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2. Changes in chloroplast ultrastructure in Pssu-ipt tobacco during plant ontogeny
- Creator:
- Synková, H., Pechová, R., and Valcke, R.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- chloroplast ultrastructure, cytokinins, grafting, granum, leaf age, Nicotiana, peroxisome, phytohormones, thylakoid, and transgenic plants
- Language:
- Multiple languages
- Description:
- Changes in chloroplast ultrastructure and total content of endogenous cytokinins (CK) were studied during different phases of plant development in transgenic Pssu-ipt tobacco (Nicotiana tabacum L. cv. Petit Havana SR1). Permanent overproduction of CK was found in both rooted (SE) and grafted (G) Pssu-ipt plants in all phases of plant development with the peak in vegetative and flowering phase in the latter ones. No such a correlation was observed in SE on the contrary to control non-transgenic plants (SR1) and grafts (SRG), which showed also CK increase at juvenile and flowering phases. No significant differences in parameters of chloroplast ultrastructure, such as length of chloroplast, starch content, granum width, and number of thylakoids per granum, were proved between chloroplasts from young mature leaves of control and transgenic tobacco during plant ontogeny. Nevertheless, several anomalies in the ultrastructure of cell organelles were found in Pssu-ipt tobacco. Amoeboid shape of chloroplasts was often observed in connection with "tubular clusters" resembling peripheral reticulum. The distinct crystalline structures located in chloroplasts might be formed by LHC protein aggregates. Smaller crystals of unknown composition were found also in mitochondria. Numerous crystalline cores were present in peroxisomes. The alterations might be the result of imbalance of phytohormone content, degradation effect of CK overproduction, or the example of acclimation to permanent stress. and H. Synková, R. Pechová, R. Valcke.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
3. Chlorophyll synthesis retardation and ultrastructural alterations to Solanum tuberosum chloroplasts in Solanum nigrum cells
- Creator:
- Fayez, K. A. and Hassanein, A. M.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- atrazine, carotenoids, cybrid, electron microscopy, granum, and thylakoid
- Language:
- Multiple languages
- Description:
- Photosynthetic pigment contents of the second sexual generation of a cybrid plant (C-18-1) resulting from Solanum nigrum genome and Solanum tuberosum plastome were compared to those of the original (S. nigrum). Chloroplast ultrastructure alterations among S. tuberosum, cybrid, and S. nigrum were also studied. Leaf segments of both the cybrid and S. nigrum plants were cultured on shoot induction medium [B5 supplemented with 0.56 g m-3 benzylaminopurine (BAP)] for one week in light, to induce adventitious bud formation. These leaf segments were then placed in darkness for 5 weeks to form a white shoot. The respective cybrid plant had the same phenotype of the fusion recipient plant (S. nigrum) and was fertile. The rate of photosynthetic pigment biosynthesis in the white cybrid shoots was lower than that of the original plant shoots after subjecting the two plants to the same conditions of different irradiation periods (0, 2, 4, 6, 8, and 10 d). At the 10-d irradiation period of two white shoot plants, the total pigment content of S. nigrum shoot increased approximately 3-fold over that of the cybrid shoot. Numbers of grana and thylakoids as well as chloroplast size were decreased in cybrid cells in comparison to those in S. tuberosum cells. Under atrazine stress, while the chloroplast ultrastructure of the cybrid cells (atrazine sensitive) was strongly influenced, the chloroplasts of S. nigrum (atrazine resistant) were not affected. and K. A. Fayez, A. M. Hassanein.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
4. Chloroplast ultrastructure, photosynthesis and accumulation of secondary metabolites in Glechoma longituba in response to irradiance
- Creator:
- Zhang, L. X., Guo, Q. S., Chang, Q. S., Zhu, Z. B., Liu, L., and Chen, Y. H.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, photosynthesis, gas exchange, light adaptation, stomatal index, thylakoid, triterpene acids, Glechoma longituba, 2, and 581
- Language:
- Multiple languages
- Description:
- Glechoma longituba (Nakai) Kupr. is a perennial shade plant with pharmaceutical importance. The aim of this study was to investigate the effects of light intensity on the growth, photosynthesis, and accumulation of secondary metabolites in G. longituba grown under six different light environments. The high light intensity decreased the leaf size, specific leaf area, and aboveground dry mass, the number of grana per chloroplast, the number of lamella per granum, the thickness of the grana, the apparent quantum efficiency, the chlorophyll (Chl) content, the concentrations of ursolic and oleanolic acid. The high light increased the stomatal density, the stoma size, the number of chloroplast per a cell, the chloroplast size, the dark respiration rate, the light saturation point, the light compensation point, and the Chl a/b ratio. With the reduction in the light intensity, the light-saturated net photosynthetic rate, the aerial dry mass per plant, and the yields of ursolic and oleanolic acid decreased after an initial increase, peaking at 16 and 33% of sunlight levels. Overall, the 16 and 33% irradiance levels were the most efficient in improving the yields and qualities of the medicinal plant. The lower light demand and growth characteristics suggest that G. longituba is an extremely shade-tolerant plant and that appropriate light intensity management might be feasible to obtain higher yields of secondary metabolites in agricultural management., L. X. Zhang, Q. S. Guo, Q. S. Chang, Z. B. Zhu, L. Liu, Y. H. Chen., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
5. Effect of copper oxide nanoparticles on growth, morphology, photosynthesis, and antioxidant response in Oryza sativa
- Creator:
- Da Costa, M. V. J. and Sharma, P. K.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, photosynthesis, ascorbate, nanoparticle, proline, superoxide dismutase, thylakoid, 2, and 581
- Language:
- Multiple languages
- Description:
- The physiological and biochemical behaviour of rice (Oryza sativa, var. Jyoti) treated with copper (II) oxide nanoparticles (CuO NPs) was studied. Germination rate, root and shoot length, and biomass decreased, while uptake of Cu in the roots and shoots increased at high concentrations of CuO NPs. The accumulation of CuO NPs was observed in the cells, especially, in the chloroplasts, and was accompanied by a lower number of thylakoids per granum. Photosynthetic rate, transpiration rate, stomatal conductance, maximal quantum yield of PSII photochemistry, and photosynthetic pigment contents declined, with a complete loss of PSII photochemical quenching at 1,000 mg(CuO NP) L-1. Oxidative and osmotic stress was evidenced by increased malondialdehyde and proline contents. Elevated expression of ascorbate peroxidase and superoxide dismutase were also observed. Our work clearly demonstrated the toxic effect of Cu accumulation in roots and shoots that resulted in loss of photosynthesis., M. V. J. Da Costa, P. K. Sharma., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
6. Influence of drought, high temperature, and carbamide cytokinin 4-PU-30 on photosynthetic activity of plants.. 2.. Chloroplast ultrastructure of primary bean leaves
- Creator:
- Stoyanova, D. and Yordanov, I.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- membrane system, Phaseolus vulgaris, starch, stress, and thylakoid
- Language:
- Multiple languages
- Description:
- Ultrastructural changes in chloroplasts of primary leaves of 15-d-old bean plants (Phaseolus vulgaris L. cv. Cheren Starozagorski) in response to a single stress (increasing water deficit, WD) as well as to combined stress (WD plus high temperature, WD+HT) were investigated under the possible protective or reparatory effects of the carbamide cytokinin 4-PU-30 [N-(2-chloro-4-pyridyl)-N-phenylurea] applied before or after the stress. Essential structural changes in chloroplast ultrastructure occurred mainly in plants that had experienced WD+HT: the thylakoids were swollen, the envelope was destroyed, and the spatial orientation of inner membrane system was not typical. Changed starch accumulation was also observed. 4-PU-30 protected chloroplast ultrastructure under WD+HT. and D. Stoyanova. I. Yordanov.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
7. Inner structure of intact chloroplasts observed by a low temperature laser scanning microscope
- Creator:
- Vácha, F., Vácha, M., Bumba, L., Hashizume, K., and Tani, T.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- chlorophyll fluorescence, grana, photosystems 1 and 2, Spinacia, and thylakoid
- Language:
- Multiple languages
- Description:
- Inner structure of isolated intact chloroplasts was observed for the first time by a method of laser scanning microscopy at the temperature of liquid nitrogen at 77 K. The microscope, based on gradient index optics, has a maximum resolution of 440 nm at the wavelength of 650 nm. Chloroplasts were excited into the Q-band of chlorophyll b by a krypton laser line at 647.6 nm and fluorescence was detected using two different interference filters. The 680 nm interference filter detects the regions where photosystem (PS) 2 mainly occurs, the 730 nm interference filter detects domains with predominant location of PS1. Since PS1 occurs mainly in stroma lamellae, whereas PS2 occurs mainly in grana regions we were able to view the structure of thylakoid membrane in isolated intact chloroplast that is the closest to in vivo state. and F. Vácha ... [et al.].
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
8. Low-temperature induced changes in the ultrastructure of maize mesophyll chloroplasts strongly depend on the chilling pattern/intensity and considerably differ among inbred and hybrid genotypes
- Creator:
- Holá, D., Kutík, J., Kočová, M., and Rothová, O.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- inheritance, peripheral reticulum, photosynthesis, plastoglobuli, stress, thylakoid, and volume density
- Language:
- Multiple languages
- Description:
- The ultrastructure and dimensions of chloroplasts in leaf mesophyll cells were quantitatively examined in three parental inbred lines of maize (Zea mays L.) and their four hybrids subjected to two types of four-week low-temperature (LT) treatment: the abrupt onset of chilling temperatures ("severe chilling", SC) and the gradual, more moderate one ("moderate chilling", MC). The relationship between the response of individual genotypes to one or the other type of chilling was analyzed as well as the possibility to predict the behaviour of chloroplasts in hybrids from that of their parents. Although selected parameters of chloroplast ultrastructure (e.g. volume densities of granal and intergranal thylakoids, plastoglobuli, and peripheral reticulum) and dimensions changed due to the exposure of maize plants to LT, no general pattern of such changes was found for this species due to the observed intraspecific variability. The response of some genotype to SC could not be predicted from its behaviour under MC (and vice versa) and no clear rules could be applied for the inheritance of chloroplast response to chilling in the general sense. Thus, great caution should be always taken when interpreting the results of studies aimed at the dissection of chloroplast ultrastructure as affected by LT, particularly in case such studies are made with one genotype or under one type of chilling only. and D. Holá ... [et al.].
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
9. The distinctive pattern of photosystem 2 activity, photosynthetic pigment accumulation, and ribulose-1,5-bisphosphate carboxylase/oxygenase content of chloroplasts along the axis of primary wheat leaf lamina
- Creator:
- Dilnawaz, F., Mohapatra, P., Misra, M., Ramaswamy, N. K., and Misra, A. N.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- carotenoids, chlorophyll, CO2 fication ability, photosystem 2, protein, thylakoid, and Triticum aestivum
- Language:
- Multiple languages
- Description:
- Wheat (Triticum aestivum L. cv. Sonalika) seedlings were grown in Hoagland solution. Primary leaves were harvested at 8, 12, and 15 d and cut into five equal segments. Contents of photosynthetic pigments and proteins, and photosystem 2 (PS2) activity increased from base to apex of these leaves. Chlorophyll (Chl) content was maximum at 12 d in all the leaf segments, but PS2 activity showed a gradual decline from 8 to 15 d in all leaf segments. In sharp contrast, the CO2 fixation ability of chloroplasts increased from 8 to 15 d. CO2 fixation ability of chloroplasts started to decline from base to apex of 15-d-old seedlings, where the content of ribulose-1,5-bisphosphate carboxylase/oxygenase large subunit (RuBPCO-LSU) increased acropetally. RuBPCO-LSU content was maximum in all the leaf segments in 12-d-old seedlings. This shows a distinctive pattern of PS2, Chl, CO2 fixation ability of chloroplasts, and RuBPCO-LSU content along the axis of leaf lamina during development and senescence. RuBPCO-LSU (54 kDa) degraded to fragments of 45, 42, 37, 19, and 16 kDa products which accumulated along the leaf axis during ageing of chloroplasts. Thus the CO2 fixation ability of chloroplasts declines earlier than PS2 activity and photosynthetic pigment contents along the leaf lamina. and F. Dilnawaz ... [et al.].
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
10. Ultraviolet-B induced changes in ultrastructure and D1/D2 proteins in cyanobacteria synechococcus sp. PCC 7942
- Creator:
- Chauhan, Sanjay, Pandey, Ritu, and Singhal, Gauri S.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- carotenoids, cell shape, chlorophyll, phycocyanin, and thylakoid
- Language:
- Multiple languages
- Description:
- Effects of ultraviolet-B (UV-B) irradiation on ultrastructure, total cellular protein, and PS2 proteins D1 and D2 of Synechococcus sp. PCC 7942 cells was studied. The scanning electron micrographs showed UV-B radiation induced bending of the cells. The transmission electron micrographs revealed disorganization and shift in thylakoid lamellar structure to one side of the cell. The cellular phycocyanin/chlorophyll ratio decreased with increasing UV-B treatment and due to this the colour of cells turned light-green. No apparent change in total cellular proteins was evident, but the contents of two major proteins of PS2, D1 and D2, showed decline due to UV-B irradiation, although to different extent. and Sanjay Chauhan, Ritu Pandey, Gauri S. Singhal.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public