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1422. 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
1423. 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
1424. 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
1425. 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
1426. Acclimation of winter wheat (Triticum aestivum, cv. Yangmai 13) to low levels of solar irradiance
- Creator:
- Zheng, Y., Mai, B., Wu, R., Feng, Y., Sofo, A., Ni, Y., Sun, J., Li, J., and Xu, J.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- botanika, botany, antioxidant enzymes, chlorophyll, electrolyte leakage, oxidative stress, and photoinhibition
- Language:
- Multiple languages
- Description:
- Winter wheat is a grass species widely planted in northern and central China, where the increase of aerosols, air pollutants and population density are causing significant reduction in solar irradiance. In order to investigate the adaptation of winter wheat (Triticum aestivum L., cv. Yangmai 13) to low irradiance conditions occurring in the downstream plain of the Yangtze River (China), plants were subjected to four solar irradiance treatments (100%, 60%, 40%, and 20% of environmental incident solar irradiance). Significant increases in chlorophyll (Chl) and xanthophyll (Xan) pigments, and decreases in Chl a/b and Xan/Chl ratios were observed in plants under low light. Light-response curves showed higher net photosynthetic rates (PN) in fully irradiated plants, that also showed a higher light-compensation point. Shaded plants maintained high values of minimal fluorescence of dark-adapted state (F0) and maximum quantum efficiency of PSII photochemistry (Fv/Fm) that assess a lower degree of photoinhibition under low light. Reduced irradiance caused decreases in effective quantum yield of PSII photochemistry (ΦPSII), electron transport rate (ETR), and nonphotochemical quenching coefficient (qN), and the promotion of excitation pressure of PSII (1 - qP). The activities of the antioxidant enzymes superoxide dismutase and peroxidase were high under reduced light whereas no light-dependent changes in catalase activity were observed. Thiobarbituric acid reactive species content and electrolyte leakage decreased under shaded plants that showed a lower photooxidative damage. The results suggest that winter wheat cv. Yangmai 13 is able to maintain a high photosynthetic efficiency under reduced solar irradiance and acclimates well to shading tolerance. The photosynthetic and antioxidant responses of winter wheat to low light levels could be important for winter wheat cultivation and productivity. and Y. Zheng ... [et al.].
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
1427. Acclimation to irradiance in seedlings of three tropical rain forest Garcinia species after simulated gap formation
- Creator:
- Guo, X. R., Cao, K. F., and Xu, Z. F.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- chlorophyll fluorescence, epidermis, leaf thickness, photoinhibition, photosynthesis, respiration, species differences, spongy/palisade ratio, and stomata density
- Language:
- Multiple languages
- Description:
- We investigated the acclimation of seedlings of three tropical rain forest sub-canopy Garcinia species (G. xanthochymus, G. cowa, and G. bracteata) after transfer from 4.5 (LI) to 40 % (HI) sunlight and 12.5 (MI) sunlight to HI (LH1 and LH2 denoting transfer from LI to HI and MI to HI transfer, respectively). The changes of chlorophyll (Chl) fluorescence, net photosynthetic rate (PN), dark respiration rate (RD), Chl content per unit area (Chlarea), leaf mass per unit area (LMA), and seedling mortality were monitored over two months after transfer. These parameters together with leaf anatomy of transferred and control seedlings (kept in LI, MI, and HI) were also examined after two months. No seedlings died during the two months. Fv/Fm, PN, and Chlarea of the transferred seedlings decreased in the first 3 to 12 d. LH1 leaves showed larger reduction in Fv/Fm (>23 % vs. <16 %) and slower recovery of Fv/Fm than LH2 leaves. PN started to recover after about one week of I transfer and approached higher values in all G. cowa seedlings and G. xanthochymus LH1 seedlings than those before the transfer. However, PN of G. bracteata seedlings approached the values before transfer. The final PN values in leaves of transferred G. xanthochymus and G. cowa seedlings approached that of leaves kept in HI, while the final PN values of transferred leaves of G. bracteata were significantly lower than that of leaves grown under HI (p<0.05). RD of G. xanthochymus LH1 seedlings and all G. cowa seedlings increased and approached the value of the seedlings in HI. The final Chlarea of both G. xanthochymus and G. cowa approached the values before transfer, but that of G. bracteata did not recover to the level before transfer. The final Chlarea of all transferred seedlings was not significantly different from that of seedlings in HI except that G. cowa LH1 seedlings had higher Chlarea than that in HI. LMA decreased within 2 d and then increased continuously until about 30 d and approached the value under HI. Spongy/palisade mesophyll ratio decreased after transfer because of the increase in palisade thickness. Leaf thickness did not change, so LMA increase of transferred seedlings was mainly due to the increase of leaf density. Thus the mature leaves under LI and MI of G. xanthochymus and G. cowa are able to acclimate to HI by leaf physiological and anatomical adjustment, while G. bracteata had limited ability to acclimate to HI. and X. R. Guo, K. F. Cao, Z. F. Xu.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
1428. Acclimation to irradiance of leaf photosynthesis and associated nitrogen reallocation in photosynthetic apparatus in the year following thinning of a young stand of Chamaecyparis obtusa
- Creator:
- Han, Q., Araki, M., and Chiba, Y.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- crown position, maximum rate of carboxylation, maximum rate of electron transport, and nitrogen reallocation
- Language:
- Multiple languages
- Description:
- In order to quantify the effects of thinning on photosynthetic parameters and associated change in leaf nitrogen (N) contents, half of the trees in a 10-year-old Chamaecyparis obtusa (Sieb. et Zucc.) Endl. stand (36° 3'N, 140°7'E) were removed, giving a final density of 1 500 trees ha-1, in May 2004. Photosynthetic photon flux density (PPFD) and leaf N and carbon (C) contents in the lower (L), middle (M), and upper (U) crowns were monitored one, three, and five months after thinning in both the thinned stand and a non-thinned control stand. In addition, leaves' photosynthetic responses to CO2 concentration were simultaneously measured in situ to estimate the maximum rates of carboxylation (Vcmax) and electron transport (Jmax). Thinning increased PPFD in the L and M crowns but not in the U crown. Vcmax in both the L and M crowns of the thinned stand increased significantly in comparison with the same crown position of the control stand in the three and five months following thinning. In addition, the thinned stand exhibited an increase in N partitioned to ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBPCO) in the L and M crowns relative to the control stand three and five months after thinning, indicating that N had been redistributed within the photosynthetic machinery. Thinning did not affect N per unit area at any of the crown positions, but significantly increased the content of N as a fraction of the total leaf dry mass in the L and M crowns three and five months after thinning. This was a consequence of a decrease in leaf dry mass due to rapid shoot growth. Thus thinning did not cause a redistribution of N between leaves. Thinning improved irradiance in the L and M crowns of C. obtusa, leading to photosynthetic acclimation. Photosynthetic acclimation in the first year mainly occurred via redistribution of N within but not between leaves. and Q. Han, M. Araki, Y. Chiba.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
1429. Acclimatization of micropropagated plantlets induces an antioxidative burst: a case study with Ulmus minor Mill.
- Creator:
- Dias, M. C., Pinto, G., and Santos, C.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- botanika, botany, antioxidant enzymes, lipid peroxidation, micropropagation, and Ulmus minor
- Language:
- Multiple languages
- Description:
- In this article, the effects of increased light intensities on antioxidant metabolism during ex vitro establishment of Ulmus minor micropropagated plants are investigated. Three month old in vitro plants were acclimatized to ex vitro conditions in a climate chamber with two different light intensities, 200 μmol m-2 s-1 (high light, HL) and 100 μmol m-2 s-1 (low light, LL) during 40 days. Immediately after ex vitro transfer, the increase of both malondialdehyde (MDA) and electrolyte leakage in persistent leaves is indicative of oxidative stress. As the acclimatization continues, an upregulation of the superoxide dismutase (SOD), catalase (CAT), and glutathione reductase (GR) enzyme activities were also observed. Simultaneously, MDA content and membrane permeability stabilized, suggesting that the antioxidant enzymes decrease the deleterious effects of reactive oxygen species (ROS) generation. Unexpectedly, newly formed leaves presented a different pattern of antioxidative profile, with high levels of MDA and membrane leakage and low antioxidant enzyme activity. Despite these differences, both leaf types looked healthy (e.g. greenish, with no necrotic spots) during the whole acclimatization period. The results indicate that micropropagated U. minor plantlets develop an antioxidant enzyme system after ex vitro transfer and that, in general, LL treatment leads to lower oxidative stress. Moreover, new leaves tolerate higher levels of ROS without the need to activate the antioxidative pathway, which suggests that the environment at which leaves are exposed during its formation determinate their ability to tolerate ROS. and M. C. Dias, G. Pinto, C. Santos.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
1430. Accumulation of photosynthetic pigments in Larix decidua Mill. and Picea abies (L.) Karst. cotyledons treated with 5-aminolevulinic acid under different irradiation
- Creator:
- Maximová, N. and Slováková, Ľudmila.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, photosynthesis, chlorophyll biosynthesis, D1 protein, light-harvesting complex, protochlorophyllide, 2, and 581
- Language:
- Multiple languages
- Description:
- European larch (Larix decidua Mill.) and Norway spruce [Picea abies (L.) Karst.] synthesize chlorophyll (Chl) in darkness. This paper compares Chl accumulation in 14-d-old dark-grown seedlings of L. decidua and P. abies after shortterm (24 h) feeding with 5-aminolevulinic acid (ALA). We used two ALA concentrations (1 and 10 mM) fed to cotyledons of both species in darkness and in continuous light. The dark-grown seedlings of L. decidua accumulated Chl only in trace amounts and the seedlings remained etiolated. In contrast, P. abies seedlings grown in darkness were green and had significantly higher Chl content. After ALA feeding, higher protochlorophyllide (Pchlide) content was observed in L. decidua than in P. abies cotyledons incubated in darkness. Although short-term ALA feeding stimulated the synthesis of Pchlide, Chl content did not change significantly in cotyledons incubated in darkness. The Chl accumulation in cotyledons fed with ALA was similar to the rate of Chl accumulation in the controls. Higher Chl accumulation was reported in control samples after illumination: 86.9% in L. decidua cotyledons and 46.4% in P. abies cotyledons. The Chl content decreased and bleaching occurred in cotyledons incubated with ALA in light due to photooxidation. Analyses of Chlbinding proteins (D1 and LHCIIb) by Western blotting proved differences between Chl biosynthesis in L. decidua and P. abies seedlings in the dark and in the light. No remarkable increase was found in protein accumulation (D1 and LHCIIb) after ALA application. Our results showed interspecific difference in Chl synthesis between two gymnosperms. Shortterm ALA feeding did not stimulate Chl synthesis, thus ALA synthesis was not the rate-limiting step in Chl synthesis in the dark., N. Maximová, Ľ. Slováková., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public