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2. Bioregulators protected photosynthetic machinery by inducing expression of photorespiratory genes under water stress in chickpea
- Creator:
- Vineeth, T. V., Kumar, .P., and Krishna, G. K.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, photosynthesis, chlorophyll fluorescence, drought, photochemical efficiency, 2, and 581
- Language:
- Multiple languages
- Description:
- Globally, water deficit is one of the major constraints in chickpea (Cicer arietinum L.) production due to substantial reduction in photosynthesis. Photorespiration often enhances under stress thereby protecting the photosynthetic apparatus from photoinhibition. Application of bioregulators is an alternative to counter adverse effects of water stress. Thus, in order to analyze the role of bioregulators in protecting the photosynthetic machinery under water stress, we performed an experiment with two contrasting chickpea varieties, i.e., Pusa 362 (Desi type) and Pusa 1108 (Kabuli type). Water deficit stress was imposed at the vegetative stage by withholding water. Just prior to exposure to water stress, plants were pretreated with thiourea (1,000 mg L-1), benzyladenine (40 mg L-1), and thidiazuron (10 mg L-1). Imposed water deficit decreased relative water content (RWC), photosynthetic rate (P N), quantum efficiency of PSII (Fv/Fm), and enhanced lipid peroxidation (LPO). However, bioregulator application maintained higher RWC, P N, Fv/Fm, and lowered LPO under water stress. Expression of Rubisco large subunit gene (RbcL) was low under water stress both in the Kabuli and Desi type. However, bioregulators strongly induced its expression. Although poor expression of two important photorespiratory genes, i.e., glycolate oxidase and glycine decarboxylase H subunit, was observed in Desi chickpea under imposed stress, bioregulators in general and cytokinins in particular strongly induced their expression. This depicts that the application of bioregulators protected the photosynthetic machinery by inducing the expression of RbcL and photorespiratory genes during water deficit stress., T. V. Vineeth, P. Kumar, G. K. Krishna., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
3. Changes in photosynthesis, pigment composition and glutathione contents in two Antarctic lichens during a light stress and recovery
- Creator:
- Balarinová, K., Barták, Miloš, Hazdrová, J., Hájek, Josef, and Jílková, J.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, karotenoidy, lišejníky, photosynthesis, carotenoids, lichenes, Antarktida, Antarctica, chlorophyll fluorescence, performance index, thallus, light stress, 2, and 581
- Language:
- Multiple languages
- Description:
- Over last decades, several studies have been focused on short-term high light stress in lichens under laboratory conditions. Such studies reported a strong photoinhibition of photosynthesis accompanied by a partial photodestruction of PSII, involvement of photoprotective mechanisms, and resynthetic processes into gradual recovery. In our paper, we applied medium [800 μmol(photon) m-2 s-1] light stress to induce negative changes in PSII funcioning as well as pigment and glutathione (GSH) content in two Antarctic fruticose lichen species. Chlorophyll (Chl) fluorescence parameters, such as potential and effective quantum yield of photosynthetic processes and fast transients (OJIP) recorded during high light exposition and recovery, revealed that Usnea antarctica was less susceptible to photoinhibition than U. aurantiaco-atra. This might be supported by a more pronounced high light-induced reduction in Chl a and b contents in U. aurantiaco-atra compared with U. antarctica. In both experimental species, total GSH showed an initial increase during the first 30-40 min of high light treatment followed by a decrease (60 min) and an increase during dark recovery. Full GSH recovery, however, was not finished in U. aurantiaco-atra even after 5 h indicating lower capacity of photoprotective mechanisms in the species. OJIP curves showed high light-induced decrease in both species, however, the recovery of the OJIPs shape to pre-photoinhibitory values was faster and more apparent in U. antarctica than in U. aurantiaco-atra. The results are discussed in terms of sensitivity of the two species to photoinhibition and their photosynthetic performance in natural environment., K. Balarinová, M. Barták, J. Hazdrová, J. Hájek, J. Jílková., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
4. Changes in winter snow depth affects photosynthesis and physiological characteristics of biological soil crusts in the Tengger Desert
- Creator:
- Hui, R., Zhao, R. M., Liu, L. C., Li, Y. X., Yang, H. T., Wang, Y. L., Xie, M., and Wang, X. Q.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, photosynthesis, biological soil crusts, chlorophyll fluorescence, photosynthetic pigments, soluble sugar, water availability, 2, and 581
- Language:
- Multiple languages
- Description:
- Water availability is a major limiting factor in desert ecosystems. However, a winter snowfall role in the growth of biological soil crusts is still less investigated. Here, four snow treatments were designed to evaluate the effects of snow depth on photosynthesis and physiological characteristics of biological soil crusts. Results showed that snow strongly affected the chlorophyll fluorescence properties. The increased snow depth led to increased contents of photosynthetic pigments and soluble proteins. However, all biological soil crusts also exhibited a decline in malondialdehyde and soluble sugar contents as snow increased. Results demonstrated that different biological soil crusts exhibited different responses to snow depth treatment due to differences in their morphological characteristics and microhabitat. In addition, interspecies differentiation in response to snow depth treatment might affect the survival of some biological soil crusts. Further, this influence might lead to changes in the structural composition and functional communities of biological soil crusts., R. Hui, R. M. Zhao, L. C. Liu, Y. X. Li, H. T. Yang, Y. L. Wang, M. Xie, X. Q. Wang., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
5. Chilling tolerance and early vigour-related characteristics evaluated in two Miscanthus genotypes
- Creator:
- Fonteyne, S., Lootens, P., Muylle, H., van den Ende, W., De Swaef, T., Reheul, D., and Roldan-Ruiz, I.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- photosynthesis, bioenergy crop, chlorophyll fluorescence, cold tolerance, leaf growth analysis, low temperature stress, 2, and 581
- Language:
- Multiple languages
- Description:
- A long growing season, mediated by the ability to grow at low temperatures early in the season, can result in higher yields in biomass of crop Miscanthus. In this paper, the chilling tolerance of two highly productive Miscanthus genotypes, the widely planted Miscanthus × giganteus and the Miscanthus sinensis genotype ‘Goliath’, was studied. Measurements in the field as well as under controlled conditions were combined with the main purpose to create basic comparison tools in order to investigate chilling tolerance in Miscanthus in relation to its field performance. Under field conditions, M. × giganteus was higher yielding and had a faster growth rate early in the growing season. Correspondingly, M. × giganteus displayed a less drastic reduction of the leaf elongation rate and of net photosynthesis under continuous chilling stress conditions in the growth chamber. This was accompanied by higher photochemical quenching and lower nonphotochemical quenching in M. × giganteus than that in M. sinensis ‘Goliath’ when exposed to chilling temperatures. No evidence of impaired stomatal conductance or increased use of alternative electron sinks was observed under chilling stress. Soluble sugar content markedly increased in both genotypes when grown at 12°C compared to 20°C. The concentration of raffinose showed the largest relative increase at 12°C, possibly serving as a protection against chilling stress. Overall, both genotypes showed high chilling tolerance for C4 plants, but M. × giganteus performed better than M. sinensis ‘Goliath’. This was not due to its capacity to resume growth earlier in the season but rather due to a higher growth rate and higher photosynthetic efficiency at low temperatures., S. Fonteyne, P. Lootens, H. Muylle, W. van den Ende, T. de Swaef, D. Reheul, I. Roldan-Ruiz., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
6. Combined stresses of light and chilling on photosynthesis of Fraxinus mandschurica seedlings in northeastern China
- Creator:
- Li, X. F., Jin, L., Zhu, C. Y., Wen, Y. J., and Wang, Y.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, mírné pásmo, photosynthesis, temperate zone, chlorophyll fluorescence, early-spring chilling, net photosynthetic rate, 2, and 581
- Language:
- Multiple languages
- Description:
- The chilling and light stresses were experimentally created to explore photosynthesis of Fraxinus mandshurica seedlings in northeast China. Net photosynthetic rate, stomatal conductance, and transpiration rate decreased significantly with the decline of temperature and light. Significant interaction effects of light and chilling were observed on gas exchange of photosynthesis. The minimal fluorescence yield of the dark-adapted state (F0) increased with increasing light and decreasing temperature. Both high and low light stresses induced the decreases of the maximal quantum yield of PSII photochemistry (Fv/Fm), photochemical quenching coefficient (qP), nonphotochemical quenching (NPQ), and electron transport rate. Decline of Fv/Fm and increased F0 were observed under decreasing temperatures. Decreased NPQ and qP at frost temperature suggest that F. mandschurica failed to dissipate excess light energy. No interactive effects of chilling and light on chlorophyll fluorescence parameters suggests that F. mandschurica seedlings might be adapted to combined stresses of light and chilling., X. F. Li, L. Jin, C. Y. Zhu, Y. J. Wen, Y. Wang., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
7. Comparative analysis of drought stress effects on photosynthesis of Eurasian and North African genotypes of wild barley
- Creator:
- Jedmowski, C., Brüggemann, W., and Bayramov, S.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, ječmen, photosynthesis, barley, Hordeum, Calvin cycle, chlorophyll fluorescence, JIP-test, performance index, photosynthetic CO2 assimilation, drought stress, Hordeum spontaneum, 2, and 581
- Language:
- Multiple languages
- Description:
- The impact of drought stress (DS) on eight Eurasian and North African genotypes of wild barley (Hordeum spontaneum) was evaluated by analysis of chlorophyll (Chl) a fluorescence fast induction curves using the JIP-test. Three-week-old, pot-grown plants were exposed to a DS treatment by withholding water for nine days. The genotype-specific impairment of the functionality of the photosynthetic electron transport chain was quantified using the relative decline of the performance indices (PIabs and PItot), two key parameters of the JIP-test. The genotypes showing the highest (HOR10164) and lowest (HOR10710) relative PIs under DS were subjected to additional experiments, including measurements of leaf gas exchange, water status, pigment content, key enzyme activity, and protein abundance. The genotypes showed a specific profile of DS-mediated inhibition of photosynthesis, associated with higher relative leaf water contents in HOR10164 at the end of the treatment. Whereas decreased photosynthetic rate in HOR10164 was mainly caused by stomatal closure, nonstomatal limitations (decreased Rubisco content and activity) were detected in HOR10710. Additional genotype specific features were the upregulation of the NADP-malate dehydrogenase in HOR10164 and a decreased fraction of QA-reducing reaction centers in HOR10710., C. Jedmowski, S. Bayramov, W. Brüggemann., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
8. Comparison of the photosynthetic characteristics in the pericarp and flag leaves during wheat (Triticum aestivum L.) caryopsis development
- Creator:
- Kong , L. A., Xie, Y., Sun, M. Z., Si, J. S., and Hu, L.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- chlorophyll fluorescence, oxygen evolution, pericarp, photosynthesis, wheat, ultrastructure, 2, and 581
- Language:
- Multiple languages
- Description:
- The pericarp of cereal crops is considered a photosynthetically active tissue. Although extensive studies have been performed on green leaves, the photosynthetic role of the pericarp in cereal caryopsis development has not been well investigated. In the present study, we investigated the anatomy, ultrastructure, chlorophyll (Chl) fluorescence, and oxygen evolution of the pericarp during caryopsis ontogenesis in field wheat (Triticum aestivum L.). The results showed that wheat pericarp cross-cells contained Chl; the grana stacks and thylakoid membranes in the cross-cells were more distinct in the pericarp than those in the flag leaves as shown by transmission electron microscopy. Chl fluorescence revealed that the photosynthetic efficiency, which was indicated by values of maximum efficiency of PSII photochemistry and effective PSII quantum yield, was lower in the pericarp compared to that of the flag leaf eight days after anthesis (DAA), whereas similar values were subsequently observed. The nonphotochemical quenching values were lower from 8-16 DAA but significantly increased in the pericarp from 24-32 DAA compared to the flag leaf. The oxygen evolution rate of the flag leaves was consistently higher than that of pericarp; notably, isolated pericarps released more oxygen than intact pericarps during caryopsis development. These results suggest that the pericarp plays a key role in caryopsis development by performing photosynthesis as well as by supplying oxygen to the endosperm and dissipating excessive energy during the grain-filling stages., L. A. Kong , Y. Xie, M. Z. Sun, J. S. Si, L. Hu., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
9. Cyanide-resistant respiratory pathway is involved in the high-light systemic acquired acclimation of kidney bean
- Creator:
- Feng, H.-Q., Tang, S.-Z., Sun, K., Jia, L.-Y., and Wang, R.-F.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, fazol obecný, photosynthesis, Phaseolus vulgaris, bean leaf, chlorophyll fluorescence, salicylhydroxamic acid, 2, and 581
- Language:
- Multiple languages
- Description:
- After exposing one half of a low light-adapted kidney bean (Phaseolus vulgaris) leaf to high light, parameters of chlorophyll (Chl) a fluorescence, such as PSII operating efficiency, PSII maximum efficiency under light, and photochemical quenching, decreased in the opposite half of the same leaf, whereas the capacity of the cyanide-resistant respiratory pathway significantly increased. When one half of the low light-adapted leaf was exposed to low light, the opposite half pretreated with 1 mM salicylhydroxamic acid (SHAM, an inhibitor of the cyanide-resistant respiratory pathway) did not exhibit significant changes in the Chl fluorescence values compared with the without SHAM pretreatment. However, after exposing one half of the low light-adapted leaf to high light, the opposite half pretreated with 1 mM SHAM showed lower Chl fluorescence values than that without SHAM pretreatment. Our results indicate that partial exposure of the low light-adapted leaf to high light can impose a systemic stress on the PSII photochemistry. The enhanced capacity of the cyanide-resistant respiratory pathway may be involved in the maintenance of the photosynthetic performance in the leaf tissues experiencing high light-induced systemic stress., H.-Q. Feng, S.-Z. Tang, K. Sun, L.-Y. Jia, R.-F. Wang., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
10. Daily temperature drop prevents inhibition of photosynthesis in tomato plants under continuous light
- Creator:
- Ikkonen, E. N., Shibaeva, T. G., Rosenqvist, E., and Ottosen, C.-O.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, photosynthesis, chlorophyll fluorescence, gas exchange, leaf area, photodamage, stomatal conductance, 2, and 581
- Language:
- Multiple languages
- Description:
- The negative effects of continuous light (CL) seen in tomato plants are often claimed to be linked to effects of offsetting the diurnal rhythm. In this study we tested whether a short-term daily temperature drop prevents the decreased photosynthetic performance seen in tomato plants grown under CL. Tomato (Lycopersicon esculentum Mill.) plantlets were grown at constant temperature of 26°C under 16-h day (16D) or 24-h day (24D) at 150 μmol m-2 s-1 PPFD. Some 24D plants were treated daily by 2 h temperature drop from 26 to 10°C (24D+DROP). Physiological disorder, such as severe leaf chlorosis, a large decrease in net photosynthetic rate, maximal quantum yield of PSII photochemistry, and the effective quantum yield of PSII photochemistry were observed in 24D, but not in 16D and 24D+DROP plants. The daily 2-h drop in temperature eliminated a negative effect of CL on photosynthesis and prevented the development of leaf chlorosis in tomato plants. This could be due to a change in carbohydrate metabolism as the short drop in temperature might allow maintenance of the diurnal rhythms., E. N. Ikkonen, T. G. Shibaeva, E. Rosenqvist, C.-O. Ottosen., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public