Showing papers on "Endosperm published in 1973"
TL;DR: The data show that the endoplasmic reticulum is the exclusive site of lecithin formation in the castor bean endosperm and establish a central role for this cytoplasmic component in the biogenesis of cell membranes.
Abstract: The properties of a discrete membranous fraction isolated on sucrose gradients from castor bean endosperm have been examined. This fraction was previously shown to be the exclusive site of phosphorylcholine-glyceride transferase. The distribution of NADPH-cytochrome c reductase and antimycin insensitive NADH-cytochrome c reductase across the gradient followed closely that of the phosphorylcholine-glyceride transferase. This fraction also had NADH diaphorase activity and contained cytochromes b5 and P 450. On sucrose gradients containing 1 mM EDTA this fraction had a mean isopycnic density of 1.12 g/cm3 and sedimented separately from the ribosomes; electron micrographs showed that it was comprised of smooth membranes. When magnesium was included in the gradients to prevent the dissociation of membrane-bound ribosomes, the isopycnic density of the membrane fraction with its associated enzymes was increased to 1.16 g/cm3 and under these conditions the electron micrographs showed that the membranes had the typical appearance of rough endoplasmic reticulum. Together these data show that the endoplasmic reticulum is the exclusive site of lecithin formation in the castor bean endosperm and establish a central role for this cytoplasmic component in the biogenesis of cell membranes.
303 citations
TL;DR: A method is described for the isolation of wheat endosperm cell walls free from non-endospermic cell walls in a 70 % ethanol medium which prevents the loss of watersoluble polymeric components.
Abstract: A method is described for the isolation of wheat endosperm cell walls free from non-endospermic cell walls in a 70 % ethanol medium which prevents the loss of watersoluble polymeric components.
228 citations
TL;DR: In a 28-day isonitrogenous feeding experiment the weight gain of weanling rats was three times higher on an IS 11758 ration and twice as high on anIS 11167 ration as weight gains on rations prepared from normal sorghum lines.
Abstract: Seeds from over 9,000 lines in the world sorghum [Sorghum bicolor (L.) Moench] collection were classified for endosperm phenotype to identify floury endosperm lines and evaluate each for potential increases in lysine concentration. Sixty-two floury endosperm lines were selected and analyzed for protein and lysine composition. Two floury lines of Ethiopian origin, IS 11167 and IS 11758, were exceptionally high in lysine at relatively high levels of protein.
The average whole grain lysine concentration of high lysine lines IS 11167 and IS 11758 was 3.34 and 3.13 (g/lOOg protein) at 15.7 and 17.2% protein, respectively. Both lines were also high in percent oil. Carbohydrate analyses of whole grain samples of the two high lysine lines were similar to that of normal sorghum grain except for a twofold increase in sucrose concentration.
The high lysine gene altered the amino acid pattern in hl hl hl endosperm tissue relative to normal endosperm checks. The major changes were increased lysine, arginine, aspartic acid, glycine, and tryptophan concentrations and decreased amounts of glutamic acid, proline, alanine, and leucine in the hl hl hl endosperm.
Inheritance studies suggest that the increased lysine concentration of each line is controlled by a single recessive gene, although it is not known whether the genes from both lines are allelic. The high lysine gene(s) present in IS 11167 and IS 11758 from Ethiopia is (are) herein designated as hl. The endosperm of kernels homozygous for the hl gene is partially dented.
The biological value of the high lysine lines was much higher than that of average sorghum lines. In a 28-day isonitrogenous feeding experiment the weight gain of weanling rats was three times higher on an IS 11758 ration and twice as high on an IS 11167 ration as weight gains on rations prepared from normal sorghum lines. When fed rations without any dilution except the usual 2% vitamin and 4% mineral supplementation, rats gained 94 g on high lysine sorghum (IS 11758) and 28.5 g on our current best nutritional quality sorghum line (IS 2319), versus 91.5 g on opaque-2 corn (Zea mays L.) and 30.2 g on normal corn in a 28-day feeding trial. Feed efficiency ratios for this trial were 3.0 for high lysine sorghum, 6.8 for IS 2319, 3.4 for opaque-2 corn, and 7.4 for normal corn.
213 citations
TL;DR: The developmental behaviour of reproductive cells was studied during premeiotic mitotic activity, meiosis in anthers and ovaries, microsporogenesis, megasporogenesis and embryo and endosperm growth in Triticum aestivum L var.
Abstract: The developmental behaviour of reproductive cells was studied during premeiotic mitotic activity, premeiotic interphase, meiosis in anthers and ovaries, microsporogenesis, megasporogenesis and embryo and endosperm growth in Triticum aestivum L. var. Chinese Spring. Particular attention was paid first to the timing and rate of cell development in the anthers and the ovary within a floret and secondly , to the timing and rate of nuclear and cell development in the young embryo and endosperm. At 20 °C the development studied lasted in each floret about 21 days starting 7 days prior to meiosis in anthers and ending 5 days after anther dehiscence and pollination. The durations of up to twenty successive cell cycles were estimated. In anthers of plants grown at 20 °C the durations of the three successive cell cycles immediately prior to the cycle which ends at first anaphase of meiosis were about 25, 35 and 55 h respectively. The increase in cell cycle time was correlated with an increase in the size of archesporial cells and their nuclei. A progressive increase in the durations of successive cell cycles as meiosis is approached has not been measured previously in a higher plant species, although it has been noted in the germ line cells of male mice. The pollen mother cells (p.m.cs) within an anther were synchronized prior to meiosis by having their development blocked somewhere in G 1 of premeiotic interphase. The developmental hold began to operate about 103 h prior to the synchronous onset of meiosis in all the p.m.cs within an anther at 20 °C. About 55 h later, when the last archesporial cell completed its final premeiotic mitosis, all the p.m.cs had accumulated in G 1 of premeiotic interphase and synchrony was complete. Premeiotic interphase after all the p.m.cs were first synchronized in G 1 until the synchronous onset of meiosis lasted about 48 h. During this period the G 1 developmental hold was released and p.m.cs initiated DNA synthesis synchronously about 12 to 15 h prior to the start of leptotene. Meiosis in p.m.cs lasted 24 h at 20 °C. Within each floret, meiosis in p.m.cs was almost or quite synchronous with, and had the same duration as, meiosis in the embryo sac mother cell. The Q 10 for meiosis in p.m.cs over the temperature range 15 to 25 °C was about 2.3. Microsporogenesis from tetrad stage until anther dehiscence lasted about 7.5 days at 20 °C. The first pollen grain mitosis (p.g.m. 1) occurred 2.5 days and second pollen grain mitosis (p.g.m. 2) 5.0 days after the end of meiosis. Concurrent with p.g.m. 1 the functional megaspore in the ovule of the same floret divided. This division was rapidly followed by two more synchronous division cycles (also concurrent with p.g.m. 1) which produced an 8-nucleate embryo sac. By p.g.m. 2 the embryo sac contained 20 to 30 antipodal cells at its chalazal end. The antipodal cells subsequently became highly polyploid and some eventually contained up to 200 times as much DNA as haploid egg nuclei. At 20 °C the sperm nuclei reached the egg and polar nuclei about 40 min after pollination. The primary endosperm nucleus divided about 6 h after pollination while the zygote did not divide until about 22 h after pollination. The endosperm often contained 16 mitotic nuclei 24 h after pollination. The nuclear division cycle during the first five division cycles was about 4.5 h. Until the tenth division cycle when the endosperm became a cellular tissue, development of endosperm nuclei was synchronous, but thereafter synchrony was progressively lost. Early embryo development was marked by a gradual decrease in the durations of successive cell cycles. This decrease was apparently correlated with a decrease in the size of embryo cells and their nuclei. Nuclear and cellular developmental rates at 20 °C were very variable. Estimates of nuclear cycle times ranged from about 60 h in the microspore to about 4.5 h in some endosperm nuclei. Nuclear volume was also very variable and ranged from about 240 μm 3 for sperm nuclei in mature microspores to about 160000 μm3 in some polyploid antipodal cells. Both the wide range of nuclear types described, and the speed with which nuclear characters changed, illustrates the remarkable plasticity of the wheat nucleus which may occur in several very different forms. A comprehensive and integrated study of development at the cellular level in reproductive tissues of a higher plant species is presented. The importance of this study is twofold. First, it allows the comparison of reproductive cell behaviour in a higher plant species and in those animal species which have been intensively examined. Secondly the availability of a description of ‘normal’ development under controlled conditions in euploid plants of Chinese Spring opens the way for comparative studies using the wide range of available mutant or chromosomally different genotypes of Chinese Spring which are known to vary in their reproductive development.
176 citations
TL;DR: The degeneration of one synergid denotes the initiation of embryo and endosperm development in the embryo sac of sunflower Helianthus annuus L and the persistent synergid is present until the late globular stage of embryogenesis.
Abstract: The degeneration of one synergid denotes the initiation of embryo and endosperm development in the embryo sac of sunflower Helianthus annuus L. The other synergid, the persistent synergid, is prese...
154 citations
TL;DR: In photosynthetic tissue, the enzyme is located outside the chloroplast, and at in vivo levels of triose-phosphates and pyridine nucleotides, the activity is probably greater than that of DPN-linked reversible d-glyceraldehyde 3-ph phosphate dehydrogenase.
Abstract: Preparations of TPN-linked nonreversible d-glyceraldehyde 3-phosphate dehydrogenase (EC 1.2.1.9), free of TPN-linked reversible d-glyceraldehyde 3-phosphate dehydrogenase, have been obtained from green shoots, etiolated shoots, and cotyledons of pea (Pisum sativum), cotyledons of peanut (Arachis hypogea), and leaves of maize (Zea mays). The properties of the enzyme were similar from each of these sources: the Km values for d-glyceraldehyde 3-phosphate and TPN were about 20 μm and 3 μm, respectively. The enzyme activity was inhibited by l-glyceraldehyde 3-phosphate, d-erythrose 4-phosphate, and phosphohydroxypyruvate. Activity was found predominantly in photosynthetic and gluconeogenic tissues of higher plants. A light-induced, phytochrome-mediated increase of enzyme activity in a photosynthetic tissue (pea shoots) was demonstrated. Appearance of enzyme activity in a gluconeogenic tissue (endosperm of castor bean, Ricinus communis) coincided with the conversion of fat to carbohydrate during germination. In photosynthetic tissue, the enzyme is located outside the chloroplast, and at in vivo levels of triose-phosphates and pyridine nucleotides, the activity is probably greater than that of DPN-linked reversible d-glyceraldehyde 3-phosphate dehydrogenase. Several possible roles for the enzyme in plant carbohydrate metabolism are considered.
116 citations
TL;DR: It is concluded that the galactomannan of fenugreek is broken down by a series of hydrolases secreted by the aleurone layer of the endosperm, which include α-galactosidase, β-mannosidases and probably also endo-β-mannanase.
Abstract: The activities of α-galactosidase, β-mannosidase and α-mannosidase were determined in extracts from the endosperm and from the embryo of fenugreek seeds at different stages of germination.
Endosperm homogenates contained little or no activity of the above enzymes in the early stages of germination, before the reserve galactomannan began to be mobilised. The onset of galactomannan breakdown coincided with the appearance of α-galactosidase and β-mannosidase activities, which increased throughout the period of galactomannan degradation and then remained constant. A similar rise in α-galactosidase and β-mannosidase activities occurred during galactomannan breakdown in dry-isolated endosperms incubated under germination conditions. The increase could be suppressed by metabolic inhibitors which also inhibit galactomannan breakdown.
Embryo homogenates contained high α-galactosidase, high α-mannosidase and some β-mannosidase activity at all stages of germination. No “oligomannosyl β-1,4 phosphorylase” activity could be detected either in the endosperm or in the embryo. It is concluded that the galactomannan of fenugreek is broken down by a series of hydrolases secreted by the aleurone layer of the endosperm. They include α-galactosidase, β-mannosidase and probably also endo-β-mannanase.
107 citations
TL;DR: The results and those reported previously on lecithin synthesis establish a major role of the endoplasmic reticulum in phospholipid and membrane synthesis in plant tissues.
Abstract: The intracellular location of several enzymes concerned with phospholipid metabolism was investigated by examining their distribution in organelles separated on sucrose gradients from total homogenates of castor bean (Ricinus communis var Hale) endosperm The enzymes phosphatidic acid phosphatase, CDP-diglyceride-inositol transferase, and phosphatidyletha-nolamine-l-serine phosphatidyl transferase were all primarily or exclusively confined to membranes of the endoplasmic reticulum These results and those reported previously on lecithin synthesis establish a major role of the endoplasmic reticulum in phospholipid and membrane synthesis in plant tissues
106 citations
TL;DR: Water and alkali-soluble arabinoxylans from isolated wheat endosperm cell walls were examined by ammonium sulphate fractionation and gel-exclusion chromatography as mentioned in this paper.
Abstract: Water- and alkali-soluble arabinoxylans from isolated wheat endosperm cell walls were examined by ammonium sulphate fractionation and gel-exclusion chromatography.
90 citations
TL;DR: Experiments with three seed-propagated mother plants indicated that the water potential of embryos may be reduced by high mother plant temperature, and both the embryos and the seeds of S. reflexa were dormant at the time of termination of embryo elongation.
Abstract: Effects of controlled temperature conditions during seed development on seed and embryo germination of Syringa vulgaris were studied using vegetatively propagated mother plants. Seeds from mother plants grown at 18–24°C were partially dormant at low (15°C) but not at high (21°C) germination temperature, while seeds from outdoors or from plants grown at 12°C were not dormant at all. Seed dormancy at low temperatures was induced as well when branches from outdoor plants were kept at 18–24°C for the last two-three weeks before harvesting. The dormancy induced by 24°C during seed development was not broken by keeping branches at 12°C for the last two-three weeks. In most cases the induced seed dormancy was broken completely by gibberellic acid.
Embryo germination at 24 or 15°C was not affected by mother plant temperature. Part of the embryos from plants grown at 24°C were, however, dormant at 9°C. The ability of embryos to germinate in osmoticum was only slightly affected by mother plant temperature.
The mechanical resistance of the endosperm was significantly higher in the seeds from plants grown at 24°C than in seeds from 12°C.
Both the embryos and the seeds of S. reflexa were dormant at the time of termination of embryo elongation. Experiments with three seed-propagated mother plants indicated that the water potential of embryos may be reduced by high mother plant temperature.
74 citations
TL;DR: In this article, a sample of Cappelle Desprez wheat was separated from a sample by micro-sieving technique and the smaller granules were found to contribute some 30% of the total weight of the starch.
Abstract: Starch granules of less than 10 μm in diameter have been separated from a sample of Cappelle Desprez wheat by a micro-sieving technique. These smaller granules were found to contribute some 30% of the total weight of the starch.
TL;DR: Endosperm liquid bathes the embryo of Phaseolus vulgaris from the heart stage through the late cotyledon state and was aspirated from many ovules of the same stage and analyzed for constituents and parameters.
Abstract: Endosperm liquid bathes the embryo of Phaseolus vulgaris from the heart stage through the late cotyledon state. This liquid was aspirated from many ovules of the same stage, pooled, and analyzed for the following constituents and parameters: [List: see text]
TL;DR: When [8-(14)C]-N(6)-(Delta(2)-isopentenyl) adenosine is incubated with the endosperm of corn (2 weeks after pollination), it is converted to N(6)(4-hydroxy-3-methylbut-2-trans-enyl), trans-ribosylzeatin, which occurs in the mycorrhizal fungus, Rhizopogon roseolus.
Abstract: When [8-14C]-N6-(Δ2-isopentenyl) adenosine is incubated with the endosperm of corn (2 weeks after pollination), it is converted to [14C]-N6-(4-hydroxy-3-methylbut-2-trans-enyl) adenosine, trans-ribosylzeatin. This biosynthetic step, N6-(Δ2-isopentenyl) adenosine to ribosylzeatin, also occurs in the mycorrhizal fungus, Rhizopogon roseolus.
TL;DR: The water soluble polsaccharide which is the predominant product at 100 μM UDPG was examined by enzymic hydrolysis and shown to be a β-1,3;1,4-glucan similar to the glucan present in the Lolium endosperm cell walls.
Journal Article•
TL;DR: The ultrastructure of endosperm protein from 7 habrids and 8 experimental lines was studied with both transmission and scanning electron microscopes as discussed by the authors, showing that protein bodies made up the major part of sorghum protein.
Abstract: The ultrastructure of endosperm protein from 7 habrids and 8 experimental lines was studied with both transmission and scanning electron microscopes. Vitreous endosperm shows a well-developed 2-component structure consisting of protein bodies embedded in a matrix protein. The aqueous alcohol-soluble fraction (prolamine) proved to be the major component of globular protein bodies. The surrounding matrix protein consisted mostly of glutelin. Globular protein bodies have a nuclear that is insoluble in aqueous alcohol. Protein bodies of almost all grain sorghums were 2-3 μm, in diam. One experimental line with above average lysine content had smaller protein bodies, a condition which verifies the negative correlation between prolamine and lysine. Distribution of protein within the sorghum kernel is similar to that of other cereal grains. The peripheral vitreous area of the kernel is rich in protein; interior areas have smaller amounts of protein. Microscopic observations show that protein bodies make up the major part of sorghum endosperm protein.
TL;DR: In GA3-treated tissue, the amylase distribution was much more diffuse, although patchy, throughout the cytoplasm and it tended to accumulate in the endosperm side of the cell.
Abstract: Gibberellic-acid(GA3)-induced α-amylase has been localised in barley aleurone layers using cytochemical methods and light microscopy. Evidence obtained from the use of a starch substrate film method as well as immunofluorescence indicated that the first amylase to appear in the cell was associated with aleurone grains, apparently with the outer membrane, and also with the peripheral cytoplasm. In GA3-treated tissue, the amylase distribution was much more diffuse, although patchy, throughout the cytoplasm and it tended to accumulate in the endosperm side of the cell. The possibility that the aleurone grain membrane is the site of gibberellin-induced enzyme synthesis and that it proliferates to become rough endoplasmic reticulum is considered. Immunological information was obtained which supports earlier indications that induced α-amylase consists of two different proteins, each with molecular heterogeneity.
TL;DR: The mixed diet supported growth better than any one of the pure fractions or any wheat diet previously tested by us and was superior to germ, the best of thepure fractions, because it was more digestible and the digested portion was more efficiently utilized for growth.
TL;DR: The activity of β-amylase in both the available and latent forms reached a maximum value at 35 days after anthesis which did not decrease thereafter, and the phosphorylase activity was low and mainly associated with the endosperm fraction.
Abstract: The enzymes α-amylase (α-1, 4-glucan 4-glucanohydrolase, 3.2.1.1), β-amylase (α-1,4-glucan maltohydrolase, 3.2.1.2) and phosphorylase (α-1,4-glucan: orthophosphate glucosyltransferase, 2.4.1.1) were assayed in whole grains of barley throughout the maturation period. α-amylase and phosphorylase had peaks of activity between 25 and 30 days after anthesis. On the other hand the activity of β-amylase in both the available and latent forms reached a maximum value at 35 days after anthesis which did not decrease thereafter. β-amylase activity was also assayed throughout development in the endosperm, aleurone, testa pericarp and embryo. Latent β-amylase reached a constant maximum value in endosperm at 35 days but available β-amylase reached a peak of activity at 25 days and then declined to zero at 45 days. Only latent β-amylase was associated with the aleurone layer and activity rose to a maximum value at 35 days. The testa pericarp had mainly latent β-amylase whose activity fell from an early maximum at 21 days to zero at 35 days. No hydrolytic activity was associated with the embryo. The phosphorylase activity was low and mainly associated with the endosperm fraction.
TL;DR: A specific β-glucan hydrolase has been used to determine the content of this mixed-linked glucan in isolated endosperm cell walls, and was shown to be a β-1,3; 1,4- glucan with approx.
TL;DR: A tentative scheme is postulated describing the structural organization of fatty acid β-oxidation and of the glyoxylate cycle in glyoxysomes.
Abstract: A procedure was developed for the isolation of membranes of glyoxysomes from the endosperm of germinating castor beans (Ricinus communis L. var. zanzibariensis). These membranes were prepared by osmotic-shock treatment of isolated glyoxysomes. In some cases this was followed by mild sonication. They were isolated by centrifugation on to a 57% (w/w) sucrose layer and purified by isopycnic sucrose gradient centrifugation.
The membrane preparations were characterized by electronmicroscopy and assayed for enzyme activities. They consisted mainly of ghost-type vesicles and were found to contain a major part of fatty acid β-oxidation, malate synthase, citrate synthase and antimycin-A-insensitive NADH-cytochrome c reductase activities of the whole glyoxysomes. Malate dehydrogenase may also be bound to the membrane to a significant extent. A tentative scheme is postulated describing the structural organization of fatty acid β-oxidation and of the glyoxylate cycle in glyoxysomes.
TL;DR: High protein endosperm produced more vigorous seedlings regardless of the embryo type grown on it, indicating that the factor(s) responsible for the greater growth of high protein seed is in the endos sperm.
Abstract: Seed of a Mexican semidwarf wheat (Triticum aestivum L. cv. Inia 66), was obtained from a nitrogen fertilizer field trial grown in Mexico. A high positive correlation was obtained between seed protein content and seedling dry weight after 3 weeks growth (r = +0.92**). The seedling dry weight was positively related to the protein content of the aleurone layer and endosperm, but not to the embryo. Small, 35 milligrams, high protein seeds (4.7 milligrams protein per seed) produced larger seedlings than large, 45 milligrams, low protein seeds (4.3 milligram protein per seed). There was no difference in the weight or protein content of embryos from low and high protein seeds and their growth was similar. Composite seeds of the two protein levels were produced by transferring embryos from one endosperm type to the other. After 4 weeks, there was no difference between the different embryo types grown on the same endosperm type. High protein endosperm produced more vigorous seedlings regardless of the embryo type grown on it, indicating that the factor(s) responsible for the greater growth of high protein seed is in the endosperm.
TL;DR: The mechanism of seed dormancy at low temperatures (15-9°C) was investigated in the seeds of Syringa josikaea, S. reflexa and S. vulgaris, and the results indicate that it prevents germination mainly due to its mechanical resistance.
Abstract: The mechanism of seed dormancy at low temperatures (15-9°C) was investigated in the seeds of Syringa josikaea, S. reflexa and S. vulgaris. Low temperature dormancy in Syringa species was mainly imposed by endosperm embedding the radicle. Different degrees of embryo dormancy may occur in S. reflexa seeds. In most cases the low temperature dormancy was broken completely by removing the endosperm around the radicle. The endosperm did not seem to contain significant quantities of germination inhibitors, and the results indicate that it prevents germination mainly due to its mechanical resistance. The mechanical resistance of endosperm did not change during chilling or during induction of dormancy by high temperature incubation. The strength of the endosperm decreased rapidly in non-dormant seeds before visible germination. Similar changes were not observed in dormant seeds. Generally, the strength of the endosperm was lower in the non- (or less) dormant species S. josikaea and S. vulgaris than in the more dormant S. reflexa seeds. The growth potential of the embryos, measured as their ability to germinate in osmotic solutions (mannitol or polyethylen glycol 4000), was increased by chilling and by GA3-treatment. The growth potential of untreated S. josikaea and S. vulgaris embryos was generally higher than that of S. reflexa embryos. Acid ethyl acetate fractions of methanol extracts from embryos of all three species contained substances with GA3-like activity in the lettuce hypocotyl test. The activity was found at Rf 0.9–1.0 on paper chromatograms run in distilled water. No significant changes in the activity were detected during chilling or prior to visible germination.
TL;DR: Four types of wall formation occur in the endosperm of chickweed Stellaria media (L.) Cyrill: freely growing walls form at the edges of the micropylar region of the embryo sac during the early heart stage of embryogenesis, and anastomosing walls which form independently of a mitotic spindle.
Abstract: Four types of wall formation occur in the endosperm of chickweed Stellaria media (L.) Cyrill. Freely growing walls form at the edges of the micropylar region of the embryo sac during the early heart stage of embryogenesis; Golgi and dilated endoplasmic reticulum may be sources of precursors for these anastomosing walls which form independently of a mitotic spindle Other walls form by means of cell plates and in a manner similar to wall regeneration reported in protoplasts. Also, wall ingrowths of the transfer cell type form on the embryo sac wall in the micropylar region and protrude into the endosperm.
TL;DR: Log phase cells of L. multiflorum endosperm grown in liquid suspension cultures contain large nuclei, mitochondria, protein bodies, compound starch granules, small vacuoles, and multilayered membranous structures.
Abstract: Log phase cells of L. multiflorum endosperm grown in liquid suspension cultures contain large nuclei, mitochondria, protein bodies, compound starch granules, small vacuoles, and multilayered membranous structures. At later stages of growth the cell organelles, protein bodies, and starch granules disappear and in senescent cultures many empty cells are seen.
TL;DR: Variations in activity of several enzymes associated with carbohydrate metabolism were recorded during the development of barley endosperm, including sucrose-UDP glucosyl transferase, and nucleosidediphosphokinase.
TL;DR: In this article, it was shown that in continuously growing callus the capacity for differentiation of organs is lost with a concurrent increase in the ploidy of the cells, and the embryo-effect can be replaced by pre-soaking the endosperm pieces in GA3 solution.
Patent•
15 Feb 1973
TL;DR: In this article, a method for HYDROPROCESSINFG WHEAT, RYE and OATS to separate the endosperm from the HUSK and the GERM TisSUES was presented.
Abstract: 1. A METHOD FOR HYDROPROCESSINFG WHEAT, RYE AND OATS TO SEPARATE THE ENDOSPERM FROM THE HUSK AND THE GERM TISSUES, SAID PROCESS COMPRISING THE STEPS OF: (A) STEEPING 1 PART BY WEIGHT OF GRAIN SELECTED FROM THE GROUP CONSISTING OF WHEAT, RYE, AND OATS IN AT LEAST 1.5 PARTS BY WEIGHT OF AN AQUEOUS ACID STEEPING MEDIUM AT TEMPERATURES RANGING FROM ABOUT 18* C. TO ABOUT 45* C. UNTIL THE GRAIN HAS SORBED STEEPING MEDIUM EQUIVALENT TO ABOUT 56% TO ABOUT 95% BY WIEGHT OF THE GRAIN, AID STEEPING MEDIUM CONTAINING ACID IN CONCENTRATION AND QUANTITY SUFFICIENT TO MAINTAIN THE PH OF SAID STEEPING MEDIUM EXTERNAL OF THE GRAIN BETWEEN 0.8 AND 2.5 AND TO REDUCE THE INTERNAL PH OF THE HYDRATED GRAIN TO SPLIT THE HUSK AND (B) MACERATING THE HYDRATED GRAIN TO SPLIT THE HUSK AND EXPOSE THE ENDOSPERM AS A PLASTIC MASS WHILE MAINTAINING AT LEAST 90% BY WEIGHT OF THE HUSK AND THE GERM ABOVE A MINIMUM DIMENSION OF 300 MICRONS; (C) DISPERSING THE MACERATED GRAIN IN AN AQUEOUS DISPERSING MEDIUM TO A SOLIDS CONCENTRATION OF FROM 4% TO ABOUT 30% AND MAINTAINING THE PH OF SAID DISPERSION BETWEEN ABOUT 2.4 AND 3.4; THE DISPERSING SHEAR BEING SUFFICIENT TO DISENGAGE THE ENDOSPERM FROM THE HUSK AND THE GERM TISSUES; AND (D) SEPARATING SAID DISPERSION INTO A PARTICULATE HUSK AND GERM FRACTION AND AN ENDOSPERM DISPERSION WHILE MAINTAINING THROUGHOUT THE PROCESS SUBSTANTIALLY ALL OF THE STARCH GRANULES IN AN INTACT, UNGELATINIZED FORM AND MAINTAINING SUBSTANTIALLY ALL OF THE GLUTEN PROTEIN IN A DISPERSIBLE AND SUBSTANTIALLY UNDERNATURED STATE WITH RESPECT TO DOUGHING FUNCTION.
TL;DR: Hexokinase (EC 2.7.1) was isolated from endosperm and scutellum of developing and germinating maize (Zea mays) seeds and a low affinity binding of glucose may have regulatory significance and may indicate the presence of a glucokinase in addition to hexokinase.
Abstract: Hexokinase (EC 2.7.1.1) was isolated from endosperm and scutellum of developing and germinating maize (Zea mays) seeds. With fructose as the variable substate, Michaelis constant values for the scutellum enzyme were about onethird those of the endosperm enzyme (0.05 versus 0.15 mm), and no developmental differences were observed. With glucose as the variable substrate, Michaelis constant values were all in the range 0.1 to 0.2 mm. The enzyme preparation from germinating scutellum was studied further; when glucose was varied over a wide range, a Michaelis constant of 3.4 mm was observed in addition to the much lower Michaelis constant noted above. This low affinity binding of glucose may have regulatory significance and may indicate the presence of a glucokinase in addition to hexokinase.
Patent•
05 Nov 1973
TL;DR: In this article, a process for recovering starch and corn oil from corn kernels is described, where the corn kernels are dry milled to separate the hulls and germ from the endosperm fractions.
Abstract: A process for recovering starch and corn oil from corn kernels. The corn kernels are dry milled to separate the hulls and germ from the endosperm fractions. At least some of the endosperm fractions are steeped in separating the starch from the gluten. The gluten is dried and the separated germ and the dried corn gluten are subjected to solvent extraction to recover corn oil.