Flax Plants Research Articles

The Biosynthesis of Cyanogenic Glycosides in Higher Plants: I. PURIFICATION AND PROPERTIES OF A URIDINE DIPHOSPHATE-GLUCOSE-KETONE CYANOHYDRIN β-GLUCOSYLTRANSFERASE FROM LINUM USITATISSIMUM L

An enzyme which catalyzes the transfer of glucose from UDP-glucose to α-hydroxyisobutyronitrile (acetone cyanohydrin) has been isolated from flax seedlings (Linum usitatissimum L). The product of this reaction was shown to be identical with linamarin, one of the two cyanogenic glucosides produced by the flax plant. The partially purified UDP-glucose-ketone cyanohydrin β-glucosyltransferase exhibited a high degree of specificity for the two aliphatic side chains of acetone and butanone cyanohydrins as well as for UDP-glucose as the glucose donor. This suggests that its natural function is to catalyze the last step in the biosynthesis of the cyanogenic glucosides linamarin and lotaustralin from the precursor cyanohydrins. In a series of steps resulting in a purification of 120-fold, the glucosyltransferase was separated from the β-glucosidase linamarase which is present in the flax plant. No requirements for metal ions or sulfhydryl reagents could be shown for the glucosyl transferase.

Effects of Different Day Lengths on the Growth and Some Properties of Fiber Cells in Flax Plant, Linum usitatissimum L.

Flax plants (var. Saginow No. 1) were grown in pots under different day length (8. 12, 14.and 16 hours). The length of the plants became longer in long days, and the flowering was promoted by the long days. However, in the short day the growth of the plant was restrained and the flowering was delayed. The number and growth of the basal branch sprouted from dicotyledonal axile increased in the short day. The long day condition increased the yield of the fibers and enlarged the diameter of the fiber cells, but the cell wall thickness of the fiber cells became larger in the plants cultivated in short day such as 8 hours. The fibers of better quality were obtained in the short day, for their fibers contained larger quantity of α-cellulose than those in the long days such as 12, 14, or 16 hours. However, in the short day such as 8 hours the lignin contents became larger than those in the longer day length plots.

ESTIMATION OF RATES OF UPTAKE OF TRACE ELEMENTS FROM THE SOIL TO SEEDS OF OILSEED FLAX

SUMMARY This research aims to model the migration of heavy metals from soil to Flax oilseeds at different development stages. Following a three- year study, we have developed a mathematical model which enables us to evaluate ris k options in the management of urban wastes, taking into account agricultural practice, physico-chemical soil properties. This study concerns two locations, each with differ ent pedological characteristics and which had been previously treated with organic materials. At each location, two different varieties of oilseed flax were grown (A and B). The first site, G in Normandy, received sewage slud ge in agronomic doses until 1998. At the second site, H in the Paris region, the poll uted area was irrigated with waste water via a sewage outfall from the early years of the 20th cen tury until 1999, while in the unpolluted area of the H site (used as a control for this stud y) integrated management has been used. Each site was divided into two areas for cultivatio n of the two varieties of Flax. Soil samples were taken at three different depths ( 0-25 cm, 25-50 cm and 50-75 cm), during four stages of flax growth (seed, growth, fl owering, ripening), and from the plants themselves. The presence of five metals, Cd, Cu, Ni , Pb and Zn was measured. The test sites were separated into two classes: ‘Po lluted’ and ‘Integrated Management’. The results show that two varieties of Flax plants react in different ways to each three families of metals (Cu-Zn, Ni-Pb, and Cd ). The results are similar, whatever the variety of Flax. Finally, the quantities of heavy metals carried by Flax seeds and their effects on risklevels are practically non-existant in the context of existing standards. Studies are continuing in this area to explain the mobility of some metals such as Zinc, taking account of interactions between metals, soil texture, and physico-chemical factors.

COMPETITION BETWEEN LINSEED FLAX AND SAPONARIA VACCARIA

Yields of flax (Linum usitatissimum) seed and straw were reduced by competition with 30 to 37 plants of Saponaria vaccaria L. (cow cockle) per m2 in field plots on heavy clay soil in Saskatchewan. Competition intensified as weed density increased. The presence of 400 weeds/m2 in 1964 and 1,013/m2 in 1965 reduced flax seed production by 61% and 73%, respectively. Competition produced a reduction in branching at the base and in the inflorescence of the flax plant rather than a reduction in the stand of flax.S. vaccaria plants were affected by competition as the density of this species was increased in a crop of flax. The average yield of straw, number of capsules, number of seeds and weight of seed per plant of S. vaccaria decreased with increasing density. At high densities, the number of seeds per capsule and weight per seed also decreased. The total yield of weed seed per plot increased with density up to around 67 to 127 plants/m2 in flax, but declined with higher densities. Straw production by S. vaccaria per plot continued to increase with increasing density.Total dry weight production by crop and weed together per unit area exceeded that of the crop alone.

ISOLATION, PROPERTIES, AND BIOLOGICAL EFFECTS OF PHOMIC ACID

Phomic acid, a toxic metabolic product of Phoma medicaginis, has been isolated from culture filtrates of the fungus. The toxin crystallizes as colorless rectangular plates having a refractive index of 0.56 and melting at 259–260 °C. It has absorption peaks at 208 and 260 mμ. The infrared spectrum of the toxin suggests that it may be an unsaturated aliphatic hydroxy acid.The toxic principle causes discoloration and drying of the leaf tip and leaf margin and a general stunting of the flax plant. It inhibits germination of seeds of flax, alfalfa, rape, and cress. The effect of phomic acid on seed germination can be reversed by glutathione and cysteine. Germination of the conidia of a few fungi is completely inhibited by the toxin, whereas it only retards the growth of the germ tube of Helminthosporium sativum. It inhibits the activity of triosephosphate dehydrogenase but not that of malic dehydrogenase. It is suggested that the toxin might act by inhibiting enzyme systems requiring sulphydryl groups for activity.

Influence of Density on Plant Variation in Fiber Flax, Linum usitatissimum L.1

Plants of fiber flax develop a log normal frequency distribution of dry weight with age and increased density. Capsule number per plant shows an even more skewed frequency distribution. Mean seed number per capsule and individual seed weight are less sensitive to density but frequency distributions are not normal.

Effects of Shading on the Growth and some Properties of Fiber Cells of Flax Plant, Linum usitatissimum L.

Flax plants (var. Saginaw No. 1) were grown in pots under different light intensities as follows: 100% (control), 43% (shaded I) and 17% (shaded II) of the solar radiation. The stem length of the plants grown in the shaded conditions became larger according to the larger elongation of internode of the stem. Dry weight of above-ground parts and bolls of the plant became smaller as the light intensity decreased. Number, diameter and cell membrane thickness of fiber-cells found in the cross section of the stem became smaller as the light intensity decreased. Particularly, the development of thickness of the cell membrane was greatly decreased by the lower light intensity. Thus, the fiber yield per plant and the fiber percentage in the dry weight of the stem became poorer as the light intensity decreased. The contents of α-cellulose in the crude cellulose were decreased by the shade treatment. On the contrary, the contents of (β+γ)-cellulose and lignin became higher by the same treatment. As the results, the shaded conditions not only reduce the fiber yield in the flax plant but also induce the reduction of the quality of the fiber.

Desaturation of fatty acids in seeds of higher plants

Photosynthesizing flax, soybean, and safflower plants were exposed to (14)CO(2) at seed-setting stage for a 1 hr period. Seed was sampled periodically thereafter and the lipids were extracted. A triglyceride-rich fraction was methanolyzed; the resultant methyl esters were analyzed by gas-liquid chromatography and assayed for radioactivity. Of the C(18) unsaturated acids, oleic was the first to acquire radioactivity, which subsequently and successively appeared in linoleic and linolenic acids. The shapes of the radioactivity-time curves provide evidence that consecutive desaturation reactions occur in the seeds of these higher plants.

Melampsora lini . [Descriptions of Fungi and Bacteria

Abstract A description is provided for Melampsora lini . Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Linum usitatissimum, L. catharticum and other species of Linum . The American Aecidium lini Dearness & House on L. virginianum differs from M. lini in having cupulate, not caeomoid, aecia. DISEASE: Flax rust. Characterized by light-yellow to orange-yellow sori containing pycnia and aecia on leaves and stems early in the growing season, followed by reddish-yellow uredia on leaves, stems and capsules during the growing season, and later, brown to black telia covered by the epidermis, chiefly on the stems. Causes serious damage to flax by weakening and disfiguring the fibres and reduces the quality and yield of linseed. GEOGRAPHICAL DISTRIBUTION: Africa, Asia, Australasia, Europe, North and South America. (CMI Map 68, 2nd Ed.) TRANSMISSION: Sporidia produced in the spring from teliospores over-wintering on crop refuse are the most common source of primary inoculum. Teliospores may also be carried on fragments of infected host tissue with the seed. Volunteer flax plants, including some wild species, may also serve as important sources of infection (Millikan, 1951), and provide a means of over-wintering of the uredial stage in New Zeland (32: 79).

Effects of Nutritional Treatments of Seed-bearing Plants on the Performance of their Progeny

HARRINGTON1 collected seed from carrot, lettuce and pepper plants showing severe deficiencies of several major nutrients and found that the deficiencies had little effect on the percentage germination of the seed. Szukalski2 applied different amounts of a phosphorus fertilizer to flax and rape plants and showed that when seed from these plants was sown in phosphorus-deficient soil, high levels of phosphorus in the seed were advantageous for seedling growth. Results from Durrant's3 experiments with flax indicated that nutritional treatments given to flax plants brought about apparently heritable changes. In the present experiments nutritional treatments were applied to watercress, pea and carrot plants and plants from their seed were raised to determine the effects of the seed-plant treatments on the progenies. This communication gives a report of the results obtained.

THE EFFECT OF TEMPERATURE ON THE OIL CONTENT AND FATTY ACID COMPOSITION OF THE OILS FROM SEVERAL OIL SEED CROPS

Plants of rape, safflower, sunflower, flax, and castor bean were grown at temperatures of 10, 16, 21, and 26.5 °C for the period of seed development. Oil content of sunflower, safflower, and castor bean was not affected by temperature. Highest oil content in rape and flax was found at the lowest temperature and a continual decrease was observed with increases in temperature. Fatty acid composition of the oil from safflower and castor bean was not affected by a change in temperature. In the other three species the amount of the more highly unsaturated fatty acids decreased as the temperature was increased. This decrease was accompanied by an increase in oleic acid. The levels of saturated fatty acids in all of the species were not affected by changes in temperature.

Effects of Gibberellic Acid on the Fixed Oils of Four Plants

The influence of gibberellic acid on the quality of fixed oils from four plants has been studied. Sesame, castor bean, sunflower, and flax plants were treated with aqueous solutions of gibberellic acid when the plants reached blooming size and at 2-week intervals until harvest. The iodine values and the quantity of unsaponifiable matter varied between samples and between oils from different species of plants. Significant variations from normal were produced in castor and sesame oils. The differences consisted of higher saponification values in both oils and a lower acid value in the latter. A higher saponification value indicating shorter chain fatty acids was the only characteristic common to all oils from treated plants. Some of the changes obtained were from plants that had insignificant or no visible morphological differences. The influence of gibberellic acid on the quality of fixed oils from four plants has been studied. Sesame, castor bean, sunflower, and flax plants were treated with aqueous solutions of gibberellic acid when the plants reached blooming size and at 2-week intervals until harvest. The iodine values and the quantity of unsaponifiable matter varied between samples and between oils from different species of plants. Significant variations from normal were produced in castor and sesame oils. The differences consisted of higher saponification values in both oils and a lower acid value in the latter. A higher saponification value indicating shorter chain fatty acids was the only characteristic common to all oils from treated plants. Some of the changes obtained were from plants that had insignificant or no visible morphological differences.

Relation of Potassium to Fusarium Wilt of Flax

POTASSIUM has been shown by several investigators to reduce the severity of Fusarium wilts and certain other diseases1–3. In our work on the uptake of nutrients by the flax plant it was found that H–469, a wilt-resistant variety, contained more potassium than a wilt-susceptible variety, IPI–64. In pursuing this lead, several experiments were carried out to investigate the relationship between potassium content and wilt susceptibility.

Influences of Some Environmental Conditions upon the Growth and Development of the Flax Plant, Linum usitatissimum L.

Flax plants (var. Saginow No. 1) were grown in pots under different conditions as follows : control (soil moisture content 20.6 % per dry soil), moistened (grown in moistened soil, 34.8 %), dried (grown in dry soil, 10.7 %), and shaded (grown under shading, 22.4 %). The stem length of the plants became larger and stem diameter increased in the moistened plot. In the later stage of growth, elongation of the plant in the control and moistened plots ceased due to the reproductive growth. However, the shaded plot did not bloom, and the stem continued to elongate. On the other hand, in the dried plot, the flowering was not uniform according to the temporary elongation of the plant after every irrigation. Thus, number of leaves decreased after the flowering stage in the control and in moistened plots, but in the shaded and dried plots, the number of leaves did not decrease until the harvest time. Dry weight of above-ground parts of the plant became larger in the moistened plot and smaller in the dried plot. However, dry weight of boll in the moistened plot decreased more than the control plot, because of the reduction of the ratio of reproductive growth to vegetative growth in the moistened plot. Number of fiber-cells found in the cross section of middle part of the stem became larger in the control plot than other experimental plots. Although in the moistened and shaded plots, number of fiber-cells was reduced to one half of those of the control plot, diameter and thickness of cell-membrane of the fiber-cells were noticeably developed in the moistened plot compared to other plots. From the consideration of the above-mentioned causes, fiber percentage in the dry weight of stem became larger in the moistened plot and became smaller in the shaded and dried plots. The fiber obtained from the moistened plot was better than that from the control plot because of the higher content of α-cellulose and the lower content of β-and γ-cellulose. However, from the dried and shaded plots the fibers of poor quality were obtained because of the lower content of α-cellulose and the higher content of lignins than that of the control plot. Particularly, from the shaded plot the fiber of the worst quality was obtained.

BYSSINOSIS PREVALENCE AND FLAX PROCESSING.

Previous evidence suggested that byssinosis in flax workers is caused by the inhalation of dust of biologically retted flax. In the present study no cases of byssinosis were found among workers in a flax plant which produces yarn by chemical degumming instead of biological retting. The absence of byssinosis in this plant could not be attributed to differences in the quantities of dust developed as compared with the conventional retting procedure. These findings support the view that the agent in flax dust which causes symptoms of byssinosis originates during biological retting of flax and is absent from unretted flax. Chemical degumming of flax appears to be superior to biological retting procedures with respect to the health of the workers.

The effects of low doses of gamma radiation on plant yields

The effects of low doses of gamma radiation from Co 60 have been tested on dormant seeds of flax, radish and cabbage, and on young plants of flax, cabbage, lettuce, clover, duckweed and pine. Fresh or dry weights were taken as a measure of yield at harvest. Only in the case of pine seedlings was significant stimulation noticed: this occurred in the dose range 2–6 rad after 9 months' growth.

Factors Affecting the Digestibility of Flax Plant Product by Sheep

Factors Affecting the Digestibility of Flax Plant Product by Sheep

Testing for resistance to Polyspora lini Laff. in flax breeding

A pot technique by which the resistance of flax plants to stem-break can be determined within one growing season is described. Since all the inoculated plants develop the seedling phase of the disease, irrespective of whether they later show resistance or susceptibility to stem-break, it is ensured that they are all exposed to similar chances of developing stem-break. The technique is unsuitable for testing resistance to the browning phase, which can be satisfactorily determined in field experiments. The pot technique provides a more exacting test of resistance to stem-break than can be applied under field conditions; varieties showing resistance in the pot test are resistant in the field. Incidence of stem-break in a susceptible flax variety was unaffected when seedlings were inoculated at different stages of development. Wide variations in the air temperature at which plants were incubated after inoculation also brought about no effects. Development of stem-break was, however, greatly influenced by conditions during growth of the plants, the highest levels of attack being associated with high air humidity.

Effect of Boron Supply on the Sugars, Soluble in 80 per cent Ethanol, in Flax Seedlings

FLAX plants (Linum usitatissimum var. Ventnor) were grown in nutrient cultures supplied with increasing concentrations of boron. The methods were such that an addition of 0.001 p.p.m. boron to the basal medium produced a large growth response. After four weeks the plants were harvested and weighed (Fig. 1). The 0 p.p.m. boron plants grew very little throughout the four weeks; both these and the 0.001 p.p.m. boron plants showed typical deficiency symptoms in stems and roots.

Environmental Conditioning of Flax

EXPERIMENTS carried out over a number of years have shown that remarkably large differences can be produced in the weight of flax plants as a result of the effect of the environment on previous generations of plants. In one experiment, all eight combinations of nitrogen, phosphorus and potassium fertilizer treatments were applied to forty plants of an inbred, self-fertilizing variety in the damp, dull season of 1954. The progeny, which were grown under a uniform set of fertilizer treatments, were cut at ground-level at maturity and weighed. The differences in the weights of the progeny (C 1 1955) due to the parental treatments are shown in Table 1. Some types are as much as two and three times the weights of others and, with the exception of the nitrogen plot, they are closely correlated with the weights produced by applying the fertilizers directly to the plants (Table 1, C 0 1955).