This study presents the first report on phenolic composition and bioactivity of ethanolic extracts of three plant species that grow in the western Balkan mountains and are used in traditional folk medicine: Valeriana montana, Salix retusa, and Campanula hercegovina. Phenolics were extracted from different aerial plant parts using 80% ethanol to assess the possibility of sustainable use of these plants as a source of bioactive compounds without disruption to the roots (for V. montana) or destruction of whole habitats (for S. retusa and C. hercegovina). The ethanolic extract of V. montana flower contained noticeable levels of apigenin and quercetin. The branches and bark of S. retusa were significantly rich in catechin, while rutin was the major phenolic found in the leaf extract of C. hercegovina. Furthermore, the flower extract of V. montana revealed the best antioxidant activity, which was comparable to 4-hydroxybenzoic acid and quercetin. Considering antimicrobial activity, the leaf extracts of V. montana and C. hercegovina demonstrated potent activity against all microbes tested, while the extracts of S. retusa were moderately effective. The presented results emphasize the potential of these plants as novel sources of bioactive compounds.

Salt stress results from excessive salt accumulation in the soil can lead to a reduction in plant growth and yield. Due to climate change, in the future climatic pressures, changed precipitation cycles and increased temperature will increase the pressures on agriculture, including increasing severity of salt stress. Brassica species contains oilseed and vegetable crops with great economic importance. Advances in understanding the mechanisms of salt stress in Brassica plants have enabled the development of approaches to better induce plant defense mechanisms at the time of their occurrence through the use of beneficial microorganisms or molecules. Both endophytic and rhizospheric microbes contribute to the mitigation of abiotic stresses in Brassica plants by promoting the growth of their host under stress conditions. In this review we summarized so far reported microorganisms with beneficial effects on Brassica plants and their mode of action. Another approach in mitigating the harmful effect of soil salinity may involve the application of different molecules that are involved in the stress response of Brassica plants. We reviewed and summarized their potential mode of action, methods of application and pointed out further research directions.

Cadmium (Cd) is a heavy metal present in atmosphere, rocks, sediments, and soils without a known role in plants. It is relatively mobile and can easily enter from soil into groundwater and contaminate the food chain. Its presence in food in excess amounts may cause severe conditions in humans, therefore prevention of cadmium entering the food chain and its removal from contaminated soils are important steps in preserving public health. In the last several years, several approaches for Cd remediation have been proposed, such as the use of soil amendments or biological systems for reduction of Cd contamination. One of the approaches is phytoremediation, which involves the use of plants for soil clean-up. In this review we summarized current data on the use of different plants in phytoremediation of Cd as well as information about different approaches which have been used to enhance phytoremediation. This includes data on the increasing metal bioavailability in the soil, plant biomass, and plant accumulation capacity as well as seed priming as a promising novel approach for phytoremediation enhancing.

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.

Changes in the environment as a result of industrialisation and urbanisation impact negatively on plant growth and crop production. Cadmium (Cd) is one of the most dangerous metals that enters the food chain, with toxic effects on plants and human health. This study evaluated the potential of Silene sendtneri as a novel hyperaccumulator and the role of seed priming in tolerance and accumulation rate of Cd. The effect of different priming agents on germination performance, root growth, seedling development, metal uptake and accumulation, antioxidant defences including enzymatic and non-enzymatic antioxidants has been assessed. Seed priming using silicic acid, proline alone or in combination with salicylic acid- enhanced germination, seedling development, and root growth under Cd stress. The same priming treatments induced an increase of water content in shoots and roots when plants were exposed to Cd. The enzymatic antioxidant response was specific for the priming agent used. An increase in ferulic acid and rutin in shoots was related to the increase of Cd concentration in the medium. The concentration of malic and oxalic acid increased significantly in shoots of plants grown on high Cd concentrations compared to low Cd concentrations. Silene sendtneri can accumulate significant levels of Cd with enhanced accumulation rate and tolerance when seeds are primed. The best results are obtained by seed priming using 1% silicic acid, proline and salicylic acid.

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.

Abstract Basil (Ocimum basilicum L.), as an aromatic and medicinal plant, exhibits numerous of genotypes that have various applications in food and pharmaceutical industries. Thus, chemical composition is an important parameter for assessing the quality of basil. Hence, twelve European basil genotypes were cultivated under the same conditions, and isolated essential oils and methanol extracts were subjected to detailed chemical analyses and testing their biological activities. According to the analysis of the volatiles, all genotypes belong to linalool chemotype, and they were clustered into two groups. Rosmarinic acid was found to be the major phenylpropanoid, following with luteoin, kaempherol, and rutin. Principal component analysis of phenolic compounds indicated segregation of genotypes in two distinct groups. Biological activities of the isolated extracts were correlated with the concentrations of the actives, and it was found that naringenin, luteolin, and kaempherol are the main carriers of antioxidant activity, while the levels of linalool correlated with tyrosinase inhibition activity. Adversely, methyl chavicol showed negative correlations with both assays. Finally, it was found that Czech genotypes (Litra and Chladek), as well as Dutch (Bush) and Italian (Fino Verde Compatto) possess significant amounts of terpenoid linalool, together with flavonoids luteolin, naringenin, and kaempherol, and therefore, have strong biological activities required for their use in food and cosmetic industries.

Abstract Ailanthus altissima (Mill.) Swingle, tree of heaven, is an exotic tree introduced as a horticultural tree in Europe and America in 18th Century. Now it is aggressively invading ecosystems. This study was aimed to estimate phytotoxic potential of essential oils (EOs) from fourteen industrial, aromatic and medicinal crops, such as Thymus sp., Pinus sp., Origanum sp. etc. against this invasive species. The phytotoxic potential was assessed through three different doses of EOs by a germination bioassay and the effects on seedling growth. Analysis of seedling growth revealed that seven EOs (Petasites hybridus, Thymus serpyllum, Thymus vulgaris, Rosmarinus officinalis, Helichrysum italicum, Matricaria chamomilla, Origanum vulgare) exhibit high phytotoxic effect resulting in 95–100% seedling mortality. Moreover, detailed GC-MS analysis of these oils showed that they are mostly comprised either of oxygenated monoterpenes or sesquiterpene hydrocarbons, which are already known as compounds with allelopathic effects. Presented results indicate these essential oils might be used as natural herbicides by foliar application of oils on young plants of Ailanthus altissima.