Drought is one of the major stress factors affecting the growth and development of plants. In this context, drought-related losses of crop plant productivity impede sustainable agriculture all over ...the world. In general, plants respond to water deficits by multiple physiological and metabolic adaptations at the molecular, cellular, and organism levels. To understand the underlying mechanisms of drought tolerance, adequate stress models and arrays of reliable stress markers are required. Therefore, in this review we comprehensively address currently available models of drought stress, based on culturing plants in soil, hydroponically, or in agar culture, and critically discuss advantages and limitations of each design. We also address the methodology of drought stress characterization and discuss it in the context of real experimental approaches. Further, we highlight the trends of methodological developments in drought stress research, i.e., complementing conventional tests with quantification of phytohormones and reactive oxygen species (ROS), measuring antioxidant enzyme activities, and comprehensively profiling transcriptome, proteome, and metabolome.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Rationale
The polyprenols are involved in some essential biosynthetic pathways and serve as ubiquitous components of cellular membranes, so their fingerprinting in natural samples is of great ...interest. Previous studies indicate that due to the high hydrophobicity of polyprenols their direct analysis by mass spectrometry with soft ionization techniques may be difficult and require preliminary off‐line derivatization. Hence, a method for rapid and sensitive screening of polyprenols is required.
Methods
A combination of thin‐film chemical deposition and matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOFMS) was used for analysis of the polyprenol profile of Abies sibirica L. extract. Polyprenol‐based monolayers were formed at the interphase of aqueous barium acetate solution, supplemented with 2,5‐dihydroxybenzoic acid, and an n‐hexane solution of polyprenols directly on a MALDI target plate.
Results
Peaks corresponding to M − H + Ba+ ions were observed in the MALDI‐TOF mass spectra of polyprenols. A total of nine polyprenol homologues were identified with a polyprenol of 16 isoprene units dominating. The limit of detection was established at the level of 6 pg. Possible mechanisms of formation of M − H + Ba+ ions of polyprenols were discussed.
Conclusions
The proposed approach can be suitable for high‐throughput screening of polyprenols in biological samples of different origin due to easy sample preparation and high sensitivity.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Metabolic fingerprinting is a powerful analytical technique, giving access to high-throughput identification and relative quantification of multiple metabolites. Because of short analysis times, ...matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) is the preferred instrumental platform for fingerprinting, although its power in analysis of free fatty acids (FFAs) is limited. However, these metabolites are the biomarkers of human pathologies and indicators of food quality. Hence, a high-throughput method for their fingerprinting is required. Therefore, here we propose a MALDI-TOF-MS method for identification and relative quantification of FFAs in biological samples of different origins. Our approach relies on formation of monomolecular Langmuir films (LFs) at the interphase of aqueous barium acetate solution, supplemented with low amounts of 2,5-dihydroxybenzoic acid, and hexane extracts of biological samples. This resulted in detection limits of 10–13–10–14 mol and overall method linear dynamic range of at least 4 orders of magnitude with accuracy and precision within 2 and 17%, respectively. The method precision was verified with eight sample series of different taxonomies, which indicates a universal applicability of our approach. Thereby, 31 and 22 FFA signals were annotated by exact mass and identified by tandem MS, respectively. Among 20 FFAs identified in Fucus algae, 14 could be confirmed by gas chromatography-mass spectrometry.
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IJS, KILJ, NUK, PNG, UL, UM
•Immobilization of Ni2+ ions at the inner surface of monodisperse spherical mesoporous SiO2 particles.•Monodisperse spherical mesoporous SiO2/Ni particles of 500±25nm diameter as metal affinity ...sorbents.•Diclofenac extraction by IMAC technique.•Addition of PFOS to IMAC eluents improves the recovery degree of diclofenac (up to 98%).•The obtained thermodynamics analysis data indicate the chemical nature of the DCF interaction with the surface of the sorbent.
In this research, a novel IMAC sorbent with high specificity for chlorine-containing compounds was developed. Ni-functionalized monodisperse spherical mesoporous silica particles of 500±25nm diameter were synthesized and their metal affinity properties were studied with the use of diclofenac as the model substance. The particles were aggregatively stable in the pH range of 3–12. The sorbent demonstrated a high adsorption capacity (0.60±0.06μg of DCF per 1mg of the sorbent) and high adsorption/desorption rate (20 and 5min was enough for the sorbent saturation and desorption of DCF, correspondingly). A mixture of eluents with addition of PFOS providing the almost complete recovery (98%) of diclofenac was first proposed. The monodispersity and the high sedimentation and aggregative stability of the particles provide the formation of a stable hydrosol even under ultrasound treatment which makes the mSiO2/Ni particles suitable for batch chromatography.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
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•Droplet-free electrospraying allows deposition of nano-metal oxide on a steel plate.•Stable coating of the target surface with the oxides of Fe, Co, Ni, Cu is achieved.•Diclofenac ...oxidation products interact with cysteine residues in human globin.•Human globin adducts with diclofenac metabolites are enriched in on-target workflow.
The strategies for integration of different orthogonal analytical procedures directly on the targets for matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) are being intensively developed over the last two decades. This methodology, which is usually referred to as “lab-on-a-plate”, proved to be the method of choice for fast and reproducible sample preparation prior to MALDI-MS analysis. To date, numerous “lab-on-a-plate” protocols for enrichment of phosphorylated peptides by metal oxide affinity chromatography (MOAC) are established. However, despite this, a straightforward and efficient implementation of the on-target workflow for selective MOAC-based enrichment of the protein adducts formed by halogen-containing xenobiotics is still missing. Therefore, here we present a successful application of droplet-free electrospraying under normal conditions for efficient deposition of metal oxide (MeOx) nanoparticles on the MALDI target. Here we employed oxides of four transition metals – Fe(III), Co(II/III), Ni(II) and Cu(II). These materials were synthesized by the microwave-assisted sol–gel approach and electrosprayed post-synthetically on a stainless steel MALDI target. Thus, stable coating of the target could be achieved without heating and any damage of its surface. As a case study, MALDI targets were deposited with MeOx nanoparticles, and human globin adducts with in vitro generated diclofenac (DCL) metabolites were enriched on spot from the tryptic digests of the protein treated with DCL oxidation mixture. This extraction procedure gave access to efficient, selective and reliable identification of the human globin adduct with decarboxylation oxidation product of DCL. The developed approach appears to be promising for in situ enrichment of halogen-containing adducts of proteins due to simplifying the sample treatment and minimizing sample losses.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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The UV-induced photocatalytic oxidation in the presence of TiO2 nanoparticles (UV/TiO2-PCO) is a more adequate approach than electrochemical oxidation to simulate the oxidative ...metabolism of diclofenac based on the comparative analysis of oxidation products using high-resolution tandem mass spectrometry. A simple and fast high-throughput technique is proposed for modeling the oxidative metabolism, which involves UV/TiO2-PCO performed directly on a MALDI target and subsequent analysis by matrix-assisted laser desorption/ionization mass spectrometry. The ranges and yields of diclofenac oxidation products obtained by the conventional bulk UV/TiO2-PCO and the proposed on-target version are in excellent agreement.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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