Papers by Helena Hnilickova
Vagos, 2009
The aim of this trial is to estimate the influence of 24-epibrassinolide on chemical structure an... more The aim of this trial is to estimate the influence of 24-epibrassinolide on chemical structure and energy content in wheat grains (cv. Ebi, Estica, Samanta, AC Helena, Mollera and Lucia). The application of 24-epibrassinolide in stress conditions has positive effect on the monitored parameters (content of lipids, proteins, enzyme determination of total starch, energy content). The cultivars AC Helena and Samanta are more tolerant to drought and high temperature in comparison with Estica and Lucia, which have low level of tolerance. Cv. Mollera demonstrates the best reaction to the application of phytohormone. The stress tolerant cultivar Samanta demonstrates the least reaction to the application of 24-epibrassinolide.
Biomass & Bioenergy, Jul 1, 2020
Cultivation of fast growing poplar (Populus sp.) clones represents an effective means for reachin... more Cultivation of fast growing poplar (Populus sp.) clones represents an effective means for reaching the 2020 target of the EU-28 renewable energy production. However, considering the continuous climate change, their growth can be markedly affected by summer heat stress episodes in Slovakia. Therefore, in this work two Canadian poplar (Populus � canadensis Moench) clones of different ecological optimum, 'Gigant' and 'Pannonia', were investigated in respect of productivity and heat stress tolerance. After three-year cultivation, tree height in the clone 'Gigant' was 8.9 m, breast trunk diameter 9.3 cm and trunk volume 0.021 m 3 compared to 7.9 m, 7.0 cm and 0.012 m 3 in clone 'Pannonia' (despite of relatively more stable trunk growth rate in summer). Trunks of the latter clone contained 12% bark (vs. 10% in 'Gigant'), 1.5% ash in the wood (vs. 3%) and showed significantly larger wood density (440 vs. 380 kg m À 3) but lower wood free energy content (14.5 vs. 16 MJ kg À 1). Both of clones were proved to be diploids (2x). Clone 'Pannonia' exhibited larger heat stress tolerance, as tested in leaves of different developmental stage exposed to 40 � C using chlorophyll fluorescence technique (decreasing from mature to juvenile leaves), lower specific leaf area and higher leaf carotenoid and cytokinin (particularly BAP derivatives) concentration. In spite of lower heat stress tolerance and higher ash content, clone 'Gigant' showed larger productivity than clone 'Pannonia', suggesting potential of the latter for cultivation in much more stressful conditions.
PLOS ONE, Apr 18, 2017
A comparative analysis of various parameters that characterize plant morphology, growth, water st... more A comparative analysis of various parameters that characterize plant morphology, growth, water status, photosynthesis, cell damage, and antioxidative and osmoprotective systems together with an iTRAQ analysis of the leaf proteome was performed in two inbred lines of maize (Zea mays L.) differing in drought susceptibility and their reciprocal F1 hybrids. The aim of this study was to dissect the parent-hybrid relationships to better understand the mechanisms of the heterotic effect and its potential association with the stress response. The results clearly showed that the four examined genotypes have completely different strategies for coping with limited water availability and that the inherent properties of the F1 hybrids, i.e. positive heterosis in morphological parameters (or, more generally, a larger plant body) becomes a distinct disadvantage when the water supply is limited. However, although a greater loss of photosynthetic efficiency was an inherent disadvantage, the precise causes and consequences of the original predisposition towards faster growth and biomass accumulation differed even between reciprocal hybrids. Both maternal and paternal parents could be imitated by their progeny in some aspects of the drought response (e.g., the absence of general protein down-regulation, changes in the levels of some carbon fixation or other photosynthetic proteins). Nevertheless, other features (e.g., dehydrin or light-harvesting protein contents, reduced chloroplast proteosynthesis) were quite unique to a particular hybrid. Our study also confirmed that the strategy for leaving stomata open even when the water supply is limited (coupled to a smaller body size and some other physiological properties), observed in one of our inbred lines, is associated with drought-resistance not only during mild drought (as we showed previously) but also during more severe drought conditions.
Steroids, Jul 1, 2014
The aim of the work was to examine the effect of brassinosteroid (24-epibrassinolide; 24E) and ec... more The aim of the work was to examine the effect of brassinosteroid (24-epibrassinolide; 24E) and ecdysteroid (20-hydroxyecdysone; 20E) on various parts of primary photosynthetic processes in maize and spinach. Additionally, the effect of steroids on gaseous exchange, pigment content and biomass accumulation was studied. The efficiency of the photosynthetic whole electron-transport chain responded negatively to the 24E or 20E treatment in both species, but there were interspecific differences regarding Photosystem (PS) II response. A positive effect on its oxygen-evolving complex and a slightly better energetical connectivity between PSII units were observed in maize whereas the opposite was true for spinach. The size of the pool of the PSI end electron acceptors was usually diminished due to 24E or 20E treatment. The treatment of plants with 24E or 20E applied individually positively influenced the content of photosynthetic pigments in maize (not in spinach). On the other hand, it did not affect gaseous exchange in maize but resulted in its reduction in spinach. Plants treated with combination of both steroids mostly did not significantly differ from the control plants. We have demonstrated for the first time that 20E applied in low (10 nM) concentration can affect various parts of photosynthetic processes similarly to 24E and that brassinosteroids regulate not only PSII but also other parts of the photosynthetic electron transport chain-but not necessarily in the same way.
Photosynthetica, Dec 1, 2010
The response of selected photosynthetic and morphological parameters of plants to drought was exa... more The response of selected photosynthetic and morphological parameters of plants to drought was examined in 5 inbred lines of maize (Zea mays L.) and their 10 F1 hybrids. The aim of the study was to establish whether the photosynthetic performance of parental genotypes under drought conditions correlates with the performance of their progeny and whether the net photosynthetic rate, the chlorophyll fluorescence parameters or the content of photosynthetic pigments could be used as reliable physiological markers for early breeding generations. The relative importance of the additive and the nonadditive (dominance, maternal) genetic effects in the inheritance of these parameters was also assessed by means of the quantitative genetics analysis. The results showed that the nonadditive genetic effects associated with a particular combination of genotypes or a particular direction of crossing are at least equally and often even more important as the additivity and that these genetic effects almost totally change with the exposure of plants to drought conditions. This was reflected in the inability to predict the response of F1 hybrids to drought on the basis of the photosynthetic performance of their parents, which indicates that the practical usability of such parameters in maize breeding programs is rather limited.
PLOS ONE, Jun 13, 2012
Understanding the response of a crop to drought is the first step in the breeding of tolerant gen... more Understanding the response of a crop to drought is the first step in the breeding of tolerant genotypes. In our study, two maize (Zea mays L.) genotypes with contrasting sensitivity to dehydration were subjected to moderate drought conditions. The subsequent analysis of their physiological parameters revealed a decreased stomatal conductance accompanied by a slighter decrease in the relative water content in the sensitive genotype. In contrast, the tolerant genotype maintained open stomata and active photosynthesis, even under dehydration conditions. Drought-induced changes in the leaf proteome were analyzed by two independent approaches, 2D gel electrophoresis and iTRAQ analysis, which provided compatible but only partially overlapping results. Drought caused the up-regulation of protective and stress-related proteins (mainly chaperones and dehydrins) in both genotypes. The differences in the levels of various detoxification proteins corresponded well with the observed changes in the activities of antioxidant enzymes. The number and levels of up-regulated protective proteins were generally lower in the sensitive genotype, implying a reduced level of proteosynthesis, which was also indicated by specific changes in the components of the translation machinery. Based on these results, we propose that the hypersensitive early stomatal closure in the sensitive genotype leads to the inhibition of photosynthesis and, subsequently, to a less efficient synthesis of the protective/detoxification proteins that are associated with drought tolerance.
Forests
The goal of renewable energy is to replace energy production from fossil fuels. In that sense, fo... more The goal of renewable energy is to replace energy production from fossil fuels. In that sense, forest biomass is essential renewables. This article presents the results of the development of energy reserves in fractions, increments and the total above-ground biomass of coniferous stands (spruce, fir, pine, larch) during their economic cycle. The experimental material comes from 22 forest stands located mainly in Central Slovakia, to a lesser extent also in Western and Eastern Slovakia. Energy reserves of coniferous stands were calculated based on the volume production of above-ground biomass fractions taken from mathematical models of yield tables and average values of their basic density and calorific value were determined. The research showed that as the age of the stands increased, the share of energy in the wood fraction increased, while it decreased in the bark fraction, and especially the branch fraction. The curves constructed in relation to the age of the stand and site inde...
Toxics
The paper evaluates the impact of car transport on the distribution and accumulation of Zn, Cu, P... more The paper evaluates the impact of car transport on the distribution and accumulation of Zn, Cu, Pb and Cd in soils, as well as in the vegetation near a newly built R4 motorway Košice-Milhosť (Slovakia). Samples were taken from surface humus layer (litter) and 0–5, 10–20 and 20–30 cm mineral layers of Cambisol and Luvisol, as well as from assimilatory organs of Fraxinus excelsior, Quercus cerris, Quercus rubra, Negundo aceroides and Anthriscus sylvestris growing in the segments of geobiocoenosis Querci-Fageta Typica. The concentrations of total Zn and Cu were determined using SensAA AAS and the total concentrations of Cd and Pb using an instrument iCE 3000 Series AAS-F. Contamination factor (CF) values showed that surface humus layer of both soil units is moderately contaminated with Zn (1 ≤ CF ˂ 3), low contaminated with Cu (CF ˂ 1) and considerably contaminated with Pb and Cd (3 ≤ CF ˂ 6). Contamination of the surface humus layer of Luvisol with Pb is very high (CF > 6), while i...
Diversity, 2021
The relationship between vegetation and selected soil characteristics in different monoculture fo... more The relationship between vegetation and selected soil characteristics in different monoculture forest types was investigated as part of a landscape restoration project after brown coal mining. Six forest types were selected: alder (Alnus sp.), spruce (Picea sp.), pine (Pinus sp.), larch (Larix sp.), long-term deciduous forest (Quercus robur, Tilia sp.), and forest created by spontaneous succession. These stands were classified into two age categories (younger and older). The soil attributes, C/N, TC, TN, pH, and A horizon depth were assessed. The observed species were categorized into functional groups by life history, life forms according to Raunkiær, and affinity to the forest environment. C/N ratio, humus thickness, and canopy cover were the main soil parameters affecting plant communities. The highest C/N values were recorded in Pinus and Larix stands, which were significantly different from deciduous and succession stands. The highest diversity index was noted in younger stands...
Life, 2020
This study analyzes the effects of acetaminophen (APAP) as a contaminant on physiological charact... more This study analyzes the effects of acetaminophen (APAP) as a contaminant on physiological characteristics of lettuce plants (Lactuca sativa L.). Experiments were provided in an experimental greenhouse with semi-controlled conditions. The effect of different amounts of contaminant was evaluated by using regression analysis. Plants were grown in five concentrations of APAP: 0 µM, 5 µM, 50 µM, 500 µM, and 5 mM for 14 days in two variants, acute and chronic. The obtained results show that the monitored parameters were demonstrably influenced by the experimental variant. Plants are more sensitive to chronic contamination compared to acute. Significant (p < 0.05) deviation in photosynthesis and fluorescence was observed compared to the control in different variants. The highest doses of APAP reduced the intensity of photosynthesis by a maximum of more than 31% compared to the control. A reduction of 18% was observed for the fluorescence parameters. Pronounced correlation was described ...
Plants, 2021
In this investigation, the effect of salt stress on Portulaca oleracea L. was monitored at salini... more In this investigation, the effect of salt stress on Portulaca oleracea L. was monitored at salinity levels of 100 and 300 mM NaCl. At a concentration of 100 mM NaCl there was a decrease in stomatal conductance (gs) simultaneously with an increase in CO2 assimilation (A) at the beginning of salt exposure (day 3). However, the leaf water potential (ψw), the substomatal concentration of CO2 (Ci), the maximum quantum yield of photosystem II (Fv/Fm), and the proline and malondialdehyde (MDA) content remained unchanged. Exposure to 300 mM NaCl caused a decrease in gs from day 3 and a decrease in water potential, CO2 assimilation, and Fv/Fm from day 9. There was a large increase in proline content and a significantly higher MDA concentration on days 6 and 9 of salt stress compared to the control group. After 22 days of exposure to 300 mM NaCl, there was a transition from the C4 cycle to crassulacean acid metabolism (CAM), manifested by a rapid increase in substomatal CO2 concentration and ...
Family Fabaceae traditionally serves as food and herbal remedies source. Several plants are alrea... more Family Fabaceae traditionally serves as food and herbal remedies source. Several plants are already used for menopausal symptoms treatment based on a presence of typical secondary metabolites, isoflavones. Beside soybean and clovers, isoflavones could be produced by other plants or in vitro cultures. This type of production can be further enhanced by elicitation that stimulates metabolites biosynthesis via stress reaction. Vanadium compounds have been already described as potential elicitors and the aim of this study was to determine an impact of NH4VO3 and VOSO4 solutions on isoflavones production in Genista tinctoria L. cell cultures. The significant increase of isoflavones content such as genistin, genistein or formononetin was measured in a nutrient medium or dry mass after NH4VO3 treatment for 24 or 48 hours. The possible transport mechanism of isoflavones was also evaluated. An incubation with different transport inhibitors prior elicitation took effect on isoflavones content ...
Molecules (Basel, Switzerland), Jan 3, 2018
The family traditionally serves as a food and herbal remedies source. Certain plants serve for tr... more The family traditionally serves as a food and herbal remedies source. Certain plants serve for treatment of menopausal symptoms based on a presence of typical secondary metabolites, isoflavones. Beside soybean and clovers, other plants or cultures in vitro can produce these molecules. A cultivation in vitro can be enhanced by elicitation that stimulates metabolites biosynthesis via stress reaction. Vanadium compounds have been already described as potential elicitors, and the aim of this study was to determine the impact of NH₄VO₃ and VOSO₄ solutions on isoflavones production in L. cell cultures. The significant increase of isoflavones content, such as genistin, genistein, or formononetin, was measured in a nutrient medium or dry mass after NH₄VO₃ treatment for 24 or 48 h. The possible transport mechanism of isoflavones release as a result of elicitation was further evaluated. An incubation with different transport inhibitors prior to elicitation took effect on isoflavones content i...
Czech Journal of Food Sciences, 2017
The content of saccharides and lipids in wheat seeds from both conventional and organic agricultu... more The content of saccharides and lipids in wheat seeds from both conventional and organic agriculture was determined based on the length of germination (0, 2, or 5 days) and germination temperature (10 and 22°C). The content of saccharides was determined by HPLC, and the total lipid content was detected by Soxhlet extraction in the course of germination. While the non-germinated seeds had the highest content of glucose (6.95 mg/g) and fructose (4.37 mg/g), in conventionally grown seeds sucrose (5.03 mg/g) and maltose (3.62 mg/g) were at the highest level. In organically and conventionally produced seeds the contents of fructose, glucose, and maltose increased due to germination. While the content of lipids increased in the seeds from organic production on the second day from 0.46 g/10 g to 0.51 g/10 g (at 10°C) and 0.64 g/10 g (at 22°C). Differences in the content of saccharides and lipids between seeds from organic and conventional agriculture were not unequivocally confirmed.
Plant, Soil and Environment, 2017
The objective of this research was to evaluate trends and relationships of energy and toxic eleme... more The objective of this research was to evaluate trends and relationships of energy and toxic elements accumulation in A-horizon (the depth of 0–5 cm) of soils and in selected plants of the hemioligotrophic (Dystric Cambisols) and oligotrophic (Skeletic-Rustic Podzols) spruce ecosystems situated along transect (750–1110 m a.s.l.) in the NP Slovenský raj (Eastern Slovakia). The results showed that EU limit values of risk elements in agricultural soils were exceeded for Cu and Cd at the altitude of 750–760 m a.s.l., and in case of Cd also above 1000 m a.s.l. Relationship between energy and toxic elements in soils revealed that with an increasing amount of energy, contents of Zn and Cu significantly declined with altitude (r > –0.5 or r > –0.9). The background value of Cu was exceeded in all plants, that of Zn for Dryopteris filix-mas and Rubus idaeus. Furthermore, excessive accumulation of Cd was revealed by all plants. Cu contents in soils were dominant in determining Cu uptake f...
PloS one, 2017
A comparative analysis of various parameters that characterize plant morphology, growth, water st... more A comparative analysis of various parameters that characterize plant morphology, growth, water status, photosynthesis, cell damage, and antioxidative and osmoprotective systems together with an iTRAQ analysis of the leaf proteome was performed in two inbred lines of maize (Zea mays L.) differing in drought susceptibility and their reciprocal F1 hybrids. The aim of this study was to dissect the parent-hybrid relationships to better understand the mechanisms of the heterotic effect and its potential association with the stress response. The results clearly showed that the four examined genotypes have completely different strategies for coping with limited water availability and that the inherent properties of the F1 hybrids, i.e. positive heterosis in morphological parameters (or, more generally, a larger plant body) becomes a distinct disadvantage when the water supply is limited. However, although a greater loss of photosynthetic efficiency was an inherent disadvantage, the precise ...
Scientia Agriculturae Bohemica, 2000
Vagos, 2009
The aim of this trial is to estimate the influence of 24-epibrassinolide on chemical structure an... more The aim of this trial is to estimate the influence of 24-epibrassinolide on chemical structure and energy content in wheat grains (cv. Ebi, Estica, Samanta, AC Helena, Mollera and Lucia). The application of 24-epibrassinolide in stress conditions has positive effect on the monitored parameters (content of lipids, proteins, enzyme determination of total starch, energy content). The cultivars AC Helena and Samanta are more tolerant to drought and high temperature in comparison with Estica and Lucia, which have low level of tolerance. Cv. Mollera demonstrates the best reaction to the application of phytohormone. The stress tolerant cultivar Samanta demonstrates the least reaction to the application of 24-epibrassinolide.
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Papers by Helena Hnilickova