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892. Image analysis of the leaf vascular network: physiological considerations
- Creator:
- Pagano, M., Corona, P., and Storchi, P.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- digitální fotoaparáty, digital cameras, výměna plynu, list, rychlost čisté fotosyntézy, kultivary, mezibuněčné koncentrace CO2, gas exchange, leaf, net photosynthetic rate, vascular network, vein density, cultivars, bundle sheath extension, 2, and 581
- Language:
- Multiple languages
- Description:
- 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
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
893. Immunological response in the mouse melanoma model after local hyperthermia
- Creator:
- Jiří Kubeš, Jiří Svoboda, Jozef Rosina, Miroslav Starec, and Anna Fišerová
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Mikrobiologie, mikrobiologie, hypertermie, melanomy, microbiology, hyperthermia, melanomas, local hyperthermia, cytotoxic cells, monocytes, CD69, 2, and 579
- Language:
- English
- Description:
- 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
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
894. Immunomodulation in insects post-treatment with abiotic agents: a review
- Creator:
- Shaurub, El-Sayed H.
- Type:
- article, články, model:article, and TEXT
- Subject:
- Zoologie, zoologie, entomologie, Insects, insecticides, chitin synthesis inhibitors, juvenile hormone analogues, inert particles, antibiotics, heavy metals, radiation, immunomodulation, 2, and 59
- Language:
- English
- Description:
- The effects of different abiotic agents that may modulate the activity of an insect’s immune system are reviewed. These agents include insecticides, chitin synthesis inhibitors, juvenile hormone analogues, inert particles, antibiotics, heavy metals, radiation and miscellaneous substances. The significance of studying immunomodulation in insects treated with abiotic agents in relation to both insect control and insect-borne parasitic diseases and the link between immunomodulation in insects post-treatment with both abiotic and biotic agents are discussed., El-Sayed H. Shaurub., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
895. Impact of arbuscular mycorrhizal fungi on the growth, water status, and photosynthesis of hybrid poplar under drought stress and recovery
- Creator:
- Liu, T., Sheng, M., Wang, C. Y., Chen, H., Li, Z., and Tang, M.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, topol, photosynthesis, poplar, Shaanxi (Čína : provincie), Shaanxi (China : Province), drought tolerance, gas exchange, nonphotochemical quenching, photosynthetic capacity, relative water content, Rhizophagus irregularis, 2, and 581
- Language:
- Multiple languages
- Description:
- 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
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
896. Impact of elevated CO2 on growth, physiology, yield, and quality of tomato (Lycopersicon esculentum Mill) cv. Arka Ashish
- Creator:
- Mamatha, H., Srinivasa Rao, N. K., Laxman, R. H., Shivashankara, K. S., Bhatt, R. M., and Pavithra, K. C.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, pigmenty, rajčata, photosynthesis, pigments, tomatoes, gas exchange, growth characteristics, leaf water status, yield characteristics, Lycopersicon esculentum Mill) cv. Arka Ashish, 2, and 581
- Language:
- Multiple languages
- Description:
- Tomato meets the dietary nutrient and antioxidant requirements of diverse populations. Being a C3 crop and an important vegetable, it is likely to be influenced by increased CO2 concentrations under climate change situation. This study was conducted to investigate the effects of elevated CO2 on overall physiology, water relations, growth, yield, and fruit quality of tomato (Lycopersicon esculentum Mill) cv. Arka Ashish. Plants were grown at elevated CO2 [550 (EC550) and 700 (EC700) ppm of CO2] in open top chambers. Increased assimilation rate, decreased stomatal conductance and transpiration rate were observed at elevated CO2 (EC) concentrations. Reduced leaf osmotic potential and increased water potential were observed at EC compared with the control (380 ppm of CO2) in flowering and fruiting stages. Lower total chlorophyll content was recorded at EC700. Plant height was significantly higher at EC550 compared with EC700. Higher number of branches was observed at EC700 as compared with plants grown at EC550 and the control. Leaf area was lower at EC700 compared with EC550 but specific leaf mass was higher at EC700. Due to higher leaf dry mass and root dry mass, the plants grown at EC700 exhibited higher total dry mass compared to EC550 and the control. Increased number of flowers and fruits together with higher fruit set led to higher fruit yield at both EC concentrations. The highest yield increase was observed at EC700. The fruits showed a lower content of phenols, flavonoids, ferric reducing antioxidant potential, total soluble solids, and titratable acidity in plants grown at EC as compared with the control. The ascorbic acid content was high at both EC700 and EC550. Carotenoids and lycopene content was low at EC700 compared to higher content observed at EC550 and the control., H. Mamatha, N. K. Srinivasa Rao, R. H. Laxman, K. S. Shivashankara, R. M. Bhatt, K. C. Pavithra., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
897. Impact of intraspecific competition on photosynthetic apparatus efficiency in potato (Solanum tuberosum) plants
- Creator:
- Olechowicz, J., Chomontowski, C., Olechowicz, P., Pietkiewicz, S., Jajoo, A., and Kalaji, Mohamed Hazem
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- chlorofyl, chlorophyll, chlorophyll fluorescence transient, intraspecific competition, performance index, photosystem II efficiency, 2, and 581
- Language:
- Multiple languages
- Description:
- Unfavourable growth conditions significantly determine the yield of crop plants. Intraspecific competition is a condition in which plants compete with each other for environmental resources. An excessive density contributes to increased competition within species, which results in disruption of photosynthesis process. According to this idea, experiments were conducted to investigate the photosynthetic response of potato (Solanum tuberosum) plants to excessive congestion. Two potato varieties of different earliness classes (Vineta and Satina) were used to evaluate the efficiency of the photosynthetic apparatus based on chlorophyll (Chl) fluorescence measurements under stress conditions. Changes in Chl contents of the tested plants were also analysed. In relation to intraspecific competition, we can conclude that the Vineta variety was less sensitive to this stress factor. In contrast, the photosynthetic apparatus of the Satina variety showed less efficient functioning under these conditions. In this study, the application of Chl fluorescence was presented for the first time in order to analyse the effects of intraspecific competition in plants., J. Olechowicz, C. Chomontowski, P. Olechowicz, S. Pietkiewicz, A. Jajoo, M. H. Kalaji., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
898. Impact of light-emitting diode irradiation on photosynthesis, phytochemical composition and mineral element content of lettuce cv. Grizzly
- Creator:
- Amoozgar, A., Mohammadi, A., and Sabzalian, M. R.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- karotenoidy, fotosyntéza, carotenoids, photosynthesis, LED technologie, hlávkový salát, obsah minerálů, fytochemikálie, LED technology, lettuce, mineral content, phytochemicals, 2, and 581
- Language:
- Multiple languages
- Description:
- Light-emitting diodes (LEDs) are a promising technology with a potential to improve the irradiance efficiency, light quality, and the light spectrum for increasing plant yield and quality. In this experiment, we investigated the impacts of various LED light qualities, including 100% red, 100% blue, 70% red + 30% blue, and 100% white, on the growth and photosynthesis, phytochemical contents, and mineral element concentrations in lettuce (Lactuca sativa L. cv. 'Grizzly') in comparison to normal greenhouse conditions. Photon flux of 300 µmol m-2 s-1 was provided for 14 h by 120 LEDs set on a 60 cm × 60 cm sheet of aluminum platform in the growth chambers, where plants were grown for 60 d. Fresh mass per plant was significantly higher when grown under 100% blue and 70% red + 30% blue LEDs compared to the other environments including greenhouse conditions. Phytochemical concentrations and a nutritive value of lettuce were also significantly affected by the light treatments. Chlorophyll and carotenoid concentrations increased in the plants grown under 70% red + 30% blue LEDs compared to those grown in the greenhouse. Vitamin C content was 2.25-fold higher in the plants grown under 100% blue LEDs compared to those grown in the greenhouse. Higher photosynthesis and maximal quantum yield of PSII photochemistry were also observed in the plants treated with LED lights. The application of LED light led to the elevated concentrations of macro-and micronutrients in lettuce possibly because of the direct effect of LED light and lower stress conditions in the growth chambers compared to the greenhouse. Although the mechanism of the changes in lettuce grown under LED is not well understood, the results of this study demonstrated that LED light could be used to enhance the growth and nutritional value of lettuce in indoor plant production facilities., A. Amoozgar, A. Mohammadi, M. R. Sabzalian., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
899. Imperfections in perfect architecture: the orb web of spiders
- Creator:
- Pasquet, Alain, Marchal, Julia, Anotaux, Mylene, and Leborgne, Raymond
- Type:
- article, články, model:article, and TEXT
- Subject:
- Zoologie, zoologie, entomologie, Arabeae, Zygiella x-notata, web construction, silky structures, anomalies, behavioural variability, 2, and 59
- Language:
- English
- Description:
- Among animal constructions, the orb webs of spiders are perfect geometrical architectural models. Webs are constructed by means of a succession of behaviours, which are often considered as instinctive and stereotyped. Anomalies in web structure are considered to be a consequence of variability in behaviour. In order to assess the variability in web structure, the spider Zygiella x-notata was allowed to build webs in the laboratory under standardized conditions. Webs (n = 127) were examined for anomalies, which were defined as modifications in the geometrical structure. Ten anomalies in the structure of webs produced by females, aged from 16 to 21 days after their adult moult, are described. The frequency of anomalies per web varies from 5 to 98. A very low percentage of the spiral elements of a web (less than 5%) were affected. Anomalies in the radii were less numerous (mean = 3 ± 3) than those in the sticky spiral (mean = 21 ± 11). Anomalies in the sticky spiral were different and more frequent in the peripheral than central parts of the webs. They were also relatively more numerous in the upper than in the lower part of the webs. Total number of anomalies was positively correlated with particular web characteristics (capture area, length of capture thread, width of the lower part of the web and mean distance between two spiral turns in the lower part) but not to the physical characteristics of the spiders (mass and size). Our results indicate that the orb webs of spiders, which are considered to be perfect geometrical structures, include anomalies mainly in the structure of the sticky spiral. These anomalies were the result of variability in behaviour during web building. In conclusion, their identification and description enable one to use them in spider webs as an index of behavioural variability., Alain Pasquet ... [et al.]., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
900. Implications of insect responses to supernormal visual releasing stimuli in intersexual communication and flower-visiting behaviour: a review
- Creator:
- Kral, Karl
- Format:
- print, počítač, and online zdroj
- Type:
- article, články, journal articles, model:article, and TEXT
- Subject:
- Zoologie, hmyz, motýli, čmelák, opylovači, insects, butterflies, bumble bees, pollinators, visual stimuli, mating, foraging, orchid mimicry, food reward, floral size, floral symmetry, ultraviolet signals, 2, and 59
- Language:
- English
- Description:
- Animals, including human beings, tend to respond more strongly to stimuli that are associated with the highest relative rewards. This applies not only to food rewards but also to reproductive success. In the present review article this issue is discussed for insects in connection with intersexual communication and flower-visiting behaviour. Implications of the preference for supernormal visual releasing stimuli are examined from a sensory and evolutionary perspective, including a consideration of the choice of potential mates and recognition of the most rewarding flowers., Karl Kral., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public