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At least 19 recordsLinked to original sources
PubMed1980

[Evaluation of work environment in the flax textile industry. V. Air microflora in the flax spinning and flax weaving rooms].

Microbiological air pollution in spinning and weaving rooms was determined by aspiration impinger using an aeroscop (Chirana, Czechoslovakia). The air samples were taken on Petri dishes with Bacto-broth-agar (Difco) or Bacto-blood-agar (Difco). After incubation at 37 degrees C for 24 h the number of bacterial or mould colonies and bacterial cells per 1 m3 of the air was calculated. The number of bacterial cells in flax spinning rooms ranged from 10.5 X 10(3) to 12,5 X 10(4), while in flax weaving rooms--from 2,4 X 10(3) to 10(4) per 1 m3 of air. In the examined samples of the air the bacterial pollution was found to dominate (45,1--95%). Gram-positive sporing bacteria were most frequently recognized. In the air of weaving rooms some moulds: Mucor sp., Circinella sp., Hormodendrum sp., Vetricillum sp., Aspergillus sp. and Penicillum sp. were also found (16.8--54%). It was observed that the microbiological air pollution in spinning and weaving rooms of flax industry was greater than in cotton industry. A wet technology of flax spinning promotes microbiological pollution in the air of this kind of workposts. A high level of mould cells in the air at workposts enhances the risk of workers' exposure to mycotoxins.

Air Microbiology↗
PubMed1985

Ventilatory responses of normal subjects to flax dust inhalation: the protective effect of autoclaving the flax.

A homogeneous batch of dew retted hackled flax was divided into two portions. One was untreated and the other was steamed for 45 minutes at 125 degrees C in three pressure/vacuum cycles in an autoclave. Dust was collected when the two flaxes were separately processed by industrial doubler and stapler machines. From untreated flax 7.2 g of dust was collected per kilogram of flax after two processing operations. From the steamed flax 4.4 g of flax was obtained per kilogram after four operations. A method was devised to disperse the dust in a room to produce dust levels similar to those encountered in a dusty mill (4.5-5.7 mg/m3). Twelve normal volunteers from the managerial staff of the linen industry of Northern Ireland inhaled the dust over six hour periods. With the untreated flax decreases were obtained in mean forced expiratory measurements of 7.6% in FEV1 and 4.5% in FVC (p less than 0.01). A double blind crossover comparison of similar levels of untreated and steamed flax dusts showed 30% less impairment of the forced expirations with steamed than with untreated flax (p less than 0.05). If these responses reflect the long term airway effects of flax dust then the steaming of flax may help in reducing byssinosis.

Adult↗
PubMed2000

Quantitation of the lignan secoisolariciresinol diglucoside in baked goods containing flax seed or flax meal.

Samples of commercially prepared white, whole wheat, flax, and multigrain breads were analyzed by a rapid RP-HPLC method for the presence of the lignan secoisolariciresinol diglucoside (SDG). SDG was detected only in products containing flax, with concentrations ranging from 0.06 to 1.98 microM/g of DW (19-602 microM/loaf). Full-fat flax meal, powdered aqueous alcohol extracts of flax seed, and SDG were added to a white bread mix and baked into loaves in a domestic bread maker. Quantitative recovery of SDG from the test breads was observed when SDG was added; however, when flax meal or aqueous alcohol extracts were added, only 73-75% of the theoretical yield of SDG was recovered. SDG was also detected in commercially prepared flax cookies, bagels, and muffins with concentrations ranging from 0.26 to 2.93 microM/g of DW. The extent of grinding of the flax seed was also shown to have a significant effect on the recovery of SDG from both flax meal breads and baked goods, with extraction of SDG from finely ground samples greater than that from course material.

Bread↗
PubMed2006

Flax seed oil and flax seed meal reduce the formation of aberrant crypt foci (ACF) in azoxymethane-induced colon cancer in Fisher 344 male rats.

Flax seed oil and flax seed meal are good sources of omega-3 fatty acids. The objective of this study was to explicate the effects of feeding flax seed oil and flax seed meal on AOM-induced aberrant crypt foci (ACF) in Fisher 344 male rats. Following an acclimatization period, rats were divided into six groups and fed AIN 93G diet Control (C), C+7 and 14% soybean oil (SBO), C+7 and 14% flax seed oil (FSO) and C+10 and 20% flax seed meal (FSM). All rats received 16 mg/kg body weight of AOM at 7 and 8 weeks of age. The rats were euthanized with CO2 at 17 weeks of age. FSM and FSO reduced the incidence of ACF which are putative precursor lesions in the development of colon cancer in the distal colon by 88% and 77%, in the proximal colon by 86% and 87% with a total reduction of 87.5% and 84%, respectively. Glutathione-S-transferase (GST) activities were significantly (P<0.05) higher in rats fed C+7 and 14% FSO and C+10 and 20% FSM, as compared to rats fed C+SBO diets. Results of this study showed that FSO and FSM reduced the incidence of AOM-induced ACF formation and may therefore be effective chemopreventive agents.

Animals↗
PubMed2003

Colonization of flax roots and early physiological responses of flax cells inoculated with pathogenic and nonpathogenic strains of Fusarium oxysporum.

Fusarium oxysporum includes nonpathogenic strains and pathogenic strains that can induce necrosis or tracheomycosis in plants. The objective of this study was to compare the abilities of a pathogenic strain (Foln3) and a nonpathogenic strain (Fo47) to colonize flax roots and to induce early physiological responses in flax cell culture suspensions. Both strains colonized the outer cortex of the root; however, plant defense reactions, i.e., the presence of wall appositions, osmiophilic material, and collapsed cells, were less frequent and less intense in a root colonized by Foln3 than by Fo47. Early physiological responses were measured in flax cell suspensions confronted with germinated microconidia of both strains. Both pathogenic (Foln3) and nonpathogenic strains (Fo47) triggered transient H(2)O(2) production in the first few minutes of the interaction, but the nonpathogenic strain also induced a second burst 3 h postinoculation. Ca(2+) influx was more intense in cells inoculated with Fo47 than in cells inoculated with Foln3. Similarly, alkalinization of the extracellular medium was higher with Fo47 than with Foln3. Inoculation of the fungi into flax cell suspensions induced cell death 10 to 20 h postinoculation, with a higher percentage of dead cells observed with Fo47 than with Foln3 beginning at 14 h. This is the first report showing that early physiological responses of flax cells can be used to distinguish pathogenic and nonpathogenic strains of the soil-borne fungus F. oxysporum.

Calcium↗
PubMed2006

Direct protein interaction underlies gene-for-gene specificity and coevolution of the flax resistance genes and flax rust avirulence genes.

Plant resistance proteins (R proteins) recognize corresponding pathogen avirulence (Avr) proteins either indirectly through detection of changes in their host protein targets or through direct R-Avr protein interaction. Although indirect recognition imposes selection against Avr effector function, pathogen effector molecules recognized through direct interaction may overcome resistance through sequence diversification rather than loss of function. Here we show that the flax rust fungus AvrL567 genes, whose products are recognized by the L5, L6, and L7 R proteins of flax, are highly diverse, with 12 sequence variants identified from six rust strains. Seven AvrL567 variants derived from Avr alleles induce necrotic responses when expressed in flax plants containing corresponding resistance genes (R genes), whereas five variants from avr alleles do not. Differences in recognition specificity between AvrL567 variants and evidence for diversifying selection acting on these genes suggest they have been involved in a gene-specific arms race with the corresponding flax R genes. Yeast two-hybrid assays indicate that recognition is based on direct R-Avr protein interaction and recapitulate the interaction specificity observed in planta. Biochemical analysis of Escherichia coli-produced AvrL567 proteins shows that variants that escape recognition nevertheless maintain a conserved structure and stability, suggesting that the amino acid sequence differences directly affect the R-Avr protein interaction. We suggest that direct recognition associated with high genetic diversity at corresponding R and Avr gene loci represents an alternative outcome of plant-pathogen coevolution to indirect recognition associated with simple balanced polymorphisms for functional and nonfunctional R and Avr genes.

Amino Acid Sequence↗
PubMed1972

Changes in the Ribonuclease Activity of Flax Cotyledons following Inoculation with Flax Rust.

There was a significant increase in the ribonuclease activity of both resistant (Bombay) and susceptible (Bison) varieties of flax (Linum usitatissimum L.) 3 to 4 days after inoculation with flax rust (Melampsora lini [Pers.] Lev., race No. 3). A second and much greater increase in the activity of this enzyme occurred only in the susceptible host at later stages of disease development. While a similar increase in ribonuclease level was also caused by mechanical injury, evidence is presented showing qualitative differences between the enzyme from parasitized tissue and that from the mechanically injured cotyledons. Comparison of the enzyme from healthy and inoculated cotyledons and from flax rust revealed the presence of a relatively unstable component and some unique catalytic properties in the enzyme from inoculated cotyledons.

Journal Article↗
PubMed1971

Changes in the transcription pattern of flax cotyledons after inoculation with flax rust.

The rate of (32)P incorporation into RNA fractions of flax cotyledons (Linum usitatissimum L. var. Bison) was found to increase two- to three-fold by 48h after inoculation with flax rust [Melampsora lini (Pers.) Lev., race no. 3]. This was accompanied by a change in the nucleotide composition of the newly transcribed sodium chloride-soluble RNA fraction. A comparison of the nucleotide composition of the RNA synthesized in the host-parasite complex at different stages of development indicated the preferential synthesis of one or more molecular species of RNA with a high A+U/G+C ratio at a relatively early stage of infection. Treatment of healthy plants with indol-3-ylacetic acid also resulted in a substantial stimulation in the rate of (32)P incorporation into RNA but this was not accompanied by a detectable change in the nucleotide ratios of the newly synthesized RNA. These results suggest that the synthesis of one of more additional RNA species or the augmented synthesis of certain species of RNA may be a specific phenomenon elicited by host-pathogen interaction.

Adenosine Monophosphate↗
PubMed1995

Isolation of a flax (Linum usitatissimum) gene induced during susceptible infection by flax rust (Melampsora lini).

In a susceptible infection of flax (Linum usitatissimum), the obligate rust pathogen (Melampsora lini) can grow in the leaf without triggering the hypersensitive resistance response. The rust establishes specialized structures (haustoria) in plant mesophyll cells and induces changes in plant subcellular organization. Subtraction hybridization methods were used to isolate cDNA clones of mRNAs that have altered expression in infected leaves. Most of the cDNAs recovered were of fungal origin, but one clone, pFIS 1 (flax inducible sequence No. 1), recovered from several independent experiments, was a plant-specified mRNA that showed a 10-fold increase in steady-state levels during susceptible growth. The increase in fis 1 mRNA levels was not seen in the resistant reaction (hypersensitive reaction) and the predicted protein sequence (551 amino acids with a predicted molecular weight of 61 kDa) has no similarity to known pathogenesis-related proteins. Searches of sequence data bases showed that fis 1 encodes a protein which contains amino acid sequence motifs that are conserved in all previously characterized aldehyde dehydrogenases.

Amino Acid Sequence↗
PubMed1997

Advances in the molecular genetic analysis of the flax-flax rust interaction.

The L6 and M rust-resistance genes, representing two of the five rust-resistance gene loci in flax (Linum usitatissimum), have been cloned. The molecular data are fully consistent with earlier genetic data: the L locus is a single gene with multiple alleles expressing different rust resistance specificities, and the M locus is complex, containing an array of about 15 similar genes. Thus, while L6 and M resistance genes have 86% nucleotide identity, their locus structure is very different. These genes encode products belonging to the nucleotide binding site-leucine-rich repeat class of disease-resistance proteins. Analysis of alleles from the L locus and chimeric genes is providing evidence suggesting that important specificity determinants occur in the C-terminal half of the proteins, the region containing the leucine-rich repeats. The isolation and characterization of the rust (Melampsora lini) avirulence genes that correspond to the cloned rust-resistance genes is one of the major challenges remaining to the understanding of this system.

Journal Article↗
PubMed1995

Effects of flaxseed and flax oil diets in a rat-5/6 renal ablation model.

The objective of this study was to assess the effects of flaxseed and flax oil diets in the rat renal ablation model. Flaxseed is a rich source of alpha-linolenic acid, an 18:3n3 omega-3 fatty acid, which has anti-atherogenic and anti-inflammatory properties. Flaxseed, but not flax oil, is also rich in lignans, which are platelet-activating factor-receptor antagonists. Rats were subjected to 5/6 nephrectomy, fed a regular laboratory diet (RLD) for 1 week, then divided into three groups to receive either the RLD (n = 8), a 15% flaxseed diet (n = 8), or a 15% flax oil diet (n = 7). Blood pressure, proteinuria, glomerular filtration rate, and urinary prostaglandins (thromboxane B2 and 6-keto prostaglandin F1 alpha) were measured presurgery and at 1 week (before dietary allotment) and 20 weeks postnephrectomy when blood for plasma lipids and kidneys for histology and tissue-phospholipid analyses were obtained. Blood pressure increased progressively in the RLD group but not in the flax diet groups. Plasma triglycerides and cholesterol increased in all groups, but this increase was significantly attenuated by both flax diets. Proteinuria increased 1 week postsurgery and continued to increase in the RLD group but not in the flax diet groups. Glomerular filtration rate decreased progressively, but this decline in renal function was attenuated significantly by the flax diets. Both of the flax diets prevented glomerulosclerosis and mesangial expansion. Renal alpha-linolenic acid was increased by both the flax diets (flax oil > flaxseed), but eicosapentaenoic acid increased in the flax oil group only. The flaxseed group had greater renal-arachidonic acid levels than the flax oil and RLD groups. The total omega-3 fatty acids increased twofold to threefold in the flax oil group compared with the two other groups. The total saturated fatty acids were lower and the polyunsaturated fatty acids were increased in both flax diet groups. A progressive increase in urinary thromboxane B2 occurred in the RLD group but not in the flaxseed group; the level decreased in the flax oil group. The ratio of prostaglandin F1 alpha/thromboxane B2 was preserved in the flax oil group only. In conclusion, the dietary flax seed and flax oil attenuated the decline in renal function and reduced glomerular injury with favorable effects on blood pressure, plasma lipids, and urinary prostaglandins. While we have not proven any specific synergistic effects of the constituents of the flaxseed diet, the benefits of flax-derived alpha-linolenic acid with or without lignans in the rat-5/6 renal ablation model seem clear from this experiment.

6-Ketoprostaglandin F1 alpha↗
PubMed2006

Effect of processing flax in beef feedlot diets on performance, carcass characteristics, and trained sensory panel ratings.

To assess the effects of flax addition and flax processing on feedlot performance and carcass characteristics, 128 yearling beef heifers (360 +/- 14 kg of initial BW) were blocked by weight and assigned randomly to feedlot diets that included no flax (control), whole flax (WHL), rolled flax (RLD; 1,300 microm), or ground flax (GRD; 700 microm). Heifers were fed a growth diet (31% corn, 30% corn silage, 18% barley malt pellets, 14% alfalfa, 4% linseed meal, and 3% supplement; DM basis) for 56 d, after which they were adapted to a finishing diet (79% corn, 7% corn silage, 7% alfalfa, 4.75% linseed meal, and 2.25% supplement; DM basis). In WHL, RLD, and GRD, flax replaced all linseed meal and partially replaced corn at 8% of diet DM. All diets provided 0.5 mg of melengestrol acetate, 2,000 IU of vitamin E, and 232 mg of monensin per heifer daily. Cattle were slaughtered by block after 96, 97, and 124 (2 blocks) d on feed. At 24 h postmortem, carcass data were collected, and a portion of the loin was removed, vacuum-packaged, and aged for 14 d. After aging, 2 steaks were removed from each loin for Warner-Bratzler shear force measurement, sensory panel evaluation, and fatty acid analysis (approximately 100 g of muscle was collected). Flax inclusion (WHL, RLD, and GRD vs. control) did not affect DMI (P = 0.79), fat thickness over the 12th rib (P = 0.32), or LM area (P = 0.23). Flax inclusion increased ADG (P = 0.006), G:F (P = 0.006), and USDA yield grade (P = 0.01). Flax processing (RLD and GRD vs. WHL) increased ADG (P = 0.05), G:F (P = 0.08), and apparent dietary NEm and NEg (P = 0.003). Muscle from heifers fed flax had greater phospholipid 18:3n-3 (P < 0.001), 20:5n-3 (P < 0.001), 22:5n-3 (P < 0.001), and 22:6n-3 (P = 0.02) fractions, and greater neutral lipid 18:3n-3 (P < 0.001). Feeding 8% flax to feedlot heifers increased gain and efficiency, and processing flax increased available energy and resulted in increased efficiency of gain. Feeding 8% flax also increased levels of n-3 fatty acids in fresh beef.

Animal Feed↗
PubMed2005

Evidence of the domestication history of flax (Linum usitatissimum L.) from genetic diversity of the sad2 locus.

A phylogenetic analysis was conducted on 34 alleles of 2.5 kb sized stearoyl-ACP desaturase II (sad2), obtained from 30 accessions of cultivated and pale flax (Linum spp.), to elucidate the history of flax domestication. The analysis supports a single domestication origin for extant cultivated flax. The phylogenetic evidence indicates that flax was first domesticated for oil, rather than fibre. The genetic diversity of the sad2 locus in cultivated flax is low when compared to that of the pale flax assayed. An absolute archaeological date could be applied to the synonymous substitution rate of sad2 in cultivated flax, yielding a high estimate of 1.60-1.71x10(-7) substitutions/site/year. The occurrence of nonsynonymous substitutions at conserved positions of the third exon in alleles from cultivated flax suggests that the locus may have been subjected to an artificial selection pressure. The elevated synonymous substitution rate is also compatible with a population expansion of flax since domestication, followed by a population decline in historic times. These findings provide new insight into flax domestication and are significant for the continuous exploration of the flax germplasm for utilization.

Crops, Agricultural↗
PubMed2001

Plant factors influencing enzyme retting of fiber and seed flax.

Retting, which is the microbial activity through which bast fibers are released from nonfiber tissues, is the limiting factor in flax processing. The objective of this work is to identify chemical and structural characteristics in a variety of fiber and seed flax types that influence enzyme retting in a recently developed method. Analyses of flax retted in a series of tests, including two enzyme rettings in some cases, indicated that lignin did not limit the separation of fibers from shive and showed that pectinases in enzyme-retting mixtures could ret fiber and seed flax. However, mature stems, such as that in flax produced for seed, had greater amounts of cutin and wax in the cleaned fiber product, suggesting that the cuticle could be a greater antiquality factor in seed versus fiber flax. With seed flax, the fraction of finer fibers produced during retting was significantly lower than with fiber flax. Results indicated that enzyme retting could be used to obtain flax fibers from seed flax stem residues and add value to this agricultural material.

Dietary Fiber↗