Data

AQTOX3415 koncna

Authors:
To read the file of this research, you can request a copy directly from the authors.

No file available

Request Full-text Paper PDF

To read the file of this research,
you can request a copy directly from the authors.

ResearchGate has not been able to resolve any citations for this publication.
Article
Full-text available
Shoot productivity was measured for Typha latifolia and Scirpus americanus. Samples were also subjected to chemical analyses. Tissue concentrations of chlorophylls a and b, carotenoids and most macronutrients declined as the plants aged. Net accumulation of these constituents per square meter usually continued during periods of dry matter increase, even though tissue concentrations were diminishing. Dry matter standing crop was the decisive factor determining quantities of chemical constituents per square meter. Uptake rates for macronutrients were generally not proportional to productivity rates. The most rapid uptake of several nutrients occurred earlier than maximum growth rates.
Article
Full-text available
Effect of selenium (Se) was studied in soybean (Glycine max (L.) Merr.) cv. Olna in Ljubljana, Slovenia. Se was added to plants as foliary spraying. Quantum yield of photosystem II (PSII) and respiratory potential measured as ETS activity of mitochondria were measured two times in the growing season. Respiratory potential was higher in young plants compared to mature plants. Se induced the lowering of respiratory potential. Addition of Se had no effect on quantum yield of photosystem II.
Article
Full-text available
The aquatic moss Fontinalis antipyretica was studied for its ability to accumulate heavy metals. In an exposure test in the River Elbe it was possible to detect an accumulation of heavy metals at the measuring sites of the water monitoring network of the state of Saxonu-Anhalt (Germany). A correlation between these results and the degrees of heavy-metal pollution in the water was only established for Zn and Cd. As a physiological parameter the induction of thiol-containing peptides such as phytochelatins and glutathione under these conditions was investigated. A positive correlation was found between phytochelatin levels and Cd levels in the moss samples. The suitability of this biochemical response to stress as a biomarker for heavy-metal pollution at field locations is discussed.
Article
Full-text available
Both amphibious species, Myosotis scorpioides and Ranunculus trichophyllus, thrive in a stressful environment (alternated flooding and drying), which is variable regarding water and radiation regimes. Plants from the field and plants grown under controlled water table maintained at 40 cm were analysed for content of chlorophyll (Chl) and UV-B screening compounds, and the efficiencies of PS2 and electron transport systems. We detected no significant differences in contents of Chl and UV-B screening compounds between submerged and aerial leaves. The measurements of respiratory potential and photochemical efficiency revealed the presence of permanent stress in M. sporpioides in the natural environment. Differences in physiological responses of submerged and aerial leaves indicated that the terrestrial environment was more favourable for M. scorpioides than for R. trichophyllus. Characteristics of both species suggested that R. trichophyllus might be a phylogenetically older aquatic plant than M. scorpioides.
Article
Full-text available
There is concern that elevated levels of selenium found in the source water of a newly formed wetland park in Las Vegas, Nevada, may have detrimental effects on local wildlife. In this study, we collected and analyzed water samples monthly for a three year period from the inflow and outflow of the system. We also gathered dominant aquatic plants and selected terrestrial plants and analyzed the water and plant tissues (root, shoot, leaf and flower) for selenium by high resolution Inductively Coupled Plasma Mass Spectrometer. Except for storm events and the introduction of an alternative low selenium content source water during summer low-flow conditions, selenium in the water was relatively stable. The concentration in the outflow tended to be slightly lower than the inflow. Concentrations of selenium in the dominant plant taxa in this wetlands were typical of ecosystems in the western United States and varied by taxa, tissue type, localized conditions (e.g., contact with selenium-laden water), and to a lesser extent, seasons. Selenium in the aquatic plant spiny naiad (Najas marina) was relatively high and may pose an ecological risk to wildlife during the late spring and summer. Additional work is underway investigating aquatic food chain accumulations of selenium as well as mass balance of selenium in the system.
Article
Full-text available
Selenium is a trace element performing important biological functions in many organisms including humans. It usually affects organisms in a strictly dosage-dependent manner being essential at low and toxic at higher concentrations. The impact of selenium on mammalian and land plant cells has been quite extensively studied. Information about algal cells is rare despite of the fact that they could produce selenium enriched biomass for biotechnology purposes. We studied the impact of selenium compounds on the green chlorococcal alga Scenedesmus quadricauda. Both the dose and chemical forms of Se were critical factors in the cellular response. Se toxicity increased in cultures grown under sulfur deficient conditions. We selected three strains of Scenedesmus quadricauda specifically resistant to high concentrations of inorganic selenium added as selenite (Na2SeO3) - strain SeIV, selenate (Na2SeO4) - strain SeVI or both - strain SeIV+VI. The total amount of Se and selenomethionine in biomass increased with increasing concentration of Se in the culturing media. The selenomethionine made up 30-40% of the total Se in biomass. In both the wild type and Se-resistant strains, the activity of thioredoxin reductase, increased rapidly in the presence of the form of selenium for which the given algal strain was not resistant. The selenium effect on the green alga Scenedesmus quadricauda was not only dose dependent, but the chemical form of the element was also crucial. With sulfur deficiency, the selenium toxicity increases, indicating interference of Se with sulfur metabolism. The amount of selenium and SeMet in algal biomass was dependent on both the type of compound and its dose. The activity of thioredoxin reductase was affected by selenium treatment in dose-dependent and toxic-dependent manner. The findings implied that the increase in TR activity in algal cells was a stress response to selenium cytotoxicity. Our study provides a new insight into the impact of selenium on green algae, especially with regard to its toxicity and bioaccumulation.
Article
Full-text available
Plants vary considerably in their physiological response to selenium (Se). Some plant species growing on seleniferous soils are Se tolerant and accumulate very high concentrations of Se (Se accumulators), but most plants are Se nonaccumulators and are Se-sensitive. This review summarizes knowledge of the physiology and biochemistry of both types of plants, particularly with regard to Se uptake and transport, biochemical pathways of assimilation, volatilization and incorporation into proteins, and mechanisms of toxicity and tolerance. Molecular approaches are providing new insights into the role of sulfate transporters and sulfur assimilation enzymes in selenate uptake and metabolism, as well as the question of Se essentiality in plants. Recent advances in our understanding of the plant's ability to metabolize Se into volatile Se forms (phytovolatilization) are discussed, along with the application of phytoremediation for the cleanup of Se contaminated environments.
Article
Full-text available
Updated estimates of the selenomethionine content of four NIST wheat reference materials have been obtained by use of a revised gas chromatography–stable-isotope dilution mass spectrometric method. The revised method makes use of digestion with methanesulfonic acid, which enables more complete recovery of endogenous selenomethionine than was previously achieved by overnight denaturing treatment in 0.1 mol L−1 HCl. The NIST wheat reference materials each contain approximately 55% of their total Se content as selenomethionine. Information about forms of Se in reference materials adds value to these materials in Se speciation studies. Estimates of selenomethionine content are also provided for other wheat samples, including several grown under conditions of exposure to high Se levels. These samples also contain approximately 55% of their total Se content as selenomethionine. The consistent level of 55% of total selenium occurring in the form of selenomethionine when the total selenium content varies by a factor of 500 is suggestive of an active mechanism of incorporation of selenium into wheat grain. Figure Selenomethionine content of wheat samples
Chapter
Two non-photosynthetic photoreceptors (phytochrome and a blue light photoreceptor) are involved in light-mediated anthocyanin synthesis in the mesocotyl of Sorghum seedlings. The present study was undertaken to investigate the kind of interaction between phytochrome and the blue light photoreceptor. The data show that phytochrome (Pfr) can only act once a blue light effect has occurred. On the other hand, the blue light effect cannot express itself without Pfr. It is concluded that there is an obligatory dependency (or sequential interaction) between the blue light effect and the light effect occurring through phytochrome, although the blue light photoreaction per se is not affected by the presence or absence of phytochrome. The latter statement is based on the results of dichromatic experiments, i.e. simultaneous, high fluence rate irradiation with two kinds of light. Blue light can be replaced by UV light. It is not clarified yet whether the effect of blue and UV light is due to the same photoreceptor.
Article
Several aquatic species were examined as potential phytoremoval agents for selenium in aqueous solutions. Selenium was initially present in concentrations of 0-100 ppm Se (as sodium selenite) in 10% Hoagland's medium, and aquatic plants were grown in the medium for one week. Four aquatic plants were studied: Cattail (Typha domingensis), duckweed (Lemna obscura), hydrilla (Hydrilla verticillata Royle), and swamp lily (Crinum americanum). Analyses were done by atomic absorption spectrometry using hydride reduction. Four replicates were done for each analysis. Each system was examined for change in fresh weight, percent removal of selenium from solution, and accumulation of selenium in the plant. At selenium concentrations of 100 ppm or less, fairly good to excellent removal was achieved (65 to 100%), depending on the plant. Exposure to concentrations greater than 100 ppm had an inhibitory effect on plant growth, so concentrations less than 100 were studied in more detail. During a one-week period, hydrilla quantitatively removed the selenium, and the fresh weight and dry weights of the plant increased. Other plants were less effective in removal of selenium or were more adversely affected by added selenium.
Article
A number of streams in Colorado were found to contain waterborne selenium concentrations that consistently exceeded the current US EPA chronic criterion of 5 {micro}g/L and often exceeded the acute criterion of 210 {micro}g/L. Despite these elevated concentrations, no biological impact was observed. These findings led to a review of selenium exposure pathways in freshwater. The literature strongly indicates that chronic selenium toxicity can result from accumulation of selenium in the sediment, movement into the food chain, and resulting dietary uptake. Chronic toxicity does not appear to be strictly a result of waterborne selenium concentrations. In fact, dissolved selenium concentrations are a poor predictor of potential chronic toxicity to freshwater organisms, when evaluated with Hill`s criteria for causal association. To develop a more reliable chronic waterborne criterion, a sediment-based method is needed to describe accurately potential chronic toxicity of selenium on a site-specific basis.
Article
In the past, ecophysiologically oriented photosynthesis research has been governed by gas-exchange measurements, mainly involving sophisticated (and costly) systems for simultaneous detection of CO2 uptake and H2O evaporation (see, e.g., Field et al. 1989). With the help of these methods, fundamental knowledge on in situ photosynthesis has been gained. Only recently, progress has been made in the development of alternative practical methods for nonintrusive assessment of in vivo photosynthesis which have the potential of not only evaluating overall quantum yield and capacity, but also allowing insights into the biochemical partial reactions and the partitioning of excitation energy (see, e.g., Snel and van Kooten 1990). As a consequence, photosynthesis research at the level of regulatory processes has been greatly stimulated, leading to important new concepts (see reviews by Foyer et al. 1990; Demmig-Adams 1990; Melis 1991; Allen 1992). In particular, chlorophyll fluorescence has evolved as a very useful and informative indicator for photosynthetic electron transport in intact leaves, algae, and isolated chloroplasts (reviews by Briantais et al. 1986; Renger and Schreiber 1986; Schreiber and Bilger 1987, 1992; Krause and Weis 1991; Karukstis 1991).
Article
A digestion mixture of H2SO4/HNO3/H2O2/HF/V2O5 was investigated for decomposition of plant samples and sensitive detection of selenium was achieved by hydride generation atomic fluorescence spectrometry (HG-AFS). The method was found to be accurate and reproducible, with a low detection limit (DL) (0.14ngg−1 solution). The repeatability of the determination was mostly around 10%, the reproducibility over a period of 8 months for determination of selenium in the standard reference material Trace Elements in Spinach Leaves, NIST 1570a, was 9% and the relative measurement uncertainty was 7% using a coverage factor of 2.3 at 95% probability. The average recovery of the whole procedure was 90%. The characteristics of this method are simple and inexpensive equipment, low consumption of chemicals and the ability to analyse many samples in a short time. The whole procedure was carried out in the same PTFE tube, and in addition only a simple cleaning procedure is needed. As a consequence of all these advantages, the described method is suitable for environmental and nutritional studies. The selenium content was determined in 44 vegetable samples from different regions of Slovenia and the contents found were in the range 0.3–77ngg−1 wet weight.
Article
A simple and sensitive spectrophotometric method of measuring electron transfer in the transport system (ETS) in marine phytoplankton has been developed and characterized. The assay is based on the reduction of the tetrazolium salt 2-(p-iodophenyl)-3-(p-nitrophenyl)-5-phenyl tetrazolium chloride (INT) by homogenates in the presence of the nonionic detergent Triton X-100. The simplicity and sensitivity of this assay have considerable advantage over existing methods of measuring ETS activity in marine samples where numerous assays must be rapidly carried out on samples which often demonstrate low activities. Several established substrates and inhibitors of electron transport in the ETS were investigated, and each is discussed in relation to the site of INT reduction in the diatoms Skeletonema costatum and Chaetoceros debilis and in the unicellular green alga Dunaliella tertiolecta. The results from these studies suggest that the maximum rate of electron transport, V max, is measured in each case.
Article
Cadmium stress on aquatic macrophytes is currently few documented and no studies were conducted on clonal populations in controlled conditions. Our aim is to assess the effect of cadmium stress on Myriophyllum alterniflorum from physiological, anatomical and phenotypical parameters among different developmental stages. An experiment was carried out in order to test the hypothesis that a high external dose of Cd affects differentially young and old leaves of watermilfoil in terms of (1) anatomical and biological parameters, (2) physiological parameters and (3) that these differences result from the overall level of oxidative stress. Cadmium stress strongly affects the morphology of chlorophyllian organs and decreases the xylem-vessel number and diameter in matures leaves. Moreover we first report a new cadmium-induced anatomical feature: a double endodermis with separated layers which limits water and gaseous losses in mature leaves. From a physiological point of view, cadmium induces at all developmental stages a reduction in chlorophyll contents, a malondialdehyde production indicating a drastic lipoperoxydation, an enhanced production of reactive-oxygen-species scavengers (free proline and in lesser parts carotenoids) and a perturbation in hydric status in M. alterniflorum clones. The results obtained support the initial hypotheses. Indeed, it should be noted that cadmium stress mainly disturbs mature-leave structure and function, increasing their ageing and senescence. This mechanism probably contributes to limit the cadmium impact on young and growing parts as cadmium is known to preferentially accumulate in senescent leaves.
Article
In the present study, the level of thiols and activity of related enzymes were investigated in coontail (Ceratophyllum demersum L.) plants to analyze their role in combating the stress caused upon exposure to cadmium (Cd; 0-10 microM) for a duration up to 7d. Plants showed the maximum accumulation of 1293 microg Cd g(-1)dw after 7d at 10 microM. Significant increases in the level of total non-protein thiols (NP-SH) including phytochelatins (PCs) as well as upstream metabolites of the PC biosynthetic pathway, cysteine and glutathione (GSH) were observed. In addition, significant increases in the activities of cysteine synthase (CS), glutathione-S-transferase (GST), glutathione reductase (GR), as well as in vitro activation of phytochelatin synthase (PCS), were noticed in response to Cd. In conclusion, under Cd stress, plants adapted to a new metabolic equilibrium of thiols through coordinated synthesis and consumption to combat Cd toxicity and to accumulate it.
Article
The aim of this work was to study selenium (Se) speciation in the potato ( Solanum tuberosum L.) cultivar Desiree, enriched in Se by foliar spraying with a water solution containing 10 mg of Se/L in the form of sodium selenate. Four combinations of treatments were used: well-watered plants with and without Se foliar spraying and drought-exposed plants with and without Se foliar spraying. Water-soluble Se compounds were extracted from potato tubers by water or enzymatic hydrolysis with the enzyme protease XIV, amylase, or a combination of protease XIV and amylase. Extraction was performed using incubation at a constant temperature and stirring (37 degrees C at 200 rpm) or by ultrasound-assisted extraction (300 W), using different extraction times. Separation of soluble Se species (SeCys2, SeMet, SeMeSeCys, selenite, and selenate) was achieved by ion-exchange chromatography, and detection was performed by inductively coupled plasma-mass spectrometry (ICP-MS). Results showed that the concentration of selenate extracted was independent of the enzymatic extraction technique (approximately 98 ng/g for drought-exposed and 308 ng/g for well-watered potato tubers), whereas the extraction yield of SeMet changed with the protocol used (10-36%). Selenate and SeMet were the main soluble Se species (representing 51-68% of total Se) in potato tubers, regardless of the growth conditions.
Article
Submerged aquatic macrophyte species Potamogeton crispus L. (curlyleaf pondweed) and Ruppia maritima L. (widegeongrass) were examined for selenium accumulation from agricultural drainage water in the field and under laboratory conditions. High concentrations of chloride and sulfate salts were found in the drainage water of the constructed wetland at Tulare Lake Drainage District, Corcorn, California. Samples of P. crispus and R. maritima collected from the field, had similar plant-tissue Se concentrations, but the rhizomes accumulated significantly greater amounts of Se than the shoot tissues. When the plants were grown in culture solution supplemented with either chloride or sulfate salt, R. maritima was found to be more salt tolerant than P. crispus, and P. crispus accumulated more Se than R. maritima. Free seleno-amino acids were detected in the plant tissue, and organic Se was detected in the culture solution after 10 days of growth. The release of organic Se into the water by the plants may have a negative impact on the wetland environment.
Article
Selenium contamination represents one of the few clear cases where environmental pollution has led to devastation of wildlife populations, most notably in agricultural drainage evaporation and power plant coal-fly ash receiving ponds. Complex biogeochemistry, in particular extensive biotransformations and foodchain transfer, governs Se ecotoxicology and toxicology, for which the mechanism(s) are still elusive. However, total waterborne Se concentration has been widely used as a criterion for regulating and mitigating Se risk in aquatic ecosystems, which does not account for Se biogeochemistry and its site-dependence. There is a need for more reliable indicator(s) that encompass Se ecotoxicity and/or toxicity. Selenomethionine warrants special attention since it simulates Se toxicosis of wildlife in laboratory feeding studies. While low in free selenomethionine, microphytes isolated from Se-laden agricultural evaporation ponds were abundant in proteinaceous selenomethionine. This prompted a more extensive survey of Se speciation in foodchain organisms including microphytes, macroinvertebrates, fish, and bird embryos residing mainly in the agricultural drainage systems of the San Joaquin Valley, California. Total Se in biomass, water-soluble fractions, and protein-rich fractions were measured along with GC-MS analysis of proteinaceous selenomethionine. In all foodchain organisms, water-soluble Se constituted the major fraction of total biomass Se, while proteinaceous Se was a substantial, if not dominant, fraction of the water-soluble Se. In turn, proteinaceous selenomethionine comprised an important fraction of proteinaceous Se. In terms of total biomass Se, an average 1400-fold of Se biomagnification from water to microphytes was observed while subsequent transfer from microphytes to macroinvertebrates exhibited an average of only 1.9-fold. The latter transfer was more consistent and greater in extent for proteinaceous Se and proteinaceous selenomethionine, which is consistent with their importance in foodchain transfer. Proteinaceous Se in the omnivorous carp (Cyprinus carpio) liver also demonstrated a relation to ovarian lesions, while deformed stilt (Himantopus mexicanus) embryo was more abundant in proteinaceous selenomethionine than were normal embryos. Although limited in the number of organisms surveyed, these findings provide an impetus for further field and laboratory feeding studies to substantiate the hypothesis that proteinaceous selenomethionine underlies Se ecotoxicity, which may in turn prove to be a reliable indicator of Se risk in aquatic ecosystems.
Article
The accumulation of red or purple flavonoids is a hallmark of plant stress. Mounting evidence points to diverse physiological functions for these compounds in the stress response. Advances are also being made toward understanding how plants control the types and amounts of flavonoids that are produced in response to different cues.
Article
Previous field studies suggested that the macroalga, muskgrass (Chara canescens Desv. & Lois), plays an important role in the removal of selenium (Se) from agricultural drainage water. This study evaluated the efficiency of Se removal from drainage water by muskgrass-vegetated wetland microcosms, and determined the extent to which muskgrass removed Se through phytoextraction and biovolatilization. Six flow-through wetland microcosms were continuously supplied with drainage water containing an average Se concentration of 22 microg L(-1) over a 24-d experimental period. The Se mass input and outflow and the rate of Se volatilization were monitored daily for each microcosm. Three microcosms containing muskgrass reduced the daily mass Se input in the inflow drainage water by 72.1%; this compared with a reduction of 50.6% of the mass Se input for three unvegetated control microcosms. Selenium accumulated in muskgrass tissues accounted for 1.9% of the total mass Se input in the microcosm, followed by 0.5% via biological volatilization. The low rates of Se volatilization from selenate-supplied muskgrass, which were 10-fold less than from selenite, were probably due to a major rate limitation in the reduction of selenate to organic forms of Se in muskgrass. This conclusion was derived from X-ray absorption spectroscopy speciation analysis, which showed that muskgrass treated with selenite contained 91% of the total Se in organic forms (selenoethers and diselenides), compared with 47% in muskgrass treated with selenate.
Article
Selenium pollution is a worldwide phenomenon and is associated with a broad spectrum of human activities, ranging from the most basic agricultural practices to the most high-tech industrial processes. Consequently, selenium contamination of aquatic habitats can take place in urban, suburban, and rural settings alike--from mountains to plains, from deserts to rainforests, and from the Arctic to the tropics. Human activities that increase waterborne concentrations of selenium are on the rise and the threat of widespread impacts to aquatic life is greater than ever before. Important sources of selenium contamination in aquatic habitats are often overlooked by environmental biologists and ecological risk assessors due to preoccupation with other, higher priority pollutants, yet selenium may pose the most serious long-term risk to aquatic habitats and fishery resources. Failure to include selenium in the list of constituents measured in contaminant screening/monitoring programs is a major mistake, both from the hazard assessment aspect and from the pollution control aspect. Once selenium contamination begins, a cascade of bioaccumulation events is set into motion which makes meaningful intervention nearly impossible. However, this cascade of events need not happen if adequate foresight and planning are exercised. Early evaluation and action are key. Prudent risk management based on environmentally sound hazard assessment and water quality goals can prevent biological impacts.
Article
The aim of this study was to characterize the biological treatment of heavy metal-contaminated water employing Myriophyllum species, namely M. spicatum L. and M. triphyllum. Both species were found to be capable of removing cadmium (Cd) from water; the latter significantly outperformed. Myriophyllum species were treated with 0, 2, 4, 6, 8, 16 mgl(-1) cadmium solutions for 24, 48, 72, 96 h, respectively. Cd uptake of both species was the lowest at 2 mgl(-1) and the highest at 16 mgl(-1). Concentration related cadmium stress on both species exhibit significant difference on pigment levels (8-16 mgl(-1)). These findings contribute to the fact that submerged aquatic plants can be used for the removal of heavy metals.
Article
The influence of ambient and filtered solar ultraviolet-B (UV)-B radiation and of selenium treatment was determined on photochemical efficiency, respiratory potential measured by electron transport system (ETS) activity, and yield in pumpkins, Cucurbita pepo L. Yield and ETS activity were higher when solar UV-B was filtered out. The results suggested that the decreased yield was related to the UV-B impaired flow of electrons in the respiratory chain. Selenium increased yield under ambient radiation conditions. However, no significant effect of excluding UV-B radiation or of treatment with selenium was observed on the photochemical efficiency of photosystem II (PSII).
Article
Especially in the last decade, a vast number of papers on Se and its role in health issues have been published. This review gives a brief, critical overview of the main analytical findings reported in these papers. Of particular interest is the Se content in different food sources worldwide and the extent to which their consumption is reflected in the Se content of human tissues and body fluids. Several food sources, both natural (Brazil nuts, garlic, Brassica juncea) and Se-enriched (yeast-based supplements), are discussed as to origin, characteristics, Se metabolism and impact of their consumption on the human body. The continuous development of new and improvement of existing analytical techniques has provided different powerful tools to unravel the Se species and their function. An up-to-date literature study on Se speciation analysis is given, illustrating how analytical chemistry in its different facets aids in the identification of Se compounds and provides insight into the complete metabolic pathway of Se throughout the human body. This review includes a detailed image of the current state-of-the-art of Se speciation analysis in these food sources and in human tissues and body fluids.
Article
In this work, microscopic X-ray absorption near-edge structure spectroscopy (mu-XANES) and confocal microscopic X-ray fluorescence analysis (mu-XRF) were used for the in vivo determination of the distribution of total selenium and for the local speciation of selenium in roots and leaves of onion. Selected Allium cepa L. plants were grown hydroponically in a standard medium containing inorganic selenium compounds (selenite or selenate). The measurements were performed in vivo, that is, on living plants without the need for any form of sampling or sample pretreatment and without the necessity for cutting plant tissues into pieces. Distinct energy differences of the XANES spectra of various selenium reference compounds having different oxidation states allow adjusting the excitation energies used for mu-XRF mapping in such a manner that the distribution of selenium in various oxidation states is obtained with a spatial resolution of a few tens of micrometers within the virtual cross section of the onion tissues. We find that the ratio of inorganic to amino acid selenium compounds differs in various subparts of the plant. Detailed in vivo investigation of the distribution of various selenium species in virtual cross sections of root tips and green leaf shows that the selenium transport takes place via different mechanisms, depending on the nature of the selenium compounds originally taken up.
Article
Increasing urbanization, industrialization and over population is leading to the degradation of the environment. The main hazardous contents of the water pollution are heavy metals etc. Water bodies are the main targets for disposing the pollutants directly or indirectly. They are again at the receiving end as the storm water, residential and commercial waste is disposed into it. The prevailing purification technologies used to remove the contaminants are too costly and sometimes non-eco friendly also. Therefore, the research is oriented towards low cost and eco friendly technology for water purification, which will be beneficial for community. The present paper is a comprehensive review of approximately 38 literature sources. The paper discusses the potential of different aquatic plants (macrophytes) in purifying water and wastewater. Experimental work was developed to test the hypothesis that nutrient enrichment enhances metal tolerance of relative macrophyte.
Extraction of photosynthetic tissues: chlorophylls and carotenoids Current Protocols in Food Analytical Chemistry
  • H K Lichtenthaler
  • C Buschmann
Lichtenthaler, H.K., Buschmann, C., 2001a. Extraction of photosynthetic tissues: chlorophylls and carotenoids. In: Wrolstad, R.E., Acree, T.E., Decker, E.A. (Eds.), Current Protocols in Food Analytical Chemistry. John Wiley & Sons Inc., New York, pp. F.4.2.1–4.2.6.