The genus Secale is small but very diverse. Despite the high economic importance, phylogenetic relationships of rye species have not been fully determined, and they are extremely important for the process of breeding of new cultivars that can be enriched with functional traits derived from wild rye species. The study analyzed the degree of relationship of 35 accessions of the genus Secale , representing 13 most often distinguished species and subspecies, originating from various seed collections in the world, based on the analysis of non-coding regions of the chloroplast (cpDNA) and mitochondrial genome (mtDNA), widely used in phylogenetic and population plant studies, because of a higher rate of evolution than the coding regions. There was no clear genetic structure between different species and subspecies, which may indicated the introgression between these taxa. The obtained data confirmed that S . vavilovii was very similar to S . cereale , which confirmed the assumption that they might share a common ancestor. The results also confirmed the divergence of S . sylvestre from other species and subspecies of rye. Areas that may be useful molecular markers in studies on closely related species of the genus Secale were also indicated.

The centromere is a chromosomal region where the kinetochore is formed, which is the attachment point of spindle fibers. Thus, it is responsible for the correct chromosome segregation during cell division. Telomeres protect chromosome ends against enzymatic degradation and fusions, and localize chromosomes in the cell nucleus. For this reason, centromeres and telomeres are parts of each linear chromosome that are necessary for their proper functioning. More and more research results show that the identity and functions of these chromosomal regions are epigenetically determined. Telomeres and centromeres are both usually described as highly condensed heterochromatin regions. However, the epigenetic nature of centromeres and telomeres is unique, as epigenetic modifications characteristic of both eu- and heterochromatin have been found in these areas. This specificity allows for the proper functioning of both regions, thereby affecting chromosome homeostasis. This review focuses on demonstrating the role of epigenetic mechanisms in the functioning of centromeres and telomeres in plants and animals.

No abstract

Sirtuins are proteins belonging to the group of NADH-dependent deacetylase and mono-ADP-ribosyltransferase enzymes. Sirtuins have been discovered for the first time in yeasts, subsequent studies have shown their presence in bacteria, plants and animals. These enzymes are frequently called longevity enzymes due to the fact that they are part of genetic apparatus involved in aging control. In animals, sirtuins are key regulators of cell defense in response to stress caused by many metabolic processes; they are also involved in the regulation of cell division, metabolism, gene silencing and genetic material repair as well as apoptosis. Thus far, only several well-known research teams have been studying plant proteins resembling animal sirtuins. Considering the fact how essential functions sirtuins play in other organisms, it is extremely interesting to understand their role in plants, especially that the knowledge about them is still limited. It is believed that the function of sirtuins in Arabidopsis thaliana is associated with mitochondrial energy metabolism. Possibly they may also control the synthesis of auxins or proteins involved in their transport, or they may be responsible for regulating cellular response to auxin action. In rice, sirtuins are necessary for the protection against genomic instability and cell damage that guarantee their growth. They also take part in a defensive response against Pseudomonas syringae. They may also be involved in the ripening of fruits.Moreover, their functions are associated with photosynthetic activity and aging of leaves.

No abstract

No abstract

DNA barcoding is a relatively new method of identifying plant species using short sequences of chloroplast DNA. Although there is a large number of studies using barcoding on various plant species, there are no such studies in the genus Secale. In this study the plant material consisted of 10 cultivated and non-cultivated species and subspecies of rye genus. Three chloroplast DNA regions (rbcL, matK, trnH-psbA) were tested for their suitability as DNA barcoding regions. Universal primers were used, and sequenced products were analyzed using Neighbor Joining and the Maximum Likelihood in the MEGA 7.1 program. We did not observe high variability in nucleotide sequences within the matK and rbcL regions. Only 2.2% of the sequences showed polymorphism in the rbcL region, while 6.5% in the matK region. The most variable trnH-psbA (15.6%) intergenic region was the most useful for rye barcoding. Individual application of the studied regions did not provide the expected results. None of the regions used in the study allowed the division of rye species and subspecies according to the adopted classification of the genus Secale. The results confirm that the use of matK and rbcL is insufficient for DNA barcoding in rye species, and better discrimination within the genus Secale can be obtained only in combination with the non-coding trnH-psbA sequence. Our results also indicate the necessity of using a different region. All of the new sequences have been deposited in Genbank.

Non-coding rDNA spacers (IGS) can vary substantially in size due to differences in the number of repetitive elements among closely related species. Three pairs of universal primers were used in this study for the amplification of non-coding regions of ribosomal (rRNA) IGS. The amplified IGS products obtained from 19 Secale accessions, which included both cultivated and noncultivated rye and which represented three species and four subspecies of the genus Secale, showed a high level of polymorphism. The PCR results were characterized by multiple bands (1-6), different sizes (750bp-3250bp) and 100% polymorphism. Cluster analysis using the neighborjoining method based on the Dice’s coefficient of genetic similarity showed a division of the studied species into two similarity groups. All the studied Secale cereale ssp. cereale were found to belong to the same similarity group. The variation in the size of the IGS among the species which was detected in this study could be due to dissimilarity between the sequences of their respective repetitive elements or between their tandem repeat numbers. The highly interspecific polymorphisms for the rDNA IGS regions suggested that IGS might be a useful molecular marker in studies of Secale species.