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2. Diurnal gas exchange and superior resources use efficiency of typical C4 species in Hunshandak Sandland, China
- Creator:
- Niu, S. L., Jiang, G. M., Li, Y. G., Gao, L. M., and Liu, M. Z.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- adaptation to arid environment, Agriophyllum, C3 species, Leymus, photosynthetic nitrogen use efficiency, stomatal conductance, transpiration rate, and water use efficiency
- Language:
- Multiple languages
- Description:
- Net photosynthetic rate (PN), transpiration rate (E), stomatal conductance (gs), leaf water potential (ψleaf), leaf nitrogen content, and photosynthetic nitrogen use efficiency (PNUE) were compared between a typical C4 plant, Agriophyllum squarrosum and a C3 plant, Leymus chinensis, in Hunshandak Sandland, China. The plant species showed different diurnal gas exchange patterns on June 12-14 when photosynthetic photon flux density (PPFD), air temperature (Tair), and water potential were moderate. PN, E, and gs of A. squarrosum showed distinct single peak while those of L. chinensis were depressed at noon and had two peaks in their diurnal courses. Gas exchange traits of both species showed midday depression under higher photosynthetic photon flux density (PPFD) and T air when Ψleaf was significantly low down on August 6-8. However, those of A. squarrosum were depressed less seriously. Moreover, A. squarrosum had higher PN, Ψleaf, water use efficiency (WUE), and PNUE than L. chinensis. Thus A. squarrosum was much more tolerant to heat and high irradiance and could utilise the resources on sand area more efficiently than L. chinensis. Hence species like A. squarrosum may be introduced and protected to reconstruct the degraded sand dunes because of their higher tolerance to stress and higher resource use efficiency. and S. L. Niu ... [et al.].
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
3. Increase in resistance to low temperature photoinhibition following ascorbate feeding is attributable to an enhanced xanthophyll cycle activity in rice (Oryza sativa L.) leaves
- Creator:
- Xu, C.-C., Lin, R.-C., Li, L.-B., and Kuang, T.-Y.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- antheraxanthin, chilling, chlorophyll fluorescence, high irradiance, photochemical quenching, thermal energy dissipation, violaxanthin, and zeaxanthin
- Language:
- Multiple languages
- Description:
- The mechanistic basis for protection of exogenous ascorbate against photoinhibition at low temperature was examined in leaves of rice (Oryza sativa L.). Exposure of intact leaves to chilling temperature resulted in a drastic decrease in the speed of development of non-photochemical fluorescence quenching (NPQ). This was related to the low temperature-imposed restriction on the formation of the fast relaxing component of NPQ (qf). Feeding with 20 mM ascorbate markedly increased the rate of qf development at chilling temperature due primarily to the enhanced rate of zeaxanthin (Z) formation. On the other hand, ascorbate feeding had no influence on photosystem 2 (PS2)-driven electron flow. The reduced state of the PS2 primary electron acceptor QA decreased in ascorbate-fed leaves exposed to high irradiance at chilling temperature owing to the increased Z-associated thermal energy dissipation in the light-harvesting antenna system of PS2. Furthermore, ascorbate feeding increased the photosynthetic apparatus of rice leaves to resist photoinhibition at low temperature. The protective effect of exogenous ascorbate was fully accounted for by the enhanced xanthophyll cycle activity. and C.-C. Xu ... [et al.].
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
4. Maternal allergy status has no impact on neonatal immune responses to allergen stimuli
- Creator:
- Lohonková, A., Novotná, O., Petrásková, P., Boráková, K., Prokešová, L., and Hrdý, J.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- allergy, allergen, cytokine, cord blood, and gene expression
- Language:
- English
- Description:
- Due to the increasing incidence of allergic diseases, there is a strong need to identify a prognostic marker pointing to increased risk of allergy development allowing introduction of early preventive measures. Cord blood seems to be a good source for searching for such marker. The capacity of cord blood cells to respond to common allergens could point to increased predisposition to later allergy development. In our study, cytokines typical of Th1 (IFN-γ), Th2 (IL-5, IL-13) and Treg (IL-10) immune responses were followed at both the level of gene expression and cytokine secretion in cord blood cells of newborns of healthy mothers (children with relatively low risk of allergy development) and allergic mothers (children with relatively high risk of allergy development) stimulated by allergens (pollen from birch and timothy grass, house dust mite, ovalbumin). We have not observed any difference in the response of cord blood cells of neonates of healthy and allergic mothers to allergen in vitro. Both gene expression and secretion of cytokines in response to allergen stimulation were comparable with the unstimulated controls. It seems that early postnatal events will be more decisive for future allergy development than prenatal sensitization of the foetal immune system with allergen in utero in allergic mothers.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
5. Responses of ribulose-1,5-bisphosphate carboxylase, protein content, and stomatal conductance to water deficit in maize, tomato, and bean
- Creator:
- Castrillo, M., Fernandez, D., A. M., Trujillo, I., and Guenni, L.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- Lycopersicum esculentum, Phaseolus vulgaris, protein, water potential, and Zea mays
- Language:
- Multiple languages
- Description:
- We compared responses of maize, tomato, and bean plants to water stress. Maize reached a severe water deficit (leaf water potential -1.90 MPa) in a longer period of time as compared with tomato and bean plants. Maize stomatal conductance (gs) decreased at mild water deficit. gs of tomato and bean decreased gradually and did not reach values as low as in maize. The protein content was maintained in maize and decreased at low water potential (ψw); in tomato it fluctuated and also decreased at low ψw; in bean it gradually decreased. Ribulose-1,5-bisphosphate carboxylase/oxygenase activity remained high at mild and moderate stress in maize and tomato plants; in bean it remained high only at mild stress. and M. Castrillo ... [et al.].
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
6. Some specific and non-specific phosphatases of the sporocyst of Fasciola hepatica. II. Enzymes associated with the membrane transport
- Creator:
- Humiczewska, Mirosława
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- Fasciola hepatica, sporocyst, phosphatases, and histochemical and cytophotometric methods
- Language:
- English
- Description:
- Using histochemical and cytophotometric methods, enzymes responsible for the membrane transport (alkaline phosphatase, adenosine triphosphatase, and 5-nucleotidase) in the developing sporocyst of Fasciola hepatica (L., 1758) were studied. The most active metabolism occurred in the germ balls of sporocysts on the 8th and 15th days of development, which is associated with intensive proliferation and subsequently differentiation of embryos within the germ balls.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public