Nicotiana tabacum Dotaz Zobrazit nápovědu
- Klíčová slova
- VIRUS DISEASES *,
- MeSH
- tabák * MeSH
- virové nemoci * MeSH
- virus tabákové mozaiky * MeSH
- Publikační typ
- časopisecké články MeSH
Hydroponic experiments were performed to examine the effect of prolonged sulfate limitation combined with cadmium (Cd) exposure in Arabidopsis thaliana and a potential Cd hyperaccumulator, Nicotiana tabacum. Low sulfate treatments (20 and 40 µM MgSO4) and Cd stress (4 µM CdCl2) showed adverse effects on morphology, photosynthetic and biochemical parameters and the nutritional status of both species. For example, Cd stress decreased NO3- root content under 20 µM MgSO4 to approximately 50% compared with respective controls. Interestingly, changes in many measured parameters, such as chlorophyll and carotenoid contents, the concentrations of anions, nutrients and Cd, induced by low sulfate supply, Cd exposure or a combination of both factors, were species-specific. Our data showed opposing effects of Cd exposure on Ca, Fe, Mn, Cu and Zn levels in roots of the studied plants. In A. thaliana, levels of glutathione, phytochelatins and glucosinolates demonstrated their distinct involvement in response to sub-optimal growth conditions and Cd stress. In shoot, the levels of phytochelatins and glucosinolates in the organic sulfur fraction were not dependent on sulfate supply under Cd stress. Altogether, our data showed both common and species-specific features of the complex plant response to prolonged sulfate deprivation and/or Cd exposure.
- Klíčová slova
- Arabidopsis thaliana, Cadmium, Heavy metal stress, Nicotiana tabacum, Sulfate,
- MeSH
- Arabidopsis * MeSH
- fytochelatiny MeSH
- glukosinoláty farmakologie MeSH
- kadmium toxicita MeSH
- kořeny rostlin MeSH
- potravní doplňky MeSH
- sírany farmakologie MeSH
- tabák MeSH
- živiny MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- fytochelatiny MeSH
- glukosinoláty MeSH
- kadmium MeSH
- sírany MeSH
Telomerase is essential for proper functioning of telomeres in eukaryotes. We cloned and characterised genes for the protein subunit of telomerase (TERT) in the allotetraploid Nicotiana tabacum (tobacco) and its diploid progenitor species Nicotiana sylvestris and Nicotiana tomentosiformis with the aim of determining if allopolyploidy (hybridisation and genome duplication) influences TERT activity and divergence. Two of the three sequence variants present in the tobacco genome (NtTERT-C/s and NtTERT-D) revealed similarity to two sequence variants found in N. sylvestris and another variant (NtTERT-C/t) was similar to TERT of N. tomentosiformis. Variants of N. sylvestris origin showed less similarity to each other (80.5 % in the genomic region; 90.1 % in the coding sequence) than that between the NtTERT-C/s and NtTERT-C/t variants (93.6 and 97.2 %, respectively). The NtTERT-D variant was truncated at the 5' end, and indels indicated that it was a pseudogene. All tobacco variants were transcribed and alternatively spliced sequences were detected. Analysis of gene arrangements uncovered a novel exon in the N-terminal domain of TERT variants, a feature that is likely to be commonly found in Solanaceae species. In addition, species-specific duplications were observed within exon 5. The putative function, copy number and evolutionary origin of these NtTERT sequence variants are discussed.
- MeSH
- alternativní sestřih MeSH
- exony MeSH
- genetická transkripce MeSH
- genetické lokusy MeSH
- genom rostlinný MeSH
- genová přestavba MeSH
- introny MeSH
- izoformy RNA MeSH
- molekulární evoluce MeSH
- molekulární sekvence - údaje MeSH
- pořadí genů MeSH
- pseudogeny MeSH
- repetitivní sekvence nukleových kyselin MeSH
- sekvence aminokyselin MeSH
- sekvence nukleotidů MeSH
- sekvenční seřazení MeSH
- tabák genetika MeSH
- telomerasa genetika MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- izoformy RNA MeSH
- telomerasa MeSH
The aim of this work was to construct transgenic plants with increased capabilities to degrade organic pollutants, such as polychlorinated biphenyls. The environmentally important gene of bacterial dioxygenase, the bphC gene, was chosen to clone into a plant of Nicotiana tabacum. The chosen bphC gene encodes 2,3-dihydroxybiphenyl-1,2-dioxygenase, which cleaves the aromatic ring of dihydroxybiphenyl, and we cloned it in fusion with the gene for β-glucuronidase (GUS), luciferase (LUC) or with a histidine tail. Several genetic constructs were designed and prepared and the possible expression of desired proteins in tobacco plants was studied by transient expression. We used genetic constructs successfully expressing dioxygenase's genes we used for preparation of transgenic tobacco plants by agrobacterial infection. The presence of transgenic DNA , mRNA and protein was determined in parental and the first filial generation of transgenic plants with the bphC gene. Properties of prepared transgenic plants will be further studied.
- Klíčová slova
- 2,3-dihydroxybiphenyl-1,2-dioxygenase, Nicotiana tabacum, bphC, phytoremediation, transgenic plant,
- MeSH
- bakteriální proteiny genetika metabolismus MeSH
- biodegradace MeSH
- Burkholderiaceae enzymologie genetika MeSH
- dioxygenasy genetika metabolismus MeSH
- geneticky modifikované rostliny enzymologie genetika metabolismus MeSH
- glukuronidasa genetika metabolismus MeSH
- klonování DNA MeSH
- luciferasy genetika metabolismus MeSH
- polychlorované bifenyly metabolismus MeSH
- rekombinantní fúzní proteiny genetika metabolismus MeSH
- tabák enzymologie genetika metabolismus MeSH
- zelené fluorescenční proteiny genetika metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- hodnotící studie MeSH
- práce podpořená grantem MeSH
- Názvy látek
- 2,3-dihydroxybiphenyl oxygenase MeSH Prohlížeč
- bakteriální proteiny MeSH
- dioxygenasy MeSH
- glukuronidasa MeSH
- luciferasy MeSH
- polychlorované bifenyly MeSH
- rekombinantní fúzní proteiny MeSH
- zelené fluorescenční proteiny MeSH
Tobacco (Nicotiana tabacum) pollen is a well-suited model for studying many fundamental biological processes owing to its well-defined and distinct development stages. It is also one of the major agents involved in the transmission of infectious viroids, which is the primary mechanism of viroid pathogenicity in plants. However, some viroids are non-transmissible and may be possibly degraded or eliminated during the gradual process of pollen development maturation. The molecular details behind the response of developing pollen against the apple fruit crinkle viroid (AFCVd) infection and viroid eradication is largely unknown. In this study, we performed an integrative analysis of the transcriptome and proteome profiles to disentangle the molecular cascade of events governing the three pollen development stages: early bicellular pollen (stage 3, S3), late bicellular pollen (stage 5, S5), and 6 h-pollen tube (PT6). The integrated analysis delivered the molecular portraits of the developing pollen against AFCVd infection, including mechanistic insights into the viroid eradication during the last steps of pollen development. The isobaric tags for label-free relative quantification (iTRAQ) with digital gene expression (DGE) experiments led us to reliably identify subsets of 5321, 5286, and 6923 proteins and 64,033, 60,597, and 46,640 expressed genes in S3, S5, and PT6, respectively. In these subsets, 2234, 2108 proteins and 9207 and 14,065 mRNAs were differentially expressed in pairwise comparisons of three stages S5 vs. S3 and PT6 vs. S5 of control pollen in tobacco. Correlation analysis between the abundance of differentially expressed mRNAs (DEGs) and differentially expressed proteins (DEPs) in pairwise comparisons of three stages of pollen revealed numerous discordant changes in mRNA/protein pairs. Only a modest correlation was observed, indicative of divergent transcription, and its regulation and importance of post-transcriptional events in the determination of the fate of early and late pollen development in tobacco. The functional and enrichment analysis of correlated DEGs/DEPs revealed the activation in pathways involved in carbohydrate metabolism, amino acid metabolism, lipid metabolism, and cofactor as well as vitamin metabolism, which points to the importance of these metabolic pathways in pollen development. Furthermore, the detailed picture of AFCVd-infected correlated DEGs/DEPs was obtained in pairwise comparisons of three stages of infected pollen. The AFCVd infection caused the modulation of several genes involved in protein degradation, nuclear transport, phytohormone signaling, defense response, and phosphorylation. Intriguingly, we also identified several factors including, DNA-dependent RNA-polymerase, ribosomal protein, Argonaute (AGO) proteins, nucleotide binding proteins, and RNA exonucleases, which may plausibly involve in viroid stabilization and eradication during the last steps of pollen development. The present study provides essential insights into the transcriptional and translational dynamics of tobacco pollen, which further strengthens our understanding of plant-viroid interactions and support for future mechanistic studies directed at delineating the functional role of candidate factors involved in viroid elimination.
- Klíčová slova
- AFCVd propagation and eradication, Nicotiana tabacum, Proteome, RNA sequencing, RT qPCR, male gametophyte, viroid degradation, viroid replication,
- MeSH
- buněčná diferenciace * MeSH
- nemoci rostlin virologie MeSH
- proteomika * MeSH
- pyl * metabolismus virologie MeSH
- rostlinné viry metabolismus MeSH
- stanovení celkové genové exprese * MeSH
- tabák * metabolismus virologie MeSH
- viroidy metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
We have examined the structure and chromatin organization of telomeres in Nicotiana tabacum. In tobacco the blocks of simple telomeric repeats (TT-TAGGG)n are many times larger than in other plants, e.g., Arabidopsis thaliana or tomato. They are resolved as multiple fragments 60-160 kb in size (in most cases 90-130 kb) on pulsed-field gel electrophoresis (PFGE) of restriction endonuclease-digested DNA. The major subtelomeric repeat of the HRS60 family forms large homogeneous blocks of a basic 180 bp motif having comparable lengths. Micrococcal nuclease (MNase) cleaves tobacco telomeric chromatin into subunits with a short repeat length of 157 +/- 5 bp; the subtelomeric heterochromatin characterized by tandemly repeated sequences of the HRS60 family is cut by MNase with a 180 bp periodicity. The monomeric and dimeric particles of telomeric and subtelomeric chromatin differ in sensitivity to MNase treatment: the telomeric particles are readily digested, producing ladders with a periodicity of 7 bp, while the subtelomeric particles appear to be rather resistant to intranucleosomal cleavage. The results presented show apparent similarities in the organization of telomeric chromatin in higher plants and mammals.
Selenium (Se) is a natural trace element, which shifts its action in a relatively narrow concentration range from nutritional role to toxicity. Although it has been well established that in plants chloroplasts are among the primary targets, the mechanism of toxicity on photosynthesis is not well understood. Here, we compared selenate and red-allotrope elemental selenium nanoparticles (red nanoSe) in in vitro tobacco cultures to investigate their effects on the structure and functions of the photosynthetic machinery. Selenate at 10 mg/L concentration retarded plant growth; it also led to a decreased chlorophyll content, accompanied with an increase in the carotenoid-to-chlorophyll ratio. Structural examinations of the photosynthetic machinery, using electron microscopy, small-angle neutron scattering and circular dichroism spectroscopy, revealed significant perturbation in the macro-organization of the pigment-protein complexes and sizeable shrinkage in the repeat distance of granum thylakoid membranes. As shown by chlorophyll a fluorescence transient measurements, these changes in the ultrastructure were associated with a significantly diminished photosystem II activity and a reduced performance of the photosynthetic electron transport, and an enhanced capability of non-photochemical quenching. These changes in the structure and function of the photosynthetic apparatus explain, at least in part, the retarded growth of plantlets in the presence of 10 mg/L selenate. In contrast, red nanoSe, even at 100 mg/L and selenate at 1 mg/L, exerted no negative effect on the growth of plantlets and affected only marginally the thylakoid membrane ultrastructure and the photosynthetic functions.
- Klíčová slova
- Chlorophyll fluorescence transients, Chloroplast thylakoid membranes, Circular dichroism, Electron microscopy, Nicotiana tabacum, Selenate and Se-nanoparticles, Small-angle neutron scattering,
- MeSH
- chlorofyl metabolismus MeSH
- chloroplasty metabolismus MeSH
- cirkulární dichroismus MeSH
- fotosyntéza fyziologie MeSH
- kyselina selenová metabolismus MeSH
- nanočástice chemie MeSH
- tabák metabolismus MeSH
- tylakoidy metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- chlorofyl MeSH
- kyselina selenová MeSH
Seeds sense temperature, nutrient levels and light conditions to inform decision making on the timing of germination. Limited light availability for photoblastic species results in irregular germination timing and losses of population germination percentage. Seed industries are therefore looking for interventions to mitigate this risk. A growing area of research is water treated with gas plasma (GPAW), in which the formed solution is a complex consisting of reactive oxygen and nitrogen species. Gas plasma technology is widely used for sterilisation and is an emerging technology in the food processing industry. The use of the GPAW on seeds has previously led to an increase in germination performance, often attributed to bolstered antioxidant defence mechanisms. However, there is a limited understanding of how the solution may influence the mechanisms that govern seed dormancy and whether photoreceptor-driven germination mechanisms are affected. In our work, we studied how GPAW can influence the mechanisms that govern photo-dependent dormancy, isolating the effects at low fluence response (LFR) and very low fluence response (VLFR). The two defined light intensity thresholds affect germination through different phytochrome photoreceptors, PHYB and PHYA, respectively; we found that GPAW showed a significant increase in population germination percentage under VLFR and further described how each treatment affects key physiological regulators.
- Klíčová slova
- gas-plasma-activated water, germination, gibberellin oxidase, photo-dependent dormancy, seed dormancy, tobacco,
- MeSH
- Arabidopsis * fyziologie MeSH
- klíčení fyziologie MeSH
- semena rostlinná fyziologie MeSH
- tabák * MeSH
- vegetační klid fyziologie MeSH
- voda MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- voda MeSH
Drought stress is one of the most frequent forms of abiotic stresses, which occurs under condition of limited water availability. In this work, the possible participation of phosphoenolpyruvate carboxylase (EC 4.1.1.31; PEPC), NADP-malic enzyme (EC 1.1.1.40; NADP-ME), and pyruvate, phosphate dikinase (EC 2.7.9.1; PPDK) in response to drought of tobacco plants (Nicotiana tabacum L., cv. W38) was investigated. Enzyme specific activities in tobacco leaves of drought stressed plants were significantly increased after 11 days of stress, PEPC 2.3-fold, NADP-ME 3.9-fold, and PPDK 2.7-fold compared to control plants. The regulation of PEPC and NADP-ME activities were studied on transcriptional level by the quantitative RT PCR and on translational level - immunochemically. The amount of NADP-ME protein and transcription of mRNA for chloroplastic NADP-ME isoform were increased indicating their enhanced synthesis de novo. On the other hand, mRNA for cytosolic isoform of NADP-ME was decreased. The changes in PEPC protein and PEPC mRNA were not substantial. Therefore regulation of PEPC activity by phosphorylation was evaluated and found to be involved in the stress response. During recovery, activities of the tested enzymes returned close to their basal levels.
- Klíčová slova
- Drought, NADP-malic enzyme, Nicotiana tabacum L., Phosphoenolpyruvate carboxylase, Pyruvate, phosphate dikinase,
- MeSH
- aklimatizace MeSH
- chloroplasty metabolismus MeSH
- fosfoenolpyruvátkarboxylasa genetika metabolismus MeSH
- fyziologický stres fyziologie MeSH
- kvantitativní polymerázová řetězová reakce MeSH
- listy rostlin enzymologie MeSH
- malátdehydrogenasa genetika metabolismus MeSH
- období sucha * MeSH
- pyruvátfosfátdikinasa genetika metabolismus MeSH
- regulace genové exprese u rostlin MeSH
- rostlinné proteiny genetika metabolismus MeSH
- tabák enzymologie genetika MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- fosfoenolpyruvátkarboxylasa MeSH
- malátdehydrogenasa MeSH
- malate dehydrogenase (oxaloacetate-decarboxylating) (NADP+) MeSH Prohlížeč
- pyruvátfosfátdikinasa MeSH
- rostlinné proteiny MeSH
