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PubMed2006

Seed vigour studies in corn, soybean and tomato in response to fish protein hydrolysates and consequences on phenolic-linked responses.

Seed priming with fish protein hydrolysates (FPH) has been studied for the enhancement of seed vigour of corn, soybean and tomato. The influence of FPH at 2.5 mL/L and 5.0 mL/L on traditional agronomic parameters for seed vigour (germination percentage, seedling weight, seedling height) and potential new vigour-associated parameters (phenolic content, antioxidant activity, guaiacol peroxidase (GuPX) activity, chlorophyll content) was investigated. FPH treatment preferentially stimulated seedling vigour in the following order: soybean>tomato>corn. For soybean, FPH at 2.5 mL/L and 5 mL/L improved the majority of the seed vigour parameters (seedling weight and height, phenolic content, antioxidant activity and chlorophyll content, and lignification-associated GuPX activity). Similarly, for tomato, FPH at 2.5 mL/L stimulated seedling weight and height, GuPX activity and chlorophyll content. However, FPH did not stimulate corn seed vigour. Our results suggest an ability of proline precursor-rich FPH to improve of plant growth and development (e.g., seed vigour) in phenolic-rich plant species through modulation of phenolic and chlorophyll metabolisms.

Animals↗
PubMed1989

The focal treatment of retinoblastoma with emphasis on xenon arc photocoagulation.

Two-hundred-seventy-eight retinoblastoma tumors in 169 patients were photocoagulated by one of two doctors with the xenon arc photocoagulator. More than 70% of tumors treated were cured by photocoagulation. The following features correlated with success: 1) size of the tumor, 2) location of the tumor and 3) elevation of the tumor. Seventy of 72 tumors (97%) up to 1 dd in size were cured while only 9 of 22 (41%) tumors larger than 5 dd were cured. The mean size of tumors cured was 2 dd, while the mean size of those that failed was 3.9 dd. Tumors located anterior to the equator were more often successfully treated (67/81 = 83%) than those posterior to the equator (44/74 = 60%). Tumors with the height equal to half the base were classified as 'low elevation', while those with heights larger than half the base diameter were classified as high elevation. Tumors with low elevation did significantly better (162/201 = 81%) than those with high elevation (33/76 = 43%). No correlation was found between success and the following features: age at diagnosis, sex, age at first photocoagulation, eye involved (right or left), time from radiation to first light coagulation, nasal versus temporal tumors or the clock hour of the tumor or category of tumor independent of size of location. Forty-four percent of tumors that failed photocoagulation went on to develop vitreous seeding and 55% required enucleation. Fifty percent of the eyes that were treated initially with photocoagulation went on to develop new tumor foci elsewhere in the eye. In all cases the new tumors appeared anterior to the equator. The children who developed additional tumors in the eye were younger (5.5 months) when photocoagulated than those who did not develop additional tumors (47.75 months). Photocoagulated retinoblastomas must be followed for at least three years before a cure is certain.

Eye Neoplasms↗
PubMed1984

Polyamine Titer in the Embryonic Axis and Cotyledons of Glycine max (L.) during Seed Growth and Maturation.

Active polyamine metabolism occurs in Glycine max (L.) seeds during development. Most (>/=97%) of putrescine (Put), spermidine (Spd), spermine (Spm), and cadaverine (Cad) are present as free forms in the growing embryo. In the cotyledon or embryonic axis, Put decreases to a nearly undetectable level, while Spd level sharply increases as seed dry weight accumulation progresses. Spm level in the axis also increases along with the Spd level. There is little change in Spm level in the cotyledons. Maturation and dehydration results in a slight reduction of Spd level in the cotyledons. Cad is present in relatively large quantities (5.5-12 micromoles per gram dry weight) in the axes of mature soybean seeds. Only traces of Cad, as expressed on a dry weight basis, are found in the developing or mature cotyledons. The synthesis and accumulation of Cad in the axis begins at the time when the axis or the seed accumulates 30 to 50% of its maximum dry weight. The Cad accumulation (0.8 nanomole per axis per day) proceeds until the later stages of dehydration. When soybean plants are subjected to complete defoliation and shade during the midpoint of seed maturation, Cad accumulation in the axis and seed dry weight accumulation ceased almost immediately. The treatment, however, does not affect the viability of soybean seeds.

Journal Article↗
PubMed2006

Regulation of seed size by hypomethylation of maternal and paternal genomes.

DNA methylation is an epigenetic modification of cytosine that is important for silencing gene transcription and transposons, gene imprinting, development, and seed viability. DNA METHYLTRANSFERASE1 (MET1) is the primary maintenance DNA methyltransferase in Arabidopsis (Arabidopsis thaliana). Reciprocal crosses between antisense MET1 transgenic and wild-type plants show that DNA hypomethylation has a parent-of-origin effect on seed size. However, due to the dominant nature of the antisense MET1 transgene, the parent with a hypomethylated genome, its gametophyte, and both the maternal and paternal genomes of the F(1) seed become hypomethylated. Thus, the distinct role played by hypomethylation at each generation is not known. To address this issue, we examined F(1) seed from reciprocal crosses using a loss-of-function recessive null allele, met1-6. Crosses between wild-type and homozygous met1-6 parents show that hypomethylated maternal and paternal genomes result in significantly larger and smaller F(1) seeds, respectively. Our analysis of crosses between wild-type and heterozygous MET1/met1-6 parents revealed that hypomethylation in the female or male gametophytic generation was sufficient to influence F(1) seed size. A recessive mutation in another gene that dramatically reduces DNA methylation, DECREASE IN DNA METHYLATION1, also causes parent-of-origin effects on F(1) seed size. By contrast, recessive mutations in genes that regulate a smaller subset of DNA methylation (CHROMOMETHYLASE3 and DOMAINS REARRANGED METHYLTRANSFERASES1 and 2) had little effect on seed size. Collectively, these results show that maternal and paternal genomes play distinct roles in the regulation of seed size in Arabidopsis.

Arabidopsis↗
PubMed2001

Effects of delta5 polyunsaturated fatty acids of maritime pine (Pinus pinaster) seed oil on the fatty acid profile of the developing brain of rats.

Conifer (pine) seeds are a potential source of dietary oils, but their safety and nutritional properties are not well established. Conifer seed oils differ from common edible vegetable oils in having a series of unusual polyunsaturated fatty acids (PUFA) with a polymethylene-interrupted (PMI) double bond system and a double bond at the delta5 position. A rat study was conducted to assess whether delta5 PMI-PUFA of conifer seeds could alter the levels of n-6 and n-3 long-chain polyunsaturated fatty acids (LC-PUFA) in mothers' milk and the developing brain of fetuses and pups. Feeding maritime pine (Pinus pinaster) seed oil (MPO) diet with a delta5 PMI-PUFA content of 1.4 g/100 g throughout pregnancy and lactation resulted in a large incorporation of delta5 PMI-PUFA in mothers' milk (5.1 +/- 0.5% of total fatty acids). The fetus (17 d old) and pup (22 d) brains, however, accumulated very little (0.6 and 0.4% of total fatty acids, respectively) delta5 PMI-PUFA. Mother's milk and pup's brain of the MPO group contained normal levels of 20:4n-6, 22:4n-6, and 20:5n-3 compared to a reference group of rats fed a fat blend of sunflower, high-oleic sunflower, and canola oils. The level of 22:6n-3, however, was slightly but significantly (P < 0.05) higher in milk and pup brain of the MPO group. These results show that delta5 PMI-PUFA of MPO exert no negative effect on the levels of n-6 and n-3 LC-PUFA in rat brain during its early development.

Animals↗
PubMed2025

Heat-Induced Secondary Dormancy Contributes to Local Adaptation in Arabidopsis thaliana.

Seeds should not germinate in conditions unsuitable for seedling growth. Dormancy, which allows seeds to remain inactive in an environment that would otherwise enable germination, helps optimise the timing of germination. Primary dormancy, developed during seed maturation on the parent plant, prevents immediate germination post-dispersal, regardless of external conditions. Secondary dormancy, however, is triggered post-dispersal when seeds face unfavourable conditions, enabling them to re-enter dormancy even if initially non-dormant. This mechanism allows seeds to fine-tune germination according to environmental conditions. In this study, we examined the role of heat-induced secondary dormancy in local adaptation by analysing natural variations within 361 Arabidopsis thaliana accessions from across Europe. We discovered that secondary dormancy acquisition varies with primary dormancy levels and after-ripening. Both primary and heat-induced secondary dormancy exhibited adaptive clines along temperature and precipitation gradients, with secondary dormancy showing a steeper cline, indicating its significant role in local adaptation. Using species distribution models, we predicted that genotypes with high secondary dormancy would show greater resilience to future climate changes. Additionally, we identified specific genomic regions controlling secondary dormancy levels including a novel candidate gene for secondary dormancy variation. Our findings show that secondary dormancy is a complex adaptive mechanism and a predominant contributor to the dormancy trait syndrome that favours plant survival in habitats exposed to harsh summers.

Arabidopsis↗
PubMed2001

Analysis of the raffinose family oligosaccharide pathway in pea seeds with contrasting carbohydrate composition.

Raffinose family oligosaccharides (RFOs) are synthesized by a set of galactosyltransferases, which sequentially add galactose units from galactinol to sucrose. The accumulation of RFOs was studied in maturing seeds of two pea (Pisum sativum) lines with contrasting RFO composition. Seeds of the line SD1 accumulated stachyose as the predominant RFO, whereas verbascose, the next higher homolog of stachyose, was almost absent. In seeds of the line RRRbRb, a high level of verbascose was accumulated alongside with stachyose. The increase in verbascose in developing RRRbRb seeds was associated with galactinol-dependent verbascose synthase activity. In addition, a galactinol-independent enzyme activity was detected, which catalyzed transfer of a galactose residue from one stachyose molecule to another. The two enzyme activities synthesizing verbascose showed an optimum at pH 7.0. Both activities were almost undetectable in SD1. Maximum activity of stachyose synthase was about 4-fold higher in RRRbRb compared with SD1, whereas the activities of galactinol synthase and raffinose synthase were only about 1.5-fold higher in RRRbRb. The levels of galactinol synthase and stachyose synthase activity were reflected by steady-state levels of corresponding mRNAs. We suggest that the accumulation of verbascose in RRRbRb was controlled by a coordinated up-regulation of the last steps of verbascose biosynthesis.

Disaccharides↗
PubMed1986

Differential synthesis in vitro of barley aleurone and starchy endosperm proteins.

To widen the selection of proteins for gene expression studies in barley seeds, experiments were performed to identify proteins whose synthesis is differentially regulated in developing and germinating seed tissues. The in vitro synthesis of nine distinct barley proteins was compared using mRNAs from isolated endosperm and aleurone tissues (developing and mature grain) and from cultured (germinating) aleurone layers treated with abscisic acid (ABA) and GA(3). B and C hordein polypeptides and the salt-soluble proteins beta-amylase, protein Z, protein C, the chymotrypsin inhibitors (CI-1 and 2), the alpha-amylase/subtilisin inhibitor (ASI) and the inhibitor of animal cell-free protein synthesis systems (PSI) were synthesized with mRNA from developing starchy endosperm tissue. Of these proteins, beta-amylase, protein Z, and CI- 1 and 2 were also synthesized with mRNA from developing aleurone cells, but ASI, PSI, and protein C were not. CI-1 and also a probable amylase/protease inhibitor (PAPI) were synthesized at high levels with mRNAs from late developing and mature aleurone. These results show that mRNAs encoding PAPI and CI-1 survive seed dessication and are long-lived in aleurone cells. Thus, expression of genes encoding ASI, PSI, protein C, and PAPI is tissue and stage-specific during seed development. Only ASI, CI-1, and PAPI were synthesized in significant amounts with mRNA from cultured aleurone layers. The levels of synthesis of PAPI and CI-1 were independent of hormone treatment. In contrast, synthesis of alpha-amylase (included as control) and of ASI showed antagonistic hormonal control: while GA promotes and ABA reduces accumulation of mRNA for alpha-amylase, these hormones have the opposite effect on ASI mRNA levels.

Journal Article↗
PubMed1991

Flavonoid and isoflavonoid distribution in developing soybean seedling tissues and in seed and root exudates.

The distribution of flavonoids, isoflavonoids, and their conjugates in developing soybean (Glycine max L.) seedling organs and in root and seed exudates has been examined. Conjugates of the isoflavones daidzein and genistein are major metabolites in all embryonic organs within the dry seed and in seedling roots, hypocotyl, and cotyledon tissues at all times after germination. Primary leaf tissues undergo a programmed shift from isoflavonoid to flavonoid metabolism 3 days after germination and become largely predominated by glycosides of the flavonols kampferol, quercetin, and isorhamnetin by 5 days. Cotyledons contain relatively constant and very high levels of conjugates of both daidzein and genistein. Hypocotyl tissues contain a third unidentified compound, P19.3, also present in multiple conjugated forms. Conjugates of daidzein, genistein, and P19.3 are at their highest levels in the hypocotyl hook and fall off progressively down the hypocotyl. These isoflavones also undergo a programmed and dramatic decrease between 2 and 4 days in the hypocotyl hook. All root sections are predominated by daidzein and its conjugates, particularly in the root tip, where they reach the highest levels in the seedling. Light has a pronounced effect on the distribution of the isoflavones; in the dark, isoflavone levels in the root tips are greatly reduced, while those in the cotyledons are higher. Finally, the conjugates of daidzein and genistein and several unidentified aromatic metabolites are selectively excreted into root and seed exudates. Analysis of seed exudates suggests that this is a continuous, but saturable event.

Journal Article↗
PubMed2006

The analysis of proteome changes in sunflower seeds induced by N+ implantation.

In this work, the proteomic changes induced by N+ ion implantation were investigated using a sunflower seed model by a two-dimensional electrophoretic analysis. To further understand the changes of total protein irradiated with N+ ion, a proteomic analysis of N+ ion implantation seeds was developed. Among approximately 369 total protein spots displayed in 2-D gels, eight specific proteins were found in non-implanted seeds while four proteins were found in implanted seeds. Six proteins were used for MALDI-TOF MS analysis, of which only two had been reported before. The proteins designated as No.29 showed 23.4% homology to MADS-box transcriptional factor HAM59, while No. 279 protein had 23.20% identity to homeobox-leucine zipper protein HAHB-4. The analysis of proteome changes induced by N+ implantation could provide a new clue to studying mutation mechanism of ion implantation. To our knowledge, this is the first report about the analysis of proteome changes induced by N+ implantation in sunflower seeds.

Amino Acid Sequence↗
PubMedDate not supplied

The NJ SEED project: evaluation of an innovative initiative for ethics training in nursing homes.

OBJECTIVES: This article reports the results of an evaluation of the New Jersey Stein Ethics Education and Development (NJ SEED) project--a statewide initiative to create, organize and educate a statewide network of regional long-term care ethics committees. The main focus of the evaluation was to measure utilization of the committees, describe how facilities have benefited from the project, and identify potential barriers to the use of this resource. METHODS: Based on administrative records from the NJ SEED project, 225 facilities were identified and asked to complete a facility survey. Ninety-three surveys were received, resulting in a 41% response rate. An additional survey of the regional ethics committees (RECs), as well as several focus groups and individual interviews were conducted to supplement the survey data. RESULTS: Fifty-eight percent of the facility respondents reported current participation in an NJ regional ethics committee. About one third (30%) of participating facilities had requested a formal case consultation (on at least one occasion) on behalf of a resident, but two thirds had consulted with their RECs on a more informal basis. Facilities that reported participating in the REC Network were more likely to have formally written policies than nonparticipants. CONCLUSIONS: Many NJ nursing homes find the statewide REC Network to be an important resource; however continued efforts need to be expended for recruiting and training facilities that are not taking full advantage of this important source of peer support and professional expertise.

Decision Making↗
PubMed1988

Temperature and seed germination.

Temperature can affect the percentage and rate of germination through at least three separate physiological processes. 1. Seeds continuously deteriorate and, unless in the meanwhile they are germinated, they will ultimately die. The rate of deterioration depends mainly on moisture content and temperature. The Q10 for rate of loss of viability in orthodox seeds consistently increases from about 2 at -10 degrees C to about 10 at 70 degrees C. 2. Most seeds are initially dormant. Relatively dry seeds continuously lose dormancy at a rate which is temperature-dependent. Unlike enzyme reactions, the Q10 remains constant over a wide range of temperature at least up to 55 degrees C, and typically has a value in the region of 2.5-3.8. Hydrated seeds respond quite differently: high temperatures generally reinforce dormancy or may even induce it. Low temperatures may also induce dormancy in some circumstances, but in many species they are stimulatory (stratification response), especially within the range -1 degree C to 15 degrees C. Small, dormant, hydrated seeds are usually also stimulated to germinate by alternating temperatures which typically interact strongly and positively with light (and often also with other factors including nitrate ions). The most important attributes of alternating temperatures are amplitude, mean temperature, the relative periods spent above and below the median temperature of the cycle (thermoperiod) and the number of cycles. 3. Once seeds have lost dormancy their rate of germination (reciprocal of the time taken to germinate) shows a positive linear relation between the base temperature (at and below which the rate is zero) and the optimum temperature (at which the rate is maximal); and a negative linear relation between the optimal temperature and the ceiling temperature (at and above which the rate is again zero). The optimum temperature for germination rate is typically higher than that required to achieve maximum percentage germination in partially dormant or partially deteriorated seed populations. None of the sub-cellular mechanisms which underlie any of these temperature relations are understood. Nevertheless, the temperature responses can all be quantified and are fundamental to designing seed stores (especially long term for genetic conservation), prescribing germination test conditions, and understanding seed ecology (especially that required for the control of weeds).

Plant Development↗
PubMed1996

Interaction of proteases with legume seed inhibitors. Molecular features.

After having found that raw black beans (Phaseolus vulgaris) were toxic, while the cooked ones constitute the basic diet of the underdeveloped peoples of the world, in the sixties, our research directed by Dr. Jaffé, concentrated mainly around the detection and identification of the heat labile toxic factors in legume seeds. A micromethod for the detection of protease inhibitors (PI) in individual seeds was developed, for the purpose of establishing that the multiple trypsin inhibitors (TI) found in the Cubagua variety were expressions of single seeds and not a mixture of a non homogenous bean lot. Six isoinhibitors were isolated and purified, all of which were "double-headed" and interacted with trypsin (T) and chymotrypsin (CHT) independently and simultaneously, as shown by electrophoresis of their binary and ternary complexes with each and both enzymes. However, their affinity for the enzymes, including elastases, was rather variable, as well as their amino acid composition which consisted of 51 units for inhibitor V, the smallest, and 83 amino acids for inhibitor I, the largest. A low molecular weight protein fraction that inhibited subtilisin (S), but recognized neither T, CHT nor pancreatic elastase was detected in 63 varieties of Phaseolus vulgaris as well as in broad beans (Vicia faba), chick peas (Cicer arietinum), jack beans (Canavalia ensiformis), kidney beans (Vigna aureus), etc., It was absent though, in soybeans (Glycine max), lentils (Lens culinaris), green peas (Pisum sativum), cowpea (Vigna sinensis) and lupine seeds (Lupinus sp). Subtilisin inhibitors (SI) were isolated from black beans, broad beans, chick peas and jack beans. Their Mr is between 8-9KD and they show a rather high stability in the presence of denaturing agents. They are specific toward microbial proteases, in addition to subtilisins, Carlsberg and BPN', they inhibit the alkaline protease from Tritirachium album (Protease K), from Aspergillus oryzae and one isolated from Streptomyces griseus, but do not interact with either animal digestive or plant thiol enzymes.

Chymotrypsin↗
PubMed2005

Game theory provides no explanation for seed size variation in grasslands.

Game theoretical models have been suggested to explain the maintenance of a remarkable variation in seed size across species in most types of vegetation. According to these models, which are based on the existence of a trade-off between seed size and seed number; smaller-seeded species can invade any species mixture due to their numerical advantage, and larger-seeded species can invade any species mixture due to their competitive superiority over smaller-seeded species during recruitment. However, till now, there is very limited evidence for seed size effects on recruitment interactions among different species. An experiment was designed using 16 species in Swedish grasslands, varying 384-fold in seed size. Species were sown pairwise and alone in disturbed versus undisturbed small plots in grazed versus ungrazed grassland, and the resulting recruitment was recorded. Seedling densities in the experimental plots were within the natural range. Both disturbance and grazing had a positive effect on recruitment. Seed size did not affect recruitment except from a tendency that increasing seed size made recruitment less dependent on disturbance. Recruitment of smaller-seeded species was not affected by the presence of larger-seeded species. Larger-seeded species did not generally win in direct contest. These results suggest that game theoretical models do not explain maintenance of seed size variation across species in these grasslands. Alternative explanations for seed size variation are that either small-scale heterogeneity provide conditions favouring a range of different seed sizes or other attributes than seed size effectively determine recruitment.

Ecosystem↗
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↗