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562. Development of chloroplast in dark-grown wheat seedlings irradiated at elevated temperature

Creator:
Singh, A. K. and Singhal, G. S.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
carotenoids, chlorophyll, nucleic acids, photosystem 2, proteins, and Triticum aestivum
Language:
Multiple languages
Description:
Elevated temperature inhibited the accumulation of chlorophyll and photosynthetic proteins, and the development of photochemical activity, however, carotenoids continued to accumulate. Signal transduction pathway involved in protochlorophyllide oxidoreductase was unaffected by elevated temperature of 38°C. Two-dimensional gel electrophoresis of stroma proteins showed similar patterns in the dark-grown seedlings and seedlings irradiated at elevated temperature, although some low molecular mass proteins accumulated at 38°C. In contrast, seedlings irradiated at 25°C showed complex pattern of proteins. Hence the development of chloroplast and its associated functions during irradiation of etiolated seedlings are inhibited by elevated temperature. and A. K. Singh, G. S. Singhal.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

563. Development of models for estimating leaf chlorophyll and nitrogen contents in tree species with respect to seasonal changes

Creator:
Mizusaki, D., Umeki, K., and Honjo, T.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
fotosyntéza, photosynthesis, Agriexpert PPW-3000, Bayesian statistics, evergreen broad-leaved species, leaf chlorophyll content, leaf nitrogen, optical meter, seasonal change, SPAD-502, 2, and 581
Language:
Multiple languages
Description:
Models were developed to estimate nondestructively chlorophyll (Chl) content per unit of leaf area (Chlarea) and nitrogen content per unit of leaf area (Narea) using readings of two optical meters for five warm-temperate, evergreen, broadleaved tree species (Castanopsis sieboldii, Cinnamomum tenuifolium, Eurya japonica, Machilus thunbergii, and Neolitsea sericea). It was determined whether models should be adjusted seasonally. Readings (were obtained six times during a year period and Chlarea and Narea were determined using destructive methods. Bayesian inference was used to estimate parameters of models that related optical meter readings to Chlarea or Narea for each species. Deviance information criterion values were used to select the best among models, including the models with seasonal adjustment. The selected models were species-specific and predicted Chlarea accurately (R2 = 0.93-0.96). The best model included parameters with seasonal adjustments for one out of five species. Model-based estimates of Narea were not as accurate as those for Chlarea, but they were still adequate (R2 = 0.64-0.82). For all species studied, the best models did not include parameters with seasonal adjustments. The estimation methods used in this study were rapid and nondestructive; thus, they could be used to assess a function of many leaves and/or repeatedly on individual leaves in the field. and D. Mizusaki, K. Umeki, T. Honjo.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

564. Development of photosystems 2 and 1 during leaf growth in grapevine seedlings probed by chlorophyll a fluorescence transient and 820 nm transmission in vivo

Creator:
Jiang, C.-D., Shi, L., Gao, H.-Y., Schansker, G., Toth, S. Z., and Strasser, R. J.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
irradiance, leaf age, oxygen evolving complex, performance index, reaction centre, and Vitis
Language:
Multiple languages
Description:
Chlorophyll (Chl) a fluorescence transient and 820-nm transmission kinetic were investigated to explore the development of photosynthetic apparatus in grapevine leaves from emergence to full expansion. In this study, all leaves at various developing stages exhibited typical Chl a fluorescence transient. In newly initiating leaves, the maximum quantum yield of primary photochemistry (ϕP0) was slightly lower (<10 %) than that in fully expanded leaves. Nevertheless, the fluorescence rise from O to J step was clearly speeded up in young leaves compared with that in fully expanded leaves. Additionally, a distinct K step appeared in young leaves at high irradiances. With leaf development, the efficiency that a trapped exciton can move an electron into the electron transport chain further than QA - (Ψ0), the quantum yield of electron transport beyond QA (ϕE0), electron transport flux per excited cross section (ET0/CS0), the amount of active photosystem (PS) 2 reaction centres per excited cross section (RC/CS0), and the performance index on cross section basis (PICS) increased gradually and rapidly. Young leaves had strikingly lower amplitude of transmission at 820 nm. A linear relationship between Ψ0 and the transmission at 820 nm (I30/I0) was evident. Based on these data, we suggest that (1) the primary photochemistry of PS2 may be not the limiting step of the photosynthetic capacity during leaf growth under natural irradiance; (2) oxygen evolving complex (OEC) might be not fully connected to PS2 at the beginning of leaf growth; (3) though there are a few functional PS1 and PS2 at the early stages of leaf development, they match perfectly. and C.-D. Jiang ... [et al.].
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

565. Developmental and photosynthetic characteristics of a photoautotrophic Chrysanthemum culture

Creator:
Cristea, V., Dalla Vecchia, F., and la Rocca, N.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
carotenoids, chlorophyll, in vitro CO2 supply, net photosynthetic rate, phosphoenolpyruvate carboxylase, photosynthetic pigments, ribulose-1,5-bisphosphate carboxylase, and suncaps
Language:
Multiple languages
Description:
Chrysanthemum plantlets were cultivated in vitro on media with 2.0, 0.3, or 0 % sucrose, or photoautotrophically without an organic carbon source but with supplementation of the culture vessel atmosphere with 2 % CO2. The photoautotrophically cultivated plantlets showed a better growth and multiplication, higher contents of chlorophyll (Chl) and carotenoids, higher Chl a/b ratio, net photosynthetic rate and ribulose-1,5-bisphosphate carboxylase/oxygenase and phosphoenolpyruvate carboxylase activities than plantlets grown on the medium with sucrose. and C. Cristea, F. Dalla Vecchia, N. la Rocca.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

566. Developmental change in CO2 compensation concentrations in Spartina alterniflora results from sigmoidal photosynthetic CO2 responses

Creator:
Bärlocher, M. O., Campbell, D. A., Al-Asaaed, S., and Ireland, R. J.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
aerenchyma, bundle sheath, Carex, leaf age, leaf anatomy, net photosynthetic rate, seasonal changes, species differences, and Zea
Language:
Multiple languages
Description:
We investigated seasonal patterns of photosynthetic responses to CO2 concentrations in Spartina alterniflora Loisel, an aerenchymous halophyte grass, from a salt marsh of the Bay of Fundy (NB, Canada), and from plants grown from rhizome in controlled-environment chambers. From late May to August, CO2 compensation concentrations (Γ) of field-grown leaves varied between 2.5-10.7 cm3(CO2) m-3, with a mean of 5.4 cm3(CO2) m-3. From September onwards field leaves showed CO2 compensation concentrations from 6.6-21.1 cm3(CO2) m-3, with a mean of 13.1 cm3 m-3 well into the C3-C4 intermediate range. The seasonal variability in Γ did not result from changing respiration, but rather from a sigmoidal response of net photosynthetic rate (PN) to applied CO2 concentration, found in all tested leaves but which became more pronounced late in the season. One explanation for the sigmoidal response of PN to external CO2 concentration could be internal delivery of CO2 from roots and rhizomes to bundle sheath cells via the aerenchyma, but the sigmoidal responses in S. alterniflora persisted out to the tips of leaves, while the aerenchyma extend only to mid-leaf. The sigmoidicity persisted when CO2 response curves were measured from low to high CO2, or from high to low CO2, and even when prolonged acclimation times were used at each CO2 concentration. and M. O. Bärlocher ... [et al.].
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

567. Developmental changes in energy dissipation in etiolated wheat seedlings during the greening process

Creator:
Garmash, E. V., Dymova, O. V., Malyshev, R. V., Plyusnina, S. N., and Golovko, T. K.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
fotosyntéza, photosynthesis, alternative respiration, energy dissipation, greening, violaxanthin cycle, wheat, 2, and 581
Language:
Multiple languages
Description:
We studied the developmental changes in photosynthetic and respiration rates and thermal dissipation processes connected with chloroplasts and mitochondria activity in etiolated wheat (Triticum aestivum L., var. Irgina) seedlings during the greening process. Etioplasts gradually developed into mature chloroplasts under continuous light [190 μmol(photon) m-2 s-1] for 48 h in 5-day-dark-grown seedlings. The net photosynthetic rate of irradiated leaves became positive after 6 h of illumination and increased further. The first two hours of de-etiolation were characterized by low values of maximum (Fv/Fm) and actual photochemical efficiency of photosystem II (PSII) and by a coefficient of photochemical quenching in leaves. Fv/Fm reached 0.8 by the end of 24 h-light period. During greening, energy-dependent component of nonphotochemical quenching of chlorophyll fluorescence, violaxanthin cycle (VXC) operation, and lipoperoxidation activity changed in a similar way. Values of these parameters were the highest at the later phase of de-etiolation (4-12 h of illumination). The respiration rate increased significantly after 2 h of greening and it was the highest after 4-6 h of illumination. It was caused by an increase in alternative respiration (AP) capacity. The strong, positive linear correlation was revealed between AP capacity and heat production in greening tissues. These results indicated that VXC in chloroplasts and AP in mitochondria were intensified as energy-dissipating systems at the later stage of greening (after 4 h), when most of prolamellar bodies converted into thylakoids, and they showed the greatest activity until the photosynthetic machinery was almost completely developed. and E. V. Garmash ... [et al.].
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

568. Developmental changes of plant affecting primary photosynthate distribution in rice leaves

Creator:
Shinano, T., Ando, K., Okazaki, K., and Osaki, M.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
14CO2, leaf position, Oryza sativa, phosphoenolpyruvate carboxylase, primary photosynthate, pyruvate kinase, and sucrose phosphate synthase
Language:
Multiple languages
Description:
Developmental changes of plant in the regulation of photosynthate distribution of leaves were studied in hydroponically cultivated rice by the 14CO2 tracer technique and analysis of the activity of the regulatory enzymes, sucrose phosphate synthase (SPS), phosphoenolpyruvate carboxylase (PEPC), and pyruvate kinase (PK). The distribution of primary photosynthates into sugars, amino acids, organic acids, sugar phosphates, proteins, and polysaccharides was determined by column chromatography. The relative primary photosynthate distribution to the sugar phosphate fraction was significantly larger in the 5th leaf than in the 6th one. Correspondingly, the Vmax of PEPC was significantly higher in the 5th than in the 6th leaf, while no significant differences between leaves were detected in the other enzymes. As a consequence, the ratio of the Vmax of SPS and PEPC was lower in the 5th than in the 6th leaf. As the 5th leaf develops before panicle initiation in rice, it predominantly supports vegetative growth, while the 6th leaf develops after panicle initiation and thus contributes mainly to reproductive growth. We conclude that the physiological properties of each leaf are regulated developmentally. When the 6th leaf became fully expanded (corresponding to the panicle initiation stage of plant), the distribution pattern of 14C was transiently changed in the 5th leaf, indicating that individual organs that are mainly involved in vegetative development are affected to some extent by the whole-plant-level physiological transformation that occurs at the transition from the vegetative to the reproductive stage. and T. Shinano ... [et al.].
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

569. Developmental phase-dependent photosynthetic responses to ultraviolet-B radiation: damage, defence, and adaptation of primary leaves of wheat seedlings

Creator:
Pradhan, M. K., Nayak, L., Joshi, P. N., Mohapatra, P. K., Patro, L., Biswal, B., and Biswal, U. C.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
anthocyanin, carotenoids, chlorophyll, flavonoids, O2 evolution, photosynthetically active radiation, phases of leaf development, senescence, and thylakoid membrane
Language:
Multiple languages
Description:
Alterations in photosynthetic capacity of primary leaves of wheat seedlings in response to ultraviolet-B (UV-B; 280-320 nm; 60 µmol m-2 s-1) exposure alone and in combination with photosynthetically active radiation (PAR; 400-800 nm; 200 µmol m-2 s-1) during different phases of leaf growth and development were assessed. UV-B exposure resulted in a phase-dependent differential loss in photosynthetic pigments, photochemical potential, photosystem 2 (PS2) quantum yield, and in vivo O2 evolution. UV-B exposure induced maximum damage to the photosynthetic apparatus during senescence phase of development. The damages were partially alleviated when UV-B exposure was accompanied by PAR. UV-B induced an enhancement in accumulation of flavonoids during all phases of development while it caused a decline in anthocyanin content during senescence. The differential changes in these parameters demonstrated the adaptation ability of leaves to UV-B stress during all phases of development and the ability was modified in UV-B+ PAR exposed samples. and M. K. Pradhan ... [et al.].
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

570. Developmental regulation of photosynthate distribution in leaves of rice

Creator:
Shinano, T., Nakajima, K., Wasaki, J., Mori, H., Zheng, T., and Osaki, M.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
glutamine synthetases, leaf development, mRNA expression, Oryza, phosphoenolpyruvate carboxylase, pyruvate kinase, ribulose-1,5-bisphosphate carboxylase, oxygenase, and sucrose phosphate synthase
Language:
Multiple languages
Description:
mRNA expression patterns of genes for metabolic key enzymes sucrose phosphate synthase (SPS), phosphoenolpyruvate carboxylase (PEPC), pyruvate kinase, ribulose 1,5-bisphosphate carboxylase/oxygenase, glutamine synthetase 1, and glutamine synthetase 2 were investigated in leaves of rice plants grown at two nitrogen (N) supplies (N0.5, N3.0). The relative gene expression patterns were similar in all leaves except for 9th leaf, in which mRNA levels were generally depressed. Though increased N supply prolonged the expression period of each mRNA, it did not affect the relative expression intensity of any mRNA in a given leaf. SPS Vmax, SPS limiting and PEPC activities, and carbon flow were examined. The ratio between PEPC activity and SPS Vmax was higher in leaves developed at the vegetative growth stage (vegetative leaves: 5th and 7th leaves) than in leaves developed after the ear primordia formation stage (reproductive leaves: 9th and flag leaves). PEPC activity and SPS Vmax decreased with declining leaf N content. After using 14CO2 the 14C photosynthate distribution in the amino acid fraction was higher in vegetative than in reproductive leaves when compared for the same leaf N status. Thus, at high PEPC/SPS activities ratio, more 14C photosynthate was distributed to the amino acid pool, whereas at higher SPS activity more 14C was channelled into the saccharide fraction. Thus, leaf ontogeny was an important factor controlling photosynthate distribution to the N- or C-pool, respectively, regardless of the leaf N status. and T. Shinano ... [et al.].
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

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