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2. Effects of phytoplasma infection on growth and photosynthesis in leaves of field grown apple (Malus pumila Mill. cv. Golden Delicious)
- Creator:
- Bertamini, M., Muthuchelian, K., Grando, M. S., and Nedunchezhian, N.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- amino acids, chlorophyll content and fluorescence, electron donor, nitrate reductase, photosystem, phytoplasma, proteins, ribulose-1,5-biphosphate carboxylase, sugars, and starch
- Language:
- Multiple languages
- Description:
- The contents of chlorophyll (Chl), leaf biomass, and soluble proteins were markedly decreased in phytoplasma infected apple leaves. Similar results were also observed for ribulose-1,5-bisphosphate carboxylase, 14CO2 fixation, and nitrate reductase activity. In contrast, the contents of sugars, starch, amino acids, and total saccharides were significantly increased in phytoplasma infected leaves. In isolated chloroplasts, phytoplasma infection caused marked inhibition of whole photosynthetic electron chain and photosystem 2 (PS2) activity. The artificial exogenous electron donor, diphenyl carbazide, significantly restored the loss of PS2 activity in infected leaves. Similar results were obtained when Fv/Fm was evaluated by in vivo Chl a fluorescence kinetic measurements. and M. Bertamini ... [et al.].
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
3. Fertilization regimes under hot conditions alter photosynthetic response of bean plants
- Creator:
- Hassan, I. A., Abou Zeid, H. M., Taia, W., Haiba, N. S., Zahran, A., Badr, R. H., El Dakak, R. A., and Shalaby, E. A.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, fazol obecný, photosynthesis, Phaseolus vulgaris, heat stress, nitrogen fertilization, photosynthetic performance, Phaseolus vulgaris L, French bean, 2, and 581
- Language:
- Multiple languages
- Description:
- We examined the effects of foliar application of various nitrogen (urea) concentrations on gas-exchange and chlorophyll (Chl) fluorescence characteristics in bean plants treated by heat stress (42/30°C, day/night temperatures). Heat stress caused reductions in contents of Chl a, Chl b, and in maximum photochemical efficiency of PSII by 13, 20, and 27%, respectively, regardless of the N treatment. However, N fertilization caused significant increases in these parameters, especially at higher N concentrations. The net photosynthetic rate and stomatal conductance were enhanced by 32, 60, and 69% and by 25, 88, and 100% due to addition of 5, 10, and 15 mM N, respectively. However, gas-exchange parameters were reduced by 24% due to heat stress. N fertilization alleviated adverse effects of heat stress., I. A. Hassan, H. M. Abou Zeid, W. Taia, N. S. Haiba, A. Zahran, R. H. Badr, R. A. El Dakak, E. A. Shalaby., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
4. Growth and leaf gas exchange characteristics in Dalbergia sissoo Roxb. and D. latifolia Roxb. under water deficit
- Creator:
- Ashraf, M., Ashraf, M. Y., Khaliq, Abdul, and Rha, Eui Shik
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- net photosynthetic rate, stomatal conductance, transpiration, and water use efficiency
- Language:
- Multiple languages
- Description:
- Forty two-month-old plants of Dalbergia sissoo and D. latifolia were subjected for 56 d to water deficit induced by withholding water. Drought stress caused a significant reduction in plant height, stem diameter, net photosynthetic rate (PN), transpiration rate (E), and stomatal conductance (gs) in both species, but the reduction was greater in D. sissoo than in D. latifolia. Water use efficiency (PN/E) was adversely affected due to water stress only in D. latifolia, and intrinsic water use efficiency (PN/gs) was increased in both species. There was a slight effect of water stress on variable to maximum fluorescence (Fv/Fm) (quantum yield of photosystem 2) in both species, but the species did not differ significantly in this attribute. and M. Ashraf ... [et al.].
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
5. Mathis, P. (ed.): Photosynthesis: from light to biosphere. Vol. I, II, III, IV, V
- Creator:
- Šesták, Z.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Language:
- Multiple languages
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
6. Modular response to salinity in the annual halophyte, Salicornia ramosissima
- Creator:
- Redondo-Gómez, S., Mateos-Naranjo, E., Parra, R., and Figueroa, M. E.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- botanika, botany, chlorophyll fluorescence, halophyte, modular response, and NaCl
- Language:
- Multiple languages
- Description:
- Chlorophyll fluorescence measurements showed that plasticity to salinity in stems of Salicornia ramosissima is expressed at a modular level, so intraplant variation should be considered in further studies. and S. Redondo-Gómez ... [et al.].
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
7. Photosynthesis, photosystem II efficiency, amino acid metabolism and ion distribution in rice (Oryza sativa L.) in response to alkaline stress
- Creator:
- Wu, Z.-H., Yang, C.-W., and Yang, M.-Y.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, rýže, photosynthesis, rice, alkaline stress, photosystem II efficiency, amino acid metabolism, 2, and 581
- Language:
- Multiple languages
- Description:
- Alkalies are important agricultural contaminants complexly affecting plant metabolism. In this study, rice seedlings were subjected to alkaline stress (NaHCO3:Na2CO3 = 9:1; pH 8.9) for 30 days. The results showed that stress mightily reduced net photosynthetic rate (PN), but slightly decreased transpiration rate and stomatal conductance. This indicated that decline of PN might be a result of nonstomatal factors. Alkaline stress caused a large accumulation of Na+ in leaves up to toxic concentration, which possibly affected chloroplast ultrastructure and photosynthesis. We found that alkaline stress reduced chlorophyll fluorescence parameters, such as ratios of Fv′/Fm′, Fv/Fm, photosystem (PS) II efficiency, and electron transport rates in rice plants, i.e. it influenced the efficiencies of photon capture and electron transport by PSII. This might be a main reason for the decrease of PN under such conditions. Deficiency of minerals could be another reason for the decline of PN. Alkaline stress lowered contents of N, K, Cu, Zn, P, and Fe in rice plants. In addition, the stress strongly affected metabolism of amino acids. This might be caused by imbalance in carbon metabolism as a result of photosynthesis reduction., Z.-H. Wu, C.-W. Yang, M.-Y. Yang., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
8. Photosynthetic responses of groundnut to itioisture stress
- Creator:
- Sharma, P., Nisha, and Malik, C. P.
- Format:
- Type:
- model:internalpart and TEXT
- Language:
- Multiple languages
- Description:
- Peanut plants were adapted to drought. Due to parahelionastic leaf movements under water stress they decreased heat load and transpiring area, Folding of leaflets minimised damage to photosynthetic apparatus by high temperatoe. A positive correlation between transpiration rate (E) and leaf water potential indicated the dependence of the latter on E. Phosphoenolpyruvate carboxylase (PEPC) activity progressively increased with increased period of stress, whereas activities of ribulose-l,5-bisphosphate carboxylase (RuBPC) and NADP-glyceraldehyde-3- phosphate dehydrogenase (NADP-G-3-PDH) decreased gradually.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
9. UV effects on chlorophylis and carotenoids of the haptophyceaen alga Pavlova
- Creator:
- Dohler, G. and Haas, F.T.
- Format:
- Type:
- model:internalpart and TEXT
- Subject:
- p-carotene, UV-B radiation, UV-A radiation, high-performance liquid chromatography, flicoxanthin, diatoxanthin, and diadinoxanthin
- Language:
- Multiple languages
- Description:
- In the temperate haptophyceaen Pavlova luíheri (Droop) Green and Pavlova sp. (not yet estimated) the dominant pigments were chlorophyll (Chl) a (57 %), fucoxanthin (17 %) and diadinoxanthin (13 %); other estimated pigments were p-carotene, Chl c, cA-fucoxanthin and diatoxanthin. UV-A of 1.7 W m-2 had no effect on pigmentation of P. luíheri, but led to a reduction of the pigment contents of Pavlova sp. The damaging effect of a high UV-A dose (11.0 W m'^) was more pronounced than that of UV-B irradiance. The strongest reduction of pigment concentrations of both Pavlova species was observed after an exposure to UV-A (11.0 W m'^) plus UV-B (1.2 W m-2). Under this combined irradiation an increase of the diatoxanthin content and a decrease of the diadinoxanthin content was found.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public