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5122. Zinc accumulation, photosynthetic gas exchange, and chlorophyll a fluorescence in Zn-stressed Miscanthus x giganteus plants
- Creator:
- Andrejić, G., Gajić, G., Prica, M., Dželetović, Ž., and Rakić, T.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- pigmenty, fotosyntéza, fytoremediace, pigments, photosynthesis, phytoremediation, Zn tolerance, 2, and 581
- Language:
- Multiple languages
- Description:
- Accumulation and distribution of zinc within Miscanthus x giganteus plants grown on elevated Zn concentrations and their photosynthetic performance were investigated. High concentrations of Zn in soils caused an increase of its concentrations in all plant organs. The bioconcentration factor, bioaccumulation factor, and translocation factor were lower than one indicating that M. x giganteus is an excluder plant species. Excessive Zn induced visible leaf damage, i.e. chlorosis and necrosis, only in the oldest leaves, pointing to Zn accumulation. Elevated amounts of Zn in leaves significantly lowered the photosynthetic rate, transpiration rate, stomatal conductance, intercellular CO2 concentrations, parameters of chlorophyll a fluorescence, and chlorophyll b content. Despite Zn excess in leaves, there was no severe reduction in the maximal quantum yield of PSII photochemistry, indicating a high photosynthetic capacity, high tolerance to elevated Zn concetrations, and ability of M. x giganteus to grow on Zn-contaminated soils., G. Andrejić, G. Gajić, M. Prica, Ž. Dželetović, T. Rakić., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
5123. Zinc and cadmium as modulating factors of the morphophysiological responses of Alternanthera tenella Colla (Amaranthaceae) under in vitro conditions
- Creator:
- Clairvil, E., Martins, J.P.R., Braga, P.C.S., Moreira, S.W., Conde, L.T., Cipriano, R., Falqueto, A.R., and Gontijo, A.B.P.L.
- Format:
- počítač and online zdroj
- Type:
- model:article and TEXT
- Subject:
- chlorophyll a fluorescence, electron transport flux, phytoremediation, plant tissue culture, and trace element
- Language:
- Multiple languages
- Description:
- Zinc (Zn) plays an important role in the physiological processes in plants and may mitigate trace element stress. The aim was to evaluate the morphophysiological responses of Alternanthera tenella plants exposed to cadmium (Cd) and Zn under in vitro conditions. Segments of A. tenella were transferred to flasks containing medium supplemented with different combinations of Cd (0, 75, or 150 μM) and Zn (0, 750, or 1,500 μM) concentrations, totalizing nine treatments. We assessed the growth traits, anatomy, chlorophyll a fluorescence by OJIPs, and tolerance index (TI). With exposure only to Cd, the plants showed physiological disorders. Zn supplementation in the medium had a positive effect on the physiological performance of plants. At concentrations ≤ 750 μM, it can partially mitigate the deleterious effects of Cd. Plants grown with Cd and Zn showed intermediate TI. The results proved the potential of Zn as a mitigator of Cd-induced stress in plants.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
5124. Zinc oxide nanoparticle-mediated changes in photosynthetic efficiency and antioxidant system of tomato plants
- Creator:
- Faizan, M., Faraz, A., Yusuf, M., Khan, S. T., and Hayat, S.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- antioxidační enzymy, výměna plynu, růst, mikronutrienty, antioxidant enzyme, gas exchange, growth, mikronutrients, 2, and 581
- Language:
- Multiple languages
- Description:
- The present study was carried out to assess the role of zinc oxide nanoparticles (ZnO-NPs) in tomato plants on growth, photosynthetic efficiency, and antioxidant system. At 20-d stage of growth, roots of tomato plants were dipped into 0, 2, 4, 8, or 16 mg(ZnO-NPs) L-1 for 15, 30, and 45 min and then seedlings were transplanted in their respective cups and allowed to grow under natural environmental conditions. At 45-d stage of growth, the ZnO-NPs treatments significantly increased growth, photosynthetic efficiency together with activities of carbonic anhydrase and antioxidant systems in a concentration- and duration-dependent manner. Moreover, the treatment by 8 mg(ZnO-NPs) L-1 for 30 min proved to be the most effective and resulted in maximum activities of antioxidant enzymes, proline accumulation and the photosynthetic rate. We concluded that presence of ZnO-NPs improved the antioxidant systems and speeded up proline accumulation that could provide stability to plants and improved photosynthetic efficiency., M. Faizan, A. Faraz, M. Yusuf, S. T. Khan, S. Hayat., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
5125. Zinc soil application enhances photosynthetic capacity and antioxidant enzyme activities in almond seedlings affected by salinity stress
- Creator:
- Amiri, A., Baninasab, B., Ghobadi, C., and Khoshgoftarmanesh, A. H.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, photosynthesis, abiotic stress, gas exchange, net assimilation rate, reactive oxygen species, 2, and 581
- Language:
- Multiple languages
- Description:
- Zinc is a critical mineral nutrient that protects plant cells from salt-induced cell damage. We tested whether the application of Zn at various concentrations [0, 5, 10, or 20 mg kg-1(soil)] would protect almond (Prunus amygdalus) seedlings subjected to salt stress (0, 30, 60, or 90 mM NaCl). All concentrations of Zn, particularly the application of 10 and 20 mg kg-1, increased the net photosynthetic rate, stomatal conductance, the maximal efficiency of PSII photochemistry, and a proline content in almond seedlings grown under salt stress; 20 mg(Zn) kg-1 was the most effective concentration. The activity of superoxide dismutase showed a significant increase under salinity stress and Zn application. The catalase activity decreased in the salt-treated seedlings, but recovered after the Zn treatment. Our results proved the positive effects of Zn on antioxidant enzyme activity scavenging the reactive oxygen species produced under salt stress., A. Amiri, B. Baninasab, C. Ghobadi, A. H. Khoshgoftarmanesh., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
5126. Život v archeologii středověku :
- Type:
- text and sborníky jubilejní
- Subject:
- Archeologie, Richter, Miroslav,, Smetánka, Zdeněk,, archeologie, and české (československé) sborníky a kolektivní monografie
- Language:
- Czech and Multiple languages
- Rights:
- unknown
5127. Zn-acquisition and its role in growth, photosynthesis, photosynthetic pigments, and biochemical changes in essential monoterpene oil(s) of Pelargonium graveolens
- Creator:
- Misra, A., Srivastava, A. K., Srivastava, N. K., and Khan, A.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- chlorophyll, Cu, dry mass, Fe, leaf area, Mn, net photosynthetic rate, plant height, saccharides, and Zn
- Language:
- Multiple languages
- Description:
- Culturing geranium at different doses of Zn from 0-1.0 g m-3 (Zn0 to Zn1.000) revealed that Zn is an antioxidant promoter, apart from its micronutrient essentiality. Zn0.250 was the critical concentration for maximum content (0.21 %) of total essential monoterpene oil(s). At Zn0.005-Zn0.250, net photosynthetic rate, and contents of chlorophyll and essential monoterpene oil(s) were affected. The maximum peroxidase activity was obtained at Zn0.250, with the production of biomolecule geraniol. We found an oxido-reducible reaction of Zn in the formation of monoterpene essential oil(s) and possibly major constituents of geraniol. and A. Misra ... [et al.].
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
5128. Zoltán Tuba: 16 May 1951 - 4 July 2009
- Creator:
- Mészáros, Ilona and Nagy, Zoltán
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- plant scientists
- Language:
- Multiple languages
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
5129. δ13C values, photosynthetic pathways, and plant functional types for some plants from saline meadows, Northeastern China
- Creator:
- Wang, R. Z.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- C4 photosynthetic pathway, saline meadow species, stable carbon isotope ratio (δ13C), and total carbon content
- Language:
- Multiple languages
- Description:
- Based on stable carbon isotope ratio (δ13C) measurements, photosynthetic pathway types were determined for 61 species in 54 genera and 24 families of flowering plants from the saline meadows of Northeastern China. Of these total vascular plants, 18 species in 17 genera from 6 families were found to have C4 photosynthesis; 43 species in 38 genera from 20 families had C3 photosynthesis. Six dicotyledonous species exhibited C4 pathway, 12 monocotyledonous species were found with C4 photosynthesis. The dicotyledonous C4 species had relative greater mean δ13C value and less total carbon content than both monocotyledonous C4 and C3 species. Most dicotyledonous C4 species were annual forbs and halophytes. Some C4 species had been previously documented, but their δ13C values varied remarkably from those of the present study. Even though there are some fluctuations for the δ13C values of some C4 species, δ13C value was still more reliable for C3 and C4 identification than the use of the enzyme ratio method and of low CO2 compensation concentration.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
5130. ΔpH-dependent fluorescence quenching and its photoprotective role in the unicellular red alga Rhodella violacea
- Creator:
- Ritz, M., Neverov, K. V., and Etienne, A.-L.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- chlorophyll irradiance, light-harvesting chlorophyll protein complex, photoinhibition, photosystems 1 and 2, and phycobilisome
- Language:
- Multiple languages
- Description:
- Plants have developed various photoprotective mechanisms to resist irradiation stress. One of the photoprotective mechanisms described in the literature for LHC2-containing organisms involves a down-regulation of photosystem (PS) 2 occurring simultaneously with the build-up of a proton gradient across the thylakoid membrane (ΔpH). It is often correlated with deepoxidation of xanthophylls located in LHC2. In Rhodophyta instead of LHC2, the peripheral antenna of PS2 consists of a large extramembrane complex, the phycobilisome (PBS), which transfers its excitation to the core antennae of PS2 composed of the CP43 and CP47 protein-chlorophyll complexes and there is no xanthophyll cycle. In the red alga Rhodella violacea a ΔpH-dependent chlorophyll (Chl) a fluorescence quenching can be formed. We characterised this quenching, studied the effects of various irradiances and inhibitors. Under photoinhibitory conditions, the ΔpH-dependent Chl fluorescence quenching exerts a photoprotective role and delays the kinetics of photoinhibition. It is the first time that such a photoprotective mechanism is described in PBS-containing organisms. and M. Ritz, K. V. Neverov, A.-L. Etienne.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public