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The effect of salinity on gas exchange and fluorescence characteristics in Lycium barbarum and Lycium chinense grown on nonsaline and saline soils was investigated. The distribution of Na+ between three types of substrates and different organs showed acropetal concentration gradient for Na+ accumulation only in L. barbarum grown on peat-moss-perlite and saline soil. Selective uptake of K+ over Na+ in the L. barbarum leaves was established. All plants grown on saline soil showed a slight inhibition of PSII activity as revealed by the quantum yield of the primary photochemical reaction. Intersystem electron transport, reduction of the end electron acceptors, and the performance index of photosynthesis declined to a greater extent in L. barbarum than that in L. chinense. The higher tolerance of L. chinense to salt stress was accompanied with the higher overall photosynthetic performance. [ABSTRACT FROM AUTHOR]

Phytoremediation is a low cost, long term, environmentally and aesthetically friendly in situ technology for toxins removal from contaminated soils (especially heavy metals and metalloids), by the roots of plants with subsequent transport to aerial plant organs. This technology is suitable for large areas, in which other approaches would be expensive and ineffective. The influence of the addition of EDTA and citrate to heavy metal contaminated soil on the activities of C4 photosynthetic enzymes, including phosphoenolpyruvate carboxylase; pyruvate, phosphate dikinase and NADP-malic enzyme in two-year-old plantlets of Paulownia tomentosa x fortunei - TF01 and Paulownia elongata x fortunei - EF02 was evaluated in a pot experiment. Treatment with 1 mM EDTA and 10 mM citrate had a protective effect against heavy metal stress through improvement of CO2 concentration mechanism and total antioxidant activity in TF01, while the application of 1 mM EDTA and 5 mM citrate enhanced antioxidant activity only in EF02. Comparative analyses of results showed that P. tomentosa x fortunei - TF01 hybrid possessed a more effective CO2 concentration mechanism and antioxidant defence under heavy metal stress than P. elongata x fortunei - EF02 and could be successfully used for phytoremediation of polluted soils. [ABSTRACT FROM AUTHOR]

The paper deals with the effect of low temperatures on nonenzymatic antioxidant defense system in the leaves of Arabis alpina plants grown from seeds collected from the French Alps (frost tolerant population, T) and from the mountain of Vercors (non-tolerant to frost, NT). Plants were grown at +22°C under control conditions and after that exposed to chilling stress (+4°C) for 4 days followed by freezing stress (-7°C) for 12h. Recovery was studied after return of the plants to +4°C (4 days) and finally to +22°C. Results showed that chilling stress enhanced MDA, H2O2 and flavonoid accumulation only in the leaves of T plants, while freezing stress decreased it. After recovery, the level of MDA and H2O2 remained higher only in T plants. The level of reducing sugars did not change only in the plants of T population after both cold treatments. Moreover, the frost stress at -7°C resulted even in stimulation of sugars production (by 30%) as compared to the control. In contrast to T, reducing sugars in NT plants declined after the chilling stress. Based on the changes in nonenzymatic antioxidant stress compounds, it can be concluded that T plants exhibited a much better response to low temperatures than NT. [ABSTRACT FROM AUTHOR]

A pot experiment was carried out to investigate the effect of salinity on leaf anatomy and antioxidant protection in two Lycium species (Lycium barbarum L. and Lycium chinense Mill.). The reduction in total leaf thickness, palisade and spongy mesophyll thickness, upper and lower epidermis was stronger in Lycium barbarum than in Lycium chinense. The two investigated Lycium species showed different antioxidant defence mechanisms under soil salinity. Based on our results we could suggest that the antioxidant capacity of Lycium barbarum L. under salinity condition was determined by increased SOD activity and glutathione content, while in Lycium chinense by higher level of SOD and CAT activities as well as increased ascorbate content. Lycium chinense demonstrated higher tolerance to salinity because its growth and leaf anatomy were less affected. [ABSTRACT FROM AUTHOR]

Essential oil quality, quantity, and antioxidant capacity of foliar fertilizedMatricaria recutitaL., grown on industrially polluted with cadmium (Cd) and lead (Pb) soil were studied. The polluted field is near the waste depository of ferrous metallurgical combine “Kremikovci”. Content of Cd and Pb in the soil exceeded permissible concentrations 4.6 and 2.0 times, respectively. The presence of high levels of heavy metals in the soil resulted in retained plant growth. InM. recutitagrown on industrially polluted soil, a decrease of root and shoot dry biomass and reduction of number of lateral steams was observed. Otherwise, the number and biomass of flowers per plant increased. Antioxidant defense in the foliar fertilized plants grown on industrially polluted soil could due mainly to increased levels of peroxidases with substrates ascorbate, glutathione, guaiacol, and hydrogen peroxide. Enhanced levels of Cd and Pb in soil did not influence essential oil yield and quality of chamomile. [ABSTRACT FROM PUBLISHER]

Nucleic acids are important biomarkers in cancer and viral diseases. However, their ultralow concentration in biological/clinical samples makes direct target detection challenging, because it leads to slow hybridization kinetics with the probe and its insufficient signal-to-noise ratio. Therefore, RNA target detection is done by molecular (target) amplification, notably by RT-PCR, which is a tedious multistep method that includes nucleic acid extraction and reverse transcription. Here, a direct method based on ultrabright dye-loaded polymeric nanoparticles in a sandwich-like hybridization assay with magnetic beads is reported. The ultrabright DNA-functionalized nanoparticle, equivalent to ≈10 000 strongly emissive rhodamine dyes, is hybridized with the magnetic bead to the RNA target, providing the signal amplification for the detection. This concept (magneto-fluorescent sandwich) enables high-throughput detection of DNA and RNA sequences of varied lengths from 48 to 1362 nt with the limit of detection down to 0.3 fm using a plate reader (15 zeptomoles), among the best reported for optical sandwich assays. Moreover, it allows semi-quantitative detection of SARS-CoV-2 viral RNA directly in clinical samples without a dedicated RNA extraction step. The developed technology, combining ultrabright nanoparticles with magnetic beads, addresses fundamental challenges in RNA detection; it is expected to accelerate molecular diagnostics of diseases., (© 2024 The Author(s). Small published by Wiley‐VCH GmbH.)

The effects of soil salinity on the functional activity of photosynthetic apparatus and pigment composition of two Paulownia lines (Paulownia tomentosa x fortunei and Paulownia elongata x elongata) were investigated. PAM chlorophyll fluorescence measurements revealed that salinity leads to: (i) an increase of the photochemical quenching coefficient (qP) and the linear electron transport rate (ETR) in both lines of Paulownia, while the maximum quantum yield of the primary photochemistry of PSII in the dark adapted state (Fv/Fm) was unaffected; (ii) improved the efficiency of the photochemical energy conversion (ФPSII); (iii) an impact on the chlorophyll fluorescence decrease ratio (RFd), which correlates to the net CO2 assimilation rate; (iv) an impact on [Formula: see text] reoxidation. The analysis of the kinetics of P700(+) reduction upon turning off far-red irradiation revealed that salinization lead to a delay of the cyclic electron transport around PSI in both studied lines as the effect on this process is more pronounced in P. tomentosa x fortunei than in (in comparison with) P. elongata x elongata. The present experimental results suggested high salt tolerance of the studied lines Paulownia, but P. tomentosa x fortunei is more tolerant to salinity than P. elongata x elongata. Molecular mechanisms involved in the Paulownia response to the soil salinity are discussed., (Copyright © 2016. Published by Elsevier Masson SAS.)

One-year-old two Paulownia lines (Ptomentosa x fortunei--TF 01 and R elongata x fortunei--EF 02) were grown, as pot experiment, in soil collected from the field of waste depository of Kremikovtzi ferrous metallurgical industry near Sofia. The soil was heavily polluted with Cd. Metals content (Ca, Mg, K, Na, Cd, Cu, Pb, Zn and Fe) in soil and its distribution in roots, stems and leaves of both lines was studied. The results showed that Ca and K accumulated more in stem, Mg, Na, Fe and Cd in root, while Pb, Cu and Zn in the leaves of both lines. The bloaccumulation factor (BF) and translocation factor (TF) were evaluated in order to determine the potential of plants in removing metals from contaminated soil. The BF for Fe, Pb, Cu and Zn in TF 01 line exceeded that of EF 02 line--5.6; 1.03; 1.20; 1.14 times, respectively. TF was higher in TF 01 line for Fe, Pb and Cd (6.0; 1.92 and 1.03, respectively), but not for Cu and Zn. The success of phytoremediation depends on plant growth and restricted distribution of heavy metals in shoots. Our results showed that stem length and total leaf area of Paulownia elongata x fortunei were higher than Paulownia tomentosa x fortuneibut BF for Cu and Zn and TF for Pb was less. BF for Cd was 1.7 times higher and TF for Zn was 1.03 times higher in Paulownia elongata x fortunei. Selected two lines (P. tomentosa x fortunei--TF 01 and P elongataxfortunei--EF02) were accumulators of Cu, Zn and Cd. Paulownia tomentosax fortunei accumulated more Pb and Zn in aboveground parts, while Paulownia elongata x fortunei--accumulated Zn only. These lines proved to be a promising species for phytoremediation of heavy metal polluted soils due to high biomass productivity.

The functional peculiarities and responses of the photosynthetic system in the flowering homoiochlorophyllous desiccation-tolerant (HDT) Haberlea rhodopensis and the non-desiccation-tolerant spinach were compared during desiccation and rehydration. Increasing rate of water loss clearly modifies the kinetic parameters of fluorescence induction, thermoluminescence emission, far-red induced P700 oxidation and oxygen evolution in the leaves of both species. The values of these parameters returned nearly to the control level after 24 h rehydration only of the leaves of HDT plant. PS II was converted in a non-functional state in desiccated spinach in accordance with the changes in membrane permeability, malondialdehyde, proline and H(2)O(2) contents. Moreover, our data showed a strong reduction of the total number of PS II centers in Haberlea without any changes in the energetics of the charge recombination. We consider this observation, together with the previously reported unusually high temperature of B-band (S(2)Q(B)-) emission of Haberlea to reflect some specific adaptive characteristics of the photosynthetic system. As far as we know this is the first time when such adaptive characteristics and mechanism of the photosynthetic system of a flowering HDT higher plant is described. These features of Haberlea can explain the fast recovery of its photosynthesis after desiccation, which enable this HDT plant to rapidly take advantage of frequent changes in water availability.