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1142. Increase of the expression and activity of ferredoxin-NADP+ oxidoreductase in the cells adapted to low CO2 in the cyanobacterium Synechocystis 6803
- Creator:
- Liu, Y. R., Ma, W. M., and Mi, H. L.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- botanika, botany, expression and activity, ferredoxin-NADP oxidoreductase, low CO2, and Synechocystis 6803
- Language:
- Multiple languages
- Description:
- To investigate the effect of low CO2 on the expression and activity of ferredoxin-NADP+ oxidoreductase (FNR) and this enzyme-mediated cyclic electron flow around photosystem I (cyclic PSI), the activity staining, immunoblotting and initial rate of P700 + reduction were measured in high- or low-CO2-grown (H or L)-cells of wild-type Synechocystis sp. strain PCC 6803 (WT) and its ΔndhB mutant (M55). Major results were depicted as follows. (1) The protein levels and activity of FNR were remarkably stimulated in L-cells of both WT and M55 relative to that in their H-cells. (2) The rate of cyclic PSI was significantly increased in L-cells of WT, not M55, when compared to that in respective H-cells. (3) N-ethylmaleimide, an inhibitor of FNR, partially inhibited the increase in the rate of cyclic PSI induced by low CO2 in both WT and M55. These findings indicated that low CO2 enhanced the expression and activity of FNR and the cyclic PSI mediated by FNR. The contribution of FNR to cyclic PSI is shortly discussed. and Y. R. Liu, W. M. Ma, H. L. Mi.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
1143. Increased thermal stability of photosystem II and the macro-organization of thylakoid membranes, induced by co-solutes, associated with changes in the lipid-phase behaviour of thylakoid membranes
- Creator:
- Kotakis, C., Akhtar, P., Zsiros, O., Garab, G., and Lambrev, P. H.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, photosynthesis, circular dichroism, merocyanine-540, non-bilayer lipids, osmolyte, time-resolved fluorescence spectroscopy, 2, and 581
- Language:
- Multiple languages
- Description:
- The principal function of the thylakoid membrane depends on the integrity of the lipid bilayer, yet almost half of the thylakoid lipids are of non-bilayer-forming type, whose exact functions are not fully understood. Non-bilayer lipids can be extruded from the membrane in the presence of high concentrations of co-solutes. We applied 2 M sucrose to induce lipid phase separation in isolated thylakoid membranes, following consequent structural and physiological effects. Circular dichroism spectroscopy indicated significant changes in the chiral macro-arrangement of the pigment-protein complexes, which were reversed after washing out the co-solute. Similarly, merocyanine-540 fluorescence suggested reversible changes in the lipid phases. The PSII function, as tested by chlorophyll fluorescence induction transients and time-resolved fluorescence, was almost unaffected. However, the presence of sucrose dramatically increased the PSII thermostability, which can partly be explained by a direct osmolyte effect and partly by the lipid phase separation stabilizing the stacked membrane., C. Kotakis, P. Akhtar, O. Zsiros, G. Garab, P. H. Lambrev., and Obsahuje bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
1144. Increased water supply promotes photosynthesis, C/N ratio, and plantamajoside accumulation in the medicinal plant Plantago depressa Willd
- Creator:
- Li, Z., Bai, W., Zhang, L., and Li, L.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- biomasa, chlorofyl, biomass, chlorophyll, změny klimatu, řízené prostředí, výměna plynu, fenolické sloučeniny, mezibuněčné koncentrace CO2, rychlost čisté fotosyntézy, stomatální vodivost, Plantago depressa, climate change, controlled environment, gas exchange, phenolic compounds, C/N ratio, intercellular CO2 concentration, net photosynthetic rate, plantamajoside, stomatal conductance, 2, and 581
- Language:
- Multiple languages
- Description:
- Anthropogenic activities are changing global precipitation regimes and result in many middle latitude arid and semiarid regions experiencing less precipitation and more extreme weather events. However, little is known about the response of active ingredient accumulation in the medicinal herb Plantago depressa Willd. Therefore, we carried out a greenhouse experiment in order to study effect of control (CK, normal water supply equal to 309 mm per four months), -30 (-WS) and +30% (+WS) of the control water supply on the photosynthesis (PN), C/N ratio, and plantamajoside accumulation in P. depressa. Our results showed that compared with the-WS and CK treatments, the +WS treatment significantly enhanced biomass, the C/N ratio, plantamajoside concentration, yield in shoots and roots, and PN, but declined the N concentration in shoots and roots. The plantamajoside concentration was positively correlated with PN, the soluble sugar content, and the C/N ratio, but negatively correlated with the N concentration. Our results suggested that, under experimental conditions, +WS increased the C/N ratio and promoted the plantamajoside accumulation of P. depressa., Z. Li, W. Bai, L. Zhang, L. Li., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
1145. Induction by drought of crassulacean acid metabolism in the terrestrial bromeliad, Puya floccosa
- Creator:
- Herrera, A., Martin, C. E., Tezara, W., Ballestrini, C., and Medina, E.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- botanika, botany, Bromeliaceae, elevation, and nocturnal acid accumulatiobn
- Language:
- Multiple languages
- Description:
- In the terrestrial bromeliad, Puya floccosa, a value of carbon isotopic composition (δ13C) of -22‰ has been previously reported, suggesting the operation of weak and/or intermediate (C3-CAM) crassulacean acid metabolism (CAM). In order to characterize the operation of CAM in P. floccosa and its possible induction by drought, plants were grown in Caracas and subjected to four independent drought cycles. Additionally, since plants of this species grow in Venezuela in a large range of elevations, leaf samples were collected at elevations ranging from 725 to 2,100 m a.s.l. in the Venezuelan Andes and the Coastal Range, in order to evaluate the effect of elevation on CAM performance. Even though nocturnal acid accumulation occurred in both watered and droughted plants, mean ΔH+ was higher in droughted than watered plants [ΔH+ = 60.17.5 and 22.9 ± 5.2 μmol g-1(FM), respectively]. The majority of plants from all the natural populations sampled had low values of δ13C not differing significantly from those of C3 plants collected as standards and δ13C did not change with elevation. We conclude that P. floccosa is capable of a weak CAM activity, with a large variability among populations and drought experiments probably due to local and temporal differences in microclimatic variables and drought stress; elevation bears no influence on values of δ13C in this species. and A. Herrera ... [et al.].
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
1146. Induction of cyclic electron flow around photosystem 1 and state transition are correlated with salt tolerance in soybean
- Creator:
- Lu, K. X., Yang, Y., He, Y., and Jiang, D. A.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- chlorophyll fluorescence induction, DBMIB, DCMU, electron flow inhibitors, light-harvesting complex, maximum photochemical efficiency, NaCl, phosphorylation, species differences, and Western blot
- Language:
- Multiple languages
- Description:
- We investigated the role of cyclic electron flow around photosystem 1 (CEF1) and state transition (ST) in two soybean cultivars that differed in salt tolerance. The CEF1 and maximum photochemical efficiency (Fv/Fm) were determined under control and NaCl (50 mM) stress and the NaCl-induced light-harvesting complex 2 (LHC2) phosphorylation in vitro was analysed in light and dark. NaCl induced the increase of CEF1 more greatly in wild soybean Glycine cyrtoloba (cv. ACC547) than in cultivated soybean Glycine max (cv. Melrose). The Fv/Fm was reduced less in G. cyrtoloba than in G. max after 10-d NaCl stress. In G. cyrtoloba, the increase of CEF1 was associated with enhancement of LHC2 phosphorylation in thylakoid membrane under both dark and light. However, in G. max the NaCl treatment decreased the LHC2 phosphorylation. Treatment with photosynthetic electron flow inhibitors (DCMU, DBMIB) inhibited LHC2 phosphorylation more in G. max than in G. cyrtoloba. Thus the NaCl-induced up-regulation in CEF1 and ST might contribute to salt resistance of G. cyrtoloba. and K. X. Lu ... [et al.].
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
1147. Induction of porphyrin biosynthesis by 5-aminolevulinic acid, glutamic acid, and 1,10-phenanthroline and their possible photodynamic action in wheat and mustard plants
- Creator:
- Toneva, V., Gechev, T., and Minkov, I.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- protochlorophyllide, photoherbicide effect, photoporphyrin IX, Triticum aestivum, and Sinapis alba
- Language:
- Multiple languages
- Description:
- The photodynamic damage of the sensitive plants wheat and mustard, treated with chlorophyll (Chl) precursors 5-aminolevulinic acid (ALA) and glutamic acid (Glu) and with 1,10-phenanthroline (Phen), was caused by tetrapyrroles, which accumulated after 17 h in the dark period, followed by 12 h of irradiation with "white light". The effect of accumulated Chl in mustard plants was accompanied by changes in the amounts of the Chls and carotenoids and by dehydration of the tissues, partial chlorosis, and necrosis. The molecular nature of the specific photodynamic sensitivity of the mustard and wheat plants under the influence of Phen and Chl precursors was important: accumulation of tetrapyrroles was a necessary, but not only reason for photodynamic damage of the plants. The degree of leaf damage was related to the amount and chemical nature of accumulated tetrapyrroles and to the greening group to which the investigated plant belongs. and V. Toneva, T. Gechev, I. Minkov.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
1148. Induction of the photosystem 2 dark formation in etiolated leaves with the involvement of exogenous chlorophyllides
- Creator:
- Domanskiï, V. P. and Fradkin, L. I.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- chlorophyll, delayed luminiscence, Hordeum vulgare, infiltration, NADPH, and reaction centre
- Language:
- Multiple languages
- Description:
- The delayed luminescence (DL) of photosystem 2 (PS2) after infiltration of 7-d-old etiolated barley leaves with chlorophyllides (Chlide) a or b followed by 2.5 h dark incubation was studied. Chlide a caused a very weak DL of PS2 just at the beginning of irradiation and the intensity of this DL was not higher when the infiltration medium contained 2 mM of NADPH. Chlide b was a somewhat more efficient inducer of PS2 formation in the dark and NADPH enhanced this efficiency 4.5 times though it did not affect the amount of esterified Chlides. The photoconversion of endogenous Pchlide led to a much higher intensity of the DL in comparison with the infiltration of Chlides, while the total amount of chlorophyll (Chl) formed was almost unchanged. The use of Chlide b together with the acetone extract from green leaves, devoid of pigments, resulted in the DL intensity comparable with that observed after Pchlide photoconversion followed by 2.5 h incubation in the dark. Dark formation of active PS2 in etiolated leaves was shown for the first time. Thus the dark formation of active PS2 may require Chl b, NADPH, and some unidentified water-soluble factor(s), synthesized in the dark after a short irradiation of etiolated leaves and inherent in green leaves. and V. P. Domanskiï, L.I. Fradkin.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
1149. Induction of water deficit tolerance in wheat due to exogenous application of plant growth regulators: membrane stability, water relations and photosynthesis
- Creator:
- Dwivedi, S. K., Arora, A., Singh, V. P., and Singh, G. P.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- stárnutí, chlorofylová fluorescence, sucho, výměna plynu, sklizeň, chlorophyll fluorescence, drought, gas exchange, senescence, yield, 2, and 581
- Language:
- Multiple languages
- Description:
- Our experiment was carried out in order to explore effects of plant growth regulators (PGR; thidiazuron, paclobutrazol, and ascorbic acid) on physiological traits of wheat genotypes under water surplus and deficit conditions. Study revealed that relative water content, membrane stability index, chlorophyll content, photosynthetic rate (PN), and maximal quantum yield of PSII improved with PGRs application across the genotypes both under irrigation and water stress. The response of HD 2733 genotype was more positive toward PGRs treatment as compared to other genotypes under water stress. Higher PN and chlorophyll contents were observed in HD 2987 followed by C 306 genotype under water-stress conditions. Moreover, Rubisco small subunit (SSU) expression was lower in wheat genotypes under water stress as compared to irrigated conditions. Application of PGRs led to upregulation of SSU under water stress, while no significant change was found in Rubisco level and activity under irrigated condition in dependence on PGRs treatments. Yield-related traits showed also significant reduction under water-stress conditions, while application of PGRs enhanced the yield and its components. Results indicated that the PGRs exhibited a positive interaction and synergetic effect on water stressed wheat plants in terms of photosynthetic machinery and yield., S. K. Dwivedi, A. Arora, V. P. Singh, G. P. Singh., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
1150. Influence of arbuscular mycorrhiza and phosphorus fertilization on the gas exchange, growth and phosphatase activity of soybean (Glycine max L.) plants
- Creator:
- Abdel-Fattah, G. M., Asrar, A. A., Al-Amri, S. M., and Abdel-Salam, E. M.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, sója, photosynthesis, soybean, arbuscular mycorrhizal symbiosis, depletion zone, root/shoot ratio, inoculum, Glomus constrictum, 2, and 581
- Language:
- Multiple languages
- Description:
- We studied the effect of arbuscular mycorrhizal (AM) fungus, Glomus constrictum (Trappe), and soil phosphorus (P) on gas-exchange parameters, growth, and nutrition of soybean plants grown in pots with sterilized soil. Two contrasting concentrations of KH2PO4, i.e. no added and 0.5 g(P) kg-1(soil), were used. Addition of soluble phosphate increased all growth parameters, P and N concentrations, and most of the studied photosynthetic parameters of both the mycorrhizal and nonmycorrhizal plants. The mycorrhizal inoculation significantly increased plant growth responses, P and N concentrations in shoot and root tissues, acid and alkaline phosphatase activities, and total soluble proteins in root tissues compared with the nonmycorrhizal plants. The stimulations were related to the level of the mycorrhizal colonization in the root tissues. The mycorrhizal plants showed significantly higher net photosynthetic rate, stomatal conductance, and transpiration rate than those of nonmycorrhizal plants, especially in soil without added P. The phosphate addition to soil reduced generally the percentage of the mycorrhizal colonization in the root tissues, and consequently the mycorrhizal benefits. In general, growth, nutrition, and photosynthetic parameters of the soybean plants showed a high degree of dependency on the mycorrhizal fungus in nonfertilized soil when compared with the soil fertilized with P. This study confirmed that AM colonization could improve growth and nutrition of the soybean plant through increasing photosynthesis in leaves, particularly at low P in soil., G. M. Abdel-Fattah, A. A. Asrar, S. M. Al-Amri, E. M. Abdel-Salam., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public