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PubMed1990

Maltooligosaccharide composition of flours, weaning foods, and gruels prepared from germinated rice, corn, mungbean, and cowpea.

Germinated rice, corn, mungbean, cowpea, and weaning foods prepared from their selected combinations were studied for their saccharide profile by TLC, total and soluble sugars content, and amylase activities in the flour and gruel samples. The enzyme system present in the germinated materials resulted in the partial digestion of carbohydrates into maltooligosaccharides, as shown by TLC pattern and soluble sugars determination of all materials germinated for 48, 72, and 96 h. Rice had the highest concentration of amylase, followed by cowpea, corn, and mungbean. The amylolytic activity produced during germination was retained in the flour despite drying and roasting processes involved. The processes of germination and gruel preparation of germinated materials contributed to the digestibility of weaning foods prepared from cereals and legumes.

Amylases↗
PubMed1979

Structure of the germinal centers in the chicken caecal tonsil: light and electron microscopic and autoradiographic studies.

The light and electron microscopic structure of the germinal center of chicken caecal tonsils were studied. Two kinds of germinal centers were revealed; the first was located deep in the lymphatic tissue close to the muscle layer of the caeca. These germinal centers frequently have an incomplete capsule, and are not, therefore, separated from the diffuse lymphatic tissue. The second kind of germinal center was located closer to the epithelium and had a complete capsule separating it from the diffuse lymphatic tissue. Both germinal centers possessed an outer dark cortical zone which contained smaller lymphoblasts (of less than 10 micron in diameter) and a central medullary area which contained larger lymphoblasts (up to 16 micron). Autoradiographic studies revealed that the small lymphoblasts of the outer cortical zone are concerned with cell generation and that the large lymphoblasts of the medullary area may have derived from the small lymphocytes. Within the medullary area of the germinal center are cells which are embedded in an intercellular substance of high density. We propose that the intercellular substance may be a product of this cell. For discussion purposes we have called this cell a secretory cell. The secretory cell may originate from a small lymphocyte-like cell.

Aging↗
PubMedDate not supplied

Generality of the prerequisite of conidium attachment to a hydrophobic substratum as a signal for germination among Phyllosticta species.

It has been shown that conidia of Phyllosticta ampelicida require attachment to a substratum to initiate germination. Furthermore this attachment occurs only on hydrophobic surfaces. This study was initiated to ascertain the breadth of this phenomenon among other species of the genus Phyllosticta. We tested 23 isolates of Phyllosticta representing at least 14 named species. These isolates were collected from North America, Asia and Africa. For 22 of the 23 isolates tested spore attachment occurred at a rate of 60-100% on hydrophobic polystyrene but at 0-5% on hydrophilic polystyrene. The one exception to the preference for a hydrophobic substratum for attachment was an unnamed species of Phyllosticta from Rhus glauca that attached less than 10% on either surface. A similar response was observed when assaying germination and appressorium formation for 17 isolates. Germination and appressorium formation for these isolates proceeded on hydrophobic polystyrene but not on nutrient agar, which is hydrophilic. In five of the tested isolates germination was high on both hydrophobic polystyrene and hydrophilic nutrient media. The isolate from Rhus glauca did not germinate appreciably on either surface. Taken together these results suggest that the requirement for conidium contact/attachment to trigger germination is pervasive to the genus Phyllosticta.

Ascomycota↗
PubMed2000

Modeling the germination kinetics of clostridium botulinum 56A spores as affected by temperature, pH, and sodium chloride.

The germination kinetics of proteolytic Clostridium botulinum 56A spores were modeled as a function of temperature (15, 22, 30 degrees C), pH (5.5, 6.0, 6.5), and sodium chloride (0.5, 2.0, 4.0%). Germination in brain heart infusion (BHI) broth was followed with phase-contrast microscopy. Data collected were used to develop the mathematical models. The germination kinetics expressed as cumulated fraction of germinated spores over time at each environmental condition were best described by an exponential distribution. Quadratic polynomial models were developed by regression analysis to describe the exponential parameter (time to 63% germination) (r2 = 0.982) and the germination extent (r2 = 0.867) as a function of temperature, pH, and sodium chloride. Validation experiments in BHI broth (pH: 5.75, 6.25; NaCl: 1.0, 3.0%; temperature: 18, 26 degrees C) confirmed that the model's predictions were within an acceptable range compared to the experimental results and were fail-safe in most cases.

Animals↗
PubMed2005

Modeling the effect of ethanol vapor on the germination time of Penicillium chrysogenum.

The influence of ethanol vapor on germination of Penicillium chrysogenum was determined on yeast nitrogen base plus glucose agar medium at 25 degrees C. Ethanol vapors were generated by 0 to 6% (wt/wt) ethanol solutions at the bottom of hermetically closed petri dishes. The logistic equation was used to describe the data as the percentage of germination versus time and to estimate the germination time. The effect of ethanol concentration on germination time was described by a new reparameterized equation, resulting in an estimated limiting ethanol concentration of 4.3%. Up to 3% ethanol, all spores germinated, and the germination time increased with increasing ethanol concentration. At 3.5 and 4%, some spores formed abnormal germ tubes and others were inhibited at the swelling stage. The inhibiting effect of ethanol was reversible under these experimental conditions.

Dose-Response Relationship, Drug↗
PubMed2001

Interspecific and intraspecific variation in seed size and germination requirements of Sarracenia (Sarraceniaceae).

Seed size and germination requirements of eight (of nine) Sarracenia species, and 13 populations of S. purpurea were studied. All species except for S. purpurea are restricted to the southeastern United States, whereas S. purpurea ranges across Canada, southward along the eastern United States into Maryland and Virginia (S. purpurea ssp. purpurea), and from New Jersey southward into northern Florida and the coast of the Gulf of Mexico (S. purpurea ssp. venosa). I tested the hypotheses that dormancy-breaking requirements vary predictably among species across a latitudinal gradient. I also sought to determine whether seed size and germination requirements were useful characters for resolving systematic and phylogenetic questions within this genus. Seed size varied significantly among species, but variability in seed size within S. purpurea exceeded the variability in seed size observed across all eight species studied. Seeds of all species are morphophysiologically dormant upon dispersal. Length of required cool, moist pretreatment varied among species, and germination in higher latitude populations is enhanced with longer pretreatment. In contrast, variability in germination requirements of subspecies, varieties, and populations of the geographically wide-ranging S. purpurea was not related clearly to geographic location (latitude or elevation). Germination requirements do not map onto a proposed phylogeny of Sarracenia, but observed differences in germination requirements of S. purpurea ssp. venosa var. burkii relative to other populations of S. purpurea support the recent proposal to elevate this variety to species status.

Journal Article↗
PubMed2002

Effects of EDTA saturated with Ca2+ (Ca-EDTA) on pig, bovine and mouse oocytes at the germinal vesicle stage during maturation culture and the involvement of chelation of Zn2+ in pronuclear formation induction by Ca-EDTA.

EDTA saturated with Ca(2+), Fe(3+) or Cu(2+) can induce parthenogenetic activation of pig oocytes at the germinal vesicle stage, whereas EDTA saturated with Zn(2+), which is unable to chelate Zn(2+), does not, indicating that chelation of Zn(2+) with EDTA saturated with Ca(2+) (Ca-EDTA) in maturing pig oocytes plays a pivotal role in the induction of parthenogenetic activation of oocytes. In the present study, the involvement of Zn(2+) chelation in the induction of parthenogenetic activation of pig oocytes at the germinal vesicle stage was confirmed first by examining the effects of concomitant addition of Zn(2+), Cu(2+) or Ni(2+) at various concentrations together with 1 mmol Ca-EDTA l(-1) to the maturation medium. The titration experiments revealed that the pronuclear formation induced by 1 mmol Ca-EDTA l(-1) was completely inhibited by the addition of > 30 micromol Zn(2+) l(-1) to the medium, but not by the addition of Cu(2+) and Ni(2+) at any concentration examined. Second, bovine and mouse oocytes at the germinal vesicle stage were cultured in medium with or without 1 mmol Ca-EDTA l(-1) for 48 h to examine the effects of Ca-EDTA treatment on these oocytes during maturation culture. Most (70-86%) of the bovine oocytes that underwent germinal vesicle breakdown matured to the MII stage via the MI phase, regardless of whether Ca-EDTA was present for the first 24 h of culture. However, 61% of oocytes that had been cultured with Ca-EDTA for 48 h formed a pronucleus without a second polar body, whereas oocytes cultured in the absence of Ca-EDTA were not observed to form a pronucleus at any time during culture. However, even when mouse oocytes at the germinal vesicle stage were cultured for up to 48 h in maturation medium containing Ca-EDTA, pronuclear formation was not observed. Finally, when bovine oocytes that had been cultured with 1 mmol Ca-EDTA l(-1) for 48 h from the germinal vesicle stage were cultured further in medium without Ca-EDTA that was supplemented with 5% fetal calf serum, only 26% of the oocytes developed to the cleaved stage, and none could develop further.

Animals↗
PubMed2003

[Distribution and germination of Alexandrium sp. cysts in coastal areas of Southeast China Sea].

Studies on the distribution and germination of Alexandrium sp. (A. tamarense + A. catenella) cysts in coastal areas of Southeast China showed that the cysts were only found at X1 and X2 of Xiamen Harbor, whose density was quite low (0.4 ind.g-1). In Guangxi, the cysts were found at G2 station, with a density of 2.5 ind.g-1. There were cysts at three stations at Minjiang River estuary. The density reaches maximum value at 4-6 cm sediment of M4 station, up to 6 ind.g-1. In Changjiang River estuary, the cysts distributed widely and had the largest density, up to 23.2 ind.g-1 at 8-10 cm sediment of DG-26 station. The distribution of Alexandrium sp.cysts was relevant to sediment type, sedimentation rate and current. Light had no effect on germination. With increasing temperature, germination and survival rates also increased, while the germination time decreased. Anoxia (0.01 mg O2.L-1) inhibited germination completely. Alexandrium sp. cysts could germinate throughout the year under favorable conditions.

China↗
PubMed2002

The effect of simulated microgravity on seed germination and seedling anatomy of Phaseolus vulgaris L.

Seed germination and root anatomy were investigated in seedlings of Phaseolus vulgaris L. developed on a slowly rotating bi-dimensional clinostat and in 1g. Germination time, percent germination, curvature and anatomy of developing root apexes were monitored on the clinostat and compared with the control. Interesting differences were found in germination and root features of the seeds developed on the clinostat compared with 1g ones: the main being germination time, root cap formation, the quantity and distribution of amyloplasts in statocytes. The use of a software to quantitatively analyse root cap anatomy allowed us to detect some differences otherwise unlikely to highlight. Our results showed that prolonged rotation on a bi-dimensional clinostat has an effect on some aspects of germination and on the statocytes that continuously perceives gravity from ever-changing directions.

Journal Article↗
PubMed1991

Effect of germination on vomitoxin level in grain.

The present investigation clarified the effect of enzymes or other substances formed during the germination process on the vomitoxin level of contaminated oats. The studies found that oats containing vomitoxin germinated very poorly; the decrease in toxins was also slight. The amount of pure vomitoxin added to toxin-free grain decreased (barley 53%, oats 40%, wheat 20%) during germination (5 d). In homogenized mixture of germinated grain (2.4 and 7 d) and toxic grain no decrease in toxin amount occurred during a 1-7 day period. In contrast, when germinating toxin free grains and toxic oats in a grain mixture the toxin level decreased at first, but later rose considerably. On the basis of these results, the utilization of germination processes for the improvement of grain containing vomitoxin is of questionable value.

Animals↗
PubMed1989

Ultrastructural analysis of germinal centers in lymph nodes of patients with HIV-1-induced persistent generalized lymphadenopathy: evidence for persistence of infection.

Germinal centers play an important role in the pathogenesis of HIV-1-induced lymphadenopathy. Cell-free retrovirus particles, gag proteins of HIV-1, and cells expressing viral RNA can be detected in these areas of the lymph node. In the present study, the ultrastructural changes and the interactions of virus with different cell types of the germinal centers were investigated. We compared the alterations of lymph nodes obtained shortly after seroconversion with those seen in longstanding lymphadenopathy. The results demonstrated that germinal centers were already infected in the early phase of the disease. However, the number of cell free virions was low. During the course of the disease, large amounts of cell free virions accumulated in the germinal centers. The persistence of germinal center infection for up to 2 years was demonstrated by detecting retrovirus particles in repeated biopsy specimens. In addition, the presence of numerous small, moderately electron dense structures that might represent defective particles of HIV-1 and influence the course of the disease were described. HIV-1 was found to replicate in lymphocytes, macrophages, and follicular dendritic cells. Quite possibly, a genomic shift may occur at the time of transmission of the virus to a novel target cell, thus, germinal centers may be one of the anatomic sites where HIV-1 acquires the ability to develop into a variant with preferential tropism for a given cell type.

AIDS-Related Complex↗
PubMed1978

The structure of the germinal disc region of the hen's ovarian follicle during the rapid growth phase.

The structure of the ovarian follicle in the region of the germinal disc, which appears as a white plaque at the surface of the oocyte, was examined by electron microscopy and compared with the non-disc region which overlies the yellow yolk mass of the oocyte in the final growth phase. The main differences concerned the granulosa cell layer and the surface layer of the oocyte. In the disc the granulosa cells were less regularly arranged and the spaces between them varied in width. Their mitotic rate was higher than that in the non-disc region, where cell division was seldom observed at maturity. The perivitelline layer was comparatively poorly developed at the periphery of the germinal vesicle in 15 mm follicles, but eventually attained a uniform thickness throughout the follicle. In the intercellular and perivitelline spaces there were smaller amounts of granular material. Marked differences were observed in the ooxyte surface layer. In 15 mm follicles the surface of the germinal disc was thrown into numerous microvilli and some narrow indentations containing macrovilli from the granulosa cells. Coated vesicles, 120 nm diameter, appeared to be invaginating from the oolemma, whereas 70 nm coated vesicles were present in the deeper cytoplasm. In follicles of more than 25 nm diameter these structural conformations were evident only at the periphery of the disc; for the most part the 120 nm coated vesicles were absent, and over the germinal vesicle microvilli were of rare occurrence. On the other hand, the bulk of the oocyte surface was highly convoluted throughout this period of growth, numerous granulosa cell macrovilli extended into deep pouches associated with 300 nm coated vesicles, and the oolemma possessed a coating of fuzzy material. These observations suggest that there is a restricted passage of yolk precursors to the surface of the germinal disc, and that the inability to transport yellow yolk into the disc is related to differences in the oolemmal surface coat and the population of coated vesicles. The surface modifications, as well as the proliferation of the granulosa cells, are likely to be influenced by the presence of the germinal vesicle.

Animals↗
PubMed1975

Protein metabolism during germination of Bacillus megaterium spores. II. Degradation of pre-existing and newly synthesized protein.

Two distinct proteolytic systems have been detected during germination of Bacillus megaterium spores: one degrading a unique class of dormant spore proteins and the other degrading primarily protein synthesized during germination. Proteolysis of dormant spore protein began by the 3rd min of germination and by 25 min had degraded 15 to 20% of the pre-existing protein to free amino acids. This reaction was not significantly ( less than 20%) different with or without amino acids or a carbon or nitrogen source in the germination medium, or when RNA synthesis, protein synthesis, or energy metabolism were inhibited. Spore coat proteins and most enzymes were not degraded in this process, rather the major substrates were a unique class of low molecular weight (6,000 to 12,000) proteins which were soluble in acetic acid. Proteins synthesized early in germination (0 to 12 min) were also degraded rapidly (20% per hour). However, proteins synthesized later in germination (90 to 100 min) were degraded more slowly (similar to 4% per hour). At all times tested proteolysis of newly synthesized protein was identical in the presence or absence of amino acids or chloramphenical in the medium, but was abolished by inhibitors of energy metabolism. Most proteins degraded in this process had molecular weights greater than 12,000 and were insoluble in acetic acid.

Amino Acids↗
PubMed1993

Identification of barley oxalate oxidase as a germin-like protein.

A barley oxalate oxidase was purified to homogeneity and the N-terminal sequences of the protein and of two peptides generated by CNBr cleavage of this protein were determined. Searches for similarities in data bank revealed that the sequences are highly homologous to the amino-acid sequence of a wheat protein, germin, which is synthesized de novo during germination. The similarity of the two proteins was confirmed by showing that anti-oxalate oxidase antibodies strongly recognize germin produced in Escherichia coli. We show that like germin, oxalate oxidase is glycosylated, resistant to SDS denaturation, heat stable, and protease resistant. Moreover, oxalate oxidase activity is strongly induced during germination of barley embryos resulting from an accumulation of the protein. Thus, we conclude that barley oxalate oxidase is a germin-like protein.

Glycoproteins↗
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↗
PubMed2000

Changes in biogenic amines in mature and germinating legume seeds and their behavior during cooking.

Ungerminated legume seeds (broad bean, chick pea and lupine) were contained all tested biogenic amines. Tryptamine (TRY) was the main biogenic amine detected, and its concentration considerably increased during the germination. beta-Phenylethylamine (PHE) was detected in small amounts and its concentration slowly increased during germination. The concentration of tyramine (TYR) showed a fluctuation pattern of changes during germination in all tested legumes. The concentrations of cadaverine (CAD) and putrescine (PUT) increased during the germination period in all tested grains. However, histamine (HIS) showed a fluctuated pattern of changes in both broad bean and lupine, and a gradual increase in chick pea. Spermidine (SPD) and spermine (SPM) contents of broad bean and chick pea showed a fluctuation pattern of change, while, a decrement trend of change was recorded for lupine along the germination period. By cooking, legume samples became free of biogenic amines which appeared in the boiling water. Heat treatment seems to have little effect on the concentration of biogenic amines in legume sprouts. The amounts of biogenic amines detected in the boiling water are less than the initial amounts of the sprouts (expected amounts).

Biogenic Amines↗
PubMed2001

Response of pollen germination and tube growth to cadmium with special reference to low concentration exposure.

Cadmium is one of the most important heavy metal pollutants highly hazardous to plants. Pollen is considered to be more sensitive to pollutants than are vegetative parts of the plants. Five herb species were tested for responses in pollen germination and tube growth to Cd exposure in vitro. Pollen germination of all the species was inhibited at Cd concentrations of 2.51 microg/mL and higher, and tube growth was inhibited at concentrations of 1.58 microg/ml and higher. Cadmium, at low concentrations, stimulated pollen tube growth. The pollen response to Cd stress exhibited interspecies differences. Vicia angustifolia and V. tetrasperma were sensitive to Cd, and were inhibited in either pollen germination or tube growth by Cd at 0.01 microg/mL. Plantago depressa was less sensitive; pollen germination and tube growth were not inhibited until the Cd concentration reached 2.51 and 1.58 microg/mL, respectively, and its tube growth displayed two stimulatory peaks; the one that appeared at 1.00 microg/mL showed the highest tube length in all species tested. These results suggest that Cd, even at low concentrations, may adversely affect plant reproduction by inhibiting pollen germination and tube growth.

Cadmium↗
PubMed2001

Recycling probability and dynamical properties of germinal center reactions.

We introduce a new model for the dynamics of centroblasts and centrocytes in a germinal center. The model reduces the germinal center reaction to the elements considered as essential and embeds proliferation of centroblasts, point mutations of the corresponding antibody types represented in a shape space, differentiation to centrocytes, selection with respect to initial antigens, differentiation of positively selected centrocytes to plasma or memory cells and recycling of centrocytes to centroblasts. We use exclusively parameters with a direct biological interpretation such that, once determined by experimental data, the model gains predictive power. Based on the experiment of Han et al. (1995b) we predict that a high rate of recycling of centrocytes to centroblasts is necessary for the germinal center reaction to work reliably. Furthermore, we find a delayed start of the production of plasma and memory cells with respect to the start of point mutations, which turns out to be necessary for the optimization process during the germinal center reaction. The dependence of the germinal center reaction on the recycling probability is analysed.

Animals↗