Comparative analysis of phenolic acids and flavonoids in shoot cultures of Eryngium alpinum L. : an endangered and protected species with medicinal value

Phenolic acids and flavonoids, important bioactive compounds of polyphenols, play a significant role in plants; their impact, mainly as antioxidants, on human health have been of great interest in recent years. The genetically uniform shoots of Eryngium alpinum L. cultured in vitro, developed via axillary buds and regenerated from callus tissue, maintained on the media supplemented with various plant growth regulators, were subjected to the phenolic acids and flavonoids quantitative analysis applying HPLC-DAD technique. In vitro cultures give the opportunity to perform the phytochemical studies on the protected species without harvesting the plant material from natural environment. Depending on the hormonal supplementation, the biomass from the shoot cultures accumulated from 11.41 to 25 times more phenolic acids [the total content ranged from 158.66 to 1817.96 mg/100 g of dry weight (DW)] and from 6.8 to 11.8 times more flavonoids (the total content ranged from 29.30 to 51.30 mg/100 g DW) than the shoots from the soil-grown plant. The polyphenols present in the shoot cultures include two phenolic acids: 3,4-dihydroxyphenylacetic and caffeic, four depsides: caftaric, neochlorogenic, chlorogenic, isochlorogenic, and rosmarinic acids, and flavonoids: aglycone-isoquercetin and glucoside-quercitrin. Most of them (apart from chlorogenic and rosmarinic acids) were detected for the first time in this species cultured in vitro. To our best knowledge, the present report is the first one that discusses establishment of Eryngium alpinum L. in vitro cultures and the shoot and callus biomass capacity to produce two subgroups of polyphenols i.e. phenolic acids and flavonoids

Taxonomy and distribution of Taraxacum sect. Erythrosperma (Asteraceae) in Poland

The dandelions from Taraxacum sect. Erythrosperma are taxonomically well distinguished and ecologically restricted to warm and sunlit habitats of steppes, dry and sandy grasslands, and distributed in temperate regions of Europe and Central Asia, with some being introduced to North America. Despite the long tradition of botanical research, the taxonomy and distribution of dandelions of T. sect. Erythrosperma is still underexplored in central Europe. In this paper, by combining traditional taxonomic studies supported by micromorphological, molecular and flow cytometry analyses as well as potential distribution modelling we shed light on taxonomical and phylogenetical relationships between members of T. sect. Erythrosperma in Poland. We also provide an identification key, species-checklist, detailed descriptions of morphology and occupated habitats as well as distribution maps for 14 Polish erythrosperms (T. bellicum, T. brachyglossum, T. cristatum, T. danubium, T. disseminatum, T. dissimile, T. lacistophyllum, T. parnassicum, T. plumbeum, T. proximum, T. sandomiriense, T. scanicum, T. tenuilobum, T. tortilobum). Finally, conservation assessments performed using the IUCN method and threat categories for all the examined species are proposed

Morphology and genome size of Epipactis helleborine (L.) Crantz (Orchidaceae) growing in anthropogenic and natural habitats

Background The process of apophytism or spreading native species to human-made habitats is one of the main elements in the creation of plant cover in anthropogenic areas. Lately, an increase of anthropogenic localities with valuable flora has been observed. Apophytes are also members of the family Orchidaceae, especially from the genus Epipactis. The aim of the study was to (i) determine and compare the phenotypic variation of E. helleborine (L.) Crantz plants in anthropogenic and natural habitats, (ii) compare the genome size of plants growing in natural and anthropogenic habitats. The results reported in this study may indicate that a habitat influences morphological characteristics of plant species. Methods Field studies were conducted on four native stands and four stands in anthropogenic areas of E. helleborine in Poland in years 2011–2013. Biometrical analyses were performed on shoots and flowers. The flowers were characterised by 25 biometric features and measured using a Nikon SMZ 800 binocular, microscopic Moticam-1SP cameras and the MIPlus07 programme (Conbest Co.). The nuclear DNA content was determined in fresh and young leaves of E. helleborine, collected from four natural and four anthropogenic populations. Results We observed that in anthropogenic populations: (i) shoots were higher than shoots from natural populations, (ii) flowers differed significantly in terms of ten biometric features between habitats, (iii) the genome size of some population differed significantly between plants growing in natural and anthropogenic habitats. Discussion According to some researchers, the presence of phenotypic variability and the occurrence of ecotypes are adaptation strategies of plants to environmental changes. In our opinion, in the case of the studied anthropogenic habitats (roadside) in which the E. helleborine populations grew, we can talk about ecofen due to the often repeated set of characteristic features, i.e., high shoots, long inflorescence and long, broad leaves. We agree, however, that it is difficult to isolate a taxonomic unit for ecofen due to the lack of experimental research

Field cress genome mapping: Integrating linkage and comparative maps with cytogenetic analysis for rDNA carrying chromosomes

Field cress (Lepidium campestre L.), despite its potential as a sustainable alternative oilseed plant, has been underutilized, and no prior attempts to characterize the genome at the genetic or molecular cytogenetic level have been conducted. Genetic maps are the foundation for anchoring and orienting annotated genome assemblies and positional cloning of candidate genes. Our principal goal was to construct a genetic map using integrated approaches of genetic, comparative and cytogenetic map analyses. In total, 503 F2 interspecific hybrid individuals were genotyped using 7,624 single nucleotide polymorphism markers. Comparative analysis demonstrated that ~57% of the sequenced loci in L. campestre were congruent with Arabidopsis thaliana (L.) genome and suggested a novel karyotype, which predates the ancestral crucifer karyotype. Aceto-orcein chromosome staining and fluorescence in situ hybridization (FISH) analyses confirmed that L. campestre, L. heterophyllum Benth. and their hybrids had a chromosome number of 2n = 2x = 16. Flow cytometric analysis revealed that both species possess 2C roughly 0.4 picogram DNA. Integrating linkage and comparative maps with cytogenetic map analyses assigned two linkage groups to their particular chromosomes. Future work could incorporate FISH utilizing A. thaliana mapped BAC clones to allow the chromosomes of field cress to be identified reliably

Morphometric traits in the fine-leaved fescues depend on ploidy level: the case of Festuca amethystina L.

Background Polyploid specimens are usually characterized by greater exuberance: they reach larger sizes and/or have a larger number of some organs. Festuca amethystina L. belongs to the section Aulaxyper. Based on morphological features, four subspecies of F. amethystina have been already identified. On the other hand, it has two cytotypes: diploid and tetraploid. The main aim of our study was to distinguish morphological differences between the cytotypes of F. amethystina, assuming that its phenotype differs significantly. Methods The nuclear DNA content was measured by flow cytometry in dry leaves from specimens originating from 13 populations of F. amethystina. Several macrometric and micrometric traits of stems, spikelets and leaf blades were taken into account in the comparative analysis of two cytotypes. Results In the case of cytotypes, specimens of tetraploids were larger than diploids. The conducted morphometric analysis of leaf cross-sections showed significant differences between the cytotypes. Discussion The research has confirmed for the first time that in the case of F. amethystina the principle of greater exuberance of polyploids is true. Differences between the cytotypes are statistically significant, however, they are not enough to make easy the distinction of cytotypes on the basis of the measurements themselves. Our findings favor the rule known in Festuca taxonomy as a whole, i.e. that the ploidy level can be one of the main classification criteria

Molecular mechanism of endoreduplication in higher plants

Proces endoreduplikacji stanowi alternatywną formę cyklu komórkowego, podczas której następuje amplifikacja jądrowego DNA, po której nie zachodzi jednak mitoza i podział komórki. Mechanizm molekularny tego procesu w dużej mierze opiera się na białkach uczestniczących w typowym cyklu komórkowym i polega na zablokowaniu mitozy wraz z ponownym zainicjowaniem replikacji DNA. W endoreduplikacji ważną rolę odgrywają kinazy zależne od cyklin oraz ich białka regulatorowe - cykliny. Podczas tego procesu aktywność tych białek jest regulowana na poziomie transkrypcyjnym i potranslacyjnym. Zmiana aktywności kinaz zależnych od cyklin może wynikać ze zmniejszenia dostępności cyklin w wyniku zablokowania ich transkrypcji oraz ze zmian statusu fosforylacji kinaz zależnych od cyklin. Może być również negatywnie regulowana poprzez fosforylację podjednostki kinazy zależnej od cyklin przez kinazę WEE1 oraz poprzez interakcję z inhibitorami kinaz zależnych od cyklin. Regulacja na poziomie potranslacyjnym polega natomiast na ukierunkowanej destrukcji cyklin przez kompleks promujący anafazę/cyklosom. Szczegółowe omówienie mechanizmów molekularnych tego procesu zostało przedstawione w poniższym artykule.Endoreduplication represents an alternative form of the cell cycle in which nuclear DNA amplification occurs, but it is not followed by mitosis and cell division. The molecular mechanism of this process is largely based on proteins involved in typical cell cycle and involves block of mitosis and re-initiation of DNA replication. Cyclin-dependent kinases and theirs regulatory proteins - cyclins are the key components of endoreduplication. During the process, activity of these proteins is regulated at the transcriptional and post-translational levels. Changes in the activity of cyclin dependent kinases may be due to a reduced availability of cyclins resulting from blocking of respective genes transcription and to changes in the status of cyclin-dependent phosphorylation of kinases. It can be also negatively regulated by phosphorylation of the cyclin-dependent kinase subunit by kinase WEE1, and by interaction with inhibitors of cyclin dependent kinases. Post-translational regulation occurs via targeted destruction of cyclins by the anaphase promoting complex/cyclosome. A detailed discussion of the molecular mechanism of these processes is presented in this article

Flow cytometric estimation of the nuclear genome size of 22 Echinops (Asteraceae) taxa from Turkey

Taxonomic classification of the genus Echinops (Asteraceae) is still unclear, mostly because of the small morphological differences between the species. Estimation of genome size is helpful in species identification and in establishing a relationship between them; however, nuclear DNA content has been established for only 25% of known Echinops species. In the present study, in addition to the chromosome number, the DNA content of species in 22 taxa belonging to 3 sections (Echinops, Oligolepis, and Ritropsis) was estimated using flow cytometry; 9 of the species are endemic to Turkey. For 16 of the species this is the first report on their genome size. The chromosome numbers of the studied species were 2n = 28, 30, 32, or 34; the 2C DNA content ranged from 5.55 to 13.96 pg, and the mean DNA content per chromosome from 0.19 to 0.45 pg. The possible chromosome rearrangements during evolution of the genus are discussed. It is suggested that the ancestral section of the genus Echinops is Oligolepis, and the most modern one Echinops. The results allowed for the verification of the taxonomic position of some Echinops species, which previously were classified based only on morphological characteristics

In Vitro Regeneration of Chrysanthemum from Ovaries and Ovules Treated with Thermal and Chemical Stimuli: Morphogenic and Cytogenetic Effects

Chrysanthemum (Chrysanthemum × morifolium (Ramat.) Hemsl.) holds a prominent position in the market of ornamental plants. To further advance chrysanthemum breeding efforts, the development of haploids may be useful. Therefore, the effect of various chemical and thermal treatments on regeneration efficiency and ploidy level in chrysanthemum was studied. Ovaries and ovules of three chrysanthemum cultivars, i.e., ‘Brasil,’ ‘Capitola,’ and ‘Jewel Time Yellow,’ were cultured either on a medium with 1 mg·L−1 2,4-dichlorophenoxyacetic acid (2,4-D) and different concentrations (0.5–1.5 mg·L−1) of thidiazuron (TDZ) or subjected to thermal shock (pretreatment temperature of 4 °C or 32 °C) and cultured on a medium with 1 mg·L−1 2,4-D and 1 mg·L−1 6-benzylaminopurine (BAP). It was found that ovaries had a greater organogenic potential (both in terms of callogenesis and shoot formation) than ovules. Microscopic analyses revealed that shoots mainly developed via indirect somatic embryogenesis from a callus developed from the ovary wall. The highest number of shoots was produced in cooled (at 4 °C) ovaries of chrysanthemum ‘Brasil’ and in ‘Jewel Time Yellow’ ovaries cultured on a medium with 1.0–1.5 mg·L−1 TDZ. The latter cultivar also had the highest potential to produce plants with an altered ploidy level (doubled and halved the number of chromosomes). This study demonstrates that manipulating factors such as temperature and thidiazuron concentration can enhance regeneration efficiency and induce altered ploidy levels in selected cultivars, offering valuable insights for chrysanthemum breeding programs

Genome Size Diversity in Rare, Endangered, and Protected Orchids in Poland

Orchidaceae is one of the largest and the most widespread plant families with many species threatened with extinction. However, only about 1.5% of orchids’ genome sizes have been known so far. The aim of this study was to estimate the genome size of 15 species and one infraspecific taxon of endangered and protected orchids growing wild in Poland to assess their variability and develop additional criterion useful in orchid species identification and characterization. Flow cytometric genome size estimation revealed that investigated orchid species possessed intermediate, large, and very large genomes. The smallest 2C DNA content possessed Liparis loeselii (14.15 pg), while the largest Cypripedium calceolus (82.10 pg). It was confirmed that the genome size is characteristic to the subfamily. Additionally, for four species Epipactis albensis, Ophrys insectifera, Orchis mascula, Orchis militaris and one infraspecific taxon, Epipactis purpurata f. chlorophylla the 2C DNA content has been estimated for the first time. Genome size estimation by flow cytometry proved to be a useful auxiliary method for quick orchid species identification and characterization