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Water deficiency compromises plant performance and yield in many habitats and in agriculture. In addition to survival of the acute drought stress period which depends on plant-genotype-specific characteristics, stress intensity and duration, also the speed and efficiency of recovery determine plant performance. Drought-induced deregulation of metabolism enhances generation of reactive oxygen species (ROS) and reactive nitrogen species (RNS) which in turn affect the redox regulatory state of the cell. Strong correlative and analytical evidence assigns a major role in drought tolerance to the redox regulatory and antioxidant system. This review compiles current knowledge on the response and function of superoxide, hydrogen peroxide and nitric oxide under drought stress in various species and drought stress regimes. The meta-analysis of reported changes in transcript and protein amounts, and activities of components of the antioxidant and redox network support the tentative conclusion that drought tolerance is more tightly linked to up-regulated ascorbate-dependent antioxidant activity than to the response of the thiol-redox regulatory network. The significance of the antioxidant system in surviving severe phases of dehydration is further supported by the strong antioxidant system usually encountered in resurrection plants.

Progress in understanding the cell biology and diseases depends on advanced imaging and labeling techniques. Here, we address this demand by exploring novel multilayered nanocomposites (MNCs) with plasmonic nanoparticles and absorbing dyes in thin nonabsorbing shells as supercontrast multimodal photoacoustic (PA) and fluorescent agents in the near-infrared range. The proof of concept was performed with gold nanorods (GNRs) and indocyanine green (ICG) dispersed in a matrix of biodegradable polymers. We demonstrated synergetic PA effects in MNCs with the gold-ICG interface that could not be achieved with ICG and GNRs alone. We also observed ultrasharp PA and emission peaks that could be associated with nonlinear PA and spaser effects, respectively. Low-toxicity multimodal MNCs with unique plasmonic, thermal and acoustic properties have the potential to make a breakthrough in PA flow cytometry and near-infrared spasers in vivo by using the synergetic interaction of plasmonic modes with a nearby absorbing medium., (© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The paper describes a new biological sensor which represents a resonator based on a segment of a rectangular waveguide of 8 GHz band with shear dimensions of 28.5 × 12.6 mm 2 . On one side, the resonator is bounded by a metallic short-circuited wall; on the other side, it is bounded by a lithium niobate plate with a porous polystyrene film. This film, applied by centrifugation and modified in high-frequency discharge plasma in argon, was used to immobilize cells of Escherichia coli K-12. This resonator was connected through a coaxial-waveguide adapter to the S parameter meter, by means of which the reflection coefficient S 11 in the plane of the lithium niobate plate was measured. The addition of an aqueous solution of ampicillin at 4-50 μg/ml to immobilized cells led to a significant change in the reflection coefficient of S 11 from - 10.15 dB to - 15.09 dB. At the same time, the resonance frequency changed insignificantly within the range 8.06-8.068 GHz. The optimal time for modifying the polystyrene film for obtaining the required porosity and the optimal time for the immobilization of the bacterial cells were determined. The immobilized cells retained their activity for 4 months at a temperature of 4 °C. The study showed the promise of such a biosensor to determine β-lactam antibiotics in aqueous solutions by using ampicillin as an example. The limit of detection of the developed biosensor with respect to ampicillin was established (4 μg/ml)., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Lipopolysaccharide (LPS) was extracted from dry bacterial cells of plant-growth-promoting bacterium Azospirillum brasilense SR8 (IBPPM 5). The O-specific polysaccharide (OPS) was obtained by mild acid hydrolysis of the lipopolysaccharide and studied by sugar analysis, 1 H and 13 C NMR spectroscopy, including 1 H, 1 H COSY, TOCSY, ROESY, and 1 H, 13 C HSQC and HMBC experiments, computational NMR-based structure analysis, and Smith degradation. The OPS was shown to contain two types of repeating units of the following structure: Both OPS structures are present in A. brasilense 54, from which structure 1 has been reported earlier (Fedonenko et al., 2011), whereas to our knowledge structure 2 has not been hitherto found in bacterial saccharides. Treatment of wheat seedling roots with LPS of A. brasilense SR8 increased the number of root hair deformations as compared to seedlings grown without LPS, but had no effect on adsorption of the bacteria to the root surface. A. brasilense SR8 was able to utilize LPS of several structurally related Azospirillum strains., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Au nanorods (AuNRs) have attracted a great interest as a platform for constructing various composite core/shell nanoparticles for theranostics applications. However, the development of robust methods for coating AuNRs with a biocompatible shell of high loading capacity and with functional groups still remains challenging. Here, we coated AuNRs with a polydopamine (PDA) shell and functionalized AuNR-PDA particles with folic acid and rhodamine 123 (R123) to fabricate AuNR-PDA-R123-folate nanocomposites. To the best of our knowledge, such AuNR-PDA-based composites combining fluorescent imaging and plasmonic phothothermal abilities have not been reported previously. The multifunctional nanoparticles were stable in cell buffer, nontoxic and suitable for targeted fluorescent imaging and photothermal therapy of cancer cells. We demonstrate the enhanced accumulation of folate-functionalized nanoparticles in folate-positive HeLa cells in contrast to the folate-negative HEK 293 cells using fluorescent microscopy. The replacement of folic acid with polyethylene glycol (PEG) leads to a decrease in nanoparticle uptake by both folate-positive and folate-negative cells. We performed NIR light-mediated targeted phototherapy using AuNR-PDA-R123-folate and obtained a remarkable cancer cell killing efficiency in vitro in comparison with only weak-efficient nontargeted PEGylated nanoparticles. Our work illustrates that AuNR-PDA could be a promising nanoplatform for multifunctional tumor theranostics in the future.

Background: A variety of spirooxindoles have demonstrated cytotoxic activity toward several cancer cell lines. This study investigates the cytotoxicity of five novel spirooxindole-pyrrolidines by using the Vero and HeLa cell lines., Methods: Vero and HeLa cells were treated with the synthesized spirooxindoles, and the cytotoxicity was evaluated by using the AlamarBlue Cell Viability Reagent and live/dead assay., Results: A series of poly-substituted pyrrolidines differing in nature and in substituent positions were obtained, with yields of 42-63%. Of the synthesized cycloadducts, 3-picolinoyl-4-(2,4-dichlorophenyl)-5-phenylspiro[indoline-3,2'-pyrrolidine]-2'-one (4) was the most cytotoxic (IC 50 < 20 μg/ml for both cell lines). Besides, 3-picolinoyl-4-(2-chlorophenyl)-5-phenylspiro[indoline-3,2'-pyrrolidine]-2'-one (1) was three times more toxic to the HeLa cancer cell line (IC 50  = 70 μg/ml) than it was to the Vero healthy cell line. The cytotoxicity of compounds 1 and 4 was confirmed with a live/dead assay. The cytotoxicity of a molecule was found to depend on the substitution nature on the benzene ring at the C-4 atom., Conclusion: 3-Picolinoyl-4-(2-chlorophenyl)-5-phenylspiro[indoline-3,2'-pyrrolidine]-2'-one (1) can be used as a source for the synthesis of novel therapeutic agents against cancer., (Copyright © 2018 Institute of Pharmacology, Polish Academy of Sciences. Published by Elsevier B.V. All rights reserved.)

Bacteria in natural associations with agricultural crops are promising for use in the improvement of clonal micropropagation of plants. We clarified the taxonomic position of Ochrobactrum cytisi strain IPA7.2 and investigated its tolerance for salinity, high temperature, and glyphosate pollution. We also tested the strain's potential to promote the growth of potato (Solanum tuberosum L.) microplants. Using the IPA7.2 draft genome (no. NZ&#95;MOEC00000000), we searched for housekeeping genes and also for the target genes encoding glyphosate tolerance and plant-growth-promoting ability. A multilocus sequence analysis of the gap, rpoB, dnaK, trpE, aroC, and recA housekeeping genes led us to identify isolate IPA7.2 as O. cytisi. The strain tolerated temperatures up to 50 °C and NaCl concentrations up to 3-4%, and it produced 8 µg ml -1 of indole-3-acetic acid. It also tolerated 6 mM glyphosate owing to the presence of type II 5-enolpyruvylshikimate-3-phosphate synthase. Finally, it was able to colonize the roots and tissues of potato microplants, an ability preserved by several generations after subculturing. We identified the development phase of potato microplants that was optimal for inoculation with O. cytisi IPA7.2. Inoculation of in vitro-grown 15-day-old microplants increased the mitotic index of root meristem cells (by 50%), the length of shoots (by 34%), the number of leaves (by 7%), and the number of roots (by 16%). Under ex vitro conditions, the inoculated plants had a greater leaf area (by 77%) and greater shoot and root dry weight (by 84 and 61%, respectively) than did the control plants. We recommend O. cytisi IPA 7.2 for use in the growing of potato microplants to improve the production of elite seed material.

Significance: Photosynthesis takes place in the chloroplast of eukaryotes, which occupies a large portion of the photosynthetic cell. The chloroplast function and integrity depend on intensive material and signal exchange between all genetic compartments and conditionally secure efficient photosynthesis and high fitness. Recent Advances: During the last two decades, the concept of mutual control of plastid performance by extraplastidic anterograde signals acting on the chloroplast and the feedback from the chloroplast to the extraplastidic space by retrograde signals has been profoundly revised and expanded. It has become clear that a complex set of diverse signals is released from the chloroplast and exceeds the historically proposed small number of information signals. Thus, it is also recognized that redox compounds and reactive oxygen species play a decisive role in retrograde signaling., Critical Issues: The diversity of processes controlled or modulated by the retrograde network covers all molecular levels, including RNA fate and translation, and also includes subcellular heterogeneity, indirect gating of other organelles' metabolism, and specific signaling routes and pathways, previously not considered. All these processes must be integrated for optimal adjustment of the chloroplast processes. Thus, evidence is presented suggesting that retrograde signaling affects translation, stress granule, and processing body (P-body) dynamics., Future Directions: Redundancy of signal transduction elements, parallelisms of pathways, and conditionally alternative mechanisms generate a robust network and system that only tentatively can be assessed by use of single-site mutants.

Two ascomycete strains were isolated from creosote-contaminated railway sleeper wood. By using a polyphasic approach combining morpho-physiological observations of colonies with molecular tools, the strains were identified as Fusarium oxysporum Schltdl. (IBPPM 543, MUT 4558; GenBank accession no. MG593980) and Lecanicillium aphanocladii Zare & W. Gams (IBPPM 542, MUT 242; GenBank accession no. MG593981). Both strains degraded hazardous pollutants, including polycyclic aromatic hydrocarbons, anthraquinone-type dyes, and oil. Oil was better degraded by F. oxysporum, but the aromatic compounds were better degraded by L. aphanocladii. With both strains, the degradation products of anthracene, phenanthrene, and fluorene were 9,10-anthraquinone, 9,10-phenanthrenequinone, and 9-fluorenone, respectively. During pollutant degradation, F. oxysporum and L. aphanocladii produced an emulsifying compound(s). Both fungi produced extracellular Mn-peroxidases, enzymes possibly involved in the fungal degradation of the pollutants. This is the first report on the ability of L. aphanocladii to degrade four-ring PAHs, anthraquinone-type dyes, and oil, with the simultaneous production of an extracellular Mn-peroxidase.

The optical activity [α] of films of chitosan and chitosan acetate was studied. [α] depended on the orientation angle θ of the film sample around the light beam. The angular dependences [α] = f(θ) (indicatrices) were processed to extract the constant term [α] 0 and four harmonics ([α] i , Fourier's series) determined by structure elements with the corresponding symmetry: the amorphous (isotropic) phase of chitosan ([α] 0 ), irregular-shaped structures ([α] 1 ), rod-shaped ones in the film plane ([α] 2 ), helical ones located perpendicular to the film surface ([α] 3 ), and crystalline structures ([α] 4 ). The contribution of individual supramolecular structures to the overall optical activity of chitosan was estimated: [α] 2 and [α] 4 predominated for the fresh chitosan acetate films, while [α] 4 did for the chitosan ones. The results of the numerical decomposition of indicatrices are in satisfactory agreement with X-ray diffractometry data. The observed regularities predetermine prospects for obtaining stereoselective chiro-optic chitosan-based materials with novel functional properties., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Plants often face combinatorial stresses in their natural environment. Here, arsenic (As) toxicity was combined with hypoxia (Hpx) in the roots of Arabidopsis thaliana as it often occurs in nature. Arsenic inhibited growth of both roots and leaves, whereas root growth almost entirely ceased in Hpx. Growth efficiently resumed, and Hpx marker transcripts decreased upon reaeration. Compromised recovery from HpxAs treatment following reaeration indicated some persistent effects of combined stresses despite lower As accumulation. Root glutathione redox potential turned more oxidized in Hpx and most strongly in HpxAs. The more oxidizing root cell redox potential and the lowered glutathione amounts may be conducive to the growth arrest of plants exposed to HpxAs. The stresses elicited changes in elemental and transcriptomic composition. Thus, calcium, magnesium, and phosphorous amounts decreased in rosettes, but the strongest decline was seen for potassium. The reorganized potassium-related transcriptome supports the conclusion that disturbed potassium homeostasis contributes to the growth phenotype. In a converse manner, photosynthesis-related parameters were hardly affected, whereas accumulated carbohydrates under all stresses and anthocyanins under Hpx exclude carbohydrate limitation. The study demonstrates the existence of both synergistic since mutually aggravating effects and antagonistic effects of single and combined stresses., (© 2018 John Wiley & Sons Ltd.)

The bacterium Azospirillum brasilense can swim and swarm owing to the rotation of a constitutive polar flagellum (Fla) and inducible lateral flagella, respectively. They also form biofilms on various interfaces. Experimental data on flagellar assembly and social behaviours in these bacteria are scarce. Here, for the first time, the chromosomal coding sequence mmsB1 for a homologue of 3-hydroxyisobutyrate dehydrogenase (protein accession Nos. ADT80774 and E7CWE2) was shown to play a role in the assembly of motile Fla and in biofilm biomass accumulation. In the previously obtained mutant SK039 of A. brasilense Sp245, an Omegon-Km insertion in mmsB1 was concurrent with changes in cell-surface properties and with suppression of Fla assembly (partial) and Fla-dependent motility (complete). Here, the immotile leaky Fla - mutant SK039 was complemented with the expression vector pRK415-borne mmsB1 gene of Sp245. In the complemented mutant, the elevated relative cell hydrophobicity and changed relative membrane fluidity of SK039 returned to the wild-type levels; also, biofilm biomass accumulation increased and even reached Sp245's levels under nutritionally rich conditions. In strain SK039 (pRK415-mmsB1), the percentage of cells with Fla became significantly higher than that in mutant SK039, and the Fla-driven swimming velocity was equal to that in strain Sp245.

Halomonas ventosae RU5S2EL, a halophilic Gram-negative bacterium isolated from salt sediments of lake Elton (Russia), was cultivated and the lipopolysaccharide was extracted by the Westphal procedure. The O-specific polysaccharide (OPS) was obtained by mild acid hydrolysis of the lipopolysaccharide and was studied by sugar analysis along with 1 H and 13 C NMR spectroscopy, including 1 H, 1 H COSY, TOCSY, ROESY, 1 H, 13 C HSQC, and HMBC experiments as well as Smith degradation. The OPS was found to consist of branched pentasaccharide repeating units of the following structure., (Copyright © 2018. Published by Elsevier Ltd.)

Bacteria Azospirillum brasilense may swim and swarm owing to the rotation of a constitutive polar flagellum (Fla) and inducible lateral flagella (Laf). They also construct sessile biofilms on various interfaces. As compared to the wild-type strain Sp245, the previously characterized Fla - Laf - flhB1 mutant Sp245.1063 accumulated less biomass in mature biofilms, which also were susceptible to the forces of hydrodynamic shear. In this study, we compared biofilms formed by strain Sp245 and its previously constructed derivatives on the interfaces between a minimal (malate-salt medium, or MSM) or rich (LB) liquid growth medium and a hydrophilic (glass) or hydrophobic (polystyrene) solid surface under static or dynamic conditions. In all experimental settings, the alterations in Sp245.1063's mature biofilm traits were partially (in MSM) or completely (in LB) rescued in the complemented mutant Sp245.1063 (pRK415-150177), which received the pRK415-borne coding sequence for the putative FlhB1 protein of the flagellar type III secretion system. Although Laf were not found in the biofilms of azospirilla, Fla was present on the biofilm cells of the complemented mutant Sp245.1063 (pRK415-150177) and other studied strains, which had normal flagellation on liquid and solid nutritional media. Accordingly, mature biofilms of these strains contained more biomass and were significantly more resistant to shaking at 140 rpm, as compared to the biofilms of the flagella-free mutant bacteria. These data proved that the polar flagellum of A. brasilense Sp245 plays a significant positive role in biofilm biomass increase and in biofilm stabilization.

The recently developed laser-induced cell transfection mediated by Au nanoparticles is a promising alternative to the well-established lipid-based transfection or to electroporation. Optoporation is based on the laser plasmonic heating of nanoparticles located near the cell membrane. However, the uncontrollable cell damage from intense laser pulses and from random attachment of nanoparticles may be crucial for transfection. We present a novel plasmonic optoporation technique that uses Au nanostar layers immobilized in culture microplate wells. HeLa cells were grown directly on Au nanostar layers, after which they were subjected to continuous-wave 808 nm laser irradiation. An Au monolayer density ~15 μg/cm 2 and an absorbed energy of about 15 to 30 J were found to be optimal for optoporation. Propidium iodide molecules were used as model penetrating agent. The transfection efficiency evaluated using fluorescence microscopy for HeLa cells transfected with pGFP under optimized optoporation conditions (95% ± 5%) was similar to the efficiency of TurboFect. The technique's efficiency (295 ± 10 relative light units, RLU), demonstrated by transfecting HeLa cells with the pCMV-GLuc 2 control plasmid, was greater than that obtained by transfection of HeLa cells with the TurboFect agent (220 ± 10 RLU). The cell viability in plasmonic optoporation (92% ± 7%), too, was greater than that in transfection with TurboFect (75% ± 7%)., (© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Recent years have seen extremely fast development of new viral nanovaccines and diagnostic agents using nanostructures prepared by biological and chemical synthesis. We used spherical gold nanoparticles (average diameter, 15 nm) as a platform for the antigen for swine transmissible gastroenteritis virus (TGEV). The literature data demonstrate that immunization of animals with the TGEV antigen coupled to gold nanoparticles (GNPs) not only activates antigen-presenting cells but also increases the proliferative activity of splenic lymphoid (antibody-forming) cells. The contents of γ-IFN, IL-1β, and IL-6 in animals immunized with GNP-antigen conjugates were found to be higher than those in intact animals or in animals given the antigen alone. The increased concentration of IL-1β in the immunized animals directly correlated with the activity of macrophages and stimulated B cells, which produce this cytokine when activated. The increased concentration of IL-6 indicates that the injected preparations are stimulatory to cellular immunity. Immunization with the TGEV antigen conjugated to GNPs as a carrier activates the respiratory activity of lymphoid cells and peritoneal macrophages, which is directly related to their transforming activity and to the activation of antibody generation. Furthermore, the use of this conjugate allows marked improvement of the structure of the animals' immune organs and restores the morphological-functional state of these organs. The microanatomical changes (increased number of follicles) indicate the activation of the B-dependent zone of the spleen and, consequently, the development of a humoral-type immunological reaction. The degradative processes observed in the animals immunized with TGEV antigen alone are evidence of weak resistance to pathogen attack. These results can be used to develop vaccines against this infection by employing TGEV antigen coupled to gold nanoparticles as a carrier.

Thirty crop species provide 90% of our food, most of which display severe yield losses under moderate salinity. Securing and augmenting agricultural yield in times of global warming and population increase is urgent and should, aside from ameliorating saline soils, include attempts to increase crop plant salt tolerance. This short review provides an overview of the processes that limit growth and yield in saline conditions. Yield is reduced if soil salinity surpasses crop-specific thresholds, with cotton, barley and sugar beet being highly tolerant, while sweet potato, wheat and maize display high sensitivity. Apart from Na + , also Cl - , Mg 2+ , SO 4 2- contribute to salt toxicity. The inhibition of biochemical or physiological processes cause imbalance in metabolism and cell signalling and enhance the production of reactive oxygen species interfering with cell redox and energy state. Plant development and root patterning is disturbed, and this response depends on redox and reactive oxygen species signalling, calcium and plant hormones. The interlink of the physiological understanding of tolerance processes from molecular processes as well as the agronomical techniques for stabilizing growth and yield and their interlinks might help improving our crops for future demand and will provide improvement for cultivating crops in saline environment.3 - contribute to salt toxicity. The inhibition of biochemical or physiological processes cause imbalance in metabolism and cell signalling and enhance the production of reactive oxygen species interfering with cell redox and energy state. Plant development and root patterning is disturbed, and this response depends on redox and reactive oxygen species signalling, calcium and plant hormones. The interlink of the physiological understanding of tolerance processes from molecular processes as well as the agronomical techniques for stabilizing growth and yield and their interlinks might help improving our crops for future demand and will provide improvement for cultivating crops in saline environment., (© 2018 German Society for Plant Sciences and The Royal Botanical Society of the Netherlands.)

We demonstrate a novel approach to the controlled loading of inorganic nanoparticles and proteins into submicron- and micron-sized porous particles. The approach is based on freezing/thawing cycles, which lead to high loading densities. The process was tested for the inclusion of Au, magnetite nanoparticles, and bovine serum albumin in biocompatible vaterite carriers of micron and submicron sizes. The amounts of loaded nanoparticles or substances were adjusted by the number of freezing/thawing cycles. Our method afforded at least a three times higher loading of magnetite nanoparticles and a four times higher loading of protein for micron vaterite particles, in comparison with conventional methods such as adsorption and coprecipitation. The capsules loaded with magnetite nanoparticles by the freezing-induced loading method moved faster in a magnetic field gradient than did the capsules loaded by adsorption or coprecipitation. Our approach allows the preparation of multicomponent nanocomposite materials with designed properties such as remote control (e.g. via the application of an electromagnetic or acoustic field) and cargo unloading. Such materials could be used as multimodal contrast agents, drug delivery systems, and sensors.

Background: The analysis of recent studies on plasmonic photothermal therapy (PPT) after intravenous administration of gold nanorods (GNRs) has demonstrated that the effectiveness of nanoparticle-assisted laser hyperthermia depends on a correct dosage strategy of nanoparticle administration. Accumulation of GNRs in tumor tissue dramatically increases the local heating of the tumor without damage to healthy tissues. However, the optimal doses of GNR intravenous injections (IVIs) for effective accumulation in tumors, and optimal protocols of PPT are not designed yet. The current study aims to improve the efficacy of PPT in tumor-bearing rats using multiple fractional intravenous administration of GNRs., Materials and Methods: For PPT experiments, the GNRs with aspect ratio of 4.1 were functionalized with thiolated polyethylene glycol (PEG) and their suspensions were used for multiple fractional intravenous administration in outbred albino male rats with experimental model of rat liver cancer (cholangiocarcinoma line PC-1). Doppler ultrasonography was performed to characterize the vascularity of transplanted rat tumors before any treatment. After a final injection of GNRs, tumor was irradiated during 15 minutes by 808-nm NIR diode laser at a power density 2.3 W/cm 2 . The animals were withdrawn from the experiment and sampling of tissues for morphological study and gold accumulation was performed 24 hours and 3 weeks after PPT., Results: The multiple IVIs of gold nanorods and further PPT of transplanted cholangiocarcinoma provided significant damage to tumor tissue resulting in pronounced necrotic mass and retardation of the tumor growth. More importantly, the proposed PPT protocol had low toxicity as evidenced by histological examination of internal organs. The efficiency of PPT depends on the presence of newly formed vasculature as revealed by the Doppler ultrasound investigation., Conclusion: The repeatable IVIs promote greater of GNR accumulation within the tumor thus resulting in higher PPT efficacy. Accompanying ultrasonography can be useful for prognosis and monitoring of treatment. Lasers Surg. Med. 50:1025-1033, 2018. © 2018 Wiley Periodicals, Inc., (© 2018 Wiley Periodicals, Inc.)

Bacterial polysaccharides are promising stimulants of protective functions in humans and animals. We investigated the ability of exopolysaccharide from the rhizobacterium Paenibacillus polymyxa CCM 1465 to induce nonspecific resistance factors in the macroorganism. We examined in vitro the effect of the exopolysaccharide, produced with different carbon sources, on the phagocytic activity of murine macrophages, on the generation of reactive oxygen species and of enzymes (acid phosphatase and myeloperoxidase), on the proliferation of murine splenocytes, and on the synthesis of proinflammatory cytokines [interleukin-1 (IL-1) and tumor necrosis factor α (TNF-α)] by human mononuclear cells. The exopolysaccharide promoted the phagocytosis of bacterial cells, activated metabolic processes in human and animal leukocytes, and moderately affected the production of TNF-α and IL-1β. The exopolysaccharides produced on media with glucose and sucrose differed in their effect on the immune cells, possibly owing to their different compositions, structures, and properties. The results validly indicate that the exopolysaccharide of P. polymyxa CCM 1465 promotes nonspecific immunity. Therefore, it can find application as a biologically active immunomodulatory substance.

Forty years ago, 12-oxophytodienoic acid (12-OPDA) was reported as a prostaglandin (PG)-like metabolite of linolenic acid found in extracts of flaxseed. Since then, numerous studies have determined the role of 12-OPDA in regulating plant immunity, seed dormancy, and germination. This review summarizes our current knowledge of the regulation of 12-OPDA synthesis in the chloroplast and 12-OPDA-dependent signaling in gene expression and targeting protein functions. We describe the properties of OPDA that are linked to the activities of PGs, which are derived from arachidonic acid and act as tissue hormones in animals, including humans. The similarity of OPDA with bioactive PGs is particularly evident for the most-studied cyclopentenone, PG 15-dPGJ2. In addition to chemical approaches towards 12-OPDA synthesis, bio-organic synthesis strategies for 12-OPDA and analogous substances have recently been established. The resulting availability of OPDA will aid the identification of additional effector proteins, help in elucidating the mechanisms of OPDA sensing and transmission, and will foster the analysis of the physiological responses to OPDA in plants. There is a need to determine the compartmentation and transport of 12-OPDA and its conjugates, over long distances as well as short. It will be important to further study OPDA in animal and human cells, for example with respect to beneficial anti-inflammatory and anti-cancer activities.

Cold temperatures restrict plant growth, geographical extension of plant species, and agricultural practices. This review deals with cold stress above freezing temperatures often defined as chilling stress. It focuses on the redox regulatory network of the cell under cold temperature conditions. Reactive oxygen species (ROS) function as the final electron sink in this network which consists of redox input elements, transmitters, targets, and sensors. Following an introduction to the critical network components which include nicotinamide adenine dinucleotide phosphate (NADPH)-dependent thioredoxin reductases, thioredoxins, and peroxiredoxins, typical laboratory experiments for cold stress investigations will be described. Short term transcriptome and metabolome analyses allow for dissecting the early responses of network components and complement the vast data sets dealing with changes in the antioxidant system and ROS. This review gives examples of how such information may be integrated to advance our knowledge on the response and function of the redox regulatory network in cold stress acclimation. It will be exemplarily shown that targeting the redox network might be beneficial and supportive to improve cold stress acclimation and plant yield in cold climate.

The structure of potential bacteriophage receptors located on cell walls of Gram-negative bacteria deposited at Belarusian collection of microorganisms was investigated. Studies by 1D and 2D 1 H and 13 C NMR spectroscopy enabled to elucidate the structure of the O-specific polysaccharides (OPS) constituting lipopolysaccharide (LPS) of some Pseudomonas species. The capacity of bacteriophage to adsorb to LPS molecules was tested., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Thiol-dependent redox regulation controls central processes in plant cells including photosynthesis. Thioredoxins reductively activate, for example, Calvin-Benson cycle enzymes. However, the mechanism of oxidative inactivation is unknown despite its importance for efficient regulation. Here, the abundant 2-cysteine peroxiredoxin (2-CysPrx), but not its site-directed variants, mediates rapid inactivation of reductively activated fructose-1,6-bisphosphatase and NADPH-dependent malate dehydrogenase (MDH) in the presence of the proper thioredoxins. Deactivation of phosphoribulokinase (PRK) and MDH was compromised in 2cysprxAB mutant plants upon light/dark transition compared to wildtype. The decisive role of 2-CysPrx in regulating photosynthesis was evident from reoxidation kinetics of ferredoxin upon darkening of intact leaves since its half time decreased 3.5-times in 2cysprxAB . The disadvantage of inefficient deactivation turned into an advantage in fluctuating light. Physiological parameters like MDH and PRK inactivation, photosynthetic kinetics and response to fluctuating light fully recovered in 2cysprxAB mutants complemented with 2-CysPrxA underlining the significance of 2-CysPrx. The results show that the 2-CysPrx serves as electron sink in the thiol network important to oxidize reductively activated proteins and represents the missing link in the reversal of thioredoxin-dependent regulation., Competing Interests: MV, KC, WT, ML, MG, HS, SM, KD No competing interests declared, (© 2018, Vaseghi et al.)

The ability of the litter-decomposing basidiomycete Stropharia rugosoannulata DSM 11372 to degrade a wide range of structurally different environmental pollutants such as polycyclic aromatic hydrocarbons (PAHs: phenanthrene, anthracene, fluorene, pyrene, and fluoranthene), synthetic anthraquinone dyes containing condensed aromatic rings, environmentally relevant alkylphenol and oxyethylated alkylphenol representatives, and oil was demonstrated within the present study. 9,10-Anthraquinone, phenanthrene-9,10-quinone, and 9-fluorenone were identified as products of anthracene, phenanthrene, and fluorene degradation, respectively. Fungal degradation was accompanied by the production of the ligninolytic enzymes: laccase and Mn peroxidase, suggesting their involvement in pollutant degradation. Extracellular polysaccharide(s) (EPS) and emulsifying compound(s) were concomitantly produced. EPS composed of mannose, glucose, and galactose was isolated from the cultivation medium, and its effects on catalytic properties of purified laccase from S. rugosoannulata (the dominating ligninolytic enzyme under the applied conditions) were studied. A simultaneous decrease of K M and V max values observed for the enzymatic oxidation of non-phenolic (2,2-azino-bis-(3-ethylbenzthiazoline-6-sulphonic acid) diammonium salt; ABTS) and phenolic compounds (2,6-dimethoxyphenol) in presence of EPS suggest an interaction of EPS and laccase resulting in a modulation of the catalytic performance of the enzyme, which has, to the best of our knowledge, not been reported before. In line with such a modulation, the laccase-catalyzed oxidation of natural aromatic compounds (veratryl alcohol, adlerol) and environmental pollutants (the alkylphenol representative nonylphenol, the diphenylmethane derivative bisphenol A, and the PAH representative anthracene) was found to be enhanced in presence of EPS. The relevance of such effects for real environmental processes and their implications remain to be investigated.

A new application of the photodynamic treatment (PDT) is presented for the opening of blood-brain barrier (BBB) and the brain clearing activation that is associated with it, including the use of gold nanoparticles as emerging photosensitizer carriers in PDT. The obtained results clearly demonstrate 2 pathways for the brain clearing: (1) using PDT-opening of BBB and intravenous injection of FITC-dextran we showed a clearance of this tracer via the meningeal lymphatic system in the subdural space; (2) using optical coherence tomography and intraparenchymal injection of gold nanorods, we observed their clearance through the exit gate of cerebral spinal fluid from the brain into the deep cervical lymph node, where the gold nanorods were accumulated. These data contribute to a better understanding of the cerebrovascular effects of PDT and shed light on mechanisms, underlying brain clearing after PDT-related opening of BBB, including clearance from nanoparticles as drug carriers., (© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The possibility of the registration of the interaction of the cells Azospirillum lipoferum Sp59b with the specific antibodies directly in the conducting suspensions by using an acoustic sensor was shown. The main element of the sensor is a piezoelectric resonator with a lateral electric field. The analysis is based on a comparison of the resonator's electrical impedance before and after the specific biological interaction between the cells and antibodies. By using this sensor one can detect and identify the bacterial cells directly in the buffer solution with the conductivity between 2.4 and 20 μS/cm. The minimum detectable concentration of the bacterial cells turned out to be ∼10 3  cells/ml and for a short time (less than 10 min). Also the possibility of the detection of the cells in the presence of the extraneous microflora was shown. The results provide the opportunities for the development of a new class of the methods for the analysis of the microbial cells in real-time directly in the buffer solution., (Copyright © 2018 Elsevier Inc. All rights reserved.)

O-specific polysaccharide was obtained by mild acid hydrolysis of the lipopolysaccharide of nitrogen-fixing bacterium Azospirillum fermentarium CC-LY743 T (IBPPM 578) and was studied by sugar analysis along with 1 H and 13 C NMR spectroscopy, including 1 H, 1 H COSY, TOCSY, ROESY, and 1 H, 13 C HSQC and HMBC experiments. The polysaccharide was found to be linear and to consist of alterating α-l-fucose and α-d-mannose residues in tetrasaccharide repeating units of the following structure: →2)-α-D-Manp-(1 → 3)-α-L-Fucp-(1 → 3)-α-D-Manp-(1 → 3)-α-L-Fucp-(1→., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Au, Ag, Se, and Si nanoparticles were synthesized from aqueous solutions of HAuCl 4 , AgNO 3 , Na 2 SeO 3 , and Na 2 SiO 3 with extra- and intracellular extracts from the xylotrophic basidiomycetes Pleurotus ostreatus , Lentinus edodes , Ganoderma lucidum , and Grifola frondosa . The shape, size, and aggregation properties of the nanoparticles depended both on the fungal species and on the extract type. The bioreduction of the metal-containing compounds and the formation rate of Au and Ag nanoparticles depended directly on the phenol oxidase activity of the fungal extracts used. The biofabrication of Se and Si nanoparticles did not depend on phenol oxidase activity. When we used mycelial extracts from different fungal morphological structures, we succeeded in obtaining nanoparticles of differing shapes and sizes. The cytotoxicity of the noble metal nanoparticles, which are widely used in biomedicine, was evaluated on the HeLa and Vero cell lines. The cytotoxicity of the Au nanoparticles was negligible in a broad concentration range (1-100 µg/mL), whereas the Ag nanoparticles were nontoxic only when used between 1 and 10 µg/mL., Competing Interests: The authors declare there are no competing interests.

We examined the effect of various concentrations of HAuCl 4 , AgNO 3 , Na 2 SeO 3 , Na 2 SiO 3 , and GeO 2 on mycelial growth of the soil basidiomycetes Agaricus bisporus and A. arvensis in submerged and solid media. Fungal mycelial extracts and cell-free culture filtrates were able to reduce ions of Au, Ag, Se, Si, and Ge compounds, forming Au 0 , Ag 0 , Se 0 , Si 0 /SiO 2 and Ge 0 /GeO 2 nanoparticles. The physical characteristics of the mycogenic nanoparticles differed depending on the species of Agaricus and the type of extract. Au nanospheres obtained with cell-free culture filtrates were of 2-5 nm diameter in A. bisporus and of 2-10 nm in A. arvensis. Nanoparticles produced by extracts of mycelia were several times larger and highly heterogenous. Ag nanoparticles produced by cell-free culture filtrates were spherical or irregular-shaped and agglomerated, whereas with extracts of mycelia, small homogenous nanospheres of 1-10 nm were formed. Se nanospheres obtained with cell-free culture filtrates were of 100-250 nm diameter in A. bisporus and of 150-550 nm diameter in A. arvensis. The particles synthesized with extracts of mycelia were of 40-140 nm in A. bisporus and of 100-250 nm in A. arvensis. Incubation of Na 2 SiO 3 with cell-free culture filtrates resulted in porous Si nanoparticles of 30-65 nm in A. bisporus and of 50-200 nm in A. arvensis. Ge nanoparticles synthesized by both Agaricus species were mostly spheres of 50-250 nm diameter., (Copyright © 2018 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.)

Modern techniques of next-generation sequencing (NGS) allow obtaining expression profile of all genes and provide an essential basis for characterizing metabolism in the organism of interest on a broad scale. An important condition for obtaining a demonstrative physiological picture using high throughput sequencing data is the availability of the genome sequence and its sufficient annotation for the target organism. However, a list of species with properly annotated genomes is limited. Transcriptome profiling is often performed in the so-called non-model organisms, which are those with unknown or poorly assembled and/or annotated genome sequences. The transcriptomes of non-model organisms are possible to investigate using algorithms of de novo assembly of the transcripts from sequences obtained as the result of RNA sequencing. A physiological interpretation of the data is difficult in this case because of the absence of annotation of the assembled transcripts and their classification by metabolic pathway and functional category. An algorithm for transcriptome profiling in non-model organisms was developed, and a transcriptome analysis was performed for the basidiomycete Lentinus edodes. The algorithm includes open access software and custom scripts and encompasses a complete analysis pipeline from the selection of cDNA reads to the functional classification of differentially expressed genes and the visualization of the results. Based on this algorithm, a comparative transcriptome analysis of the nonpigmented mycelium and brown mycelial mat was performed in L. edodes. The comparison revealed physiological differences between the two morphogenetic stages, including an induction of cell wall biogenesis, intercellular communication, ion transport, and melanization in the brown mycelial mat.

The dynamic and efficient coordination of primary photosynthetic reactions with leaf energization and metabolism under a wide range of environmental conditions is a fundamental property of plants involving processes at all functional levels. The present historical perspective covers 60 years of research aiming to understand the underlying mechanisms, linking major breakthroughs to current progress. It centers on the contributions of Ulrich Heber who had pioneered novel concepts, fundamental methods, and mechanistic understanding of photosynthesis. An important first step was the development of non-aqueous preparation of chloroplasts allowing the investigation of chloroplast metabolites ex vivo (meaning that the obtained results reflect the in vivo situation). Later on, intact chloroplasts, retaining their functional envelope membranes, were isolated in aqueous media to investigate compartmentation and exchange of metabolites between chloroplasts and external medium. These studies elucidated metabolic interaction between chloroplasts and cytoplasm during photosynthesis. Experiments with isolated intact chloroplasts clarified that oxygenation of ribulose-1.5-bisphosphate generates glycolate in photorespiration. The development of non-invasive optical methods enabled researchers identifying mechanisms that balance electron flow in the photosynthetic electron transport system avoiding its over-reduction. Recording chlorophyll a (Chl a) fluorescence allowed one to monitor, among other parameters, thermal energy dissipation by means of 'nonphotochemical quenching' of the excited state of Chl a. Furthermore, studies both in vivo and in vitro led to basic understanding of the biochemical mechanisms of freezing damage and frost tolerance of plant leaves, to SO 2 tolerance of tree leaves and dehydrating lichens and mosses.

Redox regulation, antioxidant defence, and reactive oxygen species (ROS) signalling are critical in performing and tuning metabolic activities. However, our concepts have mostly been developed for C3 plants since Arabidopsis thaliana has been the major model for research. Efforts to convert C3 plants to C4 to increase yield (such as IRRI's C4 Rice Project) entail a better understanding of these processes in C4 plants. Various photosynthetic enzymes that take part in light reactions and carbon reactions are regulated via redox components, such as thioredoxins as redox transmitters and peroxiredoxins. Hence, understanding redox regulation in the mesophyll and bundle sheath chloroplasts of C4 plants is of paramount importance: it appears impossible to utilize efficient C4 photosynthesis without understanding its exact redox needs and the regulation mechanisms used during light reactions. In this review, we discuss current knowledge on redox regulation in C3 and C4 plants, with special emphasis on the mesophyll and bundle sheath differences that are found in C4. In these two cell types in C4 plants, linear and cyclic electron transport in the chloroplasts operate differentially when compared to C3 chloroplasts, changing the redox needs of the cell. Therefore, our focus is on photosynthetic light reactions, ROS production dynamics, antioxidant defence, and thiol-based redox regulation, with the aim of providing an overview of our current knowledge.

Plants have evolved complex mechanisms to mitigate osmotic and ionic stress caused by high salinity. The effect of exogenous spermine (Spm) and spermidine (Spd) on defence responses of wheat seedlings under NaCl stress was investigated by measuring antioxidant enzyme activities and the transcript expression of corresponding genes. Exogenous Spm and Spd decreased the level of malondialdehyde, increased chlorophyll and proline contents, and modulated PSII activity in wheat seedlings under salt stress. Spermidine alleviated negative effects on CO2 assimilation induced by salt stress in addition to significantly increasing the activity and content of ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco). It appears Spd conferred salinity tolerance in wheat seedlings by enhancing photosynthetic capacity through regulation of gene expression and the activity of key CO2 assimilation enzymes. Exogenous Spm regulated activities of different antioxidant enzymes (catalase, glutathione reductase, dehydroascorbate reductase, ascorbate peroxidase, and superoxide dismutase) and efficiently modulate their transcription levels in wheat seedlings under salt stress. It is likely that Spm plays a key role in alleviating oxidative damage of salt stress by adjusting antioxidant enzyme activities in plants. In addition, exogenous Spd increased transcript level of spermine synthase under salt stress. Salinity stress also caused an increase in transcript levels of diamine oxidase (DAO) and polyamine oxidase (PAO). Exogenous Spd application resulted in a marked increase in free Spd and Spm contents under saline conditions. These results show that exogenous Spd and Spm effectively upregulated transcriptional levels of antioxidant enzyme genes and improved the defence response of plants under salt stress.

Raman spectra of liquid water and ice were measured at different temperatures. The intensity of the band assigned to bending vibrations of water molecules was observed to decrease at the liquid-to-solid transition, while the Raman line near 2200cm -1 showed an anomalously high intensity in the solid phase. A tetrahedral model was used for computer analysis of the observed spectral changes. Quantum-chemical calculations of the structure, normal vibrations and Raman spectra in the harmonic approximation, as well as frequencies and intensities of some vibrations using 1D and 2D potential energy surfaces, were carried out using B3LYP with the cc-pVTZ basis set. The influence of the number of hydrogen bonds on the frequency and Raman activity of the bending vibrations was analyzed. The possibility of hydrogen bond weakening upon excitation of the combined bending-rocking vibration due to the large amplitude of this vibration is considered., (Copyright © 2018 Elsevier B.V. All rights reserved.)

A sensor based on microstructured waveguides (MWGs) with a hollow core inner surface covered with polyelectrolyte-layer-stabilized gold nanostars was developed for the SERS sensing of dissolved analytes. A polyelectrolyte-layer coating over the inner surface of glass cladding served as a spacer, reducing nonlinear optical effects in the glass near plasmonic hotspots of nanoparticles, as a stabilizing agent for thermodynamically unstable gold nanostars and as an optical coating for the fine-tuning of MWG bandgaps. This approach can be used to construct different kinds of SERS sensors for dissolved analytes, providing conservation, the prevention of coagulation, and the drying of a liquid sample for the time required to record the signal.

The degradation of two isomeric three-ringed polycyclic aromatic hydrocarbons by the white rot fungus Pleurotus ostreatus D1 and the litter-decomposing fungus Agaricus bisporus F-8 was studied. Despite some differences, the degradation of phenanthrene and anthracene followed the same scheme, forming quinone metabolites at the first stage. The further fate of these metabolites was determined by the composition of the ligninolytic enzyme complexes of the fungi. The quinone metabolites of phenanthrene and anthracene produced in the presence of only laccase were observed to accumulate, whereas those formed in presence of laccase and versatile peroxidase were metabolized further to form products that were further included in basal metabolism (e.g. phthalic acid). Laccase can catalyze the initial attack on the PAH molecule, which leads to the formation of quinones, and that peroxidase ensures their further oxidation, which eventually leads to PAH mineralization. A. bisporus, which produced only laccase, metabolized phenanthrene and anthracene to give the corresponding quinones as the dominant metabolites. No products of further utilization of these compounds were detected. Thus, the fungi's affiliation with different ecophysiological groups and their cultivation conditions affect the composition and dynamics of production of the ligninolytic enzyme complex and the completeness of PAH utilization., (Copyright © 2018 British Mycological Society. Published by Elsevier Ltd. All rights reserved.)

Oxidation products of the poly-unsaturated fatty acids (PUFAs) arachidonic acid, α-linolenic acid and docosahexaenoic acid are bioactive in plants and animals as shown for the cyclopentenones prostaglandin 15d-PGJ 2 and PGA 2 , cis-(+)-12-oxophytodienoic acid (12-OPDA), and 14-A-4 neuroprostane. In this study an inexpensive and simple enzymatic multi-step one-pot synthesis is presented for 12-OPDA, which is derived from α-linolenic acid, and the analogous docosahexaenoic acid (DHA)-derived cyclopentenone [(4Z,7Z,10Z)-12-[[-(1S,5S)-4-oxo-5-(2Z)-pent-2-en-1yl]-cyclopent-2-en-1yl] dodeca-4,7,10-trienoic acid, OCPD]. The three enzymes utilized in this multi-step cascade were crude soybean lipoxygenase or a recombinant lipoxygenase, allene oxide synthase and allene oxide cyclase from Arabidopsis thaliana. The DHA-derived 12-OPDA analog OCPD is predicted to have medicinal potential and signaling properties in planta. With OCPD in hand, it is shown that this compound interacts with chloroplast cyclophilin 20-3 and can be metabolized by 12-oxophytodienoic acid reductase (OPR3) which is an enzyme relevant for substrate bioactivity modulation in planta., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Vibrational (Fourier transform infrared (FTIR) and Raman) spectroscopic techniques can provide unique molecular-level information on the structural and compositional characteristics of complicated biological objects. Thus, their applications in microbiology and related fields are steadily increasing. In this communication, biogenic selenium nanoparticles (Se NPs) were obtained via selenite (SeO 3 ) reduction by the bacterium Azospirillum thiophilum (strain VKM B-2513) for the first time, using an original methodology for obtaining extracellular NPs. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) showed the Se NPs to have average diameters within 160-250nm; their zeta potential was measured to be minus 18.5mV. Transmission FTIR spectra of the Se NPs separated from bacterial cells showed typical proteinacious, polysaccharide and lipid-related bands, in line with TEM data showing a thin layer covering the Se NPs surface. Raman spectra of dried Se NPs layer in the low-frequency region (under 500cm 2- ) reduction by the bacterium Azospirillum thiophilum (strain VKM B-2513) for the first time, using an original methodology for obtaining extracellular NPs. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) showed the Se NPs to have average diameters within 160-250nm; their zeta potential was measured to be minus 18.5mV. Transmission FTIR spectra of the Se NPs separated from bacterial cells showed typical proteinacious, polysaccharide and lipid-related bands, in line with TEM data showing a thin layer covering the Se NPs surface. Raman spectra of dried Se NPs layer in the low-frequency region (under 500cm -1 down to 150cm -1 ) showed a single very strong band with a maximum at 250cm -1 at half intensity), can be attributed to amorphous elementary Se. Thus, a combination of FTIR and Raman spectroscopic approaches is highly informative in non-destructive analysis of structural and compositional properties of biogenic Se NPs.-1 at half intensity), can be attributed to amorphous elementary Se. Thus, a combination of FTIR and Raman spectroscopic approaches is highly informative in non-destructive analysis of structural and compositional properties of biogenic Se NPs., (Copyright © 2017 Elsevier B.V. All rights reserved.)

The influence of the chirality of chitosan ascorbate on the gelation kinetics and the properties of hybrid silicon-chitosan-containing glycerohydrogels were studied with a deep estimation of the stereospecificity of chitosan polysalts with l- and d-ascorbic acid diastereomers and their biological effects. It has been established that l- and d-diastereomerically enriched chitosan ascorbates are characterized by a positive Cotton effect and differ in the wavelength of the maximum of the dichroic band (250 and 240 nm), as well as in the values of its specific ellipticity (21.8 × 10⁵ and 39.2 × 10⁵ deg·mL·dm -1 ·g -1 ), the sign of specific optical rotation (+ and -), the type of dispersion curves (anomalous and smooth), as well as the condensed phase morphology (anisodiametric particles with optical anisotropy and confocal domains of spherical shape, respectively). In the biomimetic sol-gel synthesis of silicon-chitosan-containing glycerohydrogels using silicon tetraglycerolate as a precursor, it was found that chitosan d-ascorbate retarded gelation. Thin congruent plates obtained from the corresponding glycerohydrogels based on chitosan d-ascorbate have higher mechanical strength and elasticity under uniaxial stretching and lower values of Young's modulus. It has been shown that the systems based on chitosan d-ascorbate show the greatest antibacterial activity against Staphylococcus aureus 209P and Escherichia coli 113-13 and significantly promote the viability of normal human dermal fibroblasts. The results of our assessment of the biological properties of chitosan polysalts are unexpected, since ascorbic acid exhibits biological activity as its l-isomer only., Competing Interests: The authors declare no conflict of interest.

Azospirillum brasilense has the ability of swimming and swarming motility owing to the work of a constitutive polar flagellum and inducible lateral flagella, respectively. The interplay between these flagellar systems is poorly understood. One of the key elements of the flagellar export apparatus is the protein FlhB. Two predicted flhB genes are present in the genome of A. brasilense Sp245 (accession nos. HE577327-HE577333). Experimental evidence obtained here indicates that the chromosomal coding sequence (CDS) AZOBR&#95;150177 (flhB1) of Sp245 is essential for the production of both types of flagella. In an flhB1:: Omegon-Km mutant, Sp245.1063, defects in polar and lateral flagellar assembly and motility were complemented by expressing the wild-type flhB1 gene from plasmid pRK415. It was found that Sp245.1063 lost the capacity for slight but statistically significant decrease in mean cell length in response to transfer from solid to liquid media, and vice versa; in the complemented mutant, this capacity was restored. It was also shown that after the acquisition of the pRK415-harbored downstream CDS AZOBR&#95;150176, cells of Sp245 and Sp245.1063 ceased to elongate on solid media. These initial data suggest that the AZOBR&#95;150176-encoded putative multisensory hybrid sensor histidine kinase-response regulator, in concert with FlhB1, plays a role in morphological response of azospirilla to changes in the hardness of a milieu.

The impact of selenium biocomposites obtained from the medicinal macrobasidiomycetes Ganoderma lucidum, Grifola umbellata, Laetiporus sulphureus, Lentinula edodes, and Pleurotus ostreatus on the viability and biofilm formation capability of the phytopathogenic Gram-positive bacterium Clavibacter michiganensis ssp. sepedonicus (Spieck. et Kotth.) (Cms) was studied. Impairment of bacterial cell viability resulting from their incubation with biocomposites was shown. The decisive role of the composites' selenium component on the biological activity under question was established. The dependence of antimicrobial effect of the selenium-containing specimen on the mushroom systematic position was revealed. The maximal activity was found for the biocomposites based on the extracellular metabolites of L. edodes and G. lucidum. When the biopolymer specimen of fungal origin was added to bacterial suspension, the Cms capability of forming biofilms was found to be distinctly dependent of the biocomposite type, and it was substantially reduced in a number of cases.

Retrograde signals from the chloroplast control expression of nuclear genes. A large fraction of these genes is affected rapidly upon light intensity shifts. This study was designed to address the interdependence of signaling pathways involved in the rapid high light response and redox and reactive oxygen species signaling by exploiting the glutathione and ascorbate deficient mutants pad2 and vtc1. In the first set of experiments the transcriptional response of the two transcription factors ERF6 and ERF105 that had previously been shown to rapidly respond to light was shown to be deregulated in the pad2 mutant but not in the vtc1 background. The transcriptional response after combining the low-to-high light transfer with methylviologen pretreatment further demonstrated the significance of glutathione in strongly modulating the retrograde response. Transcripts encoding small heat shock proteins (HSP17.4, HSP176a, HSP20-like1 and HSP20-like2) and the lipid transfer protein LTP3 were taken as markers responding to the combinatorial treatment in wild type, and most strongly in pad2 in high light or upon methylviologen treatment. A correlation with H 2 O 2 accumulation was not observed. It is concluded that glutathione-dependent processes participate in light-triggered rapid gene regulation independent on cellular H 2 O 2 ., (© 2017 Scandinavian Plant Physiology Society.)

Significance: Peroxiredoxins (Prxs) are thiol peroxidases with multiple functions in the antioxidant defense and redox signaling network of the cell. Our progressing understanding assigns both local and global significance to plant Prxs, which are grouped in four Prx types. In plants they are localized to the cytosol, mitochondrion, plastid, and nucleus. Antioxidant defense is fundamentally connected to redox signaling, cellular communication, and acclimation. The thiol-disulfide network is central part of the stress sensing and processing response and integrates information input with redox regulation. Recent Advances: Prxs function both as redox sensory system within the network and redox-dependent interactors. The processes directly or indirectly targeted by Prxs include gene expression, post-transcriptional reactions, including translation, post-translational regulation, and switching or tuning of metabolic pathways, and other cell activities. The most advanced knowledge is available for the chloroplast 2-CysPrx wherein recently a solid interactome has been defined. An in silico analysis of protein structure and coexpression reinforces new insights into the 2-CysPrx functionality., Critical Issues: Up to now, Prxs often have been investigated for local properties of enzyme activity. In vitro and ex vivo work with mutants will reveal the ability of Prxs to interfere with multiple cellular components, including crosstalk with Ca 2+ -linked signaling pathways, hormone signaling, and protein homeostasis., Future Directions: Complementation of the Prxs knockout lines with variants that mimic specific states, namely devoid of peroxidase activity, lacking the oligomerization ability, resembling the hyperoxidized decamer, or with truncated C-terminus, should allow dissecting the roles as thiol peroxidase, oxidant, interaction partner, and chaperone. Antioxid. Redox Signal. 28, 609-624.

The electro-acoustical sensor for the real-time identification of the bacteriophage FAl-SR65 is described. The polyclonal antibodies specific to the bacteriophage FAl-SR65 were for the first time obtained, and the possibility of their application to the bacteriophage detection by using the electro-acoustical method of analysis was also studied for the first time. The electro-acoustical sensor was based on the lateral electric field excited piezoelectric resonator. The frequency dependences of the real and imaginary parts of the electrical impedance of such a resonator, loaded with the virus-antibody suspension, significantly differed from those measured for the same resonator with the same virus suspension but without antibodies (control). The limit for the reliable bacteriophage detection during their interaction with the antibodies (sensitivity level) was determined to be 10 6 phages ml -1 . The obtained results demonstrate the possibility to record the bacteriophage-antibody interactions and can be used as the basis for the development of the biological sensor for the quantitative virus detection., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Azospirillum brasilense can swim and swarm owing to the activity of a constitutive polar flagellum (Fla) and inducible lateral flagella (Laf), respectively. Experimental data on the regulation of the Fla and Laf assembly in azospirilla are scarce. Here, the coding sequence (CDS) AZOBR&#95;p1160043 (fabG1) for a putative 3-oxoacyl-[acyl-carrier protein (ACP)] reductase was found essential for the construction of both types of flagella. In an immotile leaky Fla - Laf - fabG1::Omegon-Km mutant, Sp245.1610, defects in flagellation and motility were fully complemented by expressing the CDS AZOBR&#95;p1160043 from plasmid pRK415. When pRK415 with the cloned CDS AZOBR&#95;p1160045 (fliC) for a putative 65.2 kDa Sp245 Fla flagellin was transferred into the Sp245.1610 cells, the bacteria also became able to assemble a motile single flagellum. Some cells, however, had unusual swimming behavior, probably because of the side location of the organelle. Although the assembly of Laf was not restored in Sp245.1610 (pRK415-p1160045), this strain was somewhat capable of swarming motility. We propose that the putative 3-oxoacyl-[ACP] reductase encoded by the CDS AZOBR&#95;p1160043 plays a role in correct flagellar location in the cell envelope and (or) in flagellar modification(s), which are also required for the inducible construction of Laf and for proper swimming and swarming motility of A. brasilense Sp245.

The result of monitoring of natural vegetation growing on oil-contaminated (2.0-75.6 g/kg) and uncontaminated (0.04-2.0 g/kg) soils of a petroleum refinery for a period of 13 years is presented. Floristic studies showed that the families Poaceae, Asteraceae, Fabaceae, and eventually Brassicaceae were predominant in the vegetation cover of both types of soils. Over time, the projective vegetation cover of the contaminated sites increased from 46 to 90%; the species diversity increased twofold: in the ecological-cenotic structure of the flora, the number of ruderal plant species decreased; and the number of steppe, i.e., zonal, plant species increased. Using 62 dominant plant species, we conducted a field study of plant characteristics such as resistance to oil pollution, the ability to enrich the rhizosphere soil with microorganisms and bioavailable mineral nitrogen, and reduction of the concentration of petroleum hydrocarbons. The results enable us to characterize the phytoremediation potential (PRP) of the native plants and identify species that, probably, played a key role in the natural restoration of oil-contaminated soils. Statistical analysis showed correlations between the PRP constituents, and the leading role of rhizosphere microorganisms in the rhizodegradation of petroleum hydrocarbons was proven. A conditional value of PRP was proposed which allowed the investigated plants to be ranked in 11 classes. The study of a large sample of plant species showed that some plants held promise for the use in reclamation of soils in arid steppe zone, and that other species can be used for the rehabilitation of saline soils and semideserts.

Gold nanoparticles (GNPs) are advantageous as an adjuvant in the design of effective vaccines and in the preparation of high-affinity antibodies to haptens and complete antigens. Another method of activating immunocompetent cells with colloidal gold is to conjugate GNPs with CpG oligodeoxynucleotides (ODNs). We examined how the size and shape of GNPs and various combinations of GNPs and CpG ODNs 1826 affect the immune response. When animals were injected with a model antigen (BSA) coupled to gold nanospheres (diameters, 15 and 50nm), nanorods, nanoshells, and nanostars, the titers of the resultant antibodies differed substantially. The antibody titers decreased in the sequence GNPs-50nm>GNPs-15nm>nanoshells>nanostars>nanorods>native BSA. We conclude that 50 and 15nm gold nanospheres are the optimal antigen carrier and adjuvant for immunization. The highest titer of anti-BSA antibodies was detected in the blood serum of mice immunized simultaneously with BSA-GNP and CpG-GNP conjugates., (Copyright © 2017 Elsevier B.V. All rights reserved.)