Although maize (Zea mays L.) plants utilize light efficiently, the expression of high light-efficient genes and stomatal factors is regulated by light conditions and affects photosynthesis of plants. In this study, we investigated the effects of different light qualities on the expression of the photosynthetic genes, such as pep1, pdk1, ZmSTOMAGEN, and psad1, and on stomatal function in maize seedlings. For both maize genotypes, Zhengdan 958 and Xianyu 335, light with wavelengths shorter than 490 nm enhanced the expression of pdk1 and ZmSTOMAGEN, whereas the expression of pdk1 positively correlated with ZmSTOMAGEN. Light with wavelengths longer than 630 nm or shorter than 490 nm (band pass filter) increased the expression of pep1 and psad1. Although the expression of four genes in Zhengdan 958 was significantly higher than that of Xianyu 335, changes in the expression of ZmSTOMAGEN, pdk1, or pep1 exerted no significant influence on stomatal function and photosynthetic rate. Our results suggest that light with wavelengths shorter than 490 nm promoted the expression of stomatal proteins and pdk1, facilitated the absorption of inorganic elements, and contributed to stomatal function in photosynthesis. Meanwhile, light with wavelengths longer than 630 nm inhibited the expression of pep1 and pdk1. Light with wavelengths longer than 630 nm or shorter than 490 nm promoted the expression of pep1, pdk1, and psad1., T. D. Liu, X. W. Zhang, Y. Xu, S. Q. Liu, X. W. Chen., and Obsahuje bibliografii
In the present studies, we have found a fragment of amino acid sequence, called TFT motif, both in light-dependent protochlorophyllide oxidoreductase (LPOR) and in the L subunit of dark-operative (light-independent) protochlorophyllide oxidoreductases (DPOR). Amino acid residues of this motif shared similar physicochemical properties in both types of the enzymes. In the present paper, physicochemical properties of amino acid residues of this common motif, its spatial arrangement and a possible physiological role are being discussed. This is the first report when similarity between LPOR and DPOR, phylogenetically unrelated, but functionally redundant enzymes, is described., M. Gabruk ... [et al.]., and Obsahuje bibliografii
Schisandra čínská neboli klanopraška čínská (Schisandra chinensis) se využívá v tradiční čínské medicíně pro své antimikrobiální, antivirové, antimykotické a antioxidační účinky. Hlavní účinnou složkou této rostliny jsou dibenzocyklooktadienové lignany. Bylo zjištěno, že tyto lignany blokují membránové ABC-transportéry, které jsou zodpovědné za mnohočetnou lékovou rezistenci při léčbě nádorů cytostatiky., Schisandra chinensis has been used in traditional Chinese medicine for its antimicrobial, antiviral, antimycotic and antioxidative effects. The main active compounds are dibenzocyclooctadiene lignans, which inhibit membrane ABC-transporters, responsible for the multi-drug resistance of cancer cells during their treatment by cytostatics., Ondřej Vymazal, Iva Slaninová., and Práce vznikla v rámci projektu AV ČR Otevřená věda
a1_The emergence of cryptosporidiosis, a zoonotic disease of the gastrointestinal and respiratory tract caused by Cryptosporidium Tyzzer, 1907, triggered numerous screening studies of various compounds for potential anti-cryptosporidial activity, the majority of which proved ineffective. Extracts of Indonesian plants, Piper betle and Diospyros sumatrana, were tested for potential anti-cryptosporidial activity using Mastomys coucha (Smith), experimentally inoculated with Cryptosporidium proliferans Kváč, Havrdová, Hlásková, Daňková, Kanděra, Ježková, Vítovec, Sak, Ortega, Xiao, Modrý, Chelladurai, Prantlová et McEvoy, 2016. None of the plant extracts tested showed significant activity against cryptosporidia; however, the results indicate that the following issues should be addressed in similar experimental studies. The monitoring of oocyst shedding during the entire experimental trial, supplemented with histological examination of affected gastric tissue at the time of treatment termination, revealed that similar studies are generally unreliable if evaluations of drug efficacy are based exclusively on oocyst shedding. Moreover, the reduction of oocyst shedding did not guarantee the eradication of cryptosporidia in treated individuals. For treatment trials performed on experimentally inoculated laboratory rodents, only animals in the advanced phase of cryptosporidiosis should be used for the correct interpretation of pathological alterations observed in affected tissue. All the solvents used (methanol, methanol-tetrahydrofuran and dimethylsulfoxid) were shown to be suitable for these studies, i.e. they did not exhibit negative effects on the subjects. The halofuginone lactate, routinely administered in intestinal cryptosporidiosis in calves, was shown to be ineffective against gastric cryptosporidiosis in mice caused by C. proliferans., a2_In contrast, the control application of extract Arabidopsis thaliana, from which we had expected a neutral effect, turned out to have some positive impact on affected gastric tissue., Andrea Valigurová, Radka Pecková, Karel Doležal, Bohumil Sak, Dana Květoňová, Martin Kváč, Wisnu Nurcahyo, Ivona Foitová., and Obsahuje bibliografii
The apolipoprotein A-V (apo A-V) plays an important role in regulation of triglyceride (TG) concentration in serum. To better understand how apo A-V affects triglyceridemia and glucoregulation, the lipoprotein lipase (LPL) activity was determined using intravenous fat tolerance test (IVFTT) and oral glucose tolerance test (oGTT) was performed in carriers of apolipoprotein A-V gene ( APOAV) variants known to be associated with increased triglyceridemia. Twelve carriers of 19W variant, 16 carriers of -1131C variant, 1 combined heterozygote and 16 control subjects homozygous for wild type variants (19S/-1131T) were selected from a population sample and matched with respect to body mass index and age. The APOAV variants carriers had increased TG, very low density lipoprotein-TG, and apo B concentrations (p < 0.05). The LPL activity evaluated as k2 rate constant for clearance of Intralipid® was 14 % lower in APOAV variants carriers. The depression of nonesterified fatty acids (NEFA) concentration after glucose load was delayed in APOAV variants carriers in spite of the same insulinemia and glycemia. Our results suggest that variants of APOAV combined with increased triglyceridemia are associated with lower LPL activity in vivo and with disturbances of regulation of NEFA concentration after glucose load., J. Kovář, V. Adámková., and Obsahuje bibliografii a bibliografické odkazy
Zachovalé pralesovité porosty patří v České republice k ojedinělým úkazům. Přestože lesních rezervací u nás nalezneme celou řadu, ty skutečně málo dotčené nebo dlouhodobě se vyvíjející bez výrazných zásahů člověka představují pouhý zlomek. Zřejmě nejvýznamnějšími pralesům blízkými lesy jsou Boubínský prales nebo Hraničník na Šumavě a Žofínský prales v Novohradských horách. V minulosti byly málo ovlivněny činností člověka a dosti dlouhou dobu se v nich lesnicky nehospodaří. Příznivé podmínky pro přežívání vzácných druhů lišejníků a dalších organismů na těchto lokalitách jsou však omezeny jejich malou rozlohou. S větší plochou pralesa vzrůstají předpoklady pro dlouhodobou koexistenci různých fází vývoje přírodního lesa s dostatečnou variabilitou mikrostanovišť a tím se zároveň zvyšuje šance na přežití úzce specializovaných druhů. Žofínský prales patří k nejstarším chráněným územím v Evropě, je chráněn již od r. 1838. Národní přírodní rezervace Žofínský prales zaujímá v současné době 102 ha; jádrové území s pralesovitými porosty však tvoří jen 74,5 ha. Převažující dřevinou je buk, početně jsou zastoupeny také smrk a jedle. Z lichenologického hlediska jde o zcela unikátní lokalitu. Na území rezervace bylo zaznamenáno 247 druhů lišejníků, což představuje přibližně 16 % všech známých druhů z České republiky. Z hlediska epifytických a zejména epixylických (rostoucích na dřevě v různém stupni rozkladu) lišejníků je Žofínský prales zřejmě místem s největší rozmanitostí lišejníků na našem území., Žofín virgin forest forms a unique landscape, which probably predominated in mountain areas before the arrival of humans. Because of the huge diversity of lichens, the reserve is one of the most valuable lichenological localities in the Czech Republic. Many lichen taxa were recorded here for the first time in this country., and Jiří Malíček, Zdeněk Palice.
The effect of salinity on some morpho-physiological characteristics in lisianthus cultivars was investigated. Cultivars namely, Blue Picotee (C1), Champagne (C2), Lime Green (C3), and Pure White (C4), were subjected to salt stress (0-60 mM NaCl) in a sand culture and their responses were measured. Our results showed that as a salinity level increased, growth parameters, relative water content, photosynthetic pigments, and gas-exchange characteristics decreased in all cultivars, while root fresh mass, root/shoot length ratio, electrolyte leakage, and a malondialdehyde content increased. However, the changes were less pronounced in C3 and C4 compared to C1 and C2. The regression analysis of the relationship between salinity levels and seedling height or root/shoot length ratio defined two groups with different slope coefficients: C1 and C2 as salt-sensitive cultivars and C3 and C4 as salt-tolerant cultivars. Shoot dry mass and leaf area tolerance indices were less affected by salinity in C3 and C4 compared to those in C1 and C2. Further, C3 and C4 showed higher photosynthetic rates, greater stomatal conductances, and accumulated greater K+ and Ca2+ contents and K+/Na+ ratios in roots and shoots compared to those in C1 and C2. The results suggests that C3 and C4 could be recommended as resistant cultivars due to maintaining higher growth, water balance, leaf gas exchange, ion compartmentalization, and lower lipid peroxidation in response to salinity compared to C1 and C2., N. Ashrafi, A. Rezaei Nejad., and Obsahuje bibliografii
The aim of the present study was to define the stress-induced pattern of cytosolic glucocorticoid receptor (GR) and Hsp70 protein in the liver of male Wistar rats exposed to different stress models: acute (2 h/day) immobilization or cold (4 °C); chronic (21 days) isolation, crowding, swimming or isolation plus swimming and combined (chronic plus acute stress). Changes in plasma levels of corticosterone were studied by radioimmunoassay (RIA). The results obtained by Western immunoblotting showed that both acute stressors led to a significant decrease in cytosolic GR and Hsp70 levels. Compared to acute stress effects, only a weak decrease in the levels of GR and Hsp70 was demonstrated in chronic stress models. Chronically stressed rats, which were subsequently exposed to novel acute stressors (immobilization or cold), showed a lower extent of GR down-regulation when compared to acute stress. The exception was swimming, which partially restores this down-regulation. The observed changes in the levels of these major stress-related cellular proteins in liver cytosol lead to the conclusion that chronic stressors compromise intracellular GR down-regulation in the liver., D. Filipović, L. Gavrilović, S. Dronjak, M. Demajo, M. B. Radojčić., and Obsahuje bibliografii a bibliografické odkazy
Pigments absorbing 350-1,050 nm radiation have had an important role on the Earth for at least 3.5 billion years. The ion pumping rhodopsins absorb blue and green photons using retinal and pump ions across cell membranes. Bacteriochlorophylls (BChl), absorbing in the violet/blue and near infra red (NIR), power anoxygenic photosynthesis, with one photoreaction centre; and chlorophylls (Chl), absorbing in the violet/blue and red (occasionally NIR) power oxygenic photosynthesis, with two photoreaction centres. The accessory (bacterio)chlorophylls add to the spectral range (bandwidth) of photon absorption, e.g., in algae living at depth in clear oceanic water and in algae and photosynthetic (PS) bacteria in microbial mats. Organism size, via the package effect, determines the photon absorption benefit of the costs of synthesis of the pigment-protein complexes. There are unresolved issues as to the evolution of Chls vs. BChls and the role of violet/blue and NIR radiation in PS bacteria., A. W. D. Larkum, R. J. Ritchie, J. A. Raven., and Obsahuje bibliografické odkazy