In plants, hydrogen peroxide (H2O2) acts as a signalling molecule that facilitates various biochemical and physiological processes. H2O2 is a versatile molecule, involved in several cellular processes both under stress and stress-free conditions. In regulating plant metabolism under stress conditions, exogenous application of H2O2 also plays a pivotal role which is manifested in improved growth, photosynthetic capacity, and antioxidant protection. Abiotic stress is an inevitable environmental factor that extensively affects and reduces growth, quality, yield, and productivity of plants. Several signalling pathways involved in H2O2-mediated stress and defense responses have been extensively studied and there is ample scope of additional research that could further clarify the mechanism and modulating factors which regulate these pathways. An attempt has been made to dissect the role of H2O2 under low temperature stress and how it affects plant growth and development, photosynthetic capacity, regulation of antioxidant system, and signalling., T. A. Khan, M. Yusuf, Q. Fariduddin., and Obsahuje bibliografii
by O. Nordgaard. The protist plankton and the diatoms in bottom samples / by E. Jørgensen., KČSN - signatura S-E 128, Poškozené desky., and Desky skenovány z jiné signatury. S-E 128
Previous studies revealed altered levels of the circulating insulin-like growth factor-I (IGF-I) and of its binding protein-3 (IGFBP-3) in subjects with coronary atherosclerosis, metabolic syndrome and premature atherosclerosis. Hyperlipidemia is a powerful risk factor of atherosclerosis. We expected IGF-I and IGFBP-3 alterations in subjects with moderate/severe hyperlipidemia but without any clinical manifestation of atherosclerosis. Total IGF-I and IGFBP-3 were assessed in 56 patients with mixed hyperlipidemia (MHL; cholesterol>6.0 mmol/l, triglycerides>2.0 mmol/l), in 33 patients with isolated hypercholesterolemia (IHC; cholesterol>6.0 mmol/l, triglycerides<2.0 mmol/l), and in 29 healthy controls (cholesterol<6.0 mmol/l, triglycerides<2.0 mmol/l). The molar ratio of IGF-I/IGFBP-3 was used as a measure of free IGF-I. IHC subjects differed from controls by lower total IGF-I (164±60 vs. 209±73 ng/ml, p=0.01) and IGF-I/IGFBP-3 ratio (0.14±0.05 vs. 0.17±0.04, p=0.04). Compared to controls, MHL subjects had lower total IGF-I (153±54 ng/ml, p=0.0002) and IGFBP-3 (2.8±0.6 mg/ml, p<0.0001), but higher IGF-I/IGFBP-3 ratio (0.25±0.06, p<0.0001). Differences remained significant after the adjustment for clinical and biochemical covariates, except for triglycerides. Patients with both IHC and MHL have lower total IGF-I compared to controls. The mechanism is presumably different in IHC and MHL. Because of prominent reduction of IGFBP-3 in patients with MHL, they have reduced total IGF-I despite the actual elevation IGF-I/IGFBP-3 ratio as a surrogate of free IGF-I., J. Malík, T. Štulc, D. Wichterle, V. Melenovský, E. Chytilová, Z. Lacinová, J. Marek, R. Češka., and Obsahuje bibliografii a bibliografické odkazy
Hypobaria (low total atmospheric pressure) is essential in sustainable, energy-efficient plant production systems for long-term space exploration and human habitation on the Moon and Mars. There are also critical engineering, safety, and materials handling advantages of growing plants under hypobaria, including reduced atmospheric leakage from extraterrestrial base environments. The potential for producing crops under hypobaria and manipulating hypoxia (low oxygen stress) to increase health-promoting bioactive compounds is not well characterized. Here we showed that hypobaric-grown lettuce plants (25 kPa ≈ 25% of normal pressure) exposed to hypoxia (6 kPa pO2 ≈ 29% of normal pO2) during the final 3 d of the production cycle had enhanced antioxidant activity, increased synthesis of anthocyananins, phenolics, and carotenoids without reduction of photosynthesis or plant biomass. Net photosynthetic rate (PN) was not affected by total pressure. However, 10 d of hypoxia reduced PN, dark respiration rate (RD),
PN/RD ratio, and plant biomass. Growing plants under hypobaria and manipulating hypoxia during crop production to enhance health-promoting bioactive compounds is important for the health and well-being of astronauts exposed to space radiation and other stresses during long-term habitation. and C. He ... [et al.].
Analogickým studiím z Tichomoří a Mexika se podařilo experimentálně prokázat, že i lesní plži čeledi Clausiliidae - Cochlodina laminata a Alinda biplicata s rozměry těla cca 20 mm mohou projít živí zažívacím traktem středně velkých ptáků. Zajímavým poznatkem je, že ačkoli přežila pouze 2 % všech plžů, tak pokud nedošlo k poškození jejich schránky, přežilo plných 62 % jedinců nalezených v trusu., Analogously to the studies of the Pacific area and Mexico, we were able to prove experimentally that the forest snails from family Clausiliidae - Cochlodina laminata and Alinda biplicata with a body size of approximately 20 mm can pass through the digestive tract of a medium-sized bird. There is an interesting finding that although only 2% of gastropods survived at all, 62% of those with intact (undamaged) shells survived., and Jasna Simonová.
Článek přináší informace o vývoji a současném stavu ichtyofauny ve vodách pražské aglomerace. Celkem zde bylo zaznamenáno přes 50 druhů mihulí a ryb. Skladba zdejší fauny byla a je ovlivňována příslušností k labskému říčnímu systému (výskyt anadromních druhů) a rybářským obhospodařováním (vysazování násad, obhospodařování rybníků a sportovní rybolov). Z hlediska skladby ichtyofauny 8 druhů vymizelo, 15 druhů náleží mezi nepůvodní labské faunistické prvky, které se zde vyskytují přičiněním člověka. Do pražských vod je vysazováno rybáři cca 25 druhů a nejvíce jsou sportovními rybáři loveni kapr obecný, cejn velký, okoun říční, karas stříbřitý, štika obecná a candát obecný. Celkem 37 druhů je klasifikováno v různých kategoriích Červeného seznamu, pět druhů je chráněno zákonem., The development and present state of the ichtyofauna in flowing and stagnant waters in Prague are presented. In total, over 50 species of lampreys and fishes were found in the waters of the Prague conurbation. The ichtyofauna diversity in Prague waters is influenced by the location of the Elbe River system and angling activities (angling and fisheries stocking). In total, 8 species can be classified as extinct, and 15 species are nonnative. The following species are most frequently angled: Cyprinus carpio, Abramis brama, Perca fluviatilis, Carassius gibelio, Esox lucius and Sander lucioperca. Two fishes are classified as invasive aliens, namely Carassius gibelio and Pseudorasbora parva. Generally, about 25 fish species are stocked - the majority of them comes from artificial breeding. In total, 37 native species are classified into various categories of the Red List of Czech ichtyofauna and 8 species are protected by the law., and Lubomír Hanel, Jiří Vostradovský.
Dendrobium is one of the three largest genera in the Orchidaceae and is distributed throughout various habitats. We investigated photosynthesis in seven Dendrobium species and cultivars by comparing their leaf δ13C values, titratable acidity, and CO2 exchange in well-watered and drought-stressed conditions. In addition, the leaf thickness and mesophyll succulence index (Sm) were measured in well-watered conditions. Our results indicate that Dendrobium loddigesii is a typical obligate (or constitutive) CAM plant because the leaf δ13C values were -14.47 and -14.66‰ in both conditions, respectively. Others showed the leaf thickness of 0.31-0.89 mm and their δ13C values ranged from -25.68 to -28.37‰. These are not the CAM plants but they could not be classified as obligate C3 or C3/CAM intermediate plants. Dendrobium crepidatum and Dendrobium fimbriatum were further identified as the obligate C3 plants because the net CO2 uptake was positive during daytime and negative during nighttime in both conditions. In contrast, Dendrobium chrysotoxum, Dendrobium nobile, and D. nobile ‘V1’ and ‘V4’, showed no positive net CO2 uptake and low ΔH+ values during nighttime under well-watered conditions, indicating C3 photosynthesis. However, they showed the positive net CO2 uptake and large ΔH+ values during nighttime after drought-stress (21 or 28 days without H2O), indicating CAM photosynthesis. Therefore, these four species and cultivars were identified as C3/CAM intermediate (inducible or facultative) plants. In brief, obligate CAM, C3/CAM intermediate, and obligate C3 plant types all exist in the section of Dendrobium. To the best of our knowledge, this is the first report of the obligate C3 plants in Dendrobium, and these diverse photosynthetic pathways may explain their varied environmental adaptations., S. Qiu, S. Sultana, Z. D. Liu, L. Y. Yin, C. Y. Wang., and Obsahuje bibliografii
The study of leaf vascular systems is important in order to understand the fluid dynamics of water movement in leaves. Recent studies have shown how these systems can be involved in the performance of photosynthesis, which is linked to the density of the vascular network per unit of leaf area. The aim of the present study was to highlight the correlation between a leaf vein density (VD) and net photosynthetic rate (PN), which was undertaken using a digital camera, a stereoscopic microscope, and a light source. The proposed hypothesis was tested, for the first time, on the leaves of two cultivars of Vitis vinifera (L.). A significant difference was found between the VD of mature leaves of the two cultivars. VD was also significantly correlated with the maximum leaf PN. These findings support the hypothesis that the vascular system of grape leaves can be correlated with leaf photosynthesis performance., M. Pagano, P. Corona, P. Storchi., and Obsahuje bibliografii
Our study was aimed to characterize the phenotype and functional endpoints of local microwave hyperthermia (LHT, 42 °C) on tumor infiltrating and spleen leukocytes. The effectiveness of LHT applied into the tumor of B16F10 melanoma-bearing C57/BL6 mice was compared with anesthetized and non-treated animals. Subpopulations of leukocytes were analyzed using the flow cytometry, and the cytotoxic activity of splenocytes against syngeneic B16F10 melanoma and NK-sensitive YAC-1 tumor cell lines was evaluated in 51 Cr-release assay. Similarly, the in vitro modification of the heat treatment was performed using healthy and melanoma-bearing splenocytes. We found a 40 % increase of activated monocytes (CD11b+CD69+) infiltration into the tumor microenvironment. In the spleen of experimental animals, the numbers of cytotoxic T lymphocytes (CTLs-CD3+CD8+) and NK cell (CD49b+NK1.1+) raised by 22 % and 14 %, respectively, while the NK1.1+ monocytes decreases by 37 %. This was accompanied by an enhancement of cytotoxic effector function against B16F10 and YAC-1 targets in both in vivo and in vitro conditions. These results demonstrate that LHT induces better killing of syngeneic melanoma targets. Furthermore, LHT evokes the homing of activated monocytes into the tumor microenvironment and increases the counts of NK cells and CTL in the spleen., J. Kubeš, J. Svoboda, J. Rosina, M. Starec, A. Fišerová., and Obsahuje bibliografii a bibliografické údaje
Poplars (Populus spp.) are widely used in the pulp and paper industry and as bioenergy resources. Poplars require a large amount of water for biomass accumulation and lack of water is a limiting factor for poplar growth. Arbuscular mycorrhizal (AM) fungi have been previously reported to afford some plant species with greater resistance to drought stress. However, the effects of AM fungi on hybrid poplar under drought stress and recovery have not been studied. The main aim of this study was to evaluate the effects of the AM fungus, Rhizophagus irregularis, on the growth, water status, chlorophyll (Chl) content and fluorescence, and photosynthesis of poplar seedlings. The experiment was divided into three stages. At each stage of the experiment, the seedlings were subjected to a different watering regime: well-watered (prior stress), drought, and then rewatering (recovery). Measurements were taken at the end of each stage of the experiment. The results showed that mycorrhizal plants had a higher net photosynthetic rate and Chl fluorescence compared with nonmycorrhizal plants, regardless of the stage. Mycorrhizal and nonmycorrhizal plants showed different responses to drought stress: mycorrhizal plants showed better water-use efficiency and water uptake under drought stress conditions. In general, the poplar seedlings that formed the AM symbiosis with R. irregularis showed enhanced growth and reduced loss of biomass during the drought stress compared with the nonmycorrhizal seedlings., T. Liu, M. Sheng, C. Y. Wang, H. Chen, Z. Li, M. Tang., and Obsahuje bibliografii