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.

Mucilage is one of the key components of flaxseed (which is also called linseed), and exhibits unique functional properties such as high water-holding capacity, and foamability. As a result, flaxseed mucilage has applications in food, agriculture, medicine and other industries. The composition and functional properties of mucilage vary between genotypes. To explore this variation, we characterized the mucilage of nine diverse varieties of flaxseed according a range of parameters including: morphology, mucilage content, fibre content, minerals, phenolic acids, polyphenols, antimicrobial activity, and antioxidant activity. We found significant differences between the genotypes in almost all of the parameters tested. Furthermore, we found a strong correlation between several of these parameters, including antioxidant activity, hydroxycinnamic acid, and sugar content. Antimicrobial activity against Gram positive bacteria was correlated with fibre content and potassium content, while chlorogenic acid content was correlated with suppression of Gram negative bacteria. These results provide a framework for crop improvement further development of functional and value-added products from flaxseed.

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.

The worldwide steep rise of vegetable oil consumption creates an urgency to improve oilseed crop yield. Sesame ( Sesamum indicum L.) is called the “Queen of Oilseeds” due to the voluminous presence of several vitamins, minerals, antioxidants, and beneficial fatty acids; the oil is considered safe for consumption. It is widely cultivated in the tropical and subtropical regions throughout the world. However, compared to other oilseed crops, the meagre yield of sesame largely hampers its successful commercialisation. The major problems associated with this crop are early pod shattering and susceptibility to various abiotic and biotic stresses. Biotechnology-mediated crop improvement is a good alternative to slow, labour-intensive, and cumbersome conventional breeding methods. Worldwide efforts can be observed to improve targeted traits of this crop using modern biotechnological tools. However, the lack of a well-accepted regeneration and transformation protocol is the major burden in implementing biotechnological yield improvement methods in sesame, especially transgenesis-mediated gene manipulation techniques. In this review, we discussed the growth and cultivation scenario of sesame. We also depicted the important problems associated with low crop yield. Next, we represented the current progress of regeneration and associated transgenesis-mediated gene manipulation research in sesame. We also briefed on the importance of sesame whole-genome sequencing. Finally, we presented a concise discussion on the available potential genes, regulatory elements, DNA markers, and QTLs that can be used in gene manipulative and marker-assisted selection-based yield improvement programmes. Information presented in this review article could potentially be utilised for yield improvement research in sesame.

In this study, we examined over 200-year-old Ginkgo biloba L. specimens under different environmental conditions. The overall aim was to explore which factors influence their vitality and general fitness in urban environments and thus their ability to tolerate stressful habitats. In order to determine this, we used a number of different methods, including histological examinations (stomatal density and size) and physiological measurements (peroxidase enzyme activity), as well as assessing the air pollution tolerance index (APTI). The investigation of the genetic relationships between individuals was performed using flow cytometry and miRNA marker methods. The genetic tests revealed that all individuals are diploid, whereas the lus-miR168 and lus-miR408 markers indicated a kinship relation between them. These results show that the effect of different habitat characteristics can be detected through morphological and physiological responses, thus indicating relatively higher stress values for all studied individuals. A significant correlation can be found between the level of adaptability and the relatedness of the examined individuals. These results suggest that Ginkgo biloba L. is well adapted to an environment with increased stress factors and therefore suitable for use in urban areas.

Flaxseed (Linum usitatissimum L.) is renowned for having the highest concentration of lignans among all plant species worldwide. However, it also contains a notable amount of cyanogenic glycosides, prompting efforts to reduce their levels. MicroRNAs, recognized as significant epigenetic factors, hold the potential to serve as genetic markers in achieving this breeding goal. In this study, 44,885 mature microRNAs were utilized alongside one genome and four transcriptomes of flax. Twelve gene sequences were obtained for five lignan enzymes and three enzymes related to cyanogenic glycosides. Based on our in silico approach, we identified 15 microRNA families for the lignan metabolic pathway, 10 for the cyanogenic glycoside pathway, and 6 regulating both pathways. Additionally, we contributed to the annotation of the used transcriptomes and verified the functionality of the “Finding genes by keyword” algorithm available on Phytozome 13. The results obtained led to the design of a unique schema for microRNA mediated regulation in the biosynthetic pathways of lignans and cyanogenic glycosides. This research will enhance our understanding of the regulatory mechanisms of microRNA in these biosynthetic pathways, along with other specialized metabolites. The predicted microRNAs can be employed in marker-assisted selection with the breeding objective of optimizing the ratio of nutritional and antinutritional components in flaxseed while maintaining current physiological parameters.