Project description:Red clover (Trifolium pratense L.) is a highly adaptable forage crop for temperate livestock agriculture. Genetic variation can be identified, via molecular techniques, and used to assess diversity among populations that may otherwise be indistinguishable. Here we have used genotyping by sequencing (GBS) to determine the genetic variation and population structure in red clover natural populations from Europe and Asia, and varieties or synthetic populations. Cluster analysis differentiated the collection into four large regional groups: Asia, Iberia, UK, and Central Europe. The five varieties clustered with the geographical area from which they were derived. Two methods (BayeScan and Samβada) were used to search for outlier loci indicating signatures of selection. A total of 60 loci were identified by both methods, but no specific genomic region was highlighted. The rate of decay in linkage disequilibrium was fast, and no significant evidence of any bottlenecks was found. Phenotypic analysis showed that a more prostrate and spreading growth habit was predominantly found among populations from Iberia and the UK. A genome wide association study identified a single nucleotide polymorphism (SNP) located in a homologue of the VEG2 gene from pea, associated with flowering time. The identification of genetic variation within the natural populations is likely to be useful for enhancing the breeding of red clover in the future.
Project description:Rhizobia are soil-borne bacteria forming symbiotic associations with legumes and fixing atmospheric dinitrogen. The nitrogen-fixation potential depends on the type of host plants and microsymbionts as well as environmental factors that affect the distribution of rhizobia. In this study, we compared genetic diversity of bacteria isolated from root nodules of Trifolium pratense grown in two geographical regions (Tromsø, Norway and Lublin, Poland) located in distinct climatic (subpolar and temperate) zones. To characterize these isolates genetically, three PCR-based techniques (ERIC, BOX, and RFLP of the 16S-23S rRNA intergenic spacer), 16S rRNA sequencing, and multi-locus sequence analysis of chromosomal house-keeping genes (atpD, recA, rpoB, gyrB, and glnII) were done. Our results indicate that a great majority of the isolates are T. pratense microsymbionts belonging to Rhizobium leguminosarum sv. trifolii. A high diversity among these strains was detected. However, a lower diversity within the population derived from the subpolar region in comparison to that of the temperate region was found. Multi-locus sequence analysis showed that a majority of the strains formed distinct clusters characteristic for the individual climatic regions. The subpolar strains belonged to two (A and B) and the temperate strains to three R. leguminosarum genospecies (B, E, and K), respectively.
Project description:Central European grasslands, such as calcareous grasslands and oat-grass meadows, are characterized by diverse environmental conditions and management regimes. Therefore, we aimed to determine potential differences in genetic and epigenetic variation patterns between the contrasting habitats and to identify the drivers of genetic and epigenetic variation. We investigated the genetic and epigenetic variation of the ecologically variable plant species Trifolium pratense L. applying amplified fragment length polymorphism and methylation-sensitive amplification polymorphism analyses. We observed low levels of genetic and epigenetic differentiation among populations and between habitat types. Genetic and epigenetic variations were not interdependent. Thus, genetic variation was significantly isolated by habitat dissimilarity, whereas epigenetic variation was affected by environment. More specifically, we observed a significant correlation of epigenetic diversity with soil moisture and soil pH (the latter potentially resulting in phosphorus limitation). Genetic variation was, therefore, affected more strongly by habitat-specific environmental conditions induced by land use-related disturbance and gene flow patterns, while epigenetic variation was driven by challenging environmental conditions.
Project description:The use of botanical dietary supplements is becoming increasingly popular for the alleviation of hormonal-based conditions such as hot flashes, premenstrual syndrome, and fertility. Estrogen and progesterone receptors (ER and PR) play an essential role in these processes. However, despite the fact that many therapies used to alleviate gynecological conditions act through PR-mediated mechanisms, few studies have investigated or identified any herbal natural product components that act on this receptor. In the current study, we used a progesterone response element (PRE)-luciferase (Luc) reporter assay to identify four phytoprogestins present in a standardized red clover ( Trifolium pratense) extract. We found that the component irilone (1) potentiated the effect of progesterone in both endometrial and ovarian cancer cell lines. In these cancers, progesterone action is generally associated with positive outcomes; thus the potentiating effect of 1 may provide entirely new strategies for enhancing progesterone signaling as a means of mitigating conditions such as fibroids and endometriosis. Formononetin (3) and biochanin A (4) exhibited mixed agonist activity, while prunetin (2) acted only as an antagonist. Collectively, these results suggest that the effects of red clover extract repeatedly observed in cultured cells and the inverse correlation between risk of various cancers and flavonoid intake may be due, in part, to altered progesterone signaling.
Project description:IntroductionIn situ and ex situ conservation are the two main approaches for preserving genetic diversity. The advantages and disadvantages of the two approaches have been discussed but their genetic effects have not been fully evaluated.MethodsIn this study we investigate the effects of the two conservation approaches on genetic diversity in red clover. Seed samples collected from wild populations in Sweden and Norway in 1980, their subsequent generations created during seed regeneration at the gene bank and samples recollected from the same location as the original samples, were analyzed with microsatellite markers, alongside reference samples from cultivars.ResultsOverall, there was a differentiation between cultivars and the wild material and between wild material from Sweden and Norway. In general, the original collections clustered together with the later generations of the same accession in the gene bank, and with the recollected samples from the same location, and the level of diversity remained the same among samples of the same accession. Limited gene flow from cultivated varieties to the wild populations was detected; however, some wild individuals are likely to be escapees or affected by gene flow.DiscussionIn conclusion, there were examples of genetic changes within individual accessions both in situ and ex situ, as is also to be expected in any living population. However, we observed only limited genetic changes in both in situ and ex situ conservation over the generations included in this study and with the relatively large populations used in the ex situ conservation in the gene bank at NordGen.
Project description:Wildflower mixes are often planted around field margins to provide forage for pollinators. Although seed for these mixtures is often wild-sourced, for species where agricultural cultivars are available, for example red clover (Trifolium pratense), cultivars can also be included. Previous evidence suggests that plant genetic background can have a strong influence on plant-arthropod interactions and therefore the provenance and genetic background of the plants included in wildflower mixes could impact plant-pollinator interactions. We tested the performance of five individual T. pratense cultivars against two commercially available wild-sourced T. pratense populations in terms of their ability to attract potential pollinator species (focusing on bumblebees) and their floral traits using greenhouse and garden experiments. The main bumblebee observed interacting with T. pratense was Bombus pascuorum and we found no difference in the absolute number of B. pascuorum visiting the cultivars or wild populations. However, we found variation among cultivars and between wild populations in their ability to attract bumblebees, which seems to be related to their relative investment in different floral traits. There was a positive relationship between biomass and number of inflorescences produced by the wild populations of T. pratense, which was not apparent for the cultivars. This suggests that artificial selection on the cultivars has changed the G-matrix of correlated traits. We show that agricultural cultivars of T. pratense can be as effective as wild populations at attracting pollinators such as bumblebees, but that the genetic background of both cultivars and wild populations can have a significant impact on the attractiveness of the plant to pollinators. We also show divergence in the correlated traits of T. pratense cultivars and wild populations that could lead to outbreeding depression if the plants interbreed.
Project description:Air space-type variegation is the most diverse among the species of known variegated leaf plants and is caused by conspicuous intercellular spaces between the epidermal and palisade cells and among the palisade cells at non-green areas. Trifolium pratense, a species in Fabaceae with V-shaped air space-type variegation, was selected to explore the application potential of variegated leaf plants and accumulate basic data on the molecular regulatory mechanism and evolutionary history of leaf variegation. We performed comparative transcriptome analysis on young and adult leaflets of variegated and green plants and identified 43 candidate genes related to air space-type variegation formation. Most of the genes were related to cell-wall structure modification (CESA, CSL, EXP, FLA, PG, PGIP, PLL, PME, RGP, SKS, and XTH family genes), followed by photosynthesis (LHCB subfamily, RBCS, GOX, and AGT family genes), redox (2OG and GSH family genes), and nitrogen metabolism (NodGS family genes). Other genes were related to photooxidation, protein interaction, and protease degradation systems. The downregulated expression of light-responsive LHCB subfamily genes and the upregulated expression of the genes involved in cell-wall structure modification were important conditions for air space-type variegation formation in T. pratense. The upregulated expression of the ubiquitin-protein ligase enzyme (E3)-related genes in the protease degradation systems were conducive to air space-type variegation formation. Because these family genes are necessary for plant growth and development, the mechanism of the leaf variegation formation in T. pratense might be a widely existing regulation in air space-type variegation in nature.
Project description:The data provide an overview of proteomic changes in red clover (Trifolium pratense L.) in response to cold acclimation and recurrent selection for superior freezing tolerance. Proteins were extracted from crowns of two red clover cultivars grown under non-acclimated or cold-acclimated conditions, and plants obtained from the initial genetic background (TF0) and from populations obtained after three (TF3) and four cycles (TF4) of recurrent selection for superior freezing tolerance. Proteins were analyzed using a two-dimensional fluorescence difference gel electrophoresis (2D-DIGE) coupled to mass spectroscopy (MS and MS/MS). Differentially regulated proteins were subsequently identified using MALDI TOF/TOF analysis. The data are related to a recently published research article describing proteome composition changes associated with freezing tolerance in red clover, "A proteome analysis of freezing tolerance in red clover (Trifolium pratense L.)" (Bertrand et al., 2016 [1]). They are available in the ProteomeXchange Consortium database via the PRIDE partner repository under the dataset identifier PRIDE: PXD003689.