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At least 19 recordsLinked to original sources
PubMed1992

Early embryo invasion as a determinant in pea of the seed transmission of pea seed-borne mosaic virus.

Seed transmission of an isolate of pea seed-borne mosaic virus (PSbMV) in several pea genotypes has been studied. Cross-pollination experiments showed that pollen transmission of PSbMV did not occur and accordingly, virus was not detected in pollen grains by ELISA or electron microscopy. Comparative studies between two pea cultivars, one with a high incidence of seed transmission and one with none, showed that PSbMV infected the floral tissues (sepals, petals, anther and carpel) of both cultivars, but was not detected in ovules prior to fertilization. Virus was detected equally well in seed coats of the progeny in both cultivars. Analysis of virus incidence and concentration in pea seeds of different developmental stages demonstrated that in the cultivar with a high incidence of seed transmission, PSbMV directly invaded immature embryos, multiplied in the embryonic tissues and persisted during seed maturation. In contrast, the cultivar without seed transmission did not show invasion of immature embryos by the virus; there was no evidence for virus multiplication or persistence during embryo development and seed maturation. Hence seed transmission of PSbMV resulted from direct invasion of immature pea embryos by the virus and the block to seed transmission in the non-permissive cultivar probably occurred at this step.

Blotting, Northern↗
PubMed1992

Accumulation of a Brazil nut albumin in seeds of transgenic canola results in enhanced levels of seed protein methionine.

We have increased the methionine content of the seed proteins of a commercial winter variety of canola by expressing a chimeric gene encoding a methionine-rich seed protein from Brazil nut in the seeds of transgenic plants. Transgenic canola seeds accumulate the heterologous methionine-rich protein at levels which range from 1.7% to 4.0% of the total seed protein and contain up to 33% more methionine. The precursor of the methionine-rich protein is processed correctly in the seeds, resulting in the appearance of the mature protein in the 2S protein fraction. The 2S methionine-rich protein accumulates in the transgenic seeds at the same time in development as the canola 11S seed proteins and disappears rapidly upon germination of the seed. The increase in methionine in the canola seed proteins should increase the value of canola meal which is used in animal feed formulations.

Gene Expression↗
PubMed1977

[Nutritive-physiological study of sunflower seed protein isolate and spun sunflower seed protein-casein fibers].

Compared with defatted sunflower seeds, in sunflower seed globulin isolates the content of lysine and sulphur containing amino acids is decreased, the content of phenylalanine is increased. The content of the whole essential amino acids of sunflower seed globulin isolate in relation to casein is decreased. The value of the enzymatic invitro available amino acids of sunflower seed globulin is comparable with casein. The digestibility is good, the biological value is in relation to defatted sunflower seed lower. Apart from the lower content of sulphur-containing amino acids the amino acid composition of spun sunflower seed globulin/casein (I:I) fibers corresponds with the calculated value; in relation to sunflower seed globulin isolate the content of lysine and the whole essential amino acids of the spun protein fibers is increased. The enzymatic in-vitro-hydrolysis results altogether in a comparable availability of the amino acids between spun protein fibers and sunflower seed globulin isolates. The digestibility and the biological value of spun protein fibers corresponds with that of casein.

Amino Acids↗
PubMed2025

ODR1, the key seed dormancy and germination regulator, promotes seed Proanthocyanidin biosynthesis via interaction with TTG1 and modulation of MBW complex activity.

Seed dormancy and germination are crucial for both plant survival and reproduction and for crop sowing and harvesting. Proanthocyanidins (PAs), one of the most abundant seed metabolites, play a role in enhancing dormancy and inhibiting germination. Multiple regulatory factors involved in PAs biosynthesis can alter seed dormancy or germination capacity. However, whether the dormancy or germination factors reciprocally influence the PAs biosynthesis is unclear. Here, we report that ODR1, a seed dormancy and germination key factor and a transcriptional (co-) repressor, can regulate seed PAs biosynthesis and act as a transcriptional co-activator. The odr1 mutant shows lighter seed coat color, decreased PAs contents, and reduced expression of PAs biosynthesis genes, which are restored in the ODR1 complementary lines. ODR1 interacts with TTG1 and forms a complex with TTG1/TT2/TT8 (three MBW complex components), enhancing their activation on promoters of PAs biosynthesis genes like DFR and ANS. Overexpressing TTG1 in the odr1-2 mutant rescues or even reverses PA-related phenotypes of odr1-2, confirming that ODR1-mediated regulation of PAs biosynthesis is dependent on TTG1. Moreover, three homologous copies of ODR1 in rapeseed were identified, and simultaneous knockout of them reduces the PAs contents. These results revealed the previously uncharacterized functions of ODR1 in PAs biosynthesis, suggested its conservation between Arabidopsis and rapeseed, and provided important gene resources for rapeseed variety improvement.

Proanthocyanidins↗
PubMed1975

[Isothiocyanate and vinyl thio-oxazolidone contents of rape seeds and rape seed oil].

Comparative studies on the isothiocyanate content of rape-seeds and rape-seed oil show that, apart from nearly 300 mg/100 g of vinyl thio-oxazolidone, rape-seeds contain almost 200--300 mg/100 g of isothiocyanates of which 3-butenyl isothiocyanate and 4-pentenyl isothiocyanate (ratio of 4:1) are the main components as evidenced thin-layer and gaschromatographically. Only about 1 mg/100 g of isothiocyanates are found in pressed rape-seed oil; and but circa 10 mg/100 g, in extracted rape-seed oil. 3-Butenyl isothiocyanate and 4-pentenyl isothiocyanate (ratio of 4:1) are once more the main components. Thioglycerides are not detected in the oil. Vinyl thio-oxazolidone is found only in extracted rape-seed oil (about 2 mg/100 g).

Chromatography, Gas↗
PubMed1977

[Contamination of cotton seeds and of cotton seed cake by aflatoxin].

Following the discovery of aflatoxin M in cow's milk in the previous study, the contamination with aflatoxin of cotton-seed and cotton-seed cake which constitute the principal feed of local animals was measured. The samples were taken from 2 factories. The grain from the 1st factory was grown in the centre of the country in dry climate, and those from the 2nd source originated from the humid region of the north of Iran. The grain and cotton-seed cake from the 1st factory did not contain aflatoxin before storage. During storage the sample contamination amount and percent increased with time in both regions, with the dry less than the humid. In conclusion, Iranian cotton-seed and cotton-seed cake appear to be contaminated with aflatoxin B in 2 processes. The 1st is aflatoxin contamination before harvest, in the humid region of Iran; the 2nd is general storage aflatoxin contamination in both regions in which humidity and length of storage appear to be the principal factors.

Aflatoxins↗
PubMed1992

Differential manifestation of seed mortality induced by seed-specific expression of the gene for diphtheria toxin A chain in Arabidopsis and tobacco.

A pea vicilin promoter-diphtheria toxin A (DTx-A) chain gene fusion was introduced into Arabidopsis and tobacco. The chimeric Dtx-A gene behaves as a dominant, seed-lethal, Mendelian factor, and the segregation ratios are consistent with the numbers of integrated copies as revealed by Southern blotting. Germination deficiency results from distinct developmental abnormalities, thus allowing genetic dissection of seed development. The endosperm is affected first in both species. In Arabidopsis, full cellularization of the initially syncytial endosperm does not take place, which results in shrinkage and a shriveled appearance of the mature dry seed. The embryo, which appears structurally normal and lacks visible lesions, ceases to develop at the partially recurved cotyledon stage and does not use the remaining endosperm. In tobacco, peripheral degeneration and premature termination of cellular endosperm development occurs at the cotyledon initiation stage. Lesions appear in the cotyledons at the advanced cotyledon stage, but the embryo continues to grow and attains nearly the same size and level of differentiation as mature wild-type embryos before degeneration and intracellular disintegration take place throughout. Accumulation of protein bodies and other cytoplasmic inclusions is very limited and occurs only in few cells. The timing and distribution of lesions follow a pattern typical for accumulation of protein bodies in wild-type seeds. These observations are consistent with expression of the vicilin promoter in the enlargement phase of cell differentiation. A novel tissue interaction arises, when the embryo uses up all the arrested endosperm: the embryo proves to be capable of absorbing the parenchyma layers of the integument, which are normally obliterated by, and incorporated into, the endosperm.(ABSTRACT TRUNCATED AT 250 WORDS)

Arabidopsis↗
PubMed1977

Modification of the radiosensitivity of barley seed by post-treatment with caffein. IV. Effect of the moisture content of seed and storage temperature after irradiation.

The oxygen-dependent damage which develops in barley seeds with approximately 7-8 per cent moisture content disappears after post-irradiation storage in vacuo for 48 hours at 40 degrees C and for 24 hours at 50 degrees C. When the diration of storage at 40 degrees C is extended to 384 hours, oxygen-independent damage becomes potentiated. There is oxygen-dependent damage in seeds of approximately 13.3 per cent moisture content and after the seeds have been stored in vacuo at 50 degrees C, the oxygen-dependent damage begins to increase by 168 hours, and it is very significantly potentiated by 192 hours. Under these circumstances, caffeine acts as a radioprotector only as long as the precursors of oxic damage are present in the seeds. Once these sites are lost, caffeine acts only as a radiosensitizer. The oxygen-independent damage which increases with storage at high temperature is further potentiated by caffeine.

Caffeine↗
PubMed1992

Rice seed globulin: a protein similar to wheat seed glutenin.

The globulin of the seed endosperms of rice has an isoelectric point of 6.4 and a M(r) of 26,000. There is one intra-disulphide bond, but no N-linked oligosaccharide chain. The amino acid sequence of the N-terminal and internal regions of the globulin was determined and found to be homologous with that of glutenin, the storage protein in the seed endosperms of wheat. Rice globulin and wheat glutenin were rich in glycine, and glutamic acid or glutamine, and in addition, wheat glutenin cross-reacted with antibody raised against rice globulin. These results suggest that rice seed globulin represents a protein similar to wheat seed glutenin.

Amino Acid Sequence↗
PubMed1975

[Seed globulins from legumes. III. Seed globulins from broad bean (Vicia faba L.)].

The seed globulins from Vicia faba predominantly consist of two components, vicilin and legumin, which are exclusively deposited within the protein bodies of the storage cotyledons. The globulin biosynthesis commences with high intensity within a distinct phase during seed development as a consequence of reactivated genetic information. Isolation and purification of vicilin and legumin were achieved by a combination of zone precipitation, ion exchange chromatography, and gel filtration. Purity was controlled by disc electrophoresis on polyacrylamide e gels at pH 4.3 and by two dimensional immunoelectrophoresis, respectively. Vicilin prepared by zone precipitation and ion exchange chromatography consists of several serologically different proteins. One of them occupies the legumin position on polyacrylamide gels, although not identic with legumin, as revealed by tandem immunoelectrophoresis. The serological nonrelationship of vicilin and legumin was confirmed. Vicilin is characterized by micro heterogeneity which seems to indicate a molecular polymorphism.

Globulins↗
PubMed1992

Induction, purification and characterisation of acyl-ACP thioesterase from developing seeds of oil seed rape (Brassica napus).

The level of two thioesterases, acyl-CoA thioesterase and acyl-ACP thioesterase was determined during seed maturation in oil seed rape. Both thioesterase activities rose markedly prior to the onset of lipid accumulation, but the induction kinetics suggest that the activities reside on distinct polypeptides. Acyl-ACP thioesterase (EC 3.1.2.14) was purified 2000-fold using a combination of ion exchange, ACP-affinity chromatography, chromatofocusing and gel filtration. Using native gel electrophoresis, and assays for enzymic activity, two polypeptides were identified on SDS-PAGE as associated with the activity. Cleveland mapping of these polypeptides, of 38 kDa component and 33 kDa respectively, demonstrated that they are related. An antibody was prepared against the 38 kDa component, and this also recognises the 33 kDa polypeptide in highly purified preparations. Western blotting of a crude extract identifies one band at 38 kDa consistent with the 33 kDa component being a degradation product generated during purification. The native molecule has a M(r) of 70 kDa indicating a dimeric structure. The enzyme has a pH optimum of 9.5 and shows strong preference for oleoyl-ACP as substrate. The intact enzyme has an N-terminus blocked to protein sequencing. We also found that two other polypeptides co-purify with acyl-ACP thioesterase under native conditions. The N-terminal amino-acid sequence of these polypeptides is shown and their possible identity is discussed.

Amino Acid Sequence↗
PubMed1975

The contents of phytic acid in protein concentrates prepared from nigerseed, sunflower seed, rapeseed and poppy seed.

The contents of phytic acid were determined for protein-rich flours and protein concentrates prepared from nigerseed, sunflower seed, rapeseed and poppy seed. The values ranged from 6.89 to 8.80 mg phytate-P per g of fat free weight. This means that the phytate content of the analysed oilseed flours was at least about 4 times higher than the phytate content of common grain cereals. The precipitation of extracted phytic acid with trivalent Fe was an important step in the analytical procedure. The Fe:P mole ratios of the precipitates from the different oilseeds were lower than the corresponding ratios previously reported for cereal materials.

Edible Grain↗
PubMedDate not supplied

NMR study of seed hydration: the role of the seed anatomical structures in water uptake of soaked cowpeas.

A NMR method based on the analysis of the transverse magnetization decay curve of water protons, was employed to study the hydration process of commercial cowpeas. In order to investigate the role of the different anatomical parts of the seeds, hilum and micropyle, or alternatively seed coat, were inhibited by a water resistant epoxy resin. The kinetic constant for the hydration of the different sets of beans was measured.

Epoxy Resins↗
PubMedDate not supplied

Seeded growth of calcium phosphates: effect of different calcium phosphate seed material.

Seed crystals of OCP, TCP, and HAP are effective nucleators of DCPD in stable supersaturated solutions under conditions in which DCPD is the predominant phase. The crystals will grow with the second-order kinetics (TCa = 5.0 X 10(-3)M, Tp = 1.0 X 10(-2)M [pH, 5.60]) characteristic of DCPD. TCP is the least efficient, DCPD growth taking place only after an initial induction period. In all instances, the rate of DCPD crystallization is proportional to the square of the supersaturation with respect to DCPD, and the reaction is surface controlled. Scanning electron micrographs show an amorphous or microcrystalline precursor to the development of the characteristic platelets of DCPD. In stable supersaturated calcium phosphate solutions at a physiologic pH (TCa = 1.4 X 10(-3)M, Tp = 8.0 X 10(-4)M [pH, 7.40]), only OCP and HAP seed crystals are effective nucleators. The efficiency of OCP as a nucleator adds further evidence for its participation as a precursor in the precipitation of HAP under these conditions.

Calcium Phosphates↗
PubMed1992

Physico-chemical composition and characterisation of the seed and seed oil of Sclerocarya birrea.

The physicochemical composition of Sclerocarya birrea was assessed by standard methods and was found to contain 11.0% Crude oil, 17.2% Carbohydrate, 36.70% Crude protein 3.4% fibre and 0.9% crude saponins. The fatty acid distribution in the seed oil was obtained by fractionating the volatised fatty acid by GC-MS. The oil is made up of nine fatty acids of which palmitic, stearic and arachidonic acids are the most dominant.

Fruit↗
PubMed1992

Mechanism of ligand-protein interaction in plant seed thiamin-binding proteins. Probing the binding site of protein isolated from buckwheat seeds with a series of thiamin-related compounds.

Affinities of 14 thiamin derivatives or antagonists to a thiamin-binding protein isolated from buckwheat seeds were determined. A competitive displacement of radiolabeled thiamin by unlabeled ligand was analysed by a computerized model-fitting procedure. The dissociation constant of the thiamin-protein complex was 0.93 microM. Most modifications in ligand chemical structure weakened the ligand-protein interaction. A model of the thiamin-binding site is suggested. The hydroxyethyl-chain of thiamin while protein-bound appears to be excluded from the binding region. A positively charged quaternary nitrogen atom of the thiazolium ring probably interacts with some negative group(s) of protein. The rest of the thiazolium ring as well as the amino group of the pyrimidine fragment serve as additional anchors. The three structural features of the thiamin molecule accounting for binding contribute equally to overall binding energy by about 11-12 kJ/mol.

Binding Sites↗