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152. Photosynthesis in leaves of Nicotiana tabacum L. infected with tobacco mosaic virus
- Creator:
- Wilhelmová, N., Procházková, D., Šindelářová, M., and Šindelář, L.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- carotenoids, chlorophyll, chlorophyll fluorescence, electron transport, photosynthetic efficiency, photosystem 2, and tobacco
- Language:
- Multiple languages
- Description:
- In tobacco leaves inoculated with tobacco mosaic virus (TMV), changes in chlorophyll (Chl) and carotenoid contents, parameters of slow Chl fluorescence kinetics, i.e. the maximum quantum yield of photosystem (PS2) photochemistry Fv/Fm, the effective quantum yield of photochemical energy conversion in PS2 Φ2, ratio of quantum yields of photochemical and concurrent non-photochemical processes in PS2 Fv/F0, non-photochemical quenching (NPQ), and photochemical activities of isolated chloroplasts from systemically infected tobacco leaves were investigated. We compared two successive stages of infection, the first in the stage of vein clearing at 9th day post inoculation (dpi) and the second at 22nd dpi when two different regions, i.e. light- (LGI) or dark-green (DGI) islands in the infected leaf were apparent and symptoms were fully developed. These two different regions were measured separately. The Chl and carotenoid contents in infected leaves decreased with a progression of infection and were lowest in LGI in the second stage. Also the ratio of Chl a/b declined in similar manner. The maximum quantum yield of PS2 photochemistry Fv/Fm, was decreased in the following order: first stage, DGI, and LGI. The same is true for the ratio Fv/F0. The decrease of Φ2 in infected leaves declined as compared to their controls. On the contrary, NPQ increased in infected leaves, the highest value was found in the first infection stage. Photochemical activities of the whole electron transport chain in isolated chloroplasts dramatically declined with the progression of symptoms, the lowest value was in LGI. Similarly, but to a lesser extent, the activity of PS2 in isolated chloroplasts decreased in infected leaves. Generally, the most marked impairment of the photosynthetic apparatus was manifested in the LGI of infected leaves. and N. Wilhelmová ... [et al.].
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
153. Photosynthesis in Platycerium coronarium (Koenig ex Mueller) Desv.
- Creator:
- Ong, Bee-Lian, NG, Sock-Ling, and Wee, Yeow-Chin
- Format:
- Type:
- model:internalpart and TEXT
- Subject:
- chlorophyll, specific leaf mass, senescence, respiration rate, quantum yield, net photosynthetic rate, nest and pendulous fronds, dry and fresh mass, and compensation and saturation irradiance
- Language:
- Multiple languages
- Description:
- In the dimorphic stag’s hom fem, Platycerium coronarium (Koenig ex Mueller) Desv., photosynthetic characters and chlorophyll (Chl) contents were deteiinined in both nést and pendulous fronds at different stages of ontogeny and at different positions along the longest length of each frond. Area-specific radiant energy- saturated net photosynthetic (P^) and dark respiration rates, dry mass-specific Chl content and quantum yield increased during frond development and decreased when senescence set in. Radiant energy-saturated and dry-mass specific Chl content were greatest in the youngest tissues of each frond. In addition to the functions ascribed to the nést (water and nutrient collection) and pendulous (reproduction) fronds, the results indicate the important roles of both frond types in providing Chemical energy to the growth and survival of the plant.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
154. Photosynthesis of cockspur [Echinochloa crus-galli (L.) Beauv.] at sites of naturally elevated CO2 concentration
- Creator:
- Vodnik, D., Pfanz, H., Maček, I., Kastelec, D., Lojen, S., and Batič, F.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- carbon dioxide springs, chlorophyll, CO2 compensation concentration, intercellular CO2 concentration, net photosynthetic rate, plant height, stomatal conductance, and δ13C
- Language:
- Multiple languages
- Description:
- High abundance of cockspur (Echinochloa crus-galli) at the geothermal carbon dioxide spring area in Stavešinci indicates that this species is able to grow under widely varying CO2 concentrations. Living cockspur plants can even be found very close to gas-releasing vents where growth is significantly reduced. Plant height correlated well with CO2 exposure. The δ13C value of the CO2 spring air was -3.9 ‰ and δ13C values of high-, medium-, and low-CO2 plants were -10.14, -10.44, and -11.95 ‰, respectively. Stomatal response directly followed the prevailing CO2 concentrations, with the highest reduction of stomatal conductance in high CO2 concentration grown plants. Analysis of the curves relating net photosynthetic rate to intercellular CO2 concentration (PN-Ci curves) revealed higher CO2 compensation concentration in plants growing at higher CO2 concentration. This indicates adjustment of respiration and photosynthetic carbon assimilation according to the prevailing CO2 concentrations during germination and growth. There was no difference in other photosynthetic parameters measured. and D. Vodnik ... [et al.].
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
155. Photosynthesis of Hedera canariensis var. azorica variegated leaves as affected by ozone
- Creator:
- Soldatini, G. F., Nali, C., Guidi, L., and Lorenzini, G.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- chlorophyll, fluorescence, ivy, net photosynthetic rate, stomatal conductance, and transpiration
- Language:
- Multiple languages
- Description:
- A differential response to long-term ozone exposures (50 and 100 mm3 m-3) was observed in the green and white areas of variegated leaves of Hedera canariensis var. azorica L. In green tissue the photosynthetic activity was depressed via a stomatal mechanism, and in white regions no effect was observed. Chlorophyll fluorescence parameters remained unchanged in green portions, whereas in the white ones Fm and Fv/Fm significantly diminished following ozone fumigation. and G. F. Soldatini ... [et al.].
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
156. Photosynthesis, water-use efficiency and δ13C of five cowpea genotypes grown in mixed culture and at different densities with sorghum
- Creator:
- Makoi, J. H. J. R., Chimphango, S. B. M., and Dakora, F. D.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- botanika, botany, chlorophyll, cultivars, discrimination, gas exchange, intercropping, isotope, monocropping, plant stand, species, and varieties
- Language:
- Multiple languages
- Description:
- A field experiment involving two planting densities (83,333 and 166,666 plants per ha), two cropping systems (monoculture and mixed culture) and five cowpea [Vigna unguiculata L. (Walp.)] genotypes was conducted at Nietvoorbij (33°54S, 18°14E), Stellenbosch, South Africa, to select cowpea material with superior growth and water-use efficiency (WUE). The results showed significantly higher photosynthetic rates, stomatal conductance and transpiration in leaves of plants at low density and in monoculture due to greater chlorophyll (Chl) levels relative to those at high density and in mixed culture. As a result, C concentration in leaves and the amount of C, P, K, Ca, Mg, Fe, Cu, Zn, Mn, and B accumulated in shoots at low density and under monoculture were also much higher. Even though no marked differences in photosynthetic rates were found between and among the five cowpea genotypes, leaf C concentration and shoot C, P, K, Ca, Mg, Fe, Cu, Zn, Mn, and B contents differed considerably, with Sanzie exhibiting the highest C concentration and C, P, K, Ca, Mg, Fe, Cu, Zn, Mn, and B contents in shoots, followed by Bensogla and Omondaw, while ITH98-46 and TVu1509 had the lowest shoot concentration and contents of C, P, K, Ca, Mg, Fe, Cu, Zn, Mn, and B. WUE (calculated as photosynthate produced per unit water molecule transpired) was significantly greater in plants at low density and monoculture relative to those at high density and in mixed culture. Isotopic analysis revealed significant differences in δ13C values of sorghum [Sorghum bicolor L. (Moench.)] and cowpea, with higher δ13C values being obtained for plants at low density and in monoculture relative to those at high density or in mixed culture. The five cowpea genotypes also showed significant differences in δ13C values, with Sanzie exhibiting the most negative value (i.e. low WUE) and ITH98-46, the least negative δ13C value (i.e. high WUE). Whether measured isotopically or from gas-exchange studies, sorghum (a C4 species) exhibited much higher WUE relative to cowpea (a C3 species). Both correlation and regression analyses revealed a positive relationship between WUE from gas-exchange studies and δ13C values from isotopic analysis of cowpea and sorghum shoots. and J. H. J. R. Makoi, S. B. M. Chimphango, F. D. Dakora
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
157. Photosynthetic activity in seed wings of Dipterocarpaceae in a masting year: Does wing photosynthesis contribute to reproduction?
- Creator:
- Kenzo, T., Ichie, T., Ninomiya, I., and Koike, T.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- chlorophyll, daily carbon gain, Dipterocarpus, Dryobalanops, respiration, Sarawak, sepal, Shorea, tropical rainforest, and Vatica
- Language:
- Multiple languages
- Description:
- The photosynthetic rate of seed wings developed from sepals was compared with the leaf photosynthetic rate in nine dipterocarp tree species (Dipterocarpus pachyphyllus, Dryobalanops aromatica, Dryobalanops lanceolata, Shorea beccariana, Shorea ferruginea, Shorea macroptera ssp. bailonii, Shorea macroptera ssp. macropterifolia, Shorea pilosa, and Vatica spp.). The wings showed positive photosynthetic activity, but at much lower rates than in the leaves. The daily CO2 uptake of wings showed slightly negative values in diurnal gas exchange measurements, even in D. aromatica that showed the highest photosynthetic capacity of all nine species. This low photosynthetic rate in the wings may be the result of low nitrogen and chlorophyll contents in the wing compared with leaves. However, the wings had a higher C/N ratio than leaves, and were thicker. Hence, dipterocarp wings have physical strength and defence against herbivores as higher priorities than photosynthetic activity. and T. Kenzo ... [et al.].
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
158. Photosynthetic and growth responses of two mustard cultivars differing in phytocystatin activity under cadmium stress
- Creator:
- Per, T. S., Khan, S., Asgher, M., Bano, B., and Khan, N. A.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- kadmium, bavlna, chlorofyl, cadmium, cotton, chlorophyll, fluorescence chlorofylu, fluorescenční spektra, oblast listu, phytocystatin, suchá rostlinná hmota, kultivary, rychlost přenosu elektronů, kaštan, chlorophyll fluorescence, fluorescence spectra, leaf area, plant dry mass, ascorbate peroxidase, ATP-sulphurylase, cultivars, effective quantum yield of PSII photochemistry, electron transport rate, chestnut, maximal quantum yield of PSII photochemistry, 2, and 581
- Language:
- Multiple languages
- Description:
- Cadmium inhibits photosynthetic capacity of plants by disturbing protein conformations, whereas phytocystatins prevent degradation of target proteins and are involved in abiotic stress tolerance. Two mustard (Brassica juncea L.) cultivars, Ro Agro 4001 and Amruta, were grown with Cd (50 µM) in order to study physiological and biochemical basis of differences in Cd tolerance. Amruta accumulated higher Cd and H2O2 concentrations in leaves than that of Ro Agro 4001. Cd significantly decreased photosynthesis and growth of plants in both cultivars by reducing a chlorophyll content, gas exchange parameters, and activity of Rubisco; the effects were more prominent in Amruta than those in Ro Agro 4001. The greater photosynthesis and growth of Ro Agro 4001 under Cd stress might be attributed to its higher phytocystatin activity together with greater ascorbate peroxidase activity, photosynthetic nitrogen-use efficiency, sulphur assimilation (ATP-sulphurylase activity and S content), and contents of cysteine and reduced glutathione compared to Amruta. In contrast, the activity of superoxide dismutase (SOD) was higher in Amruta than that of Ro Agro 4001 under control conditions, whereas the Cd treatment increased significantly the SOD activity in both cultivars with the greater increase in Ro Agro 4001. The fluorescence spectra of phytocystatin showed a lesser change in Ro Agro 4001 under Cd stress than that in Amruta suggesting higher resistance of Ro Agro 4001 to Cd. The higher phytocystatin activity under Cd stress in Ro Agro 4001 compared to Amruta enabled the plants to protect their proteins more efficiently. This resulted in a greater increase of photosynthetic capacity in Ro Agro 4001 than that of Amruta. Thus, the phytocystatin activity may be considered as a physiological parameter for augmenting photosynthesis and growth of mustard under Cd stress., T. S. Per, S. Khan, M. Asgher, B. Bano, N. A. Khan., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
159. Photosynthetic characteristics of Ipomoea pescaprae Forsk. under NaCl stress
- Creator:
- Venkatesan, A., Venkatesalu, V., and Chellappan, K.P.
- Format:
- Type:
- model:internalpart and TEXT
- Subject:
- chlorophyll, ill reaction activity, net photosynthetic rate, photosystem 2, and salinity
- Language:
- Multiple languages
- Description:
- Sodium chloride salinity had enhanced the photosynthetic rate, photosystem 2 activity and chlorophyll synthesis in isolated leaf cells of Ipomoea pescaprae up to 200 mM NaCl. The salt treated plants did not show any shift in the mode of photosynthesis.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
160. Photosynthetic characteristics of non-leaf organs of winter wheat cultivars differing in ear type and their relationship with grain mass per ear
- Creator:
- Wang, Zhi-Min, Wei, Ai-Li, and Zheng, Dan-Man
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- chlorophyll, net synthetic rate, photosystem 2, ribulose-1,5-bisphosphate carboxylase/oxygenase, and Triticum aestivum
- Language:
- Multiple languages
- Description:
- Chlorophyll content, photosystem 2 functioning (Fv/Fm, Fv/F0), activity of ribulose-1,5-bisphosphate carboxylase/oxygenase, and net photosynthetic rates (PN) of flag leaf blade, sheath, peduncle, and ear organs were assessed in large-ear type (Pin 7) and small-ear type (ND93) wheat cultivars. Some differences were found in photosynthetic properties between different green plant parts, the values of all studied parameters in ear parts being higher in Pin7 than in ND93. Furthermore, ear surface areas and ear PN in 26 wheat genotypes measured at anthesis showed highly significant positive correlation with grain mass per ear. Hence a greater capability of ear photosynthesis may result in a greater grain yield in large-ear type cultivars. and Zhi-Min Wang, Ai-Li Wei, Dan-Man Zheng.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public