Influence of different extraction techniques on recovery, purity, antioxidant activities, and microstructure of flaxseed gum.

Four extraction techniques (that is, hot water extraction [HWE], alkaline-acidic extraction [AAE], ultrasound assisted extraction [UAE], and microwave assisted extraction [MAE]) were compared for flaxseed gum extraction and their influence on the yield, purity, structural characterization (monosaccharide composition, molecular weight distribution, and microstructure by transmission electron microscope), and antioxidant activity (in terms of scavenging ability of 2,2-diphenyl-1-picrylhydrazyl [DPPH], 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid [ABTS], and reducing power) was investigated. The HWE achieved higher yield (8.96%) than UAE (7.84%) followed by MAE (7.01%) and AAE (6.44%). Moreover, the four flaxseed gum (FSG) samples exhibited the identical monosaccharide composition, but slight difference was observed in the content, whereas the molecular weight ratios exhibited significant difference. All samples displayed concentration-dependent manner for all antioxidant assays. UAE-FSG showed significant higher scavenging ability on DPPH free radical, ABTS free radical, reducing power, and ß-carotene bleaching assay followed by HWE-FSG, MAE-FSG, and AAE-FSG. Overall results showed that UAE was favorable to the purity of FSG, whereas HWE was more advantageous to improve the extraction yield and facile as it requires no special equipment. PRACTICAL APPLICATION: Extraction methods directly affect the recovery and purity of the extracted compound. Thus, this study could help in selection of appropriate extraction method for FSG. The results suggested that FSG possesses potential healthcare application in food industry because of their nutrition composition and antioxidant activities, and thus, it can be used for formulation of functional food as a natural antioxidant agent.

Inter-retrotransposon amplified polymorphism markers revealed long terminal repeat retrotransposon insertion polymorphism in flax cultivated on the experimental fields around Chernobyl.

Ionizing radiation in environment comes from various natural and anthropogenic sources. The effect of radioactivity released after the CNPP (Chernobyl Nuclear Power Plant) on plant systems remains of great interest. Even now, more than three decades after the nuclear accident, the long-lived radionuclides represent a strong stress factor. Herein, the emphasis has been placed on analysis of genetic variability represented by activation of LTR (Long Terminal Repeat)-retrotransposons. Polymorphism in LTR-retrotransposon insertions has been investigated throughout the genome of two flax varieties, Kyivskyi and Bethune. For this purpose, two retrotransposon-based marker techniques, IRAP (Inter-Retrotransposon Amplified Polymorphism) and iPBS (inter-Primer Binding Site), have been employed. The hypothesis that chronic radioactive stress may induce mechanism of retransposition has been supported by the activation of FL9, FL11 and FL12 LTR-retrotransposons in flax seeds harvested from radioactive environment. Out of two retrotransposon-based approaches, IRAP appears to be more suitable for identification of LTR-retrotransposon polymorphism. Even though the LTR-retrotransposon polymorphism was identified, the results suggest the high level of plant adaptation in the radioactive Chernobyl area. However, it is not really surprising that plants developed an effective strategy to survive in radio-contaminated environment over the past 30 years.

Photoperiod sensitivity of Canadian flax cultivars and 5-azacytidine treated early flowering derivative lines.

BACKGROUND: Early flowering and maturing flax (Linum usitatissimum L.) cultivars are better adapted than lines with a longer reproductive phase for the short growing season of the northern Canadian Prairies. We examined the role of long days (LD) and short days (SD) on the time taken to flower in five established flax cultivars and three mutant-derived F10 lines. The photoperiod sensitivity of these eight different genotypes was determined using a reciprocal transfer experiment involving weekly transfers between LD and SD environments. RESULTS: The genotypes tested had varying degrees of photoperiod sensitivity and demonstrated reduced time to flowering if exposed to LD environments prior to a critical time point. The duration of each of the three phases of vegetative growth differed among the genotypes studied. Transfers from SD to LD shortened the vegetative stage, reduced time to flowering, and extended the reproductive phase in the genotypes studied. Mutant-derived lines RE1/2/3 flowered significantly earlier compared to CDC Sorrel, CDC Bethune, Flanders, Prairie Thunder, and Royal. Modelling of the flowering times indicated that transferring the cultivars from SD to LD increased the photoperiod sensitive time; however, different reproductive phases for mutant lines were not defined as parsimonious models were not identified. Expression of the putative flax homologs for CONSTANS (CO), FLOWERING LOCUS T (FT), and GIGANTEA (GI) was examined in the leaves of Royal and RE1/2/3 plants at 10, 15, 19 and 29 days after planting. Expression of putative FT homologs was detected in all three early-flowering lines but expression was negligible, or not detected, in Royal. CONCLUSIONS: Models defining the three phases of reproductive development were established for the five cultivars studied; however, it was not possible to identify these phases for the three early flowering and photoperiod insensitive epimutant-derived lines. A putative flax homolog of FT, a key regulator of flowering time, is more highly expressed in RE plants, which may condition the day-length insensitivity in the early flowering 'epimutant' lines.

Systems biology is an efficient tool for investigation of low-dose chronic irradiation influence on plants in the Chernobyl zone.

The paper discusses different methodological approaches to the study of transgenerational alterations of metabolic pathways in soybean and flax seeds in the process of adaptation to chronic irradiation in the Chernobyl alienation zone. A combination of general biological methods and novel approaches, such as genomics, proteomics, cytogenetics, and mutagenesis, allows researchers to analyze an organism's systemic response and identify the latent chronic irradiation effects in plants from the Chernobyl zone. The proteomic approaches are especially efficient, since they range from the identification of changes in abundance and folding of individual proteins to the characterization of posttranslational modifications, trends of qualitative changes during seed maturation, or protein-protein interactions during plant growth and development under permanent impacts of stress factors. The application of proteomics opens new horizons in the understanding of the hidden mechanisms behind the impact of chronic low-dose radiation on living cells and makes it possible to visualize metabolic network alterations regardless of their transcriptional, translational, or epigenetic nature.

Radioactive Chernobyl environment has produced high-oil flax seeds that show proteome alterations related to carbon metabolism during seed development.

Starting in 2007, we have grown soybean (Glycine max [L.] Merr. variety Soniachna) and flax (Linum usitatissimum, L. variety Kyivskyi) in the radio-contaminated Chernobyl area and analyzed the seed proteomes. In the second-generation flax seeds, we detected a 12% increase in oil content. To characterize the bases for this increase, seed development has been studied. Flax seeds were harvested in biological triplicate at 2, 4, and 6 weeks after flowering and at maturity from plants grown in nonradioactive and radio-contaminated plots in the Chernobyl area for two generations. Quantitative proteomic analyses based on 2-D gel electrophoresis (2-DE) allowed us to establish developmental profiles for 199 2-DE spots in both plots, out of which 79 were reliably identified by tandem mass spectrometry. The data suggest a statistically significant increased abundance of proteins associated with pyruvate biosynthesis via cytoplasmic glycolysis, L-malate decarboxylation, isocitrate dehydrogenation, and ethanol oxidation to acetaldehyde in early stages of seed development. This was followed by statistically significant increased abundance of ketoacyl-[acylcarrier protein] synthase I related to condensation of malonyl-ACP with elongating fatty acid chains. On the basis of these and previous data, we propose a preliminary model for plant adaptation to growth in a radio-contaminated environment. One aspect of the model suggests that changes in carbon assimilation and fatty acid biosynthesis are an integral part of plant adaptation.

Evaluation of changes in lipid peroxidation, ROS production, surface structures, secondary metabolites and yield of linseed (Linum usitatissimum L.) under individual and combined stress of ultraviolet-B and ozone using open top chambers.

The individual and interactive effects of supplemental UV-B (sUV-B) (ambient + 7.2 kJ m(-2) d(-1)) and elevated O3 (ambient + 10 ppb) were evaluated under field conditions using open top chambers on two cultivars, Padmini and T-397 of linseed (Linum usitatissimum L.). Mean monthly surface level of O3 concentrations varied from 27.7 ppb to 59.0 ppb during the experimental period. Both UV-B and O03 induced the production of ROS (H2O2 and O2*-), resulting in significant damage of membranes due to lipid peroxidation and electrolyte leakage. Synthesis of secondary metabolites (flavonoids, anthocyanin, lignin and wax) was also enhanced in all the treatments, whereas biomass and yield were reduced. Alterations in frequency of stomata and wax distribution were also observed through scanning electron microscopy (SEM). Cultivar Padmini was found to be more sensitive because of higher damage of membrane vis-a-vis reduction in biomass and seed yield. However, concentrations of flavonoids, anthocyanin, lignin and wax were higher in T-397, suggesting its relative resistance against applied stress. Combined exposure of sUV-B and O3 was less harmful, as compared to their individual treatment. Among the three treatments, O3 was found to be more detrimental for overall growth and sUV-B for economic yield.

Interactive effect of supplemental ultraviolet B and elevated ozone on seed yield and oil quality of two cultivars of linseed (Linum usitatissimum L.) carried out in open top chambers.

BACKGROUND: Current scenarios of global climate change predict a significant increase in ultraviolet B (UV-B) and tropospheric ozone (O3) in the near future. Both UV-B and O3 can have detrimental effects on the productivity and yield quality of important agricultural crops. The present study was conducted to investigate the individual and interactive effects of supplemental UV-B (sUV-B) (ambient + 7.2 kJ m⁻² day⁻¹) and O3 (ambient + 10 ppb) on the yield and oil quality of two cultivars of linseed (Linum usitatissimum L.). RESULTS: The mean monthly ambient O3 concentration varied from 27.7 to 59.0 ppb during the experimental period. O3 affected fruit formation, while sUV-B was mainly responsible for ovule abortion. Seed sugar and protein contents showed maximum reduction in O3-treated plants, while mineral nutrient levels were most affected by sUV-B + O3 treatment. Rancid oil of low nutritional quality and containing long-chain fatty acids was favoured along with a decrease in oil content. CONCLUSION: sUV-B and O3 individually as well as in combination caused deterioration of the yield and quality of oil and seeds of linseed. However, the individual effect of O3 was more damaging than the effect of sUV-B or sUV-B + O3, and cultivar T-397 performed better than Padmini.

Effect of gamma-irradiation on some chemical characteristics and volatile content of linseed.

The effect of irradiation (2.5, 4.0, 5.5, and 7.0 kGy) on chemical properties and volatile contents of linseed was investigated. Consistent decreases were observed in both protein and oil content of the irradiated linseed samples with increasing irradiation doses. The ash content of the irradiated linseed samples increased significantly (P<.05) with increasing irradiation doses except for 5.5 kGy. Irradiation treatment caused irregular changes in palmitic and stearic acid content. Although styrene and p-xylene content decreased as a result of irradiation, 1-hexanol content only decreased at 7.0 kGy. Benzaldehyde, p-cymene, and nonanol were not determined at irradiation doses above 4.0 kGy.

Agricultural recovery of a formerly radioactive area: II. Systematic proteomic characterization of flax seed development in the remediated Chernobyl area.

Molecular characterization of crop plants grown in remediated, formerly radioactive, areas could establish a framework for future agricultural use of these areas. Recently, we have established a quantitative reference map for mature flax seed proteins (Linum usitatissimum L.) harvested from a remediated plot in Chernobyl town. Herein we describe results from our ongoing studies of this subject, and provide a proteomics-based characterization of developing flax seeds harvested from same field. A quantitative approach, based on 2-dimensional electrophoresis (2-DE) and tandem mass spectrometry, yielded expression profiles for 379 2-DE spots through seed development. Despite the paucity of genomic resources for flax, the identity for 102 proteins was reliably determined. These proteins were sorted into 11 metabolic functional classes. Proteins of unknown function comprise the largest group, and displayed a pattern of decreased abundance throughout seed development. Analysis of the composite expression profiles for metabolic protein classes revealed specific expression patterns during seed development. For example, there was an overall decrease in abundance of the glycolytic enzymes during seed development.

Supplemental ultraviolet-B and ozone: impact on antioxidants, proteome and genome of linseed (Linum usitatissimum L. cv. Padmini).

The present investigation used Linum usitatissimum L. cv. Padmini (linseed), under field conditions in open-top chambers, to evaluate the interactive effects of supplemental ultraviolet-B (sUV-B; ambient +7.2 kJ · m(-2) · d(-1)) and ozone (O(3); ambient +10 ppb). Treatment of plants with sUV-B and O(3) , individually or in combination, caused several changes in enzymatic and non-enzymatic components of the antioxidant defence system. Photo-oxidative damage caused by sUV-B and O(3) , included lipid peroxidation, changed protein profiles and caused DNA strand breakage. One-dimensional gel electrophoresis revealed that proteins of 222.24 and 50.5 kDa are specific and appear after sUV-B and O(3) exposure, and could be used as indicator proteins. Effects of sUV-B and O(3) given separately are more detrimental as compared to combined treatment. Mutational and structural alterations in linseed DNA after these stresses were also examined using RAPD with ten different primers. The study concluded that both stresses, i.e. sUV-B and O(3) , are phytotoxic, causing significant changes in metabolites, antioxidants, the leaf proteome and the genome of linseed, but their interactive effect was always less than additive.

[Effect of the extremely weak alternating magnetic fields on the regeneration of planarians and the gravitropic response of plants].

The influence of extremely weak alternating magnetic fields (EW AMF) directed colinearly to the static Earth magnetic field on the rate of regeneration of planarians and the rate of gravitropic response in the stem segments of flax has been studied. The value of bioeffects of EW AMF is determined by the parameter gamma B(AC)/f, where y is the gyromagnetic ratio of the magnetic moments induced by the orbital movements of electrons in atoms, and B(AC) and f correspond to magnetic induction and frequency of the alternating magnetic component. It was shown that the magnitude of bioeffects depends on the amplitude (at fixed 1000 Hz - frequency) and frequency (at fixed 192 nT - amplitude) of the alternating component. Maxima of bioeffects are observed at gamma B(AC)/f = 0.9; 2.75, and minor maxima gamma B(AC)/f = 4.5; 6.1. The bioeffects are absent at gamma B(AC)/f = 1.8, 3.8, 5.3, 6.7. The positions of the maxima and minima of bioeffects correspond to the theoretical prediction (at gamma = 14000 Hz/microT). Primary targets for the EW AMF of this type are the magnetic moments induced by the orbital movements of electrons in atoms.

Influence of light intensity and selection scheme on regeneration time of transgenic flax plants.

This study aimed at establishing a protocol to increase the number of regenerated shoots and to limit the recovery of "escapes" during the regeneration of transgenic flax plants (cv Barbara). Here, we describe how light, adapted media and selection scheme could stimulate the transformation process, the organogenic potentiality of calli (by a factor of 3.2) and accelerate the transgenic shoot regeneration (by a factor of about 2). On comparison of the transformation rate observed while using low light (LL) and high light (HL) a considerable enhancement from 0.12 to 5.7% was evident. The promotive effect of light might also had a direct beneficial effect on transgenic plant production time leading to a reduction of more than 4 months in the time need to obtain transgenic seeds. All data indicate that HL plays a role on growth and on protein, rubisco and pigment contents by stimulating the gene implicated in photosynthetic and Calvin cycle processes.

Dehydrating of flax fiber with microwave heating for biocomposite production.

The feasibility of microwave dehydrating flax fiber was evaluated using a commercial domestic microwave oven at four power settings representing 200, 300, 400 and 500 Watt (W) power level. Due to the possibility of local heating and consequent fiber degradation, the changes in color of the flax fiber at different levels of temperature were also investigated. The dehydration processes at various power levels were simulated by Page model. Based on visual inspection, color analysis and scanning electron microscopy (SEM) of the fiber, it was revealed that discoloration of the fiber occurred at about 170 degrees C. At 200 and 300 W power level, after 10 minutes of dehydrating, the moisture content of the fiber reached from initial 7.9% close to 2.0 and 1.0%, respectively. For 400 W power level, the moisture content of the fiber dropped to 0. 10% in about 9.5 minutes. Major discoloration of the fiber was noticed when dehydration was proceed beyond 4.5 minutes for 500 W treatment. The Page model very well fitted the experimental data. The coefficients of determination calculated from the model and the experimental data increased with increase in applied microwave power

Plant sensitivity to low intensity 105 GHz electromagnetic radiation.

Exposing seedlings of the flax, Linum usitatissimum L., to a variety of weak environmental stresses followed by a 2 day calcium deprivation, triggers the common response of production of epidermal meristems (actively dividing groups of cells) in the hypocotyl, which is the part of the stem between the root and the cotyledons (the pre-existing leaves in the embryo). This production reaches a plateau of 10-20 meristems after a month in the case of mechanical stimulation and cold shock. Recently, we have shown that radiation from a global system for mobile communication (GSM) telephone also triggers production of meristems with a plateau of around six meristems. Here, we show that a single 2 h exposure to radiation emitted at 105 GHz at non-thermal levels by a Gunn oscillator induces meristem production with kinetics similar to that induced by weak environmental stimuli and radiation from GSM telephone.