Oksana Sytar

Low PSI content limits the photoprotection of PSI and PSII in early growth stages of chlorophyll b -deficient wheat mutant lines

In vivo analyses of electron and proton transport-related processes as well as photoprotective responses were carried out at different stages of growth in chlorophyll b (Chl b)-deficient mutant lines (ANK-32A and ANK-32B) and wild type (WT) of wheat (Triticum aestivum L.). In addition to a high Chl a–b ratio, ANK mutants had a lower content of photo-oxidizable photosystem I (PSI, Pm), and several parameters indicated a low PSI/PSII ratio. Moreover, simultaneous measurements of Chl fluorescence and P700 indicated a shift of balance between redox poise of the PSII acceptor side and the PSII donor side, with preferential reduction of the plastoquinone pool, resulting in an over reduced PSI acceptor side (high ΦNA values). This was the probable reason for PSI inactivation observed in the ANK mutants, but not in WT. In later growth phases, we observed partial relief of “chlorina symptoms,” toward WT. Measurements of ΔA520 decay confirmed that, in early growth stages, the ANK mutants with low PSI content had a limited capacity to build up the transthylakoid proton gradient (ΔpH) needed to trigger non-photochemical quenching (NPQ) and to regulate the electron transport by cytochrome b6/f. Later, the increase in the PSI/PSII ratio enabled ANK mutants to reach full NPQ, but neither over reduction of the PSI acceptor side nor PSI photoinactivation due to imbalance between the activity of PSII and PSI was mitigated. Thus, our results support the crucial role of proper regulation of linear electron transport in the protection of PSI against photoinhibition. Moreover, the ANK mutants of wheat showing the dynamic developmental changes in the PSI/PSII ratio are presented here as very useful models for further studies.

Impact of Metal and Metal Oxide Nanoparticles on Plant: A Critical Review

An increasing need of nanotechnology in various industries may cause a huge environment dispersion of nanoparticles in coming years. A concern about nanoparticles interaction with flora and fauna is raised due to a growing load of it in the environment. In recent years, several investigators have shown impact of nanoparticles on plant growth and their accumulation in food source. This review examines the research performed in the last decade to show how metal and metal oxide nanoparticles are influencing the plant metabolism. We addressed here, the impact of nanoparticle on plant in relation to its size, concentration, and exposure methodology. Based on the available reports, we proposed oxidative burst as a general mechanism through which the toxic effects of nanoparticles are spread in plants. This review summarizes the current understanding and the future possibilities of plant-nanoparticle research.

The application of multiplex fluorimetric sensor for the analysis of flavonoids content in the medicinal herbs family Asteraceae, Lamiaceae, Rosaceae

BackgroundThe aim of our research work was to quantify total flavonoid contents in the leaves of 13 plant species family Asteraceae, 8 representatives of family Lamiaceae and 9 plant species belonging to family Rosaceae, using the multiplex fluorimetric sensor. Fluorescence was measured using optical fluorescence apparatus Multiplex(R) 3 (Force-A, France) for non-destructive flavonoids estimation. The content of total flavonoids was estimated by FLAV index (expressed in relative units), that is deduced from flavonoids UV absorbing properties.ResultsAmong observed plant species, the highest amount of total flavonoids has been found in leaves of Helianthus multiflorus (1.65 RU) and Echinops ritro (1.27 RU), Rudbeckia fulgida (1.13 RU) belonging to the family Asteraceae. Lowest flavonoid content has been observed in the leaves of marigold (Calendula officinalis) (0.14 RU) also belonging to family Asteraceae. The highest content of flavonoids among experimental plants of family Rosaceae has been estimated in the leaves of Rosa canina (1.18 RU) and among plant species of family Lamiaceae in the leaves of Coleus blumei (0.90 RU).ConclusionsThis research work was done as pre-screening of flavonoids content in the leaves of plant species belonging to family Asteraceae, Lamiaceae and Rosaceae. Results indicated that statistically significant differences (P > 0.05) in flavonoids content were observed not only between families, but also among individual plant species within one family.

Applying hyperspectral imaging to explore natural plant diversity towards improving salt stress tolerance.

Salinity represents an abiotic stress constraint affecting growth and productivity of plants in many regions of the world. One of the possible solutions is to improve the level of salt resistance using natural genetic variability within crop species. In the context of recent knowledge on salt stress effects and mechanisms of salt tolerance, this review present useful phenomic approach employing different non-invasive imaging systems for detection of quantitative and qualitative changes caused by salt stress at the plant and canopy level. The focus is put on hyperspectral imaging technique, which provides unique opportunities for fast and reliable estimate of numerous characteristics associated both with various structural, biochemical and physiological traits. The method also provides possibilities to combine plant and canopy analyses with a direct determination of salinity in soil. The future perspectives in salt stress applications as well as some limits of the method are also identified.

Comparative analysis of bioactive phenolic compounds composition from 26 medicinal plants

Bioactive phenolic compounds are powerful antioxidants in traditionally used medicinal and industrial crop plants and have attracted increased interest in the last years in their application and role in non-destructive methodology for pre-screening analysis of some stress factors. In this study the qualitative target was linked with future possible applications of received data for improving non-destructive methodology as well as for improving existing knowledge regarding antioxidant content in some plant species. Comparative analysis of total phenolics, flavonoid contents, phenolic acid composition, and antioxidant activity in known east central Europe medicinal and industrial crop plants of 26 species of families Asteraceae, Rosaceae and Lamiaceae was done. Among the investigated leaf extracts the highest total phenolic, total flavonoid contents and antioxidant activity have been seen for Stachys byzantine L. (Lamiaceae), Calendula officinalis L. (Asteraceae) and for Potentilla recta L. (Rosaceae). The highest syringic acid content has been found in the leaf extracts of plant family Asteraceae – in the range from 0.782 to 5.078 mg g−1 DW. The representative’s family Rosaceae has a higher content of p-anisic acid in the range 0.334–3.442 mg g−1DW compared to the leaf extracts of families Lamiaceae and Asteraceae. The comparative study showed significant differences of content of phenolic acids in the leaf extracts of different representative’s families Rosaceae, Asteraceae and Lamiaceae. We suggest that the presence of some phenolic acids can be used as a possible marker for family botanical specifications of representative families Asteraceae and Rosaceae. It was supposed that some pharmacological effects can be connected with the analyzed data.

Free Radicals Scavenging Capacity, Antidiabetic and Antihypertensive Activities of Flavonoid-Rich Fractions from Leaves of Trichilia emetica and Opilia amentacea in an Animal Model of Type 2 Diabetes Mellitus.

Trichilia emetica and Opilia amentacea traditional Burkinabe medicinal plants were investigated to determine their therapeutic potential to inhibit key enzymes in carbohydrate metabolism, which has relevance to the management of type 2 diabetes. In vitro and in vivo antioxidant and antihypertensive potential and antilipidemia and antihyperglycemia activities in an animal model of type 2 diabetes mellitus have been studied. The antioxidant activity of the flavonoids from leaves of Trichilia emetica and Opilia amentacea has been evaluated using β-carotene-linoleic acid system, 1,1-diphenyl-2-picrylhydrazyl inhibitory activity, chelation of iron (II) ions, and lipid peroxidation which showed more pronounced antioxidant capacities of Trichilia emetica. Total cholesterol concentrations decreased in an animal model of type 2 diabetes mellitus under effects of flavonoid-rich fractions from leaves of Trichilia emetica and Opilia amentacea has been observed. Extract of flavonoid-rich fractions from Trichilia emetica shown maximum radical scavenging activity and possessed marked antiamylase activity which may be due to the presence of certain secondary metabolites. Suggested better antihyperglycemia, antilipidemia, and antihypertensive properties of flavonoid-rich fractions from Trichilia emetica compared to the extract of Opilia amentacea are demonstrating antidiabetic potential of Trichilia emetica as therapeutic targets for the management of type 2 diabetes.

Antidiarrheal and antimicrobial profiles extracts of the leaves from Trichilia emetica Vahl. (Meliaceae)

Objective: To evaluate anti-diarrhoeal and antimicrobial activities of the bioactive fraction of Trichilia emetica in order to provide a scientific basis for the management of gastroenteritis in Burkina Faso. Methods: To do this, polyphenols content of extract and fractions were investigated. FolinCiocalteu, AlCl3 methods and tannic acid respectively were used for polyphenols content. The in vivo antidiarrhoeal activity was done using Swiss albino mice of both sexes. In vitro antimicrobial activity (disc-diffusion assay, minimum inhibitory concentration and minimum microbicidal concentration or minimal bactericidal concentration) was assessed using seven bacteria strains (Gram-negative and Gram-positive). Results: About our study, it was found that ethyl acetate fraction effective attenuation factior (EAF) elicits the higher total phenolics and total flavonoids contents compared to the extracts of leaves of Trichilia emetica. EAF of Trichilia emetica Vahl., has positive effects in a dose dependent manner against diarrhoea induced by castor oil in experimental mice. The bioactive fraction also showed good antimicrobial activity against all tested Gram-negative and Grampositive bacteria strains. It was shown that experimental bacteria strains were more sensitive to the EAF effect compared to the ciprofloxacin. Conclusions: The obtained results allow justifying the traditional uses of Trichilia emetica and possess good antidiarrhoeal and antimicrobial activities of EAF from Trichilia emetica. Results of the present study have clearly supported the utilization of Trichilia emetica in Burkina Faso traditional medicine.

Strategies to Mitigate the Salt Stress Effects on Photosynthetic Apparatus and Productivity of Crop Plants

Soil salinization represents one of the major limiting factors of future increase in crop production through the expansion or maintaining of cultivation area in the future. High salt levels in soils or irrigation water represent major environmental concerns for agriculture in semiarid and arid zones. Recent advances in research provide great opportunities to develop effective strategies to improve crop salt tolerance and yield in different environments affected by the soil salinity. It was clearly demonstrated that plants employ both the common adaptative responses and the specific reactions to salt stress. The review of research results presented here may be helpful to understand the physiological, metabolic, developmental, and other reactions of crop plants to salinity, resulting in the decrease of biomass production and yield. In addition, the chapter provides an overview of modern studies on how to mitigate salt stress effects on photosynthetic apparatus and productivity of crop plants with the help of phytohormones, glycine betaine, proline, polyamines, paclobutrazol, trace elements, and nanoparticles. To understand well these effects and to discover new ways to improve productivity in salinity stress conditions, it is necessary to utilize efficiently possibilities of promising techniques and approaches focused on improvement of photosynthetic traits and photosynthetic capacity, which determines yield under salt stress conditions.

Effect of chlorocholine chlorid on phenolic acids accumulation and polyphenols formation of buckwheat plants

BackgroundEffect of chlorocholine chloride (CCC) on phenolic acids composition and polyphenols accumulation in various anatomical parts (stems, leaves and inflorescences) of common buckwheat (Fagopyrum esculentum Moench) in the early stages of vegetation period were surveyed.ResultsTreatment of buckwheat seeds with 2% of CCC has been increased content of total phenolics in the stems, leaves and inflorescences. On analyzing the different parts of buckwheat plants, 9 different phenolic acids – vanilic acid, ferulic acid, trans-ferulic acid, chlorogenic acid, salycilic acid, cinamic acid, p-coumaric acid, p-anisic acid, methoxycinamic acid and catechins were identified. The levels of identified phenolic acids varied not only significantly among the plant organs but also between early stages of vegetation period. Same changes as in contents of chlorogenic acid, ferulic acid, trans-ferulic acid were found for content of salycilic acid. The content of these phenolic acids has been significant increased under effect of 2% CCC treatment at the phase I (formation of buds) in the stems and at the phase II (beginning of flowering) in the leaves and then inflorescences respectively. The content of catechins as potential buckwheat antioxidants has been increased at the early stages of vegetation period after treatment with 2% CCC.ConclusionsThe obtained results suggest that influence of CCC on the phenolics composition can be a result of various mechanisms of CCC uptake, transforming and/or its translocation in the buckwheat seedlings.

Possible ways of fagopyrin biosynthesis and production in buckwheat plants.

The present work extends knowledge about possible biosynthesis of fagopyrin in buckwheat plants by providing possible candidate genes for its biosynthesis and the role of type III polyketide synthases (PKSs). Moreover, new information is presented about the possible connection between naphthodianthrones and phenolic biosynthesis. Possible regulation of fagopyrin biosynthesis and production under different growth conditions is also discussed.