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33512. Tocopherols modulate leaf vein arrangement and composition without impacting photosynthesis
- Creator:
- Stewart, J. J., Adams, William W., Cohu, C. M., and Demmig-Adams, Barbara
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- vitamin E, foliar vasculature, leaf venation, vein density, vitamin E deficiency, xylem, 2, and 581
- Language:
- Multiple languages
- Description:
- Growth of the tocopherol-deficient vte1 mutant and Col-0 wild type of Arabidopsis thaliana in a sunlit glasshouse revealed both similarities and differences between genotypes. Photosynthetic capacity and leaf mesophyll features did not differ between mutant and wild type. Likewise, the total volume of water conduits (tracheary elements, TEs), sugar conduits (sieve elements, SEs), and sugar-loading cells (companion and phloem parenchyma cells) on a leaf area basis were unaffected by tocopherol deficiency. However, tocopherol deficiency yielded smaller and more numerous minor veins with fewer phloem cells and smaller TEs, resulting in greater ratios of TEs to SEs. The smaller TEs in the vte1 mutant may present a decreased risk for cavitation under high evaporative demand or in response to freezing. In turn, compensation for fewer phloem cells and smaller TEs by more numerous veins may bolster resistance to cavitation at no cost to photosynthetic capacity., J. J. Stewart, W. W. Adams, C. M. Cohu, B. Demmig-Adams., and Obsahuje bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
33513. Tolerance a jazyk literatury
- Creator:
- Pantůček, Svetozár
- Format:
- Type:
- model:internalpart and TEXT
- Language:
- Czech
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
33514. Tolerance mechanisms in Cassia alata exposed to cadmium toxicity - potential use for phytoremediation
- Creator:
- Silva, J. R. R., Fernandes, A. R., Silva Junior, M. L., Santos, C. R. C., and Lobato, A. K. S.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- těžké kovy, heavy metals, kadmium, fytoremediace, cadmium, phytoremediation, detoxifikace, výměna plynu, reaktivní formy kyslíku, remediace, detoxification, gas exchange, reactive oxygen species, remediation, Cassia alata, 2, and 581
- Language:
- Multiple languages
- Description:
- Cadmium is often detected in areas contaminated by heavy metals and the incidence of this element in dangerous concentrations has been increasing due to anthropogenic activities. The aim of this research was to determine Cd concentrations in tissues, quantify compounds, pigments and enzymes, and to evaluate the gas exchange. Our aim was also to identify components that can modify and contribute to tolerance of Cassia alata against Cd toxicity. We used five Cd concentrations (0, 22, 44, 88, and 132 μM) to validate our hypothesis. The Cd concentrations in tissues of C. alata plants increased significantly, compared with the control treatment, in the following graduated sequence: root > leaf > stem. Progressive enhancement in glutathione (GSH) was verified in plants treated with all Cd concentrations used, when compared with treatment without Cd. Antioxidant enzyme activities presented similar patterns with progressive enhancements, being a desirable characteristic for plants with a potential to hyperaccumulate Cd. Our results suggest that C. alata plants can be used for phytoremediation programs. Their defense mechanism is based on Cd accumulation in roots, coupled with increase in GSH and the efficient activity of antioxidant enzymes that contribute to minimize the oxidative stress and consequently improve the protection of the metabolic machinery., J. R. R. Silva, A. R. Fernandes, M. L. Silva Junior, C. R. C. Santos, A. K. S. Lobato., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
33515. Tolerance of canola to drought and salinity stresses in terms of root water uptake model parameters
- Creator:
- Yanagawa, Aki and Fujimaki, Haruyuki
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- irrigation with saline water, biofuel crops, electrical conductivity, and Feddes’s model
- Language:
- Slovak
- Description:
- Canola (Brassica napus) is cultivated for oil as a biofuel crop. Few quantitative data concerning its tolerance to abiotic stresses has been presented. We evaluated the tolerances of canola to drought and salinity stresses in terms of parameter values in a macroscopic root water uptake model. We conducted an experiment using nine columns with two plants in each: three columns were under drought stresses, another three were under saline stress and others provided potential transpiration. Two soil moisture and salinity probes were inserted into each of the six columns under stress to monitor water content and electrical conductivity. Weight of the columns was manually measured to obtain daily transpiration. Water uptake at each depth and time was calculated by substituting linearly interpolated matric and osmotic potentials into the stress response function. Determined stress response functions indicated that canola is more sensitive to drought compared to Jatropha. While, it was found to be as tolerant as Jatropha to salinity stress in terms of transpiration. Matric potential was more determining than osmotic potential to root water uptake of canola.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
33516. Tolerance of Mitragyna parvifolia (Roxb.) Korth. seedlings to NaCl salinity
- Creator:
- Bidalia, A., Hanief, M., and Rao, K. S.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fluorescence chlorofylu, výměna plynu, analýza růstu, efektivita využívání vody, dlouhodobá salinita, chlorophyll fluorescence, gas exchange, growth analysis, water-use efficiency, Kadam, long-term salinity, 2, and 581
- Language:
- Multiple languages
- Description:
- Increase in salinity is predicted to affect plant growth and survival in most arid and semiarid regions worldwide. Mitragyna parvifolia (Roxb.) Korth. is an important medicinal tree species distributed throughout the semiarid regions of India; however, it is facing a threat of its extinction in its natural habitat. We examined the effects of increasing NaCl salinity on two-month-old M. parvifolia seedlings grown in an environment-controlled chamber and exposed to soils of different electrical conductivity (EC) caused by NaCl [0-5 (control), 5-10, 10-15, 15-20, and 20-25 dS m-1)] for 85 days. Seedlings transferred to soil of EC >15 dS m-¹ did not survive beyond 1 week. Increase in the Na+ concentration negatively correlated with their height and positively correlated with their water-use efficiency (WUE). However, leaf area, net photosynthetic rate (PN), stomatal conductance, and transpiration rate showed varying correlations and an overall decrease in these parameters compared with the control. At EC of 10-15 dS m-1, the seedling height was reduced by 37% and PN was lowered by 50% compared with those of the control. An increase in the Na+/K+ ratio was observed with increasing salinity. The maximum quantum efficiency of PSII significantly decreased with increasing salinity compared with the control. Our results suggest that the increase in salinity reduced the overall performance of the M. parvifolia seedlings. However, the maintenance of WUE and maximum quantum efficiency of PSII might help M. parvifolia to tolerate NaCl salinity of 15 dS m-1., A. Bidalia, M. Hanief, K. S. Rao., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
33517. Tolerance problems for generalized eigenvectors of interval fuzzy matrices
- Creator:
- Gavalec, Martin, Myšková, Helena, Plavka, Ján, and Ponce, Daniela
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- interval generalized eigenvector and fuzzy matrix
- Language:
- English
- Description:
- Fuzzy algebra is a special type of algebraic structure in which classical addition and multiplication are replaced by maximum and minimum (denoted ⊕ and ⊗ , respectively). The eigenproblem is the search for a vector x (an eigenvector) and a constant λ (an eigenvalue) such that A⊗x=λ⊗x , where A is a given matrix. This paper investigates a generalization of the eigenproblem in fuzzy algebra. We solve the equation A⊗x=λ⊗B⊗x with given matrices A,B and unknown constant λ and vector x . Generalized eigenvectors have interesting and useful properties in the various computational tasks with inexact (interval) matrix and vector inputs. This paper studies the properties of generalized interval eigenvectors of interval matrices. Three types of generalized interval eigenvectors: strongly tolerable generalized eigenvectors, tolerable generalized eigenvectors and weakly tolerable generalized eigenvectors are proposed and polynomial procedures for testing the obtained equivalent conditions are presented.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
33518. Tolerance to acute ischemia in adult male and female spontaneously hypertensive rats
- Creator:
- Josef Bešík, Ondrej Szárszoi, Jaroslav Kuneš, Ivan Netuka, Jan Malý, František Kolář, Jan Pirk, and Bohuslav Ošťádal
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie, hypertenze, pohlavní rozdíly, physiology, hypertension, sex differences, srdeční tolerance, ischemické / reperfuzní poškození, spontánně hypertenzivní krysy, genderové rozdíly, cardiac tolerance, ischemia / reperfusion injury, spontaneously hypertensive rats, gender differences, 14, and 612
- Language:
- English
- Description:
- Clinical and experimental studies have repeatedly indicated that overloaded hearts have a higher vulnerability to ischemia/reperfusion injury. The aim of the present study was to answer the question whether the degree of tolerance to oxygen deprivation in hearts of spontaneously hypertensive rats (SHR) may be sex-dependent. For this purpose, adult SHR and their normotensive control Wistar Kyoto (WKY) rats were used. The isolated hearts were perfused according to Langendorff at constant pressure (proportionally adjusted to the blood pressure in vivo). Recovery of contractile parameters (left ventricular systolic, diastolic and developed pressure as well as the peak rate of developed pressure) was measured during reperfusion after 20 min of global no-flow ischemia in 5 min intervals. Mean arterial blood pressure was measured by direct puncture of carotid artery under light ether anesthesia in a separate group of animals. The degree of hypertension was comparable in both sexes of SHR. The recovery of contractile functions in SHR males and females was significantly lower than in WKY rats during the whole investigated period. There was no sex difference in the recovery of WKY animals; on the other hand, the recovery was significantly better in SHR females than in SHR males. It may be concluded that the hearts of female SHR are more resistant to ischemia/reperfusion injury as compared with male SHR. This fact could have important clinical implications for the treatment of cardiovascular disease in women., J. Bešík, O. Szárszoi, J. Kuneš, I. Netuka, J. Malý, F. Kolář, J. Pirk, B. Ošťádal., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
33519. Tolerance to water stress in tomato cultivars
- Creator:
- Srinivasa Rao, N. K. , Bhatt, R. M., and Sadashiva, A. T.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Language:
- Multiple languages
- Description:
- The effects of plant water stress imposed at vegetative, flowering, and fruiting stages of four cultivars of tomato (Lycopersicon esculentum Mill.) on net photosynthetic rate (PN), stomatal conductance (gs), transpiration rate (E), osmotic adjustment, and crop water stress index (CWSI) were investigated. Osmotic adjustment was the highest in cv. Arka Meghali, followed by cv. RFS-1. CWSI was lowest in cv. Arka Meghali and highest in cv. Pusa Ruby. Significant reduction in gs, E, and PN was observed in all the cultivars. The maximum reduction in E was observed in cv. Arka Saurabh during the fruiting stage (62.4 %) and maximum reduction in PN at the flowering stage in Pusa Ruby (53.1 %). Maximum PN was observed in Arka Meghali under water stress. The values of internal CO2 concentration (Ci) did not follow the decrease in gs which might be taken as an indication of mesophyll (non-stomatal) limitation to PN. Magnitude of PN decrease accompanying gs reductions varied in the four cultivars. Arka Meghali which had highest rate of gas exchange efficiency (PN/gs) under water deficits can be recommended for rainfed cultivation. and N. K. Srinivasa Rao, R. M. Bhatt, A. T. Sadashiva.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
33520. Tolerance to waterlogging in young Euterpe oleracea plants
- Creator:
- Pereira, T. S., Lobato, A. K. S., Alves, G. A. R., Ferreira, R. N., Silva, O. N., Martins Filho, A. P. , Pereira, E. S., and Sampaio, L. S.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, photosynthesis, Amazonka (řeka : oblast), Amazonas (Brazil), abiotic stress, açaí palm, ascorbate, glutathione, submergence, Euterpe oleracea, 2, and 581
- Language:
- Multiple languages
- Description:
- This study investigated whether gas exchange and the present content of antioxidant compounds can contribute to the survival of Euterpe oleracea plants in environments of frequent waterlogging. A factorial randomised, experimental design included two distinct water conditions (waterlogging and control) and five evaluation times (0, 6, 12, 18, and 24 d). Gasexchange parameters, leaf temperature, electrolyte leakage, and contents of antioxidant compounds were measured. Waterlogging did not promote significant alterations in net photosynthetic rate and transpiration, and stomatal conductance was reduced only after 18 d. Malondialdehyde and glutathione contents did not significantly change during waterlogging. Additionally, electrolyte leakage was significant only after 18 d of waterlogging. Thus, this study revealed that maintenance in gas exchange and antioxidant compounds might contribute to the survival of E. oleracea plants in environments exposed to waterlogging., T. S. Pereira, A. K. S. Lobato, G.A.R. Alves, R.N. Ferreira, O.N. Silva, A. P. Martins Filho, E.S. Pereira, L.S. Sampaio., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public