UDK: 582.661.51:631.53.027]:547.913 In order to investigate the effects of seed priming with silver fir and oregano essential oils on certain important seedling characteristic and seed vigour of interesting endemic and horticultural species Silene sendtneri, an experiment was conducted based on randomized completely design with three replications. Traits such as germination rate, water content, dry weight, vigour index and photosynthetic pigments were analysed. Results revealed that the seedlings obtained with priming seeds showed increased growth, water content, vigour and photosynthetic pigment contents but decreased germination rate and dry weight compared with that obtained with non-primed seeds. Analysis of seed priming effects had demonstrated even germination rate is smaller the seedling vigour is slightly higher especially with all oregano oil treatments. We suggest that oregano oil has a potential as a priming agent for improvement of seedling synchrony, although at lower rate of germination.

Kale (Brassica oleracea var. acephala) is known as a vegetable with good tolerance of environmental stress and numerous beneficial properties for human health, which are attributed to different phytochemicals. In the present study, investigation of how low temperatures affect proline, pigments and specialized metabolites content was performed using 8-weeks old kale plants subjected to chilling (at 8 °C, for 24 h) followed by short freezing (at −8 °C, for 1 h after previous acclimation at 8 °C, for 23 h). Plants growing at 21 °C served as a control. In both groups of plants (exposed to low temperatures and exposed to short freezing) a significant increase in proline content (14% and 49%, respectively) was recorded. Low temperatures (8 °C) induced an increase of pigments (total chlorophylls 7%) and phytochemicals (phenolic acids 3%; flavonoids 5%; carotenoids 15%; glucosinolates 21%) content, while exposure to freezing showed a different trend dependent upon observed parameter. After freezing, the content of chlorophylls, carotenoids, and total phenolic acids retained similar levels as in control plants and amounted to 14.65 ± 0.36 mg dw g−1, 2.58 ± 0.05 mg dw g−1 and 13.75 ± 0.07 mg dw CEA g−1, respectively. At the freezing temperature, total polyphenol content increased 13% and total flavonoids and glucosinolates content decreased 21% and 54%, respectively. Our results suggest that acclimatization (23 h at 8 °C) of kale plants can be beneficial for the accumulation of pigments and phytochemicals, while freezing temperatures affect differently specialized metabolite synthesis. The study suggests that growing temperature during kale cultivation must be considered as an important parameter for producers that are orientated towards production of crops with an increasing content of health-related compounds.

Gentiana lutea L. is a medicinal plant the roots of which are primarily used in treatments of various human digestive disorders, but also the production of alcoholic liquors. The roots (radix) of G. lutea are described in the European Pharmacopeia, but knowledge about the chemical composition and biological activities of its aerial parts is still limited. Thus, until today aerial parts of this species have not been used in medical treatments or consumed. Therefore, flowers, leaves, and stems extracts of G. lutea obtained by using four different extraction solvents (petrol ether, chloroform, ethanol, and water) were examined for their chemical composition and biological activities. High concentrations of salicylic acid, apigenin, and naringenin were recorded for ethanol stem extracts, while significant amounts of kaempferol were detected in leaves and flowers in chloroform and water extracts, respectively. The highest antioxidant potential was recorded for flower and stem petrol ether extracts with the lowest IC50 values, ranging from 94.46 ± 9.45 to 105.38 ± 10.54 μg/mL. Ethanol extracts of flowers and stems showed moderate antioxidant activity (IC50 143.15 ± 14.32 and 146.90 ± 14.69 μg/mL) as well as strong antimicrobial activity against Candida albicans (21.00 ± 1.00 and 27.50 ± 1.78 mm inhibition zones, respectively). In addition, ethanol extracts had higher antimycotic activity compared to naturally occurring phenolic compounds that are used as positive controls. Moreover, statistical analysis of the activities of plant extracts and single compounds showed that levels of chlorogenic and caffeic acids strongly correlate with the biological activities of the extracts, i.e., they are the main carriers of these biological activities. The presented results indicate the possible use of aerial parts of G. lutea as a natural preservative, as well as a antimicrobial agent, which significantly amplifies the benefits of this medicinal crop and greatly affects the sustainability of cultivated Gentiana plantation.

Although epigenetic modifications have been intensely investigated over the last decade due to their role in crop adaptation to rapid climate change, it is unclear which epigenetic changes are heritable and therefore transmitted to their progeny. The identification of epigenetic marks that are transmitted to the next generations is of primary importance for their use in breeding and for the development of new cultivars with a broad-spectrum of tolerance/resistance to abiotic and biotic stresses. In this review, we discuss general aspects of plant responses to environmental stresses and provide an overview of recent findings on the role of transgenerational epigenetic modifications in crops. In addition, we take the opportunity to describe the aims of EPI-CATCH, an international COST action consortium composed by researchers from 28 countries. The aim of this COST action launched in 2020 is: (1) to define standardized pipelines and methods used in the study of epigenetic mechanisms in plants, (2) update, share, and exchange findings in epigenetic responses to environmental stresses in plants, (3) develop new concepts and frontiers in plant epigenetics and epigenomics, (4) enhance dissemination, communication, and transfer of knowledge in plant epigenetics and epigenomics.

The phenolic composition, as well as the antioxidant and antimicrobial activities of two poorly investigated Achillea species, Achillea lingulata Waldst. and the endemic Achillea abrotanoides Vis., were studied. To obtain a more detailed phytochemical profile, four solvents with different polarities were used for the preparation of the plant extracts whose phenolic composition was analyzed using UHPLC-MS/MS (ultra-high performance liquid chromatography-tandem mass spectrometry). The results indicate that both of the investigated Achillea species are very rich in both phenolic acids and flavonoids, but that their profiles differ significantly. Chloroform extracts from both species had the highest yields and were the most chemically versatile. The majority of the examined extracts showed antimicrobial activity, while ethanolic extracts from both species were potent against all tested microorganisms. Furthermore, the antioxidant activity of the extracts was evaluated. It was found that the ethanolic extracts possessed the strongest antioxidant activities, although these extracts did not contain the highest amounts of detected phenolic compounds. In addition, several representatives of phenolic compounds were also assayed for these biological activities. Results suggest that ethanol is a sufficient solvent for the isolation of biologically active compounds from both Achillea species. Moreover, it was shown that the flavonoids naringenin and morin are mainly responsible for these antimicrobial activities, while caffeic, salicylic, chlorogenic, p-coumaric, p-hydroxybenzoic, and rosmarinic acid are responsible for the antioxidant activities of the Achillea extracts.

Abiotic stressors such as extreme temperatures, drought, flood, light, salt, and heavy metals alter biological diversity and crop production worldwide. Therefore, it is important to know the mechanisms by which plants cope with stress conditions. Polyphenols, which are the largest group of plant-specialized metabolites, are generally recognized as molecules involved in stress protection in plants. This diverse group of metabolites contains various structures, from simple forms consisting of one aromatic ring to more complex ones consisting of large number of polymerized molecules. Consequently, all these molecules, depending on their structure, may show different roles in plant growth, development, and stress protection. In the present review, we aimed to summarize data on how different polyphenol structures influence their biological activity and their roles in abiotic stress responses. We focused our review on phenolic acids, flavonoids, stilbenoids, and lignans.

Cadmium (Cd) is abundant heavy metal with highly toxic effect on plants. The aim of presented study was to investigate the effect of seed priming using salicylic acid on cadmium tolerance in lettuce. The tolerance level was evaluated using germination speed and percentage, fresh and dry seedling weight, water and photosynthetic pigments content. Control seeds were primed using distilled water. In control plants cadmium induced reduction of germination rate, fresh and dry weight, water and chlorophyll content. Seed priming using salicylic acid, on the other hand, induced increased resistance of lettuce to cadmium toxicity. Increase in germination rate, fresh mass and water content were recorded for plants subjected to 5 mM Cd, grown from seeds primed using salicylic acid. Results obtained by this study suggested that salicylic acid can be used as priming agent in order to alleviate Cd toxicity on lettuce.

Antifungal, antimicrobial, insecticidal and antioxidant activities of Origanum vulgare L. provide the basis for suggesting that oregano plant extracts may be useful for prevention and treatment of many infection. The main goal of this study was to determine antimicrobial and antioxidant activities of methanolic and aqueous extracts from the leaves and flowers of Origanum vulgare. Antimicrobial testing of plant extracts was done using well diffusion method. Activity of extracts were tested against Gram positive bacteria: Staphylococcus aureus ATCC 25923, methicillin-resistant Staphylococcus aureus (MRSA) ATCC 33591, Bacillus subtilis ATCC 6633, Enterococcus faecalis ATCC 29212 and five Gram-negative bacteria: Salmonella abony ATCC 6017, Salmonella enterica serovar Enteritidis ATCC 31194, Pseudomonas aeruginosa ATCC 9027, Escherichia coli ATCC 25922, extended-spectrum β-lactamase (ESBL) producing Escherichia coli ATCC 35218 and fungi Candida albicans ATCC 1023. Antibiotics ampicillin, streptomycin and antimycotic nystatin were used as positive controle. The antioxidant activity was determined by using the DPPH (1,1-diphenyl-2-picrylhydrazyl) method. The highest values for inhibition zone for methanolic and aqueous extracts were recorded for Gram positive Bacillus subtilis, Staphylococcus aureus and MRSA. Methanolic extracts exhibited antibacterial activity against tested Gram negative bacteria in variable degree while the growth of these bacteria was not inhibited by aqueous extracts. Tested fungi Candida albicans was not susceptible to investigated oregano extracts. All the extracts showed moderate to potent antioxidant activity, among which the methanolic flower extract demonstrated the strongest antioxidant activity with the IC50 value of 0.205 mg/mL. Therefore it can be concluded that flower and leaf oregano extracts have great antibacterial and antioxidant potential.

Abstract Detailed analysis of phenolic composition and antioxidant and antimicrobial activities of Verbascum glabratum subsp. bosnense (K. Malý) Murb., an endemic species of southeastern Dinaric Alps was performed for the first time. The phenolic composition measured via UHPLC-MS/MS of four extract with different polarity suggested this plant species is very rich in both phenolic acids and flavonoids. Ethanol extract was chemically the most versatile containing 12 compounds with quercitrin and rosmarinic acid as the majors, while water extracts were rich in 4-hydroxybenzoic acid, salicylic acid, morin, and apigenin. All extracts showed high antioxidant potential measured spectrophotometrically with IC50 values ranging 0.139 - 0.021 mg/mL. Antimicrobial testing using agar diffusion test showed that ethanol extract was the most potent against all tested organisms. Also, these activities are correlated with the content of phenolic compounds, which suggest they are active ingredients of the extracts. Graphical Abstract