Submergence sensitivity of durum wheat, bread wheat and barley at the germination stage

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Iduna Arduini

2016-06-01

Full Text Available Soil waterlogging at initial growth stages can cause heavy yield losses of winter cereals. Therefore, the screening for submergence tolerance traits in seeds of commercial varieties is of high concern worldwide. Ten Italian varieties of durum wheat (Triticum durum Desf., bread wheat (T. aestivum L. and barley (Hordeum vulgare L. were investigated for their ability to germinate in submerged conditions and to recover after submergence periods of three to 15 days. Submergence prevented germination and decreased germinability, at rates that increased with duration of submergence. Sensitivity ranked in the order: barley >durum wheat >bread wheat. We related the higher sensitivity of barley to its slower germination and slightly higher leakage of electrolytes, whereas the percentage of abnormal seedlings was lower than in other species. It was less than 4%, compared to less than 15 and 8% in durum wheat and bread wheat, respectively. Wide varietal differences were found in all species. According to variety, after 6-day submergence, germinability ranged from 2 to 42% in barley, from 5 to 80% in durum wheat, and from 30 to 77% in bread wheat. Varieties with more than 40% seed survival were three, six and seven per species, in the same order. The differential submergence sensitivity of varieties indicates a potential to select for waterlogging tolerance within Italian genotypes of winter cereal crops.

Knockin’ on pollen’s door: live cell imaging of early polarization events in germinating Arabidopsis pollen

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Frank eVogler

2015-04-01

Full Text Available Pollen tubes are an excellent system for studying the cellular dynamics and complex signaling pathways that coordinate polarized tip growth. Although several signaling mechanisms acting in the tip-growing pollen tube have been described, our knowledge on the subcellular and molecular events during pollen germination and growth site selection at the pollen plasma membrane is rather scarce. To simultaneously track germinating pollen from up to 12 genetically different plants we developed an inexpensive and easy mounting technique, suitable for every standard microscope setup. We performed high magnification live-cell imaging during Arabidopsis pollen activation, germination, and the establishment of pollen tube tip growth by using fluorescent marker lines labeling either the pollen cytoplasm, vesicles, the actin cytoskeleton or the sperm cell nuclei and membranes. Our studies revealed distinctive vesicle and F-actin polarization during pollen activation and characteristic growth kinetics during pollen germination and pollen tube formation. Initially, the germinating Arabidopsis pollen tube grows slowly and forms a uniform roundish bulge, followed by a transition phase with vesicles heavily accumulating at the growth site before switching to rapid tip growth. Furthermore, we found the two sperm cells to be transported into the pollen tube after the phase of rapid tip growth has been initiated. The method presented here is suitable to quantitatively study subcellular events during Arabidopsis pollen germination and growth, and for the detailed analysis of pollen mutants with respect to pollen polarization, bulging, or growth site selection at the pollen plasma membrane.

Allelopathic Effect of Leaf Water Extract of Hoary alyssum (Berteroa incana L. at Rosette Stage on Seed Germination

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H. Madani

2012-07-01

Full Text Available The allelopathic effects of leaves at rosette stage of the hoary alyssum (Berteroa incana L. against some associated grasses like, prairie June grass (Koeleria macrantha, Idaho fescue (Festuca idahoensis, blue-bunch wheatgrass (Pseudoroegneria spicata and cheat grass (Bromus tectorum and its own were investigated. The experiment al materials used were the leaf extracts and its allelopathic effects on seed germination and seedling emergence of the abave mentioned grasses in Petri dishes. According to our study, leaves of hoary alyssum rosettes at stage have the potential to reduce germination rate, root and shoot growth of pasture grasses and hoary alyssum itself due to its allelopathic effect. The leaf leachate solution bioassays also showed that the germination of cheat grass was more susceptible to 4% solution of allelopathic extract of leaves. Hoary alyssum leaf extract also exhibited allelopathic self-inhibition, in both seedling root and shoot growth at 2 and 4% concentrations. Self- inhibitory allelopathic effects of hoary alyssum could also be important in preventing seed germination and seedling establishment of neighboring plant.

Genetic analysis of cold tolerance at the germination and booting stages in rice by association mapping.

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Yinghua Pan

Full Text Available Low temperature affects the rice plants at all stages of growth. It can cause severe seedling injury and male sterility resulting in severe yield losses. Using a mini core collection of 174 Chinese rice accessions and 273 SSR markers we investigated cold tolerance at the germination and booting stages, as well as the underlying genetic bases, by association mapping. Two distinct populations, corresponding to subspecies indica and japonica showed evident differences in cold tolerance and its genetic basis. Both subspecies were sensitive to cold stress at both growth stages. However, japonica was more tolerant than indica at all stages as measured by seedling survival and seed setting. There was a low correlation in cold tolerance between the germination and booting stages. Fifty one quantitative trait loci (QTLs for cold tolerance were dispersed across all 12 chromosomes; 22 detected at the germination stage and 33 at the booting stage. Eight QTLs were identified by at least two of four measures. About 46% of the QTLs represented new loci. The only QTL shared between indica and japonica for the same measure was qLTSSvR6-2 for SSvR. This implied a complicated mechanism of old tolerance between the two subspecies. According to the relative genotypic effect (RGE of each genotype for each QTL, we detected 18 positive genotypes and 21 negative genotypes in indica, and 19 positive genotypes and 24 negative genotypes in japonica. In general, the negative effects were much stronger than the positive effects in both subspecies. Markers for QTL with positive effects in one subspecies were shown to be effective for selection of cold tolerance in that subspecies, but not in the other subspecies. QTL with strong negative effects on cold tolerance should be avoided during MAS breeding so as to not cancel the effect of favorable QTL at other loci.

Genome-wide association study of salt tolerance at the seed germination stage in rice.

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Shi, Yingyao; Gao, Lingling; Wu, Zhichao; Zhang, Xiaojing; Wang, Mingming; Zhang, Congshun; Zhang, Fan; Zhou, Yongli; Li, Zhikang

2017-05-30

Improving the salt tolerance of direct-seeding rice at the seed germination stage is a major breeding goal in many Asian rice-growing countries, where seedlings must often establish in soils with a high salt content. Thus, it is important to understand the genetic mechanisms of salt tolerance in rice and to screen for germplasm with salt tolerance at the seed germination stage. Here, we investigated seven seed germination-related traits under control and salt-stress conditions and conducted a genome-wide association study based on the re-sequencing of 478 diverse rice accessions. The analysis used a mixed linear model and was based on 6,361,920 single nucleotide polymorphisms in 478 rice accessions grouped into whole, indica, and non-indica panels. Eleven loci containing 22 significant salt tolerance-associated single nucleotide polymorphisms were identified based on the stress-susceptibility indices (SSIs) of vigor index (VI) and mean germination time (MGT). From the SSI of VI, six major loci were identified, explaining 20.2% of the phenotypic variation. From the SSI of MGT, five major loci were detected, explaining 26.4% of the phenotypic variation. Of these, seven loci on chromosomes 1, 5, 6, 11, and 12 were close to six previously identified quantitative gene loci/genes related to tolerance to salinity or other abiotic stresses. The strongest association region for the SSI of MGT was identified in a ~ 13.3 kb interval (15450039-15,463,330) on chromosome 1, near salt-tolerance quantitative trait loci controlling the Na + : K + ratio, total Na + uptake, and total K + concentration. The strongest association region for the SSI of VI was detected in a ~ 164.2 kb interval (526662-690,854) on chromosome 2 harboring two nitrate transporter family genes (OsNRT2.1 and OsNRT2.2), which affect gene expression under salt stress. The haplotype analysis indicated that OsNRT2.2 was associated with subpopulation differentiation and its minor/rare tolerant haplotype was

Chronic exposure to a low concentration of bisphenol A during follicle culture affects the epigenetic status of germinal vesicles and metaphase II oocytes.

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Trapphoff, Tom; Heiligentag, Martyna; El Hajj, Nady; Haaf, Thomas; Eichenlaub-Ritter, Ursula

2013-12-01

To determine whether exposure to low concentrations of the endocrine disrupting chemical bisphenol A (BPA) during follicle culture and oocyte growth alters the methylation status of differentially methylated regions (DMRs) of imprinted genes and histone posttranslational modification patterns in mammalian oocytes. Comparative and control study. Experimental laboratory. C57/Bl6JxCBA/Ca mice. Exposure of oocytes to 3 nM or 300 nM BPA during follicle culture from preantral to antral stage. Methylation status of DMRs of maternally imprinted (Snrpn, Igf2r, and Mest) and paternally imprinted gene(s) (H19) in mouse germinal vesicle oocytes; trimethylation of histone H3K9, acetylation of histone H4K12, and distance between centromeres of sister chromatids in metaphase II oocytes. Exposure to 3 nM BPA was associated with slightly accelerated follicle development, statistically significant increases in allele methylation errors in DMRs of maternally imprinted genes, and statistically significant decreases in histone H3K9 trimethylation and interkinetochore distance. The disturbances in oocyte genomic imprinting and modification of posttranslational histone and centromere architecture provide the first link between low BPA exposures and induction of epigenetic changes that may contribute to chromosome congression failures and meiotic errors, and to altered gene expression that might affect health of the offspring. Copyright © 2013 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Proteins induced by salt stress in tomato germinating seeds

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Torres-Shumann, S.; Godoy, J.A.; del Pozo, O.; Pintor-Toro, J.A.

1989-01-01

Salt effects on protein synthesis in tomato germinating seeds were investigated by two-dimensional polyacrilamide gel electrophoresis of proteins labeled in vivo with ( 35 S)-Methionine. Seeds germinating in NaCl were analyzed at three germination stages (4mm long radicals, 15mm long radicles and expanding cotyledons) and compared to those germinating in water. At the first germination stage several basic proteins of M.W. 13Kd, 16Kd, 17Kd and 18Kd were detected in only salt germinating seeds. Other basic proteins of M.W. 12Kd, 50Kd and 54Kd were salt-induced at the second and third stage of germination. One 14Kd acid protein is observed in every assayed stage and shows several phosphorylated forms. The levels of expression of these proteins are directly correlated to assayed NaCl concentrations. All of these proteins, except 17Kd, are also induced by abscisic acid (ABA) in the same germination stages. A cooperative effect on the synthesis of these proteins is observed when both ABA and NaCl are present

Time-lapse cinematography study of the germinal vesicle behaviour in mouse primary oocytes treated with activators of protein kinases A and C.

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Alexandre, H; Mulnard, J

1988-12-01

A passive erratic movement of the germinal vesicle (GV), already visible in small incompetent oocytes, is followed by an active scalloping of the nuclear membrane soon before GV breakdown (GVBD) in cultured competent oocytes. Maturation can be inhibited by activators of protein kinase A (PK-A) and protein kinase C (PK-C). Our time-lapse cinematography analysis allowed us to describe an unexpected behaviour of the GV when PK-C, but not PK-A, is activated: GV undergoes a displacement toward the cortex according to the same biological clock which triggers the programmed translocation of the spindle in control oocytes. It is concluded that, when oocytes become committed to undergo maturation, the cytoplasm acquires a PK-A-controlled "centrifugal displacement property" which is not restricted to the spindle.

Maternal vernalization and vernalization-pathway genes influence progeny seed germination.

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Auge, Gabriela A; Blair, Logan K; Neville, Hannah; Donohue, Kathleen

2017-10-01

Different life stages frequently respond to the same environmental cue to regulate development so that each life stage is matched to its appropriate season. We investigated how independently each life stage can respond to shared environmental cues, focusing on vernalization, in Arabidopsis thaliana plants. We first tested whether effects of rosette vernalization persisted to influence seed germination. To test whether genes in the vernalization flowering pathway also influence germination, we assessed germination of functional and nonfunctional alleles of these genes and measured their level of expression at different life stages in response to rosette vernalization. Rosette vernalization increased seed germination in diverse ecotypes. Genes in the vernalization flowering pathway also influenced seed germination. In the Columbia accession, functional alleles of most of these genes opposed the germination response observed in the ecotypes. Some genes influenced germination in a manner consistent with their known effects on FLOWERING LOCUS C gene regulation during the transition to flowering. Others did not, suggesting functional divergence across life stages. Despite persistent effects of environmental conditions across life stages, and despite pleiotropy of genes that affect both flowering and germination, the function of these genes can differ across life stages, potentially mitigating pleiotropic constraints and enabling independent environmental regulation of different life stages. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

RNA synthesis during germination of UV-irradiated Dictyostelium discoideum spores

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Okaichi, Kumio

1987-01-01

UV irradiation to the spores of Dictyostelium discoideum NC4 resulted in a more prolonged delay of amoeba-emergence from swollen spores with increasing UV fluence. During the germination, an inhibition of total RNA synthesis and a shift of stage of maximum RNA synthesis to the later period were observed. The maximum poly(A) + RNA synthetic activity was found on an early stage of amoeba-emergence prior about 1 h to the beginning of rRNA synthesis in unirradiated spore germination; but, in UV-irradiated spore germination, the stage of maximum poly(A) + RNA synthesis shifted to the later stage of germination with increasing UV fluence. A decreased synthesis of poly(A) + RNA and a severe inhibition of rRNA synthesis were observed on UV-irradiated and germinated spores, but no significant inhibition of 4 - 5 S RNA synthesis was detected. Actinomycin D suppressed almost completely the rRNA synthesis of emerged amoebae but the drug apparently did not affect the emergence of amoebae at any stage of germination. It was postulated that the delay of amoeba-emergence in UV-irradiated spore must be mainly due to the shift of the stage of maximum synthesis of poly(A) + RNA to the later stage of germination. (author)

Association analysis of salt tolerance in cowpea (Vigna unguiculata (L.) Walp) at germination and seedling stages

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Cowpea is one of the most important cultivated legumes in Africa. The worldwide annual production in cowpea dry seed is 5.4 million metric tons. However, cowpea is unfavorably affected by salinity stress at germination and seedling stages, which is exacerbated by the effects of climate change. The l...

Are calcifying matrix vesicles in atherosclerotic lesions of cellular origin?

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Bobryshev, Yuri V; Killingsworth, Murray C; Huynh, Thuan G; Lord, Reginald S A; Grabs, Anthony J; Valenzuela, Stella M

2007-03-01

Over recent years, the role of matrix vesicles in the initial stages of arterial calcification has been recognized. Matrix calcifying vesicles have been isolated from atherosclerotic arteries and the biochemical composition of calcified vesicles has been studied. No studies have yet been carried out to examine the fine structure of matrix vesicles in order to visualize the features of the consequent stages of their calcification in arteries. In the present work, a high resolution ultrastructural analysis has been employed and the study revealed that matrix vesicles in human atherosclerotic lesions are heterogeneous with two main types which we classified. Type I calcified vesicles were presented by vesicles surrounded by two electron-dense layers and these vesicles were found to be resistant to the calcification process in atherosclerotic lesions in situ. Type II matrix vesicles were presented by vesicles surrounded by several electron-dense layers and these vesicles were found to represent calcifying vesicles in atherosclerotic lesions. To test the hypothesis that calcification of matrix vesicles surrounded by multilayer sheets may occur simply as a physicochemical process, independently from the cell regulation, we produced multilamellar liposomes and induced their calcification in vitro in a manner similar to that occurring in matrix vesicles in atherosclerotic lesions in situ.

Accessory nuclei revisited: the translocation of snRNPs from the germinal vesicle to the periphery of the future embryo.

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Biliński, Szczepan M; Kloc, Małgorzata

2002-03-01

Oocytes of certain insects contain peculiar organelles termed accessory nuclei (AN). These organelles originate by budding off from the envelope of the oocyte nucleus and contain 1-2 dense inclusions immersed in a translucent ground substance. We have demonstrated that in the wasp Vespula germanica each inclusion consists of two elements: a spherical body, and a hemispherical structure composed of numerous 20-30 nm particles. Immunoelectron microscopy and whole-mount in situ hybridization have shown that the inclusions contain AgNOR-staining proteins, p80-coilin, Sm proteins, and small nuclear RNAs (snRNAs). These results indicate that the inclusions and hemispherical structures are homologous to Cajal bodies and B-snurposomes of Xenopus germinal vesicles, respectively. During previtellogenesis, AN (together with their Cajal bodies) migrate to the cortical ooplasm of the oocyte where they reside at least until the onset of embryogenesis. We suggest that AN are vehicles for the transport and localization of snRNPs to the periphery of the oocyte, i.e., to the region where the blastoderm of the embryo develops and where there is a requirement for a high concentration of RNA-processing factors.

Effects of stress temperatures of germination on polyamine titers of soybean seeds

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Pineda-Mejia, Renan

High and low stress temperatures during seed germination and seedling development limit total germination and the rate of germination and growth. Changes in polyamine (PA) concentrations in seeds of different species have been associated with germination, growth and environmental stresses such as temperature, drought, oxygen, chilling injury and osmotic conditions. Two studies were conducted to determine the effect of stress temperatures during germination and seedling development on polyamine titers in soybean seeds. Three germination temperatures, 25, 30, and 36°C were used in the first study to evaluate their influence on changes in polyamine concentrations in soybean seeds germinated at 76 and 90 hours. The polyamines (PAs), cadaverine (Cad), putrescine (Put), spermidine (Spd), agmatine (Agm), and spermine (Spin) were quantified by HPLC using a cation exchange column and an electrochemical detector. Cad, Put, Agm, and Spd declined as the germination temperatures increased from 25 to 36°C. Conversely, Spin increased considerably with an increase in temperature. Total germination was reduced from 97.2 to 92.5% as germination temperatures increased from 25 to 36°C. Germination time did not affect Cad, Agm and Spm, and total germination, however, the interaction between temperature and germination time for Put and Spd concentrations was significant. In the second study, changes in PA concentrations, seedling growth, germination time (t50), fresh and dry weight, and moisture content were measured in the embryonic axis and cotyledons of soybean seeds germinated at 10 and 25°C through six stages of germination dry seed (DS), testa split (TS), radicle at 10 mm (Ra-10), root hairs visible (RHV), secondary root primordia (SRP), and complete seedling (CS). The concentrations of Cad and Put in the embryonic axis, were significantly higher in seeds germinated under low temperature than in seeds at 25°C (approximately 10 and 3 fold respectively). However, this

Association mapping of soybean seed germination under salt stress.

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Kan, Guizhen; Zhang, Wei; Yang, Wenming; Ma, Deyuan; Zhang, Dan; Hao, Derong; Hu, Zhenbin; Yu, Deyue

2015-12-01

Soil salinity is a serious threat to agriculture sustainability worldwide. Seed germination is a critical phase that ensures the successful establishment and productivity of soybeans in saline soils. However, little information is available regarding soybean salt tolerance at the germination stage. The objective of this study was to identify the genetic mechanisms of soybean seed germination under salt stress. One natural population consisting of 191 soybean landraces was used in this study. Soybean seeds produced in four environments were used to evaluate the salt tolerance at their germination stage. Using 1142 single-nucleotide polymorphisms (SNPs), the molecular markers associated with salt tolerance were detected by genome-wide association analysis. Eight SNP-trait associations and 13 suggestive SNP-trait associations were identified using a mixed linear model and the TASSEL 4.0 software. Eight SNPs or suggestive SNPs were co-associated with two salt tolerance indices, namely (1) the ratio of the germination index under salt conditions to the germination index under no-salt conditions (ST-GI) and (2) the ratio of the germination rate under salt conditions to the germination rate under no-salt conditions (ST-GR). One SNP (BARC-021347-04042) was significantly associated with these two traits (ST-GI and ST-GR). In addition, nine possible candidate genes were located in or near the genetic region where the above markers were mapped. Of these, five genes, Glyma08g12400.1, Glyma08g09730.1, Glyma18g47140.1, Glyma09g00460.1, and Glyma09g00490.3, were verified in response to salt stress at the germination stage. The SNPs detected could facilitate a better understanding of the genetic basis of soybean salt tolerance at the germination stage, and the marker BARC-021347-04042 could contribute to future breeding for soybean salt tolerance by marker-assisted selection.

The Effects of Cold Stress at Germination and Seedling Stages on Antioxidant Enzymes and Some Physiological Aspects of Chickpea (Cicer arientinum.

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S. Wanaei

2012-04-01

Full Text Available In order to investigate the effects of cold stress on antioxidant enzymes and physiological characteristics in chickpea, two separate experiments were conducted at germination and seedling stages. Each experiment with six temperature levels (T1(control=15C°, T2=5C°, T3=0C°, T4=-5C°, T5=-10C° and T6=-15C° and three varieties (V1=Pirouz V2=ILC482 V3=Bivaniej was carried out in a randomized complete block design with three replications at controlled condition in crop physiological laboratory of Kurdistan university at 2009. The results showed that cold treatment increased Catalase and Peroxdase activity, cell membrane injury and H2O2 concentration significantly. The temperature -5C° treatment had the most influence on physiological traits. Based on germination stage trial, ILC482 was known as resistance cultivar and Pirouz showed highest sensitivity to cold treatments. There were positive and significant correlation between H2O2 concentration with Catalase (r = 0.98** and Peroxidase (r = 0.89** at germination stage. Peroxidase activity was about tenfold more of the Catalase activity. In general, the results showed that cold stress increased reactive oxygen species; these product lead to oxidative damages to cell membrane.

Optimization of soaking stage in technological process of wheat germination by hydroponic method when objective function is defined implicitly

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Koneva, M. S.; Rudenko, O. V.; Usatikov, S. V.; Bugayets, N. A.; Tamova, M. Yu; Fedorova, M. A.

2018-05-01

The increase in the efficiency of the "numerical" technology for solving computational problems of parametric optimization of the technological process of hydroponic germination of wheat grains is considered. In this situation, the quality criteria are contradictory and a part of them is given by implicit functions of many variables. One of the main stages, soaking, determining the time and quality of germinated wheat grain is studied, when grain receives the required amount of moisture and air oxygen for germination and subsequently accumulates enzymes. A solution algorithm for this problem is suggested implemented by means of software packages Statistica v.10 and MathCAD v.15. The use of the proposed mathematical models describing the processes of hydroponic soaking of spring soft wheat varieties made it possible to determine optimal conditions of germination. The results of investigations show that the type of aquatic environment used for soaking has a great influence on the process of water absorption, especially the chemical composition of the germinated material. The use of the anolyte of electrochemically activated water (ECHA-water) intensifies the process from 5.83 to 4 hours for wheat variety «Altayskaya 105» and from 13 to 8.8 hours - for «Pobla Runo».

Effects of graphene on seed germination and seedling growth

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Zhang, Ming; Gao, Bin, E-mail: bg55@ufl.edu [University of Florida, Department of Agricultural and Biological Engineering (United States); Chen, Jianjun [University of Florida, Department of Environmental Horticulture and Mid-Florida Research & Education Center (United States); Li, Yuncong [University of Florida, Soil and Water Science Department Tropical Research & Education Center (United States)

2015-02-15

The environmental impact of graphene has recently attracted great attention. In this work, we show that graphene at a low concentration affected tomato seed germination and seedling growth. Graphene-treated seeds germinated much faster than control seeds. Analytical results indicated that graphene penetrated seed husks. The penetration might break the husks to facilitate water uptake, resulting in faster germination and higher germination rates. At the stage of seedling growth, graphene was also able to penetrate root tip cells. Seedlings germinated from graphene-treated seeds had slightly lower biomass accumulation than the control, but exhibited significantly longer stems and roots than the control, which suggests that graphene, in contrast with other nanoparticles, had different effects on seedling growth. Taken together, our results imply that graphene played complicated roles in affecting the initial stage of seed germination and subsequent seedling growth.

Monte Carlo simulation of the seed germination process

International Nuclear Information System (INIS)

Gladyszewska, B.; Koper, R.

2000-01-01

Paper presented a mathematical model of seed germination process based on the Monte Carlo method and theoretical premises resulted from the physiology of seed germination suggesting three consecutive stages: physical, biochemical and physiological. The model was experimentally verified by determination of germination characteristics for seeds of ground tomatoes, Promyk cultivar, within broad range of temperatures (from 15 to 30 deg C)

Seed after-ripening and dormancy determine adult life history independently of germination timing.

Science.gov (United States)

de Casas, Rafael Rubio; Kovach, Katherine; Dittmar, Emily; Barua, Deepak; Barco, Brenden; Donohue, Kathleen

2012-05-01

• Seed dormancy can affect life history through its effects on germination time. Here, we investigate its influence on life history beyond the timing of germination. • We used the response of Arabidopsis thaliana to chilling at the germination and flowering stages to test the following: how seed dormancy affects germination responses to the environment; whether variation in dormancy affects adult phenology independently of germination time; and whether environmental cues experienced by dormant seeds have an effect on adult life history. • Dormancy conditioned the germination response to low temperatures, such that prolonged periods of chilling induced dormancy in nondormant seeds, but stimulated germination in dormant seeds. The alleviation of dormancy through after-ripening was associated with earlier flowering, independent of germination date. Experimental dormancy manipulations showed that prolonged chilling at the seed stage always induced earlier flowering, regardless of seed dormancy. Surprisingly, this effect of seed chilling on flowering time was observed even when low temperatures did not induce germination. • In summary, seed dormancy influences flowering time and hence life history independent of its effects on germination timing. We conclude that the seed stage has a pronounced effect on life history, the influence of which goes well beyond the timing of germination. © 2012 The Authors. New Phytologist © 2012 New Phytologist Trust.

The fate and role of macromolecules synthesized during mammalian oocyte meiotic maturation. I. Autoradiographic topography of newly synthesized RNA and protein in the germinal vesicle of the pig and rabbit

International Nuclear Information System (INIS)

Motlik, J.; Kopecny, V.; Pivko, J.

1978-01-01

Pig and rabbit oocytes were cytoautoradiographically checked for their synthetic activities during meiotic maturation. Tritiated uridine and lysine or 35 S-methionine were introduced into the culture medium in which the oocytes were maintained either immediately at the beginning of the germinal vesicle breakdown in vitro or after reaching a more advanced stage of this process in vitro or in vivo. Some oocytes were maintained thereafter in a cold medium to trace the metabolism of the labelled protein. In addition to uridine- 3 H incorporation into the nucleolus and nucleoplasm, during pig oocyte maturation it was found that an intensive RNA synthesis site appeared in association with condensing chromocentres of the GV II. A considerable proportion of oocytes from slaughterhouse material did not show intensive GV activity in RNA synthesis during maturation in vitro. In the pig and rabbit oocyte it was shown that the newly synthesized 3 H-lysine-labelled protein accumulated to a high degree in the GV and in the nucleolus. The labelled protein accumulated in the GV up to the stage of GV IV (pig) and persisted during the chase period in the ooplasm; it was found to be associated with chromosomes of metaphase I (pig) or metaphase II (rabbit) of the meiotic division. The process of protein accumulation in the GV was not influenced by meiotic arrest during oocyte culture in autologous follicular fluid. A similar accumulation of the label in the GV was detected in oocytes which were cultured in a medium enriched by 35 S-methionine. In some oocytes the labelled protein failed to accumulate in the nucleolar area during maturation in vitro

Planteose as a storage carbohydrate required for early stage of germination of Orobanche minor and its metabolism as a possible target for selective control

Science.gov (United States)

Wakabayashi, Takatoshi; Joseph, Benesh; Yasumoto, Shuhei; Akashi, Tomoyoshi; Aoki, Toshio; Harada, Kazuo; Muranaka, Satoru; Bamba, Takeshi; Fukusaki, Eiichiro; Takeuchi, Yasutomo; Yoneyama, Koichi; Muranaka, Toshiya; Sugimoto, Yukihiro; Okazawa, Atsushi

2015-01-01

Root parasitic weeds in Orobanchaceae cause serious damage to worldwide agriculture. Germination of the parasites requires host-derived germination stimulants, such as strigolactones, as indicators of host roots within reach of the parasite’s radicles. This unique germination process was focused on to identify metabolic pathways required for germination, and to design a selective control strategy. A metabolomic analysis of germinating seeds of clover broomrape, Orobanche minor, was conducted to identify its distinctive metabolites. Consequently, a galactosyl-sucrose trisaccharide, planteose (α-d-galactopyranosyl-(1→6)-β-d-fructofuranosyl-(2→1)-α-d-glucopyranoside), was identified as a metabolite that decreased promptly after reception of the germination stimulant. To investigate the importance of planteose metabolism, the effects of several glycosidase inhibitors were examined, and nojirimycin bisulfite (NJ) was found to alter the sugar metabolism and to selectively inhibit the germination of O. minor. Planteose consumption was similar in NJ-treated seeds and non-treated germinating seeds; however, NJ-treated seeds showed lower consumption of sucrose, a possible intermediate of planteose metabolism, resulting in significantly less glucose and fructose. This inhibitory effect was recovered by adding glucose. These results suggest that planteose is a storage carbohydrate required for early stage of germination of O. minor, and NJ inhibits germination by blocking the supply of essential glucose from planteose and sucrose. Additionally, NJ selectively inhibited radicle elongation of germinated seeds of Orobanchaceae plants (Striga hermonthica and Phtheirospermum japonicum). Thus, NJ will be a promising tool to develop specific herbicides to the parasites, especially broomrapes, and to improve our understanding of the molecular mechanisms of this unique germination. PMID:25821071

Ultrastructural examination of lead localisation in germinating seeds of Raphanus sativus

Energy Technology Data Exchange (ETDEWEB)

Lane, S.D.; Martin, E.S.

1982-07-01

Transmission electron microscopy of lead-contaminated germinating seeds has revealed that major sites of lead deposition exist within the cell wall and in association with spherosome-like vesicles common in all cells. There was also evidence of contamination of the plasmalemma, vacuole and subsequently the nucleus. In general radicle and hypocotyl tissue showed more extensive contamination than the cotyledons. The observations are discussed in relation to cell structure and development.

Planteose as a storage carbohydrate required for early stage of germination of Orobanche minor and its metabolism as a possible target for selective control.

Science.gov (United States)

Wakabayashi, Takatoshi; Joseph, Benesh; Yasumoto, Shuhei; Akashi, Tomoyoshi; Aoki, Toshio; Harada, Kazuo; Muranaka, Satoru; Bamba, Takeshi; Fukusaki, Eiichiro; Takeuchi, Yasutomo; Yoneyama, Koichi; Muranaka, Toshiya; Sugimoto, Yukihiro; Okazawa, Atsushi

2015-06-01

Root parasitic weeds in Orobanchaceae cause serious damage to worldwide agriculture. Germination of the parasites requires host-derived germination stimulants, such as strigolactones, as indicators of host roots within reach of the parasite's radicles. This unique germination process was focused on to identify metabolic pathways required for germination, and to design a selective control strategy. A metabolomic analysis of germinating seeds of clover broomrape, Orobanche minor, was conducted to identify its distinctive metabolites. Consequently, a galactosyl-sucrose trisaccharide, planteose (α-d-galactopyranosyl-(1→6)-β-d-fructofuranosyl-(2→1)-α-d-glucopyranoside), was identified as a metabolite that decreased promptly after reception of the germination stimulant. To investigate the importance of planteose metabolism, the effects of several glycosidase inhibitors were examined, and nojirimycin bisulfite (NJ) was found to alter the sugar metabolism and to selectively inhibit the germination of O. minor. Planteose consumption was similar in NJ-treated seeds and non-treated germinating seeds; however, NJ-treated seeds showed lower consumption of sucrose, a possible intermediate of planteose metabolism, resulting in significantly less glucose and fructose. This inhibitory effect was recovered by adding glucose. These results suggest that planteose is a storage carbohydrate required for early stage of germination of O. minor, and NJ inhibits germination by blocking the supply of essential glucose from planteose and sucrose. Additionally, NJ selectively inhibited radicle elongation of germinated seeds of Orobanchaceae plants (Striga hermonthica and Phtheirospermum japonicum). Thus, NJ will be a promising tool to develop specific herbicides to the parasites, especially broomrapes, and to improve our understanding of the molecular mechanisms of this unique germination. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental

Seed reserve utilization and hydrolytic enzyme activities in germinating seeds of sweet corn

International Nuclear Information System (INIS)

Cheng, X.; Xiong, F.; Wang, C.; He, S.; Zhou, Y.

2018-01-01

In this study, two sh2 sweet corn cultivars (i.e., the initial seed dry weight for FT018 and TB010 was 0.16+-0.02 g/grain and 0.09+-0.01 g/grain, respectively) were used to determine the physiological characteristics of seed reserve utilization in germination. The data implied that the weight of mobilized seed reserve (WMSR) and seed reserve utilization efficiency (SRUE) increased with seed germination. FT018 exhibited higher SRUE than TB010 due to its sufficient energy production for growth. Sugar (sucrose and fructose) contents were at different levels in the germinating seed of sh2 sweet corn. The protein content and number of protein species were highest in the early stage of germination. Enzyme activity in the germinating seed indicated that enzymes for starch and sugar hydrolysis were important and that enzyme activities significantly differed at each germination stage and between the cultivars under dark conditions. Succinate dehydrogenase, sucrose synthase, and glucose-6-phosphate dehydrogenase accumulated in the late germination stage. Thus, appropriate efforts should be focused on improving the seed reserve utilization in sweet corn by identifying the physiological mechanism of germinating seed. (author)

Vesicles Are Persistent Features of Different Plastids.

Science.gov (United States)

Lindquist, Emelie; Solymosi, Katalin; Aronsson, Henrik

2016-10-01

Peripheral vesicles in plastids have been observed repeatedly, primarily in proplastids and developing chloroplasts, in which they are suggested to function in thylakoid biogenesis. Previous observations of vesicles in mature chloroplasts have mainly concerned low temperature pretreated plants occasionally treated with inhibitors blocking vesicle fusion. Here, we show that such vesicle-like structures occur not only in chloroplasts and proplastids, but also in etioplasts, etio-chloroplasts, leucoplasts, chromoplasts and even transforming desiccoplasts without any specific pretreatment. Observations are made both in C3 and C4 species, in different cell types (meristematic, epidermis, mesophyll, bundle sheath and secretory cells) and different organs (roots, stems, leaves, floral parts and fruits). Until recently not much focus has been given to the idea that vesicle transport in chloroplasts could be mediated by proteins, but recent data suggest that the vesicle system of chloroplasts has similarities with the cytosolic coat protein complex II system. All current data taken together support the idea of an ongoing, active and protein-mediated vesicle transport not only in chloroplasts but also in other plastids, obviously occurring regardless of chemical modifications, temperature and plastid developmental stage. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Profiling and functional classification of esterases in olive (Olea europaea) pollen during germination.

Science.gov (United States)

Rejón, Juan D; Zienkiewicz, Agnieszka; Rodríguez-García, María Isabel; Castro, Antonio J

2012-10-01

A pollen grain contains a number of esterases, many of which are released upon contact with the stigma surface. However, the identity and function of most of these esterases remain unknown. In this work, esterases from olive pollen during its germination were identifided and functionally characterized. The esterolytic capacity of olive (Olea europaea) pollen was examined using in vitro and in-gel enzymatic assays with different enzyme substrates. The functional analysis of pollen esterases was achieved by inhibition assays by using specific inhibitors. The cellular localization of esterase activities was performed using histochemical methods. Olive pollen showed high levels of non-specific esterase activity, which remained steady after hydration and germination. Up to 20 esterolytic bands were identified on polyacrylamide gels. All the inhibitors decreased pollen germinability, but only diisopropyl fluorophosphate (DIFP) hampered pollen tube growth. Non-specific esterase activity is localized on the surface of oil bodies (OBs) and small vesicles, in the pollen intine and in the callose layer of the pollen tube wall. Acetylcholinesterase (AChE) activity was mostly observed in the apertures, exine and pollen coat, and attached to the pollen tube wall surface and to small cytoplasmic vesicles. In this work, for the first time a systematic functional characterization of esterase enzymes in pollen from a plant species with wet stigma has been carried out. Olive pollen esterases belong to four different functional groups: carboxylesterases, acetylesterases, AChEs and lipases. The cellular localization of esterase activity indicates that the intine is a putative storage site for esterolytic enzymes in olive pollen. Based on inhibition assays and cellular localization of enzymatic activities, it can be concluded that these enzymes are likely to be involved in pollen germination, and pollen tube growth and penetration of the stigma.

Germination and biochemical changes in ‘Formosa’ papaya seeds treated with plant hormones

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Rafael Fonsêca Zanotti

2014-04-01

Full Text Available This study aimed to investigate the effects of growth regulators on germination rates and biochemical compound concentrations in Carica papaya L. seeds (‘Formosa’ group. The seeds were harvested from fruits at maturation stages 3 and 5 (50 and 75% yellow fruit skin, respectively. The effects of 2-chloroethylphosphonic acid (CEPA, KNO3 and gibberellic acid (GA3on seed germination, germination index speed, soluble sugars, starch, lipids, soluble proteins and total proteins of the papaya seeds were evaluated. The seeds from stage 5 showed a higher rate of germination 30 days after sowing than did the seeds from stage 3. Treatment with CEPA decreased seed germination, apparently due to decreased starch mobilization; the opposite response was observed following KNO3 treatment. GA3, alone or in combination with KNO3, stimulated an increase in lipid mobilization. In general, with the exception of CEPA, all growth regulators tested were effective in overcoming seed dormancy, and KNO3 was the most effective. The seeds from stage 3 fruits treated with KNO3 or KNO3 + GA3 had higher rates of germination at 14 days.

Sugar apple (Annona squamosa L., Annonaceae seed germination: morphological and anatomical changes

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Fabio Ernesto Martínez-Maldonado

2013-08-01

Full Text Available The anon or sugar apple is a species of the Annona genus, widely distributed in the world and in Colombia and a fruit with great potential in domestic and international markets. However, the technical information related to the aspects of propagation and production is limited. In the present study, the morphological and anatomical changes during seed germination of the sugar apple were determined using histological techniques and photographic records. The results show that seed germination is a process that takes place in two stages: testa rupture and endosperm rupture-radicle protrusion. In the post-germination stages, the induction and formation of lateral roots that were endogenously produced from the primary root from the pericycle were seen. The endosperm underwent morphological changes that increased its volume during imbibition and degraded in the final stages of germination, which could be indicative of endosperm weakening and reduction of mechanical strength imposed by embryo growth, which was required to complete germination in A. squamosa

Microorganisms control during processing of germinated brown rice

International Nuclear Information System (INIS)

Suzuki, K.; Maekawa, T.

1999-01-01

In order to limit the growth of microorganisms during processing of germinated brown rice (GBR), three kinds of operations for sanitation control were investigated. For a surface-disinfection treatment of brown rice, soaking in 1% of sodium hypochlorite for 10min. and 0.1% of calcium preparation solutions for 10min. at 30°C, resulted in 2log decrease by aerobic plate count in culture water after 1h of the germination processing. Soaking in 10% of sodium hypochlorite for 10min. and 1% of calcium preparation solutions for 10min at 30°C were found to inhibit germination, respectively. During the germination processing, including aeration stage and non-aeration stage, continuous ultraviolet irradiation on the culture water in the water tank resulted in limited bacterial growth in culture water below 102CFU/ml by aerobic plate count. Moreover, the turbidity of the culture water was improved by filtration of the stored water using activated carbon-hollow fiber filter. The filtration by activated carbon-hollow fiber filter during the germination processing was an effective method to eliminate microorganisms and contamination factor during GBR production. It also improved the efficiency of ultraviolet irradiation effect on the culture water

Effect of salinity on tomato (Lycopersicon esculentum Mill.) during seed germination stage.

Science.gov (United States)

Singh, Jogendra; Sastry, E V Divakar; Singh, Vijayata

2012-01-01

A study was conducted using ten genetically diverse genotypes along with their 45F1 (generated by diallel mating) under normal and salt stress conditions. Although, tomato (Lycopersicon esculentum Mill.) is moderately sensitive to salinity but more attention to salinity is yet to be required in the production of tomato. In present study, germination rate, speed of germination, dry weight ratio and Na(+)/K(+) ratio in root and shoot, were the parameters assayed on three salinity levels; control, 1.0 % NaCl and 3.0 % NaCl with Hoagland's solution. Increasing salt stress negatively affected growth and development of tomato. When salt concentration increased, germination of tomato seed was reduced and the time needed to complete germination lengthened, root/shoot dry weight ratio was higher and Na(+) content increased but K(+) content decreased. Among the varieties, Sel-7 followed by Arka Vikas and crosses involving them as a parent were found to be the more tolerant genotypes in the present study on the basis of studied parameters.

Secondary Metabolites Produced during the Germination of Streptomyces coelicolor

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Matouš Čihák

2017-12-01

Full Text Available Spore awakening is a series of actions that starts with purely physical processes and continues via the launching of gene expression and metabolic activities, eventually achieving a vegetative phase of growth. In spore-forming microorganisms, the germination process is controlled by intra- and inter-species communication. However, in the Streptomyces clade, which is capable of developing a plethora of valuable compounds, the chemical signals produced during germination have not been systematically studied before. Our previously published data revealed that several secondary metabolite biosynthetic genes are expressed during germination. Therefore, we focus here on the secondary metabolite production during this developmental stage. Using high-performance liquid chromatography-mass spectrometry, we found that the sesquiterpenoid antibiotic albaflavenone, the polyketide germicidin A, and chalcone are produced during germination of the model streptomycete, S. coelicolor. Interestingly, the last two compounds revealed an inhibitory effect on the germination process. The secondary metabolites originating from the early stage of microbial growth may coordinate the development of the producer (quorum sensing and/or play a role in competitive microflora repression (quorum quenching in their nature environments.

Distribution of alpha3, alpha5 and alpha(v) integrin subunits in mature and immature human oocytes.

Science.gov (United States)

Capmany, G; Mart, M; Santaló, J; Bolton, V N

1998-10-01

The distribution of three integrin subunits, alpha3, alpha5 and alpha(v), in immature and mature human oocytes has been examined using immunofluorescence and confocal microscopy. The results demonstrate that both alpha5 and alpha(v) are present at the germinal vesicle stage, while alpha3 was only detected in oocytes after germinal vesicle breakdown, in metaphase I and II stage oocytes. The cortical concentration of integrin subunits alpha3 and alpha5 is consistent with their localization in the oolemma. In contrast, the homogeneous distribution of alpha(v) throughout the oocyte suggests the existence of cytoplasmic reservoirs of this protein in the oocyte.

Interference of the Histone Deacetylase Inhibits Pollen Germination and Pollen Tube Growth in Picea wilsonii Mast.

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Yaning Cui

Full Text Available Histone deacetylase (HDAC is a crucial component in the regulation of gene expression in various cellular processes in animal and plant cells. HDAC has been reported to play a role in embryogenesis. However, the effect of HDAC on androgamete development remains unclear, especially in gymnosperms. In this study, we used the HDAC inhibitors trichostatin A (TSA and sodium butyrate (NaB to examine the role of HDAC in Picea wilsonii pollen germination and pollen tube elongation. Measurements of the tip-focused Ca2+ gradient revealed that TSA and NaB influenced this gradient. Immunofluorescence showed that actin filaments were disrupted into disorganized fragments. As a result, the vesicle trafficking was disturbed, as determined by FM4-64 labeling. Moreover, the distribution of pectins and callose in cell walls was significantly altered in response to TSA and NaB. Our results suggest that HDAC affects pollen germination and polarized pollen tube growth in Picea wilsonii by affecting the intracellular Ca2+ concentration gradient, actin organization patterns, vesicle trafficking, as well as the deposition and configuration of cell wall components.

Mobilization and Role of Starch, Protein, and Fat Reserves during Seed Germination of Six Wild Grassland Species.

Science.gov (United States)

Zhao, Ming; Zhang, Hongxiang; Yan, Hong; Qiu, Lu; Baskin, Carol C

2018-01-01

Since seed reserves can influence seed germination, the quantitative and qualitative differences in seed reserves may relate to the germination characteristics of species. The purpose of our study was to evaluate the correlation between germination and seed reserves, as well as their mobilization during germination of six grassland species ( Chloris virgata , Kochia scoparia , Lespedeza hedysaroides , Astragalus adsurgens , Leonurus artemisia , and Dracocephalum moldavica ) and compare the results with domesticated species. We measured starch, protein, and fat content in dry seeds and the initial absorption of water during imbibition. Starch, soluble protein, fat, and soluble sugar content also were determined at five stages during germination. Starch, protein, and fat reserves in dry seeds were not significantly correlated with germination percentage and rate (speed), but soluble sugar and soluble protein contents at different germination stages were positively significantly correlated with germination rate for the six species. Starch was mainly used during seed imbibition, and soluble protein was used from the imbibition stage to the highest germination stage. Fat content for all species remained relatively constant throughout germination for six species, regardless of the proportion of other seed reserves in the seeds. Our results for fat utilization differ from those obtained for cultivated grasses and legumes. These results provide new insight on the role of seed reserves as energy resources in germination for wild species.

Mobilization and Role of Starch, Protein, and Fat Reserves during Seed Germination of Six Wild Grassland Species

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Ming Zhao

2018-02-01

Full Text Available Since seed reserves can influence seed germination, the quantitative and qualitative differences in seed reserves may relate to the germination characteristics of species. The purpose of our study was to evaluate the correlation between germination and seed reserves, as well as their mobilization during germination of six grassland species (Chloris virgata, Kochia scoparia, Lespedeza hedysaroides, Astragalus adsurgens, Leonurus artemisia, and Dracocephalum moldavica and compare the results with domesticated species. We measured starch, protein, and fat content in dry seeds and the initial absorption of water during imbibition. Starch, soluble protein, fat, and soluble sugar content also were determined at five stages during germination. Starch, protein, and fat reserves in dry seeds were not significantly correlated with germination percentage and rate (speed, but soluble sugar and soluble protein contents at different germination stages were positively significantly correlated with germination rate for the six species. Starch was mainly used during seed imbibition, and soluble protein was used from the imbibition stage to the highest germination stage. Fat content for all species remained relatively constant throughout germination for six species, regardless of the proportion of other seed reserves in the seeds. Our results for fat utilization differ from those obtained for cultivated grasses and legumes. These results provide new insight on the role of seed reserves as energy resources in germination for wild species.

Dynamics of fatty acid vesicles in response to pH stimuli

DEFF Research Database (Denmark)

Ikari, Keita; Sakuma, Yuka; Jimbo, Takehiro

2015-01-01

We investigate the dynamics of decanoic acid/decanoate (DA) vesicles in response to pH stimuli. Two types of dynamic processes induced by the micro injection of NaOH solutions are sequentially observed: deformations and topological transitions. In the deformation stage, DA vesicles show a series...

DEVELOPMENT OF AN EFFICIENT METHOD FOR in vitro GERMINATION OF SORGHUM POLLEN

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José Luis Anaya-López

2011-10-01

Full Text Available The in vitro pollen germination of sorghum is useful in viability, physiology and genetic transformation studies of pollen. However, the media reported are not efficient. The aim of this study was to formulate an artificial medium, and to determine the optimal conditions for in vitro pollen germination of sorghum. We used a factorial arrangement of concentrations of sucrose, boric acid and calcium nitrate, also evaluated the effect of pH, relative humidity, the physical state of the medium and the stage of flower development over germination. The conditions described in this paper allowed to obtain up to 51% of in vitro pollen germination from 14 varieties of sorghum. These findings show that for increasing in vitro germination, optimal formulation of the medium is required, as well as control over relative humidity and phonological stage of pollen collection.

The Effects of water and salt stresses on germination in two bread ...

African Journals Online (AJOL)

Results showed those germination rate was delayed by both solutions in both varieties, with differences between genotypes among growth stages, given that Saisonez genotype showed a higher germination rate than Cascogne genotype in NaCl. NaCl had a lesser effect on genotypes in terms of germination rate and the ...

Primary vesicles, vesicle-rich segregation structures and recognition of primary and secondary porosities in lava flows from the Paraná igneous province, southern Brazil

Science.gov (United States)

Barreto, Carla Joana S.; de Lima, Evandro F.; Goldberg, Karin

2017-04-01

This study focuses on a volcanic succession of pāhoehoe to rubbly lavas of the Paraná-Etendeka Province exposed in a single road profile in southernmost Brazil. This work provides an integrated approach for examining primary vesicles and vesicle-rich segregation structures at the mesoscopic scale. In addition, this study provides a quantitative analysis of pore types in thin section. We documented distinct distribution patterns of vesicle and vesicle-rich segregation structures according to lava thickness. In compound pāhoehoe lavas, the cooling allows only vesicles (pipe vesicles to be frozen into place. In inflated pāhoehoe lavas, vesicles of different sizes are common, including pipe vesicles, and also segregation structures such as proto-cylinders, cylinders, cylinder sheets, vesicle sheets, and pods. In rubbly lavas, only vesicles of varying sizes occur. Gas release from melt caused the formation of primary porosity, while hydrothermal alteration and tectonic fracturing are the main processes that generated secondary porosity. Although several forms of porosity were created in the basaltic lava flows, the precipitation of secondary minerals within the pores has tended to reduce the original porosities. Late-stage fractures could create efficient channel networks for possible hydrocarbon/groundwater migration and entrapment owing to their ability to connect single pores. Quantitative permeability data should be gathered in future studies to confirm the potential of these lavas for store hydrocarbons or groundwater.

Albendazole in environment: faecal concentrations in lambs and impact on lower development stages of helminths and seed germination.

Science.gov (United States)

Prchal, Lukáš; Podlipná, Radka; Lamka, Jiří; Dědková, Tereza; Skálová, Lenka; Vokřál, Ivan; Lecová, Lenka; Vaněk, Tomáš; Szotáková, Barbora

2016-07-01

Albendazole (ABZ), widely used benzimidazole anthelmintic, administered to animals enters via excrements into environment and may impact non-target organisms. Moreover, exposure of lower development stages of helminths to anthelmintics may also encourage the development of drug-resistant strains of helminths. In present project, the kinetics of ABZ (10 mg kg(-1) p.o.) and its metabolite (ABZ.SO, ABZSO2) elimination in faeces from treated Texel lambs were studied using UHPLC/MS/MS with the aim to find out their concentrations achievable in the environment. Consequently, the effect of these compounds on lower development stages of Barber's pole worm (Haemonchus contortus) and on germination of white mustard (Sinapis alba) seeds was evaluated. The results showed that ABZ concentrations in faeces excreted in 4-60 h after treatment were above the concentrations lethal for H. contortus eggs. Moreover, pre-incubation with sub-lethal doses of ABZ and ABZ.SO did not increase the resistance of H. contortus eggs and larvae to anthelmintics. On the other hand, concentrations of ABZ and ABZ.SO in faeces are so high that might have negative influence on non-target soil invertebrates. As neither ABZ nor its metabolites affect the germination of mustard seeds, phytoremediation could be considered as potential tool for detoxification of ABZ in the environment.

Germination failure is not a critical stage of reproductive isolation between three congeneric orchid species.

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De Hert, Koen; Honnay, Olivier; Jacquemyn, Hans

2012-11-01

In food-deceptive orchid species, postmating reproductive barriers (fruit set and embryo mortality) have been shown to be more important for reproductive isolation than premating barriers (pollinator isolation). However, currently there is very little knowledge about whether germination failure acts as a reproductive barrier in hybridizing orchid species. In this study, we investigated germination and protocorm development of pure and hybrid seeds of three species of the orchid genus Dactylorhiza. To test the hypothesis that germination failure contributed to total reproductive isolation, reproductive barriers based on germination were combined with already available data on early acting barriers (fruit set and embryo mortality) to calculate the relative and absolute contributions of these barriers to reproductive isolation. Protocorms were formed in all crosses, indicating that both hybrid and pure seeds were able to germinate and grow into protocorms. Also, the number of protocorms per seed packet was not significantly different between hybrid and pure seeds. High fruit set, high seed viability, and substantial seed germination resulted in very low reproductive isolation (average RI = 0.05). In two of six interspecific crosses, hybrids performed even better than the intraspecific crosses. Very weak postmating reproductive barriers were observed between our study species and may explain the frequent occurrence of first-generation hybrids in mixed Dactylorhiza populations. Germination failure, which is regarded as one of the most important bottlenecks in the orchid life cycle, was not important for reproductive isolation.

Weak Static and Extremely Low Frequency Magnetic Fields Affect In Vitro Pollen Germination

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Lucietta Betti

2011-01-01

Full Text Available This study concerns the effects of a weak static magnetic field (MF at 10 μT oriented downward, combined with a 16-Hz sinusoidal MF (10 μT, on in vitro pollen germination of kiwifruit (Actinidia deliciosa. Extremely low frequency magnetic field (ELF-MF exposure was carried out by a signal generator unit connected to a copper wire solenoid, inside which samples where placed. Two different kinds of treatment were performed: direct and indirect. In the direct treatment, pollen samples were directly exposed during rehydration, germination, or both. In the indirect treatment, the pollen growth medium was prepared with water aliquots (at standard temperature of 20°C and pH = 6.74 that were exposed before use for 8 or 24 h. The main purpose of our research was to identify a biological marker (in vitro pollen germination in a stressing growth medium without Ca2+ susceptible to the effects of direct or indirect ELF-MF exposure. The working variable was the pollen germination rate, as detected blind after 3 h 30 min by an Axioplan microscope. A directionally consistent recovery of germination percentage was observed both for direct exposure (during germination and both rehydration and germination phases and water-mediated exposure (with water exposed for 24 h and immediately used. Our results suggest that the ELF-MF treatment might partially remove the inhibitory effect caused by the lack of Ca2+ in the culture medium, inducing a release of internal Ca2+ stored in the secretory vesicles of pollen plasma membrane. Although preliminary, findings seem to indicate the in vitro pollen performance as adequate to study the effects of ELF-MFs on living matter.

Evaluation and Selection for Drought Tolerance in Iranian Fenugreek (Trigonella foenum-graecum Landraces at Germination and Seedling Growth Stages

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D. Sadeghzadeh Ahari

2016-07-01

germination percentage, root and stem lengths, root and stem fresh weights, root and stem dry weights, Kashan and Neyshaboor were the most tolerant and Rey and Khash were the most susceptible landraces among the studied genotypes at germination and seedling growth stages. Conclusion: It could be concluded that, there are differences among the Iranian fenugreek landraces in case of reaction to drought stress at germination and seedling growth stages that shows suitable diversity among them. Moreover, using from less than -4 bar drought stress levels recommended for screening and selection of drought tolerance fenugreek genotypes. Also, it is recommended attention to Iranian fenugreek landraces and using the hidden potentials of them same as drought tolerance and resistance. It is suggested protection of them as a precious genetically resources in gene bank.

Study on the optimal moisture adding rate of brown rice during germination by using segmented moisture conditioning method.

Science.gov (United States)

Cao, Yinping; Jia, Fuguo; Han, Yanlong; Liu, Yang; Zhang, Qiang

2015-10-01

The aim of this study was to find out the optimal moisture adding rate of brown rice during the process of germination. The process of water addition in brown rice could be divided into three stages according to different water absorption speeds in soaking process. Water was added with three different speeds in three stages to get the optimal water adding rate in the whole process of germination. Thus, the technology of segmented moisture conditioning which is a method of adding water gradually was put forward. Germinated brown rice was produced by using segmented moisture conditioning method to reduce the loss of water-soluble nutrients and was beneficial to the accumulation of gamma aminobutyric acid. The effects of once moisture adding amount in three stages on the gamma aminobutyric acid content in germinated brown rice and germination rate of brown rice were investigated by using response surface methodology. The optimum process parameters were obtained as follows: once moisture adding amount of stage I with 1.06 %/h, once moisture adding amount of stage II with 1.42 %/h and once moisture adding amount of stage III with 1.31 %/h. The germination rate under the optimum parameters was 91.33 %, which was 7.45 % higher than that of germinated brown rice produced by soaking method (84.97 %). The content of gamma aminobutyric acid in germinated brown rice under the optimum parameters was 29.03 mg/100 g, which was more than two times higher than that of germinated brown rice produced by soaking method (12.81 mg/100 g). The technology of segmented moisture conditioning has potential applications for studying many other cereals.

iTRAQ and RNA-Seq Analyses Provide New Insights into Regulation Mechanism of Symbiotic Germination of Dendrobium officinale Seeds (Orchidaceae).

Science.gov (United States)

Chen, Juan; Liu, Si Si; Kohler, Annegret; Yan, Bo; Luo, Hong Mei; Chen, Xiao Mei; Guo, Shun Xing

2017-06-02

Mycorrhizal fungi colonize orchid seeds and induce germination. This so-called symbiotic germination is a critical developmental process in the lifecycle of all orchid species. However, the molecular changes that occur during orchid seed symbiotic germination remain largely unknown. To better understand the molecular mechanism of orchid seed germination, we performed a comparative transcriptomic and proteomic analysis of the Chinese traditional medicinal orchid Dendrobium officinale to explore the change in protein expression at the different developmental stages during asymbiotic and symbiotic germination and identify the key proteins that regulate the symbiotic germination of orchid seeds. Among 2256 identified plant proteins, 308 were differentially expressed across three developmental stages during asymbiotic and symbiotic germination, and 229 were differentially expressed during symbiotic germination compared to asymbiotic development. Of these, 32 proteins were coup-regulated at both the proteomic and transcriptomic levels during symbiotic germination compared to asymbiotic germination. Our results suggest that symbiotic germination of D. officinale seeds shares a common signaling pathway with asymbiotic germination during the early germination stage. However, compared to asymbiotic germination, fungal colonization of orchid seeds appears to induce higher and earlier expression of some key proteins involved in lipid and carbohydrate metabolism and thus improves the efficiency of utilization of stored substances present in the embryo. This study provides new insight into the molecular basis of orchid seed germination.

The unique stem cell system of the immortal larva of the human parasite Echinococcus multilocularis

Science.gov (United States)

2014-01-01

Background It is believed that in tapeworms a separate population of undifferentiated cells, the germinative cells, is the only source of cell proliferation throughout the life cycle (similar to the neoblasts of free living flatworms). In Echinococcus multilocularis, the metacestode larval stage has a unique development, growing continuously like a mass of vesicles that infiltrate the tissues of the intermediate host, generating multiple protoscoleces by asexual budding. This unique proliferation potential indicates the existence of stem cells that are totipotent and have the ability for extensive self-renewal. Results We show that only the germinative cells proliferate in the larval vesicles and in primary cell cultures that undergo complete vesicle regeneration, by using a combination of morphological criteria and by developing molecular markers of differentiated cell types. The germinative cells are homogeneous in morphology but heterogeneous at the molecular level, since only sub-populations express homologs of the post-transcriptional regulators nanos and argonaute. Important differences are observed between the expression patterns of selected neoblast marker genes of other flatworms and the E. multilocularis germinative cells, including widespread expression in E. multilocularis of some genes that are neoblast-specific in planarians. Hydroxyurea treatment results in the depletion of germinative cells in larval vesicles, and after recovery following hydroxyurea treatment, surviving proliferating cells grow as patches that suggest extensive self-renewal potential for individual germinative cells. Conclusions In E. multilocularis metacestodes, the germinative cells are the only proliferating cells, presumably driving the continuous growth of the larval vesicles. However, the existence of sub-populations of the germinative cells is strongly supported by our data. Although the germinative cells are very similar to the neoblasts of other flatworms in function and

Enhanced tocopherol levels during early germination events in Chamaerops humilis var. humilis seeds.

Science.gov (United States)

Siles, Laura; Alegre, Leonor; Tijero, Verónica; Munné-Bosch, Sergi

2015-10-01

Most angiosperms accumulate vitamin E in the form of tocopherols in seeds, exerting a protective antioxidant role. However, several palm trees principally accumulate tocotrienols, rather than tocopherols, in seeds, as it occurs in other monocots. To unravel the protective role of either tocopherols or tocotrienols against lipid peroxidation during seed germination in Chamaerops humilis var. humilis; seed viability, natural and induced germination capacity, seed water content, malondialdehyde levels (as an indicator of the extent of lipid peroxidation) and vitamin E levels (including both tocopherols and tocotrienols) were examined at various germination phases in a simulated, natural seed bank. At the very early stages of germination (operculum removal), malondialdehyde levels increased 2.8-fold, to decrease later up to 74%, thus indicating a transient lipid peroxidation at early stages of germination. Tocopherol levels were absent in quiescent seeds and did not increase during operculum removal, but increased later presumably dampening malondialdehyde accumulation. Thereafter, tocopherols continued increasing, while lipid peroxidation levels decreased. By contrast, tocotrienols levels remained constant or even decreased as germination progressed, showing no correlation with lipid peroxidation levels. We hypothesize that despite their high tocotrienol content, seeds synthesize tocopherols during germination to protect lipids from peroxidation events. Copyright © 2015 Elsevier Ltd. All rights reserved.

Vesicles and vesicle fusion: coarse-grained simulations

DEFF Research Database (Denmark)

Shillcock, Julian C.

2010-01-01

of vesicles that is crucial for this transport is their ability to fuse to target membranes and release their contents to the distal side. In industry, some personal care products contain vesicles to help transport reagents across the skin, and research on drug formulation shows that packaging active......Biological cells are highly dynamic, and continually move material around their own volume and between their interior and exterior. Much of this transport encapsulates the material inside phospholipid vesicles that shuttle to and fro, fusing with, and budding from, other membranes. A feature...

Behavior of 15N-labelled amino acids in germinated corn

International Nuclear Information System (INIS)

Samukawa, Kisaburo; Yamaguchi, Masuro

1979-01-01

By investigating the rise and fall of 15 N-labelled amino acids in germinated corns, the behavior of amino radicals in free amino acids, the influence of the hydrolysis products of stored proteins on free amino acids and the change from heterotrophy to autotrophy of seeds were clarified. The amount of amino acid production depending on external nitrogen was very small in the early period of germination. 15 N incorporation into proline was not observed in the early period of germination, which suggested that the proline may be nitrogen-storing source. Most of the amino-state nitrogen of asparagine accumulated at the time of germination was internal nitrogen, and this fact suggested that aspartic acid serve as the acceptor of ammonia produced in the early stage of germination. 15 N content increased significantly on 9 th day after germination, and decreased on 12 th day. These facts prove that there are always active decomposition and production of protein in plant body. (Kobatake, H.)

Emergence and stability of intermediate open vesicles in disk-to-vesicle transitions.

Science.gov (United States)

Li, Jianfeng; Zhang, Hongdong; Qiu, Feng; Shi, An-Chang

2013-07-01

The transition between two basic structures, a disk and an enclosed vesicle, of a finite membrane is studied by examining the minimum energy path (MEP) connecting these two states. The MEP is constructed using the string method applied to continuum elastic membrane models. The results reveal that, besides the commonly observed disk and vesicle, open vesicles (bowl-shaped vesicles or vesicles with a pore) can become stable or metastable shapes. The emergence, stability, and probability distribution of these open vesicles are analyzed. It is demonstrated that open vesicles can be stabilized by higher-order elastic energies. The estimated probability distribution of the different structures is in good agreement with available experiments.

Quantal basis of vesicle growth and information content, a unified approach.

Science.gov (United States)

Nitzany, Eyal; Hammel, Ilan; Meilijson, Isaac

2010-09-07

Secretory vesicles express a periodic multimodal size distribution. The successive modes are integral multiples of the smallest mode (G(1)). The vesicle content ranges from macromolecules (proteins, mucopolysaccharides and hormones) to low molecular weight molecules (neurotransmitters). A steady-state model has been developed to emulate a mechanism for the introduction of vesicles of monomer size, which grow by a unit addition mechanism, G(1)+G(n)-->G(n+1) which, at a later stage are eliminated from the system. We describe a model of growth and elimination transition rates which adequately illustrates the distributions of vesicle population size at steady-state and upon elimination. Consequently, prediction of normal behavior and pathological perturbations is feasible. Careful analysis of spontaneous secretion, as compared to short burst-induced secretion, suggests that the basic character-code for reliable communication should be within a range of only 8-10 vesicles' burst which may serve as a yes/no message. Copyright 2010 Elsevier Ltd. All rights reserved.

Embryo development and corresponding factors affecting in vitro germination of Cymbidium faberi × C. sinense hybrid seeds

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Li Fengtong

2016-01-01

Full Text Available A better understanding of embryo development would provide insights into seed quality and subsequent germination events in the interspecific hybridization of Cymbidium faberi ‘Jiepeimei’ × C. sinense ‘Qijianheimo’. At the mature stage, 26.1% of the ovules were abnormal. Most of the hybrid embryos could develop normally. Abortions mainly occurred at the zygote (9.5% and 2-4-celled embryo (15.1% stages. No germination was observed at 90 and 105 days after pollination (DAP, when the embryo was at the early globular stage, with abundant organelles but no storage materials. During 110-130 DAP, the globular embryo was formed and the starch grains began to accumulate in plastids. The hybrid seeds collected at 120 DAP showed initiation of germination. Germination significantly increased at 135 DAP and was maximal at 150 DAP, during which period the hybrid embryos developed into the late globular stage. The storage materials, i.e. lipid and protein bodies, began to accumulate and the filamentary structures derived from suspensor cells still persisted. After the seeds matured (160 DAP, the germination percentage declined sharply. Safranin staining revealed that the outer seed coat was totally cuticularized and the inner seed coat appeared as a cuticle layer enclosing the embryo proper tightly, which may be the main factor inhibiting the subsequent germination of hybrid seeds. In conclusion, 150 DAP should be the opportune time for the in vitro germination of C. faberi ‘Jiepeimei’ × C. sinense ‘Qijianheimo’ hybrid seeds.

Barley germination

DEFF Research Database (Denmark)

Daneri-Castro, Sergio N.; Svensson, Birte; Roberts, Thomas H.

2016-01-01

germination. Lastly, the application of metabolomics to barley grain germination provides essential data on biochemical processes, including insights into the formation of compounds that contribute to malt quality. To maximize the benefits of the 'omics' revolution to the malting industry, there is a need......Germination of barley grain is central to the malting industry and is a valuable model for cereal grain germination. Our current understanding of the complexity of germination at the molecular level is facilitated by access to genomic, transcriptomic, proteomic and metabolomic data. Here we review...... of germination in the context of industrial malting. For transcriptomics, recent advances in sequencing the barley genome allow next-generation sequencing approaches to reveal novel effects of variety and environment on germination. For proteomics, selection of the source tissue(s) and the protein extraction...

myo-Inositol synthesis from [1-3H]glucose in Phaseolus vulgaris L. during early stages of germination

International Nuclear Information System (INIS)

Sasaki, K.; Taylor, I.E.P.

1986-01-01

Radiolabeled D-[1- 3 H]glucose was fed by imbibition under sterile conditions to bean (Phaseolus vulgaris L.) seeds. After 72 and 96 hours of feeding, the 3 H was located in uronic acid and pentose residues as well as hexose residues of cell wall polysaccharides in growing hypocotyl and root. Free myo-inositol present in cotyledons, hypocotyl, and root also contained 3 H, showing that de novo synthesis of myo-inositol from [1- 3 H]glucose did occur during the first 72 hours of germination. More than 90% of the labeled, free myo-inositol was present in the cotyledons. The 3 H percentage in trifluoroacetic acid-soluble arabinaose residues of cell wall polysaccharides from 72-hour-old bean hypocotyls was only half of their mole percentage. On the other hand, 3 H percentages in hexose residues were higher than their mole percentages. The results suggest that myo-inositol is synthesized from reserve sugars during the very early stages of germination, and that the newly synthesized myo-inositol, as well as that stored in cotyledons, can be used for the construction of new hypocotyl and root cell wall polysaccharides after conversion into uronic acids and pentoses via the myo-inositol oxidation pathway

Role of seed germination in adaptation and reproductive isolation in Arabidopsis lyrata.

Science.gov (United States)

Hämälä, Tuomas; Mattila, Tiina M; Leinonen, Päivi H; Kuittinen, Helmi; Savolainen, Outi

2017-07-01

Seed germination is an important developmental and life history stage. Yet, the evolutionary impact of germination has mainly been studied in the context of dormancy, or for its role in reproductive isolation between species. Here, we aim to examine multiple consequences of genetic divergence on germination traits between two Arabidopsis lyrata subspecies: ssp. petraea (Eurasia) and ssp. lyrata (North America). Postdormancy germination time, a potentially adaptive trait, showed differentiation between the populations, and quantitative trait loci (QTL) mapping revealed that the trait variation is mainly controlled by two antagonistic loci. These QTL areas contain several candidate genes with known function in postdormancy germination in A. thaliana. The sequence variation of three genes was consistent with differential selection, and they also included fixed nonsynonymous substitutions with potential to account for the phenotypic differentiation. We further show that the divergence between the subspecies has led to a slight but significant reduction in hybrid germination proportions, indicating incipient reproductive isolation. Comparison of reciprocal F 1 and F 2 progenies suggests that Bateson-Dobzhansky-Muller incompatibilities likely act through uniparentally inherited factors. Examination of genomewide transmission ratio distortion further revealed that cytonuclear interactions cause substantial pregermination inviability in the hybrids. These results confirm that seed germination has adaptive potential beyond the dormancy stage and that hybrid seed inviability can be one of the first reproductive barriers to arise during divergence. © 2017 John Wiley & Sons Ltd.

Ultrasound-guided seminal vesicle biopsies in prostate cancer

NARCIS (Netherlands)

Wymenga, LFA; Duisterwinkel, FJ; Groenier, K; Mensink, HJA

2000-01-01

Invasion of prostatic adenocarcinoma into the seminal vesicles (SV) is generally accepted as an index of poor prognosis. The pre-operative identification of SV invasion is an important element in staging since it may alter subsequent treatment decisions. We studied the possibility of diagnosing SV

Biochemical Changes Associated with Germinating Rice Grains and Germination Improvement

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Subajiny VELUPPILLAI

2009-09-01

Full Text Available To determine biochemical changes during the germination of rice grains (Oryza sativa L. subsp. indica var. Mottaikaruppan and to improve germination rate using gibberellic acid and surfactants [sodium dodecyl sulfate (SDS (1.0 g/L and Triton-X−100 (1.0 mL/L], whole rice grains soaked in distilled water for 12 h at 30°C were germinated in the dark at 30°C for five days. The highest germination rate (77.1% was obtained on the 5th day. An increase in the content of reducing sugars from 7.3 to 58.1 mg/g DM (dry matter was observed from the 1st day of germination. Free amino acids and soluble protein contents increased to 3.69 and 5.29 mg/g DM, respectively on the 5th day of germination. Total protein content decreased from 100.5 to 91.0 g/kg DM during germination. Increases in amylolytic (1.1 to 190.0 U/g DM and proteolytic (0 to 0.12 U/g DM activities were observed during germination. Effects of different concentrations of gibberellic acid on the germination of rice grains were evaluated and 0.1 g/L was found to promote germination. When effects of gibberellic acid (0.1 g/L and surfactants were evaluated individually and together, higher germination rate was observed in the control experiment (grains germinated in distilled water, whereas giberellic acid and surfactants decreased the germination rate. Therefore, the flour obtained from the grains germinated for four days using distilled water to obtain high content of soluble materials and enzyme activities can be used in preparation of bakery items.

Behavior of /sup 15/N-labelled amino acids in germinated corn

Energy Technology Data Exchange (ETDEWEB)

Samukawa, K; Yamaguchi, M [Osaka Prefectural Univ., Sakai (Japan). Coll. of Agriculture

1979-06-01

By investigating the rise and fall of /sup 15/N-labelled amino acids in germinated corns, the behavior of amino radicals in free amino acids, the influence of the hydrolysis products of stored proteins on free amino acids and the change from heterotrophy to autotrophy of seeds were clarified. The amount of amino acid production depending on external nitrogen was very small in the early period of germination. /sup 15/N incorporation into proline was not observed in the early period of germination, which suggested that the proline may be nitrogen-storing source. Most of the amino-state nitrogen of asparagine accumulated at the time of germination was internal nitrogen, and this fact suggested that aspartic acid serve as the acceptor of ammonia produced in the early stage of germination. /sup 15/N content increased significantly on 9 th day after germination, and decreased on 12 th day. These facts prove that there are always active decomposition and production of protein in plant body.

Comparative study of drought and salt stress effects on germination and seedling growth of pea

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Petrović Gordana

2016-01-01

Full Text Available Seed germination is first critical and the most sensitive stage in the life cycle of plants compromise the seedlings establishment. Salt and drought tolerance testing in initial stages of plant development is of vital importance, because the seed with more rapid germination under salt or water deficit conditions may be expected to achieve a rapid seedling establishment, resulting in higher yields. The aim of this study was to determine whether the pea seed germination and seedling growth were inhibited by the salt toxicity and osmotic effect during the seedling development, and also identification of the sensitive seedling growth parameters in response to those stresses. Based on the obtained results, pea has been presented to be more tolerant to salt than water stress during germination and early embryo growth. Investigated cultivars showed greater susceptibility to both abiotic stresses when it comes growth parameters compared to seed germination. [Projekat Ministarstva nauke Republike Srbije, br. TR-31024 i br. TR-31022

Repeated Stand-Replacing Crown Fires Affect Seed Morphology and Germination in Aleppo pine

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Antonio Saracino

2017-06-01

Full Text Available Post-fire reproductive niche of Aleppo pine (Pinus halepensis is deeply interlaced with fire products. Indeed, the high pH and low osmotic potentials of ash beds under burnt crowns constitute the main constraints to seed germination. In this study, we aim to investigate whether fire recurrence, through the physico-chemical constraints imposed by the ash beds, affects the reproduction ability of P. halepensis at the germination stage. To this aim, Aleppo pine seeds were collected in neighboring even-aged stands subjected to 0, 1, or 2 fires (namely fire cohorts, and seed morphology and germination performance, in terms of cumulative germination and germination kinetics, were studied under increasing osmotic potentials (from 0.0 to −1.2 MPa and pH (from 6 to 11. Besides fire history, the role of ontogenetic age of mother plants on seed morphology and germination was also investigated. Differences in seed morphology among the three cohorts have been highlighted in a multivariate context, with anisotropic enlargement of the seeds produced by pine stands experiencing repeated fires. The patterns of seed germination varied primarily in relation to the fire cohort, with seeds from the pine stand experiencing repeated fires exhibiting enhanced tolerance to pH stress. Conversely, germination performances under osmotic constraints mainly depends on tree ontogenetic stage, with an involvement of fire history especially in the timing of seed germination. Our results suggest that, at least in the short term, fire recurrence does not constrain the reproduction ability of Aleppo pine. These results highlight the need for further research to elucidate the mechanisms behind these responses to recurrent fires.

Repeated Stand-Replacing Crown Fires Affect Seed Morphology and Germination in Aleppo pine

Science.gov (United States)

Saracino, Antonio; Bellino, Alessandro; Allevato, Emilia; Mingo, Antonio; Conti, Stefano; Rossi, Sergio; Bonanomi, Giuliano; Carputo, Domenico; Mazzoleni, Stefano

2017-01-01

Post-fire reproductive niche of Aleppo pine (Pinus halepensis) is deeply interlaced with fire products. Indeed, the high pH and low osmotic potentials of ash beds under burnt crowns constitute the main constraints to seed germination. In this study, we aim to investigate whether fire recurrence, through the physico-chemical constraints imposed by the ash beds, affects the reproduction ability of P. halepensis at the germination stage. To this aim, Aleppo pine seeds were collected in neighboring even-aged stands subjected to 0, 1, or 2 fires (namely fire cohorts), and seed morphology and germination performance, in terms of cumulative germination and germination kinetics, were studied under increasing osmotic potentials (from 0.0 to −1.2 MPa) and pH (from 6 to 11). Besides fire history, the role of ontogenetic age of mother plants on seed morphology and germination was also investigated. Differences in seed morphology among the three cohorts have been highlighted in a multivariate context, with anisotropic enlargement of the seeds produced by pine stands experiencing repeated fires. The patterns of seed germination varied primarily in relation to the fire cohort, with seeds from the pine stand experiencing repeated fires exhibiting enhanced tolerance to pH stress. Conversely, germination performances under osmotic constraints mainly depends on tree ontogenetic stage, with an involvement of fire history especially in the timing of seed germination. Our results suggest that, at least in the short term, fire recurrence does not constrain the reproduction ability of Aleppo pine. These results highlight the need for further research to elucidate the mechanisms behind these responses to recurrent fires. PMID:28713415

Vesicle electrohydrodynamics.

Science.gov (United States)

Schwalbe, Jonathan T; Vlahovska, Petia M; Miksis, Michael J

2011-04-01

A small amplitude perturbation analysis is developed to describe the effect of a uniform electric field on the dynamics of a lipid bilayer vesicle in a simple shear flow. All media are treated as leaky dielectrics and fluid motion is described by the Stokes equations. The instantaneous vesicle shape is obtained by balancing electric, hydrodynamic, bending, and tension stresses exerted on the membrane. We find that in the absence of ambient shear flow, it is possible that an applied stepwise uniform dc electric field could cause the vesicle shape to evolve from oblate to prolate over time if the encapsulated fluid is less conducting than the suspending fluid. For a vesicle in ambient shear flow, the electric field damps the tumbling motion, leading to a stable tank-treading state.

Vesicles and vesicle gels - structure and dynamics of formation

International Nuclear Information System (INIS)

Gradzielski, M

2003-01-01

Vesicles constitute an interesting morphology formed by self-aggregating amphiphilic molecules. They exhibit a rich structural variety and are of interest both from a fundamental point of view (for studying closed bilayer systems) and from a practical point of view (whenever one is interested in the encapsulation of active molecules). In many circumstances vesicular structures have to be formed by external forces, but of great interest are amphiphilic systems, where they form spontaneously. Here the question arises of whether this means that they are also thermodynamically stable structures, which at least in some systems appears to be the case. If such vesicles are well defined in size, it is possible to pack them densely and thereby form vesicle gels that possess highly elastic properties even for relatively low volume fractions of amphiphile. Conditions for the formation and the microstructure of such vesicle gels have been studied in some detail for the case of unilamellar vesicles. Another important and topical issue is the dynamics of vesicle formation/breakdown, as the understanding of the transition process will open the way to a deeper understanding of their stability and also allow controlling of the structures formed, by means of their formation processes. Significant progress in the study of the transformation processes has been achieved, in particular by means of time-resolved scattering experiments. (topical review)

Maturation and germination of somatic embryos of Sorghum bicolor (L. Moench cultivar 'CIAP 132R-05'

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Silvio de J Martínez

2017-03-01

Full Text Available In sorghum [Sorghum bicolor (L. Moench], developed protocols for plant regeneration via somatic embryogenesis do not include maturation stage. The present work was carried out with the aim of achieving the maturation and germination of sorghum somatic embryos in cultivar 'CIAP 132R-05'. It were studied four concentrations of sucrose (30, 50, 70 and 90 g l-1, two of abscisic acid (0.25 and 0.5 μM and a control without this growth regulator. Germination initiation (days and number of somatic embryos with complete germination were evaluated in three periods (1 - 7, 8 - 14 and 15 - 21 days of culture. In addition, the effect of 6-BAP (8.9, 17.8 and 26.6 μM on somatic embryo germination was determined. The germination start time (days and after 21 days the number of somatic embryos with complete germination and plants with malformations were determined. The addition of 70 g l-1 sucrose in the culture medium without abscisic acid increased the germination of the somatic embryos to 37.2 plants per embryo group (0.5 g of fresh mass. The highest number of somatic embryos germinated was obtained with 17.78 μM 6-BAP in the germination culture medium. It was demonstrated the need of a maturation stage in the sorghum somatic embryogenesis to increase the germination percentage.   Keywords: somatic embryogenesis, sorghum, sucrose, 6-BAP

Effect of Salinity and Drought Stresses on Germination Stage and Growth of Black Cumin (Bunium Persicum Boiss

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H. R. Saeedi Goraghani

2017-06-01

Full Text Available Introduction Range plants have important and crucial roles in medicinal industry andtogether with scarcity and low quality of the water and soil resources, prevent a quick recovery of the soil plant covering. Because of these restrictions, it is important to consider the use of salt and drought tolerant species for plantation and to preserve plant cover. In this sense, the use of native species such as black cumin (Bunium persicum Boiss may be of interest due to their medicinal characteristics and potential ability to adapt to adverse conditions (dry and saline conditions. Black cumin (B. persicum as a medicinal plant plays a vital role in Iranian medicine so there is a need to know about the factors affecting their growth and propagation. Materials and Methods To investigate the effects of drought and salt stresses on germination and growth in black cumin two separate experiments were conducted. Drought stress was applied through incubation in four different concentrations of PEG 6000 that provide solutions with water potentials ranging from -0.2 to -0.8 MPa (including control and four levels of dryness. Salinity treatments (including control and four levels of salinity were prepared by adding molar concentrations of NaCl to provide a range of salinity from 50 to 300 mM. Germination percentage and speed was calculated by computation of germinated seeds every day. Growth parameters (rootlet, shoot and seedling length total, allometric index and seed vigority were obtained accordingly. Results and Discussion Seeds under both drought and salt stress showed significant reduction in germination percentage, germination rate, radicle length, plumule length, and alometric and seed vigor indices. This trend was much pronounced under high levels of NaCl and low levels of water potentials, so that germination at Ψs = -0.6 MP was completely stopped. Conclusions Assessment of drought and salt stresses on germination and growth in black cumin is very

Influence of x-ray irradiation on the proliferative ability of the germinal layer cells of Echinococcus multilocularis

International Nuclear Information System (INIS)

Ohnishi, Kenji

1986-01-01

Influence of X-ray irradiation on the proliferative ability of the germinal layer cells of larval Echinococcus multilocularis was studied by using small sterile hydatids containing vesicles composed of a non-cellular laminated layer and a cellular germinal layer. The small sterile hydatids were irradiated by X-ray at dose levels of 5,000, 15,000, 25,000, 35,000, 45,000 or 55,000 R and implanted into the peritoneal cavity of Chinese hamsters. Fully developed hydatids were recognized in all cases irradiated at up to 35,000 R, when assessed 113 days after implantation. At 45,000 R, 2 out of 6 animals showed small, fully developed hydatids. No such hydatid was found in the other 4 animals nor in any of the animals implanted with hydatids irradiated at 55,000 R. No structural differences were observed between fully developed hydatids originating from the irradiated and non-irradiated small hydatids. These results indicate that the tolerance limit of the germinal layer cells is between 45,000 R and 55,000 R. (author)

Transcriptional regulatory programs underlying barley germination and regulatory functions of Gibberellin and abscisic acid

Science.gov (United States)

2011-01-01

Background Seed germination is a complex multi-stage developmental process, and mainly accomplished through concerted activities of many gene products and biological pathways that are often subjected to strict developmental regulation. Gibberellins (GA) and abscisic acid (ABA) are two key phytohormones regulating seed germination and seedling growth. However, transcriptional regulatory networks underlying seed germination and its associated biological pathways are largely unknown. Results The studies examined transcriptomes of barley representing six distinct and well characterized germination stages and revealed that the transcriptional regulatory program underlying barley germination was composed of early, late, and post-germination phases. Each phase was accompanied with transcriptional up-regulation of distinct biological pathways. Cell wall synthesis and regulatory components including transcription factors, signaling and post-translational modification components were specifically and transiently up-regulated in early germination phase while histone families and many metabolic pathways were up-regulated in late germination phase. Photosynthesis and seed reserve mobilization pathways were up-regulated in post-germination phase. However, stress related pathways and seed storage proteins were suppressed through the entire course of germination. A set of genes were transiently up-regulated within three hours of imbibition, and might play roles in initiating biological pathways involved in seed germination. However, highly abundant transcripts in dry barley and Arabidopsis seeds were significantly conserved. Comparison with transcriptomes of barley aleurone in response to GA and ABA identified three sets of germination responsive genes that were regulated coordinately by GA, antagonistically by ABA, and coordinately by GA but antagonistically by ABA. Major CHO metabolism, cell wall degradation and protein degradation pathways were up-regulated by both GA and seed

Transcriptional regulatory programs underlying barley germination and regulatory functions of Gibberellin and abscisic acid

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Lin Li

2011-06-01

Full Text Available Abstract Background Seed germination is a complex multi-stage developmental process, and mainly accomplished through concerted activities of many gene products and biological pathways that are often subjected to strict developmental regulation. Gibberellins (GA and abscisic acid (ABA are two key phytohormones regulating seed germination and seedling growth. However, transcriptional regulatory networks underlying seed germination and its associated biological pathways are largely unknown. Results The studies examined transcriptomes of barley representing six distinct and well characterized germination stages and revealed that the transcriptional regulatory program underlying barley germination was composed of early, late, and post-germination phases. Each phase was accompanied with transcriptional up-regulation of distinct biological pathways. Cell wall synthesis and regulatory components including transcription factors, signaling and post-translational modification components were specifically and transiently up-regulated in early germination phase while histone families and many metabolic pathways were up-regulated in late germination phase. Photosynthesis and seed reserve mobilization pathways were up-regulated in post-germination phase. However, stress related pathways and seed storage proteins were suppressed through the entire course of germination. A set of genes were transiently up-regulated within three hours of imbibition, and might play roles in initiating biological pathways involved in seed germination. However, highly abundant transcripts in dry barley and Arabidopsis seeds were significantly conserved. Comparison with transcriptomes of barley aleurone in response to GA and ABA identified three sets of germination responsive genes that were regulated coordinately by GA, antagonistically by ABA, and coordinately by GA but antagonistically by ABA. Major CHO metabolism, cell wall degradation and protein degradation pathways were up

Proteomic analysis of embryonic axis of Pisum sativum seeds during germination and identification of proteins associated with loss of desiccation tolerance

DEFF Research Database (Denmark)

Wang, Wei-Qing; Møller, Ian Max; Song, Song-Quan

2012-01-01

Seed germination is an important stage in life cycle of higher plants. The germination processes and its associated loss of desiccation tolerance, however, are still poorly understood. In present study, pea seeds were used to study changes in embryonic axis proteome during germination by 2-DE...... and mass spectrometry. We identified a total of 139 protein spots showing a significant (>2-fold) change during germination. The results show that seed germination is not only the activation of a series of metabolic processes, but also involves reorganization of cellular structure and activation...... of protective systems. To uncouple the physiological processes of germination and its associated loss of desiccation tolerance, we used the fact that pea seeds have different desiccation tolerance when imbibed in water, CaCl2 and methylviologen at the same germination stage. We compared the proteome amongst...

Freezing tolerance of conifer seeds and germinants.

Science.gov (United States)

Hawkins, B J; Guest, H J; Kolotelo, D

2003-12-01

Survival after freezing was measured for seeds and germinants of four seedlots each of interior spruce (Picea glauca x engelmannii complex), lodgepole pine (Pinus contorta Dougl. ex Loud.), Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) and western red cedar (Thuja plicata Donn ex D. Donn). Effects of eight seed treatments on post-freezing survival of seeds and germinants were tested: dry, imbibed and stratified seed, and seed placed in a growth chamber for 2, 5, 10, 15, 20 or 30 days in a 16-h photoperiod and a 22/17 degrees C thermoperiod. Survival was related to the water content of seeds and germinants, germination rate and seedlot origin. After freezing for 3 h at -196 degrees C, dry seed of most seedlots of interior spruce, Douglas-fir and western red cedar had 84-96% germination, whereas lodgepole pine seedlots had 53-82% germination. Freezing tolerance declined significantly after imbibition in lodgepole pine, Douglas-fir and interior spruce seed (western red cedar was not tested), and mean LT50 of imbibed seed of these species was -30, -24.5 and -20 degrees C, respectively. Freezing tolerance continued to decline to a minimum LT50 of -4 to -7 degrees C after 10 days in a growth chamber for interior spruce, Douglas-fir and lodgepole pine, or after 15 days for western red cedar. Minimum freezing tolerance was reached at the stage of rapid hypocotyl elongation. In all species, a slight increase in freezing tolerance of germinants was observed once cotyledons emerged from the seed coat. The decrease in freezing tolerance during the transition from dry to germinating seed correlated with increases in seed water content. Changes in freezing tolerance between 10 and 30 days in the growth chamber were not correlated with seedling water content. Within a species, seedlots differed significantly in freezing tolerance after 2 or 5 days in the growth chamber. Because all seedlots of interior spruce and lodgepole pine germinated quickly, there was no correlation

The Effect of Seed Priming and Accelerated Aging on Germination and Physiochemical Changes in Milk Thistle (Silybum marianum

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Ghasem PARMOON

2013-05-01

Full Text Available Effects of seed priming and aging on some physiological characteristics of Milk thistle was studied in a factoral experiment based on Complete Randomized Design (CRD. Tratments were included hydro priming (using distilled water, halo priming (0, 1.5, 3, 4.5 and 6% KNO3 and accelerated aging (0, 2, 4 and 6 days under 45°C and 95% humidity in three replications. Determined parameters were germination charactristics including germination percentage, daily germination speed, mean time of germination, seed vigor index, hypocutile length and hypocutile dry weight. Activity of catalase, peroxidase and polyphenol oxidase were determined at 12 hours after imbibition and seedling stage. According to results of this experiment, germination percentage, seed vigor and seedling growth of seeds were increased under all priming treatments. Improving the catalase and peroxidase activity led to decrease the aging damages. Germination characteristics were improved under both priming treatments at the beginning of germination as well as seedling growth. Polyphenol oxidase activity was increased in the pre-treated seeds but decreased in seedling growth stage. Aging treatments led to reduce the germination percentage, daily germination speed, seed vigor and seedling growth while the germination time was increased. Accelerated aging caused to reduce the germination rate and seedling growth of milk thistle that is probably due to increasing the lipid peroxidation, free radical increment and decreasing the antioxidants activity. The greatest and lowest antioxidants activity, the germination percentage, germination speed and seed vigor were respectively observed under priming using 3% KNO3 concentration and control seeds.

Structural Features of Sugars That Trigger or Support Conidial Germination in the Filamentous Fungus Aspergillus niger

Science.gov (United States)

Hayer, Kimran; Stratford, Malcolm

2013-01-01

The asexual spores (conidia) of Aspergillus niger germinate to produce hyphae under appropriate conditions. Germination is initiated by conidial swelling and mobilization of internal carbon and energy stores, followed by polarization and emergence of a hyphal germ tube. The effects of different pyranose sugars, all analogues of d-glucose, on the germination of A. niger conidia were explored, and we define germination as the transition from a dormant conidium into a germling. Within germination, we distinguish two distinct stages, the initial swelling of the conidium and subsequent polarized growth. The stage of conidial swelling requires a germination trigger, which we define as a compound that is sensed by the conidium and which leads to catabolism of d-trehalose and isotropic growth. Sugars that triggered germination and outgrowth included d-glucose, d-mannose, and d-xylose. Sugars that triggered germination but did not support subsequent outgrowth included d-tagatose, d-lyxose, and 2-deoxy-d-glucose. Nontriggering sugars included d-galactose, l-glucose, and d-arabinose. Certain nontriggering sugars, including d-galactose, supported outgrowth if added in the presence of a complementary triggering sugar. This division of functions indicates that sugars are involved in two separate events in germination, triggering and subsequent outgrowth, and the structural features of sugars that support each, both, or none of these events are discussed. We also present data on the uptake of sugars during the germination process and discuss possible mechanisms of triggering in the absence of apparent sugar uptake during the initial swelling of conidia. PMID:23995938

Structural features of sugars that trigger or support conidial germination in the filamentous fungus Aspergillus niger.

Science.gov (United States)

Hayer, Kimran; Stratford, Malcolm; Archer, David B

2013-11-01

The asexual spores (conidia) of Aspergillus niger germinate to produce hyphae under appropriate conditions. Germination is initiated by conidial swelling and mobilization of internal carbon and energy stores, followed by polarization and emergence of a hyphal germ tube. The effects of different pyranose sugars, all analogues of d-glucose, on the germination of A. niger conidia were explored, and we define germination as the transition from a dormant conidium into a germling. Within germination, we distinguish two distinct stages, the initial swelling of the conidium and subsequent polarized growth. The stage of conidial swelling requires a germination trigger, which we define as a compound that is sensed by the conidium and which leads to catabolism of d-trehalose and isotropic growth. Sugars that triggered germination and outgrowth included d-glucose, d-mannose, and d-xylose. Sugars that triggered germination but did not support subsequent outgrowth included d-tagatose, d-lyxose, and 2-deoxy-d-glucose. Nontriggering sugars included d-galactose, l-glucose, and d-arabinose. Certain nontriggering sugars, including d-galactose, supported outgrowth if added in the presence of a complementary triggering sugar. This division of functions indicates that sugars are involved in two separate events in germination, triggering and subsequent outgrowth, and the structural features of sugars that support each, both, or none of these events are discussed. We also present data on the uptake of sugars during the germination process and discuss possible mechanisms of triggering in the absence of apparent sugar uptake during the initial swelling of conidia.

Influence of foliar fertilization with manganese on germination, vigor and storage time of RR soybean seeds

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Vanessa Leonardo Ignácio

2015-10-01

Full Text Available ABSTRACTThis study aimed to evaluate the influence of foliar fertilizer doses containing Mn of phenological stages of suggested application in RR soybeans, to recover management damages with glyphosate at postemergence application on seed vigor in post-harvest and post six months storage. The seeds originated from a field experiment conducted , which included two applications of glyphosate, concomitant with foliar fertilizer in growth stages V4 and V6, with 0.00, 113.50 and 227.00 mg ha-1doses of Mn2+. Germination, GSI (Germination Speed Index, electrical conductivity tests and the first count of seeds were conducted. The application of Mn did not affect the physiological quality of RR soy in postharvest. However, in post-storage, higher doses of Mn had a negative effect on tests of abnormal seedlings, GSI and electrical conductivity. The applications of Mn, regardless of the developmental stage, did not interfere in the germination and first count tests, with and without storage. The electrical conductivity test showed a higher correlation with the seed germination test in the post-harvest treatment.

Proteome-Level Analysis of Metabolism- and Stress-Related Proteins during Seed Dormancy and Germination in Gnetum parvifolium.

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Chang, Ermei; Deng, Nan; Zhang, Jin; Liu, Jianfeng; Chen, Lanzhen; Zhao, Xiulian; Abbas, M; Jiang, Zeping; Shi, Shengqing

2018-03-21

Gnetum parvifolium is a rich source of materials for traditional medicines, food, and oil, but little is known about the mechanism underlying its seed dormancy and germination. In this study, we analyzed the proteome-level changes in its seeds during germination using isobaric tags for relative and absolute quantitation. In total, 1,040 differentially expressed proteins were identified, and cluster analysis revealed the distinct time points during which signal transduction and oxidation-reduction activity changed. Gene Ontology analysis showed that "carbohydrate metabolic process" and "response to oxidative stress" were the main enriched terms. Proteins associated with starch degradation and antioxidant enzymes were important for dormancy-release, while proteins associated with energy metabolism and protein synthesis were up-regulated during germination. Moreover, protein-interaction networks were mainly associated with heat-shock proteins. Furthermore, in accord with changes in the energy metabolism- and antioxidant-related proteins, indole-3-acetic acid, Peroxidase, and soluble sugar content increased, and the starch content decreased in almost all six stages of dormancy and germination analyzed (S1-S6). The activity of superoxide dismutase, abscisic acid, and malondialdehyde content increased in the dormancy stages (S1-S3) and then decreased in the germination stages (S4-S6). Our results provide new insights into G. parvifolium seed dormancy and germination at the proteome and physiological levels, with implications for improving seed propagation.

Revealing proteins associated with symbiotic germination of Gastrodia elata by proteomic analysis.

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Zeng, Xu; Li, Yuanyuan; Ling, Hong; Chen, Juan; Guo, Shunxing

2018-03-06

Gastrodia elata, a mycoheterotrophic orchid, is a well-known medicinal herb. In nature, the seed germination of G. elata requires proper fungal association, because of the absence of endosperm. To germinate successfully, G. elata obtains nutrition from mycorrhizal fungi such as Mycena. However, Mycena is not able to supply nutrition for the further development and enlargement of protocorms into tubers, flowering and fruit setting of G. elata. To date, current genomic studies on this topic are limited. Here we used the proteomic approach to explore changes in G. elata at different stages of symbiotic germination. Using mass spectrometry, 3787 unique proteins were identified, of which 599 were classified as differentially accumulated proteins. Most of these differentially accumulated proteins were putatively involved in energy metabolism, plant defense, molecular signaling, and secondary metabolism. Among them, the defense genes (e.g., pathogenesis-/wound-related proteins, peroxidases, and serine/threonine-protein kinase) were highly expressed in late-stage protocorms, suggesting that fungal colonization triggered the significant defense responses of G. elata. The present study indicated the metabolic change and defensive reaction could disrupt the balance between Mycena and G. elata during mycorrhizal symbiotic germination.

Comparison of Different Vitrification Procedures on Developmental Competence of Mouse Germinal Vesicle Oocytes in the Presence or Absence of Cumulus Cells

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Mojdeh Salehnia

2009-01-01

Full Text Available Background: An evaluation of the developmental competence of vitrified mouse germinal vesicle(GV oocytes with various equilibration and vitrification times; in the presence or absence ofcumulus cells and by comparison between the cryotop method and straws was performed.Materials and Methods: Mouse GV oocytes were considered in cumulus-denuded oocytes(CDOs and cumulus-oocyte complexes (COCs groups. Their survival and developmental rateswere studied in the following experiments: (I exposure to different equilibration times (0, 3 and5 minutes and vitrification (1, 3 and 5 minutes without plunging in LN2 as toxicity tests, (IIoocytes were vitrified using straws followed by exposure to equilibration solution for 0, 3 and 5minutes and vitrification solution for 1 and 3 minutes, and (III oocytes were vitrified by cryotopfollowing exposure to equilibration for 5 minutes and vitrification for 1 minute, respectively.Results: Maturation and developmental rates of the COCs were higher than CDOs in the nonvitrifiedgroup (p<0.05. The survival and maturation rates were low in all oocytes exposed tovitrification solution for 5 minutes (p <0.05. In vitrified CDOs and COCs using straws, the survivalrates ranged from 56.9% to 85.4% and 44.0% to 84.5%, and the maturation rates from 35.3% to56.8% and 25.8% to 56.2%, respectively; which were lower than non-vitrified samples (p <0.05.Cryotop vitrified oocytes showed higher survival, maturation and fertilization rates when comparedto straw in both CDOs and COCs (p <0.05.Conclusion: The presence of cumulus cells improves developmental competence of GV oocytesin control groups but it did not affect the vitrified group. Vitrification of mouse GV oocytes usingcryotop was more effective than straws, however both vitrification techniques did not improve thecleavage rate.

Changes of the phenolic compounds and antioxidant activities in germinated adlay seeds.

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Xu, Lei; Wang, Pei; Ali, Barkat; Yang, Na; Chen, Yisheng; Wu, Fengfeng; Xu, Xueming

2017-09-01

Over the years, germinated adlay products have been used as both food source and folk medicine. This study investigated the changes of total phenolic content (TPC), total flavonoid content (TFC), antioxidant activities, and phenolic acid profiles of adlay seed during germination. Results revealed that phenolic compounds and antioxidant activities varied with the germination stages. Germination significantly increased the free form phenolic and flavonoid contents by 112.5% and 168.3%, respectively. However, both of the bound form phenolic and flavonoid contents significantly decreased after germination. Phenolic acid compositions were quantified via HPLC analysis, and the levels of vanillic, p-coumaric, caffeic, hydroxybenzoic and protocatechuic acids in the free phenolic extracts were found to be significantly increased. The improvement of the free and total phenolic and flavonoid contents by the germination process led to a significant enhancement of the antioxidant activities (evaluated by the ABTS, FRAP and ORAC assays). The TPC showed the highest correlation with ORAC values (r = 0.9979). Germinated adlay had higher free and total phenolic and flavonoid contents, and antioxidant activities than ungerminated adlay. This study indicates that germinated adlay could be a promising functional food, more suitable for human consumption. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Targeting Echinococcus multilocularis stem cells by inhibition of the Polo-like kinase EmPlk1.

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Andreas Schubert

2014-06-01

Full Text Available Alveolar echinococcosis (AE is a life-threatening disease caused by larvae of the fox-tapeworm Echinococcus multilocularis. Crucial to AE pathology is continuous infiltrative growth of the parasite's metacestode stage, which is driven by a population of somatic stem cells, called germinative cells. Current anti-AE chemotherapy using benzimidazoles is ineffective in eliminating the germinative cell population, thus leading to remission of parasite growth upon therapy discontinuation.We herein describe the characterization of EmPlk1, encoded by the gene emplk1, which displays significant homologies to members of the Plk1 sub-family of Polo-like kinases that regulate mitosis in eukaryotic cells. We demonstrate germinative cell-specific expression of emplk1 by RT-PCR, transcriptomics, and in situ hybridization. We also show that EmPlk1 can induce germinal vesicle breakdown when heterologously expressed in Xenopus oocytes, indicating that it is an active kinase. This activity was significantly suppressed in presence of BI 2536, a Plk1 inhibitor that has been tested in clinical trials against cancer. Addition of BI 2536 at concentrations as low as 20 nM significantly blocked the formation of metacestode vesicles from cultivated Echinococcus germinative cells. Furthermore, low concentrations of BI 2536 eliminated the germinative cell population from mature metacestode vesicles in vitro, yielding parasite tissue that was no longer capable of proliferation.We conclude that BI 2536 effectively inactivates E. multilocularis germinative cells in parasite larvae in vitro by direct inhibition of EmPlk1, thus inducing mitotic arrest and germinative cell killing. Since germinative cells are decisive for parasite proliferation and metastasis formation within the host, BI 2536 and related compounds are very promising compounds to complement benzimidazoles in AE chemotherapy.

Improvised Media for In Vitro Pollen Germination of some Species of Apocynaceae

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Reshmi Chatterjee

2014-09-01

Full Text Available Pollen germination forms one of the most important stage post pollination prior to fertilization. This is essential for proper seed setting and seed development. In vitro pollen germination test is the most reliable way of assessing the pollen viability. In the present study pollen grains of seven genera under Apocynaceae family namely, Allamanda, Alstonia, Catharanthus, Nerium, Plumeria, Thevetia and Tabernaemontana were tested in some basic cultural media, such as Brewbaker’s media, 6% Glucose solution, 4% Calcium Nitrate solution and 3% Boron solution. Alstonia pollen grains exhibited highest percentage of germination rate in all the cultural media. Glucose and Brewbaker’s media is found to be highly suitable for efficient pollen germination in all the genera. Boron solution is effective for germination of pollen grains of tree species. In vitro pollen germination can be easily carried out in laboratories. These results can be utilised in plant breeding programmes to improve cultivar and varieties. DOI: http://dx.doi.org/10.3126/ije.v3i3.11074 International Journal of Environment Vol.3(3 2014: 146-153

Activity of enzymes that hydrolyze sucrose and raffinose in the first stages of germination of Lactuca sativa cv. Grand rapids. [Invertase, alpha-galactosidose, and sucrose synthetase were observed

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Slabnik, E.; Calderon, P.; Diaz, H.

1981-01-01

The activities of enzymes capable of metabolizing raffinose and sucrose on achenes of lettuce were studied. During the first stages of germination, evidence was obtained for the occurrence of invertase in the endosperm and embryonic axis. Alpha-galactosidase was localized in the endosperm and cotyledons. Sucrose synthetase was present in the dry seed.

Salinity Effects on Germination Properties ofPurslane (Portulaca oleracea L.

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m Kafi

2011-02-01

Full Text Available Abstract In order to study seed germination and seedling growth responses of purslane to different levels of salinity, an experiment was conducted in a completely randomized desgin with six levels of salinity (0, 7, 14, 21, 28 and 35 dS/m using NaCl and five replications. Persentage and rate of germination, length and dry weight of radicle and plumule were measured, and ratio radicle to plumule length, mean germination time and seedling vigor index were calculated. The results showed that up to 28 dS/m salinity did not impose any significant different in germination percentage compared with control, but in 35 dS/m salinity it decreased to 19%. germination rate did not show any significant different up to 14 dS/m in comparison with control but beyond this level it significantly decreased with increasing salt stress. Mean germination time up to 21 dS/m did not have significant different in comparison with control, but increased with increasing salinity significantly. Length, fresh and dry weight of radicle and plumule, and seedling vigor index significantly decreased by increasing salinity. Ratio of radicle to plumule length decreased with increasing salt concentration, but there were not significant different among salt levels. According to the results, the germination stage of purslane is remarkably resistant to elevated levels of salinity and it seems that by exerting proper management in farms, it could be established in saline environments. Keywords: Plumule, Radicle, Seedlings of purslane

Effect of Aqueous Extracts from Weed Species on Germination and Initial Growth in Raphanus sativus L.

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Anisoara STRATU

2015-12-01

Full Text Available The current paper presents the results of a study on the effects of aqueous extracts from five weed species (Amaranthus retroflexus, Cirsium arvense, Convolvulus arvensis, Echinochloa crus-galii, Setaria verticillata on germination and initial growth in Raphanus sativus L. The following indicators have been analyzed: indices of germination (the germination percentage; the speed of germination; the speed of accumulated germination and the coefficient of germination rate, the length of the root and hypocotyls, the pH of aqueous extracts, the UV-Vis absorption spectra of aqueous extracts. The results of the investigations showed the following aspects: the aqueous extracts reduced the values of calculated germination indices and root growth in the first ontogenetic stages of the test species; the pH of the extracts was slightly acid to neutral. Qualitative spectrophotometric analysis indicated the possible presence of phenolic and organic compounds in the extracts. C. arvense, S. verticillata and E. crus-galii presented the most pronounced effect on germination and growth processes.

Formation of Oligovesicular Vesicles by Micromanipulation

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Yukihisa Okumura

2011-09-01

Full Text Available Cell-sized lipid bilayer membrane vesicles (giant vesicles, GVs or semi-vesicles were formed from egg yolk phosphatidylcholine on a platinum electrode under applied electric voltage by electroformation. Micromanipulation of the semi-vesicle by first pressing its membrane with a glass microneedle and then withdrawing the needle left a GV in the interior of the vesicle. During the process, an aqueous solution of Ficoll that filled the needle was introduced into the newly formed inner vesicle and remained encapsulated. Approximately 50% of attempted micromanipulation resulted in the formation of an inner daughter vesicle, “microvesiculation”. By repeating the microvesiculation process, multiple inner GVs could be formed in a single parent semi-vesicle. A semi-vesicle with inner GVs could be detached from the electrode by scraping with a microneedle, yielding an oligovesicular vesicle (OVV with desired inner aqueous contents. Microvesiculation of a GV held on the tip of a glass micropipette was also possible, and this also produced an OVV. Breaking the membrane of the parent semi-vesicle by micromanipulation with a glass needle after microvesiculation, released the inner GVs. This protocol may be used for controlled formation of GVs with desired contents.

Oocyte transport: Developmental competence of bovine oocytes arrested at germinal vesicle stage by cycloheximide under air.

Science.gov (United States)

Hashimoto, Shu; Kimura, Kouji; Iwata, Hisataka; Takakura, Ryo

2003-02-01

The effects of the medium (TCM 199 or SOFaa) and temperature (20 or 39 C) during meiotic arrest by cycloheximide (CHX) under air on the developmental competence of bovine oocytes after in vitro maturation (IVM) and fertilization (IVF) were investigated. Oocytes were maintained in meiotic arrest by 10 microg/ml CHX in a 50-microl droplet of 25-mM HEPES-buffered TCM 199 (H199) at 39 C or synthetic oviduct fluid (HSOFaa) at 20 or 39 C in air for 24 h. After release from the arrest, the oocytes was matured and fertilized in vitro and their developmental competence was examined. The developmental rate of oocytes arrested in HSOFaa at 20 C to the blastocyst stage was similar to that of non-arrested oocytes but was significantly higher (Ptransport conditions, we also investigated the meiotic arrest of oocytes maintained in a 0.25-ml straw by CHX individually with 10 microl HSOFaa or as a group (40-50 oocytes) with 170-200 microl HSOFaa at 20 C in air for 24 h. After release from meiotic arrest, the developmental competence of these oocytes was assessed similarly. The developmental rate of oocytes treated with CHX individually was similar to that of those treated with CHX in 50-microl droplet of HSOFaa at 20 C. However, the developmental rate of oocytes treated with CHX as a group was lower than that of oocytes treated with CHX in a 50-microl droplet. Five blastocysts developed from oocytes maintained in meiotic arrest in a plastic straw were transferred to five recipient heifers. Consequently, three recipients became pregnant and 2 calves were delivered. The results of the present study indicate that bovine oocytes treated with CHX in HSOFaa at 20 C under air retain the same developmental competence as non-arrested oocytes.

Germination of Aspergillus niger conidia is triggered by nitrogen compounds related to L-amino acids.

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Hayer, Kimran; Stratford, Malcolm; Archer, David B

2014-10-01

Conidial germination is fundamentally important to the growth and dissemination of most fungi. It has been previously shown (K. Hayer, M. Stratford, and D. B. Archer, Appl. Environ. Microbiol. 79:6924-6931, 2013, http://dx.doi.org/10.1128/AEM.02061-13), using sugar analogs, that germination is a 2-stage process involving triggering of germination and then nutrient uptake for hyphal outgrowth. In the present study, we tested this 2-stage germination process using a series of nitrogen-containing compounds for the ability to trigger the breaking of dormancy of Aspergillus niger conidia and then to support the formation of hyphae by acting as nitrogen sources. Triggering and germination were also compared between A. niger and Aspergillus nidulans using 2-deoxy-D-glucose (trigger), D-galactose (nontrigger in A. niger but trigger in A. nidulans), and an N source (required in A. niger but not in A. nidulans). Although most of the nitrogen compounds studied served as nitrogen sources for growth, only some nitrogen compounds could trigger germination of A. niger conidia, and all were related to L-amino acids. Using L-amino acid analogs without either the amine or the carboxylic acid group revealed that both the amine and carboxylic acid groups were essential for an L-amino acid to serve as a trigger molecule. Generally, conidia were able to sense and recognize nitrogen compounds that fitted into a specific size range. There was no evidence of uptake of either triggering or nontriggering compounds over the first 90 min of A. niger conidial germination, suggesting that the germination trigger sensors are not located within the spore. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Effect of sodium fluoride on phytase activity during germination of Pisum sativum L. seeds

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Hauskrecht, I

1972-01-01

The effects of fluoride ion, in concentrations varying from 0 to 4 mM F/sup -/, on phytase activity in the course of germination of Pisum sativum L. seeds and in the course of incubation in vitro are reported. The fluoride ion in 1 mM concentration cause a significant 80% decrease of the phytase activity in the incubation medium and a 24% decrease in the course of germination. The inhibition of phytase, as well as its synthesis, by fluoride ion during germination may influence the metabolism of phosphorus at the initial stage of ontogenesis.

The effects of free amino acids profiles on seeds germination/dormancy and seedlings development of two genetically different cultivars of Yemeni Pomegranates

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Alhadi Fatima A.

2012-04-01

Full Text Available Plant seeds used rely on a wide range of internal mechanisms and physio-chemical factors to ensure their germination under favorable environmental conditions. Most plant seeds have complex process of germination, including water, oxygen, temperature availability, genome-wide gene expression, signal transduction, hormones stimulations, inhibitors removal and catalytic protein synthesis. In addition, influences of seeds nutrient values such as, protein, lipids, sugars and free amino acids have a special importance. Regarding, seeds free amino acids. Discussion of these individual factors needs to be put in context of their role in germination processes. Regarding, free amino acids seed storage, there is limited information about their relevant functions in activation and/or deactivation of required metabolic mechanisms and interactive compounds involved in this process in commercial plant cultivars. Therefore, current study was aimed to determine the probable influence of free amino acid compositions of seeds on germination process of two different (Punica granatum L. pomegranate cultivars including wild type Automi cultivar and edible Khazemi cultivar. In particular, we focused on the impact of amino acids contents variations on germination process and associated AAs compositional changes during various stages of germination and seedlings establishment. Amino acid analysis using HPLC detected all the essential and non-essential amino acids in the raw seeds of the studied cultivars, Automi and Khazemi along with AAs compositional changes occurred during different stages of seed germination. These AAs have been extensively analyzed in the context of their role in dormancy breaking capacities in plants species. Automi raw seeds are rich in Phe, that, is strongly related to ABA synthesis and hence might be responsible for the dormancy of Automi seeds, Khazemi raw seeds have sufficient levels of Arg, Glu and Met that have been reported to enhance

In vitro pollen quantity, viability and germination tests in quince

African Journals Online (AJOL)

use

2011-11-21

Nov 21, 2011 ... rootstock pollens were collected in April from the unopened pink balloon-stage flowers on mature trees ..... their pollen characteristics to be used in cross breeding ... viability and germination levels for pistachio and terebinth in.

The Effects of Temperature and Salinity on Germination and Seedling Growth Characteristics of Sesame (Sesamum indicum Landraces

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E Izadi-Darbandi

2012-10-01

Full Text Available Seed germination is a crucial stage in the plant life cycle and salt tolerance during germination stage is vital for the establishment of plants in saline soils. In order to evaluation of sesame (Sesamum indicum landraces germination to salinity stress at different temperature, an experiment was conducted at Ferdowsi University of Mashhad, Collage of Agriculture during 2009. Experimental type was complete randomized design in factorial arrangement with 4 replications. Factors included salinity at 7 levels (0, -2, -3, -4, -6, -8, -10 and -12 bar, temperature at 3 levels (15°c, 20°c, 25°c and 3 sesame landraces (Sabzevar, Kalat and Oltan. Results showed that germination parameters (germination percentage, germination rate, root length, shoot length, dry weight of roots and dry weight of shoots in all landraces were significantly (p≤0.01 affected by salinity and temperature. Increasing salinity reduced all above parameters in sesame cultivars, so that highest tolerated dose of salt was obtained in 25°c and increasing of temperature reduced effects of salinity. The highest germination percent was observed in salinity between 0 to -4 bar at 25°c. Sabzevar and Oltan landraces exhibited the highest and the lowest indicators at different temperatures respectively. According to these results, it seems that in saline condition and temperature variation, Sabzevar is the appropriate sesame landraces for optimal seedling establishment.

Vesicle-based rechargeable batteries

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Stanish, I.; Singh, A. [Center for Bio/Molecular Science and Engineering, Naval Research Laboratory, 4555 Overlook Ave., S.W., Washington, DC 20375 (United States); Lowy, D.A. [Nova Research, Inc., 1900 Elkin St., Alexandria, VA 22308 (United States); Hung, C.W. [Department of Chemical Engineering, University of Maryland, College Park, MD 20742 (United States)

2005-05-02

Vesicle-based rechargeable batteries can be fabricated by mounting polymerized vesicles filled with ferrocyanide or ferricyanide to a conductive surface. The potential can be adjusted by changing the concentration ratio of hydroquinone and benzoquinone bound to the vesicle membranes. These batteries show promise as a means of supplying portable power for future autonomous nanosystems. (Abstract Copyright [2005], Wiley Periodicals, Inc.)

In vitro spore germination and gametophytic growth development of ...

African Journals Online (AJOL)

The effects of sucrose, pH and plant growth hormones on spore germination percentage and gametophyte growths of Pteris tripartita were studied. Various morphological structures of gametophytes were observed namely, filamentous, spatulate and heart stages in the MS culture medium with hormones. After 15 days, the ...

Membrane damage and solute leakage from germinating pea seed under cadmium stress

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Rahoui, Sondes, E-mail: rahoui.sondes@yahoo.fr [Bio-Physiologie Cellulaires, Departement des Sciences de la Vie, Faculte des Sciences de Bizerte, 7021 Zarzouna (Tunisia); Chaoui, Abdelilah, E-mail: cabdelilah1@yahoo.fr [Bio-Physiologie Cellulaires, Departement des Sciences de la Vie, Faculte des Sciences de Bizerte, 7021 Zarzouna (Tunisia); El Ferjani, Ezzeddine, E-mail: ezzferjani2002@yahoo.fr [Bio-Physiologie Cellulaires, Departement des Sciences de la Vie, Faculte des Sciences de Bizerte, 7021 Zarzouna (Tunisia)

2010-06-15

Seed germination represents a limiting stage of plant life cycle under heavy metal stress situation. Delay in germination can be associated with disorders in the event chain of germinative metabolism which is a highly complex multistage process, but one of underlying metabolic activities following imbibition of seed is the storage mobilization. The influence of cadmium on carbohydrates and aminoacids export from cotyledon to embryonic axis during germination of pea seed was investigated. Compared to the control, Cd caused a restriction in reserve mobilization as evidenced by the pronounced increase in cotyledon/embryo ratios of total soluble sugars, glucose, fructose and aminoacids. Moreover, the nutrient concentrations, as well as the electrical conductivity of germination medium were determined to quantify the extent of solute leakage. Such nutrients were lost into the imbibition medium at the expense of suitable mobilization to the growing embryonic axis. This was concomitant with an over-accumulation of lipid peroxidation products in Cd-poisoned embryonic tissues. However, the impairment of membrane integrity cannot be due to a stimulation in lipoxygenase activity, since the later was markedly inhibited after Cd exposure.

Membrane damage and solute leakage from germinating pea seed under cadmium stress

International Nuclear Information System (INIS)

Rahoui, Sondes; Chaoui, Abdelilah; El Ferjani, Ezzeddine

2010-01-01

Seed germination represents a limiting stage of plant life cycle under heavy metal stress situation. Delay in germination can be associated with disorders in the event chain of germinative metabolism which is a highly complex multistage process, but one of underlying metabolic activities following imbibition of seed is the storage mobilization. The influence of cadmium on carbohydrates and aminoacids export from cotyledon to embryonic axis during germination of pea seed was investigated. Compared to the control, Cd caused a restriction in reserve mobilization as evidenced by the pronounced increase in cotyledon/embryo ratios of total soluble sugars, glucose, fructose and aminoacids. Moreover, the nutrient concentrations, as well as the electrical conductivity of germination medium were determined to quantify the extent of solute leakage. Such nutrients were lost into the imbibition medium at the expense of suitable mobilization to the growing embryonic axis. This was concomitant with an over-accumulation of lipid peroxidation products in Cd-poisoned embryonic tissues. However, the impairment of membrane integrity cannot be due to a stimulation in lipoxygenase activity, since the later was markedly inhibited after Cd exposure.

[Effects of simulated acid rain on seed germination and seedling growth of different type corn Zea mays].

Science.gov (United States)

Zhang, Hai-Yan

2013-06-01

Taking normal corn, waxy corn, pop corn, and sweet corn as test materials, this paper studied their seed germination and seedling growth under effects of simulated acid rain (pH 6.0, 5.0, 4.0, 3.0, 2.0, and 1.0). Simulated acid rain at pH 2.0-5.0 had no significant effects on the seed germination and seedling growth, but at pH 1.0, the germination rate of normal corn, waxy corn, pop corn, and sweet corn was 91.3%, 68.7%, 27.5%, and 11.7%, respectively. As compared with those at pH 6.0 (CK), the germination rate, germination index, vigor index, germination velocity, shoot height, root length, shoot and root dry mass, and the transformation rate of stored substances at pH 1.0 had significant decrease, and the average germination time extended apparently. At pH 1.0, the effects of acid rain were greater at seedling growth stage than at germination stage, and greater on underground part than on aboveground part. Due to the differences in gene type, normal corn and waxy corn had the strongest capability against acid rain, followed by pop corn, and sweet corn. It was suggested that corn could be categorized as an acid rain-tolerant crop, the injury threshold value of acid rain was likely between pH 1.0 and pH 2.0, and normal corn and waxy corn would be prioritized for planting in acid rain-stricken area.

Irradiation-induced fusion between giant vesicles and photoresponsive large unilamellar vesicles containing malachite green derivative.

Science.gov (United States)

Uda, Ryoko M; Yoshikawa, Yuki; Kitaba, Moe; Nishimoto, Noriko

2018-07-01

Light-initiated fusion between vesicles has attracted much attention in the research community. In particular, fusion between photoresponsive and non-photoresponsive vesicles has been of much interest in the development of systems for the delivery of therapeutic agents to cells. We have performed fusion between giant vesicles (GVs) and photoresponsive smaller vesicles containing malachite green (MG) derivative, which undergoes ionization to afford a positive charge on the molecule by irradiation. The fusion proceeds as the concentration of GV lipid increases toward equimolarity with the lipid of the smaller vesicle. It is also dependent on the molar percentage of photoionized MG in the lipid of the smaller vesicle. On the other hand, the fusion is hardly affected by the anionic component of the GV. The photoinduced fusion was characterized by two methods, involving the mixing of lipid membranes and of aqueous contents. Fluorescence microscopy revealed that irradiation triggered the fusion of a single GV with the smaller vesicles containing MG. Copyright © 2018 Elsevier B.V. All rights reserved.

Influence de différents traitements de prégermination des graines de Vigna unguiculata (L. Walp. sur les performances germinatives et la tolérance au stress hydrique

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Boucelha, L.

2015-01-01

Full Text Available Influence of different pre-germination treatments of Vigna unguiculata (L. Walp. seeds on germination performance and water stress tolerance. Description of the subject. Priming or hardening is a pregermination treatment. This treatment consists of incorporating an osmotic seed treatment (osmopriming or a hormonal (hormopriming and/or a redehydration (hydropriming treatment. The approach allows the elimination of dormancy, homogenization (synchronization of germination, better growth, earlier flowering and a tolerance to abiotic stresses such as drought and salinity. In this kind of treatment, the seed is soaked and then dehydrated before radicle breakthrough, i.e. during the reversible phase of germination. Thus, the seed can return to its initial stage without any damage. Objectives. In this paper, we aimed to study the consequences of hydropriming and osmopriming (by PEG6000 at 10 and 30% on cowpea seeds (Vigna unguiculata, on germination performance and on the water stress tolerance of plants from these seeds. Method. Vigna unguiculata seeds were hydroprimed, hydroprimed twice or osmoprimed (with PEG6000 10 and 30%. For each treatment, germination performance (germination capacity, speed and the water stress tolerance of the plants were studied. Results. Results showed that increased hardness of the seed allowed a faster, more uniform germination and better growth of both the radicle and aerial parts. We also demonstrated that a double redehydration was more effective in improving these parameters. Conclusions. Application of these pretreatments, adapted according to the plant species, will has the capacity to improve seed germination and crop yield, as well as tolerance to water deficit.

Seed germination and seedling establishment of some wild almond ...

African Journals Online (AJOL)

In the last experiment, the establishment and vigor of 14 accessions from eight almond species have been evaluated in plastic bags in outdoor conditions. Two ecotypes of Prunus spp. had the highest stem diameter and length at all growing stages. Keywords: Amygdalus, germination percentage, index vigor, root initiation, ...

Proteomic analysis of Magnolia sieboldii K. Koch seed germination.

Science.gov (United States)

Lu, Xiu-Jun; Zhang, Xiao-Lin; Mei, Mei; Liu, Guang-Lin; Ma, Bei-Bei

2016-02-05

Magnolia sieboldii is a deciduous tree native to China. This species has a deep dormancy characteristic. To better understand seed germination, we used protein analysis of changes in seed protein at 0, 65, 110 and 150 d of stratification. Comparative 2DE analysis of M. sieboldii seed protein profiles at 0, 65, 110 and 150 d of stratification revealed 80 differentially abundance protein species. Comparative analysis showed that ADP-glucose pyrophosphorylase small subunit was degraded during germination. In particular, it was degraded almost completely at 110 d of germination. Starch granules in the microstructure decreased after 65 d of stratification. Starch granules provided a sufficient amount of substrates and ATPs for subsequent germination. Four storage protein species were identified, of which all were down accumulated. Spots 44 and 46 had different MW and pI values, spots 36 and 46 had nearly the same MW with pI shift in the 2-DE gels, suggesting that they might be present as different isoforms of the same protein family and the post translational modification. Our results suggested that degradation of starch granules and storage protein species prepared the seed embryo for growth, as well as regulated seed germination. The present proteomics analysis provides novel insights into the mobilisation of nutrient reserves during the germination of M. sieboldii seeds. To better understand seed germination, a complex developmental process, we developed a proteome analysis of M. sieboldii seed. We performed the first comprehensive proteomic and microstructure analysis during different seed stratification stages of M. sieboldii. Among the 80 protein species, 26 were identified, 7 and 14 protein species were up or down accumulated significantly. Many of the identified key proteins were involved in embryo development, starch biosynthesis and energy metabolism, Microstructure of stratification seed analysis revealed degradation of starch was used for preparing the seed

Comparison of Gene Expression Profiles in Human Germinal Vesicle Before and After Cytoplasmic Transfer From Mature Oocytes in Iranian Infertile Couples

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Fatemeh Sadat Hoseini

2016-08-01

Full Text Available Objective: To evaluate the effect of cytoplasm transfer from mature oocytes to germinal vesicle(GVs on promoting the maturation of cytoplasm of GV at the mRNA level.Materials and methods: Sixty six in vitro fertilization (IVF operations between June 2012 and November 2013 were included in this study. Totally 120 GVs were obtained. Normal GVs were categorized into 3 groups (n = 40 randomly: the first comprised oocytes that did not receive the cytoplasm of mature oocytes; the second group comprised oocytes that did not receive the cytoplasm of mature oocytes but were incubated for 24 h; and the third group comprised oocytes that received 10-15% the cytoplasm of mature oocytes and were then incubated for 24 h. Each group was separately analyzed by quantitative polymerase chain reaction (qPCR and the expression levels of selected genes were assessed.Results: The expression levels of genes involved in the cytoplasmic maturity, and energy-producing mitochondria were significantly higher in the pooled oocytes of 2nd control group than those of the 1st control and intervention groups (p < 0.001. The genes involved in the meiosis, spindle check point, DNA repairing and cell cycle checkpoint did not have any expression in the 1st and intervention groups; however, these genes were expressed in the 2nd group, significantly. In the 2nd group, the highest expression level was observed for genes involved in the DNA repairing and cell cycle checkpoint. In the intervention group, none of the genes were expressed except for energy-producing mitochondria gene; even in this case, the expression level of this gene in this group of oocytes was significantly lower than that in other groups (p < 0.001. After 24 h meiosis assumption was significantly higher in the third group than in the second group (95% vs. 68%, p < 0.001.Conclusion: The cytoplasm transfer technique is not effective in cytoplasmic maturity of the recipient GV oocytes. In contrast, 24-hr in

Single-vesicle imaging reveals different transport mechanisms between glutamatergic and GABAergic vesicles

NARCIS (Netherlands)

Farsi, Z.; Preobraschenski, J.; Bogaart, G. van den; Riedel, D.; Jahn, R.; Woehler, A.

2016-01-01

Synaptic transmission is mediated by the release of neurotransmitters, which involves exo-endocytotic cycling of synaptic vesicles. To maintain synaptic function, synaptic vesicles are refilled with thousands of neurotransmitter molecules within seconds after endocytosis, using the energy provided

A proteomics study of in vitro cyst germination and appressoria formation in ¤Phytophthora infestans¤

DEFF Research Database (Denmark)

Ebstrup, T.; Saalbach, G.; Egsgaard, H.

2005-01-01

A proteomics study using two-dimensional gel electrophoresis (2-DE) and mass spectrometry was performed on Phytophthora infestans. Proteins from cysts, germinated cysts and appressoria grown in vitro were isolated and separated by 2-DE. Statistical quantitative analysis of the protein spots from ...... five independent experiments of each developmental stage revealed significant up-regulation of ten spots on gels from germinated cysts compared to cysts. Five spots were significantly up-regulated on gels from appressoria compared to germinated cysts and one of these up-regulated spots...

Single-vesicle imaging reveals different transport mechanisms between glutamatergic and GABAergic vesicles.

Science.gov (United States)

Farsi, Zohreh; Preobraschenski, Julia; van den Bogaart, Geert; Riedel, Dietmar; Jahn, Reinhard; Woehler, Andrew

2016-02-26

Synaptic transmission is mediated by the release of neurotransmitters, which involves exo-endocytotic cycling of synaptic vesicles. To maintain synaptic function, synaptic vesicles are refilled with thousands of neurotransmitter molecules within seconds after endocytosis, using the energy provided by an electrochemical proton gradient. However, it is unclear how transmitter molecules carrying different net charges can be efficiently sequestered while maintaining charge neutrality and osmotic balance. We used single-vesicle imaging to monitor pH and electrical gradients and directly showed different uptake mechanisms for glutamate and γ-aminobutyric acid (GABA) operating in parallel. In contrast to glutamate, GABA was exchanged for protons, with no other ions participating in the transport cycle. Thus, only a few components are needed to guarantee reliable vesicle filling with different neurotransmitters. Copyright © 2016, American Association for the Advancement of Science.

Germination and seedling establishment in orchids: a complex of requirements.

Science.gov (United States)

Rasmussen, Hanne N; Dixon, Kingsley W; Jersáková, Jana; Těšitelová, Tamara

2015-09-01

Seedling recruitment is essential to the sustainability of any plant population. Due to the minute nature of seeds and early-stage seedlings, orchid germination in situ was for a long time practically impossible to observe, creating an obstacle towards understanding seedling site requirements and fluctuations in orchid populations. The introduction of seed packet techniques for sowing and retrieval in natural sites has brought with it important insights, but many aspects of orchid seed and germination biology remain largely unexplored. The germination niche for orchids is extremely complex, because it is defined by requirements not only for seed lodging and germination, but also for presence of a fungal host and its substrate. A mycobiont that the seedling can parasitize is considered an essential element, and a great diversity of Basidiomycota and Ascomycota have now been identified for their role in orchid seed germination, with fungi identifiable as imperfect Rhizoctonia species predominating. Specificity patterns vary from orchid species employing a single fungal lineage to species associating individually with a limited selection of distantly related fungi. A suitable organic carbon source for the mycobiont constitutes another key requirement. Orchid germination also relies on factors that generally influence the success of plant seeds, both abiotic, such as light/shade, moisture, substrate chemistry and texture, and biotic, such as competitors and antagonists. Complexity is furthermore increased when these factors influence seeds/seedling, fungi and fungal substrate differentially. A better understanding of germination and seedling establishment is needed for conservation of orchid populations. Due to the obligate association with a mycobiont, the germination niches in orchid species are extremely complex and varied. Microsites suitable for germination can be small and transient, and direct observation is difficult. An experimental approach using several

Effect of Aqueous Extracts from Weed Species on Germination and Initial Growth in Raphanus sativus L.

Directory of Open Access Journals (Sweden)

Anisoara STRATU

2015-12-01

Full Text Available The current paper presents the results of a study on the effects of aqueous extracts from five weed species (Amaranthus retroflexus, Cirsium arvense, Convolvulus arvensis, Echinochloa crus-galii, Setaria verticillata on germination and initial growth in Raphanus sativus L. The following indicators have been analyzed: indices of germination (the germination percentage; the speed of germination; the speed of accumulated germination and the coefficient of germination rate, the length of the root and hypocotyls, the pH of aqueous extracts, the UV-Vis absorption spectra of aqueous extracts. The results of the investigations showed the following aspects: the aqueous extracts reduced the values of calculated germination indices and root growth in the first ontogenetic stages of the test species; the pH of the extracts was slightly acid to neutral. Qualitative spectrophotometric analysis indicated the possible presence of phenolic and organic compounds in the extracts. C. arvense, S. verticillata and E. crus-galii presented the most pronounced effect on germination and growth processes.

Isolation of tissues and preservation of RNA from intact, germinated barley grain.

Science.gov (United States)

Betts, Natalie S; Berkowitz, Oliver; Liu, Ruijie; Collins, Helen M; Skadhauge, Birgitte; Dockter, Christoph; Burton, Rachel A; Whelan, James; Fincher, Geoffrey B

2017-08-01

Isolated barley (Hordeum vulgare L.) aleurone layers have been widely used as a model system for studying gene expression and hormonal regulation in germinating cereal grains. A serious technological limitation of this approach has been the inability to confidently extrapolate conclusions obtained from isolated tissues back to the whole grain, where the co-location of several living and non-living tissues results in complex tissue-tissue interactions and regulatory pathways coordinated across the multiple tissues. Here we have developed methods for isolating fragments of aleurone, starchy endosperm, embryo, scutellum, pericarp-testa, husk and crushed cell layers from germinated grain. An important step in the procedure involves the rapid fixation of the intact grain to freeze the transcriptional activity of individual tissues while dissection is effected for subsequent transcriptomic analyses. The developmental profiles of 19 611 gene transcripts were precisely defined in the purified tissues and in whole grain during the first 24 h of germination by RNA sequencing. Spatial and temporal patterns of transcription were validated against well-defined data on enzyme activities in both whole grain and isolated tissues. Transcript profiles of genes involved in mitochondrial assembly and function were used to validate the very early stages of germination, while the profiles of genes involved in starch and cell wall mobilisation matched existing data on activities of corresponding enzymes. The data will be broadly applicable for the interrogation of co-expression and differential expression patterns and for the identification of transcription factors that are important in the early stages of grain and seed germination. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

Lab and Field Warming Similarly Advance Germination Date and Limit Germination Rate for High and Low Elevation Provenances of Two Widespread Subalpine Conifers

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Lara M. Kueppers

2017-11-01

Full Text Available Accurately predicting upslope shifts in subalpine tree ranges with warming requires understanding how future forest populations will be affected by climate change, as these are the seed sources for new tree line and alpine populations. Early life history stages are particularly sensitive to climate and are also influenced by genetic variation among populations. We tested the climate sensitivity of germination and initial development for two widely distributed subalpine conifers, using controlled-environment growth chambers with one temperature regime from subalpine forest in the Colorado Rocky Mountains and one 5 °C warmer, and two soil moisture levels. We tracked germination rate and timing, rate of seedling development, and seedling morphology for two seed provenances separated by ~300 m elevation. Warming advanced germination timing and initial seedling development by a total of ~2 weeks, advances comparable to mean differences between provenances. Advances were similar for both provenances and species; however, warming reduced the overall germination rate, as did low soil moisture, only for Picea engelmannii. A three-year field warming and watering experiment planted with the same species and provenances yielded responses qualitatively consistent with the lab trials. Together these experiments indicate that in a warmer, drier climate, P. engelmannii germination, and thus regeneration, could decline, which could lead to declining subalpine forest populations, while Pinus flexilis forest populations could remain robust as a seed source for upslope range shifts.

Abscisic acid and osmoticum prevent germination of developing alfalfa embryos, but only osmoticum maintains the synthesis of developmental proteins.

Science.gov (United States)

Xu, N; Coulter, K M; Derek Bewley, J

1990-10-01

Developing seeds of alfalfa (Medicago sativa L.) acquire the ability to germinate during the latter stages of development, the maturation drying phase. Isolated embryos placed on Murashige and Skoog medium germinate well during early and late development, but poorly during mid-development; however, when placed on water they germinate well only during the latter stage of development. Germination of isolated embryos is very slow and poor when they are incubated in the presence of surrounding seed structures (the endosperm or seed coat) taken from the mid-development stages. This inhibitory effect is also achieved by incubating embryos in 10(-5) M abscisic acid (ABA). Endogenous ABA attains a high level during mid-development, especially in the endosperm. Seeds developing in pods treated with fluridone (1-methyl-3-phenyl-5[3-(trifluoromethyl)-phenyl]-4(1H)-pyridinone) contain low levels of ABA during mid-development, and the endosperm and seed coat only weakly inhibit the germination of isolated embryos. However, intact seeds from fluridone-treated pods do not germinate viviparously, which is indicative that ABA alone is not responsible for maintaining seeds in a developing state. Application of osmoticum (e.g. 0.35 M sucrose) to isolated developing embryos prevents their germination. Also, in the developing seed in situ the osmotic potential is high. Thus internal levels of osmoticum may play a role in preventing germination of the embryo and maintaining development. Abscisic acid and osmoticum impart distinctly different metabolic responses on developing embryos, as demonstrated by their protein-synthetic capacity. Only in the presence of osmoticum do embryos synthesize proteins which are distinctly recognizable as those synthesized by developing embryos in situ, i.e. when inside the pod. Abscisic acid induces the synthesis of a few unique proteins, but these arise even in mature embryos treated with ABA. Thus while both osmoticum and ABA prevent precocious

Contrasting germination responses to vegetative canopies experienced in pre- vs. post-dispersal environments

Science.gov (United States)

Leverett, Lindsay D.; Auge, Gabriela A.; Bali, Aman; Donohue, Kathleen

2016-01-01

to light cues after dispersal. Alternatively, reduced germination requirements could be adaptive by allowing seeds to germinate faster and reduce competition in later stages even though competition is not yet present in the seedling environment. The masking of genetic variation by maturation under a canopy, moreover, could impede evolutionary responses to selection on germination. PMID:27551028

Asymbiotic seed germination and in vitro seedling development of ...

African Journals Online (AJOL)

STORAGESEVER

2008-10-20

Oct 20, 2008 ... (M) and Knudson 'C' (KC) were evaluated for seed germination and early ... running tap water and Teepol. ... blade. The powdery seeds were inoculated on the surface of agar ... an interval of one week to trace different stages of development of .... round in shape and radially symmetrical that turned to.

Effect of Salinity on Germination and Its Relationship with Vegetative growth in Bromus danthoniae Genotypes from Saline and Non-Saline Areas of Iran

Directory of Open Access Journals (Sweden)

M. Rezaei

2018-02-01

Full Text Available Bromus danthoniae Trin. is an annual grass species that is well adapted to harsh climates and could be considered as an important genetic resources for tolerance to environmental stresses such as salinity. In this study, 24 genotypes collected from Ilam, Kurdistan, Kermanshah (non-saline areas and West Azerbaijan (saline area: shores of Uremia Salt Lake provinces of Iran were investigated at the germination stage under salt treatments with concentrations of 0, 60, 120, 180, 240 and 300 mM sodium chloride. Germination percentage, germination rate index, seed vigor, root length, shoot length and seedling fresh and dry weights were measured. In addition, the relationship between the percentage of germination in 300 mM sodium chloride and the survival rate (% after four weeks in 350 mM sodium chloride at the vegetative stage was evaluated. The results of analysis of variance showed that salinity treatments caused significant reductions in all the studied traits. Genotypic variation and the interaction of genotype × salt treatments were also significant. Genotypes USLN3 and KER4 were found to be the most tolerant and sensitive genotypes to salinity stress, with 13% and 98% reduction in germination percentage at 300 mM NaCl, respectively. Cluster analysis divided the genotypes into three groups, with one group containing only tolerant genotypes from Uremia Salt Lake, another one comprising only sensitive genotypes from non-saline regions, and the third one containing genotypes from both regions. The correlation between the germination percentage and the survival rate at the vegetative stage was not significant, indicating that different mechanisms are, perhaps, responsible for salinity tolerance at the germination and vegetative stages in B. danthoniae.

Incorporation of 15N-inorganic nitrogen into free-amino acids in germinating corn

International Nuclear Information System (INIS)

Samukawa, Kisaburo; Yamaguchi, Masuro

1979-01-01

Incorporation of 15 N-labeled compounds, (K 15 NO 3 ) and ( 15 NH 4 ) 2 SO 4 , into free-amino acids was measured in germinating corn. Sterilized seeds of sweet corn (Choko No. 865) were sown on the filter papers soaked in 10 ml of the solution containing one of the labeled compounds (40 ppm N, 99 atom % excess) in petri dishes and germinated at 30 deg C. After 48 hours and 72 hours, 15 N-incorporation was measured in 5 seedlings selected owing to uniform growth. A GC-MS was used for measuring the ratio of 15 N isotopes present in free-amino acids. 15 N incorporation into free-amino acids hardly occurred when corn was germinated in the solution containing K 15 NO 3 , which suggested that endogenous nitrogen was used during the early germination stage of corn when nitrate is present. Incorporation into amino acids was greater when corn was germinated in the medium containing ( 15 NH 4 ) 2 SO 4 , than the case of the solution containing K 15 NO 3 . When corn was germinated in the solution containing ( 15 NH 4 ) 2 SO 4 , assimilation of 15 N into asparagine or aspartic acid was comparatively higher than that into the other amino acids, though the incorporation rate was low. Thus, in intact germinating corn, the hydrolyzed product of protein was utilized for germination with priority, and dependence on exogenous nitrogen was low. (Kaihara, S.)

Fusion of Nonionic Vesicles

DEFF Research Database (Denmark)

Bulut, Sanja; Oskolkova, M. Z.; Schweins, R.

2010-01-01

We present an experimental study of vesicle fusion using light and neutron scattering to monitor fusion events. Vesicles are reproducibly formed with an extrusion procedure using an single amphiphile triethylene glycol mono-n-decyl ether in water. They show long-term stability for temperatures ar...... a barrier to fusion changing from 15 k(B)T at T = 26 degrees C to 10k(H) T at T = 35 degrees C. These results are compatible with the theoretical predictions using the stalk model of vesicle fusion....

Mean germination time and germination rate of oat seeds subjected to stationary magnetic field

International Nuclear Information System (INIS)

Martinez Ramirez, Elvira; Florez Garcia, Mercedes; Carbonell, Maria Victoria; Amaya Garcia de la Escosura, Jose Manuel

2007-01-01

The objective of the present study is to determine and quantify the effect produced by stationary magnetic fields on oat seed germination (Avena sativa, L. var. c obena ) . For this purpose, seeds were exposed to a magnetic field 125 mT of 250 mT during different periods of time: 20 minutes (E1, E5), 1 hour (E2, E6), 24 hours (E3, E7), or in a conic form (E4, E8) during the whole germination process. Germination tests were carried out under laboratory conditions with cylindrical magnets to obtain the magnetic field. For magnetic treatment seed on Petri dishes were placed on magnets during time necessary for each treatment. Seeds without exposition to the magnetic field were used as control group. Parameters used for germination speed analysis were: number of germinated seeds (G), mean germination time (MGT) and necessary time for germination of 1, 10, 25, 50 and 75% of N number of speeds used for each treatment (T1, T10, T25, T50, and T75). These parameters were supplied through the software Seed calculator, as well as the corresponding germination curves. In general, from the results obtained it can be said that the time required to obtain different germination percentages was lower for seeds exposed to the magnetic field (treatments E1 and E8). Reduction in time for E1 treatment stands up with 20 a minutes-exposition-time to 125 mT. MGT obtained for seeds with magnetic treatment E1 was significantly lower (11.48%) than the control group. Parameters T1, T10, T25 were also lower for seeds submitted to treatment, obtaining reductions of 46.62 %, 24.02 % and 13.46 % respectively. Reduction in germination parameters indicates that germination speed is higher. Because parameters T1 and T10 are related to the beginning of germination, this study represents a progress in germination and a reduction in the induction phase in most of the magnetic treatments applied. Previous studies done by authors about the influence of stationary magnetic fields have shown increases in

Characterization of yeast extracellular vesicles: evidence for the participation of different pathways of cellular traffic in vesicle biogenesis.

Directory of Open Access Journals (Sweden)

Débora L Oliveira

2010-06-01

Full Text Available Extracellular vesicles in yeast cells are involved in the molecular traffic across the cell wall. In yeast pathogens, these vesicles have been implicated in the transport of proteins, lipids, polysaccharide and pigments to the extracellular space. Cellular pathways required for the biogenesis of yeast extracellular vesicles are largely unknown.We characterized extracellular vesicle production in wild type (WT and mutant strains of the model yeast Saccharomyces cerevisiae using transmission electron microscopy in combination with light scattering analysis, lipid extraction and proteomics. WT cells and mutants with defective expression of Sec4p, a secretory vesicle-associated Rab GTPase essential for Golgi-derived exocytosis, or Snf7p, which is involved in multivesicular body (MVB formation, were analyzed in parallel. Bilayered vesicles with diameters at the 100-300 nm range were found in extracellular fractions from yeast cultures. Proteomic analysis of vesicular fractions from the cells aforementioned and additional mutants with defects in conventional secretion pathways (sec1-1, fusion of Golgi-derived exocytic vesicles with the plasma membrane; bos1-1, vesicle targeting to the Golgi complex or MVB functionality (vps23, late endosomal trafficking revealed a complex and interrelated protein collection. Semi-quantitative analysis of protein abundance revealed that mutations in both MVB- and Golgi-derived pathways affected the composition of yeast extracellular vesicles, but none abrogated vesicle production. Lipid analysis revealed that mutants with defects in Golgi-related components of the secretory pathway had slower vesicle release kinetics, as inferred from intracellular accumulation of sterols and reduced detection of these lipids in vesicle fractions in comparison with WT cells.Our results suggest that both conventional and unconventional pathways of secretion are required for biogenesis of extracellular vesicles, which demonstrate the

A Germination Simulation.

Science.gov (United States)

Hershey, David R.

1995-01-01

Presents an activity that involves using sponge seedlings to demonstrate the germination process without the usual waiting period. Discusses epigeous versus hypogeous germination, and cotyledon number and biodiversity. (JRH)

The International Society for Extracellular Vesicles launches the first massive open online course on extracellular vesicles

OpenAIRE

L?sser, Cecilia; Th?ry, Clotilde; Buz?s, Edit I.; Mathivanan, Suresh; Zhao, Weian; Gho, Yong Song; L?tvall, Jan

2016-01-01

The International Society for Extracellular Vesicles (ISEV) has organised its first educational online course for students and beginners in the field of extracellular vesicles (EVs). This course, “Basics of Extracellular Vesicles,” uses recorded lectures from experts in the field and will be open for an unlimited number of participants. The course is divided into 5 modules and can be accessed at www.coursera.org/learn/extracellular-vesicles. The first module is an introduction to the field co...

The use of transcription inhibitors in the study of the mechanism of abscisic acid action in germinating triticale caryopses

Directory of Open Access Journals (Sweden)

Stanisław Weidner

2014-01-01

Full Text Available The study was conducted on germinating triticale (var. Grado caryopses. The purpose of the experiments was to compare the effect of selected inhibitors of transcription with the action of abscisic acid during germination of caryopses. The following inhibitors were used: α-amanitin, cordycepin, cycloheximide and 5-fluorouracil. Studied were the synthesis of total and polyribosomal RNA, the process of polyribosome formation and the synthesis of ribosomal proteins. The effect of exogenous ABA, especially in the early stages of germination, was not similar to any of the four above inhibitors of transcription. After 12 h of imbibition at a lowered temperature and 3 h of germination, ABA caused a relatively low level of inhibition of RNA synthesis, whereas all of the inhibitors used halted RNA synthesis in embryos by about 50-60%. After 6 h of germination, the same proportion of polyribosomes in the total ribosome fraction (46% was found in both the embryos from the control sample and treated with ABA. The use of inhibitors brought this figure down to below 40%. The conclusion is drawn that in the early stages of germination, regulation of protein synthesis by ABA in triticale caryopses must occur on a level other than transcription.

High-Throughput Scoring of Seed Germination.

Science.gov (United States)

Ligterink, Wilco; Hilhorst, Henk W M

2017-01-01

High-throughput analysis of seed germination for phenotyping large genetic populations or mutant collections is very labor intensive and would highly benefit from an automated setup. Although very often used, the total germination percentage after a nominated period of time is not very informative as it lacks information about start, rate, and uniformity of germination, which are highly indicative of such traits as dormancy, stress tolerance, and seed longevity. The calculation of cumulative germination curves requires information about germination percentage at various time points. We developed the GERMINATOR package: a simple, highly cost-efficient, and flexible procedure for high-throughput automatic scoring and evaluation of germination that can be implemented without the use of complex robotics. The GERMINATOR package contains three modules: (I) design of experimental setup with various options to replicate and randomize samples; (II) automatic scoring of germination based on the color contrast between the protruding radicle and seed coat on a single image; and (III) curve fitting of cumulative germination data and the extraction, recap, and visualization of the various germination parameters. GERMINATOR is a freely available package that allows the monitoring and analysis of several thousands of germination tests, several times a day by a single person.

Seminal vesicle cycts

International Nuclear Information System (INIS)

Alpern, M.B.; Dorfman, R.E.; Gross, B.H.; Gottlieb, C.A.; Sandler, M.A.

1990-01-01

PURPOSE: Adult polycystic kidney disease (APKCD), an autosomal dominant disorder, causes cyst formation in the kidney, liver, pancreas, esophagus, ovaries, uterus, and brain. This paper describes four APKCD patients with CT evidence of seminal vesicle cysts (SVCs). Four patients (aged 45-65 years) underwent abdominal/pelvic CT with oral and intravenous contrast material. Three were evaluated for possible renal transplantation and one for sepsis material. All seminal vesicles contained cystic masses with fluid that measured between 0 and 30 HU. Seminal vesicle thickness was 3-4 cm (normal, 1.5 cm). High-density walls separated the 3-12-mm diameter cysts. All patients demonstrated typical renal stigmata of APKCD. One patient had hepatic cysts, and none had cysts elsewhere. Postmortem examination in one patient confirmed the SVCs

Soybean mother plant exposure to temperature stress and its effect on germination under osmotic stress

International Nuclear Information System (INIS)

Khalil, S.K.; Rehman, A.; Khan, A.Z.; Mexal, J.G.; Zubair, M.; Wahab, S.; Khalil, I.H.; Mohammad, F.

2010-01-01

High temperature reduces quality of soybean seed developed at different positions on the plant. The objective of this research was to study the quality of seed produced under different temperature regimes located at different position in the canopy. Soybean plants grown in pots were transferred at first pod stage to three growth chambers fixed at 18/10, 25/15 and 32/20 deg. C day/night temperature having 13/11 hrs day/night length. The plants remained in growth chambers until physiological maturity. Seeds harvested from each growth chamber were exposed to osmotic stress having osmotic potential of -0.5 MPa and unstressed control. Both stressed and control treatments were germinated in three growth chambers fixed at 18, 25 and 35 deg. C. Seed developed at lowest temperature (18/10 deg. C day/night) had maximum germination. Germination decreased linearly with increased day/night temperature and lowest germination was recorded at highest temperature of 32/20 deg. C (day/night). Seed developed at bottom position was heaviest and had better germination compared with seed developed at middle and top position. Seed germination was highest at 25 deg. C and took fewer days to 50% germination than 18 and 25 deg. C. Osmotic stress decreased germination and delayed days to 50% germination than control. It can be concluded that optimum temperature for seed development was 18/10 deg. C (day/night) whereas best germination temperature was 25 deg. C. (author)

Effects of low dose gamma-ray radiation on the seed germination and physiological activity of vegetable crops

Energy Technology Data Exchange (ETDEWEB)

Kim, J. S.; Baek, M. H.; Lee, Y. G. [KAERI, Taejon (Korea, Republic of); Jung, K. H. [Kyunghee Univ., Yongin (Korea, Republic of)

2000-10-01

To determine the effect of low dose gamma-ray radiation on the germination rate and physiology of germinative seeds of Chinese cabbage(Brassica campestris L. cv. Hanyoreum) and radish(Raphanus sativus L. cv. Chungsukoungzoung). The germination rate of irradiation group was higher than that of the control. Especially it was highest at the early stage of induction. The germination rate of Chinese cabbage increased at 4 Gy-, 10 Gy- and 50 Gy irradiation group and that of radish increased at 2 Gy-, 6 Gy- and 10 Gy irradiation group. The seedling height of Chinese cabbage and radish increased positively in low dose irradiation group. The seedling height of Chinese cabbage was noticeably higher at 4 Gy and 10 Gy irradiation group and that of radish at 6 Gy irradiation group. The protein contents of seeds irradiated with low dose gamma-ray radiation was increased compared to that of the control especially at the early stage of induction. The enzyme activity of seeds irradiated with low dose of gamma-ray radiation was increased at 4 Gy and 10 Gy irradiation group. These results suggest that the germination and physiological activity of old seeds could be stimulated promisingly by the low dose gamma-ray radiation.

Impermeability effects in three-dimensional vesicles

International Nuclear Information System (INIS)

Biscari, P; Canevese, S M; Napoli, G

2004-01-01

We analyse the effects of the impermeability constraint on the equilibrium shapes of a three-dimensional vesicle hosting a rigid inclusion. A given alteration of the inclusion and/or vesicle parameters leads to shape modifications of different orders of magnitude, when applied to permeable or impermeable vesicles. Moreover, the enclosed-volume constraint wrecks the uniqueness of stationary equilibrium shapes, and gives rise to pear-shaped or stomatocyte-like vesicles

Investigation of seed vigor and germination of canola cultivars under less irrigation in padding stage and after it.

Science.gov (United States)

Noori, S Ahmad Sadat; Khalaj, Hamideh; Rad, A Hosein Shirani; Alahdadi, Iraj; Akbari, Gh Abbas; Abadi, M Reza Labafi H

2007-09-01

The laboratory experiment was a factorial based on a Completely Randomized Design with four replications during 2005. Factors included two irrigation levels (normal irrigation (irrigation after 60 mm evaporation from class a pan) and less irrigation in padding stage and after it) and six winter cultivars (Licord, Okapi, Orient, SLMO64, Zarfam and Opera). The seeds used in this experiment produced under less irrigation (moderate drought stress) and they were three months in storage. The seed vigor was tested in laboratory experiment by three vigor tests, including Standard Germination test, cold test, Accelerated Ageing Test. Result showed that the accelerated aging test had significant differences on all of character in this study. Mean Comparing, showed canola cultivars had significant effect on Root/ Shoot ratio, abnormal seedling, hard seed, seedling fresh weight, MTG and FGP. Less irrigation levels had significant effect on total and shoot length, ratio root/shoot length and MTG.

7 CFR 201.63 - Germination.

Science.gov (United States)

2010-01-01

... 7 Agriculture 3 2010-01-01 2010-01-01 false Germination. 201.63 Section 201.63 Agriculture... REGULATIONS Tolerances § 201.63 Germination. The following tolerances are applicable to the percentage of germination and also to the sum of the germination plus the hard seed when 400 or more seeds are tested. Mean...

GERMINATOR: a software package for high-throughput scoring and curve fitting of Arabidopsis seed germination.

Science.gov (United States)

Joosen, Ronny V L; Kodde, Jan; Willems, Leo A J; Ligterink, Wilco; van der Plas, Linus H W; Hilhorst, Henk W M

2010-04-01

Over the past few decades seed physiology research has contributed to many important scientific discoveries and has provided valuable tools for the production of high quality seeds. An important instrument for this type of research is the accurate quantification of germination; however gathering cumulative germination data is a very laborious task that is often prohibitive to the execution of large experiments. In this paper we present the germinator package: a simple, highly cost-efficient and flexible procedure for high-throughput automatic scoring and evaluation of germination that can be implemented without the use of complex robotics. The germinator package contains three modules: (i) design of experimental setup with various options to replicate and randomize samples; (ii) automatic scoring of germination based on the color contrast between the protruding radicle and seed coat on a single image; and (iii) curve fitting of cumulative germination data and the extraction, recap and visualization of the various germination parameters. The curve-fitting module enables analysis of general cumulative germination data and can be used for all plant species. We show that the automatic scoring system works for Arabidopsis thaliana and Brassica spp. seeds, but is likely to be applicable to other species, as well. In this paper we show the accuracy, reproducibility and flexibility of the germinator package. We have successfully applied it to evaluate natural variation for salt tolerance in a large population of recombinant inbred lines and were able to identify several quantitative trait loci for salt tolerance. Germinator is a low-cost package that allows the monitoring of several thousands of germination tests, several times a day by a single person.

MR imaging of the seminal vesicles

International Nuclear Information System (INIS)

Edson, S.B.; Hricak, H.; Chun-Fang Chang, Y.

1987-01-01

The seminal vesicles of 56 healthy males and 23 males with pathologic conditions were studied with a .35-T magnet and spin-echo (SE) techniques (repetition time/echo time [msec] = 500/30 and 2,000/60). The authors analyzed (1) the size and relative signal intensity of seminal vesicles compared to surrounding fat, muscle, or urine; (2) the effect of aging on the size and signal intensity of the vesicles, and (3) the appearance of the seminal vesicles in different pathologic conditions. In the transverse plane, the normal seminal vesicle measures 31 +- 7 mm in length and 17 +- 4 mm in width. Its size or signal intensity did not change significantly with age. On SE = 500/30 images the seminal vesicles were isointense with muscle; on SE = 2,000/60 images they were isointense or slightly hypointense relative to fat. MR imaging was highly sensitive for displaying seminal vesicle pathology, based on asymmetry in size and changes in signal intensities. MR imaging provides unique information but its role in pathologic conditions needs to be further explored

Autoradiographic study of protein synthesis recovery in root cells of Zea mays embryos during early stages of germination

International Nuclear Information System (INIS)

Deltour, Roger

1977-01-01

Recovery of protein synthesis was studied in primary root of germinating Zea mays embryos. [H 3 ] leucine or [H 3 ] lysine was provided for two hours at 16 0 C to embryos excised from kernels at various times after the beginning of germination. Protein synthesis (probably dependent on long-lived mRNA stocked in dormant embryo root cells) resumed during the first two hours of seed imbibition [fr

Autoradiographic study of protein synthesis recovery in root cells of Zea mays embryos during early stages of germination

Energy Technology Data Exchange (ETDEWEB)

Deltour, R [Liege Univ. (Belgium)

1977-05-02

Recovery of protein synthesis was studied in primary root of germinating Zea mays embryos. (H/sup 3/) leucine or (H/sup 3/) lysine was provided for two hours at 16/sup 0/C to embryos excised from kernels at various times after the beginning of germination. Protein synthesis (probably dependent on long-lived mRNA stocked in dormant embryo root cells) resumed during the first two hours of seed imbibition.

Effects of arbuscular mycorrhizal fungi and maternal plant sex on seed germination and early plant establishment.

Science.gov (United States)

Varga, Sandra

2015-03-01

• Arbuscular mycorrhizal fungi usually enhance overall plant performance, yet their effects on seed germination and early plant establishment, crucial steps in plant cycles, are generally overlooked. In gynodioecious species, sexual dimorphism in these traits has been reported, with females producing seeds that germinate at a faster rate than seeds from hermaphrodites.• Using the gynodioecious plant Geranium sylvaticum, I investigated in a greenhouse experiment whether the presence of arbuscular mycorrhizal spores affects seed germination and early plant establishment, examining at the same time whether the sex of the mother producing the seeds also influences these parameters and whether sex-specific interactions between these two factors exist.• The presence of arbuscular mycorrhizal spores in the soil decreased seed germination, did not affect plant survival, but did increase plant growth. Moreover, no significant differences in seed traits were detected between the sexes of the plants producing the seeds.• This study demonstrates that arbuscular mycorrhizal fungi may have contrasting effects for plants during early life stages and that mycorrhizal effects can take place even at the precolonization stage. © 2015 Botanical Society of America, Inc.

Recruitment and SNARE-mediated fusion of vesicles in furrow membrane remodeling during cytokinesis in zebrafish embryos

International Nuclear Information System (INIS)

Ming Liwai; Webb, Sarah E.; Lee, Karen W.; Miller, Andrew L.

2006-01-01

Cytokinesis is the final stage in cell division that serves to partition cytoplasm and daughter nuclei into separate cells. Membrane remodeling at the cleavage plane is a required feature of cytokinesis in many species. In animal cells, however, the precise mechanisms and molecular interactions that mediate this process are not yet fully understood. Using real-time imaging in live, early stage zebrafish embryos, we demonstrate that vesicles labeled with the v-SNARE, VAMP-2, are recruited to the cleavage furrow during deepening in a microtubule-dependent manner. These vesicles then fuse with, and transfer their VAMP-2 fluorescent label to, the plasma membrane during both furrow deepening and subsequent apposition. This observation indicates that new membrane is being inserted during these stages of cytokinesis. Inhibition of SNAP-25 (a cognate t-SNARE of VAMP-2), using a monoclonal antibody, blocked VAMP-2 vesicle fusion and furrow apposition. Transient expression of mutant forms of SNAP-25 also produced defects in furrow apposition. SNAP-25 inhibition by either method, however, did not have any significant effect on furrow deepening. Thus, our data clearly indicate that VAMP-2 and SNAP-25 play an essential role in daughter blastomere apposition, possibly via the delivery of components that promote the cell-to-cell adhesion required for the successful completion of cytokinesis. Our results also support the idea that new membrane addition, which occurs during late stage cytokinesis, is not required for furrow deepening that results from contractile band constriction

Spontaneous charged lipid transfer between lipid vesicles.

Science.gov (United States)

Richens, Joanna L; Tyler, Arwen I I; Barriga, Hanna M G; Bramble, Jonathan P; Law, Robert V; Brooks, Nicholas J; Seddon, John M; Ces, Oscar; O'Shea, Paul

2017-10-03

An assay to study the spontaneous charged lipid transfer between lipid vesicles is described. A donor/acceptor vesicle system is employed, where neutrally charged acceptor vesicles are fluorescently labelled with the electrostatic membrane probe Fluoresceinphosphatidylethanolamine (FPE). Upon addition of charged donor vesicles, transfer of negatively charged lipid occurs, resulting in a fluorescently detectable change in the membrane potential of the acceptor vesicles. Using this approach we have studied the transfer properties of a range of lipids, varying both the headgroup and the chain length. At the low vesicle concentrations chosen, the transfer follows a first-order process where lipid monomers are transferred presumably through the aqueous solution phase from donor to acceptor vesicle. The rate of transfer decreases with increasing chain length which is consistent with energy models previously reported for lipid monomer vesicle interactions. Our assay improves on existing methods allowing the study of a range of unmodified lipids, continuous monitoring of transfer and simplified experimental procedures.

Asada-Halliwell pathway maintains redox status in Dioscorea alata tuber which helps in germination.

Science.gov (United States)

Sharma, Shruti; Sehrawat, Ankita; Deswal, Renu

2016-09-01

Reactive Oxygen Species (ROS) are important regulatory molecules governing physiological processes. In the present study a biochemical and proteome level comparison of two contrasting growth stages of Dioscorea alata tuber namely germinating and mature tuber was performed in order to understand the tuber physiology and biochemistry. Existence of all the component enzymes [APx (ascorbate peroxidase), GR (glutathione reductase), DHAR (dehydroascorbate reductase), MDHAR (mono-dehydroascorbate reductase)] and major products [ascorbate (ASC) and glutathione (GSH)] of the cycle showed an operational Asada-Halliwell cycle in the tuber. A 2.65 fold increase in ASC content & a 3.8 fold increase in GR activity fortified the redox milieu during germination. In contrast a 5 fold higher H2O2 content (due to 3.08 fold lower APx activity) and accumulation of reactive nitrogen species (RNS) such as nitric oxide (NO, 2.4-fold) and S-nitrosothiol (SNO, 2.08 fold) contributed to overall oxidative conditions in the mature tuber. The carbonic anhydrase (CA, 7.5 fold), DHAR (5.31 fold) and MDHAR (7 fold) activities were higher in the germinating tuber in comparison with the mature tuber. GSNO negatively regulated the CA (3.6 & 3.95 fold), MDHAR (7.5 & 1.5 fold) and APx (2.3 & 1.81 fold) while another NO donor, CysNO negatively regulated the DHAR (2.24 & 1.32 fold) activity in the mature and germinating stages respectively indicating again that the lesser inhibition by NO (via nitrosylation) may be because of overall reducing environment in the germinating tuber. Increased SNO leading to S-nitrosylation of dioscorin was confirmed by Biotin switch assay. This is the first report showing dioscorin nitrosylation. The present analysis showed differential redox regulation and also suggests the physiological relevance of CA, DHAR, MDHAR, APx & GR in tuber germination for the first time. These enzymes may be used as potential markers of tuber germination in future. Copyright © 2016 Elsevier

Seed dormancy and germination.

Science.gov (United States)

Penfield, Steven

2017-09-11

Reproduction is a critical time in plant life history. Therefore, genes affecting seed dormancy and germination are among those under strongest selection in natural plant populations. Germination terminates seed dispersal and thus influences the location and timing of plant growth. After seed shedding, germination can be prevented by a property known as seed dormancy. In practise, seeds are rarely either dormant or non-dormant, but seeds whose dormancy-inducing pathways are activated to higher levels will germinate in an ever-narrower range of environments. Thus, measurements of dormancy must always be accompanied by analysis of environmental contexts in which phenotypes or behaviours are described. At its simplest, dormancy can be imposed by the formation of a simple physical barrier around the seed through which gas exchange and the passage of water are prevented. Seeds featuring this so-called 'physical dormancy' often require either scarification or passage through an animal gut (replete with its associated digestive enzymes) to disrupt the barrier and permit germination. In other types of seeds with 'morphological dormancy' the embryo remains under-developed at maturity and a dormant phase exists as the embryo continues its growth post-shedding, eventually breaking through the surrounding tissues. By far, the majority of seeds exhibit 'physiological dormancy' - a quiescence program initiated by either the embryo or the surrounding endosperm tissues. Physiological dormancy uses germination-inhibiting hormones to prevent germination in the absence of the specific environmental triggers that promote germination. During and after germination, early seedling growth is supported by catabolism of stored reserves of protein, oil or starch accumulated during seed maturation. These reserves support cell expansion, chloroplast development and root growth until photoauxotrophic growth can be resumed. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Ultrasound-responsive ultrathin multiblock copolyamide vesicles

Science.gov (United States)

Huang, Lei; Yu, Chunyang; Huang, Tong; Xu, Shuting; Bai, Yongping; Zhou, Yongfeng

2016-02-01

This study reports the self-assembly of novel polymer vesicles from an amphiphilic multiblock copolyamide, and the vesicles show a special structure with an ultrathin wall thickness of about 4.5 nm and a combined bilayer and monolayer packing model. Most interestingly, the vesicles are ultrasound-responsive and can release the encapsulated model drugs in response to ultrasonic irradiation.This study reports the self-assembly of novel polymer vesicles from an amphiphilic multiblock copolyamide, and the vesicles show a special structure with an ultrathin wall thickness of about 4.5 nm and a combined bilayer and monolayer packing model. Most interestingly, the vesicles are ultrasound-responsive and can release the encapsulated model drugs in response to ultrasonic irradiation. Electronic supplementary information (ESI) available: Details of experiments and characterization, and FT-IR, TEM, DPD, FL and micro-DSC results. See DOI: 10.1039/c5nr08596a

Effects of low dose gamma irradiation on the germination and physiological activity of old red pepper (Capsicum annuum L.) seed

Energy Technology Data Exchange (ETDEWEB)

Kim, Jae Sung; Back, Myung Hwa; Lee, Hae Youn; Lee, Young Keun [KAERI, Daejeon (Korea, Republic of)

2001-12-15

To observe the stimulating effects of low dose gamma radiation on the germination and physiological activity of germinating seeds of old red pepper (Capsicum annuum L. cv, Jokwang and cv. Hongkwang), seeds were irradiated at the dose of 2{approx}50 Gy. The germination rate of irradiation group was higher than that of the control. Especially it was highest at the early stage of induction. The germination rate at 7 days after sowing in Jokwang and Hongkwang cultivar was high as 74% and 11% at 4 Gy and 8 Gy irradiation group, respectively. The seedling height of Jokwang cultivar was noticeably high at 4 Gy irradiation group and that of Hongkwang cultivar at 8 Gy Irradiation group. The protein contents of seedlings from seeds irradiated with low dose gamma radiation of Jokwang cultivar increased at the late stage of induction and that of Hongkwang cultivar at the early stage of induction. Catalase and peroxidase activities of seedlings from seeds irradiated with low dose gamma radiation of Jokwang cultivar increased at 4 Gy irradiation group and that of Hongkwang cultivar at 8 Gy irradiation group.

Effects of germination season on life history traits and on transgenerational plasticity in seed dormancy in a cold desert annual.

Science.gov (United States)

Lu, Juan J; Tan, Dun Y; Baskin, Carol C; Baskin, Jerry M

2016-04-27

The maternal environment can influence the intensity of seed dormancy and thus seasonal germination timing and post-germination life history traits. We tested the hypotheses that germination season influences phenotypic expression of post-germination life history traits in the cold desert annual Isatis violascens and that plants from autumn- and spring-germinating seeds produce different proportions of seeds with nondeep and intermediate physiological dormancy (PD). Seeds were sown in summer and flexibility in various life history traits determined for plants that germinated in autumn and in spring. A higher percentage of spring- than of autumn-germinating plants survived the seedling stage, and all surviving plants reproduced. Number of silicles increased with plant size (autumn- > spring-germinating plants), whereas percent dry mass allocated to reproduction was higher in spring- than in autumn-germinating plants. Autumn-germinating plants produced proportionally more seeds with intermediate PD than spring-germinating plants, while spring-germinating plants produced proportionally more seeds with nondeep PD than autumn-germinating plants. Flexibility throughout the life history and transgenerational plasticity in seed dormancy are adaptations of I. violascens to its desert habitat. Our study is the first to demonstrate that autumn- and spring-germinating plants in a species population differ in proportion of seeds produced with different levels of PD.

Evaluation of drought and salinity stress effects on germination and ...

African Journals Online (AJOL)

To study the effect of polyethylene glycol (PEG) and NaCl stress on germination and early seedling stages on two cultivars of maize, two separated experiment were laid out at seed laboratory in Iran in 2011. This investigation was performed as factorial experiment under completely randomized design (CRD) with three ...

A note on the effect of gamma-irradiation on the seed germination of Linum usitatissimum L

International Nuclear Information System (INIS)

Ghouse, A.K.M.; Abidi, S.H.; Kazmi, Reshma

1979-01-01

A study on the effect of different acute doses of gamma-irradiation on the seeds of Linum usitatissimum L. varieties Heera, Mukta and T 397 revealed that the process of germination has been retarded, particularly, at its initial stage, under the influence of this ionizing agency, although the overall germination percentage does not vary to any considerable extent under the different intensities of irradiation tested. (auth.)

Responsive Polydiacetylene Vesicles for Biosensing Microorganisms

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Estelle Lebègue

2018-02-01

Full Text Available Polydiacetylene (PDA inserted in films or in vesicles has received increasing attention due to its property to undergo a blue-to-red colorimetric transition along with a change from non-fluorescent to fluorescent upon application of various stimuli. In this review paper, the principle for the detection of various microorganisms (bacteria, directly detected or detected through the emitted toxins or through their DNA, and viruses and of antibacterial and antiviral peptides based on these responsive PDA vesicles are detailed. The analytical performances obtained, when vesicles are in suspension or immobilized, are given and compared to those of the responsive vesicles mainly based on the vesicle encapsulation method. Many future challenges are then discussed.

Introducing a prognostic score for pretherapeutic assessment of seminal vesicle invasion in patients with clinically localized prostate cancer

International Nuclear Information System (INIS)

Salomon, Laurent; Porcher, Raphaeel; Anastasiadis, Aristotelis G.; Levrel, Olivier; Saint, Fabian; Taille, Alexandre de la; Vordos, Dimitrios; Cicco, Antony; Hoznek, Andras; Chopin, Dominique; Abbou, Clement-Claude; Lagrange, Jean-Leon

2003-01-01

Purpose: To identify prostate cancer patients who will have the most likely benefit from sparing the seminal vesicles during 3D conformal radiation therapy. Methods and materials: From 1988 to 2001, 532 patients underwent radical prostatectomy for clinically localized prostate cancer. Primary endpoint was the pathological evidence of seminal vesicle invasion. Variables for univariate and multivariate analyses were age, prostate weight, clinical stage, PSA level, Gleason score, number and site of positive prostate sextant biopsies. Multivariate logistic regression with backward stepwise variable selection was used to identify a set of independent predictors of seminal vesicle invasion, and the variable selection procedure was validated by non-parametric bootstrap. Results: Seminal vesicle invasion was reported in 14% of the cases. In univariate analysis, all variables except age and prostate weight were predictors of seminal vesicle invasion. In multivariate analysis, only the number of positive biopsies (P<0.0001), Gleason score (P<0.007) and PSA (P<0.0001) were predictors for seminal vesicles invasion. Based on the multivariate model, we were able to develop a prognostic score for seminal vesicle invasion, which allowed us to discriminate two patient groups: A group with low risk of seminal vesicles invasion (5.7%), and the second with a higher risk of seminal vesicles invasion (32.7%). Conclusions: Using the number of positive biopsies, Gleason score and PSA, it is possible to identify patients with low risk of seminal vesicles invasion. In this population, seminal vesicles might be excluded as a target volume in radiation therapy of prostate cancer

Comparative study of the germination of Ulva prolifera gametes on various substrates

Science.gov (United States)

Geng, Huixia; Yan, Tian; Zhou, Mingjiang; Liu, Qing

2015-09-01

Since 2007, massive green tides have occurred every summer in the southern Yellow Sea (YS), China. They have caused severe ecological consequences and huge economic losses. Ulva prolifera originated from Subei Shoal of the YS was confirmed as causative species of the green tides. The Porphyra yezoensis aquaculture rafts in the Subei Shoal have been highly suspected to be the "seed bed" of the green tides, because U. prolifera abundantly fouled the Porphyra yezoensis aquaculture facilities. Besides, various habitats of aquaculture ponds along the Jiangsu coastline and mudflat in the Subei Shoal were proposed to be possible sources of green tides. To understand the "seed" of the green tides in the southern YS and mitigate the original biomass of the green tide, various materials used as substrates for the germination of U. prolifera gametes were tested in this study. Culture experiments showed the following: 1) materials used in the P. yezoensis rafts (plastic, bamboo, jute rope, plastic rope, nylon netting, and plastic netting) displayed a significantly higher germination rate than those associated with mudflats and aquaculture ponds (mud, sand and rock); 2) plastics were the best substrates for the germination of U. prolifera gametes; 3) poor germination was found on old fronds of U. prolifera,, and rubber showed inhibitory effect on germination. The success in germination on P. yezoensis rafts related materials supports the notion that these mariculture structures may be involved in acting as a seed bed for green tide macroalgae. The lack of germination on rubber surfaces may suggest one way to limit the proliferation of early stages of U. prolifera.

The use of cluster analysis for plant grouping by their tolerance to soil contamination with hydrocarbons at the germination stage.

Science.gov (United States)

Potashev, Konstantin; Sharonova, Natalia; Breus, Irina

2014-07-01

Clustering was employed for the analysis of obtained experimental data set (42 plants in total) on seed germination in leached chernozem contaminated with kerosene. Among investigated plants were 31 cultivated plants from 11 families (27 species and 20 varieties) and 11 wild plant species from 7 families, 23 annual and 19 perennial/biannual plant species, 11 monocotyledonous and 31 dicotyledonous plants. Two-dimensional (two-parameter) clustering approach, allowing the estimation of tolerance of germinating seeds using a pair of independent parameters (С75%, V7%) was found to be most effective. These parameters characterized the ability of seeds to both withstand high concentrations of contaminants without the significant reduction of the germination, and maintain high germination rate within certain contaminant concentrations. The performed clustering revealed a number of plant features, which define the relation of a particular plant to a particular tolerance cluster; it has also demonstrated the possibility of generalizing the kerosene results for n-tridecane, which is one of the typical kerosene components. In contrast to the "manual" plant ranking based on the assessment of germination at discrete concentrations of the contaminant, the proposed clustering approach allowed a generalized characterization of the seed tolerance/sensitivity to hydrocarbon contaminants. Copyright © 2014 Elsevier B.V. All rights reserved.

Germination Shifts of C3 and C4 Species under Simulated Global Warming Scenario

Science.gov (United States)

Zhang, Hongxiang; Yu, Qiang; Huang, Yingxin; Zheng, Wei; Tian, Yu; Song, Yantao; Li, Guangdi; Zhou, Daowei

2014-01-01

Research efforts around the world have been increasingly devoted to investigating changes in C3 and C4 species' abundance or distribution with global warming, as they provide important insight into carbon fluxes and linked biogeochemical cycles. However, changes in the early life stage (e.g. germination) of C3 and C4 species in response to global warming, particularly with respect to asymmetric warming, have received less attention. We investigated germination percentage and rate of C3 and C4 species under asymmetric (+3/+6°C at day/night) and symmetric warming (+5/+5°C at day/night), simulated by alternating temperatures. A thermal time model was used to calculate germination base temperature and thermal time constant. Two additional alternating temperature regimes were used to test temperature metrics effect. The germination percentage and rate increased continuously for C4 species, but increased and then decreased with temperature for C3 species under both symmetric and asymmetric warming. Compared to asymmetric warming, symmetric warming significantly overestimated the speed of germination percentage change with temperature for C4 species. Among the temperature metrics (minimum, maximum, diurnal temperature range and average temperature), maximum temperature was most correlated with germination of C4 species. Our results indicate that global warming may favour germination of C4 species, at least for the C4 species studied in this work. The divergent effects of asymmetric and symmetric warming on plant germination also deserve more attention in future studies. PMID:25137138

Germination shifts of C3 and C4 species under simulated global warming scenario.

Science.gov (United States)

Zhang, Hongxiang; Yu, Qiang; Huang, Yingxin; Zheng, Wei; Tian, Yu; Song, Yantao; Li, Guangdi; Zhou, Daowei

2014-01-01

Research efforts around the world have been increasingly devoted to investigating changes in C3 and C4 species' abundance or distribution with global warming, as they provide important insight into carbon fluxes and linked biogeochemical cycles. However, changes in the early life stage (e.g. germination) of C3 and C4 species in response to global warming, particularly with respect to asymmetric warming, have received less attention. We investigated germination percentage and rate of C3 and C4 species under asymmetric (+3/+6°C at day/night) and symmetric warming (+5/+5°C at day/night), simulated by alternating temperatures. A thermal time model was used to calculate germination base temperature and thermal time constant. Two additional alternating temperature regimes were used to test temperature metrics effect. The germination percentage and rate increased continuously for C4 species, but increased and then decreased with temperature for C3 species under both symmetric and asymmetric warming. Compared to asymmetric warming, symmetric warming significantly overestimated the speed of germination percentage change with temperature for C4 species. Among the temperature metrics (minimum, maximum, diurnal temperature range and average temperature), maximum temperature was most correlated with germination of C4 species. Our results indicate that global warming may favour germination of C4 species, at least for the C4 species studied in this work. The divergent effects of asymmetric and symmetric warming on plant germination also deserve more attention in future studies.

Live Cell Imaging During Germination Reveals Dynamic Tubular Structures Derived from Protein Storage Vacuoles of Barley Aleurone Cells

Directory of Open Access Journals (Sweden)

Verena Ibl

2014-09-01

Full Text Available The germination of cereal seeds is a rapid developmental process in which the endomembrane system undergoes a series of dynamic morphological changes to mobilize storage compounds. The changing ultrastructure of protein storage vacuoles (PSVs in the cells of the aleurone layer has been investigated in the past, but generally this involved inferences drawn from static pictures representing different developmental stages. We used live cell imaging in transgenic barley plants expressing a TIP3-GFP fusion protein as a fluorescent PSV marker to follow in real time the spatially and temporally regulated remodeling and reshaping of PSVs during germination. During late-stage germination, we observed thin, tubular structures extending from PSVs in an actin-dependent manner. No extensions were detected following the disruption of actin microfilaments, while microtubules did not appear to be involved in the process. The previously-undetected tubular PSV structures were characterized by complex movements, fusion events and a dynamic morphology. Their function during germination remains unknown, but might be related to the transport of solutes and metabolites.

Reduced germination success of temperate grassland seeds sown in dung: consequences for post-dispersal seed fate.

Science.gov (United States)

Milotić, T; Hoffmann, M

2016-11-01

Endozoochory is one of the main drivers shaping temperate grassland communities by maintaining plant populations of its constituents and enabling plants to colonize new habitats. Successful endozoochorous dispersal implies that seeds not only get consumed and survive the digestive tract but are also able to develop into viable seedlings in a dung environment. We experimentally assessed the germination probability and timing of 15 annual and perennial temperate European grassland species in cattle and horse dung and in different climatic conditions (greenhouse and outdoor conditions). Interspecific variation in germinability and germination timing are found, while life strategy had only an effect on germination timing. We found adverse effects of both cattle and horse dung on the germination characteristics of all tested grassland species, but the effects of cattle dung were more pronounced. In comparison with the control treatment, fewer seeds emerged in dung and more time was needed to germinate. Also, germination metrics clearly differed between the artificial greenhouse and outdoor conditions, with generally a lower germinability in outdoor conditions. According to our results, a large cost seems to be associated with endozoochorous dispersal in this stage of the life cycle, as seed dispersal effectiveness strongly depends on the quality of the deposition site with a lowered survival and germination probability when seeds are deposited in dung. © 2016 German Botanical Society and The Royal Botanical Society of the Netherlands.

Effect of Irrigation with Contaminated Water by Cloth Detergent on Seed Germination Traits and Early Growth of Sunflower (Helianthus annuus L.

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Hassan HEIDARI

2013-02-01

Full Text Available One of the sources for irrigation is sewage. Contaminated water may affect seed germination and plant growth. A laboratory experiment and a pot experiment were conducted in 2012 to determine the effect of different doses of detergent on seed germination traits and early growth of sunflower (Helianthus annuus L.. The experiments included eight doses of cloth detergent (0, 0.00002, 0.0002, 0.002, 0.02, 0.2, 2, 20 g/L. Results showed that 20 and 2 g/L of detergent severely reduced seed germination, plant height, leaf number per plant, total biomass and stem weight. 20 g/L of detergent reduced shoot length, root length, seedling weight and seed vigor. Seed germination stage was more sensitive to contaminated water than early growth stage. The results demonstrated that irrigating sunflower by contaminated water with household cleaning products at high concentration should be avoided.

Transcriptome of extracellular vesicles released by hepatocytes.

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Felix Royo

Full Text Available The discovery that the cells communicate through emission of vesicles has opened new opportunities for better understanding of physiological and pathological mechanisms. This discovery also provides a novel source for non-invasive disease biomarker research. Our group has previously reported that hepatocytes release extracellular vesicles with protein content reflecting the cell-type of origin. Here, we show that the extracellular vesicles released by hepatocytes also carry RNA. We report the messenger RNA composition of extracellular vesicles released in two non-tumoral hepatic models: primary culture of rat hepatocytes and a progenitor cell line obtained from a mouse foetal liver. We describe different subpopulations of extracellular vesicles with different densities and protein and RNA content. We also show that the RNA cargo of extracellular vesicles released by primary hepatocytes can be transferred to rat liver stellate-like cells and promote their activation. Finally, we provide in vitro and in vivo evidence that liver-damaging drugs galactosamine, acetaminophen, and diclofenac modify the RNA content of these vesicles. To summarize, we show that the extracellular vesicles secreted by hepatocytes contain various RNAs. These vesicles, likely to be involved in the activation of stellate cells, might become a new source for non-invasive identification of the liver toxicity markers.

High Pressure Germination of Bacillus subtilis Spores with Alterations in Levels and Types of Germination Proteins

Science.gov (United States)

2014-01-01

1ITLE AND SUBTITLE 5a CONTRACTNUMBER High pressure germination of Bacillus subtilis spores with W911NF-09-l-0286 alterations in levels and types of...A moderate high pressure (mHP) of 150 megaPascals (MPa) triggers germination of Bacillus subtilis spores via germinant receptors (GRs), while...germination by a very high pressure (vHP) of550 MPa is GR-independent. The mHP and vHP germination of Bacillus subtilis spores with different levels ofGRs

Effect of Osmotic Stress on Seed Germination Indices of Nigella sativa and Silybum marianum

OpenAIRE

H Balouchi; A. Yadavi; M. Movahedi Dehnavi

2012-01-01

Evaluation of medicinal plants to drought and salt stress tolerance, in an attempt to plant them under drought and saline regions, is of utmost importance. Environmental stresses, especially drought and salt, reduce the global crop yields more than other factors. Selection of drought tolerant crops at germination stage, usually is, the fast and low cost method. In order to study the effect of osmotic stress on germination indices of black cumin and milk thistle, an experiment carried out in a...

Spontaneous Vesicle Recycling in the Synaptic Bouton

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Sven eTruckenbrodt

2014-12-01

Full Text Available The trigger for synaptic vesicle exocytosis is Ca2+, which enters the synaptic bouton following action potential stimulation. However, spontaneous release of neurotransmitter also occurs in the absence of stimulation in virtually all synaptic boutons. It has long been thought that this represents exocytosis driven by fluctuations in local Ca2+ levels. The vesicles responding to these fluctuations are thought to be the same ones that release upon stimulation, albeit potentially triggered by different Ca2+ sensors. This view has been challenged by several recent works, which have suggested that spontaneous release is driven by a separate pool of synaptic vesicles. Numerous articles appeared during the last few years in support of each of these hypotheses, and it has been challenging to bring them into accord. We speculate here on the origins of this controversy, and propose a solution that is related to developmental effects. Constitutive membrane traffic, needed for the biogenesis of vesicles and synapses, is responsible for high levels of spontaneous membrane fusion in young neurons, probably independent of Ca2+. The vesicles releasing spontaneously in such neurons are not related to other synaptic vesicle pools and may represent constitutively releasing vesicles (CRVs rather than bona fide synaptic vesicles. In mature neurons, constitutive traffic is much dampened, and the few remaining spontaneous release events probably represent bona fide spontaneously releasing synaptic vesicles (SRSVs responding to Ca2+ fluctuations, along with a handful of CRVs that participate in synaptic vesicle turnover.

Spontaneous transfer of gangliotetraosylceramide between phospholipid vesicles

International Nuclear Information System (INIS)

Brown, R.E.; Sugar, I.P.; Thompson, T.E.

1985-01-01

The transfer kinetics of the neutral glycosphingolipid gangliotetraosylceramide (asialo-GM1) were investigated by monitoring tritiated asialo-GM1 movement from donor to acceptor vesicles. Two different methods were employed to separate donor and acceptor vesicles at desired time intervals. In one method, a negative charge was imparted to dipalmitoylphosphatidylcholine donor vesicles by including 10 mol% dipalmitoylphosphatidic acid. Donors were separated from neutral dipalmitoylphosphatidylcholine acceptor vesicles by ion-exchange chromatography. In the other method, small, unilamellar donor vesicles and large, unilamellar acceptor vesicles were coincubated at 45 degrees C and then separated at desired time intervals by molecular sieve chromatography. The majority of asialo-GM1 transfer to acceptor vesicles occurred as a slow first-order process with a half-time of about 24 days assuming that the relative concentration of asialo-GM1 in the phospholipid matrix was identical in each half of the donor bilayer and that no glycolipid flip-flop occurred. Asialo-GM1 net transfer was calculated relative to that of [ 14 C]cholesteryl oleate, which served as a nontransferable marker in the donor vesicles. A nearly identical transfer half-time was obtained when the phospholipid matrix was changed from dipalmitoylphosphatidylcholine to palmitoyloleoylphosphatidylcholine. Varying the acceptor vesicle concentration did not significantly alter the asialo-GM1 transfer half-time. This result is consistent with a transfer mechanism involving diffusion of glycolipid through the aqueous phase rather than movement of glycolipid following formation of collisional complexes between donor and acceptor vesicles. (Abstract Truncated)

Thermal buffering capacity of the germination phenotype across the environmental envelope of the Cactaceae.

Science.gov (United States)

Seal, Charlotte E; Daws, Matthew I; Flores, Joel; Ortega-Baes, Pablo; Galíndez, Guadalupe; León-Lobos, Pedro; Sandoval, Ana; Ceroni Stuva, Aldo; Ramírez Bullón, Natali; Dávila-Aranda, Patricia; Ordoñez-Salanueva, Cesar A; Yáñez-Espinosa, Laura; Ulian, Tiziana; Amosso, Cecilia; Zubani, Lino; Torres Bilbao, Alberto; Pritchard, Hugh W

2017-12-01

Recruitment from seeds is among the most vulnerable stage for plants as global temperatures change. While germination is the means by which the vast majority of the world's flora regenerate naturally, a framework for accurately predicting which species are at greatest risk of germination failure during environmental perturbation is lacking. Taking a physiological approach, we assess how one family, the Cactaceae, may respond to global temperature change based on the thermal buffering capacity of the germination phenotype. We selected 55 cactus species from the Americas, all geo-referenced seed collections, reflecting the broad environmental envelope of the family across 70° of latitude and 3700 m of altitude. We then generated empirical data of the thermal germination response from which we estimated the minimum (T b ), optimum (T o ) and ceiling (T c ) temperature for germination and the thermal time (θ 50 ) for each species based on the linearity of germination rate with temperature. Species with the highest T b and lowest T c germinated fastest, and the interspecific sensitivity of the germination rate to temperature, as assessed through θ 50 , varied tenfold. A left-skewed asymmetry in the germination rate with temperature was relatively common but the unimodal pattern typical of crop species failed for nearly half of the species due to insensitivity to temperature change at T o . For 32 fully characterized species, seed thermal parameters correlated strongly with the mean temperature of the wettest quarter of the seed collection sites. By projecting the mean temperature of the wettest quarter under two climate change scenarios, we predict under the least conservative scenario (+3.7°C) that 25% of cactus species will have reduced germination performance, whilst the remainder will have an efficiency gain, by the end of the 21st century. © 2017 John Wiley & Sons Ltd.

Amyloglucosidase enzymatic reactivity inside lipid vesicles

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Kim Jin-Woo

2007-10-01

Full Text Available Abstract Efficient functioning of enzymes inside liposomes would open new avenues for applications in biocatalysis and bioanalytical tools. In this study, the entrapment of amyloglucosidase (AMG (EC 3.2.1.3 from Aspergillus niger into dipalmitoylphosphatidylcholine (DPPC multilamellar vesicles (MLVs and large unilamellar vesicles (LUVs was investigated. Negative-stain, freeze-fracture, and cryo-transmission electron microscopy images verified vesicle formation in the presence of AMG. Vesicles with entrapped AMG were isolated from the solution by centrifugation, and vesicle lamellarity was identified using fluorescence laser confocal microscopy. The kinetics of starch hydrolysis by AMG was modeled for two different systems, free enzyme in aqueous solution and entrapped enzyme within vesicles in aqueous suspension. For the free enzyme system, intrinsic kinetics were described by a Michaelis-Menten kinetic model with product inhibition. The kinetic constants, Vmax and Km, were determined by initial velocity measurements, and Ki was obtained by fitting the model to experimental data of glucose concentration-time curves. Predicted concentration-time curves using these kinetic constants were in good agreement with experimental measurements. In the case of the vesicles, the time-dependence of product (glucose formation was experimentally determined and simulated by considering the kinetic behavior of the enzyme and the permeation of substrate into the vesicle. Experimental results demonstrated that entrapped enzymes were much more stable than free enyzme. The entrapped enzyme could be recycled with retention of 60% activity after 3 cycles. These methodologies can be useful in evaluating other liposomal catalysis operations.

Germination shifts of C3 and C4 species under simulated global warming scenario.

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Hongxiang Zhang

Full Text Available Research efforts around the world have been increasingly devoted to investigating changes in C3 and C4 species' abundance or distribution with global warming, as they provide important insight into carbon fluxes and linked biogeochemical cycles. However, changes in the early life stage (e.g. germination of C3 and C4 species in response to global warming, particularly with respect to asymmetric warming, have received less attention. We investigated germination percentage and rate of C3 and C4 species under asymmetric (+3/+6°C at day/night and symmetric warming (+5/+5°C at day/night, simulated by alternating temperatures. A thermal time model was used to calculate germination base temperature and thermal time constant. Two additional alternating temperature regimes were used to test temperature metrics effect. The germination percentage and rate increased continuously for C4 species, but increased and then decreased with temperature for C3 species under both symmetric and asymmetric warming. Compared to asymmetric warming, symmetric warming significantly overestimated the speed of germination percentage change with temperature for C4 species. Among the temperature metrics (minimum, maximum, diurnal temperature range and average temperature, maximum temperature was most correlated with germination of C4 species. Our results indicate that global warming may favour germination of C4 species, at least for the C4 species studied in this work. The divergent effects of asymmetric and symmetric warming on plant germination also deserve more attention in future studies.

Optogenetic acidification of synaptic vesicles and lysosomes.

Science.gov (United States)

Rost, Benjamin R; Schneider, Franziska; Grauel, M Katharina; Wozny, Christian; Bentz, Claudia; Blessing, Anja; Rosenmund, Tanja; Jentsch, Thomas J; Schmitz, Dietmar; Hegemann, Peter; Rosenmund, Christian

2015-12-01

Acidification is required for the function of many intracellular organelles, but methods to acutely manipulate their intraluminal pH have not been available. Here we present a targeting strategy to selectively express the light-driven proton pump Arch3 on synaptic vesicles. Our new tool, pHoenix, can functionally replace endogenous proton pumps, enabling optogenetic control of vesicular acidification and neurotransmitter accumulation. Under physiological conditions, glutamatergic vesicles are nearly full, as additional vesicle acidification with pHoenix only slightly increased the quantal size. By contrast, we found that incompletely filled vesicles exhibited a lower release probability than full vesicles, suggesting preferential exocytosis of vesicles with high transmitter content. Our subcellular targeting approach can be transferred to other organelles, as demonstrated for a pHoenix variant that allows light-activated acidification of lysosomes.

PsVPS1, a dynamin-related protein, is involved in cyst germination and soybean infection of Phytophthora sojae.

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Delong Li

Full Text Available Plant pathogens secrete effector proteins to suppress plant immunity. However, the mechanism by which oomycete pathogens deliver effector proteins during plant infection remains unknown. In this report, we characterized a Phytophthora sojae vps1 gene. This gene encodes a homolog of the Saccharomyces cerevisiae vacuolar protein sorting gene vps1 that mediates budding of clathrin-coated vesicles from the late Golgi, which are diverted from the general secretory pathway to the vacuole. PsVPS1-silenced mutants were generated using polyethylene glycol-mediated protoplast stable transformation and were viable but had reduced extracellular protein activity. The PsVPS1-silenced mutants showed impaired hyphal growth, and the shapes of the vacuoles were highly fragmented. Silencing of PsVPS1 affected cyst germination as well as the polarized growth of germinated cysts. Silenced mutants showed impaired invasion of susceptible soybean plants regardless of wounding. These results suggest that PsVPS1 is involved in vacuole morphology and cyst development. Moreover, it is essential for the virulence of P. sojae and extracellular protein secretion.

Phytotoxicity of nanoparticles: Inhibition of seed germination and root growth

Energy Technology Data Exchange (ETDEWEB)

Lin Daohui [Department of Environmental Science, Zhejiang University, Hangzhou 310028 (China); Department of Plant, Soil and Insect Sciences, University of Massachusetts, Stockbridge Hall, Amherst, MA 01003 (United States); Xing Baoshan [Department of Plant, Soil and Insect Sciences, University of Massachusetts, Stockbridge Hall, Amherst, MA 01003 (United States)], E-mail: bx@pssci.umass.edu

2007-11-15

Plants need to be included to develop a comprehensive toxicity profile for nanoparticles. Effects of five types of nanoparticles (multi-walled carbon nanotube, aluminum, alumina, zinc, and zinc oxide) on seed germination and root growth of six higher plant species (radish, rape, ryegrass, lettuce, corn, and cucumber) were investigated. Seed germination was not affected except for the inhibition of nanoscale zinc (nano-Zn) on ryegrass and zinc oxide (nano-ZnO) on corn at 2000 mg/L. Inhibition on root growth varied greatly among nanoparticles and plants. Suspensions of 2000 mg/L nano-Zn or nano-ZnO practically terminated root elongation of the tested plant species. Fifty percent inhibitory concentrations (IC{sub 50}) of nano-Zn and nano-ZnO were estimated to be near 50 mg/L for radish, and about 20 mg/L for rape and ryegrass. The inhibition occurred during the seed incubation process rather than seed soaking stage. These results are significant in terms of use and disposal of engineered nanoparticles. - Engineered nanoparticles can inhibit the seed germination and root growth.

Phytotoxicity of nanoparticles: Inhibition of seed germination and root growth

International Nuclear Information System (INIS)

Lin Daohui; Xing Baoshan

2007-01-01

Plants need to be included to develop a comprehensive toxicity profile for nanoparticles. Effects of five types of nanoparticles (multi-walled carbon nanotube, aluminum, alumina, zinc, and zinc oxide) on seed germination and root growth of six higher plant species (radish, rape, ryegrass, lettuce, corn, and cucumber) were investigated. Seed germination was not affected except for the inhibition of nanoscale zinc (nano-Zn) on ryegrass and zinc oxide (nano-ZnO) on corn at 2000 mg/L. Inhibition on root growth varied greatly among nanoparticles and plants. Suspensions of 2000 mg/L nano-Zn or nano-ZnO practically terminated root elongation of the tested plant species. Fifty percent inhibitory concentrations (IC 50 ) of nano-Zn and nano-ZnO were estimated to be near 50 mg/L for radish, and about 20 mg/L for rape and ryegrass. The inhibition occurred during the seed incubation process rather than seed soaking stage. These results are significant in terms of use and disposal of engineered nanoparticles. - Engineered nanoparticles can inhibit the seed germination and root growth

Trafficking of astrocytic vesicles in hippocampal slices

International Nuclear Information System (INIS)

Potokar, Maja; Kreft, Marko; Lee, So-Young; Takano, Hajime; Haydon, Philip G.; Zorec, Robert

2009-01-01

The increasingly appreciated role of astrocytes in neurophysiology dictates a thorough understanding of the mechanisms underlying the communication between astrocytes and neurons. In particular, the uptake and release of signaling substances into/from astrocytes is considered as crucial. The release of different gliotransmitters involves regulated exocytosis, consisting of the fusion between the vesicle and the plasma membranes. After fusion with the plasma membrane vesicles may be retrieved into the cytoplasm and may continue to recycle. To study the mobility implicated in the retrieval of secretory vesicles, these structures have been previously efficiently and specifically labeled in cultured astrocytes, by exposing live cells to primary and secondary antibodies. Since the vesicle labeling and the vesicle mobility properties may be an artifact of cell culture conditions, we here asked whether the retrieving exocytotic vesicles can be labeled in brain tissue slices and whether their mobility differs to that observed in cell cultures. We labeled astrocytic vesicles and recorded their mobility with two-photon microscopy in hippocampal slices from transgenic mice with fluorescently tagged astrocytes (GFP mice) and in wild-type mice with astrocytes labeled by Fluo4 fluorescence indicator. Glutamatergic vesicles and peptidergic granules were labeled by the anti-vesicular glutamate transporter 1 (vGlut1) and anti-atrial natriuretic peptide (ANP) antibodies, respectively. We report that the vesicle mobility parameters (velocity, maximal displacement and track length) recorded in astrocytes from tissue slices are similar to those reported previously in cultured astrocytes.

On the Computing Potential of Intracellular Vesicles.

Science.gov (United States)

Mayne, Richard; Adamatzky, Andrew

2015-01-01

Collision-based computing (CBC) is a form of unconventional computing in which travelling localisations represent data and conditional routing of signals determines the output state; collisions between localisations represent logical operations. We investigated patterns of Ca2+-containing vesicle distribution within a live organism, slime mould Physarum polycephalum, with confocal microscopy and observed them colliding regularly. Vesicles travel down cytoskeletal 'circuitry' and their collisions may result in reflection, fusion or annihilation. We demonstrate through experimental observations that naturally-occurring vesicle dynamics may be characterised as a computationally-universal set of Boolean logical operations and present a 'vesicle modification' of the archetypal CBC 'billiard ball model' of computation. We proceed to discuss the viability of intracellular vesicles as an unconventional computing substrate in which we delineate practical considerations for reliable vesicle 'programming' in both in vivo and in vitro vesicle computing architectures and present optimised designs for both single logical gates and combinatorial logic circuits based on cytoskeletal network conformations. The results presented here demonstrate the first characterisation of intracelluar phenomena as collision-based computing and hence the viability of biological substrates for computing.

Assessment of Paclobutrazol’s Time and Concentration of Foliar Application on Production and Germination of Potato (Solanum tuberosum L. Mini-tube

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B Saadatian

2018-02-01

and sand with 3:3:4 ratios, formed the substrate. Potato plantlets were fed with corrected Hoagland solution. Treatments were foliar application of paclobutrazol at two growth stages (stolen initiation and tuber initiation and six concentrations (control, 20, 40, 60, 80 and 100 mg l-1. Foliar application of mentioned concentrations implemented in the final hours of day. After 95 days from transplanting, number of mini-tuber in plant, mini-tuber length, mini-tuber diameter and mean of mini-tuber weight were measured. Then, mini-tubers saved to fridge with 8±2ºC and 10% relative humidity. Two months later, mini-tuber’s germination was measured. Finally, time of achievement to 5, 10, 50, 90 and 95 germination percentage was measured with Germin program. Beside that, rate of germination was calculated with equation 1: (1 R50 and D50: rate of germination (1/h and time of achievement to 50% germination, respectively. Analysis of variance and correlation between trials was done with SAS 9.1 Software. Means comparison measured with least significant difference test (LSD at 5% probability level. Results and Discussion The main effects and interactions of paclobutrazol foliar application and growth stages, on number of mini-tuber in plant, mini-tuber length, mini-tuber diameter, mean of mini-tuber weight and time of achievement to 5, 10, 50, 90 and 95 germination percentage trials were significant. But interaction between foliar application and growth stages was not significant at germination rate trial. The effect of foliar application on maintained trials in tuber initiation stage was lower than stolen initiation. Increase in paclobutrazol concentration increased mini-tuber dormancy and reduced germination rate. Paclobutrazol application in tuber initiation stage had more inhibition on mini-tuber germination. With increase in paclobotrazol concentration, time of achievement to 5, 10, 50, 90 and 95% germination were 11, 13, 17, 19 and 17% in comparison between foliar

A new vision of the origin and the oocyte development in the Ostariophysi applied to Gymnotus sylvius (Teleostei: Gymnotiformes

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Gisleine Fernanda França

Full Text Available Based on new knowledge coming from marine perciform species, the origin of oocytes and their development in the Ostariophysi, Gymnotus sylvius is described. In both Gymnotus sylvius and marine perciform fish, oogonia are found in the germinal epithelium that forms the surface of the ovarian lamellae. At the commencement of folliculogenesis, proliferation of oogonia and their entrance into meiosis gives rise to germ cell nests that extend into the stroma from the germinal epithelium. Both cell nests and the germinal epithelium are supported by the same basement membrane that separates them from the stroma. At the time of meiotic arrest, oocytes in a cell nest become separated one from the other as processes of prefollicle cells, these being derived from epithelial cells in the germinal epithelium, gradually encompass and individualize them while also synthesizing a basement membrane around themselves during folliculogenesis. The oocyte enters primary growth while still within the cell nest. At the completion of folliculogenesis, the oocyte and follicle cells, composing the follicle, are encompassed by a basement membrane. The follicle remains connected to the germinal epithelium as the both share a portion of common basement membrane. Cells originating from the stroma encompass the ovarian follicle, except where there is a shared basement membrane, to form the theca. The follicle, basement membrane and theca form the follicular complex. Oocyte development occurs inside the follicular complex. Development is divided into the stages primary and secondary growth, oocyte maturation and ovulation. Cortical alveoli appear in the ooplasm just prior to the beginning of secondary growth, the vitellogenic stage that begins with yolk deposition and proceeds until the oocyte is full-grown and the ooplasm is filled with yolk globules. Maturation is characterized by the germinal vesicle or nuclear migration, germinal vesicle breakdown or nuclear envelop

7 CFR 201.20 - Germination.

Science.gov (United States)

2010-01-01

... 7 Agriculture 3 2010-01-01 2010-01-01 false Germination. 201.20 Section 201.20 Agriculture... REGULATIONS Labeling Agricultural Seeds § 201.20 Germination. The label shall show the percentage of germination each kind, or kind and variety, or kind and type, or kind and hybrid of agricultural seed present...

Is Drought Tolerance in Maize (Zea Mays L.) Cultivars at the Juvenile Stage Maintained at the Reproductive Stage

International Nuclear Information System (INIS)

Bashir, N.; Mahmood, S.; Zafar, Z. U.; Athar, H. R.; Manzoor, H.; Rasul, S.

2016-01-01

Among several abiotic stresses, drought or water scarcity is a major constraint for crop production in many parts of the world. Six maize (Zea mays L.) cultivars; DTC, EV-77, EV-78, EV-79, Faisalabad mays, and 6621 were evaluated for drought tolerance at germination and seedling stages. Distilled deionized water was used as control but uniform drought stress was induced using 3, 6 and 9 percent of polyethylene glycol-6000 (PEG-6000) which correspond to osmotic potential of -0.0466, -0.0759 and -0.0876 MPa, respectively. PEG influenced the germination and growth of the cultivars in a concentration dependent manner but the highest level of PEG induced more drastic decline for the various attributes studied. The cultivars showed significantly variable responses to different levels of PEG. The result of study clearly suggested variability of characters for drought tolerance among maize cultivars. Based on the pattern of variability for various attributes, 3 groups of cultivars can be classified. The cultivar 6621 had a consistent degree of sensitivity to drought in terms the reduction of various attributes studied. The second group includes DTC which showed a steady tolerance ((germination percentage (GP), energy of emergence (EG), germination rate (GR), root fresh and dry weight (RFW and RDW), shoot fresh and dry weight (SFW and SDW), dry biomass tolerance index (DBTI) and seedling vigor index (SVI)) thus seemed to provide some manifestation of drought tolerance. For the third group of cultivars, pattern of drought tolerance was independent for germination, growth and physiological indices as an incoherent variability of attributes was observed. A similar pattern of variability for a number of characters to simulated water stress in the cultivar DTC served as reliable determinants for drought tolerance in maize. To assess maintenance of degree of drought tolerance selected maize cultivars, a field experiment was also conducted. Kernel yield, 1000- kernel weight (g

Thermodynamics and kinetics of vesicles formation processes.

Science.gov (United States)

Guida, Vincenzo

2010-12-15

Vesicles are hollow aggregates, composed of bilayers of amphiphilic molecules, dispersed into and filled with a liquid solvent. These aggregates can be formed either as equilibrium or as out of equilibrium meta-stable structures and they exhibit a rich variety of different morphologies. The surprising richness of structures, the vast range of industrial applications and the presence of vesicles in a number of biological systems have attracted the interest of numerous researchers and scientists. In this article, we review both the thermodynamics and the kinetics aspects of the phenomena of formation of vesicles. We start presenting the thermodynamics of bilayer membranes formation and deformation, with the aim of deriving the conditions for the existence of equilibrium vesicles. Specifically, we use the results from continuum thermodynamics to discuss the possibility of formation of stable equilibrium vesicles, from both mixed amphiphiles and single component systems. We also link the bilayer membrane properties to the molecular structure of the starting amphiphiles. In the second part of this article, we focus on the dynamics and kinetics of vesiculation. We review the process of vesicles formation both from planar lamellar phase under shear and from isotropic micelles. In order to clarify the physical mechanisms of vesicles formation, we continuously draw a parallel between emulsification and vesiculation processes. Specifically, we compare the experimental results, the driving forces and the relative scaling laws identified for the two processes. Describing the dynamics of vesicles formation, we also discuss why non equilibrium vesicles can be formed by kinetics control and why they are meta-stable. Understanding how to control the properties, the stability and the formation process of vesicles is of fundamental importance for a vast number of industrial applications. Copyright © 2009. Published by Elsevier B.V.

Portable Diagnostics and Rapid Germination

Energy Technology Data Exchange (ETDEWEB)

Dunn, Zachary Spencer [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2016-12-01

In the Bioenergy and Defense Department of Sandia National Laboratories, characterization of the BaDx (Bacillus anthracis diagnostic cartridge) was performed and rapid germination chemistry was investigated. BaDx was tested with complex sample matrixes inoculated with Bacillus anthracis, and the trials proved that BaDx will detect Bacillus anthracis in a variety of the medium, such as dirt, serum, blood, milk, and horse fluids. The dimensions of the device were altered to accommodate an E. coli or Listeria lateral flow immunoassay, and using a laser printer, BaDx devices were manufactured to identify E. coli and Listeria. Initial testing with E. coli versions of BaDx indicate that the device will be viable as a portable diagnostic cartridge. The device would be more effective with faster bacteria germination; hence studies were performed the use of rapid germination chemistry. Trials with calcium dipicolinic acid displayed increased cell germination, as shown by control studies using a microplate reader. Upon lyophilization the rapid germination chemistry failed to change growth patterns, indicating that the calcium dipicolinic acid was not solubilized under the conditions tested. Although incompatible with the portable diagnostic device, the experiments proved that the rapid germination chemistry was effective in increasing cell germination.

Cargo Release from Polymeric Vesicles under Shear

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Yingying Guo

2018-03-01

Full Text Available In this paper we study the release of cargo from polymeric nano-carriers under shear. Vesicles formed by two star block polymers— A 12 B 6 C 2 ( A B C and A 12 B 6 A 2 ( A B A —and one linear block copolymer— A 14 B 6 ( A B , are investigated using dissipative particle dynamics (DPD simulations. A - and C -blocks are solvophobic and B -block is solvophilic. The three polymers form vesicles of different structures. The vesicles are subjected to shear both in bulk and between solvophobic walls. In bulk shear, the mechanisms of cargo release are similar for all vesicles, with cargo travelling through vesicle membrane with no preferential release location. When sheared between walls, high cargo release rate is only observed with A B C vesicle after it touches the wall. For A B C vesicle, the critical condition for high cargo release rate is the formation of wall-polymersome interface after which the effect of shear rate in promoting cargo release is secondary. High release rate is achieved by the formation of solvophilic pathway allowing cargo to travel from the vesicle cavity to the vesicle exterior. The results in this paper show that well controlled target cargo release using polymersomes can be achieved with polymers of suitable design and can potentially be very useful for engineering applications. As an example, polymersomes can be used as carriers for surface active friction reducing additives which are only released at rubbing surfaces where the additives are needed most.

Smoke-induced seed germination in California chaparral

Science.gov (United States)

Keeley, J.E.; Fotheringham, C.J.

1998-01-01

The California chaparral community has a rich flora of species with different mechanisms for cuing germination to postfire conditions. Heat shock triggers germination of certain species but has no stimulatory effect on a great many other postfire species that are chemically stimulated by combustion products. Previous reports have shown that charred wood will induce germination, and here we report that smoke also induces germination in these same species. Smoke is highly effective, often inducing 100% germination in deeply dormant seed populations with 0% control germination. Smoke induces germination both directly and indirectly by aqueous or gaseous transfer from soil to seeds. Neither nitrate nor ammonium ions were effective in stimulating germination of smoke-stimulated species, nor were most of the quantitatively important gases generated by biomass smoke. Nitrogen dioxide, however, was very effective at inducing germination in Caulanthus heterophyllus (Brassicaceae), Emmenanthe penduliflora (Hydrophyllaceae), Phacelia grandiflora (Hydrophyllaceae), and Silene multinervia (Caryophyllaceae). Three species, Dendromecon rigida (Papaveraceae), Dicentra chrysantha, and Trichostema lanatum (Lamiaceae), failed to germinate unless smoke treatment was coupled with prior treatment of 1 yr soil storage. Smoke-stimulated germination was found in 25 chaparral species, representing 11 families, none of which were families known for heat-shock-stimulated germination. Seeds of smoke-stimulated species have many analogous characteristics that separate them from most heat-shock-stimulated seeds, including: (1) outer seed coats that are highly textured, (2) a poorly developed outer cuticle, (3) absence of a dense palisade tissue in the seed coat, and (4) a subdermal membrane that is semipermeable, allowing water passage but blocking entry of large (molecular mass > 500) solutes. Tentative evidence suggests that permeability characteristics of this subdermal layer are altered by

Germination of Afrocarpus usambarensis and Podocarpus ...

African Journals Online (AJOL)

ACSS

farm planting. Seed germination of .... 235. Germination of Afrocarpus usambarensis and Podocarpus milanjianus seeds. Table 2. Mean seed germination of A. usambarensis and P. milanjianus. Species .... National Forestry Authority and District.

Squamous cell carcinoma of the seminal vesicle. Review of the related literature and case report

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V. B. Matveev

2015-01-01

Full Text Available Seminal vesicle tumors are very rare malignancies which are not diagnosed in daily clinical oncology practice. Primary malignant tumors in seminal vesicle are difficult to define due to the lack of specific symptoms in the early stages of the disease. Another obstacle of proper diagnosis is the frequent invasion of tumors of the surrounding organs, especially the prostate, rectum and bladder which is difficult to differentiate. Very often seminal vesicle tumors are difficult to detect. Digital rectal examination as well as transrectal ultrasound scan (US could reveal a bulky mass in the retrovesical space. Computed tomography and magnetic resonance imaging (MRI are the main diagnostic methods which could help to reveal pathologic masses in the region of seminal vesicles. Levels of prostate-specific antigen, carcinoembryonic antigen and tumor markers specific for colorectal cancer are negative in seminal vesicle tumors.The world experience of treating seminal vesicle tumors is very limited. There is paucity of data regarding appropriate choice of surgical approach and further treatment strategy and most of the time the treatment is individualized and based on very scarce information. At the same time surgical approach may vary significantly from vesiculectomy to pelvic exenteration. Possibility of using any regimens of adjuvant radiation therapy, chemotherapy or hormone therapy is highly debatable. However, aggressive surgical approach with radical tumor removal followed by extended lymphodissection shows the most favorable results in survival of patients suffering from seminal vesicle cancer.Squamous cell carcinoma of the seminal vesicles is presumed to be an extremely rare disease as there are only 3 reports of it in the world literature. We report a case of patient B. suffering from squamous cell carcinoma of the right seminal vesicle whom we conducted an aggressive surgical approach – prostatovesiculectomy followed by resection of the

Comparative seed germination traits in alpine and subalpine grasslands: higher elevations are associated with warmer germination temperatures.

Science.gov (United States)

Fernández-Pascual, E; Jiménez-Alfaro, B; Bueno, Á

2017-01-01

Seed germination traits in alpine grasslands are poorly understood, despite the sensitivity of these communities to climate change. We hypothesise that germination traits predict species occurrence along the alpine-subalpine elevation gradient. Phylogenetic comparative analyses were performed using fresh seeds of 22 species from alpine and subalpine grasslands (1600-2400 m) of the Cantabrian Mountains, Spain (43° N, 5° W). Laboratory experiments were conducted to characterise germinability, optimum germination temperature and effect of cold and warm stratification on dormancy breaking. Variability in these traits was reduced by phylogenetic principal component analysis (phyl.PCA). Phylogenetic generalised least squares regression (PGLS) was used to fit a model in which species average elevation was predicted from their position on the PCA axes. Most subalpine species germinated in snow-like conditions, whereas most alpine species needed accumulation of warm temperatures. Phylogenetic signal was low. PCA1 ordered species according to overall germinability, whilst PCA2 ordered them according to preference for warm or cold germination. PCA2 significantly predicted species occurrence in the alpine-subalpine gradient, as higher elevation species tended to have warmer germination preferences. Our results show that germination traits in high-mountain grasslands are closely linked to the alpine-subalpine gradient. Alpine species, especially those from stripped and wind-edge communities, prefer warmer germination niches, suggesting that summer emergence prevents frost damage during seedling establishment. In contrast, alpine snowfield and subalpine grassland plants have cold germination niches, indicating that winter emergence may occur under snow to avoid drought stress. © 2016 German Botanical Society and The Royal Botanical Society of the Netherlands.

Frugivory and the effects of ingestion by bats on the seed germination of three pioneering plants

Science.gov (United States)

de Carvalho-Ricardo, Maria C.; Uieda, Wilson; Fonseca, Renata Cristina B.; Rossi, Marcelo N.

2014-02-01

The dispersion and seedling establishment of pioneering plants can be favoured by the presence of frugivorous bats because the bats usually improve seed germination after ingestion. Although seed germinability is known to vary greatly after ingestion by different bats, the relative contribution of each bat species to seed germination within plant communities is poorly understood. In this study, we first determined the fauna of frugivorous bats in a semideciduous seasonal forest remnant in southern Brazil and subsequently identified the plant species of the seeds passed through their guts. Second, the germination performance (i.e., germination percentage and speed) of the seeds of three pioneering plants (Piper aduncum, Piper hispidinervum and Solanum granuloso-leprosum) ingested by the most abundant bats was compared with that of the non-ingested seeds (seeds collected from fruits). Additionally, the effects on seed germination of different bat species were compared. During one year, five species of frugivorous bats were caught, and the seeds of eleven identifiable plant species (not counting those of undetermined species) were found in their faeces. We found that the germination performance of the seeds of Piper species was significantly enhanced after ingestion by bats, whereas S. granuloso-leprosum seeds had neutral or reduced germinability when seeds in faeces were compared with pulp-removed seeds. Our results revealed that the bat species that were captured exerted different effects upon seed germination; such a disparity is expected to result in different rates of early establishment of these pioneer plants in tropical forests, most likely affecting forest composition and structure, particularly during the initial stages of succession.

Salt Stress Represses Soybean Seed Germination by Negatively Regulating GA Biosynthesis While Positively Mediating ABA Biosynthesis.

Science.gov (United States)

Shu, Kai; Qi, Ying; Chen, Feng; Meng, Yongjie; Luo, Xiaofeng; Shuai, Haiwei; Zhou, Wenguan; Ding, Jun; Du, Junbo; Liu, Jiang; Yang, Feng; Wang, Qiang; Liu, Weiguo; Yong, Taiwen; Wang, Xiaochun; Feng, Yuqi; Yang, Wenyu

2017-01-01

Soybean is an important and staple oilseed crop worldwide. Salinity stress has adverse effects on soybean development periods, especially on seed germination and post-germinative growth. Improving seed germination and emergence will have positive effects under salt stress conditions on agricultural production. Here we report that NaCl delays soybean seed germination by negatively regulating gibberellin (GA) while positively mediating abscisic acid (ABA) biogenesis, which leads to a decrease in the GA/ABA ratio. This study suggests that fluridone (FLUN), an ABA biogenesis inhibitor, might be a potential plant growth regulator that can promote soybean seed germination under saline stress. Different soybean cultivars, which possessed distinct genetic backgrounds, showed a similar repressed phenotype during seed germination under exogenous NaCl application. Biochemical analysis revealed that NaCl treatment led to high MDA (malondialdehyde) level during germination and the post-germinative growth stages. Furthermore, catalase, superoxide dismutase, and peroxidase activities also changed after NaCl treatment. Subsequent quantitative Real-Time Polymerase Chain Reaction analysis showed that the transcription levels of ABA and GA biogenesis and signaling genes were altered after NaCl treatment. In line with this, phytohormone measurement also revealed that NaCl considerably down-regulated active GA 1 , GA 3 , and GA 4 levels, whereas the ABA content was up-regulated; and therefore ratios, such as GA 1 /ABA, GA 3 /ABA, and GA 4 /ABA, are decreased. Consistent with the hormonal quantification, FLUN partially rescued the delayed-germination phenotype caused by NaCl-treatment. Altogether, these results demonstrate that NaCl stress inhibits soybean seed germination by decreasing the GA/ABA ratio, and that FLUN might be a potential plant growth regulator that could promote soybean seed germination under salinity stress.

Salt Stress Represses Soybean Seed Germination by Negatively Regulating GA Biosynthesis While Positively Mediating ABA Biosynthesis

Directory of Open Access Journals (Sweden)

Kai Shu

2017-08-01

Full Text Available Soybean is an important and staple oilseed crop worldwide. Salinity stress has adverse effects on soybean development periods, especially on seed germination and post-germinative growth. Improving seed germination and emergence will have positive effects under salt stress conditions on agricultural production. Here we report that NaCl delays soybean seed germination by negatively regulating gibberellin (GA while positively mediating abscisic acid (ABA biogenesis, which leads to a decrease in the GA/ABA ratio. This study suggests that fluridone (FLUN, an ABA biogenesis inhibitor, might be a potential plant growth regulator that can promote soybean seed germination under saline stress. Different soybean cultivars, which possessed distinct genetic backgrounds, showed a similar repressed phenotype during seed germination under exogenous NaCl application. Biochemical analysis revealed that NaCl treatment led to high MDA (malondialdehyde level during germination and the post-germinative growth stages. Furthermore, catalase, superoxide dismutase, and peroxidase activities also changed after NaCl treatment. Subsequent quantitative Real-Time Polymerase Chain Reaction analysis showed that the transcription levels of ABA and GA biogenesis and signaling genes were altered after NaCl treatment. In line with this, phytohormone measurement also revealed that NaCl considerably down-regulated active GA1, GA3, and GA4 levels, whereas the ABA content was up-regulated; and therefore ratios, such as GA1/ABA, GA3/ABA, and GA4/ABA, are decreased. Consistent with the hormonal quantification, FLUN partially rescued the delayed-germination phenotype caused by NaCl-treatment. Altogether, these results demonstrate that NaCl stress inhibits soybean seed germination by decreasing the GA/ABA ratio, and that FLUN might be a potential plant growth regulator that could promote soybean seed germination under salinity stress.

Effect of industrial pollution on seed germination

Energy Technology Data Exchange (ETDEWEB)

Iqbal, M.Z.; Qadir, S.A.

1973-01-01

The germination behavior of seeds in polluted waters and polluted soil extracts was found to be identical, only a few species behaved differently. Prosopis juliflora, Haloxylon recurvum, Acacia senegal showed best germination in the two conditions but Prosopis juliflora was the most resistant to pollution. In Suaeda fruticosa no germination took place in the control treatment whereas highest germination (70%) was seen in treatment with polluted soil extract of EPLA. Blepharis sindica showed a stimulating effect of polluted water on germination, whereas low germination was observed when their seeds were treated with the soil extract of the same site. 40% germination of Suaeda monoica was seen in polluted water of Carbon and Ribbon Mfg. Co., whereas 30% germination was found in a control treatment. Low percentage of germination was found when the seeds of Cassia holosericea were treated with polluted waters of different industries as compared to soil extract treatments of the same industries. Datura alba showed 50, 30 and 10% seed germination in polluted soil extract of Carbon and Ribbon Mfg. Co., in control and in polluted water of Darbar Soap Works, respectively. 5 references, 1 table.

Changes in ultraviolet resistance and photoproduct formation as early events in spore germination of Bacillus cereus T

International Nuclear Information System (INIS)

Irie, R.

1978-01-01

In order to determine the timing of the change in the state of DNA in bacterial spores during the course of germination, L-alanine-induced germination of Bacillus cereus spores was interrupted by 0.3M CaCl 2 as an inhibitor, and the resulting semi-refractive spores (spores at the end of the first phase of germination) were examined for UV-resistance and photoproduct formation. Upon UV-irradiation, these spores, still having a semi-refractile core as observed under a phase-contrast microscope, gave rise to mainly the cyclobutane-type thymine dimer. It was concluded that change in the stats of the spore DNA occurs early in the process of germination, i.e. before the refractility of the core is lost. It was also found that CaCl 2 markedly prolonged the duration of the transient UV-resistant stage. (author)

[The research of Valeriana amurensis seed germination characteristics].

Science.gov (United States)

Liu, Juan; Yang, Chun-Rong; Jiang, Bo; Fang, Min; Du, Juan

2011-10-01

To study the effect of different treatments on the Valeriana amurensis seed germination rate. Used different chemical reagents and seed soakings on the routine germination test and the orthogonal test of the Valeriana amurensis seed, calculated the germination rate under different germination condition. Valeriana amurensis treated with different chemical reagends had different germination rate. The suitable immersion time could enhance Valeriana amurensis seed germination rate. Different treatment time, different disposal temperature, different germination temperature would have an impact on the Valeriana amurensis seed germination rate. In order to raise the Valeriana amurensis seed germination rate, use appropriate treatment on the seed before plant seeds; The seed growing must under suitable time and temperature.

Oxygen requirement of germinating flax seeds

Science.gov (United States)

Kuznetsov, Oleg A.; Hasenstein, K. H.

2003-05-01

Plant experiments in earth orbit are typically prepared on the ground and germinated in orbit to study gravity effects on the developing seedlings. Germination requires the breakdown of storage compounds, and this metabolism depends upon respiration, making oxygen one of the limiting factors in seed germination. In microgravity lack of run-off of excess water requires careful testing of water dispensation and oxygen availability. In preparation for a shuttle experiment (MICRO on STS-107) we studied germination and growth of flax ( Linum usitatissimum L.) seedlings in the developed hardware (Magnetic Field Chamber, MFC). We tested between four to 32 seeds per chamber (air volume = 14 mL) and after 36 h measured the root length. At 90 μl O 2 per seed (32 seeds/chamber), the germination decreased from 94 to 69%, and the root length was reduced by 20%, compared to 8 seeds per chamber. Based on the percent germination and root length obtained in controlled gas mixtures between 3.6 and 21.6% O 2 we determined the lower limit of reliable germination to be 10 vol. % O 2 at atmospheric pressure. Although the oxygen available in the MFC's can support the intended number of seeds, the data show that seed storage and microgravity-related limitations may reduce germination.

Seed germination behavior of swallow wort

Directory of Open Access Journals (Sweden)

amir hosein pahlavani

2009-06-01

Full Text Available The exotic plant, Swallow- wort, a twining perennial of the Milkweed family, has become increasingly invasive in some place of Iran, especially orchards. Increased knowledge of wort germination biology would facilitate development of an optimum control program. Germination of Swallow wort seeds as affected by environmental factors was studied under controlled-environment growth chamber conditions. The following studies were conducted in plant Pests & Diseases Research Institute during the years 2003-4: 1- Effect of constant temperature on germination that including 10, 15, 18, 20, 25, 30, 35 and 40˚C; 2- Effect of light on constant germination; 3- Effect of temperature fluctuations on seed germination: 15/7, 20/12, 25/17 and 30/22˚C. All experiments were conducted with 8 replications. Swallow wort seeds showed no dormancy when detachment from mother plant. Seed germination was strongly influenced by temperature. Light did not play a crucial role on seed germination of this weed. Therefore Swallow wort seeds were not photoblastic and temperature fluctuations did not increase seed germination of Swallow wort. The above characteristics are very important in making swallowwort an invasive weed. Having precise information of these traits enables us to a better management and control of this troublesome weed.

In vitro culture techniques as a tool of sugarcane bud germination ...

African Journals Online (AJOL)

STORAGESEVER

2008-10-20

Oct 20, 2008 ... and shoot growth under salt stress with different NaCl concentrations (0, 17, 34, 68 and 102 mM) using cultivar NCo310. ... techniques could be used to evaluate salt stress effects in sugarcane at the germination stage. Key words: in vitro culture, .... l'Enseignement Supérieur, de la Formation des Cadres et.

Factors influencing seed germination in Cerrado grasses

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Rosana Marta Kolb

2016-03-01

Full Text Available Few studies address the ecology of herbs of Cerrado grasslands, which are ecosystems where the long dry season, high temperatures, insolation, fire and invasive grasses greatly influencing germination and the establishment of plants. We assessed germination of 13 species of Poaceae from Cerrado grasslands under nursery conditions or in germination chambers, the latter with i recently collected seeds and seeds after six months storage, ii under constant and alternating temperatures, and iii in the presence and absence of light. Germinability, mean germination time (MGT and required light were quantified to elucidate factors involved in successful germination. Germinability was low for most grasses, probably because of low seed viability. For most species, germinability and MGT were not altered by seed storage. Germination percentages were higher at alternating temperatures and in the presence of light, factors that are more similar to natural environmental situations compared with constant temperature or the absence of light. Our findings indicate that alternating temperatures and light incidence are key factors for germination of species of Poaceae. The maintenance of these environmental factors, which are crucial for the conservation of Cerrado grasslands, depends on appropriate management interventions, such as fire management and the control of biological invasion.

Phytotoxicity of glyphosate in the germination of and its effect on germinated seedlings

Directory of Open Access Journals (Sweden)

Subinoy Mondal

2017-08-01

Full Text Available The present study evaluated the effects of glyphosate on Pisum sativum germination as well as its effect on the physiology and biochemistry of germinated seedlings. Different physico-chemical biomarkers, viz., chlorophyll, root and shoot length, total protein and soluble sugar, along with sodium and potassium concentration, were investigated in germinated seedlings at different glyphosate concentrations. This study reports the influence of different concentrations of glyphosate on pea seeds and seedlings. Physicochemical biomarkers were significantly changed by glyphosate exposure after 15 days. The germination of seedlings under control conditions (0 mg/L was 100% after 3 days of treatment but at 3 and 4 mg/L glyphosate, germination was reduced to 55 and 40%, respectively. Physiological parameters like root and shoot length decreased monotonically with increasing glyphosate concentration, at 14 days of observation. Average root and shoot length (n=30 in three replicates were reduced to 14.7 and 17.6%, respectively, at 4 mg/L glyphosate. Leaf chlorophyll content also decreased, with a similar trend to root and shoot length, but the protein content initially decreased and then increased with an increase in glyphosate concentration to 3 mg/L. The study suggests that glyphosate reduces the soluble sugar content significantly, by 21.6% (v/v. But internal sodium and potassium tissue concentrations were significantly altered by glyphosate exposure with increasing concentrations of glyphosate. Biochemical and physiological analysis also supports the inhibitory effect of glyphosate on seed germination and biochemical effects on seedlings.

Describing phytotoxic effects on cumulative germination

OpenAIRE

Dias, L.S.

2001-01-01

Phytotoxic studies strongly depend on evaluation of germination responses, which implies the need for adequate procedures to account for distinct aspects of the germinative process. For this, indices, comparisons among treatments at various times, and model fitting have been proposed. The objective of this work is to compare the three approaches and select the one providing greater insight and precision. Speed of germination, speed of accumulated germination, the coefficient of the rate of ge...

Seeds and plantlets of Myrciaria dubia “camu-camu”: biometry, germination, and initial growth

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Anderson E. Medina Bardales

2014-06-01

Full Text Available The objectives were to determine seed biometrics, recording cellular respiration in the imbibition process, evaluate the effect of inducing chemicals in germination and early growth analysis. Cellular respiration during imbibition was measured by reduction of methylene blue and Janus Green B. The inductor effect of five chemical compounds in germination was evaluated. Initial growth was recorded by stereoscopic. Results showed that the seeds have an average weight of 520 ± 172 mg, length of 13.50 ± 1.76 mm, width of 10.61 ± 1.14 mm, and thickness of 4.68 ± 0 62 mm. These variables showed significant correlations (r of 0.494 to 0.897 and p 90% and 65% respectively. Seedling initial growth consisted of six stages and occurred over a period of 22 days after radicle emergence. In conclusion, M. dubia seeds show wide variation in their biometrics (weight, length, width and thickness, but show significant correlations with each other. Likewise, seeds are metabolically active in imbibition process, and germination is induced by sodium nitrite and potassium cyanide. Furthermore, seedling initial growth to occur over a period of 22 days after emergence of the radicle and consists of six distinct stages.

Synaptic Vesicle Endocytosis in Different Model Systems

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Quan Gan

2018-06-01

Full Text Available Neurotransmission in complex animals depends on a choir of functionally distinct synapses releasing neurotransmitters in a highly coordinated manner. During synaptic signaling, vesicles fuse with the plasma membrane to release their contents. The rate of vesicle fusion is high and can exceed the rate at which synaptic vesicles can be re-supplied by distant sources. Thus, local compensatory endocytosis is needed to replenish the synaptic vesicle pools. Over the last four decades, various experimental methods and model systems have been used to study the cellular and molecular mechanisms underlying synaptic vesicle cycle. Clathrin-mediated endocytosis is thought to be the predominant mechanism for synaptic vesicle recycling. However, recent studies suggest significant contribution from other modes of endocytosis, including fast compensatory endocytosis, activity-dependent bulk endocytosis, ultrafast endocytosis, as well as kiss-and-run. Currently, it is not clear whether a universal model of vesicle recycling exist for all types of synapses. It is possible that each synapse type employs a particular mode of endocytosis. Alternatively, multiple modes of endocytosis operate at the same synapse, and the synapse toggles between different modes depending on its activity level. Here we compile review and research articles based on well-characterized model systems: frog neuromuscular junctions, C. elegans neuromuscular junctions, Drosophila neuromuscular junctions, lamprey reticulospinal giant axons, goldfish retinal ribbon synapses, the calyx of Held, and rodent hippocampal synapses. We will compare these systems in terms of their known modes and kinetics of synaptic vesicle endocytosis, as well as the underlying molecular machineries. We will also provide the future development of this field.

Global Transcriptomic Analysis Reveals the Mechanism of Phelipanche aegyptiaca Seed Germination.

Science.gov (United States)

Yao, Zhaoqun; Tian, Fang; Cao, Xiaolei; Xu, Ying; Chen, Meixiu; Xiang, Benchun; Zhao, Sifeng

2016-07-15

Phelipanche aegyptiaca is one of the most destructive root parasitic plants of Orobanchaceae. This plant has significant impacts on crop yields worldwide. Conditioned and host root stimulants, in particular, strigolactones, are needed for unique seed germination. However, no extensive study on this phenomenon has been conducted because of insufficient genomic information. Deep RNA sequencing, including de novo assembly and functional annotation was performed on P. aegyptiaca germinating seeds. The assembled transcriptome was used to analyze transcriptional dynamics during seed germination. Key gene categories involved were identified. A total of 274,964 transcripts were determined, and 53,921 unigenes were annotated according to the NR, GO, COG, KOG, and KEGG databases. Overall, 5324 differentially expressed genes among dormant, conditioned, and GR24-treated seeds were identified. GO and KEGG enrichment analyses demonstrated numerous DEGs related to DNA, RNA, and protein repair and biosynthesis, as well as carbohydrate and energy metabolism. Moreover, ABA and ethylene were found to play important roles in this process. GR24 application resulted in dramatic changes in ABA and ethylene-associated genes. Fluridone, a carotenoid biosynthesis inhibitor, alone could induce P. aegyptiaca seed germination. In addition, conditioning was probably not the indispensable stage for P. aegyptiaca, because the transcript level variation of MAX2 and KAI2 genes (relate to strigolactone signaling) was not up-regulated by conditioning treatment.

Global Transcriptomic Analysis Reveals the Mechanism of Phelipanche aegyptiaca Seed Germination

Directory of Open Access Journals (Sweden)

Zhaoqun Yao

2016-07-01

Full Text Available Phelipanche aegyptiaca is one of the most destructive root parasitic plants of Orobanchaceae. This plant has significant impacts on crop yields worldwide. Conditioned and host root stimulants, in particular, strigolactones, are needed for unique seed germination. However, no extensive study on this phenomenon has been conducted because of insufficient genomic information. Deep RNA sequencing, including de novo assembly and functional annotation was performed on P. aegyptiaca germinating seeds. The assembled transcriptome was used to analyze transcriptional dynamics during seed germination. Key gene categories involved were identified. A total of 274,964 transcripts were determined, and 53,921 unigenes were annotated according to the NR, GO, COG, KOG, and KEGG databases. Overall, 5324 differentially expressed genes among dormant, conditioned, and GR24-treated seeds were identified. GO and KEGG enrichment analyses demonstrated numerous DEGs related to DNA, RNA, and protein repair and biosynthesis, as well as carbohydrate and energy metabolism. Moreover, ABA and ethylene were found to play important roles in this process. GR24 application resulted in dramatic changes in ABA and ethylene-associated genes. Fluridone, a carotenoid biosynthesis inhibitor, alone could induce P. aegyptiaca seed germination. In addition, conditioning was probably not the indispensable stage for P. aegyptiaca, because the transcript level variation of MAX2 and KAI2 genes (relate to strigolactone signaling was not up-regulated by conditioning treatment.

Life cycle inventory for the production of germinated oil palm seeds at a selected seed production unit in Malaysia

Science.gov (United States)

Khairuddin, Nik Sasha Khatrina; Ismail, B. S.; Muhamad, Halimah; May, Choo Yuen

2013-11-01

The increasing global demand for edible oil has encouraged Malaysia to increase the areas under oil palm cultivation. The total demand for germinated oil palm seeds in the years 2009, 2010, 2011 and 2012 were 86.4, 76.5, 72.6 and 75.2 million, respectively. Production of germinated oil palm seeds is the first link in the palm oil supply chain. Therefore, good management practices at seed production stage is required to ensure only high quality germinated oil palm seeds are produced before sale to customers. Life cycle assessment (LCA) has been used as a tool to assess environmental impact of the processes throughout a product's lifespan and this approach is an important tool for assessing green house gas (GHG) emission. For this study, a gate-to-gate life cycle inventory (LCI) of a single germinated oil palm seed production unit was carried out. The functional unit used for this LCI was one germinated oil palm seed. To determine the environmental impact for the production of germinated oil palm seeds, information on the inputs were obtained. The inputs for the production of germinated oil palm seeds involved materials such as polyethylene bags, electricity, water, chemicals and fungicides. For this study, the system boundary involved seed germination process and management of germinated oil palm seeds. It was found that the amount of input such as materials and energy used in the production of germinated oil palm seeds was very minimal.

The Effect of Salinity on Seed Germination and Seedling Growth of Four Medicinal Plant Species

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H Javadi

2014-07-01

Full Text Available To study the effect of salinity stress on seed germination and seedling growth of four medicinal plants, Nigella sativa L., Cannabis sativa L., Trigonella foenum graecum and Cynara scolymus L. an experiment was conducted in the botany laboratory of Islamic Azad University, Birjand branch. A completely randomized design (CRD with 3 replications was used as separately for each species. Treatments were consisted of six salinity (NaCl concentrations (0, 4, 8, 12, 16 and 20 dS m-1. The measured traits were root, shoot and seedling length, dry and fresh weight of seedling, germination rate and percent, seed vigor index, seedling water content and root/ shoot ratio. Salinity stress reduced significantly shoot, root and seedling length of the species. Increasing of salinity stress declined dry and fresh weight of Trigonella foenum and Nigella sativa L. and dry weight of Cannabis sativa L.. Seedling water content and root/ shoot ratio of Nigella sativa L. increased in salinity treatments. Increasing of salinity stress declined germination rate and percent in Nigella sativa L., but in other species (Cannabis sativa L., Trigonella foenum graecum and Cynara scolymus only germination rate decreased. Trigonella foenum graecum germinated completely (%100 in all salinity treatments. Increasing of salinity until 16 dS m-1 reduced seed germination of Nigella sativa. Seed germination of Nigella sativa did not occurred in the highest salinity stress (20 dS m-1. Totally the results showed that in the germination stage, Trigonella foenum graecum and Cannabis sativa were relatively tolerate to salinity stress but Nigella sativa L. was the most sensitive one

Sinapic acid or its derivatives interfere with abscisic acid homeostasis during Arabidopsis thaliana seed germination.

Science.gov (United States)

Bi, Baodi; Tang, Jingliang; Han, Shuang; Guo, Jinggong; Miao, Yuchen

2017-06-06

Sinapic acid and its esters have broad functions in different stages of seed germination and plant development and are thought to play a role in protecting against ultraviolet irradiation. To better understand the interactions between sinapic acid esters and seed germination processes in response to various stresses, we analyzed the role of the plant hormone abscisic acid (ABA) in the regulation of sinapic acid esters involved in seed germination and early seedling growth. We found that exogenous sinapic acid promotes seed germination in a dose-dependent manner in Arabidopsis thaliana. High-performance liquid chromatography mass spectrometry analysis showed that exogenous sinapic acid increased the sinapoylcholine content of imbibed seeds. Furthermore, sinapic acid affected ABA catabolism, resulting in reduced ABA levels and increased levels of the ABA-glucose ester. Using mutants deficient in the synthesis of sinapate esters, we showed that the germination of mutant sinapoylglucose accumulator 2 (sng2) and bright trichomes 1 (brt1) seeds was more sensitive to ABA than the wild-type. Moreover, Arabidopsis mutants deficient in either abscisic acid deficient 2 (ABA2) or abscisic acid insensitive 3 (ABI3) displayed increased expression of the sinapoylglucose:choline sinapoyltransferase (SCT) and sinapoylcholine esterase (SCE) genes with sinapic acid treatment. This treatment also affected the accumulation of sinapoylcholine and free choline during seed germination. We demonstrated that sinapoylcholine, which constitutes the major phenolic component in seeds among various minor sinapate esters, affected ABA homeostasis during seed germination and early seedling growth in Arabidopsis. Our findings provide insights into the role of sinapic acid and its esters in regulating ABA-mediated inhibition of Arabidopsis seed germination in response to drought stress.

Oxygen requirement of germinating flax seeds

Science.gov (United States)

Kuznetsov, Oleg A.; Hasenstein, K. H.; Hasentein, K. H. (Principal Investigator)

2003-01-01

Plant experiments in earth orbit are typically prepared on the ground and germinated in orbit to study gravity effects on the developing seedlings. Germination requires the breakdown of storage compounds, and this metabolism depends upon respiration, making oxygen one of the limiting factors in seed germination. In microgravity lack of run-off of excess water requires careful testing of water dispensation and oxygen availability. In preparation for a shuttle experiment (MICRO on STS-107) we studied germination and growth of flax (Linum usitatissimum L.) seedlings in the developed hardware (Magnetic Field Chamber, MFC). We tested between four to 32 seeds per chamber (air volume=14 mL) and after 36 h measured the root length. At 90 microliters O2 per seed (32 seeds/chamber), the germination decreased from 94 to 69%, and the root length was reduced by 20%, compared to 8 seeds per chamber. Based on the percent germination and root length obtained in controlled gas mixtures between 3.6 and 21.6% O2 we determined the lower limit of reliable germination to be 10 vol. % O2 at atmospheric pressure. Although the oxygen available in the MFC's can support the intended number of seeds, the data show that seed storage and microgravity-related limitations may reduce germination. c2003 Published by Elsevier Ltd on behalf of COSPAR.

Germination of Avena fatua under different gaseous environments

Energy Technology Data Exchange (ETDEWEB)

Hart, J.W.; Berrie, A.M.M.

1966-01-01

The atmosphere in which seeds germinate can profoundly affect the level of germination and dormancy. Seeds were germinated in atmospheres containing various concentrations of carbon dioxide and oxygen. At the same time the effect of light on these systems was examined. The germination of partially dormant populations of wild oat seed is inhibited by white light. This response to light is most apparent when the caryopsis is enclosed in the pales. Investigations into the effect of the ambient atmosphere on germination have indicated that, while oxygen is a necessary factor in the germination of this species, carbon dioxide also has an effect. A lack of carbon dioxide increases the degree of light inhibition of germination; 3% carbon dioxide (by volume) allows germination in light; 20% carbon dioxide inhibits germination in light and darkness at all tested oxygen concentrations.

DOES JASMONIC ACID PREVENT THE GERMINATION

OpenAIRE

ÇAVUŞOĞLU, Kürşat

2009-01-01

Abstract: Effect of jasmonic acid on seed germination and seedling growth of barley (Hordeum vulgare L. cv. Bülbül 89) was investigated in the present study. Jasmonic acid concentrations less than 1500 µM have not inhibited the seed germination, while 1500 and 2000 µM jasmonic acid levels caused atypical germination. The germination was completely inhibited at 3000 µM level of jasmonic acid. However, the seedling growth clearly slowed down with increasing concentrations of jasmonic acid. Furt...

Additive effects on the energy barrier for synaptic vesicle fusion cause supralinear effects on the vesicle fusion rate

DEFF Research Database (Denmark)

Schotten, Sebastiaan; Meijer, Marieke; Walter, Alexander Matthias

2015-01-01

supralinear effects on the fusion rate. To test this prediction experimentally, we developed a method to assess the number of releasable vesicles, rate constants for vesicle priming, unpriming, and fusion, and the activation energy for fusion by fitting a vesicle state model to synaptic responses induced......-linear effects of genetic/pharmacological perturbations on synaptic transmission and a novel interpretation of the cooperative nature of Ca2+-dependent release....

Germination, survival and growth of three vascular plants on biological soil crusts from a Mexican tropical desert.

Science.gov (United States)

Godínez-Alvarez, H; Morín, C; Rivera-Aguilar, V

2012-01-01

Information about the effects of biological soil crusts (BSC) on germination, seedling survival and growth of vascular plants is controversial because they can have positive, neutral or negative effects. This controversy may be because most studies conducted until now have just analysed one or two recruitment stages independently. To understand the BSC effects on vascular plants, it is necessary to consider each stage of the recruitment process and synthesise all this information. The goal of this study was twofold. First, we analyse germination, seedling survival and growth of three vascular plants (Agave marmorata, Prosopis laevigata and Neobuxbaumia tetetzo) on BSC (cyanobacteria and mixed crust) from a tropical desert region of south-central México. Second, we synthesise the information to determine the total effect of BSC on plant species performance. We conducted experiments under controlled conditions to evaluate the proportion of germinated seeds, proportion of surviving seedlings and seedling dry weight in BSC and bare soil. Results showed that BSC have different effects on germination, seedling survival and growth of plant species. Plant species performance was qualitatively higher on BSC than bare soil. The highest performance of A. marmorata and P. laevigata was observed on cyanobacteria and mixed crusts, respectively. The highest performance of N. tetetzo was on both crust types. © 2011 German Botanical Society and The Royal Botanical Society of the Netherlands.

Phytotoxicity of glyphosate in the germination of Pisum sativum and its effect on germinated seedlings

OpenAIRE

Mondal, Subinoy; Kumar, Mousumi; Haque, Smaranya; Kundu, Debajyoti

2017-01-01

The present study evaluated the effects of glyphosate on Pisum sativum germination as well as its effect on the physiology and biochemistry of germinated seedlings. Different physico-chemical biomarkers, viz., chlorophyll, root and shoot length, total protein and soluble sugar, along with sodium and potassium concentration, were investigated in germinated seedlings at different glyphosate concentrations. This study reports the influence of different concentrations of glyphosate on pea seeds a...

Salt stress and temperatures on the germination and initial growth of ‘jurema-de-embira’ (Mimosa ophthalmocentra seedlings

Directory of Open Access Journals (Sweden)

Narjara W. Nogueira

Full Text Available ABSTRACT The objective of this study was to evaluate the effects of salinity on the germination and initial growth of ‘jurema-de-embira’ (Mimosa ophthalmocentra seedlings at different temperatures. The experiment was installed in a completely randomized design, in a factorial scheme of eight salt concentrations (0; 4.0; 8.0; 12.0; 16.0; 20.0; 24.0 and 28.0 dS m-1 and four temperatures (25, 30, 35 and 20-30 °C in four replicates of 25 seeds under an 8-h photoperiod in Biochemical Oxygen Demand germinators. The variables analyzed were: germination, germination speed index, shoot and root lengths, and shoot, root and total dry matter. Temperature variation influences the response of ‘jurema-de-embira’ seeds to salinity, and the salt stress is intensified by the increase in temperature. ‘Jurema-de-embira’ is tolerant to salt stress in the germination stage, showing satisfactory germination up to the salinity level 20 dS m-1, at temperatures below 30 °C. The initial growth of ‘jurema-de-embira’ plants is satisfactory up to salinity of 12 dS m-1, at temperatures below 30 °C.

Extracellular vesicles: Exosomes, microvesicles, and friends

NARCIS (Netherlands)

Raposo, G.; Stoorvogel, W.|info:eu-repo/dai/nl/074352385

2013-01-01

Cells release into the extracellular environment diverse types of membrane vesicles of endosomal and plasma membrane origin called exosomes and microvesicles, respectively. These extracellular vesicles (EVs) represent an important mode of intercellular communication by serving as vehicles for

GERMINATION STUDIES ON Tabebuia impetiginosa Mart. SEEDS

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Edvaldo Aparecido Amaral da Silva

2004-06-01

Full Text Available Seed germination and seedling production of native forest tree species are an important step in ex situ conservation programs and in the reforestation with ecological purposes. Therefore, understanding seed germination and its regulation is mandatory for the complete success of the conservation programs and revegetation techniques. Thus, morphological studies, temperature requirements for seed germination and its control by gibberellins (GAs were studied in Tabebuia impetiginosa (“ipê-roxo” seeds. The best temperature for germination under constant light was 30oC. The imbibition of T. impetiginosa seeds followed the common triphasic pattern, with most of the seeds attaining phase II at 24 hours and phase III at 72 hours of imbibition. Visible germination, as radicle elongation, started at 30 hours in water-imbibed seeds and at 24 hours in GA-imbibed seeds. Seeds imbibed in Paclobutrazol, an inhibitor of GA biosynthesis, failed to germinate. However, application of exogenous gibberellins overcame inhibition and allowed germination, suggesting that GAs are regulators of Tabebuia impetiginosa seed germination. The results suggested that germination in Tabebuia impetiginosa seeds is controlled by elongation of the radicle and gibberellins may play an important role in regulating it. The possible role of gibberellins is discussed.

Efeito da maturação e temperatura na germinação de sementes de Phoenix canariensis hort. ex Chabaud - Arecaceae Effect of maturation stage and temperature on germination of Phoenix canariensis Hort. ex Chabaud (Arecaceae seeds

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Ricardo Soares Pimenta

2010-02-01

Full Text Available Phoenix canariensis hort. ex Chabaud, originária das Ilhas Canárias, é uma palmeira que apresenta grande valor ornamental. A propagação das palmeiras, de modo geral, é considerada lenta, desuniforme e influenciada por vários fatores, como estádio de maturação e temperatura. Devido à sua importância e à falta de informações na literatura sobre a propagação da espécie, este trabalho teve como objetivo estudar o efeito do estádio de maturação e da temperatura na germinação de sementes de P. canariensis. Realizou-se um experimento cujo delineamento experimental foi inteiramente casualizado em esquema fatorial 2 x 5 (2 para maturação e 5 para temperatura, com quatro repetições de 25 sementes. Frutos de colorações alaranjada (intermediário e marrom (maduro foram despolpados e os diásporos, colocados em caixas plásticas (tipo gerbox contendo vermiculita como substrato, nas temperaturas de 25, 30, 35, 20-30 e 25-35 ºC, com fotoperíodo de 16 h de luz e 8 h de escuro, utilizando-se câmaras incubadoras tipo BOD com controle de temperatura e fotoperíodo. Pelos resultados, conclui-se que a condição que permitiu maior porcentagem de germinação das sementes de P. canariensis foi a partir de frutos maduros (de coloração marrom, na temperatura alternada de 20-30 ºC, atingindo 98% de germinação.Phoenix canariensis Hort. ex Chabaud is a palm tree of great ornamental value native to the Canary Islands. Its commercial propagation is done by sexual means and there are only few studies on seed germination under the influence of various factors such as maturation stage and temperature. We tried to evaluate the seed germination of P. canariensis using fruits at different maturarion stages under different temperatures. The experiment was arranged in a complete randomized design in a 2 x 5 factorial scheme (two maturation stages and five temperature conditions, with four samples containing 25 seeds each. Brownish and orangish

Multiple paths to similar germination behavior in Arabidopsis thaliana.

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Burghardt, Liana T; Edwards, Brianne R; Donohue, Kathleen

2016-02-01

Germination timing influences plant fitness, and its sensitivity to temperature may cause it to change as climate shifts. These changes are likely to be complex because temperatures that occur during seed maturation and temperatures that occur post-dispersal interact to define germination timing. We used the model organism Arabidopsis thaliana to determine how flowering time (which defines seed-maturation temperature) and post-dispersal temperature influence germination and the expression of genetic variation for germination. Germination responses to temperature (germination envelopes) changed as seeds aged, or after-ripened, and these germination trajectories depended on seed-maturation temperature and genotype. Different combinations of genotype, seed-maturation temperature, and after-ripening produced similar germination envelopes. Likewise, different genotypes and seed-maturation temperatures combined to produce similar germination trajectories. Differences between genotypes were most likely to be observed at high and low germination temperatures. The germination behavior of some genotypes responds weakly to maternal temperature but others are highly plastic. We hypothesize that weak dormancy induction could synchronize germination of seeds dispersed at different times. By contrast, we hypothesize that strongly responsive genotypes may spread offspring germination over several possible germination windows. Considering germination responses to temperature is important for predicting phenology expression and evolution in future climates. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

Selected aspects of tiny vetch [Vicia hirsuta (L. Gray S.F.] seed ecology: generative reproduction and effects of seed maturity and seed storage on seed germination

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Magdalena Kucewicz

2012-12-01

Full Text Available Vicia hirsuta (L. Gray S.F. (tiny vetch is a common and persistent segetal weed. Tiny vetch seeds and pods reach different stages of maturity during the crop harvest season. Some seeds that mature before cereal harvest are shed in the field and deposited in the soil seed bank, while others become incorporated into seed material. The objective of this study was to describe selected aspects of tiny vetch seed ecology: to determine the rate of individual reproduction of vetch plants growing in winter and spring grain crops and to evaluate the germination of seeds at different stages of maturity, subject to storage conditions. The seeds and pods of V. hirsuta were sorted according to their development stages at harvest and divided into two groups. The first group was stored under laboratory conditions for two months. In the autumn of the same year, the seeds were subjected to germination tests. The remaining seeds were stored in a storeroom, and were planted in soil in the spring. The germination rate was evaluated after 8 months of storage. Potential productivity (developed pods and flowers, fruit buds was higher in plants fruiting in winter wheat than in spring barley. Vetch plants produced around 17-26% more pods (including cracked, mature, greenish-brown and green pods and around 25% less buds in winter wheat than in spring barley. Immature seeds were characterized by the highest germination capacity. Following storage under laboratory conditions and stratification in soil, mature seeds germinated at a rate of several percent. After storage in a storeroom, seeds at all three development stages broke dormancy at a rate of 72- 75%. The high germination power of tiny vetch seeds stored in a storeroom indicates that this plant can be classified as an obligatory speirochoric weed species.

Studying the effects of different levels of salinity which caused by NaCl on early growth and germination of Lactuca Sativa L. seedling

OpenAIRE

KESHAVARZI MOHAMMAD HOSEIN BIJEH

2012-01-01

Soil salinity is one of the most important constraints that limit crop production in arid and semi arid regions. Seed germination is a critical stage in the history of plants and salt tolerance during germination is crucial for the establishment of plants that grow in saline soils. This research was carried out in order to test the effects of different salinity levels on germination and early growth of lettuce (Lactuca Sativa L.). The experiment was carried out using completely randomized des...

Transcriptome analysis of Phelipanche aegyptiaca seed germination mechanisms stimulated by fluridone, TIS108, and GR24.

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Ya Zhou Bao

Full Text Available P. aegyptiaca is one of the most destructive root parasitic plants worldwide, causing serious damage to many crop species. Under natural conditions P. aegyptiaca seeds must be conditioned and then stimulated by host root exudates before germinating. However, preliminary experiments indicated that TIS108 (a triazole-type inhibitor of strigolactone and fluridone (FL, an inhibitor of carotenoid-biosynthesis both stimulated the germination of P. aegyptiaca seeds without a water preconditioning step (i.e. unconditioned seeds. The objective of this study was to use deep RNA sequencing to learn more about the mechanisms by which TIS108 and FL stimulate the germination of unconditioned P. aegyptiaca seeds. Deep RNA sequencing was performed to compare the mechanisms of germination in the following treatments: (i unconditioned P. aegyptiaca seeds with no other treatment, (ii unconditioned seeds treated with 100 mg/L TIS108, (iii unconditioned seeds treated with 100 mg/L FL + 100 mg/L GA3, (iv conditioned seeds treated with sterile water, and (v conditioned seeds treated with 0.03 mg/L GR24. The de novo assembled transcriptome was used to analyze transcriptional dynamics during seed germination. The key gene categories involved in germination were also identified. The results showed that only 119 differentially expressed genes were identified in the conditioned treatment vs TIS108 treatment. This indicated that the vast majority of conditions for germination were met during the conditioning stage. Abscisic acid (ABA and gibberellic acid (GA played important roles during P. aegyptiaca germination. The common pathway of TIS108, FL+GA3, and GR24 in stimulating P. aegyptiaca germination was the simultaneous reduction in ABA concentrations and increase GA concentrations. These results could potentially aid the identification of more compounds that are capable of stimulating P. aegyptiaca germination. Some potential target sites of TIS108 were also identified in

Transcriptome analysis of Phelipanche aegyptiaca seed germination mechanisms stimulated by fluridone, TIS108, and GR24.

Science.gov (United States)

Bao, Ya Zhou; Yao, Zhao Qun; Cao, Xiao Lei; Peng, Jin Feng; Xu, Ying; Chen, Mei Xiu; Zhao, Si Feng

2017-01-01

P. aegyptiaca is one of the most destructive root parasitic plants worldwide, causing serious damage to many crop species. Under natural conditions P. aegyptiaca seeds must be conditioned and then stimulated by host root exudates before germinating. However, preliminary experiments indicated that TIS108 (a triazole-type inhibitor of strigolactone) and fluridone (FL, an inhibitor of carotenoid-biosynthesis) both stimulated the germination of P. aegyptiaca seeds without a water preconditioning step (i.e. unconditioned seeds). The objective of this study was to use deep RNA sequencing to learn more about the mechanisms by which TIS108 and FL stimulate the germination of unconditioned P. aegyptiaca seeds. Deep RNA sequencing was performed to compare the mechanisms of germination in the following treatments: (i) unconditioned P. aegyptiaca seeds with no other treatment, (ii) unconditioned seeds treated with 100 mg/L TIS108, (iii) unconditioned seeds treated with 100 mg/L FL + 100 mg/L GA3, (iv) conditioned seeds treated with sterile water, and (v) conditioned seeds treated with 0.03 mg/L GR24. The de novo assembled transcriptome was used to analyze transcriptional dynamics during seed germination. The key gene categories involved in germination were also identified. The results showed that only 119 differentially expressed genes were identified in the conditioned treatment vs TIS108 treatment. This indicated that the vast majority of conditions for germination were met during the conditioning stage. Abscisic acid (ABA) and gibberellic acid (GA) played important roles during P. aegyptiaca germination. The common pathway of TIS108, FL+GA3, and GR24 in stimulating P. aegyptiaca germination was the simultaneous reduction in ABA concentrations and increase GA concentrations. These results could potentially aid the identification of more compounds that are capable of stimulating P. aegyptiaca germination. Some potential target sites of TIS108 were also identified in our

Slow sedimentation and deformability of charged lipid vesicles.

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Iván Rey Suárez

Full Text Available The study of vesicles in suspension is important to understand the complicated dynamics exhibited by cells in in vivo and in vitro. We developed a computer simulation based on the boundary-integral method to model the three dimensional gravity-driven sedimentation of charged vesicles towards a flat surface. The membrane mechanical behavior was modeled using the Helfrich Hamiltonian and near incompressibility of the membrane was enforced via a model which accounts for the thermal fluctuations of the membrane. The simulations were verified and compared to experimental data obtained using suspended vesicles labelled with a fluorescent probe, which allows visualization using fluorescence microscopy and confers the membrane with a negative surface charge. The electrostatic interaction between the vesicle and the surface was modeled using the linear Derjaguin approximation for a low ionic concentration solution. The sedimentation rate as a function of the distance of the vesicle to the surface was determined both experimentally and from the computer simulations. The gap between the vesicle and the surface, as well as the shape of the vesicle at equilibrium were also studied. It was determined that inclusion of the electrostatic interaction is fundamental to accurately predict the sedimentation rate as the vesicle approaches the surface and the size of the gap at equilibrium, we also observed that the presence of charge in the membrane increases its rigidity.

Matrix vesicles in the fibrous cap of atherosclerotic plaque: possible contribution to plaque rupture.

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Bobryshev, Y V; Killingsworth, M C; Lord, R S A; Grabs, A J

2008-10-01

Plaque rupture is the most common type of plaque complication and leads to acute ischaemic events such as myocardial infarction and stroke. Calcification has been suggested as a possible indicator of plaque instability. Although the role of matrix vesicles in the initial stages of arterial calcification has been recognized, no studies have yet been carried out to examine a possible role of matrix vesicles in plaque destabilization. Tissue specimens selected for the present study represented carotid specimens obtained from patients undergoing carotid endarterectomy. Serial frozen cross-sections of the tissue specimens were cut and mounted on glass slides. The thickness of the fibrous cap (FCT) in each advanced atherosclerotic lesion, containing a well developed lipid/necrotic core, was measured at its narrowest sites in sets of serial sections. According to established criteria, atherosclerotic plaque specimens were histologically subdivided into two groups: vulnerable plaques with thin fibrous caps (FCT <100 microm) and presumably stable plaques, in which fibrous caps were thicker than 100 microm. Twenty-four carotid plaques (12 vulnerable and 12 presumably stable plaques) were collected for the present analysis of matrix vesicles in fibrous caps. In order to provide a sufficient number of representative areas from each plaque, laser capture microdissection (LCM) was carried out. The quantification of matrix vesicles in ultrathin sections of vulnerable and stable plaques revealed that the numbers of matrix vesicles were significantly higher in fibrous caps of vulnerable plaques than those in stable plaques (8.908+0.544 versus 6.208+0.467 matrix vesicles per 1.92 microm2 standard area; P= 0.0002). Electron microscopy combined with X-ray elemental microanalysis showed that some matrix vesicles in atherosclerotic plaques were undergoing calcification and were characterized by a high content of calcium and phosphorus. The percentage of calcified matrix vesicles

Zinnia Germination and Lunar Soil Amendment

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Reese, Laura

2017-01-01

Germination testing was performed to determine the best method for germinating zinnias. This method will be used to attempt to germinate the zinnia seeds produced in space. It was found that seed shape may be critically important in determining whether a seed will germinate or not. The ability of compost and worm castings to remediate lunar regolith simulant for plant growth was tested. It was found that neither treatment effectively improves plant growth in lunar regolith simulant. A potential method of improving lunar regolith simulant by mixing it with arcillite was discovered.

Phylogeny, habitat together with biological and ecological factors can influence germination of 36 subalpine Rhododendron species from the eastern Tibetan Plateau.

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Wang, Yongji; Lai, Liming; Du, Hui; Jiang, Lianhe; Wang, Fei; Zhang, Chao; Zhuang, Ping; Zheng, Yuanrun

2018-04-01

The reproductive stages of the life cycle are crucial in explaining the distribution patterns of plant species because of their extreme vulnerability to environmental conditions. Despite reported evidence that seed germination is related to habitat macroclimatic characteristics, such as mean annual temperature, the effect of this trait in controlling plant species distribution has not yet been systematically and quantitatively evaluated. To learn whether seed germination can predict species distribution along altitude gradients, we examined germination data of 36 Rhododendron species in southeastern Tibet originating from contrasting altitudes, habitats, plant heights, seed masses, and phylogenies. Germination varied significantly with altitude, habitat, plant height, and phylogeny and was higher in the light than in the dark. Germination percentage was highest at 10:20°C in the light and 15:25°C in the dark. As altitude increased, germination percentages first rose and then decreased, being highest at 3,500-4,000 m. Germination percentage and rate were highest on rocky slopes, increasing as seed mass and plant height rose. Variations in germination percentage and rate were not significant at subgenera, section, and subsection levels, but they were significant at species level. The results suggested that the relationship between germination and altitude may provide insights into species distribution patterns. Further, germination patterns are a result of long-term evolution as well as taxonomic constraints.

Expression and localization of heterogeneous nuclear ribonucleoprotein K in mouse ovaries and preimplantation embryos

International Nuclear Information System (INIS)

Zhang, Ping; Wang, Ningling; Lin, Xianhua; Jin, Li; Xu, Hong; Li, Rong; Huang, Hefeng

2016-01-01

Heterogeneous nuclear ribonucleoprotein K (hnRNP K), an evolutionarily conserved protein, is involved in several important cellular processes that are relevant to cell proliferation, differentiation, apoptosis, and cancer development. However, details of hnRNP K expression during mammalian oogenesis and preimplantation embryo development are lacking. The present study investigates the expression and cellular localization of K protein in the mouse ovaries and preimplantation embryos using immunostaining. We demonstrate, for the first time, that hnRNP K is abundantly expressed in the nuclei of mouse oocytes in primordial, primary and secondary follicles. In germ vesicle (GV)-stage oocytes, hnRNP K accumulates in the germinal vesicle in a spot distribution manner. After germinal vesicle breakdown, speckled hnRNP K is diffusely distributed in the cytoplasm. However, after fertilization, the K protein relocates into the female and male pronucleus and persists in the blastomere nuclei. Localization of K protein in the human ovary and ovarian granulosa cell tumor (GCT) was also investigated. Overall, this study provides important morphological evidence to better understand the possible roles of hnRNP K in mammalian oogenesis and early embryo development. - Highlights: • HnRNP K localizes in the nucleus of GV-stage oocyte in a punctate distribution. • HnRNP K strongly accumulates in zygotic pronuclei as condensed spots. • The localization of hnRNP K during oogenesis and embryogenesis is characteristic. • HnRNP K might have an important role in oogenesis and embryonic development.

Expression and localization of heterogeneous nuclear ribonucleoprotein K in mouse ovaries and preimplantation embryos

Energy Technology Data Exchange (ETDEWEB)

Zhang, Ping [The International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai (China); Wang, Ningling [Department of Assisted Reproduction, Shanghai Ninth People' s Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai (China); Lin, Xianhua; Jin, Li [The International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai (China); Xu, Hong, E-mail: xuhong1168@126.com [The International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai (China); Li, Rong [The International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai (China); Huang, Hefeng, E-mail: huanghefg@hotmail.com [The International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai (China)

2016-02-26

Heterogeneous nuclear ribonucleoprotein K (hnRNP K), an evolutionarily conserved protein, is involved in several important cellular processes that are relevant to cell proliferation, differentiation, apoptosis, and cancer development. However, details of hnRNP K expression during mammalian oogenesis and preimplantation embryo development are lacking. The present study investigates the expression and cellular localization of K protein in the mouse ovaries and preimplantation embryos using immunostaining. We demonstrate, for the first time, that hnRNP K is abundantly expressed in the nuclei of mouse oocytes in primordial, primary and secondary follicles. In germ vesicle (GV)-stage oocytes, hnRNP K accumulates in the germinal vesicle in a spot distribution manner. After germinal vesicle breakdown, speckled hnRNP K is diffusely distributed in the cytoplasm. However, after fertilization, the K protein relocates into the female and male pronucleus and persists in the blastomere nuclei. Localization of K protein in the human ovary and ovarian granulosa cell tumor (GCT) was also investigated. Overall, this study provides important morphological evidence to better understand the possible roles of hnRNP K in mammalian oogenesis and early embryo development. - Highlights: • HnRNP K localizes in the nucleus of GV-stage oocyte in a punctate distribution. • HnRNP K strongly accumulates in zygotic pronuclei as condensed spots. • The localization of hnRNP K during oogenesis and embryogenesis is characteristic. • HnRNP K might have an important role in oogenesis and embryonic development.

Bubble-induced microstreaming: guiding and destroying lipid vesicles

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Marmottant, Philippe; Hilgenfeldt, Sascha

2002-11-01

Micron-sized bubbles respond with strong oscillations when submitted to ultrasound. This has led to their use as echographic contrast enhancers. The large energy and force densities generated by the collapsing bubbles also make them non-invasive mechanical tools: Recently, it has been reported that the interaction of cavitating bubbles with nearby cells can render the latter permeable to large molecules (sonoporation), suggesting prospects for drug delivery and gene transfection. We have developed a laboratory setup that allows for a controlled study of the interaction of single microbubbles with single lipid bilayer vesicles. Substituting vesicles for cell membranes is advantageous because the mechanical properties of vesicles are well-known. Microscopic observations reveal that vesicles near a bubble follow the vivid streaming motion set up by the bubble. The vesicles "bounce" off the bubble, being periodically accelerated towards and away from it, and undergo well-defined shape deformations along their trajectory in accordance with fluid-dynamical theory. Break-up of vesicles could also be observed.

An increase in pectin methyl esterase activity accompanies dormancy breakage and germination of yellow cedar seeds.

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Ren, C; Kermode, A R

2000-09-01

Pectin methyl esterase (PME) (EC 3.1.1.11) catalyzes the hydrolysis of methylester groups of cell wall pectins. We investigated the role of this enzyme in dormancy termination and germination of yellow cedar (Chamaecyparis nootkatensis [D. Don] Spach) seeds. PME activity was not detected in dormant seeds of yellow cedar but was induced and gradually increased during moist chilling; high activity coincided with dormancy breakage and germination. PME activity was positively correlated to the degree of dormancy breakage of yellow cedar seeds. The enzyme produced in different seed parts and in seeds at different times during moist chilling, germination, and early post-germinative growth consisted of two isoforms, both basic with isoelectric points of 8.7 and 8.9 and the same molecular mass of 62 kD. The pH optimum for the enzyme was between 7.4 and 8.4. In intact yellow cedar seeds, activities of the two basic isoforms of PME that were induced in embryos and in megagametophytes following dormancy breakage were significantly suppressed by abscisic acid. Gibberellic acid had a stimulatory effect on the activities of these isoforms in embryos and megagametophytes of intact seeds at the germinative stage. We hypothesize that PME plays a role in weakening of the megagametophyte, allowing radicle emergence and the completion of germination.

Effect of canopy position on germination and seedling survival of epiphytic bromeliads in a Mexican humid montane forest.

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Winkler, Manuela; Hülber, Karl; Hietz, Peter

2005-05-01

Seeds of epiphytes must land on branches with suitable substrates and microclimates to germinate and for the resulting seedlings to survive. It is important to understand the fate of seeds and seedlings in order to model populations, but this is often neglected when only established plants are included in analyses. The seeds of five bromeliad species were exposed to different canopy positions in a Mexican montane forest, and germination and early seedling survival were recorded. Additionally, the survival of naturally dispersed seedlings was monitored in a census over 2.5 years. Survival analysis, a procedure rarely used in plant ecology, was used to study the influence of branch characteristics and light on germination and seedling survival in natural and experimental populations. Experimental germination percentages ranged from 7.2 % in Tillandsia deppeana to 33.7 % in T. juncea, but the seeds of T. multicaulis largely failed to germinate. Twenty months after exposure between 3.5 and 9.4 % of the seedlings were still alive. There was no evidence that canopy position affected the probability of germination, but time to germination was shorter in less exposed canopy positions indicating that higher humidity accelerates germination. More experimental seedlings survived when canopy openness was high, whereas survival in census-seedlings was influenced by moss cover. While mortality decreased steadily with age in juveniles of the atmospheric Tillandsia, in the more mesomorphic Catopsis sessiliflora mortality increased dramatically in the dry season. Seedling mortality, rather than the failure to germinate, accounts for the differential distribution of epiphytes within the canopy studied. With few safe sites to germinate and high seedling mortality, changes of local climate may affect epiphyte populations primarily through their seedling stage.

Adverse effect of urease on salt stress during seed germination in Arabidopsis thaliana.

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Bu, Yuanyuan; Kou, Jing; Sun, Bo; Takano, Testuo; Liu, Shenkui

2015-05-22

Seed germination is a critical stage in the development of crops that grow in saline soils. We noticed that seeds of an Arabidopsis urease mutant have significantly increased salt stress tolerance. To understand why, we treated the wild type (WT) with a urease inhibitor and found that its salt stress tolerance was also improved. We hypothesized that urease acting on urea generates NH₄⁺, which probably exacerbates salt stress. As expected, the urease inhibitor significantly decreased the NH₄⁺ level in WT seeds. These findings suggest that blocking urease activity improves salt tolerance during seed germination by lowering the concentration of NH₄⁺. Copyright © 2015. Published by Elsevier B.V.

Determination of Cardinal Temperatures and Germination Respond to Different Temperature for Five Lawns Cultivars

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hadi khavari

2017-08-01

Full Text Available Introduction: Germination of every plant species respond to temperature variation in particular way. Germination is critical stage in plant life cycle. Seed germination is a complex biological process that is influenced by various environmental and genetic factors. The effects of temperature on plant development are the basis for models used to predict the timing of germination. Estimation of the cardinal temperatures, including base, optimum, and maximum, is essential because rate of development increases between base and optimum, decreases between optimum and maximum, and ceases above the maximum and below the base temperatures. Usually, a linear increase in germination rate is associated with an increase in temperature from base temperature (Tb to an optimum. An increase of temperature from the optimum will reduce the germination rate to zero. To determine the best planting date for plants, it is necessary to find the base (Tb, optimum (To and maximum temperatures (Tc for seed germination. These are known as cardinal temperatures. Modelling of seed germination is considered an effective approach to determining cardinal temperatures for most plant species, although these methods have some limitations due to unpredictable biological changes. The results of fitting mechanical models are useful for evaluating seed quality, germination rate, germination percentage, germination uniformity and seed performance under different environmental stresses such as salinity, drought, and freezing. Regression models incorporating more parameters can produce more precise estimates. Cardinal temperature was determined using segmented and logistic models in millet varieties and seedling emergence of wheat. In the dent-like model at lower-than-optimum temperature, a linear relationship holds between temperature and germination rate. This relationship remains linear at higher-than-optimum temperatures, but with a reducing trend. With increasing temperature

The role of arginine metabolic pathway during embryogenesis and germination in maritime pine (Pinus pinaster Ait.).

Science.gov (United States)

Llebrés, María-Teresa; Pascual, María-Belén; Debille, Sandrine; Trontin, Jean-François; Harvengt, Luc; Avila, Concepción; Cánovas, Francisco M

2018-03-01

Vegetative propagation through somatic embryogenesis is critical in conifer biotechnology towards multivarietal forestry that uses elite varieties to cope with environmental and socio-economic issues. An important and still sub-optimal process during in vitro maturation of somatic embryos (SE) is the biosynthesis and deposition of storage proteins, which are rich in amino acids with high nitrogen (N) content, such as arginine. Mobilization of these N-rich proteins is essential for the germination and production of vigorous somatic seedlings. Somatic embryos accumulate lower levels of N reserves than zygotic embryos (ZE) at a similar stage of development. To understand the molecular basis for this difference, the arginine metabolic pathway has been characterized in maritime pine (Pinus pinaster Ait.). The genes involved in arginine metabolism have been identified and GFP-fusion constructs were used to locate the enzymes in different cellular compartments and clarify their metabolic roles during embryogenesis and germination. Analysis of gene expression during somatic embryo maturation revealed high levels of transcripts for genes involved in the biosynthesis and metabolic utilization of arginine. By contrast, enhanced expression levels were only observed during the last stages of maturation and germination of ZE, consistent with the adequate accumulation and mobilization of protein reserves. These results suggest that arginine metabolism is unbalanced in SE (simultaneous biosynthesis and degradation of arginine) and could explain the lower accumulation of storage proteins observed during the late stages of somatic embryogenesis.

EFFECTS OF PRE-GERMINATION TREATMENTS AND STORAGE ON GERMINATION OF Astronium fraxinifolium SCHOTT (ANACARDIACEAE DIASPORES

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Lílian de Lima Braga

2014-06-01

Full Text Available http://dx.doi.org/10.5902/1980509814577The goal of this study was to evaluate the germination and the storage capacity of Astronium fraxinifolium diaspores. Six pre-germination treatments were used in the experiment: control treatment (intact diaspores; diaspores immersed in water at room temperature (25º C for 5 min; diaspores immersed in water at 70° C for 5 min; diaspores immersed in water at 100° C for 5 min; diaspores immersed in sodium hypochlorite solution (1:1000 for 2 min; and diaspores mechanically scarified with sandpaper #80. To evaluate storage conditions, we tested two different types of packaging (permeable paper bag and transparent glass jar and two environmental conditions (cold chamber and room conditions, resulting in four treatments. The germination tests were performed for zero (control and 60, 120, 180, 240, 300 and 360 days after storage. The effects of different treatments on germination and storage of diaspores were evaluated by ANOVA, followed by Tukey test. Regarding to pre-germination treatments, high germination rates were observed in the hypochlorite (98.0 ± 4.22%, control (97.0 ± 4.83%, water at room temperature (96.0 ± 6.99% and water at 70º C (83.0 ± 29.08% treatments. Thus, Astronium fraxinifolium diaspores do not present dormancy. During storage, the diaspores remained viable throughout the study period with high germination rates, except for the treatment in paper bags placed in the cold chamber, in which the diaspores lost their viability in the eighth month of storage. Therefore, this is not a recommended storage method for this species.

Spontaneous transfer of ganglioside GM1 between phospholipid vesicles

International Nuclear Information System (INIS)

Brown, R.E.; Thompson, T.E.

1987-01-01

The transfer kinetics of the negatively charged glycosphingolipid II 3 -N-acetylneuraminosyl-gangliotetraosylceramide (GM 1 ) were investigated by monitoring tritiated GM 1 movement between donor and acceptor vesicles. After appropriate incubation times at 45 0 C, donor and acceptor vesicles were separated by molecular sieve chromatography. Donors were small unilamellar vesicles produced by sonication, whereas acceptors were large unilamellar vesicles produced by either fusion or ethanol injection. Initial GM 1 transfer to acceptors followed first-order kinetics with a half-time of about 40 h assuming that GM 1 is present in equal mole fractions in the exterior and interior surfaces of the donor vesicle bilayer and that no glycolipid flip-flop occurs. GM 1 net transfer was calculated relative to that of [ 14 C]cholesteryl oleate, which served as a nontransferable marker in the donor vesicles. Factors affecting the GM 1 interbilayer transfer rate included phospholipid matrix composition, initial GM 1 concentration in donor vesicles, and the GM 1 distribution in donor vesicles with respect to total lipid symmetry. The findings provide evidence that GM 1 is molecularly dispersed at low concentrations within liquid-crystalline phospholipid bilayers

ABC Triblock Copolymer Vesicles with Mesh-like Morphology

Science.gov (United States)

Zhao, Wei; Russell, Thomas; Grason, Gregory

2010-03-01

Polymer vesicles can be made from poly(isoprene-b-styrene-b-2-vinylpyridene) (PI-b-PS-b-P2VP) triblock copolymer under the confinement of anodic aluminum oxide (AAO) membrane. It was found that these vesicles have well-defined, nanoscopic size and a microphase-separated hydrophobic core, comprised of PS and PI blocks. Vesicle formation was tracked using both transmission and scanning electron microscopy. A mesh-like morphology formed in the core at a well-defined composition of three blocks. Confinement played an important role in generating these vesicles with such an unusual morphology.

Changes in germination characteristics and seedling growth ...

African Journals Online (AJOL)

Changes in germination characteristics and seedling growth between storage ... for up to 1 year and the second group was used for un-stored germination test. ... seed germination performance without loss of longevity of tall fescue species, ...

Germination and storage of caranda seeds (Copernicia alba

Directory of Open Access Journals (Sweden)

Tathiana Elisa Masetto

2012-12-01

Full Text Available Caranda is a Brazilian native palm tree, belonging to Arecaceae family and occurring, predominan,t in the Brazilian Swampland. This work studied the germination and the caranda seeds storage behavior. The germination study was carried out in the temperatures of 25ºC and 30ºC in constant white light and the alternate temperature of 20/30ºC with 10 hours of darkness for the lowest temperature and 14 hours of light for the highest temperature, using paper and paper roll as substratum. At the end of test, the germination percentage, germination speed index, germination medium time and the primary root length were evaluated. After the seeds improvement, it was obtained two sub-samples destined for 30 days storage in two invironments: cold and dry chamber (16ºC/55% UR and freezer (-18ºC. The following tests, water content, germination, germination medium time and primary root length were evaluated. The caranda seeds germination in paper roll and on paper is favored by the temperature of 20/30ºC in paper roll and on paper and paper roll on 30ºC. The freezing and cold camera storage during 30 days are efficient to reduce the germination medium time of caranda seeds and to keep the germination percentage.

Hybrid, Nanoscale Phospholipid/Block Copolymer Vesicles

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Bo Liedberg

2013-09-01

Full Text Available Hybrid phospholipid/block copolymer vesicles, in which the polymeric membrane is blended with phospholipids, display interesting self-assembly behavior, incorporating the robustness and chemical versatility of polymersomes with the softness and biocompatibility of liposomes. Such structures can be conveniently characterized by preparing giant unilamellar vesicles (GUVs via electroformation. Here, we are interested in exploring the self-assembly and properties of the analogous nanoscale hybrid vesicles (ca. 100 nm in diameter of the same composition prepared by film-hydration and extrusion. We show that the self-assembly and content-release behavior of nanoscale polybutadiene-b-poly(ethylene oxide (PB-PEO/1-palmitoyl-2-oleoyl-sn-glycero-3-phosphatidylcholine (POPC hybrid phospholipid/block copolymer vesicles can be tuned by the mixing ratio of the amphiphiles. In brief, these hybrids may provide alternative tools for drug delivery purposes and molecular imaging/sensing applications and clearly open up new avenues for further investigation.

[Study on germination characteristics of Disporum cantoniense].

Science.gov (United States)

Huang, Nan; Wang, Hua-Lei; Zhao, Zhi; Liu, Hong-Chang; Luo, Chun-Li; Li, Jin-Ling; Luo, Fu-Lai; Huang, Ming-Jin

2012-11-01

To study the seed germination characteristic and optimal germination condition of wild Disporum cantoniense. Used wild Disporum cantoniense seed as the test materials, the rate of water absorption of the seed was determined. The germination rates under different conditions, along a temperature gradient (15, 20, 25 and 30 degres C), in light or dark, on top or between wet filter papers, and keeping or removing the seed coat, were determined respectively using petri dish method. At the same time germination trends were observed. The thousand seed weight was 33.24 g, and the seed water-absorbing reached saturation pot after soaking for 30 h. Higher germination rates were respectively recorded at 25 degrees C, between filter papers, and in dark after 24 h soaking in the pretreatment solution. The optimal condition for the germination of the seed of wild Disporum cantoniense is as follow: keeping testa, seed soaking for 24 h in seed germination agent and being incubated between wet filter papers in dark at 25 degrees C.

Surface ultrastructural studies on the germination, penetration and conidial development of Aspergillus flavus Link:Fries infecting silkworm, Bombyx mori Linn.

Science.gov (United States)

Kumar, Vineet; Singh, G P; Babu, A M

2004-01-01

Aspergillosis is a common disease of the silkworm Bombyx mori Linn., caused by an insect mycopathogen Aspergillus flavus Link:Fries. The present study reveals the germination, penetration and conidial development of A. flavus on the larval integument of B. mori under SEM. Four different strains (NB18, KA, NB4D2 and NB7) of B. mori was surface inoculated with ca. of 1 x 10(6) conidia/ml. Each conidium germinated on the cuticle approximately 6 h after inoculation, forming a humpy or suctorial appressoria within 24 h. The hyphae which entered into haemocoel 2 day post-inoculation, grew and multiplied extensively, forming a mycelial complex, causing death of the host larva in about 4-5 days. This occurred with minimal breakdown of the internal tissues. Death of the host was followed by ramification of the fungus through the mesodermal and epidermal tissues, leading to larval mummification about 5-6 days after inoculation. Extensive fungal growths on the entire larval body followed, consisting of aerial hyphae, which developed branched conidiophores. The aerial hyphae with abundant conidiophores formed a confluent yellowish green fungal mat over the entire larval body in 6-7 days of post-inoculation. The tip of each emerging conidiophores gradually dilated and developed to become a bulbous head known as the vesicle. A large number of conidiogenous cells were produced over the entire surface of vesicle, which later developed into finger-like projections termed as sterigmata or phialides. The phialides matured within 2 days after the aerial hyphae emerged as evidenced by chains of conidia at their tips. The conidia were globose with externally roughened walls. The life cycle of the fungus on B. mori was completed in six to seven days.

Genetically Controlled Fusion, Exocytosis and Fission of Artificial Vesicles

DEFF Research Database (Denmark)

Bönzli, Eva; Hadorn, Maik; De Lucrezia, Davide

if a special class of viral proteins, termed fusogenic peptides, were added to the external medium. In the present work, we intend to develop genetically controlled fusion, fission and exocytosis of vesicles by the synthesis of peptides within vesicles. First, we enclosed synthesized peptides in vesicles...... to induce in a next step fusion of adjacent vesicles, fission and exocytosis of nested vesicles. Second, we will replace the peptides by an enclosed cell-free expression system to internally synthesize fusion peptides. To control the gene expression, different mechanisms are available, e.g. addition...... fusion, fission and exocytosis....

Characteristics of the larval Echinococcus vogeli Rausch and Bernstein, 1972 in the natural intermediate host, the paca, Cuniculus paca L. (Rodentia: Dasyproctidae).

Science.gov (United States)

Rausch, R L; D'Alessandro, A; Rausch, V R

1981-09-01

In Colombia, the natural intermediate host of Echinococcus vogeli Rausch and Bernstein, 1972 is the paca, Cuniculus paca L. (Rodentia: Dasyproctidae). The larval cestode develops in the liver of the host, where it usually is situated superficially, partly exposed beneath Glisson's capsule. The infective larva consists of a subspherical to asymmetrical, fluid-filled vesicle, up to 30 mm in diameter, enclosed by a thick laminated membrane. It typically contains numerous chambers, often interconnected, produced by endogenous proliferation of germinal and laminated tissue, within which brood capsules arise in an irregular pattern from the germinal layer. Invasive growth by means of exogenous proliferation, typical of infections in man, was not observed in the natural intermediate host. The development of the larval cestode is described on the basis of material from pacas, supplemented by observations on early-stage lesions in experimentally infected nutrias, Myocastor coypus (Molina) (Rodentia: Capromyidae). The tissue response is characterized for early-stage, mature (infective), and degenerating larvae in the comparatively long-lived intermediate host. In addition to previously reported differences in size and form of rostellar hooks, other morphologic characteristics are defined by which the larval stage of E. vogeli is distinguished from that of E. oligarthrus (Diesing, 1863). Pathogenesis by the larval E. vogeli in man, like that by the larval E. multilocularis Leuckart, 1863, is the consequence of atypical proliferation of vesicles attributable to parasite-host incompatibility.

Synaptic vesicle distribution by conveyor belt.

Science.gov (United States)

Moughamian, Armen J; Holzbaur, Erika L F

2012-03-02

The equal distribution of synaptic vesicles among synapses along the axon is critical for robust neurotransmission. Wong et al. show that the continuous circulation of synaptic vesicles throughout the axon driven by molecular motors ultimately yields this even distribution. Copyright © 2012 Elsevier Inc. All rights reserved.

Oxygen dependency of germinating Brassica seeds

Science.gov (United States)

Park, Myoung Ryoul; Hasenstein, Karl H.

2016-02-01

Establishing plants in space, Moon or Mars requires adaptation to altered conditions, including reduced pressure and composition of atmospheres. To determine the oxygen requirements for seed germination, we imbibed Brassica rapa seeds under varying oxygen concentrations and profiled the transcription patterns of genes related to early metabolism such as starch degradation, glycolysis, and fermentation. We also analyzed the activity of lactate dehydrogenase (LDH) and alcohol dehydrogenase (ADH), and measured starch degradation. Partial oxygen pressure (pO2) greater than 10% resulted in normal germination (i.e., protrusion of radicle about 18 hours after imbibition) but lower pO2 delayed and reduced germination. Imbibition in an oxygen-free atmosphere for three days resulted in no germination but subsequent transfer to air initiated germination in 75% of the seeds and the root growth rate was transiently greater than in roots germinated under ambient pO2. In hypoxic seeds soluble sugars degraded faster but the content of starch after 24 h was higher than at ambient oxygen. Transcription of genes related to starch degradation, α-amylase (AMY) and Sucrose Synthase (SUS), was higher under ambient O2 than under hypoxia. Glycolysis and fermentation pathway-related genes, glucose phosphate isomerase (GPI), 6-phosphofructokinase (PFK), fructose 1,6-bisphosphate aldolase (ALD), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), pyruvate decarboxylase (PDC), LDH, and ADH, were induced by low pO2. The activity of LDH and ADH was the highest in anoxic seeds. Germination under low O2 conditions initiated ethanolic fermentation. Therefore, sufficient oxygen availability is important for germination before photosynthesis provides necessary oxygen and the determination of an oxygen carrying capacity is important for uniform growth in space conditions.

A scenario for a genetically controlled fission of artificial vesicles

DEFF Research Database (Denmark)

Bönzli, Eva; Hadorn, Maik; Jørgensen, Mikkel Girke

2011-01-01

to vesicles (Hanczyc et al. 2003). In the present work, we developed a scenario how a genetically controlled fission of vesicles may be achieved by the synthesis of a special class of viral proteins within artificial vesicles. Because the authors already have a lot of experience in the water-in-oil emulsion...... be incorporated into vesicles, and therefore allow the synthesis of a large number of proteins (Noireaux et al. 2005). However, vesicle fission remains one of the upcoming challenges in the artificial cell project (Noireaux et al. 2011). So far, vesicle fission is implemented by applying mechanical stress...

Molecular characterization of exosome-like vesicles from breast cancer cells

International Nuclear Information System (INIS)

Kruger, Stefan; Elmageed, Zakaria Y Abd; Hawke, David H; Wörner, Philipp M; Jansen, David A; Abdel-Mageed, Asim B; Alt, Eckhard U; Izadpanah, Reza

2014-01-01

Membrane vesicles released by neoplastic cells into extracellular medium contain potential of carrying arrays of oncogenic molecules including proteins and microRNAs (miRNA). Extracellular (exosome-like) vesicles play a major role in cell-to-cell communication. Thus, the characterization of proteins and miRNAs of exosome-like vesicles is imperative in clarifying intercellular signaling as well as identifying disease markers. Exosome-like vesicles were isolated using gradient centrifugation from MCF-7 and MDA-MB 231 cultures. Proteomic profiling of vesicles using liquid chromatography-mass spectrometry (LC-MS/MS) revealed different protein profiles of exosome-like vesicles derived from MCF-7 cells (MCF-Exo) than those from MDA-MB 231 cells (MDA-Exo). The protein database search has identified 88 proteins in MDA-Exo and 59 proteins from MCF-Exo. Analysis showed that among all, 27 proteins were common between the two exosome-like vesicle types. Additionally, MDA-Exo contains a higher amount of matrix-metalloproteinases, which might be linked to the enhanced metastatic property of MDA-MB 231 cells. In addition, microarray analysis identified several oncogenic miRNA between the two types vesicles. Identification of the oncogenic factors in exosome-like vesicles is important since such vesicles could convey signals to non-malignant cells and could have an implication in tumor progression and metastasis

Astrocytic Vesicle Mobility in Health and Disease

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Robert Zorec

2013-05-01

Full Text Available Astrocytes are no longer considered subservient to neurons, and are, instead, now understood to play an active role in brain signaling. The intercellular communication of astrocytes with neurons and other non-neuronal cells involves the exchange of molecules by exocytotic and endocytotic processes through the trafficking of intracellular vesicles. Recent studies of single vesicle mobility in astrocytes have prompted new views of how astrocytes contribute to information processing in nervous tissue. Here, we review the trafficking of several types of membrane-bound vesicles that are specifically involved in the processes of (i intercellular communication by gliotransmitters (glutamate, adenosine 5'-triphosphate, atrial natriuretic peptide, (ii plasma membrane exchange of transporters and receptors (EAAT2, MHC-II, and (iii the involvement of vesicle mobility carrying aquaporins (AQP4 in water homeostasis. The properties of vesicle traffic in astrocytes are discussed in respect to networking with neighboring cells in physiologic and pathologic conditions, such as amyotrophic lateral sclerosis, multiple sclerosis, and states in which astrocytes contribute to neuroinflammatory conditions.

EXTRACELLULAR VESICLES: CLASSIFICATION, FUNCTIONS AND CLINICAL RELEVANCE

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A. V. Oberemko

2014-12-01

Full Text Available This review presents a generalized definition of vesicles as bilayer extracellular organelles of all celular forms of life: not only eu-, but also prokaryotic. The structure and composition of extracellular vesicles, history of research, nomenclature, their impact on life processes in health and disease are discussed. Moreover, vesicles may be useful as clinical instruments for biomarkers, and they are promising as biotechnological drug. However, many questions in this area are still unresolved and need to be addressed in the future. The most interesting from the point of view of practical health care represents a direction to study the effect of exosomes and microvesicles in the development and progression of a particular disease, the possibility of adjusting the pathological process by means of extracellular vesicles of a particular type, acting as an active ingredient. Relevant is the further elucidation of the role and importance of exosomes to the surrounding cells, tissues and organs at the molecular level, the prospects for the use of non-cellular vesicles as biomarkers of disease.

Nicotinamidase activity is important for germination.

Science.gov (United States)

Hunt, Lee; Holdsworth, Michael J; Gray, Julie E

2007-08-01

It has been suggested that nicotinamide must be degraded during germination; however, the enzyme responsible and its physiological role have not been previously studied. We have identified an Arabidopsis gene, NIC2, that is expressed at relatively high levels in mature seed, and encodes a nicotinamidase enzyme with homology to yeast and bacterial nicotinamidases. Seed of a knockout mutant, nic2-1, had reduced nicotinamidase activity, retarded germination and impaired germination potential. nic2-1 germination was restored by after-ripening or moist chilling, but remained hypersensitive to application of nicotinamide or ABA. Nicotinamide is a known inhibitor of NAD-degrading poly(ADP-ribose) polymerases (PARP enzymes) that are implicated in DNA repair. We found reduced poly(ADP)ribosylation levels in nic2-1 seed, which were restored by moist chilling. Furthermore, nic2-1 seed had elevated levels of NAD, and germination was hypersensitive to methyl methanesulphonate (MMS), suggesting that PARP activity and DNA repair responses were impaired. We suggest that nicotinamide is normally metabolized by NIC2 during moist chilling or after-ripening, which relieves inhibition of PARP activity and allows DNA repair to occur prior to germination.

Combining Ability for Germination Traits in Jatropha curcas L.

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A. K. M. Aminul Islam

2013-01-01

Full Text Available Six parents of Jatropha curcas were crossed in half diallel fashion, and the F1s were evaluated to determine the combining ability for nine germination parameters. The ratio between general combining ability (GCA and specific combining ability (SCA variances indicated preponderance of additive gene action for all the characters except germination percentage, time of 50% germination, seedling length, and seedling vigor index. The parents P1 and P2 were the best general combiner for most of the characters studied. The cross P1×P5 was the best specific combiner for speed of emergence, germination percentage, germination energy, germination index, and seedling vigor index, the cross P2×P5 for mean germination time, time of 50% germination, and seedling length, and the cross P4×P5 for number of days to first germination. The germination percentage varied from 58.06 to 92.76% among the parents and 53.43 to 98.96% among the hybrids. The highest germination (98.96% was observed in hybrid P2×P4, and none of the hybrids or parents showed 100% germination. The highest germination index (GI and seedling vigor index (SVI were found in hybrid P1×P5 and P2×P5, respectively. The results of this study provide clue for the improvement of Jatropha variety through breeding program.

A marked animal-vegetal polarity in the localization of Na(+),K(+) -ATPase activity and its down-regulation following progesterone-induced maturation.

Science.gov (United States)

Mohanty, Basant Kumar; Gupta, Brij L

2012-02-01

The stage-VI Xenopus oocyte has a very distinct animal-vegetal polarity with structural and functional asymmetry. In this study, we show the expression and distribution pattern of Na(+),K(+) -ATPase in stage-VI oocytes, and its changes following progesterone-induced maturation. Using enzyme-specific electron microscopy phosphatase histochemistry, [(3) H]-ouabain autoradiography, and immunofluorescence cytochemistry at light microscopic level, we find that Na(+),K(+) -ATPase activity is mainly confined to the animal hemisphere. Electron microscopy histochemical results also suggest that polarized distribution of Na(+),K(+) -ATPase activity persists following progesterone-induced maturation, and it becomes gradually more polarized towards the animal pole. The time course following progesterone-induced maturation suggests that there is an initial up-regulation and then gradual down-regulation of Na(+),K(+) -ATPase activity leading to germinal vesicle breakdown (GVBD). By GVBD, the Na(+),K(+) -ATPase activity is completely down-regulated due to endocytotic removal of pump molecules from the plasma membrane into the sub-cortical region of the oocyte. This study provides the first direct evidence for a marked asymmetric localization of Na(+),K(+) -ATPase activity in any vertebrate oocyte. Here, we propose that such asymmetry in Na(+),K(+) -ATPase activity in stage-VI oocytes, and their down-regulation following progesterone-induced maturation, is likely to have a role in the active state of the germinal vesicle in stage-VI oocytes and chromosomal condensation after GVBD. Copyright © 2011 Wiley Periodicals, Inc.

Effect of the Application of Gibberellin (GA3 on Tomato Seed Germination (Solanum Lycopersicum L. Variety Santa Cruz

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Yuli Alexandra Deaquiz-Oyola

2013-12-01

Full Text Available The tomato is one of the most important vegetable, economical and nutritionally, around the world. For this reason the germination process in the tomato is a vital stage in the growth and development of plants. In this study, the effect of different doses of gibberellin over the germination of Santa Cruz variety tomato seeds was evaluated. The seeds were embedded for 24 hours in different concentrations of gibberellic acid, sown in a peat substrate in the screen house of the UPTC. A complete randomized design was used with 4 treatments corresponding to 0, 100, 200 and 400 mg L-1 of GAs with three replicates, for a total of 12 experimental units (EU, and each unit with 35 seeds. The treatment of 0 mg L-1 had a favorable impact on the mean germination time (GT, average speed of germination (ASG and germination percentage (GP, showing significant differences with respect to the other treatments. The seeds soaked in 400 mg L-1 of GAs presented the lowest values in the variables GT, ASG and GP, attributed to negative effect this type of hormone over this tomato variety, which delayed the death of the embryo and the seed germination.

Molecular mobility in Medicago truncatula seed during early stage of germination: Neutron scattering and NMR investigations

Energy Technology Data Exchange (ETDEWEB)

Falourd, Xavier [UR1268 Biopolymères Interactions Assemblages, INRA, F-44316 Nantes (France); Natali, Francesca [CNR-IOM-OGG, c/o Institut Laue-Langevin, 6 rue Jules Horowitz, BP 156, 38042 Grenoble Cedex 9 (France); Institut Laue-Langevin, 6 rue Jules Horowitz, BP 156, 38042 Grenoble Cedex 9 (France); Peters, Judith [Institut Laue-Langevin, 6 rue Jules Horowitz, BP 156, 38042 Grenoble Cedex 9 (France); Université Joseph Fourier UFR PhITEM, BP 53, 38041 Grenoble Cedex 9 (France); Institut de Biologie Structurale, 41 rue Jules Horowitz, 38027 Grenoble Cedex 1 (France); Foucat, Loïc, E-mail: Loic.Foucat@nantes.inra.fr [UR1268 Biopolymères Interactions Assemblages, INRA, F-44316 Nantes (France)

2014-01-15

Highlights: • Neutron scattering and NMR approaches were used to characterize seed germination. • A parallel between macromolecular motions and water dynamics was established. • Freezing/thawing cycle revealed a hysteresis connected to the seed hydration level. - Abstract: First hours of Medicago truncatula (MT) seeds germination were investigated using elastic incoherent neutron scattering (EINS) and nuclear magnetic resonance (NMR), to follow respectively how macromolecular motions and water mobility evolve when water permeates into the seed. From EINS results, it was shown that there is an increase in macromolecular mobility with the water uptake. Changes in NMR relaxation parameters reflected microstructural changes associated with the recovery of the metabolic processes. The EINS investigation of the effect of temperature on macromolecular motions showed that there is a relationship between the amount of water in the seeds and the effect of freezing–thawing cycle. The NMR relaxometry results obtained at 253 K allowed establishing possible link between the freezing of water molecules tightly bound to macromolecules and their drastic motion restriction around 250 K, as observed with EINS at the highest water content.

Klf8 regulates left-right asymmetric patterning through modulation of Kupffer's vesicle morphogenesis and spaw expression.

Science.gov (United States)

Lin, Che-Yi; Tsai, Ming-Yuan; Liu, Yu-Hsiu; Lu, Yu-Fen; Chen, Yi-Chung; Lai, Yun-Ren; Liao, Hsin-Chi; Lien, Huang-Wei; Yang, Chung-Hsiang; Huang, Chang-Jen; Hwang, Sheng-Ping L

2017-07-17

Although vertebrates are bilaterally symmetric organisms, their internal organs are distributed asymmetrically along a left-right axis. Disruption of left-right axis asymmetric patterning often occurs in human genetic disorders. In zebrafish embryos, Kupffer's vesicle, like the mouse node, breaks symmetry by inducing asymmetric expression of the Nodal-related gene, spaw, in the left lateral plate mesoderm (LPM). Spaw then stimulates transcription of itself and downstream genes, including lft1, lft2, and pitx2, specifically in the left side of the diencephalon, heart and LPM. This developmental step is essential to establish subsequent asymmetric organ positioning. In this study, we evaluated the role of krüppel-like factor 8 (klf8) in regulating left-right asymmetric patterning in zebrafish embryos. Zebrafish klf8 expression was disrupted by both morpholino antisense oligomer-mediated knockdown and a CRISPR-Cas9 system. Whole-mount in situ hybridization was conducted to evaluate gene expression patterns of Nodal signalling components and the positions of heart and visceral organs. Dorsal forerunner cell number was evaluated in Tg(sox17:gfp) embryos and the length and number of cilia in Kupffer's vesicle were analyzed by immunocytochemistry using an acetylated tubulin antibody. Heart jogging, looping and visceral organ positioning were all defective in zebrafish klf8 morphants. At the 18-22 s stages, klf8 morphants showed reduced expression of genes encoding Nodal signalling components (spaw, lft1, lft2, and pitx2) in the left LPM, diencephalon, and heart. Co-injection of klf8 mRNA with klf8 morpholino partially rescued spaw expression. Furthermore, klf8 but not klf8△zf overexpressing embryos showed dysregulated bilateral expression of Nodal signalling components at late somite stages. At the 10s stage, klf8 morphants exhibited reductions in length and number of cilia in Kupffer's vesicle, while at 75% epiboly, fewer dorsal forerunner cells were observed

Practical aspects of temperature intervention in germination and post-germination development of bacterial spores

International Nuclear Information System (INIS)

Stastna, J.; Vinter, V.; Babicka, J.

1974-01-01

Temperature dependence of germination and post-germination growth was studied in the spores of B a c i l l u s c e r e u s NCIB 8122. It was found that a temperature of 5 0 C slowed down germination, with the cells showing the capacity of synthetizing only a limited amount of proteins. The synthesis of the cellular wall, however, went on for another few hours. Thick-walled, less permeable and less metabolically active cells formed having an altered ultrastructure. A prolonged cultivation at 30 0 C resulted in the reduction of living cells while the low cultivation temperature (5 0 C) was found to have a protective effect. Pre-irradiation with 30g krad of gamma radiation increased the sensitivity of surviving cells to the cultivation conditions. Spores in the post-germination period were found to be much more resistent and alternating use of low and higher temperatures had little effect on growth

Hierarchical unilamellar vesicles of controlled compositional heterogeneity.

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Maik Hadorn

Full Text Available Eukaryotic life contains hierarchical vesicular architectures (i.e. organelles that are crucial for material production and trafficking, information storage and access, as well as energy production. In order to perform specific tasks, these compartments differ among each other in their membrane composition and their internal cargo and also differ from the cell membrane and the cytosol. Man-made structures that reproduce this nested architecture not only offer a deeper understanding of the functionalities and evolution of organelle-bearing eukaryotic life but also allow the engineering of novel biomimetic technologies. Here, we show the newly developed vesicle-in-water-in-oil emulsion transfer preparation technique to result in giant unilamellar vesicles internally compartmentalized by unilamellar vesicles of different membrane composition and internal cargo, i.e. hierarchical unilamellar vesicles of controlled compositional heterogeneity. The compartmentalized giant unilamellar vesicles were subsequently isolated by a separation step exploiting the heterogeneity of the membrane composition and the encapsulated cargo. Due to the controlled, efficient, and technically straightforward character of the new preparation technique, this study allows the hierarchical fabrication of compartmentalized giant unilamellar vesicles of controlled compositional heterogeneity and will ease the development of eukaryotic cell mimics that resemble their natural templates as well as the fabrication of novel multi-agent drug delivery systems for combination therapies and complex artificial microreactors.

seed germination and seedlings growth

African Journals Online (AJOL)

STORAGESEVER

2007-12-17

Dec 17, 2007 ... The role of 20E in plant physiology including seed germination is not studied. ..... GA3, ABA and CKs on lettuce Lactuca sativa seed germination are ..... Practical uses for ecdysteroids in mammals and humans: an update. J.

Etude des potentialites germinatives pour une regeneration ...

African Journals Online (AJOL)

... taux de germination a été obtenu avec des graines de petites tailles à la température ambiante (32°C). Le traitement préalable à l'eau de javel à 8% accroît le taux de germination (40% de réponse). La lumière et l'obscurité n'ont aucun effet sur la germination. Mots clés : Neocarya macrophylla, germination, régénération.

Seed germination in relation to the invasiveness in spiny amaranth and edible amaranth in Xishuangbanna, SW China.

Science.gov (United States)

Ye, Juan; Wen, Bin

2017-01-01

Both spiny and edible amaranths (Amaranthus spinosus and A. tricolor) are exotic annuals in China that produce numerous small seeds every year. Spiny amaranth has become a successful invader and a troublesome weed in Xishuangbanna, but edible amaranth has not, although it is widely grown as a vegetable there. As seed germination is one of the most important life-stages contributing to the ability of a plant to become invasive, we conducted experiments to compare the effects of high temperature and water stress on seed germination in two varieties each of spiny amaranth and edible amaranth. Overall, the seeds of both amaranth species exhibited adaptation to high temperature and water stress, including tolerance to ground temperatures of 70°C for air-dried seeds, which is consistent with their behavior in their native ranges in the tropics. As expected, the invasive spiny amaranth seeds exhibited higher tolerance to both continuous and daily periodic high-temperature treatment at 45°C, and to imbibition-desiccation treatment, compared to edible amaranth seeds. Unexpectedly, edible amaranth seeds exhibited higher germination at extreme temperatures (10°C, 15°C, and 40°C), and at lower water potential (below -0.6 MPa). It is likely that cultivation of edible amaranth has selected seed traits that include rapid germination and germination under stressful conditions, either of which, under natural conditions, may result in the death of most germinating edible amaranth seeds and prevent them from becoming invasive weeds in Xishuangbanna. This study suggests that rapid germination and high germination under stress conditions-excellent seed traits for crops and for many invasive species-might be a disadvantage under natural conditions if these traits are asynchronous with natural local conditions that support successful germination.

Seed germination in relation to the invasiveness in spiny amaranth and edible amaranth in Xishuangbanna, SW China.

Directory of Open Access Journals (Sweden)

Juan Ye

Full Text Available Both spiny and edible amaranths (Amaranthus spinosus and A. tricolor are exotic annuals in China that produce numerous small seeds every year. Spiny amaranth has become a successful invader and a troublesome weed in Xishuangbanna, but edible amaranth has not, although it is widely grown as a vegetable there. As seed germination is one of the most important life-stages contributing to the ability of a plant to become invasive, we conducted experiments to compare the effects of high temperature and water stress on seed germination in two varieties each of spiny amaranth and edible amaranth. Overall, the seeds of both amaranth species exhibited adaptation to high temperature and water stress, including tolerance to ground temperatures of 70°C for air-dried seeds, which is consistent with their behavior in their native ranges in the tropics. As expected, the invasive spiny amaranth seeds exhibited higher tolerance to both continuous and daily periodic high-temperature treatment at 45°C, and to imbibition-desiccation treatment, compared to edible amaranth seeds. Unexpectedly, edible amaranth seeds exhibited higher germination at extreme temperatures (10°C, 15°C, and 40°C, and at lower water potential (below -0.6 MPa. It is likely that cultivation of edible amaranth has selected seed traits that include rapid germination and germination under stressful conditions, either of which, under natural conditions, may result in the death of most germinating edible amaranth seeds and prevent them from becoming invasive weeds in Xishuangbanna. This study suggests that rapid germination and high germination under stress conditions-excellent seed traits for crops and for many invasive species-might be a disadvantage under natural conditions if these traits are asynchronous with natural local conditions that support successful germination.

Intracellular vesicle acidification promotes maturation of infectious poliovirus particles.

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Alexsia L Richards

Full Text Available The autophagic pathway acts as part of the immune response against a variety of pathogens. However, several pathogens subvert autophagic signaling to promote their own replication. In many cases it has been demonstrated that these pathogens inhibit or delay the degradative aspect of autophagy. Here, using poliovirus as a model virus, we report for the first time bona fide autophagic degradation occurring during infection with a virus whose replication is promoted by autophagy. We found that this degradation is not required to promote poliovirus replication. However, vesicular acidification, which in the case of autophagy precedes delivery of cargo to lysosomes, is required for normal levels of virus production. We show that blocking autophagosome formation inhibits viral RNA synthesis and subsequent steps in the virus cycle, while inhibiting vesicle acidification only inhibits the final maturation cleavage of virus particles. We suggest that particle assembly, genome encapsidation, and virion maturation may occur in a cellular compartment, and we propose the acidic mature autophagosome as a candidate vesicle. We discuss the implications of our findings in understanding the late stages of poliovirus replication, including the formation and maturation of virions and egress of infectious virus from cells.

Ganglioside GM1 spontaneous transfer between phospholipid vesicles

International Nuclear Information System (INIS)

Brown, R.E.; Sugar, I.P.; Thompson, T.E.

1986-01-01

The transfer kinetics of the monosiaylated glycosphingolipid, GM 1 , between different size phospholipid vesicles was measured using molecular sieve chromatography. At desired time intervals, small unilamellar donor vesicles were separated from large unilamellar acceptor vesicles by elution from a Sephacryl S-500 column [ 3 H]-GM 1 net transfer was calculated relative to [ 14 C]-cholesteryl oleate, which served as a nontransferable marker in the donor vesicles. The initial GM 1 transfer rate between 1-palmitoyl-2-oleoyl phosphatidylcholine vesicles at 45 0 C deviated slightly from first order kinetics and possessed a half time of 3.6 days. This transfer half time is an order of magnitude shorter than that observed from the desiaylated derivative of GM 1 . The transfer kinetics are consistent with the authors recent electron microscopic results suggesting a molecular distribution of GM 1 in liquid-crystalline phosphatidylcholine bilayers

7 CFR 201.53 - Source of seeds for germination.

Science.gov (United States)

2010-01-01

... REGULATIONS Germination Tests in the Administration of the Act § 201.53 Source of seeds for germination. (a) When both purity and germination tests are required, seeds for germination shall be taken from the... to size or appearance. (b) When only a germination test is required and the pure seed is estimated or...

Influence of environmental factors on the germination of Urena lobata L. and its response to herbicides.

Directory of Open Access Journals (Sweden)

Tahir Hussain Awan

Full Text Available Urena lobata is becoming a noxious and invasive weed in rangelands, pastures, and undisturbed areas in the Philippines. This study determined the effects of seed scarification, light, salt and water stress, amount of rice residue, and seed burial depth on seed germination and emergence of U. lobata; and evaluated the weed's response to post-emergence herbicides. Germination was stimulated by both mechanical and chemical seed scarifications. The combination of the two scarification methods provided maximum (99% seed germination. Germination was slightly stimulated when seeds were placed in light (65% compared with when seeds were kept in the dark (46%. Sodium chloride concentrations ranging from 0 to 200 mM and osmotic potential ranging from 0 to -1.6 MPa affected the germination of U. lobata seeds significantly. The osmotic potential required for 50% inhibition of the maximum germination was -0.1 MPa; however, some seeds germinated at -0.8 MPa, but none germinated at -1.6 MPa. Seedling emergence and biomass increased with increase in rice residue amount up to 4 t ha(-1, but declined beyond this amount. Soil surface placement of weed seeds resulted in the highest seedling emergence (84%, which declined with increase in burial depth. The burial depth required for 50% inhibition of maximum emergence was 2 cm; emergence was greatly reduced (93% at burial depth of 4 cm or more. Weed seedling biomass also decreased with increase in burial depth. Bispyribac-sodium, a commonly used herbicide in rice, sprayed at the 4-leaf stage of the weed, provided 100% control, which did not differ much with 2,4-D (98%, glyphosate (97%, and thiobencarb + 2,4-D (98%. These herbicides reduced shoot and root biomass by 99-100%.

Influence of diesel fuel on seed germination

International Nuclear Information System (INIS)

Adam, Gillian; Duncan, Harry

2002-01-01

The volatile fraction of diesel fuel played a major role in delaying seed emergence and reducing percentage germination. - The use of plant-based systems to remediate contaminated soils has become an area of intense scientific study in recent years and it is apparent that plants which grow well in contaminated soils need to be identified and screened for use in phytoremediation technologies. This study investigated the effect of diesel fuel on germination of selected plant species. Germination response varied greatly with plant species and was species specific, as members of the same plant family showed differential sensitivity to diesel fuel contamination. Differences were also seen within plant subspecies. At relatively low levels of diesel fuel contamination, delayed seed emergence and reduced percentage germination was observed for the majority of plant species investigated. Results suggest the volatile fraction of diesel fuel played an influential role in delaying seed emergence and reducing percentage germination. In addition, the remaining diesel fuel in the soil added to this inhibitory effect on germination by physically impeding water and oxygen transfer between the seed and the surrounding soil environment, thus hindering the germination response

Profiling extracellular vesicle release by the filarial nematode Brugia malayi reveals sex-specific differences in cargo and a sensitivity to ivermectin.

Directory of Open Access Journals (Sweden)

Hiruni Harischandra

2018-04-01

Full Text Available The filarial nematode Brugia malayi is an etiological agent of Lymphatic Filariasis. The capability of B. malayi and other parasitic nematodes to modulate host biology is recognized but the mechanisms by which such manipulation occurs are obscure. An emerging paradigm is the release of parasite-derived extracellular vesicles (EV containing bioactive proteins and small RNA species that allow secretion of parasite effector molecules and their potential trafficking to host tissues. We have previously described EV release from the infectious L3 stage B. malayi and here we profile vesicle release across all intra-mammalian life cycle stages (microfilariae, L3, L4, adult male and female worms. Nanoparticle Tracking Analysis was used to quantify and size EVs revealing discrete vesicle populations and indicating a secretory process that is conserved across the life cycle. Brugia EVs are internalized by murine macrophages with no preference for life stage suggesting a uniform mechanism for effector molecule trafficking. Further, the use of chemical uptake inhibitors suggests all life stage EVs are internalized by phagocytosis. Proteomic profiling of adult male and female EVs using nano-scale LC-MS/MS described quantitative and qualitative differences in the adult EV proteome, helping define the biogenesis of Brugia EVs and revealing sexual dimorphic characteristics in immunomodulatory cargo. Finally, ivermectin was found to rapidly inhibit EV release by all Brugia life stages. Further this drug effect was also observed in the related filarial nematode, the canine heartworm Dirofilaria immitis but not in an ivermectin-unresponsive field isolate of that parasite, highlighting a potential mechanism of action for this drug and suggesting new screening platforms for anti-filarial drug development.

IAA production during germination of Orobanche spp. seeds.

Science.gov (United States)

Slavov, Slavtcho; van Onckelen, Henry; Batchvarova, Rossitza; Atanassov, Atanas; Prinsen, Els

2004-07-01

Broomrapes (Orobanche spp.) are parasitic plants, whose growth and development fully depend on the nutritional connection established between the parasite and the roots of the respective host plant. Phytohormones are known to play a role in establishing the specific Orobanche-host plant interaction. The first step in the interaction is seed germination triggered by a germination stimulant secreted by the host-plant roots. We quantified indole-3-acetic acid (IAA) and abscisic acid (ABA) during the seed germination of tobacco broomrape (Orobanche ramosa) and sunflower broomrape (O. cumana). IAA was mainly released from Orobanche seeds in host-parasite interactions as compared to non-host-parasite interactions. Moreover, germinating seeds of O. ramosa released IAA as early as 24 h after the seeds were exposed to the germination stimulant, even before development of the germ tube. ABA levels remained unchanged during the germination of the parasites' seeds. The results presented here show that IAA production is probably part of a mechanism triggering germination upon the induction by the host factor, thus resulting in seed germination.

DELAY OF GERMINATION 1 mediates a conserved coat-dormancy mechanism for the temperature- and gibberellin-dependent control of seed germination

OpenAIRE

Graeber, K.; Linkies, A.; Steinbrecher, T.; Tarkowská, D. (Danuše); Turečková, V. (Veronika); Ignatz, M.; Voegele, A.; Urbanová, T. (Terezie); Strnad, M. (Miroslav); Leubner-Metzger, G. (Gerhard)

2014-01-01

Seed germination is an important life-cycle transition because it determines subsequent plant survival and reproductive success. To detect optimal spatiotemporal conditions for germination, seeds act as sophisticated environmental sensors integrating information such as ambient temperature. Here we show that the DELAY OF GERMINATION 1 (DOG1) gene, known for providing dormancy adaptation to distinct environments, determines the optimal temperature for seed germination. By reciprocal gene-swapp...

Methods for assessing Phytophthora ramorum chlamydospore germination

Science.gov (United States)

Joyce Eberhart; Elilzabeth Stamm; Jennifer Parke

2013-01-01

Germination of chlamydospores is difficult to accurately assess when chlamydospores are attached to remnants of supporting hyphae. We developed two approaches for closely observing and rigorously quantifying the frequency of chlamydospore germination in vitro. The plate marking and scanning method was useful for quantifying germination of large...

Low-resolution simulations of vesicle suspensions in 2D

Science.gov (United States)

Kabacaoğlu, Gökberk; Quaife, Bryan; Biros, George

2018-03-01

Vesicle suspensions appear in many biological and industrial applications. These suspensions are characterized by rich and complex dynamics of vesicles due to their interaction with the bulk fluid, and their large deformations and nonlinear elastic properties. Many existing state-of-the-art numerical schemes can resolve such complex vesicle flows. However, even when using provably optimal algorithms, these simulations can be computationally expensive, especially for suspensions with a large number of vesicles. These high computational costs can limit the use of simulations for parameter exploration, optimization, or uncertainty quantification. One way to reduce the cost is to use low-resolution discretizations in space and time. However, it is well-known that simply reducing the resolution results in vesicle collisions, numerical instabilities, and often in erroneous results. In this paper, we investigate the effect of a number of algorithmic empirical fixes (which are commonly used by many groups) in an attempt to make low-resolution simulations more stable and more predictive. Based on our empirical studies for a number of flow configurations, we propose a scheme that attempts to integrate these fixes in a systematic way. This low-resolution scheme is an extension of our previous work [51,53]. Our low-resolution correction algorithms (LRCA) include anti-aliasing and membrane reparametrization for avoiding spurious oscillations in vesicles' membranes, adaptive time stepping and a repulsion force for handling vesicle collisions and, correction of vesicles' area and arc-length for maintaining physical vesicle shapes. We perform a systematic error analysis by comparing the low-resolution simulations of dilute and dense suspensions with their high-fidelity, fully resolved, counterparts. We observe that the LRCA enables both efficient and statistically accurate low-resolution simulations of vesicle suspensions, while it can be 10× to 100× faster.

Germination of red alder seed.

Science.gov (United States)

M.A. Radwan; D.S. DeBell

1981-01-01

Red alder seeds were collected from six locations throughout the natural range of the species. Each seed lot was obtained from a single tree, and the seeds were used to determine germination with and without stratification treatment. Irrespective of treatment, germination varied significantly (P

Germination and elongation of flax in microgravity

Science.gov (United States)

Levine, Howard G.; Anderson, Ken; Boody, April; Cox, Dave; Kuznetsov, Oleg A.; Hasenstein, Karl H.

2003-05-01

This experiment was conducted as part of a risk mitigation payload aboard the Space Shuttle Atlantis on STS-101. The objectives were to test a newly developed water delivery system, and to determine the optimal combination of water volume and substrate for the imbibition and germination of flax ( Linum usitatissimum) seeds in space. Two different combinations of germination paper were tested for their ability to absorb, distribute, and retain water in microgravity. A single layer of thick germination paper was compared with one layer of thin germination paper under a layer of thick paper. Paper strips were cut to fit snugly into seed cassettes, and seeds were glued to them with the micropyle ends pointing outward. Water was delivered in small increments that traveled through the paper via capillary action. Three water delivery volumes were tested, with the largest (480 μL) outperforming the 400 μL, and 320 μL volumes for percent germination (90.6%) and root growth (mean = 4.1 mm) during the 34-hour spaceflight experiment. The ground control experiment yielded similar results, but with lower rates of germination (84.4%) and shorter root lengths (mean = 2.8 mm). It is not clear if the roots emerged more quickly in microgravity and/or grew faster than the ground controls. The single layer of thick germination paper generally exhibited better overall growth than the two layered option. Significant seed position effects were observed in both the flight and ground control experiments. Overall, the design of the water delivery system, seed cassettes and the germination paper strip concept was validated as an effective method for promoting seed germination and root growth under microgravity conditions.

The oxygen requirement of germinating flax seeds

Science.gov (United States)

Kuznetsov, O.; Hasenstein, K.

Experiments for earth orbit are typically prepared on the ground and often germinated in orbit in order to study gravity effects on developing seedlings. Germination requires the breakdown of storage compounds and respiration. In orbit the formation of a water layer around the seed may further limit oxygen availability. Therefore, the oxygen content of the available gas volume is one of the limiting factors for seed germination. In preparation for an upcoming shuttle experiment (MICRO on STS-107) we studied germination and growth of flax (Linum usitatissimum L.) seedlings in the developed hardware. We tested per seed chamber (gas volume = 14 mL, O2 = 2.9 mL) between 4 to 32 seeds glued to germination paper by 1% (w/v) gum guar. A lexan cover and a gasket hermetically sealed each of the eight chambers. For imbibition of the seeds a previously optimized amount of distilled water was dispensed through sealed inlets. The seedlings were allowed to grow for either 32 to 48 h on a clinostat or without microgravity simulation. Then their root length was measured. With 32 seeds per chamber, four times the intended number of seeds for the flight, the germination rate decreased from 94 to 69%, and the root length was reduced by 20%. Experiments on the germination and root length in controlled atmospheres (5, 10, 15 and 21% O2 ) suggest that germination and growth for two days requires about 200 :l of O (1 mL air) per seed. Our2 experiments correlate oxygen dependency from seed mass and germination temperature, and analyze accumulation of gaseous metabolites (supported by NASA grant NAG10-0190).

Seminal vesicle intrafraction motion analysed with cinematic magnetic resonance imaging

International Nuclear Information System (INIS)

Gill, Suki; Dang, Kim; Fox, Chris; Bressel, Mathias; Kron, Tomas; Bergen, Noelene; Ferris, Nick; Owen, Rebecca; Chander, Sarat; Tai, Keen Hun; Foroudi, Farshad

2014-01-01

This study analyses seminal vesicle displacement relative to the prostate and in relation to treatment time. A group of eleven patients undergoing prostate cancer radiotherapy were imaged with a continuous 3 T cine-MRI in the standard treatment setup position. Four images were recorded every 4 seconds for 15 minutes in the sagittal plane and every 6.5 seconds for 12 minutes in the coronal plane. The prostate gland and seminal vesicles were contoured on each MRI image. The coordinates of the centroid of the prostate and seminal vesicles on each image was analysed for displacement against time. Displacements between the 2.5 percentile and 97.5 percentile (i.e. the 2.5% trimmed range) for prostate and seminal vesicle centroid displacements were measured for 3, 5, 10 and 15 minutes time intervals in the anterior-posterior (AP), left-right (LR) and superior-inferior (SI) directions. Real time prostate and seminal vesicle displacement was compared for individual patients. The 2.5% trimmed range for 3, 5, 10 and 15 minutes for the seminal vesicle centroids in the SI direction measured 4.7 mm; 5.8 mm; 6.5 mm and 7.2 mm respectively. In the AP direction, it was 4.0 mm, 4.5 mm, 6.5 mm, and 7.0 mm. In the LR direction for 3, 5 and 10 minutes; for the left seminal vesicle, it was 2.7 mm, 2.8 mm, 3.4 mm and for the right seminal vesicle, it was 3.4 mm, 3.3 mm, and 3.4 mm. The correlation between the real-time prostate and seminal vesicle displacement varied substantially between patients indicating that the relationship between prostate displacement and seminal vesicles displacement is patient specific with the majority of the patients not having a strong relationship. Our study shows that seminal vesicle motion increases with treatment time, and that the prostate and seminal vesicle centroids do not move in unison in real time, and that an additional margin is required for independent seminal vesicle motion if treatment localisation is to the prostate

The International Society for Extracellular Vesicles launches the first massive open online course on extracellular vesicles.

Science.gov (United States)

Lässer, Cecilia; Théry, Clotilde; Buzás, Edit I; Mathivanan, Suresh; Zhao, Weian; Gho, Yong Song; Lötvall, Jan

2016-01-01

The International Society for Extracellular Vesicles (ISEV) has organised its first educational online course for students and beginners in the field of extracellular vesicles (EVs). This course, "Basics of Extracellular Vesicles," uses recorded lectures from experts in the field and will be open for an unlimited number of participants. The course is divided into 5 modules and can be accessed at www.coursera.org/learn/extracellular-vesicles. The first module is an introduction to the field covering the nomenclature and history of EVs. Module 2 focuses on the biogenesis and uptake mechanisms of EVs, as well as their RNA, protein and lipid cargo. Module 3 covers the collection and processing of cell culture media and body fluids such as blood, breast milk, cerebrospinal fluid and urine prior to isolation of EVs. Modules 4 and 5 present different isolation methods and characterisation techniques utilised in the EV field. Here, differential ultracentrifugation, size-exclusion chromatography, density gradient centrifugation, kit-based precipitation, electron microscopy, cryo-electron microscopy, flow cytometry, atomic-force microscopy and nanoparticle-tracking analysis are covered. This first massive open online course (MOOC) on EVs was launched on 15 August 2016 at the platform "Coursera" and is free of charge.

Ca2+-dependent mobility of vesicles capturing anti-VGLUT1 antibodies

International Nuclear Information System (INIS)

Stenovec, Matjaz; Kreft, Marko; Grilc, Sonja; Potokar, Maja; Kreft, Mateja Erdani; Pangrsic, Tina; Zorec, Robert

2007-01-01

Several aspects of secretory vesicle cycle have been studied in the past, but vesicle trafficking in relation to the fusion site is less well understood. In particular, the mobility of recaptured vesicles that traffic back toward the central cytoplasm is still poorly defined. We exposed astrocytes to antibodies against the vesicular glutamate transporter 1 (VGLUT1), a marker of glutamatergic vesicles, to fluorescently label vesicles undergoing Ca 2+ -dependent exocytosis and examined their number, fluorescence intensity, and mobility by confocal microscopy. In nonstimulated cells, immunolabeling revealed discrete fluorescent puncta, indicating that VGLUT1 vesicles, which are approximately 50 nm in diameter, cycle slowly between the plasma membrane and the cytoplasm. When the cytosolic Ca 2+ level was raised with ionomycin, the number and fluorescence intensity of the puncta increased, likely because the VGLUT1 epitopes were more accessible to the extracellularly applied antibodies following Ca 2+ -triggered exocytosis. In nonstimulated cells, the mobility of labeled vesicles was limited. In stimulated cells, many vesicles exhibited directional mobility that was abolished by cytoskeleton-disrupting agents, indicating dependence on intact cytoskeleton. Our findings show that postfusion vesicle mobility is regulated and may likely play a role in synaptic vesicle cycle, and also more generally in the genesis and removal of endocytic vesicles

Is seed conditioning essential for Orobanche germination?

Science.gov (United States)

Plakhine, Dina; Ziadna, Hammam; Joel, Daniel M

2009-05-01

Parasitic Orobanchaceae germinate only after receiving a chemical stimulus from roots of potential host plants. A preparatory phase of several days that follows seed imbibition, termed conditioning, is known to be required; thereafter the seeds can respond to germination stimulants. The aim of this study was to examine whether conditioning is essential for stimulant receptivity. Non-conditioned seeds of both Orobanche cumana Wallr. and O. aegyptiaca Pers. [syn. Phelipanche aegyptiaca (Pers.) Pomel] were able to germinate in response to chemical stimulation by GR24 even without prior conditioning. Stimulated seeds reached maximal germination rates about 2 weeks after the onset of imbibition, no matter whether the seeds had or had not been conditioned before stimulation. Whereas the lag time between stimulation and germination response of non-conditioned seeds was longer than for conditioned seeds, the total time between imbibition and germination was shorter for the non-conditioned seeds. Unlike the above two species, O. crenata Forsk. was found to require conditioning prior to stimulation. Seeds of O. cumana and O. aegyptiaca are already receptive before conditioning. Thus, conditioning is not involved in stimulant receptivity. A hypothesis is put forward, suggesting that conditioning includes (a) a parasite-specific early phase that allows the imbibed seeds to overcome the stress caused by failing to receive an immediate germination stimulus, and (b) a non-specific later phase that is identical to the pregermination phase between seed imbibition and actual germination that is typical for all higher plants.

Roles of gibberellins and abscisic acid in regulating germination of Suaeda salsa dimorphic seeds under salt stress

Directory of Open Access Journals (Sweden)

Weiqiang eLi

2016-01-01

Full Text Available Seed heteromorphism observed in many halophytes is an adaptive phenomenon toward high salinity. However, the relationship between heteromorphic seed germination and germination-related hormones under salt stress remains elusive. To gain an insight into this relationship, the roles of gibberellins (GAs and abscisic acid (ABA in regulating germination of Suaeda salsa dimorphic brown and black seeds under salinity were elucidated by studying the kinetics of the two hormones during germination of the two seed types with or without salinity treatment. Morphological analysis suggested that brown and black are in different development stage. The content of ABA was higher in dry brown than in black seeds, which gradually decreased after imbibition in water and salt solutions. Salt stress induced ABA accumulation in both germinating seed types, with higher induction effect on black than brown seeds. Black seeds showed lower germination percentage than brown seeds under both water and salt stress, which might be attributed to their higher ABA sensitivity rather than the difference in ABA content between black and brown seeds. Bioactive GA4 and its biosynthetic precursors showed higher levels in brown than in black seeds, whereas deactivated GAs showed higher content in black than brown seeds in dry or in germinating water or salt solutions. High salinity inhibited seed germination through decreasing the levels of GA4 in both seeds, and the inhibited effect of salt stress on GA4 level of black seeds was more profound than that of brown seeds. Taken together higher GA4 content, and lower ABA sensitivity contributed to the higher germination percentage of brown seeds than black seeds in water and salinity; increased ABA content and sensitivity, and decreased GA4 content by salinity were more profound in black than brown seeds, which contributed to lower germination of black seeds than brown seeds in salinity. The differential regulation of ABA and GA

Minimal experimental requirements for definition of extracellular vesicles and their functions: a position statement from the International Society for Extracellular Vesicles.

Science.gov (United States)

Lötvall, Jan; Hill, Andrew F; Hochberg, Fred; Buzás, Edit I; Di Vizio, Dolores; Gardiner, Christopher; Gho, Yong Song; Kurochkin, Igor V; Mathivanan, Suresh; Quesenberry, Peter; Sahoo, Susmita; Tahara, Hidetoshi; Wauben, Marca H; Witwer, Kenneth W; Théry, Clotilde

2014-01-01

Secreted membrane-enclosed vesicles, collectively called extracellular vesicles (EVs), which include exosomes, ectosomes, microvesicles, microparticles, apoptotic bodies and other EV subsets, encompass a very rapidly growing scientific field in biology and medicine. Importantly, it is currently technically challenging to obtain a totally pure EV fraction free from non-vesicular components for functional studies, and therefore there is a need to establish guidelines for analyses of these vesicles and reporting of scientific studies on EV biology. Here, the International Society for Extracellular Vesicles (ISEV) provides researchers with a minimal set of biochemical, biophysical and functional standards that should be used to attribute any specific biological cargo or functions to EVs.

Characterization of physical and biochemical changes in plasma treated spinach seed during germination

Science.gov (United States)

Hye Ji, Sang; Ki, Se Hoon; Kang, Min Ho; Choi, Jin Sung; Park, Yeunsoo; Oh, Jaesung; Kim, Seong Bong; Yoo, Suk Jae; Choi, Eun Ha; Park, Gyungsoon

2018-04-01

Despite the accumulating data on the effect of plasma on seed germination, mechanisms of plasma action need more extensive research. In a previous study, we observed that high voltage nanosecond pulsed plasma enhanced the germination of spinach seeds and subsequent seedling growth. As a follow-up study, we investigated the physico-chemical, biochemical, and molecular changes in seed after plasma treatment, focusing on the early germination stage, to elucidate mechanism(s) for the stimulating effects of plasma on seed germination. The primary radicle protruded from seeds exposed to high voltage nanosecond pulsed plasma (one shot) slightly faster than the control seeds. The hydrophilicity of the seed surface significantly increased after treatment with high voltage nanosecond pulsed plasma (one shot). However, a very subtle increase in water uptake by plasma treated seeds was observed. Raman and FTIR spectroscopy analyses on chloroform extract of seed coats demonstrated no significant chemical etching on the surface of plasma treated seeds. This may be related to no dramatic increase in water absorption by seeds. The level of GA hormone and starch hydrolysis inside the plasma treated seeds was significantly elevated within 24 h. Taken together, our results suggest that high voltage nanosecond pulsed plasma may not only enhance hydrophilicity of the seed surface but also stimulate biochemical and molecular processes inside seed, leading to enhanced embryonic development.

Calmodulin stimulation of calcium transport in carrot microsomal vesicles

International Nuclear Information System (INIS)

Pierce, W.S.; Sze, H.

1987-01-01

ATP-dependent 45 Ca 2+ uptake into microsomal vesicles isolated from cultured carrot cells (Daucus carota Danvers) was stimulated 2-3 fold by 5 ug/ml calmodulin (CaM). Microsomal vesicles separated with a linear sucrose gradient showed two peaks with CaM-stimulated Ca 2+ uptake activities. One peak (at 1.12 g/cc) comigrated with the activity of the antimycin A-insensitive NADH-dependent cytochrome c reductase. This transport activity was enhanced 10-20 fold by 10 mM oxalate and appeared to be associates with vesicles derived primarily from the ER. The other peak of CaM-stimulated Ca 2+ uptake (at 1.17 g/cc) was not affected by oxalate. These vesicles are probably derived from the plasma membrane. Preliminary experiments with the low-density vesicles (ER) vesicles, indicate that inositol-1,4,5-trisphosphate caused a transient reduction in intravesicular Ca 2+ . These results are consistent with the ER being an important site of intracellular Ca 2+ regulation

Germination of beans and snap beans seed

Directory of Open Access Journals (Sweden)

Zdravković Milan

2000-01-01

Full Text Available The aim of this study was to investigate germination of good bean seed of the variety Galeb and the bad bean seed of the same variety. We were also interested in germination of bean and snap bean seed damaged by grain weevil, and in germination of the seed treated by freezing which was aimed at controlling grain weevil by cold. We also recorded the differences between bean and snap bean seed, which was or was not treated by freezing in laboratory conditions. This investigation was carried out by applying the two factorial block system. The obtained results were evaluated by the variance analysis and x2 test These results suggest that the bean seed of a bad fraction had low levels of germination, but still it was present. Although the seed of good appearance was carefully selected, germination was slightly lower than it should have been. The seed with the large amount of grain weevils performed a high level germination in laboratory conditions. There were no differences in germination between the seed injured by grain weevil either in beans or in snap beans. As for the seed treated or untreated by freezing, there also were no differences between beans and snap beans. .

The morphology of Ichthyophonus sp. in their mugilid hosts (Pisces: Teleostei) and following cultivation in vitro. A light and electron microscopy study.

Science.gov (United States)

Franco-Sierra, A; Alvarez-Pellitero, P

1999-07-01

The morphology of Ichthyophonus sp., a parasite of Mugil capito and Liza saliens, was investigated by light and transmission electron microscopy. The most frequent stage found in the fish hosts was the multinucleate spore, though germinating stages, hyphae, and endospores were also found. Different development patterns were observed in the media assayed for in vitro culture. Optimal growth and development were obtained in Eagle's minimum essential medium (MEM) supplemented with 10% fetal bovine serum at pH 7. Ultrastructural features of multinucleate spores, both in the fish host and in culture, were a fibrillar thick wall and an electron-lucent matrix, with large glycogen granules, some electron-dense bodies, large vacuoles, lipid inclusions, and endoplasmic reticulum mainly appearing among the nuclei. Mitochondria with scarce tubulovesicular cristae were observed in the different stages, mainly near the wall and the germinating sites. Condensed heterochromatin was rarely seen. A nucleus-associated organelle (NAO) was frequently observed, and dictyosome cisternae and vesicles appeared in its vicinity.

Germination and storage of pollen

NARCIS (Netherlands)

Visser, T.

1955-01-01

Germination of pear pollen markedly improved when boric acid was added to the medium. The pollen was more sensitive to boron in water than in 10 % sugar solution. Supplying weak solutions of boron to pear branches before flowering resulted in a good germination of the pollen in sugar solution

Deformation of phospholipid vesicles in an optical stretcher

OpenAIRE

Delabre , Ulysse; Feld , Kasper; Crespo , Eleonore; Whyte , Graeme; Sykes , Cecile; Seifert , Udo; Guck , Jochen

2015-01-01

International audience; Phospholipid vesicles are common model systems for cell membranes. Important aspects of the membrane function relate to its mechanical properties. Here we have investigated the deformation behaviour of phospholipid vesicles in a dual-beam laser trap, also called an optical stretcher. This study explicitly makes use of the inherent heating present in such traps to investigate the dependence of vesicle deformation on temperature. By using lasers with different wavelength...

Single-vesicle detection and analysis of peptide-induced membrane permeabilization

DEFF Research Database (Denmark)

Kristensen, Kasper; Ehrlich, Nicky; Henriksen, Jonas Rosager

2015-01-01

The capability of membrane-active peptides to disrupt phospholipid membranes is often studied by investigating peptide-induced leakage of quenched fluorescent molecules from large unilamellar lipid vesicles. In this article, we explore two fluorescence microscopy-based single-vesicle detection...... methods as alternatives to the quenching-based assays for studying peptide-induced leakage from large unilamellar lipid vesicles. Specifically, we use fluorescence correlation spectroscopy (FCS) to study the leakage of fluorescent molecules of different sizes from large unilamellar lipid vesicles...... dispersed in aqueous solution, and we use confocal imaging of surface-immobilized large unilamellar lipid vesicles to investigate whether there are heterogeneities in leakage between individual vesicles. Of importance, we design an experimental protocol that allows us to quantitatively correlate the results...

Factors Defining Field Germination of Oilseed Radish Seeds

Directory of Open Access Journals (Sweden)

N.V. Dorofeev

2013-08-01

Full Text Available Influence of temperature, depth of crops and granulometric of soil structure on germination speed, laboratory and field germination of oilseed radish seeds were studied. It was established that the period of seed-germination is defined both by temperature and granulometric structure of soil. The highest field germination was marked on sandy loam at depth of crops' seeds at 3 cm and 20°С.

Germination and elongation of flax in microgravity

Science.gov (United States)

Levine, Howard G.; Anderson, Ken; Boody, April; Cox, Dave; Kuznetsov, Oleg A.; Hasenstein, Karl H.

2003-01-01

This experiment was conducted as part of a risk mitigation payload aboard the Space Shuttle Atlantis on STS-101. The objectives were to test a newly developed water delivery system, and to determine the optimal combination of water volume and substrate for the imbibition and germination of flax (Linum usitatissimum) seeds in space. Two different combinations of germination paper were tested for their ability to absorb, distribute, and retain water in microgravity. A single layer of thick germination paper was compared with one layer of thin germination paper under a layer of thick paper. Paper strips were cut to fit snugly into seed cassettes, and seeds were glued to them with the micropyle ends pointing outward. Water was delivered in small increments that traveled through the paper via capillary action. Three water delivery volumes were tested, with the largest (480 microliters) outperforming the 400 microliters and 320 microliters volumes for percent germination (90.6%) and root growth (mean=4.1 mm) during the 34-hour spaceflight experiment. The ground control experiment yielded similar results, but with lower rates of germination (84.4%) and shorter root lengths (mean=2.8 mm). It is not clear if the roots emerged more quickly in microgravity and/or grew faster than the ground controls. The single layer of thick germination paper generally exhibited better overall growth than the two layered option. Significant seed position effects were observed in both the flight and ground control experiments. Overall, the design of the water delivery system, seed cassettes and the germination paper strip concept was validated as an effective method for promoting seed germination and root growth under microgravity conditions. c2003 COSPAR. Published by Elsevier Ltd. All rights reserved.

Plasma membrane aquaporins mediates vesicle stability in broccoli.

Directory of Open Access Journals (Sweden)

Maria Del Carmen Martínez-Ballesta

Full Text Available The use of in vitro membrane vesicles is attractive because of possible applications in therapies. Here we aimed to compare the stability and functionality of plasma membrane vesicles extracted from control and salt-treated broccoli. The impact of the amount of aquaporins was related to plasma membrane osmotic water permeability and the stability of protein secondary structure. Here, we describe for first time an increase in plant aquaporins acetylation under high salinity. Higher osmotic water permeability in NaCl vesicles has been related to higher acetylation, upregulation of aquaporins, and a more stable environment to thermal denaturation. Based on our findings, we propose that aquaporins play an important role in vesicle stability.

Active elastohydrodynamics of vesicles in narrow blind constrictions

Science.gov (United States)

Fai, T. G.; Kusters, R.; Harting, J.; Rycroft, C. H.; Mahadevan, L.

2017-11-01

Fluid-resistance limited transport of vesicles through narrow constrictions is a recurring theme in many biological and engineering applications. Inspired by the motor-driven movement of soft membrane-bound vesicles into closed neuronal dendritic spines, here we study this problem using a combination of passive three-dimensional simulations and a simplified semianalytical theory for the active transport of vesicles forced through constrictions by molecular motors. We show that the motion of these objects is characterized by two dimensionless quantities related to the geometry and to the strength of forcing relative to the vesicle elasticity. We use numerical simulations to characterize the transit time for a vesicle forced by fluid pressure through a constriction in a channel and find that relative to an open channel, transport into a blind end leads to the formation of a smaller forward-flowing lubrication layer that strongly impedes motion. When the fluid pressure forcing is complemented by forces due to molecular motors that are responsible for vesicle trafficking into dendritic spines, we find that the competition between motor forcing and fluid drag results in multistable dynamics reminiscent of the real system. Our study highlights the role of nonlocal hydrodynamic effects in determining the kinetics of vesicular transport in constricted geometries.

Minimal experimental requirements for definition of extracellular vesicles and their functions: a position statement from the International Society for Extracellular Vesicles

Directory of Open Access Journals (Sweden)

Jan Lötvall

2014-12-01

Full Text Available Secreted membrane-enclosed vesicles, collectively called extracellular vesicles (EVs, which include exosomes, ectosomes, microvesicles, microparticles, apoptotic bodies and other EV subsets, encompass a very rapidly growing scientific field in biology and medicine. Importantly, it is currently technically challenging to obtain a totally pure EV fraction free from non-vesicular components for functional studies, and therefore there is a need to establish guidelines for analyses of these vesicles and reporting of scientific studies on EV biology. Here, the International Society for Extracellular Vesicles (ISEV provides researchers with a minimal set of biochemical, biophysical and functional standards that should be used to attribute any specific biological cargo or functions to EVs.

Seed germination response to high temperature and water stress in three invasive Asteraceae weeds from Xishuangbanna, SW China.

Science.gov (United States)

Yuan, Xia; Wen, Bin

2018-01-01

Crassocephalum crepidioides, Conyza canadensis, and Ageratum conyzoides are alien annuals naturalized in China, which produce a large number of viable seeds every year. They widely grow in Xishuangbanna, becoming troublesome weeds that compete with crops for water and nutrients. As seed germination is among the most important life-stages which contribute to plant distribution and invasiveness, its adaptation to temperature and water stress were investigated in these three species. Results showed that: (1) These three species have wide temperature ranges to allow seed germination, i.e., high germination and seedling percentages were achieved between 15°C and 30°C, but germination was seriously inhibited at 35°C; only A. conyzoides demonstrated relative preference for warmer temperatures with approximately 25% germination and seedling percentage at 35°C; (2) light was a vital germination prerequisite for C. crepidioides and A. conyzoides, whereas most C. canadensis seeds germinated in full darkness; (3) Although all three species have good adaptation to bare ground habitat characterized by high temperatures and water stress, including their tolerance to soil surface temperatures of 70°C in air-dried seeds, A. conyzoides seeds exhibited higher tolerance to both continuous and daily periodic high-temperature treatment at 40°C, and to water restriction (e.g., ca. 65% seeds germinated to -0.8 MPa created by NaCl), which is consistent with their field behavior in Xishuangbanna. This study suggests that seed high-temperature tolerance contributes to the weed attributes of these three species, and that adaptation to local micro-habitats is a critical determinant for invasiveness of an alien plant.

Differential Effects of Carbohydrates on Arabidopsis Pollen Germination.

Science.gov (United States)

Hirsche, Jörg; García Fernández, José M; Stabentheiner, Edith; Großkinsky, Dominik K; Roitsch, Thomas

2017-04-01

Pollen germination as a crucial process in plant development strongly depends on the accessibility of carbon as energy source. Carbohydrates, however, function not only as a primary energy source, but also as important signaling components. In a comprehensive study, we analyzed various aspects of the impact of 32 different sugars on in vitro germination of Arabidopsis pollen comprising about 150 variations of individual sugars and combinations. Twenty-six structurally different mono-, di- and oligosaccharides, and sugar analogs were initially tested for their ability to support pollen germination. Whereas several di- and oligosaccharides supported pollen germination, hexoses such as glucose, fructose and mannose did not support and even considerably inhibited pollen germination when added to germination-supporting medium. Complementary experiments using glucose analogs with varying functional features, the hexokinase inhibitor mannoheptulose and the glucose-insensitive hexokinase-deficient Arabidopsis mutant gin2-1 suggested that mannose- and glucose-mediated inhibition of sucrose-supported pollen germination depends partially on hexokinase signaling. The results suggest that, in addition to their role as energy source, sugars act as signaling molecules differentially regulating the complex process of pollen germination depending on their structural properties. Thus, a sugar-dependent multilayer regulation of Arabidopsis pollen germination is supported, which makes this approach a valuable experimental system for future studies addressing sugar sensing and signaling. © The Author 2017. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Membrane Protrusion Coarsening and Nanotubulation within Giant Unilamellar Vesicles

KAUST Repository

Węgrzyn, Ilona

2011-11-16

Hydrophobic side groups on a stimuli-responsive polymer, encapsulated within a single giant unilamellar vesicle, enable membrane attachment during compartment formation at elevated temperatures. We thermally modulated the vesicle through implementation of an IR laser via an optical fiber, enabling localized directed heating. Polymer-membrane interactions were monitored using confocal imaging techniques as subsequent membrane protrusions occurred and lipid nanotubes formed in response to the polymer hydrogel contraction. These nanotubes, bridging the vesicle membrane to the contracting hydrogel, were retained on the surface of the polymer compartment, where they were transformed into smaller vesicles in a process reminiscent of cellular endocytosis. This development of a synthetic vesicle system containing a stimuli-responsive polymer could lead to a new platform for studying inter/intramembrane transport through lipid nanotubes. © 2011 American Chemical Society.

Effect of magnetic field on seed germination and seedling growth of sunflower

Science.gov (United States)

Matwijczuk, A.; Kornarzyński, K.; Pietruszewski, S.

2012-07-01

The impact of a variable magnetic field, magnetically treated water and a combination of both these factors on the germination of seeds and the final mass at the initial stage of growth sunflower plants was presented. Investigations were carried out in pots filled with sand, tin an air-conditioned plant house with no access to daylight using fluorescent light as illumination. A statistical significance positive impact was achieved for the samples subjected to the interaction of both stimulating factors simultaneously, the magnetic field and the impact of treated water several times on the speed of seed germination and final plant mass. Negative impacts were obtained for the majority of the test cases, for the magnetically treated water, the short duration of activity of the magnetic field and for the connection of the magnetic field and low-flow times.

Symbiotic germination of three species of epiphytic orchids susceptible to genetic erosion, from Soconusco (Chiapas, Mexico

Directory of Open Access Journals (Sweden)

Vincenzo Bertolini

2012-02-01

Full Text Available The Soconusco region of southeast Mexico has almost a quarter of the orchid species registered in Mexico and 37 threatened species (NOM-059-SEMARNAT-2001, many with severely reduced and non-viable populations. We chose two of the most threatened species, Rossioglossum grande (Lindl. Garay and G. C. Kenn. and Cuitlauzina convallarioides (Schltr. Dressler and N. H. Williams and a rare species recently discovered in the region, Rhynchostele bictoniensis (Bateman Soto Arenas and Salazar, to study the mycorrhizal fungi associated with the roots, isolate them and use them to induce seed germination and promote development in asymbiotically produced protocorms, in the laboratory. We isolated ten strains of Rhizoctonia-like orchid mycorrhizal fungi from Rossioglossum grande and three from Cuitlauzina convallarioides. Using selected fungal strains from the same species, we tested for the promotion of further development of asymbiotically pre-germinated protocorms of R. grande and the promotion of seed germination of C. convallarioides. In the case of R. bictoniensis, we studied the effects on seed germination of nine strains of Rhizoctonia-like fungi isolated from other orchid species. For R. grande, after 10 months, one strain of Rhizoctonia promoted development of the pre-germinated protocorms, and almost 90% of the protocorms produced rhizoids. For C. convallarioides, after 3 months, one fungal strain promoted protocorm development to the stage where they produced green tissue under illumination, suggesting the onset of photosynthesis. For R. bictoniensis three of the fungal strains (from other orchid species promoted germination and, after 4 months, autotrophic protocorms.

The International Society for Extracellular Vesicles launches the first massive open online course on extracellular vesicles

Directory of Open Access Journals (Sweden)

Cecilia Lässer

2016-12-01

Full Text Available The International Society for Extracellular Vesicles (ISEV has organised its first educational online course for students and beginners in the field of extracellular vesicles (EVs. This course, “Basics of Extracellular Vesicles,” uses recorded lectures from experts in the field and will be open for an unlimited number of participants. The course is divided into 5 modules and can be accessed at www.coursera.org/learn/extracellular-vesicles. The first module is an introduction to the field covering the nomenclature and history of EVs. Module 2 focuses on the biogenesis and uptake mechanisms of EVs, as well as their RNA, protein and lipid cargo. Module 3 covers the collection and processing of cell culture media and body fluids such as blood, breast milk, cerebrospinal fluid and urine prior to isolation of EVs. Modules 4 and 5 present different isolation methods and characterisation techniques utilised in the EV field. Here, differential ultracentrifugation, size-exclusion chromatography, density gradient centrifugation, kit-based precipitation, electron microscopy, cryo-electron microscopy, flow cytometry, atomic-force microscopy and nanoparticle-tracking analysis are covered. This first massive open online course (MOOC on EVs was launched on 15 August 2016 at the platform “Coursera” and is free of charge.

on seed germination and growth of Garcinia kola

African Journals Online (AJOL)

SARAH

2016-07-31

Jul 31, 2016 ... Seed germination tests: After 72 h of fermentation in plastic bags, seeds were ... Models (GLM) procedure of the R statistical version 9.1 was used to identify traits .... L-1) had accelerated seed germination. Germination rates.

Specificity of fungal associations of Pyroleae and Monotropa hypopitys during germination and seedling development.

Science.gov (United States)

Johansson, V A; Bahram, M; Tedersoo, L; Kõljalg, U; Eriksson, O

2017-05-01

Mycoheterotrophic plants obtain organic carbon from associated mycorrhizal fungi, fully or partially. Angiosperms with this form of nutrition possess exceptionally small 'dust seeds' which after germination develop 'seedlings' that remain subterranean for several years, fully dependent on fungi for supply of carbon. Mycoheterotrophs which as adults have photosynthesis thus develop from full to partial mycoheterotrophy, or autotrophy, during ontogeny. Mycoheterotrophic plants may represent a gradient of variation in a parasitism-mutualism continuum, both among and within species. Previous studies on plant-fungal associations in mycoheterotrophs have focused on either germination or the adult life stages of the plant. Much less is known about the fungal associations during development of the subterranean seedlings. We investigated germination and seedling development and the diversity of fungi associated with germinating seeds and subterranean seedlings (juveniles) in five Monotropoideae (Ericaceae) species, the full mycoheterotroph Monotropa hypopitys and the putatively partial mycoheterotrophs Pyrola chlorantha, P. rotundifolia, Moneses uniflora and Chimaphila umbellata. Seedlings retrieved from seed sowing experiments in the field were used to examine diversity of fungal associates, using pyrosequencing analysis of ITS2 region for fungal identification. The investigated species varied with regard to germination, seedling development and diversity of associated fungi during juvenile ontogeny. Results suggest that fungal host specificity increases during juvenile ontogeny, most pronounced in the fully mycoheterotrophic species, but a narrowing of fungal associates was found also in two partially mycoheterotrophic species. We suggest that variation in specificity of associated fungi during seedling ontogeny in mycoheterotrophs represents ongoing evolution along a parasitism-mutualism continuum. © 2017 John Wiley & Sons Ltd.

ABC triblock copolymer vesicles with mesh-like morphology.

Science.gov (United States)

Zhao, Wei; Chen, Dian; Hu, Yunxia; Grason, Gregory M; Russell, Thomas P

2011-01-25

Polymer vesicles made from poly(isoprene-b-styrene-b-2-vinyl pyridine) (PI-b-PS-b-P2VP) triblock copolymer confined within the nanopores of an anodic aluminum oxide (AAO) membrane are studied. It was found that these vesicles have well-defined, nanoscopic size, and complex microphase-separated hydrophobic membranes, comprised of the PS and PI blocks, while the coronas are formed by the P2VP block. Vesicle formation was tracked using both transmission and scanning electron microscopy. A mesh-like morphology formed in the membrane at a well-defined composition of the three blocks that can be tuned by changing the copolymer composition. The nanoscale confinement, copolymer composition, and subtle molecular interactions contribute to the generation of these vesicles with such unusual morphologies.

Vesicle interactions with polyamino acids and antibody: in vitro and in vivo studies

International Nuclear Information System (INIS)

Dunnick, J.K.; McDougall, I.R.; Aragon, S.; Goris, M.L.; Kriss, J.P.

1975-01-01

Artificial spherules or vesicles of 900 A in diameter formed from phosphatidylcholine and gangliosides and enclosing /sup 99m/TcO 4 - (standard preparation) survive intact in the circulation of the mouse. Polyamino acids and protein have been incorporated into and onto the vesicles; such vesicles remain intact as determined by diffusion dialysis studies and by electron paramagnetic resonance studies of vesicles enclosing spin label. In studying the distribution of polyamino acid-vesicles and protein vesicles in vivo, it was found that the latter distribute differently from standard vesicles or free protein alone whereas aromatic polyamino acid-vesicles concentrate in the liver and spleen to a greater extent than standard vesicles. The permeability and stability characteristics of vesicles may be preserved when they are modified by the addition of protein or polyamino acids and that such modification of vesicles may be associated with an alteration of their fate in vivo. The potential exists to use vesicles as carriers of radiopharmaceuticals and other drugs and to direct the vesicles preferentially to tissue targets in vivo. (U.S.)

Evolution of 'smoke' induced seed germination in pyroendemic plants

Science.gov (United States)

Keeley, J. E.; Pausas, J.G.

2016-01-01

Pyroendemics are plants in which seedling germination and successful seedling recruitment are restricted to immediate postfire environments. In many fire-prone ecosystems species cue their germination to immediate postfire conditions. Here we address how species have evolved one very specific mechanism, which is using the signal of combustion products from biomass. This is often termed ‘smoke’ stimulated germination although it was first discovered in studies of charred wood effects on germination of species strictly tied to postfire conditions (pyroendemics). Smoke stimulated germination has been reported from a huge diversity of plant species. The fact that the organic compound karrikin (a product of the degradation of cellulose) is a powerful germination cue in many species has led to the assumption that this compound is the only chemical responsible for smoke-stimulated germination. Here we show that smoke-stimulated germination is a complex trait with different compounds involved. We propose that convergent evolution is a more parsimonious model for smoke stimulated germination, suggesting that this trait evolved multiple times in response to a variety of organic and inorganic chemical triggers in smoke. The convergent model is congruent with the evolution of many other fire-related traits.

7 CFR 201.6 - Germination.

Science.gov (United States)

2010-01-01

... REGULATIONS Records for Agricultural and Vegetable Seeds § 201.6 Germination. The complete record shall include the records of all laboratory tests for germination and hard seed for each lot of seed offered for transportation in whole or in part. The record shall show the kind of seed, lot number, date of test, percentage...

Vesicle dynamics in shear and capillary flows

International Nuclear Information System (INIS)

Noguchi, Hiroshi; Gompper, Gerhard

2005-01-01

The deformation of vesicles in flow is studied by a mesoscopic simulation technique, which combines multi-particle collision dynamics for the solvent with a dynamically triangulated surface model for the membrane. Shape transitions are investigated both in simple shear flows and in cylindrical capillary flows. We focus on reduced volumes, where the discocyte shape of fluid vesicles is stable, and the prolate shape is metastable. In simple shear flow at low membrane viscosity, the shear induces a transformation from discocyte to prolate with increasing shear rate, while at high membrane viscosity, the shear induces a transformation from prolate to discocyte, or tumbling motion accompanied by oscillations between these two morphologies. In capillary flow, at small flow velocities the symmetry axis of the discocyte is found not to be oriented perpendicular to the cylinder axis. With increasing flow velocity, a transition to a prolate shape occurs for fluid vesicles, while vesicles with shear-elastic membranes (like red blood cells) transform into a coaxial parachute-like shape

Gene expression at each stage of the life cycle of spore-forming bacteria: different sensitivity of transcription to antibiotics which act on DNA gyrase.

Science.gov (United States)

Matsuda, M; Kameyama, T

1985-01-01

Effects of antibiotics acting on DNA gyrase, novobiocin and nalidixic acid on RNA synthesis during germination, vegetative growth and sporulation of Bacillus subtilis were examined. These drugs were relatively ineffective in inhibiting RNA synthesis of phase Gm 1 (5-15 min) during germination but effective in those of Gm 2 (15-40 min) and Gm 3 (40-60 min) during germination (Matsuda and Kameyama 1980). No distinguishable inhibitory effects of RNA synthesis in B. subtilis NOVr1TT mutant could be detected by novobiocin. RNA synthesis of Gm 2 and Gm 3 of this mutant was inhibited by nalidixic acid. When novobiocin was added to exponential vegetative cell or sporulating cell culture at T0 and T1 stage, the rate of RNA synthesis was inhibited by 80% for 5 min following addition of the drug. However, RNA synthesis after T2 of sporulation became resistant toward novobiocin, as was the case at an early stage of germination. RNA profiles from transcripts synthesized on administration of NOV suggested that the suppression of the synthesis of 23S and 16S rRNA is relatively greater than 4 to 5S RNA at the middle stage of germination and at vegetative growth stage in the presence of NOV. Our present data suggest that DNA gyrase is involved in the regulation of gene transcription during middle and late phases of germination, vegetative growth and T0 and T1 of sporulation. The transcription during early phase of germination and sporulation after T2 may proceed independently of this enzyme.

Sugar-based gemini surfactant with a vesicle-to-micelle transition at acidic pH and a reversible vesicle flocculation near neutral pH

NARCIS (Netherlands)

Johnsson, M; Wagenaar, A; Engberts, JBFN

2003-01-01

A sugar-based (reduced glucose) gemini surfactant forms vesicles in dilute aqueous solution near neutral pH. At lower pH, there is a vesicle-to-micelle transition within a narrow pH region (pH 6.0-5.6). The vesicles are transformed into large cylindrical micelles that in turn are transformed into

COMPARATIVE GERMINATION RESPONSES OF COWPEA AND ...

African Journals Online (AJOL)

iya beji

inadequate soil moisture (25%) in both cowpea and maize with greater effect on ... Of all factors controlling productivity, seed germination and vigour are pre- .... depth and date of first irrigation on seed cane germination of two commercial.

Studying the effects of different levels of salinity which caused by NaCl on early growth and germination of Lactuca Sativa L. seedling

Directory of Open Access Journals (Sweden)

Mohammad Hosein Bijeh Keshavarzi

2012-04-01

Full Text Available Soil salinity is one of the most important constraints that limit crop production in arid and semi arid regions. Seed germination is a critical stage in the history of plants and salt tolerance during germination is crucial for the establishment of plants that grow in saline soils. This research was carried out in order to test the effects of different salinity levels on germination and early growth of lettuce (Lactuca Sativa L.. The experiment was carried out using completely randomized design in four replication in 2011 Zabol University laboratory Iran. The results showed that by increasing salinity, percentage and race of germination decreased, So that, in the 150 mM of salinity level, germination reached to minimized (8.33%. Other measured parameters such as plumule length, radicle length, dry and wet weight decreased as well. All the results analyzed by SAS statistical software and comparison of average had done by Duncan test on 5% possible level.

Three-dimensional computed tomography-guided monotherapeutic pararectal brachytherapy of prostate cancer with seminal vesicle invasion

International Nuclear Information System (INIS)

Koutrouvelis, Panos; Lailas, Niko; Hendricks, Fred; Gil-Montero, Guillermo; Sehn, James; Katz, Stuart

2001-01-01

Purpose: To treat patients with prostate cancer and seminal vesicle invasion with monotherapeutic three dimensional computed tomography (3-DCT)-guided posterior pararectal brachytherapy. Methods and materials: Three hundred and sixty two patients with clinical stage T1 a,b or T2 a,b of prostate cancer were referred for 3-DCT-guided brachytherapy. Each underwent further staging with 3-D CT-guided pararectal biopsy of the seminal vesicles under local anesthesia during the pre-treatment CT-planning. Forty-three patients (12%) were upstaged to T3 cNoMo disease. In the set of 43 patients, Eight had Gleason's score≤6, 24 Gleason's score=7, and 11 patients ≥8. Initial PSA was 20 in 18 patients. Of the 43 patients, 37 patients were treated monotherapeutically with 3-D CT-guided brachytherapy. No patients received hormone therapy after the implant. The prescribed dosage to the seminal vesicles and prostate is 120 Gy with Pd-103 seeds and 144 Gy with 1-125 seeds. Results: The prescribed dosage was achieved in all 37 patient's throughout the seminal vesicles whose range of target radiation extended 5-10 mm outside the target in the adjacent fat as calculated with post-implant CT-dosimetry with Varian Brachy Vision or MMS software. Prostate Specific Antigen (PSA) outcome data were available in 34 patients treated with monotherapy and follow up ranged from 12-56 months (median, 24 months). Decreased PSA levels were stratified into six groups based on the presenting Gleason's score and initial PSA. In the first group (with Gleason's score≤6 and initial PSA 20 ng/ml), PSA decreased to less than 0.5 ng/ml in four out of eight patients (50%). All of the patients in the fourth group (with Gleason's score≥8 and initial PSA 20 ng/ml). There were no patients with Gleason's score of 1-6 and greater than 20 ng/ml initial PSA. Patients, irrespective of the Gleason's score and PSA, had an overall response of decreased PSA (less than 1 ng/ml) of 79%. Conclusion: 3-D CT

Germination traits of three weed species in Kosovo

Directory of Open Access Journals (Sweden)

A. Mehmeti

2010-02-01

Full Text Available Amaranthus retroflexus, Echinochloa crus-galli and Datura stramonium are the most important weed species in Kosovo. They cause severe yield depression, contaminate fodder and negatively affect growth and reproduction of other weed species. To counteract these problems, specific strategies need to be developed. Such strategies should consider information on species germination traits. In this context, our study provides information on temperature requirements for germination. Seeds of A. retroflexus, E. crus-galli and D. stramonium were harvested in two sub-regions of Kosovo (western and eastern parts differing in climate and land use. They were set for germination experiments in growth chambers at temperatures ranging from 3 to 35 °C and under field conditions. In both experiments, the germination rate differed between species and provenances. In the growth chamber experiment, germination of all three species was negligible below 15 °C and reached the highest rates between 24 and 30 °C. Seeds originating from the western part of Kosovo had higher germination rates and required a lower temperature for germination than seeds originating from the eastern part. In the field experiment, the time-dependent germination behaviour of D. stramonium differed between provenances. In general, germination started when soil temperature was above 18 °C and continued as long as the soil was moist. The results are discussed in the context of the need to develop weed management strategies against these weeds in Kosovo.

Peptone and tomato extract induced early stage of embryo development of Dendrobium phalaenopsis Orchid

Directory of Open Access Journals (Sweden)

Nintya Setiari

2017-04-01

Full Text Available Germination and growth of orchid seeds can be accelerated by the addition of organic supplement and plant extract in culture medium. The objective of this study was to determine the effect of peptone and tomato extract on early stage of embryo development of Dendrobium phalaenopsis orchids. Orchid seeds were sown on NP and VW medium with addition of 10% of CW (NPCW and VWCW.  Five weeks after seed germination, about 58.03% seed germination was observed on VWCW medium, and only 37.45% seed germination on NPCW. Tomato extract and peptone were added in VWCW, resulting VWCWTP medium. After 4-8 weeks on VWCWTP, 94.42% seeds was germinated into plantlet, but only 67.30% germinated seeds on VWCW. To get optimal growth and development of  D.  phalaenopsis orchids embryos in the in vitro condition, supplement of 100 ml.L-1 coconut water, 100 mg.L-1 tomato extract and 2 mg.L-1 peptone into VW basic medium is required.

The pleiotropic effects of the seed germination inhibitor germostatin.

Science.gov (United States)

Ye, Yajin; Zhao, Yang

2016-01-01

Seed dormancy and germination are the most important adaptive traits of seed plants, which control the germination in a proper space and time. Internal genetic factors together with environmental cues govern seed dormancy and germination. Abscisic acid (ABA), a key phytohormone induces seed dormancy and inhibits seed germination through its molecular genetic signaling network responding the seed inherent physiological and environmental factors. Recently, auxin has been shown to be another phytohormone that induces seed dormancy. We have recently shown that germonstatin (GS), a small synthetic molecule identified by high through-put chemical genetic screenings, inhibits seed germination through up-regulating auxin signaling and inducing auxin biosynthesis. GERMOSTATIN RESISTANCE LOCUS 1 (GSR1) encodes a plant homeodomain (PHD) finger protein and is responsible for GS seed germination inhibition. Its knockdown mutant gsr1 displays decreased dormancy. In this report, we show that GS is not an ABA analog and provided 2 other GS-resistant mutants related to the chemical's function in seed germination inhibition other than gsr1, suggesting that GS may have pleiotropic effects through targeting different pathway governing seed germination.

Differential Expression of Hox and Notch Genes in Larval and Adult Stages of Echinococcus granulosus.

Science.gov (United States)

Dezaki, Ebrahim Saedi; Yaghoobi, Mohammad Mehdi; Taheri, Elham; Almani, Pooya Ghaseminejad; Tohidi, Farideh; Gottstein, Bruno; Harandi, Majid Fasihi

2016-10-01

This investigation aimed to evaluate the differential expression of HoxB7 and notch genes in different developmental stages of Echinococcus granulosus sensu stricto. The expression of HoxB7 gene was observed at all developmental stages. Nevertheless, significant fold differences in the expression level was documented in the juvenile worm with 3 or more proglottids, the germinal layer from infected sheep, and the adult worm from an experimentally infected dog. The notch gene was expressed at all developmental stages of E. granulosus ; however, the fold difference was significantly increased at the microcysts in monophasic culture medium and the germinal layer of infected sheep in comparison with other stages. The findings demonstrated that the 2 aforementioned genes evaluated in the present study were differentially expressed at different developmental stages of the parasite and may contribute to some important biological processes of E. granulosus .

Effect of Osmotic Stress on Seed Germination Indices of Nigella sativa and Silybum marianum

Directory of Open Access Journals (Sweden)

H Balouchi

2012-04-01

Full Text Available Evaluation of medicinal plants to drought and salt stress tolerance, in an attempt to plant them under drought and saline regions, is of utmost importance. Environmental stresses, especially drought and salt, reduce the global crop yields more than other factors. Selection of drought tolerant crops at germination stage, usually is, the fast and low cost method. In order to study the effect of osmotic stress on germination indices of black cumin and milk thistle, an experiment carried out in a completely randomized design with four replications at the Seed Technology Laboratoary of Yasouj University in 2008. Treatments were 0 (as control, -2.4, -4.8, -7.2 and -9.4 bar osmotic potentials created by using PEG 6000. Results showed that, decreasing of osmotic potential reduced speed of germination and its percentage, root and shoot lengths and dry matter in these two plants. Black cumin showed higher tolerance, to -4.8 bar osmotic potential, as compared to milk thistle. However, milk thistle showed higher tolerance to drought stress, up to this osmotic potential (-4.8 bar, compared to black cumin. Milk thistle had lower germination speed and percentage at higher drought stress as compared to black cumin. Generally, milk thistle showed better growth and survival than black cumin due to its higher root and shoot length and dry matter.

Pulsed-laser polymerization in compartmentalized liquids. 1. Polymerization in vesicles

NARCIS (Netherlands)

Jung, M.; Casteren, van I.A.; Monteiro, M.J.; Herk, van A.M.; German, A.L.

2000-01-01

Polymerization in vesicles is a novel type of polymerization in heterogeneous media, leading to parachute-like vesicle-polymer hybrid morphologies. To explore the kinetics of vesicle polymerizations and to learn more about the actual locus of polymerization we applied the pulsed-laser polymerization

Frequency-dependent electrodeformation of giant phospholipid vesicles in AC electric field

Science.gov (United States)

2010-01-01

A model of vesicle electrodeformation is described which obtains a parametrized vesicle shape by minimizing the sum of the membrane bending energy and the energy due to the electric field. Both the vesicle membrane and the aqueous media inside and outside the vesicle are treated as leaky dielectrics, and the vesicle itself is modeled as a nearly spherical shape enclosed within a thin membrane. It is demonstrated (a) that the model achieves a good quantitative agreement with the experimentally determined prolate-to-oblate transition frequencies in the kilohertz range and (b) that the model can explain a phase diagram of shapes of giant phospholipid vesicles with respect to two parameters: the frequency of the applied alternating current electric field and the ratio of the electrical conductivities of the aqueous media inside and outside the vesicle, explored in a recent paper (S. Aranda et al., Biophys J 95:L19–L21, 2008). A possible use of the frequency-dependent shape transitions of phospholipid vesicles in conductometry of microliter samples is discussed. PMID:21886342

7 CFR 201.54 - Number of seeds for germination.

Science.gov (United States)

2010-01-01

... REGULATIONS Germination Tests in the Administration of the Act § 201.54 Number of seeds for germination. At least 400 seeds shall be tested for germination; except that in mixtures, 200 seeds of each of those... 7 Agriculture 3 2010-01-01 2010-01-01 false Number of seeds for germination. 201.54 Section 201.54...

Development and characterization of nanopore system for nano-vesicle analysis

Science.gov (United States)

Goyal, Gaurav

Nano-vesicles have recently attracted a lot of attention in research and medical communities and are very promising next-generation drug delivery vehicles. This is due to their biocompatibility, biodegradability and their ability to protect drug cargo and deliver it to site-specific locations, while maintaining the desired pharmacokinetic profile. The interaction of these drug loaded vesicles with the recipient cells via adsorption, endocytosis or receptor mediated internalization involve significant bending and deformation and is governed by mechanical properties of the nano-vesicles. Currently, the mechanical characteristics of nano-vesicles are left unexplored because of the difficulties associated with vesicle analysis at sub-100 nm length scale. The need for a complete understanding of nano-vesicle interaction with each other and the recipient cells warrants development of an analytical tool capable of mechanical investigation of individual vesicles at sub-100 nm scale. This dissertation presents investigation of nano-vesicle deformability using resistive pulse sensing and solid-state nanopore devices. The dissertation is divided into four chapters. Chapter 1 discusses the motivation, specific aims and presents an overview of nanoparticle characterization techniques, resistive pulse sensing background and principles, techniques for fabricating solid-state nanopores, as well the deformation behavior of giant vesicles when placed in electric field. Chapter 2 is dedicated to understanding of the scientific principles governing transport of sub-100 nm particles in dilute solutions. We investigated the translocation of rigid nanoparticles through nanopores at salt concentrations exosomes derived from human breast cancer cell line. Exosomes also exhibit co-translocational deformation behavior; however, they appear to be less affected by the deforming force inside the nanopore compared to the DOPC liposomes. We believe, the results of this research will bring about a

Factors affecting the germination of hybrid rose achenes

NARCIS (Netherlands)

Vries, De D.P.; Dubois, L.A.M.

2015-01-01

The smooth germination of mature Hybrid rose achenes is hampered by (i) hardseededness (HS), (ii) primary dormancy (PD) and (iii) germination polymorphism (GP). HS is owing to the hard pericarp. PD is, in principle, a natural phenomenon that protects the seeds from precocious germination. For

Isolation and characterization of urinary extracellular vesicles: implications for biomarker discovery.

Science.gov (United States)

Merchant, Michael L; Rood, Ilse M; Deegens, Jeroen K J; Klein, Jon B

2017-12-01

Urine is a valuable diagnostic medium and, with the discovery of urinary extracellular vesicles, is viewed as a dynamic bioactive fluid. Extracellular vesicles are lipid-enclosed structures that can be classified into three categories: exosomes, microvesicles (or ectosomes) and apoptotic bodies. This classification is based on the mechanisms by which membrane vesicles are formed: fusion of multivesicular bodies with the plasma membranes (exosomes), budding of vesicles directly from the plasma membrane (microvesicles) or those shed from dying cells (apoptotic bodies). During their formation, urinary extracellular vesicles incorporate various cell-specific components (proteins, lipids and nucleic acids) that can be transferred to target cells. The rigour needed for comparative studies has fueled the search for optimal approaches for their isolation, purification, and characterization. RNA, the newest extracellular vesicle component to be discovered, has received substantial attention as an extracellular vesicle therapeutic, and compelling evidence suggests that ex vivo manipulation of microRNA composition may have uses in the treatment of kidney disorders. The results of these studies are building the case that urinary extracellular vesicles act as mediators of renal pathophysiology. As the field of extracellular vesicle studies is burgeoning, this Review focuses on primary data obtained from studies of human urine rather than on data from studies of laboratory animals or cultured immortalized cells.

ISEV position paper: extracellular vesicle RNA analysis and bioinformatics

Directory of Open Access Journals (Sweden)

Andrew F. Hill

2013-12-01

Full Text Available Extracellular vesicles (EVs are the collective term for the various vesicles that are released by cells into the extracellular space. Such vesicles include exosomes and microvesicles, which vary by their size and/or protein and genetic cargo. With the discovery that EVs contain genetic material in the form of RNA (evRNA has come the increased interest in these vesicles for their potential use as sources of disease biomarkers and potential therapeutic agents. Rapid developments in the availability of deep sequencing technologies have enabled the study of EV-related RNA in detail. In October 2012, the International Society for Extracellular Vesicles (ISEV held a workshop on “evRNA analysis and bioinformatics.” Here, we report the conclusions of one of the roundtable discussions where we discussed evRNA analysis technologies and provide some guidelines to researchers in the field to consider when performing such analysis.

Extracellular vesicles: fundamentals and clinical relevance

Directory of Open Access Journals (Sweden)

Wael Nassar

2015-01-01

Full Text Available All types of cells of eukaryotic organisms produce and release small nanovesicles into their extracellular environment. Early studies have described these vesicles as ′garbage bags′ only to remove obsolete cellular molecules. Valadi and colleagues, in 2007, were the first to discover the capability of circulating extracellular vesicles (EVs to horizontally transfer functioning gene information between cells. These extracellular vesicles express components responsible for angiogenesis promotion, stromal remodeling, chemoresistance, genetic exchange, and signaling pathway activation through growth factor/receptor transfer. EVs represent an important mode of intercellular communication by serving as vehicles for transfer between cells of membrane and cytosolic proteins, lipids, signaling proteins, and RNAs. They contribute to physiology and pathology, and they have a myriad of potential clinical applications in health and disease. Moreover, vesicles can pass the blood-brain barrier and may perhaps even be considered as naturally occurring liposomes. These cell-derived EVs not only represent a central mediator of the disease microenvironment, but their presence in the peripheral circulation may serve as a surrogate for disease biopsies, enabling real-time diagnosis and disease monitoring. In this review, we′ll be addressing the characteristics of different types of extracellular EVs, as well as their clinical relevance and potential as diagnostic markers, and also define therapeutic options.

The Bretherton Problem for a Vesicle

Science.gov (United States)

Barakat, Joseph; Spann, Andrew; Shaqfeh, Eric

2016-11-01

The motion of a lipid bilayer vesicle through a circular tube is investigated by singular perturbation theory in the limit of vanishing clearance. The vesicle is treated as a sac of fluid enclosed by a thin, elastic sheet that admits a bending stiffness. It is assumed that the vesicle is axisymmetric and swollen to a near-critical volume such that the clearance "e" between the membrane and the tube wall is very small. In this limit, bending resistance is of negligible importance compared to the isotropic tension, allowing the vesicle to be treated as a "no-slip bubble." The effective membrane tension is found to scale inversely with "e" raised to the 3/2 power with a comparatively weak Marangoni gradient. The extra pressure drop is found to have a leading contribution due to the cylindrical midsection, which scales inversely with "e," as well as a correction due to the end caps, which scales inversely with the square root of "e." The apparent viscosity is predicted as a unique function of the geometry. The theory exhibits excellent agreement with a simplified, "quasi-parallel" theory and with direct numerical simulations using the boundary element method. The results of this work are compared to those for bubbles, rigid particles, and red blood cells in confined flows.

Ethylene, seed germination, and epinasty.

Science.gov (United States)

Stewart, E R; Freebairn, H T

1969-07-01

Ethylene activity in lettuce seed (Lactuca satina) germination and tomato (Lycopersicon esculentum) petiole epinasty has been characterized by using heat to inhibit ethylene synthesis. This procedure enabled a separation of the production of ethylene from the effect of ethylene. Ethylene was required in tomato petioles to produce the epinastic response and auxin was found to be active in producing epinasty through a stimulation of ethylene synthesis with the resulting ethylene being responsible for the epinasty. In the same manner, it was shown that gibberellic acid stimulated ethylene synthesis in lettuce seeds. The ethylene produced then in turn stimulated the seeds to germinate. It was hypothesized that ethylene was the intermediate which caused epinasty or seed germination. Auxin and gibberellin primarily induced their response by stimulating ethylene production.

Proteomic analysis during of spore germination of Moniliophthora perniciosa, the causal agent of witches' broom disease in cacao.

Science.gov (United States)

Mares, Joise Hander; Gramacho, Karina Peres; Santos, Everton Cruz; da Silva Santiago, André; Santana, Juliano Oliveira; de Sousa, Aurizângela Oliveira; Alvim, Fátima Cerqueira; Pirovani, Carlos Priminho

2017-08-17

Moniliophthora perniciosa is a phytopathogenic fungus responsible for witches' broom disease of cacao trees (Theobroma cacao L.). Understanding the molecular events during germination of the pathogen may enable the development of strategies for disease control in these economically important plants. In this study, we determined a comparative proteomic profile of M. perniciosa basidiospores during germination by two-dimensional SDS-PAGE and mass spectrometry. A total of 316 proteins were identified. Molecular changes during the development of the germinative tube were identified by a hierarchical clustering analysis based on the differential accumulation of proteins. Proteins associated with fungal filamentation, such as septin and kinesin, were detected only 4 h after germination (hag). A transcription factor related to biosynthesis of the secondary metabolite fumagillin, which can form hybrids with polyketides, was induced 2 hag, and polyketide synthase was observed 4 hag. The accumulation of ATP synthase, binding immunoglobulin protein (BiP), and catalase was validated by western blotting. In this study, we showed variations in protein expression during the early germination stages of fungus M. perniciosa. Proteins associated with fungal filamentation, and consequently with virulence, were detected in basidiospores 4 hag., for example, septin and kinesin. We discuss these results and propose a model of the germination of fungus M. perniciosa. This research can help elucidate the mechanisms underlying basic processes of host invasion and to develop strategies for control of the disease.

Functionalization of Block Copolymer Vesicle Surfaces

Directory of Open Access Journals (Sweden)

Wolfgang Meier

2011-01-01

Full Text Available In dilute aqueous solutions certain amphiphilic block copolymers self-assemble into vesicles that enclose a small pool of water with a membrane. Such polymersomes have promising applications ranging from targeted drug-delivery devices, to biosensors, and nanoreactors. Interactions between block copolymer membranes and their surroundings are important factors that determine their potential biomedical applications. Such interactions are influenced predominantly by the membrane surface. We review methods to functionalize block copolymer vesicle surfaces by chemical means with ligands such as antibodies, adhesion moieties, enzymes, carbohydrates and fluorophores. Furthermore, surface-functionalization can be achieved by self-assembly of polymers that carry ligands at their chain ends or in their hydrophilic blocks. While this review focuses on the strategies to functionalize vesicle surfaces, the applications realized by, and envisioned for, such functional polymersomes are also highlighted.

Genetically controlled fusion, exocytosis and fission of artificial vesicles-a roadmap

DEFF Research Database (Denmark)

Bönzli, Eva; Hadorn, Maik; de Lucrezia, Davide

2011-01-01

were shown to fuse if a special class of viral proteins, termed fusogenic peptides, were added to the external medium (Nomura et al. 2004). In the present work, we intend to develop genetically controlled fusion, fission and exocytosis of vesicles by the synthesis of peptides within vesicles. First, we...... enclosed synthesized peptides in vesicles to induce in a next step fusion of adjacent vesicles, fission and exocytosis of nested vesicles. Second, we will replace the peptides by an enclosed cell-free expression system to internally synthesize fusion peptides. To control the gene expression, different...

Spore germination and gametophyte development of Cyathea atrovirens (Langsd. & Fisch. Domin (Cyatheaceae under different pH conditions

Directory of Open Access Journals (Sweden)

C. Rechenmacher

Full Text Available Cyathea atrovirens (Langsd. & Fisch. Domin, an intensely exploited tree fern, is found inside forests in several succession stages, as well as in swamps, roadsides and unused fields in the Rio dos Sinos basin, in the state of Rio Grande do Sul, southern Brazil. This study evaluated the in vitro germination and gametophyte development of C.atrovirens under different pH conditions, as well as spore viability after different storage times at 7 ºC. The lowest germination rate of spores was obtained at pH 7.0. At pH 5.0 to 6.5, laminar gametophyte development started at 20 to 30 days of culture. Antheridia and archegonia were first observed at 35 and 128 days, respectively. Storage at 7 ºC did not affect germination rates. The capability of germination at different pH levels may explain the occurrence of the species in a wide range of habitats. The present study contributes to the understanding of the full life-cycle of C. atrovirens and to the analysis of the influence of abiotic components, providing information for the cultivation, management and conservation of the species.

Neuronal Depolarization Drives Increased Dopamine Synaptic Vesicle Loading via VGLUT.

Science.gov (United States)

Aguilar, Jenny I; Dunn, Matthew; Mingote, Susana; Karam, Caline S; Farino, Zachary J; Sonders, Mark S; Choi, Se Joon; Grygoruk, Anna; Zhang, Yuchao; Cela, Carolina; Choi, Ben Jiwon; Flores, Jorge; Freyberg, Robin J; McCabe, Brian D; Mosharov, Eugene V; Krantz, David E; Javitch, Jonathan A; Sulzer, David; Sames, Dalibor; Rayport, Stephen; Freyberg, Zachary

2017-08-30

The ability of presynaptic dopamine terminals to tune neurotransmitter release to meet the demands of neuronal activity is critical to neurotransmission. Although vesicle content has been assumed to be static, in vitro data increasingly suggest that cell activity modulates vesicle content. Here, we use a coordinated genetic, pharmacological, and imaging approach in Drosophila to study the presynaptic machinery responsible for these vesicular processes in vivo. We show that cell depolarization increases synaptic vesicle dopamine content prior to release via vesicular hyperacidification. This depolarization-induced hyperacidification is mediated by the vesicular glutamate transporter (VGLUT). Remarkably, both depolarization-induced dopamine vesicle hyperacidification and its dependence on VGLUT2 are seen in ventral midbrain dopamine neurons in the mouse. Together, these data suggest that in response to depolarization, dopamine vesicles utilize a cascade of vesicular transporters to dynamically increase the vesicular pH gradient, thereby increasing dopamine vesicle content. Copyright © 2017 Elsevier Inc. All rights reserved.

Overall energy conversion efficiency of a photosynthetic vesicle

Energy Technology Data Exchange (ETDEWEB)

Sener, Melih [Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, United States; Department of Physics, University of Illinois at Urbana-Champaign, Urbana, United States; Strumpfer, Johan [Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, United States; Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign, Urbana, United States; Singharoy, Abhishek [Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, United States; Hunter, C. Neil [Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, United Kingdom; Schulten, Klaus [Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, United States; Department of Physics, University of Illinois at Urbana-Champaign, Urbana, United States; Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign, Urbana, United States

2016-08-26

The chromatophore of purple bacteria is an intracellular spherical vesicle that exists in numerous copies in the cell and that efficiently converts sunlight into ATP synthesis, operating typically under low light conditions. Building on an atomic-level structural model of a low-light-adapted chromatophore vesicle from Rhodobacter sphaeroides, we investigate the cooperation between more than a hundred protein complexes in the vesicle. The steady-state ATP production rate as a function of incident light intensity is determined after identifying quinol turnover at the cytochrome bc1 complex (cytbc1) as rate limiting and assuming that the quinone/quinol pool of about 900 molecules acts in a quasi-stationary state. For an illumination condition equivalent to 1% of full sunlight, the vesicle exhibits an ATP production rate of 82 ATP molecules/s. The energy conversion efficiency of ATP synthesis at illuminations corresponding to 1%–5% of full sunlight is calculated to be 0.12-0.04, respectively. The vesicle stoichiometry, evolutionarily adapted to the low light intensities in the habitat of purple bacteria, is suboptimal for steady-state ATP turnover for the benefit of protection against over-illumination.

Pre-Infection Stages of Austropuccinia psidii in the Epidermis of Eucalyptus Hybrid Leaves with Different Resistance Levels

Directory of Open Access Journals (Sweden)

Renata Ruiz Silva

2017-10-01

Full Text Available Rust is a major Eucalyptus spp. disease, which is especially damaging for early-stage plants. The aim of this study was to verify the pre-infection process of Austropuccinia psidii (A. psidii in the leaves of three phenological stages of Eucalyptus clones with different resistance levels. Plants from the hybrids of Eucalyptus urophylla × Eucalyptus grandis (E. grandis with variable levels of resistance to this disease were used. The pathogen was inoculated in vitro on abaxial leaf discs of first, third, and fifth leaf stages and maintained under conditions suitable for disease development. Subsequently, samples from these discs were collected 24 and 120 h after inoculation and processed using scanning electron microscopy analysis. No symptoms were seen in any leaf stage of the resistant clone. Additionally, a low incidence of A. psidii germination (1.3–2% and appressoria (0–0.5% in three leaf stages was observed. However, the first leaf stage of the susceptible clone presented germination of large numbers of urediniospores (65% with appressoria (55% and degradation of the cuticle and wax. From the third stage, the percentage of germinated urediniospores (<15% and appressoria (<2% formation of this clone decreased. Protrusions on the leaf surface, associated with the pathogen, were observed on the first and third leaf stages of the resistant clone and on the fifth stage of the susceptible clone, suggesting a possible defensive plant reaction.

Assembly of cells and vesicles for organ engineering

International Nuclear Information System (INIS)

Taguchi, Tetsushi

2011-01-01

The development of materials and technologies for the assembly of cells and/or vesicles is a key for the next generation of tissue engineering. Since the introduction of the tissue engineering concept in 1993, various types of scaffolds have been developed for the regeneration of connective tissues in vitro and in vivo. Cartilage, bone and skin have been successfully regenerated in vitro, and these regenerated tissues have been applied clinically. However, organs such as the liver and pancreas constitute numerous cell types, contain small amounts of extracellular matrix, and are highly vascularized. Therefore, organ engineering will require the assembly of cells and/or vesicles. In particular, adhesion between cells/vesicles will be required for regeneration of organs in vitro. This review introduces and discusses the key technologies and materials for the assembly of cells/vesicles for organ regeneration. (topical review)

Tumors of germinal cells

International Nuclear Information System (INIS)

Plazas, Ricardo; Avila, Andres

2002-01-01

The tumors of germinal cells (TGC) are derived neoplasia of the primordial germinal cells that in the life embryonic migrant from the primitive central nervous system until being located in the gonads. Their cause is even unknown and they represent 95% of the testicular tumors. In them, the intention of the treatment is always healing and the diagnostic has improved thanks to the results of the handling multidisciplinary. The paper includes topics like their incidence and prevalence, epidemiology and pathology, clinic and diagnoses among other topics

High-throughput scoring of seed germination

NARCIS (Netherlands)

Ligterink, Wilco; Hilhorst, Henk W.M.

2017-01-01

High-throughput analysis of seed germination for phenotyping large genetic populations or mutant collections is very labor intensive and would highly benefit from an automated setup. Although very often used, the total germination percentage after a nominated period of time is not very

Pre-treating Seed to Enhance Germination of Desert Shrubs

Energy Technology Data Exchange (ETDEWEB)

W. K. Ostler; D. C. Anderson; D. J. Hansen

2002-06-01

Creosotebush [Larrea tridentata (D.C.) Cav.] and white bursage [Ambrosia dumosa (A. Gray) W.W. Payne] seeds were subjected to pre-treatments of rinsing and soaking in water and thiourea to enhance germination in laboratory experiments. The effects of darkness, temperature, seed source, and soil moisture were also evaluated in the laboratory. The best pre-treatment from the laboratory experiments, rinsing with water for 36 hours followed by drying, was field-tested at Fort Irwin, California. Two sites and two seeding dates (early March and mid April) were determined for each site. Five mulch treatments (no mulch, straw, gravel, chemical stabilizer, and plastic) were evaluated in combination with the seed pre-treatments. Field emergence was greatly enhanced with the seed pre-treatment for white bursage during the March (18-42% increase in germination) and April seedings (16-23% increase in germination). Creosotebush showed poor germination during March (2-5%) when soil temperatures averaged 15 C, but germination increased during the April trials (6-43%) when soil temperatures averaged 23 C. The seed pre-treatment during the April trials increased germination from 16-23%. The plastic mulch treatment increased germination dramatically during both the March and April trials. The plastic mulch increased soil temperatures (8-10 C)and maintained high humidity during germination. Both the chemical stabilizer and the gravel mulches improved germination over the control while the straw mulch decreased germination. These results suggest that seed pre-treatments combined with irrigation and mulch are effective techniques to establish these two dominant Mojave Desert species from seed.

Biochemical and morphological characterization of light and heavy sarcoplasmic reticulum vesicles

Energy Technology Data Exchange (ETDEWEB)

Campbell, Kevin Peter [Univ. of Rochester, NY (United States)

1978-01-01

Light (30 to 32.5% sucrose) and heavy (38.5 to 42% sucrose) sarcoplasmic reticulum vesicles (LSR,HSR) were isolated from rabbit leg muscle using a combination of differential centrifugation and isopycnic zonal ultracentrifugation. Thin-section electron microscopy of LSR vesicles reveals empty vesicles of various sizes and shapes whereas the HSR vesicles appear as rounded vesicles of uniform size filled with electron dense material, similar to that seen in the terminal cisternae of the sarcoplasmic reticulum. The sucrose HSR vesicles have an additional morphological feature which appears as membrane projections that resemble the SR feet. The freeze-fracture morphology of either type of SR reveals an asymmetric distribution of intramembraneous particles in the same orientation and distribution as the sarcoplasmic reticulum in vivo. Biochemical studies were made on the content of Ca, Mg, ATPase, and protein of the vesicles and phosphorylation of the vesicles. The biochemical and morphological data indicate that the LSR is derived from the longitudinal sarcoplasmic reticulum and the HSR is derived from the terminal cisternae of the sarcoplasmic reticulum, contains junctional SR membrane and has three unique proteins (calsequestrin, an intrinsic 30,000 dalton protein and a 9000 dalton proteolipid).

Conserved Transcriptional Regulatory Programs Underlying Rice and Barley Germination

Science.gov (United States)

Lin, Li; Tian, Shulan; Kaeppler, Shawn; Liu, Zongrang; An, Yong-Qiang (Charles)

2014-01-01

Germination is a biological process important to plant development and agricultural production. Barley and rice diverged 50 million years ago, but share a similar germination process. To gain insight into the conservation of their underlying gene regulatory programs, we compared transcriptomes of barley and rice at start, middle and end points of germination, and revealed that germination regulated barley and rice genes (BRs) diverged significantly in expression patterns and/or protein sequences. However, BRs with higher protein sequence similarity tended to have more conserved expression patterns. We identified and characterized 316 sets of conserved barley and rice genes (cBRs) with high similarity in both protein sequences and expression patterns, and provided a comprehensive depiction of the transcriptional regulatory program conserved in barley and rice germination at gene, pathway and systems levels. The cBRs encoded proteins involved in a variety of biological pathways and had a wide range of expression patterns. The cBRs encoding key regulatory components in signaling pathways often had diverse expression patterns. Early germination up-regulation of cell wall metabolic pathway and peroxidases, and late germination up-regulation of chromatin structure and remodeling pathways were conserved in both barley and rice. Protein sequence and expression pattern of a gene change quickly if it is not subjected to a functional constraint. Preserving germination-regulated expression patterns and protein sequences of those cBRs for 50 million years strongly suggests that the cBRs are functionally significant and equivalent in germination, and contribute to the ancient characteristics of germination preserved in barley and rice. The functional significance and equivalence of the cBR genes predicted here can serve as a foundation to further characterize their biological functions and facilitate bridging rice and barley germination research with greater confidence. PMID

[Study on conditions of seed germination of Cistanche].

Science.gov (United States)

Qiao, Xue-Yi; Wang, Hua-Lei; Guo, Yu-Hai

2007-09-01

To study the effect of fluridone concentration, stimulating period, temperature and salt on the seed germination of three species of Cistanche. The seeds were cultured in Petri dish, and the germination percentage was counted. The highest germination percentage was observed in Cistanche tubulosa, C. deserticola, C. sala seeds pre-treated by 0.1 mg x L(-1) fluridone for 24-29 h. The optimal temperature for the seeds germination of three species of Cistanche was at 20-30 degrees C, and the seeds did not germinate at sub-or supraoptimal temperatures (5 and 35 degrees C). The salt tolerance of C. sala seeds was strong, and the critical value of NaCl concentration was 0.04 mol x L(-1). By contrast, C. tubulosa and C. deserticola seeds were more sensitive to the salt stress, the critical value of NaCl concentration was 0.02 mol x L(-1). The optimal germination condition and the method of testing germination percentage of three species of Cistanche seeds are as follow: the seeds are pre-treated by 0.1 mg x L(-1) fluridone for 24 h and then cultured at 20-30 degrees C in salt solution which concentration is lower than 0.02 mol x L(-1).

Interaction of a potyviral VPg with anionic phospholipid vesicles

International Nuclear Information System (INIS)

Rantalainen, Kimmo I.; Christensen, Peter A.; Hafren, Anders; Otzen, Daniel E.; Kalkkinen, Nisse; Maekinen, Kristiina

2009-01-01

The viral genome-linked protein (VPg) of Potato virus A (PVA) is a multifunctional protein that belongs to a class of intrinsically disordered proteins. Typically, this type of protein gains a more stable structure upon interactions or posttranslational modifications. In a membrane lipid strip overlay binding assay, PVA VPg was found to bind phosphatidylserine (PS), but not phosphatidylcholine (PC). According to circular dichroism spectroscopy, the secondary structure of PVA VPg was stabilized upon interactions with PS and phosphatidylglycerol (PG), but not with PC vesicles. It is possible that this stabilization favored the formation of α-helical structures. Limited tryptic digestion showed that the interaction with anionic vesicles protected certain, otherwise accessible, trypsin cleavage sites. An electron microscopy study revealed that interaction with VPg substantially increased the vesicle diameter and caused the formation of pore or plaque-like electron dense spots on the vesicle surface, which gradually led to disruption of the vesicles.

The Germination of Some Species Tropical Legume Seeds

Directory of Open Access Journals (Sweden)

Eko Poetri

2005-09-01

Full Text Available A study to evaluate the seed germination of Leucaena pallida under climatic and soil conditions in Palu was conducted in village of Taipa, Sub district of North Palu, District of Palu. To compare with other species of legume trees however, this study involved Leucaena leucocephala cv Tarramba, Leucaena leucocephala cv Gumph and Gliricidia maculata. This experiment used completely randomized design with species of tropical tree legumes as treatment.  Each treatment was replicated five times.  Each experimental unit consisted of one tray (size 12.5 x 25 cm and planted by 20 seed.  Each tray was filled with soil while the seeds were planted one cm deep.  All seeds were immersed in warm water (600C for five minutes before planted.  The base of the trays were drilled to create some holes for water to drain out.  The trays were sprayed twice daily (07.00 am and 03.00 pm to keep the soil to be moist using a very smooth sprayer.  The variables recorded included the initiation time of germination, the range time of germination and the percentage of seed germination.  The data obtained were analyses using the Minitab 11. Least significance difference was used to test for possible differences between treatment means. The result revealed that initiation time of germination and the range of germination were not varied (P>0.05 among the seeds tested. The initiation time of germination ranged between 9 to 12 d after sowing.  Gliricidia maculata seed has the shortest period to germinate (12-16 d after sowing, meanwhile Leucaena leucocephala cv. Tarramba appear to be the longest (9-17 d after sowing. The highest seed viability was 60% in Leucaena leucocephala, cv Gump while the lowest was found in Gliricidia maculata (29%. In addition, both Leucaena pallida and Leucaena leucocephala cv Tarramba had medium seed germination (40% and 53% respectively. (Animal Production 7(3: 156-160 (2005Key Words: Seed, Germination, Tropical Leguminous

Spin State As a Probe of Vesicle Self-Assembly

OpenAIRE

Kim, Sanghoon; Bellouard, Christine; Eastoe, Julian; Canilho, Nadia; Rogers, Sarah E; Ihiawakrim, Dris; Ersen, Ovidiu; Pasc, Andreea

2016-01-01

A novel system of paramagnetic vesicles was designed using ion pairs of iron-containing surfactants. Unilamellar vesicles (diameter ≈ 200 nm) formed spontaneously and were characterized by cryogenic transmission electron microscopy, nanoparticle tracking analysis, and light and small-angle neutron scattering. Moreover, for the first time, it is shown that magnetization measurements can be used to investigate self-assembly of such functionalized systems, giving information on the vesicle compo...

Comparative analysis of regulatory elements in different germin-like ...

African Journals Online (AJOL)

STORAGESEVER

INTRODUCTION. Germin and germin-like proteins (GLPs) is a member of ..... analysis of germin-like protein gene 2 promoter from Oryza sativa L. ssp. Indica. ... esculenta Crantz) root proteome: Protein identification and differential expression.

Biochemical and morphological characterization of light and heavy sarcoplasmic reticulum vesicles. Volume I

Energy Technology Data Exchange (ETDEWEB)

Campbell, Kevin Peter [Univ. of Rochester, NY (United States)

1978-01-01

Light (30 to 32.5% sucrose) and heavy (38.5 to 42% sucrose) sarcoplasmic reticulum vesicles (LSR, HSR) were isolated from rabbit leg muscle. They were then diluted and washed with sucrose or KCl and referred to as sucrose or KCl washed vesicles. Thin-section electron microscopy of LSR vesicles reveals empty vesicles of various sizes and shapes where as the HSR vesicles appear as rounded vesicles of uniform size filled with electron dense material. The LSR consists of predominantly Ca²⁺ + Mg²⁺ ATPase (80 to 90%), a small amount of the high affinity Ca binding protein (5%), and a 5000 dalton proteolipid. The sucrose HSR vesicles contain the Ca²⁺ + Mg²⁺ ATPase (50%), Calsequestrin (25%), high affinity Ca binding protein (5%), one extrinsic 34,000 dalton protein (3%), one intrinsic 30,000 dalton protein (3%), a 9000 dalton proteolipid, and a 5000 dalton proteolipid. The sucrose--washed HSR vesicles contain greater than three times the calcium content of the sucrose washed LSR vesicles where as the KCl--washed vesicles contain less than 15 nmoles Ca²⁺ mg of protein each. The light and heavy sarcoplasmic reticulum vesicles were both able to accumulate calcium in the presence of ATP. Exchange of methanesulfonate for chloride resulted in the release of calcium from both the light and heavy SR vesicles. Sucrose causes a slight inhibition of chloride--induced calcium release from the heavy SR vesicles but it greatly reduces the release of calcium from the light SR vesicles. Sodium dantrolene (20 uM) has no effect on the release of calcium from the light SR vesicles but it inhibits the release of calcium from the heavy SR vesicles. The results indicate that the chloride--induced release of calcium may be acting by two mechanisms, osmotic swelling and depolarization.

Biochemical and morphological characterization of light and heavy sarcoplasmic reticulum vesicles. Volume I

International Nuclear Information System (INIS)

Campbell, K.P.

1978-01-01

Light (30 to 32.5% sucrose) and heavy (38.5 to 42% sucrose) sarcoplasmic reticulum vesicles (LSR, HSR) were isolated from rabbit leg muscle. They were then diluted and washed with sucrose or KCl and referred to as sucrose or KCl washed vesicles. Thin-section electron microscopy of LSR vesicles reveals empty vesicles of various sizes and shapes where as the HSR vesicles appear as rounded vesicles of uniform size filled with electron dense material. The LSR consists of predominantly Ca 2+ + Mg 2+ ATPase (80 to 90%), a small amount of the high affinity Ca binding protein (5%), and a 5000 dalton proteolipid. The sucrose HSR vesicles contain the Ca 2+ + Mg 2+ ATPase (50%), Calsequestrin (25%), high affinity Ca binding protein (5%), one extrinsic 34,000 dalton protein (3%), one intrinsic 30,000 dalton protein (3%), a 9000 dalton proteolipid, and a 5000 dalton proteolipid. The sucrose--washed HSR vesicles contain greater than three times the calcium content of the sucrose washed LSR vesicles where as the KCl--washed vesicles contain less than 15 nmoles Ca 2+ /mg of protein each. The light and heavy sarcoplasmic reticulum vesicles were both able to accumulate calcium in the presence of ATP. Exchange of methanesulfonate for chloride resulted in the release of calcium from both the light and heavy SR vesicles. Sucrose causes a slight inhibition of chloride--induced calcium release from the heavy SR vesicles but it greatly reduces the release of calcium from the light SR vesicles. Sodium dantrolene (20 uM) has no effect on the release of calcium from the light SR vesicles but it inhibits the release of calcium from the heavy SR vesicles. The results indicate that the chloride--induced release of calcium may be acting by two mechanisms, osmotic swelling and depolarization

Asymbiotic germination of immature embryos of a medicinally ...

African Journals Online (AJOL)

H.piri

La germination no simuotica de las semillas de orquideas. Bol. Real. Soc. Esp. Hist. Nat. 21:250-260. Knudson L (1922). Non–symbiotic germination of orchid seeds. Bot. Gaz. 73:1-25. Knudson L (1925). Physiological study of the asymbiotic germination of orchid seeds. Bot. Gaz. 79:345-379. Lawler LJ (1984). Ethnobotany ...

Investigation of coriander germination (Coriandrum sativum L.

Directory of Open Access Journals (Sweden)

Aćimović Milica

2013-01-01

Full Text Available Coriander seed yield (Coriandrum sativum L. depends of many factors during vegetation period, and also depend of seed quality. Coriander fruit (Coriandri fructus which is used like spice and in medicinal purpose, and also in food and pharmacy, in the same time is and seed material. Because of that, it is very important to take care about its quality. In this paper is analyzed seed material obtained from field experiments village Mošorin, in 2011, and investigated was conducted in harvest year, and one year later. In harvest year, germination energy in average was 38,21%, and total germination 72,75%. After one year, germination energy was statistically significant smaller - 16,50%, as like total germination which was 67,42%.

Germination conditions affect physicochemical properties of germinated brown rice flour.

Science.gov (United States)

Charoenthaikij, Phantipha; Jangchud, Kamolwan; Jangchud, Anuvat; Piyachomkwan, Kuakoon; Tungtrakul, Patcharee; Prinyawiwatkul, Witoon

2009-01-01

Germinated brown rice has been reported to be nutritious due to increased free gamma-aminobutyric acid (GABA). The physicochemical properties of brown rice (BR) and glutinous brown rice (GNBR) after germination as affected by different steeping times (24, 36, 48, and 72 h depending on the rice variety) and pHs of steeping water (3, 5, 7, and as-is) were determined and compared to those of the nongerminated one (control). As the steeping time increased or pH of steeping water decreased, germinated brown rice flours (GBRF) from both BR and GNBR had greater reducing sugar, free GABA and alpha-amylase activity; while the total starch and viscosity were lower than their respective controls. GBRFs from both BR and GNBR prepared after 24-h steeping time at pH 3 contained a high content of free GABA at 32.70 and 30.69 mg/100 g flour, respectively. The peak viscosity of GBRF obtained from both BR and GNBR (7.42 to 228.22 and 4.42 to 58.67 RVU, respectively) was significantly lower than that of their controls (255.46 and 190.17 RVU, respectively). The principal component analysis indicated that the important variables for discriminating among GBRFs, explained by the first 2 components at 89.82% of total explained variance, were the pasting profiles, alpha-amylase activity, and free GABA.

Study the effect of salinity levels and seed priming on germination and seedling properties of two medicinal plant species from Asteraceae family

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M. Kafi

2016-04-01

Full Text Available Soil and water sources salinity are important constrains which threat the sustainable agriculture production in Iran. In order to evaluate the effect of different antioxidants and salinity levels on germination and seedling properties of two medicinal species (Cnicus benedictus L., and (Cichorium intybus L., an experiment was conducted using a factorial based on completely randomized design with four replications at Special Crops Laboratory of Ferdowsi University of Mashhad. The studied factor for each plant included: seed priming at 4 levels including control (distilled water, ascorbic acid (40 mM, gibberlic acid (75 mg.lit-1 and salicylic acid (1.5 mM, and five salinity levels according to electrical conductivity by adding NaCl to distilled water (control, 5,10,15 and 20 ds.m-1. According to results, pretreatment with salicylic acid improved all of the germination and seedling properties in Cnicus benedictus L. but gibberlic acid could to improved germination and seedling properties in Cichorium intybus L. species. There were strong correlation between germination rate and radical and caulicle length especially on Cichorium intybus species. Generally, seed priming with gibberlic acid and salicylic acid could improve germination and seedling properties of these two species. Both species showed a reliable tolerance to NaCl salinity at germination stage, and germination was 60% compared with control at 20 ds.m-1 treatment.

Vesicle fusion with bilayer lipid membrane controlled by electrostatic interaction

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Azusa Oshima

2017-09-01

Full Text Available The fusion of proteoliposomes is a promising approach for incorporating membrane proteins in artificial lipid membranes. In this study, we employed an electrostatic interaction between vesicles and supported bilayer lipid membranes (s-BLMs to control the fusion process. We combined large unilamellar vesicles (LUVs containing anionic lipids, which we used instead of proteoliposomes, and s-BLMs containing cationic lipids to control electrostatic interaction. Anionic LUVs were never adsorbed or ruptured on the SiO2 substrate with a slight negative charge, and selectively fused with cationic s-BLMs. The LUVs can be fused effectively to the target position. Furthermore, as the vesicle fusion proceeds and some of the positive charges are neutralized, the attractive interaction weakens and finally the vesicle fusion saturates. In other words, we can control the number of LUVs fused with s-BLMs by controlling the concentration of the cationic lipids in the s-BLMs. The fluidity of the s-BLMs after vesicle fusion was confirmed to be sufficiently high. This indicates that the LUVs attached to the s-BLMs were almost completely fused, and there were few intermediate state vesicles in the fusion process. We could control the position and amount of vesicle fusion with the s-BLMs by employing an electrostatic interaction.

La préparation des catalyseurs. Première partie : Germination et croissance des particules. Importance de la sursaturation du milieu Preparation of Catalysts. Part One: Particle Germination and Growth. Importance of the Supersaturation of the Medium

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Marcilly C.

2006-11-01

Full Text Available Cet article présente les deux notions fondamentales et générales de germination et croissance des particules ou cristaux élémentaires qui peuvent former aussi bien le support du catalyseur que l'agent actif dispersé à sa surface. Germination et croissance sont deux étapes très importantes qui interviennent à divers stades de la préparation des catalyseurs : précipitation, séchage, calcination, etc. On montre que le paramètre essentiel qui régit ces deux étapes et qui détermine la dimension, la structure et le faciès des particules élémentaires est la sursaturation du milieu. This article describes the two fundamental and general concepts of germination and growth of elementary particles or crystals which may form either the catalyst support or the dispersed active agent on its surface. Germination and growth are two very important steps which occur at dif-ferent stages of the preparation of catalysts, i,e. precipitation, drying, calcination, etc. The supersaturation of the medium is shown to be the essential parameter governing these two steps and determining the size, structure and facies of elementary particles.

Cyrtopodium paludicolum germination with two Tulasnella isolates

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Otieres Cirino de Carvalho

2017-11-01

Full Text Available ABSTRACT Symbiosis between orchid seeds and mycorrhizal fungi has been reported to be a determining factor in the success of germination and protocorm development in vitro. The aim of this study was to isolate and identify by molecular analysis the mycorrhizal fungus associated with Cyrtopodium paludicolum, and to evaluate its efficiency in facilitating seed germination and development. Germination experiments were carried out using a fungus isolated from C. paludicolum (CH01 and Epidendrum secundum (M65, which has been successfully used a number of times in symbiotic germination. The experiments were conducted in a completely randomized design with treatments of CH01, M65 as well as under asymbiotic conditions. The mycobiont CH01 was successfully isolated from Cyrtopodium paludicolum and identified as Tulasnella sp. Treatments with both fungi reached a higher germination percentage than under asymbiotic conditions, indicating no specificity in the relationship between Cyrtopodium paludicolum and the fungi. The results presented have the potential to advance research into the propagation and conservation of C. paludicolum, a native of the Cerrado biome.

Biorhythms in conifer seed germination during extended storage

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James P. Barnett; N.I. Marnonov

1989-01-01

A proportion of sound seeds of conifer species do not germinate during certain periods of the year, even when conditions are favorable. Mamonov et al. (1986) report that the non-germinating seeds have apparently undergone physiological changes that affected germination. This phenomenon may be due to seasonal periodicity, or biorhythms. As early as the mid-1930'...

Germination phenology determines the propensity for facilitation and competition.

Science.gov (United States)

Leverett, Lindsay D

2017-09-01

A single plant can interact both positively and negatively with its neighbors through the processes of facilitation and competition, respectively. Much of the variation in the balance of facilitation and competition that individuals experience can be explained by the degree of physical stress and the sizes or ages of plants during the interaction. Germination phenology partly controls both of these factors, but its role in defining the facilitation-competition balance has not been explicitly considered. I performed an experiment in a population of the winter annual Arabidopsis thaliana (Brassicaceae) to test whether germinating during physically stressful periods leads to facilitation while germinating during periods that promote growth and reproduction leads to competition. I manipulated germination and neighbor presence across two years in order to quantify the effects of the local plant community on survival, fecundity, and total fitness as a function of germination phenology. Neighbors increased survival when germination occurred under conditions that were unsuitable for survival, but they reduced fecundity in germinants that were otherwise the most fecund. Later germination was associated with facilitation in the first year but competition in the second year. These episodes of facilitation and competition opposed each other, leading to no net effect of neighbors when averaged over all cohorts. These results indicate that variation in germination timing can explain some of the variation in the facilitation-competition balance in plant communities. © 2017 by the Ecological Society of America.

Temperature and substrate on Plukenetia volubilis L. seed germination

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Givanildo Z. da Silva

Full Text Available ABSTRACT The objective of this work was to evaluate the effect of temperature and substrate on the germination of P. volubilis seeds. Seeds harvested from 25 matrix plants were submitted, in two studies, to conditions of (i sowing in rolled paper towel at the temperatures of 10, 15, 20, 25, 30, 35, 40, and 45 °C, for the evaluation of germination, first count of germination, germination speed index and mean time for germination, and (ii sowing in the substrates paper towel, sand, Bioplant®, Bioplant® and micron, superfine, fine, medium and coarse vermiculite. The same evaluations mentioned in the first study were conducted at the temperature of 30 oC, as well as plant growth. The treatment replicates were distributed in a completely randomized block design and the effects of temperature were compared by polynomial regression analysis. The substrates were compared by the Scott-Knott test at 0.05 probability level. The data show that the ideal range of temperature for the germination of P. volubilis is between 25 and 30 °C. The temperature of 20 °C is the minimum for germination and those above 35 °C are lethal to these seeds. The most favorable substrate for P. volubilis seed germination is micron or fine vermiculite.

Effect of cooking on functional properties of germinated black glutinous rice (KKU-ULR012

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Thapanan Konwatchara

2014-06-01

Full Text Available The aim of this research was to investigate the changes in functional properties of germinated black glutinous rice (KKU-ULR012 after cooking. Black glutinous rice grains were obtained from Faculty of Agriculture, Khon Kaen University, Thailand. The rough grains were soaked for 12 hrs, then germinated for 30 hrs at 35±2°C (95%RH, dried at 45±2°C for 8 hrs, dehusked and cooked either using a microwave oven or a pressure cooker. The cooked grains were dehydrated in two stages, 85±2°C for 1 hr and 45±2°C for 12 hrs until the final moisture content was 10±2%wb. The antioxidant activity, anthocyanins, GABA and -oryzanol contents, and the microstructure of the dehydrated grains were then characterized. Germination process induced a 2.55 fold increase in GABA content compared to non-germinated KKU-ULR012. The germinated KKU-ULR012 gave DPPH value, anthocyanins and -oryzanol contents of 33.74±0.15 mgTrolox/100gdb, 182.89±0.48 mg/100gdb and 37.72±0.16 mg/100gdb, respectively. Anthocyanins in cooked germinated KKU-ULR012 diminished almost 88-89% after cooking. The cooking methods employed strongly influenced the antioxidant activity and anthocyanins content that the pressure cooking tended to prevent loss of anthocyanin content and antioxidant activity. The GABA, -oryzanol and antho-cyanins contents and antioxidant activity of germinated grains cooked in the pressure cooker were higher than the samples cooked in the microwave oven (p<0.05. For pressure cooking, the cooked grains gave DPPH, ABTS, anthocyanins and -oryzanol contents of 9.89±0.35 mgTrolox/100gdb, 1.79±0.04 mgTrolox/100gdb, 21.60±0.14 mg/100gdb and 37.16±0.70 mg/100gdb, respectively. The rice grains cooked by pressure cooking were more moist and sticky than the grains cooked by microwave cooking. The microstructure examined by SEM showed that the center of the dehydrated cooked rice grain was smooth indicating starch gelatinization whereas the surface revealed

Effect of water and saline stress on germination of Atriplex nummularia (Chenopodiaceae)

International Nuclear Information System (INIS)

Ruiz, Monica B; Parera, Carlos A

2013-01-01

Saline soils, characteristic of arid zones, can affect the germination of the species due to low water potential or ion toxicity. The effect of water and saline stress on germination was evaluated in atriplex nummularia a potential source of forage for arid zones. the seeds were scarified to reduce the inhibitory effect on germination and incubated in at 23 Celsius degrade on germination paper imbibed with solutions of sodium chloride (NaCl) and polyethylene glycol (peg) at three water potentials: -0,5; -1,0 and -1,5 MPA. The percentage germination and germination speed were significantly affected by the concentration of the solution and the solute used. While more negative osmotic potentials, the percentage of germination and germination speed were significantly lower. The seeds germinated in peg solution have higher germination and germination speed than the seeds germinated in NaCl, especially in -1,0 MPA. The data suggest that the seeds of a. nummularia show sensitivity to the presence of Na+ and Cl- ions affecting the germination process.

Functional transferred DNA within extracellular vesicles

Energy Technology Data Exchange (ETDEWEB)

Cai, Jin [Department of Cardiology, Daping Hospital, The Third Military Medical University, Chongqing 400042 (China); Department of Neurology, Jinling Hospital, Nanjing University School of Medicine, Jiangsu Province (China); Wu, Gengze [Department of Cardiology, Daping Hospital, The Third Military Medical University, Chongqing 400042 (China); Jose, Pedro A. [Division of Nephrology, Department of Medicine and Physiology, University of Maryland, School of Medicine, Baltimore, MD 21201 (United States); Zeng, Chunyu, E-mail: Chunyuzeng01@163.com [Department of Cardiology, Daping Hospital, The Third Military Medical University, Chongqing 400042 (China)

2016-11-15

Extracellular vesicles (EVs) are small membrane vesicles including exosomes and shedding vesicles that mediated a cell-to-cell communication. EVs are released from almost all cell types under both physiological and pathological conditions and incorporate nuclear and cytoplasmic molecules for intercellular delivery. Besides protein, mRNA, and microRNA of these molecules, as recent studies show, specific DNA are prominently packaged into EVs. It appears likely that some of exosomes or shedding vesicles, bearing nuclear molecules are released upon bubble-like blebs. Specific interaction of EVs with susceptible recipients performs the uptake of EVs into the target cells, discharging their cargo including nuclear and cytoplasmic macromolecules into the cytosol. These findings expand the nucleic acid content of EVs to include increased levels of specific DNA. Thus, EVs contain a repertoire of genetic information available for horizontal gene transfer and potential use as blood biomarkers for cancer and atherosclerosis. In this review, the focus is on the characteristics, biological functions, and roles in diseases of DNA within EVs. - Highlights: • This review is focused on the DNA within EVs including its characteristics, biological functions, and roles in diseases. • It is clear that DNA within EVs might have important physiological and pathological roles in various diseases. • Knowledge in this area may provides us alternative methods for disease diagnosis or therapy in the future.

Functional transferred DNA within extracellular vesicles

International Nuclear Information System (INIS)

Cai, Jin; Wu, Gengze; Jose, Pedro A.; Zeng, Chunyu

2016-01-01

Extracellular vesicles (EVs) are small membrane vesicles including exosomes and shedding vesicles that mediated a cell-to-cell communication. EVs are released from almost all cell types under both physiological and pathological conditions and incorporate nuclear and cytoplasmic molecules for intercellular delivery. Besides protein, mRNA, and microRNA of these molecules, as recent studies show, specific DNA are prominently packaged into EVs. It appears likely that some of exosomes or shedding vesicles, bearing nuclear molecules are released upon bubble-like blebs. Specific interaction of EVs with susceptible recipients performs the uptake of EVs into the target cells, discharging their cargo including nuclear and cytoplasmic macromolecules into the cytosol. These findings expand the nucleic acid content of EVs to include increased levels of specific DNA. Thus, EVs contain a repertoire of genetic information available for horizontal gene transfer and potential use as blood biomarkers for cancer and atherosclerosis. In this review, the focus is on the characteristics, biological functions, and roles in diseases of DNA within EVs. - Highlights: • This review is focused on the DNA within EVs including its characteristics, biological functions, and roles in diseases. • It is clear that DNA within EVs might have important physiological and pathological roles in various diseases. • Knowledge in this area may provides us alternative methods for disease diagnosis or therapy in the future.

Compartmentalization and Transport in Synthetic Vesicles

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Christine eSchmitt

2016-02-01

Full Text Available Nano-scale vesicles have become a popular tool in life sciences. Besides liposomes that are generated from phospholipids of natural origin, polymersomes fabricated of synthetic block copolymers enjoy increasing popularity, as they represent more versatile membrane building blocks that can be selected based on their specific physicochemical properties, like permeability, stability or chemical reactivity.In this review, we focus on the application of simple and nested artificial vesicles in synthetic biology. First, we provide an introduction into the utilization of multi-compartmented vesosomes as compartmentalized nano-scale bioreactors. In the bottom-up development of protocells from vesicular nano-reactors, the specific exchange of pathway intermediates across compartment boundaries represents a bottleneck for future studies. To date, most compartmented bioreactors rely on unspecific exchange of substrates and products. This is either based on changes in permeability of the coblock polymer shell by physicochemical triggers or by the incorporation of unspecific porin proteins into the vesicle membrane. Since the incorporation of membrane transport proteins into simple and nested artificial vesicles offers the potential for specific exchange of substances between subcompartments, it opens new vistas in the design of protocells. Therefore we devote the main part of the review to summarize the technical advances in the use of phospholipids and block copolymers for the reconstitution of membrane proteins.

Physiological quality and gene expression related to heat-resistant proteins at different stages of development of maize seeds.

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Andrade, T; Von Pinho, E V R; Von Pinho, R G; Oliveira, G E; Andrade, V; Fernandes, J S

2013-09-13

We quantified and characterized the expression of heat-resistant proteins during seed development of maize lines with distinct levels of tolerance to high drying temperature. A corn field was planted for multiplication of seeds of different lines, two tolerant and two non-tolerant to high drying temperatures. Harvest of the seeds was carried out at various stages of development and they were then subjected to tests of moisture content, germination, first count of germination, accelerated aging, and cold test. The seeds were stored in a freezer for later analysis of expression of heat-resistant proteins by means of real-time PCR, electrophoresis, and spectrophotometry. We observed that heat-resistant proteins are expressed in a differential manner in seeds from different lines and at different stages of development. The expression of heat-resistant proteins was earlier in lines tolerant to high drying temperatures. Greater germination and vigor values was found for seeds collected at the last stage of development.

Chromatic response of polydiacetylene vesicle induced by the permeation of methotrexate.

Science.gov (United States)

Shin, Min Jae; Kim, Ye Jin; Kim, Jong-Duk

2015-07-07

The noble vesicular system of polydiacetylene showed a red shift using two types of detecting systems. One of the systems involves the absorption of target materials from the outer side of the vesicle, and the other system involves the permeation through the vesicular layers from within the vesicle. The chromatic mixed vesicles of N-(2-aminoethyl)pentacosa-10,12-diynamide (AEPCDA) and dimethyldioctadecylammonium chloride (DODAC) were fabricated by sonication, followed by polymerization by UV irradiation. The stability of monomeric vesicles was observed to increase with the polymerization of the vesicles. Methotrexate was used as a target material. The polymerized mixed vesicles having a blue color were exposed to a concentration gradient of methotrexate, and a red shift was observed indicating the adsorption of methotrexate on the polydiacetylene bilayer. In order to check the chromatic change by the permeation of methotrexate, we separated the vesicle portion, which contained methotrexate inside the vesicle, and checked chromatic change during the permeation of methotrexate through the vesicle. The red shift apparently indicates the disturbance in the bilayer induced by the permeation of methotrexate. The maximum contrast of color appeared at the equal molar ratio of AEPCDA and DODAC, indicating that the formation of flexible and deformable vesicular layers is important for red shift. Therefore, it is hypothesized that the system can be applicable for the chromatic detection of the permeation of methotrexate through the polydiacetylene layer.

Anaesthetics stop diverse plant organ movements, affect endocytic vesicle recycling and ROS homeostasis, and block action potentials in Venus flytraps.

Science.gov (United States)

Yokawa, K; Kagenishi, T; Pavlovic, A; Gall, S; Weiland, M; Mancuso, S; Baluška, F

2017-12-11

Anaesthesia for medical purposes was introduced in the 19th century. However, the physiological mode of anaesthetic drug actions on the nervous system remains unclear. One of the remaining questions is how these different compounds, with no structural similarities and even chemically inert elements such as the noble gas xenon, act as anaesthetic agents inducing loss of consciousness. The main goal here was to determine if anaesthetics affect the same or similar processes in plants as in animals and humans. A single-lens reflex camera was used to follow organ movements in plants before, during and after recovery from exposure to diverse anaesthetics. Confocal microscopy was used to analyse endocytic vesicle trafficking. Electrical signals were recorded using a surface AgCl electrode. Mimosa leaves, pea tendrils, Venus flytraps and sundew traps all lost both their autonomous and touch-induced movements after exposure to anaesthetics. In Venus flytrap, this was shown to be due to the loss of action potentials under diethyl ether anaesthesia. The same concentration of diethyl ether immobilized pea tendrils. Anaesthetics also impeded seed germination and chlorophyll accumulation in cress seedlings. Endocytic vesicle recycling and reactive oxygen species (ROS) balance, as observed in intact Arabidopsis root apex cells, were also affected by all anaesthetics tested. Plants are sensitive to several anaesthetics that have no structural similarities. As in animals and humans, anaesthetics used at appropriate concentrations block action potentials and immobilize organs via effects on action potentials, endocytic vesicle recycling and ROS homeostasis. Plants emerge as ideal model objects to study general questions related to anaesthesia, as well as to serve as a suitable test system for human anaesthesia. © The Authors 2017. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Effect of Gamma Radiation on Amino Acid Based Vesicle Carrying Radiosensitizer

International Nuclear Information System (INIS)

Nur Ratasha Alia Mohd Rosli; Faizal Mohamed; Muhammad Amir Syafiq Mohd Sah; Irman Abdul Rahman

2014-01-01

Vesicles has been developed and studied to be used as a medium to transport radiosensitizer in treating cancer cells by increasing its sensitivity effectively towards the radiation given during radiotherapy. This study was conducted to investigate the effect of gamma radiation on amino acid-based vesicle carrying radiosensitizer. Amino acid based vesicles carrying radiosensitizer were synthesized using sonication method with sodium N-lauroylsarcosinate hydrate and decanol being the primary surfactant, while hydrogen peroxide and sodium hyaluronate as the encapsulated radiosensitizer. The synthesized vesicle was then irradiated at radiation doses equivalent to those given during radiotherapy. Irradiated vesicle carrying radiosensitizer were then characterized using Transmission Electron Microscopy (TEM), Fourier Transform Infrared Spectroscopy (FTIR) and Polarized Light Microscope. Results obtained shows that there were no significant changes in morphology and molecular conformation of the synthesized vesicle after irradiation. Even at higher radiation dose of 100 Gray and 200 Gray, the results remained unchanged. This indicates that the synthesized vesicle carrying radiosensitizer is morphologically and spectroscopically stable even at high radiation doses. (author)

Gold nanoparticles covalently assembled onto vesicle structures as possible biosensing platform

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M. Fátima Barroso

2016-05-01

Full Text Available In this contribution a strategy is shown to covalently immobilize gold nanoparticles (AuNPs onto vesicle bilayers with the aim of using this nanomaterial as platform for the future design of immunosensors. A novel methodology for the self-assembly of AuNPs onto large unilamellar vesicle structures is described. The vesicles were formed with 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC and 1-undecanethiol (SH. After, the AuNPs photochemically synthesized in pure glycerol were mixed and anchored onto SH–DOPC vesicles. The data provided by voltammetry, spectrometry and microscopy techniques indicated that the AuNPs were successfully covalently anchored onto the vesicle bilayer and decorated vesicles exhibit a spherical shape with a size of 190 ± 10 nm. The developed procedure is easy, rapid and reproducible to start designing a possible immunosensor by using environmentally friendly procedures.

Optimization of jenipapo in vitro seed germination process

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Rafaela Ribeiro de Souza

Full Text Available ABSTRACT The in vitro seed germination is an effective alternative for quickly obtaining explants with sanitary quality. However, jenipapo seeds present slow and uneven germination. Therefore, internal and external factors to seed which directly interfere in the process, they must be identified, in order to adapt better techniques to obtain seedlings. In this sense, this work aimed to optimize the in vitro germination of Genipa americana L. seeds by evaluating different factors (light quality, GA3 treatment, pre-soaking in distilled water, growing media and stratification in the dark. It was found that the seed germination of G. americana was indifferent to light, however, the best results were obtained under conditions of continuous darkness; There was no effect of the application of exogenous GA3; The pre-soaking in distilled water for 48 h contributes to obtaining better germination rates; And the reduction in MS medium salts, and laminating the pretreatment in the dark maximizes the germination potential of seeds.Therefore, the optimal conditions for in vitro germination of G. americana L. seeds requires pre-soaking in distilled water for 48 hours and inoculation into culture media consisting of 1/2 MS + 15 g L-1 sucrose, with stratification in the dark for 16 days, followed by the transfer to growth chambers with lighting provided by white fluorescent lamps.

Pseudomonas aeruginosa vesicles associate with and are internalized by human lung epithelial cells

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Kuehn Meta J

2009-02-01

Full Text Available Abstract Background Pseudomonas aeruginosa is the major pathogen associated with chronic and ultimately fatal lung infections in patients with cystic fibrosis (CF. To investigate how P. aeruginosa-derived vesicles may contribute to lung disease, we explored their ability to associate with human lung cells. Results Purified vesicles associated with lung cells and were internalized in a time- and dose-dependent manner. Vesicles from a CF isolate exhibited a 3- to 4-fold greater association with lung cells than vesicles from the lab strain PAO1. Vesicle internalization was temperature-dependent and was inhibited by hypertonic sucrose and cyclodextrins. Surface-bound vesicles rarely colocalized with clathrin. Internalized vesicles colocalized with the endoplasmic reticulum (ER marker, TRAPα, as well as with ER-localized pools of cholera toxin and transferrin. CF isolates of P. aeruginosa abundantly secrete PaAP (PA2939, an aminopeptidase that associates with the surface of vesicles. Vesicles from a PaAP knockout strain exhibited a 40% decrease in cell association. Likewise, vesicles from PAO1 overexpressing PaAP displayed a significant increase in cell association. Conclusion These data reveal that PaAP promotes the association of vesicles with lung cells. Taken together, these results suggest that P. aeruginosa vesicles can interact with and be internalized by lung epithelial cells and contribute to the inflammatory response during infection.

Interaction and rheology of vesicle suspensions in confined shear flow

Science.gov (United States)

Shen, Zaiyi; Farutin, Alexander; Thiébaud, Marine; Misbah, Chaouqi

2017-10-01

Dynamics and rheology of a confined suspension of vesicles (a model for red blood cells) are studied numerically in two dimensions by using an immersed boundary lattice Boltzmann method. We pay particular attention to the link between the spatiotemporal organization and the rheology of the suspension. Besides confinement, we analyze the effect of concentration of the suspension, ϕ (defined as the area fraction occupied by the vesicles in the simulation domain), as well as the viscosity contrast λ (defined as the ratio between the viscosity of the fluid inside the vesicles, ηint, and that of the suspending fluid, ηext). The hydrodynamic interaction between two vesicles is shown to play a key role in determining the spatial organization. For λ =1 , the pair of vesicles settles into an equilibrium state with constant interdistance, which is regulated by the confinement. The equilibrium interdistance increases with the gap between walls, following a linear relationship. However, no stable equilibrium interdistance between two tumbling vesicles is observed for λ =10 . A quite ordered suspension is observed concomitant with the existence of an equilibrium interdistance between a vesicle pair. However, a disordered suspension prevails when no pair equilibrium interdistance exists, as occurs for tumbling vesicles. We then analyze the rheology, focusing on the effective viscosity, denoted as η , as well as on normalized viscosity, defined as [η ] =(η -ηext) /(ηextϕ ) . Ordering of the suspension is accompanied by a nonmonotonic behavior of [η ] with ϕ , while η exhibits plateaus. The nonmonotonic behavior of [η ] is suppressed when a disordered pattern prevails.

Biogenesis and function of Porphyromonas gingivalis outer membrane vesicles

Science.gov (United States)

Xie, H

2015-01-01

Porphyromonas gingivalis is one of the keystone pathogens associated with chronic periodontitis. All P. gingivalis strains examined thus far produce outer membrane vesicles. Recent studies have found that vesicles possess some well-known virulence factors of P. gingivalis such as adhesins, toxins and proteolytic enzymes. Carrying most of the characteristic features of their parent P. gingivalis cells, vesicles communicate with host cells and other members of microbial biofilms, resulting in the transmission of virulence factors into these host cells and the formation of pathogenic bacteria-dominated microbial communities. An in-depth understanding of both the nature and role of vesicles in the pathogenicity of P. gingivalis is both important and timely, particularly when speaking of periodontitis and its related systemic effects. PMID:26343879

Proteomic Analysis of Lettuce Seed Germination and Thermoinhibition by Sampling of Individual Seeds at Germination and Removal of Storage Proteins by Polyethylene Glycol Fractionation1

Science.gov (United States)

Song, Bin-Yan; Deng, Zhi-Jun; Wang, Yue; Liu, Shu-Jun; Møller, Ian Max; Song, Song-Quan

2015-01-01

Germination and thermoinhibition in lettuce (Lactuca sativa ‘Jianyexianfeng No. 1’) seeds were investigated by a proteomic comparison among dry seeds, germinated seeds at 15°C, at 15°C after imbibition at 25°C for 48 h, or at 25°C in KNO3 (all sampled individually at germination), and ungerminated seeds at 25°C, a thermoinhibitory temperature. Before two-dimensional gel electrophoresis analysis, storage proteins (greater than 50% of total extractable protein) were removed by polyethylene glycol precipitation, which significantly improved the detection of less abundant proteins on two-dimensional gels. A total of 108 protein spots were identified to change more than 2-fold (P lettuce seed germination and thermoinhibition. Accumulation of three proteins and expression of five genes participating in the mevalonate (MVA) pathway of isoprenoid biosynthesis correlated positively with seed germinability. Inhibition of this pathway by lovastatin delayed seed germination and increased the sensitivity of germination to abscisic acid. MVA pathway-derived products, cytokinins, partially reversed the lovastatin inhibition of germination and released seed thermoinhibition at 25°C. We conclude that the MVA pathway for isoprenoid biosynthesis is involved in lettuce seed germination and thermoinhibition. PMID:25736209

Factors Affecting the Germination of Akinetes of Nodularia spumigena (Cyanobacteriaceae)

OpenAIRE

Huber, Ann L.

1985-01-01

Nutritional and physical factors which influence the germination of akinetes of Nodularia spumigena (Cyanobacteriaceae) were examined. Low concentrations of phosphorus (45 μM, inhibited germination. Salinities of >20‰ were inhibitory to germination. Optimum temperatures were 22°C or greater. Germination did not take place in the dark, but only very low light intensities (0.5 microeinstein m−2 s−1) were necessary to initiate germination. Red light (620 to 665 nm) was required. More than 24 h o...

Imbibition and germination in the seeds of Heliotropium supinum L.

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Ramesh C. Bhatia

2014-01-01

Full Text Available Imbibition in the seeds of Heliotropium supinum L. varies under different temperatures. The optimum temperatures for imbibition and germination are also different. For germination 39% imbibition is essential, and this capability is achieved by 12-week-old seeds. With duration of dry storage imbibition increases. The imbibition and germination percentages decline on re-dry storage of seeds after embeding in mud. A soil moisture of 44% is optimal for germination. A correlation exists between imbibition and germination.

A model for quantification of temperature profiles via germination times

DEFF Research Database (Denmark)

Pipper, Christian Bressen; Adolf, Verena Isabelle; Jacobsen, Sven-Erik

2013-01-01

Current methodology to quantify temperature characteristics in germination of seeds is predominantly based on analysis of the time to reach a given germination fraction, that is, the quantiles in the distribution of the germination time of a seed. In practice interpolation between observed...... time and a specific type of accelerated failure time models is provided. As a consequence the observed number of germinated seeds at given monitoring times may be analysed directly by a grouped time-to-event model from which characteristics of the temperature profile may be identified and estimated...... germination fractions at given monitoring times is used to obtain the time to reach a given germination fraction. As a consequence the obtained value will be highly dependent on the actual monitoring scheme used in the experiment. In this paper a link between currently used quantile models for the germination...

Ovarian morphometric characterization and in vitro maturation of oocytes obtained from buffalo (Bubalus bubalis ovaries – partial results

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F.C. Landim-Alvarenga

2010-02-01

Full Text Available Buffalo ovaries were collected from a slaughterhouse (Frigol, Brazil and transported to the laboratory in saline solution at 36º C. The ovaries were dissected to realize the evaluations (weight, length, width and height of the ovary; corpus luteum and dominant follicle diameters. The Cumulus-oocyte complexes (COCs were recovered by aspiration of 2-8 mm follicles. Selected COCs were matured in TCM 199 supplemented with 10% fetal bovine serum, sodium pyruvate, LH, FSH, estradiol and gentamicin. In vitro maturation was carried out at 38.5° C for 22-24 h and 34-36 h. For the evaluation of the nuclear maturation the oocytes were placed in TCM 199 medium added with type v hialuronidase where the granulosa cells were extracted. The denuded oocytes were transferred to 10 μl of Hoescht 33342 and the chromosomic configuration was evaluated. The oocytes were classified according to meiosis stage in: Germinal Vesicle, Germinal Vesicle Breakdown, Metaphase I, Metaphase II and Degenerated. The means of weight, length, width and height of the ovary were 3.83 g, 2.27 cm, 1.08 cm and 1.56 cm, respectively. The means of corpus luteum and dominant follicle diameters were 1.40 cm and 7.77 mm. The proportion of oocytes that reached metaphase II stage was: 36.68%.

Determination of Germination Response to Temperature and Water Potential for a Wide Range of Cover Crop Species and Related Functional Groups.

Science.gov (United States)

Tribouillois, Hélène; Dürr, Carolyne; Demilly, Didier; Wagner, Marie-Hélène; Justes, Eric

2016-01-01

A wide range of species can be sown as cover crops during fallow periods to provide various ecosystem services. Plant establishment is a key stage, especially when sowing occurs in summer with high soil temperatures and low water availability. The aim of this study was to determine the response of germination to temperature and water potential for diverse cover crop species. Based on these characteristics, we developed contrasting functional groups that group species with the same germination ability, which may be useful to adapt species choice to climatic sowing conditions. Germination of 36 different species from six botanical families was measured in the laboratory at eight temperatures ranging from 4.5-43°C and at four water potentials. Final germination percentages, germination rate, cardinal temperatures, base temperature and base water potential were calculated for each species. Optimal temperatures varied from 21.3-37.2°C, maximum temperatures at which the species could germinate varied from 27.7-43.0°C and base water potentials varied from -0.1 to -2.6 MPa. Most cover crops were adapted to summer sowing with a relatively high mean optimal temperature for germination, but some Fabaceae species were more sensitive to high temperatures. Species mainly from Poaceae and Brassicaceae were the most resistant to water deficit and germinated under a low base water potential. Species were classified, independent of family, according to their ability to germinate under a range of temperatures and according to their base water potential in order to group species by functional germination groups. These groups may help in choosing the most adapted cover crop species to sow based on climatic conditions in order to favor plant establishment and the services provided by cover crops during fallow periods. Our data can also be useful as germination parameters in crop models to simulate the emergence of cover crops under different pedoclimatic conditions and crop

Adhesion signals of phospholipid vesicles at an electrified interface.

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DeNardis, Nadica Ivošević; Žutić, Vera; Svetličić, Vesna; Frkanec, Ruža

2012-09-01

General adhesion behavior of phospholipid vesicles was examined in a wide range of potentials at the mercury electrode by recording time-resolved adhesion signals. It was demonstrated that adhesion-based detection is sensitive to polar headgroups in phospholipid vesicles. We identified a narrow potential window around the point of zero charge of the electrode where the interaction of polar headgroups of phosphatidylcholine vesicles with the substrate is manifested in the form of bidirectional signals. The bidirectional signal is composed of the charge flow due to the nonspecific interaction of vesicle adhesion and spreading and of the charge flow due to a specific interaction of the negatively charged electrode and the most exposed positively charged choline headgroups. These signals are expected to appear only when the electrode surface charge density is less than the surface charge density of the choline groups at the contact interface. In comparison, for the negatively charged phosphatidylserine vesicles, we identified the potential window at the mercury electrode where charge compensation takes place, and bidirectional signals were not detected.

v-SNAREs control exocytosis of vesicles from priming to fusion.

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Borisovska, Maria; Zhao, Ying; Tsytsyura, Yaroslav; Glyvuk, Nataliya; Takamori, Shigeo; Matti, Ulf; Rettig, Jens; Südhof, Thomas; Bruns, Dieter

2005-06-15

SNARE proteins (soluble NSF-attachment protein receptors) are thought to be central components of the exocytotic mechanism in neurosecretory cells, but their precise function remained unclear. Here, we show that each of the vesicle-associated SNARE proteins (v-SNARE) of a chromaffin granule, synaptobrevin II or cellubrevin, is sufficient to support Ca(2+)-dependent exocytosis and to establish a pool of primed, readily releasable vesicles. In the absence of both proteins, secretion is abolished, without affecting biogenesis or docking of granules indicating that v-SNAREs are absolutely required for granule exocytosis. We find that synaptobrevin II and cellubrevin differentially control the pool of readily releasable vesicles and show that the v-SNARE's amino terminus regulates the vesicle's primed state. We demonstrate that dynamics of fusion pore dilation are regulated by v-SNAREs, indicating their action throughout exocytosis from priming to fusion of vesicles.

Dormancy and germination in short-lived lepidium perfoliatu l. (brassicaceae) seeds

International Nuclear Information System (INIS)

Tang, An-Jun; Tian, M.; Long, Chun-Lin

2010-01-01

To understand germination timing in an ecological context, the response to environmental events that effect seed dormancy is central and has to be combined with knowledge of germination responses to different ecological factors. In this study, seed dormancy, germination and seedling survival of annual short-lived clasping pepper weed Lepidium perfoliatum L. (Brassicaceae) were investigated. Three types of pre-treatments viz., various temperature dry storage, light and water stress were tested as possible dormancy and survival-affecting environmental events. Fresh mature seeds were greatly dormant. Warm (30 deg. C) dry storage more facilitated breaking dormancy, they germinated well under apt conditions (e.g. 20 deg. C and 10/20 deg. C plus periodic light, 14 h/d). For those seeds which underwent after-ripening, they could germinate at a range of constant temperatures (4, 10, 15, 20, 25, and 30 deg. C) and one alternating temperature (10/20 deg. C). Under alternating temperature regimes, the final percent germination of L. perfoliatum seeds increased from 37 deg. C to 93% when temperature altered from 4/10 deg. C to 10/20 deg. C in light, then decreased with increasing temperature. The germination pattern under constant temperature conditions was similar to that under alternating temperature and significant differences in final percent germinations and rates of germination were observed among different temperatures. Under different light treatments, final germination of showed significant differences, only with 35% of germination percentage in dark, much lower than those in red and white light (i.e. 93% and 91%, respectively). GA3 could promote the germination of non-dormant seeds in dark. When water potentials were reduced, final percent germination decreased dramatically, and few seeds germinated at -0.98 MPa (generated by PEG-8000). The changes of proline content in resultant seedlings were reverse to that of final percent germination with changing water

Assessment of salinity tolerance in bell pepper (capsicum annuum l.) genotypes on the basis of germination, emergence and growth attributes

International Nuclear Information System (INIS)

Tehseen, S.; Ayyub, C.M.; Amjad, M.

2016-01-01

Abiotic stresses are principal threat to crop growth and productivity all over the world. The most devastating one is soil salinity which adversely affects the plants, so a comprehensive study was conducted to categorize different available bell pepper (Capsicum annuum L.) genotypes into salt tolerant, moderately tolerant and sensitive ones on the basis of germination and emergence parameters. Genotypes were exposed to different saline treatments (2, 4, 6 and 8 dS m-1) along with control (0 dS m-1). Germination test, conducted in petri dishes in incubator, revealed that salinity stress significantly decreased final germination percentage, germination index and embryo axis length of tested genotypes. On the other hand, mean germination time and time to 50% seeds germination were increased with the increasing salinity level from 2 to 8 dS m-1. Emergence test of bell pepper genotypes conducted in pots under greenhouse conditions, shown that salinity decreased the seedlings fresh and dry biomass, number of leaves, leaf area and root and shoot length. On the basis of overall percent decrease ranking table, genotypes were grouped into comparatively salt tolerant (Zard, Tasty, Super shimla, Aristotle), moderately tolerant (Capistrano, CW-03, Kaka-01, Orable, Yolo wonder, Crusadar) and sensitive ones (PEP-311, Admiral, Lafayette, Colossol). From these results, it can be extracted that germination and emergence tests are reliable screening tools for evaluating pepper genotypes for salt stress at seedling stage. Moreover, results of this study can be useful for local farmers to utilize their marginal soils by growing relatively salt tolerant bell pepper genotypes. (author)

Temperature in the seeds germination of pitaya genotypes

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Alessandro Borini Lone

2014-09-01

Full Text Available The optimum temperature for germination of cacti vary with the species. With this work, we aimed to evaluate the seeds germination of pitaya genotypes under different temperatures. The used genotypes were: Hylocereus undatus (PB, H. polyrhizus (PV, Selenicereus megalanthus (PA, H. undatus x H. costaricensis (PH1 and H. costaricensis x H. undatus (PH2. For each genotype we used four replicates of 50 seeds, in a completely randomized design. The sowing was carried out on blotter paper in boxes type Gerbox ®, maintained at temperatures of 15, 20, 25, 30 and 35 oC constant and 15-25, 20-30 and 25-35 oC alternating with photoperiod 12 hours. The test lasted 30 days which were appraised the germination percentage, the germination speed index and the average time of germination. For seeds germination of PB, the result obtained in the temperature of 25 oC didn’t differ of the obtained to 30 and 20-30 oC, however it was superior to the others temperatures. In PV, the result at 25 oC didn’t differ of the obtained to 20 and 30 oC, being superior to the results of the others temperatures. For PA, the best result was obtained to 25 oC. In PH1, the temperatures of 25, 30 and 20-30 oC presented superiors results to the others. For PH2, the result obtained in 15-25oC didn’t differ of the obtained at 25 oC, however it was superior to the others temperatures. The constants temperatures of 25 and 30 °C and alternating 20-30 °C are suitable for germination of H. undatus and for the hybrid H. undatus x H. costaricensis. For H. polyrhizus, constant temperatures of 20, 25 to 30 °C are suitable for seed germination. The constant temperature of 25 °C is the most suitable for the germination of S. megalanthus. For the hybrid H. costaricensis x H. undatus, constant temperature of 25 °C and alternating 15-25°C are suitable for seed germination.

Effect of Estrogen and Progeterone on seed germination

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Nirmala

Full Text Available Early pregnancy detection in dairy cattle is an integral part of a successful animal husbandry practice. A simple seed germination technique (Punyakoti test comprises observation of differential seed germination response of wheat seeds to diluted fresh urine samples as reflected by significant inhibition of germination percentage in pregnant cow urine when compared to non pregnant cow urine. Hormone metabolites excreted through urine might affect the seed germination in pregnant cow urine. In the present study an attempt was made to test the effect of hormones (in their natural forms at different concentrations of estrogen (17-ß estradiol and progesterone on wheat and green gram germination. Stock solutions of estrogen and progesterone were prepared in alcohol (1mg/ml and serial dilutions made using distilled water to get the concentrations of T1=10, T2=1, T3=0.1 and T4=0.01 μg/ml respectively in treatment groups. About 15 seeds each of wheat and green gram were taken in sterile Petri dishes into which 15ml of each test preparation was poured. The treatments were compared with distilled water and alcohol controls. The study was conducted for a period of five days during which seed germination was observed after 48 hrs and shoot lengths were also measured by the end of study. The average seed germination and shoot length in treatment groups did not vary significantly (P>0.05 when compared with that of control groups. Thus from the present study, it can be concluded that estrogen and progesterone in their natural form will not affect seed germination and shoot length. [Veterinary World 2008; 1(8.000: 241-242

Germination of Aspergillus niger conidia

OpenAIRE

Hayer, Kimran

2014-01-01

Aspergillus niger is a black-spored filamentous fungus that forms asexual spores called conidospores (‘conidia’). Germination of conidia, leading to the formation of hyphae, is initiated by conidial swelling and mobilisation of endogenous carbon and energy stores, followed by polarisation and emergence of a hyphal germ tube. These morphological and biochemical changes which define the model of germination have been studied with the aim of understanding how conidia sense and utilise different...

Temperature Effects on Cuscuta campestris Yunk. Seed Germination

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Marija Sarić-Krsmanović

2013-01-01

Full Text Available Studies of biological characteristics of seeds and conditions for their germination havea major importance for planning and executing rational measures of weed control. Theaim of this study was to investigate the effect of different temperatures on germinationof C. campestris seeds. Three treatments (T1- storage at room temperature; T2 – exposureto 4°C for 30 days; T3 – scarification by concentrated sulphuric acid differing in manipulationwith seeds before germination were tested at different temperatures (5°C, 10°C, 15°C,20°C, 25°C, 30°C, 35°C, 40°C, 45°C. Germinated seeds were counted daily for ten days andthe length of seedlings was measured on the last day. The results showed that differencesin germination of C. campestris seeds were very prominent between temperatures, as wellas between treatments T1, T2 and T3. Seeds failed to germinate at 5°C and 45°C in all treatments(T1, T2, T3. Germination ranged from 6.25 at 10°C to 96.88%, the highest percentage,achieved at 30°C.

Immunolocalization and Changes of Hydroxyproline-Rich Glycoproteins During Symbiotic Germination of Dendrobium officinale.

Science.gov (United States)

Li, Yuan-Yuan; Chen, Xiao-Mei; Zhang, Ying; Cho, Yu-Hsiu; Wang, Ai-Rong; Yeung, Edward C; Zeng, Xu; Guo, Shun-Xing; Lee, Yung-I

2018-01-01

Hydroxyproline-rich glycoproteins (HRGPs) are abundant cell wall components involved in mycorrhizal symbiosis, but little is known about their function in orchid mycorrhizal association. To gain further insight into the role of HRGPs in orchid symbiosis, the location and function of HRGPs were investigated during symbiotic germination of Dendrobium officinale . The presence of JIM11 epitope in developing protocorms was determined using immunodot blots and immunohistochemical staining procedures. Real-time PCR was also employed to verify the expression patterns of genes coding for extensin-like genes selected from the transcriptomic database. The importance of HRGPs in symbiotic germination was further investigated using 3,4-dehydro-L-proline (3,4-DHP), an inhibitor of HRGP biosynthesis. In symbiotic cultures, immunodot blots of JIM11 signals were moderate in mature seeds, and the signals became stronger in swollen embryos. After germination, signal intensities decreased in developing protocorms. In contrast, in asymbiotic cultures, JIM11 signals were much lower as compared with those stages in symbiotic cultures. Immunofluorescence staining enabled the visualization of JIM11 epitope in mature embryo and protocorm cells. Positive signals were initially localized in the larger cells near the basal (suspensor) end of uninfected embryos, marking the future colonization site of fungal hyphae. After 1 week of inoculation, the basal end of embryos had been colonized, and a strong signal was detected mostly at the mid- and basal regions of the enlarging protocorm. As protocorm development progressed, the signal was concentrated in the colonized cells at the basal end. In colonized cells, signals were present in the walls and intracellularly associated with hyphae and the pelotons. The precise localization of JIM11 epitope is further examined by immunogold labeling. In the colonized cells, gold particles were found mainly in the cell wall and the interfacial matrix near the

Up-regulating the abscisic acid inactivation gene ZmABA8ox1b contributes to seed germination heterosis by promoting cell expansion.

Science.gov (United States)

Li, Yangyang; Wang, Cheng; Liu, Xinye; Song, Jian; Li, Hongjian; Sui, Zhipeng; Zhang, Ming; Fang, Shuang; Chu, Jinfang; Xin, Mingming; Xie, Chaojie; Zhang, Yirong; Sun, Qixin; Ni, Zhongfu

2016-04-01

Heterosis has been widely used in agriculture, but the underlying molecular principles are still largely unknown. During seed germination, we observed that maize (Zea mays) hybrid B73/Mo17 was less sensitive than its parental inbred lines to exogenous abscisic acid (ABA), and endogenous ABA content in hybrid embryos decreased more rapidly than in the parental inbred lines. ZmABA8ox1b, an ABA inactivation gene, was consistently more highly up-regulated in hybrid B73/Mo17 than in its parental inbred lines at early stages of seed germination. Moreover, ectopic expression of ZmABA8ox1b obviously promoted seed germination in Arabidopsis Remarkably, microscopic observation revealed that cell expansion played a major role in the ABA-mediated maize seed germination heterosis, which could be attributed to the altered expression of cell wall-related genes. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Intact deposition of cationic vesicles on anionic cellulose fibers: Role of vesicle size, polydispersity, and substrate roughness studied via streaming potential measurements.

Science.gov (United States)

Kumar, Abhijeet; Gilson, Laurent; Henrich, Franziska; Dahl, Verena; Kleinen, Jochen; Gambaryan-Roisman, Tatiana; Venzmer, Joachim

2016-07-01

Understanding the mechanism of intact vesicle deposition on solid surfaces is important for effective utilization of vesicles as active ingredient carriers in applications such as drug delivery and fabric softening. In this study, the deposition of large (davg=12μm) and small (davg=0.27μm) cationic vesicles of ditallowethylester dimethylammonium chloride (DEEDMAC) on smooth and rough anionic cellulose fibers is investigated. The deposition process is studied quantitatively using streaming potential measurements and spectrophotometric determination of DEEDMAC concentrations. Natural and regenerated cellulose fibers, namely cotton and viscose, having rough and smooth surfaces, respectively, are used as adsorbents. Equilibrium deposition data and profiles of substrate streaming potential variation with deposition are used to gain insights into the fate of vesicles upon deposition and the deposition mechanism. Intact deposition of DEEDMAC vesicles is ascertained based on streaming potential variation with deposition in the form of characteristic saturating profiles which symbolize particle-like deposition. The same is also confirmed by confocal fluorescence microscopy. Substrate roughness is found to considerably influence the deposition mechanism which, in a novel application of electrokinetic methods, is elucidated via streaming potential measurements. Copyright © 2016 Elsevier Inc. All rights reserved.

Salt tolerance of physalis during germination and seedling growth

International Nuclear Information System (INIS)

Yildirim, E.; Karlidag, H.

2011-01-01

The study was conducted to evaluate the effect of NaCl salinity on germination and emergence of Physalis ixocarpa and Physalis peruviana. Seeds of P. ixocarpa and P. peruviana were germinated by the use of 0, 30, 60, 90, 120 and 180 mM NaCl solutions in petri dishes. Final germination percentage (FGP) decreased with the increase in NaCl concentration. Both species germinated at the ranges of salinity. P. peruviana gave the greater germination percentages under salt stress than P. ixocarpa. NaCl salinity at different concentrations adversely affected germination rates. For seedling growth, seeds of both species were sown at 10 mm depth in plastic trays filled with peat to determine final emergence percentage (FEP). The trays were irrigated manually to saturation every day with 0, 30, 60, 90, 120, 150 or 180 mM NaCl solutions to maintain the level of salinity. Salinity affected seed emergence and seedlings growth more than seed germination. The study showed that no emergence of Physalis was observed at 90, 120 and 180 mM NaCl salinity. Fresh and dry weights of normal seedlings were also evaluated. Salt stress significantly decreased the plant fresh and dry weight of both species. Based on the results of the experiment, it can be concluded that seedling emergence and growth is more sensitive to salt stress than seed germination in Physalis. (author)

Dynamics of coarsening in multicomponent lipid vesicles with non-uniform mechanical properties

Science.gov (United States)

Funkhouser, Chloe M.; Solis, Francisco J.; Thornton, K.

2014-04-01

Multicomponent lipid vesicles are commonly used as a model system for the complex plasma membrane. One phenomenon that is studied using such model systems is phase separation. Vesicles composed of simple lipid mixtures can phase-separate into liquid-ordered and liquid-disordered phases, and since these phases can have different mechanical properties, this separation can lead to changes in the shape of the vesicle. In this work, we investigate the dynamics of phase separation in multicomponent lipid vesicles, using a model that couples composition to mechanical properties such as bending rigidity and spontaneous curvature. The model allows the vesicle surface to deform while conserving surface area and composition. For vesicles initialized as spheres, we study the effects of phase fraction and spontaneous curvature. We additionally initialize two systems with elongated, spheroidal shapes. Dynamic behavior is contrasted in systems where only one phase has a spontaneous curvature similar to the overall vesicle surface curvature and systems where the spontaneous curvatures of both phases are similar to the overall curvature. The bending energy contribution is typically found to slow the dynamics by stabilizing configurations with multiple domains. Such multiple-domain configurations are found more often in vesicles with spheroidal shapes than in nearly spherical vesicles.

Secondary metabolites profiles and antioxidant activities of germinated brown and red rice

Science.gov (United States)

Nurnaistia, Y.; Aisyah, S.; Munawaroh, H. S. H.; Zackiyah

2018-05-01

The research aims to investigate the effect of germination on the secondary metabolite profiles and antioxidant activity of brown and red rice. The germination was performed by using a simple laboratory-scale machine that was designed and optimized to provide conditions that support the germination process. The germination was carried out for 2 days in dark conditions at 26°C and 99% humidity. Analysis of the secondary metabolite profile of ungerminated and germinated rice was performed using LC-MS. The antioxidant activities of ungerminated and germinated rice were done by using DPPH method. The results showed that the profiles of secondary metabolites of brown and red rice changed after germination. Some peaks were found to be induced in the germinated rice. However, some peaks were also loss during germination. The antioxidant activity of brown rice was slightly increased due to the germination, from 11.2% to 22.5%. Meanwhile the antioxidant activity of red rice was decreased after germination, from 73.8% to 60.0%.

Getting there: vesicles en route for plant cytokinesis

NARCIS (Netherlands)

Ozdoba, A.

2007-01-01

In dividing plant cells, membranous vesicles (60-80 nm in diameter) are transported to the site where a new cell wall that separates the daughter cells is formed. In this thesis the physical parameters size and stiffness that vesicles require to reach the forming cell plate were studied. Synthetic

Spin State As a Probe of Vesicle Self-Assembly.

Science.gov (United States)

Kim, Sanghoon; Bellouard, Christine; Eastoe, Julian; Canilho, Nadia; Rogers, Sarah E; Ihiawakrim, Dris; Ersen, Ovidiu; Pasc, Andreea

2016-03-02

A novel system of paramagnetic vesicles was designed using ion pairs of iron-containing surfactants. Unilamellar vesicles (diameter ≈ 200 nm) formed spontaneously and were characterized by cryogenic transmission electron microscopy, nanoparticle tracking analysis, and light and small-angle neutron scattering. Moreover, for the first time, it is shown that magnetization measurements can be used to investigate self-assembly of such functionalized systems, giving information on the vesicle compositions and distribution of surfactants between the bilayers and the aqueous bulk.

Transcript profiles uncover temporal and stress-induced changes of metabolic pathways in germinating sugar beet seeds

Directory of Open Access Journals (Sweden)

Windhövel Andrea

2008-12-01

Full Text Available Abstract Background With a cultivation area of 1.75 Mio ha and sugar yield of 16.7 Mio tons in 2006, sugar beet is a crop of great economic importance in Europe. The productivity of sugar beet is determined significantly by seed vigour and field emergence potential; however, little is known about the molecular mechanisms underlying these traits. Both traits exhibit large variations within sugar beet germplasm that have been difficult to ascribe to either environmental or genetic causes. Among potential targets for trait improvement, an enhancement of stress tolerance is considered because of the high negative influence of environmental stresses on trait parameters. Extending our knowledge of genetic and molecular determinants of sugar beet germination, stress response and adaptation mechanisms would facilitate the detection of new targets for breeding crop with an enhanced field emergence potential. Results To gain insight into the sugar beet germination we initiated an analysis of gene expression in a well emerging sugar beet hybrid showing high germination potential under various environmental conditions. A total of 2,784 ESTs representing 2,251 'unigenes' was generated from dry mature and germinating seeds. Analysis of the temporal expression of these genes during germination under non-stress conditions uncovered drastic transcriptional changes accompanying a shift from quiescent to metabolically active stages of the plant life cycle. Assay of germination under stressful conditions revealed 157 genes showing significantly different expression patterns in response to stress. As deduced from transcriptome data, stress adaptation mechanisms included an alteration in reserve mobilization pathways, an accumulation of the osmoprotectant glycine betaine, late embryogenesis abundant proteins and detoxification enzymes. The observed transcriptional changes are supposed to be regulated by ABA-dependent signal transduction pathway. Conclusion This study

Origins of microstructural transformations in charged vesicle suspensions: the crowding hypothesis.

Science.gov (United States)

Seth, Mansi; Ramachandran, Arun; Murch, Bruce P; Leal, L Gary

2014-09-02

It is observed that charged unilamellar vesicles in a suspension can spontaneously deflate and subsequently transition to form bilamellar vesicles, even in the absence of externally applied triggers such as salt or temperature gradients. We provide strong evidence that the driving force for this deflation-induced transition is the repulsive electrostatic pressure between charged vesicles in concentrated suspensions, above a critical effective volume fraction. We use volume fraction measurements and cryogenic transmission electron microscopy imaging to quantitatively follow both the macroscopic and microstructural time-evolution of cationic diC18:1 DEEDMAC vesicle suspensions at different surfactant and salt concentrations. A simple model is developed to estimate the extent of deflation of unilamellar vesicles caused by electrostatic interactions with neighboring vesicles. It is determined that when the effective volume fraction of the suspension exceeds a critical value, charged vesicles in a suspension can experience "crowding" due to overlap of their electrical double layers, which can result in deflation and subsequent microstructural transformations to reduce the effective volume fraction of the suspension. Ordinarily in polydisperse colloidal suspensions, particles interacting via a repulsive potential transform into a glassy state above a critical volume fraction. The behavior of charged vesicle suspensions reported in this paper thus represents a new mechanism for the relaxation of repulsive interactions in crowded situations.

Chickpea seeds germination rational parameters optimization

Science.gov (United States)

Safonova, Yu A.; Ivliev, M. N.; Lemeshkin, A. V.

2018-05-01

The paper presents the influence of chickpea seeds bioactivation parameters on their enzymatic activity experimental results. Optimal bioactivation process modes were obtained by regression-factor analysis: process temperature - 13.6 °C, process duration - 71.5 h. It was found that in the germination process, the proteolytic, amylolytic and lipolytic enzymes activity increased, and the urease enzyme activity is reduced. The dependences of enzyme activity on chickpea seeds germination conditions were obtained by mathematical processing of experimental data. The calculated data are in good agreement with the experimental ones. This confirms the optimization efficiency based on experiments mathematical planning in order to determine the enzymatic activity of chickpea seeds germination optimal parameters of bioactivated seeds.

Sensitivity of spore germination and germ tube elongation of Saccharina japonica to metal exposure.

Science.gov (United States)

Han, Taejun; Kong, Jeong-Ae; Kang, Hee-Gyu; Kim, Seon-Jin; Jin, Gyo-Sun; Choi, Hoon; Brown, Murray T

2011-11-01

The sensitivity of early life stages of the brown seaweed Saccharina japonica to six metals (Cd, Cu, Hg, Ni, Pb, Zn) and two waste-water samples were investigated and a new toxicity bioassay developed. The two endpoints used were spore germination and germ tube elongation with an exposure time of 24 h. Optimal test conditions determined for photon irradiance, pH, salinity and temperature were darkness, pH 8, 35‰ and 15°C, respectively. The toxicity ranking of five metals was: Hg (EC(50) of 41 and 42 μg l(-1)) > Cu (120 and 81 μg l(-1)) > Ni (2,009 and 1,360 μg l(-1)) > Zn (3,024 and 3,897 μg l(-1)) > Pb (4,760 and 4,429 μg l(-1)) > Cd (15,052 and 7,541 μg l(-1)) for germination and germ tube elongation, respectively. The sensitivities to Cd, Cu and Ni were greater in germ tube elongation than in germination process. When tested against two different waste-water samples (processed animal and printed circuit board waste-water) values of EC(50) were between 21.29 and 32.02% for germination and between 5.33 and 8.98% for germ tube elongation. Despite differences in their chemical composition, the toxic effects of waste-water samples, as indicated by EC(50) values, did not differ significantly for the same endpoints. The CV range for both germination and germ tube elongation was between 4.61 and 37.69%, indicating high levels of precision of the tests. The results compare favourably with those from more established test procedures employing micro- and macroalgae. The advantages and potential limitations of the bioassay for the assessment of anthropogenic impacts on coastal ecosystems and commercial cultivation areas in near-shore environments are discussed.

Integral equation methods for vesicle electrohydrodynamics in three dimensions

Science.gov (United States)

Veerapaneni, Shravan

2016-12-01

In this paper, we develop a new boundary integral equation formulation that describes the coupled electro- and hydro-dynamics of a vesicle suspended in a viscous fluid and subjected to external flow and electric fields. The dynamics of the vesicle are characterized by a competition between the elastic, electric and viscous forces on its membrane. The classical Taylor-Melcher leaky-dielectric model is employed for the electric response of the vesicle and the Helfrich energy model combined with local inextensibility is employed for its elastic response. The coupled governing equations for the vesicle position and its transmembrane electric potential are solved using a numerical method that is spectrally accurate in space and first-order in time. The method uses a semi-implicit time-stepping scheme to overcome the numerical stiffness associated with the governing equations.

Metabolism and the triggering of germination of Bacillus megaterium

International Nuclear Information System (INIS)

Scott, I.R.; Ellar, D.J.

1978-01-01

L-[2,3- 3 H]Alanine was used to probe for metabolism of alanine during triggering of germination of spores of Bacillus megaterium KM. No detectable incorporation of label into any compound, including water, was found, indicating that any metabolism involving the alanine germinant must be at a very low rate and also that alanine racemase is absent from spores of this strain. Spores were germinated in 3 H 2 0 to find if any of the many metabolic reactions causing irreversible incorporation of 3 H into reaction products took place during triggering og germination. No incorporation was detected until 2-3 min after addition of germinants. It is therefore concluded that a wide variety of metabolic routes, including glycolysis, the tricarboxylic acid cycle, the pentose phosphate pathway and amino acid metabolism are either not involved in the reactions causing the triggering of germination or operate at an extremely low rate during this process. (author)

Biochemical and morphological characterization of light and heavy sarcoplasmic reticulum vesicles

Energy Technology Data Exchange (ETDEWEB)

Campbell, K.P.

1978-01-01

Light and heavy sarcoplasmic reticulum vesicles isolated from rabbit leg muscle have been used in a study of chloride-induced calcium release. The biochemical and morphological data indicate that light sarcoplasmic reticulum vesicles are derived from the longitudinal reticulum and heavy sarcoplasmic reticulum vesicles are derived from the terminal cisternae of the sarcoplasmic reticulum. The light and heavy sarcoplasmic reticulum vesicles were both able to accumulate calcium in the presence of ATP to amounts greater than 100 nmoles Ca/sup + +/ per mg of protein in less than one minute. Light and heavy sarcoplasmic reticulum vesicles each had a biphasic time course of calcium uptake. The initial uptake was followed by a rapid release after approximately one minute, of 30 to 40% of the accumulated calcium, which was then followed by a slower phase of calcium accumulation. Results indicate that the chloride induced release of calcium may be acting by two mechanisms, osmotic swelling and depolarization. The release of calcium from the light SR vesicles is probably due to osmotic swelling and the release of calcium from the heavy SR vesicles is probably due to depolarization.

Theory of Disk-to-Vesicle Transformation

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Li, Jianfeng; Shi, An-Chang

2009-03-01

Self-assembled membranes from amphiphilic molecules, such as lipids and block copolymers, can assume a variety of morphologies dictated by energy minimization of system. The membrane energy is characterized by a bending modulus (κ), a Gaussian modulus (κG), and the line tension (γ) of the edge. Two basic morphologies of membranes are flat disks that minimize the bending energy at the cost of the edge energy, and enclosed vesicles that minimize the edge energy at the cost of bending energy. In our work, the transition from disk to vesicle is studied theoretically using the string method, which is designed to find the minimum energy path (MEP) or the most probable transition path between two local minima of an energy landscape. Previous studies of disk-to-vesicle transition usually approximate the transitional states by a series of spherical cups, and found that the spherical cups do not correspond to stable or meta-stable states of the system. Our calculation demonstrates that the intermediate shapes along the MEP are very different from spherical cups. Furthermore, some of these transitional states can be meta-stable. The disk-to-vesicle transition pathways are governed by two scaled parameters, κG/κ and γR0/4κ, where R0 is the radius of the disk. In particular, a meta-stable intermediate state is predicted, which may correspond to the open morphologies observed in experiments and simulations.

Effect of Arthrobacter agilis UMCV2 on germination and growth of Pinus devoniana Lindley

Directory of Open Access Journals (Sweden)

Wilber Montejo-Mayo

2016-03-01

Full Text Available Soil microorganisms are essential for growth, emergence and development in all plants. In our study we decided to evaluate the effect that A. agilis UMCV2 rhizobacteria had on germination and growth of plants of economic-forest interest as P. devoniana to an age of 65 days. Our results show that the UMCV2 bacteria promoted growth of P. devoniana at this early stage of development, further highlighting that despite the short time of interaction between these two, the bacterium was able to increase the rate of germination, increase the size of shoot and generate a proliferation of lateral roots. The data shows a huge potential for using inoculum both in the greenhouse and in open ground and generate a growth promoting species of interest in both agricultural and forest, thereby reducing production periods depending on the crop.

The site effect on germinability of mugwort (Artemisia vulgaris L. achenes

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Jan Winkler

2005-01-01

Full Text Available Mugwort (Artemisia vulgaris L. extremely spreads on uncultivated agricultural land and expands to arable land. Three sites were chosen in the local area of Uherské Hradiště: field (arable land, balk (adjacent to arable land and rubble heap (distant from arable land. At each site, 50 plants were selected from which mature achenes were collected in 2002 and 2003. The achenes germinated in a laboratory at a room temperature and were subjected to various germination conditions. A part of them was exposed to the temperature of – 20 °C in a freezer, the other part was stored at a room temperature. The germination was carried out either on filter paper in Petri dishes or in 30 mm layer of siliceous sand. One part of the achenes germinated in daylight, the other part in Petri dishes in the dark. The achenes cultivated in siliceous sand were covered with a 5 mm layer of the sand. The results were statistically assessed using Unistat software, analysis of variance and methods of least significant differences (LSD. Total average germinability of mugwort achenes was 67,7 %. The differences in germinability of frozen (66,7 % and non-frozen (72,6 % achenes were not statistically significant. Germinability of the achenes that matured in 2003 (69,9 % was highly significantly higher than that of the achenes matured in 2002 (65,4 %. The achenes germinated highly significantly more (77,9 % in daylight as compared with those germinated in the dark (57,4 %. Germinability of the achenes that germinated in siliceous sand was highly significantly higher (70,7 % than of those that germinated in Petri dishes (64,7 %. Germinability of the achenes matured in the field (64,1 % was significantly lower in comparison with the germinability of the achenes from a balk (69,7 % and rubble heap (69,2 %. The results of germinability of the achenes that matured in a rubble heap and balk did not significantly differ.

Reduced triacylglycerol mobilization during seed germination and early seedling growth in Arabidopsis containing nutritionally important polyunsaturated fatty acids

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Pushkar Shrestha

2016-09-01

Full Text Available There are now several examples of plant species engineered to synthesise and accumulate nutritionally important polyunsaturated fatty acids in their seed triacylglycerols (TAG. The utilization of such TAG in germinating seeds of such transgenic plants was unknown. In this study, we examined the TAG utilization efficiency during seed germination in transgenic Arabidopsis seeds containing several examples of these fatty acids. Seed TAG species with native fatty acids had higher utilization rate than the TAG species containing transgenically produced polyunsaturated fatty acids. Conversely, quantification of the fatty acid components remaining in the total TAG after early stages of seed germination revealed that the undigested TAGs tended to contain an elevated level of the engineered polyunsaturated fatty acids (PUFA. LC-MS analysis further revealed asymmetrical mobilization rates for the individual TAG species. TAGs which contained multiple PUFA fatty acids were mobilized slower than the species containing single PUFA. The mobilised engineered fatty acids were used in de novo membrane lipid synthesis during seedling development.

On the number of genes controlling the grass stage in longleaf pine

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C. Dana Nelson; C. Weng; Thomas L. Kubisiak; M. Stine; C.L. Brown

2003-01-01

The grass stage is an inherent and distinctive developmental trait of longleaf pine (Pinus palustris), in which height growth in the first few years after germination is suppressed. In operational forestry practice the grass stage extends for nvo to several years and often plays a role in planting failures and decisions to plant alternative species....

Vesicle dynamics in a confined Poiseuille flow: from steady state to chaos.

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Aouane, Othmane; Thiébaud, Marine; Benyoussef, Abdelilah; Wagner, Christian; Misbah, Chaouqi

2014-09-01

Red blood cells (RBCs) are the major component of blood, and the flow of blood is dictated by that of RBCs. We employ vesicles, which consist of closed bilayer membranes enclosing a fluid, as a model system to study the behavior of RBCs under a confined Poiseuille flow. We extensively explore two main parameters: (i) the degree of confinement of vesicles within the channel and (ii) the flow strength. Rich and complex dynamics for vesicles are revealed, ranging from steady-state shapes (in the form of parachute and slipper shapes) to chaotic dynamics of shape. Chaos occurs through a cascade of multiple periodic oscillations of the vesicle shape. We summarize our results in a phase diagram in the parameter plane (degree of confinement and flow strength). This finding highlights the level of complexity of a flowing vesicle in the small Reynolds number where the flow is laminar in the absence of vesicles and can be rendered turbulent due to elasticity of vesicles.

Proteomic analysis of lettuce seed germination and thermoinhibition by sampling of individual seeds at germination and removal of storage proteins by polyethylene glycol fractionation.

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Wang, Wei-Qing; Song, Bin-Yan; Deng, Zhi-Jun; Wang, Yue; Liu, Shu-Jun; Møller, Ian Max; Song, Song-Quan

2015-04-01

Germination and thermoinhibition in lettuce (Lactuca sativa 'Jianyexianfeng No. 1') seeds were investigated by a proteomic comparison among dry seeds, germinated seeds at 15°C, at 15°C after imbibition at 25°C for 48 h, or at 25°C in KNO3 (all sampled individually at germination), and ungerminated seeds at 25°C, a thermoinhibitory temperature. Before two-dimensional gel electrophoresis analysis, storage proteins (greater than 50% of total extractable protein) were removed by polyethylene glycol precipitation, which significantly improved the detection of less abundant proteins on two-dimensional gels. A total of 108 protein spots were identified to change more than 2-fold (Pseeds than in ungerminated 25°C seeds. Gene expression of 12 of those proteins correlated well with the protein accumulation. Methionine metabolism, ethylene production, lipid mobilization, cell elongation, and detoxification of aldehydes were revealed to be potentially related to lettuce seed germination and thermoinhibition. Accumulation of three proteins and expression of five genes participating in the mevalonate (MVA) pathway of isoprenoid biosynthesis correlated positively with seed germinability. Inhibition of this pathway by lovastatin delayed seed germination and increased the sensitivity of germination to abscisic acid. MVA pathway-derived products, cytokinins, partially reversed the lovastatin inhibition of germination and released seed thermoinhibition at 25°C. We conclude that the MVA pathway for isoprenoid biosynthesis is involved in lettuce seed germination and thermoinhibition. © 2015 American Society of Plant Biologists. All Rights Reserved.

Enhancement of gama-aminobutyric acid (GABA) and other health-related metabolites in germinated red rice (Oryza sativa L.) by ultrasonication.

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Ding, Junzhou; Ulanov, Alexander V; Dong, Mengyi; Yang, Tewu; Nemzer, Boris V; Xiong, Shanbai; Zhao, Siming; Feng, Hao

2018-01-01

Red rice (Oryza sativa L.) that has a red (reddish brown) bran layer in de-hulled rice is known to contain rich biofunctional components. Germination is an effective technique to improve the nutritional quality, digestibility, and flavor of de-hulled rice. Ultrasonication, a form of physical stimulation, has been documented as a novel approach to improve the nutritional quality of plant-based food. This study was undertaken to test the use of ultrasound to enhance the nutritional value of red rice. Ultrasonication (5min, 16W/L) was applied to rice during soaking or after 66h germination. Changes of metabolites (amino acids, sugars, and organic acids) in red rice treated by ultrasonication were determined using a GC/MS plant primary metabolomics analysis platform. Differential expressed metabolites were identified through multivariate statistical analysis. Results showed that γ-aminobutyric acid (GABA) and riboflavin (vitamin B 2 ) in red rice significantly increased after germination for 72h, and then experienced a further increase after treatment by ultrasound at different stages during germination. The metabolomics analysis showed that some plant metabolites, i.e. GABA, O-phosphoethanolamine, and glucose-6-phosphate were significantly increased after the ultrasonic treatment (VIP>1.5) in comparison with the untreated germinated rice. The findings of this study showed that controlled germination with ultrasonic stress is an effective method to enhance GABA and other health-promoted components in de-hulled rice. Copyright © 2017 Elsevier B.V. All rights reserved.

The mechanism underlying fast germination of tomato cultivar LA2711.

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Yang, Rongchao; Chu, Zhuannan; Zhang, Haijun; Li, Ying; Wang, Jinfang; Li, Dianbo; Weeda, Sarah; Ren, Shuxin; Ouyang, Bo; Guo, Yang-Dong

2015-09-01

Seed germination is important for early plant morphogenesis as well as abiotic stress tolerance, and is mainly controlled by the phytohormones abscisic acid (ABA) and gibberellic acid (GA). Our previous studies identified a salt-tolerant tomato cultivar, LA2711, which is also a fast-germinating genotype, compared to its salt-sensitive counterpart, ZS-5. In an effort to further clarify the mechanism underlying this phenomenon, we compared the dynamic levels of ABA and GA4, the transcript abundance of genes involved in their biosynthesis and catabolism as well as signal transduction between the two cultivars. In addition, we tested seed germination sensitivity to ABA and GAs. Our results revealed that insensitivity of seed germination to exogenous ABA and low ABA content in seeds are the physiological mechanisms conferring faster germination rates of LA2711 seeds. SlCYP707A2, which encodes an ABA catabolic enzyme, may play a decisive role in the fast germination rate of LA2711, as it showed a significantly higher level of expression in LA2711 than ZS-5 at most time points tested during germination. The current results will enable us to gain insight into the mechanism(s) regarding seed germination of tomato and the role of fast germination in stress tolerance. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Effect of fungicides on Wyoming big sagebrush seed germination

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Robert D. Cox; Lance H. Kosberg; Nancy L. Shaw; Stuart P. Hardegree

2011-01-01

Germination tests of Wyoming big sagebrush (Artemisia tridentata Nutt. ssp. wyomingensis Beetle & Young [Asteraceae]) seeds often exhibit fungal contamination, but the use of fungicides should be avoided because fungicides may artificially inhibit germination. We tested the effect of seed-applied fungicides on germination of Wyoming big sagebrush at 2 different...

Phospholipid Vesicles in Materials Science

Energy Technology Data Exchange (ETDEWEB)

Granick, Steve [Univ. of Illinois, Champaign, IL (United States)

2016-05-11

The objective of this research was to develop the science basis needed to deploy phospholipid vesicles as functional materials in energy contexts. Specifically, we sought to: (1) Develop an integrated molecular-level understanding of what determines their dynamical shape, spatial organization, and responsiveness to complex, time-varying environments; and (2) Develop understanding of their active transportation in crowded environments, which our preliminary measurements in cells suggest may hold design principles for targeting improved energy efficiency in new materials systems. The methods to do this largely involved fluorescence imaging and other spectroscopy involving single particles, vesicles, particles, DNA, and endosomes. An unexpected importance outcome was a new method to image light-emitting diodes during actual operation using super-resolution spectroscopy.

Chemical inhibitors of viviparous germination in the fruit of watermelon.

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Kobayashi, Yoshiki; Nabeta, Kensuke; Matsuura, Hideyuki

2010-09-01

It is well known that the seeds of watermelon [Citrullus lanatus (Thunb.) Matsum and Nakai] have a high potential to germinate when the fruit has ripened. When removed from the mature fruit, the seeds can germinate under appropriate conditions. However, it is unclear why they cannot germinate in the flesh of the fruit. Here, we show that cis-ABA and its β-D-glucopyranosyl ester (ABA-β-GE) accumulate in the flesh of the fruit at levels high enough to inhibit seed germination. This result indicates the existence of chemical factors that inhibit viviparous seed germination of watermelon.

Two Novel Rab2 Interactors Regulate Dense-core Vesicle Maturation

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Ailion, Michael; Hannemann, Mandy; Dalton, Susan; Pappas, Andrea; Watanabe, Shigeki; Hegermann, Jan; Liu, Qiang; Han, Hsiao-Fen; Gu, Mingyu; Goulding, Morgan Q.; Sasidharan, Nikhil; Schuske, Kim; Hullett, Patrick; Eimer, Stefan; Jorgensen, Erik M.

2014-01-01

Summary Peptide neuromodulators are released from a unique organelle: the dense-core vesicle. Dense-core vesicles are generated at the trans-Golgi, and then sort cargo during maturation before being secreted. To identify proteins that act in this pathway, we performed a genetic screen in Caenorhabditis elegans for mutants defective in dense-core vesicle function. We identified two conserved Rab2-binding proteins: RUND-1, a RUN domain protein, and CCCP-1, a coiled-coil protein. RUND-1 and CCCP-1 colocalize with RAB-2 at the Golgi, and rab-2, rund-1 and cccp-1 mutants have similar defects in sorting soluble and transmembrane dense-core vesicle cargos. RUND-1 also interacts with the Rab2 GAP protein TBC-8 and the BAR domain protein RIC-19, a RAB-2 effector. In summary, a new pathway of conserved proteins controls the maturation of dense-core vesicles at the trans-Golgi network. PMID:24698274

Physical mapping of a 330 X 10(3)-base-pair region of the Myxococcus xanthus chromosome that is preferentially labeled during spore germination

International Nuclear Information System (INIS)

Komano, T.; Inouye, S.; Inouye, M.

1985-01-01

Myxococcus xanthus was pulse-labeled with [ 3 H]thymidine immediately after germination of dimethyl sulfoxide-induced spores. The restriction enzyme digests of the total chromosomal DNA from the pulse- labeled cells were analyzed by one-dimensional as well as two- dimensional agarose gel electrophoresis. Four PstI fragments preferentially labeled at a very early stage of germination were cloned into the unique PstI site of pBR322. By using these clones as probes, a restriction enzyme map was established covering approximately 6% of the total M. xanthus genome (330 X 10(3) base pairs). The distribution of the specific activities of the restriction fragments pulse-labeled after germination suggests a bidirectional mode of DNA replication from a fixed origin

Vesicle biomechanics in a time-varying magnetic field.

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