Search

Start Over Subject 581 Date Unknown

402. Rearrangement of leaf traits with changing source-sink relationship in blueberry (Vaccinium corymbosum L.) leaves

Creator:
Jorquera-Fontena, E., Alberdi, M., Reyes-Díaz, M., and Franck, N.
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
uhlík, karotenoidy, ovoce, pigmenty, carbon, carotenoids, fruit, pigments, výměna plynu, fotosyntetické pigmenty, rozpustné cukry, borůvky, list, brusnice chocholičnatá, gas exchange, photosynthetic pigments, soluble sugars, nitrogen, blueberries, dark respiration rate, girdling, leaf, stomatal conductance, source-sink relationship, 2, and 581
Language:
Multiple languages
Description:
The source-sink relationship is one of major determinants of plant performance. The influence of reproductive sink demand on light-saturated photosynthesis (Pmax), dark respiration (RD), stomatal conductance (gs), intrinsic water-use efficiency (WUEi), contents of soluble sugar (SSC), nitrogen, carbon, and photosynthetic pigments was examined in blueberry (Vaccinium corymbosum L. cv. ‘Brigitta’) during the final stage of rapid fruit growth. Measurements were performed three times per day on developed, sun-exposed leaves of girdled shoots with 0.1, 1, and 10 fruit per leaf (0.1F:L, 1F:L, and 10F:L, respectively) and nongirdled shoots bearing one fruit per leaf (NG). Girdling and lower fruit amount induced lower Pmax, gs, N, and total chlorophyll (Chl) and higher WUEi, SSC, RD, Chl a/b ratio and carotenoids-to-chlorophylls ratio (Car/Chl) for the 1F:L and 0.1F:L treatments. The impact of girdling was counterbalanced by 10F:L, with NG and 10F:L having similar values. Variables other than Pmax, RD, gs, WUEi, and SSC were unaffected throughout the course of the day. Pmax and gs decreased during the course of the day, but gs decreased more than Pmax in the afternoon, while WUEi was increasing in almost all treatments. SSC increased from the morning until afternoon, whereas RD peaked at noon regardless of the treatment. Generally, Pmax was closely and negatively correlated to SSC, indicating that sugar-sensing mechanisms played an important role in regulation of blueberry leaf photosynthesis. With respect to treatments, Pmax and N content were positively related, while RD was not associated to substrate availability. The enhanced Car/Chl ratio showed a higher photoprotection under the lower sink demand. Changes in the source-sink relationship in 'Brigitta' blueberry led to a rearrangement of physiological and structural leaf traits which allowed adjusting the daily balance between carbon assimilation and absorbed light energy., E. Jorquera-Fontena, M. Alberdi, M. Reyes-Díaz, N. Franck., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

403. Reduction of photosynthetic apparatus plays a key role in survival of the microalga Haematococcus pluvialis (Chlorophyceae) at freezing temperatures

Creator:
Chekanov, K., Vasilieva, S., Solovchenko, A., and Lobakova, E.
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
fotosyntéza, photosynthesis, cold stress, Haematococcys pluvialis, stress tolerance, 2, and 581
Language:
Multiple languages
Description:
The microalga Haematococcus pluvialis is a biotechnologically important microorganism producing a ketocarotenoid astaxanthin. Haematococcus exists either as metabolically active vegetative cells with a high chlorophyll content or astaxanthin-rich haematocysts (aplanospores). This microalga featuring outstanding tolerance to a wide range of adverse conditions is a highly suitable model for studies of freezing tolerance in phototrophs. The retention of H. pluvialis cell viability after freezing-thawing is ascribed to elevated antioxidant enzyme activity and high ketocarotenoid content. However, we report that only haematocysts characterized by a lower photosynthetic activity were resistant to freezing-thawing even without cryoprotectant addition. The key factors of haematocyst freezing tolerance were assumed to be a low water content, rigid cell walls, reduction of the membranous structures, photosynthesis downregulation, and low chlorophyll content. Collectively, viability of Haematoccus after freezing-thawing can be improved by forcing the transition of vegetative cells to freeze-tolerant haematocysts before freezing., K. Chekanov, S. Vasilieva, A. Solovchenko, E. Lobakova., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

404. Regulating photoprotection improves photosynthetic growth and biomass production in QC-site mutant cells of the cyanobacterium Synechocystis sp. PCC 6803

Creator:
Huang, J.-Y., Hung, N.-T., Lin, K.-M., Chiu, Y.-F., and Chu, H.-A.
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
cytochromy, fotosyntéza, ochrana před ultrafialovým zářením, cytochromes, photosynthesis, photoprotection, cytochrome b559, photosystem II, 2, and 581
Language:
Multiple languages
Description:
We characterized the photosynthetic growth of wild-type (WT) and QC-site mutant cells of the cyanobacterium Synechocystis sp. PCC 6803 grown in a photobioreactor under medium-intensity [~70 μmol(photon) m-2 s-1] and high-intensity [~200 μmol(photon) m-2 s-1] light conditions. Photosynthetic growth rate (the exponential phase) increased about 1.1-1.2 fold for the A16FJ, S28Aβ, and V32Fβ mutant compared with WT cells under medium-intensity light and about 1.2-1.3 fold under high-intensity light. Biomass production increased about 17-20% for A16FJ and S28Aβ mutant cells as compared with WT cells under medium-intensity light and about 14-17% for A16FJ and V32Fβ mutant cells under high-intensity light. The greater photosynthetic growth rate and biomass production of these QC-site mutant cells could be attributed to the increased photosynthesis efficiency and decreased dissipation of wasteful energy from phycobilisomes in mutants vs. WT cells. Our results support that manipulation of photoprotection may improve photosynthesis and biomass production of photosynthetic organisms., J.-Y. Huang, N.-T. Hung, K.-M. Lin, Y.-F. Chiu, H.-A. Chu., and Obsahuje bibliografické odkazy
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

405. Relationship between flavonoids and photoprotection in shade-developed Erigeron breviscapus transferred to sunlight

Creator:
Zhou, R., Su, W. H., Zhang, G. F., Zhang, Y. N., and Guo, X. R.
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
fotosyntéza, photosynthesis, chlorophyll fluorescence, flavonoid, phenolics, protection, photodamage, 2, and 581
Language:
Multiple languages
Description:
Flavonoids are thought to participate in protection of the photosynthetic apparatus against photoinhibition under excessive light. Flavone glycoside, scutellarin, is a main active ingredient extracted from Erigeron breviscapus, the plant used in Chinese medicine. Shade-developed leaves of E. breviscapus were transferred from shade to full sunlight to quantify a relationship between the concentration of leaf scutellarin and tolerance to high radiation stress or the recovery from photoinhibition. The maximal quantum yield of PSII photochemistry showed a diurnal fluctuation in both shaded and sunlit leaves throughout the day. It indicated dynamic photoinhibition in the leaves of Erigeron, i.e., higher photoinhibition at solar noon and lower one in the morning and late afternoon. The sun-developed leaves reached the higher scutellarin content and values of nonphotochemical quenching coefficient with a lower degree of photoinhibition than the shade-developed leaves. When the shade-developed leaves were transferred to full sunlight, the content of scutellarin was declining continuously for 10 d and then was increasing for 15 d. After 50 d, all leaves became the sun-developed leaves with their scutellarin contents of about 138.5 ± 5.2 mg g-1(dry mass, DM) which was significantly higher than that of the shade-developed leaves [107.8 ± 9.8 mg g-1(DM)]. During acclimatization, the degree of photoinhibition was negatively correlated with the scutellarin content. Our results demonstrated a synchronous fluctuation between the flavonoid content and degree of protection against photoinhibition., R. Zhou, W. H. Su, G. F. Zhang, Y. N. Zhang, X. R. Guo., and Obsahuje seznam literatury
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

406. Relationship between photosynthetic pigments and chlorophyll fluorescence in soybean under varying phosphorus nutrition at ambient and elevated CO2

Creator:
Singh, S. K., Reddy, V. R., Fleisher, D. H., and Timlin, D. J.
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
podíl chlorofyl/karotenoidy, fotochemické zhášení, vztahy, reakční křivky, chlorophyll/carotenoids ratio, energy dissipation, photochemical quenching, relationships, response curves, 2, and 581
Language:
Multiple languages
Description:
To assess the relationship between chlorophyll (Chl) fluorescence (CF) and photosynthetic pigments, soybean was grown under varying phosphorus (P) nutrition at ambient and elevated CO2 (EC). The EC stimulated, but P deficiency decreased plant height, node numbers, and leaf area concomitantly with the rates of stem elongation, node addition, and leaf area expansion. Under P deficiency, CF parameters and pigments declined except that carotenoids (Car) were relatively stable indicating its role in photoprotection. The CF parameters were strongly related with Chl concentration but not with Chl a/b or Car. However, total Chl/Car showed the strongest association with CF parameters such as quantum efficiency and yield of photosystem II. This relationship was not affected by CO2 treatment. The high correlation between CF and total Chl/Car underscores the significance of the quantification of both, Chl and Car concentrations, to understand the photochemistry and underlying processes of photoprotection and mechanisms of excess energy dissipation in a given environment., S. K. Singh, V. R. Reddy, D. H. Fleisher, D. J. Timlin., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

407. Relationship between photosynthetic rate, water use and leaf structure in desert annual and perennial forbs differing in their growth

Creator:
Gonzalez-Paleo, L. and Ravetta, D. A.
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
fotosyntéza, photosynthesis, leaf anatomy, Physaria, relative growth rate, specific leaf area, total biomass, xylem anatomy, 2, and 581
Language:
Multiple languages
Description:
Specific leaf area (SLA) is a key trait to screen plants for ecological performance and productivity; however, the relationship between SLA and photosynthesis is not always up-scalable to growth when comparing multiple species with different life cycles. We explored leaf anatomy in annual and perennial species of Physaria, and related it to photosynthesis and water loss. The annual Physaria gracilis had higher SLA, thinner leaves, and lower investment in protective tissues, than perennial P. mendocina. Physaria angustifolia (annual), and P. pinetorum (perennial) showed intermediate values. Both perennials had a thicker palisade and high photosynthesis, relative to annuals. The larger leaf veins of perennials should allow high water availability to the mesophyll. The thicker palisade should determine high resistance to water flow and help explain their high water-use efficiency. These leaf functions reflect the construction of long-lived leaves that efficiently use resources under environmental limitations of arid environments., L. Gonzalez-Paleo, D. A. Ravetta., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

408. Relationship between root vigour, photosynthesis and biomass in soybean cultivars during 87 years of genetic improvement in the northern China

Creator:
Cui, X., Dong, Y., Gi, P., Wang, H., Xu, K., and Zhang, Z.
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
fotosyntéza, photosynthesis, breeding, gas exchange, Glycine max, root biomass, 2, and 581
Language:
Multiple languages
Description:
During the last century, the world soybean yield has been constantly enhancing at a remarkable rate. Factors limiting the soybean yield may be multiple. It is widely acknowledged that changes of root metabolism can influence aboveground characteristics, such as the seed yield and photosynthesis. In this study, we considered root bleeding sap mass (BSM) and root activity (RA) as indicators of the root growth vigour. We used 27 soybean cultivars, spanning from 1923 to 2009, to evaluate the contribution of root characteristic improvement to efficient photosynthesis and dry matter production. The BSM, RA, net photosynthetic rate (P N), and organ biomass were measured at different growth stages, such as the fourth leaf node, flowering, podding, and seed-filling stage. Our results showed that the soybean cultivars increased their biomass and P N thanks to genetic improvement. At the same time, BSM and RA also increased in dependence on a year of cultivar release. However, both P N and biomass were positively correlated with root characteristics only at the podding stage. Our data revealed that the improved root characteristic may have contributed to the enhanced photosynthesis, biomass, and yield of soybean cultivars during last 87 years of genetic improvement. We suggest that BSM and RA could be used as important indexes for further practice in soybean production improvement., X. Cui, Y. Dong, P. Gi, H. Wang, K. Xu, Z. Zhang., and Obsahuje seznam literatury
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

409. Relationship of photosynthetic efficiency and seed-setting rate in two contrasting rice cultivars under chilling stress

Creator:
Wang, L.-Z., Wang, L.-M., Xiang, H.-T., Luo, Y., Li, R., Li, Z.-J., Wang, C.-Y., and Meng, Y.
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
peroxidázy, chlorofyl, peroxidases, chlorophyll, kyselina abscisová, fluorescence chlorofylu, malondialdehyde, prolin, superoxid dismutáza, antioxidační enzymy, abscisic acid, chlorophyll fluorescence, proline, superoxide dismutase, antioxidative enzymes, 2, and 581
Language:
Multiple languages
Description:
Low temperature during the vegetative stage affects rice (Oryza sativa L.) seed-setting rate in Heilongjiang province at Northeast China. However, little is known about changes of the photosynthetic rate and physiological response in contrasting rice cultivars during chilling periods. In this study, two rice cultivars with different chilling tolerance were treated with 15°C from June 27 to July 7. The chilling-susceptive cultivar, Longjing11 (LJ11), showed a significant decrease in a ripening rate and seed-setting rate after being treated for four days, whilst chilling-tolerant cultivar, Kongyu131 (KY131), was only slightly affected after 4-d treatment. The photosynthetic activities, chlorophyll contents, and antioxidative enzyme activities in LJ11 decreased significantly along with the chilling treatment. The decrease in ß-carotene contents might play a role as it could cause direct photooxidation of chlorophylls and lead to the inhibition of the photosynthetic apparatus. In the meantime, no significant damage was found in leaves of KY131 from June 27 to July 11. In conclusion, the chilling-tolerance mechanism of rice is tightly related to the photosynthetic rate, metabolism of reactive oxygen species, and scavenging system in the vegetative stage., L.-Z. Wang, L.-M. Wang, H.-T. Xiang, Y. Luo, R. Li, Z.-J. Li, C.-Y. Wang, Y. Meng., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

410. Response of dominant grassland species in the temperate steppe of Inner Mongolia to different land uses at leaf and ecosystem levels

Creator:
Liu, M., Gong, J. R., Pan, Y., Luo, Q. P., Zhai, Z. W., Yang, L. L., and Xu, S.
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
osmoregulace, osmoregulation, výměna plynu, efektivita využívání vody, gas exchange, water-use efficiency, 2, and 581
Language:
Multiple languages
Description:
In order to study the responses of dominant species to different land uses in the semiarid temperate grassland of Inner Mongolia, we tested the physiological responses of Stipa grandis, Leymus chinensis, and Artemisia frigida to mowing, grazing exclusion, and grazing land uses at the leaf and ecosystem levels. The grazing-exclusion and mowing sites released CO2, but the grazing site was a net carbon sink. L. chinensis and S. grandis contributed more to the ecosystem CO2 exchange than A. frigida. At the grazing-exclusion and mowing sites, Leymus chinensis and Stipa grandis both exhibited a higher light-saturation point and higher maximum photosynthetic rate than that at the grazing site, which increased photosynthesis and growth compared to those at the grazing site. In contrast, A. frigida possessed a higher nitrogen content than the other species, and more of the light energy used for photosynthesis, particularly at the grazing site., M. Liu, J. R. Gong, Y. Pan, Q. P. Luo, Z. W. Zhai, L. L. Yang, S. Xu., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public