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532. Water stress and abscisic acid treatments induce the CAM pathway in the epiphytic fern Vittaria lineata (L.) Smith
- Creator:
- Minardi, B. D., Voytena, A. P. L., Santos, M., and Randi, Á. M.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, pigmenty, photosynthesis, pigments, Brazílie, Brasil, chlorophyll fluorescence, malate, morphoanatomy, photosynthetic pathway, Vittaria lineata, 2, and 581
- Language:
- Multiple languages
- Description:
- Among various epiphytic ferns found in the Brazilian Atlantic Forest, we studied Vittaria lineata (L.) Smith (Polypodiopsida, Pteridaceae). Anatomical characterization of the leaf was carried out by light microscopy, fluorescence microscopy, and scanning electron microscopy. V. lineata possesses succulent leaves with two longitudinal furrows on the abaxial surface. We observed abundant stomata inside the furrows, glandular trichomes, paraphises, and sporangia. We examined malate concentrations in leaves, relative water content (RWC), photosynthetic pigments, and chlorophyll (Chl) a fluorescence in control, water-deficient, and abscisic acid (ABA)-treated plants. Plants subjected to drought stress (DS) and treated by exogenous ABA showed significant increase in the malate concentration, demonstrating nocturnal acidification. These findings suggest that V. lineata could change its mode of carbon fixation from C3 to the CAM pathway in response to drought. No significant changes in RWC were observed among treatments. Moreover, although plants subjected to stress treatments showed a significant decline in the contents of Chl a and b, the concentrations of carotenoids were stable. Photosynthetic parameters obtained from rapid light curves showed a significant decrease after DS and ABA treatments., B. D. Minardi, A. P. L. Voytena, M. Santos, Á. M. Randi., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
533. Water-deficiency effects on single leaf gas exchange and on C4 pathway enzymes of maize genotypes with differing abiotic stress tolerance
- Creator:
- Sicher, Richard, Bunce, J., Barnaby, J., and Bailey, B.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, sucha, kukuřice, photosynthesis, C4 photosynthesis, drought, enzyme activities, gene expression, phosphoenolpyruvate carboxylase, maize, abiotic stress, 2, and 581
- Language:
- Multiple languages
- Description:
- Responses to drought were studied using two maize inbred lines (B76 and B106) and a commercial maize hybrid (Zea mays L. cv. Silver Queen) with differing resistance to abiotic stress. Maize seedlings were grown in pots in controlled environment chambers for 17 days and watering was withheld from one half the plants for an additional 11 days. On the final treatment date, leaf water potentials did not differ among genotypes and were -0.84 and -1.49 MPa in the water sufficient and insufficient treatments, respectively. Greater rates of CO2 assimilation were retained by the stress tolerant maize inbred line, B76, in comparison to the other two genotypes 11 days after watering was withheld. Rates of CO2 assimilation for all three genotypes were unaffected by decreasing the measurement O2 concentration from 21 to 2% (v/v). Activities of phosphoenolpyruvate carboxylase (PEPC), NADP-malic enzyme (NADP-ME), and NADP malate dehydrogenase were inhibited from 25 to 49% by the water deficiency treatment. Genotypic differences also were detected for the activities of NADP-ME and for PEPC. Changes of transcript abundance for the three C4 pathway enzymes also varied among watering treatments and genotypes. However, examples where transcripts decreased due to drought were associated with the two stress susceptible genotypes. The above results showed that enzymes in the C4 photosynthetic pathway were less inhibited by drought in stress tolerant compared to stress susceptible maize genotypes., R. Sicher, J. Bunce, J. Barnaby, B. Bailey., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
534. Zdeněk Šesták and Photosynthetica, a tribute
- Creator:
- Lichtenthaler, H. K.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- Šesták, Zdeněk, 1932-2008, odborné časopisy, fotosyntéza, professional journals, photosynthesis, 2, and 581
- Language:
- Multiple languages
- Description:
- On the occasion of the 50th anniversary of the international journal Photosynthetica in 2017 we briefly report on the establishment of this journal and on Dr. Zdeněk Šesták, the renowned researcher of photosynthesis processes who, in cooperation with the Czechoslovak Academy of Sciences, founded this essential science journal in Prague in 1967., H. K. Lichtenthaler., Obsahuje bibliografii, and Ozvláštněné číslování stránek článku 1-6. teprve na ně se napojuje pokračování stránkování navazující na 1. číslo časopisu
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
535. 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
536. 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
537. 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
538. Zušlechťování rostlin dle praktických zkušeností
- Creator:
- Mackovík, Jindřich
- Publisher:
- Min. zemědělství Republiky československé
- Format:
- print, text, regular print, and 56 s. : fotogr., tab
- Type:
- model:monograph and TEXT
- Subject:
- Obecná botanika, šlechtění rostlin, 581.3, 2, 581, and UF09
- Language:
- Czech
- Description:
- Jindřich Mackovík
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public