Lignans, as secondary metabolites synthesized within a phenylpropanoid pathway, play various roles in plants, including their involvement in growth and plant defense processes. The health and nutritional benefits of lignans are unquestionable, and many studies have been devoted to these attributes. Although the regulatory role of miRNAs in the biosynthesis of secondary metabolites has been widely reported, there is no systematic review available on the miRNA-based regulatory mechanism of lignans biosynthesis. However, the genetic background of lignan biosynthesis in plants is well characterized. We attempted to put together a regulatory mosaic based on current knowledge describing miRNA-mediated regulation of genes, enzymes, or transcription factors involved in this biosynthesis process. At the same time, we would like to underline the fact that further research is necessary to improve our understanding of the miRNAs regulating plant lignan biosynthesis by exploitation of current approaches for functional identification of miRNAs.

Some seeds of flowering plants can differentiate their seed coat epidermis into the specialized cell layer producing a hydrophilic mucilage with several ecological functions, such as seed hydration, protection, spatial fixation, stimulation of metabolic activity and development of seed. Due to the species- and genotype-dependent variabilities in the chemical composition of mucilage, mucilage does not display the same functional properties and its role depends on the respective species and environment. Mucilaginous substances, depending on their composition, exhibit many preventive and curative effects for human and animal health, which has significant potential in the agricultural, food, cosmetic and pharmaceutical industries. This paper summarizes the ecological, biological, and functional properties of mucilaginous plant substances and highlights their significant nutritional potential in terms of the development of functional foods, and nutraceuticals and dietary supplements. A paragraph describing the gene regulation of seed mucilage synthesis is included, and some recommendations for the direction of further research on mucilaginous substances are outlined.

Naturally occurring lignans are present in seeds, nuts, cereals, vegetables, and fruits. Lignans play various roles in plants and their multipurpose functions of different organisms including humans is considerable. They are involved in plant defence mechanisms through their antioxidant, antiviral, antibacterial, and antifungal properties. The lignans content may be affected by a variety of factors such as genotype, tissue type, geographic origin, local environmental conditions, nutrition, and plant maturity. Interactive relationships between individual factors are also considered. This review aimed to summarize the biological functions of lignans for plants and empasize the importance of these compounds for the added value of individual genotypes of plant food resources. Understanding the biological functions of lignans in plants can provide solutions to the ever-increasing requirements for the production of functional foods. Flaxseed is the richest source of lignans, and as such is considered the model species for lignans studies. Within our review, one paragraph is focused on the properties and biological functions of flax lignans.

Plants have metabolites and mechanisms that provide them with the basic building blocks for germination, growth, and reproduction processes, while providing them with protection and increasing their adaptation to environmental stresses. Due to their multifunctional significance, cyanogenic glycosides (CNG) indicate the importance of their role in the plant organism. Their diversity and biochemical origin are worth noting. Paradoxically, several nutritionally important food sources of plant origin are characterized by the presence of cyanogenic glycosides in various tissues. Processing approaches of plant food resources ensure a reduction in the content of these ingredients to an acceptable safe level. Different bacteria-based biotechnological processes are applied to minimize the content of CNG in food products. For the usability and identification of the added value of plant food resources, it is important to know the functions and importance of antinutritional components of metabolism with a consequent impact on nutrition and health. In the review we provided a comprehensive view of the importance and potential of CNG in plants with a focus on food sources, where the model object was presented by linseed.

Aesculus hippocastanum L. ˈBaumaniiˈ (syn.: A. hippocastanum L. ˈFlore Plenoˈ; A. hippocastanum ˈPlenaˈ) is a rarely cultivated cultivar characterized by fully white and sterile flowers, and as a result it does not produce fruit. For identification and characterization of the morphological, molecular, and biochemical parameters of this cultivar, we performed the pollen viability test, morphological analysis of flowers, assay of miRNA-based markers and biochemical analyses. The results show that the germination of pollen grains in artificial media reached 0 % and the pistil in flowers was undeveloped. The antioxidant activity, total polyphenol and flavonoid content exhibited the highest values of all three tested parameters (1.5540 mg TEAC/g FM; 3.7278 mg GAE/g FM and 1.328 mg CAE/g FM) in the extracts from A. hippocastanum ˈBaumaniiˈ. The applied miRNA-based markers showed a sample-specific and tissue-specific genomic polymorphism. Various DNA fingerprinting profiles between the flowers and leaf samples of fruiting and barren trees were noted. URL: https://www.upjs.sk/pracoviska/botanicka-zahrada/odborne-aktivity/contents-abstracts/