Due to the presence of toxic pollutants, soils in former military areas need remedial actions with environmentally friendly methods. Greenhouse experiments were conducted to investigate the aided phytostabilization of multi-heavy metals (HMs), i.e. Cd, Cr, Cu, Ni, Pb, Zn, in post-military soil by Festuca rubra and three mineral amendments (diatomite, dolomite and halloysite). The amendments were applied at 0 and 3.0% to each pot filled with 5 kg of polluted soil. After seven weeks of the phytostabilization, selected soil properties, biomass yield of F. rubra and immobilization of HMs by their accumulation in plant and redistribution among individual fractions in soil were determined. In addition, ecotoxicology parameters of non-amended and amended soil were established using Phytotoxkit (Sinapsis alba) and Ostracodtoxkit (Heterocypris incongruens) tests. The addition of halloysite significantly increased F. rubra biomass. Diatomite significantly increased both the Cd, Cu, Pb and Cr concentrations in the roots and the pH of the soil. The application of halloysite significantly decreased the Cd and Zn contents of the soil after the completion of the experiment. Dolomite and halloysite were more effective in HM immobilization in soil by decreasing their content in an exchangeable fraction than diatomite. These soil amendments significantly differentiated the length of S. alba roots and had a positive effect on the development of H. incongruens.
- MeSH
- biodegradace MeSH
- biomasa MeSH
- Festuca chemie růst a vývoj MeSH
- hořčík chemie MeSH
- jíl chemie MeSH
- kořeny rostlin růst a vývoj MeSH
- látky znečišťující půdu analýza MeSH
- půda chemie MeSH
- regenerace a remediace životního prostředí metody MeSH
- těžké kovy analýza MeSH
- uhličitan vápenatý chemie MeSH
- vojenská zařízení * MeSH
- Publikační typ
- časopisecké články MeSH
Tall fescue (Festuca arundinacea Schreb) shows remarkable tolerance to lead (Pb), but the mechanisms involved in metal tolerance are not yet well understood. Here, tall fescue were firstly cultivated hydroponically with Pb2+ (0, 50, 200 and 1000 mg/L) for 14 days. The results showed that remodeling of root architecture plays important roles in tolerance of tall fescue to Pb2+ stress. Increased cell wall (CW) components contribute to restrict high amount of Pb2+ in roots. Additionally, the uronic acid contents of pectin, hemicellulose 1 (HC1) and hemicellulose 2 (HC2) increased under Pb2+ stress. We further observed that tall fescue cultivated with H2O2 showed similar remodeling of root architecture as Pb2+ treatment. Furthermore, pectin, HC1 and HC2 fractions were sequentially extracted from 0 and 10 mM H2O2 treated roots, and Pb2+ adsorption capacity and contents of carboxyl groups of pectin and HC2 fractions were steadily increased under H2O2 treatment in vitro. Our results suggest that degrees of esterification of pectin and HC2 are regulated by H2O2. High amount of low-esterified pectin and HC2 offer more carboxyl groups, provide more Pb2+ binding sites, and restrict more Pb2+ in the CW, which may enhance tolerance of tall fescue to Pb2+ stress.
- MeSH
- buněčná stěna účinky léků metabolismus MeSH
- esterifikace MeSH
- Festuca účinky léků metabolismus MeSH
- kořeny rostlin účinky léků metabolismus MeSH
- látky znečišťující půdu metabolismus toxicita MeSH
- olovo metabolismus toxicita MeSH
- oxidační stres účinky léků MeSH
- polysacharidy chemie metabolismus MeSH
- reaktivní formy kyslíku metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
BACKGROUND: Cultivated grasses are an important source of food for domestic animals worldwide. Increased knowledge of their genomes can speed up the development of new cultivars with better quality and greater resistance to biotic and abiotic stresses. The most widely grown grasses are tetraploid ryegrass species (Lolium) and diploid and hexaploid fescue species (Festuca). In this work, we characterized repetitive DNA sequences and their contribution to genome size in five fescue and two ryegrass species as well as one fescue and two ryegrass cultivars. RESULTS: Partial genome sequences produced by Illumina sequencing technology were used for genome-wide comparative analyses with the RepeatExplorer pipeline. Retrotransposons were the most abundant repeat type in all seven grass species. The Athila element of the Ty3/gypsy family showed the most striking differences in copy number between fescues and ryegrasses. The sequence data enabled the assembly of the long terminal repeat (LTR) element Fesreba, which is highly enriched in centromeric and (peri)centromeric regions in all species. A combination of fluorescence in situ hybridization (FISH) with a probe specific to the Fesreba element and immunostaining with centromeric histone H3 (CENH3) antibody showed their co-localization and indicated a possible role of Fesreba in centromere function. CONCLUSIONS: Comparative repeatome analyses in a set of fescues and ryegrasses provided new insights into their genome organization and divergence, including the assembly of the LTR element Fesreba. A new LTR element Fesreba was identified and found in abundance in centromeric regions of the fescues and ryegrasses. It may play a role in the function of their centromeres.
Adaptive responses are probably the most effective long-term responses of populations to climate change, but they require sufficient evolutionary potential upon which selection can act. This requires high genetic variance for the traits under selection and low antagonizing genetic covariances between the different traits. Evolutionary potential estimates are still scarce for long-lived, clonal plants, although these species are predicted to dominate the landscape with climate change. We studied the evolutionary potential of a perennial grass, Festuca rubra, in western Norway, in two controlled environments corresponding to extreme environments in natural populations: cold-dry and warm-wet, the latter being consistent with the climatic predictions for the country. We estimated genetic variances, covariances, selection gradients and response to selection for a wide range of growth, resource acquisition and physiological traits, and compared their estimates between the environments. We showed that the evolutionary potential of F. rubra is high in both environments, and genetic covariances define one main direction along which selection can act with relatively few constraints to selection. The observed response to selection at present is not sufficient to produce genotypes adapted to the predicted climate change under a simple, space for time substitution model. However, the current populations contain genotypes which are pre-adapted to the new climate, especially for growth and resource acquisition traits. Overall, these results suggest that the present populations of the long-lived clonal plant may have sufficient evolutionary potential to withstand long-term climate changes through adaptive responses.
- MeSH
- biologická evoluce * MeSH
- ekosystém MeSH
- Festuca genetika fyziologie MeSH
- klimatické změny * MeSH
- selekce (genetika) MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Norsko MeSH
Species response to climate change is influenced by predictable (selective) and unpredictable (random) evolutionary processes. To understand how climate change will affect present-day species, it is necessary to assess their adaptive potential and distinguish it from the effects of random processes. This will allow predicting how different genotypes will respond to forecasted environmental change. Space for time substitution experiments are an elegant way to test the response of present day populations to climate variation in real time. Here we assess neutral and putatively adaptive variation in 11 populations of Festuca rubra situated along crossed gradients of temperature and moisture using molecular markers and phenotypic measurements, respectively. By comparing population differentiation in putatively neutral molecular markers and phenotypic traits (QST-FST comparisons), we show the existence of adaptive differentiation in phenotypic traits and their plasticity across the climatic gradient. The observed patterns of differentiation are due to the high genotypic and phenotypic differentiation of the populations from the coldest (and wettest) environment. Finally, we observe statistically significant covariation between markers and phenotypic traits, which is likely caused by isolation by adaptation. These results contribute to a better understanding of the current adaptation and evolutionary potential to face climate change of a widespread species. They can also be extrapolated to understand how the studied populations will adjust to upcoming climate change without going through the lengthy process of phenotyping.
Contamination of soil by copper (Cu) has become a serious problem throughout the world, causing the reduction of agricultural yield and harmful effects on human health by entering the food chain. A glasshouse pot experiment was designed to evaluate the potential use of halloysite as an immobilizing agent in the aided phytostabilization of Cu-contaminated soil, usingFestuca rubraL. The content of Cu in plants, i.e., total and extracted by 0.01 M CaCl₂, was determined using the method of spectrophotometry. Cu content in the tested parts ofF. rubradiffered significantly when halloysite was applied to the soil, as well as with increasing concentrations of Cu. The addition of halloysite significantly increased plant biomass. Cu accumulated in the roots, thereby reducing its toxicity to the aerial parts of the plant. The obtained values of bioconcentration and translocation factors observed for halloysite treatment indicate the effectiveness of usingF. rubrain phytostabilization techniques.
The Festuca genus is thought to be the most numerous genus of the Poaceae family. One of the most agronomically important forage grasses, Festuca pratensis Huds. is treated as a model plant to study the molecular mechanisms associated with tolerance to winter stresses, including frost. However, the precise mapping of the genes governing stress tolerance in this species is difficult as its karyotype remains unrecognized. Only two F. pratensis chromosomes with 35S and 5S rDNA sequences can be easily identified, but its remaining chromosomes have not been distinguished to date. Here, two libraries derived from F. pratensis nuclear DNA with various contents of repetitive DNA sequences were used as sources of molecular probes for fluorescent in situ hybridisation (FISH), a BAC library and a library representing sequences most frequently present in the F. pratensis genome. Using FISH, six groups of DNA sequences were revealed in chromosomes on the basis of their signal position, including dispersed-like sequences, chromosome painting-like sequences, centromeric-like sequences, knob-like sequences, a group without hybridization signals, and single locus-like sequences. The last group was exploited to develop cytogenetic maps of diploid and tetraploid F. pratensis, which are presented here for the first time and provide a remarkable progress in karyotype characterization.
- MeSH
- chromozomy rostlin genetika MeSH
- diploidie MeSH
- Festuca genetika růst a vývoj MeSH
- fyziologický stres genetika MeSH
- genová knihovna MeSH
- hybridizace genetická MeSH
- hybridizace in situ fluorescenční MeSH
- karyotypizace MeSH
- nízká teplota MeSH
- repetitivní sekvence nukleových kyselin genetika MeSH
- RNA ribozomální 5S genetika MeSH
- tetraploidie MeSH
- Publikační typ
- časopisecké články MeSH
FISH is a useful method to identify individual chromosomes in a karyotype and to discover their structural changes accompanying genome evolution and speciation. DNA probes for FISH should be chromosome specific and/or exhibit specific patterns of distribution along each chromosome. Such probes are not available in many plants including meadow fescue (Festuca pratensis Huds.), an important forage grass species. In the present study, various DNA repeats identified in Illumina shotgun sequences specific to chromosome 4F of F. pratensis were used as probes for FISH to develop the molecular karyotype of meadow fescue and to reveal a long-range molecular organization of its chromosomes. Five tandem repeats produced specific patterns on individual chromosomes. Their use in combination with probes for rRNA genes enabled the establishment of the molecular karyotype of meadow fescue. Most of the mobile genetic elements were dispersed along all the chromosomes except for the DNA transposon CACTA, which was localized preferentially to telomeric and subtelomeric regions, and a putative LTR element, which was localized to (peri)centromeric regions. Cytogenetic mapping of the 5 tandem repeats in other accessions of meadow fescue showed a highly similar distribution and confirmed the versatility and robustness of these probes.
Festulolium are hybrids between fescue (Festuca) and ryegrass (Lolium) species and combine high seed yield of ryegrasses with abiotic stress tolerance of fescues. Chromosomes of Festuca and Lolium present in Festulolium freely pair and recombine, which results in highly variable progeny where every single plant has a unique chromosome constitution. Thus, the stability of the genomic composition in Festulolium cultivars is an important issue. In this work, we used in situ hybridization to examine the genomic composition (understood as the proportion of parental genomes present) over 3 consecutive generations of propagation via outcrossing (the first one being the generation used for cultivar registration) of 3 Festulolium cultivars. Our analysis revealed that the genome composition largely differs among the plants from individual cultivars but appears to be relatively stable over the generations. A gradual shift in the genome composition towards Lolium observed in the early generations of hybrids appears to reach a plateau where the proportions of parental genomes become stabilized. Nevertheless, the proportion remains unbalanced to a certain extent (always in favor of the Lolium genome) in each cultivar. Our observations indicate a possibility to modulate genomic composition in hybrids by breeders' selection without a compromise on stability.
In germinating seeds under unfavorable environmental conditions, the mobilization of stores in the cotyledons is delayed, which may result in a different modulation of carbohydrates balance and a decrease in seedling vigor. Tall fescue (Festuca arundinacea Schreb.) caryopses grown at 4°C in the dark for an extended period in complete absence of nutrients, showed an unexpected ability to survive. Seedlings grown at 4°C for 210 days were morphologically identical to seedlings grown at 23°C for 21 days. After 400 days, seedlings grown at 4°C were able to differentiate plastids to chloroplast in just few days once transferred to the light and 23°C. Tall fescue exposed to prolonged period at 4°C showed marked anatomical changes: cell wall thickening, undifferentiated plastids, more root hairs and less xylem lignification. Physiological modifications were also observed, in particular related to sugar content, GA and ABA levels and amylolytic enzymes pattern. The phytohormones profiles exhibited at 4 and 23°C were comparable when normalized to the respective physiological states. Both the onset and the completion of germination were linked to GA and ABA levels, as well as to the ratio between these two hormones. All plants showed a sharp decline in carbohydrate content, with a consequent onset of gradual sugar starvation. This explained the slowed then full arrest in growth under both treatment regimes. The analysis of amylolytic activity showed that Ca2+ played a central role in the stabilization of several isoforms. Overall, convergence of starvation and hormone signals meet in crosstalk to regulate germination, growth and development in tall fescue.
- MeSH
- alfa-amylasy metabolismus MeSH
- buněčná stěna metabolismus fyziologie MeSH
- časové faktory MeSH
- Festuca metabolismus fyziologie MeSH
- fyziologická adaptace fyziologie účinky záření MeSH
- fyziologický stres fyziologie MeSH
- gibereliny metabolismus MeSH
- kořeny rostlin metabolismus fyziologie MeSH
- kotyledon metabolismus fyziologie MeSH
- kyselina abscisová metabolismus MeSH
- lignin metabolismus MeSH
- nízká teplota MeSH
- rostlinné proteiny metabolismus MeSH
- sacharidy analýza MeSH
- semenáček fyziologie MeSH
- světlo MeSH
- tma MeSH
- vápník metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
