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102. Cestou zážitkové pedagogiky
- Creator:
- Čekanová, Markéta
- Format:
- bez média and svazek
- Type:
- article, text, články, journal articles, model:article, and TEXT
- Subject:
- Biologické vědy, Techmania science center (projekt), biologie, zážitková pedagogika, studium a výuka, biology, experience pedagogy, study and teaching, Plzeň (Česko), Plzeň (Czechia), vědecké parky, výuka, 2, and 57/59
- Language:
- Czech
- Description:
- Markéta Čekanová.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
103. Changes in chloroplast ultrastructure in leaves of drought-stressed maize inbred lines
- Creator:
- Shao, R. X., Xin, L. F., Zheng, H. F., Li, L. L., Ran, W. L., Mao, J., and Yang, Q. H.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, photosynthesis, biomass, chlorophyll, maize, membrane peroxidation, water content, 2, and 581
- Language:
- Multiple languages
- Description:
- Chloroplasts are commonly the site of the earliest abiotic injury visible in plant ultrastructure. In this study, six inbred lines of maize (Zea mays L.) were used to analyze changes in the ultrastructure of chloroplasts and related physiological parameters under conditions of drought stress simulated by 20% polyethylene glycol 6000 (-0.6 MPa) for two days. Chloroplasts of three maize lines proved to be more sensitive. They showed changes in the ultrastructure in response to drought, including damage of thylakoid membranes, an increase in the number and size of plastoglobuli, swelling of thylakoid membranes both stromal and granal, disorganization of the thylakoid membrane system, an obvious increase in the intrathylakoid space, and a decrease in the length-to-width ratio and area of chloroplasts. In addition, the contents of malondialdehyde increased markedly in the sensitive lines. Contrary to the sensitive lines, stable structures and shapes of chloroplasts were observed in the drought-resistant lines; it could be considered as an advantage contributing to drought tolerance in the plants. In addition, the drought index of leaf fresh mass (LMDI) in the drought-sensitive lines was ≤ 0.5, which was also associated with a lower content of leaf chlorophyll. In contrast, drought tolerance coincided with lesser growth reduction, and higher LMDI and leaf chlorophyll content., R. X. Shao, L. F. Xin, H. F. Zheng, L. L. Li, W. L. Ran, J. Mao, Q. H. Yang., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
104. Changes in photosynthesis, pigment composition and glutathione contents in two Antarctic lichens during a light stress and recovery
- Creator:
- Balarinová, K., Barták, Miloš, Hazdrová, J., Hájek, Josef, and Jílková, J.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, karotenoidy, lišejníky, photosynthesis, carotenoids, lichenes, Antarktida, Antarctica, chlorophyll fluorescence, performance index, thallus, light stress, 2, and 581
- Language:
- Multiple languages
- Description:
- Over last decades, several studies have been focused on short-term high light stress in lichens under laboratory conditions. Such studies reported a strong photoinhibition of photosynthesis accompanied by a partial photodestruction of PSII, involvement of photoprotective mechanisms, and resynthetic processes into gradual recovery. In our paper, we applied medium [800 μmol(photon) m-2 s-1] light stress to induce negative changes in PSII funcioning as well as pigment and glutathione (GSH) content in two Antarctic fruticose lichen species. Chlorophyll (Chl) fluorescence parameters, such as potential and effective quantum yield of photosynthetic processes and fast transients (OJIP) recorded during high light exposition and recovery, revealed that Usnea antarctica was less susceptible to photoinhibition than U. aurantiaco-atra. This might be supported by a more pronounced high light-induced reduction in Chl a and b contents in U. aurantiaco-atra compared with U. antarctica. In both experimental species, total GSH showed an initial increase during the first 30-40 min of high light treatment followed by a decrease (60 min) and an increase during dark recovery. Full GSH recovery, however, was not finished in U. aurantiaco-atra even after 5 h indicating lower capacity of photoprotective mechanisms in the species. OJIP curves showed high light-induced decrease in both species, however, the recovery of the OJIPs shape to pre-photoinhibitory values was faster and more apparent in U. antarctica than in U. aurantiaco-atra. The results are discussed in terms of sensitivity of the two species to photoinhibition and their photosynthetic performance in natural environment., K. Balarinová, M. Barták, J. Hazdrová, J. Hájek, J. Jílková., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
105. Changes in photosynthetic activity in five common hybrids of oil palm (Elaeis guineensis Jacq.) seedlings under water deficit
- Creator:
- Suresh, K., Nagamani, C., Kantha, D. L., and Kumar, M. K.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- botanika, botany, drought, Elaeis guineensis Jacq., gas exchange, stomatal conductance, water deficit, 2, and 58
- Language:
- Multiple languages
- Description:
- The leaf water potential, gas-exchange parameters and chlorophyll fluorescence were evaluated in five common oil palm (Elaeis guineensis Jacq.) tenera hybrids 913X1988, 1425X2277, 748X1988, 7418X1988, and 690X1988 under water deficit with an aim to identify hybrids which can cope up better under such conditions and understand possible differences among hybrids in relation to the physiological mechanisms triggered by water deficit. Our findings indicate oil palm hybrids 913X1988, 1425X2277, and 7418X1988 maintained higher leaf water potentials than the other hybrids. Hybrids 7418X1988 and 1425X2277 recorded lower stomatal conductance after water deficit, which resulted in higher intrinsic water-use efficiency. The excess light energy produced due to decreased photosynthesis in 7418X1988 and 690X1988 hybrids under water deficit was dissipated as heat by higher nonphotochemical quenching. The maximum efficiency of photosystem II was not affected, even after withholding water for 24 days, suggesting an increased efficiency of photoprotection mechanisms in all these oil palm hybrids., K. Suresh ... [et al.]., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
106. Changes in plant growth and photosynthetic performance of Zizania latifolia exposed to different phosphorus concentrations under hydroponic condition
- Creator:
- Yan, N., Zhang, Y.-L., Xue, H.-M., Zhang, X.-H., Wang, Z.-D., Shi, L.-Y., and Guo, D.-P.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, photosynthesis, chlorophyll a fluorescence, growth characteristics, phosphorus availability, 2, and 581
- Language:
- Multiple languages
- Description:
- The effects of phosphate concentration on plant growth and photosynthetic performance were examined in leaves of Zizania latifolia. Plants were grown for four weeks in a solution containing 0, 0.16, 0.64, and 2.56 mM orthophosphate. The results showed that the highest net photosynthetic rate (P N) was achieved at 0.64 mM orthophosphate, which corresponded to the maximum content of organic phosphorus in leaves. Low phosphorus (low-P) content in the culture solution inhibited plant growth, affecting plant height, leaf length, leaf number, tiller number, and fresh mass of leaf, sheath, culm, root, and total plant. In addition, we observed that low-P (0.16 mM) did not hinder the growth of roots but increased the root:shoot ratio, and significantly decreased the chlorophyll content, P N, stomatal conductance, and transpiration rate, but increased the intercellular CO2 concentration. Additionally, low-P significantly decreased the maximum carboxylation rate of Rubisco, the maximum rate of ribulose-1,5-bisphosphate regeneration, the effective quantum yield of PSII photochemistry, photochemical quenching coefficient, and electron transport rate, but increased the nonphotochemical quenching. However, the maximal quantum yield of PSII photochemistry was not significantly affected by low-P. High phosphorus (2.56 mM) caused only a slight decrease in gas-exchange parameters. Therefore, the decrease in growth of P-deficient Z. latifolia plants could be attributed to the lowered photosynthetic rate., N. Yan, Y.-L. Zhang, H.-M. Xue, X.-H. Zhang, Z.-D. Wang, L.-Y. Shi, D.-P. Guo., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
107. Changes in stomatal characteristics and photochemical efficiency during leaf development in six species of Sorbus
- Creator:
- Čaňová, I., Ďurkovič, J., Hladká, D., and Lukáčik, Ivan
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- botanika, botany, phenological stages, photochemical efficiency, Sorbus chamaemespilus, 2, and 58
- Language:
- Multiple languages
- Description:
- Measurements of Sorbus stomata size and density, maximal photochemical efficiency of photosystem II (Fv/Fm), variable-to-initial fluorescence ratio (Fv/F0) and potential electron acceptor capacity (‘area’) were performed during leaf development in four parental diploid species, S. aria, S. aucuparia, S. chamaemespilus, S. torminalis, and two hybrid species, S. hazslinszkyana and S. intermedia. In fully expanded mature leaves, stomata lengths and densities were significantly larger in the shrub S. chamaemespilus than in the five tree species. The best performance of both the Fv/Fm and the Fv/F0 ratio was recorded in S. intermedia, whereas S. chamaemespilus had the highest value of ‘area’. From a physiological point of view, the results of this study showed that the photosystem II reaction centers remained intact functionally through all phenological stages of leaf expansion for all examined species of Sorbus., I. Čaňová ... [et al.]., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
108. Changes in thermic limits and acclimation assessment for an alpine plant by chlorophyll fluorescence analysis: Fv/Fmvs. Rfd
- Creator:
- Perera-Castro, A. V., Brito, P., and González-Rodríguez, A. M.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- horko, vysoká hora, Národní park Teide, teplotní odolnost, index vitality, freezing acclimation, heat, high mountain, Teide National Park, temperature resistance, vitality index, 2, and 581
- Language:
- Multiple languages
- Description:
- A comparison between maximum quantum yield of PSII photochemistry (Fv/Fm) and chlorophyll fluorescence decrease ratio (Rfd) for low and high temperature resistance was assessed in a seasonal study of the acclimation in Pterocephalus lasiospermus. Analyzing the regression adjustment of both parameters and the lethal temperatures (LT50), Rfd resulted in being a more sensitive indicator for low and high temperature treatments, since the thermic resistance estimated with Rfd parameter was never higher than those estimated with Fv/Fm. Furthermore, the use of Fv/Fm led to an overestimation of the acclimation phenomena, with 6ºC of a maximum difference between both parameters. Using Rfd as the indicator parameter, P. lasiospermus acclimated to low temperatures but it kept on being a sensitive species (the lowest LT50 values only achieved -9.9 ± 0.3ºC). However, no heat acclimation was observed (LT50 around 43.5ºC). Thus, according to Rfd evaluation of the thermic threshold, this species could be in risk of damage at low temperatures in this alpine ecosystem., A. V. Perera-Castro, P. Brito, A. M. González-Rodríguez., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
109. Changes in winter snow depth affects photosynthesis and physiological characteristics of biological soil crusts in the Tengger Desert
- Creator:
- Hui, R., Zhao, R. M., Liu, L. C., Li, Y. X., Yang, H. T., Wang, Y. L., Xie, M., and Wang, X. Q.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, photosynthesis, biological soil crusts, chlorophyll fluorescence, photosynthetic pigments, soluble sugar, water availability, 2, and 581
- Language:
- Multiple languages
- Description:
- Water availability is a major limiting factor in desert ecosystems. However, a winter snowfall role in the growth of biological soil crusts is still less investigated. Here, four snow treatments were designed to evaluate the effects of snow depth on photosynthesis and physiological characteristics of biological soil crusts. Results showed that snow strongly affected the chlorophyll fluorescence properties. The increased snow depth led to increased contents of photosynthetic pigments and soluble proteins. However, all biological soil crusts also exhibited a decline in malondialdehyde and soluble sugar contents as snow increased. Results demonstrated that different biological soil crusts exhibited different responses to snow depth treatment due to differences in their morphological characteristics and microhabitat. In addition, interspecies differentiation in response to snow depth treatment might affect the survival of some biological soil crusts. Further, this influence might lead to changes in the structural composition and functional communities of biological soil crusts., R. Hui, R. M. Zhao, L. C. Liu, Y. X. Li, H. T. Yang, Y. L. Wang, M. Xie, X. Q. Wang., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
110. Changes of extracellular matrix of rat cornea after exposure to hypoxia
- Creator:
- Gabriela Mahelková, Jiří Korynta, Moravová, A., Jana Novotná, and Richard Vytášek
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Biochemie. Molekulární biologie. Biofyzika, oftalmologie, rohovka, hypoxie, ophthalmology, cornea, hypoxia, metalloproteinase, oxidative damage, nitrotyrosine, 2, and 577
- Language:
- English
- Description:
- The purpose of the study was to check whether hypoxia of corneal tissue increases the collagenolytic activity due to release of reactive oxygen and nitrogen species. Rats were exposed to hypoxia 10 % O2 for 4, 14, and 21 days. The radical tissue injury was measured by the level of nitrotyrosine and changes in the lipoperoxide-related fluorophores. Collagen protein composition was analyzed by slab gel electrophoresis. The activity of gelatinolytic enzymes was studied using the zymography. The vascularization of the corneas was measured. We found no differences in the corneal tissue in the gel electrophoretic profile of collagenous proteins and gelatinolytic activity between normoxic and hypoxic rats. We did not find any sign of radical tissue injury. There were no changes in the vascularization of corneas after exposition to hypoxia. The environmental 10 % hypoxia does not induce radical tissue injury and an increase of collagenolytic activity in the rat cornea., G. Mahelková, J. Korynta, A. Moravová, J. Novotná, R. Vytášek, J. Wilhelm., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public