
Katarína Ondreičková, Marcela Gubišová, Jozef Gubiš, Lenka Klčová and Miroslav Horník
Application of sewage sludge to soil is a potentially inexpensive source of nutrition for plants, but may contain undesirable and toxic substances, e.g. heavy metals. Alterations in microbial communities can serve as an environmental indicator of possible soil contamination. We used two molecular fingerprinting methods (Automated Ribosomal Intergenic Spacer Analysis, ARISA and Terminal Restriction Fragment Length Polymorphism, T-RFLP) to study changes in the genetic diversity of bacterial communities in the rhizosphere of Arundo donax L. cultivated in the soil fertilised with additive based on sewage sludge from wastewater treatment plant and agricultural by-products represented by crushed corn hobs and wastes from grain mill industry. The metagenomic DNA extracted from rhizosphere samples were collected in August and November 2014. The amount of mgDNA was statistically higher in samples with additive than in control samples without it in both dates. The Venn diagrams showed that operational taxonomic units which were common to all samples were represented in 32.8% in ARISA and 43.4% in T-RFLP. However, based on Principal component analysis and subsequent PERMANOVA statistical tests did not confirm significant differences in the rhizosphere of control plants and plants grown in the soil supplemented with sewage sludge in dose 5 and 15 t/ha present in the additive.
Katarína Ondreičková, Andrej Ficek, Daniel Mihálik, Marcela Gubišová, Martina Hudcovicová, Hana Drahovská and Ján Kraic
The terminal restriction fragment length polymorphism munities from different collecting places was evaluated was used to determine the bacterial diversity in rhizo- by principal component analysis. Results showed that sphere of maize (Zea mays L.) collected from four sites the most different bacterial community originated from of experimental field plot in two dates of the vegetation marginal part of the experimental field plot collected in season (July and September). The 16S rRNA gene was September was caused probably by combination of the amplified from metagenomic DNA using universal eubac- marginal effect and drought before sampling date in Sep- terial primers and PCR products were digested separately tember. Other rhizosphere samples showed from moderate with three restriction enzymes. Significant differences in to small differences in the structure of the bacterial com- the number of terminal restriction fragments among rhi- munity. Nevertheless, significant differences among all zosphere samples and between sampling dates were not collected bacterial communities were not observed. detected (P < 0.05). Variation within the bacterial communities from different collecting places was evaluated by principal component analysis. Results showed that the most different bacterial community originated from marginal part of the experimental field plot collected in September was caused probably by combination of the marginal effect and drought before sampling date in September. Other rhizosphere samples showed from moderate to small differences in the structure of the bacterial community. Nevertheless, significant differences among all collected bacterial communities were not observed.
Denisa Partelová, Klára Kuglerová, Yevheniia Konotop, Miroslav Horník, Juraj Lesný, Marcela Gubišová, Jozef Gubiš, Peter Kováč and Ildikó Matušíková
The current findings show that positron emission tomography (PET), primarily developed for medical diagnostic imaging, can be applied in plant studies to analyze the transport and allocation of wide range of compounds labelled with positronemitting radioisotopes. This work is focused on PET analysis of the uptake and transport of 2-deoxy-2-fluoro[18F]-D-glucose (2-[18F]FDG), as a model of photoassimilates, in tissues of giant reed (Arundo donax L. var. versicolor) as a potential energy crop. The absorption of 2-[18F]FDG and its subsequent transport in plant tissues were evaluated in both acropetal and basipetal direction as well. Visualization and quantification of the uptake and transport of 2-[18F]FDG in plants immersed with the root system into a 2-[18F]FDG solution revealed a significant accumulation of 18F radioactivity in the roots. The transport rate in plants was increased in the order of plant exposure through: stem > mechanically damaged root system > intact root system. PET analysis in basipetal direction, when the plant was immersed into the 2-[18F]FDG solution with the cut area of the leaf of whole plant, showed minimal translocation of 2-[18F]FDG into the other plant parts. The PET results were verified by measuring the accumulated radioactivity of 18F by direct gamma-spectrometry.