Do chromium-resistant bacterial symbionts of hyperaccumulator Callitriche cophocarpa support their host in phytobial remediation of water?

Callitriche cophocarpa Sendtn. is a macrophyte widely distributed in aquatic systems of the temperate climate zone and a known hyperaccumulator of chromium. Ten pure symbiotic bacterial isolates of C. cophocarpa were obtained and identified. Three of the isolates showed the highest resistance to Cr(VI): Microbacterium sp. (Ct1), Aeromonas sp. (Ct3) and Acinetobacter sp. (Ct6). Acinetobacter sp. (Ct6) was able to survive up to a concentration of 104 mg/L (2 mM). The isolates were also able to effectively detoxify Cr(VI) by reducing it to Cr(III). We tested whether inoculation of plants with a consortium consisting of Ct1, Ct3 and Ct6 affects: (1) the phytoextraction of chromium from leachates, (2) the physiological state of plants after Cr(VI) treatment. The solutions were landfill leachates and contained 10.7 mg/L of Cr(VI) - an amount 530 times exceeding the legal limits. We influenced the plants with Cr in two steps, each lasting for 10 days, first using mature shoots and then apical ones. The highest Cr content concomitant with the highest bioconcentration factor (BCF) were found in the inoculated plants: 1274 and 119 mg/kg dry mass (d.m.), respectively. The physiological status of the plants was assessed by biometric tests and advanced chlorophyll fluorescence analyses. The photosynthetic activity of mature shoots was influenced by Cr(VI) more negatively than that of young apical shoots. The inoculation with the bacterial consortium significantly reduced the negative effect of Cr(VI) on mature organs. In some cases the inoculated mature plants exhibited photosynthetic activity that was even higher than in the control plants. The results unequivocally show a beneficial effect of C. cophocarpa inoculation with the tested isolates resulting in a significant improvement of the phytoremediation properties of this aquatic chromium hyperaccumulator.

Quinces (Cydonia oblonga, Chaenomeles sp., and Pseudocydonia sinensis) as Medicinal Fruits of the Rosaceae Family: Current State of Knowledge on Properties and Use.

In recent years, the evaluation of many plant-derived compounds as potential new drugs or functional foods has become an active research topic. The morphological characteristics of quinces of the genera Cydonia sp., Chaenomeles sp., and Pseuocydonia sp. are largely similar, which is why these fruits are often confused. Although they have been appreciated in Asia for centuries as a valuable component of local ethnomedicine, they are less known in Western countries, and scientific knowledge about their health benefits remains fragmentary. This literature review summarizes studies on the content of chemical compounds responsible for the health-promoting and functional properties of the quince fruit. It focuses on the content of carotenoids, vitamins, minerals, and carboxylic acids, although the main emphasis is on the content and diversity of bioactive polyphenols, which are extremely abundant in these fruits. The quince fruits are rich in antioxidants and compounds with proven anti-inflammatory, anticancer, antiallergic, and immunomodulatory effects. Their phytochemicals effectively regulate glycemia and improve the blood lipid profile, suggesting potential antidiabetic and cardioprotective benefits. Analysis of chemical characteristics showed that the Chaenomeles fruits. are underestimated as functional food ingredients. Studies on the molecular effects of their bioactive compounds and species-specific genomic analyses are sorely lacking in the scientific literature.

The Content of Selected Bioactive Compounds in Wines Produced from Dehydrated Grapes of the Hybrid Variety 'Hibernal' as a Factor Determining the Method of Producing Straw Wines.

Sweet wines are appreciated worldwide; many are produced by fermenting the must of dehydrated (semi-dried) grapes, using methods that vary from region to region. The aim of this study was to evaluate the basic chemical and oenological characteristics of wines obtained by three technologies of production. The wines were made from a hybrid cultivar 'Hibernal', grown under cool climate conditions. 'Hibernal' is a hybrid variety. This 'Hibernal' variety is widely cultivated in central and eastern Europe, where it is of great economic importance. Wines produced from this variety are popular in local markets. In comparison with the production of varieties belonging to Vitis vinifera, a very small percentage of the 'Hibernal' variety is cultivated. The methods used in the experiment for the production of wines were: classical method in the Italian passito style, modification of the passito style with a seven-day maceration of grapes, and a method of production in the Tokaj wine style at five Puttonyos. Basic chemical parameters, acid profile, total phenolic content, antioxidant and antiradical capacities, and quantitative analysis of selected polyphenols was performed. The sensory features and quality of the wines was assessed using a sommelier analysis based on The Wine & Spirit Education Trust guidelines. The results indicated that the seven-day maceration of the dehydrated grapes resulted in the highest polyphenol content, as well as the largest antioxidant and antiradical contents. The oenological evaluation of wines produced by the Tokaj method and Italian passito method with seven-day maceration found that the wines were appreciated due to their rich taste, flavor, and overall quality. The present study confirms the promising opportunities to obtain special sweet wine with a valuable composition and oenological characteristics in regions with cooler climates.

Stem Photosynthesis-A Key Element of Grass Pea (Lathyrus sativus L.) Acclimatisation to Salinity.

Grass pea (Lathyrus sativus) is a leguminous plant of outstanding tolerance to abiotic stress. The aim of the presented study was to describe the mechanism of grass pea (Lathyrus sativus L.) photosynthetic apparatus acclimatisation strategies to salinity stress. The seedlings were cultivated in a hydroponic system in media containing various concentrations of NaCl (0, 50, and 100 mM), imitating none, moderate, and severe salinity, respectively, for three weeks. In order to characterise the function and structure of the photosynthetic apparatus, Chl a fluorescence, gas exchange measurements, proteome analysis, and Fourier-transform infrared spectroscopy (FT-IR) analysis were done inter alia. Significant differences in the response of the leaf and stem photosynthetic apparatus to severe salt stress were observed. Leaves became the place of harmful ion (Na+) accumulation, and the efficiency of their carboxylation decreased sharply. In turn, in stems, the reconstruction of the photosynthetic apparatus (antenna and photosystem complexes) activated alternative electron transport pathways, leading to effective ATP synthesis, which is required for the efficient translocation of Na+ to leaves. These changes enabled efficient stem carboxylation and made them the main source of assimilates. The observed changes indicate the high plasticity of grass pea photosynthetic apparatus, providing an effective mechanism of tolerance to salinity stress.

Antioxidants and Health-Beneficial Nutrients in Fruits of Eighteen Cucurbita Cultivars: Analysis of Diversity and Dietary Implications.

Aging is accompanied by gradual accumulation of molecular damage within cells in response to oxidative stress resulting from adverse environmental factors, inappropriate lifestyle, and numerous diseases. Adequate antioxidant intake is a key factor of proper diet. The study aimed to assess the antioxidant/antiradical capacities of Cucurbita fruits (18 cultivars of the species: C. maxima Duch., C. moschata Duch., C. pepo L., and C. ficifolia Bouché) grown in central Europe. The analyses were based on the FRAP (ferric reducing antioxidant power), CUPRAC (cupric ion reducing antioxidant capacity), and DPPH (2,2-diphenyl-1-picrylhydrazyl radical) assays. The content of phenolic compounds and ß-carotene was evaluated with HPLC (high performance liquid chromatography), while the main macro- and micronutrients by ICP-OES (inductively coupled plasma mass spectrometry). The results revealed high intraspecies variability within the Cucurbita genus. The Japanese 'Kogigu' fruits were distinguished as extraordinary sources of phenolic compounds, including syringic and protocatechuic acids, catechin, and kaempferol. Another popular cultivar 'Hokkaido' exhibited the highest antioxidant and antiradical capacities. Most of the fruits proved to be rich sources of zinc and copper. The obtained data are discussed in the context of optimized nutrition of the elderly and suggest that Cucurbita fruits should become daily components of their diet.

Selected metal content and antioxidant capacity of Sambucus nigra flowers from the urban areas versus soil parameters and traffic intensity.

The metal accumulation and antioxidant contents in flowers of wild specimens of European elder (Sambucus nigra L.), a famous medicinal plant and valuable component in the urban landscape, were determined. The total reflection X-ray fluorescence revealed the presence of K, Rb, Ca, Sr, Cr, Mn, Fe, Cu, and Zn associated with flowers. A typical, large, non-industrial city with considerable traffic and atmospheric pollution resulting from smog was chosen as a place of sampling. Obtained results were correlated with selected parameters of soil and the intensity of surrounding traffic. The flowers were relatively rich in elements K, Ca, Cu, Rb, and antioxidants, while it did not accumulate heavy metals potentially bioavailable in the soil. The correlation between street traffic and the content of Fe, Cr, and Zn in elderflowers was revealed; the metal quantities were below levels harmful to humans. Flowers from the city center exhibited higher antioxidant and radical scavenging capacities comparing to plants from the areas of little traffic. The antioxidant parameters were negatively correlated with the silty fraction content and positively with the potentially bioavailable levels of Ti and Mn in soils and increased with the amount of Rb in the flowers. It was proven for the first time that the urban specimens of wild S. nigra can perform as a local source of beneficial flowers providing cost-effective support in disease prevention and treatment.

Accumulation patterns of Cr in Callitriche organs--qualitative and quantitative analysis.

The aims of this study were both the qualitative and quantitative analysis of chromium accumulation in the shoots of Callitriche cophocarpa. This globally distributed, submersed macrophyte exhibits outstanding Cr phytoremediation capacity in an aquatic environment. Cr was applied separately for 7 days at two stable forms as Cr(VI) and Cr(III), known from their diverse physicochemical properties and toxicities. The maps of Cr depositions in young leaves, mature leaves, and stems were obtained by micro X-ray fluorescence spectroscopy (µXRF). The detailed analysis of XRF maps was done based on Image-Pro PLUS (Media Cybernetics) software. Cr was accumulated either in trichomes or vascular bundles in respect to the element speciation and the plant organ. The concentration of Cr significantly increased in the following order: Cr(VI) mature leaves < Cr(VI) young leaves = Cr(VI) stems < Cr(III) young leaves ≤ Cr(III) mature leaves ≤ Cr(III) stems. The observed differences in distribution and accumulation of Cr were correlated with the different reduction potential of Cr(VI) by particular plant organs. The reduction of Cr(VI) is considered the main detoxification mechanism of the highly toxic Cr(VI) form. The unique L-band electron resonance spectrometer (L-band EPR) was applied to follow the reduction of Cr(VI) to Cr(III) in the studied material.

Content of carotenoids in roots of seventeen cultivars of Daucus carota L.

The aim of this study was to compare the content of carotenoids in seventeen cultivars of carrots grown in Poland. Conventional orange cultivars with rarely grown were compared: white, yellow and purple with yellow core cultivars. To determine the content of carotenoids, extracts from lyophilized carrot roots were prepared and analyzed by spectrophotometric as well as HPLC methods with DAD detector. The highest content of carotenoids was found in cultivars: 'Korund F(1)' (48 mg/100g of fresh weight) and 'Salsa F(1)' (36 mg/100g of fresh weight). The antioxidant properties of selected cultivars were compared using the DPPH method.

Calorimetric studies of the effect of cis-carotenoids on the thermotropic phase behavior of phosphatidylcholine bilayers.

Carotenoid geometry is a factor that determines their solubility and orientation in the lipid membrane as well as antioxidant capacities and bioavailability. The effects of the cis-isomers of carotenoids (zeaxanthin and beta-carotene) on the thermotropic properties of lipid membranes formed with dimyristoylphosphatidylcholine (DMPC) and dipalmitoylphosphatidylcholine (DPPC) were investigated by means of differential scanning calorimetry. The results were compared with the effects caused by the all-trans-isomer. Both the trans and cis isomers of zeaxanthin shifted the main phase transition temperature to lower values and decreased the cooperativity of the phase transition. The effect of all-trans zeaxanthin on the physical properties of the lipid bilayers has been shown to strongly depend on the hydrocarbon chain length of the membrane. In the case of cis-zeaxanthin this relationship is weaker.

Thermotropic phase behaviour of alpha-dipalmitoylphosphatidylcholine multibilayers is influenced to various extents by carotenoids containing different structural features--evidence from differential scanning calorimetry.

Carotenoids are the effective modulators of physical properties of model and natural membranes. To demonstrate the relationship between the structure of carotenoids and their effect on the molecular dynamics of membranes, we have investigated the influence of five structurally different carotenoids: beta-carotene, lycopene, lutein, violaxanthin, zeaxanthin and additionally carotane--a fully saturated derivative of beta-carotene, on thermotropic phase behaviour of dipalmitoylphosphatidylcholine (DPPC) multilamellar vesicles by means of differential scanning calorimetry (DSC). The results obtained indicate that the carotenoids used modulated the thermotropic properties of multibilayers to various extents, broadening the pretransition and the main phase transition peaks and shifting them to lower temperatures. Pronounced decrease of pretransition enthalpy (DeltaH(p)) proves that carotenoids very strongly alter the membrane properties in its gel phase. Comparison of the influence of several carotenoids shows that a rigid, polyisoprenoid chain plays a basic role in altering the thermotropic properties of such membranes and the presence of rings without oxygen-containing groups has a minor significance for the observed interactions. Carotenoids containing epoxy and/or hydroxy groups attached to their rings modify the thermotropic phase behaviour of DPPC multilamellar vesicles stronger than carotenes--a result of their orientation in the DPPC bilayer.

Kinetics of violaxanthin de-epoxidation by violaxanthin de-epoxidase, a xanthophyll cycle enzyme, is regulated by membrane fluidity in model lipid bilayers.

This paper describes violaxanthin de-epoxidation in model lipid bilayers. Unilamellar egg yolk phosphatidylcholine (PtdCho) vesicles supplemented with monogalactosyldiacylglycerol were found to be a suitable system for studying this reaction. Such a system resembles more the native thylakoid membrane and offers better possibilities for studying kinetics and factors controlling de-epoxidation of violaxanthin than a system composed only ofmonogalactosyldiacylglycerol and is commonly used in xanthophyll cycle studies. The activity of violaxanthin de-epoxidase (VDE) strongly depended on the ratio of monogalactosyldiacylglycerol to PtdCho in liposomes. The mathematical model of violaxanthin de-epoxidation was applied to calculate the probability of violaxanthin to zeaxanthin conversion at different phases of de-epoxidation reactions. Measurements of deepoxidation rate and EPR-spin label study at different temperatures revealed that dynamic properties of the membrane are important factors that might control conversion of violaxanthin to antheraxanthin. A model of the molecular mechanism of violaxanthin de-epoxidation where the reversed hexagonal structures (mainly created by monogalactosyldiacylglycerol) are assumed to be required for violaxanthin conversion to zeaxanthin is proposed. The presence of monogalactosyldiacylglycerol reversed hexagonal phase was detected in the PtdCho/monogalactosyldiacylglycerol liposomes membrane by 31P-NMR studies. The availability of violaxanthin for de-epoxidation is a diffusion-dependent process controlled by membrane fluidity. The significance of the presented results for understanding themechanism of violaxanthin de-epoxidation in native thylakoid membranes is discussed.

Comparative X-ray studies on the interaction of carotenoids with a model phosphatidylcholine membrane.

The interaction of structurally different carotenoids with a membrane molecular model was examined by X-ray diffraction. The selected compounds were beta-carotene, lycopene, lutein, violaxanthin, zeaxanthin, and additionally carotane, a fully saturated derivative of beta-carotene. They present similarities and differences in their rigidity, the presence of terminal ionone rings and hydroxy and epoxy groups bound to the rings. The membrane models were multibilayers of dipalmitoylphosphatidylcholine (DPPC), chosen for this investigation because the 3 nm thickness of the hydrophobic core of its bilayer coincides with the thickness of the hydrophobic core of thylakoid membranes and the length of the carotenoid molecules. Results indicate that the six compounds induced different types and degrees of structural perturbations to DPPC bilayers in aqueous media. They were interpreted in terms of the molecular characteristics of DPPC and the carotenoids. Lycopene and violaxanthin induced the highest structural damage to the acyl chain and polar headgroup regions of DPPC bilayers, respectively.