Katarzyna Możdżeń

Metabolic activity, the chemical composition of biomass and photosynthetic activity of Chlorella vulgaris under different light spectra in photobioreactors.

Omitting the far‐red in LED lighting for bioreactors is inexplicable because it affects photosynthetic efficiency and photomorphogenetic activity. Therefore, this work compares three light sources (fluorescent—white light (WL), and LED: blue + red—BRL and blue + red + far‐red—BRFRL) for cultures of Chlorella vulgaris. Metabolic activity was determined by isothermal calorimetry. Changes in the chemical composition of biomass were examined by spectrofluorimetry and Raman spectroscopy. Maximum quantum yield of photosystem II was determined on the basis of chlorophyll a fluorescence parameters. The algae grown under BRL produced significantly more thermal energy than those cultured under BRFRL and WL. The Raman spectra of cultures showed characteristic bands for carotenoids, chlorophyll, phenolics, lipids, aliphatic carbohydrates, pectins, and disaccharides. According to the cluster analysis, the chemical composition of cultures grown under BRL and BRFRL was very similar, whereas the WL represented a distinct group. BRL and BRFRL stimulated the biosynthesis of an unidentified compound(s) with fluorescence maximum at 614 nm. At the beginning of the cultivation, photosystem II had very weak photochemical activity. Under BRFRL, ratios of Fv/Fm reached the maximum after 4 days, whereas under BRL and WL, after 6 days of cultivation. The results point to the favorable influence of the far‐red on the metabolism of microalgae.

Toxic effects of high copper content on physiological processes in Pinus sylvestris L.

The aim of this study was to determine the impact of increased copper contents on selected physiological processes in oneyear-old Pinus sylvestris L. needles from a former German timber storage area in Warcino Forest District, a subject to an environmental quality survey. Samples were collected from the area with the high copper content in the soil. The control area was a nearby pine tree stand showing unimpeded growth. The significant growth inhibition was found in dwarf shoots and whole needles, increased water content, and reduced dry mass were also observed. The chlorophyll content was lowered, while 20% higher electrolyte leakage was found. Chlorophyll a fluorescence indicated only higher values of the nonphotochemical quenching in P. sylvestris from the Cu-site. Significant differences were shown in the rate of gas exchange measured by changes in carbon dioxide or oxygen concentration. The intensity of photosynthesis in needles of P. sylvestris from the Cu-site measured by CO2 uptake was considerably higher than that of oxygen production. The rate of respiration in the needles from the Cu-site measured by the amount of released CO2 was higher only by 15%, while according to O2 consumed, the rate increased by 30% in relation to the control. Our results suggest that the copper accumulation in P. sylvestris needles affected the morphology and physiology of the studied organs.

Photosynthesis and sucrose metabolism in leaves of Arabidopsis thaliana aos, ein4 and rcd1 mutants as affected by wounding

We have investigated the influence of mechanical wounding of Arabidopsis rosette leaves on photochemical activity of photosystem II, gas exchange, sugar content and sucrose metabolism in wild-type plants and mutants impaired in hormonal balance. The aos (jasmonate deficiency), rcd1 (reduced sensitivity to ABA, ethylene, and methyl-jasmonate), and ein4 (ethylene insensitivity) mutants have been used. Generally, mechanical injury led to dynamic changes in metabolism, especially in sugar and carotenoid contents. Whereas all mutants showed lower photosynthesis and respiration in comparison to the wild-type plants, leaf wounding caused a decrease in respiration in aos and ein4, and an increase in respiration in wild type. The mechanical injury triggered an increase of the activities of sucrose hydrolysing enzymes, such as sucrose synthase (SuSy) and several types of invertases, which was most evident in case of rcd1 and aos plants. This was correlated with injury-related changes in soluble sugars in the mutants, but not in wild-type plants where sugar content was not significantly affected by wounding. The results confirm the key role of stress hormones, such as jasmonate and ethylene, in mediating stress responses after wounding. The outcome of the experiments also underlines important roles of SuSy and invertase in regeneration of injured tissues, most probably by providing precursors for cell wall biosynthesis and by modulating sugar-signalling in plant cells.

Photosynthetic efficiency of endosymbiotic algae of Paramecium bursaria originating from locations with cold and warm climates

Abstract Paramecium bursaria (Ciliophora) is a cosmopolitan unicellular organism that plays a significant role in aquatic ecosystems. P. bursaria contains symbiotic algae and this association is a mutual symbiosis. The aim of the present study was to determine the activity of photosystem II (PSII) in Chlorella sp. inside P. bursaria cells. Ciliates were incubated for 7 days at different temperatures from 6 to 18°C, under the circadian cycle: 12 h light/12 h dark, at light intensity of 200 μmol m-2 s-1 and under constant darkness conditions. The control group was kept at a temperature of 18°C under constant light conditions. Changes in PSII were monitored using different fluorescence parameters. Differences in responses between endosymbiotic algae of two P. bursaria strains – Ard7 from a warm climate and KD64 from a cold climate – were determined. The highest photosynthetic activity of P. bursaria green endosymbionts was observed at a temperature of 18°C, regardless of the light conditions. Algae from warm climate were more sensitive to cold temperature stress than algae from P. bursaria collected in cold climate.

Phytic acid, iron and zinc content in wheat ploidy levels and amphiploids: the impact of genotype and planting seasons

ABSTRACT Micronutrient deficiency is one of the most common and widespread nutritional issues. Among the factors mitigating the bioavailability of Zn (zinc) and Fe (iron), phytic acid plays a key role; therefore, in order to scrutinize genetic alterations ‎related to micronutrient and phytate contents, we examined the concentrations of zinc, iron, and phytic acid, as well as its mole ratio to ‎zinc in various wheat species grown in two planting seasons. The concentrations of phytic acid and its mole ratio to zinc were 0.61‒1.55 g kg−1 dry weight and 1.88‒4.17 for autumn, and 0.97‒2.02 g kg−1 dry weight and 2.10‒4.05 for spring planting. There was a significant discrepancy among wheat species; tritipyrum had the highest concentration of iron, phytic acid and its mole ratio to zinc, and T. monococcum and T. aestivum recorded reasonable zinc bioavailability. Correlation studies between grain phytic acid concentrations and other measured traits revealed various relationships, denoting an irrefutable impact of planting season and wheat ploidy levels on modification of wheat genotypes. The characters contributing more positively with principal component (PC) 1 were Zn and Fe under spring planting and Fe under autumn planting. Spike number per square meter, biological yield and grain yield in spring cultivation, and grain zinc concentration in autumn cultivation were positively correlated to principal component (PC) 2. Given that the concentration of Fe and Zn in all the studied genotypes is relatively high and due to the existence of other desirable agronomic traits, this study believes that it could possibly enhance the applicability of some of these genotypes for breeding purposes.

Environmental awareness of students living near selected national parks in countries of visegrád group

The aim of this study was to evaluate environmental awareness of young people and effectiveness of education used by national parks. The research occurred in the period from 2012 to 2014. The Veľká Fatra National Park (Slovakia), Bohemian Switzerland National Park (Czech Republic), Bieszczady National Park (Poland) and Bükki National Park (Hungary) as parks of countries of the Visegrád Group were analysed. The study was focused on the target group of students of gymnasiums and secondary schools in the regions where national parks are located and outside these regions. In all the analysed countries we used a questionnaire, which was distributed among 1301 students. For each respondent, answers were entered in a spreadsheet and statistically analysed. The following non-parametric statistical tests were used: Kruskal-Wallis, Friedman, Wilcoxon and parametric ANOVA. The best results were noted among students from Poland and the Czech Republic. In other countries of the Visegrád Group therefore it is appropriate to introduce actions aiming at increasing the ecological awareness of students, according to the models of education functioning in national parks and schools in Poland and the Czech Republic. It is also necessary to revise the ways in which national environmental education exists in all studied countries, as well as to strengthen volunteer activities.

Synanthropization of riparian plant communities in the Ojców National Park (Southern Poland)

Abstract Although riparian forests are still common in Europe, their variants - similar to natural forests - are rare. They are, as communities, early stages of forest-shrub succession, particularly vulnerable to the expansion of neophytes for which they are an important type of vegetation that enables their spread. In the Ojców National Park (ON P), these types of phytocoenoses are heavily influenced by anthropogenic pressure. The preservation of their biodiversity is particularly difficult because of the fragmentation and small area occupied by the Park - just 2.89 ha. There have been no data on synanthropization of ON P riparian forests until now. The ‘conservation status’ of these communities was determined by examining the degree of anthropophyte participation in their floristic composition. This determination is necessary to take effective preventive measures. In 2012-2014, phytosociological studies were carried out on the ON P riparian communities. A particular attention was paid to the presence and quantitative participation of alien species in research plots. The obtained results revealed that there were 189 plant species in alluvial forests of the ON P, including 80 synanthropic species. The group of synanthropes comprised 32 anthropophytes: 5 diaphytes, 9 archaeophytes and 18 kenophytes.