Root system structure
Dotaz
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... .: The Nervous system. Part A. ... ... Central nervous system drugs. 1963. xvi, 703 stran -- Volume 2.: The Nervous system . Part B. ... ... Central nervous system drugs. 1965. xiv, 486 stran -- Volume 3.: The Nervous system. Part C. ... ... Autonomic nervous system drugs. 1967. xii, 519 stran ... ... Chemical Transmitters in the Central Nervous System 416 -- V. ...
Physiological pharmacology
3 svazky : ilustrace ; 24 cm
- MeSH
- autonomní nervový systém účinky léků MeSH
- centrální nervový systém účinky léků MeSH
- cholinergní látky MeSH
- látky ovlivňující centrální nervový systém MeSH
- látky tlumící činnost CNS MeSH
- léčivé přípravky MeSH
- nervosvalové blokátory MeSH
- stimulanty centrálního nervového systému MeSH
- Konspekt
- Farmacie. Farmakologie
- NLK Obory
- farmacie a farmakologie
- NLK Publikační typ
- kolektivní monografie
xxi, 1015 s. : il. + 8 s.obr.příl.
- MeSH
- infekční nemoci MeSH
- Publikační typ
- příručky MeSH
- Konspekt
- Patologie. Klinická medicína
- NLK Obory
- infekční lékařství
Introduced organic pollutants in all ecosystem compartments can cause stress resulting in a wide range of responses including different root development. In this study, the effects of a polycyclic aromatic hydrocarbon-fluoranthene (FLT; 0.1, 1 and 7 mg L(-1)) on the growth, morphology and anatomical structure of roots of pea and maize was evaluated. In comparison with pea, significant stimulation of root system growth of maize caused by 0.1 mg L(-1) (total length longer by 25%, number of lateral roots by 35%) and its reduction (total length by 34%) already by 1 mg L(-1) FLT is the proof of different interspecies sensitivity to low and higher environmental loading. Nevertheless in both plant species a high loading 7 mg L(-1) FLT significantly reduced both growth (total length by 95% in pea, 94% in maize) and the number of lateral roots (by 78% in pea, 94% in maize). Significantly increased thickness of root of both maize and pea was caused by 7 mg L(-1) FLT and in maize already by 0.1 mg L(-1) FLT. It may be mainly connected with an enlargement of stele area (up to 50% in pea and 25% in maize). Increased xylem area in root tip (by up to 385% in pea, 167% in maize) and zone of maturation (up to 584% in pea, 70% in maize) and its higher portion in stele area of root tip (by 9% in pea, 21% in maize), mainly in roots exposed 7 mg L(-1) FLT, are a proof of an early differentiation of vascular tissue and a shortening of root elongation zone. Moreover in both plant species exposed to this treatment, the decline of rhizodermis cells and external layers of primary cortex was found and also significant deformation of primordia of lateral roots was recorded.
- MeSH
- fluoreny toxicita MeSH
- fyziologický stres MeSH
- hrách setý anatomie a histologie účinky léků fyziologie MeSH
- kořeny rostlin anatomie a histologie účinky léků fyziologie MeSH
- kukuřice setá anatomie a histologie účinky léků fyziologie MeSH
- látky znečišťující půdu toxicita MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Autoři v předkládané práci porovnávají stupeň čistoty stěny kořenového kanálku po ruční preparaci přímočarou obvodovou technikou pomocí Hedstroemových pilníčků, dále „modifikovanou metodou dvojího kónusu za použití balancované síly", dále po strojové preparaci systémem rotačních kořenových nástrojů Wizard CD Plus (všechny nástroje výrobce Medin, ČR) a po strojové preparaci oscilačním systémem AET Endo — EZE (Ultradent, USA). Za srovnatelných podmínek byla na extrahovaných zubech provedena zmíněná preparace. Po skončené preparaci byly zuby podélně rozštípnuty a vyšetřeny v rastrovacím elektronovém mikroskopu. Stupeň čistoty stěny kořenového kanálku byl měřen třístupňovou škálou. Část vzorků byla rozdělena příčnými řezy a pozorována lupou v pětinásobném zvětšení. Na plastových bločcích byla porovnána časová náročnost přímočaré obvodové techniky a rotační strojové preparace. Strojová preparace systémem Wizard CD Plus vykazovala výsledky plně srovnatelné s ruční preparací. Systém AET Endo — Eze vykazoval horší výsledky v porovnání s ostatními systémy. U všech způsobů opracování kořenového kanálku byla nalezena nedostatečně opracovaná místa. Čas potřebný pro strojovou preparaci byl kratší v porovnání s ruční preparací.
The authors compare the cleaning effect of various root canal preparation techniques (hand as well as power driven preparation). Two hand techniques (circumferential filing and balanced force technique) and two power driven techniques (the rotary system Wizard CD Plus, Medin, CR, and oscillating NiTi instruments AET Endo-EZE, Ultradent, USA) were used. The preparation was provided under standard conditions (lubrication with the EDTA gel, rinsing with 2% NaOCl). After the preparation the specimen were split longitudinaly and observed in SEM using the three step scala of the cleanliness of the root canal walls. Part of the specimen was split transversaly and observed macroscopically with magnification 5x. The time of the preparation (circumferential filing and rotary preparation) was comapred using the clear resin blocks. The cleanliness of the root canal walls after the hand preparation techniques was comparable to that after the rotary preparation. The preparation using the oscillating instruments (AET Endo —EZE) showed more smear layer and debris in comparsion to the others methods. In all cases the unprepared areas were found. The preparation with the rotary instruments was less time consuming in compasrion to the circumferential filing.
Formins are evolutionarily conserved eukaryotic proteins engaged in actin nucleation and other aspects of cytoskeletal organization. Angiosperms have two formin clades with multiple paralogs; typical plant Class I formins are integral membrane proteins that can anchor cytoskeletal structures to membranes. For the main Arabidopsis housekeeping Class I formin, FH1 (At3g25500), plasmalemma localization was documented in heterologous expression and overexpression studies. We previously showed that loss of FH1 function increases cotyledon epidermal pavement cell shape complexity via modification of actin and microtubule organization and dynamics. Here, we employ transgenic Arabidopsis expressing green fluorescent protein-tagged FH1 (FH1-GFP) from its native promoter to investigate in vivo behavior of this formin using advanced microscopy techniques. The fusion protein is functional, since its expression complements the fh1 loss-of-function mutant phenotype. Accidental overexpression of FH1-GFP results in a decrease in trichome branch number, while fh1 mutation has the opposite effect, indicating a general role of this formin in controlling cell shape complexity. Consistent with previous reports, FH1-GFP associates with membranes. However, the protein exhibits surprising actin- and secretory pathway-dependent dynamic localization and relocates between cellular endomembranes and the plasmalemma during cell division and differentiation in root tissues, with transient tonoplast localization at the transition/elongation zones border. FH1-GFP also accumulates in actin-rich regions of cortical cytoplasm and associates with plasmodesmata in both the cotyledon epidermis and root tissues. Together with previous reports from metazoan systems, this suggests that formins might have a shared (ancestral or convergent) role at cell-cell junctions.
Similarly to plants from terrestrial ecosystems, aquatic species harbour wide spectra of root-associated fungi (RAF). However, comparably less is known about fungal diversity in submerged roots. We assessed the incidence and diversity of RAF in submerged aquatic plants using microscopy, culture-dependent and culture-independent techniques. We studied RAF of five submerged isoetid species collected in four oligotrophic freshwater lakes in Norway. Levels of dark septate endophytes (DSE) colonization differed among the lakes and were positively related to the organic matter content and negatively related to pH. In total, we identified 41 fungal OTUs using culture-dependent and culture-independent techniques, belonging to Mucoromycotina, Chytridiomycota, Glomeromycota, Ascomycota as well as Basidiomycota. Sequences corresponding to aquatic hyphomycetes (e.g. Nectria lugdunensis, Tetracladium furcatum and Varicosporium elodeae) were obtained. Eight arbuscular mycorrhizal taxa belonging to the orders Archaeosporales, Diversisporales and Glomerales were also detected. However, the vast majority of the fungal species detected (e.g. Ceratobasidium sp., Cryptosporiopsis rhizophila, Leptodontidium orchidicola, and Tuber sp.) have previously been known only from roots of terrestrial plants. The abundance and phylogenetic distribution of mycorrhizal as well as nonmycorrhizal fungi in the roots of submerged plants have reshaped our views on the fungal diversity in aquatic environment.
- MeSH
- Ascomycota genetika růst a vývoj izolace a purifikace MeSH
- Basidiomycota genetika růst a vývoj izolace a purifikace MeSH
- ekosystém MeSH
- endofyty klasifikace genetika růst a vývoj izolace a purifikace MeSH
- fylogeneze MeSH
- houby klasifikace genetika růst a vývoj izolace a purifikace MeSH
- jezera mikrobiologie MeSH
- kořeny rostlin mikrobiologie MeSH
- mykorhiza klasifikace genetika MeSH
- rostliny mikrobiologie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Norsko MeSH
BACKGROUND AND AIMS: The maize lrt1 (lateral rootless1) mutant is impaired in its development of lateral roots during early post-embryonic development. The aim of this study was to characterize, in detail, the influences that the mutation exerts on lateral root initiation and the subsequent developments, as well as to describe the behaviour of the entire plant under variable environmental conditions. METHODS: Mutant lrt1 plants were cultivated under different conditions of hydroponics, and in between sheets of moist paper. Cleared whole mounts and anatomical sections were used in combination with both selected staining procedures and histochemical tests to follow root development. Root surface permeability tests and the biochemical quantification of lignin were performed to complement the structural data. KEY RESULTS: The data presented suggest a redefinition of lrt1 function in lateral roots as a promoter of later development; however, neither the complete absence of lateral roots nor the frequency of their initiation is linked to lrt1 function. The developmental effects of lrt1 are under strong environmental influences. Mutant primordia are affected in structure, growth and emergence; and the majority of primordia terminate their growth during this last step, or shortly thereafter. The lateral roots are impaired in the maintenance of the root apical meristem. The primary root shows disturbances in the organization of both epidermal and subepidermal layers. The lrt1-related cell-wall modifications include: lignification in peripheral layers, the deposition of polyphenolic substances and a higher activity of peroxidase. CONCLUSIONS: The present study provides novel insights into the function of the lrt1 gene in root system development. The lrt1 gene participates in the spatial distribution of initiation, but not in its frequency. Later, the development of lateral roots is strongly affected. The effect of the lrt1 mutation is not as obvious in the primary root, with no influences observed on the root apical meristem structure and maintenance; however, development of the epidermis and cortex are impaired.
- MeSH
- buněčná stěna metabolismus MeSH
- epidermis rostlin anatomie a histologie genetika růst a vývoj MeSH
- hydroponie MeSH
- kořeny rostlin cytologie genetika růst a vývoj MeSH
- kukuřice setá cytologie genetika růst a vývoj MeSH
- lignin metabolismus MeSH
- meristém cytologie genetika růst a vývoj MeSH
- mutace MeSH
- polyfenoly metabolismus MeSH
- regulace genové exprese u rostlin * MeSH
- rostlinné proteiny genetika metabolismus MeSH
- semenáček cytologie genetika růst a vývoj MeSH
- výhonky rostlin cytologie genetika růst a vývoj MeSH
- vývojová regulace genové exprese MeSH
- životní prostředí MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Superficiální hemosideróza centrálního nervstva je vzácné chronicko-progresivní onemocnění způsobené ukládáním hemosiderinu v mozkových plenách, povrchových strukturách mozku, míchy a hlavových nervů. Příčinou je opakované krváceni do subarachnoidálních prostor při rupture aneuryzmatu či cévní malformace, při traumatech s krvácením do likvorových prostor v oblasti mozku a míchy, po operacích mozku apod. Diskutovány jsou i možnosti vlivu rádioterapie a angiopatie při amyloidóze na podkladě mutace transthyretinového genu. Klinickému obrazu dominují progredující oboustranná porucha sluchu, mozečková a míšní symptomatika. Onemocnění vede v konečné fázi k těžké invalidizaci pacienta. Základní diagnostickou metodou je magnetická rezonance, kde je patrný hemosiderinový lem na povrchu mozku a míchy. Vyšetření mozkomíšního moku prokazuje ve zhruba polovině případů známky proběhlé hemoragie. Pro průkaz vzácné amyloidózy jako příčiny angiopatie je nutný histologický průkaz depozit amyloidu, pro potvrzení typu amyloidózy genetické vyšetření. Přestože se jedná o obtížně léčitelné onemocnění způsobující irreverzibilní poškození, je třeba na něj pomýšlet při kumulaci typických symptomů či náhodném MR záchytu. Nalezneme-li zdroj krvácení, je naděje na zastavení progrese pomocí operačního ošetření zdroje.
Superficial hemosiderosis of the central nervous system is a rare chronic progressive disease caused by the deposition of hemosiderin in the meninges, brain and spinal cord surface and cranial nerves. It results from recurrent haemorrhage into the subarachnoid space due to dural pathology, CSF cavity lesion, cervical root pathology, tumor, vascular abnormity, etc. The influence of radiation and the role of transthyretin amyloidosis-related angiopathy have been also discussed. Typical clinical manifestation is characterized by progressive bilateral sensorineural hearing loss, cerebellar ataxia and myelopathy. The disorder can potentially lead to serious disability. The essential method of diagnosis is MRI, which shows a rim of hemosiderin around the structures mentioned above. The cerebrospinal fluid examination reveals haemorrhage or xanthochromia in about half of cases. Biopsy and DNA examination are necessary for the diagnosis of transthyretin-related amyloidosis as a cause of the CNS angiopathy. Although superficial hemosiderosis is a disorder potentially resulting in irreversible damage to the CNS and, unfortunately, a condition difficult to treat, it should be taken into consideration when cummulation of typical symptoms is present or by an accidential finding on MRI. There is a good chance to prevent the disease progression by surgical treatment if the source of the bleeding is revealed.
- MeSH
- amyloidóza diagnóza MeSH
- cerebelární ataxie diagnóza etiologie MeSH
- hemosideróza diagnóza komplikace MeSH
- lidé MeSH
- nemoci centrálního nervového systému diagnóza klasifikace MeSH
- poruchy sluchu diagnóza etiologie MeSH
- subarachnoidální krvácení diagnóza etiologie MeSH
- Check Tag
- lidé MeSH
- ženské pohlaví MeSH
- Publikační typ
- kazuistiky MeSH
The tree root-mycorhizosphere plays a key role in resource uptake, but also in the adaptation of forests to changing environments. The adaptive foraging mechanisms of ectomycorrhizal (EcM) and fine roots of Picea abies, Pinus sylvestris and Betula pendula were evaluated along a gradient from temperate to subarctic boreal forest (38 sites between latitudes 48°N and 69°N) in Europe. Variables describing tree resource uptake structures and processes (absorptive fine root biomass and morphology, nitrogen (N) concentration in absorptive roots, extramatrical mycelium (EMM) biomass, community structure of root-associated EcM fungi, soil and rhizosphere bacteria) were used to analyse relationships between root system functional traits and climate, soil and stand characteristics. Absorptive fine root biomass per stand basal area increased significantly from temperate to boreal forests, coinciding with longer and thinner root tips with higher tissue density, smaller EMM biomass per root length and a shift in soil microbial community structure. The soil carbon (C) : N ratio was found to explain most of the variability in absorptive fine root and EMM biomass, root tissue density, N concentration and rhizosphere bacterial community structure. We suggest a concept of absorptive fine root foraging strategies involving both qualitative and quantitative changes in the root-mycorrhiza-bacteria continuum along climate and soil C : N gradients.
- MeSH
- Bacteria metabolismus MeSH
- biologické modely MeSH
- biomasa MeSH
- bříza mikrobiologie MeSH
- dusík analýza MeSH
- fyziologická adaptace * MeSH
- kořeny rostlin anatomie a histologie mikrobiologie fyziologie MeSH
- mycelium fyziologie MeSH
- mykorhiza fyziologie MeSH
- půdní mikrobiologie MeSH
- rhizosféra MeSH
- tajga * MeSH
- uhlík analýza MeSH
- zeměpis MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Evropa MeSH