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145. Acclimation and photoprotection of young gametophytes of Acrostichum danaeifolium to UV-B stress

Creator:
Randi, A. M., Freitas, M. C. A., Rodrigues, A. C., Maraschin, M., and Torres, M. A.
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
fotosyntéza, karotenoidy, chlorofyl, photosynthesis, carotenoids, chlorophyll, gametophyte development, phenolic compounds, ultrastructure, ultraviolet-B radiation, Acrostichum danaeifolium, 2, and 581
Language:
Multiple languages
Description:
The effect of ultraviolet B radiation (UV-B) on cellular ultrastructure, chlorophyll (Chl), carotenoids, and total phenolics of Acrostichum danaeifolium gametophytes was analyzed. The control group of spores was germinated under standard conditions, while the test group of spores was germinated with additional UV-B for 30 min every day for 34 d. The cell characteristics were preserved in gametophytes irradiated with UV-B, but the number of starch grains increased in the chloroplasts and the more developed grana organization in contrast to the chloroplasts of the control group. Chl a content decreased, while Chl b content increased in the gametophytes cultivated with UV-B for 34 d. Contents of lutein and zeaxanthin decreased and trans-β-carotene concentration was enhanced in the gametophytes irradiated with UV-B. The content of total phenolic compounds increased in the gametophytes cultivated with UV-B. Therefore our data suggest that the gametophytes of A. danaeifolium, a fern endemic to the mangrove biome, were sensitive to enhancement of UV-B radiation at the beginning of their development and they exhibited alterations in their ultrastructure, pigment contents, and protective mechanisms of the photosynthetic apparatus, when exposed to this radiation., A. M. Randi, M. C. A. Freitas, A. C. Rodrigues, M. Maraschin, M. A. Torres., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

146. Acclimation of C3 photosynthesis to elevated CO2: hypotheses and experimental evidence

Creator:
Reining, E.
Format:
print
Type:
model:internalpart and TEXT
Language:
Multiple languages
Description:
Acclimation of the photosynthesis of C3 plants to elevated atmospheric CO2 concentrations is ffequently observed. Some hypotheses ffequently proposed to explain this phenomenon are: (7) stomatal closure; (2) inhibition of photosynthesis by starch accumulation, and (5) reduced activity or concentration of ribulose-1,5- bisphosphate carboxylase/oxygenase. These hypotheses are compared with experimental evidence ffom the literature.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

147. Acclimation of photosynthesis in a boreal grass (Phalaris arundinacea L.) under different temperature, CO2, and soil water regimes

Creator:
Ge, Z.-M., Zhou, X., Kellomäki, S., Zhang, C., Peltola, H., Martikainen, P. J., and Wang, K. Y.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
botanika, botany, acclimation of photosynthesis, carbon dioxide, carboxylation efficiency, electron transport, temperature, water deficit, 2, and 58
Language:
Multiple languages
Description:
a1_The aim of this work was to study the acclimation of photosynthesis in a boreal grass (Phalaris arundinacea L.) grown in controlled environment chambers under elevated temperature (ambient + 3.5°C) and CO2 (700 μmol mol-1) with varying soil water regimes. More specifically, we studied, during two development stages (early: heading; late: florescence completed), how the temperature response of light-saturated net photosynthetic rate (Psat), maximum rate of ribulose-1,5-bisphosphate carboxylase/oxygenase activity (Vcmax) and potential rate of electron transport (Jmax) acclimatized to the changed environment. During the early growing period, we found a greater temperature-induced enhancement of Psat at higher measurement temperatures, which disappeared during the late stage. Under elevated growth temperature, Vcmax and Jmax at lower measurement temperatures (5-15°C) were lower than those under ambient growth temperature during the early period. When the measurements were done at 20-30°C, the situation was the opposite. During the late growing period, Vcmax and Jmax under elevated growth temperature were consistently lower across measurement temperatures. CO2 enrichment significantly increased Psat with higher intercellular CO2 compared to ambient CO2 treatment, however, elevated CO2 slightly decreased Vcmax and Jmax across measurement temperatures, probably due to down-regulation acclimation. For two growing periods, soil water availability affected the variation in photosynthesis and biochemical parameters much more than climatic treatment did. Over two growing periods, Vcmax and Jmax were on average 36.4 and 30.6%, respectively, lower with low water availability compared to high water availability across measurement temperatures. During the late growing period, elevated growth temperature further reduced the photosynthesis under low water availability., a2_Vcmax and Jmax declined along with the decrease in nitrogen content of leaves as growing period progressed, regardless of climatic treatment and water regime. We suggest that, for grass species, seasonal acclimation of the photosynthetic parameters under varying environmental conditions needed to be identified to fairly estimate the whole-life photosynthesis., Z.-M. Ge ... [et al.]., Obsahuje poznámky, and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

148. Acclimation of photosynthesis to temperature in Arabidopsis thaliana and Brassica oleracea

Creator:
Bunce, J. A.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
chlorophyll fluorescence, mesophyll conductance to CO2, photosynthetic electron transport, species differences, and triose phosphate utilization ratio
Language:
Multiple languages
Description:
Plants differ in how much the response of net photosynthetic rate (PN) to temperature (T) changes with the T during leaf development, and also in the biochemical basis of such changes in response. The amount of photosynthetic acclimation to T and the components of the photosynthetic system involved were compared in Arabidopsis thaliana and Brassica oleracea to determine how well A. thaliana might serve as a model organism to study the process of photosynthetic acclimation to T. Responses of single-leaf gas exchange and chlorophyll fluorescence to CO2 concentration measured over the range of 10-35 °C for both species grown at 15, 21, and 27 °C were used to determine the T dependencies of maximum rates of carboxylation (VCmax), photosynthetic electron transport (Jmax), triose phosphate utilization rate (TPU), and mesophyll conductance to carbon dioxide (g'm). In A. thaliana, the optimum T of PN at air concentrations of CO2 was unaffected by this range of growth T, and the T dependencies of VCmax, Jmax, and g'm were also unaffected by growth T. There was no evidence of TPU limitation of PN in this species over the range of measurement conditions. In contrast, the optimum T of PN increased with growth T in B. oleracea, and the T dependencies of VCmax, Jmax, and g'm, as well as the T at which TPU limited PN all varied significantly with growth T. Thus B. oleracea had much a larger capacity to acclimate photosynthetically to moderate T than did A. thaliana.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

149. Acclimation of photosystem 2 function of Norway spruce induced during first season under elevated CO2 in lamellar domes

Creator:
Kalina, J., Čajánek, M., Kurasová, I., Špunda, V., Vrána, J., and Marek, M. V.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
chlorophyll fluorescence induction, dry and fresh matter, and Picea abies
Language:
Multiple languages
Description:
Since July 28th, 1997 the two experimental mini-stands of young Norway spruce [Picea abies (L.) Karst.] have been grown in lamellar domes at ambient (AC) and elevated concentrations of CO2 [EC, i.e., ambient + 350 µmol(CO2) mol-1]. Before the start of exposure to EC (June 1997) the dependencies of photosystem 2 (PS2) quantum yield (Y) on irradiance, estimating the efficiency of PPFD utilisation in PS2 photochemistry, were the same for AC and EC shoots. After one month of EC simulation (August 1997), Y values were higher for EC needles as compared with the AC ones (by 1-42 %), whereas two months later (October 1997) an opposite effect was observed (decrease of Y by from 1 to 33 %). By chlorophyll a (Chl a) fluorescence induction the effects of EC on PS2 function were further characterised. During the first month a moderate improvement of PS2 function was estimated for EC needles from slightly higher potential yield of PS2 photochemistry (FV/FM, by 1 %) and reduced amount of inactive PS2 reaction centres (relative Fp1 level, by 15 %). However, the prolonged exposure to EC led firstly to a slight but significant decrease of FV/FM (by 3 %), secondly to a reduction of half time of fluorescence rise (t1/2, by 14 %), and finally to pronounced accumulation of inactive PS2 reaction centres (by 41 %). From the gradual response of individual Chl a fluorescence parameters we suggest a probable sequence of events determining the stimulation and subsequent depression of PS2 function for Norway spruce during the first season under EC. and J. Kalina ... [et al.].
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

150. Acclimation of two distinct plant species, spring barley and Norway spruce, to combined effect of various irradiance and CO2 concentration during cultivation in controlled environment

Creator:
Kurasová, I., Kalina, J., Urban, O., Štroch, M., and Špunda, V.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
β-carotene, carotenoids, chlorophylls, Hordeum vulgare, non-radiative dissipation, photosynthesis, Picea abies, and xanthophyll cycle
Language:
Multiple languages
Description:
The short-term acclimation (10-d) of Norway spruce [Picea abies (L.) Karst] to elevated CO2 concentration (EC) in combination with low irradiance (100 μmol m-2 s-1) resulted in stimulation of CO2 assimilation (by 61 %), increased total chlorophyll (Chl) content (by 17 %), significantly higher photosystem 2 (PS2) photochemical efficiency (Fv/Fm; by 4 %), and reduced demand on non-radiative dissipation of absorbed excitation energy corresponding with enhanced capacity of photon utilisation within PS2. On the other hand, at high cultivation irradiance (1 200 μmol m-2 s-1) both Norway spruce and spring barley (Hordeum vulgare L. cv. Akcent) responded to EC by reduced photosynthetic capacity and prolonged inhibition of Fv/Fm accompanied with enhanced non-radiative dissipation of absorbed photon energy. Norway spruce needles revealed the expressive retention of zeaxanthin and antheraxanthin (Z+A) in darkness and higher violaxanthin (V) convertibility (yielding even 95 %) under all cultivation regimes in comparison with barley plants. In addition, the non-photochemical quenching of minimum Chl a fluorescence (SV0), expressing the extent of non-radiative dissipation of absorbed photon energy within light-harvesting complexes (LHCs), linearly correlated with V conversion to Z+A very well in spruce, but not in barley plants. Finally, a key role of the Z+A-mediated non-radiative dissipation within LHCs in acclimation of spruce photosynthetic apparatus to high irradiance alone and in combination with EC was documented by extremely high SV0 values, fast induction of non-radiative dissipation of absorbed photon energy, and its stability in darkness. and I. Kurasová ... [et al.].
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

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