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Sample records for mature imbibed seeds

  1. ABA inhibits germination but not dormancy release in mature imbibed seeds of Lolium rigidum Gaud.

    PubMed Central

    Goggin, Danica E.; Steadman, Kathryn J.; Emery, R. J. Neil; Farrow, Scott C.; Benech-Arnold, Roberto L.; Powles, Stephen B.

    2009-01-01

    Dormancy release in imbibed annual ryegrass (Lolium rigidum Gaud.) seeds is promoted in the dark but inhibited in the light. The role of abscisic acid (ABA) in inhibition of dormancy release was found to be negligible, compared with its subsequent effect on germination of dormant and non-dormant seeds. Inhibitors of ABA metabolism had the expected effects on seed germination but did not influence ABA concentration, suggesting that they act upon other (unknown) factors regulating dormancy. Although gibberellin (GA) synthesis was required for germination, the influence of exogenous GA on both germination and dormancy release was minor or non-existent. Embryo ABA concentration was the same following treatments to promote (dark stratification) and inhibit (light stratification) dormancy release; exogenous ABA had no effect on this process. However, the sensitivity of dark-stratified seeds to ABA supplied during germination was lower than that of light-stratified seeds. Therefore, although ABA definitely plays a role in the germination of annual ryegrass seeds, it is not the major factor mediating inhibition of dormancy release in imbibed seeds. PMID:19487389

  2. ABA inhibits germination but not dormancy release in mature imbibed seeds of Lolium rigidum Gaud.

    PubMed

    Goggin, Danica E; Steadman, Kathryn J; Emery, R J Neil; Farrow, Scott C; Benech-Arnold, Roberto L; Powles, Stephen B

    2009-01-01

    Dormancy release in imbibed annual ryegrass (Lolium rigidum Gaud.) seeds is promoted in the dark but inhibited in the light. The role of abscisic acid (ABA) in inhibition of dormancy release was found to be negligible, compared with its subsequent effect on germination of dormant and non-dormant seeds. Inhibitors of ABA metabolism had the expected effects on seed germination but did not influence ABA concentration, suggesting that they act upon other (unknown) factors regulating dormancy. Although gibberellin (GA) synthesis was required for germination, the influence of exogenous GA on both germination and dormancy release was minor or non-existent. Embryo ABA concentration was the same following treatments to promote (dark stratification) and inhibit (light stratification) dormancy release; exogenous ABA had no effect on this process. However, the sensitivity of dark-stratified seeds to ABA supplied during germination was lower than that of light-stratified seeds. Therefore, although ABA definitely plays a role in the germination of annual ryegrass seeds, it is not the major factor mediating inhibition of dormancy release in imbibed seeds.

  3. Transcriptional profiling of imbibed Brassica napus seed.

    PubMed

    Li, Fengling; Wu, Xianzhong; Tsang, Edward; Cutler, Adrian J

    2005-12-01

    Using an Arabidopsis microarray, we compared gene expression between germinating Brassica napus seeds and seeds in which germination was inhibited either by polyethylene glycol (PEG) or by the abscisic acid (ABA) analog PBI429, which produces stronger and longer lasting ABA-like effects. A total of 40 genes were induced relative to the germinating control by both treatments. Conspicuous among these were genes associated with late seed development. We identified 36 genes that were downregulated by both PEG and PBI429. Functions of these genes included carbohydrate metabolism, cell wall-related processes, detoxification of reactive oxygen, and triacylglycerol breakdown. The PBI429 treatment produced an increase in endogenous ABA and increased ABA catabolism. However, PEG treatment did not result in similar effects. The transcription factor ABI5 was consistently upregulated by both treatments and PKL was downregulated. These results suggest a greater importance of ABA signaling and reduced importance of GA signaling in nongerminating seeds.

  4. A histone methyltransferase inhibits seed germination by increasing PIF1 mRNA expression in imbibed seeds.

    PubMed

    Lee, Nayoung; Kang, Hyojin; Lee, Daeyoup; Choi, Giltsu

    2014-04-01

    Phytochrome-interacting factor 1 (PIF1) inhibits light-dependent seed germination. The specific function of PIF1 in seed germination is partly due to its high level of expression in imbibed seeds, but the associated regulatory factors have not been identified. Here we show that mutation of the early flowering in short days (EFS) gene, encoding an H3K4 and H3K36 methyltransferase, decreases the level of H3K36me2 and H3K36me3 but not H3K4me3 at the PIF1 locus, reduces the targeting of RNA polymerase II to the PIF1 locus, and reduces mRNA expression of PIF1 in imbibed seeds. Consistently, the efs mutant geminated even under the phyBoff condition, and had an expression profile of PIF1 target genes similar to that of the pif1 mutant. Introduction of an EFS transgene into the efs mutant restored the level of H3K36me2 and H3K36me3 at the PIF1 locus, the high-level expression of PIF1 mRNA, the expression pattern of PIF1 target genes, and the light-dependent germination of these seeds. Introduction of a PIF1 transgene into the efs mutant also restored the expression pattern of PIF1 target genes and light-dependent germination in imbibed seeds, but did not restore the flowering phenotype. Taken together, our results indicate that EFS is necessary for high-level expression of PIF1 mRNA in imbibed seeds.

  5. Physiological Mechanisms Only Tell Half Story: Multiple Biological Processes are involved in Regulating Freezing Tolerance of Imbibed Lactuca sativa Seeds

    PubMed Central

    Jaganathan, Ganesh K.; Han, Yingying; Li, Weijie; Song, Danping; Song, Xiaoyan; Shen, Mengqi; Zhou, Qiang; Zhang, Chenxue; Liu, Baolin

    2017-01-01

    The physiological mechanisms by which imbibed seeds survive freezing temperatures in their natural environment have been categorized as freezing avoidance by supercooling and freezing tolerance by extracellular freeze-desiccation, but the biochemical and molecular mechanisms conferring seed freezing tolerance is unexplored. In this study, using imbibed Lactuca sativa seeds we show that fast cooled seeds (60 °C h−1) suffered significantly higher membrane damage at temperature between −20 °C and −10 °C than slow cooled (3 °Ch−1) seeds (P < 0.05), presumably explaining viability loss during fast cooling when temperature approaches −20 °C. Total soluble sugars increase in low temperature environment, but did not differ significantly between two cooling rates (P > 0.05). However, both SOD activity and accumulation of free proline were induced significantly after slow cooling to −20 °C compared with fast cooling. RNA-seq demonstrated that multiple pathways were differentially regulated between slow and fast cooling. Real-time verification of some differentially expressed genes (DEGs) revealed that fast cooling caused mRNA level changes of plant hormone and ubiquitionation pathways at higher sub-zero temperature, whilst slow cooling caused mRNA level change of those pathways at lower sub-zero ttemperatures. Thus, we conclude that imbibed seed tolerate low temperature not only by physiological mechanisms but also by biochemical and molecular changes. PMID:28287125

  6. Physiological Mechanisms Only Tell Half Story: Multiple Biological Processes are involved in Regulating Freezing Tolerance of Imbibed Lactuca sativa Seeds.

    PubMed

    Jaganathan, Ganesh K; Han, Yingying; Li, Weijie; Song, Danping; Song, Xiaoyan; Shen, Mengqi; Zhou, Qiang; Zhang, Chenxue; Liu, Baolin

    2017-03-13

    The physiological mechanisms by which imbibed seeds survive freezing temperatures in their natural environment have been categorized as freezing avoidance by supercooling and freezing tolerance by extracellular freeze-desiccation, but the biochemical and molecular mechanisms conferring seed freezing tolerance is unexplored. In this study, using imbibed Lactuca sativa seeds we show that fast cooled seeds (60 °C h(-1)) suffered significantly higher membrane damage at temperature between -20 °C and -10 °C than slow cooled (3 °Ch(-1)) seeds (P < 0.05), presumably explaining viability loss during fast cooling when temperature approaches -20 °C. Total soluble sugars increase in low temperature environment, but did not differ significantly between two cooling rates (P > 0.05). However, both SOD activity and accumulation of free proline were induced significantly after slow cooling to -20 °C compared with fast cooling. RNA-seq demonstrated that multiple pathways were differentially regulated between slow and fast cooling. Real-time verification of some differentially expressed genes (DEGs) revealed that fast cooling caused mRNA level changes of plant hormone and ubiquitionation pathways at higher sub-zero temperature, whilst slow cooling caused mRNA level change of those pathways at lower sub-zero ttemperatures. Thus, we conclude that imbibed seed tolerate low temperature not only by physiological mechanisms but also by biochemical and molecular changes.

  7. Role of Seed Coat in Imbibing Soybean Seeds Observed by Micro-magnetic Resonance Imaging

    PubMed Central

    Koizumi, Mika; Kikuchi, Kaori; Isobe, Seiichiro; Ishida, Nobuaki; Naito, Shigehiro; Kano, Hiromi

    2008-01-01

    Background and Aims Imbibition of Japanese soybean (Glycine max) cultivars was studied using micro-magnetic resonance imaging (MRI) in order to elucidate the mechanism of soaking injury and the protective role of the seed coat. Methods Time-lapse images during water uptake were acquired by the single-point imaging (SPI) method at 15-min intervals, for 20 h in the dry seed with seed coat, and for 2 h in seeds with the seed coat removed. The technique visualized water migration within the testa and demonstrated the distortion associated with cotyledon swelling during the very early stages of water uptake. Key Results Water soon appeared in the testa and went around the dorsal surface of the seed from near the raphe, then migrated to the hilum region. An obvious protrusion was noted when water reached the hypocotyl and the radicle, followed by swelling of the cotyledons. A convex area was observed around the raphe with the enlargement of the seed. Water was always incorporated into the cotyledons from the abaxial surfaces, leading to swelling and generating a large air space between the adaxial surfaces. Water uptake greatly slowed, and the internal structures, veins and oil-accumulating tissues in the cotyledons developed after the seed stopped expanding. When the testa was removed from the dry seeds before imbibition, the cotyledons were severely damaged within 1·5 h of water uptake. Conclusions The activation of the water channel seemed unnecessary for water entry into soybean seeds, and the testa rapidly swelled with steeping in water. However, the testa did not regulate the water incorporation in itself, but rather the rate at which water encountered the hypocotyl, the radicle, and the cotyledons through the inner layer of the seed coat, and thus prevented the destruction of the seed tissues at the beginning of imbibition. PMID:18565982

  8. Dormant and after-Ripened Arabidopsis thaliana Seeds are Distinguished by Early Transcriptional Differences in the Imbibed State

    PubMed Central

    Dekkers, Bas J. W.; Pearce, Simon P.; van Bolderen-Veldkamp, R. P. M.; Holdsworth, Michael J.; Bentsink, Leónie

    2016-01-01

    Seed dormancy is a genetically controlled block preventing the germination of imbibed seeds in favorable conditions. It requires a period of dry storage (after-ripening) or certain environmental conditions to be overcome. Dormancy is an important seed trait, which is under selective pressure, to control the seasonal timing of seed germination. Dormant and non-dormant (after-ripened) seeds are characterized by large sets of differentially expressed genes. However, little information is available concerning the temporal and spatial transcriptional changes during early stages of rehydration in dormant and non-dormant seeds. We employed genome-wide transcriptome analysis on seeds of the model plant Arabidopsis thaliana to investigate transcriptional changes in dry seeds upon rehydration. We analyzed gene expression of dormant and after-ripened seeds of the Cvi accession over four time points and two seed compartments (the embryo and surrounding single cell layer endosperm), during the first 24 h after sowing. This work provides a global view of gene expression changes in dormant and non-dormant seeds with temporal and spatial detail, and these may be visualized via a web accessible tool (http://www.wageningenseedlab.nl/resources). A large proportion of transcripts change similarly in both dormant and non-dormant seeds upon rehydration, however, the first differences in transcript abundances become visible shortly after the initiation of imbibition, indicating that changes induced by after-ripening are detected and responded to rapidly upon rehydration. We identified several gene expression profiles which contribute to differential gene expression between dormant and non-dormant samples. Genes with enhanced expression in the endosperm of dormant seeds were overrepresented for stress-related Gene Ontology categories, suggesting a protective role for the endosperm against biotic and abiotic stress to support persistence of the dormant seed in its environment. PMID

  9. Dormancy induction by summer temperatures and/or desiccation in imbibed seeds of trumpet daffodils Narcissus alcaracensis and N. longispathus (Amaryllidaceae).

    PubMed

    Herranz, J M; Copete, E; Copete, M A; Márquez, J; Ferrandis, P

    2017-01-01

    We analysed the effects of summer temperatures (28/14 °C) and/or desiccation (from 48% to 8% humidity) on imbibed Narcissus alcaracensis and N. longispathus seeds with an elongating embryo. In the N. alcaracensis seeds that overcame dormancy (embryo elongation = 27.14%), exposure to high temperatures induced secondary dormancy and reduced subsequent embryo growth. A further 3-month cold stratification (5 °C) was required to break secondary dormancy. Desiccation in early embryo growth stages (elongation = 11.42%) also reduced germination. Desiccation in the seeds in a more advanced growth stage (i.e. embryo elongation = 27.14%) induced secondary dormancy, which the further 3-month cold stratification did not overcome. When desiccation was preceded by high temperatures, seeds better overcame secondary dormancy (i.e. longer embryo elongation and seed germination). Treatments did not affect seed viability. In the N. longispathus seeds that overcame dormancy (embryo elongation = 59.21%), exposure to high temperatures induced secondary dormancy and they needed a further 1-month stratification at 15/4 °C + 2 months at 5 °C to reactivate the germination process. When embryo elongation was 42.10%, seed desiccation totally impeded subsequent germination. When embryo elongation reached 59.21%, desiccation induced secondary dormancy, which was not overcome by the above-described stratification treatment. When desiccation was preceded by high temperatures, seeds better overcame dormancy. Stress treatments killed 5-10% of seeds. This study suggests that the seeds of species with complex morphophysiological dormancy (MPD) levels are sensitive to desiccation in early embryo development stages, as opposed to the seeds of species with deep simple epicotyl MPD, which better tolerate water stress.

  10. Optimum harvest maturity for Leymus chinensis seed

    PubMed Central

    Lin, Jixiang; Wang, Yingnan; Qi, Mingming; Li, Xiaoyu; Yang, Chunxue; Wang, Yongcui

    2016-01-01

    ABSTRACT Timely harvest is critical to achieve maximum seed viability and vigour in agricultural production. However, little information exists concerning how to reap the best quality seeds of Leymus chinensis, which is the dominant and most promising grass species in the Songnen Grassland of Northern China. The objective of this study was to investigate and evaluate possible quality indices of the seeds at different days after peak anthesis. Seed quality at different development stages was assessed by the colours of the seed and lemmas, seed weight, moisture content, electrical conductivity of seed leachate and germination indices. Two consecutive years of experimental results showed that the maximum seed quality was recorded at 39 days after peak anthesis. At this date, the colours of the seed and lemmas reached heavy brown and yellow, respectively. The seed weight was highest and the moisture content and the electrical conductivity of seed leachate were lowest. In addition, the seed also reached its maximum germination percentage and energy at this stage, determined using a standard germination test (SGT) and accelerated ageing test (AAT). Thus, Leymus chinensis can be harvested at 39 days after peak anthesis based on the changes in parameters. Colour identification can be used as an additional indicator to provide a more rapid and reliable measure of optimum seed maturity; approximately 10 days after the colour of the lemmas reached yellow and the colour of the seed reached heavy brown, the seed of this species was suitable for harvest. PMID:27170257

  11. 7 CFR 1427.174 - Maturity of seed cotton loans.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 10 2013-01-01 2013-01-01 false Maturity of seed cotton loans. 1427.174 Section 1427..., DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS COTTON Recourse Seed Cotton Loans § 1427.174 Maturity of seed cotton loans. Seed cotton loans mature on demand by CCC but no later than May 31...

  12. 7 CFR 1427.174 - Maturity of seed cotton loans.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Maturity of seed cotton loans. 1427.174 Section 1427..., DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS COTTON Recourse Seed Cotton Loans § 1427.174 Maturity of seed cotton loans. Seed cotton loans mature on demand by CCC but no later than May 31...

  13. 7 CFR 1427.174 - Maturity of seed cotton loans.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 10 2011-01-01 2011-01-01 false Maturity of seed cotton loans. 1427.174 Section 1427..., DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS COTTON Recourse Seed Cotton Loans § 1427.174 Maturity of seed cotton loans. Seed cotton loans mature on demand by CCC but no later than May 31...

  14. 7 CFR 1427.174 - Maturity of seed cotton loans.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 10 2014-01-01 2014-01-01 false Maturity of seed cotton loans. 1427.174 Section 1427..., DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS COTTON Recourse Seed Cotton Loans § 1427.174 Maturity of seed cotton loans. Seed cotton loans mature on demand by CCC but no later than May 31...

  15. 7 CFR 1427.174 - Maturity of seed cotton loans.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 10 2012-01-01 2012-01-01 false Maturity of seed cotton loans. 1427.174 Section 1427..., DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS COTTON Recourse Seed Cotton Loans § 1427.174 Maturity of seed cotton loans. Seed cotton loans mature on demand by CCC but no later than May 31...

  16. Tomato seeds maturity detection system based on chlorophyll fluorescence

    NASA Astrophysics Data System (ADS)

    Li, Cuiling; Wang, Xiu; Meng, Zhijun

    2016-10-01

    Chlorophyll fluorescence intensity can be used as seed maturity and quality evaluation indicator. Chlorophyll fluorescence intensity of seed coats is tested to judge the level of chlorophyll content in seeds, and further to judge the maturity and quality of seeds. This research developed a detection system of tomato seeds maturity based on chlorophyll fluorescence spectrum technology, the system included an excitation light source unit, a fluorescent signal acquisition unit and a data processing unit. The excitation light source unit consisted of two high power LEDs, two radiators and two constant current power supplies, and it was designed to excite chlorophyll fluorescence of tomato seeds. The fluorescent signal acquisition unit was made up of a fluorescence spectrometer, an optical fiber, an optical fiber scaffolds and a narrowband filter. The data processing unit mainly included a computer. Tomato fruits of green ripe stage, discoloration stage, firm ripe stage and full ripe stage were harvested, and their seeds were collected directly. In this research, the developed tomato seeds maturity testing system was used to collect fluorescence spectrums of tomato seeds of different maturities. Principal component analysis (PCA) method was utilized to reduce the dimension of spectral data and extract principal components, and PCA was combined with linear discriminant analysis (LDA) to establish discriminant model of tomato seeds maturity, the discriminant accuracy was greater than 90%. Research results show that using chlorophyll fluorescence spectrum technology is feasible for seeds maturity detection, and the developed tomato seeds maturity testing system has high detection accuracy.

  17. Seed maturation regulators are related to the control of seed dormancy in wheat (Triticum aestivum L.).

    PubMed

    Rikiishi, Kazuhide; Maekawa, Masahiko

    2014-01-01

    In Arabidopsis, the regulation network of the seed maturation program controls the induction of seed dormancy. Wheat EST sequences showing homology with the master regulators of seed maturation, leafy cotyledon1 (LEC1), LEC2 and FUSCA3 (FUS3), were searched from databases and designated respectively as TaL1L (LEC1-LIKE), TaL2L (LEC2-LIKE), and TaFUS3. TaL1LA, TaL2LA and TaFUS3 mainly expressed in seeds or embryos, with the expression limited to the early stages of seed development. Results show that tissue-specific and developmental-stage-dependent expressions are similar to those of seed maturation regulators in Arabidopsis. In wheat cultivars, the expression level of TaL1LA is correlated significantly with the germination index (GI) of whole seeds at 40 days after pollination (DAP) (r =  -0.83**). Expression levels of TaFUS3 and TaL2LA are significantly correlated respectively with GIs at 40 DAP and 50 DAP, except for dormant cultivars. No correlation was found between the expression level of TaVP1, orthologue of ABA insensitive3 (ABI3), and seed dormancy. Delay of germination1 (DOG1) was identified as a quantitative trait locus (QTL) for the regulation of seed dormancy in Arabidopsis. Its promoter has RY motif, which is a target sequence of LEC2. Significant correlation was found between the expression of TaDOG1 and seed dormancy except for dormant cultivars. These results indicate that TaL1LA, TaL2LA, and TaFUS3 are wheat orthologues of seed maturation regulators. The expressions of these genes affect the level of seed dormancy. Furthermore, the pathways, which involve seed maturation regulators and TaDOG1, are important for regulating seed dormancy in wheat.

  18. Proteomic analysis of mature Lagenaria siceraria seed.

    PubMed

    Kumari, Neha; Tajmul, Md; Yadav, Savita

    2015-04-01

    Lagenaria siceraria (bottle gourd) class belongs to Magnoliopsida family curcurbitaceae that is a traditionally used medicinal plant. Fruit of this plant are widely used as a therapeutic vegetable in various diseases, all over the Asia and Africa. Various parts of this plant like fruit, seed, leaf and root are used as alternative medicine. In the present study, primarily, we have focused on proteomic analysis of L. siceraria seed using phenol extraction method for protein isolation. Twenty-four colloidal coomassie blue stained protein spots were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF/MS) after resolving on two-dimensional gel electrophoresis. Out of 24 identified protein spots, four were grouped as unidentified proteins which clearly suggest that less work has been done in the direction of plant seed proteomics. These proteins have been found to implicate in various functions such as biosynthesis of plant cell wall polysaccharides and glycoproteins, serine/threonine kinase activity, plant disease resistance and transferase activity against insects by means of insecticidal and larval growth inhibitory, anti-HIV, antihelmintic and antimicrobial properties. By Blast2GO annotation analysis, amongst the identified proteins of L. siceraria, molecular function for majority of proteins has indispensable role in catalytic activity, few in binding activity and antioxidant activity; it is mostly distributed in cell, organelle, membrane and macromolecular complex. Most of them involved in biological process such as metabolic process, cellular process, response to stimulus, single organism process, signalling, biological recognition, cellular component organization or biogenesis and localization.

  19. Protein profile of mature soybean seeds and prepared soybean milk.

    PubMed

    Capriotti, Anna Laura; Caruso, Giuseppe; Cavaliere, Chiara; Samperi, Roberto; Stampachiacchiere, Serena; Zenezini Chiozzi, Riccardo; Laganà, Aldo

    2014-10-08

    The soybean (Glycine max (L.) Merrill) is economically the most important bean in the world, providing a wide range of vegetable proteins. Soybean milk is a colloidal solution obtained as water extract from swelled and ground soybean seeds. Soybean proteins represent about 35-40% on a dry weight basis and they are receiving increasing attention with respect to their health effects. However, the soybean is a well-recognized allergenic food, and therefore, it is urgent to define its protein components responsible for the allergenicity in order to develop hypoallergenic soybean products for sensitive people. The main aim of this work was the characterization of seed and milk soybean proteome and their comparison in terms of protein content and specific proteins. Using a shotgun proteomics approach, 243 nonredundant proteins were identified in mature soybean seeds.

  20. Dissecting the proteome of pea mature seeds reveals the phenotypic plasticity of seed protein composition.

    PubMed

    Bourgeois, Michael; Jacquin, Françoise; Savois, Vincent; Sommerer, Nicolas; Labas, Valérie; Henry, Céline; Burstin, Judith

    2009-01-01

    Pea (Pisum sativum L.) is the most cultivated European pulse crop and the pea seeds mainly serve as a protein source for monogastric animals. Because the seed protein composition impacts on seed nutritional value, we aimed at identifying the determinants of its variability. This paper presents the first pea mature seed proteome reference map, which includes 156 identified proteins (http://www.inra.fr/legumbase/peaseedmap/). This map provides a fine dissection of the pea seed storage protein composition revealing a large diversity of storage proteins resulting both from gene diversity and post-translational processing. It gives new insights into the pea storage protein processing (especially 7S globulins) as a possible adaptation towards progressive mobilization of the proteins during germination. The nonstorage seed proteome revealed the presence of proteins involved in seed defense together with proteins preparing germination. The plasticity of the seed proteome was revealed for seeds produced in three successive years of cultivation, and 30% of the spots were affected by environmental variations. This work pinpoints seed proteins most affected by environment, highlighting new targets to stabilize storage protein composition that should be further analyzed.

  1. Seed maturation: Simplification of control networks in plants.

    PubMed

    Devic, Martine; Roscoe, Thomas

    2016-11-01

    Networks controlling developmental or metabolic processes in plants are often complex as a consequence of the duplication and specialisation of the regulatory genes as well as the numerous levels of transcriptional and post-transcriptional controls added during evolution. Networks serve to accommodate multicellular complexity and increase robustness to environmental changes. Mathematical simplification by regrouping genes or pathways in a limited number of hubs has facilitated the construction of models for complex traits. In a complementary approach, a biological simplification can be achieved by using genetic modification to understand the core and singular ancestral function of the network, which is likely to be more prevalent within the plant kingdom rather than specific to a species. With this viewpoint, we review examples of simplification successfully undertaken in yeast and other organisms. A strategy of progressive complementation of single, double and triple mutants of seed maturation confirmed the fundamental role of the AFL sub-family of B3 transcription factors as master regulators of seed maturation, illustrating that biological simplification of complex networks could be more widely applied in plants. Defining minimal control networks will facilitate evolutionary comparisons of regulatory processes and the identification of an essential gene set for synthetic biology.

  2. The role of recovery of mitochondrial structure and function in desiccation tolerance of pea seeds.

    PubMed

    Wang, Wei-Qing; Cheng, Hong-Yan; Møller, Ian M; Song, Song-Quan

    2012-01-01

    Mitochondrial repair is of fundamental importance for seed germination. When mature orthodox seeds are imbibed and germinated, they lose their desiccation tolerance in parallel. To gain a better understanding of this process, we studied the recovery of mitochondrial structure and function in pea (Pisum sativum cv. Jizhuang) seeds with different tolerance to desiccation. Mitochondria were isolated and purified from the embryo axes of control and imbibed-dehydrated pea seeds after (re-)imbibition for various times. Recovery of mitochondrial structure and function occurred both in control and imbibed-dehydrated seed embryo axes, but at different rates and to different maximum levels. The integrity of the outer mitochondrial membrane reached 96% in all treatments. However, only the seeds imbibed for 12 h and then dehydrated recovered the integrity of the inner mitochondrial membrane (IMM) and State 3 (respiratory state in which substrate and ADP are present) respiration (with NADH and succinate as substrate) to the control level after re-imbibition. With increasing imbibition time, the degree to which each parameter recovered decreased in parallel with the decrease in desiccation tolerance. The tolerance of imbibed seeds to desiccation increased and decreased when imbibed in CaCl(2) and methylviologen solution, respectively, and the recovery of the IMM integrity similarly improved and weakened in these two treatments, respectively. Survival of seeds after imbibition-dehydration linearly increased with the increase in ability to recover the integrity of IMM and State 3 respiration, which indicates that recovery of mitochondrial structure and function during germination has an important role in seed desiccation tolerance.

  3. The pivotal role of abscisic acid signaling during transition from seed maturation to germination.

    PubMed

    Yan, An; Chen, Zhong

    2016-11-23

    Seed maturation and germination are two continuous developmental processes that link two distinct generations in spermatophytes; the precise genetic control of these two processes is, therefore, crucially important for the survival of the next generation. Pieces of experimental evidence accumulated so far indicate that a concerted action of endogenous signals and environmental cues is required to govern these processes. Plant hormone abscisic acid (ABA) has been suggested to play a predominant role in directing seed maturation and maintaining seed dormancy under unfavorable environmental conditions until antagonized by gibberellins (GA) and certain environmental cues to allow the commencement of seed germination when environmental conditions are favorable; therefore, the balance of ABA and GA is a major determinant of the timing of seed germination. Due to the advent of new technologies and system biology approaches, molecular studies are beginning to draw a picture of the sophisticated genetic network that drives seed maturation during the past decade, though the picture is still incomplete and many details are missing. In this review, we summarize recent advances in ABA signaling pathway in the regulation of seed maturation as well as the transition from seed maturation to germination, and highlight the importance of system biology approaches in the study of seed maturation.

  4. Differential expression of wheat aspartic proteinases, WAP1 and WAP2, in germinating and maturing seeds.

    PubMed

    Tamura, Tomoko; Terauchi, Kaede; Kiyosaki, Toshihiro; Asakura, Tomiko; Funaki, Junko; Matsumoto, Ichiro; Misaka, Takumi; Abe, Keiko

    2007-04-01

    Two aspartic proteinase (AP) cDNA clones, WAP1 and WAP2, were obtained from wheat seeds. Proteins encoded by these clones shared 61% amino acid sequence identity. RNA blotting analysis showed that WAP1 and WAP2 were expressed in both germinating and maturing seeds. The level of WAP2 mRNA expression was clearly weaker than that of WAP1 in all tissues of seeds during germination and maturation. APs purified from germinating seeds were enzymatically active and digested the wheat storage protein, gluten. To elucidate the physiological functions of WAP1 and WAP2 in seeds, we investigated the localisation of WAP1 and WAP2 by in situ hybridisation. In germinating seeds investigated 24h after imbibition, both WAP1 and WAP2 were expressed in embryos, especially in radicles and shoots, scutellum, and the aleurone layer. In maturing seeds, WAP1 was expressed in the whole embryo, with slightly stronger expression in radicles and shoots. WAP1 was also expressed in the aleurone layer 3 weeks after flowering. Strong signals of WAP1 mRNA were detected in the whole embryo and aleurone layer 6 weeks after flowering. On the other hand, WAP2 was scarcely detected in seeds 3 weeks after flowering, and thereafter weak signals began to appear in the whole embryo. WAP1 and WAP2 were expressed widely in germinating and maturing seeds. Such diversity in site- and stage-specific expression of the two enzymes suggests their differential functions in wheat seeds.

  5. Effects of pollen supply and quality on seed formation and maturation in Pinus densiflora.

    PubMed

    Iwaizumi, Masakazu G; Takahashi, Makoto

    2012-07-01

    To understand the detailed mechanisms underlying variations in seed productivity per cone, it is important to examine simultaneously the effects of two pollination mode components (pollen supply and quality) on two seed production processes (seed formation and maturation). We conducted artificial pollination experiments with four pollination treatments (selfing, polycross, no-pollination and open-pollination treatments) in each of two vertical crown layers (upper and lower) for 19 Pinus densiflora ramets. We measured formed seeds as a proportion of ovules (P(Form)), and filled seeds as a proportion of formed seeds (P(Fill)) per cone in each treatment and layer, and inferred the relative influences of pollination mode and resource availability on seed productivity. In the no-pollination treatment, no seeds were formed in any cones of all five ramets. The Generalized Linear Model showed that there were no significant differences in P(Form) both between selfing and polycross treatments and upper and lower layers. The mean P(Fill) values in the selfing treatment were significantly lower than those in the polycross treatment in both layers. The mean P(Fill)s of the two layers did not differ significantly in the selfing treatment, but did in the open-pollination and polycross treatments. The results show that pollen supply affects mainly seed formation, whereas pollen quality affects mainly seed maturation. Resource availability also affects mainly seed maturation, if pollen quality is higher than a certain threshold.

  6. Transcriptome Analysis of Chilling-Imbibed Embryo Revealed Membrane Recovery Related Genes in Maize

    PubMed Central

    He, Fei; Shen, Hangqi; Lin, Cheng; Fu, Hong; Sheteiwy, Mohamed S.; Guan, Yajing; Huang, Yutao; Hu, Jin

    2017-01-01

    The delayed seed germination and poor seedling growth caused by imbibitional chilling injury was common phenomenon in maize seedling establishment. In this study, RNA sequencing technology was used to comprehensively investigate the gene expressions in chilling-imbibed maize embryo and to reveal the underlying mechanism of chilling injury at molecular level. Imbibed seeds for 2 h at 5°C (LT2) were selected and transcriptomic comparative analysis was performed. Among 327 DEGs indentified between dry seed (CK0) and LT2, 15 specific genes with plasma membrane (PM) relevant functions belonging to lipid metabolism, stress, signaling and transport were characterized, and most of them showed down-regulation pattern under chilling stress. When transferred to 25°C for recovery (LT3), remarkable changes occurred in maize embryo. There were 873 DEGs including many PM related genes being identified between LT2 and LT3, some of which showing significant increase after 1 h recovery. Moreover, 15 genes encoding intracellular vesicular trafficking proteins were found to be exclusively differential expressed at recovery stage. It suggested that the intracellular vesicle trafficking might be essential for PM recovery through PM turnover. Furthermore, transcriptome analyses on imbibed embryos under normal condition (25°C) were also made as a contrast. A total of 651 DEGs were identified to mainly involved in protein metabolism, transcriptional regulation, signaling, and energy productions. Overall, the RNA-Seq results provided us a deep knowledge of imbibitional chilling injury on plasma membrane and a new view on PM repaired mechanism during early seed imbibition at transcriptional level. The DEGs identified in this work would be useful references in future seed germination research. PMID:28101090

  7. Retarded Embryo Development 1 (RED1) regulates embryo development, seed maturation and plant growth in Arabidopsis.

    PubMed

    Du, Qian; Wang, Huanzhong

    2016-07-20

    Plant seeds accumulate large amounts of protein and carbohydrate as storage reserves during maturation. Thus, understanding the genetic control of embryo and seed development may provide bioengineering tools for yield improvement. In this study, we report the identification of Retarded Embryo Development 1 (RED1) gene in Arabidopsis, whose two independent T-DNA insertion mutant lines, SALK_085642 (red1-1) and SALK_022583 (red1-2), show a retarded embryo development phenotype. The embryogenesis process ceases at the late heart stage in red1-1 and at the bent-cotyledon stage in red1-2, respectively, resulting in seed abortion in both lines. The retarded embryo development and seed abortion phenotypes reverted to normal when RED1 complementation constructs were introduced into mutant plants. Small red1-2 homozygous plants can be successfully rescued by culturing immature seeds, indicating that seed abortion likely results from compromised tolerance to the desiccation process associated with seed maturation. Consistent with this observation, red1-2 seeds accumulate less protein, and the expression of two late embryo development reporter transgenes, LEA::GUS and β-conglycinin::GUS, was significantly weak and started relatively late in the red1-2 mutant lines compared to the wild type. The RED1 gene encodes a plant specific novel protein that is localized in the nucleus. These results indicate that RED1 plays important roles in embryo development, seed maturation and plant growth.

  8. Loss of Mitochondrial Malate Dehydrogenase Activity Alters Seed Metabolism Impairing Seed Maturation and Post-Germination Growth in Arabidopsis.

    PubMed

    Sew, Yun Shin; Ströher, Elke; Fenske, Ricarda; Millar, A Harvey

    2016-06-01

    Mitochondrial malate dehydrogenase (mMDH; EC 1.1.1.37) has multiple roles; the most commonly described is its catalysis of the interconversion of malate and oxaloacetate in the tricarboxylic acid cycle. The roles of mMDH in Arabidopsis (Arabidopsis thaliana) seed development and germination were investigated in mMDH1 and mMDH2 double knockout plants. A significant proportion of mmdh1mmdh2 seeds were nonviable and developed only to torpedo-shaped embryos, indicative of arrested seed embryo growth during embryogenesis. The viable mmdh1mmdh2 seeds had an impaired maturation process that led to slow germination rates as well as retarded post-germination growth, shorter root length, and decreased root biomass. During seed development, mmdh1mmdh2 showed a paler green phenotype than the wild type and exhibited deficiencies in reserve accumulation and reduced final seed biomass. The respiration rate of mmdh1mmdh2 seeds was significantly elevated throughout their maturation, consistent with the previously reported higher respiration rate in mmdh1mmdh2 leaves. Mutant seeds showed a consistently higher content of free amino acids (branched-chain amino acids, alanine, serine, glycine, proline, and threonine), differences in sugar and sugar phosphate levels, and lower content of 2-oxoglutarate. Seed-aging assays showed that quiescent mmdh1mmdh2 seeds lost viability more than 3 times faster than wild-type seeds. Together, these data show the important role of mMDH in the earliest phases of the life cycle of Arabidopsis.

  9. Dynamic quantitative trait locus analysis of seed vigor at three maturity stages in rice.

    PubMed

    Liu, Liangfeng; Lai, Yanyan; Cheng, Jinping; Wang, Ling; Du, Wenli; Wang, Zhoufei; Zhang, Hongsheng

    2014-01-01

    Seed vigor is an important characteristic of seed quality. In this study, one rice population of recombinant inbred lines (RILs) was used to determine the genetic characteristics of seed vigor, including the germination potential, germination rate, germination index and time for 50% of germination, at 4 (early), 5 (middle) and 6 weeks (late) after heading in two years. A total of 24 additive and 9 epistatic quantitative trait loci (QTL) for seed vigor were identified using QTL Cartographer and QTLNetwork program respectively in 2012; while 32 simple sequence repeat (SSR) markers associated with seed vigor were detected using bulked segregant analysis (BSA) in 2013. The additive, epistatic and QTL × development interaction effects regulated the dry maturity developmental process to improve seed vigor in rice. The phenotypic variation explained by each additive, epistatic QTL and QTL × development interaction ranged from 5.86 to 40.67%, 4.64 to 11.28% and 0.01 to 1.17%, respectively. The QTLs were rarely co-localized among the different maturity stages; more QTLs were expressed at the early maturity stage followed by the late and middle stages. Twenty additive QTLs were stably expressed in two years which might play important roles in establishment of seed vigor in different environments. By comparing chromosomal positions of these stably expressed additive QTLs with those previously identified, the regions of QTL for seed vigor are likely to coincide with QTL for grain size, low temperature germinability and seed dormancy; while 5 additive QTL might represent novel genes. Using four selected RILs, three cross combinations of seed vigor for the development of RIL populations were predicted; 19 elite alleles could be pyramided by each combination.

  10. Dynamic Quantitative Trait Locus Analysis of Seed Vigor at Three Maturity Stages in Rice

    PubMed Central

    Cheng, Jinping; Wang, Ling; Du, Wenli; Wang, Zhoufei; Zhang, Hongsheng

    2014-01-01

    Seed vigor is an important characteristic of seed quality. In this study, one rice population of recombinant inbred lines (RILs) was used to determine the genetic characteristics of seed vigor, including the germination potential, germination rate, germination index and time for 50% of germination, at 4 (early), 5 (middle) and 6 weeks (late) after heading in two years. A total of 24 additive and 9 epistatic quantitative trait loci (QTL) for seed vigor were identified using QTL Cartographer and QTLNetwork program respectively in 2012; while 32 simple sequence repeat (SSR) markers associated with seed vigor were detected using bulked segregant analysis (BSA) in 2013. The additive, epistatic and QTL × development interaction effects regulated the dry maturity developmental process to improve seed vigor in rice. The phenotypic variation explained by each additive, epistatic QTL and QTL × development interaction ranged from 5.86 to 40.67%, 4.64 to 11.28% and 0.01 to 1.17%, respectively. The QTLs were rarely co-localized among the different maturity stages; more QTLs were expressed at the early maturity stage followed by the late and middle stages. Twenty additive QTLs were stably expressed in two years which might play important roles in establishment of seed vigor in different environments. By comparing chromosomal positions of these stably expressed additive QTLs with those previously identified, the regions of QTL for seed vigor are likely to coincide with QTL for grain size, low temperature germinability and seed dormancy; while 5 additive QTL might represent novel genes. Using four selected RILs, three cross combinations of seed vigor for the development of RIL populations were predicted; 19 elite alleles could be pyramided by each combination. PMID:25536503

  11. Phenotypic Characteristics as Predictors of Phytosterols in Mature Cycas micronesica Seeds.

    PubMed

    Marler, Thomas E; Shaw, Christopher A

    2009-01-01

    The relationship between mature Cycas micronesica K.D. Hill seed sterol concentration and content and plant or seed phenotypic characteristics was established by multiple regression. Combined models were significant for free but not glycosylated sterols. Reduced models revealed leaf number as the only significant predictor. Free and glycosylated sterol concentrations were unaffected throughout the range of several predictors: tree height (1.7 to 5.8 m), seed fresh weight (48 to 120 g), seed load (one to 76 seeds per plant), and estimated tree age (32 to 110 years). The free and glycosylated sterol phenotypes were also not dependent on the presence/absence of developed embryos in mature seeds. The significant response to leaf number was subtle with an increase of 43 leaves associated with a 0.1-mg increase in free sterol per gram seed fresh weight. This is the first report for any cycad that discusses reproductive or physiological traits in the context of allometric relations. Results indicate a highly constrained phenotypic plasticity of Cycas gametophyte sterol and steryl glucoside concentration and seed content in relation to whole plant and organ size variation.

  12. Using RNA-Seq to profile soybean seed development from fertilization to maturity.

    PubMed

    Jones, Sarah I; Vodkin, Lila O

    2013-01-01

    To understand gene expression networks leading to functional properties and compositional traits of the soybean seed, we have undertaken a detailed examination of soybean seed development from a few days post-fertilization to the mature seed using Illumina high-throughput transcriptome sequencing (RNA-Seq). RNA was sequenced from seven different stages of seed development, yielding between 12 million and 78 million sequenced transcripts. These have been aligned to the 79,000 gene models predicted from the soybean genome recently sequenced by the Department of Energy Joint Genome Institute. Over one hundred gene models were identified with high expression exclusively in young seed stages, starting at just four days after fertilization. These were annotated as being related to many basic components and processes such as histones and proline-rich proteins. Genes encoding storage proteins such as glycinin and beta-conglycinin had their highest expression levels at the stages of largest fresh weight, confirming previous knowledge that these storage products are being rapidly accumulated before the seed begins the desiccation process. Other gene models showed high expression in the dry, mature seeds, perhaps indicating the preparation of pathways needed later, in the early stages of imbibition. Many highly-expressed gene models at the dry seed stage are, as expected, annotated as hydrophilic proteins associated with low water conditions, such as late embryogenesis abundant (LEA) proteins and dehydrins, which help preserve the cellular structures and nutrients within the seed during desiccation. More significantly, the power of RNA-Seq to detect genes expressed at low levels revealed hundreds of transcription factors with notable expression in at least one stage of seed development. Results from a second biological replicate demonstrate high reproducibility of these data revealing a comprehensive view of the transciptome of seed development in the cultivar Williams, the

  13. A local dormancy cline is related to the seed maturation environment, population genetic composition and climate

    PubMed Central

    Fernández-Pascual, Eduardo; Jiménez-Alfaro, Borja; Caujapé-Castells, Juli; Jaén-Molina, Ruth; Díaz, Tomás Emilio

    2013-01-01

    Background and Aims Seed dormancy varies within species in response to climate, both in the long term (through ecotypes or clines) and in the short term (through the influence of the seed maturation environment). Disentangling both processes is crucial to understand plant adaptation to environmental changes. In this study, the local patterns of seed dormancy were investigated in a narrow endemic species, Centaurium somedanum, in order to determine the influence of the seed maturation environment, population genetic composition and climate. Methods Laboratory germination experiments were performed to measure dormancy in (1) seeds collected from different wild populations along a local altitudinal gradient and (2) seeds of a subsequent generation produced in a common garden. The genetic composition of the original populations was characterized using intersimple sequence repeat (ISSR) PCR and principal co-ordinate analysis (PCoA), and its correlation with the dormancy patterns of both generations was analysed. The effect of the local climate on dormancy was also modelled. Key Results An altitudinal dormancy cline was found in the wild populations, which was maintained by the plants grown in the common garden. However, seeds from the common garden responded better to stratification, and their release from dormancy was more intense. The patterns of dormancy variation were correlated with genetic composition, whereas lower temperature and summer precipitation at the population sites predicted higher dormancy in the seeds of both generations. Conclusions The dormancy cline in C. somedanum is related to a local climatic gradient and also corresponds to genetic differentiation among populations. This cline is further affected by the weather conditions during seed maturation, which influence the receptiveness to dormancy-breaking factors. These results show that dormancy is influenced by both long-and short-term climatic variation. Such processes at such a reduced spatial

  14. [Dehydration in the cryopreservation of moist plant tissues and in seed maturation].

    PubMed

    Chetverikova, E P

    2008-01-01

    The possibility of long-term cryopreservation of plant objects depends on their water content. In orthodox seeds, it decreases at the late stage of maturation and is accompanied by the synthesis of protectors--sugars and proteins. These seeds easily withstand cryopreservation. Organs with a high water content, meristems, and recalcitrant seeds are dried in presence of sucrose before plunging in liquid nitrogen. In orthodox seeds, artificially dried moist seeds, and meristems, the cellular content forms glass structures that are estimated in frozen materials by differential scanning calorimetry and electron paramagnetic resonance methods. It is proposed that the glass cellular content is connected with the duration of cryopreservation. Methodical approaches to successive cryopreservation of moist plant tissues are described.

  15. 'US Early Pride', a very low-seeded, early-maturing mandarin hybrid

    Technology Transfer Automated Retrieval System (TEKTRAN)

    ‘US Early Pride’ is an irradiation-induced, very low-seeded mutant of the ‘Fallglo’ mandarin hybrid [‘Bower’ (Citrus reticulata Blanco x (C. paradisi Macf. X C. reticulata) x Temple’]. Mature ‘Fallglo’ budwood was irradiated in 1991 using 3 kRAD units of gamma irradiation from a Cobalt-60 source in ...

  16. Effects of endophyte-infected fescue seed on physiological parameters of mature female meat goats

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objectives of the study were to determine if consumption of endophyte-infected (E+) tall fescue seed would affect thermoregulation and dry matter intake (DMI) in mature female meat goats. During the 4 week study, goats (n = 18) were assigned to one of three treatments (n = 6 per treatment) and f...

  17. Development of sunflower oil and composition with respect to seed moisture and physiological maturity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Desiccants/harvest aids are becoming more commonly used to hasten sunflower harvest. The current recommendation is to apply a desiccant (e.g., glyphosate and paraquat) at 35% or less seed moisture at physiological maturity (PM). Desiccating as early as possible without sacrificing yield may be a des...

  18. Seedling development and evaluation of genetic stability of cryopreserved Dendrobium hybrid mature seeds.

    PubMed

    Galdiano, Renato Fernandes; de Macedo Lemos, Eliana Gertrudes; de Faria, Ricardo Tadeu; Vendrame, Wagner Aparecido

    2014-03-01

    Vitrification, a simple, fast, and recommended cryopreservation method for orchid germplasm conservation, was evaluated for Dendrobium hybrid "Dong Yai" mature seeds. The genetic stability of regenerated seedlings was also evaluated using flow cytometry. Mature seeds from this hybrid were submitted to plant vitrification solution (PVS2) for 0, 0.5, 1, 2, 3, 4, 5, or 6 h at 0 °C. Subsequently, they were plunged into liquid nitrogen (LN) at -196 °C for 1 h and recovered in half-strength Murashige and Skoog culture medium (1/2 MS), and seed germination was evaluated after 30 days. Seeds directly submitted to LN did not germinate after cryopreservation. Seeds treated with PVS2 between 1 and 3 h presented the best germination (between 51 and 58%), although longer exposure to PVS2 returned moderated germination (39%). Germinated seeds were further subcultured in P-723 culture medium and developed whole seedlings in vitro after 180 days, with no abnormal characteristics, diseases, or nutritional deficiencies. Seedlings were successfully acclimatized under greenhouse conditions with over 80% survival. Flow cytometry analysis revealed no chromosomal changes on vitrified seedlings, as well as seedlings germinated from the control treatment (direct exposure to LN). These findings indicate that vitrification is a feasible and safe germplasm cryopreservation method for commercial Dendrobium orchid hybrid conservation.

  19. Synchrony between fruit maturation and effective dispersers' foraging activity increases seed protection against seed predators.

    PubMed

    Boulay, Raphaël; Carro, Francisco; Soriguer, Ramón C; Cerdá, Xim

    2007-10-22

    The evolution of pollination and seed dispersal mutualisms is conditioned by the spatial and temporal co-occurrence of animals and plants. In the present study we explore the timing of seed release of a myrmecochorous plant (Helleborus foetidus) and ant activity in two populations in southern Spain during 2 consecutive years. The results indicate that fruit dehiscence and seed shedding occur mostly in the morning and correspond to the period of maximum foraging activity of the most effective ant dispersers. By contrast, ant species that do not transport seeds and/or that do not abound near the plants are active either before or after H. foetidus diaspores are released. Experimental analysis of diet preference for three kinds of food shows that effective ant dispersers are mostly scavengers that readily feed on insect corpses and sugars. Artificial seed depots suggest that seeds deposited on the ground out of the natural daily time window of diaspore releasing are not removed by ants and suffer strong predation by nocturnal rodents Apodemus sylvaticus. Nevertheless, important inter-annual variations in rodent populations cast doubts on their real importance as selection agents. We argue that traits allowing synchrony between seed presentation and effective partners may constitute a crucial pre-adaptation for the evolution of plant-animal mutualisms involving numerous animal partners.

  20. [Evolution of tocopherols in relation of unsaturated fatty acids during maturation of seeds of rapeseed (Brassica napus L.)].

    PubMed

    Sebei, Khaled; Boukhchina, Sadok; Kallel, Habib

    2007-01-01

    The oil content increases during the maturation of seeds (rise of 30%), but decreases at the end of seed maturation. Differences between SDS-PAGE total protein profiles were shown. Polyunsaturated fatty acids contents increase during middle-maturation. Contents of alpha and gamma tocopherols increase with time. This increase is explained by the fact that tocopherols participate actively in the protection of membranes whose phospholipids consist of polyunsaturated fatty acids (PUFAs).

  1. Coffee seeds isotopic composition as a potential proxy to evaluate Minas Gerais, Brazil seasonal variations during seed maturation

    NASA Astrophysics Data System (ADS)

    Rodrigues, Carla; Maia, Rodrigo; Brunner, Marion; Carvalho, Eduardo; Prohaska, Thomas; Máguas, Cristina

    2010-05-01

    Plant seeds incorporate the prevailing climate conditions and the physiological response to those conditions (Rodrigues et al., 2009; Rodrigues et al., submitted). During coffee seed maturation the biochemical compounds may either result from accumulated material in other organs such as leafs and/or from new synthesis. Accordingly, plant seeds develop in different stages along a particular part of the year, integrating the plant physiology and seasonal climatic conditions. Coffee bean is an extremely complex matrix, rich in many products derived from both primary and secondary metabolism during bean maturation. Other studies (De Castro and Marraccini, 2006) have revealed the importance of different coffee plant organs during coffee bean development as transfer tissues able to provide compounds (i.e. sugars, organic acids, etc) to the endosperm where several enzymatic activities and expressed genes have been reported. Moreover, it has been proved earlier on that green coffee bean is a particularly suitable case-study (Rodrigues et al., 2009; Rodrigues et al., submitted), not only due to the large southern hemispheric distribution but also because of this product high economic interest. The aim of our work was to evaluate the potential use of green coffee seeds as a proxy to seasonal climatic conditions during coffee bean maturation, through an array of isotopic composition determinations. We have determined carbon, nitrogen, oxygen and sulfur isotopic composition (by IRMS - Isotope Ratio Mass Spectrometry) as well as strontium isotope abundance (by MC-ICP-MS; Multicollector Inductively Coupled Plasma Mass Spectrometry), of green coffee beans harvested at different times at Minas Gerais, Brazil. The isotopic composition data were combined with air temperature and relative humidity data registered during the coffee bean developmental period, and with the parent rock strontium isotopic composition. Results indicate that coffee seeds indeed integrate the interactions

  2. Proteome Analysis of Grain Filling and Seed Maturation in Barley1

    PubMed Central

    Finnie, Christine; Melchior, Sabrina; Roepstorff, Peter; Svensson, Birte

    2002-01-01

    In monocotyledonous plants, the process of seed development involves the deposition of reserves in the starchy endosperm and development of the embryo and aleurone layer. The final stages of seed development are accompanied by an increase in desiccation tolerance and drying out of the mature seed. We have used two-dimensional gel electrophoresis for a time-resolved study of the changes in proteins that occur during seed development in barley (Hordeum vulgare). About 1,000 low-salt extractable protein spots could be resolved on the two-dimensional gels. Protein spots were divided into six categories according to the timing of appearance or disappearance during the 5-week period of comparison. Nineteen different proteins or protein fragments in 36 selected spots were identified by matrix-assisted laser-desorption ionization time of flight mass spectrometry (MS) or nano-electrospray tandem MS/MS. Some proteins were present throughout development (for example, cytosolic malate dehydrogenase), whereas others were associated with the early grain filling (ascorbate peroxidase) or desiccation (Cor14b) stages. Most noticeably, the development process is characterized by an accumulation of low-Mr α-amylase/trypsin inhibitors, serine protease inhibitors, and enzymes involved in protection against oxidative stress. We present examples of proteins not previously experimentally observed, differential extractability of thiol-bound proteins, and possible allele-specific spot variation. Our results both confirm and expand on knowledge gained from previous analyses of individual proteins involved in grain filling and maturation. PMID:12114584

  3. Seed development and maturation in early spring-flowering Galanthus nivalis and Narcissus pseudonarcissus continues post-shedding with little evidence of maturation in planta

    PubMed Central

    Newton, Rosemary J.; Hay, Fiona R.; Ellis, Richard H.

    2013-01-01

    Background and Aims Seeds of the moist temperate woodland species Galanthus nivalis and Narcissus pseudonarcissus, dispersed during spring or early summer, germinated poorly in laboratory tests. Seed development and maturation were studied to better understand the progression from developmental to germinable mode in order to improve seed collection and germination practices in these and similar species. Methods Phenology, seed mass, moisture content and ability to germinate and tolerate desiccation were monitored during seed development until shedding. Embryo elongation within seeds was investigated during seed development and under several temperature regimes after shedding. Key Results Seeds were shed at high moisture content (>59 %) with little evidence that dry mass accumulation or embryo elongation were complete. Ability to germinate developed prior to the ability of some seeds to tolerate enforced desiccation. Germination was sporadic and slow. Embryo elongation occurred post-shedding in moist environments, most rapidly at 20 °C in G. nivalis and 15 °C in N. pseudonarcissus. The greatest germination also occurred in these regimes, 78 and 48 %, respectively, after 700 d. Conclusions Seeds of G. nivalis and N. pseudonarcissus were comparatively immature at shedding and substantial embryo elongation occurred post-shedding. Seeds showed limited desiccation tolerance at dispersal. PMID:23478943

  4. MicroRNAs and their putative targets in Brassica napus seed maturation

    PubMed Central

    2013-01-01

    Background MicroRNAs (miRNAs) are 20–21 nucleotide RNA molecules that suppress the transcription of target genes and may also inhibit translation. Despite the thousands of miRNAs identified and validated in numerous plant species, only small numbers have been identified from the oilseed crop plant Brassica napus (canola) – especially in seeds. Results Using next-generation sequencing technologies, we performed a comprehensive analysis of miRNAs during seed maturation at 9 time points from 10 days after flowering (DAF) to 50 DAF using whole seeds and included separate analyses of radicle, hypocotyl, cotyledon, embryo, endosperm and seed coat tissues at 4 selected time points. We identified more than 500 conserved miRNA or variant unique sequences with >300 sequence reads and also found 10 novel miRNAs. Only 27 of the conserved miRNA sequences had been previously identified in B. napus (miRBase Release 18). More than 180 MIRNA loci were identified/annotated using the B. rapa genome as a surrogate for the B.napus A genome. Numerous miRNAs were expressed in a stage- or tissue-specific manner suggesting that they have specific functions related to the fine tuning of transcript abundance during seed development. miRNA targets in B. napus were predicted and their expression patterns profiled using microarray analyses. Global correlation analysis of the expression patterns of miRNAs and their targets revealed complex miRNA-target gene regulatory networks during seed development. The miR156 family was the most abundant and the majority of the family members were primarily expressed in the embryo. Conclusions Large numbers of miRNAs with diverse expression patterns, multiple-targeting and co-targeting of many miRNAs, and complex relationships between expression of miRNAs and targets were identified in this study. Several key miRNA-target expression patterns were identified and new roles of miRNAs in regulating seed development are suggested. miR156, miR159, miR172, mi

  5. Inference of Longevity-Related Genes from a Robust Coexpression Network of Seed Maturation Identifies Regulators Linking Seed Storability to Biotic Defense-Related Pathways

    PubMed Central

    Righetti, Karima; Vu, Joseph Ly; Pelletier, Sandra; Vu, Benoit Ly; Glaab, Enrico; Lalanne, David; Pasha, Asher; Patel, Rohan V.; Provart, Nicholas J.; Verdier, Jerome; Leprince, Olivier

    2015-01-01

    Seed longevity, the maintenance of viability during storage, is a crucial factor for preservation of genetic resources and ensuring proper seedling establishment and high crop yield. We used a systems biology approach to identify key genes regulating the acquisition of longevity during seed maturation of Medicago truncatula. Using 104 transcriptomes from seed developmental time courses obtained in five growth environments, we generated a robust, stable coexpression network (MatNet), thereby capturing the conserved backbone of maturation. Using a trait-based gene significance measure, a coexpression module related to the acquisition of longevity was inferred from MatNet. Comparative analysis of the maturation processes in M. truncatula and Arabidopsis thaliana seeds and mining Arabidopsis interaction databases revealed conserved connectivity for 87% of longevity module nodes between both species. Arabidopsis mutant screening for longevity and maturation phenotypes demonstrated high predictive power of the longevity cross-species network. Overrepresentation analysis of the network nodes indicated biological functions related to defense, light, and auxin. Characterization of defense-related wrky3 and nf-x1-like1 (nfxl1) transcription factor mutants demonstrated that these genes regulate some of the network nodes and exhibit impaired acquisition of longevity during maturation. These data suggest that seed longevity evolved by co-opting existing genetic pathways regulating the activation of defense against pathogens. PMID:26410298

  6. Breaking dormancy in freshly matured seeds of Elymus sibiricus, an important forage grass in the Tibetan Plateau.

    PubMed

    Zhang, J Q; Wang, Y R

    2015-09-22

    Elymus sibiricus L. is an important forage grass widely distributed in Asia and is usually a dominant species on Tibetan Plateau alpine grasslands. Here, we used the seed development indices of 1000 seed weight, seed moisture content, and seed viability to compare the seed characteristics at 10, 20, 30, 40, 50, and 60 days after anthesis (DAA) in five populations of E. sibiricus growing in Gannan, China. Additionally, seeds collected at 60 DAA were air-dried for one month, and the primary germination percentage (GP) was determined in the laboratory. Treatment of seeds with 0.2% KNO3, 100 mg/L cytokinin, and 500 mg/L GA3 were tested for their effects on dormancy. A primary GP of 16% was found after 12 d of 15/25°C incubation, with no differences among the five populations. The 1000 seed weight and seed viability steadily increased and moisture content continuously fell with DAA. The optimal harvest time for E. sibiricus in an alpine pasture was 50 DAA. No effect on dormancy was found after treating seeds with 0.2% KNO3 or 100 mg/L cytokinin; however, a low concentration of GA3 induced a prompt and synchronized germination. Freshly matured E. sibiricus seeds were classified to be in non-deep physiologically dormant. Treatment of seeds with GA3 before sowing enhanced the emergence speed and seedling uniformity in E. sibiricus.

  7. Spatial distribution of epigenetic modifications in Brachypodium distachyon embryos during seed maturation and germination.

    PubMed

    Wolny, Elzbieta; Braszewska-Zalewska, Agnieszka; Hasterok, Robert

    2014-01-01

    Seed development involves a plethora of spatially and temporally synchronised genetic and epigenetic processes. Although it has been shown that epigenetic mechanisms, such as DNA methylation and chromatin remodelling, act on a large number of genes during seed development and germination, to date the global levels of histone modifications have not been studied in a tissue-specific manner in plant embryos. In this study we analysed the distribution of three epigenetic markers, i.e. H4K5ac, H3K4me2 and H3K4me1 in 'matured', 'dry' and 'germinating' embryos of a model grass, Brachypodium distachyon (Brachypodium). Our results indicate that the abundance of these modifications differs considerably in various organs and tissues of the three types of Brachypodium embryos. Embryos from matured seeds were characterised by the highest level of H4K5ac in RAM and epithelial cells of the scutellum, whereas this modification was not observed in the coleorhiza. In this type of embryos H3K4me2 was most evident in epithelial cells of the scutellum. In 'dry' embryos H4K5ac was highest in the coleorhiza but was not present in the nuclei of the scutellum. H3K4me1 was the most elevated in the coleoptile but absent from the coleorhiza, whereas H3K4me2 was the most prominent in leaf primordia and RAM. In embryos from germinating seeds H4K5ac was the most evident in the scutellum but not present in the coleoptile, similarly H3K4me1 was the highest in the scutellum and very low in the coleoptile, while the highest level of H3K4me2 was observed in the coleoptile and the lowest in the coleorhiza. The distinct patterns of epigenetic modifications that were observed may be involved in the switch of the gene expression profiles in specific organs of the developing embryo and may be linked with the physiological changes that accompany seed desiccation, imbibition and germination.

  8. Loss of Mitochondrial Malate Dehydrogenase Activity Alters Seed Metabolism Impairing Seed Maturation and Post-Germination Growth in Arabidopsis1[OPEN

    PubMed Central

    2016-01-01

    Mitochondrial malate dehydrogenase (mMDH; EC 1.1.1.37) has multiple roles; the most commonly described is its catalysis of the interconversion of malate and oxaloacetate in the tricarboxylic acid cycle. The roles of mMDH in Arabidopsis (Arabidopsis thaliana) seed development and germination were investigated in mMDH1 and mMDH2 double knockout plants. A significant proportion of mmdh1mmdh2 seeds were nonviable and developed only to torpedo-shaped embryos, indicative of arrested seed embryo growth during embryogenesis. The viable mmdh1mmdh2 seeds had an impaired maturation process that led to slow germination rates as well as retarded post-germination growth, shorter root length, and decreased root biomass. During seed development, mmdh1mmdh2 showed a paler green phenotype than the wild type and exhibited deficiencies in reserve accumulation and reduced final seed biomass. The respiration rate of mmdh1mmdh2 seeds was significantly elevated throughout their maturation, consistent with the previously reported higher respiration rate in mmdh1mmdh2 leaves. Mutant seeds showed a consistently higher content of free amino acids (branched-chain amino acids, alanine, serine, glycine, proline, and threonine), differences in sugar and sugar phosphate levels, and lower content of 2-oxoglutarate. Seed-aging assays showed that quiescent mmdh1mmdh2 seeds lost viability more than 3 times faster than wild-type seeds. Together, these data show the important role of mMDH in the earliest phases of the life cycle of Arabidopsis. PMID:27208265

  9. Proteomic comparison between maturation drying and prematurely imposed drying of Zea mays seeds reveals a potential role of maturation drying in preparing proteins for seed germination, seedling vigor, and pathogen resistance.

    PubMed

    Wang, Wei-Qing; Ye, Jian-Qing; Rogowska-Wrzesinska, Adelina; Wojdyla, Katarzyna I; Jensen, Ole Nørregaard; Møller, Ian Max; Song, Song-Quan

    2014-02-07

    We have studied the role(s) of maturation drying in the acquisition of germinability, seedling vigor and pathogen resistance by comparing the proteome changes in maize embryo and endosperm during mature and prematurely imposed drying. Prematurely imposed dried seeds at 40 days after pollination (DAP) germinated almost as well as mature seeds (at 65 DAP), but their seedling growth was slower and they were seriously infected by fungi. A total of 80 and 114 proteins were identified to change at least two-fold (p < 0.05) in abundance during maturation drying in embryo and endosperm, respectively. Fewer proteins (48 and 59 in embryo and endosperm, respectively) changed in abundance during prematurely imposed drying. A number of proteins, 33 and 38 in embryo and endosperm, respectively, changed similarly in abundance during both maturation and prematurely imposed drying. Storage proteins were abundant in this group and may contribute to the acquisition of seed germinability. However, a relatively large number of proteins changed in the embryo (47 spots) and endosperm (76 spots) specifically during maturation drying. Among these proteins, storage proteins in the embryo and defense proteins in the endosperm may be particularly important for seedling vigor and resistance to fungal infection, respectively.

  10. Combining association mapping and transcriptomics identify HD2B histone deacetylase as a genetic factor associated with seed dormancy in Arabidopsis thaliana.

    PubMed

    Yano, Ryoichi; Takebayashi, Yumiko; Nambara, Eiji; Kamiya, Yuji; Seo, Mitsunori

    2013-06-01

    Seed dormancy is an important adaptive trait that enables germination at the proper time, thereby ensuring plant survival after germination. In Arabidopsis, considerable variation exists in the degree of seed dormancy among wild-type accessions (ecotypes). In this paper, we identify a plant-specific HD2 histone deacetylase gene, HD2B (At5g22650), as a genetic factor associated with seed dormancy. First, genome-wide association mapping of 113 accessions was used to identify single nucleotide polymorphisms that possibly explain natural variation for seed dormancy. Integration of genome-wide association mapping and transcriptome analysis during cold-induced dormancy cycling identified HD2B as the most plausible candidate gene, and quantitative RT-PCR analysis demonstrated that HD2B expression was up-regulated by cold and after-ripening (dry storage of mature seed), treatments that are known to break seed dormancy. Interestingly, quantitative RT-PCR analysis in 106 accessions revealed that the expression of HD2B in imbibed seeds was significantly suppressed in most of the dormant accessions compared with less-dormant accessions, suggesting that suppression of HD2B expression may be important to maintain seed dormancy in dormant accessions. In addition, transgenic seeds of a dormant Cvi-0 accession that carried a 2.5 kb genomic DNA fragment of HD2B cloned from a less-dormant Col-0 accession ((Col)HD2B/Cvi-0) exhibited reduced seed dormancy accompanied by enhanced expression of HD2B when after-ripened or cold-imbibed. Endogenous levels of gibberellin were found to be increased in the imbibed seeds of after-ripened (Col)HD2B/Cvi-0 compared with wild-type Cvi-0. These results suggest that HD2B plays a role in seed dormancy and/or germinability in Arabidopsis thaliana.

  11. Extraction, quantification, and antioxidant activities of phenolics from pericarp and seeds of bitter melons (Momordica charantia) harvested at three maturity stages (immature, mature, and ripe).

    PubMed

    Horax, Ronny; Hettiarachchy, Navam; Chen, Pengyin

    2010-04-14

    Bitter melon (Momordica charantia) is an exotic vegetable used for consumption and medicinal purposes mainly throughout Asia. Phenolics were extracted from pericarp (fleshy portion) and seeds of bitter melons harvested at three maturation stages (immature, mature, and ripe) using ethanol and water solvent systems. Total phenolic assessment demonstrated 80% of ethanol to be the optimal solvent level to extract phenolics either from pericarp or seed. Main phenolic constituents in the extracts were catechin, gallic acid, gentisic acid, chlorogenic acid, and epicatechin. Free radical scavenging assay using 2,2-diphenyl-1-picrylhydrazyl (DPPH) demonstrated the bitter melon extracts as slow rate free radical scavenging agents. There were low correlations between the total phenolic contents and antiradical power values of the extracts, suggesting a possible interaction among the phenolic constituents occurred. Bitter melon phenolic extracts contain natural antioxidant substances, and could be used as antioxidant agents in suitable food products.

  12. Catalog of genetic variants within mature microRNA seed regions in chicken

    PubMed Central

    Zorc, Minja; Omejec, Sandra; Tercic, Dusan; Holcman, Antonija; Dovc, Peter; Kunej, Tanja

    2015-01-01

    MicroRNA (miRNA) is a class of noncoding RNA important in posttranscriptional regulation of target genes. The regulation mechanism requires complementarity between target mRNA and the miRNA region responsible for their recognition and binding, also called the seed region. It has been estimated that each miRNA targets approximately 200 genes and genetic variability of miRNA genes has been associated with phenotypic variation and disease susceptibility in humans, livestock species, and model organisms. Polymorphisms in miRNA genes especially within the seed region could therefore represent biomarkers for phenotypic traits important in livestock animals. Using the updated Version 5.0 of our previously developed bioinformatics tool miRNA SNiPer we assembled polymorphic miRNA genes in chicken. Out of 740 miRNA genes 263 were polymorphic, among them 77 had SNPs located within the mature region, and 29 of them within the miRNA seed region. Because several polymorphisms in databases result from sequencing errors, we performed experimental validation of polymorphisms located within 4 selected miRNA genes in chicken (gga-mir-1614, −1644, −1648, and −1657). We confirmed the presence of nine polymorphisms and identified 3 additional novel polymorphisms within primary miRNA regions in chicken representing 3 layer-type breeds, one layer-type hybrid, and one meat-type intercrossed population. The developed catalog of mir-SNPs in chicken can serve researchers as a starting point for association studies dealing with poultry production traits and designing functional experiments. PMID:26175051

  13. Catalog of genetic variants within mature microRNA seed regions in chicken.

    PubMed

    Zorc, Minja; Omejec, Sandra; Tercic, Dusan; Holcman, Antonija; Dovc, Peter; Kunej, Tanja

    2015-09-01

    MicroRNA (miRNA) is a class of noncoding RNA important in posttranscriptional regulation of target genes. The regulation mechanism requires complementarity between target mRNA and the miRNA region responsible for their recognition and binding, also called the seed region. It has been estimated that each miRNA targets approximately 200 genes and genetic variability of miRNA genes has been associated with phenotypic variation and disease susceptibility in humans, livestock species, and model organisms. Polymorphisms in miRNA genes especially within the seed region could therefore represent biomarkers for phenotypic traits important in livestock animals. Using the updated Version 5.0 of our previously developed bioinformatics tool miRNA SNiPer we assembled polymorphic miRNA genes in chicken. Out of 740 miRNA genes 263 were polymorphic, among them 77 had SNPs located within the mature region, and 29 of them within the miRNA seed region. Because several polymorphisms in databases result from sequencing errors, we performed experimental validation of polymorphisms located within 4 selected miRNA genes in chicken (gga-mir-1614, -1644, -1648, and -1657). We confirmed the presence of nine polymorphisms and identified 3 additional novel polymorphisms within primary miRNA regions in chicken representing 3 layer-type breeds, one layer-type hybrid, and one meat-type intercrossed population. The developed catalog of mir-SNPs in chicken can serve researchers as a starting point for association studies dealing with poultry production traits and designing functional experiments.

  14. Cold stratification and exogenous nitrates entail similar functional proteome adjustments during Arabidopsis seed dormancy release.

    PubMed

    Arc, Erwann; Chibani, Kamel; Grappin, Philippe; Jullien, Marc; Godin, Béatrice; Cueff, Gwendal; Valot, Benoit; Balliau, Thierry; Job, Dominique; Rajjou, Loïc

    2012-11-02

    Despite having very similar initial pools of stored mRNAs and proteins in the dry state, mature Arabidopsis seeds can either proceed toward radicle protrusion or stay in a dormant state upon imbibition. Dormancy breaking, a prerequisite to germination completion, can be induced by different treatments though the underlying mechanisms remain elusive. Thus, we investigated the consequence of such treatments on the seed proteome. Two unrelated dormancy-releasing treatments were applied to dormant seeds, namely, cold stratification and exogenous nitrates, in combination with differential proteomic tools to highlight the specificities of the imbibed dormant state. The results reveal that both treatments lead to highly similar proteome adjustments. In the imbibed dormant state, enzymes involved in reserve mobilization are less accumulated and it appears that several energetically costly processes associated to seed germination and preparation for subsequent seedling establishment are repressed. Our data suggest that dormancy maintenance is associated to an abscisic-acid-dependent recapitulation of the late maturation program resulting in a higher potential to cope with environmental stresses. The comparison of the present results with previously published -omic data sets reinforces and extends the assumption that post-transcriptional, translational, and post-translational regulations are determinant for seed germination.

  15. Gene expression programs during Brassica oleracea seed maturation, osmopriming, and germination are indicators of progression of the germination process and the stress tolerance level.

    PubMed

    Soeda, Yasutaka; Konings, Maurice C J M; Vorst, Oscar; van Houwelingen, Adele M M L; Stoopen, Geert M; Maliepaard, Chris A; Kodde, Jan; Bino, Raoul J; Groot, Steven P C; van der Geest, Apolonia H M

    2005-01-01

    During seed maturation and germination, major changes in physiological status, gene expression, and metabolic events take place. Using chlorophyll sorting, osmopriming, and different drying regimes, Brassica oleracea seed lots of different maturity, stress tolerance, and germination behavior were created. Through careful physiological analysis of these seed lots combined with gene expression analysis using a dedicated cDNA microarray, gene expression could be correlated to physiological processes that occurred within the seeds. In addition, gene expression was studied during early stages of seed germination, prior to radicle emergence, since very little detailed information of gene expression during this process is available. During seed maturation expression of many known seed maturation genes, such as late-embryogenesis abundant or storage-compound genes, was high. Notably, a small but distinct subgroup of the maturation genes was found to correlate to seed stress tolerance in osmoprimed and dried seeds. Expression of these genes rapidly declined during priming and/or germination in water. The majority of the genes on the microarray were up-regulated during osmopriming and during germination on water, confirming the hypothesis that during osmopriming, germination-related processes are initiated. Finally, a large group of genes was up-regulated during germination on water, but not during osmopriming. These represent genes that are specific to germination in water. Germination-related gene expression was found to be partially reversible by physiological treatments such as slow drying of osmoprimed seeds. This correlated to the ability of seeds to withstand stress.

  16. Assessment of Soybean Flowering and Seed Maturation Time in Different Latitude Regions of Kazakhstan

    PubMed Central

    Abugalieva, Saule; Didorenko, Svetlana; Anuarbek, Shynar; Volkova, Lubov; Gerasimova, Yelena; Sidorik, Ivan

    2016-01-01

    Soybean is still a minor crop in Kazakhstan despite an increase in planting area from 4,500 to 11,400 km2 between 2006 and 2014. However, the Government’s recently accepted crop diversification policy projects the expansion of soybean cultivation area to more than 40,000 km2 by 2020. The policy is targeting significant expansion of soybean production in South-eastern, Eastern, and Northern regions of Kazakhstan. Successful realization of this policy requires a comprehensive characterization of plant growth parameters to identify optimal genotypes with appropriate adaptive phenotypic traits. In this study 120 soybean accessions from different parts of the World, including 18 accessions from Kazakhstan, were field tested in South-eastern, Eastern, and Northern regions of the country. These studies revealed positive correlation of yield with flowering time in Northern Kazakhstan, with seed maturity time in Eastern Kazakhstan, and with both these growth stages in South-eastern Kazakhstan. It was determined that in South-eastern, Eastern and Northern regions of Kazakhstan the majority of productive genotypes were in maturity groups MGI, MG0, and MG00, respectively. The accessions were genotyped for four major maturity genes (E1, E2, E3, and E4) in order to assess the relationship between E loci and agronomic traits. The allele composition of the majority of accessions was e1-as/e2/E3/E4 (specific frequencies 57.5%, 91.6%, 65.0%, and 63.3%, respectively). Accessions with dominant alleles in either E3 or E4 genes showed higher yield in all three regions, although the specific genotype associated with greatest productivity was different for each site. Genotype-environment interaction studies based on yield performances suggest that South-east and East regions formed one mega-environment, which was well separated from North Kazakhstan where significantly earlier time to maturation is required. The results provide important insights into the relationship between genetic

  17. WRINKLED1 specifies the regulatory action of LEAFY COTYLEDON2 towards fatty acid metabolism during seed maturation in Arabidopsis.

    PubMed

    Baud, Sébastien; Mendoza, Monica Santos; To, Alexandra; Harscoët, Erwana; Lepiniec, Loïc; Dubreucq, Bertrand

    2007-06-01

    The WRINKLED1 (WRI1) transcription factor has been shown to play a role of the utmost importance during oil accumulation in maturing seeds of Arabidopsis thaliana. However, little is known about the regulatory processes involved. In this paper, comprehensive functional analyses of three new mutants corresponding to null alleles of wri1 confirm that the induction of WRI1 is a prerequisite for fatty acid synthesis and is important for normal embryo development. The strong expression of WRI1 specifically detected at the onset of the maturation phase in oil-accumulating tissues of A. thaliana seeds is fully consistent with this function. Complementation experiments carried out with various seed-specific promoters emphasized the importance of a tight regulation of WRI1 expression for proper oil accumulation, raising the question of the factors controlling WRI1 transcription. Interestingly, molecular and genetic analyses using an inducible system demonstrated that WRI1 is a target of LEAFY COTYLEDON2 and is necessary for the regulatory action of LEC2 towards fatty acid metabolism. In addition to this, quantitative RT-PCR experiments suggested that several genes encoding enzymes of late glycolysis, the fatty acid synthesis pathway, and the biotin and lipoic acid biosynthetic pathways are targets of WRI1. Taken together, these results indicate new relationships in the regulatory model for the control of oil synthesis in maturing A. thaliana seeds. In addition, they exemplify how metabolic and developmental processes affecting the developing embryo can be coordinated at the molecular level.

  18. The role of the persistent fruit wall in seed water regulation in Raphanus raphanistrum (Brassicaceae)

    PubMed Central

    Cousens, Roger D.; Young, Kenneth R.; Tadayyon, Ali

    2010-01-01

    Background and Aims Dry fruits remain around the seeds at dispersal in a number of species, especially the Brassicaceae. Explanations for this vary, but usually involve mechanisms of innate dormancy. We speculate that, instead, a persistent fruit may give additional protection through control of dehydration, to species growing in arid or Mediterranean environments where water is sporadic. Methods X-rays and weight measurements were used to determine the extent to which Raphanus raphanistrum seeds within mature fruits imbibe water, and germination tests determined the roles of the fruit and seed coat in seed dormancy. Rates of water uptake and desiccation, and seedling emergence were compared with and without the fruit. Finally, germinability of seeds extracted from fruits was determined after various periods of moist conditions followed by a range of dry conditions. Key Results Most seeds rapidly take up water within the fruit, but they do not fully imbibe when compared with naked seeds. The seed coat is more important than the dry fruit wall in maintaining seed dormancy. The presence of a dry fruit slows emergence from the soil by up to 6–8 weeks. The fruit slows the rate of desiccation of the seed to a limited extent. The presence of the fruit for a few days during imbibition somehow primes more seeds to germinate than if the fruit is absent; longer moist periods within the pod appear to induce dormancy. Conclusions The fruit certainly modifies the seed environment as external conditions change between wet and dry, but not to a great extent. The major role seems to be: (a) the physical restriction of imbibition and germination; and (b) the release and then re-imposition of dormancy within the seed. The ecological significance of the results requires more research under field conditions. PMID:19889801

  19. SCARECROW-LIKE15 interacts with HISTONE DEACETYLASE19 and is essential for repressing the seed maturation programme

    PubMed Central

    Gao, Ming-Jun; Li, Xiang; Huang, Jun; Gropp, Gordon M.; Gjetvaj, Branimir; Lindsay, Donna L.; Wei, Shu; Coutu, Cathy; Chen, Zhixiang; Wan, Xiao-Chun; Hannoufa, Abdelali; Lydiate, Derek J.; Gruber, Margaret Y.; Chen, Z. Jeffrey; Hegedus, Dwayne D.

    2015-01-01

    Epigenetic regulation of gene expression is critical for controlling embryonic properties during the embryo-to-seedling phase transition. Here we report that a HISTONE DEACETYLASE19 (HDA19)-associated regulator, SCARECROW-LIKE15 (SCL15), is essential for repressing the seed maturation programme in vegetative tissues. SCL15 is expressed in and GFP-tagged SCL15 predominantly localizes to, the vascular bundles particularly in the phloem companion cells and neighbouring specialized cells. Mutation of SCL15 leads to a global shift in gene expression in seedlings to a profile resembling late embryogenesis in seeds. In scl15 seedlings, many genes involved in seed maturation are markedly derepressed with concomitant accumulation of seed 12S globulin; this is correlated with elevated levels of histone acetylation at a subset of seed-specific loci. SCL15 physically interacts with HDA19 and direct targets of HDA19–SCL15 association are identified. These studies reveal that SCL15 acts as an HDA19-associated regulator to repress embryonic traits in seedlings. PMID:26129778

  20. Direct Gene Transfer into Plant Mature Seeds via Electroporation After Vacuum Treatment

    NASA Astrophysics Data System (ADS)

    Hagio, Takashi

    A number of direct gene transfer methods have been used successfully in plant genetic engineering, providing powerful tools to investigate fundamental and applied problems in plant biology (Chowrira et al., 1996; D'halluin et al., 1992; Morandini and Salamini, 2003; Rakoczy-Trojanowska, 2002; Songstad et al., 1995). In cereals, several methods have been found to be suitable for obtaining transgenic plant; these include bombardment of scutellum (Hagio et al., 1995) and inflorescence cultures (He et al., 2001), and silicon carbide fiber-mediated DNA delivery (Asano et al., 1991) and Agrobacterium tumefaciens transformation (Potrykus, 1990). Electroporation of cereal protoplasts also has proved successful but it involves prolonged cell treatments and generally is limited by the difficulties of regeneration from cereal protoplast cultures (Fromm et al., 1987). Many laboratories worldwide are now using Agrobacterium as a vehicle for routine production of transgenic crop plants. The primary application of the particle system (Klein et al., 1987) has been for transformation of species recalcitrant to conventional Agrobacterium (Binns, 1990) or protoplast methods. But these conventional methods can be applied to the species and varieties that are amenable to tissue culture (Machii et al., 1998). Mature seeds are readily available and free from the seasonal limits that immature embryo, inflorescence, and anther have. This method enables us to produce transgenic plants without time-consuming tissue culture process.

  1. Crystal structure of mature 2S albumin from Moringa oleifera seeds.

    PubMed

    Ullah, Anwar; Mariutti, Ricardo Barros; Masood, Rehana; Caruso, Icaro Putinhon; Costa, Gustavo Henrique Gravatim; Millena de Freita, Cristhyane; Santos, Camila Ramos; Zanphorlin, Leticia Maria; Rossini Mutton, Márcia Justino; Murakami, Mario Tyago; Arni, Raghuvir Krishnaswamy

    2S albumins, the seed storage proteins, are the primary sources of carbon and nitrogen and are involved in plant defense. The mature form of Moringa oleifera (M. oleifera), a chitin binding protein isoform 3-1 (mMo-CBP3-1) a thermostable antifungal, antibacterial, flocculating 2S albumin is widely used for the treatment of water and is potentially interesting for the development of both antifungal drugs and transgenic crops. The crystal structure of mMo-CBP3-1 determined at 1.7 Å resolution demonstrated that it is comprised of two proteolytically processed α-helical chains, stabilized by four disulfide bridges that is stable, resistant to pH changes and has a melting temperature (TM) of approximately 98 °C. The surface arginines and the polyglutamine motif are the key structural factors for the observed flocculating, antibacterial and antifungal activities. This represents the first crystal structure of a 2S albumin and the model of the pro-protein indicates the structural changes that occur upon formation of mMo-CBP3-1 and determines the structural motif and charge distribution patterns for the diverse observed activities.

  2. Differential Contribution of Malic Enzymes during Soybean and Castor Seeds Maturation

    PubMed Central

    Righini, Silvana; Badia, Mariana Beatriz; Andreo, Carlos Santiago; Drincovich, María Fabiana; Saigo, Mariana

    2016-01-01

    Malic enzymes (ME) catalyze the decarboxylation of malate generating pyruvate, CO2 and NADH or NADPH. In some organisms it has been established that ME is involved in lipids biosynthesis supplying carbon skeletons and reducing power. In this work we studied the MEs of soybean and castor, metabolically different oilseeds. The comparison of enzymatic activities, transcript profiles and organic acid contents suggest different metabolic strategies operating in soybean embryo and castor endosperm in order to generate precursors for lipid biosynthesis. In castor, the malate accumulation pattern agrees with a central role of this metabolite in the provision of carbon to plastids, where the biosynthesis of fatty acids occurs. In this regard, the genome of castor possesses a single gene encoding a putative plastidic NADP-ME, whose expression level is high when lipid deposition is active. On the other hand, NAD-ME showed an important contribution to the maturation of soybean embryos, perhaps driving the carbon relocation from mitochondria to plastids to support the fatty acids synthesis in the last stages of seed filling. These findings provide new insights into intermediary metabolism in oilseeds and provide new biotechnological targets to improve oil yields. PMID:27347875

  3. New cross talk between ROS, ABA and auxin controlling seed maturation and germination unraveled in APX6 deficient Arabidopsis seeds.

    PubMed

    Chen, Changming; Twito, Shir; Miller, Gad

    2014-01-01

    Successful execution of germination program greatly depends on the seeds' oxidative homeostasis. We recently identified new roles for the H2O2-reducing enzyme ascorbate peroxidase 6 (APX6) in germination control and seeds' stress tolerance. APX6 replaces APX1 as the dominant APX in dry seeds, and its loss-of-function results in reduced germination due to over accumulation of ROS and oxidative damage. Metabolic analyses in dry apx6 seeds, revealed altered homeostasis of primary metabolites including accumulation of TCA cycle metabolites, ABA and auxin, supporting a novel role for APX6 in regulating cellular metabolism. Increased sensitivity of apx6 mutants to ABA or IAA in germination assays indicated impaired perception of these signals. Relative suppression of ABI3 and ABI5 expression, and induction of ABI4, suggested the activation of a signaling route inhibiting germination in apx6 seeds that is independent of ABI3. Here we provide additional evidence linking ABI4 with ABA- and auxin-controlled inhibition of germination and suggest a hypothetical model for the role of APX6 in the regulation of the crosstalk between these hormones and ROS.

  4. Proteomics analysis in mature seed of four peanut cultivars using two-dimensional gel electrophoresis reveals distinct differential expression of storage, anti-nutritive, and allergenic proteins

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Protein profiles of total seed proteins isolated from mature seeds of four peanut cultivars, New Mexico Valencia C (NM Valencia C), Tamspan 90, Georgia Green, and NC-7, were studied using two-dimensional gel electrophoresis coupled with nano electrospray ionization liquid chromatography tandem mass ...

  5. ZEAXANTHIN EPOXIDASE Activity Potentiates Carotenoid Degradation in Maturing Seed1[OPEN

    PubMed Central

    Magallanes-Lundback, Maria; Lipka, Alexander E.; Angelovici, Ruthie; DellaPenna, Dean

    2016-01-01

    Elucidation of the carotenoid biosynthetic pathway has enabled altering the composition and content of carotenoids in various plants, but to achieve desired nutritional impacts, the genetic components regulating carotenoid homeostasis in seed, the plant organ consumed in greatest abundance, must be elucidated. We used a combination of linkage mapping, genome-wide association studies (GWAS), and pathway-level analysis to identify nine loci that impact the natural variation of seed carotenoids in Arabidopsis (Arabidopsis thaliana). ZEAXANTHIN EPOXIDASE (ZEP) was the major contributor to carotenoid composition, with mutants lacking ZEP activity showing a remarkable 6-fold increase in total seed carotenoids relative to the wild type. Natural variation in ZEP gene expression during seed development was identified as the underlying mechanism for fine-tuning carotenoid composition, stability, and ultimately content in Arabidopsis seed. We previously showed that two CAROTENOID CLEAVAGE DIOXYGENASE enzymes, CCD1 and CCD4, are the primary mediators of seed carotenoid degradation, and here we demonstrate that ZEP acts as an upstream control point of carotenoid homeostasis, with ZEP-mediated epoxidation targeting carotenoids for degradation by CCD enzymes. Finally, four of the nine loci/enzymatic activities identified as underlying natural variation in Arabidopsis seed carotenoids also were identified in a recent GWAS of maize (Zea mays) kernel carotenoid variation. This first comparison of the natural variation in seed carotenoids in monocots and dicots suggests a surprising overlap in the genetic architecture of these traits between the two lineages and provides a list of likely candidates to target for selecting seed carotenoid variation in other species. PMID:27208224

  6. Rice aldehyde dehydrogenase7 is needed for seed maturation and viability.

    PubMed

    Shin, Jun-Hye; Kim, Sung-Ryul; An, Gynheung

    2009-02-01

    Aldehyde dehydrogenases (ALDHs) catalyze the irreversible oxidation of a wide range of reactive aldehydes to their corresponding carboxylic acids. Although the proteins have been studied from various organisms and at different growth stages, their roles in seed development have not been well elucidated. We obtained T-DNA insertional mutants in OsALDH7, which is remarkably inducible by oxidative and abiotic stresses. Interestingly, endosperms from the osaldh7 null mutants accumulated brown pigments during desiccation and storage. Extracts from the mutant seeds showed a maximum absorbance peak at 360 nm, the wavelength that melanoidin absorbs. Under UV light, those extracts also exhibited much stronger fluorescence than the wild type, suggesting that the pigments are melanoidin. These pigments started to accumulate in the late seed developmental stage, the time when OsALDH7 expression began to increase significantly. Purified OsALDH7 protein showed enzyme activities to malondialdehyde, acetaldehyde, and glyceraldehyde. These results suggest that OsALDH7 is involved in removing various aldehydes formed by oxidative stress during seed desiccation. The mutant seeds were more sensitive to our accelerated aging treatment and accumulated more malondialdehyde than the wild type. These data imply that OsALDH7 plays an important role in maintaining seed viability by detoxifying the aldehydes generated by lipid peroxidation.

  7. HSI2 Repressor Recruits MED13 and HDA6 to Down-Regulate Seed Maturation Gene Expression Directly During Arabidopsis Early Seedling Growth.

    PubMed

    Chhun, Tory; Chong, Suet Yen; Park, Bong Soo; Wong, Eriko Chi Cheng; Yin, Jun-Lin; Kim, Mijung; Chua, Nam-Hai

    2016-08-01

    Arabidopsis HSI2 (HIGH-LEVEL EXPRESSION OF SUGAR-INDUCIBLE GENE 2) which carries a EAR (ERF-associated amphiphilic repression) motif acts as a repressor of seed maturation genes and lipid biosynthesis, whereas MEDIATOR (MED) is a conserved multiprotein complex linking DNA-bound transcription factors to RNA polymerase II transcription machinery. How HSI2 executes its repressive function through MED is hitherto unknown. Here, we show that HSI2 and its homolog, HSI2-lik (HSL1), are able to form homo- and heterocomplexes. Both factors bind to the TRAP240 domain of MED13, a subunit of the MED CDK8 module. Mutant alleles of the med13 mutant show elevated seed maturation gene expression and increased lipid accumulation in cotyledons; in contrast, HSI2- or MED13-overexpressing plants display the opposite phenotypes. The overexpression phenotypes of HSI2 and MED13 are abolished in med13 and hsi2 hsl1, respectively, indicating that HSI2 and MED13 together are required for these functions. The HSI2 C-terminal region interacts with HDA6, whose overexpression also reduces seed maturation gene expression and lipid accumulation. Moreover, HSI2, MED13 and HDA6 bind to the proximal promoter and 5'-coding regions of seed maturation genes. Taken together, our results suggest that HSI2 recruits MED13 and HDA6 to suppress directly a subset of seed maturation genes post-germination.

  8. Carbohydrate composition of mature and immature faba bean (Vicia faba L.) seeds from diverse origins

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Faba bean (Vicia faba L.) is a valuable pulse crop for human consumption. The low molecular weight carbohydrates (LMWC): glucose, fructose, sucrose (GFS), raffinose, stachyose, and verbascose (RFO- raffinose family oligosaccharides) in faba bean seeds are significant components of human nutrition an...

  9. Fatty Acid Composition of Developing Sea Buckthorn (Hippophae rhamnoides L.) Berry and the Transcriptome of the Mature Seed

    PubMed Central

    Fatima, Tahira; Snyder, Crystal L.; Schroeder, William R.; Cram, Dustin; Datla, Raju; Wishart, David; Weselake, Randall J.; Krishna, Priti

    2012-01-01

    Background Sea buckthorn (Hippophae rhamnoides L.) is a hardy, fruit-producing plant known historically for its medicinal and nutraceutical properties. The most recognized product of sea buckthorn is its fruit oil, composed of seed oil that is rich in essential fatty acids, linoleic (18∶2ω-6) and α-linolenic (18∶3ω-3) acids, and pulp oil that contains high levels of monounsaturated palmitoleic acid (16∶1ω-7). Sea buckthorn is fast gaining popularity as a source of functional food and nutraceuticals, but currently has few genomic resources; therefore, we explored the fatty acid composition of Canadian-grown cultivars (ssp. mongolica) and the sea buckthorn seed transcriptome using the 454 GS FLX sequencing technology. Results GC-MS profiling of fatty acids in seeds and pulp of berries indicated that the seed oil contained linoleic and α-linolenic acids at 33–36% and 30–36%, respectively, while the pulp oil contained palmitoleic acid at 32–42%. 454 sequencing of sea buckthorn cDNA collections from mature seeds yielded 500,392 sequence reads, which identified 89,141 putative unigenes represented by 37,482 contigs and 51,659 singletons. Functional annotation by Gene Ontology and computational prediction of metabolic pathways indicated that primary metabolism (protein>nucleic acid>carbohydrate>lipid) and fatty acid and lipid biosynthesis pathways were highly represented categories. Sea buckthorn sequences related to fatty acid biosynthesis genes in Arabidopsis were identified, and a subset of these was examined for transcript expression at four developing stages of the berry. Conclusion This study provides the first comprehensive genomic resources represented by expressed sequences for sea buckthorn, and demonstrates that the seed oil of Canadian-grown sea buckthorn cultivars contains high levels of linoleic acid and α-linolenic acid in a close to 1∶1 ratio, which is beneficial for human health. These data provide the foundation for further studies on

  10. Proteomic Analysis of the Protein Expression Profile in the Mature Nigella sativa (Black Seed).

    PubMed

    Alanazi, Ibrahim O; Benabdelkamel, Hicham; Alfadda, Assim A; AlYahya, Sami A; Alghamdi, Waleed M; Aljohi, Hasan A; Almalik, Abdulaziz; Masood, Afshan

    2016-08-01

    Nigella sativa (N. sativa) seed has been used as an important nutritional flavoring agent and in traditional medicine for treating many illnesses since ancient times. Understanding the proteomic component of the seed may lead to enhance the understanding of its structural and biological functional complexity. In this study, we have analyzed its proteome profile based on gel-based proteome mapping technique that includes one-dimensional gel electrophoresis followed by liquid chromatography and tandem mass spectrometry strategy. We have not come across any such studies that have been performed in N. sativa seeds up to date. A total of 277 proteins were identified, and their functional, metabolic, and location-wise annotations were carried out using the UniProt database. The majority of proteins identified in the proteome dataset based on their function were those involved in enzyme catalytic activity, nucleotide binding, and protein binding while the major cellular processes included regulation of biological process followed by regulation of secondary biological process, cell organization and biogenesis, protein metabolism, and transport. The identified proteome was localized mainly to the nucleus then to the cytoplasm, plasma membrane, mitochondria, plastid, and others. A majority of the proteins were involved in biochemical pathways involving carbohydrate metabolism, amino acid and shikimate pathway, lipid metabolism, nucleotide, cell organization and biogenesis, transport, and defense processes. The identified proteins in the dataset help to improve our understanding of the pathways involved in N. sativa seed metabolism and its biochemical features and detail out useful information that may help to utilize these proteins. This study could thus pave a way for future further high-throughput studies using a more targeted proteomic approach.

  11. [Effects of high temperature and humidity stress at the physiological maturity stage on seed vigor, main nutrients and coat structure of spring soybean].

    PubMed

    Shu, Ying-Jie; Wang, Shuang; Tao, Yuan; Song, Li-Run; Huang, Li-Yan; Zhou, Yu-Li; Ma, Hao

    2014-05-01

    A pot experiment was conducted to investigate the effects of high temperature and humidity stress [(40 +/- 2) degrees C/(30 +/- 2) degrees C, RH (95 +/- 5)%/(70 +/- 5)%, 10 h/14 h (day/night)] at the physiological maturity stage of two spring soybean cultivars (Xiangdou No. 3 and Ningzhen No. 1) on seed vigor indices, main nutritional components and coat anatomical structure. High temperature and humidity stress were found to cause the decrease of seed viability, germination potential, and germination percentage as well as the dehydrogenase and acid phosphatase activities, but increased the seed cell membrane permeability as well as H+, soluble sugar and leucine levels in the seed soaking liquid of each cultivar. Moreover, the stress led to irregular changes of seed oil and protein contents and alteration of anatomical structure of episperm and hilum in the two cultivars. A shortterm stress (less than 5 h) had no significant impact on seed vigor, but a long-term one (more than 48 h) caused rapid decrease of seed vigor indices. Xiangdou No. 3 showed less decreases in seed germination potential and enzyme activities, and less increase in extravasation content in the seed soaking liquid, had compact seed coat and intact hilum, suggesting it was more resistant to high temperature and humidity stress.

  12. A Regulatory Network-Based Approach Dissects Late Maturation Processes Related to the Acquisition of Desiccation Tolerance and Longevity of Medicago truncatula Seeds1[C][W][OPEN

    PubMed Central

    Verdier, Jerome; Lalanne, David; Pelletier, Sandra; Torres-Jerez, Ivone; Righetti, Karima; Bandyopadhyay, Kaustav; Leprince, Olivier; Chatelain, Emilie; Vu, Benoit Ly; Gouzy, Jerome; Gamas, Pascal; Udvardi, Michael K.; Buitink, Julia

    2013-01-01

    In seeds, desiccation tolerance (DT) and the ability to survive the dry state for prolonged periods of time (longevity) are two essential traits for seed quality that are consecutively acquired during maturation. Using transcriptomic and metabolomic profiling together with a conditional-dependent network of global transcription interactions, we dissected the maturation events from the end of seed filling to final maturation drying during the last 3 weeks of seed development in Medicago truncatula. The network revealed distinct coexpression modules related to the acquisition of DT, longevity, and pod abscission. The acquisition of DT and dormancy module was associated with abiotic stress response genes, including late embryogenesis abundant (LEA) genes. The longevity module was enriched in genes involved in RNA processing and translation. Concomitantly, LEA polypeptides accumulated, displaying an 18-d delayed accumulation compared with transcripts. During maturation, gulose and stachyose levels increased and correlated with longevity. A seed-specific network identified known and putative transcriptional regulators of DT, including ABSCISIC ACID-INSENSITIVE3 (MtABI3), MtABI4, MtABI5, and APETALA2/ ETHYLENE RESPONSE ELEMENT BINDING PROTEIN (AtAP2/EREBP) transcription factor as major hubs. These transcriptional activators were highly connected to LEA genes. Longevity genes were highly connected to two MtAP2/EREBP and two basic leucine zipper transcription factors. A heat shock factor was found at the transition of DT and longevity modules, connecting to both gene sets. Gain- and loss-of-function approaches of MtABI3 confirmed 80% of its predicted targets, thereby experimentally validating the network. This study captures the coordinated regulation of seed maturation and identifies distinct regulatory networks underlying the preparation for the dry and quiescent states. PMID:23929721

  13. A regulatory network-based approach dissects late maturation processes related to the acquisition of desiccation tolerance and longevity of Medicago truncatula seeds.

    PubMed

    Verdier, Jerome; Lalanne, David; Pelletier, Sandra; Torres-Jerez, Ivone; Righetti, Karima; Bandyopadhyay, Kaustav; Leprince, Olivier; Chatelain, Emilie; Vu, Benoit Ly; Gouzy, Jerome; Gamas, Pascal; Udvardi, Michael K; Buitink, Julia

    2013-10-01

    In seeds, desiccation tolerance (DT) and the ability to survive the dry state for prolonged periods of time (longevity) are two essential traits for seed quality that are consecutively acquired during maturation. Using transcriptomic and metabolomic profiling together with a conditional-dependent network of global transcription interactions, we dissected the maturation events from the end of seed filling to final maturation drying during the last 3 weeks of seed development in Medicago truncatula. The network revealed distinct coexpression modules related to the acquisition of DT, longevity, and pod abscission. The acquisition of DT and dormancy module was associated with abiotic stress response genes, including late embryogenesis abundant (LEA) genes. The longevity module was enriched in genes involved in RNA processing and translation. Concomitantly, LEA polypeptides accumulated, displaying an 18-d delayed accumulation compared with transcripts. During maturation, gulose and stachyose levels increased and correlated with longevity. A seed-specific network identified known and putative transcriptional regulators of DT, including ABSCISIC ACID-INSENSITIVE3 (MtABI3), MtABI4, MtABI5, and APETALA2/ ETHYLENE RESPONSE ELEMENT BINDING PROTEIN (AtAP2/EREBP) transcription factor as major hubs. These transcriptional activators were highly connected to LEA genes. Longevity genes were highly connected to two MtAP2/EREBP and two basic leucine zipper transcription factors. A heat shock factor was found at the transition of DT and longevity modules, connecting to both gene sets. Gain- and loss-of-function approaches of MtABI3 confirmed 80% of its predicted targets, thereby experimentally validating the network. This study captures the coordinated regulation of seed maturation and identifies distinct regulatory networks underlying the preparation for the dry and quiescent states.

  14. Oxidation and cyclization of casbene in the biosynthesis of Euphorbia factors from mature seeds of Euphorbia lathyris L.

    PubMed Central

    Luo, Dan; Callari, Roberta; Hamberger, Britta; Wubshet, Sileshi Gizachew; Nielsen, Morten T.; Andersen-Ranberg, Johan; Hallström, Björn M.; Cozzi, Federico; Lindberg Møller, Birger; Hamberger, Björn

    2016-01-01

    The seed oil of Euphorbia lathyris L. contains a series of macrocyclic diterpenoids known as Euphorbia factors. They are the current industrial source of ingenol mebutate, which is approved for the treatment of actinic keratosis, a precancerous skin condition. Here, we report an alcohol dehydrogenase-mediated cyclization step in the biosynthetic pathway of Euphorbia factors, illustrating the origin of the intramolecular carbon–carbon bonds present in lathyrane and ingenane diterpenoids. This unconventional cyclization describes the ring closure of the macrocyclic diterpene casbene. Through transcriptomic analysis of E. lathyris L. mature seeds and in planta functional characterization, we identified three enzymes involved in the cyclization route from casbene to jolkinol C, a lathyrane diterpene. These enzymes include two cytochromes P450 from the CYP71 clan and an alcohol dehydrogenase (ADH). CYP71D445 and CYP726A27 catalyze regio-specific 9-oxidation and 5-oxidation of casbene, respectively. When coupled with these P450-catalyzed monooxygenations, E. lathyris ADH1 catalyzes dehydrogenation of the hydroxyl groups, leading to the subsequent rearrangement and cyclization. The discovery of this nonconventional cyclization may provide the key link to complete elucidation of the biosynthetic pathways of ingenol mebutate and other bioactive macrocyclic diterpenoids. PMID:27506796

  15. Proteomic analysis of mature soybean seeds from the Chernobyl area suggests plant adaptation to the contaminated environment.

    PubMed

    Danchenko, Maksym; Skultety, Ludovit; Rashydov, Namik M; Berezhna, Valentyna V; Mátel, L'ubomír; Salaj, Terézia; Pret'ová, Anna; Hajduch, Martin

    2009-06-01

    The explosion in one of the four reactors of the Chernobyl Nuclear Power Plant (CNPP, Chernobyl) caused the worst nuclear environmental disaster ever seen. Currently, 23 years after the accident, the soil in the close vicinity of CNPP is still significantly contaminated with long-living radioisotopes, such as (137)Cs. Despite this contamination, the plants growing in Chernobyl area were able to adapt to the radioactivity, and survive. The aim of this study was to investigate plant adaptation mechanisms toward permanently increased level of radiation using a quantitative high-throughput proteomics approach. Soybeans of a local variety (Soniachna) were sown in contaminated and control fields in the Chernobyl region. Mature seeds were harvested and the extracted proteins were subjected to two-dimensional gel electrophoresis (2-DE). In total, 9.2% of 698 quantified protein spots on 2-D gel were found to be differentially expressed with a p-value seed storage proteins are involved in plant adaptation mechanism to radioactivity in the Chernobyl region.

  16. Micro-CT observations of the 3D distribution of calcium oxalate crystals in cotyledons during maturation and germination in Lotus miyakojimae seeds.

    PubMed

    Yamauchi, Daisuke; Tamaoki, Daisuke; Hayami, Masato; Takeuchi, Miyuki; Karahara, Ichirou; Sato, Mayuko; Toyooka, Kiminori; Nishioka, Hiroshi; Terada, Yasuko; Uesugi, Kentaro; Takano, Hidekazu; Kagoshima, Yasushi; Mineyuki, Yoshinobu

    2013-06-01

    The cotyledon of legume seeds is a storage organ that provides nutrients for seed germination and seedling growth. The spatial and temporal control of the degradation processes within cotyledons has not been elucidated. Calcium oxalate (CaOx) crystals, a common calcium deposit in plants, have often been reported to be present in legume seeds. In this study, micro-computed tomography (micro-CT) was employed at the SPring-8 facility to examine the three-dimensional distribution of crystals inside cotyledons during seed maturation and germination of Lotus miyakojimae (previously Lotus japonicus accession Miyakojima MG-20). Using this technique, we could detect the outline of the embryo, void spaces in seeds and the cotyledon venation pattern. We found several sites that strongly inhibited X-ray transmission within the cotyledons. Light and polarizing microscopy confirmed that these areas corresponded to CaOx crystals. Three-dimensional observations of dry seeds indicated that the CaOx crystals in the L. miyakojimae cotyledons were distributed along lateral veins; however, their distribution was limited to the abaxial side of the procambium. The CaOx crystals appeared at stage II (seed-filling stage) of seed development, and their number increased in dry seeds. The number of crystals in cotyledons was high during germination, suggesting that CaOx crystals are not degraded for their calcium supply. Evidence for the conservation of CaOx crystals in cotyledons during the L. miyakojimae germination process was also supported by the biochemical measurement of oxalic acid levels.

  17. Tracking sesamin synthase gene expression through seed maturity in wild and cultivated sesame species--a domestication footprint.

    PubMed

    Pathak, N; Bhaduri, A; Bhat, K V; Rai, A K

    2015-09-01

    Sesamin and sesamolin are the major oil-soluble lignans present in sesame seed, having a wide range of biological functions beneficial to human health. Understanding sesame domestication history using sesamin synthase gene expression could enable delineation of the sesame putative progenitor. This report examined the functional expression of sesamin synthase (CYP81Q1) during capsule maturation (0-40 days after flowering) in three wild Sesamum species and four sesame cultivars. Among the cultivated accessions, only S. indicum (CO-1) exhibited transcript abundance of sesamin synthase along with high sesamin content similar to S. malabaricum, while the other cultivated sesame showed low expression. The sesamin synthase expression analysis, coupled with quantification of sesamin level, indicates that sesamin synthase was not positively favoured during domestication. The sesamin synthase expression pattern and lignan content, along with phylogenetic analysis suggested a close relationship of cultivated sesame and the wild species S. malabaricum. The high genetic identity between the two species S. indicum and S. malabaricum points towards the role of the putative progenitor S. malabaricum in sesame breeding programmes to broaden the genetic base of sesame cultivars. This study emphasises the need to investigate intraspecific and interspecific variation in the primary, secondary and tertiary gene pools to develop superior sesame genotypes.

  18. Antimicrobial activity of crude epicarp and seed extracts from mature avocado fruit (Persea americana) of three cultivars.

    PubMed

    Raymond Chia, Teck Wah; Dykes, Gary A

    2010-07-01

    The epicarp and seed of Persea Americana Mill. var. Hass (Lauraceae), Persea Americana Mill. var. Shepard, and Persea americana Mill. var Fuerte cultivars of mature avocados (n = 3) were ground separately and extracted with both absolute ethanol and distilled water. Extracts were analyzed for antimicrobial activity using the microtiter broth microdilution assay against four Gram-positive bacteria, six Gram-negative bacteria, and one yeast. Antimicrobial activity against two molds was determined by the hole plate method. The ethanol extracts showed antimicrobial activity (104.2-416.7 microg/mL) toward both Gram-positive and Gram-negative bacteria (except Escherichia coli), while inhibition of the water extracts was only observed for Listeria monocytogenes (93.8-375.0 microg/mL) and Staphylococcus epidermidis (354.2 microg/mL). The minimum concentration required to inhibit Zygosaccharomyces bailii was 500 microg/mL for the ethanol extracts, while no inhibition was observed for the water extracts. No inhibition by either ethanol or water extracts was observed against Penicillium spp. and Aspergillus flavus.

  19. EMS mutagenesis in mature seed-derived rice calli as a new method for rapidly obtaining TILLING mutant populations

    PubMed Central

    2014-01-01

    Background TILLING (Targeting Induced Local Lesions IN Genomes) is a reverse genetic method that combines chemical mutagenesis with high-throughput genome-wide screening for point mutation detection in genes of interest. However, this mutation discovery approach faces a particular problem which is how to obtain a mutant population with a sufficiently high mutation density. Furthermore, plant mutagenesis protocols require two successive generations (M1, M2) for mutation fixation to occur before the analysis of the genotype can begin. Results Here, we describe a new TILLING approach for rice based on ethyl methanesulfonate (EMS) mutagenesis of mature seed-derived calli and direct screening of in vitro regenerated plants. A high mutagenesis rate was obtained (i.e. one mutation in every 451 Kb) when plants were screened for two senescence-related genes. Screening was carried out in 2400 individuals from a mutant population of 6912. Seven sense change mutations out of 15 point mutations were identified. Conclusions This new strategy represents a significant advantage in terms of time-savings (i.e. more than eight months), greenhouse space and work during the generation of mutant plant populations. Furthermore, this effective chemical mutagenesis protocol ensures high mutagenesis rates thereby saving in waste removal costs and the total amount of mutagen needed thanks to the mutagenesis volume reduction. PMID:24475756

  20. Effect of maturity stage on the content of ash components in raw and preserved grass pea (Lathyrus sativus L.) seeds.

    PubMed

    Lisiewska, Zofia; Korus, Anna; Kmiecik, Waldemar; Gebczyński, Piotr

    2006-01-01

    The grains of grass pea cultivar krab of dry matter content at the level of 26-40 g/100 g were used in the production of preserves by freezing and canning in air tight containers. The content of ash and its alkalinity and of potassium, magnesium, calcium, iron, total phosphorus, and phytic phosphorus was determined in raw and blanched material, in frozen products stored for six months and then cooked to consumption consistency, and in sterilized canned products after the same storage period. With the increasing degree of maturity the content of all the above constituents calculated per 100 g fresh matter, increased. Blanching considerably reduced the level of ash and its alkalinity, of potassium, and of phytic phosphorus. The cooking of frozen seeds and the sterilization in salty brine caused a reduction of the components analysed except for the content of ash, its alkalinity, and of calcium. In comparison with canned sterilized preserves in cooked frozen grains a higher content of all the mineral components was determined.

  1. Phomopsis seed infection and time of harvest effects on seed phenol, ligin, and isoflavones in maturity V soybean genotypes differing in phomopsis resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this research was to evaluate phenolic compounds (total phenol, lignin, and isoflavones) in seed of susceptible (S), moderately resistant (MR), and resistant (R) soybean genotypes to phomopsis seed decay disease under irrigated and nonirrigated conditions. Seeds were evaluated at ph...

  2. Changes in Chenopodium rubrum seeds with aging.

    PubMed

    Mitrović, Aleksandra; Ducić, Tanja; Liric-Rajlić, Ivana; Radotić, Ksenija; Zivanović, Branka

    2005-06-01

    We studied antioxidative system, germination, growth, and flowering in vitro in Chenopodium rubrum seeds of different ages. Peroxidase, superoxide dismutase, and catalase activity, as well as glutathione status, were determined in 2.5-h imbibed seeds. Germination was tested under controlled conditions. Growth and flowering of plants were tested in vitro. The enzyme activities and glutathione content were higher in younger seeds. Germination declines with seed age. Plants derived from older seeds were smaller, and flowering percentage was lower compared to plants derived from younger seeds. Gibberellic acid reduced the difference in growth and flowering between plants derived from seeds different in age.

  3. Molecular cloning of the cDNA coding for the (R)-(+)-mandelonitrile lyase of Prunus amygdalus: temporal and spatial expression patterns in flowers and mature seeds.

    PubMed

    Suelves, M; Puigdomènech, P

    1998-10-01

    A gene highly expressed in the floral organs of almond (Prunus amygdalus Batsch), and coding for the cyanogenic enzyme (R)-(+)-mandelonitrile lyase (EC 4.1.2.10), has been identified and the full-length cDNA sequenced. The temporal expression pattern in maturing seeds and during floral development was analyzed by RNA blot, and the highest mRNA levels were detected in floral tissues. The spatial mRNA accumulation pattern in almond flower buds was also analyzed by in-situ hybridization. The mRNA levels were compared during seed maturation and floral development in fruit and floral samples from cultivars classified as homozygous or heterozygous for the sweet-almond trait or homozygous for the bitter trait. No correlation was found between these characteristics and levels of mandelonitrile lyase mRNA, suggesting that the presence of this protein is not the limiting factor in the production of hydrogen cyanide.

  4. Improvement of efficient in vitro regeneration potential of mature callus induced from Malaysian upland rice seed (Oryza sativa cv. Panderas)

    PubMed Central

    Mohd Din, Abd Rahman Jabir; Iliyas Ahmad, Fauziah; Wagiran, Alina; Abd Samad, Azman; Rahmat, Zaidah; Sarmidi, Mohamad Roji

    2015-01-01

    A new and rapid protocol for optimum callus production and complete plant regeneration has been assessed in Malaysian upland rice (Oryza sativa) cv. Panderas. The effect of plant growth regulator (PGR) on the regeneration frequency of Malaysian upland rice (cv. Panderas) was investigated. Mature seeds were used as a starting material for callus induction experiment using various concentrations of 2,4-D and NAA. Optimal callus induction frequency at 90% was obtained on MS media containing 2,4-D (3 mg L−1) and NAA (2 mg L−1) after 6 weeks while no significant difference was seen on tryptophan and glutamine parameters. Embryogenic callus was recorded as compact, globular and light yellowish in color. The embryogenic callus morphology was further confirmed with scanning electron microscopy (SEM) analysis. For regeneration, induced calli were treated with various concentrations of Kin (0.5–1.5 mg L−1), BAP, NAA and 0.5 mg L−1 of TDZ. The result showed that the maximum regeneration frequency (100%) was achieved on MS medium containing BAP (0.5 mg L−1), Kin (1.5 mg L−1), NAA (0.5 mg L−1) and TDZ (0.5 mg L−1) within four weeks. Developed shoots were successfully rooted on half strength MS free hormone medium and later transferred into a pot containing soil for acclimatization. This cutting-edge finding is unique over the other existing publishable data due to the good regeneration response by producing a large number of shoots. PMID:26858569

  5. Effects of boron nutrition and water stress on nitrogen fixation, seed d15N and d13C daynamics, and seed composition in soybean cultivars differing in maturities

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Water stress is a major abiotic stress factor, resulting in a major yield loss and poor seed quality. Little information is available on the effects of B nutrition on seed composition under water stress. Therefore, the objective of the current research was to investigate the effects of foliar B nutr...

  6. Maturity Effects on Contamination of High-Oleic Peanut Lots with Normal-Oleic Seeds of a Large Seeded Virginia Type Peanut Variety.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The need to segregate high- and normal-oleic peanut seeds has lead to investigations into potential sources of mixing. Previous work in our lab examined the development of in two lines of virginia type seeds, Bailey (normal-oleic) and Spain (high-oleic) for changes in the oleic to linoleic ratios (...

  7. The Vigna unguiculata Gene Expression Atlas (VuGEA) from de novo assembly and quantification of RNA-seq data provides insights into seed maturation mechanisms.

    PubMed

    Yao, Shaolun; Jiang, Chuan; Huang, Ziyue; Torres-Jerez, Ivone; Chang, Junil; Zhang, Heng; Udvardi, Michael; Liu, Renyi; Verdier, Jerome

    2016-10-01

    Legume research and cultivar development are important for sustainable food production, especially of high-protein seed. Thanks to the development of deep-sequencing technologies, crop species have been taken to the front line, even without completion of their genome sequences. Black-eyed pea (Vigna unguiculata) is a legume species widely grown in semi-arid regions, which has high potential to provide stable seed protein production in a broad range of environments, including drought conditions. The black-eyed pea reference genotype has been used to generate a gene expression atlas of the major plant tissues (i.e. leaf, root, stem, flower, pod and seed), with a developmental time series for pods and seeds. From these various organs, 27 cDNA libraries were generated and sequenced, resulting in more than one billion reads. Following filtering, these reads were de novo assembled into 36 529 transcript sequences that were annotated and quantified across the different tissues. A set of 24 866 unique transcript sequences, called Unigenes, was identified. All the information related to transcript identification, annotation and quantification were stored into a gene expression atlas webserver (http://vugea.noble.org), providing a user-friendly interface and necessary tools to analyse transcript expression in black-eyed pea organs and to compare data with other legume species. Using this gene expression atlas, we inferred details of molecular processes that are active during seed development, and identified key putative regulators of seed maturation. Additionally, we found evidence for conservation of regulatory mechanisms involving miRNA in plant tissues subjected to drought and seeds undergoing desiccation.

  8. Proteomic Analysis of Seed Dormancy in Arabidopsis1[W

    PubMed Central

    Chibani, Kamel; Ali-Rachedi, Sonia; Job, Claudette; Job, Dominique; Jullien, Marc; Grappin, Philippe

    2006-01-01

    The mechanisms controlling seed dormancy in Arabidopsis (Arabidopsis thaliana) have been characterized by proteomics using the dormant (D) accession Cvi originating from the Cape Verde Islands. Comparative studies carried out with freshly harvested dormant and after-ripened non-dormant (ND) seeds revealed a specific differential accumulation of 32 proteins. The data suggested that proteins associated with metabolic functions potentially involved in germination can accumulate during after-ripening in the dry state leading to dormancy release. Exogenous application of abscisic acid (ABA) to ND seeds strongly impeded their germination, which physiologically mimicked the behavior of D imbibed seeds. This application resulted in an alteration of the accumulation pattern of 71 proteins. There was a strong down-accumulation of a major part (90%) of these proteins, which were involved mainly in energetic and protein metabolisms. This feature suggested that exogenous ABA triggers proteolytic mechanisms in imbibed seeds. An analysis of de novo protein synthesis by two-dimensional gel electrophoresis in the presence of [35S]-methionine disclosed that exogenous ABA does not impede protein biosynthesis during imbibition. Furthermore, imbibed D seeds proved competent for de novo protein synthesis, demonstrating that impediment of protein translation was not the cause of the observed block of seed germination. However, the two-dimensional protein profiles were markedly different from those obtained with the ND seeds imbibed in ABA. Altogether, the data showed that the mechanisms blocking germination of the ND seeds by ABA application are different from those preventing germination of the D seeds imbibed in basal medium. PMID:17028149

  9. Complementation of Seed Maturation Phenotypes by Ectopic Expression of ABSCISIC ACID INSENSITIVE3, FUSCA3 and LEAFY COTYLEDON2 in Arabidopsis.

    PubMed

    Roscoe, Thomas T; Guilleminot, Jocelyne; Bessoule, Jean-Jacques; Berger, Frédéric; Devic, Martine

    2015-06-01

    ABSCISIC ACID INSENSITIVE3 (ABI3), FUSCA3 (FUS3) and LEAFY COTYLEDON2 (LEC2), collectively the AFL, are master regulators of seed maturation processes. This study examined the role of AFL in the production of seed reserves in Arabidopsis. Quantification of seed reserves and cytological observations of afl mutant embryos show that protein and lipid but not starch reserves are spatially regulated by AFL. Although AFL contribute to a common regulation of reserves, ABI3 exerts a quantitatively greater control over storage protein content whereas FUS3 controls lipid content to a greater extent. Although ABI3 controls the reserve content throughout the embryo, LEC2 and FUS3 regulate reserves in distinct embryonic territories. By analyzing the ability of an individual ectopically expressed AFL to suppress afl phenotypes genetically, we show that conserved domains common to each component of the AFL are sufficient for the initiation of storage product synthesis and the establishment of embryo morphology. This confirms redundancy among the AFL and indicates a threshold necessary for function within the AFL pool. Since no individual AFL was able to suppress the tolerance to desiccation, mid- and late-maturation programs were uncoupled.

  10. The regulatory gamma subunit SNF4b of the sucrose non-fermenting-related kinase complex is involved in longevity and stachyose accumulation during maturation of Medicago truncatula seeds.

    PubMed

    Rosnoblet, Claire; Aubry, Catherine; Leprince, Olivier; Vu, Benoit Ly; Rogniaux, Hélène; Buitink, Julia

    2007-07-01

    The sucrose non-fermenting-related kinase complex (SnRK1) is a heterotrimeric complex that plays a central role in metabolic adaptation to nutritional or environmental stresses. Here we investigate the role of a regulatory gamma-subunit of the complex, MtSNF4b, in Medicago truncatula seeds. Western blot indicated that MtSNF4b accumulated during seed filling, whereas it disappeared during imbibition of mature seeds. Gel filtration chromatography suggested that MtSNF4b assembled into a complex (450-600 kDa) at the onset of maturation drying, and dissociated during subsequent imbibition. Drying of desiccation-tolerant radicles led to a reassembly of the complex, in contrast to sensitive tissues. Silencing of MtSNF4b using a RNA interference (RNAi) approach resulted in a phenotype with reduced seed longevity, evident from the reduction in both germination percentage and seedling vigour in aged RNAi MtSNF4b seeds compared with the wild-type seeds. In parallel to the assembly of the complex, seeds of the RNAi MtSNF4b lines showed impaired accumulation of raffinose family oligosaccharides compared with control seeds. In mature seeds, the amount of stachyose was reduced by 50-80%, whereas the sucrose content was 60% higher. During imbibition, the differences in non-reducing sugar compared with the control disappeared in parallel to the disassembly of the complex. No difference was observed in dry weight or reserve accumulation such as proteins, lipids and starch. These data suggest that the regulatory gamma-subunit MtSNF4b confers a specific and temporal function to SnRK1 complexes in seeds, improving seed longevity and affecting the non-reducing sugar content at later stages of seed maturation.

  11. ITS2 barcoding DNA region combined with high resolution melting (HRM) analysis of Hyoscyami Semen, the mature seed of Hyoscyamus niger.

    PubMed

    Xiong, Chao; Hu, Zhi-Gang; Tu, Yuan; Liu, He-Gang; Wang, Ping; Zhao, Ming-Ming; SHIi, Yu-Hua; Wu, Lan; Sun, Wei; Chen, Shi-Lin

    2016-12-01

    Hyoscyami Semen, the mature dried seed of Hyoscyamus niger L., has long been used as a traditional Chinese medicine to treat human diseases. Hyoscyami Semen is found in local markets in China. In markets, sellers and buyers commonly inadvertently mix the seeds of H. niger with the seeds of related species such as Hygrophila salicifolia (Vahl) Nees, Astragalus complanatus R. Br., Cuscuta australis R. Br., Cuscuta chinensis Lam., and Impatiens balsamina L. because of their similar morphologies or similar names. Thus, developing a reliable method for discriminating H. niger seeds from its adulterants is necessary to reduce confusion and ensure the safe use of Hyoscyami Semen. The present study was designed to evaluate the efficiency of high-resolution melting analysis combined with DNA barcoding (Bar-HRM) with internal transcribed spacer 2 to discriminate H. niger. Our results show that Bar-HRM successfully identified the adulterants and detected the proportion of H. niger DNA extract within an admixture. In particular, HRM detected H. niger DNA extract in A. complanatus DNA extract at concentrations as low as 1%. In conclusion, the Bar-HRM method developed in the present study for authenticating H. niger is rapid and cost-effective. It can be used in the future to guarantee the purity of Hyoscyami Semen for the clinical use.

  12. Extracellular Vesicles Containing P301L Mutant Tau Accelerate Pathological Tau Phosphorylation and Oligomer Formation but Do Not Seed Mature Neurofibrillary Tangles in ALZ17 Mice.

    PubMed

    Baker, Siân; Polanco, Juan Carlos; Götz, Jϋrgen

    2016-10-04

    In Alzheimer's disease, the distribution of neurofibrillary tangles, a histological hallmark comprised of phosphorylated forms of the protein tau, follows a distinct pattern through anatomically connected brain regions. The well-documented correlation between the severity of tau pathology and disease progression implies a prion-like seeding and spreading mechanism for tau. Experimentally, this has been addressed in transgenic mice by the injection of protein lysates isolated from brains of transgenic mice or patients with tauopathies, including AD, that were shown to behave like seeds, accelerating tau pathology and tangle formation in predisposed mice. More specifically, in vivo data suggest that brain lysates from mice harboring the P301S mutation of tau can seed protein aggregation when injected into the hippocampi of human wild-type tau transgenic ALZ17 mice. Here, we compared the seeding potential of lysates and extracellular vesicles enriched for exosomes (EVs) from wild-type and human P301L tau transgenic rTg4510 mouse brains. We show that transgenic EVs cause increased tau phosphorylation and soluble oligomer formation in a manner comparable to that of freely available proteins in brain lysates, a prerequisite for the formation of mature protein aggregates.

  13. Chromodomain, Helicase and DNA-binding CHD1 protein, CHR5, are involved in establishing active chromatin state of seed maturation genes.

    PubMed

    Shen, Yuan; Devic, Martine; Lepiniec, Loïc; Zhou, Dao-Xiu

    2015-08-01

    Chromatin modification and remodelling are the basis for epigenetic regulation of gene expression. LEAFY COTYLEDON 1 (LEC1), LEAFY COTYLEDON 2 (LEC2), ABSCISIC ACID-INSENSITIVE 3 (ABI3) and FUSCA3 (FUS3) are key regulators of embryo development and are repressed after seed maturation. The chromatin remodelling CHD3 protein PICKLE (PKL) is involved in the epigenetic silencing of the genes. However, the chromatin mechanism that establishes the active state of these genes during early embryo development is not clear. We show that the Arabidopsis CHD1-related gene, CHR5, is activated during embryo development. Mutation of the gene reduced expression of LEC1, ABI3 and FUS3 in developing embryo and accumulation of seed storage proteins. Analysis of double mutants revealed an antagonistic function between CHR5 and PKL in embryo gene expression and seed storage protein accumulation, which likely acted on the promoter region of the genes. CHR5 was shown to be associated with the promoters of ABI3 and FUS3 and to be required to reduce nucleosome occupancy near the transcriptional start site. The results suggest that CHR5 is involved in establishing the active state of embryo regulatory genes by reducing nucleosomal barrier, which may be exploited to enhance seed protein production.

  14. A class II KNOX gene, KNOX4, controls seed physical dormancy

    PubMed Central

    Chai, Maofeng; Zhou, Chuanen; Molina, Isabel; Fu, Chunxiang; Nakashima, Jin; Li, Guifen; Zhang, Wenzheng; Park, Jongjin; Tang, Yuhong; Jiang, Qingzhen

    2016-01-01

    Physical dormancy of seed is an adaptive trait that widely exists in higher plants. This kind of dormancy is caused by a water-impermeable layer that blocks water and oxygen from the surrounding environment and keeps embryos in a viable status for a long time. Most of the work on hardseededness has focused on morphological structure and phenolic content of seed coat. The molecular mechanism underlying physical dormancy remains largely elusive. By screening a large number of Tnt1 retrotransposon-tagged Medicago truncatula lines, we identified nondormant seed mutants from this model legume species. Unlike wild-type hard seeds exhibiting physical dormancy, the mature mutant seeds imbibed water quickly and germinated easily, without the need for scarification. Microscopic observations of cross sections showed that the mutant phenotype was caused by a dysfunctional palisade cuticle layer in the seed coat. Chemical analysis found differences in lipid monomer composition between the wild-type and mutant seed coats. Genetic and molecular analyses revealed that a class II KNOTTED-like homeobox (KNOXII) gene, KNOX4, was responsible for the loss of physical dormancy in the seeds of the mutants. Microarray and chromatin immunoprecipitation analyses identified CYP86A, a gene associated with cutin biosynthesis, as one of the downstream target genes of KNOX4. This study elucidated a novel molecular mechanism of physical dormancy and revealed a new role of class II KNOX genes. Furthermore, KNOX4-like genes exist widely in seed plants but are lacking in nonseed species, indicating that KNOX4 may have diverged from the other KNOXII genes during the evolution of seed plants. PMID:27274062

  15. DNA damage checkpoint kinase ATM regulates germination and maintains genome stability in seeds.

    PubMed

    Waterworth, Wanda M; Footitt, Steven; Bray, Clifford M; Finch-Savage, William E; West, Christopher E

    2016-08-23

    Genome integrity is crucial for cellular survival and the faithful transmission of genetic information. The eukaryotic cellular response to DNA damage is orchestrated by the DNA damage checkpoint kinases ATAXIA TELANGIECTASIA MUTATED (ATM) and ATM AND RAD3-RELATED (ATR). Here we identify important physiological roles for these sensor kinases in control of seed germination. We demonstrate that double-strand breaks (DSBs) are rate-limiting for germination. We identify that desiccation tolerant seeds exhibit a striking transcriptional DSB damage response during germination, indicative of high levels of genotoxic stress, which is induced following maturation drying and quiescence. Mutant atr and atm seeds are highly resistant to aging, establishing ATM and ATR as determinants of seed viability. In response to aging, ATM delays germination, whereas atm mutant seeds germinate with extensive chromosomal abnormalities. This identifies ATM as a major factor that controls germination in aged seeds, integrating progression through germination with surveillance of genome integrity. Mechanistically, ATM functions through control of DNA replication in imbibing seeds. ATM signaling is mediated by transcriptional control of the cell cycle inhibitor SIAMESE-RELATED 5, an essential factor required for the aging-induced delay to germination. In the soil seed bank, seeds exhibit increased transcript levels of ATM and ATR, with changes in dormancy and germination potential modulated by environmental signals, including temperature and soil moisture. Collectively, our findings reveal physiological functions for these sensor kinases in linking genome integrity to germination, thereby influencing seed quality, crucial for plant survival in the natural environment and sustainable crop production.

  16. The transcriptomes of dormant leafy spurge seeds under alternating temperature are differentially affected by a germination-enhancing pretreatment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seed dormancy is an important stage in the life cycle of many non-domesticated plants, often characterized by the temporary failure to germinate under conditions that normally favor the process. Pre-treating dormant imbibed seeds at a constant temperate accelerated germination of leafy spurge seeds ...

  17. Resistance mechanisms to toxin-mediated charcoal rot infection in maturity group III soybean: role of seed phenol lignin soflavones sugars and seed minerals in charcoal rot resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Charcoal rot is a disease caused by the fungus Macrophomina phaseolina (Tassi) Goid, and thought to infect the plants through roots by a toxin-mediated mechanism, resulting in yield loss and poor seed quality, especially under drought conditions. The mechanism by which this infection occurs is not y...

  18. WRKY41 controls Arabidopsis seed dormancy via direct regulation of ABI3 transcript levels not downstream of ABA.

    PubMed

    Ding, Zhong Jie; Yan, Jing Ying; Li, Gui Xin; Wu, Zhong Chang; Zhang, Shu Qun; Zheng, Shao Jian

    2014-09-01

    Although seed dormancy is an important agronomic trait, its molecular basis is poorly understood. ABSCISIC ACID INSENSITIVE 3 (ABI3) plays an essential role in the establishment of seed dormancy. Here, we show that the lack of a seed-expressed WRKY transcription factor, WRKY41, confers reduced primary seed dormancy and thermoinhibition, phenotypes resembling those for a lack of ABI3. Loss-of-function abi3-17 and wrky41 alleles also both confer reduced sensitivity to ABA during germination and early seedling growth. Absence of WRKY41 decreases ABI3 transcript abundance in maturing and imbibed seeds, whereas transgenically overexpressing WRKY41 increases ABI3 expression. Moreover, transgenic overexpression of ABI3 completely restores seed dormancy phenotypes on wrky41. ChIP-qPCR and EMSA reveal that WRKY41 binds directly to the ABI3 promoter through three adjacent W-boxes, and a transactivation assay indicates that these W-boxes are essential for ABI3 expression. Whilst RT-qPCR analysis shows that the regulation of ABI3 by WRKY41 is not through ABA and other factors known to promote ABI3 transcription during seed maturation and germination, we also show that high concentrations of ABA might promote negative feedback regulation of WRKY41 expression. Finally, analysis of the wrky41 aba2 double mutant confirms that WRKY41 and ABA collaboratively regulate ABI3 expression and seed dormancy. In summary, our results demonstrate that WRKY41 is an important regulator of ABI3 expression, and hence of seed dormancy.

  19. Fagopyritol B1, O-alpha-D-galactopyranosyl-(1-->2)-D-chiro-inositol, a galactosyl cyclitol in maturing buckwheat seeds associated with desiccation tolerance.

    PubMed

    Horbowicz, M; Brenac, P; Obendorf, R L

    1998-05-01

    O-alpha-D-Galactopyranosyl-(1-->2)-D-chiro-inositol, herein named fagopyritol B1, was identified as a major soluble carbohydrate (40% of total) in buckwheat (Fagopyrum esculentum Moench, Polygonaceae) embryos. Analysis of hydrolysis products of purified compounds and of the crude extract led to the conclusion that buckwheat embryos have five alpha-galactosyl D-chiro-inositols: fagopyritol A1 and fagopyritol B1 (mono-galactosyl D-chiro-inositol isomers), fagopyritol A2 and fagopyritol B2 (di-galactosyl D-chiro-inositol isomers), and fagopyritol B3 (tri-galactosyl D-chiro-inositol). Other soluble carbohydrates analyzed by high-resolution gas chromatography included sucrose (42% of total), D-chiro-inositol, myo-inositol, galactinol, raffinose and stachyose (1% of total), but no reducing sugars. All fagopyritols were readily hydrolyzed by alpha-galactosidase (EC 3.2.1.22) from green coffee bean, demonstrating alpha-galactosyl linkage. Retention time of fagopyritol B1 was identical to the retention time of O-alpha-D-galactopyranosyl-(1-->2)-D-chiro-inositol from soybean (Glycine max (L.) Merrill, Leguminosae), suggesting that the alpha-galactosyl linkage is to the 2-position of D-chiro-inositol. Accumulation of fagopyritol B1 was associated with acquisition of desiccation tolerance during seed development and maturation in planta, and loss of fagopyritol B1 correlated with loss of desiccation tolerance during germination. Embryos of seeds grown at 18 degrees C, a condition that favors enhanced seed vigor and storability, had a sucrose-to-fagopyritol B1 ratio of 0.8 compared to a ratio of 2.46 for seeds grown at 25 degrees C. We propose that fagopyritol B1 facilitates desiccation tolerance and storability of buckwheat seeds.

  20. Digital gene expression analysis of mature seeds of transgenic maize overexpressing Aspergillus niger phyA2 and its non-transgenic counterpart.

    PubMed

    Rao, Jun; Yang, Litao; Wang, Congmao; Zhang, Dabing; Shi, Jianxin

    2013-01-01

    The next generation sequencing technologies have been recently used for transcriptome analysis in many organisms because of the decreased sequencing cost and increased sequence output. In this study, we used digital gene expression (DGE) technique to compare the transcriptomic changes in mature seeds between transgenic maize overexpressing Aspergillus niger phyA2 and its non-transgenic counterpart. Deep sequencing of DGE libraries of the transgenic and its non-transgenic counterpart seeds generated 3,783,500 and 3,790,500 reads of 21-nucleotide, respectively, with frequencies spanning over four orders of magnitude. In transgenic maize, 53.97% of the unambiguous signature tags were mapped to the maize B73 reference genome, and 46.47% of genes were detected by at least two reads; in non-transgenic maize, the corresponding numbers were 51.38% and 47.39%. Compared with non-transgenic counterpart, about 12% of detected genes were differentially expressed in the transcriptome of transgenic maize seeds. Among these differentially expressed genes, there were 23 transcription factors in 14 families and no allergen genes. Pathway enrichment analysis revealed that 21 pathways were significantly affected by the transgenic event, in which the pathway involved in protein processing in endoplasmic reticulum was the most significantly affected. Results from this study indicated that both intended and unintended transcriptomic changes occurred in the transgenic maize, thus emphasizing the importance of transcriptome profiling in risk assessment of transgenic events.

  1. Stable genetic transformation of castor (Ricinus communis L.) via particle gun-mediated gene transfer using embryo axes from mature seeds.

    PubMed

    Sailaja, M; Tarakeswari, M; Sujatha, M

    2008-09-01

    The first successful attempt to produce stably transformed castor plants through direct gene transfer using particle gun (BioRad) is described. Decotyledonated embryos from mature seeds were germinated and the embryonic axis was induced to proliferate on Murashige and Skoog (MS) medium supplemented with 0.5 mg l(-1) thidiazuron (TDZ) and subjected to bombardment after 5-7 days of pre-incubation. The physical parameters for transient transformation were optimized using the UidA gene encoding beta-glucuronidase (GUS) as the reporter gene and with hygromycin-phosphotransferase (hptII) gene as selectable marker. Statistical analysis revealed that helium pressure, target distance, osmoticum, microcarrier type and size, DNA quantity, explant type and number of bombardments had significant influence on transformation efficiency, while the effect of genotype was non-significant. Of the different variables evaluated, embryonic axes from mature seeds, a target distance of 6.0 cm, helium pressure of 1,100 psi, 0.6 microm gold microcarriers, single time bombardment and with both pre- and post-osmoticum were found ideal. Selection of putative transformants was done on MS medium supplemented with 0.5 mg l(-1) BA and hygromycin (20, 40 and 60 mg l(-1)) for 3 cycles. The stable integration of the incorporated gene into castor genome was confirmed with PCR and Southern analysis of T0 and T1 plants. Transformation frequency in terms of plants grown to maturity and showing the presence of the introduced genes was 1.4%. The present results demonstrate the possibility of transformation of embryonic meristematic tissues of castor through particle delivery system.

  2. Mass spectrometry imaging of mature cotton embryos with altered seed oil and protein reserves from diverse cotton (Gossypium sp.) genotypes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The domestication and breeding of cotton for elite, high-fiber cultivars has directly led to reduced genetic variation of seed constituents within currently cultivated accessions. A large screen of cottonseed embryos was carried out using time-domain 1H nuclear magnetic resonance (TD-NMR) for alter...

  3. Seed moisture at physiological maturity in oilseed and confectionary sunflower hybrids in the Northern U.S.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Desiccating sunflower (Helianthus annuus L.) to hasten harvest has become a common practice in the northern U.S. and can aid in reducing yield loss associated with severe weather and bird predation. Currently, it is recommended to apply desiccants to sunflower at 35% or less seed moisture correspond...

  4. Immature Seed Endosperm and Embryo Proteomics of the Lotus (Nelumbo Nucifera Gaertn.) by One-Dimensional Gel-Based Tandem Mass Spectrometry and a Comparison with the Mature Endosperm Proteome

    PubMed Central

    Moro, Carlo F.; Fukao, Yoichiro; Shibato, Junko; Rakwal, Randeep; Agrawal, Ganesh Kumar; Shioda, Seiji; Kouzuma, Yoshiaki; Yonekura, Masami

    2015-01-01

    Lotus (Nelumbo nucifera Gaertn.) seed proteome has been the focus of our studies, and we have recently established the first proteome dataset for its mature seed endosperm. The current study unravels the immature endosperm, as well as the embryo proteome, to provide a comprehensive dataset of the lotus seed proteins and a comparison between the mature and immature endosperm tissues across the seed’s development. One-dimensional gel electrophoresis (SDS-PAGE) linked with tandem mass spectrometry provided a protein inventory of the immature endosperm (122 non-redundant proteins) and embryo (141 non-redundant proteins) tissues. Comparing with the previous mature endosperm dataset (66 non-redundant proteins), a total of 206 non-redundant proteins were identified across all three tissues of the lotus seed. Results revealed some significant differences in proteome composition between the three lotus seed tissues, most notably between the mature endosperm and its immature developmental stage shifting the proteins from nutrient production to nutrient storage. PMID:28248268

  5. 7 CFR 201.58a - Indistinguishable seeds.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... in a glass container. (3) Chemical reaction: When seeds have imbibed, remove excess water and add... subjected to the chemical test as follows: (1) Preparation of test solution: Add 3 grams of cupric sulfate... that a complete reaction has taken place between CuSO4 and NH4 OH; otherwise fumes from excess...

  6. 7 CFR 201.58a - Indistinguishable seeds.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... in a glass container. (3) Chemical reaction: When seeds have imbibed, remove excess water and add... subjected to the chemical test as follows: (1) Preparation of test solution: Add 3 grams of cupric sulfate... that a complete reaction has taken place between CuSO4 and NH4 OH; otherwise fumes from excess...

  7. 7 CFR 201.58a - Indistinguishable seeds.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... in a glass container. (3) Chemical reaction: When seeds have imbibed, remove excess water and add... subjected to the chemical test as follows: (1) Preparation of test solution: Add 3 grams of cupric sulfate... that a complete reaction has taken place between CuSO4 and NH4 OH; otherwise fumes from excess...

  8. 7 CFR 201.58a - Indistinguishable seeds.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... in a glass container. (3) Chemical reaction: When seeds have imbibed, remove excess water and add... subjected to the chemical test as follows: (1) Preparation of test solution: Add 3 grams of cupric sulfate... that a complete reaction has taken place between CuSO4 and NH4 OH; otherwise fumes from excess...

  9. 7 CFR 201.58a - Indistinguishable seeds.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... in a glass container. (3) Chemical reaction: When seeds have imbibed, remove excess water and add... subjected to the chemical test as follows: (1) Preparation of test solution: Add 3 grams of cupric sulfate... that a complete reaction has taken place between CuSO4 and NH4 OH; otherwise fumes from excess...

  10. Electrophysiology of pumpkin seeds: Memristors in vivo

    PubMed Central

    Volkov, Alexander G.; Nyasani, Eunice K.; Tuckett, Clayton; Greeman, Esther A.; Markin, Vladislav S.

    2016-01-01

    ABSTRACT Leon Chua, the discoverer of a memristor, theoretically predicted that voltage gated ion channels can be memristors. We recently found memristors in different plants such as the Venus flytrap, Mimosa pudica, Aloe vera, apple fruits, and in potato tubers. There are no publications in literature about the existence of memristors in seeds. The goal of this work was to discover if pumpkin seeds might have memristors. We selected Cucurbita pepo L., cv. Cinderella, Cucurbita maxima L. cv Warty Goblin, and Cucurbita maxima L., cv. Jarrahdale seeds for this analysis. In these seeds, we found the presence of resistors with memory. The analysis was based on cyclic voltammetry where a memristor should manifest itself as a nonlinear two-terminal electrical element, which exhibits a pinched hysteresis loop on a current-voltage plane for any bipolar cyclic voltage input signal. Dry dormant pumpkin seeds have very high electrical resistance without memristive properties. The electrostimulation by bipolar sinusoidal or triangular periodic waves induces electrical responses in imbibed pumpkin seeds with fingerprints of memristors. Tetraethylammonium chloride, an inhibitor of voltage gated K+ channels, transforms a memristor to a resistor in pumpkin seeds. NPPB (5-Nitro-2-(3-phenylpropylamino)benzoic acid) inhibits the memristive properties of imbibed pumpkin seeds. The discovery of memristors in pumpkin seeds creates a new direction in the understanding of electrophysiological phenomena in seeds. PMID:26926652

  11. Electrophysiology of pumpkin seeds: Memristors in vivo.

    PubMed

    Volkov, Alexander G; Nyasani, Eunice K; Tuckett, Clayton; Greeman, Esther A; Markin, Vladislav S

    2016-01-01

    Leon Chua, the discoverer of a memristor, theoretically predicted that voltage gated ion channels can be memristors. We recently found memristors in different plants such as the Venus flytrap, Mimosa pudica, Aloe vera, apple fruits, and in potato tubers. There are no publications in literature about the existence of memristors in seeds. The goal of this work was to discover if pumpkin seeds might have memristors. We selected Cucurbita pepo L., cv. Cinderella, Cucurbita maxima L. cv Warty Goblin, and Cucurbita maxima L., cv. Jarrahdale seeds for this analysis. In these seeds, we found the presence of resistors with memory. The analysis was based on cyclic voltammetry where a memristor should manifest itself as a nonlinear two-terminal electrical element, which exhibits a pinched hysteresis loop on a current-voltage plane for any bipolar cyclic voltage input signal. Dry dormant pumpkin seeds have very high electrical resistance without memristive properties. The electrostimulation by bipolar sinusoidal or triangular periodic waves induces electrical responses in imbibed pumpkin seeds with fingerprints of memristors. Tetraethylammonium chloride, an inhibitor of voltage gated K(+) channels, transforms a memristor to a resistor in pumpkin seeds. NPPB (5-Nitro-2-(3-phenylpropylamino)benzoic acid) inhibits the memristive properties of imbibed pumpkin seeds. The discovery of memristors in pumpkin seeds creates a new direction in the understanding of electrophysiological phenomena in seeds.

  12. Libidibia ferrea Mature Seeds Promote Antinociceptive Effect by Peripheral and Central Pathway: Possible Involvement of Opioid and Cholinergic Receptors

    PubMed Central

    Sawada, Luis Armando; Monteiro, Vanessa Sâmia da Conçeição; Rabelo, Guilherme Rodrigues; Dias, Germana Bueno; Da Cunha, Maura; do Nascimento, José Luiz Martins; Bastos, Gilmara de Nazareth Tavares

    2014-01-01

    Libidibia ferrea (LF) is a medicinal plant that holds many pharmacological properties. We evaluated the antinociceptive effect in the LF aqueous seed extract and Lipidic Portion of Libidibia ferrea (LPLF), partially elucidating their mechanisms. Histochemical tests and Gas chromatography of the LPLF were performed to characterize its fatty acids. Acetic acid-induced abdominal constriction, formalin-induced pain, and hot-plate test in mice were employed in the study. In all experiments, aqueous extract or LPLF was administered systemically at the doses of 1, 5, and 10 mg/kg. LF aqueous seed extract and LPLF demonstrated a dose-dependent antinociceptive effect in all tests indicating both peripheral anti-inflammatory and central analgesia properties. Also, the use of atropine (5 mg/kg), naloxone (5 mg/kg) in the abdominal writhing test was able to reverse the antinociceptive effect of the LPLF, indicating that at least one of LF lipids components is responsible for the dose related antinociceptive action in chemical and thermal models of nociception in mice. Together, the present results suggested that Libidibia ferrea induced antinociceptive activity is possibly related to its ability to inhibit opioid, cholinergic receptors, and cyclooxygenase-2 pathway, since its main component, linoleic acid, has been demonstrated to produce such effect in previous studies. PMID:24860820

  13. Transcriptome Profile of Near-Isogenic Soybean Lines for β-Conglycinin α-Subunit Deficiency during Seed Maturation

    PubMed Central

    Song, Bo; An, Lixin; Han, Yanjing; Gao, Hongxiu; Ren, Hongbo; Zhao, Xue; Wei, Xiaoshuang; Krishnan, Hari B.

    2016-01-01

    Crossing, backcrossing, and molecular marker-assisted background selection produced a soybean (Glycine max) near-isogenic line (cgy-2-NIL) containing the cgy-2 allele, which is responsible for the absence of the allergenic α-subunit of β-conglycinin. To identify α-null-related transcriptional changes, the gene expressions of cgy-2-NIL and its recurrent parent DN47 were compared using Illumina high-throughput RNA-sequencing of samples at 25, 35, 50, and 55 days after flowering (DAF). Seeds at 18 DAF served as the control. Comparison of the transcript profiles identified 3,543 differentially expressed genes (DEGs) between the two genotypes, with 2,193 genes downregulated and 1,350 genes upregulated. The largest numbers of DEGs were identified at 55 DAF. The DEGs identified at 25 DAF represented a unique pattern of GO category distributions. KEGG pathway analyses identified 541 altered metabolic pathways in cgy-2-NIL. At 18DAF, 12 DEGs were involved in arginine and proline metabolism. The cgy-2 allele in the homozygous form modified the expression of several Cupin allergen genes. The cgy-2 allele is an alteration of a functional allele that is closely related to soybean protein amino acid quality, and is useful for hypoallergenic soybean breeding programs that aim to improve seed protein quality. PMID:27532666

  14. Seed Development and Germination

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seed is the fertilized and matured ovule of angiosperms and gymnosperms and represents a crucial stage in the life cycle of plants. Seeds of diverse plant species may display differences in size, shape and color. Despite apparent morphological variations, most mature seeds consist of three major com...

  15. Seed Detection and Discrimination by Ground Beetles (Coleoptera: Carabidae) Are Associated with Olfactory Cues.

    PubMed

    Kulkarni, Sharavari S; Dosdall, Lloyd M; Spence, John R; Willenborg, Christian J

    2017-01-01

    Olfactory ability is an element of fitness in many animals, guiding choices among alternatives such as mating partners or food. Ground beetles (Coleoptera; Carabidae), exhibit preferences for prey, and some species are well-known weed seed predators. We used olfactometer-based bioassays to determine if olfactory stimuli are associated with detection of Brassica napus L., Sinapis arvensis L., and Thlaspi arvense L. seeds by ground beetles characteristic of agroecosystems, and whether behavioural responses to seed odors depended on seed physiological state (imbibed or unimbibed). Imbibed B.napus seeds were preferred over other weed species by two of the three carabid species tested. Only A. littoralis responded significantly to unimbibed seeds of B. napus. Sensitivity to olfactory cues appeared to be highly specific as all carabid species discriminated between the olfactory cues of imbibed brassicaceous weed seeds, but did not discriminate between weed seeds that were unimbibed. Overall, our data suggest that depending on seed physiological state, odours can play an important role in the ability of carabids to find and recognize seeds of particular weed species.

  16. Seed Detection and Discrimination by Ground Beetles (Coleoptera: Carabidae) Are Associated with Olfactory Cues

    PubMed Central

    2017-01-01

    Olfactory ability is an element of fitness in many animals, guiding choices among alternatives such as mating partners or food. Ground beetles (Coleoptera; Carabidae), exhibit preferences for prey, and some species are well-known weed seed predators. We used olfactometer-based bioassays to determine if olfactory stimuli are associated with detection of Brassica napus L., Sinapis arvensis L., and Thlaspi arvense L. seeds by ground beetles characteristic of agroecosystems, and whether behavioural responses to seed odors depended on seed physiological state (imbibed or unimbibed). Imbibed B.napus seeds were preferred over other weed species by two of the three carabid species tested. Only A. littoralis responded significantly to unimbibed seeds of B. napus. Sensitivity to olfactory cues appeared to be highly specific as all carabid species discriminated between the olfactory cues of imbibed brassicaceous weed seeds, but did not discriminate between weed seeds that were unimbibed. Overall, our data suggest that depending on seed physiological state, odours can play an important role in the ability of carabids to find and recognize seeds of particular weed species. PMID:28107464

  17. Mitochondrial structural and antioxidant system responses to aging in oat (Avena sativa L.) seeds with different moisture contents.

    PubMed

    Xia, Fangshan; Wang, Xianguo; Li, Manli; Mao, Peisheng

    2015-09-01

    We observed the relationship between lifespan and mitochondria, including antioxidant systems, ultrastructure, and the hydrogen peroxide and malondialdehyde contents in 4 h imbibed oat (Avena sativa L.) seeds that were aged with different moisture contents (4%, 10% and 16%) for 0 (the control), 8, 16, 24, 32 and 40 d at 45 °C. The results showed that the decline in the oat seed vigor and in the integrity of the mitochondrial ultrastructure occurred during the aging process, and that these changes were enhanced by higher moisture contents. Mitochondrial antioxidants in imbibed oat seeds aged with a 4% moisture content were maintained at higher levels than imbibed oat seeds aged with a 10% and 16% moisture content. These results indicated that the levels of mitochondrial antioxidants and malondialdehyde after imbibition were related to the integrity of the mitochondrial membrane in aged oat seeds. The scavenging role of mitochondrial superoxide dismutase was inhibited in imbibed oat seeds aged at the early stage. Monodehydroascorbate reductase and dehydroascorbate reductase played more important roles than glutathione reductase in ascorbate regeneration in aged oat seeds during imbibition.

  18. Osmoconditioning prevents the onset of microtubular cytoskeleton and activation of cell cycle and is detrimental for germination of Jatropha curcas L. seeds.

    PubMed

    de Brito, C D; Loureiro, M B; Ribeiro, P R; Vasconcelos, P C T; Fernandez, L G; de Castro, R D

    2016-11-01

    Jatropha curcas is an oilseed crop renowned for its tolerance to a diverse range of environmental stresses. In Brazil, this species is grown in semiarid regions where crop establishment requires a better understanding of the mechanisms underlying appropriate seed, seedling and plant behaviour under water restriction conditions. In this context, the objective of this study was to investigate the physiological and cytological profiles of J. curcas seeds in response to imbibition in water (control) and in polyethylene glycol solution (osmoticum). Seed germinability and reactivation of cell cycle events were assessed by means of different germination parameters and immunohistochemical detection of tubulin and microtubules, i.e. tubulin accumulation and microtubular cytoskeleton configurations in water imbibed seeds (control) and in seeds imbibed in the osmoticum. Immunohistochemical analysis revealed increasing accumulation of tubulin and appearance of microtubular cytoskeleton in seed embryo radicles imbibed in water from 48 h onwards. Mitotic microtubules were only visible in seeds imbibed in water, after radicle protrusion, as an indication of cell cycle reactivation and cell proliferation, with subsequent root development. Imbibition in osmoticum prevented accumulation of microtubules, i.e. activation of cell cycle, therefore germination could not be resumed. Osmoconditioned seeds were able to survive re-drying and could resume germination after re-imbibition in water, however, with lower germination performance, possibly due to acquisition of secondary dormancy. This study provides important insights into understanding of the physiological aspects of J. curcas seed germination in response to water restriction conditions.

  19. Impact of protective agents and drying methods on desiccation tolerance of Salix nigra L. seeds.

    PubMed

    Santagapita, Patricio R; Ott Schneider, Helena; Agudelo-Laverde, Lina M; Buera, M Pilar

    2014-09-01

    Willow seeds are classified as orthodox, but they show some recalcitrant characteristics, as they lose viability in a few weeks at room temperature. The aim of this work was to improve the desiccation tolerance of willow seeds (Salix nigra L.), as a model of sensitive materials to dehydration, through imbibition in solutions and later vacuum (VD) or freeze-drying (FD). Imbibition was conducted with 45% w/v trehalose or polyethylene glycol 400 -PEG- or water prior to dehydration treatments. Water- and especially trehalose-imbibed seeds subjected to VD showed better germination capability with respect to the freeze-dried ones. Water crystallization was mainly responsible for the great loss of capability germination observed in water- or trehalose-imbibed seeds subjected to FD. PEG behavior was better when seeds were FD instead of VD. DSC thermograms of seeds allowed to identify two thermal transitions corresponding to lipids melting and to proteins denaturation. This last transition reveals information about proteins state/functionality. Dehydration of control and PEG- or water-imbibed seeds affected proteins functionality leading to lower germinability. In the case of trehalose-imbibed seeds subjected to VD, proteins maintained their native state along dehydration, and the seeds showed a great germination capacity for all the water content range. Germinated seeds showed higher luminosity (L*), greenness (a*) and yellowness (b*) values than not-germinated seeds independently of the employed agent. Present work reveals that the presence of adequate protective agents as well the dehydration method were the main critical factors involved in willow seed desiccation tolerance.

  20. Loss of desiccation tolerance in Copaifera langsdorffii Desf. seeds during germination.

    PubMed

    Pereira, W V S; Faria, J M R; Tonetti, O A O; Silva, E A A

    2014-05-01

    This study evaluated the loss of desiccation tolerance in C. langsdorffii seeds during the germination process. Seeds were imbibed for 24, 48, 72, 96, 120 and 144 hours and dried to the initial moisture content, kept in this state for 3 days after which they were submitted to pre-humidification and rehydration. Ultraestructural evaluations were done aiming to observe the cell damage caused by the dry process. Desiccation tolerance was evaluated in terms of the percentage of normal seedlings. Seeds not submitted to the drying process presented 61% of normal seedlings, and after 24 hours of imbibition, followed by drying, the seeds presented the same percentage of survival. However, after 48 hours of imbibition, seeds started to lose the desiccation tolerance. There was twenty six percent of normal seedlings formed from seeds imbibed for 96 hours and later dried and rehydrated. Only 5% of seeds imbibed for 144 hours, dried and rehydrated formed normal seedlings. At 144 hours of imbibition followed the dry process, there was damage into the cell structure, indicating that the seeds were unable to keep the cell structure during the drying process. Copaifera langsdorffii seeds loses the desiccation tolerance at the start of Phase 2 of imbibition.

  1. Seed Anatomy and Water Uptake in Relation to Seed Dormancy in Opuntia tomentosa (Cactaceae, Opuntioideae)

    PubMed Central

    Orozco-Segovia, A.; Márquez-Guzmán, J.; Sánchez-Coronado, M. E.; Gamboa de Buen, A.; Baskin, J. M.; Baskin, C. C.

    2007-01-01

    Background and Aims There is considerable confusion in the literature concerning impermeability of seeds with ‘hard’ seed coats, because the ability to take up (imbibe) water has not been tested in most of them. Seeds of Opuntia tomentosa were reported recently to have a water-impermeable seed coat sensu lato (i.e. physical dormancy), in combination with physiological dormancy. However, physical dormancy is not known to occur in Cactaceae. Therefore, the aim of this study was to determine if seeds of O. tomentosa are water-permeable or water-impermeable, i.e. if they have physical dormancy. Methods The micromorphology of the seed coat and associated structures were characterized by SEM and light microscopy. Permeability of the seed-covering layers was assessed by an increase in mass of seeds on a wet substrate and by dye-tracking and uptake of tritiated water by intact versus scarified seeds. Key Results A germination valve and a water channel are formed in the hilum–micropyle region during dehydration and ageing in seeds of O. tomentosa. The funicular envelope undoubtedly plays a role in germination of Opuntia seeds via restriction of water uptake and mechanical resistance to expansion of the embryo. However, seeds do not exhibit any of three features characteristic of those with physical dormancy. Thus, they do not have a water-impermeable layer(s) of palisade cells (macrosclereids) or a water gap sensu stricto and they imbibe water without the seed coat being disrupted. Conclusions Although dormancy in seeds of this species can be broken by scarification, they have physiological dormancy only. Further, based on information in the literature, it is concluded that it is unlikely that any species of Opuntia has physical dormancy. This is the first integrative study of the anatomy, dynamics of water uptake and dormancy in seeds of Cactaceae subfamily Opuntioideae. PMID:17298989

  2. Effect of temperature and water availability during late maturation of the soybean seed on germ and cotyledon isoflavone content and composition

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soybean seeds contain high levels of isoflavones (genistein, daidzein, glycitein), which have been associated with many positive human health effects. Seed isoflavone content is strongly influenced by both environment and genotype. The isoflavone concentration and composition of the soybean seed ger...

  3. Radiation effects on Brassica seeds and seedlings

    NASA Astrophysics Data System (ADS)

    Deoli, Naresh; Hasenstein, Karl H.

    2016-07-01

    Space radiation consists of high energy charged particles and affects biological systems, but because of its stochastic, non-directional nature is difficult to replicate on Earth. Radiation damages biological systems acutely at high doses or cumulatively at low doses through progressive changes in DNA organization. These damages lead to death or cause of mutations. While radiation biology typically focuses on mammalian or human systems, little is known as to how radiation affects plants. In addition, energetic ion beams are widely used to generate new mutants in plants considering their high-LET (Linear Energy Transfer) as compared to gamma rays and X-rays. Understanding the effect of ionizing radiation on plant provides a basis for studying effects of radiation on biological systems and will help mitigate (space) radiation damage in plants. We exposed dry and imbibed Brassica rapa seeds and seedling roots to proton beams of varying qualities and compared the theoretical penetration range of different energy levels with observable growth response. We used 1, 2 and 3 MeV protons in air at the varying fluences to investigate the effect of direct irradiation on the seeds (1012 - 1015 ions/cm2) and seedlings (1013 ions/cm2). The range of protons in the tissue was calculated using Monte-Carlo based SRIM (Stopping and Range of Ions in Matter) software. The simulation and biological results indicate that ions did not penetrate the tissue of dry or hydrated seeds at all used ion energies. Therefore the entire energy was transferred to the treated tissue. Irradiated seeds were germinated vertically under dim light and roots growth was observed for two days after imbibition. The LD50 of the germination was about 2×1014 ions/cm2 and about 5×1014 ions/cm2 for imbibed and dry seeds, respectively. Since seedlings are most sensitive to gravity, the change in gravitropic behavior is a convenient means to assess radiation damage on physiological responses other than direct tissue

  4. Rice PROTEIN l-ISOASPARTYL METHYLTRANSFERASE isoforms differentially accumulate during seed maturation to restrict deleterious isoAsp and reactive oxygen species accumulation and are implicated in seed vigor and longevity.

    PubMed

    Petla, Bhanu Prakash; Kamble, Nitin Uttam; Kumar, Meenu; Verma, Pooja; Ghosh, Shraboni; Singh, Ajeet; Rao, Venkateswara; Salvi, Prafull; Kaur, Harmeet; Saxena, Saurabh Chandra; Majee, Manoj

    2016-07-01

    PROTEIN l-ISOASPARTYL O-METHYLTRANSFERASE (PIMT) is a protein-repairing enzyme involved in seed vigor and longevity. However, the regulation of PIMT isoforms during seed development and the mechanism of PIMT-mediated improvement of seed vigor and longevity are largely unknown. In this study in rice (Oryza sativa), we demonstrate the dynamics and correlation of isoaspartyl (isoAsp)-repairing demands and PIMT activity, and their implications, during seed development, germination and aging, through biochemical, molecular and genetic studies. Molecular and biochemical analyses revealed that rice possesses various biochemically active and inactive PIMT isoforms. Transcript and western blot analyses clearly showed the seed development stage and tissue-specific accumulation of active isoforms. Immunolocalization studies revealed distinct isoform expression in embryo and aleurone layers. Further analyses of transgenic lines for each OsPIMT isoform revealed a clear role in the restriction of deleterious isoAsp and age-induced reactive oxygen species (ROS) accumulation to improve seed vigor and longevity. Collectively, our data suggest that a PIMT-mediated, protein repair mechanism is initiated during seed development in rice, with each isoform playing a distinct, yet coordinated, role. Our results also raise the intriguing possibility that PIMT repairs antioxidative enzymes and proteins which restrict ROS accumulation, lipid peroxidation, etc. in seed, particularly during aging, thus contributing to seed vigor and longevity.

  5. An active Mitochondrial Complex II Present in Mature Seeds Contains an Embryo-Specific Iron–Sulfur Subunit Regulated by ABA and bZIP53 and Is Involved in Germination and Seedling Establishment

    PubMed Central

    Restovic, Franko; Espinoza-Corral, Roberto; Gómez, Isabel; Vicente-Carbajosa, Jesús; Jordana, Xavier

    2017-01-01

    Complex II (succinate dehydrogenase) is an essential mitochondrial enzyme involved in both the tricarboxylic acid cycle and the respiratory chain. In Arabidopsis thaliana, its iron–sulfur subunit (SDH2) is encoded by three genes, one of them (SDH2.3) being specifically expressed during seed maturation in the embryo. Here we show that seed SDH2.3 expression is regulated by abscisic acid (ABA) and we define the promoter region (-114 to +49) possessing all the cis-elements necessary and sufficient for high expression in seeds. This region includes between -114 and -32 three ABRE (ABA-responsive) elements and one RY-enhancer like element, and we demonstrate that these elements, although necessary, are not sufficient for seed expression, our results supporting a role for the region encoding the 5’ untranslated region (+1 to +49). The SDH2.3 promoter is activated in leaf protoplasts by heterodimers between the basic leucine zipper transcription factors bZIP53 (group S1) and bZIP10 (group C) acting through the ABRE elements, and by the B3 domain transcription factor ABA insensitive 3 (ABI3). The in vivo role of bZIP53 is further supported by decreased SDH2.3 expression in a knockdown bzip53 mutant. By using the protein synthesis inhibitor cycloheximide and sdh2 mutants we have been able to conclusively show that complex II is already present in mature embryos before imbibition, and contains mainly SDH2.3 as iron–sulfur subunit. This complex plays a role during seed germination sensu-stricto since we have previously shown that seeds lacking SDH2.3 show retarded germination and now we demonstrate that low concentrations of thenoyltrifluoroacetone, a complex II inhibitor, also delay germination. Furthermore, complex II inhibitors completely block hypocotyl elongation in the dark and seedling establishment in the light, highlighting an essential role of complex II in the acquisition of photosynthetic competence and the transition from heterotrophy to autotrophy. PMID

  6. An active Mitochondrial Complex II Present in Mature Seeds Contains an Embryo-Specific Iron-Sulfur Subunit Regulated by ABA and bZIP53 and Is Involved in Germination and Seedling Establishment.

    PubMed

    Restovic, Franko; Espinoza-Corral, Roberto; Gómez, Isabel; Vicente-Carbajosa, Jesús; Jordana, Xavier

    2017-01-01

    Complex II (succinate dehydrogenase) is an essential mitochondrial enzyme involved in both the tricarboxylic acid cycle and the respiratory chain. In Arabidopsis thaliana, its iron-sulfur subunit (SDH2) is encoded by three genes, one of them (SDH2.3) being specifically expressed during seed maturation in the embryo. Here we show that seed SDH2.3 expression is regulated by abscisic acid (ABA) and we define the promoter region (-114 to +49) possessing all the cis-elements necessary and sufficient for high expression in seeds. This region includes between -114 and -32 three ABRE (ABA-responsive) elements and one RY-enhancer like element, and we demonstrate that these elements, although necessary, are not sufficient for seed expression, our results supporting a role for the region encoding the 5' untranslated region (+1 to +49). The SDH2.3 promoter is activated in leaf protoplasts by heterodimers between the basic leucine zipper transcription factors bZIP53 (group S1) and bZIP10 (group C) acting through the ABRE elements, and by the B3 domain transcription factor ABA insensitive 3 (ABI3). The in vivo role of bZIP53 is further supported by decreased SDH2.3 expression in a knockdown bzip53 mutant. By using the protein synthesis inhibitor cycloheximide and sdh2 mutants we have been able to conclusively show that complex II is already present in mature embryos before imbibition, and contains mainly SDH2.3 as iron-sulfur subunit. This complex plays a role during seed germination sensu-stricto since we have previously shown that seeds lacking SDH2.3 show retarded germination and now we demonstrate that low concentrations of thenoyltrifluoroacetone, a complex II inhibitor, also delay germination. Furthermore, complex II inhibitors completely block hypocotyl elongation in the dark and seedling establishment in the light, highlighting an essential role of complex II in the acquisition of photosynthetic competence and the transition from heterotrophy to autotrophy.

  7. Regulation of hormone metabolism in Arabidopsis seeds: phytochrome regulation of abscisic acid metabolism and abscisic acid regulation of gibberellin metabolism.

    PubMed

    Seo, Mitsunori; Hanada, Atsushi; Kuwahara, Ayuko; Endo, Akira; Okamoto, Masanori; Yamauchi, Yukika; North, Helen; Marion-Poll, Annie; Sun, Tai-Ping; Koshiba, Tomokazu; Kamiya, Yuji; Yamaguchi, Shinjiro; Nambara, Eiji

    2006-11-01

    In a wide range of plant species, seed germination is regulated antagonistically by two plant hormones, abscisic acid (ABA) and gibberellin (GA). In the present study, we have revealed that ABA metabolism (both biosynthesis and inactivation) was phytochrome-regulated in an opposite fashion to GA metabolism during photoreversible seed germination in Arabidopsis. Endogenous ABA levels were decreased by irradiation with a red (R) light pulse in dark-imbibed seeds pre-treated with a far-red (FR) light pulse, and the reduction in ABA levels in response to R light was inhibited in a phytochrome B (PHYB)-deficient mutant. Expression of an ABA biosynthesis gene, AtNCED6, and the inactivation gene, CYP707A2, was regulated in a photoreversible manner, suggesting a key role for the genes in PHYB-mediated regulation of ABA metabolism. Abscisic acid-deficient mutants such as nced6-1, aba2-2 and aao3-4 exhibited an enhanced ability to germinate relative to wild type when imbibed in the dark after irradiation with an FR light pulse. In addition, the ability to synthesize GA was improved in the aba2-2 mutant compared with wild type during dark-imbibition after an FR light pulse. Activation of GA biosynthesis in the aba2-2 mutant was also observed during seed development. These data indicate that ABA is involved in the suppression of GA biosynthesis in both imbibed and developing seeds. Spatial expression patterns of the AtABA2 and AAO3 genes, responsible for last two steps of ABA biosynthesis, were distinct from that of the GA biosynthesis gene, AtGA3ox2, in both imbibed and developing seeds, suggesting that biosynthesis of ABA and GA in seeds occurs in different cell types.

  8. Dormancy termination of western white pine (Pinus monticola Dougl. Ex D. Don) seeds is associated with changes in abscisic acid metabolism.

    PubMed

    Feurtado, J Allan; Ambrose, Stephen J; Cutler, Adrian J; Ross, Andrew R S; Abrams, Suzanne R; Kermode, Allison R

    2004-02-01

    Western white pine (Pinus monticola) seeds exhibit deep dormancy at maturity and seed populations require several months of moist chilling to reach their uppermost germination capacities. Abscisic acid (ABA) and its metabolites, phaseic acid (PA), dihydrophaseic acid (DPA), 7'-hydroxy ABA (7'OH ABA) and ABA-glucose ester (ABA-GE), were quantified in western white pine seeds during dormancy breakage (moist chilling) and germination using an HPLC-tandem mass spectrometry method with multiple reaction monitoring and internal standards incorporating deuterium-labeled analogs. In the seed coat, ABA and metabolite levels were high in dry seeds, but declined precipitously during the pre-moist-chilling water soak to relatively low levels thereafter. In the embryo and megagametophyte, ABA levels decreased significantly during moist chilling, coincident with an increase in the germination capacity of seeds. ABA catabolism occurred via several routes, depending on the stage and the seed tissue. Moist chilling of seeds led to increases in PA and DPA levels in both the embryo and megagametophyte. Within the embryo, 7'OH ABA and ABA-GE also accumulated during moist chilling; however, 7'OH ABA peaked early in germination. Changes in ABA flux, i.e. shifts in the ratio between biosynthesis and catabolism, occurred at three distinct stages during the transition from dormant seed to seedling. During moist chilling, the relative rate of ABA catabolism exceeded ABA biosynthesis. This trend became even more pronounced during germination, and germination was also accompanied by a decrease in the ABA catabolites DPA and PA, presumably as a result of their further metabolism and/or leaching/transport. The transition from germination to post-germinative growth was accompanied by a shift toward ABA biosynthesis. Dormant imbibed seeds, kept in warm moist conditions for 30 days (after an initial 13 days of soaking), maintained high ABA levels, while the amounts of PA, 7'OH ABA, and DPA

  9. Induction of 9-cis-epoxycarotenoid dioxygenase in Arabidopsis thaliana seeds enhances seed dormancy.

    PubMed

    Martínez-Andújar, Cristina; Ordiz, M Isabel; Huang, Zhonglian; Nonogaki, Mariko; Beachy, Roger N; Nonogaki, Hiroyuki

    2011-10-11

    Full understanding of mechanisms that control seed dormancy and germination remains elusive. Whereas it has been proposed that translational control plays a predominant role in germination, other studies suggest the importance of specific gene expression patterns in imbibed seeds. Transgenic plants were developed to permit conditional expression of a gene encoding 9-cis-epoxycarotenoid dioxygenase 6 (NCED6), a rate-limiting enzyme in abscisic acid (ABA) biosynthesis, using the ecdysone receptor-based plant gene switch system and the ligand methoxyfenozide. Induction of NCED6 during imbibition increased ABA levels more than 20-fold and was sufficient to prevent seed germination. Germination suppression was prevented by fluridone, an inhibitor of ABA biosynthesis. In another study, induction of the NCED6 gene in transgenic seeds of nondormant mutants tt3 and tt4 reestablished seed dormancy. Furthermore, inducing expression of NCED6 during seed development suppressed vivipary, precocious germination of developing seeds. These results indicate that expression of a hormone metabolism gene in seeds can be a sole determinant of dormancy. This study opens the possibility of developing a robust technology to suppress or promote seed germination through engineering pathways of hormone metabolism.

  10. Identification and characterization of a matrix metalloproteinase (Pta1-MMP) expressed during Loblolly pine (Pinus taeda) seed development, germination completion, and early seedling establishment.

    PubMed

    Ratnaparkhe, Supriya M; Egertsdotter, E M Ulrika; Flinn, Barry S

    2009-07-01

    Extracellular matrix (ECM) modifications occur during plant growth, development, and in response to environmental stimuli. Key modulators of ECM modification in vertebrates, the extracellular matrix metalloproteinases (MMPs), have also been described in a few plants. Here, we report the identification of Loblolly pine (Pinus taeda) Pta1-MMP and its characterization during seed development and germination. Pta1-MMP protein has the structural characteristics of other plant MMPs, the recombinant protein exhibits Zn(2+)-dependent protease activity, and is inhibited by EDTA and the active site-binding hydroxamate inhibitor GM6001. The Pta1-MMP gene is expressed in both embryo and megagametophyte, with transcript levels increasing in both during the period from proembryo to early cotyledonary stage, then declining during late embryogenesis and maturation drying. Protein extracts exhibited similar developmental-stage MMP-like activity. Seed germination was stimulated by GA(3) and inhibited by ABA, and the timing of germination completion was mirrored by the presence of MMP-like protease activity in both water- and GA(3)-imbibed embryos. Pta1-MMP gene transcript levels increased in association with radicle protrusion for both GA(3)- and water-treated embryos, in agreement with MMP-like activity. In contrast, by 11 days after imbibition, Pta1-MMP gene transcripts in ABA-treated embryos were at levels similar to the other treatments, although MMP-like activity was not observed. The application of GM6001 during Loblolly pine seed germination inhibited radicle protrusion. Our results suggest that MMP activity may be involved in ECM modification, facilitating the cell division and expansion required during seed development, germination completion, and subsequent seedling establishment.

  11. ELECTROCHEMICAL PROPERTIES, MECHANICAL TESTING, AND GEL MORPHOLOGY STUDY OF PHOSPHORIC ACID-DOPED META-POLYBENZIMIDAZOLE MEMBRANES VIA CONVENTIONALLY IMBIBING AND THE SOL-GEL PROCESS

    SciTech Connect

    Perry, Kelly A; More, Karren Leslie; Benicewicz, Brian

    2009-01-01

    Proton exchange membrane (PEM) research has been directed at phosphoric acid (PA)-doped polybenzimidazole (PBI) membranes since the 1990s. PEM fuel cells based on PA-doped PBI membranes produced via a sol-gel transition process have achieved lifetimes >10,000hrs with low degradation rates. It has been suggested that the gel morphology of the PA-doped PBI membranes is responsible for their excellent electrochemical performance. Thus, a study has been underway to characterize the microstructure of PA-doped PBI membranes, and to correlate structure with performance. However, PA-doped PBI membranes present special challenges for microscopy analysis, as these membranes are extremely sensitive to the electron beam and high vacuum conditions. This paper will discuss and compare the mechanical, electrochemical, and cryo-SEM analyses of PA-doped meta-PBI membranes produced via conventional imbibing and the sol-gel process.

  12. Ectopic overexpression of castor bean LEAFY COTYLEDON2 (LEC2) in Arabidopsis triggers the expression of genes that encode regulators of seed maturation and oil body proteins in vegetative tissues.

    PubMed

    Kim, Hyun Uk; Jung, Su-Jin; Lee, Kyeong-Ryeol; Kim, Eun Ha; Lee, Sang-Min; Roh, Kyung Hee; Kim, Jong-Bum

    2013-01-01

    The LEAFY COTYLEDON2 (LEC2) gene plays critically important regulatory roles during both early and late embryonic development. Here, we report the identification of the LEC2 gene from the castor bean plant (Ricinus communis), and characterize the effects of its overexpression on gene regulation and lipid metabolism in transgenic Arabidopsis plants. LEC2 exists as a single-copy gene in castor bean, is expressed predominantly in embryos, and encodes a protein with a conserved B3 domain, but different N- and C-terminal domains to those found in LEC2 from Arabidopsis. Ectopic overexpression of LEC2 from castor bean under the control of the cauliflower mosaic virus (CaMV) 35S promoter in Arabidopsis plants induces the accumulation of transcripts that encodes five major transcription factors (the LEAFY COTYLEDON1 (LEC1), LEAFY COTYLEDON1-LIKE (L1L), FUSCA3 (FUS3), and ABSCISIC ACID INSENSITIVE 3 (ABI3) transcripts for seed maturation, and WRINKELED1 (WRI1) transcripts for fatty acid biosynthesis), as well as OLEOSIN transcripts for the formation of oil bodies in vegetative tissues. Transgenic Arabidopsis plants that express the LEC2 gene from castor bean show a range of dose-dependent morphological phenotypes and effects on the expression of LEC2-regulated genes during seedling establishment and vegetative growth. Expression of castor bean LEC2 in Arabidopsis increased the expression of fatty acid elongase 1 (FAE1) and induced the accumulation of triacylglycerols, especially those containing the seed-specific fatty acid, eicosenoic acid (20:1(Δ11)), in vegetative tissues.

  13. Mediated proton transport through Nafion 117 membranes imbibed with varying concentrations of aqueous VOSO4 (VO2+) and NH4VO3 (VO2+) in 2 M H2SO4

    NASA Astrophysics Data System (ADS)

    Suarez, Sophia; Paterno, Domenec

    2016-11-01

    We performed an extensive study on Nafion 117 membrane imbibed with various concentrations of aqueous ammonium metavanadate (NH4VO3), and vanadyl sulfate (VOSO4), in 2 M H2SO4 over the temperature range of 20-100 °C, using 1H NMR and AC Impedance spectroscopies. The objective was to determine the effect of the tetravalent (VO2+) and pentavalent (VO2+) vanadium ions on the proton transport of Nafion 117.1H NMR chemical shift and linewidth data show greater short-range proton transport for the VO2+ imbibed membranes compared with the VO2+. However, the local environments seem to differ in that while the data for VO2+ imbibed membranes seem to follow more the trends observed for water hydrated Nafion 117, those for the VO2+ followed the trend of its aqueous bulk vanadium solvents, indicating that viscosity plays a larger role for the VO2+ imbibed membranes compared to the VO2+.

  14. Plants grow better if seeds see green.

    PubMed

    Sommer, Andrei P; Franke, Ralf-Peter

    2006-07-01

    We report on the response of dry plant seeds to their irradiation with intense green light applied at biostimulatory doses. Red and near-infrared light delivered by lasers or arrays of light emitting diodes applied at such doses have been shown previously by us to have effects on mammalian cells. Effects include cell proliferation and elevation of cell vitality, and have practical applications in various biomedical fields. Growth processes induced by photoreceptor stimulation (phytochromes and cryptochromes) in plant seeds with green light were described so far only for imbibed seeds. In this paper, we show that irradiation of dry cress, radish and carrot seeds with intense green light (laser or arrays of light emitting diodes), applied at biostimulatory doses, resulted in a significant increase in biomass--14, 26, and 71 days after seeding, respectively. In the case of radish and carrot, the irradiation led to important changes in the root-to-foliage surface ratio. Seeds with a potential to grant growth acceleration could be of special interest in agricultural applications, and could even compensate for shorter growth seasons caused by climate change.

  15. Plants grow better if seeds see green

    NASA Astrophysics Data System (ADS)

    Sommer, Andrei P.; Franke, Ralf-Peter

    2006-07-01

    We report on the response of dry plant seeds to their irradiation with intense green light applied at biostimulatory doses. Red and near-infrared light delivered by lasers or arrays of light emitting diodes applied at such doses have been shown previously by us to have effects on mammalian cells. Effects include cell proliferation and elevation of cell vitality, and have practical applications in various biomedical fields. Growth processes induced by photoreceptor stimulation (phytochromes and cryptochromes) in plant seeds with green light were described so far only for imbibed seeds. In this paper, we show that irradiation of dry cress, radish and carrot seeds with intense green light (laser or arrays of light emitting diodes), applied at biostimulatory doses, resulted in a significant increase in biomass—14, 26, and 71 days after seeding, respectively. In the case of radish and carrot, the irradiation led to important changes in the root-to-foliage surface ratio. Seeds with a potential to grant growth acceleration could be of special interest in agricultural applications, and could even compensate for shorter growth seasons caused by climate change.

  16. Purification and characterization of Moschatin, a novel type I ribosome-inactivating protein from the mature seeds of pumpkin (Cucurbita moschata), and preparation of its immunotoxin against human melanoma cells.

    PubMed

    Xia, Heng Chuan; Li, Feng; Li, Zhen; Zhang, Zu Chuan

    2003-10-01

    A novel ribosome-inactivating protein designated Moschatin from the mature seeds of pumpkin (Cucurbita moschata) has been successively purified to homogeneity, using ammonium sulfate precipitation, CM-cellulose 52 column chromatography, Blue Sepharose CL-6B Affinity column chromatography and FPLC size-exclusion column chromatography. Moschatin is a type 1 RIP with a pI of 9.4 and molecular weight of approximately 29 kD. It is a rRNA N-glycosidase and potently blocked the protein synthesis in the rabbit reticulocyte lysate with a IC50 of 0.26 nM. Using the anti-human melanoma McAb Ng76, a novel immunotoxin Moschatin-Ng76 was prepared successfully and it efficiently inhibited the growth of targeted melanoma cells M21 with a IC50 of 0.04 nM, 1500 times lower than that of free Moschatin. The results implied that Moschatin could be used as a new potential anticancer agent.

  17. The novel gene CpEdi-9 from the resurrection plant C. plantagineum encodes a hydrophilic protein and is expressed in mature seeds as well as in response to dehydration in leaf phloem tissues.

    PubMed

    Rodrigo, Maria Jesus; Bockel, Christine; Blervacq, Anne-Sophie; Bartels, Dorothea

    2004-08-01

    The resurrection plant Craterostigma plantagineum Hochst. is used as an experimental system to investigate desiccation tolerance in higher plants. A search for genes activated during early stages of dehydration identified the gene CpEdi-9, which is expressed in mature seeds and in response to dehydration in the phloem cells of vascular tissues of leaves. Elements for the tissue-specific expression pattern reside in the isolated promoter of the CpEdi-9 gene, as shown through the analysis of transgenic plants. The CpEdi-9 promoter could be a suitable tool for expressing genes in the vascular system of dehydrated plants. CpEdi-9 encodes a small (10 kDa) hydrophilic protein, which does not have significant sequence homologies to known genes. The predicted protein CpEDI-9 shares some physicochemical features with LEA proteins from plants and a nematode. Based on the unique expression pattern and on the nucleotide sequence we propose that CpEdi-9 defines a new class of hydrophilic proteins that are supposed to contribute to cellular protection during dehydration. This group of proteins may have evolved because desiccation tolerance requires the abundant expression of protective proteins during early stages of dehydration in all tissues.

  18. [Non-thermal effect of GSM electromagnetic radiation on quality of pea seeds].

    PubMed

    Veselova, T V; Veselovskiĭ, V A; Deev, L I; Baĭzhumanov, A A

    2012-01-01

    The seeds with low level of room temperature phosphorescence (RTP) were selected from a lot of air-dry peas (Pisum sativum) with 62% germination. These strong seeds (95-97% germination percentage) in air-dry, imbibed or emerged states were exposed to 905 MHz GSM-band electromagnetic radiation (EMR). The following effects of EMR were observed. Fraction II with higher RTP level appeared in the air-dry seeds. The germination rate decreased 2-3 fold in the air-dry, swollen and sprouting seeds due to an increase in the ratio of the seedlings with morphological defects (from 3 to 38%) and suffocated seeds (from 1 to 15%). We suggest tentative mechanisms to account for the decreased fitness of peas under GSM-band EMR (905 MHz); also discussed is the role of non-enzymatic hydrolysis of carbohydrates and amino-carbonyl reaction in this process.

  19. Seed germination and vigor.

    PubMed

    Rajjou, Loïc; Duval, Manuel; Gallardo, Karine; Catusse, Julie; Bally, Julia; Job, Claudette; Job, Dominique

    2012-01-01

    Germination vigor is driven by the ability of the plant embryo, embedded within the seed, to resume its metabolic activity in a coordinated and sequential manner. Studies using "-omics" approaches support the finding that a main contributor of seed germination success is the quality of the messenger RNAs stored during embryo maturation on the mother plant. In addition, proteostasis and DNA integrity play a major role in the germination phenotype. Because of its pivotal role in cell metabolism and its close relationships with hormone signaling pathways regulating seed germination, the sulfur amino acid metabolism pathway represents a key biochemical determinant of the commitment of the seed to initiate its development toward germination. This review highlights that germination vigor depends on multiple biochemical and molecular variables. Their characterization is expected to deliver new markers of seed quality that can be used in breeding programs and/or in biotechnological approaches to improve crop yields.

  20. Oxidative Phosphorylation in Germinating Lettuce Seeds (Lactuca sativa) during the First Hours of Imbibition

    PubMed Central

    Hourmant, Annick; Pradet, Alain

    1981-01-01

    Experiments with lettuce seeds during the first hours of imbibition showed that oxygen is necessary to sustain high adenine nucleotide ratios and consequently, energy charge values are higher than 0.8 as is usually the case in normally metabolizing tissues. The energy charge value (0.2) of dry seeds soaked in aerated water increased to normal values (0.8) within 30 minutes. The energy charge value of seeds imbibed under cyanide or nitrogen stayed at low values, about 0.3 for 30 minutes. Nitrogen and cyanide treatment of seeds imbibed in aerated water produced a decrease of energy charge to low values within 3 minutes. During the first minutes of imbibition, the oxygen uptake is cyanide-sensitive. The effect of the uncoupler carbonyl cyanide p-trifluoromethoxyphenyl hydrazone was not as clear-cut. However, results were obtained which agree with the occurrence of oxidative phosphorylation during the first hours of imbibition. These results indicate that a normal cytochromic pathway synthesizes ATP during the first minutes and hours following the imbibition of lettuce seeds. PMID:16661970

  1. Seed size selection by olive baboons.

    PubMed

    Kunz, Britta Kerstin; Linsenmair, Karl Eduard

    2008-10-01

    Seed size is an important plant fitness trait that can influence several steps between fruiting and the establishment of a plant's offspring. Seed size varies considerably within many plant species, yet the relevance of the trait for intra-specific fruit choice by primates has received little attention. Primates may select certain seed sizes within a species for a number of reasons, e.g. to decrease indigestible seed load or increase pulp intake per fruit. Olive baboons (Papio anubis, Cercopithecidae) are known to select seed size in unripe and mature pods of Parkia biglobosa (Mimosaceae) differentially, so that pods with small seeds, and an intermediate seed number, contribute most to dispersal by baboons. We tested whether olive baboons likewise select for smaller ripe seeds within each of nine additional fruit species whose fruit pulp baboons commonly consume, and for larger seeds in one species in which baboons feed on the seeds. Species differed in fruit type and seed number per fruit. For five of these species, baboons dispersed seeds that were significantly smaller than seeds extracted manually from randomly collected fresh fruits. In contrast, for three species, baboons swallowed seeds that were significantly longer and/or wider than seeds from fresh fruits. In two species, sizes of ingested seeds and seeds from fresh fruits did not differ significantly. Baboons frequently spat out seeds of Drypetes floribunda (Euphorbiaceae) but not those of other plant species having seeds of equal size. Oral processing of D. floribunda seeds depended on seed size: seeds that were spat out were significantly larger and swallowed seeds smaller, than seeds from randomly collected fresh fruits. We argue that seed size selection in baboons is influenced, among other traits, by the amount of pulp rewarded per fruit relative to seed load, which is likely to vary with fruit and seed shape.

  2. Ecophysiological characteristics of the seed of the tropical forest pioneer Urera caracasana (Urticaceae).

    PubMed

    Orozco-Segovia, A; Vàzquez-Yanes, C; Coates-Estrada, R; Pérez-Nasser, N

    1987-12-01

    Urera caracasana (Jacq.) Griseb is a small, fast-growing evergreen pioneer tree which colonizes openings in the tropical rain forest of 'Los Tuxtlas', Veracruz, Mèxico. Annual seed production by 10 trees was estimated to range from 0.4 x 10(5) to 1.6 x 10(6) seeds per tree. Fifteen species of resident and migratory birds were observed to visit the plants and disperse the seeds. Most seeds imbibed in petri dishes placed on the forest floor beneath a small opening in the canopy, where the red/far-red ratio of the light was around 1.0, germinated within 2 weeks. Germination beneath the forest canopy, where the red/far-red ratio of the light was approximately 0.2, was much slower and did not exceed 40%. A minimum of 4 h daily exposure to unfiltered natural light was required for rapid germination in the forest. In the laboratory rapid germination at 25 degrees C required a minimum of 4 h white light. However, if temperature during the light period was 35 degrees C, 30 min exposure to white light daily was sufficient to induce germination. Seeds that failed to germinate when imbibed for 60-360 days in petri dishes placed on the forest floor beneath the forest canopy, germinated rapidly in the laboratory when held at 25 degrees C and exposed daily to 12 h white or red light. Seeds imbibed for 120 days or more beneath the forest canopy were also induced to germinate by 12 h daily exposure to far-red light when this was combined with a 35/25 degrees C day/night temperature regime. Seeds buried in vermiculite-filled nylon mesh bags disappeared rapidly with few remaining after 2 months. Seeds that survived remained viable and germinated when incubated in petri dishes at 25 degrees C. Initially, buried seeds required light for germination. However, after 17 months' burial, seeds germinated in darkness when transferred to the laboratory and incubated on agar at 25 degrees C.

  3. Ascorbic acid and reactive oxygen species are involved in the inhibition of seed germination by abscisic acid in rice seeds.

    PubMed

    Ye, Nenghui; Zhu, Guohui; Liu, Yinggao; Zhang, Aying; Li, Yingxuan; Liu, Rui; Shi, Lu; Jia, Liguo; Zhang, Jianhua

    2012-03-01

    The antagonism between abscisic acid (ABA) and gibberellin (GA) plays a key role in controlling seed germination, but the mechanism of antagonism during this process is not known. The possible links among ABA, reactive oxygen species (ROS), ascorbic acid (ASC), and GA during rice seed germination were investigated. Unlike in non-seed tissues where ROS production is increased by ABA, ABA reduced ROS production in imbibed rice seeds, especially in the embryo region. Such reduced ROS also led to an inhibition of ASC production. GA accumulation was also suppressed by a reduced ROS and ASC level, which was indicated by the inhibited expression of GA biosynthesis genes, amylase genes, and enzyme activity. Application of exogenous ASC can partially rescue seed germination from ABA treatment. Production of ASC, which acts as a substrate in GA biosynthesis, was significantly inhibited by lycorine which thus suppressed the accumulation of GA. Consequently, expression of GA biosynthesis genes was suppressed by the low levels of ROS and ASC in ABA-treated seeds. It can be concluded that ABA regulates seed germination in multiple dimensions. ROS and ASC are involved in its inhibition of GA biosynthesis.

  4. [Seed aging and survival mechanisms].

    PubMed

    Grappin, Philippe; Bourdais, Gildas; Collet, Boris; Godin, Béatrice; Job, Dominique; Ogé, Laurent; Jullien, Marc; Rajjou, Loïc

    2008-01-01

    Aging and death are universal to living systems. In temperate climate latitudes the mature seeds of higher plants are exposed to aging and have developed resistance mechanisms allowing survival and plant propagation. In addition to the physicochemical properties of the seed that confer stress resistance, the protein metabolism contributes importantly to longevity mechanisms. Recently, genetic studies have demonstrated the occurrence of the Protein L-isoaspartyl methyltransferase repair enzyme in controlling age-related protein damages and seed survival. These protective mechanisms by protein repair are widespread in all kingdoms, so that the use of seeds as models to study these controlling processes offers the prospect of understanding longevity mechanisms better.

  5. Ecosystem services from keystone species: diversionary seeding and seed-caching desert rodents can enhance Indian ricegrass seedling establishment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seeds of Achnatherum hymenoides (Indian ricegrass), a native bunchgrass on arid western rangelands, are naturally dispersed by seed-caching rodent species, particularly Dipodomys spp. (kangaroo rats). These animals cache large quantities of seeds when mature seeds are available and recover most of t...

  6. Investigation of gamma-irradiated vegetable seeds with high-resolution solid-state 13C NMR.

    PubMed

    Bardet, Michel; Maron, Sébastien; Foray, Marie Françoise; Berger, Maurice; Guillermo, Armel

    2004-04-01

    13C solid-state NMR was used to investigate the effects of gamma radiation on vegetable seeds, Pisum sativum and Latuca sativa, at absorbed doses that inhibit their germination. By combining single-pulse excitation and cross-polarization experiments under magic angle spinning, both liquid and solid domains of seeds can be characterized. We showed that the liquid domains, mostly made of triacylglycerols (TAG), of vegetable seeds are not sensitive to radiation. The main structural changes have been observed in the embryonic axes of seeds when the seeds are water-imbibed before irradiation. These results rule out a starting hypothesis concerning the potential role of TAG contained in oil bodies as a potential source of aldehydes that could further react with DNA moiety.

  7. Control of macaw palm seed germination by the gibberellin/abscisic acid balance.

    PubMed

    Bicalho, E M; Pintó-Marijuan, M; Morales, M; Müller, M; Munné-Bosch, S; Garcia, Q S

    2015-09-01

    The hormonal mechanisms involved in palm seed germination are not fully understood. To better understand how germination is regulated in Arecaceae, we used macaw palm (Acrocomia aculeata (Jacq.) Lodd. Ex Mart.) seed as a model. Endogenous hormone concentrations, tocopherol and tocotrienol and lipid peroxidation during germination were studied separately in the embryo and endosperm. Evaluations were performed in dry (D), imbibed (I), germinated (G) and non-germinated (NG) seeds treated (+GA3 ) or not treated (control) with gibberellins (GA). With GA3 treatment, seeds germinated faster and to a higher percentage than control seeds. The +GA3 treatment increased total bioactive GA in the embryo during germination relative to the control. Abscisic acid (ABA) concentrations decreased gradually from D to G in both tissues. Embryos of G seeds had a lower ABA content than NG seeds in both treatments. The GA/ABA ratio in the embryo was significantly higher in G than NG seeds. The +GA3 treatment did not significantly affect the GA/ABA ratio in either treatment. Cytokinin content increased from dry to germinated seeds. Jasmonic acid (JA) increased and 1-aminocyclopropane-1-carboylic acid (ACC) decreased after imbibition. In addition, α-tocopherol and α-tocotrienol decreased, while lipid peroxidation increased in the embryo during germination. We conclude that germination in macaw palm seed involves reductions in ABA content and, consequently, increased GA/ABA in the embryo. Furthermore, the imbibition process generates oxidative stress (as observed by changes in vitamin E and MDA).

  8. Effect of freezing and canning on the content of selected vitamins and pigments in seeds of two grass pea (Lathyrus sativus L.) cultivars at the not fully mature stage.

    PubMed

    Korus, Anna; Lisiewska, Zofia; Kmiecik, Waldemar

    2002-08-01

    Seeds of the grass pea (Lathyrus sativus L.) cultivars Derek and Krab, with a dry matter content of about 33%, were used for freezing and for canning. The content of vitamins C, B1, and B2 and of carotenoids, beta-carotene, and chlorophylls was determined in raw and blanched material, in frozen products after 6-month storage before and after cooking to consumption consistency, and in canned products after 6-month storage. In comparison with the cultivar Krab, raw seeds of Derek contained 45% more vitamin C, 14% more total chlorophylls, 13% less thiamine (vitamin B1), and 7% less riboflavin (vitamin B2). The level of carotenoids was similar. Blanching of seeds led to a statistically significant decrease only in the content of vitamin C. Freezing and frozen storage significantly lowered the level of vitamin C and chlorophylls. The cooking of frozen seeds and the production of canned products and their storage resulted in a statistically verified reduction in the content of components analysed in all the samples. Greater losses were found in products prepared from seeds of the cv. Krab. After cooking, frozen seeds contained more of all the analysed components than the canned products.

  9. Morphological analysis of seed shape in Arabidopsis thaliana reveals altered polarity in mutants of the ethylene signaling pathway.

    PubMed

    Robert, Céline; Noriega, Arturo; Tocino, Angel; Cervantes, Emilio

    2008-06-16

    The shape of Arabidopsis thaliana dry seed is described here as a prolate spheroid. The accuracy of this approximation is discussed. Considering its limitations, it allows a geometric approximation to the analysis of changes occurring in seed shape during imbibition prior to seed germination as well as the differences in shape between genotypes and their changes during imbibition. The triple mutant ein2-1, ers1-2, etr1-7 presents notable alterations in seed shape. In addition, seeds of this and other mutants in the ethylene signaling pathway (ctr1-1, eto1-1, etr1-1, ein2-1) show different response to imbibition than the wild type. Imbibed seeds of the wild type increase their asymmetry compared with the dry seeds. This is detected by the relative changes in the curvature values in both poles. Thus, during imbibition of the wild-type seeds, the reduction in curvature values observed in the basal pole gives them an ovoid shape. In contrast, in the seeds of the ethylene mutants, reduction in curvature values occurs in both basal and apical poles, and its shape remains as a prolate spheroid. Our data indicate that the ethylene signaling pathway is involved, in general, in the complex regulation of seed shape and, in particular, in the establishment of polarity in seeds, controlling curvature values in the seed poles.

  10. Seed Germination

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Initiation of seed germination is a critical decision for plants. It is important for seed populations under natural conditions to spread the timing of germination of individual seeds to maximize the probability of species survival. Therefore, seeds have evolved the multiple layers of mechanisms tha...

  11. Tissue-specific hormonal profiling during dormancy release in macaw palm seeds.

    PubMed

    Ribeiro, Leonardo M; Garcia, Queila S; Müller, Maren; Munné-Bosch, Sergi

    2015-04-01

    Little is known about the control exerted by hormones in specific tissues during germination and post-germinative development in monocot seeds, whose embryos have complex structures and can remain dormant for long periods of time. Here the tissue-specific hormonal profile of macaw palm (Acrocomia aculeata) seeds overcoming dormancy and seedling during initial development was examined. Endogenous hormonal concentrations were determined in the cotyledonary petiole, haustorium, operculum, endosperm adjacent to the embryo and peripheral endosperm of dry dormant seeds, imbibed seeds trapped in phase I of germination, and germinating (phase 2 and phase 3) seeds 2, 5, 10 and 15 days after sowing. Evaluations were performed on seeds treated for overcoming dormancy by removal of the operculum and by immersion in a gibberellic acid (GA3 ) solution. Removal of the operculum effectively helped in overcoming dormancy, which was associated with the synthesis of active gibberellins (GAs) and cytokinins (CKs), as well as reductions of abscisic acid (ABA) in the cotyledonary petiole. In imbibed seeds trapped in phase I of germination, exogenous GA3 caused an increase in active GAs in the cotyledonary petiole and operculum and reduction in ABA in the operculum. Initial seedling development was associated with increases in the CK/auxin ratio in the haustorium and GA levels in the endosperm which is possibly related to the mobilization of metabolic reserves. Increases in salicylic acid (SA) and jasmonic acid (JA) concentrations were associated with the development of the vegetative axis. Hormones play a crucial tissue-specific role in the control of dormancy, germination and initial development of seedlings in macaw palm, including a central role not only for GAs and ABA, but also for CKs and other hormones.

  12. Oxygen dependency of germinating Brassica seeds

    NASA Astrophysics Data System (ADS)

    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.

  13. Germination of Croton urucurana L. seeds exposed to different storage temperatures and pre-germinative treatments.

    PubMed

    Scalon, Silvana P Q; Mussury, Rosilda M; Lima, Andréa A

    2012-03-01

    The present work evaluated the germinability and vigor of Croton urucurana seeds. 1) Seeds were sorted by color (caramel, gray and black) and were subjected to seven different pre-germination treatments followed by incubation at 20ºC, 25°C or 20/30°C. 2) Seeds were stored in cold chambers or at room temperature for up to 300 days and were subsequently incubated at 20/30ºC in a germination chamber or under greenhouse conditions. Only gray seeds showed significant germination rates. The highest first count percentages of total germination and the highest germination speed indices were observed in control seeds and in those which were treated with water or 200 mg.L(-1) gibberellic acid for 12 hours. Seeds stored under refrigeration showed the highest values for all of the characteristics examined, as well as less electrical conductivity of the imbibing solution. Seedlings were more vigorous when seeds were stored for 300 days in a cold chamber. The seedlings production can be increased by incubating the seeds at alternating temperatures (20/30°C). The seeds do not need pre-germination treatments.

  14. Physiological characteristics and related gene expression of after-ripening on seed dormancy release in rice.

    PubMed

    Du, W; Cheng, J; Cheng, Y; Wang, L; He, Y; Wang, Z; Zhang, H

    2015-11-01

    After-ripening is a common method used for dormancy release in rice. In this study, the rice variety Jiucaiqing (Oryza sativa L. subsp. japonica) was used to determine dormancy release following different after-ripening times (1, 2 and 3 months). Germination speed, germination percentage and seedling emergence increased with after-ripening; more than 95% germination and 85% seedling emergence were observed following 1 month of after-ripening within 10 days of imbibition, compared with <45% germination and 20% seedling emergence in freshly harvested seed. Hence, 3 months of after-ripening could be considered a suitable treatment period for rice dormancy release. Dormancy release by after-ripening is mainly correlated with a rapid decline in ABA content and increase in IAA content during imbibition. Subsequently, GA(1)/ABA, GA(7)/ABA, GA(12)/ABA, GA(20)/ABA and IAA/ABA ratios significantly increased, while GA(3)/ABA, GA(4)/ABA and GAs/IAA ratio significantly decreased in imbibed seeds following 3 months of after-ripening, thereby altering α-amylase activity during seed germination. Peak α-amylase activity occurred at an earlier germination stage in after-ripened seeds than in freshly harvested seeds. Expression of ABA, GA and IAA metabolism genes and dormancy-related genes was regulated by after-ripening time upon imbibition. Expression of OsCYP707A5, OsGA2ox1, OsGA2ox2, OsGA2ox3, OsILR1, OsGH3-2, qLTG3-1 and OsVP1 increased, while expression of Sdr4 decreased in imbibed seeds following 3 months of after-ripening. Dormancy release through after-ripening might be involved in weakening tissues covering the embryo via qLTG3-1 and decreased ABA signalling and sensitivity via Sdr4 and OsVP1.

  15. Precursor of kunitz trypsin inhibitor in soybean seeds

    SciTech Connect

    McGrain, A.; Chen, J.; Tan-Wilson, A. )

    1990-05-01

    Kunitz soybean trypsin inhibitor (KSTI) appears to be synthesized in precursor form which is converted by proteolytic digestion to the mature form of KSTI. Two forms of anti-cross-reacting material are evident when Western blots of extracts of developing seeds are analyzed. The precursor form increases to maximum levels as seed lengths increase to 11 mm. As the seed matures to 13 mm and turns yellow, precursor levels decrease while mature KSTI levels increase. The conversion of precursor to mature form could be demonstrated in vitro in seed extracts. The conversion could also be demonstrated in excised seeds pulse-labeled with ({sup 14}C)-leucine as loss of radioactivity from the precursor and appearance in the mature KSTI form.

  16. Proteomic Analysis Reveals Proteins Involved in Seed Imbibition under Salt Stress in Rice

    PubMed Central

    Xu, Enshun; Chen, Mingming; He, Hui; Zhan, Chengfang; Cheng, Yanhao; Zhang, Hongsheng; Wang, Zhoufei

    2017-01-01

    Enhancement of salinity tolerance during seed germination is very important for direct seeding in rice. In this study, the salt-tolerant japonica landrace Jiucaiqing was used to determine the regulators that are involved in seed imbibition under salt stress. Briefly, the comparative proteomic analysis was conducted between dry (0 h) and imbibed (24 h) seeds with 150 mM NaCl. Under salt stress, the uptake of water increased rapidly before 24 h imbibition (Phase I), followed by a plateau of seed imbibition from 24 to 96 h imbibition (Phase II). We identified 14 proteins involved in seed imbibition, in which the majority of these proteins were involved in energy supply and storage protein. The early imbibition process was mediated by protein catabolism; the most of proteins were down-regulated after 24 h imbibition. Eleven genes in salt stress treated seeds were expressed early during the seed imbibition in comparison to control seeds. By comparison, 2,3-bisphosphoglycerate-independent phosphoglycerate mutase (BPM), glutelin (GLU2.2 and GLU2.3), glucose-1-phosphate adenylyltransferase large subunit (GAS8), and cupin domain containing protein (CDP3.1 and CDP3.2) were near the regions of quantitative trait loci (QTLs) for seed dormancy, seed reserve utilization, and seed germination in Jiucaiqing. In particular, CDP3.1 was co-located in the region of qIR-3 for imbibition rate, and qGP-3 for germination percentage. The role of CDP3.1 was verified in enhancing seed germination under salt stress using T-DNA mutant. The identified proteins might be applicable for the improvement of seed germination under salt stress in rice. PMID:28105039

  17. Proteomic Analysis Reveals Proteins Involved in Seed Imbibition under Salt Stress in Rice.

    PubMed

    Xu, Enshun; Chen, Mingming; He, Hui; Zhan, Chengfang; Cheng, Yanhao; Zhang, Hongsheng; Wang, Zhoufei

    2016-01-01

    Enhancement of salinity tolerance during seed germination is very important for direct seeding in rice. In this study, the salt-tolerant japonica landrace Jiucaiqing was used to determine the regulators that are involved in seed imbibition under salt stress. Briefly, the comparative proteomic analysis was conducted between dry (0 h) and imbibed (24 h) seeds with 150 mM NaCl. Under salt stress, the uptake of water increased rapidly before 24 h imbibition (Phase I), followed by a plateau of seed imbibition from 24 to 96 h imbibition (Phase II). We identified 14 proteins involved in seed imbibition, in which the majority of these proteins were involved in energy supply and storage protein. The early imbibition process was mediated by protein catabolism; the most of proteins were down-regulated after 24 h imbibition. Eleven genes in salt stress treated seeds were expressed early during the seed imbibition in comparison to control seeds. By comparison, 2,3-bisphosphoglycerate-independent phosphoglycerate mutase (BPM), glutelin (GLU2.2 and GLU2.3), glucose-1-phosphate adenylyltransferase large subunit (GAS8), and cupin domain containing protein (CDP3.1 and CDP3.2) were near the regions of quantitative trait loci (QTLs) for seed dormancy, seed reserve utilization, and seed germination in Jiucaiqing. In particular, CDP3.1 was co-located in the region of qIR-3 for imbibition rate, and qGP-3 for germination percentage. The role of CDP3.1 was verified in enhancing seed germination under salt stress using T-DNA mutant. The identified proteins might be applicable for the improvement of seed germination under salt stress in rice.

  18. Cytokinins and Expression of SWEET, SUT, CWINV and AAP Genes Increase as Pea Seeds Germinate

    PubMed Central

    Jameson, Paula E.; Dhandapani, Pragatheswari; Novak, Ondrej; Song, Jiancheng

    2016-01-01

    Transporter genes and cytokinins are key targets for crop improvement. These genes are active during the development of the seed and its establishment as a strong sink. However, during germination, the seed transitions to being a source for the developing root and shoot. To determine if the sucrose transporter (SUT), amino acid permease (AAP), Sugar Will Eventually be Exported Transporter (SWEET), cell wall invertase (CWINV), cytokinin biosynthesis (IPT), activation (LOG) and degradation (CKX) gene family members are involved in both the sink and source activities of seeds, we used RT-qPCR to determine the expression of multiple gene family members, and LC-MS/MS to ascertain endogenous cytokinin levels in germinating Pisum sativum L. We show that genes that are actively expressed when the seed is a strong sink during its development, are also expressed when the seed is in the reverse role of being an active source during germination and early seedling growth. Cytokinins were detected in the imbibing seeds and were actively biosynthesised during germination. We conclude that, when the above gene family members are targeted for seed yield improvement, a downstream effect on subsequent seed germination or seedling vigour must be taken into consideration. PMID:27916945

  19. A close look at cotton seed coat fragments with AFISPro

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seed coat fragments (SCF) can cause spinning problems and fabric defects, which ultimately cause financial losses to the cotton industry. SCF are parts of a seed coat that have been broken from the surface of either mature or immature seeds during mechanical processing. The objective of this study ...

  20. Measurements of seed coat fragments in cotton fibers and fabrics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seed coat fragments (SCF) are parts of a seed coat that have been broken from the surface of either mature or immature seeds during mechanical processing. SCF can cause spinning problems and fabric defects, which ultimately cause losses to the cotton industry. The objective of this study was to dev...

  1. Geographic variation in the flood-induced fluctuating temperature requirement for germination in Setaria parviflora seeds.

    PubMed

    Mollard, F P O; Insausti, P

    2011-07-01

    Our aim was to search for specific seed germinative strategies related to flooding escape in Setaria parviflora, a common species across the Americas. For this purpose, we investigated induction after floods, in relation to fluctuating temperature requirements for germination in seeds from mountain, floodplain and successional grasslands. A laboratory experiment was conducted in which seeds were imbibed or immersed in water at 5°C. Seeds were also buried in flood-prone and upland grasslands and exhumed during the flooding season. Additionally, seeds were buried in flooded or drained grassland mesocosms. Germination of exhumed seeds was assayed at 25°C or at 20°C/30°C in the dark or in the presence of red light pulses. After submergence or soil flooding, a high fraction (>32%) of seeds from the floodplain required fluctuating temperatures to germinate. In contrast, seeds from the mountains showed maximum differences in germination between fluctuating and constant temperature treatment only after imbibition (35%) or in non-flooded soil conditions (40%). The fluctuating temperature requirement was not clearly related to the foregoing conditions in the successional grassland seeds. Maximum germination could also be attained with red light pulses to seeds from mountain and successional grasslands. Results show that the fluctuating temperature requirement might help floodplain seeds to germinate after floods, indicating a unique feature of the dormancy of S. parviflora seeds from floodplains, which suggests an adaptive advantage aimed at postponing emergence during inundation periods. In contrast, the fluctuating temperature required for germination among seeds from mountain and successional grasslands show its importance for gap detection.

  2. Water uptake and oil distribution during imbibition of seeds of western white pine (Pinus monticola Dougl. ex D. Don) monitored in vivo using magnetic resonance imaging.

    PubMed

    Terskikh, Victor V; Feurtado, J Allan; Ren, Chengwei; Abrams, Suzanne R; Kermode, Allison R

    2005-04-01

    Dry or fully imbibed seeds of western white pine (Pinus monticola Dougl. ex D. Don) were studied using high-resolution magnetic resonance imaging (MRI). Analyses of the dry seed revealed many of the gross anatomical features of seed structure. Furthermore, the non-invasive nature of MRI allowed for a study of the dynamics of water and oil distribution during in situ imbibition of a single seed with time-lapse chemical shift selective MRI. During soaking of the dry seed, water penetrated through the seed coat and megagametophyte. The cotyledons of the embryo (located in the chalazal end of the seed) were the first to show hydration followed by the hypocotyl and later the radicle. After penetrating the seed coat, water in the micropylar end of the seed likely also contributed to further hydration of the embryo; however, the micropyle itself did not appear to be a site for water entry into the seed. A model that describes the kinetics of the earlier stages of imbibition is proposed. Non-viable pine seeds captured with MRI displayed atypical imbibition kinetics and were distinguished by their rapid and uncontrolled water uptake. The potential of MR microimaging for detailed studies of water uptake and distribution during the soaking, moist chilling ("stratification"), and germination of conifer seeds is discussed.

  3. Electropriming of wheatgrass seeds using pulsed electric fields enhances antioxidant metabolism and the bioprotective capacity of wheatgrass shoots

    PubMed Central

    Leong, Sze Ying; Burritt, David John; Oey, Indrawati

    2016-01-01

    The influence of pulsed electric field (PEF) (0.5–2 kV/cm) treatment of wheatgrass (Triticum aestivum L.) seeds, with different water contents, on antioxidant metabolism in the resultant seedlings was investigated. Imbibing seeds to a water content of 45% or greater prior to PEF treatment increased the glutathione level and activities of superoxide dismutase, catalase, glutathione reductase, glutathione peroxidase and ascorbate peroxidase in the resultant seedlings, compared to untreated controls. Pre-culture of human intestinal Caco-2 cells with simulated gastrointestinal digests of electrostimulated seedlings enhanced the ability of Caco-2 cells to cope with H2O2-induced oxidative damage, determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and lactate dehydrogenase (LDH) release assays. The Caco-2 cell MTT and LDH assays correlated better with the increases in seedling glutathione content and antioxidant enzyme activities compared to the 2, 2-diphenyl-1-picrylhydrazyl (DPPH) total antioxidant capacity assay, an assay commonly used to determine the ability of plant extracts to protect cells from oxidative damage. These results demonstrate for the first time that PEF treatment of imbibed seeds can stimulate changes in metabolism in the resultant seedlings, increasing the bioprotective potential of their shoots/sprouts and hence value as functional foods. PMID:27147445

  4. Seed production temperature regulation of primary dormancy occurs through control of seed coat phenylpropanoid metabolism.

    PubMed

    MacGregor, Dana R; Kendall, Sarah L; Florance, Hannah; Fedi, Fabio; Moore, Karen; Paszkiewicz, Konrad; Smirnoff, Nicholas; Penfield, Steven

    2015-01-01

    Environmental changes during seed production are important drivers of lot-to-lot variation in seed behaviour and enable wild species to time their life history with seasonal cues. Temperature during seed set is the dominant environmental signal determining the depth of primary dormancy, although the mechanisms though which temperature changes impart changes in dormancy state are still only partly understood. We used molecular, genetic and biochemical techniques to examine the mechanism through which temperature variation affects Arabidopsis thaliana seed dormancy. Here we show that, in Arabidopsis, low temperatures during seed maturation result in an increase in phenylpropanoid gene expression in seeds and that this correlates with higher concentrations of seed coat procyanidins. Lower maturation temperatures cause differences in coat permeability to tetrazolium, and mutants with increased seed coat permeability and/or low procyanidin concentrations are less able to enter strongly dormant states after exposure to low temperatures during seed maturation. Our data show that maternal temperature signalling regulates seed coat properties, and this is an important pathway through which the environmental signals control primary dormancy depth.

  5. Water uptake, priming, drying and storage effects in Cassia excelsa Schrad seeds.

    PubMed

    Jeller, H; Perez, S C; Raizer, J

    2003-02-01

    The aims of this study were to evaluate the effects of osmotic potential on the water uptake curve in Cassia excelsa seeds and use the results to analyze the effects of dehydration and storage on primed seed germination. Seeds were imbibed in distilled water and polyethylene glicol (PEG 6000) osmotic solutions at -0.2, -0.4, and -0.6 MPa, at 20 degrees C. The radicle emergence and seed moisture content were evaluated at 6-hour intervals during 240 hours. Afterwards, seeds were primed in distilled water and PEG 6000 solutions at -0.2, -0.4, and -0.6 MPa for 48, 72, 96, and 168 hours at 20 degrees C, followed by air drying and storage for 15 days at 5 degrees C. The lower the osmotic potential, the higher the time required for priming. The osmoconditioning yields benefits with PEG solutions at 0.0 and -0.2 MPa; seed improvements were maintained during storage for 15 days at 5 degrees C, but were reverted by seed drying.

  6. Identification of genes involved in rice seed priming in the early imbibition stage.

    PubMed

    Cheng, J; Wang, L; Zeng, P; He, Y; Zhou, R; Zhang, H; Wang, Z

    2017-01-01

    Phase II of seed imbibition is a critical process during seed priming. To identify genes involved in rice seed priming, the altered proteins between the dry and imbibed (24 h) seeds were compared using a two-dimensional gel electrophoresis system in this study. Ten significantly changed proteins (fold change ≥ twofold; P < 0.01) were successfully identified, which could be categorised as carbohydrate and protein biosynthesis and metabolism-related, signalling-related, storage and stress-related proteins. A meta-analysis indicated that the highest expression of the identified genes was at the milk and dough stages and in the endosperm tissue. Quantitative real-time PCR analysis showed that there was significant variation in gene expression (except FAD-dependent oxidoreductase) in embryos during seed priming (0-48 h). The expression of genes associated with stress appeared at the early imbibition stage, while those associated with carbohydrate metabolism, protein synthesis and signalling increased at the late imbibition stage. Three identified proteins (glucose-1-phosphate adenylyltransferase large subunit, aminotransferase and prolamin precursor) had similar transcript and protein expression patterns in embryos. Based on phenotype and gene expression, the optimal stop time for seed priming is 24 h, when these three genes have relatively low expression, followed by significant induction during imbibition in embryos. These three genes are ideal candidate biomarkers for rice seed priming.

  7. Carbonhydrate Content and Root Growth in Seeds Germinated Under Salt Stress: Implications for Seed Conditioning

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sugars and sugar alcohols have well documented roles in salt tolerance in whole plants and maturing seeds. Less is known, however, about possible effects of these compounds during germination. Seeds from mannitol-accumulating salt-tolerant celery [Apium graveloens L. var. dulce (P. Mill.) DC], non...

  8. Development of simple algorithm for direct and rapid determination of cotton maturity from FTIR spectroscopy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fourier transform infrared (FTIR) spectra of seed and lint cottons were collected to explore the potential for the discrimination of immature cottons from mature ones and also for the determination of actual cotton maturity. Spectral features of immature and mature cottons revealed large differences...

  9. Direct and rapid determination of cotton maturity by FT-Mid-IR technique

    Technology Transfer Automated Retrieval System (TEKTRAN)

    FT-mid-IR (FT-MIR) spectra of seed and lint cottons were collected to explore the potential for the discrimination of immature cottons from mature ones and also for the determination of actual cotton maturity. Spectral features of immature and mature cottons revealed large differences in the 1200-90...

  10. Ultrastructure of mature protein body in the starchy endosperm of dry cereal grain.

    PubMed

    Saito, Yuhi; Shigemitsu, Takanari; Tanaka, Kunisuke; Morita, Shigeto; Satoh, Shigeru; Masumura, Takehiro

    2010-01-01

    The development of the protein body in the late stage of seed maturation is poorly understood, because electron-microscopy of mature cereal endosperm is technically difficult. In this study, we attempted to modify the existing method of embedding rice grain in resin. The modified method revealed the ultrastructures of the mature protein body in dry cereal grains.

  11. Dynamics of the antioxidant system during seed osmopriming, post-priming germination, and seedling establishment in Spinach (Spinacia oleracea).

    PubMed

    Chen, Keting; Arora, Rajeev

    2011-02-01

    Osmopriming is a pre-sowing treatment that improves seed germination performance and stress tolerance. To understand osmopriming physiology, and its association with post-priming stress tolerance, we investigated the antioxidant system dynamics during three stages: during osmopriming, post-priming germination, and seedling establishment. Spinach seeds (Spinacia oleracea L. cv. Bloomsdale) were primed with -0.6 MPa PEG at 15°C for 8 d, and dried at room temperature for 2 d. Unprimed and primed germinating seeds/seedlings were subjected to a chilling and desiccation stresses. Seed/seedling samples were collected for antioxidant assays and germination performance and stress tolerance were evaluated. Our data indicate that: (1) during osmopriming the transition of seeds from dry to germinating state represses the antioxidant pathways (residing in dry seeds) that involve CAT and SOD enzymes but stimulates another pathway (only detectable in imbibed seeds) involving APX; (2) a renewal of antioxidant system, possibly required by seedling establishment, occurs after roughly 5 d of germination; (3) osmopriming strengthens the antioxidant system and increases seed germination potential, resulting in an increased stress tolerance in germinating seeds. Osmopriming-mediated promotive effect on stress tolerance, however, may diminish in relatively older (e.g. ~5-week) seedlings.

  12. HFR1 sequesters PIF1 to govern the transcriptional network underlying light-initiated seed germination in Arabidopsis.

    PubMed

    Shi, Hui; Zhong, Shangwei; Mo, Xiaorong; Liu, Na; Nezames, Cynthia D; Deng, Xing Wang

    2013-10-01

    Seed germination is the first step for seed plants to initiate a new life cycle. Light plays a predominant role in promoting seed germination, where the initial phase is mediated by photoreceptor phytochrome B (phyB). Previous studies showed that phytochrome-interacting factor1 (PIF1) represses seed germination downstream of phyB. Here, we identify a positive regulator of phyB-dependent seed germination, long hypocotyl in far-red1 (HFR1). HFR1 blocks PIF1 transcriptional activity by forming a heterodimer with PIF1 that prevents PIF1 from binding to DNA. Our whole-genomic analysis shows that HFR1 and PIF1 oppositely mediate the light-regulated transcriptome in imbibed seeds. Through the HFR1-PIF1 module, light regulates expression of numerous genes involved in cell wall loosening, cell division, and hormone pathways to initiate seed germination. The functionally antagonistic HFR1-PIF1 pair constructs a fail-safe mechanism for fine-tuning seed germination during low-level illumination, ensuring a rapid response to favorable environmental changes. This study identifies the HFR1-PIF1 pair as a central module directing the whole genomic transcriptional network to rapidly initiate light-induced seed germination.

  13. Changes in seed water status as characterized by NMR in developing soybean seed grown under moisture stress conditions

    SciTech Connect

    Krishnan, P. Singh, Ravender; Verma, A.P.S.; Joshi, D.K.; Singh, Sheoraj

    2014-02-21

    Highlights: • In developing soybean seeds, moisture stress resulted in more proportion of water to bound state. • These changes are further corroborated by concomitant changes in seed metabolites. • Thus there exists a moisture stress and development stage dependence of seed tissue water status. - Abstract: Changes in water status of developing seeds of Soybean (Glycine max L. Merrill.) grown under different moisture stress conditions were characterized by proton nuclear magnetic resonance (NMR)- spin–spin relaxation time (T{sub 2}). A comparison of the seed development characteristics, composition and physical properties indicated that, characteristics like seed weight, seed number/ear, rate of seed filling increased with development stages but decreased with moisture stress conditions. The NMR- spin–spin relaxation (T{sub 2}) component like bound water increased with seed maturation (40–50%) but decreased with moisture stress conditions (30–40%). The changes in seed water status to increasing levels of moisture stress and seed maturity indicates that moisture stress resulted in more proportion of water to bound state and intermediate state and less proportion of water in free-state. These changes are further corroborated by significant changes in protein and starch contents in seeds under high moisture stress treatments. Thus seed water status during its development is not only affected by development processes but also by moisture stress conditions. This study strongly indicated a clear moisture stress and development stage dependence of seed tissue water status in developing soybean seeds.

  14. Mature Teachers Matter

    ERIC Educational Resources Information Center

    Berl, Patricia Scallan

    2005-01-01

    In this article, the author discusses the consequences of losing mature teachers due to voluntary separation or retirement and the mindset of a mature teacher that is different from younger teachers in a number of ways. Mature teachers are colleagues over 45 years of age possessing significant experience in the field. Future trends in teacher…

  15. [Dynamics of Quercus variabilis seed rain and soil seed bank in different habitats on the north slope of Qinling Mountains].

    PubMed

    Wu, Min; Zhang, Wen-Hui; Zhou, Jian-Yun; Ma, Chuang; Ma, Li-Wei

    2011-11-01

    In order to explore the dynamics of Quercus variabilis seed rain and soil seed bank in different habitats on the north slope of Qinling Mountains, three kinds of micro-habitats (understory, forest gap, and forest edge) were selected, with the seed rain quantity and quality of Q. variabilis, seed amount and viability in soil seed bank, as well as the seedling development of Q. variabilis studied. The seed rain of Q. variabilis started from mid August, reached the peak in mid September-early October, and ended at the beginning of November, and there existed differences in the dissemination process, occurrence time, and composition of the seed rain among the three micro-habitats. The seed rain had the maximum intensity (39.55 +/- 5.56 seeds x m(-2)) in understory, the seeds had the earliest landing time, the longest lasting duration, and the highest viability in forest gap, and the mature seeds had the largest proportion in forest edge, accounting for 58.7% of the total. From the ending time of seed rain to next August, the total reserve of soil seed bank was the largest in understory and the smallest in forest edge. In the three habitats, the amount of mature and immature seeds, that of seeds eaten by animals, and the seed viability in soil seed bank all decreased with time. In contrast, the number of moldy seeds increased. The seeds were mainly concentrated in litter layer, a few of them were in 0-2 cm soil layer, and few were in 2-5 cm soil layer. The density of the seedlings varied with habitats, being the largest in forest gap, followed by in forest edge, and the least in understory, which suggested that forest gap was more suitable for the seed germination and seedling growth of Q. variabilis, and thus, appropriate thinning should be taken to increase forest gap to provide favorable conditions for the natural regeneration of Q. variabilis forest.

  16. The role of the testa during development and in establishment of dormancy of the legume seed

    PubMed Central

    Smýkal, Petr; Vernoud, Vanessa; Blair, Matthew W.; Soukup, Aleš; Thompson, Richard D.

    2014-01-01

    Timing of seed germination is one of the key steps in plant life cycles. It determines the beginning of plant growth in natural or agricultural ecosystems. In the wild, many seeds exhibit dormancy and will only germinate after exposure to certain environmental conditions. In contrast, crop seeds germinate as soon as they are imbibed usually at planting time. These domestication-triggered changes represent adaptations to cultivation and human harvesting. Germination is one of the common sets of traits recorded in different crops and termed the “domestication syndrome.” Moreover, legume seed imbibition has a crucial role in cooking properties. Different seed dormancy classes exist among plant species. Physical dormancy (often called hardseededness), as found in legumes, involves the development of a water-impermeable seed coat, caused by the presence of phenolics- and suberin-impregnated layers of palisade cells. The dormancy release mechanism primarily involves seed responses to temperature changes in the habitat, resulting in testa permeability to water. The underlying genetic controls in legumes have not been identified yet. However, positive correlation was shown between phenolics content (e.g., pigmentation), the requirement for oxidation and the activity of catechol oxidase in relation to pea seed dormancy, while epicatechin levels showed a significant positive correlation with soybean hardseededness. myeloblastosis family of transcription factors, WD40 proteins and enzymes of the anthocyanin biosynthesis pathway were involved in seed testa color in soybean, pea and Medicago, but were not tested directly in relation to seed dormancy. These phenolic compounds play important roles in defense against pathogens, as well as affecting the nutritional quality of products, and because of their health benefits, they are of industrial and medicinal interest. In this review, we discuss the role of the testa in mediating legume seed germination, with a focus on

  17. Seed rain, soil seed bank, seed loss and regeneration of Castanopsis fargesii (Fagaceae) in a subtropical evergreen broad-leaved forest

    USGS Publications Warehouse

    Du, X.; Guo, Q.; Gao, X.; Ma, K.

    2007-01-01

    Understanding the seed rain and seed loss dynamics in the natural condition has important significance for revealing the natural regeneration mechanisms. We conducted a 3-year field observation on seed rain, seed loss and natural regeneration of Castanopsis fargesii Franch., a dominant tree species in evergreen broad-leaved forests in Dujiangyan, southwestern China. The results showed that: (1) there were marked differences in (mature) seed production between mast (733,700 seeds in 2001) and regular (51,200 and 195,600 seeds in 2002 and 2003, respectively) years for C. fargesii. (2) Most seeds were dispersed in leaf litter, humus and 0-2 cm depth soil in seed bank. (3) Frequency distributions of both DBH and height indicated that C. fargesii had a relatively stable population. (4) Seed rain, seed ground density, seed loss, and leaf fall were highly dynamic and certain quantity of seeds were preserved on the ground for a prolonged time due to predator satiation in both the mast and regular years so that the continuous presence of seed bank and seedling recruitments in situ became possible. Both longer time observations and manipulative experiments should be carried out to better understand the roles of seed dispersal and regeneration process in the ecosystem performance. ?? 2006 Elsevier B.V. All rights reserved.

  18. Continued results of the seeds in space experiment

    NASA Technical Reports Server (NTRS)

    Alston, Jim A.

    1992-01-01

    Two million seeds of 120 different varieties representing 106 species, 97 genera, and 55 plant families were flown aboard the Long Duration Exposure Facility (LDEF). The seeds were housed on the Space Exposed Experiment Developed for Students (SEEDS) tray in the sealed canister number 6 and in two small vented canisters. The seeds were germinated and the germination rates and development of the resulting plants compared to the control seed that stayed in the storage facility. There was a better survival rate in the sealed canister in space than in the storage facility. At least some of the seed in the vented canisters survived the exposure to vacuum for almost six years. The number of observed mutations was very low. In the initial testing, the small seeded crops were not grown to maturity to check for mutation and obtain a second generation seed. These small seeded crops are now being grown for evaluation.

  19. Involvement of reactive oxygen species in endosperm cap weakening and embryo elongation growth during lettuce seed germination.

    PubMed

    Zhang, Yu; Chen, Bingxian; Xu, Zhenjiang; Shi, Zhaowan; Chen, Shanli; Huang, Xi; Chen, Jianxun; Wang, Xiaofeng

    2014-07-01

    Endosperm cap (CAP) weakening and embryo elongation growth are prerequisites for the completion of lettuce seed germination. Although it has been proposed that the cell wall loosening underlying these processes results from an enzymatic mechanism, it is still unclear which enzymes are involved. Here it is shown that reactive oxygen species (ROS), which are non-enzymatic factors, may be involved in the two processes. In Guasihong lettuce seeds imbibed in water, O2·(-) and H2O2 accumulated and peroxidase activity increased in the CAP, whereas its puncture force decreased. In addition, in the radicle, the increase in embryo growth potential was accompanied by accumulation of O2·(-) and an increase in peroxidase activity. Imbibing seeds in 0.3% sodium dichloroisocyanurate (SDIC) reduced endosperm viability and the levels of O2·(-), H2O2, and peroxidase activity in the CAP, whereas the decrease in its puncture force was inhibited. However, in the embryo, SDIC did not affect the accumulation of O2·(-), peroxidase activity, and the embryo growth potential. As a result, SDIC caused atypical germination, in which the endosperm ruptured at the boundary between the CAP and lateral endosperm. ROS scavengers and ROS generation inhibitors inhibited the CAP weakening and also decreased the embryo growth potential, thus decreasing the percentage of seed germination. Exogenous ROS and ROS generation inducers increased the percentage of CAP rupture to some extent, and the addition of H2O2 to 0.3% SDIC enabled some seeds to undergo typical germination.

  20. ABA crosstalk with ethylene and nitric oxide in seed dormancy and germination

    PubMed Central

    Arc, Erwann; Sechet, Julien; Corbineau, Françoise; Rajjou, Loïc; Marion-Poll, Annie

    2013-01-01

    Dormancy is an adaptive trait that enables seed germination to coincide with favorable environmental conditions. It has been clearly demonstrated that dormancy is induced by abscisic acid (ABA) during seed development on the mother plant. After seed dispersal, germination is preceded by a decline in ABA in imbibed seeds, which results from ABA catabolism through 8′-hydroxylation. The hormonal balance between ABA and gibberellins (GAs) has been shown to act as an integrator of environmental cues to maintain dormancy or activate germination. The interplay of ABA with other endogenous signals is however less documented. In numerous species, ethylene counteracts ABA signaling pathways and induces germination. In Brassicaceae seeds, ethylene prevents the inhibitory effects of ABA on endosperm cap weakening, thereby facilitating endosperm rupture and radicle emergence. Moreover, enhanced seed dormancy in Arabidopsis ethylene-insensitive mutants results from greater ABA sensitivity. Conversely, ABA limits ethylene action by down-regulating its biosynthesis. Nitric oxide (NO) has been proposed as a common actor in the ABA and ethylene crosstalk in seed. Indeed, convergent evidence indicates that NO is produced rapidly after seed imbibition and promotes germination by inducing the expression of the ABA 8′-hydroxylase gene, CYP707A2, and stimulating ethylene production. The role of NO and other nitrogen-containing compounds, such as nitrate, in seed dormancy breakage and germination stimulation has been reported in several species. This review will describe our current knowledge of ABA crosstalk with ethylene and NO, both volatile compounds that have been shown to counteract ABA action in seeds and to improve dormancy release and germination. PMID:23531630

  1. ABA crosstalk with ethylene and nitric oxide in seed dormancy and germination.

    PubMed

    Arc, Erwann; Sechet, Julien; Corbineau, Françoise; Rajjou, Loïc; Marion-Poll, Annie

    2013-01-01

    Dormancy is an adaptive trait that enables seed germination to coincide with favorable environmental conditions. It has been clearly demonstrated that dormancy is induced by abscisic acid (ABA) during seed development on the mother plant. After seed dispersal, germination is preceded by a decline in ABA in imbibed seeds, which results from ABA catabolism through 8'-hydroxylation. The hormonal balance between ABA and gibberellins (GAs) has been shown to act as an integrator of environmental cues to maintain dormancy or activate germination. The interplay of ABA with other endogenous signals is however less documented. In numerous species, ethylene counteracts ABA signaling pathways and induces germination. In Brassicaceae seeds, ethylene prevents the inhibitory effects of ABA on endosperm cap weakening, thereby facilitating endosperm rupture and radicle emergence. Moreover, enhanced seed dormancy in Arabidopsis ethylene-insensitive mutants results from greater ABA sensitivity. Conversely, ABA limits ethylene action by down-regulating its biosynthesis. Nitric oxide (NO) has been proposed as a common actor in the ABA and ethylene crosstalk in seed. Indeed, convergent evidence indicates that NO is produced rapidly after seed imbibition and promotes germination by inducing the expression of the ABA 8'-hydroxylase gene, CYP707A2, and stimulating ethylene production. The role of NO and other nitrogen-containing compounds, such as nitrate, in seed dormancy breakage and germination stimulation has been reported in several species. This review will describe our current knowledge of ABA crosstalk with ethylene and NO, both volatile compounds that have been shown to counteract ABA action in seeds and to improve dormancy release and germination.

  2. Galactinol as marker for seed longevity.

    PubMed

    de Souza Vidigal, Deborah; Willems, Leo; van Arkel, Jeroen; Dekkers, Bas J W; Hilhorst, Henk W M; Bentsink, Leónie

    2016-05-01

    Reduced seed longevity or storability is a major problem in seed storage and contributes to increased costs in crop production. Here we investigated whether seed galactinol contents could be predictive for seed storability behavior in Arabidopsis, cabbage and tomato. The analyses revealed a positive correlation between galactinol content and seed longevity in the three species tested, which indicates that this correlation is conserved in the Brassicaceae and beyond. Quantitative trait loci (QTL) mapping in tomato revealed a co-locating QTL for galactinol content and seed longevity on chromosome 2. A candidate for this QTL is the GALACTINOL SYNTHASE gene (Solyc02g084980.2.1) that is located in the QTL interval. GALACTINOL SYNTHASE is a key enzyme of the raffinose family oligosaccharide (RFO) pathway. To investigate the role of enzymes in the RFO pathway in more detail, we applied a reverse genetics approach using T-DNA knock-out lines in genes encoding enzymes of this pathway (GALACTINOL SYNTHASE 1, GALACTINOL SYNTHASE 2, RAFFINOSE SYNTHASE, STACHYOSE SYNTHASE and ALPHA-GALACTOSIDASE) and overexpressors of the cucumber GALACTINOL SYNTHASE 2 gene in Arabidopsis. The galactinol synthase 2 mutant and the galactinol synthase 1 galactinol synthase 2 double mutant contained the lowest seed galactinol content which coincided with lower seed longevity. These results show that galactinol content of mature dry seed can be used as a biomarker for seed longevity in Brassicaceae and tomato.

  3. Seed dispersal limitations shift over time in tropical forest restoration.

    PubMed

    Reid, J Leighton; Holl, Karen D; Zahawi, Rakan A

    2015-06-01

    Past studies have shown that tropical forest regeneration on degraded farmlands is initially limited by lack of seed dispersal, but few studies have tracked changes in abundance and composition of seed rain past the first few years after land abandonment. We measured seed rain for 12 months in 10 6-9-year-old restoration sites and five mature, reference forests in southern Costa Rica in order to learn (1) if seed rain limitation persists past the first few years of regeneration; (2) how restoration treatments influence seed community structure and composition; and (3) whether seed rain limitation is contingent on landscape context. Each restoration site contained three 0.25-ha treatment plots: (1) a naturally regenerating control, (2) tree islands, and (3) a mixed-species tree plantation. Sites spanned a deforestation gradient with 9-89% forest area within 500 m around the treatment plots. Contrary to previous studies, we found that tree seeds were abundant and ubiquitous across all treatment plots (585.1 ± 142.0 seeds · m(-2) · yr(-1) [mean ± SE]), indicating that lack of seed rain ceased to limit forest regeneration within the first decade of recovery. Pioneer trees and shrubs comprised the vast majority of seeds, but compositional differences between restoration sites and reference forests were driven by rarer, large-seeded species. Large, animal-dispersed tree seeds were more abundant in tree islands (4.6 ± 2.9 seeds · m(-2) · yr(-1)) and plantations (5.8 ± 3.0 seeds · m(-2) · yr(-1)) than control plots (0.2 ± 0.1 seeds · m(-2) · yr(-1)), contributing to greater tree species richness in actively restored plots. Planted tree species accounted for < 1% of seeds. We found little evidence for landscape forest cover effects on seed rain, consistent with previous studies. We conclude that seed rain limitation shifted from an initial, complete lack of tree seeds to a specific limitation on large-seeded, mature forest species over the first decade

  4. [Adolescent brain maturation].

    PubMed

    Holzer, L; Halfon, O; Thoua, V

    2011-05-01

    Recent progress in neuroscience has yielded major findings regarding brain maturation during adolescence. Unlike the body, which reaches adult size and morphology during this period, the adolescent brain is still maturing. The prefrontal cortex appears to be an important locus of maturational change subserving executive functions that may regulate emotional and motivational issues. The recent expansion of the adolescent period has increased the lag between the onset of emotional and motivational changes activated by puberty and the completion of cognitive development-the maturation of self-regulatory capacities and skills that are continuing to develop long after puberty has occurred. This "disconnect" predicts risk for a broad set of behavioral and emotional problems. Adolescence is a critical period for high-level cognitive functions such as socialization that rely on maturation of the prefrontal cortex. Intervention during the period of adolescent brain development provides opportunities and requires an interdisciplinary approach.

  5. Scanning electron microscopy in characterizing seeds of some leguminous trees

    NASA Astrophysics Data System (ADS)

    Ghosh, Nabarun; Chatterjee, Amiyanghshu; Smith, Don W.

    2009-05-01

    SEM has greatly increased our knowledge of the microstructure of seeds. Mature seed coats are rather thick walled and stable in a vacuum: this allows quick preparation for SEM examination, without the need of complicated dehydration techniques. The low level of technical expenditure required, in combination with the high structural diversity exhibited and the intuitive ability to understand the "three dimensional", often aesthetically appealing micro-structures visualized, has turned seed-coat studies into a favorite tool of many taxonomists. We used dry mature seeds of 26 species of 4 Leguminous genera, Acacia, Albizia, Cassia and Dalbergia to standardize a procedure for identifying the seeds through SEM on the seed surface and seed sections. We cut transverse and longitudinal sections of the seeds and observed the sections from different regions of seeds: midseed, near the hilum and two distal ends. Light microscopy showed the color, texture, pleurograms, fissures and hilum at lower magnification. The anatomical study with SEM on the seed sections revealed the size, shape, and number of tiers and cellular organization of the epidermis, hypodermis, endosperm and internal structural details. We found the ornamentation pattern of the seeds including undulations, reticulations and rugae that were species specific. Species of Dalbergia (assamica, latifolia and sissoo), Albizia (odoratissima and procera), Acaia (arabica and catechu) and Cassia (glauca, siamia and spectabilis) are difficult to distinguish externally, but SEM studies provided enough characteristic features to distinguish from the other. This technique could be valuable in identifying seeds of important plant species for conservation and trading.

  6. Flavonoids Released Naturally from Alfalfa Seeds Enhance Growth Rate of Rhizobium meliloti1

    PubMed Central

    Hartwig, Ueli A.; Joseph, Cecillia M.; Phillips, Donald A.

    1991-01-01

    Alfalfa (Medicago sativa L.) releases different flavonoids from seeds and roots. Imbibing seeds discharge 3′,4′,5,7-substituted flavonoids; roots exude 5-deoxy molecules. Many, but not all, of these flavonoids induce nodulation (nod) genes in Rhizobium meliloti. The dominant flavonoid released from alfalfa seeds is identified here as quercetin-3-O-galactoside, a molecule that does not induce nod genes. Low concentrations (1-10 micromolar) of this compound, as well as luteolin-7-O-glucoside, another major flavonoid released from germinating seeds, and the aglycones, quercetin and luteolin, increase growth rate of R. meliloti in a defined minimal medium. Tests show that the 5,7-dihydroxyl substitution pattern on those molecules was primarily responsible for the growth effect, thus explaining how 5-deoxy flavonoids in root exudates fail to enhance growth of R. meliloti. Luteolin increases growth by a mechanism separate from its capacity to induce rhizobial nod genes, because it still enhanced growth rate of R. meliloti lacking functional copies of the three known nodD genes. Quercetin and luteolin also increased growth rate of Pseudomonas putida. They had no effect on growth rate of Bacillus subtilis or Agrobacterium tumefaciens, but they slowed growth of two fungal pathogens of alfalfa. These results suggest that alfalfa can create ecochemical zones for controlling soil microbes by releasing structurally different flavonoids from seeds and roots. PMID:16668056

  7. Mobilization of storage materials during light-induced germination of tomato (Solanum lycopersicum) seeds.

    PubMed

    Eckstein, Aleksandra; Jagiełło-Flasińska, Dominika; Lewandowska, Aleksandra; Hermanowicz, Paweł; Appenroth, Klaus-J; Gabryś, Halina

    2016-08-01

    The aim of this study was to analyze the metabolism of storage materials in germinating tomato (Solanum lycopersicum) seeds and to determine whether it is regulated by light via phytochromes. Wild type, single and multiple phytochrome A, B1 and B2 mutants were investigated. Imbibed seeds were briefly irradiated with far-red or far-red followed by red light, and germinated in darkness. Triacylglycerols and starch were quantified using biochemical assays in germinating seeds and seedlings during the first 5 days of growth. To investigate the process of fat-carbohydrate transformation, the activity of the glyoxylate cycle was assessed. Our results confirm the role of phytochrome in the control of tomato seed germination. Phytochromes A and B2 were shown to play specific roles, acting antagonistically in far-red light. While the breakdown of triacylglycerols proceeded independently of light, phytochrome control was visible in the next stages of the lipid-carbohydrate transformation. The key enzymes of the glyoxylate cycle, isocitrate lyase and malate synthase, were regulated by phytochrome(s). This was reflected in a greater increase of starch content during seedling growth in response to additional red light treatment. This study is the first attempt to build a comprehensive image of storage material metabolism regulation by light in germinating dicotyledonous seeds.

  8. Oxidative metabolism-related changes in cryogenically stored neem (Azadirachta indica A. Juss) seeds.

    PubMed

    Varghese, Boby; Naithani, Subhash Chandra

    2008-05-05

    The seeds of Azadirachta indica were successfully cryopreserved for 12 months with 45% survival following drying to 0.16 g H(2)O g(-1) dry mass (DM). Highest survival (94-96%) was recorded during the first month of cryostorage. Subsequent cryopreservation up to 12 months resulted in decreasing germination. Post-thawing pre-heat treatment enhanced the recovery marginally in seeds cryopreserved from 3 to 12 months. Viability of cryostored seeds was negatively correlated with leachate conductivity and accumulation of thiobarbituric acid reactive substances (TBRS) estimated in cotyledons and axes. Leachate conductivity of imbibed seeds was low during the first month of cryostorage but increased gradually with the duration of cryostorage to a maximum after 12 months. TBRS accumulation was gradual throughout cryostorage. Relatively low amounts of active oxygen species (AOS) detected during the first month of cryostorage were closely associated with very high activities of superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX) in seeds (cotyledons and axes). Marked accumulation of AOS from 3 to 12 months was associated with decrease in antioxidant enzyme activity.

  9. Using μPIXE for quantitative mapping of metal concentration in Arabidopsis thaliana seeds

    PubMed Central

    Schnell Ramos, Magali; Khodja, Hicham; Mary, Viviane; Thomine, Sébastien

    2013-01-01

    Seeds are a crucial stage in plant life. They contain the nutrients necessary to initiate the development of a new organism. Seeds also represent an important source of nutrient for human beings. Iron (Fe) and zinc (Zn) deficiencies affect over a billion people worldwide. It is therefore important to understand how these essential metals are stored in seeds. In this work, Particle-Induced X-ray Emission with the use of a focused ion beam (μPIXE) has been used to map and quantify essential metals in Arabidopsis seeds. In agreement with Synchrotron radiation X-ray fluorescence (SXRF) imaging and Perls/DAB staining, μPIXE maps confirmed the specific pattern of Fe and Mn localization in the endodermal and subepidermal cell layers in dry seeds, respectively. Moreover, μPIXE allows absolute quantification revealing that the Fe concentration in the endodermal cell layer reaches ~800 μg·g−1 dry weight. Nevertheless, this cell layer accounts only for about half of Fe stores in dry seeds. Comparison between Arabidopsis wild type (WT) and mutant seeds impaired in Fe vacuolar storage (vit1-1) or release (nramp3nramp4) confirmed the strongly altered Fe localization pattern in vit1-1, whereas no alteration could be detected in nramp3nramp4 dry seeds. Imaging of imbibed seeds indicates a dynamic localization of metals as Fe and Zn concentrations increase in the subepidermal cell layer of cotyledons after imbibition. The complementarities between μPIXE and other approaches as well as the importance of being able to quantify the patterns for the interpretation of mutant phenotypes are discussed. PMID:23761799

  10. Biomechanical, biochemical, and morphological mechanisms of heat shock-mediated germination in Carica papaya seed

    PubMed Central

    Webster, Rachel E.; Waterworth, Wanda M.; Stuppy, Wolfgang; West, Christopher E.; Ennos, Roland; Bray, Clifford M.; Pritchard, Hugh W.

    2016-01-01

    Carica papaya (papaya) seed germinate readily fresh from the fruit, but desiccation induces a dormant state. Dormancy can be released by exposure of the hydrated seed to a pulse of elevated temperature, typical of that encountered in its tropical habitat. Carica papaya is one of only a few species known to germinate in response to heat shock (HS) and we know little of the mechanisms that control germination in tropical ecosystems. Here we investigate the mechanisms that mediate HS-induced stimulation of germination in pre-dried and re-imbibed papaya seed. Exogenous gibberellic acid (GA3 ≥250 µM) overcame the requirement for HS to initiate germination. However, HS did not sensitise seeds to GA3, indicative that it may act independently of GA biosynthesis. Seed coat removal also overcame desiccation-imposed dormancy, indicative that resistance to radicle emergence is coat-imposed. Morphological and biomechanical studies identified that neither desiccation nor HS alter the physical structure or the mechanical strength of the seed coat. However, cycloheximide prevented both seed coat weakening and germination, implicating a requirement for de novo protein synthesis in both processes. The germination antagonist abscisic acid prevented radicle emergence but had no effect on papaya seed coat weakening. Desiccation therefore appears to reduce embryo growth potential, which is reversed by HS, without physically altering the mechanical properties of the seed coat. The ability to germinate in response to a HS may confer a competitive advantage to C. papaya, an opportunistic pioneer species, through detection of canopy removal in tropical forests. PMID:27811004

  11. Biomechanical, biochemical, and morphological mechanisms of heat shock-mediated germination in Carica papaya seed.

    PubMed

    Webster, Rachel E; Waterworth, Wanda M; Stuppy, Wolfgang; West, Christopher E; Ennos, Roland; Bray, Clifford M; Pritchard, Hugh W

    2016-12-01

    Carica papaya (papaya) seed germinate readily fresh from the fruit, but desiccation induces a dormant state. Dormancy can be released by exposure of the hydrated seed to a pulse of elevated temperature, typical of that encountered in its tropical habitat. Carica papaya is one of only a few species known to germinate in response to heat shock (HS) and we know little of the mechanisms that control germination in tropical ecosystems. Here we investigate the mechanisms that mediate HS-induced stimulation of germination in pre-dried and re-imbibed papaya seed. Exogenous gibberellic acid (GA3 ≥250 µM) overcame the requirement for HS to initiate germination. However, HS did not sensitise seeds to GA3, indicative that it may act independently of GA biosynthesis. Seed coat removal also overcame desiccation-imposed dormancy, indicative that resistance to radicle emergence is coat-imposed. Morphological and biomechanical studies identified that neither desiccation nor HS alter the physical structure or the mechanical strength of the seed coat. However, cycloheximide prevented both seed coat weakening and germination, implicating a requirement for de novo protein synthesis in both processes. The germination antagonist abscisic acid prevented radicle emergence but had no effect on papaya seed coat weakening. Desiccation therefore appears to reduce embryo growth potential, which is reversed by HS, without physically altering the mechanical properties of the seed coat. The ability to germinate in response to a HS may confer a competitive advantage to C. papaya, an opportunistic pioneer species, through detection of canopy removal in tropical forests.

  12. Changes in seed water status as characterized by NMR in developing soybean seed grown under moisture stress conditions.

    PubMed

    Krishnan, P; Singh, Ravender; Verma, A P S; Joshi, D K; Singh, Sheoraj

    2014-02-21

    Changes in water status of developing seeds of Soybean (Glycine max L. Merrill.) grown under different moisture stress conditions were characterized by proton nuclear magnetic resonance (NMR)- spin-spin relaxation time (T2). A comparison of the seed development characteristics, composition and physical properties indicated that, characteristics like seed weight, seed number/ear, rate of seed filling increased with development stages but decreased with moisture stress conditions. The NMR- spin-spin relaxation (T2) component like bound water increased with seed maturation (40-50%) but decreased with moisture stress conditions (30-40%). The changes in seed water status to increasing levels of moisture stress and seed maturity indicates that moisture stress resulted in more proportion of water to bound state and intermediate state and less proportion of water in free-state. These changes are further corroborated by significant changes in protein and starch contents in seeds under high moisture stress treatments. Thus seed water status during its development is not only affected by development processes but also by moisture stress conditions. This study strongly indicated a clear moisture stress and development stage dependence of seed tissue water status in developing soybean seeds.

  13. A Race for Survival: Can Bromus tectorum Seeds Escape Pyrenophora semeniperda-caused Mortality by Germinating Quickly?

    PubMed Central

    Beckstead, Julie; Meyer, Susan E.; Molder, Cherrilyn J.; Smith, Caitlyn

    2007-01-01

    Background and Aims Pathogen–seed interactions may involve a race for seed resources, so that seeds that germinate more quickly, mobilizing reserves, will be more likely to escape seed death than slow-germinating seeds. This race-for-survival hypothesis was tested for the North American seed pathogen Pyrenophora semeniperda on seeds of the annual grass Bromus tectorum, an invasive plant in North America. In this species, the seed germination rate varies as a function of dormancy status; dormant seeds germinate slowly if at all, whereas non-dormant seeds germinate quickly. Methods Three experimental approaches were utilized: (a) artificial inoculations of mature seeds that varied in primary dormancy status and wounding treatment; (b) naturally inoculated undispersed seeds that varied in primary dormancy status; and (c) naturally inoculated seeds from the carry-over seed bank that varied in degree of secondary dormancy, habitat of origin and seed age. Key Results In all three approaches, seeds that germinated slowly were usually killed by the pathogen, whereas seeds that germinated quickly frequently escaped. Pyrenophora semeniperda reduced B. tectorum seed banks. Populations in drier habitats sustained 50 times more seed mortality than a population in a mesic habitat. Older carry-over seeds experienced 30 % more mortality than younger seeds. Conclusions Given the dramatic levels of seed death and the ability of this pathogen to reduce seed carry-over, it is intriguing to consider whether P. semeniperda could be used to control B. tectorum through direct reduction of its seed bank. PMID:17353206

  14. MYB76 Inhibits Seed Fatty Acid Accumulation in Arabidopsis

    PubMed Central

    Duan, Shaowei; Jin, Changyu; Li, Dong; Gao, Chenhao; Qi, Shuanghui; Liu, Kaige; Hai, Jiangbo; Ma, Haoli; Chen, Mingxun

    2017-01-01

    The MYB family of transcription factors is important in regulatory networks controlling development, metabolism and responses to biotic and abiotic stresses in Arabidopsis. However, their role in regulating fatty acid accumulation in seeds is still largely unclear. Here, we found that MYB76, localized in the nucleus, was predominantly expressed in developing seeds during maturation. The myb76 mutation caused a significant increase in the amounts of total fatty acids and several major fatty acid compositions in mature seeds, suggesting that MYB76 functioned as an important repressor during seed oil biosynthesis. RNA sequencing and quantitative real-time PCR analysis revealed remarkable alteration of numerous genes involved in photosynthesis, fatty acid biosynthesis, modification, and degradation, and oil body formation in myb76 seeds at 12 days after pollination. These results help us to understand the novel function of MYB76 and provide new insights into the regulatory network of MYB transcriptional factors controlling seed oil accumulation in Arabidopsis. PMID:28270825

  15. Dormancy as exaptation to protect mimetic seeds against deterioration before dispersal

    PubMed Central

    Brancalion, Pedro H. S.; Novembre, Ana D. L. C.; Rodrigues, Ricardo R.; Marcos Filho, Júlio

    2010-01-01

    Background and Aims Mimetic seeds simulate the appearance of fleshy fruits and arilled seeds without producing nutritive tissues as a reward for seed dispersers. In this strategy of seed dispersal, seeds may remain attached to the mother plant for long periods after maturity, increasing their availability to naïve seed dispersers. The hypothesis that seed coat impermeability in many tropical Fabaceae with mimetic seeds serves as an exaptation to protect the seeds from deterioration and rotting while awaiting dispersal was investigated. Methods Seed coat impermeability was evaluated in five mimetic-seeded species of tropical Fabaceae in south-eastern Brazil (Abarema langsdorffii, Abrus precatorius, Adenanthera pavonina, Erythrina velutina and Ormosia arborea) and in Erythrina speciosa, a ‘basal’ species in its genus, which has monochromatic brown seeds and no mimetic displays. Seed hardness was evaluated as a defence against accelerated ageing (humid chamber at 41 °C for 144 h). Seed development and physiological potential of O. arborea was evaluated and the effect of holding mature seeds in pods on the mother plant in the field for a period of 1 year under humid tropical conditions was compared with seeds stored under controlled conditions (15 °C and 40 % relative air humidity). Key Results All five mimetic-seeded species, and E. speciosa, showed strong coat impermeability, which protected the seeds against deterioration in accelerated ageing. Most O. arborea seeds only became dormant 2 months after pod dehiscence. Germination of seeds after 1 year on the plant in a humid tropical climate was 56 %, compared with 80 % for seeds stored in controlled conditions (15 °C, 45 % relative humidity). Seedling shoot length after 1 year did not differ between seed sources. Conclusions Dormancy acts in mimetic-seeded species as an exaptation to reduce seed deterioration, allowing an increase in their effective dispersal period and mitigating the losses incurred by low

  16. The 120-yr period for Dr. Beal's seed viability experiment.

    PubMed

    Telewski, Frank W; Zeevaart, Jan A D

    2002-08-01

    After 120 yr of burial in moist, well-aerated sand, 23 seeds of Verbascum blattaria and two seeds of a Verbascum sp. germinated and produced normal plants (50% germination for Verbascum). After a 6-wk cold treatment, a single seed of Malva rotundifolia germinated also, producing a normal plant (2% germination). Plants were grown to maturity in a greenhouse, and flowering was induced by exposure to a 6-wk cold treatment. Flowers were artificially pollinated to produce seed of both Verbascum blattaria and Malva rotundifolia. The Verbascum sp. failed to set seed. Collected seeds were subsequently germinated, producing normal plants. F(1) seeds of V. blattaria had a germination of 64%. Seeds (6%) of M. rotundifolia germinated after a cold treatment.

  17. Continued results of the seeds in space experiment

    NASA Technical Reports Server (NTRS)

    Alston, Jim A.

    1993-01-01

    Two million seeds of 120 different varieties representing 106 species, 97 genera, and 55 plant families were flown aboard the Long Duration Exposure Facility (LDEF). The seed were housed on the Space Exposed Experiment Developed for Students (SEEDS) tray in the sealed canister number 6 and in two small vented canisters. The tray was in the F-2 position. The seed were germinated and the germination rates and the development of the resulting plants were compared to the performance of the control seed that stayed in Park Seed's seed storage facility. The initial results were presented in a paper at the First LDEF Post-Retrieval Symposium. There was a better survival rate of the seed in the sealed canister in space than in the storage facility at Park Seed. At least some of the seed in each of the vented canisters survived the exposure to vacuum for almost six years. The number of observed apparent mutations was very low. In the initial testing, the small seeded crops were not grown to maturity to check for mutations and obtain second generation seed. These small seeded crops have now been grown for evaluation and second generation seed collected.

  18. ‘WhiteAcre-DG’, a Small-seeded, Cream-type Southernpea with an Enhanced Persistent Green Seed Phenotype

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The USDA has released a high yielding, small-seeded, cream-type southernpea cultivar that has a persistent green seed phenotype conditioned by both the green cotyledon gene (gc) and the green testa gene (gt). The new cultivar, named ‘WhiteAcre-DG’, can be harvested at the dry-pod stage of maturity ...

  19. Identification of a characteristic antioxidant, anthrasesamone F, in black sesame seeds and its accumulation at different seed developmental stages.

    PubMed

    Furumoto, Toshio; Nishimoto, Kiyoshi

    2016-01-01

    Assay-guided fractionation of the methanol extract from black seeds of sesame (Sesamum indicum L.) led to the isolation of an active compound that had a 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity. This antioxidant was confirmed to be anthrasesamone F, an anthraquinone derivative previously isolated from different black sesame seeds and biogenetically related to other anthrasesamones in sesame roots. The radical scavenging assay showed that anthrasesamone F had more potent activity than Trolox. The content of anthrasesamone F in different parts and at different developmental stages of black sesame seeds was investigated to clarify the accumulation pattern of this antioxidant in the black seeds. Anthrasesamone F was localized in the seed coat of black seeds and accumulated after the seed coat color changed to black. The content of anthrasesamone F increased gradually with seed maturation and drastically on air-drying, the final stage in sesame cultivation.

  20. Toward Teacher Maturity.

    ERIC Educational Resources Information Center

    Pickle, Judy

    1985-01-01

    The essence of teacher maturity can be synthesized into personal, professional, and process domains. Although overlapping, these categories add a multidimensional approach to the search for what is good in teaching and provide a model for professional development. (MT)

  1. Project SEED.

    ERIC Educational Resources Information Center

    Chemical and Engineering News, 1986

    1986-01-01

    Reports on Project SEED (Summer Educational Experience for the Disadvantaged) a project in which high school students from low-income families work in summer jobs in a variety of academic, industrial, and government research labs. The program introduces the students to career possibilities in chemistry and to the advantages of higher education.…

  2. Visualizing Antibody Affinity Maturation in Germinal Centers

    PubMed Central

    Tas, Jeroen M.J.; Mesin, Luka; Pasqual, Giulia; Targ, Sasha; Jacobsen, Johanne T.; Mano, Yasuko M.; Chen, Casie S.; Weill, Jean-Claude; Reynaud, Claude-Agnès; Browne, Edward P.; Meyer-Hermann, Michael; Victora, Gabriel D.

    2016-01-01

    Antibodies somatically mutate to attain high affinity in germinal centers (GCs). There, competition between B cell clones and among somatic mutants of each clone drives an increase in average affinity across the population. The extent to which higher-affinity cells eliminating competitors restricts clonal diversity is unknown. By combining multiphoton microscopy and sequencing, we show that tens to hundreds of distinct B cell clones seed each GC, and that GCs lose clonal diversity at widely disparate rates. Furthermore, efficient affinity maturation can occur in the absence of homogenizing selection, ensuring that many clones can mature in parallel within the same GC. Our findings have implications for development of vaccines in which antibodies with non-immunodominant specificities must be elicited, as is the case for HIV-1 and influenza. PMID:26912368

  3. Organization of lipid reserves in cotyledons of primed and aged sunflower seeds.

    PubMed

    Walters, Christina; Landré, Pierre; Hill, Lisa; Corbineau, Françoise; Bailly, Christophe

    2005-10-01

    Imbibing sunflower (Helianthus annuus L., cv. Briosol) seeds at water potentials between -2 MPa and -5 MPa leads to faster (priming) or slower (accelerated ageing) germination depending on the temperature and duration of treatment. Mobilization of food reserves may be associated with the changes in seed vigor. To study this, morphological, biochemical and phase properties of lipid, the major food reserve in sunflower, were compared in freshly harvested (i.e., control), primed and aged sunflower cotyledons using electron microscopy, biochemical analyses and differential scanning calorimetry, respectively. Lipid bodies became smaller and more dispersed throughout the cytoplasm during priming and ageing. Despite ultrastructural changes, there were few measured changes in biochemistry of the neutral lipid component; lipid content, proportion of saturated and unsaturated fatty acids and level of free fatty acids were unchanged in primed and slightly aged seeds, with only severely aged seeds showing a net decrease in polyunsaturated fatty acids and an increase in free fatty acids. Subtle changes in the calorimetric behavior of lipids within sunflower cotyledons were observed. Sunflower lipids exhibited polymorphic crystalline and amorphous solid phases when cooled to <-100 degrees C, but priming decreased the rate of crystallization in vivo and ageing increased the rate of crystallization, but decreased percentage crystallinity. The observed changes in thermal behavior in vivo are consistent with losses and gains, respectively, of interacting non-lipid moieties in the triacylglycerol matrix.

  4. A detailed survey of seed coat flavonoids in developing seeds of Brassica napus L.

    PubMed

    Auger, Bathilde; Marnet, Nathalie; Gautier, Véronique; Maia-Grondard, Alessandra; Leprince, Françoise; Renard, Michel; Guyot, Sylvain; Nesi, Nathalie; Routaboul, Jean-Marc

    2010-05-26

    Proanthocyanidins (PAs) are seed coat flavonoids that impair the digestibility of Brassica napus meal. Development of low-PA lines is associated with a high-quality meal and with increased contents in oil and proteins, but requires better knowledge of seed flavonoids. Flavonoids in Brassica mature seed are mostly insoluble so that very few qualitative and quantitative data are available yet. In the present study, the profiling of seed coat flavonoids was established in eight black-seeded B. napus genotypes, during seed development when soluble flavonoids were present and predominated over the insoluble forms. Thirteen different flavonoids including (-)-epicatechin, five procyanidins (PCs which are PAs composed of epicatechin oligomers only) and seven flavonols (quercetin-3-O-glucoside, quercetin-dihexoside, isorhamnetin-3-O-glucoside, isorhamnetin-hexoside-sulfate, isorhamnetin-dihexoside, isorhamnetin-sinapoyl-trihexoside and kaempferol-sinapoyl-trihexoside) were identified and quantified using liquid chromatography coupled to electrospray ionization-mass spectrometry (LC-ESI-MS(n)). These flavonol derivatives were characterized for the first time in the seed coat of B. napus, and isorhamnetin-hexoside-sulfate and isorhamnetin-sinapoyl-trihexoside were newly identified in Brassica spp. High amounts of PCs accumulated in the seed coat, with solvent-soluble polymers of (-)-epicatechin reaching up to 10% of the seed coat weight during seed maturation. In addition, variability for both PC and flavonol contents was observed within the panel of eight black-seeded genotypes. Our results provide new insights into breeding for low-PC B. napus genotypes.

  5. Ecosystem services from keystone species: diversionary seeding and seed-caching desert rodents can enhance Indian ricegrass seedling establishment

    USGS Publications Warehouse

    Longland, William; Ostoja, Steven M.

    2013-01-01

    Seeds of Indian ricegrass (Achnatherum hymenoides), a native bunchgrass common to sandy soils on arid western rangelands, are naturally dispersed by seed-caching rodent species, particularly Dipodomys spp. (kangaroo rats). These animals cache large quantities of seeds when mature seeds are available on or beneath plants and recover most of their caches for consumption during the remainder of the year. Unrecovered seeds in caches account for the vast majority of Indian ricegrass seedling recruitment. We applied three different densities of white millet (Panicum miliaceum) seeds as “diversionary foods” to plots at three Great Basin study sites in an attempt to reduce rodents' over-winter cache recovery so that more Indian ricegrass seeds would remain in soil seedbanks and potentially establish new seedlings. One year after diversionary seed application, a moderate level of Indian ricegrass seedling recruitment occurred at two of our study sites in western Nevada, although there was no recruitment at the third site in eastern California. At both Nevada sites, the number of Indian ricegrass seedlings sampled along transects was significantly greater on all plots treated with diversionary seeds than on non-seeded control plots. However, the density of diversionary seeds applied to plots had a marginally non-significant effect on seedling recruitment, and it was not correlated with recruitment patterns among plots. Results suggest that application of a diversionary seed type that is preferred by seed-caching rodents provides a promising passive restoration strategy for target plant species that are dispersed by these rodents.

  6. MYB89 Transcription Factor Represses Seed Oil Accumulation1[OPEN

    PubMed Central

    Li, Dong; Jin, Changyu; Duan, Shaowei; Zhu, Yana; Qi, Shuanghui; Liu, Kaige; Gao, Chenhao; Ma, Haoli; Liao, Yuncheng

    2017-01-01

    In many higher plants, seed oil accumulation is precisely controlled by intricate multilevel regulatory networks, among which transcriptional regulation mainly influences oil biosynthesis. In Arabidopsis (Arabidopsis thaliana), the master positive transcription factors, WRINKLED1 (WRI1) and LEAFY COTYLEDON1-LIKE (L1L), are important for seed oil accumulation. We found that an R2R3-MYB transcription factor, MYB89, was expressed predominantly in developing seeds during maturation. Oil and major fatty acid biosynthesis in seeds was significantly promoted by myb89-1 mutation and MYB89 knockdown; thus, MYB89 was an important repressor during seed oil accumulation. RNA sequencing revealed remarkable up-regulation of numerous genes involved in seed oil accumulation in myb89 seeds at 12 d after pollination. Posttranslational activation of a MYB89-glucocorticoid receptor fusion protein and chromatin immunoprecipitation assays demonstrated that MYB89 inhibited seed oil accumulation by directly repressing WRI1 and five key genes and by indirectly suppressing L1L and 11 key genes involved in oil biosynthesis during seed maturation. These results help us to understand the novel function of MYB89 and provide new insights into the regulatory network of transcriptional factors controlling seed oil accumulation in Arabidopsis. PMID:27932421

  7. Phagosome maturation: aging gracefully.

    PubMed Central

    Vieira, Otilia V; Botelho, Roberto J; Grinstein, Sergio

    2002-01-01

    Foreign particles and apoptotic bodies are eliminated from the body by phagocytic leucocytes. The initial stage of the elimination process is the internalization of the particles into a plasma membrane-derived vacuole known as the phagosome. Such nascent phagosomes, however, lack the ability to kill pathogens or to degrade the ingested targets. These properties are acquired during the course of phagosomal maturation, a complex sequence of reactions that result in drastic remodelling of the phagosomal membrane and contents. The determinants and consequences of the fusion and fission reactions that underlie phagosomal maturation are the topic of this review. PMID:12061891

  8. Predispersal predation of an understory rainforest herb Aphelandra aurantiaca (Acanthaceae) in gaps and mature forest.

    PubMed

    Calvo-Irabién, L M; Islas-Luna, A

    1999-08-01

    The opening of a canopy gap at Los Tuxtlas rainforest has an impact on populations of the understory herb Aphelandra aurantiaca: the ratio of recruited seedlings per reproductive individual is 1:17 in mature forest vs. gaps. Predation occurring before seed dispersal seems a plausible explanation for this observed difference. In a field experiment, in which insecticide was applied to plants growing in gaps and mature forest, we evaluated the extent to which herbivore damage to flowers, fruits, and seeds reduces the number of seeds available for seedling establishment. Under natural conditions, ∼30% of the flowers and >70% of the capsules of A. aurantiaca showed herbivore damage, but its impact changed depending on the type of forest habitat. Flower and fruit herbivores caused more damage in closed forest than in gaps, and this difference was even bigger under the insecticide treatment. Insecticide effectiveness varied depending on the type of forest patch. The highest herbivore impact on seeds was found in the mature forest without insecticide treatment, where most seeds were destroyed. The percentages of seed damage reported here show that predispersal predation is limiting seedling recruitment, especially in mature forest. Other possible explanations might be differences in insect composition, densities, and behavior between gaps and mature forest.

  9. Brain maturation and epilepsy.

    PubMed

    Dulac, Olivier; Milh, Mathieu; Holmes, Gregory L

    2013-01-01

    At full term, both glutamate and gamma-amino-butyric acid (GABA) are excitatory; cortical synapses are beginning to appear, there is little myelin in the cerebral hemispheres, and long tracts hardly start to develop. Neonatal myoclonic encephalopathy can result from premature activation of N-methyl-D-aspartate (NMDA) transmission. Benign neonatal seizures and migrating partial seizures in infancy could involve excessive or premature excitability of deep cortical layers. Benign rolandic epilepsy and continuous spike waves in slow sleep are consistent with an excess of both excitatory and inhibitory cortical synapses. West and Lennox-Gastaut syndromes express age-related diffuse cortical hyperexcitability, the pattern depending on the age of occurrence; synchronization of spikes is becoming possible with maturation of the myelin. Idiopathic generalized epilepsy is itself modulated by maturation that causes frontal hyperexcitability generating myoclonic-astatic seizures, between the ages of infantile and juvenile myoclonic epilepsies. Physiological delay of hippocampo-neocortical pathways maturation could account for the delayed occurrence of mesial temporal epilepsy following infantile damage, whereas premature maturation could contribute to fronto-temporal damage characteristic of fever-induced epileptic encephalopathy in school-age children, a dramatic school-age epileptic encephalopathy.

  10. Maturation in Larch 1

    PubMed Central

    Greenwood, Michael S.; Hopper, Catherine A.; Hutchison, Keith W.

    1989-01-01

    The time course of maturation in eastern larch (Larix laricina [Du Roi] K. Koch) was examined by grafting scions from trees of different ages onto 2-year-old root stock and following scion development for several years. Height, diameter, foliar chlorophyll content, and rooting ability of scion-derived cuttings all varied linearly as a function of log10 age. Chlorophyll content (milligrams per gram of dry weight) increased while height, diameter, and ability to root decreased with age (P < 0.01). The tendency toward orthotropic growth and branch formation per centimeter of main stem decreased abruptly between age 1 and 5 years (P < 0.01). Total chlorophyll content of both long and short shoot foliage increased by 30 to 50% with increasing age, but the chlorophyll a/b ratio did not change. Also, juvenile long shoot needles were significantly longer than mature (P < 0.01). Surprisingly, the juvenile scions produced more total strobili over two successive years, but the mature scions produced a significantly higher proportion of male strobili (P < 0.001 year 1; P < 0.02 year 2). The age-related changes in foliar traits were not associated with changes in DNA methylation between juvenile and mature scions. Using HPLC, we found that 20% of foliar DNA cytosine residues were methylated in both scion types. Images Figure 1 PMID:16666785

  11. Mature Students Studying Mathematics.

    ERIC Educational Resources Information Center

    Hirst, Keith

    1999-01-01

    Discusses mature students in the single subject area of mathematics in a single institution and makes comparisons with traditional universities. Reviews some features of the age distribution, entry qualifications, degree-class distribution, non-completion rates and gender distribution. (Author/ASK)

  12. Involvement of Polyamine Oxidase-Produced Hydrogen Peroxide during Coleorhiza-Limited Germination of Rice Seeds

    PubMed Central

    Chen, Bing-Xian; Li, Wen-Yan; Gao, Yin-Tao; Chen, Zhong-Jian; Zhang, Wei-Na; Liu, Qin-Jian; Chen, Zhuang; Liu, Jun

    2016-01-01

    Seed germination is a complicated biological process that requires regulated enzymatic and non-enzymatic reactions. The action of polyamine oxidase (PAO) produces hydrogen peroxide (H2O2), which promotes dicot seed germination. However, whether and, if so, how PAOs regulate monocot seed germination via H2O2 production is unclear. Herein, we report that the coleorhiza is the main physical barrier to radicle protrusion during germination of rice seed (a monocot seed) and that it does so in a manner similar to that of dicot seed micropylar endosperm. We found that H2O2 specifically and steadily accumulated in the coleorhizae and radicles of germinating rice seeds and was accompanied by increased PAO activity as the germination percentage increased. These physiological indexes were strongly decreased in number by guazatine, a PAO inhibitor. We also identified 11 PAO homologs (OsPAO1–11) in the rice genome, which could be classified into four subfamilies (I, IIa, IIb, and III). The OsPAO genes in subfamilies I, IIa, and IIb (OsPAO1–7) encode PAOs, whereas those in subfamily III (OsPAO8–11) encode histone lysine-specific demethylases. In silico-characterized expression profiles of OsPAO1–7 and those determined by qPCR revealed that OsPAO5 is markedly upregulated in imbibed seeds compared with dry seeds and that its transcript accumulated to a higher level in embryos than in the endosperm. Moreover, its transcriptional abundance increased gradually during seed germination in water and was inhibited by 5 mM guazatine. Taken together, these results suggest that PAO-generated H2O2 is involved in coleorhiza-limited rice seed germination and that OsPAO5 expression accounts for most PAO expression and activity during rice seed germination. These findings should facilitate further study of PAOs and provide valuable information for functional validation of these proteins during seed germination of monocot cereals. PMID:27570530

  13. Seed Treatment. Bulletin 760.

    ERIC Educational Resources Information Center

    Lowery, Harvey C.

    This manual gives a definition of seed treatment, the types of seeds normally treated, diseases and insects commonly associated with seeds, fungicides and insecticides used, types of equipment used for seed treatment, and information on labeling and coloring of treated seed, pesticide carriers, binders, stickers, and safety precautions. (BB)

  14. Seed Treatment. Manual 92.

    ERIC Educational Resources Information Center

    Missouri Univ., Columbia. Agricultural Experiment Station.

    This training manual provides information needed to meet minimum EPA standards for certification as a commercial applicator of pesticides in the seed treatment category. The text discusses pests commonly associated with seeds; seed treatment pesticides; labels; chemicals and seed treatment equipment; requirements of federal and state seed laws;…

  15. Two biologically distinct isolates of Zucchini yellow mosaic virus lack seed transmissibility in cucumber.

    PubMed

    Glasa, M; Kollerova, E

    2007-01-01

    The seed transmission of the Zucchini yellow mosaic virus (ZYMV) was studied in cucumber using two isolates unrelated in their biological characteristics. Although the virus could be readily detected in mature seeds harvested from infected cucumbers, the seedlings obtained from infected germinated seeds tested negative for ZYMV using both ELISA and RT-PCR assays. No evidence was obtained for transmission of two ZYMV isolates through seeds.

  16. Seed Development in Ipomoea lacunosa (Convolvulaceae), with Particular Reference to Anatomy of the Water Gap

    PubMed Central

    Gehan Jayasuriya, K. M. G.; Baskin, Jerry M.; Geneve, Robert L.; Baskin, Carol C.

    2007-01-01

    Background and Aims Disruption of one or both of the bulges (water gap) in the seed coat adjacent to the micropyle is responsible for breaking physical dormancy (PY) in seeds of Ipomoea lacunosa and other taxa of Convolvulaceae. Hitherto, neither ontogeny of these bulges nor onset of PY together with anatomical development and maturation drying of the seed had been studied in this family. The aims of this study were to monitor physiological and anatomical changes that occur during seed development in I. lacunosa, with particular reference to ontogeny of the water gap. Methods Developmental anatomy (ontogeny) of seed coat and dry mass, length, moisture content, germinability and onset of seed coat impermeability to water were monitored from pollination to seed maturity. Blocking/drying and dye-tracking experiments were done to identify site of moisture loss during the final stages of seed drying. Key Results Physiological maturity of seeds occurred 22 d after pollination (DAP), and 100 % of seeds germinated 24 DAP. Impermeability of the seed coat developed 27–30 DAP, when seed moisture content was 13 %. The hilar fissure was identified as the site of moisture loss during the final stages of seed drying. The entire seed coat developed from the two outermost layers of the integument. A transition zone, i.e. a weak margin where seed coat ruptures during dormancy break, formed between the bulge and hilar ring and seed coat away from the bulge. Sclereid cells in the transition zone were square, whereas they were elongated under the bulge. Conclusions Although the bulge and other areas of the seed coat have the same origin, these two cell layers underwent a different series of periclinal and anticlinal divisions during bulge development (beginning a few hours after pollination) than they did during development of the seed coat away from the bulge. Further, the boundary between the square sclereids in the transition zone and the elongated ones of the bulge delineate the

  17. Influence of microgravity on ultrastructure and storage reserves in seeds of Brassica rapa L

    NASA Technical Reports Server (NTRS)

    Kuang, A.; Xiao, Y.; McClure, G.; Musgrave, M. E.

    2000-01-01

    Successful plant reproduction under spaceflight conditions has been problematic in the past. During a 122 d opportunity on the Mir space station, full life cycles of Brassica rapa L. were completed in microgravity in a series of three experiments in the Svet greenhouse. Ultrastructural and cytochemical analyses of storage reserves in mature dry seeds produced in these experiments were compared with those of seeds produced during a high-fidelity ground control. Additional analyses were performed on developing Brassica embryos, 15 d post pollination, which were produced during a separate experiment on the Shuttle (STS-87). Seeds produced on Mir had less than 20% of the cotyledon cell number found in seeds harvested from the ground control. Cytochemical localization of storage reserves in mature cotyledons showed that starch was retained in the spaceflight material, whereas protein and lipid were the primary storage reserves in ground control seeds. Protein bodies in mature cotyledons produced in space were 44% smaller than those in the ground control seeds. Fifteen days after pollination, cotyledon cells from mature embryos formed in space had large numbers of starch grains, and protein bodies were absent, while in developing ground control seeds at the same stage, protein bodies had already formed and fewer starch grains were evident. These data suggest that both the late stage of seed development and maturation are changed in Brassica by growth in a microgravity environment. While gravity is not absolutely required for any step in the plant life cycle, seed quality in Brassica is compromised by development in microgravity.

  18. Influence of microgravity on ultrastructure and storage reserves in seeds of Brassica rapa L.

    PubMed

    Kuang, A; Xiao, Y; McClure, G; Musgrave, M E

    2000-06-01

    Successful plant reproduction under spaceflight conditions has been problematic in the past. During a 122 d opportunity on the Mir space station, full life cycles of Brassica rapa L. were completed in microgravity in a series of three experiments in the Svet greenhouse. Ultrastructural and cytochemical analyses of storage reserves in mature dry seeds produced in these experiments were compared with those of seeds produced during a high-fidelity ground control. Additional analyses were performed on developing Brassica embryos, 15 d post pollination, which were produced during a separate experiment on the Shuttle (STS-87). Seeds produced on Mir had less than 20% of the cotyledon cell number found in seeds harvested from the ground control. Cytochemical localization of storage reserves in mature cotyledons showed that starch was retained in the spaceflight material, whereas protein and lipid were the primary storage reserves in ground control seeds. Protein bodies in mature cotyledons produced in space were 44% smaller than those in the ground control seeds. Fifteen days after pollination, cotyledon cells from mature embryos formed in space had large numbers of starch grains, and protein bodies were absent, while in developing ground control seeds at the same stage, protein bodies had already formed and fewer starch grains were evident. These data suggest that both the late stage of seed development and maturation are changed in Brassica by growth in a microgravity environment. While gravity is not absolutely required for any step in the plant life cycle, seed quality in Brassica is compromised by development in microgravity.

  19. Storage Reserve Accumulation in Arabidopsis: Metabolic and Developmental Control of Seed Filling

    PubMed Central

    Baud, Sébastien; Dubreucq, Bertrand; Miquel, Martine; Rochat, Christine; Lepiniec, Loïc

    2008-01-01

    In the life cycle of higher plants, seed development is a key process connecting two distinct sporophytic generations. Seed development can be divided into embryo morphogenesis and seed maturation. An essential metabolic function of maturing seeds is the deposition of storage compounds that are mobilised to fuel post-germinative seedling growth. Given the importance of seeds for food and animal feed and considering the tremendous interest in using seed storage products as sustainable industrial feedstocks to replace diminishing fossil reserves, understanding the metabolic and developmental control of seed filling constitutes a major focus of plant research. Arabidopsis thaliana is an oilseed species closely related to the agronomically important Brassica oilseed crops. The main storage compounds accumulated in seeds of A. thaliana consist of oil stored as triacylglycerols (TAGs) and seed storage proteins (SSPs). Extensive tools developed for the molecular dissection of A. thaliana development and metabolism together with analytical and cytological procedures adapted for very small seeds have led to a good description of the biochemical pathways producing storage compounds. In recent years, studies using these tools have shed new light on the intricate regulatory network controlling the seed maturation process. This network involves sugar and hormone signalling together with a set of developmentally regulated transcription factors. Although much remains to be elucidated, the framework of the regulatory system controlling seed filling is coming into focus. PMID:22303238

  20. Seed sojourn and fast viability loss constrain seedling production of a prominent riparian protection plant Salix variegata Franch

    PubMed Central

    Ayi, Qiaoli; Zeng, Bo; Liu, Jianhui; Shi, Shaohua; Niu, Hangang; Lin, Feng; Zhang, Yeyi

    2016-01-01

    Salix variegata Franch, a prominent plant applied in riparian shelter vegetation in Three Gorges reservoir region of China, produces many seeds every year but generates only a few or no seedlings. Whether the low seedling production of S. variegata is caused by seed sterility or by rapid loss of seed viability remains unknown. We investigated the sojourn time of mature seeds in capsules produced in early, mid, and late reproductive season and the germinability of mature seeds fresh or stored after different period of time. The sojourn time of seeds in capsules was 2.89, 3.95, and 4.72 days in early, mid, and late reproductive season, respectively. The maximal germination percentage of non-stored fresh seeds produced in early, mid, and late reproductive season was 93.33%, 78.67%, and 40%, respectively, which indicates mature seeds were not sterile. The longest viability-retaining time of seeds produced in early, mid, and late reproductive season was only 8, 16, 16 days, respectively, indicating that mature seeds of S. variegata lost viability very rapidly. Mature seeds possessed good viability, but their rapid viability loss caused the low seedling production and hampered the population growth of S. variegata in the riparian area of Three Gorges reservoir region. PMID:27881868

  1. Assessing ant seed predation in threatened plants: a case study

    NASA Astrophysics Data System (ADS)

    Albert, María José; Escudero, Adrián; Iriondo, José María

    2005-11-01

    Erodium paularense is a threatened plant species that is subject to seed predation by the granivorous ant Messor capitatus. In this paper we assessed the intensity and pattern of ant seed predation and looked for possible adaptive strategies at the seed and plant levels to cope with this predation. Seed predation was estimated in 1997 and 1998 at the population level by comparing total seed production and ant consumption, assessed by counting seed hulls in refuse piles. According to this method, ant seed predation ranged between 18% and 28%. A more detailed and direct assessment conducted in 1997 raised this estimate to 43%. In this assessment spatial and temporal patterns of seed predation by ants were studied by mapping all nest entrances in the studied area and marking the mature fruits of 109 reproductive plants with a specific colour code throughout the seed dispersal period. Intact fruit coats were later recovered from the refuse piles, and their mother plants and time of dispersal were identified. Seeds dispersed at the end of the dispersal period had a greater probability of escaping from ant seed predation. Similarly, in plants with late dispersal a greater percentage of seeds escaped from ant predation. Optimum dispersal time coincided with the maximum activity of granivorous ants because, at this time, ants focused their harvest on other plant species of the community. It was also observed that within-individual seed dispersal asynchrony minimised seed predation. From a conservation perspective, results show that the granivorous ant-plant interaction cannot be assessed in isolation and that the intensity of its effects basically depends on the seed dispersal pattern of the other members of the plant community. Furthermore, this threat must be assessed by considering the overall situation of the target population. Thus, in E. paularense, the strong limitation of safe-sites for seedling establishment reduces the importance of seed predation.

  2. Delayed visual maturation.

    PubMed Central

    Cole, G F; Hungerford, J; Jones, R B

    1984-01-01

    Sixteen blind babies who were considered to be showing the characteristics of delayed visual maturation were studied prospectively. The diagnosis was made on clinical grounds, and the criteria for this are discussed. All of these infants developed visual responses between 4 and 6 months of age and had normal or near normal visual acuities by 1 year of age. Long term follow up, however, has shown neurological abnormalities in some of these children. PMID:6200080

  3. Photoinduced Seed Germination of Oenothera biennis L

    PubMed Central

    Ensminger, Peter A.; Ikuma, Hiroshi

    1987-01-01

    General characteristics of light-induced germination of Oenothera biennis L. seeds were investigated at 24°C. During dark imbibition, seeds reached maximal respiration in 7 hours and maximal water content and photosensitivity in 24 hours. After dark imbibition of 24 hours, seeds required a long exposure (>36 hours) to red or white light for maximal germination. Two photoperiods (12 and 2 hours) separated by a period of darkness of 10 to 16 hours gave near maximal germination. For the two photoperiod regime, the first light potentiates a reversible phytochrome response by the second light. A 35°C treatment for 2 to 3 hours in the dark immediately prior or subsequent to 8 hours of light caused a higher percentage of germination. A 2 hour treatment at 35°C also potentiates a reversible phytochrome response. Halved seeds germinated at 100% in light or darkness indicating that the light requirement of the seeds is lost in the halving procedure. After-ripened seeds required less light and germinated more rapidly and at higher percentages than seeds tested shortly after maturation. PMID:16665824

  4. Development of Simple Algorithms in Direct, Non-destructive, and Rapid Determination of Cotton Fiber Maturity from FT-IR/ATR Spectroscopy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    FT-IR/ATR spectra of seed and lint cottons were collected to explore the potential for the discrimination of immature cottons from mature ones and also for the determination of actual cotton maturity. Spectral features of immature and mature cottons revealed large differences in the 1200-900 cm-1 re...

  5. De novo assembly and characterization of germinating lettuce seed transcriptome using Illumina paired-end sequencing.

    PubMed

    Liu, Shu-Jun; Song, Shun-Hua; Wang, Wei-Qing; Song, Song-Quan

    2015-11-01

    At supraoptimal temperature, germination of lettuce (Lactuca sativa L.) seeds exhibits a typical germination thermoinhibition, which can be alleviated by sodium nitroprusside (SNP) in a nitric oxide-dependent manner. However, the molecular mechanism of seed germination thermoinhibition and its alleviation by SNP are poorly understood. In the present study, the lettuce seeds imbibed at optimal temperature in water or at supraoptimal temperature with or without 100 μM SNP for different periods of time were used as experimental materials, the total RNA was extracted and sequenced, we gained 147,271,347 raw reads using Illumina paired-end sequencing technique and assembled the transcriptome of germinating lettuce seeds. A total of 51,792 unigenes with a mean length of 849 nucleotides were obtained. Of these unigenes, a total of 29,542 unigenes were annotated by sequence similarity searching in four databases, NCBI non-redundant protein database, SwissProt protein database, euKaryotic Ortholog Groups database, and NCBI nucleotide database. Among the annotated unigenes, 22,276 unigenes were assigned to Gene Ontology database. When all the annotated unigenes were searched against the Kyoto Encyclopedia of Genes and Genomes Pathway database, a total of 8,810 unigenes were mapped to 5 main categories including 260 pathways. We first obtained a lot of unigenes encoding proteins involved in abscisic acid (ABA) signaling in lettuce, including 11 ABA receptors, 94 protein phosphatase 2Cs and 16 sucrose non-fermenting 1-related protein kinases. These results will help us to better understand the molecular mechanism of seed germination, thermoinhibition of seed germination and its alleviation by SNP.

  6. Rapid identification of lettuce seed germination mutants by bulked segregant analysis and whole genome sequencing.

    PubMed

    Huo, Heqiang; Henry, Isabelle M; Coppoolse, Eric R; Verhoef-Post, Miriam; Schut, Johan W; de Rooij, Han; Vogelaar, Aat; Joosen, Ronny V L; Woudenberg, Leo; Comai, Luca; Bradford, Kent J

    2016-11-01

    Lettuce (Lactuca sativa) seeds exhibit thermoinhibition, or failure to complete germination when imbibed at warm temperatures. Chemical mutagenesis was employed to develop lettuce lines that exhibit germination thermotolerance. Two independent thermotolerant lettuce seed mutant lines, TG01 and TG10, were generated through ethyl methanesulfonate mutagenesis. Genetic and physiological analyses indicated that these two mutations were allelic and recessive. To identify the causal gene(s), we applied bulked segregant analysis by whole genome sequencing. For each mutant, bulked DNA samples of segregating thermotolerant (mutant) seeds were sequenced and analyzed for homozygous single-nucleotide polymorphisms. Two independent candidate mutations were identified at different physical positions in the zeaxanthin epoxidase gene (ABSCISIC ACID DEFICIENT 1/ZEAXANTHIN EPOXIDASE, or ABA1/ZEP) in TG01 and TG10. The mutation in TG01 caused an amino acid replacement, whereas the mutation in TG10 resulted in alternative mRNA splicing. Endogenous abscisic acid contents were reduced in both mutants, and expression of the ABA1 gene from wild-type lettuce under its own promoter fully complemented the TG01 mutant. Conventional genetic mapping confirmed that the causal mutations were located near the ZEP/ABA1 gene, but the bulked segregant whole genome sequencing approach more efficiently identified the specific gene responsible for the phenotype.

  7. PECTIN METHYLESTERASE INHIBITOR6 Promotes Arabidopsis Mucilage Release by Limiting Methylesterification of Homogalacturonan in Seed Coat Epidermal Cells[C][W

    PubMed Central

    Saez-Aguayo, Susana; Ralet, Marie-Christine; Berger, Adeline; Botran, Lucy; Ropartz, David; Marion-Poll, Annie; North, Helen M.

    2013-01-01

    Imbibed seeds of the Arabidopsis thaliana accession Djarly are affected in mucilage release from seed coat epidermal cells. The impaired locus was identified as a pectin methylesterase inhibitor gene, PECTIN METHYLESTERASE INHIBITOR6 (PMEI6), specifically expressed in seed coat epidermal cells at the time when mucilage polysaccharides are accumulated. This spatio-temporal regulation appears to be modulated by GLABRA2 and LEUNIG HOMOLOG/MUCILAGE MODIFIED1, as expression of PMEI6 is reduced in mutants of these transcription regulators. In pmei6, mucilage release was delayed and outer cell walls of epidermal cells did not fragment. Pectin methylesterases (PMEs) demethylate homogalacturonan (HG), and the majority of HG found in wild-type mucilage was in fact derived from outer cell wall fragments. This correlated with the absence of methylesterified HG labeling in pmei6, whereas transgenic plants expressing the PMEI6 coding sequence under the control of the 35S promoter had increased labeling of cell wall fragments. Activity tests on seeds from pmei6 and 35S:PMEI6 transgenic plants showed that PMEI6 inhibits endogenous PME activities, in agreement with reduced overall methylesterification of mucilage fractions and demucilaged seeds. Another regulator of PME activity in seed coat epidermal cells, the subtilisin-like Ser protease SBT1.7, acts on different PMEs, as a pmei6 sbt1.7 mutant showed an additive phenotype. PMID:23362209

  8. Harvest time of Cryptomeria japonica seeds depending on climate factors

    NASA Astrophysics Data System (ADS)

    Son, Seog-Gu; Kim, Hyo-Jeong; Kim, Chang-Soo; Byun, Kwang-Ok

    2010-05-01

    Sound seeds should have good germination rates and seed germination can be influenced by several factors. Seed picking time is regarded as one of the necessary elements to obtain sound seeds. From a clonal seed orchard of Cryptomeria japonica located in southern part of Korean peninsular, cones were picked about every 10 days from 30th of July 2005 to 30th of October in both 2005 and 2006. We have also analyzed the effects of climatic factors about two consecutive years on seed productivity. From the picked cones, seeds were collected and these germination ability, seed size and embryo shapes were investigated according to cone picking time. The 1,000-seed weight picked on 18th of August was 3.3 g and 5.3 g on 30th of September 2005and 2006. The size of seeds picked from 18th of August to 30th of September increased from 19.3 mm to 21.3 mm in length and from 15.8 mm to 18.5 mm in width. Depending on picking time, various shapes of embryos, including embryos with liquid material, jellied material and fully matured ones were observed. Germination aspects also varied throughout the test days. About two weeks after seeding in a glass petri-dish, germinal apparatuses appeared from each test seed sets which had been picked from after 10 August 2005 and 10 August 2006. The germination rates started from 10.7% from seeds picked 20 August 2006. Average germination rate in 2005 was 18.3 and 19.6 in 2006. In 2005, the highest germination rate was 34.3% from seeds picked on the 30th of September. In 2006, the highest germination rate was 31.7% for seeds picked at the same date as the 2005 seeds. After September, the highest germination rate for picked seeds decreased in both 2005 and 2006. Among the climatic factors, monthly sum of temperature and of precipitation were the main factors for maturation of C. japonica seeds. The results implied that the best cone picking time for the Korean C. japonica seed orchard to be around the end of September.

  9. Characterization of molecular mobility within the glassy matrix of dry seeds using mechanical properties: pea cotyledon as a test study

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seed glasses form during maturation drying and regulate seed longevity. Seeds continue to age within the glassy state and, even during cryogenic storage, viability eventually declines. Inevitability of aging suggests some level of molecular motion within the glassy matrix and quantifying these “rel...

  10. Potent endogenous allelopathic compounds in Lepidium sativum seed exudate: effects on epidermal cell growth in Amaranthus caudatus seedlings.

    PubMed

    Iqbal, Amjad; Fry, Stephen C

    2012-04-01

    Many plants exude allelochemicals--compounds that affect the growth of neighbouring plants. This study reports further studies of the reported effect of cress (Lepidium sativum) seed(ling) exudates on seedling growth in Amaranthus caudatus and Lactuca sativa. In the presence of live cress seedlings, both species grew longer hypocotyls and shorter roots than cress-free controls. The effects of cress seedlings were allelopathic and not due to competition for resources. Amaranthus seedlings grown in the presence of cress allelochemical(s) had longer, thinner hypocotyls and shorter, thicker roots--effects previously attributed to lepidimoide. The active principle was more abundant in cress seed exudate than in seedling (root) exudates. It was present in non-imbibed seeds and releasable from heat-killed seeds. Release from live seeds was biphasic, starting rapidly but then continuing gradually for 24 h. The active principle was generated by aseptic cress tissue and was not a microbial digestion product or seed-treatment chemical. Crude seed exudate affected hypocotyl and root growth at ~25 and ~450 μg ml(-1) respectively. The exudate slightly (28%) increased epidermal cell number along the length of the Amaranthus hypocotyl but increased total hypocotyl elongation by 129%; it resulted in a 26% smaller hypocotyl circumference but a 55% greater epidermal cell number counted round the circumference. Therefore, the effect of the allelochemical(s) on organ morphology was imposed primarily by regulation of cell expansion, not cell division. It is concluded that cress seeds exude endogenous substances, probably including lepidimoide, that principally regulate cell expansion in receiver plants.

  11. Dormancy-specific imprinting underlies maternal inheritance of seed dormancy in Arabidopsis thaliana

    PubMed Central

    Piskurewicz, Urszula; Iwasaki, Mayumi; Susaki, Daichi; Megies, Christian; Kinoshita, Tetsu; Lopez-Molina, Luis

    2016-01-01

    Mature seed dormancy is a vital plant trait that prevents germination out of season. In Arabidopsis, the trait can be maternally regulated but the underlying mechanisms sustaining this regulation, its general occurrence and its biological significance among accessions are poorly understood. Upon seed imbibition, the endosperm is essential to repress the germination of dormant seeds. Investigation of genomic imprinting in the mature seed endosperm led us to identify a novel set of imprinted genes that are expressed upon seed imbibition. Remarkably, programs of imprinted gene expression are adapted according to the dormancy status of the seed. We provide direct evidence that imprinted genes play a role in regulating germination processes and that preferential maternal allelic expression can implement maternal inheritance of seed dormancy levels. DOI: http://dx.doi.org/10.7554/eLife.19573.001 PMID:28005006

  12. Free and glycosylated sterol bioaccumulation in developing Cycas micronesica seeds.

    PubMed

    Marler, Thomas E; Shaw, Christopher A

    2009-07-15

    The bioaccumulation of free and glycosylated forms of stigmasterol and β-sitosterol were determined from Cycas micronesica K.D. Hill seeds throughout seed ontogeny. Per-seed pool of the four compounds increased linearly from 2 to 24 months, indicating no developmental period elicited a major shift in the rate of bioaccumulation. The slopes were not homogeneous, signifying a change in relative sterol profile concomitant with seed maturation. This shift was in favour of the glucosides, as their rate of accumulation exceeded that of the free sterols. Stigmasterol content exceeded that of β-sitosterol, but ontogeny did not influence the ratio of these dominant sterols. The quantity and quality of sterol exposure during consumption of foods prepared from gametophytes by humans is strongly influenced by age of harvested seeds. Results are critical for a further understanding of the link between human neurodegenerative diseases and historical consumption of foods derived from the seed gametophyte tissue.

  13. Genome-wide miRNA seeds prediction in Archaea.

    PubMed

    Wang, Shengqin; Xu, Yuming; Lu, Zuhong

    2014-01-01

    Growing evidence indicates that miRNA genes exist in the archaeal genome, though the functional role of such noncoding RNA remains unclear. Here, we integrated the phylogenetic information of available archaeal genomes to predict miRNA seeds (typically defined as the 2-8 nucleotides of mature miRNAs) on the genomic scale. Finally, we found 2649 candidate seeds with significant conservation signal. Eleven of 29 unique seeds from previous study support our result (P value <0.01), which demonstrates that the pipeline is suitable to predict experimentally detectable miRNA seeds. The statistical significance of the overlap between the detected archaeal seeds and known eukaryotic seeds shows that the miRNA may evolve before the divergence of these two domains of cellular life. In addition, miRNA targets are enriched for genes involved in transcriptional regulation, which is consistent with the situation in eukaryote. Our research will enhance the regulatory network analysis in Archaea.

  14. Vocational Maturity and Self Concepts.

    ERIC Educational Resources Information Center

    Helbing, Hans

    The relationship between separate dimensions of vocational maturity and different self-concept and identity variables were examined. Subjects were Dutch students, age 14-18 years. The vocational maturity dimensions were measured by Dutch adaptations of American vocational maturity scales. Instruments for self-concept and identity measurement were…

  15. Identification of a molecular dialogue between developing seeds of Medicago truncatula and seedborne xanthomonads.

    PubMed

    Terrasson, Emmanuel; Darrasse, Armelle; Righetti, Karima; Buitink, Julia; Lalanne, David; Ly Vu, Benoit; Pelletier, Sandra; Bolingue, William; Jacques, Marie-Agnès; Leprince, Olivier

    2015-07-01

    Plant pathogenic bacteria disseminate and survive mainly in association with seeds. This study addresses whether seeds are passive carriers or engage a molecular dialogue with pathogens during their development. We developed two pathosystems using Medicago truncatula with Xanthomonas alfalfae subsp. alfalfae (Xaa), the natural Medicago sp. pathogen and Xanthomonas campestris pv. campestris (Xcc), a Brassicaceae pathogen. Three days after flower inoculation, the transcriptome of Xcc-infected pods showed activation of an innate immune response that was strongly limited in Xcc mutated in the type three secretion system, demonstrating an incompatible interaction of Xcc with the reproductive structures. In contrast, the presence of Xaa did not result in an activation of defence genes. Transcriptome profiling during development of infected seeds exhibited time-dependent and differential responses to Xcc and Xaa. Gene network analysis revealed that the transcriptome of Xcc-infected seeds was mainly affected during seed filling whereas that of Xaa-infected seeds responded during late maturation. The Xcc-infected seed transcriptome exhibited an activation of defence response and a repression of targeted seed maturation pathways. Fifty-one percent of putative ABSCISIC ACID INSENSITIVE3 targets were deregulated by Xcc, including oleosin, cupin, legumin and chlorophyll degradation genes. At maturity, these seeds displayed decreased weight and increased chlorophyll content. In contrast, these traits were not affected by Xaa infection. These findings demonstrate the existence of a complex molecular dialogue between xanthomonads and developing seeds and provides insights into a previously unexplored trade-off between seed development and pathogen defence.

  16. Dissociation of motor maturation.

    PubMed

    DiMario, Francis J

    2003-06-01

    We prospectively acquired clinical data regarding the presentation, evaluation, and developmental progress of all patients identified with dissociated motor maturation to define their clinical outcomes. Children (N = 8) referred for evaluation of suspected cerebral palsy because of delayed sitting or walking and identified to have dissociated motor maturation were followed with serial clinical examination. All displayed the characteristic "sitting on air" posture while held in vertical suspension and had otherwise normal developmental assessments. This posture is composed of the hips held in flexion and abduction with the knees extended and feet plantar or dorsiflexed. Three children were initially evaluated at 10 months of age owing to absence of sitting and five other children were evaluated at a mean of 14 months (range 12-19 months) owing to inability to stand. Follow-up evaluations were conducted over a mean of 10.5 months (range 5-34 months). Five children were born prematurely at 34 to 36 weeks gestation. Denver Developmental Screening Test and general and neurologic examinations were normal except to note hypotonia in six children and the "sitting on air" posture in all of the children. Four children have older siblings or parents who "walked late" (after 15 months). On average, the children attained sitting by 8 months (range 7-10 months). One child did not crawl prior to independent walking, two children scooted rather than crawled, and five children crawled at an average of 13.5 months (range 10-16 months). All children cruised by a mean of 18 months (range 16-21.5 months) and attained independent walking by 20.1 months (range 18-25 months). Neuroimaging and serum creatine kinase enzyme testing were normal in two children who were tested. These eight children conform to the syndrome of dissociated motor maturation. The "sitting on air" posture serves as a diagnostic sign and anticipated excellent prognosis, but follow-up is required to ensure a normal

  17. Comparative proteomic analysis of embryos between a maize hybrid and its parental lines during early stages of seed germination.

    PubMed

    Guo, Baojian; Chen, Yanhong; Zhang, Guiping; Xing, Jiewen; Hu, Zhaorong; Feng, Wanjun; Yao, Yingyin; Peng, Huiru; Du, Jinkun; Zhang, Yirong; Ni, Zhongfu; Sun, Qixin

    2013-01-01

    In spite of commercial use of heterosis in agriculture, the molecular basis of heterosis is poorly understood. It was observed that maize hybrid Zong3/87-1 exhibited an earlier onset or heterosis in radicle emergence. To get insights into the underlying mechanism of heterosis in radicle emergence, differential proteomic analysis between hybrid and its parental lines was performed. In total, the number of differentially expressed protein spots between hybrid and its parental lines in dry and 24 h imbibed seed embryos were 134 and 191, respectively, among which 47.01% (63/134) and 34.55% (66/191) protein spots displayed nonadditively expressed pattern. Remarkably, 54.55% of nonadditively accumulated proteins in 24 h imbibed seed embryos displayed above or equal to the level of the higher parent patterns. Moreover, 155 differentially expressed protein spots were identified, which were grouped into eight functional classes, including transcription & translation, energy & metabolism, signal transduction, disease & defense, storage protein, transposable element, cell growth & division and unclassified proteins. In addition, one of the upregulated proteins in F1 hybrids was ZmACT2, a homolog of Arabidopsis thaliana ACT7 (AtACT7). Expressing ZmACT2 driven by the AtACT7 promoter partially complemented the low germination phenotype in the Atact7 mutant. These results indicated that hybridization between two parental lines can cause changes in the expression of a variety of proteins, and it is concluded that the altered pattern of gene expression at translational level in the hybrid may be responsible for the observed heterosis.

  18. A dynamic interplay between phytohormones is required for fruit development, maturation, and ripening

    PubMed Central

    McAtee, Peter; Karim, Siti; Schaffer, Robert; David, Karine

    2013-01-01

    Plant species that bear fruit often utilize expansion of an ovary (carpel) or accessory tissue as a vehicle for seed dispersal. While the seed(s) develop, the tissue(s) of the fruit follow a common progression of cell division and cell expansion, promoting growth of the fruit. Once the seed is fully developed, the fruit matures and the surrounding tissue either dries or ripens promoting the dissemination of the seed. As with many developmental processes in plants, plant hormones play an important role in the synchronization of signals between the developing seed and its surrounding fruit tissue(s), regulating each phase of fruit development. Following pollination, fruit set is achieved through a de-repression of growth and an activation of cell division via the action of auxin and/or cytokinin and/or gibberellin. Following fruit set, growth of the fruit is facilitated through a relatively poorly studied period of cell expansion and endoreduplication that is likely regulated by similar hormones as in fruit set. Once the seeds reach maturity, fruit become ready to undergo ripening and during this period there is a major switch in relative hormone levels of the fruit, involving an overall decrease in auxin, gibberellin, and cytokinin and a simultaneous increase in abscisic acid and ethylene. While the role of hormones in fruit set and ripening is well documented, the knowledge of the roles of other hormones during growth, maturation, and some individual ripening components is sketchy. PMID:23616786

  19. Maturation in Larch 1

    PubMed Central

    Hutchison, Keith W.; Sherman, Christopher D.; Weber, Jill; Smith, Sandra Schiller; Singer, Patricia B.; Greenwood, Michael S.

    1990-01-01

    The effect of maturation on the morphological and photosynthetic characteristics, as well as the expression of two genes involved in photosynthesis in the developing, current year foliage of Eastern larch (Larix laricina [Du Roi]) is described. These effects were observed on foliage during the third growing season after grafting of scions from trees of different ages onto 2 year old rootstock. Specific leaf weight (gram dry weight per square meter), leaf cross-sectional area (per square millimeter), and chlorophyll content (milligram per gram dry weight) all increase with increasing age in long shoot foliage from both indoor- and outdoor-grown trees. Net photosynthesis (NPS) (mole of CO2 per square millimeter per second) increases with age on indoor- but not outdoor-grown trees. NPS also increases with increased chlorophyll content, but outdoor-grown scions of all ages had higher chlorophyll content, and chlorophyll does not appear to be limiting for NPS outdoors. To extend these studies of maturation-related differences in foliar morphology and physiology to the molecular genetic level, sequences were cloned from the cab and rbsS gene families of larch. Both cab and rbcS gene families are expressed in foliage but not in roots, and they are expressed in light-grown seedlings of larch but only at very low levels in dark-grown seedlings (~2% of light-grown seedlings). Steady-state cab mRNA levels are relatively higher (~40%) in newly expanding short shoot foliage from juvenile plants compared to mature plants. Unlike cab, the expression of the rbcS gene family did not seem to vary with age. These data show that the maturation-related changes in morphological and physiological phenotypes are associated with changes in gene expression. No causal relationship has been established, however. Indeed, we conclude that the faster growth of juvenile scions reported previously (MS Greenwood, CA Hopper, KW Hutchison [1989] Plant Physiol 90: 406-412) is not due to increased NPS

  20. Seed storage at elevated partial pressure of oxygen, a fast method for analysing seed ageing under dry conditions

    PubMed Central

    Groot, S. P. C.; Surki, A. A.; de Vos, R. C. H.; Kodde, J.

    2012-01-01

    Background and Aims Despite differences in physiology between dry and relative moist seeds, seed ageing tests most often use a temperature and seed moisture level that are higher than during dry storage used in commercial practice and gene banks. This study aimed to test whether seed ageing under dry conditions can be accelerated by storing under high-pressure oxygen. Methods Dry barley (Hordeum vulgare), cabbage (Brassica oleracea), lettuce (Lactuca sativa) and soybean (Glycine max) seeds were stored between 2 and 7 weeks in steel tanks under 18 MPa partial pressure of oxygen. Storage under high-pressure nitrogen gas or under ambient air pressure served as controls. The method was compared with storage at 45 °C after equilibration at 85 % relative humidity and long-term storage at the laboratory bench. Germination behaviour, seedling morphology and tocopherol levels were assessed. Key Results The ageing of the dry seeds was indeed accelerated by storing under high-pressure oxygen. The morphological ageing symptoms of the stored seeds resembled those observed after ageing under long-term dry storage conditions. Barley appeared more tolerant of this storage treatment compared with lettuce and soybean. Less-mature harvested cabbage seeds were more sensitive, as was the case for primed compared with non-primed lettuce seeds. Under high-pressure oxygen storage the tocopherol levels of dry seeds decreased, in a linear way with the decline in seed germination, but remained unchanged in seeds deteriorated during storage at 45 °C after equilibration at 85 % RH. Conclusions Seed storage under high-pressure oxygen offers a novel and relatively fast method to study the physiology and biochemistry of seed ageing at different seed moisture levels and temperatures, including those that are representative of the dry storage conditions as used in gene banks and commercial practice. PMID:22967856

  1. Notice of Release of WhiteAcre-DG, a Small-seeded, Cream-type Southernpea with an Enhanced Persistent Green Seed Phenotype

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The USDA has developed a high yielding, small-seeded, cream-type southernpea cultivar that has a persistent green seed phenotype conditioned by both the green cotyledon gene (gc) and the green testa gene (gt). The new cultivar, named WhiteAcre-DG, can be harvested at the dry-pod stage of maturity w...

  2. A seed coat-specific promoter for canola.

    PubMed

    El-Mezawy, Aliaa; Wu, Limin; Shah, Saleh

    2009-12-01

    The canola industry generates more than $11 billion of yearly income to the Canadian economy. One problem of meal quality is the dark polyphenolic pigments that accumulate in the seed coat. Seed coat-specific promoters are a pre-requisite to regulate the genes involved in seed coat development and metabolism. The beta-glucuronidase (GUS) reporter gene was used to test an Arabidopsis promoter in developing and mature seeds of canola (Brassica napus). The promoter tested is the regulatory region of the laccase gene (AtLAC15) from Arabidopsis thaliana. The AtLAC15 promoter::GUS construct was inserted into canola double haploid line DH12075 using Agrobacterium-mediated transformation. Southern blot analysis using a 536 bp GUS probe showed variation among the transformed plants in the T-DNA copy numbers and the position of the insertion in their genomes. Histochemical assay of the GUS enzyme in different tissues (roots, leaves, stem, pollen grains, flowers, siliques, embryos and seed coats) showed ascending GUS activity only in the seed coat from 10 days after pollination (DAP) to the fully mature stage (35 DAP). GUS stain was observed in the mucilage cell layer, in the outer integument layer of the seed coat but not in the inner integument. The AtLAC15 promoter exhibited a specificity and expression level that is useful as a seed coat-specific promoter for canola.

  3. Proteomic analysis of rice (Oryza sativa) seeds during germination.

    PubMed

    Yang, Pingfang; Li, Xiaojuan; Wang, Xiaoqin; Chen, Hui; Chen, Fan; Shen, Shihua

    2007-09-01

    Although seed germination is a major subject in plant physiological research, there is still a long way to go to elucidate the mechanism of seed germination. Recently, functional genomic strategies have been applied to study the germination of plant seeds. Here, we conducted a proteomic analysis of seed germination in rice (Oryza sativa indica cv. 9311) - a model monocot. Comparison of 2-DE maps showed that there were 148 proteins displayed differently in the germination process of rice seeds. Among the changed proteins, 63 were down-regulated, 69 were up-regulated (including 20 induced proteins). The down-regulated proteins were mainly storage proteins, such as globulin and glutelin, and proteins associated with seed maturation, such as "early embryogenesis protein" and "late embryogenesis abundant protein", and proteins related to desiccation, such as "abscisic acid-induced protein" and "cold-regulated protein". The degradation of storage proteins mainly happened at the late stage of germination phase II (48 h imbibition), while that of seed maturation and desiccation associated proteins occurred at the early stage of phase II (24 h imbibition). In addition to alpha-amylase, the up-regulated proteins were mainly those involved in glycolysis such as UDP-glucose dehydrogenase, fructokinase, phosphoglucomutase, and pyruvate decarboxylase. The results reflected the possible biochemical and physiological processes of germination of rice seeds.

  4. Dynamic distribution and the role of abscisic acid during seed development of a lady’s slipper orchid, Cypripedium formosanum

    PubMed Central

    Lee, Yung-I; Chung, Mei-Chu; Yeung, Edward C.; Lee, Nean

    2015-01-01

    Background and Aims Although abscisic acid (ABA) is commonly recognized as a primary cause of seed dormancy, there is a lack of information on the role of ABA during orchid seed development. In order to address this issue, the localization and quantification of ABA were determined in developing seeds of Cypripedium formosanum. Methods The endogenous ABA profile of seeds was measured by enzyme-linked immunosorbent assay (ELISA). Temporal and spatial distributions of ABA in developing seeds were visualized by immunohistochemical staining with monoclonal ABA antibodies. Fluoridone was applied to test the causal relationship between ABA content and seed germinability. Key Results ABA content was low at the proembryo stage, then increased rapidly from 120 to 150 days after pollination (DAP), accompanied by a progressive decrease in water content and seed germination. Immunofluorescence signals indicated an increase in fluorescence over time from the proembryo stage to seed maturation. From immunogold labelling, gold particles could be seen within the cytoplasm of embryo-proper cells during the early stages of seed development. As seeds approached maturity, increased localization of gold particles was observed in the periplasmic space, the plasmalemma between embryo-proper cells, the surface wall of the embryo proper, and the inner walls of inner seed-coat cells. At maturity, gold particles were found mainly in the apoplast, such as the surface wall of the embryo proper, and the shrivelled inner and outer seed coats. Injection of fluoridone into capsules resulted in enhanced germination of mature seeds. Conclusions The results indicate that ABA is the key inhibitor of germination in C. formosanum. The distinct accumulation pattern of ABA suggests that it is synthesized in the cytosol of embryo cells during the early stages of seed development, and then exported to the apoplastic region of the cells for subsequent regulatory processes as seeds approach maturity. PMID

  5. Sequential steps for developmental arrest in Arabidopsis seeds.

    PubMed

    Raz, V; Bergervoet, J H; Koornneef, M

    2001-01-01

    The continuous growth of the plant embryo is interrupted during the seed maturation processes which results in a dormant seed. The embryo continues development after germination when it grows into a seedling. The embryo growth phase starts after morphogenesis and ends when the embryo fills the seed sac. Very little is known about the processes regulating this phase. We describe mutants that affect embryo growth in two sequential developmental stages. Firstly, embryo growth arrest is regulated by the FUS3/LEC type genes, as mutations in these genes cause a continuation of growth in immature embryos. Secondly, a later stage of embryo dormancy is regulated by ABI3 and abscisic acid; abi3 and aba1 mutants exhibit premature germination only after embryos mature. Mutations affecting both developmental stages result in an additive phenotype and double mutants are highly viviparous. Embryo growth arrest is regulated by cell division activities in both the embryo and the endosperm, which are gradually switched off at the mature embryo stage. In the fus3/lec mutants, however, cell division in both the embryo and endosperm is not arrested, but rather is prolonged throughout seed maturation. Furthermore ectopic cell division occurs in seedlings. Our results indicate that seed dormancy is secured via at least two sequential developmental processes: embryo growth arrest, which is regulated by cell division and embryo dormancy.

  6. [Research advance in seed germination of desert woody plants].

    PubMed

    Chang, Wei; Wu, Jian-guo; Liu, Yan-hong

    2007-02-01

    This paper reviewed the research methods of desert woody plants seed germination, and the effects of internal and external ecological factors on it. Most researchers use incubator and artificial climate chamber to dispose the seeds, while field investigation was few involved. Seed dormancy is the important physiological factor affecting germination, while seed size, mass and color are closely correlated with its maturity and vigor. The poor permeability of seed capsule is a barrier that restrains the germination, which can be weakened or eliminated by shaving, cutting, treating with low temperature, and dipping in chemical reagent, etc. Seed water content has a close correlation with its storage life and water-absorbing capability. Suitable temperature is the prerequisite of seed germination, while changing temperature can accelerate the germination. Soil moisture content is a limiting factor, while illumination is not so essential to the seed germination of most desert woody plants. Sand-burying plays an important role in the seed germination through regulating illumination, temperature, and soil moisture content. Salinity stress restrains the seed germination of desert woody plants observably. In further studies, the effects of multi-factors and the eco-physiological and molecular biological mechanisms of germination should be more concerned.

  7. Callose Deposition Is Responsible for Apoplastic Semipermeability of the Endosperm Envelope of Muskmelon Seeds1

    PubMed Central

    Yim, Kyu-Ock; Bradford, Kent J.

    1998-01-01

    Semipermeable cell walls or apoplastic “membranes” have been hypothesized to be present in various plant tissues. Although often associated with suberized or lignified walls, the wall component that confers osmotic semipermeability is not known. In muskmelon (Cucumis melo L.) seeds, a thin, membranous endosperm completely encloses the embryo, creating a semipermeable apoplastic envelope. When dead muskmelon seeds are allowed to imbibe, solutes leaking from the embryo are retained within the envelope, resulting in osmotic water uptake and swelling called osmotic distention (OD). The endosperm envelope of muskmelon seeds stained with aniline blue, which is specific for callose (β-1,3-glucan). Outside of the aniline-blue-stained layer was a Sudan III- and IV-staining (lipid-containing) layer. In young developing seeds 25 d after anthesis (DAA) that did not exhibit OD, the lipid layer was already present but callose had not been deposited. At 35 DAA, callose was detected as distinct vesicles or globules in the endosperm envelope. A thick callose layer was evident at 40 DAA, coinciding with development of the capacity for OD. Removal of the outer lipid layer by brief chloroform treatment resulted in more rapid water uptake by both viable and nonviable (boiled) seeds, but did not affect semipermeability of the endosperm envelope. The aniline-blue-staining layer was digested by β-1,3-glucanase, and these envelopes lost OD. Thus, apoplastic semipermeability of the muskmelon endosperm envelope is dependent on the deposition of a thick callose-containing layer outside of the endosperm cell walls. PMID:9733528

  8. CFD - Mature Technology?

    NASA Technical Reports Server (NTRS)

    Kwak, Dochan

    2005-01-01

    Over the past 30 years, numerical methods and simulation tools for fluid dynamic problems have advanced as a new discipline, namely, computational fluid dynamics (CFD). Although a wide spectrum of flow regimes are encountered in many areas of science and engineering, simulation of compressible flow has been the major driver for developing computational algorithms and tools. This is probably due to a large demand for predicting the aerodynamic performance characteristics of flight vehicles, such as commercial, military, and space vehicles. As flow analysis is required to be more accurate and computationally efficient for both commercial and mission-oriented applications (such as those encountered in meteorology, aerospace vehicle development, general fluid engineering and biofluid analysis) CFD tools for engineering become increasingly important for predicting safety, performance and cost. This paper presents the author's perspective on the maturity of CFD, especially from an aerospace engineering point of view.

  9. Pigment composition and location in honey locust (Gleditsia triacanthos) seeds before and after desiccation.

    PubMed

    Schoefs, Benoit

    2002-03-01

    Gleditsia triacanthos L. pods were harvested at San Lorenzo del Escorial, Madrid, Spain, before and after seed desiccation. Maturing green pods, harvested from trees, contained soft light-green seeds, whereas fully mature brown pods, collected on the ground, contained hard dark-green seeds. Based on visual inspection of seeds, it was determined that the green color is located in the cotyledons and embryo of soft seeds but mainly in the seed coat of hard seeds. High performance liquid chromatographic analysis indicated that both hard and soft seeds contained the same set of photosynthetic pigments as fully developed leaves, but in different proportions. The hard and soft seeds mainly differed in their chlorophyll a to chlorophyll b ratio and in the composition of the xanthophyll cycle pool of pigments. Fluorescence at -196 degrees C revealed that the molecular organization of the pigment molecules in the seed coat of hard seeds differed from that in intact cotyledons of soft seeds and intact green leaves. The -196 degrees C fluorescence spectra also revealed the presence of a small heterogenous pool of non-photoactive protochlorophyll(ide)s, similar to those found in dark-grown tissues of gymnosperms and angiosperms.

  10. Ability of lupine seeds to germinate and to tolerate desiccation as related to changes in free radical level and antioxidants in freshly harvested seeds.

    PubMed

    Garnczarska, Małgorzata; Bednarski, Waldemar; Jancelewicz, Mariusz

    2009-01-01

    Seeds of yellow lupine (Lupinus luteus L. cv. Juno) were collected throughout their development on the mother plant to determine whether the ability to germinate and to tolerate desiccation is related to the level of free radicals and the changes in the redox state of ascorbate and glutathione as well as the activities of antioxidative enzymes. Electron paramagnetic resonance (EPR)-based analyses showed that development of lupine seed was accompanied by generation of free radicals with g(1) and g(2) values of 2.0049+/-0.0004 and 2.0029+/-0.0003, respectively. Free radical level increased significantly 25 DAF and decreased thereafter. The amount of hydrogen peroxide was high in fresh immature seeds and decreased during maturation drying. Ascorbate accumulated in lupine embryos during early seed filling stage whereas glutathione content increased during late seed filling phase. During maturation drying the redox state of both ascorbate and glutathione pools shifted towards the oxidized forms. While superoxide dismutase (SOD, EC 1.15.1.1), and ascorbate peroxidase (APX, EC 1.11.1.11) activities remained high at the early seed filling stage the activities of both dehydroascorbate reductase (DHAR, EC 1.8.5.1) and glutathione reductase (GR, EC 1.6.4.2) and that of catalase (CAT, EC 1.11.1.6) increased before seeds reached physiological maturity and decreased thereafter. The changes of isoform patterns of antioxidative enzymes were observed during seed maturation. Immature lupine seeds tested immediately after harvest acquired the ability to germinate when less than half-filled and reached high tolerance to desiccation just after physiological maturity. The physiological implications of the changes in antioxidative machinery for the acquisition of desiccation tolerance and seeds germinability are discussed.

  11. Developmental changes in the germinability, desiccation tolerance, hardseededness, and longevity of individual seeds of Trifolium ambiguum

    PubMed Central

    Hay, F. R.; Smith, R. D.; Ellis, R. H.; Butler, L. H.

    2010-01-01

    Background and Aims Using two parental clones of outcrossing Trifolium ambiguum as a potential model system, we examined how during seed development the maternal parent, number of seeds per pod, seed position within the pod, and pod position within the inflorescence influenced individual seed fresh weight, dry weight, water content, germinability, desiccation tolerance, hardseededness, and subsequent longevity of individual seeds. Methods Near simultaneous, manual reciprocal crosses were carried out between clonal lines for two experiments. Infructescences were harvested at intervals during seed development. Each individual seed was weighed and then used to determine dry weight or one of the physiological behaviour traits. Key Results Whilst population mass maturity was reached at 33–36 days after pollination (DAP), seed-to-seed variation in maximum seed dry weight, when it was achieved, and when maturation drying commenced, was considerable. Individual seeds acquired germinability between 14 and 44 DAP, desiccation tolerance between 30 and 40 DAP, and the capability to become hardseeded between 30 and 47 DAP. The time for viability to fall to 50 % (p50) at 60 % relative humidity and 45 °C increased between 36 and 56 DAP, when the seed coats of most individuals had become dark orange, but declined thereafter. Individual seed f. wt at harvest did not correlate with air-dry storage survival period. Analysing survival data for cohorts of seeds reduced the standard deviation of the normal distribution of seed deaths in time, but no sub-population showed complete uniformity of survival period. Conclusions Variation in individual seed behaviours within a developing population is inherent and inevitable. In this outbreeder, there is significant variation in seed longevity which appears dependent on embryo genotype with little effect of maternal genotype or architectural factors. PMID:20228084

  12. The development of transgenic crops to improve human health by advanced utilization of seed storage proteins.

    PubMed

    Maruyama, Nobuyuki; Mikami, Bunzo; Utsumi, Shigeru

    2011-01-01

    Seed storage proteins are a major component of mature seeds. They are utilized as protein sources in foods. We designed seed storage proteins containing bioactive peptides based on their three-dimensional structures. Furthermore, to create crops with enhanced food qualities, we developed transgenic crops producing seed storage proteins with bioactive peptides. This strategy promises to prevent lifestyle-related diseases by simple daily food consumption. In this review, we discuss a strategy to develop transgenic crops to improve human health by advanced utilization of seed storage proteins.

  13. Mitochondrial biogenesis in plants during seed germination.

    PubMed

    Law, Simon R; Narsai, Reena; Whelan, James

    2014-11-01

    Mitochondria occupy a central role in the eukaryotic cell. In addition to being major sources of cellular energy, mitochondria are also involved in a diverse range of functions including signalling, the synthesis of many essential organic compounds and a role in programmed cell death. The active proliferation and differentiation of mitochondria is termed mitochondrial biogenesis and necessitates the coordinated communication of mitochondrial status within an integrated cellular network. Two models of mitochondrial biogenesis have been defined previously, the growth and division model and the maturation model. The former describes the growth and division of pre-existing mature organelles through a form of binary fission, while the latter describes the propagation of mitochondria from structurally and biochemically simple promitochondrial structures that upon appropriate stimuli, mature into fully functional mitochondria. In the last decade, a number of studies have utilised seed germination in plants as a platform for the examination of the processes occurring during mitochondrial biogenesis. These studies have revealed many new aspects of the tightly regulated procession of events that define mitochondrial biogenesis during this period of rapid development. A model for mitochondrial biogenesis that supports the maturation of mitochondria from promitochondrial structures has emerged, where mitochondrial signalling plays a crucial role in the early steps of seed germination.

  14. Function of antioxidant enzymes and metabolites during maturation of pea fruits.

    PubMed

    Matamoros, Manuel A; Loscos, Jorge; Dietz, Karl-Josef; Aparicio-Tejo, Pedro M; Becana, Manuel

    2010-01-01

    In plant cells, antioxidants keep reactive oxygen species at low concentrations, avoiding oxidative damage while allowing them to play crucial functions in signal transduction. However, little is known about the role of antioxidants during fruit maturation, especially in legumes. Snap pea (Pisum sativum) plants, which have edible fruits, were grown under nodulating and non-nodulating conditions. Fruits were classified in three maturity stages and antioxidants were determined in the seeds and seedless pods. Maturation or prolonged storage of fruits at 25 degrees C led to a decline in antioxidant activities and metabolites and in gamma-glutamylcysteine synthetase protein. Notable exceptions were superoxide dismutase activity and glutathione peroxidase protein, which increased in one or both of these processes. During maturation, cytosolic peroxiredoxin decreased in seeds but increased in pods, and ascorbate oxidase activity was largely reduced in seeds. In stored fruits, ascorbate oxidase activity was nearly abolished in seeds but doubled in pods. It is concluded that symbiotic nitrogen fixation is as effective as nitrogen fertilization in maintaining the antioxidant capacity of pea fruits and that, contrary to climacteric fruits, a general decrease in antioxidants during maturation does not involve oxidative stress. Results underscore the importance of the antioxidant system in reproductive organs and point to ascorbate-glutathione metabolism and cytosolic peroxiredoxin as key players in pea fruit development.

  15. Maturational and Non-Maturational Factors in Heritage Language Acquisition

    ERIC Educational Resources Information Center

    Moon, Ji Hye

    2012-01-01

    This dissertation aims to understand the maturational and non-maturational aspects of early bilingualism and language attrition in heritage speakers who have acquired their L1 incompletely in childhood. The study highlights the influential role of age and input dynamics in early L1 development, where the timing of reduction in L1 input and the…

  16. Discovery and purification of a fungal protease secreted by Bipolaris zeicola that modifies maize seed endochitinase

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Healthy maize seeds have two basic endochitinases, chitA and chitB, with antifungal properties. A comparison of the isoenzyme profiles of symptomatic fungal-infested maize seeds, removed at harvest from ears that we wound inoculated in the late milk stage of maturity with one of several common ear-...

  17. Isoflavones in soybean seeds: Genetic variation and environmental effects in field-grown crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Both controlled environment and field studies indicate that isoflavones, a dietary source of a class of bioactive phytochemicals present primarily in soybean seeds, increase greatly when seeds mature under cooler conditions or when plants are well-watered. Environmental effects can be superimposed ...

  18. The functions of the endosperm during seed germination.

    PubMed

    Yan, Dawei; Duermeyer, Lisza; Leoveanu, Catalina; Nambara, Eiji

    2014-09-01

    In angiosperms, a double fertilization event initiates the development of two distinct structures, the embryo and endosperm. The endosperm plays an important role in supporting embryonic growth by supplying nutrients, protecting the embryo and controlling embryo growth by acting as a mechanical barrier during seed development and germination. Its structure and function in the mature dry seed is divergent and specialized among different plant species. A subset of endospermic tissues are composed of living cells even after seed maturation, and play an active role in the regulation of seed germination. Transcriptome analysis has provided new insights into the regulatory functions of the endosperm during seed germination. It is well known that the embryo secretes signals to the endosperm to induce the degradation of the seed reserve and to promote endosperm weakening during germination. Recent advances in seed biology have shown that the endosperm is capable of sensing environmental signals, and can produce and secrete signals to regulate the growth of the embryo. Thus, germination is a systemic response that involves bidirectional interactions between the embryo and endosperm.

  19. 7 CFR 201.18 - Other agricultural seeds (crop seeds).

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Other agricultural seeds (crop seeds). 201.18 Section... SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling Agricultural Seeds § 201.18 Other agricultural seeds...

  20. Seed Treatment. Sale Publication 4076.

    ERIC Educational Resources Information Center

    Wamsley, Mary Ann, Ed.; Vermeire, Donna M., Ed.

    This guide gives information about types of seeds that may require chemical protection against pests, seed treatment pesticide formulations, seed treatment methods, labeling treated seed, and safety and environmental precautions. (Author/BB)

  1. Evidence of eelgrass (Zostera marina) seed dispersal by northern diamondback terrapin (Malaclemys terrapin terrapin) in lower Chesapeake Bay.

    PubMed

    Tulipani, Diane C; Lipcius, Romuald N

    2014-01-01

    The initial discovery in May 2009 of eelgrass (Zostera marina) seeds in fecal samples of wild-caught northern diamondback terrapins (Malaclemys terrapin terrapin) was the first field evidence of eelgrass seed ingestion in this species. This finding suggested the potential of terrapins as seed dispersers in eelgrass beds, which we sampled for two additional years (2010 and 2011). Seeds were only found in feces of terrapins captured prior to June 8 in all three years, coinciding with eelgrass seed maturation and release. Numbers of seeds in terrapin feces varied annually and decreased greatly in 2011 after an eelgrass die off in late 2010. The condition of seeds in terrapin feces was viable-mature, germinated, damaged, or immature. Of terrapins captured during time of seed release, 97% were males and juvenile females, both of which had head widths <30 mm. The fraction of individuals with ingested seeds was 33% for males, 35% for small females, and only 6% for large (mature) females. Probability of seed ingestion decreased exponentially with increasing terrapin head width; only males and small females (head width <30 mm) were likely to be vectors of seed dispersal. The characteristic that diamondback terrapins have well-defined home ranges allowed us to estimate the number of terrapins potentially dispersing eelgrass seeds annually. In seagrass beds of the Goodwin Islands region (lower York River, Virginia), there were 559 to 799 terrapins, which could disperse between 1,341 and 1,677 eelgrass seeds annually. These would represent a small proportion of total seed production within a single seagrass bed. However, based on probable home range distances, terrapins can easily traverse eelgrass meadow boundaries, thereby dispersing seeds beyond the bed of origin. Given the relatively short dispersion distance of eelgrass seeds, the diamondback terrapin may be a major source of inter-bed seed dispersal and genetic diversity.

  2. Evidence of Eelgrass (Zostera marina) Seed Dispersal by Northern Diamondback Terrapin (Malaclemys terrapin terrapin) in Lower Chesapeake Bay

    PubMed Central

    Tulipani, Diane C.; Lipcius, Romuald N.

    2014-01-01

    The initial discovery in May 2009 of eelgrass (Zostera marina) seeds in fecal samples of wild-caught northern diamondback terrapins (Malaclemys terrapin terrapin) was the first field evidence of eelgrass seed ingestion in this species. This finding suggested the potential of terrapins as seed dispersers in eelgrass beds, which we sampled for two additional years (2010 and 2011). Seeds were only found in feces of terrapins captured prior to June 8 in all three years, coinciding with eelgrass seed maturation and release. Numbers of seeds in terrapin feces varied annually and decreased greatly in 2011 after an eelgrass die off in late 2010. The condition of seeds in terrapin feces was viable-mature, germinated, damaged, or immature. Of terrapins captured during time of seed release, 97% were males and juvenile females, both of which had head widths <30 mm. The fraction of individuals with ingested seeds was 33% for males, 35% for small females, and only 6% for large (mature) females. Probability of seed ingestion decreased exponentially with increasing terrapin head width; only males and small females (head width <30 mm) were likely to be vectors of seed dispersal. The characteristic that diamondback terrapins have well-defined home ranges allowed us to estimate the number of terrapins potentially dispersing eelgrass seeds annually. In seagrass beds of the Goodwin Islands region (lower York River, Virginia), there were 559 to 799 terrapins, which could disperse between 1,341 and 1,677 eelgrass seeds annually. These would represent a small proportion of total seed production within a single seagrass bed. However, based on probable home range distances, terrapins can easily traverse eelgrass meadow boundaries, thereby dispersing seeds beyond the bed of origin. Given the relatively short dispersion distance of eelgrass seeds, the diamondback terrapin may be a major source of inter-bed seed dispersal and genetic diversity. PMID:25072473

  3. Career Maturity of Welfare Recipients.

    ERIC Educational Resources Information Center

    Beckman, Carol M.

    To investigate the career maturity of welfare recipients, this thesis examines six independent variables: (1) race; (2) sex; (3) age; (4) level of formal education; (5) general intelligence; and (6) locus of control. Scales taken from the Career Maturity Inventory served as the dependent variables. The sample consisted of 83 welfare recipients who…

  4. Career Education and Career Maturity.

    ERIC Educational Resources Information Center

    Trebilco, Geoffrey R.

    1984-01-01

    Investigated the relationships between career maturity and career curriculum in 38 Melbourne metropolitan secondary schools (N=2280 students) using an Australian adaption of the Career Development Inventory. Results confirmed that schools with career education programs achieved higher gains in student career maturity. (JAC)

  5. Parthenocarpy and Seed Predation by Insects in Bursera morelensis

    PubMed Central

    Ramos-Ordoñez, María F.; Márquez-Guzmán, Judith; Del Coro Arizmendi, Ma.

    2008-01-01

    Background and Aims While parthenocarpy (meaning the production of fruits without seeds) may limit fecundity in many plants, its function is not clear; it has been proposed, however, that it might be associated with a strategy to avoid seed predation. Bursera morelensis is a dioecious endemic plant that produces fruits with and without seeds, and its fruits are parasitized by insects. Its reproductive system is not well described and no published evidence of parthenocarpy exists for the species. The purpose of this work was to describe the breeding system of B. morelensis and its relationship to seed predation by insects. Methods The breeding system was described using pollination experiments, verifying the presence of parthenocarpic fruits and apomictic seeds. Reproductive structures from flower buds to mature fruits were quantified. For fruits, an anatomical and histological characterization was made. The number of fruits in which seeds had been predated by insects was correlated with parthenocarpic fruit production. Key Results The major abortion of reproductive structures occurred during fruit set. The results discard the formation of apomictic seeds. Flowers that were not pollinated formed parthenocarpic fruits and these could be distinguished during early developmental stages. In parthenocarpic fruits in the first stages of development, an unusual spread of internal walls of the ovary occurred invading the locule and preventing ovule development. Unlike fruits with seeds, parthenocarpic fruits do not have calcium oxalate crystals in the ovary wall. Both fruit types can be separated in the field at fruit maturity by the presence of dehiscence, complete in seeded and partial in parthenocarpic fruits. Trees with more parthenocarpic fruits had more parasitized fruits. Conclusions This is the first time the anatomy of parthenocarpic fruits in Burseraceae has been described. Parthenocarpic fruits in B. morelensis might function as a deceit strategy for insect seed

  6. Preservation of recalcitrant seeds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recalcitrant and intermediate seeds are not included in seed banks because of misperceptions that these efforts would be futile. Between 20 and 25% of the Earth’s angiosperm species are estimated to produce recalcitrant or intermediate seeds. These species are more prevalent in the tropics and sub...

  7. Seed Proteomics"

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Proteomic analysis of seeds encounters some specific problems that do not impinge on analyses of other plant cells, tissues, or organs. There are anatomic considerations. Seeds comprise the seed coat, the storage organ(s), and the embryonic axis. Are these to be studied individually or as a compo...

  8. Going to Seed.

    ERIC Educational Resources Information Center

    Powell, Richard R.

    1984-01-01

    Describes a unit on seeds designed to introduce students to their scientific and nutritional uses. Unit activities are easily done, employ a variety of process skills, and can be used at various grade levels. Suggests field trips to gather seeds, seed sprouting, and making cookies out of various whole grains. (JM)

  9. Needs of Seeds

    ERIC Educational Resources Information Center

    Keeley, Page

    2011-01-01

    The "Needs of Seeds" formative assessment probe can be used to find out whether students recognize that seeds have needs both similar to and different from plants and other living organisms (Keeley, Eberle, and Tugel 2007). The probe reveals whether students overgeneralize the needs of seeds by assuming they have the same needs as the adult plants…

  10. Proteome-wide characterization of sugarbeet seed vigor and its tissue specific expression

    PubMed Central

    Catusse, Julie; Strub, Jean-Marc; Job, Claudette; Van Dorsselaer, Alain; Job, Dominique

    2008-01-01

    Proteomic analysis of mature sugarbeet seeds led to the identification of 759 proteins and their specific tissue expression in root, cotyledons, and perisperm. In particular, the proteome of the perispermic storage tissue found in many seeds of the Caryophyllales is described here. The data allowed us to reconstruct in detail the metabolism of the seeds toward recapitulating facets of seed development and provided insights into complex behaviors such as germination. The seed appears to be well prepared to mobilize the major classes of reserves (the proteins, triglycerides, phytate, and starch) during germination, indicating that the preparation of the seed for germination is mainly achieved during its maturation on the mother plant. Furthermore, the data revealed several pathways that can contribute to seed vigor, an important agronomic trait defined as the potential to produce vigorous seedlings, such as glycine betaine accumulation in seeds. This study also identified several proteins that, to our knowledge, have not previously been described in seeds. For example, the data revealed that the sugarbeet seed can initiate translation either through the traditional cap-dependent mechanism or by a cap-independent process. The study of the tissue specificity of the seed proteome demonstrated a compartmentalization of metabolic activity between the roots, cotyledons, and perisperm, indicating a division of metabolic tasks between the various tissues. Furthermore, the perisperm, although it is known as a dead tissue, appears to be very active biochemically, playing multiple roles in distributing sugars and various metabolites to other tissues of the embryo. PMID:18635686

  11. Reduced seed germination in Arabidopsis over-expressing SWI/SNF2 ATPase genes.

    PubMed

    Leeggangers, Hendrika A C F; Folta, Adam; Muras, Aleksandra; Nap, Jan-Peter; Mlynarova, Ludmila

    2015-02-01

    In the life of flowering plants, seed germination is a critical step to ensure survival into the next generation. Generally the seed prior to germination has been in a dormant state with a low rate of metabolism. In the transition from a dormant seed to a germinating seed, various epigenetic mechanisms play a regulatory role. Here, we demonstrate that the over-expression of chromatin remodeling ATPase genes (AtCHR12 or AtCHR23) reduced the frequency of seed germination in Arabidopsis thaliana up to 30% relative to the wild-type seeds. On the other hand, single loss-of-function mutations of the two genes did not affect seed germination. The reduction of germination in over-expressing mutants was more pronounced in stress conditions (salt or high temperature), showing the impact of the environment. Reduced germinations upon over-expression coincided with increased transcript levels of seed maturation genes and with reduced degradation of their mRNAs stored in dry seeds. Our results indicate that repression of AtCHR12/23 gene expression in germinating wild-type Arabidopsis seeds is required for full germination. This establishes a functional link between chromatin modifiers and regulatory networks towards seed maturation and germination.

  12. Genome-Wide Dissection of the MicroRNA Expression Profile in Rice Embryo during Early Stages of Seed Germination

    PubMed Central

    He, Dongli; Wang, Qiong; Wang, Kun; Yang, Pingfang

    2015-01-01

    The first 24 hours after imbibition (HAI) is pivotal for rice seed germination, during which embryo cells switch from a quiescent state to a metabolically active state rapidly. MicroRNAs (miRNAs) have increasingly been shown to play important roles in rice development. Nevertheless, limited knowledge about miRNA regulation has been obtained in the early stages of rice seed germination. In this study, the small RNAs (sRNAs) from embryos of 0, 12, and 24 HAI rice seeds were sequenced to investigate the composition and expression patterns of miRNAs. The bioinformatics analysis identified 289 miRNA loci, including 59 known and 230 novel miRNAs, and 35 selected miRNAs were confirmed by stem-loop real-time RT-PCR. Expression analysis revealed that the dry and imbibed seeds have unique miRNA expression patterns compared with other tissues, particularly for the dry seeds. Using three methods, Mireap, psRNATarget and degradome analyses, 1197 potential target genes of identified miRNAs involved in various molecular functions were predicted. Among these target genes, 39 had significantly negative correlations with their corresponding miRNAs as inferred from published transcriptome data, and 6 inversely expressed miRNA-target pairs were confirmed by 5ʹ-RACE assay. Our work provides an inventory of miRNA expression profiles and miRNA-target interactions in rice embryos, and lays a foundation for further studies of miRNA-mediated regulation in initial seed germination. PMID:26681181

  13. Far-red Sensitive Dark Processes Essential for Light- and Gibberellin-induced Germination of Lettuce Seed

    PubMed Central

    Negbi, M.; Black, M.; Bewley, J. D.

    1968-01-01

    The action of prolonged far-red on seed germination was studied in Lactuca sativa L. var. Grand Rapids. Exposure of imbibed seeds to 6 hours far-red before the application of gibberellic acid (GA3) and thiourea completely prevented germination. Using GA3, this far-red was effective after the sixth hour of imbibition. At 6, 12, and 18 hours of imbibition equal durations of far-red had equal effects. The kinetics of far-red action was investigated: it was found that although far-red for several hours, irrespective of the energy level, was needed for maximum inhibition, shorter durations (15 and 30 mins) were also appreciably effective provided they were followed by several hours darkness before the supply of GA3. This is taken to indicate the existence of labile product(s) of the action of a far-red sensitive pigment. Evidence is provided for the existence of promotive dark processes controlled by this pigment, which are essential for germination whether triggered by GA3, thiourea or red-light. A model for the operation of the pigment system is proposed and its role in the germination mechanism of this seed is discussed. PMID:16656733

  14. The effect of burial depth on removal of seeds of Phytolacca americana.

    SciTech Connect

    Orrock, John, L.: Damschen, Ellen, I.

    2007-04-01

    Abstract - Although burial is known to have important effects on seed predation in a variety of habitats, the role of burial depth in affecting the removal of seeds in early successional systems is poorly known. Phytolacca American (pokeweed) is a model species to examine the role of burial depth in affecting seed removal because it is common in early-successional habitats, studies suggest that seed removal is indicative of seed predation, and seed predation is related to the recruitment of mature plants. To determine how burial depth affects P. americana seed removal, 20 seeds of P. americana were buried at depths of 0, 1, or 3 cm in early-successional habitats at the Savannah River Site in South Carolina for over 6 weeks. The frequency with which seeds were encountered (as measured by the removal of at least one seed) and the proportion of seeds removed was significantly greater when seeds were on the soil surface (0 cm depth) compared to seeds that were buried 1 cm or 3 cm; there was no difference in encounter or removal between seeds at 1 cm or 3 cm. Our findings suggest that burial may have important consequences for P. americana population dynamics, because seed survival depends upon whether or not the seed is buried, and relatively shallow burial can yield large increases in seed survival. Because seed limitation is known to be an important determinant of plant community composition in early successional systems, our work suggests that burial may play an unappreciated role in the dynamics of these communities by reducing predator-mediated seed limitation.

  15. Evidence for participation of the methionine sulfoxide reductase repair system in plant seed longevity

    PubMed Central

    Châtelain, Emilie; Satour, Pascale; Laugier, Edith; Ly Vu, Benoit; Payet, Nicole; Rey, Pascal; Montrichard, Françoise

    2013-01-01

    Seeds are in a natural oxidative context leading to protein oxidation. Although inevitable for proper progression from maturation to germination, protein oxidation at high levels is detrimental and associated with seed aging. Oxidation of methionine to methionine sulfoxide is a common form of damage observed during aging in all organisms. This damage is reversible through the action of methionine sulfoxide reductases (MSRs), which play key roles in lifespan control in yeast and animal cells. To investigate the relationship between MSR capacity and longevity in plant seeds, we first used two Medicago truncatula genotypes with contrasting seed quality. After characterizing the MSR family in this species, we analyzed gene expression and enzymatic activity in immature and mature seeds exhibiting distinct quality levels. We found a very strong correlation between the initial MSR capacities in different lots of mature seeds of the two genotypes and the time to a drop in viability to 50% after controlled deterioration. We then analyzed seed longevity in Arabidopsis thaliana lines, in which MSR gene expression has been genetically altered, and observed a positive correlation between MSR capacity and longevity in these seeds as well. Based on our data, we propose that the MSR repair system plays a decisive role in the establishment and preservation of longevity in plant seeds. PMID:23401556

  16. Evidence for participation of the methionine sulfoxide reductase repair system in plant seed longevity.

    PubMed

    Châtelain, Emilie; Satour, Pascale; Laugier, Edith; Ly Vu, Benoit; Payet, Nicole; Rey, Pascal; Montrichard, Françoise

    2013-02-26

    Seeds are in a natural oxidative context leading to protein oxidation. Although inevitable for proper progression from maturation to germination, protein oxidation at high levels is detrimental and associated with seed aging. Oxidation of methionine to methionine sulfoxide is a common form of damage observed during aging in all organisms. This damage is reversible through the action of methionine sulfoxide reductases (MSRs), which play key roles in lifespan control in yeast and animal cells. To investigate the relationship between MSR capacity and longevity in plant seeds, we first used two Medicago truncatula genotypes with contrasting seed quality. After characterizing the MSR family in this species, we analyzed gene expression and enzymatic activity in immature and mature seeds exhibiting distinct quality levels. We found a very strong correlation between the initial MSR capacities in different lots of mature seeds of the two genotypes and the time to a drop in viability to 50% after controlled deterioration. We then analyzed seed longevity in Arabidopsis thaliana lines, in which MSR gene expression has been genetically altered, and observed a positive correlation between MSR capacity and longevity in these seeds as well. Based on our data, we propose that the MSR repair system plays a decisive role in the establishment and preservation of longevity in plant seeds.

  17. Seed Oil and Composition Development in Two Sunflower Hybrids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Desiccants/harvest aids are becoming more commonly used to hasten sunflower harvest. Currently, it is recommended that desiccants such as glyphosate and paraquat be applied at 35% or less seed moisture at physiological maturity (PM). Recently, Johnson and Gesch (2009) showed that PM for two commerci...

  18. Respiration hastens maturation and lowers yield in rice.

    PubMed

    Sitaramam, V; Bhate, R; Kamalraj, P; Pachapurkar, S

    2008-07-01

    Role of respiration in plant growth remains an enigma. Growth of meristematic cells, which are not photosynthetic, is entirely driven by endogenous respiration. Does respiration determine growth and size or does it merely burn off the carbon depleting the biomass? We show here that respiration of the germinating rice seed, which is contributed largely by the meristematic cells of the embryo, quantitatively correlates with the dynamics of much of plant growth, starting with the time for germination to the time for flowering and yield. Seed respiration appears to define the quantitative phenotype that contributes to yield via growth dynamics that could be discerned even in commercial varieties, which are biased towards higher yield, despite considerable susceptibility of the dynamics to environmental perturbations. Intrinsic variation, irreducible despite stringent growth conditions, required independent validation of relevant physiological variables both by critical sampling design and by constructing dendrograms for the interrelationships between variables that yield high consensus. More importantly, seed respiration, by mediating the generation clock time via variable time for maturation as seen in rice, directly offers the plausible basis for the phenotypic variation, a major ecological stratagem in a variable environment with uncertain water availability. Faster respiring rice plants appear to complete growth dynamics sooner, mature faster, resulting in a smaller plant with lower yield. Counter to the common allometric views, respiration appears to determine size in the rice plant, and offers a valid physiological means, within the limits of intrinsic variation, to help parental selection in breeding.

  19. Expression of genes controlling unsaturated fatty acids biosynthesis and oil deposition in developing seeds of Sacha inchi (Plukenetia volubilis L.).

    PubMed

    Wang, Xiaojuan; Liu, Aizhong

    2014-10-01

    Sacha inchi (Plukenetia volubilis L., Euphorbiaceae) seed oil is rich in α-linolenic acid, a kind of n-3 fatty acids with many health benefits. To discover the mechanism underlying α-linolenic acid accumulation in sacha inchi seeds, preliminary research on sacha inchi seed development was carried out from one week after fertilization until maturity, focusing on phenology, oil content, and lipid profiles. The results suggested that the development of sacha inchi seeds from pollination to mature seed could be divided into three periods. In addition, investigations on the effect of temperature on sacha inchi seeds showed that total oil content decreased in the cool season, while unsaturated fatty acid and linolenic acid concentrations increased. In parallel, expression profiles of 17 unsaturated fatty acid related genes were characterized during seed development and the relationships between gene expression and lipid/unsaturated fatty acid accumulation were discussed.

  20. Stability in and correlation between factors influencing genetic quality of seed lots in seed orchard of Pinus tabuliformis Carr. over a 12-year span.

    PubMed

    Li, Wei; Wang, Xiaoru; Li, Yue

    2011-01-01

    Coniferous seed orchards require a long period from initial seed harvest to stable seed production. Differential reproductive success and asynchrony are among the main factors for orchard crops year-to-year variation in terms of parental gametic contribution and ultimately the genetic gain. It is fundamental in both making predictions about the genetic composition of the seed crop and decisions about orchard roguing and improved seed orchard establishment. In this paper, a primary Chinese pine seed orchard with 49 clones is investigated for stability, variation and correlation analysis of factors which influence genetic quality of the seed lots from initial seed harvest to the stable seed production over a 12 years span. Results indicated that the reproductive synchrony index of pollen shedding has shown to be higher than that of the strobili receptivity, and both can be drastically influenced by the ambient climate factors. Reproductive synchrony index of the clones has certain relative stability and it could be used as an indication of the seed orchard status during maturity stage; clones in the studied orchard have shown extreme differences in terms of the gametic and genetic contribution to the seed crop at the orchard's early production phase specifically when they severe as either female or male parents. Those differences are closely related to clonal sex tendency at the time of orchard's initial reproduction. Clonal gamete contribution as male and female parent often has a negative correlation. Clone utilization as pollen, seed or both pollen and seed donors should consider the role it would play in the seed crop; due to numerous factors influencing on the mating system in seed orchards, clonal genetic contribution as male parent is uncertain, and it has major influence on the genetic composition in the seed orchard during the initial reproductive and seed production phase.

  1. 12-oxo-phytodienoic acid accumulation during seed development represses seed germination in Arabidopsis.

    PubMed

    Dave, Anuja; Hernández, M Luisa; He, Zhesi; Andriotis, Vasilios M E; Vaistij, Fabián E; Larson, Tony R; Graham, Ian A

    2011-02-01

    Arabidopsis thaliana COMATOSE (CTS) encodes an ABC transporter involved in peroxisomal import of substrates for β-oxidation. Various cts alleles and mutants disrupted in steps of peroxisomal β-oxidation have previously been reported to exhibit a severe block on seed germination. Oxylipin analysis on cts, acyl CoA oxidase1 acyl CoA oxidase2 (acx1 acx2), and keto acyl thiolase2 dry seeds revealed that they contain elevated levels of 12-oxo-phytodienoic acid (OPDA), jasmonic acid (JA), and JA-Ile. Oxylipin and transcriptomic analysis showed that accumulation of these oxylipins occurs during late seed maturation in cts. Analysis of double mutants generated by crossing cts with mutants in the JA biosynthesis pathway indicate that OPDA, rather than JA or JA-Ile, contributes to the block on germination in cts seeds. We found that OPDA was more effective at inhibiting wild-type germination than was JA and that this effect was independent of CORONATINE INSENSITIVE1 but was synergistic with abscisic acid (ABA). Consistent with this, OPDA treatment increased ABA INSENSITIVE5 protein abundance in a manner that parallels the inhibitory effect of OPDA and OPDA+ABA on seed germination. These results demonstrate that OPDA acts along with ABA to regulate seed germination in Arabidopsis.

  2. Gravity independence of seed-to-seed cycling in Brassica rapa

    NASA Technical Reports Server (NTRS)

    Musgrave, M. E.; Kuang, A.; Xiao, Y.; Stout, S. C.; Bingham, G. E.; Briarty, L. G.; Levenskikh, M. A.; Sychev, V. N.; Podolski, I. G.

    2000-01-01

    Growth of higher plants in the microgravity environment of orbital platforms has been problematic. Plants typically developed more slowly in space and often failed at the reproductive phase. Short-duration experiments on the Space Shuttle showed that early stages in the reproductive process could occur normally in microgravity, so we sought a long-duration opportunity to test gravity's role throughout the complete life cycle. During a 122-d opportunity on the Mir space station, full life cycles were completed in microgravity with Brassica rapa L. in a series of three experiments in the Svet greenhouse. Plant material was preserved in space by chemical fixation, freezing, and drying, and then compared to material preserved in the same way during a high-fidelity ground control. At sampling times 13 d after planting, plants on Mir were the same size and had the same number of flower buds as ground control plants. Following hand-pollination of the flowers by the astronaut, siliques formed. In microgravity, siliques ripened basipetally and contained smaller seeds with less than 20% of the cotyledon cells found in the seeds harvested from the ground control. Cytochemical localization of storage reserves in the mature embryos showed that starch was retained in the spaceflight material, whereas protein and lipid were the primary storage reserves in the ground control seeds. While these successful seed-to-seed cycles show that gravity is not absolutely required for any step in the plant life cycle, seed quality in Brassica is compromised by development in microgravity.

  3. The seed nuclear proteome.

    PubMed

    Repetto, Ombretta; Rogniaux, Hélène; Larré, Colette; Thompson, Richard; Gallardo, Karine

    2012-01-01

    Understanding the regulatory networks coordinating seed development will help to manipulate seed traits, such as protein content and seed weight, in order to increase yield and seed nutritional value of important food crops, such as legumes. Because of the cardinal role of the nucleus in gene expression, sub-proteome analyses of nuclei from developing seeds were conducted, taking advantage of the sequences available for model species. In this review, we discuss the strategies used to separate and identify the nuclear proteins at a stage when the seed is preparing for reserve accumulation. We present how these data provide an insight into the complexity and distinctive features of the seed nuclear proteome. We discuss the presence of chromatin-modifying enzymes and proteins that have roles in RNA-directed DNA methylation and which may be involved in modifying genome architecture in preparation for seed filling. Specific features of the seed nuclei at the transition between the stage of cell divisions and that of cell expansion and reserve deposition are described here which may help to manipulate seed quality traits, such as seed weight.

  4. Indirect interactions among tropical tree species through shared rodent seed predators: a novel mechanism of tree species coexistence.

    PubMed

    Garzon-Lopez, Carol X; Ballesteros-Mejia, Liliana; Ordoñez, Alejandro; Bohlman, Stephanie A; Olff, Han; Jansen, Patrick A

    2015-08-01

    The coexistence of numerous tree species in tropical forests is commonly explained by negative dependence of recruitment on the conspecific seed and tree density due to specialist natural enemies that attack seeds and seedlings ('Janzen-Connell' effects). Less known is whether guilds of shared seed predators can induce a negative dependence of recruitment on the density of different species of the same plant functional group. We studied 54 plots in tropical forest on Barro Colorado Island, Panama, with contrasting mature tree densities of three coexisting large seeded tree species with shared seed predators. Levels of seed predation were far better explained by incorporating seed densities of all three focal species than by conspecific seed density alone. Both positive and negative density dependencies were observed for different species combinations. Thus, indirect interactions via shared seed predators can either promote or reduce the coexistence of different plant functional groups in tropical forest.

  5. Role of peroxidase in the development of water-impermeable seed coats in Sida spinosa L.

    PubMed

    Egley, G H; Paul, R N; Vaughn, K C; Duke, S O

    1983-04-01

    The seed coats of S. spinosa (prickly sida, Malvaceae) become impermeable to water during seed development on the mother plant. After the seeds have dehydrated during the final maturation stages, piercing of seed coats is necessary to induce imbibition of water and germination. Onset of impermeability occurs during seed coat browning, well in advance of seed dehydration. I. Marbach and A.M. Mayer (1975, Plant Physiol. 56, 93-96) implicated polyphenol oxidase (PO; EC 1.10.3.1) as catechol oxidase in the formation of insoluble polymers during development of coat impermeability in a wild strain of pea (Pisum elatius) seeds. We found, however, that peroxidase (EC 1.11.1.7), not PO, is instrumental in the development of water-impermeable seed coats in prickly sida. We isolated coats and embryos from seeds harvested at several stages of development. Highest peroxidase activity of coat extracts correlated well with the developmental stages of maximum conversion of soluble phenolics to insoluble lignin polymers. Although seed extracts oxidized dihydroxyphenylalanine, this activity was eliminated by catalase, indicating that the oxidation of phenolics in the coat is catalyzed by peroxidase rather than PO. Histochemical localization of peroxidase was strongest in the palisade layer; both the level and time of appearance of activity was proportional to the spectrophotometric assays of seed-coat extracts. The presence of peroxidase and the absence of PO in the seed coat were also confirmed with immunocytochemistry. Our results support the view that peroxidase is involved in the polymerization of soluble phenolics to insoluble lignin polymers during development of prickly sida seed coats, causing the formation of a water-impermeable barrier prior to seed dehydration. As dehydration proceeds, the chalazal area finally becomes impermeable resulting in the hard mature seeds of prickly sida.

  6. Effect of Seed Position on Parental Plant on Proportion of Seeds Produced with Nondeep and Intermediate Physiological Dormancy

    PubMed Central

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

    2017-01-01

    The position in which seeds develop on the parental plant can have an effect on dormancy-break and germination. We tested the hypothesis that the proportion of seeds with intermediate physiological dormancy (PD) produced in the proximal position on a raceme of Isatis violascens plants is higher than that produced in the distal position, and further that this difference is related to temperature during seed development. Plants were watered at 3-day intervals, and silicles and seeds from the proximal (early) and distal (late) positions of racemes on the same plants were collected separately and tested for germination. After 0 and 6 months dry storage at room temperature (afterripening), silicles and seeds were cold stratified for 0–16 weeks and tested for germination. Mean daily maximum and minimum temperatures during development/maturation of the two groups of seeds did not differ. A higher proportion of seeds with the intermediate level than with the nondeep level of PD was produced by silicles in the proximal position than by those in the distal position, while the proportion of seeds with nondeep PD was higher in the distal than in the proximal position of the raceme. The differences were not due only to seed mass. Since temperature and soil moisture conditions were the same during development of the seeds in the raceme, differences in proportion of seeds with intermediate and nondeep PD are attributed to position on parental plant. The ecological consequence of this phenomenon is that it ensures diversity in dormancy-breaking and germination characteristics within a seed cohort, a probable bet-hedging strategy. This is the first demonstration of position effects on level of PD in the offspring. PMID:28232842

  7. Effect of Seed Position on Parental Plant on Proportion of Seeds Produced with Nondeep and Intermediate Physiological Dormancy.

    PubMed

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

    2017-01-01

    The position in which seeds develop on the parental plant can have an effect on dormancy-break and germination. We tested the hypothesis that the proportion of seeds with intermediate physiological dormancy (PD) produced in the proximal position on a raceme of Isatis violascens plants is higher than that produced in the distal position, and further that this difference is related to temperature during seed development. Plants were watered at 3-day intervals, and silicles and seeds from the proximal (early) and distal (late) positions of racemes on the same plants were collected separately and tested for germination. After 0 and 6 months dry storage at room temperature (afterripening), silicles and seeds were cold stratified for 0-16 weeks and tested for germination. Mean daily maximum and minimum temperatures during development/maturation of the two groups of seeds did not differ. A higher proportion of seeds with the intermediate level than with the nondeep level of PD was produced by silicles in the proximal position than by those in the distal position, while the proportion of seeds with nondeep PD was higher in the distal than in the proximal position of the raceme. The differences were not due only to seed mass. Since temperature and soil moisture conditions were the same during development of the seeds in the raceme, differences in proportion of seeds with intermediate and nondeep PD are attributed to position on parental plant. The ecological consequence of this phenomenon is that it ensures diversity in dormancy-breaking and germination characteristics within a seed cohort, a probable bet-hedging strategy. This is the first demonstration of position effects on level of PD in the offspring.

  8. SNP markers linked to QTL conditioning plant height, lodging, and maturity in soybean

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soybean (Glycine max L. Merr.) is a major crop and a leading source of protein meal and edible oil worldwide. Plant height (PHT), lodging (LDG), and days to maturity (MAT) are three important agronomic traits that influence the seed yield of soybean. The objective of this study was to map quantitati...

  9. Relationship between 5S and 20S forms of malate synthase in maturing cottonseeds

    SciTech Connect

    Turley, R.B.; Trelease, R.N.

    1987-04-01

    Malate synthase (MS) activity appears and increases during seed maturation persists during desiccation, then increases again following germination. Because different modes of synthesis and organelle import of MS may occur in maturing and germinated seeds, a comparative study was performed. A comparison of immunoprecipitations from in-vivo-labeled seeds (/sup 35/S-met) and in-vitro translations of Poly A+ RNA (wheat germ) showed no detectable differences in subunit mol wt. When MS activity first appears (42 DPA) only the cytosolic 5S form is found in rate-zonal gradients (5-25% sucrose). At 48 DPA, O d, and 48 h germinated seeds both the 5S and glyoxysomal 20S forms are present, with the 20S becoming more prevalent. Western blots of SDS-PAGE gels showed that no other form(s) of MS (inactive) are present in rate-zonal fractions. Calculations of radiospecific activity (per MS activity) of 5S and 20S forms radiolabeled in vivo (/sup 35/S-met) at various time periods provided further convincing evidence that there is a 5S precursor to 20S product relationship during both seed maturation and seedling growth.

  10. Current perspectives on the hormonal control of seed development in Arabidopsis and maize: a focus on auxin

    PubMed Central

    Locascio, Antonella; Roig-Villanova, Irma; Bernardi, Jamila; Varotto, Serena

    2014-01-01

    The seed represents the unit of reproduction of flowering plants, capable of developing into another plant, and to ensure the survival of the species under unfavorable environmental conditions. It is composed of three compartments: seed coat, endosperm and embryo. Proper seed development depends on the coordination of the processes that lead to seed compartments differentiation, development and maturation. The coordination of these processes is based on the constant transmission/perception of signals by the three compartments. Phytohormones constitute one of these signals; gradients of hormones are generated in the different seed compartments, and their ratios comprise the signals that induce/inhibit particular processes in seed development. Among the hormones, auxin seems to exert a central role, as it is the only one in maintaining high levels of accumulation from fertilization to seed maturation. The gradient of auxin generated by its PIN carriers affects several processes of seed development, including pattern formation, cell division and expansion. Despite the high degree of conservation in the regulatory mechanisms that lead to seed development within the Spermatophytes, remarkable differences exist during seed maturation between Monocots and Eudicots species. For instance, in Monocots the endosperm persists until maturation, and constitutes an important compartment for nutrients storage, while in Eudicots it is reduced to a single cell layer, as the expanding embryo gradually replaces it during the maturation. This review provides an overview of the current knowledge on hormonal control of seed development, by considering the data available in two model plants: Arabidopsis thaliana, for Eudicots and Zea mays L., for Monocots. We will emphasize the control exerted by auxin on the correct progress of seed development comparing, when possible, the two species. PMID:25202316

  11. Developmental changes in mineral contents of soybean seed coats and embryos

    SciTech Connect

    Laszlo, J.A. )

    1990-05-01

    Little is known about mineral metabolism in legume seeds during development and maturation. This study examines the distribution of Mg, Ca, Cu, Fe, Zn and Mn between seed coat and embryo in five soybean (Glycine max (L.) Merr.) cultivars during seed development. Levels of Mg and Fe in seed coat and embryo varied with reproductive growth stage, but in no consistent manner across the various cultivars. Seed coat Ca and Zn levels initially decreased, then rose in the final stages of development, while embryonic mineral levels decreased or remained constant. Cu and Mn contents of seed coats initially increased, then dropped -- accompanied by an increase of these minerals in the embryo. These findings suggest that cationic metals are not passively assimilated in conjunction with dry matter accumulation, but rather are subject to ion-specific seed coat unloading, transport, and cotyledonary uptake processes.

  12. Primary seed dormancy: a temporally multilayered riddle waiting to be unlocked.

    PubMed

    Chahtane, Hicham; Kim, Woohyun; Lopez-Molina, Luis

    2016-10-11

    Primary seed dormancy is an important adaptive plant trait whereby seed germination is blocked under conditions that would otherwise be favorable for germination. This trait is found in newly produced mature seeds of many species, but not all. Once produced, dry seeds undergo an aging time period, called dry after-ripening, during which they lose primary dormancy and gradually acquire the capacity to germinate when exposed to favorable germination conditions. Primary seed dormancy has been extensively studied not only for its scientific interest but also for its ecological, phenological, and agricultural importance. Nevertheless, the mechanisms underlying primary seed dormancy and its regulation during after-ripening remain poorly understood. Here we review the principal developmental stages where primary dormancy is established and regulated prior to and during seed after-ripening, where it is progressively lost. We attempt to identify and summarize what is known about the molecular and genetic mechanisms intervening over time in each of these stages.

  13. 7 CFR 51.3746 - Mature.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ..., CERTIFICATION, AND STANDARDS) United States Standards for Grades of Honey Dew and Honey Ball Type Melons Definitions § 51.3746 Mature. Mature means that the melon has reached the stage of maturity which will...

  14. 7 CFR 51.3746 - Mature.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Standards for Grades of Honey Dew and Honey Ball Type Melons Definitions § 51.3746 Mature. Mature means that the melon has reached the stage of maturity which will insure the proper completion of the...

  15. 7 CFR 51.3746 - Mature.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Standards for Grades of Honey Dew and Honey Ball Type Melons Definitions § 51.3746 Mature. Mature means that the melon has reached the stage of maturity which will insure the proper completion of the...

  16. 7 CFR 51.3746 - Mature.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ..., CERTIFICATION, AND STANDARDS) United States Standards for Grades of Honey Dew and Honey Ball Type Melons Definitions § 51.3746 Mature. Mature means that the melon has reached the stage of maturity which will...

  17. 7 CFR 51.3746 - Mature.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Standards for Grades of Honey Dew and Honey Ball Type Melons Definitions § 51.3746 Mature. Mature means that the melon has reached the stage of maturity which will insure the proper completion of the...

  18. A statistical analysis to assess the maturity and stability of six composts.

    PubMed

    Komilis, Dimitrios P; Tziouvaras, Ioannis S

    2009-05-01

    Despite the long-time application of organic waste derived composts to crops, there is still no universally accepted index to assess compost maturity and stability. The research presented in this article investigated the suitability of seven types of seeds for use in germination bioassays to assess the maturity and phytotoxicity of six composts. The composts used in the study were derived from cow manure, sea weeds, olive pulp, poultry manure and municipal solid waste. The seeds used in the germination bioassays were radish, pepper, spinach, tomato, cress, cucumber and lettuce. Data were analyzed with an analysis of variance at two levels and with pair-wise comparisons. The analysis revealed that composts rendered as phytotoxic to one type of seed could enhance the growth of another type of seed. Therefore, germination indices, which ranged from 0% to 262%, were highly dependent on the type of seed used in the germination bioassay. The poultry manure compost was highly phytotoxic to all seeds. At the 99% confidence level, the type of seed and the interaction between the seeds and the composts were found to significantly affect germination. In addition, the stability of composts was assessed by their microbial respiration, which ranged from approximately 4 to 16g O(2)/kg organic matter and from 2.6 to approximately 11g CO(2)-C/kg C, after seven days. Initial average oxygen uptake rates were all less than approximately 0.35g O(2)/kg organic matter/h for all six composts. A high statistically significant correlation coefficient was calculated between the cumulative carbon dioxide production, over a 7-day period, and the radish seed germination index. It appears that a germination bioassay with radish can be a valid test to assess both compost stability and compost phytotoxicity.

  19. Preformed Seeds Modulate Native Insulin Aggregation Kinetics.

    PubMed

    Dutta, Colina; Yang, Mu; Long, Fei; Shahbazian-Yassar, Reza; Tiwari, Ashutosh

    2015-12-10

    Insulin aggregates under storage conditions via disulfide interchange reaction. It is also known to form aggregates at the site of repeated injections in diabetes patients, leading to injection amyloidosis. This has fueled research in pharmaceutical and biotechnology industry as well as in academia to understand factors that modulate insulin stability and aggregation. The main aim of this study is to understand the factors that modulate aggregation propensity of insulin under conditions close to physiological and measure effect of "seeds" on aggregation kinetics. We explored the aggregation kinetics of insulin at pH 7.2 and 37 °C in the presence of disulfide-reducing agent dithiothreitol (DTT), using spectroscopy (UV-visible, fluorescence, and Fourier transform infrared spectroscopy) and microscopy (scanning electron microscopy, atomic force microscopy) techniques. We prepared insulin "seeds" by incubating disulfide-reduced insulin at pH 7.2 and 37 °C for varying lengths of time (10 min to 12 h). These seeds were added to the native protein and nucleation-dependent aggregation kinetics was measured. Aggregation kinetics was fastest in the presence of 10 min seeds suggesting they were nascent. Interestingly, intermediate seeds (30 min to 4 h incubation) resulted in formation of transient fibrils in 4 h that converted to amorphous aggregates upon longer incubation of 24 h. Overall, the results show that insulin under disulfide reducing conditions at pH and temperature close to physiological favors amorphous aggregate formation and seed "maturity" plays an important role in nucleation dependent aggregation kinetics.

  20. A role for seed storage proteins in Arabidopsis seed longevity.

    PubMed

    Nguyen, Thu-Phuong; Cueff, Gwendal; Hegedus, Dwayne D; Rajjou, Loïc; Bentsink, Leónie

    2015-10-01

    Proteomics approaches have been a useful tool for determining the biological roles and functions of individual proteins and identifying the molecular mechanisms that govern seed germination, vigour and viability in response to ageing. In this work the dry seed proteome of four Arabidopsis thaliana genotypes, that carry introgression fragments at the position of seed longevity quantitative trait loci and as a result display different levels of seed longevity, was investigated. Seeds at two physiological states, after-ripened seeds that had the full germination ability and aged (stored) seeds of which the germination ability was severely reduced, were compared. Aged dry seed proteomes were markedly different from the after-ripened and reflected the seed longevity level of the four genotypes, despite the fact that dry seeds are metabolically quiescent. Results confirmed the role of antioxidant systems, notably vitamin E, and indicated that protection and maintenance of the translation machinery and energy pathways are essential for seed longevity. Moreover, a new role for seed storage proteins (SSPs) was identified in dry seeds during ageing. Cruciferins (CRUs) are the most abundant SSPs in Arabidopsis and seeds of a triple mutant for three CRU isoforms (crua crub cruc) were more sensitive to artificial ageing and their seed proteins were highly oxidized compared with wild-type seeds. These results confirm that oxidation is involved in seed deterioration and that SSPs buffer the seed from oxidative stress, thus protecting important proteins required for seed germination and seedling formation.

  1. A role for seed storage proteins in Arabidopsis seed longevity

    PubMed Central

    Nguyen, Thu-Phuong; Cueff, Gwendal; Hegedus, Dwayne D; Rajjou, Loïc; Bentsink, Leónie

    2015-01-01

    Proteomics approaches have been a useful tool for determining the biological roles and functions of individual proteins and identifying the molecular mechanisms that govern seed germination, vigour and viability in response to ageing. In this work the dry seed proteome of four Arabidopsis thaliana genotypes, that carry introgression fragments at the position of seed longevity quantitative trait loci and as a result display different levels of seed longevity, was investigated. Seeds at two physiological states, after-ripened seeds that had the full germination ability and aged (stored) seeds of which the germination ability was severely reduced, were compared. Aged dry seed proteomes were markedly different from the after-ripened and reflected the seed longevity level of the four genotypes, despite the fact that dry seeds are metabolically quiescent. Results confirmed the role of antioxidant systems, notably vitamin E, and indicated that protection and maintenance of the translation machinery and energy pathways are essential for seed longevity. Moreover, a new role for seed storage proteins (SSPs) was identified in dry seeds during ageing. Cruciferins (CRUs) are the most abundant SSPs in Arabidopsis and seeds of a triple mutant for three CRU isoforms (crua crub cruc) were more sensitive to artificial ageing and their seed proteins were highly oxidized compared with wild-type seeds. These results confirm that oxidation is involved in seed deterioration and that SSPs buffer the seed from oxidative stress, thus protecting important proteins required for seed germination and seedling formation. PMID:26184996

  2. Crystallization on prestructured seeds.

    PubMed

    Jungblut, Swetlana; Dellago, Christoph

    2013-01-01

    The crystallization transition of an undercooled monodisperse Lennard-Jones fluid in the presence of small prestructured seeds is studied with transition path sampling combined with molecular dynamics simulations. Compared to the homogeneous crystallization, clusters of a few particles arranged into a face- and body-centered cubic structure enhance the crystallization, while icosahedrally ordered seeds do not change the reaction rate. We identify two distinct nucleation regimes-close to the seed and in the bulk. Crystallites form close to the face- and body-centered structures and tend to stay away from the icosahedrally ordered seeds.

  3. A quick SEED tutorial

    USGS Publications Warehouse

    Ringler, Adam; Evans, John R.

    2015-01-01

    A number of different government-funded seismic data centers offer free open-access data (e.g., U.S. Geological Survey, National Earthquake Information Center, the Incorporated Research Institutions for Seismology (IRIS), and Data Management System), which can be freely downloaded and shared among different members of the community (Lay, 2009). To efficiently share data, it is important that different data providers follow a common format. The Standard for the Exchange of Earthquake Data (SEED) provides one such format for storing seismic and other geophysical data. The SEED format is widely used in earthquake seismology; however, SEED and its structure can be difficult for many first-time users (ourselves included). Below is a quick tutorial that outlines the basic structure of SEED format. This write-up is in no way intended to replace the comprehensive SEED manual (Ahern et al., 2009), and instead of going into the details of any specific part of the SEED format we refer the reader to the manual for additional details. The goal of this write-up is to succinctly explain the basic structure of SEED format as well as the associated jargon, as most commonly used now, in a colloquial way so that novice users of SEED can become more familiar with the format and its application quickly. Our goal is to give the reader the necessary background so that when problems or questions about SEED format arise they will have some understanding of where they should look for more details or from where the problem might be stemming. As a secondary goal, we hope to help the reader become familiar with the SEED manual (Ahern et al., 2009), which contains detailed information about all aspects of the SEED format.

  4. Examining Children's Models of Seed.

    ERIC Educational Resources Information Center

    Jewell, Natalie

    2002-01-01

    Reports research that examines children's models of seed. Explores the conceptions held by children (N=75) of germination and seed formation. Concludes that children hold a restricted meaning for the term 'seed'. (DDR)

  5. GROWING SEEDS, TEACHER'S GUIDE.

    ERIC Educational Resources Information Center

    Elementary Science Study, Newton, MA.

    THIS TEACHER'S GUIDE IS DESIGNED FOR USE WITH AN ELEMENTARY SCIENCE STUDY UNIT, "GROWING SEEDS," IN WHICH SUCH BASIC SCIENCE SKILLS AND PROCESSES AS MEASUREMENT, OBSERVATION, AND HYPOTHESIS FORMATION ARE INTRODUCED THROUGH STUDENT ACTIVITIES INVOLVING SEEDS, GERMINATION, AND SEEDLING GROWTH. THE MATERIALS WERE DEVELOPED FOR USE IN…

  6. Role of Abscisic Acid in the Induction of Desiccation Tolerance in Developing Seeds of Arabidopsis thaliana

    PubMed Central

    Meurs, Cor; Basra, Amarjit S.; Karssen, Cees M.; van Loon, Leendert C.

    1992-01-01

    In contrast to wild-type seeds of Arabidopsis thaliana and to seeds deficient in (aba) or insensitive to (abi3) abscisic acid (ABA), maturing seeds of recombinant (aba,abi3) plants fail to desiccate, remain green, and lose viability upon drying. These double-mutant seeds acquire only low levels of the major storage proteins and are deficient in several low mol wt polypeptides, both soluble and bound, and some of which are heat stable. A major heat-stable glycoprotein of more than 100 kilodaltons behaves similarly; during seed development, it shows a decrease in size associated with the abi3 mutation. In seeds of the double mutant from 14 to 20 days after pollination, the low amounts of various maturation-specific proteins disappear and many higher mol wt proteins similar to those occurring during germination are induced, but no visible germination is apparent. It appears that in the aba,abi3 double mutant seed development is not completed and the program for seed germination is initiated prematurely in the absence of substances protective against dehydration. Seeds may be made desiccation tolerant by watering the plants with the ABA analog LAB 173711 or by imbibition of isolated immature seeds, 11 to 15 days after pollination, with ABA and sucrose. Whereas sucrose stimulates germination and may protect dehydration-sensitive structures from desiccation damage, ABA inhibits precocious germination and is required to complete the program for seed maturation and the associated development of desiccation tolerance. ImagesFigure 1Figure 2Figure 4Figure 5Figure 6Figure 8 PMID:16668818

  7. Ribosome maturation in E. coli.

    PubMed

    Silengo, L; Altruda, F; Dotto, G P; Lacquaniti, F; Perlo, C; Turco, E; Mangiarotti, G

    1977-01-01

    In vivo and in vitro experiments have shown that processing of ribosomal RNA is a late event in ribosome biogenesis. The precursor form of RNA is probably necessary to speed up the assembly of ribomal proteins. Newly formed ribosomal particles which have already entered polyribosomes differ from mature ribosomes not only in their RNA content but also in their susceptibility to unfolding in low Mg concentration and to RNase attack. Final maturation of new ribosomes is probably dependent on their functioning in protein synthesis. Thus only those ribosomes which have proven to be functional may be converted into stable cellular structures.

  8. [Quality classification criteria of Paeonia suffruticosa seeds].

    PubMed

    Cao, Ya-yue; Zhu, Zai-biao; Guo, Qiao-sheng; Liu, Li; Wang, Chang-lin

    2015-02-01

    In order to establish the quality classification criteria of Paeonia suffruticosa seeds, thirty-one batches of P. suffruticosa seeds from different provenances were selected. The seed rooting rate, seed germination rate, seed purity, seed viability, 1,000-seed weight and moisture content were determined and analyzed through SPSS 20.0 software. Seed rooting rate, seed germination rate and seed purity were selected as the main index for classification, while 1,000-seed weight, seed viability and moisture content could be used as important references. The seed quality grading of P. suffruticosa was set as three grades. The seed quality of each grade should meet following requirements: For the first grade seeds, seed rooting rate ≥ 80%, seed germination rate ≥ 80%, seed purity ≥ 90%, seed viability ≥ 80%, 1,000-seed weight ≥ 250 g, moisture content, ≤ 10. For the second grade seeds, seed rooting rate ≥ 50%, seed germination rate ≥ 60%, seed purity ≥ 70%, seed viability ≥ 75%, 1,000-seed weight ≥ 225 g, moisture content ≤ 10. For the third grade seeds, seed rooting rate ≥ 20%, seed germination rate ≥ 45%, seed purity ≥ 60%, seed viability ≥ 45%, 1,000-seed weight ≥ 205 g, moisture content ≤ 10. The quality classification criteria of P. suffruticosa seeds have been initially established.

  9. Dehydration-induced redistribution of amphiphilic molecules between cytoplasm and lipids is associated with desiccation tolerance in seeds.

    PubMed

    Buitink, J; Leprince, O; Hoekstra, F A

    2000-11-01

    This study establishes a relationship between desiccation tolerance and the transfer of amphiphilic molecules from the cytoplasm into lipids during drying, using electron paramagnetic resonance spectroscopy of amphiphilic spin probes introduced into imbibed radicles of pea (Pisum sativum) and cucumber (Cucumis sativa) seeds. Survival following drying and a membrane integrity assay indicated that desiccation tolerance was present during early imbibition and lost in germinated radicles. In germinated cucumber radicles, desiccation tolerance could be re-induced by an incubation in polyethylene glycol (PEG) before drying. In desiccation-intolerant radicles, partitioning of spin probes into lipids during dehydration occurred at higher water contents compared with tolerant and PEG-induced tolerant radicles. The difference in partitioning behavior between desiccation-tolerant and -intolerant tissues could not be explained by the loss of water. Consequently, using a two-phase model system composed of sunflower or cucumber oil and water, physical properties of the aqueous solvent that may affect the partitioning of amphiphilic spin probes were investigated. A significant relationship was found between the partitioning of spin probes and the viscosity of the aqueous solvent. Moreover, in desiccation-sensitive radicles, the rise in cellular microviscosity during drying commenced at higher water contents compared with tolerant or PEG-induced tolerant radicles, suggesting that the microviscosity of the cytoplasm may control the partitioning behavior in dehydrating seeds.

  10. Pigmented Soybean (Glycine max) Seed Coats Accumulate Proanthocyanidins during Development.

    PubMed Central

    Todd, J. J.; Vodkin, L. O.

    1993-01-01

    The dominant I gene inhibits accumulation of anthocyanin pigments in the epidermal layer of soybean (Glycine max) seed coats. Seed-coat color is also influenced by the R locus and by the pubescence color alleles (T, tawny; t, gray). Protein and RNA from cultivars with black (i,R,T) and brown (i,r,T) seed coats are difficult to extract. To determine the nature of the interfering plant products, we examined seed-coat extracts from Clark isogenic lines for flavonoids, anthocyanins, and possible proanthocyanidins by thin-layer chromatography. We show that yellow seed-coat varieties (I) do not accumulate anthocyanins (anthocyanidin glycosides) or proanthocyanidins (polymeric anthocyanidins). Mature, black (i,R,T) and imperfect-black (i,R,t) seed coats contained anthocyanins, whereas mature, brown (i,r,T) and buff (i,r,t) seed coats did not contain anthocyanins. In contrast, all colored (i) genotypes tested positive for the presence of proanthocyanidins by butanol/ HCl and 0.5% vanillin assays. Immature, black (i,R,T) and brown (i,r,T) seed coats contained significant amounts of procyanidin, a 3[prime],4[prime]-hydroxylated proanthocyanidin. Immature, black (i,R,T) or brown (i,r,T) seed-coat extracts also tested positive for the ability to precipitate proteins in a radial diffusion assay and to bind RNA in vitro. Imperfect-black (i,R,t) or buff (i,r,t) seed coats contained lesser amounts of propelargonidin, a 4[prime]-hydroxylated proanthocyanidin. Seed-coat extracts from these genotypes did not have the ability to precipitate protein or bind to RNA. In summary, the dominant I gene controls inhibition of not only anthocyanins but also proanthocyanidins in soybean seed coats. In homozygous recessive i genotypes, the T-t gene pair determines the types of proanthocyanidins present, which is consistent with the hypothesis that the T locus encodes a microsomal 3[prime]-flavonoid hydroxylase. PMID:12231856

  11. The fruit of Bursera: structure, maturation and parthenocarpy

    PubMed Central

    Ramos-Ordoñez, María F.; Arizmendi, M. del Coro; Márquez-Guzmán, Judith

    2012-01-01

    Background and aims The deterioration of seasonally tropical dry forests will stop with the implementation of management plans for this ecosystem. To develop these plans, we require information regarding aspects such as germination and the presence of ‘empty seeds’ of representative species—like, for example, Bursera, a genus with a high number of endemic species of the Mesoamerican Hotspot—that would enable us to propagate its species. The main purpose of this study is to describe the phenological and structural characteristics of fruits of 12 Bursera species and provide useful data for future studies on germination and seed dispersal, and to acquire new and useful information to understand the phylogenetic relationships of the Burseraceae family. Methodology We described the phenology of fruit ripening in 12 species of Bursera. Fruits were collected from the study sites in three different stages of development. The histochemical and anatomical characteristics of fruits of all species were described with the use of inclusion techniques and scanning microscopy. Principal results There is a time gap between the development of the ovary and the development of the ovule in the 12 studied species. The exposed pseudoaril during the dispersion stage is an indicator of the seed's maturity and the fruit's viability. The Bursera fruit shows the same structural pattern as that of Commiphora, as well as many similarities with species of the Anacardiaceae family. All species develop parthenocarpic fruits that retain the structural characteristics of the immature fruits: soft tissues rich in nitrogen compounds and few chemical and physical defences. Insects were found mainly inside the parthenocarpic fruits in eight species of Bursera. Conclusions The dispersion unit in Bursera consists of a seed, a lignified endocarp that protects the seed, and a pseudoaril that helps attract seed dispersers. The production of parthenocarpic fruits is energy saving; however, it is

  12. The earliest seeds

    USGS Publications Warehouse

    Gillespie, W.H.; Rothwell, G.W.; Scheckler, S.E.

    1981-01-01

    Lagenostomalean-type seeds in bifurcating cupule systems have been discovered in the late Devonian Hampshire Formation of Randolph County, West Virginia, USA (Fig. 1). The associated megaflora, plants from coal balls, and vertebrate and invertebrate faunas demonstrate that the material is Famennian; the microflora indicates a more specific Fa2c age. Consequently, these seeds predate Archaeosperma arnoldii1 from the Fa2d of northeastern Pennsylvania, the oldest previously reported seed. By applying precision fracture, transfer, de??gagement, and thin-section techniques to selected cupules from the more than 100 specimens on hand, we have determined the three-dimensional morphology and histology of the seeds (Fig. 2a-h, k) and cupule systems. A comparison with known late Devonian to early Carboniferous seeds reveals that ours are more primitively organized than all except Genomosperma2,3. ?? 1981 Nature Publishing Group.

  13. Vermicomposting of food waste: assessing the stability and maturity

    PubMed Central

    2012-01-01

    The vermicompost using earthworms (Eisenia Fetida) was produced from food waste and chemical parameters (EC, pH, carbon to nitrogen contents (C/N)) and germination bioassay was examined in order to assess the stability and maturity indicators during the vermicomposting process. The seed used in the germination bioassay was cress. The ranges of EC, pH, C/N and germination index were 7.5-4.9 mS/cm, 5.6-7.53, 30.13-14.32% and 12.8-58.4%, respectively. The germination index (GI) value revealed that vermicompost rendered as moderate phytotoxic to cress seed. Pearson correlation coefficient was used to evaluate the relationship between the parameters. High statistically significant correlation coefficient was calculated between the GI value and EC in the vermicompost at the 99% confidence level. The C/N value showed that the vermicompost was stable. As a result of these observations, stability test alone, was not able to ensure high vermicompost quality. Therefore, it appears that determining vermicompost quality requires a simultaneous use of maturity and stability tests. PMID:23369642

  14. Accumulation of tocopherols and tocotrienols during seed development of grape (Vitis vinifera L. cv. Albert Lavallée).

    PubMed

    Horvath, G; Wessjohann, L; Bigirimana, J; Monica, H; Jansen, M; Guisez, Y; Caubergs, R; Horemans, N

    2006-01-01

    Tocopherols and tocotrienols are present in mature seeds. Yet, little is known about the physiological role and the metabolism of these compounds during seed development. Here we present data on tocopherol and tocotrienol accumulation during seed development in Vitis vinifera L. cv. Albert Lavallée (Royal). This species was chosen for its ability to synthesize both tocopherols and tocotrienols. It is shown here for the first time that during seed development there are significant differences in localization and accumulation kinetics of tocopherols and tocotrienols. Tocopherols are found homogeneously dispersed throughout all tissues of the seed, in concentrations ranging from 20 to 100 microg tocopherol per g dry weight. Tocopherol levels decrease gradually during seed development. In contrast, tocotrienols are only found in the endosperm of the seeds, accumulating in a sigmoid fashion during the maturation period of seed development. Tocotrienol levels were found to be (54+/-7.4) microg/g dry seed in 90-day-old seeds of V. vinifera L. Furthermore, tocotrienol biosynthesis is demonstrated in these seeds during tocotrienol accumulation and in an endosperm fraction isolated at 75 days after flowering.

  15. Increase of seed germination, growth and membrane integrity of wheat seedlings by exposure to static and a 10-KHz electromagnetic field.

    PubMed

    Payez, Atefeh; Ghanati, Faezeh; Behmanesh, Mehrdad; Abdolmaleki, Parviz; Hajnorouzi, Abazar; Rajabbeigi, Elham

    2013-12-01

    There is a large body of experimental data demonstrating various effects of magnetic field (MF) on plants growth and development. Although the mechanism(s) of perception of MF by plants is not yet elucidated, there is a possibility that like other stimuli, MF exerts its effects on plants by changing membrane integrity and conductance of its water channels, thereby influencing growth characteristics. In this study, the seeds of wheat (Triticum aestivum L. cv. Kavir) were imbibed in water overnight and then treated with or without a 30-mT static magnetic field (SMF) and a 10-kHz electromagnetic field (EMF) for 4 days, each 5 h. Water uptake of seeds reduced 5 h of the treatment with EMF but did not show changes in SMF treatment. Exposure to both magnetic fields did not affect germination percent of the seeds but increased the speed of germination, compared to the control group. Treatment with EMF significantly reduced seedling length and subsequently vigor index I, while SMF had no effects on these parameters. Both treatments significantly increased vigor index II, compared to the control group. These treatments also remarkably increased catalase activity and proline contents of seedlings but reduced the activity of peroxidase, the rate of lipid peroxidation and electrolyte leakages of membranes. The results suggest promotional effects of EMFs on membrane integrity and growth characteristics of wheat seedlings.

  16. Class I β-1,3-Glucanase and Chitinase Are Expressed in the Micropylar Endosperm of Tomato Seeds Prior to Radicle Emergence1

    PubMed Central

    Wu, Chun-Ta; Leubner-Metzger, Gerhard; Meins, Frederick; Bradford, Kent J.

    2001-01-01

    β-1,3-Glucanase (EC 3.2.1.39) and chitinase (EC 3.2.1.14) mRNAs, proteins, and enzyme activities were expressed specifically in the micropylar tissues of imbibed tomato (Lycopersicon esculentum Mill.) seeds prior to radicle emergence. RNA hybridization and immunoblotting demonstrated that both enzymes were class I basic isoforms. β-1,3-Glucanase was expressed exclusively in the endosperm cap tissue, whereas chitinase localized to both endosperm cap and radicle tip tissues. β-1,3-Glucanase and chitinase appeared in the micropylar tissues of gibberellin-deficient gib-1 tomato seeds only when supplied with gibberellin. Accumulation of β-1,3-glucanase mRNA, protein and enzyme activity was reduced by 100 μM abscisic acid, which delayed or prevented radicle emergence but not endosperm cap weakening. In contrast, expression of chitinase mRNA, protein, and enzyme activity was not affected by abscisic acid. Neither of these enzymes significantly hydrolyzed isolated tomato endosperm cap cell walls. Although both β-1,3-glucanase and chitinase were expressed in tomato endosperm cap tissue prior to radicle emergence, we found no evidence that they were directly involved in cell wall modification or tissue weakening. Possible functions of these hydrolases during tomato seed germination are discussed. PMID:11457981

  17. Adolescent Maturation in Transitioning Cultures.

    ERIC Educational Resources Information Center

    Mulroy, Kevin; Palacios, Anna; Reid, Robert E.

    This is a theoretical study of adolescent maturation within a cultural context. Personality development and disintegration due to the pressure of a dominant culture on a minority culture is considered. An attempt is made to understand how teachers might assist students to work out their psychological growth by story telling. The need for cultural…

  18. Psychosocial Maturity or Social Desirability?

    ERIC Educational Resources Information Center

    Greenberger, Ellen

    The psychosocial maturity scale (PSM) described in several earlier papers is a self-report questionnaire. It is vulnerable, as are other questionnaires of this type, to respondents' wishes to present themselves in a socially desirable light. In this study, scores on two social desirability scales are examined in relation to PSM. Correlations…

  19. Enticing Mature Females into College.

    ERIC Educational Resources Information Center

    Loseth, Lexie; Moreau, Linda

    Following a review of the literature on mature female students, this paper examines enrollment trends in a selection of colleges in Alberta (Canada) and presents the findings of a survey of returning women students at Red Deer College. The literature review highlights factors related to the personal and professional development of women graduates…

  20. Human oocyte maturation in vitro.

    PubMed

    Coticchio, Giovanni; Dal-Canto, Mariabeatrice; Guglielmo, Maria-Cristina; Mignini-Renzini, Mario; Fadini, Rubens

    2012-01-01

    Oocytes from medium-sized antral follicles have already completed their growth phase and, if released from the follicular environment and cultured in vitro, are able to resume the meiotic process and mature. However, in vitro maturation (IVM) does not entirely support all the nuclear and cytoplasmic changes that occur physiologically as an effect of the ovulatory stimulus. Regardless, oocyte IVM is widely applied for the breeding of agriculturally important species. In assisted reproduction technology, IVM has been proposed as an alternative treatment to circumvent the drawbacks of standard ovarian stimulation regimens. Initially introduced to eliminate the risks of ovarian hyperstimulation syndrome afflicting women presenting with polycystic ovaries, subsequently IVM has been suggested to represent an additional approach suitable also for normovulatory patients. So far, in children born from IVM cycles, no doubts of an increased incidence of congenital abnormalities have been raised. Many more births would be achieved if novel IVM systems, currently dominated by empiricism, could be conceived according to more physiological criteria. Recent findings shedding new light on the control of meiotic progression, the support of cumulus cells to the oocyte cellular reorganization occurring during maturation, and the modulation of the stimulus that promotes oocyte maturation downstream the mid-cycle gonadotropin signal are likely to provide crucial hints for the development of more efficient IVM systems.

  1. Magnetic stimulation of marigold seed

    NASA Astrophysics Data System (ADS)

    Afzal, I.; Mukhtar, K.; Qasim, M.; Basra, S. M. A.; Shahid, M.; Haq, Z.

    2012-10-01

    The effects of magnetic field treatments of French marigold seeds on germination, early seedling growth and biochemical changes of seedlings were studied under controlled conditions. For this purpose, seeds were exposed to five different magnetic seed treatments for 3 min each. Most of seed treatments resulted in improved germination speed and spread, root and shoot length, seed soluble sugars and a-amylase activity. Magnetic seed treatment with 100 mT maximally improved germination, seedling vigour and starch metabolism as compared to control and other seed treatments. In emergence experiment, higher emergence percentage (4-fold), emergence index (5-fold) and vigorous seedling growth were obtained in seeds treated with 100 mT. Overall, the enhancement of marigold seeds by magnetic seed treatment with 100 mT could be related to enhanced starch metabolism. The results suggest that magnetic field treatments of French marigold seeds have the potential to enhance germination, early growth and biochemical parameters of seedlings.

  2. Effect of mango weevil (Coleoptera: Curculionidae) damage on mango seed viability in Hawaii.

    PubMed

    Follett, P A; Gabbard, Z

    2000-08-01

    The mango weevil, Cryptorhynchus (= Sternochetus) mangiferae (F.), is a federally quarantined pest that prevents shipment of mangos from Hawaii into the continental United States. Although this monophagous weevil allegedly causes reduced seed germination, damage to the fruit pulp, and premature fruit drop in mangos, there are few studies examining these potential sources of crop loss. We conducted studies to assess the effect of mango weevil infestation on seed viability while making observations on the frequency of pulp feeding. Naturally infested seeds from mature fruit were planted in pots and scored for successful germination. Germination rates for infested seeds were equal to those of uninfested control seeds in a polyembryonic cultivar ('Common'), whereas germination was significantly reduced for infested seeds of a monoembryonic cultivar ('Haden') compared with uninfested control seeds but germination of infested seeds was still > 70%. To assess seed tolerance of damage, seeds were artificially damaged by cutting away 25, 50, or 75% of the cotyledon before planting and scored for germination. None of the damage treatments was significantly different from the undamaged controls, indicating that mango seeds can withstand substantial damage and still germinate successfully. Over the 2-yr period we conducted experiments, only four of 3,602 mango fruits (0.11%) showed evidence of direct feeding damage to the pulp. Results suggest that C. mangiferae is a less serious pest of mangos than previously thought.

  3. Comprehensive developmental profiles of gene activity in regions and subregions of the Arabidopsis seed

    PubMed Central

    Belmonte, Mark F.; Kirkbride, Ryan C.; Stone, Sandra L.; Pelletier, Julie M.; Bui, Anhthu Q.; Yeung, Edward C.; Hashimoto, Meryl; Fei, Jiong; Harada, Corey M.; Munoz, Matthew D.; Le, Brandon H.; Drews, Gary N.; Brady, Siobhan M.; Goldberg, Robert B.; Harada, John J.

    2013-01-01

    Seeds are complex structures that consist of the embryo, endosperm, and seed-coat regions that are of different ontogenetic origins, and each region can be further divided into morphologically distinct subregions. Despite the importance of seeds for food, fiber, and fuel globally, little is known of the cellular processes that characterize each subregion or how these processes are integrated to permit the coordinated development of the seed. We profiled gene activity genome-wide in every organ, tissue, and cell type of Arabidopsis seeds from fertilization through maturity. The resulting mRNA datasets offer the most comprehensive description of gene activity in seeds with high spatial and temporal resolution, providing unique insights into the function of understudied seed regions. Global comparisons of mRNA populations reveal unexpected overlaps in the functional identities of seed subregions. Analyses of coexpressed gene sets suggest that processes that regulate seed size and filling are coordinated across several subregions. Predictions of gene regulatory networks based on the association of transcription factors with enriched DNA sequence motifs upstream of coexpressed genes identify regulators of seed development. These studies emphasize the utility of these datasets as an essential resource for the study of seed biology. PMID:23319655

  4. Differentially expressed seed aging responsive heat shock protein OsHSP18.2 implicates in seed vigor, longevity and improves germination and seedling establishment under abiotic stress.

    PubMed

    Kaur, Harmeet; Petla, Bhanu P; Kamble, Nitin U; Singh, Ajeet; Rao, Venkateswara; Salvi, Prafull; Ghosh, Shraboni; Majee, Manoj

    2015-01-01

    Small heat shock proteins (sHSPs) are a diverse group of proteins and are highly abundant in plant species. Although majority of these sHSPs were shown to express specifically in seed, their potential function in seed physiology remains to be fully explored. Our proteomic analysis revealed that OsHSP18.2, a class II cytosolic HSP is an aging responsive protein as its abundance significantly increased after artificial aging in rice seeds. OsHSP18.2 transcript was found to markedly increase at the late maturation stage being highly abundant in dry seeds and sharply decreased after germination. Our biochemical study clearly demonstrated that OsHSP18.2 forms homooligomeric complex and is dodecameric in nature and functions as a molecular chaperone. OsHSP18.2 displayed chaperone activity as it was effective in preventing thermal inactivation of Citrate Synthase. Further, to analyze the function of this protein in seed physiology, seed specific Arabidopsis overexpression lines for OsHSP18.2 were generated. Our subsequent functional analysis clearly demonstrated that OsHSP18.2 has ability to improve seed vigor and longevity by reducing deleterious ROS accumulation in seeds. In addition, transformed Arabidopsis seeds also displayed better performance in germination and cotyledon emergence under adverse conditions. Collectively, our work demonstrates that OsHSP18.2 is an aging responsive protein which functions as a molecular chaperone and possibly protect and stabilize the cellular proteins from irreversible damage particularly during maturation drying, desiccation and aging in seeds by restricting ROS accumulation and thereby improves seed vigor, longevity and seedling establishment.

  5. Programmed cell death during development of cowpea (Vigna unguiculata (L.) Walp.) seed coat.

    PubMed

    Lima, Nathália Bastos; Trindade, Fernanda Gomes; da Cunha, Maura; Oliveira, Antônia Elenir Amâncio; Topping, Jennifer; Lindsey, Keith; Fernandes, Kátia Valevski Sales

    2015-04-01

    The seed coat develops primarily from maternal tissues and comprises multiple cell layers at maturity, providing a metabolically dynamic interface between the developing embryo and the environment during embryogenesis, dormancy and germination of seeds. Seed coat development involves dramatic cellular changes, and the aim of this research was to investigate the role of programmed cell death (PCD) events during the development of seed coats of cowpea [Vigna unguiculata (L.) Walp.]. We demonstrate that cells of the developing cowpea seed coats undergo a programme of autolytic cell death, detected as cellular morphological changes in nuclei, mitochondria, chloroplasts and vacuoles, DNA fragmentation and oligonucleosome accumulation in the cytoplasm, and loss of membrane viability. We show for the first time that classes 6 and 8 caspase-like enzymes are active during seed coat development, and that these activities may be compartmentalized by translocation between vacuoles and cytoplasm during PCD events.

  6. Embryonal Control of Yellow Seed Coat Locus ECY1 Is Related to Alanine and Phenylalanine Metabolism in the Seed Embryo of Brassica napus

    PubMed Central

    Wang, Fulin; He, Jiewang; Shi, Jianghua; Zheng, Tao; Xu, Fei; Wu, Guanting; Liu, Renhu; Liu, Shengyi

    2016-01-01

    Seed coat color is determined by the type of pigment deposited in the seed coat cells. It is related to important agronomic traits of seeds such as seed dormancy, longevity, oil content, protein content and fiber content. In Brassica napus, inheritance of seed coat color is related to maternal effects and pollen effects (xenia effects). In this research we isolated a mutation of yellow seeded B. napus controlled by a single Mendelian locus, which is named Embryonal Control of Yellow seed coat 1 (Ecy1). Microscopy of transverse sections of the mature seed show that pigment is deposited only in the outer layer of the seed coat. Using Illumina Hisequation 2000 sequencing technology, a total of 12 GB clean data, 116× coverage of coding sequences of B. napus, was achieved from seeds 26 d after pollination (DAP). It was assembled into 172,238 independent transcripts, and 55,637 unigenes. A total of 139 orthologous genes of Arabidopsis transparent testa (TT) genes were mapped in silico to 19 chromosomes of B. napus. Only 49 of the TT orthologous genes are transcribed in seeds. However transcription of all orthologs was independent of embryonal control of seed coat color. Only 55 genes were found to be differentially expressed between brown seeds and the yellow mutant. Of these 55, 50 were upregulated and five were downregulated in yellow seeds as compared to their brown counterparts. By KEGG classification, 14 metabolic pathways were significantly enriched. Of these, five pathways: phenylpropanoid biosynthesis, cyanoamino acid metabolism, plant hormone signal transduction, metabolic pathways, and biosynthesis of secondary metabolites, were related with seed coat pigmentation. Free amino acid quantification showed that Ala and Phe were present at higher levels in the embryos of yellow seeds as compared to those of brown seeds. This increase was not observed in the seed coat. Moreover, the excess amount of free Ala was exactly twice that of Phe in the embryo. The pigment

  7. Interaction between parental environment and genotype affects plant and seed performance in Arabidopsis

    PubMed Central

    He, Hanzi; de Souza Vidigal, Deborah; Snoek, L. Basten; Schnabel, Sabine; Nijveen, Harm; Hilhorst, Henk; Bentsink, Leónie

    2014-01-01

    Seed performance after dispersal is highly dependent on parental environmental cues, especially during seed formation and maturation. Here we examine which environmental factors are the most dominant in this respect and whether their effects are dependent on the genotypes under investigation. We studied the influence of light intensity, photoperiod, temperature, nitrate, and phosphate during seed development on five plant attributes and thirteen seed attributes, using 12 Arabidopsis genotypes that have been reported to be affected in seed traits. As expected, the various environments during seed development resulted in changed plant and/or seed performances. Comparative analysis clearly indicated that, overall, temperature plays the most dominant role in both plant and seed performance, whereas light has a prominent impact on plant traits. In comparison to temperature and light, nitrate mildly affected some of the plant and seed traits while phosphate had even less influence on those traits. Moreover, clear genotype-by-environment interactions were identified. This was shown by the fact that individual genotypes responded differentially to the environmental conditions. Low temperature significantly increased seed dormancy and decreased seed longevity of NILDOG1 and cyp707a1-1, whereas low light intensity increased seed dormancy and decreased seed longevity of NILDOG3 and NILDOG6. This also indicates that different genetic and molecular pathways are involved in the plant and seed responses. By identifying environmental conditions that affect the dormancy vs longevity correlation in the same way as previously identified naturally occurring loci, we have identified selective forces that probably shaped evolution for these important seed traits. PMID:25240065

  8. Interaction between parental environment and genotype affects plant and seed performance in Arabidopsis.

    PubMed

    He, Hanzi; de Souza Vidigal, Deborah; Snoek, L Basten; Schnabel, Sabine; Nijveen, Harm; Hilhorst, Henk; Bentsink, Leónie

    2014-12-01

    Seed performance after dispersal is highly dependent on parental environmental cues, especially during seed formation and maturation. Here we examine which environmental factors are the most dominant in this respect and whether their effects are dependent on the genotypes under investigation. We studied the influence of light intensity, photoperiod, temperature, nitrate, and phosphate during seed development on five plant attributes and thirteen seed attributes, using 12 Arabidopsis genotypes that have been reported to be affected in seed traits. As expected, the various environments during seed development resulted in changed plant and/or seed performances. Comparative analysis clearly indicated that, overall, temperature plays the most dominant role in both plant and seed performance, whereas light has a prominent impact on plant traits. In comparison to temperature and light, nitrate mildly affected some of the plant and seed traits while phosphate had even less influence on those traits. Moreover, clear genotype-by-environment interactions were identified. This was shown by the fact that individual genotypes responded differentially to the environmental conditions. Low temperature significantly increased seed dormancy and decreased seed longevity of NILDOG1 and cyp707a1-1, whereas low light intensity increased seed dormancy and decreased seed longevity of NILDOG3 and NILDOG6. This also indicates that different genetic and molecular pathways are involved in the plant and seed responses. By identifying environmental conditions that affect the dormancy vs longevity correlation in the same way as previously identified naturally occurring loci, we have identified selective forces that probably shaped evolution for these important seed traits.

  9. A systems biology approach toward understanding seed composition in soybean

    PubMed Central

    2015-01-01

    Background The molecular, biochemical, and genetic mechanisms that regulate the complex metabolic network of soybean seed development determine the ultimate balance of protein, lipid, and carbohydrate stored in the mature seed. Many of the genes and metabolites that participate in seed metabolism are unknown or poorly defined; even more remains to be understood about the regulation of their metabolic networks. A global omics analysis can provide insights into the regulation of seed metabolism, even without a priori assumptions about the structure of these networks. Results With the future goal of predictive biology in mind, we have combined metabolomics, transcriptomics, and metabolic flux technologies to reveal the global developmental and metabolic networks that determine the structure and composition of the mature soybean seed. We have coupled this global approach with interactive bioinformatics and statistical analyses to gain insights into the biochemical programs that determine soybean seed composition. For this purpose, we used Plant/Eukaryotic and Microbial Metabolomics Systems Resource (PMR, http://www.metnetdb.org/pmr, a platform that incorporates metabolomics data to develop hypotheses concerning the organization and regulation of metabolic networks, and MetNet systems biology tools http://www.metnetdb.org for plant omics data, a framework to enable interactive visualization of metabolic and regulatory networks. Conclusions This combination of high-throughput experimental data and bioinformatics analyses has revealed sets of specific genes, genetic perturbations and mechanisms, and metabolic changes that are associated with the developmental variation in soybean seed composition. Researchers can explore these metabolomics and transcriptomics data interactively at PMR. PMID:25708381

  10. The proteome of seed development in the model legume Lotus japonicus.

    PubMed

    Dam, Svend; Laursen, Brian S; Ornfelt, Jane H; Jochimsen, Bjarne; Staerfeldt, Hans Henrik; Friis, Carsten; Nielsen, Kasper; Goffard, Nicolas; Besenbacher, Søren; Krusell, Lene; Sato, Shusei; Tabata, Satoshi; Thøgersen, Ida B; Enghild, Jan J; Stougaard, Jens

    2009-03-01

    We have characterized the development of seeds in the model legume Lotus japonicus. Like soybean (Glycine max) and pea (Pisum sativum), Lotus develops straight seed pods and each pod contains approximately 20 seeds that reach maturity within 40 days. Histological sections show the characteristic three developmental phases of legume seeds and the presence of embryo, endosperm, and seed coat in desiccated seeds. Furthermore, protein, oil, starch, phytic acid, and ash contents were determined, and this indicates that the composition of mature Lotus seed is more similar to soybean than to pea. In a first attempt to determine the seed proteome, both a two-dimensional polyacrylamide gel electrophoresis approach and a gel-based liquid chromatography-mass spectrometry approach were used. Globulins were analyzed by two-dimensional polyacrylamide gel electrophoresis, and five legumins, LLP1 to LLP5, and two convicilins, LCP1 and LCP2, were identified by matrix-assisted laser desorption ionization quadrupole/time-of-flight mass spectrometry. For two distinct developmental phases, seed filling and desiccation, a gel-based liquid chromatography-mass spectrometry approach was used, and 665 and 181 unique proteins corresponding to gene accession numbers were identified for the two phases, respectively. All of the proteome data, including the experimental data and mass spectrometry spectra peaks, were collected in a database that is available to the scientific community via a Web interface (http://www.cbs.dtu.dk/cgi-bin/lotus/db.cgi). This database establishes the basis for relating physiology, biochemistry, and regulation of seed development in Lotus. Together with a new Web interface (http://bioinfoserver.rsbs.anu.edu.au/utils/PathExpress4legumes/) collecting all protein identifications for Lotus, Medicago, and soybean seed proteomes, this database is a valuable resource for comparative seed proteomics and pathway analysis within and beyond the legume family.

  11. Water Relations of Seed Development and Germination in Muskmelon (Cucumis melo L.) 1

    PubMed Central

    Welbaum, Gregory E.; Bradford, Kent J.

    1988-01-01

    Total water potential (ψ), solute potential, and turgor potential of field-grown muskmelon (Cucumis melo L.) fruit tissue (pericarp) and seeds were determined by thermocouple psychrometry at 5-day intervals from 10 to 65 days after anthesis (DAA). Fruit maturity occurred between 44 and 49 DAA, and seed germination ability developed between 35 and 45 DAA. Pericarp ψ was essentially constant at approximately −0.75 megapascal (MPa) from 10 to 25 DAA, then decreased to a minimum value of −1.89 MPa at 50 DAA before increasing to −1.58 MPa at 65 DAA. Seed ψ remained relatively constant at approximately −0.5 MPa from 10 to 30 DAA then decreased to −2.26 MPa at 50 to 60 DAA before increasing to −2.01 MPa at 65 DAA. After a rapid increase to 20 DAA, seed fresh weight declined until 30 DAA due to net water loss, despite continuing dry weight gain. As fruit and seed growth rates decreased, turgor potential initially increased, then declined to small values when growth ceased. A disequilibrium in ψ was measured between seeds and pericarp both early and late in development. From 20 to 40 DAA, the ψ gradient was from the seed to the tissue, coinciding with water loss from the seeds. From 50 to 65 DAA, seed ψ decreased, causing a reversal of the ψ gradient and a slight increase in seed water content. The partitioning of solutes between symplast and apoplast may create and maintain ψ gradients between the pericarp and seed. The low solute potential within the pericarp due to solute accumulation and loss of cellular compartmentation during ripening and sensecence may be involved in prevention of precocious germination of mature seeds. PMID:16665921

  12. Morphology, ecophysiology and germination of seeds of the neotropical tree Alibertia patinoi (Rubiaceae).

    PubMed

    Escobar Escobar, Diego Fernando; Torres, Alba Marina

    2013-06-01

    Alibertia patinoi (Rubiaceae) is of economic and cultural importance for communities in the Colombian Pacific and Amazon regions, where it is cultivated and mature fruits are highly appreciated and consumed. Since there is a lack of knowledge of the seed physiology of this species, we describe here the germination behavior and morphometry of seeds of Alibertia patinoi, and relate them to its habitat. Fruits were collected from a mixed food crop and a commercial plantation in Guaimía village, Buenaventura, Colombia, a tropical rain forest area. We measured length, width, thickness, mass (n = 1 400), and moisture content of seeds (n = 252). Primary dormancy tests were conducted (n = 200), followed by imbibition (n=252) and germination dynamics, under different conditions of light and temperature specific to understory and forest clearings (n = 300 seeds). Finally, seed storage behavior was established (n = 100 seeds). We observed that size and mass of seeds had a narrow range of values that did not differ within or among fruits and that the species did not exhibit primary dormancy. The seeds are recalcitrant, and recently harvested seeds exhibited higher seed moisture content (ca. 44%) and continuous metabolism. The seed germination percentage was observed to be higher under the specific dense canopy forest light and temperature conditions; furthermore, neither enriched far-red light nor darkness conditions inhibited germination. We concluded that rapid germination could be the establishment strategy of this species. Also, the physiological traits (i.e., rapid germination rate, low germination requirements, absence of primary dormancy, and recalcitrant behavior) and seed size and mass, suggest that A. patinoi is adapted to conditions of mature tropical rain forests.

  13. Water Relations of Seed Development and Germination in Muskmelon (Cucumis melo L.) 1

    PubMed Central

    Welbaum, Gregory E.; Bradford, Kent J.

    1990-01-01

    We previously reported that an apparent water potential disequilibrium is maintained late in muskmelon (Cucumis melo L.) seed development between the embryo and the surrounding fruit tissue (mesocarp). To further investigate the basis of this phenomenon, the permeability characteristics of the tissues surrounding muskmelon embryos (the mucilaginous endocarp, the testa, a 2- to 4-cell-layered perisperm and a single cell layer of endosperm) were examined from 20 to 65 days after anthesis (DAA). Water passes readily through the perisperm envelope (endosperm + perisperm), testa, and endocarp at all stages of development. Electrolyte leakage (conductivity of imbibition solutions) of individual intact seeds, decoated seeds (testa removed), and embryos (testa and perisperm envelope removed) was measured during imbibition of freshly harvested seeds. The testa accounted for up to 80% of the total electrolyte leakage. Leakage from decoated seeds fell by 8- to 10-fold between 25 and 45 DAA. Presence of the perisperm envelope prior to 40 DAA had little effect on leakage, while in more mature seeds, it reduced leakage by 2- to 3-fold. In mature seeds, freezing, soaking in methanol, autoclaving, accelerated aging, and other treatments which killed the embryos had little effect on leakage of intact or decoated seeds, but caused osmotic swelling of the perisperm envelope due to the leakage of solutes from the embryo into the space between the embryo and perisperm. The semipermeability of the perisperm envelope of mature seeds did not depend upon cellular viability or lipid membrane integrity. After maximum seed dry weight is attained (35-40 DAA), the perisperm envelope prevents the diffusion of solutes, but not of water, between the embryo and the surrounding testa, endocarp, and mesocarp tissue. Images Figure 5 PMID:16667368

  14. Effects of growth temperature and carbon dioxide enrichment on soybean seed components at different stages of development.

    PubMed

    Xu, Guangli; Singh, Shardendu; Barnaby, Jinyoung; Buyer, Jeffrey; Reddy, Vangimalla; Sicher, Richard

    2016-11-01

    Soybean plants were grown to maturity in controlled environment chambers and at the onset of flowering three temperature treatments were imposed that provided optimum [28/24 °C], low [22/18 °C] or high [36/32 °C] chamber air temperatures. In addition, plants were treated continuously with either 400 or 800 μmol mol(-1) CO2. Seeds were harvested at 42, 53, 69 and 95 days after planting (i.e., final maturity). This study quantified 51 metabolites in developing soybean seeds, plus total lipids and proteins were measured at maturity. About 80% of measured soluble carbohydrates, amines and organic acids decreased to low levels in mature seeds, although important exceptions were raffinose, ribose/arabinose, citrate and all eight fatty acids. This suggested that the metabolism of young seeds supported lipid and protein synthesis. A total of 35 and 9 metabolites differed among temperature and CO2 treatments, respectively, and treatment effects were predominately observed on the first and second samplings. However, shikimate, pinitol and oleate were increased by high temperature treatments in mature seeds. The above results indicated that CO2 enrichment primarily altered metabolite levels during the initial stages of seed development and this was likely due to enhanced photosynthate formation in leaves.

  15. Control of seed development in Arabidopsis thaliana by atmospheric oxygen

    NASA Technical Reports Server (NTRS)

    Kuang, A.; Crispi, M.; Musgrave, M. E.

    1998-01-01

    Seed development is known to be inhibited completely when plants are grown in oxygen concentrations below 5.1 kPa, but apart from reports of decreased seed weight little is known about embryogenesis at subambient oxygen concentrations above this critical level. Arabidopsis thaliana (L.) Heynh. plants were grown full term under continuous light in premixed atmospheres with oxygen partial pressures of 2.5, 5.1, 10.1, 16.2 and 21.3 kPa O2, 0.035 kPa CO2 and the balance nitrogen. Seeds were harvested for germination tests and microscopy when siliques had yellowed. Seed germination was depressed in O2 treatments below 16.2 kPa, and seeds from plants grown in 2.5 kPa O2 did not germinate at all. Fewer than 25% of the seeds from plants grown in 5.1 kPa oxygen germinated and most of the seedlings appeared abnormal. Light and scanning electron microscopic observation of non-germinated seeds showed that these embryos had stopped growing at different developmental stages depending upon the prevailing oxygen level. Embryos stopped growing at the heart-shaped to linear cotyledon stage in 5.1 kPa O2, at around the curled cotyledon stage in 10.1 kPa O2, and at the premature stage in 16.2 kPa O2. Globular and heart-shaped embryos were observed in sectioned seeds from plants grown in 2.5 kPa O2. Tissue degeneration caused by cell autolysis and changes in cell structure were observed in cotyledons and radicles. Transmission electron microscopy of mature seeds showed that storage substances, such as protein bodies, were reduced in subambient oxygen treatments. The results demonstrate control of embryo development by oxygen in Arabidopsis.

  16. Transcriptomic features of Pecten maximus oocyte quality and maturation.

    PubMed

    Pauletto, Marianna; Milan, Massimo; Huvet, Arnaud; Corporeau, Charlotte; Suquet, Marc; Planas, Josep V; Moreira, Rebeca; Figueras, Antonio; Novoa, Beatriz; Patarnello, Tomaso; Bargelloni, Luca

    2017-01-01

    The king scallop Pecten maximus is a high valuable species of great interest in Europe for both fishery and aquaculture. Notably, there has been an increased investment to produce seed for enhancement programmes of wild scallop populations. However, hatchery production is a relatively new industry and it is still underdeveloped. Major hurdles are spawning control and gamete quality. In the present study, a total of 14 scallops were sampled in the bay of Brest (Brittany, France) to compare transcriptomic profiles of mature oocytes collected by spawning induction or by stripping. To reach such a goal, a microarray analysis was performed by using a custom 8x60K oligonucleotide microarray representing 45,488 unique scallop contigs. First we identified genes that were differentially expressed depending on oocyte quality, estimated as the potential to produce D-larvae. Secondly, we investigated the transcriptional features of both stripped and spawned oocytes. Genes coding for proteins involved in cytoskeletal dynamics, serine/threonine kinases signalling pathway, mRNA processing, response to DNA damage, apoptosis and cell-cycle appeared to be of crucial importance for both oocyte maturation and developmental competence. This study allowed us to dramatically increase the knowledge about transcriptional features of oocyte quality and maturation, as well as to propose for the first time putative molecular markers to solve a major bottleneck in scallop aquaculture.

  17. Transcriptomic features of Pecten maximus oocyte quality and maturation

    PubMed Central

    Milan, Massimo; Huvet, Arnaud; Corporeau, Charlotte; Suquet, Marc; Planas, Josep V.; Moreira, Rebeca; Figueras, Antonio; Novoa, Beatriz; Patarnello, Tomaso; Bargelloni, Luca

    2017-01-01

    The king scallop Pecten maximus is a high valuable species of great interest in Europe for both fishery and aquaculture. Notably, there has been an increased investment to produce seed for enhancement programmes of wild scallop populations. However, hatchery production is a relatively new industry and it is still underdeveloped. Major hurdles are spawning control and gamete quality. In the present study, a total of 14 scallops were sampled in the bay of Brest (Brittany, France) to compare transcriptomic profiles of mature oocytes collected by spawning induction or by stripping. To reach such a goal, a microarray analysis was performed by using a custom 8x60K oligonucleotide microarray representing 45,488 unique scallop contigs. First we identified genes that were differentially expressed depending on oocyte quality, estimated as the potential to produce D-larvae. Secondly, we investigated the transcriptional features of both stripped and spawned oocytes. Genes coding for proteins involved in cytoskeletal dynamics, serine/threonine kinases signalling pathway, mRNA processing, response to DNA damage, apoptosis and cell-cycle appeared to be of crucial importance for both oocyte maturation and developmental competence. This study allowed us to dramatically increase the knowledge about transcriptional features of oocyte quality and maturation, as well as to propose for the first time putative molecular markers to solve a major bottleneck in scallop aquaculture. PMID:28253290

  18. Seeds in Flight

    ERIC Educational Resources Information Center

    Martin, Willard K.

    1978-01-01

    Discussed are the seed dispersal mechanisms of six different plants: big-leaf maple, pincushion tree, tree of heaven, squirting cucumber, digger pine, and bull thistle. Elaborate color and black-and-white drawings illustrate the text. (MA)

  19. Tomato seeds for LDEF

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Tomato seeds are prepared for their launch aboard the Langley's Long Duration Exposure Facility. Photograph published in Winds of Change, 75th Anniversary NASA publication (page 119), by James Schultz.

  20. Fishing for Seeds.

    ERIC Educational Resources Information Center

    Science and Children, 2001

    2001-01-01

    Describes a method to collect seeds that are dispersed from weeds while avoiding some outdoor hazards such as rough terrain or animals. Describes a plan for creating a weed fishing pole and includes a materials list. (SAH)

  1. Effects of Parental Temperature and Nitrate on Seed Performance are Reflected by Partly Overlapping Genetic and Metabolic Pathways.

    PubMed

    He, Hanzi; Willems, Leo A J; Batushansky, Albert; Fait, Aaron; Hanson, Johannes; Nijveen, Harm; Hilhorst, Henk W M; Bentsink, Leónie

    2016-03-01

    Seed performance is affected by the seed maturation environment, and previously we have shown that temperature, nitrate and light intensity were the most influential environmental factors affecting seed performance. Seeds developed in these environments were selected to assess the underlying metabolic pathways, using a combination of transcriptomics and metabolomics. These analyses revealed that the effects of the parental temperature and nitrate environments were reflected by partly overlapping genetic and metabolic networks, as indicated by similar changes in the expression levels of metabolites and transcripts. Nitrogen metabolism-related metabolites (asparagine, γ-aminobutyric acid and allantoin) were significantly decreased in both low temperature (15 °C) and low nitrate (N0) maturation environments. Correspondingly, nitrogen metabolism genes (ALLANTOINASE, NITRATE REDUCTASE 1, NITRITE REDUCTASE 1 and NITRILASE 4) were differentially regulated in the low temperature and nitrate maturation environments, as compared with control conditions. High light intensity during seed maturation increased galactinol content, and displayed a high correlation with seed longevity. Low light had a genotype-specific effect on cell surface-encoding genes in the DELAY OF GERMINATION 6-near isogenic line (NILDOG6). Overall, the integration of phenotypes, metabolites and transcripts led to new insights into the regulation of seed performance.

  2. Maturation of Oocytes in Vitro.

    PubMed

    Lonergan, Patrick; Fair, Trudee

    2016-01-01

    Only a fraction of oocytes present in the ovaries at birth are ever ovulated during the lifetime of a female mammal. In vitro maturation (IVM) offers the possibility to exploit what is a largely untapped biological resource. Although IVM is used routinely for the in vitro production of embryos in domestic species, especially cattle, its clinical use in human-assisted reproduction is still evolving. The successful recapitulation in vitro of the events associated with successful oocyte maturation is not always achieved, with the majority of immature oocytes typically failing to develop to the blastocyst stage. Evidence suggests that although culture conditions throughout in vitro embryo production may have a modest influence on the developmental potential of the early embryo, the quality of the oocyte at the start of the process is the key factor determining the proportion of oocytes developing to the blastocyst stage.

  3. Maternal environment affects the genetic basis of seed dormancy in Arabidopsis thaliana.

    PubMed

    Postma, Froukje M; Ågren, Jon

    2015-02-01

    The genetic basis of seed dormancy, a key life history trait important for adaptive evolution in plant populations, has yet been studied only using seeds produced under controlled conditions in greenhouse environments. However, dormancy is strongly affected by maternal environmental conditions, and interactions between seed genotype and maternal environment have been reported. Consequently, the genetic basis of dormancy of seeds produced under natural field conditions remains unclear. We examined the effect of maternal environment on the genetic architecture of seed dormancy using a recombinant inbred line (RIL) population derived from a cross between two locally adapted populations of Arabidopsis thaliana from Italy and Sweden. We mapped quantitative trait loci (QTL) for dormancy of seeds produced in the greenhouse and at the native field sites of the parental genotypes. The Italian genotype produced seeds with stronger dormancy at fruit maturation than did the Swedish genotype in all three environments, and the maternal field environments induced higher dormancy levels compared to the greenhouse environment in both genotypes. Across the three maternal environments, a total of nine dormancy QTL were detected, three of which were only detected among seeds matured in the field, and six of which showed significant QTL × maternal environment interactions. One QTL had a large effect on dormancy across all three environments and colocalized with the candidate gene DOG1. Our results demonstrate the importance of studying the genetic basis of putatively adaptive traits under relevant conditions.

  4. Maturation of the adolescent brain

    PubMed Central

    Arain, Mariam; Haque, Maliha; Johal, Lina; Mathur, Puja; Nel, Wynand; Rais, Afsha; Sandhu, Ranbir; Sharma, Sushil

    2013-01-01

    Adolescence is the developmental epoch during which children become adults – intellectually, physically, hormonally, and socially. Adolescence is a tumultuous time, full of changes and transformations. The pubertal transition to adulthood involves both gonadal and behavioral maturation. Magnetic resonance imaging studies have discovered that myelinogenesis, required for proper insulation and efficient neurocybernetics, continues from childhood and the brain’s region-specific neurocircuitry remains structurally and functionally vulnerable to impulsive sex, food, and sleep habits. The maturation of the adolescent brain is also influenced by heredity, environment, and sex hormones (estrogen, progesterone, and testosterone), which play a crucial role in myelination. Furthermore, glutamatergic neurotransmission predominates, whereas gamma-aminobutyric acid neurotransmission remains under construction, and this might be responsible for immature and impulsive behavior and neurobehavioral excitement during adolescent life. The adolescent population is highly vulnerable to driving under the influence of alcohol and social maladjustments due to an immature limbic system and prefrontal cortex. Synaptic plasticity and the release of neurotransmitters may also be influenced by environmental neurotoxins and drugs of abuse including cigarettes, caffeine, and alcohol during adolescence. Adolescents may become involved with offensive crimes, irresponsible behavior, unprotected sex, juvenile courts, or even prison. According to a report by the Centers for Disease Control and Prevention, the major cause of death among the teenage population is due to injury and violence related to sex and substance abuse. Prenatal neglect, cigarette smoking, and alcohol consumption may also significantly impact maturation of the adolescent brain. Pharmacological interventions to regulate adolescent behavior have been attempted with limited success. Since several factors, including age, sex

  5. Maturity model for enterprise interoperability

    NASA Astrophysics Data System (ADS)

    Guédria, Wided; Naudet, Yannick; Chen, David

    2015-01-01

    Historically, progress occurs when entities communicate, share information and together create something that no one individually could do alone. Moving beyond people to machines and systems, interoperability is becoming a key factor of success in all domains. In particular, interoperability has become a challenge for enterprises, to exploit market opportunities, to meet their own objectives of cooperation or simply to survive in a growing competitive world where the networked enterprise is becoming a standard. Within this context, many research works have been conducted over the past few years and enterprise interoperability has become an important area of research, ensuring the competitiveness and growth of European enterprises. Among others, enterprises have to control their interoperability strategy and enhance their ability to interoperate. This is the purpose of the interoperability assessment. Assessing interoperability maturity allows a company to know its strengths and weaknesses in terms of interoperability with its current and potential partners, and to prioritise actions for improvement. The objective of this paper is to define a maturity model for enterprise interoperability that takes into account existing maturity models while extending the coverage of the interoperability domain. The assessment methodology is also presented. Both are demonstrated with a real case study.

  6. Seed dispersal in fens

    USGS Publications Warehouse

    Middleton, B.; Van Diggelen, R.; Jensen, K.

    2006-01-01

    Question: How does seed dispersal reduce fen isolation and contribute to biodiversity? Location: European and North American fens. Methods: This paper reviews the literature on seed dispersal to fens. Results: Landscape fragmentation may reduce dispersal opportunities thereby isolating fens and reducing genetic exchange. Species in fragmented wetlands may have lower reproductive success, which can lead to biodiversity loss. While fens may have always been relatively isolated from each other, they have become increasingly fragmented in modern times within agricultural and urban landscapes in both Europe and North America. Dispersal by water, animals and wind has been hampered by changes related to development in landscapes surrounding fens. Because the seeds of certain species are long-lived in the seed bank, frequent episodes of dispersal are not always necessary to maintain the biodiversity of fens. However, of particular concern to restoration is that some dominant species, such as the tussock sedge Carex stricta, may not disperse readily between fens. Conclusions: Knowledge of seed dispersal can be used to maintain and restore the biodiversity of fens in fragmented landscapes. Given that development has fragmented landscapes and that this situation is not likely to change, the dispersal of seeds might be enhanced by moving hay or cattle from fens to damaged sites, or by reestablishing lost hydrological connections. ?? IAVS; Opulus Press.

  7. Genetic behaviour of earliness related traits and seed yield in chickpea (Cicer arietinum L.).

    PubMed

    Monpara, B A; Dhameliya, H R

    2013-09-15

    Genetic analysis of five quantitative traits related to earliness and seed yield in chickpea was carried out using eight segregating populations (F2 generations) and their nine parents. Characters included in the study were days to flowering, flowering period, days to maturity, plant height and seed yield per plant. The results showed that no consistency in magnitude of genetic parameters was observed in any cross populations. However, the F2 of P1xP4 exhibited high magnitude of heritability coupled with high genetic advance and GCV for flowering period, days to maturity and plant height and high heritability with moderate genetic advance and GCV for seed yield per plant. This indicated the involvement of additive gene action and potential for development of early maturing genotypes with enhanced seed yield. Correlation study revealed that days to flowering, flowering period and days to maturity recorded significant positive association among themselves. Though, their associations with seed yield per plant were weak in certain genetic backgrounds, otherwise almost non-significant. Thus, correlation studies revealed that selection for earliness will not directly increase productivity. The possibility of combining components of earliness with yield-promoting alleles was suggested.

  8. High acid invertase activity for a prolonged period in developing seeds/podwall of wild chickpea is detrimental to seed filling.

    PubMed

    Kaur, Harinderjeet; Gupta, Anil Kumar; Kaur, Narinder; Sandhu, Jeet Singh

    2012-10-01

    In the present study factors responsible for low seed biomass in wild Cicer species has been investigated. Cicer judaicum and chickpea cultivar PBG-1 were investigated to compare activities of some enzymes involved in carbon metabolism in podwall and seeds during crop development. Seed filling duration in wild species was about 15 days shorter than that of cultivated varieties due to rapid loss of moisture content and hence resulted in earlier maturity and reduced seed biomass. Longer seed filling duration appeared to be an important factor responsible for greater biomass of chickpea seeds. Because of absence of phosphoenol pyruvate carboxylase from 25-35 days after flowering and low sucrose synthase activities, the podwall of C. judaicum is not in a position to contribute significantly to the sink filling capacity of seeds. High acid invertase, low sucrose synthase activities during seed storage phase cause detrimental effect on seed filling and resulting in highly reduced sink strength and productivity of wild species. Successful transfer of stress tolerance from wild Cicer species to chickpea cultivars need to prevent the transfer of these observed unfavourable biochemical factors so that the productivity of chickpea crop remains unaffected during utilization of wild Cicer species in chickpea improvement.

  9. An investigation of the effects of stage of ensilage on Nassella neesiana seeds, for reducing seed viability and injury to livestock.

    PubMed

    Weller, S L; Florentine, S K; Sillitoe, J F; Grech, C J; McLaren, D A

    2016-03-01

    The noxious weed Nassella neesiana is established on a wide range of productive land throughout southeastern Australia. N. neesiana seeds, when mature, are sharp, causing injury to livestock, thus posing a problem in fodder bales. To reduce infestations of agricultural weeds in situ, production of silage from weed-infested pastures is practised as part of integrated weed management (IWM). However, there is little data to demonstrate whether this process is useful to reduce infestations or the harmful properties of N. neesiana. Therefore, the minimum duration of ensilage required to reduce the viability of N. neesiana seeds was investigated, both with and without addition of ensilage inoculants in this process. Also, the decreasing propensity of the seeds to injure livestock, after various times and conditions of ensilage, was assessed. Ensilage inoculant reduced seed germination probability to zero after 35 days. When no inoculant was added, zero viability was achieved after 42 days. A qualitative assessment of the hardness of ensilaged seeds found seed husks were softer (and therefore safer) after 42 days, whether inoculant was used or not. Therefore, we suggest that both the viability of N. neesiana seeds and hardness of seed casings are significantly reduced after 42 days, thereby reducing the risks of seed dispersal and injury to livestock.

  10. An investigation of the effects of stage of ensilage on Nassella neesiana seeds, for reducing seed viability and injury to livestock

    NASA Astrophysics Data System (ADS)

    Weller, S. L.; Florentine, S. K.; Sillitoe, J. F.; Grech, C. J.; McLaren, D. A.

    2016-03-01

    The noxious weed Nassella neesiana is established on a wide range of productive land throughout southeastern Australia. N. neesiana seeds, when mature, are sharp, causing injury to livestock, thus posing a problem in fodder bales. To reduce infestations of agricultural weeds in situ, production of silage from weed-infested pastures is practised as part of integrated weed management (IWM). However, there is little data to demonstrate whether this process is useful to reduce infestations or the harmful properties of N. neesiana. Therefore, the minimum duration of ensilage required to reduce the viability of N. neesiana seeds was investigated, both with and without addition of ensilage inoculants in this process. Also, the decreasing propensity of the seeds to injure livestock, after various times and conditions of ensilage, was assessed. Ensilage inoculant reduced seed germination probability to zero after 35 days. When no inoculant was added, zero viability was achieved after 42 days. A qualitative assessment of the hardness of ensilaged seeds found seed husks were softer (and therefore safer) after 42 days, whether inoculant was used or not. Therefore, we suggest that both the viability of N. neesiana seeds and hardness of seed casings are significantly reduced after 42 days, thereby reducing the risks of seed dispersal and injury to livestock.

  11. An investigation of the effects of stage of ensilage on Nassella neesiana seeds, for reducing seed viability and injury to livestock

    PubMed Central

    Weller, S. L.; Florentine, S. K.; Sillitoe, J. F.; Grech, C. J.; McLaren, D. A.

    2016-01-01

    The noxious weed Nassella neesiana is established on a wide range of productive land throughout southeastern Australia. N. neesiana seeds, when mature, are sharp, causing injury to livestock, thus posing a problem in fodder bales. To reduce infestations of agricultural weeds in situ, production of silage from weed-infested pastures is practised as part of integrated weed management (IWM). However, there is little data to demonstrate whether this process is useful to reduce infestations or the harmful properties of N. neesiana. Therefore, the minimum duration of ensilage required to reduce the viability of N. neesiana seeds was investigated, both with and without addition of ensilage inoculants in this process. Also, the decreasing propensity of the seeds to injure livestock, after various times and conditions of ensilage, was assessed. Ensilage inoculant reduced seed germination probability to zero after 35 days. When no inoculant was added, zero viability was achieved after 42 days. A qualitative assessment of the hardness of ensilaged seeds found seed husks were softer (and therefore safer) after 42 days, whether inoculant was used or not. Therefore, we suggest that both the viability of N. neesiana seeds and hardness of seed casings are significantly reduced after 42 days, thereby reducing the risks of seed dispersal and injury to livestock. PMID:26925589

  12. Seed coat color and seed weight contribute differential responses of targeted metabolites in soybean seeds.

    PubMed

    Lee, Jinwook; Hwang, Young-Sun; Kim, Sun Tae; Yoon, Won-Byong; Han, Won Young; Kang, In-Kyu; Choung, Myoung-Gun

    2017-01-01

    The distribution and variation of targeted metabolites in soybean seeds are affected by genetic and environmental factors. In this study, we used 192 soybean germplasm accessions collected from two provinces of Korea to elucidate the effects of seed coat color and seeds dry weight on the metabolic variation and responses of targeted metabolites. The effects of seed coat color and seeds dry weight were present in sucrose, total oligosaccharides, total carbohydrates and all measured fatty acids. The targeted metabolites were clustered within three groups. These metabolites were not only differently related to seeds dry weight, but also responded differentially to seed coat color. The inter-relationship between the targeted metabolites was highly present in the result of correlation analysis. Overall, results revealed that the targeted metabolites were diverged in relation to seed coat color and seeds dry weight within locally collected soybean seed germplasm accessions.

  13. The Seed Composition of Arabidopsis Mutants for the Group 3 Sulfate Transporters Indicates a Role in Sulfate Translocation within Developing Seeds1[C][W][OA

    PubMed Central

    Zuber, Hélène; Davidian, Jean-Claude; Aubert, Grégoire; Aimé, Delphine; Belghazi, Maya; Lugan, Raphaël; Heintz, Dimitri; Wirtz, Markus; Hell, Rüdiger; Thompson, Richard; Gallardo, Karine

    2010-01-01

    Sulfate is required for the synthesis of sulfur-containing amino acids and numerous other compounds essential for the plant life cycle. The delivery of sulfate to seeds and its translocation between seed tissues is likely to require specific transporters. In Arabidopsis (Arabidopsis thaliana), the group 3 plasmalemma-predicted sulfate transporters (SULTR3) comprise five genes, all expressed in developing seeds, especially in the tissues surrounding the embryo. Here, we show that sulfur supply to seeds is unaffected by T-DNA insertions in the SULTR3 genes. However, remarkably, an increased accumulation of sulfate was found in mature seeds of four mutants out of five. In these mutant seeds, the ratio of sulfur in sulfate form versus total sulfur was significantly increased, accompanied by a reduction in free cysteine content, which varied depending on the gene inactivated. These results demonstrate a reduced capacity of the mutant seeds to metabolize sulfate and suggest that these transporters may be involved in sulfate translocation between seed compartments. This was further supported by sulfate measurements of the envelopes separated from the embryo of the sultr3;2 mutant seeds, which showed differences in sulfate partitioning compared with the wild type. A dissection of the seed proteome of the sultr3 mutants revealed protein changes characteristic of a sulfur-stress response, supporting a role for these transporters in providing sulfate to the embryo. The mutants were affected in 12S globulin accumulation, demonstrating the importance of intraseed sulfate transport for the synthesis and maturation of embryo proteins. Metabolic adjustments were also revealed, some of which could release sulfur from glucosinolates. PMID:20702726

  14. The seed composition of Arabidopsis mutants for the group 3 sulfate transporters indicates a role in sulfate translocation within developing seeds.

    PubMed

    Zuber, Hélène; Davidian, Jean-Claude; Aubert, Grégoire; Aimé, Delphine; Belghazi, Maya; Lugan, Raphaël; Heintz, Dimitri; Wirtz, Markus; Hell, Rüdiger; Thompson, Richard; Gallardo, Karine

    2010-10-01

    Sulfate is required for the synthesis of sulfur-containing amino acids and numerous other compounds essential for the plant life cycle. The delivery of sulfate to seeds and its translocation between seed tissues is likely to require specific transporters. In Arabidopsis (Arabidopsis thaliana), the group 3 plasmalemma-predicted sulfate transporters (SULTR3) comprise five genes, all expressed in developing seeds, especially in the tissues surrounding the embryo. Here, we show that sulfur supply to seeds is unaffected by T-DNA insertions in the SULTR3 genes. However, remarkably, an increased accumulation of sulfate was found in mature seeds of four mutants out of five. In these mutant seeds, the ratio of sulfur in sulfate form versus total sulfur was significantly increased, accompanied by a reduction in free cysteine content, which varied depending on the gene inactivated. These results demonstrate a reduced capacity of the mutant seeds to metabolize sulfate and suggest that these transporters may be involved in sulfate translocation between seed compartments. This was further supported by sulfate measurements of the envelopes separated from the embryo of the sultr3;2 mutant seeds, which showed differences in sulfate partitioning compared with the wild type. A dissection of the seed proteome of the sultr3 mutants revealed protein changes characteristic of a sulfur-stress response, supporting a role for these transporters in providing sulfate to the embryo. The mutants were affected in 12S globulin accumulation, demonstrating the importance of intraseed sulfate transport for the synthesis and maturation of embryo proteins. Metabolic adjustments were also revealed, some of which could release sulfur from glucosinolates.

  15. Effects of Row-Type, Row-Spacing, Seeding Rate, Soil-Type, and Cultivar Differences on Soybean Seed Nutrition under US Mississippi Delta Conditions.

    PubMed

    Bellaloui, Nacer; Bruns, Herbert A; Abbas, Hamed K; Mengistu, Alemu; Fisher, Daniel K; Reddy, Krishna N

    2015-01-01

    The new Early Soybean Production System (ESPS), developed in the Midsouth USA, including the Mississippi delta, resulted in higher yield under irrigated and non-irrigated conditions. However, information on the effects of the agricultural practices such as row-type (RT: twin- vs. single-row), row-spacing, (RS), seeding rate (SR), soil-type (ST) on seed nutrition under the ESPS environment in the Mississippi delta is very limited. Our previous research in the Mississippi delta showed these agricultural practices altered seed nutrients in one cultivar only. However, whether these effects on seed nutrients will be exhibited by other soybean cultivars with earlier and later maturities across multiple years are not yet known. Therefore, the objective of this research was to evaluate the effects of agricultural practices and cultivar (Cv) differences on seed nutrition in clay and sandy soils under ESPS environment of high heat and drought. Two field experiments were conducted; one experiment was conducted in 2009 and 2010, and the other in 2008, 2009, and 2010 under irrigated conditions. Soybean were grown on 102 cm single-rows and on 25 cm twin-rows with 102 cm centers at seeding rates of 20, 30, 40, and 50 seeds m(-2). Two soybean cultivars (94M80 with earlier maturity; and GP 533 with later maturity) were used. Results showed that increasing seeding rate resulted in increases of protein, sucrose, glucose, raffinose, B, and P concentrations on both single- and twin-rows. However, this increase became either constant or declined at the higher rates (40 and 50 seeds m(-2)). Protein and linolenic acid concentrations were higher in GP 533 than in 94M80 on both row-types, but oil and oleic acid concentrations were in 94M80 than GP 533. Generally, cultivar GP 533 accumulated more seed constituents in seeds than 94M80. In 2010, there were no clear responses of seed nutrients to SR increase in both cultivars, perhaps due to drier year and high heat in 2010. It is concluded

  16. Effects of Row-Type, Row-Spacing, Seeding Rate, Soil-Type, and Cultivar Differences on Soybean Seed Nutrition under US Mississippi Delta Conditions

    PubMed Central

    Reddy, Krishna N.

    2015-01-01

    The new Early Soybean Production System (ESPS), developed in the Midsouth USA, including the Mississippi delta, resulted in higher yield under irrigated and non-irrigated conditions. However, information on the effects of the agricultural practices such as row-type (RT: twin- vs. single-row), row-spacing, (RS), seeding rate (SR), soil-type (ST) on seed nutrition under the ESPS environment in the Mississippi delta is very limited. Our previous research in the Mississippi delta showed these agricultural practices altered seed nutrients in one cultivar only. However, whether these effects on seed nutrients will be exhibited by other soybean cultivars with earlier and later maturities across multiple years are not yet known. Therefore, the objective of this research was to evaluate the effects of agricultural practices and cultivar (Cv) differences on seed nutrition in clay and sandy soils under ESPS environment of high heat and drought. Two field experiments were conducted; one experiment was conducted in 2009 and 2010, and the other in 2008, 2009, and 2010 under irrigated conditions. Soybean were grown on 102 cm single-rows and on 25 cm twin-rows with 102 cm centers at seeding rates of 20, 30, 40, and 50 seeds m–2. Two soybean cultivars (94M80 with earlier maturity; and GP 533 with later maturity) were used. Results showed that increasing seeding rate resulted in increases of protein, sucrose, glucose, raffinose, B, and P concentrations on both single- and twin-rows. However, this increase became either constant or declined at the higher rates (40 and 50 seeds m–2). Protein and linolenic acid concentrations were higher in GP 533 than in 94M80 on both row-types, but oil and oleic acid concentrations were in 94M80 than GP 533. Generally, cultivar GP 533 accumulated more seed constituents in seeds than 94M80. In 2010, there were no clear responses of seed nutrients to SR increase in both cultivars, perhaps due to drier year and high heat in 2010. It is concluded

  17. 7 CFR 51.2651 - Mature.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ..., CERTIFICATION, AND STANDARDS) United States Standards for Grades for Sweet Cherries 1 Definitions § 51.2651 Mature. Mature means that the cherries have reached the stage of growth which will insure the...

  18. 7 CFR 51.3058 - Mature.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ..., CERTIFICATION, AND STANDARDS) United States Standards for Florida Avocados Definitions § 51.3058 Mature. Mature means that the avocado has reached a stage of growth which will insure a proper completion of...

  19. 7 CFR 51.2651 - Mature.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ..., CERTIFICATION, AND STANDARDS) United States Standards for Grades for Sweet Cherries 1 Definitions § 51.2651 Mature. Mature means that the cherries have reached the stage of growth which will insure the...

  20. Career Maturity: The Construct and its Measurement.

    ERIC Educational Resources Information Center

    Savickas, Mark L.

    1984-01-01

    Describes vocational maturity and assists counselors in identifying what the various career maturity instruments measure. Discusses task variable measures, intervening variable measures, response variable measures, and methods of choosing an instrument. (JAC)

  1. Seed rain generated by bats under Cerrado's pasture remnant trees in a Neotropical savanna.

    PubMed

    Ragusa-Netto, J; Santos, A A

    2015-11-01

    In this study we described the seed rain generated by bats under four Cerrado's tree species common within pastures, Buchenavia tomentosa, Couepia grandiflora, Licania humilis and Qualea grandiflora. We analyzed the similarity among the four tree species in terms of seed rain composition, and compared the number of seeds and seed species deposited under them. Besides that, we assessed the relationship between seed rain intensity and the density of each tree species. Then, we randomly selected 10 mature trees of each species to sample seed rain. We recorded a total of 4892 bat dispersed seeds from 11 species. Also, we observed that along the year seed deposition varied substantially under all trees. At least two seed sub-communities could be distinguished according to tree species used by bats as feeding roost. One related to Couepia grandiflora and Licania humilis, and the other to Buchenavia tomentosa and Qualea grandiflora trees. The variability of seed rain composition in any particular tree and the range of actual seed fall into a particular species indicate patchiness in seed rain, and the overall results appear to be consistent in terms of a substantial and diverse seed rain generated by bats in a highly anthropized landscape. This is the first study concerning seed dispersal by bats in modified Brazilian Cerrado, one of the most endangered biomes in the world. In this respect, by preserving a dense and diverse collection of remnant trees within today's pastures may, potentially, contribute to a faster Cerrado recovery in extensive areas that can be reclaimed for restoration in the future.

  2. Galactinol synthase enzyme activity influences raffinose family oligosaccharides (RFO) accumulation in developing chickpea (Cicer arietinum L.) seeds.

    PubMed

    Gangola, Manu P; Jaiswal, Sarita; Kannan, Udhaya; Gaur, Pooran M; Båga, Monica; Chibbar, Ravindra N

    2016-05-01

    To understand raffinose family oligosaccharides (RFO) metabolism in chickpea (Cicer arietinum L.) seeds, RFO accumulation and corresponding biosynthetic enzymes activities were determined during seed development of chickpea genotypes with contrasting RFO concentrations. RFO concentration in mature seeds was found as a facilitator rather than a regulating step of seed germination. In mature seeds, raffinose concentrations ranged from 0.38 to 0.68 and 0.75 to 0.99 g/100 g, whereas stachyose concentrations varied from 0.79 to 1.26 and 1.70 to 1.87 g/100 g indicating significant differences between low and high RFO genotypes, respectively. Chickpea genotypes with high RFO concentration accumulated higher concentrations of myo-inositol and sucrose during early seed developmental stages suggesting that initial substrate concentrations may influence RFO concentration in mature seeds. High RFO genotypes showed about two to three-fold higher activity for all RFO biosynthetic enzymes compared to those with low RFO concentrations. RFO biosynthetic enzymes activities correspond with accumulation of individual RFO during seed development.

  3. Differential expression of two ß-amylase genes (Bmy1 and Bmy2) in developing and mature barley grain

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Barley (Hordeum vulgare L.) endosperm-specific (Bmy1) and ubiquitous (Bmy2) ß-amylase were studied during the late maturation phase of seed development in four genotypes. Sequencing of Bmy2 from genomic DNA revealed six polymorphisms in the introns and two synonymous SNPs in the coding region. Acc...

  4. An Endosperm-Associated Cuticle Is Required for Arabidopsis Seed Viability, Dormancy and Early Control of Germination

    PubMed Central

    Loubery, Sylvain; Utz-Pugin, Anne; Bailly, Christophe; Mène-Saffrané, Laurent; Lopez-Molina, Luis

    2015-01-01

    Cuticular layers and seeds are prominent plant adaptations to terrestrial life that appeared early and late during plant evolution, respectively. The cuticle is a waterproof film covering plant aerial organs preventing excessive water loss and protecting against biotic and abiotic stresses. Cutin, consisting of crosslinked fatty acid monomers, is the most abundant and studied cuticular component. Seeds are dry, metabolically inert structures promoting plant dispersal by keeping the plant embryo in an arrested protected state. In Arabidopsis thaliana seeds, the embryo is surrounded by a single cell endosperm layer itself surrounded by a seed coat layer, the testa. Whole genome analyses lead us to identify cutin biosynthesis genes as regulatory targets of the phytohormones gibberellins (GA) and abscisic acid (ABA) signaling pathways that control seed germination. Cutin-containing layers are present in seed coats of numerous species, including Arabidopsis, where they regulate permeability to outer compounds. However, the role of cutin in mature seed physiology and germination remains poorly understood. Here we identify in mature seeds a thick cuticular film covering the entire outer surface of the endosperm. This seed cuticle is defective in cutin-deficient bodyguard1 seeds, which is associated with alterations in endospermic permeability. Furthermore, mutants affected in cutin biosynthesis display low seed dormancy and viability levels, which correlates with higher levels of seed lipid oxidative stress. Upon seed imbibition cutin biosynthesis genes are essential to prevent endosperm cellular expansion and testa rupture in response to low GA synthesis. Taken together, our findings suggest that in the course of land plant evolution cuticular structures were co-opted to achieve key physiological seed properties. PMID:26681322

  5. An Endosperm-Associated Cuticle Is Required for Arabidopsis Seed Viability, Dormancy and Early Control of Germination.

    PubMed

    De Giorgi, Julien; Piskurewicz, Urszula; Loubery, Sylvain; Utz-Pugin, Anne; Bailly, Christophe; Mène-Saffrané, Laurent; Lopez-Molina, Luis

    2015-12-01

    Cuticular layers and seeds are prominent plant adaptations to terrestrial life that appeared early and late during plant evolution, respectively. The cuticle is a waterproof film covering plant aerial organs preventing excessive water loss and protecting against biotic and abiotic stresses. Cutin, consisting of crosslinked fatty acid monomers, is the most abundant and studied cuticular component. Seeds are dry, metabolically inert structures promoting plant dispersal by keeping the plant embryo in an arrested protected state. In Arabidopsis thaliana seeds, the embryo is surrounded by a single cell endosperm layer itself surrounded by a seed coat layer, the testa. Whole genome analyses lead us to identify cutin biosynthesis genes as regulatory targets of the phytohormones gibberellins (GA) and abscisic acid (ABA) signaling pathways that control seed germination. Cutin-containing layers are present in seed coats of numerous species, including Arabidopsis, where they regulate permeability to outer compounds. However, the role of cutin in mature seed physiology and germination remains poorly understood. Here we identify in mature seeds a thick cuticular film covering the entire outer surface of the endosperm. This seed cuticle is defective in cutin-deficient bodyguard1 seeds, which is associated with alterations in endospermic permeability. Furthermore, mutants affected in cutin biosynthesis display low seed dormancy and viability levels, which correlates with higher levels of seed lipid oxidative stress. Upon seed imbibition cutin biosynthesis genes are essential to prevent endosperm cellular expansion and testa rupture in response to low GA synthesis. Taken together, our findings suggest that in the course of land plant evolution cuticular structures were co-opted to achieve key physiological seed properties.

  6. 7 CFR 51.1158 - Mature.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... § 51.1158 Mature. Mature shall have the same meaning assigned the term in the Florida Citrus Code, Chapter 601, 1995 Edition, and the Official Rules Affecting the Florida Citrus Industry, in effect as of February 12, 1995. These orange maturity requirements are contained in the Florida Citrus Code, Chapter...

  7. 7 CFR 51.1823 - Mature.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Mature. Mature shall have the same meaning assigned the term in the Florida Citrus Code, Chapter 601, 1995 Edition, and the Official Rules Affecting the Florida Citrus Industry, in effect as of February 12, 1995. These tangerine maturity requirements are contained in the Florida Citrus Code, Chapter...

  8. 7 CFR 51.1158 - Mature.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... § 51.1158 Mature. Mature shall have the same meaning assigned the term in the Florida Citrus Code, Chapter 601, 1995 Edition, and the Official Rules Affecting the Florida Citrus Industry, in effect as of February 12, 1995. These orange maturity requirements are contained in the Florida Citrus Code, Chapter...

  9. 7 CFR 51.1823 - Mature.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Mature. Mature shall have the same meaning assigned the term in the Florida Citrus Code, Chapter 601, 1995 Edition, and the Official Rules Affecting the Florida Citrus Industry, in effect as of February 12, 1995. These tangerine maturity requirements are contained in the Florida Citrus Code, Chapter...

  10. 7 CFR 51.767 - Mature.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Mature. Mature shall have the same meaning assigned the term in the Florida Citrus Code, Chapter 601, 1995 Edition, and the Official Rules Affecting the Florida Citrus Industry, in effect as of February 12, 1995. These grapefruit maturity requirements are contained in the Florida Citrus Code, Chapter...

  11. 7 CFR 51.767 - Mature.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Mature. Mature shall have the same meaning assigned the term in the Florida Citrus Code, Chapter 601, 1995 Edition, and the Official Rules Affecting the Florida Citrus Industry, in effect as of February 12, 1995. These grapefruit maturity requirements are contained in the Florida Citrus Code, Chapter...

  12. Career Maturity in High School Age Females.

    ERIC Educational Resources Information Center

    Pedro, Joan Daniels

    1982-01-01

    Examined career maturity in high school females by using a set of general career-maturity and gender-specific, career-related measures, and an alternate career-maturity criterion measure, career-planning involvement. Results indicated significant relationships between achievement orientation and occupational information and knowledge of women's…

  13. 7 CFR 906.11 - Maturity.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 8 2011-01-01 2011-01-01 false Maturity. 906.11 Section 906.11 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... RIO GRANDE VALLEY IN TEXAS Order Regulating Handling Definitions § 906.11 Maturity. Maturity...

  14. Production of high levels of poly-3-hydroxybutyrate in plastids of Camelina sativa seeds.

    PubMed

    Malik, Meghna R; Yang, Wenyu; Patterson, Nii; Tang, Jihong; Wellinghoff, Rachel L; Preuss, Mary L; Burkitt, Claire; Sharma, Nirmala; Ji, Yuanyuan; Jez, Joseph M; Peoples, Oliver P; Jaworski, Jan G; Cahoon, Edgar B; Snell, Kristi D

    2015-06-01

    Poly-3-hydroxybutyrate (PHB) production in plastids of Camelina sativa seeds was investigated by comparing levels of polymer produced upon transformation of plants with five different binary vectors containing combinations of five seed-specific promoters for expression of transgenes. Genes encoding PHB biosynthetic enzymes were modified at the N-terminus to encode a plastid targeting signal. PHB levels of up to 15% of the mature seed weight were measured in single sacrificed T1 seeds with a genetic construct containing the oleosin and glycinin promoters. A more detailed analysis of the PHB production potential of two of the best performing binary vectors in a Camelina line bred for larger seed size yielded lines containing up to 15% polymer in mature T2 seeds. Transmission electron microscopy showed the presence of distinct granules of PHB in the seeds. PHB production had varying effects on germination, emergence and survival of seedlings. Once true leaves formed, plants grew normally and were able to set seeds. PHB synthesis lowered the total oil but not the protein content of engineered seeds. A change in the oil fatty acid profile was also observed. High molecular weight polymer was produced with weight-averaged molecular weights varying between 600 000 and 1 500 000, depending on the line. Select lines were advanced to later generations yielding a line with 13.7% PHB in T4 seeds. The levels of polymer produced in this study are the highest reported to date in a seed and are an important step forward for commercializing an oilseed-based platform for PHB production.

  15. Germination and soil seed bank traits of Podocarpus angustifolius (Podocarpaceae): an endemic tree species from Cuban rain forests.

    PubMed

    Ferrandis, Pablo; Bonilla, Marta; Osorio, Licet del Carmen

    2011-09-01

    Podocarpus angustifolius is an endangered recalcitrant-seeded small tree, endemic to mountain rain forests in the central and Pinar del Río regions in Cuba. In this study, the germination patterns of P. angustifolius seeds were evaluated and the nature of the soil seed bank was determined. Using a weighted two-factor design, we analyzed the combined germination response to seed source (i.e. freshly matured seeds directly collected from trees versus seeds extracted from soil samples) and pretreatment (i.e. seed water-immersion for 48h at room temperature). Germination was delayed for four weeks (= 30 days) in all cases, regardless of both factors analyzed. Moreover, nine additional days were necessary to achieve high germination values (in the case of fresh, pretreated seeds). These results overall may indicate the existence of a non-deep simple morphophysiological dormancy in P. angustifolius seeds. The water-immersion significantly enhanced seed germination, probably as a result of the hydration of recalcitrant seeds. Although germination of seeds extracted from soil samples was low, probably due to aging and pathogen effects throughout the time of burial, the study revealed the existence of a persistent soil seed bank (at least short-termed) of approximately 42 viable seeds per m2 in the upper 10cm of soil. Such a record is noteworthy since references to persistent soil seed banks in recalcitrant-seeded species are scarce in the literature. The population consequences derived from the formation of persistent soil seed banks in this endangered species are discussed.

  16. Seed Transmission of Pseudoperonospora cubensis

    PubMed Central

    Cohen, Yigal; Rubin, Avia E.; Galperin, Mariana; Ploch, Sebastian; Runge, Fabian; Thines, Marco

    2014-01-01

    Pseudoperonospora cubensis, an obligate biotrophic oomycete causing devastating foliar disease in species of the Cucurbitaceae family, was never reported in seeds or transmitted by seeds. We now show that P. cubensis occurs in fruits and seeds of downy mildew-infected plants but not in fruits or seeds of healthy plants. About 6.7% of the fruits collected during 2012–2014 have developed downy mildew when homogenized and inoculated onto detached leaves and 0.9% of the seeds collected developed downy mildew when grown to the seedling stage. This is the first report showing that P. cubensis has become seed-transmitted in cucurbits. Species-specific PCR assays showed that P. cubensis occurs in ovaries, fruit seed cavity and seed embryos of cucurbits. We propose that international trade of fruits or seeds of cucurbits might be associated with the recent global change in the population structure of P. cubensis. PMID:25329308

  17. Seeds in space experiment results

    NASA Technical Reports Server (NTRS)

    Alston, Jim A.

    1991-01-01

    Two million seeds of 120 different varieties representing 106 species, 97 genera, and 55 plant families were flown aboard the Long Duration Exposure Facility (LDEF). The seeds were housed on the space exposed experiment developed for students (SEEDS) tray in sealed canister number six and in two small vented canisters. The tray was in the F-2 position. The seeds were germinated and the germination rates and development of the resulting plants compared to the control seed that stayed in Park Seed's seed storage facility. The initial results are presented. There was a better survival rate in the sealed canister in space than in the storage facility at Park Seed. At least some of the seeds in each of the vented canisters survived the exposure to vacuum for almost six years. The number of observed apparent mutations was very low.

  18. Automated seed manipulation and planting

    NASA Technical Reports Server (NTRS)

    Garcia, Ray; Herrera, Javier; Holcomb, Scott; Kelly, Paul; Myers, Scott; Rosendo, Manny; Sivitz, Herbert; Wolsefer, Dave

    1988-01-01

    The Mechanical Division fabricated three seed separators utilizing pressure gradients to move and separate wheat seeds. These separators are called minnow buckets and use air, water, or a combination of both to generate the pressure gradient. Electrostatic fields were employed in the seed separator constructed by the Electrical Division. This separator operates by forcing a temporary electric dipole on the wheat seeds and using charged electrodes to attract and move the seeds. Seed delivery to the hydroponic growth tray is accomplished by the seed cassette. The cassette is compatible with all the seed separators, and it consists of a plastic tube threaded with millipore filter paper. During planting operations, the seeds are placed in an empty cassette. The loaded cassette is then placed in the growth tray and nutrient solution provided. The solution wets the filter paper and capillary action draws the nutrients up to feed the seeds. These seeding systems were tested and showed encouraging results. Seeds were effectively separated and the cassette can support the growth of wheat plants. Problems remaining to be investigated include improving the success of delivering the seeds to the cassette and providing adequate spacing between seeds for the electric separator.

  19. [Arrest of maturation in spermatogenesis].

    PubMed

    Francavilla, S; Bellocci, M; Martini, M; Bruno, B; Moscardelli, S; Fabbrini, A; Properzi, G

    1982-07-30

    The ultrastructural aspects of the germinal epithelium of 10 infertile men affected by maturative arrest of spermatogenesis were studied. We noted an increased number of malformed germinal cells. Marginal nuclear vescicles were present in spermatogonia of patients affected by spermatogonial arrest. The few spermatid present in the germinal epithelium of the patients affected by a spermatidic arrest presented changes of the nuclear condensation, the acrosome, and the tail. The Sertoli cells presented an immature aspect of the nucleus and changes of the "mantle". A possible correlation between the Sertoli cells changes and the altered spermatogenesis was proposed.

  20. Phenotype of normal hairline maturation.

    PubMed

    Rassman, William R; Pak, Jae P; Kim, Jino

    2013-08-01

    Hairlines change shape with age, starting at birth. A good head of hair is frequently present some time after ages 3 to 5 years. The look of childhood has its corresponding hairline, and, as the child grows and develops into adulthood, facial morphology migrate changes from a childlike look to a more mature look. This article discusses the dynamics of hairline evolution and the phenotypic variations of the front and side hairlines in men and women. A modeling system is introduced that provides a common language to define the various anatomic points of the full range of hairlines.

  1. Magnetic-seeding filtration

    SciTech Connect

    Ying, T.Y.; Chin, C.J.; Lu, S.C.; Yiacoumi, S.

    1997-10-01

    Magnetic-seeding filtration consists of two steps: heterogeneous particle flocculation of magnetic and nonmagnetic particles in a stirred tank and high-gradient magnetic filtration (HGMF). The effects of various parameters affecting magnetic-seeding filtration (HGMF). The effects of various parameters affecting magnetic seeding filtration are theoretically and experimentally investigated. A trajectory model that includes hydrodynamic resistance, van der Waals, and electrostatic forces is developed to calculate the flocculation frequency in a turbulent-shear regime. Fractal dimension is introduced to simulate the open structure of aggregates. A magnetic-filtration model that consists of trajectory analysis, a particle build-up model, a breakthrough model, and a bivariate population-balance model is developed to predict the breakthrough curve of magnetic-seeding filtration. A good agreement between modeling results and experimental data is obtained. The results show that the model developed in this study can be used to predict the performance of magnetic-seeding filtration without using empirical coefficients or fitting parameters. 35 refs., 7 figs., 1 tab.

  2. Academic Achievement of High School Students in Relation to Their Anxiety, Emotional Maturity and Social Maturity

    ERIC Educational Resources Information Center

    Puar, Surjit Singh

    2013-01-01

    The present study has been designed to investigate the non-cognitive variables like anxiety, emotional maturity and social maturity and their relationship with academic achievement and also to see the locale-wise differences on the basis of their anxiety, emotional maturity and social maturity. The study was conducted over a sample of 400 (200…

  3. The Relationship Between Cognitive Career Maturity and Self-Reported Career Maturity of High School Students.

    ERIC Educational Resources Information Center

    Westbrook, Bert W.; And Others

    1987-01-01

    Investigated relationship between scores on measures of cognitive career maturity and self-reported career maturity in high school sophomores (N=391) and juniors (N=283). Results suggest that there is no relationship between measured career maturity competencies and self-reported career maturity competencies of high school students. (Author/NB)

  4. Effect of Different Titanium Surfaces on Maturation of Murine Bone Marrow-Derived Dendritic Cells

    PubMed Central

    Zheng, Xiaofei; Zhou, Fengjuan; Gu, Yifei; Duan, Xiaobo; Mo, Anchun

    2017-01-01

    Dendritic cells (DCs) play a pivotal role in the host response to implanted biomaterials. Osseointegration of titanium (Ti) implant is an immunological and inflammatory-driven process. However, the role of DCs in this complex process is largely unknown. This study aimed to investigate the effect of different Ti surfaces on DC maturation, and evaluate its subsequent potential on osteogenic differentiation of preosteoblasts. Murine bone marrow-derived DCs were seeded on Ti disks with different surface treatments, including pretreatment (PT), sandblasted/acid-etched (SLA) and modified SLA (modSLA) surface. Compared with DCs cultured on PT and SLA surfaces, the cells seeded on modSLA surface demonstrated a more round morphology with lower expression of CD86 and MHC-II, the DC maturation markers. Those cells also secreted high levels of anti-inflammatory cytokine IL-10 and TGF-β. Notably, addition of conditioned medium (CM) from modSLA-induced DCs significantly increased the mRNA expression of Runx2 and ALP as well as ALP activity by murine preosteoblast MC3T3-E1 cells. Our data demonstrated that Ti disks with different surfaces lead to differential DCs responses. PT and SLA surfaces induce DCs mature, while DCs seeded on modSLA-Ti surface maintain an immature phenotype and exhibit a potential of promoting osteogenic differentiation of MC3T3-E1 cells. PMID:28157196

  5. Effect of Different Titanium Surfaces on Maturation of Murine Bone Marrow-Derived Dendritic Cells

    NASA Astrophysics Data System (ADS)

    Zheng, Xiaofei; Zhou, Fengjuan; Gu, Yifei; Duan, Xiaobo; Mo, Anchun

    2017-02-01

    Dendritic cells (DCs) play a pivotal role in the host response to implanted biomaterials. Osseointegration of titanium (Ti) implant is an immunological and inflammatory-driven process. However, the role of DCs in this complex process is largely unknown. This study aimed to investigate the effect of different Ti surfaces on DC maturation, and evaluate its subsequent potential on osteogenic differentiation of preosteoblasts. Murine bone marrow-derived DCs were seeded on Ti disks with different surface treatments, including pretreatment (PT), sandblasted/acid-etched (SLA) and modified SLA (modSLA) surface. Compared with DCs cultured on PT and SLA surfaces, the cells seeded on modSLA surface demonstrated a more round morphology with lower expression of CD86 and MHC-II, the DC maturation markers. Those cells also secreted high levels of anti-inflammatory cytokine IL-10 and TGF-β. Notably, addition of conditioned medium (CM) from modSLA-induced DCs significantly increased the mRNA expression of Runx2 and ALP as well as ALP activity by murine preosteoblast MC3T3-E1 cells. Our data demonstrated that Ti disks with different surfaces lead to differential DCs responses. PT and SLA surfaces induce DCs mature, while DCs seeded on modSLA-Ti surface maintain an immature phenotype and exhibit a potential of promoting osteogenic differentiation of MC3T3-E1 cells.

  6. Increasing abscisic acid levels by immunomodulation in barley grains induces precocious maturation without changing grain composition.

    PubMed

    Staroske, Nicole; Conrad, Udo; Kumlehn, Jochen; Hensel, Götz; Radchuk, Ruslana; Erban, Alexander; Kopka, Joachim; Weschke, Winfriede; Weber, Hans

    2016-04-01

    Abscisic acid (ABA) accumulates in seeds during the transition to the seed filling phase. ABA triggers seed maturation, storage activity, and stress signalling and tolerance. Immunomodulation was used to alter the ABA status in barley grains, with the resulting transgenic caryopses responding to the anti-ABA antibody gene expression with increased accumulation of ABA. Calculation of free versus antibody-bound ABA reveals large excess of free ABA, increasing signficantly in caryopses from 10 days after fertilization. Metabolite and transcript profiling in anti-ABA grains expose triggered and enhanced ABA-functions such as transcriptional up-regulation of sucrose-to-starch metabolism, storage protein synthesis and ABA-related signal transduction. Thus, enhanced ABA during transition phases induces precocious maturation but negatively interferes with growth and development. Anti-ABA grains display broad constitutive gene induction related to biotic and abiotic stresses. Most of these genes are ABA- and/or stress-inducible, including alcohol and aldehyde dehydrogenases, peroxidases, chaperones, glutathione-S-transferase, drought- and salt-inducible proteins. Conclusively, ABA immunomodulation results in precocious ABA accumulation that generates an integrated response of stress and maturation. Repression of ABA signalling, occurring in anti-ABA grains, potentially antagonizes effects caused by overshooting production. Finally, mature grain weight and composition are unchanged in anti-ABA plants, although germination is somewhat delayed. This indicates that anti-ABA caryopses induce specific mechanisms to desensitize ABA signalling efficiently, which finally yields mature grains with nearly unchanged dry weight and composition. Such compensation implicates the enormous physiological and metabolic flexibilities of barley grains to adjust effects of unnaturally high ABA amounts in order to ensure and maintain proper grain development.

  7. Seeds in Chernobyl: the database on proteome response on radioactive environment.

    PubMed

    Klubicová, Katarína; Vesel, Martin; Rashydov, Namik M; Hajduch, Martin

    2012-01-01

    Two serious nuclear accidents during the last quarter century (Chernobyl, 1986 and Fukushima, 2011) contaminated large agricultural areas with radioactivity. The database "Seeds in Chernobyl" (http://www.chernobylproteomics.sav.sk) contains the information about the abundances of hundreds of proteins from on-going investigation of mature and developing seed harvested from plants grown in radioactive Chernobyl area. This database provides a useful source of information concerning the response of the seed proteome to permanently increased level of ionizing radiation in a user-friendly format.

  8. Identification and disruption of an Arabidopsis zinc finger gene controlling seed germination

    PubMed Central

    Papi, Maura; Sabatini, Sabrina; Bouchez, David; Camilleri, Christine; Costantino, Paolo; Vittorioso, Paola

    2000-01-01

    We describe here the Arabidopsis gene DAG1, encoding a zinc finger transcription factor of the Dof family, and show that it is involved in the control of seed germination. By a reverse genetics approach, we isolated an Arabidopsis mutant line with one T-DNA insertion in DAG1. Seeds from homozygous knockout dag1-1 plants do not develop dormancy and germinate also in the absence of light. Segregation analysis indicates that the effect of the mutation is maternal. Accordingly, in situ mRNA hybridizations reveal expression of DAG1 in the vascular tissue of the flower and maturing fruit but not in the seed. PMID:10640273

  9. Sexual maturation of female Saguinus oedipus oedipus

    SciTech Connect

    Tardif, S.D.

    1982-01-01

    This study is an examination of the process of female sexual maturation in the cotton-top tamarin, Saguinus oedipus oedipus, a South-American primate of the family, Callitrichidae. Two types of questions are addressed. The first question is whether the type of social grouping in which a young female lives affects the rate of her sexual maturation. Specifically, is there a difference between the maturation rate of a female housed with a strange adult male and a female housed with her natal group (i.e., her parents and various siblings). Second, the effect of sexual maturation on various social interactions is examined. Specifically are male-female interactions in mated pairs and mother-daughter interactions in natal groups changed by the sexual maturation of the young females. The mother's presence was not related to the daughter's maturation age. However, whether the natal group, as a whole, inhibited maturation, or unrelated males accelerated maturation, or both, remains unknown. Most of the behavioral interactions involving maturing females were unchanged by maturation. There was some indication that certain behaviors were affected by maturation, but only if a strange unrelated male was present.

  10. Soybean seed proteome rebalancing

    PubMed Central

    Herman, Eliot M.

    2014-01-01

    The soybean seed’s protein content and composition are regulated by both genetics and physiology. Overt seed protein content is specified by the genotype’s genetic framework and is selectable as a breeding trait. Within the genotype-specified protein content phenotype soybeans have the capacity to rebalance protein composition to create differing proteomes. Soybeans possess a relatively standardized proteome, but mutation or targeted engineering can induce large-scale proteome rebalancing. Proteome rebalancing shows that the output traits of seed content and composition result from two major types of regulation: genotype and post-transcriptional control of the proteome composition. Understanding the underlying mechanisms that specifies the seed proteome can enable engineering new phenotypes for the production of a high-quality plant protein source for food, feed, and industrial proteins. PMID:25232359

  11. Neural networks predict tomato maturity stage

    NASA Astrophysics Data System (ADS)

    Hahn, Federico

    1999-03-01

    Almost 40% of the total horticultural produce exported from Mexico the USA is tomato, and quality is fundamental for maintaining the market. Many fruits packed at the green-mature stage do not mature towards a red color as they were harvested before achieving its physiological maturity. Tomato gassed for advancing maturation does not respond on those fruits, and repacking is necessary at terminal markets, causing losses to the producer. Tomato spectral signatures are different on each maturity stage and tomato size was poorly correlated against peak wavelengths. A back-propagation neural network was used to predict tomato maturity using reflectance ratios as inputs. Higher success rates were achieved on tomato maturity stage recognition with neural networks than with discriminant analysis.

  12. Physiological thermoregulation of mature alligators.

    PubMed

    Smith, E N; Standora, E A; Robertson, S L

    1984-01-01

    A 67.1 kg alligator (Alligator mississippiensis), tested in air, heated twice as fast as it cooled. The cooling thermal time constant was 425 min while alive. Warming and cooling thermal time constants were 421 min after death. The thermal time constant was not appropriate in describing warming in air of mature alligators. Surface and subdermal heat flow measurements of the 67.1 kg animal indicate greater blood flow in the skin during warming compared to cooling. Two mature alligators, 49.9 and 103 kg, were heated and cooled in water. Warming time constants were 67 and 110 min respectively. Cooling time constants were 180 and 246 min. Data from this study were combined with previously published thermal time constants for alligators providing regression equations for alligators ranging from 37 g to 103 kg. Regression equations for alligators tested in water are: tau w = 8.81 M050 tau c = 12.6 M0.62. Time constants (tau) are in minutes (w = warming, c = cooling) with all measurements in stirred water; mass, M, is in kg. Thermal conductance and metabolism data are combined to provide an estimate of the amount the body temperature of theoretical alligators ranging from 50 g to 1000 kg would be elevated by metabolism. A body temperature of 34.2 degrees C is predicted for a 1000 kg theoretical alligator in 30 degrees C water.

  13. Membrane remodeling during reticulocyte maturation

    PubMed Central

    Liu, Jing; Guo, Xinhua; Mohandas, Narla; Chasis, Joel A.

    2010-01-01

    The transition of reticulocytes into erythrocytes is accompanied by extensive changes in the structure and properties of the plasma membrane. These changes include an increase in shear resistance, loss of surface area, and acquisition of a biconcave shape. The processes by which these changes are effected have remained largely undefined. Here we examine how the expression of 30 distinct membrane proteins and their interactions change during murine reticulocyte maturation. We show that tubulin and cytosolic actin are lost, whereas the membrane content of myosin, tropomyosin, intercellular adhesion molecule-4, glucose transporter-4, Na-K-ATPase, sodium/hydrogen exchanger 1, glycophorin A, CD47, Duffy, and Kell is reduced. The degradation of tubulin and actin is, at least in part, through the ubiquitin-proteasome degradation pathway. In regard to the protein-protein interactions, the formation of membrane-associated spectrin tetramers from dimers is unperturbed, whereas the interactions responsible for the formation of the membrane-skeletal junctions are weaker in reticulocytes, as is the attachment of transmembrane proteins to these structures. This weakness, in part, results from the elevated phosphorylation of 4.1R in reticulocytes, which leads to a decrease in shear resistance by reducing its interaction with spectrin and actin. These observations begin to unravel the mechanistic basis of crucial changes accompanying reticulocyte maturation. PMID:20038785

  14. Sexual maturation in kokanee Oncorhynchus nerka

    USGS Publications Warehouse

    Patterson, S.D.; Scarnecchia, D.L.; Congleton, J.L.

    2008-01-01

    We used observational and experimental approaches to obtain information on factors affecting the timing of maturation of kokanee Oncorhynchus nerka, a semelparous, landlocked salmon. Gonadal staging criteria were developed and applied to three kokanee populations in Idaho lakes and reservoirs. Testes were classified into three stages: immature (stage one, S1), maturing (S2), and mature (S3). Ovaries were classified into eight stages: immature (S1-S3), transitional (stage S4), maturing (S5-S7), and mature (S8). Males entered the maturing stage (S2) in February through April of the spawning year. Females entered maturing stage (S5) as early as July of the year before the spawning year, and as late as March of the spawning year. Three hatchery experiments demonstrated that attainment of a larger body size 10 to 16 months before spawning increased the likelihood of initiation of maturation in both sexes. No gonads in a state of regression were observed. A gonadosomatic index above 0.1 by early July was a good indicator of a maturing male, and a gonadosomatic index above 1.0 by early July was a good indicator of a maturing female. Instantaneous growth rates were not good predictors of maturation, but attaining a size threshold of 18 to 19 cm in the fall was a good predictor of maturation the following year. This improved knowledge of kokanee maturation will permit more effectively management of the species for age, growth and size at maturity as well as for contributions to fisheries. ?? 2008 by the Northwest Scientific Association. All rights reserved.

  15. Magnetic-seeding filtration

    SciTech Connect

    Depaoli, D.

    1996-10-01

    This task will investigate the capabilities of magnetic-seeding filtration for the enhanced removal of magnetic and nonmagnetic particulates from liquids. This technology appies to a wide range of liquid wastes, including groundwater, process waters, and tank supernatant. Magnetic-seeding filtration can be used in several aspects of treatment, such as (1) removal of solids, particularly those in the colloidal-size range that are difficult to remove by conventional means; (2) removal of contaminants by precipitation processes; and (3) removal of contaminants by sorption processes.

  16. Reprogramming of Seed Metabolism Facilitates Pre-harvest Sprouting Resistance of Wheat

    PubMed Central

    Liu, Caixiang; Ding, Feng; Hao, Fuhua; Yu, Men; Lei, Hehua; Wu, Xiangyu; Zhao, Zhengxi; Guo, Hongxiang; Yin, Jun; Wang, Yulan; Tang, Huiru

    2016-01-01

    Pre-harvest sprouting (PHS) is a worldwide problem for wheat production and transgene antisense-thioredoxin-s (anti-trx-s) facilitates outstanding resistance. To understand the molecular details of PHS resistance, we analyzed the metabonomes of the transgenic and wild-type (control) wheat seeds at various stages using NMR and GC-FID/MS. 60 metabolites were dominant in these seeds including sugars, organic acids, amino acids, choline metabolites and fatty acids. At day-20 post-anthesis, only malate level in transgenic wheat differed significantly from that in controls whereas at day-30 post-anthesis, levels of amino acids and sucrose were significantly different between these two groups. For mature seeds, most metabolites in glycolysis, TCA cycle, choline metabolism, biosynthesis of proteins, nucleotides and fatty acids had significantly lower levels in transgenic seeds than in controls. After 30-days post-harvest ripening, most metabolites in transgenic seeds had higher levels than in controls including amino acids, sugars, organic acids, fatty acids, choline metabolites and NAD+. These indicated that anti-trx-s lowered overall metabolic activities of mature seeds eliminating pre-harvest sprouting potential. Post-harvest ripening reactivated the metabolic activities of transgenic seeds to restore their germination vigor. These findings provided essential molecular phenomic information for PHS resistance of anti-trx-s and a credible strategy for future developing PHS resistant crops. PMID:26860057

  17. Reprogramming of Seed Metabolism Facilitates Pre-harvest Sprouting Resistance of Wheat

    NASA Astrophysics Data System (ADS)

    Liu, Caixiang; Ding, Feng; Hao, Fuhua; Yu, Men; Lei, Hehua; Wu, Xiangyu; Zhao, Zhengxi; Guo, Hongxiang; Yin, Jun; Wang, Yulan; Tang, Huiru

    2016-02-01

    Pre-harvest sprouting (PHS) is a worldwide problem for wheat production and transgene antisense-thioredoxin-s (anti-trx-s) facilitates outstanding resistance. To understand the molecular details of PHS resistance, we analyzed the metabonomes of the transgenic and wild-type (control) wheat seeds at various stages using NMR and GC-FID/MS. 60 metabolites were dominant in these seeds including sugars, organic acids, amino acids, choline metabolites and fatty acids. At day-20 post-anthesis, only malate level in transgenic wheat differed significantly from that in controls whereas at day-30 post-anthesis, levels of amino acids and sucrose were significantly different between these two groups. For mature seeds, most metabolites in glycolysis, TCA cycle, choline metabolism, biosynthesis of proteins, nucleotides and fatty acids had significantly lower levels in transgenic seeds than in controls. After 30-days post-harvest ripening, most metabolites in transgenic seeds had higher levels than in controls including amino acids, sugars, organic acids, fatty acids, choline metabolites and NAD+. These indicated that anti-trx-s lowered overall metabolic activities of mature seeds eliminating pre-harvest sprouting potential. Post-harvest ripening reactivated the metabolic activities of transgenic seeds to restore their germination vigor. These findings provided essential molecular phenomic information for PHS resistance of anti-trx-s and a credible strategy for future developing PHS resistant crops.

  18. Fiber and seed loss from seed cotton cleaning machinery

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fiber and seed loss from seed cotton cleaning equipment in cotton gins occurs, but the quantity of material lost, factors affecting fiber and seed loss, and the mechanisms that cause material loss are not well understood. Two experiments were conducted to evaluate the effects of different factors on...

  19. Multiple seeds sensitivity using a single seed with threshold.

    PubMed

    Egidi, Lavinia; Manzini, Giovanni

    2015-08-01

    Spaced seeds are a fundamental tool for similarity search in biosequences. The best sensitivity/selectivity trade-offs are obtained using many seeds simultaneously: This is known as the multiple seed approach. Unfortunately, spaced seeds use a large amount of memory and the available RAM is a practical limit to the number of seeds one can use simultaneously. Inspired by some recent results on lossless seeds, we revisit the approach of using a single spaced seed and considering two regions homologous if the seed hits in at least t sufficiently close positions. We show that by choosing the locations of the don't care symbols in the seed using quadratic residues modulo a prime number, we derive single seeds that when used with a threshold t > 1 have competitive sensitivity/selectivity trade-offs, indeed close to the best multiple seeds known in the literature. In addition, the choice of the threshold t can be adjusted to modify sensitivity and selectivity a posteriori, thus enabling a more accurate search in the specific instance at issue. The seeds we propose also exhibit robustness and allow flexibility in usage.

  20. Asparagine slows down the breakdown of storage lipid and degradation of autophagic bodies in sugar-starved embryo axes of germinating lupin seeds.

    PubMed

    Borek, Sławomir; Paluch-Lubawa, Ewelina; Pukacka, Stanisława; Pietrowska-Borek, Małgorzata; Ratajczak, Lech

    2017-02-01

    The research was conducted on embryo axes of yellow lupin (Lupinus luteus L.), white lupin (Lupinus albus L.) and Andean lupin (Lupinus mutabilis Sweet), which were isolated from imbibed seeds and cultured for 96h in vitro under different conditions of carbon and nitrogen nutrition. Isolated embryo axes were fed with 60mM sucrose or were sugar-starved. The effect of 35mM asparagine (a central amino acid in the metabolism of germinating lupin seeds) and 35mM nitrate (used as an inorganic kind of nitrogen) on growth, storage lipid breakdown and autophagy was investigated. The sugar-starved isolated embryo axes contained more total lipid than axes fed with sucrose, and the content of this storage compound was even higher in sugar-starved isolated embryo axes fed with asparagine. Ultrastructural observations showed that asparagine significantly slowed down decomposition of autophagic bodies, and this allowed detailed analysis of their content. We found peroxisomes inside autophagic bodies in cells of sugar-starved Andean lupin embryo axes fed with asparagine, which led us to conclude that peroxisomes may be degraded during autophagy in sugar-starved isolated lupin embryo axes. One reason for the slower degradation of autophagic bodies was the markedly lower lipolytic activity in axes fed with asparagine.

  1. Physical View of Cloud Seeding

    ERIC Educational Resources Information Center

    Tribus, Myron

    1970-01-01

    Reviews experimental data on various aspects of climate control. Includes a discussion of (1) the physics of cloud seeding, (2) the applications of cloud seeding, and (3) the role of statistics in the field of weather modification. Bibliography. (LC)

  2. Development of the Potential for Cyanogenesis in Maturing Black Cherry (Prunus serotina Ehrh.) Fruits 1

    PubMed Central

    Swain, Elisabeth; Li, Chun Ping; Poulton, Jonathan E.

    1992-01-01

    Biochemical changes related to cyanogenesis (hydrogen cyanide production) were monitored during maturation of black cherry (Prunus serotina Ehrh.) fruits. At weekly intervals from flowering until maturity, fruits (or selected parts thereof) were analyzed for (a) fresh and dry weights, (b) prunasin and amygdalin levels, and (c) levels of the catabolic enzymes amygdalin hydrolase, prunasin hydrolase, and mandelonitrile lyase. During phase I (0-28 days after flowering [DAF]), immature fruits accumulated prunasin (mean: 3 micromoles/fruit) but were acyanogenic because they lacked the above enzymes. Concomitant with cotyledon development during mid-phase II, the seeds began accumulating both amygdalin (mean: 3 micromoles/seed) and the catabolic enzymes and were highly cyanogenic upon tissue disruption. Meanwhile, prunasin levels rapidly declined and were negligible by maturity. During phases II (29-65 DAF) and III (66-81 DAF), the pericarp also accumulated amygdalin, whereas its prunasin content declined toward maturity. Lacking the catabolic enzymes, the pericarp remained acyanogenic throughout all developmental stages. ImagesFigure 2Figure 4 PMID:16668810

  3. Novel seed adaptations of a monocotyledon seagrass in the wavy sea.

    PubMed

    Soong, Keryea; Chiu, Shau-Ting; Chen, Ching-Nen Nathan

    2013-01-01

    Returning to the sea, just like invasion of land, has occurred in many groups of animals and plants. For flowering plants, traits adapted to the terrestrial environments have to change or adopt a new function to allow the plants to survive and prosper in the sea where water motion tends to rotate and move seeds. In this investigation, how seeds of the seagrass Thalassia hemprichii (Hydrocharitaceae), a common monocotyledon in the Indo-Pacific, adapt to the wavy environment was studied. Mature seeds were collected from Dongsha Atoll in South China Sea. The effects of light qualities on seed germination, the seed morphology, the unipolar distribution of starch granules in the endosperms and growth of root hair-like filamentous cells from basal surface of the seeds were all found to differ from those of terrestrial monocotyledons. Physiologically, germination of the seeds was stimulated by blue light rather than red light. Morphologically, the bell-shaped seeds coupled with the unipolar distribution of starch granules in the enlarged bases helped maintain their upright posture on the tidal seafloor. Growth of root hair-like filamentous cells from the basal surface of the seeds prior to primary root growth served to attach onto sediments, providing leverage and attachment required by the primary roots to insert into sediments. These filamentous cells grasped coral sand but not silicate sand, demonstrating a habitat preference of this species.

  4. Global 5-methylcytosine alterations in DNA during ageing of Quercus robur seeds

    PubMed Central

    Michalak, Marcin; Plitta-Michalak, Beata P.; Naskręt-Barciszewska, Mirosława; Barciszewski, Jan; Bujarska-Borkowska, Barbara; Chmielarz, Paweł

    2015-01-01

    Background and Aims Epigenetic regulation plays an important role in the management of plant growth, development and response to stress factors, and several reports have indicated that DNA methylation plays a critical role in seed development and viability. This study examines changes in 5-methylcytosine (m5C) levels in the DNA of seeds during ageing, a process that has important implications for plant conservation and agriculture. Methods Changes in the global level of m5C were measured in mature seeds of oak, Quercus robur. The extent of DNA methylation was measured using a protocol based on two-dimensional thin-layer chromatography. Viability of seeds was determined by germination and seedling emergence tests. Key Results An ageing-related decrease in total m5C during storage of recalcitrant seeds was highly and significantly correlated with a decrease in seed viability, as reflected by a reduction in germination (r = 0·8880) and seedling emergence (r = 0·8269). Conclusions The decrease in viability during ageing of Q. robur seeds is highly correlated with a global decline in the amount of m5C in genomic DNA, and it is possible that this may represent a typical response to ageing and senescence in recalcitrant seeds. Potential mechanisms that drive changes in genomic DNA methylation during ageing are discussed, together with their implications for seed viability. PMID:26133690

  5. Modelling phenolic and technological maturities of grapes by means of the multivariate relation between organoleptic and physicochemical properties.

    PubMed

    Meléndez, E; Ortiz, M C; Sarabia, L A; Íñiguez, M; Puras, P

    2013-01-25

    The ripeness of grapes at the harvest time is one of the most important parameters for obtaining high quality red wines. Traditionally the decision of harvesting is to be taken only after analysing sugar concentration, titratable acidity and pH of the grape juice (technological maturity). However, these parameters only provide information about the pulp ripeness and overlook the real degree of skins and seeds maturities (phenolic maturity). Both maturities, technological and phenolic, are not simultaneously reached, on the contrary they tend to separate depending on several factors: grape variety, cultivar, adverse weather conditions, soil, water availability and cultural practices. Besides, this divergence is increasing as a consequence of the climate change (larger quantities of CO(2), less rain, and higher temperatures). 247 samples collected in vineyards representative of the qualified designation of origin Rioja from 2007 to 2011 have been analysed. Samples contain the four grape varieties usual in the elaboration of Rioja wines ('tempranillo', 'garnacha', 'mazuelo' and 'graciano'). The present study is the first systematic investigation on the maturity of grapes that includes the organoleptic evaluation of the degree of grapes maturity (sugars/acidity maturity, aromatic maturity of the pulp, aromatic maturity of the skins and tannins maturity) together with the values of the physicochemical parameters (probable alcohol degree, total acidity, pH, malic acid, K, total index polyphenolics, anthocyans, absorbances at 420, 520 and 620 nm, colour index and tartaric acid) determined over the same samples. A varimax rotation of the latent variables of a PLS model between the physicochemical variables and the mean of four sensory variables allows identifying both maturities. Besides, the position of the samples in the first plane defines the effect that the different factors exert on both phenolic and technological maturities.

  6. Effects of pollination limitation and seed predation on female reproductive success of a deceptive orchid.

    PubMed

    Walsh, Ryan P; Arnold, Paige M; Michaels, Helen J

    2014-06-09

    For many species of conservation significance, multiple factors limit reproduction. This research examines the contributions of plant height, number of flowers, number of stems, pollen limitation and seed predation to female reproductive success in the deceit-pollinated orchid, Cypripedium candidum. The deceptive pollination strategy employed by many orchids often results in high levels of pollen limitation. While increased floral display size may attract pollinators, C. candidum's multiple, synchronously flowering stems could promote selfing and also increase attack by weevil seed predators. To understand the joint impacts of mutualists and antagonists, we examined pollen limitation, seed predation and the effects of pollen source over two flowering seasons (2009 and 2011) in Ohio. In 2009, 36 pairs of plants size-matched by flower number, receiving either supplemental hand or open pollination, were scored for fruit maturation, mass of seeds and seed predation. Pollen supplementation increased proportion of flowers maturing into fruit, with 87 % fruit set when hand pollinated compared with 46 % for naturally pollinated flowers. Inflorescence height had a strong effect, as taller inflorescences had higher initial fruit set, while shorter stems had higher predation. Seed predation was seen in 73 % of all fruits. A parallel 2011 experiment that included a self-pollination treatment and excluded seed predators found initial and final fruit set were higher in the self and outcross pollination treatments than in the open-pollinated treatment. However, seed mass was higher in both open pollinated and outcross pollination treatments compared with hand self-pollinated. We found greater female reproductive success for taller flowering stems that simultaneously benefited from increased pollination and reduced seed predation. These studies suggest that this species is under strong reinforcing selection to increase allocation to flowering stem height. Our results may help

  7. Effects of pollination limitation and seed predation on female reproductive success of a deceptive orchid

    PubMed Central

    Walsh, Ryan P.; Arnold, Paige M.; Michaels, Helen J.

    2014-01-01

    For many species of conservation significance, multiple factors limit reproduction. This research examines the contributions of plant height, number of flowers, number of stems, pollen limitation and seed predation to female reproductive success in the deceit-pollinated orchid, Cypripedium candidum. The deceptive pollination strategy employed by many orchids often results in high levels of pollen limitation. While increased floral display size may attract pollinators, C. candidum's multiple, synchronously flowering stems could promote selfing and also increase attack by weevil seed predators. To understand the joint impacts of mutualists and antagonists, we examined pollen limitation, seed predation and the effects of pollen source over two flowering seasons (2009 and 2011) in Ohio. In 2009, 36 pairs of plants size-matched by flower number, receiving either supplemental hand or open pollination, were scored for fruit maturation, mass of seeds and seed predation. Pollen supplementation increased proportion of flowers maturing into fruit, with 87 % fruit set when hand pollinated compared with 46 % for naturally pollinated flowers. Inflorescence height had a strong effect, as taller inflorescences had higher initial fruit set, while shorter stems had higher predation. Seed predation was seen in 73 % of all fruits. A parallel 2011 experiment that included a self-pollination treatment and excluded seed predators found initial and final fruit set were higher in the self and outcross pollination treatments than in the open-pollinated treatment. However, seed mass was higher in both open pollinated and outcross pollination treatments compared with hand self-pollinated. We found greater female reproductive success for taller flowering stems that simultaneously benefited from increased pollination and reduced seed predation. These studies suggest that this species is under strong reinforcing selection to increase allocation to flowering stem height. Our results may help

  8. Modelling long-distance seed dispersal in heterogeneous landscapes.

    SciTech Connect

    Levey, Douglas, J.; Tewlsbury, Joshua, J.; Bolker, Benjamin, M.

    2008-01-01

    1. Long-distance seed dispersal is difficult to measure, yet key to understanding plant population dynamics and community composition. 2. We used a spatially explicit model to predict the distribution of seeds dispersed long distances by birds into habitat patches of different shapes. All patches were the same type of habitat and size, but varied in shape. They occurred in eight experimental landscapes, each with five patches of four different shapes, 150 m apart in a matrix of mature forest. The model was parameterized with smallscale movement data collected from field observations of birds. In a previous study we validated the model by testing its predictions against observed patterns of seed dispersal in real landscapes with the same types and spatial configuration of patches as in the model. 3. Here we apply the model more broadly, examining how patch shape influences the probability of seed deposition by birds into patches, how dispersal kernels (distributions of dispersal distances) vary with patch shape and starting location, and how movement of seeds between patches is affected by patch shape. 4. The model predicts that patches with corridors or other narrow extensions receive higher numbers of seeds than patches without corridors or extensions. This pattern is explained by edgefollowing behaviour of birds. Dispersal distances are generally shorter in heterogeneous landscapes (containing patchy habitat) than in homogeneous landscapes, suggesting that patches divert the movement of seed dispersers, ‘holding’ them long enough to increase the probability of seed defecation in the patches. Dispersal kernels for seeds in homogeneous landscapes were smooth, whereas those in heterogenous landscapes were irregular. In both cases, long-distance (> 150 m) dispersal was surprisingly common, usually comprising approximately 50% of all dispersal events. 5. Synthesis . Landscape heterogeneity has a large influence on patterns of long-distance seed dispersal. Our

  9. Corridors cause differential seed predation.

    SciTech Connect

    Orrock, John L.; Damschen, Ellen I.

    2005-06-01

    Orrock, John, L., and Ellen I. Damschen. 2005. Corridors cause differential seed predation. Ecol. Apps. 15(3):793-798. Abstract. Corridors that connect disjunct populations are heavily debated in conservation, largely because the effects of corridors have rarely been evaluated by replicated, large-scale studies. Using large-scale experimental landscapes, we found that, in addition to documented positive effects, corridors also have negative impacts on bird-dispersed plants by affecting seed predation, and that overall predation is a function of the seeds primary consumer (rodents or arthropods). Both large-seeded Prunus serotina and small-seeded Rubus allegheniensis experienced greater predation in connected patches. However, P. serotina experienced significantly less seed predation compared to R. allegheniensis in unconnected patches, due to decreased impacts of rodent seed predators on this large-seeded species. Viewed in light of previous evidence that corridors have beneficial impacts by increasing pollination and seed dispersal, this work demonstrates that corridors may have both positive and negative effects for the same plant species at different life stages. Moreover, these effects may differentially affect plant species within the same community: seeds primarily consumed by rodents suffer less predation in unconnected patches. By shifting the impact of rodent and arthropod seed predators, corridors constructed for plant conservation could lead to shifts in the seed bank.

  10. Seeds: A Celebration of Science.

    ERIC Educational Resources Information Center

    Melton, Bob

    The Space Exposed Experiment Developed for Students (SEEDS) Project offered science classes at the 5-12 and college levels the opportunity to conduct experiments involving tomato seeds that had been space-exposed over long periods of time. SEEDS kits were complete packages obtained from the National Aeronautics and Space Administration (NASA) for…

  11. Maturation of the MOUTh Intervention

    PubMed Central

    Jablonski-Jaudon, Rita A.; Kolanowski, Ann M.; Winstead, Vicki; Jones-Townsend, Corteza; Azuero, Andres

    2016-01-01

    The purpose of the current article is to describe a personalized practice originally conceived as a way to prevent and minimize care-resistant behavior to provide mouth care to older adult with dementia. The original intervention, Managing Oral Hygiene Using Threat Reduction Strategies (MOUTh), matured during the clinical trial study into a relationship-centered intervention with emphasis on developing strategies that support residents behavioral health and staff involved in care. Relationships that were initially pragmatic (i.e., focused on the task of completing mouth care) developed into more personal and responsive relationships that involved deeper engagement between mouth care providers and nursing home (NH) residents. Mouth care was accomplished and completed in a manner enjoyable to NH residents and mouth care providers. The MOUTh intervention may also concurrently affirm the dignity and personhood of the care recipient because of its emphasis on connecting with older adults. PMID:26934969

  12. The SEED Initiative

    ERIC Educational Resources Information Center

    Teich, Carolyn R.

    2011-01-01

    Committed to fulfilling the promise of the green economy, the American Association of Community Colleges (AACC) launched the Sustainability Education and Economic Development (SEED) initiative (www.theseedcenter.org) in October 2010. The project advances sustainability and clean energy workforce development practices at community colleges by…

  13. The Seeds of Change.

    ERIC Educational Resources Information Center

    Viola, Herman J.

    1991-01-01

    Discusses "Seeds of Change," a Columbian quincentenary exhibition at the Smithsonian Institution. Describes the rapid transformation of the Americas after contact with the Europeans. Reports that the exhibit explores the destruction of the native population by disease, war, slavery, the ongoing decimation of the rain forest, and the…

  14. Seed cotton unloading systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this article was to review the literature and describe the current technology used by U.S. cotton gins for seed cotton unloading. Unloading systems supply the gin with raw material. Their essential functions are 1) to remove non-cotton materials such as protective covers used duri...

  15. Magnetic-seeding filtration

    SciTech Connect

    DePaoli, D.W.; Tsouris, C.; Yiacoumi, Sotira

    1997-10-01

    Magnetic-seeding filtration is a technology under development for the enhanced removal of magnetic and non-magnetic particulates from liquids. This process involves the addition of a small amount of magnetic seed particles (such as naturally occurring iron oxide) to a waste suspension, followed by treatment with a magnetic filter. Non-magnetic and weakly magnetic particles are made to undergo nonhomogeneous flocculation with the seed particles, forming flocs of high magnetic susceptibility that are readily removed by a conventional high-gradient magnetic filter. This technology is applicable to a wide range of liquid wastes, including groundwater, process waters, and tank supernatants. Magnetic-seeding filtration may be used in several aspects of treatment, such as (1) removal of solids, particularly those in the colloidal size range that are difficult to remove by conventional means; (2) removal of contaminants by precipitation processes; and (3) removal of contaminants by sorption processes. Waste stream characteristics for which the technology may be applicable include (1) particle sizes ranging from relatively coarse (several microns) to colloidal particles, (2) high or low radiation levels, (3) broad-ranging flow rates, (4) low to moderate solids concentration, (5) cases requiring high decontamination factors, and (6) aqueous or non-aqueous liquids. At this point, the technology is at the bench-scale stage of development; laboratory studies and fundamental modeling are currently being employed to determine the capabilities of the process.

  16. The coexistence of acorns with different maturation patterns explains acorn production variability in cork oak.

    PubMed

    Pons, Josep; Pausas, Juli G

    2012-07-01

    In dry areas such as Mediterranean ecosystems, fluctuations in seed production are typically explained by resource (water) availability. However, acorn production in cork oak (Quercus suber) populations shows a very low relationship to weather. Because cork oak trees produce acorns with different maturation patterns (annual and biennial), we hypothesized that acorn production in coexisting individuals with a different dominant acorn maturation type should respond differently to climatic factors and that disaggregating the trees according to their acorn-maturation pattern should provide a more proximal relation to weather factors. We assessed acorn production variability in fragmented cork oak populations of the eastern Iberian Peninsula by counting the total number of acorns in 155 trees during an 8-year period. An initial assessment of acorn production variability in relation to weather parameters yielded very low explained variance (7%). However, after the trees were grouped according to their dominant acorn maturation pattern, weather parameters were found to account for 44% of the variability in acorn crops, with trees with annual acorns exhibiting mast fruiting in years with reduced spring frost and shorter summer droughts and trees with biennial acorns showing the opposite pattern. Thus, conditions that negatively affect annual production could be beneficial for biennial production (and vice versa). The results highlight the importance of the resource-matching hypothesis for explaining acorn production in Quercus suber and suggest that different seed maturation types within a population may allow the species to deal with highly variable weather conditions. They also emphasize the importance of understanding acorn maturation patterns for interpreting masting cycles.

  17. Tree Seed Technology Training Course: Student Outline.

    ERIC Educational Resources Information Center

    Bonner, F. T.; And Others

    This manual is intended primarily to train seed collectors, seed-plant managers, seed analysts, and nursery managers, but can serve as a resource for any training course in forest regeneration. It includes both temperate and tropical tree species of all intended uses and covers the following topics: seed biology, seed collection, seed handling,…

  18. 7 CFR 201.15 - Weed seeds.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 3 2012-01-01 2012-01-01 false Weed seeds. 201.15 Section 201.15 Agriculture... REGULATIONS Labeling Agricultural Seeds § 201.15 Weed seeds. The percentage of weed seeds shall include seeds of plants considered weeds in the State into which the seed is offered for transportation...

  19. 7 CFR 201.15 - Weed seeds.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Weed seeds. 201.15 Section 201.15 Agriculture... REGULATIONS Labeling Agricultural Seeds § 201.15 Weed seeds. The percentage of weed seeds shall include seeds of plants considered weeds in the State into which the seed is offered for transportation...

  20. 7 CFR 201.15 - Weed seeds.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 3 2014-01-01 2014-01-01 false Weed seeds. 201.15 Section 201.15 Agriculture... REGULATIONS Labeling Agricultural Seeds § 201.15 Weed seeds. The percentage of weed seeds shall include seeds of plants considered weeds in the State into which the seed is offered for transportation...

  1. 7 CFR 201.15 - Weed seeds.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false Weed seeds. 201.15 Section 201.15 Agriculture... REGULATIONS Labeling Agricultural Seeds § 201.15 Weed seeds. The percentage of weed seeds shall include seeds of plants considered weeds in the State into which the seed is offered for transportation...

  2. 7 CFR 201.15 - Weed seeds.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Weed seeds. 201.15 Section 201.15 Agriculture... REGULATIONS Labeling Agricultural Seeds § 201.15 Weed seeds. The percentage of weed seeds shall include seeds of plants considered weeds in the State into which the seed is offered for transportation...

  3. 7 CFR 201.30 - Hard seed.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Hard seed. 201.30 Section 201.30 Agriculture..., Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling Vegetable Seeds § 201.30 Hard seed. The label shall show the percentage of hard seed,...

  4. Seed germination and life history syndromes in the California chaparral

    USGS Publications Warehouse

    Keeley, J.E.

    1991-01-01

    -refractory seed syndrome, includes species that are resilient to frequent fires (mostly by vegetative resprouting), but require fire-free periods for recruiting new seedlings. Included are shrubs, subshrubs, suffrutescents, lianas, geophytes and annuals. All are linked by the characteristic that their seeds germinate in the absence of cues related to wildfires. In many cases no form of seed dormancy is present and the seeds germinate soon after dispersal; consequently these species do not accumulate a persistent seed bank. Germination and seedling establishment is independent of fire and thus opportunities for population expansion are also independent of fire. The demographic pattern of seedling recruitment varies with the life form. For shrubs, seedling recruitment may be restricted to sites free of fire for periods of a hundred years or more. Recruitment appears to require relatively mesic conditions and this may account for the patchy distribution of these species within the matrix of relatively arid sites. Finding such sites has selected for propagules specialized for wind or animal dispersal; the majority are bird dispersed. These shrub species all disperse fruits in fall and winter and this may have been selected to take advantage of migratory birds as well as to time dispersal to the winter rains typical of the mediterranean-climate. Germination typically occurs within several weeks of the first fall or winter rains. Maturation of flowers and fruits during the summer and fall drought may account for the distribution of these species on more mesic sites. Seed mass of these species is large and this may have been selected to provide an advantage to seedlings establishing under the canopy of this dense shrub community.

  5. Embryo development in association with asymbiotic seed germination in vitro of Paphiopedilum armeniacum S. C. Chen et F. Y. Liu

    PubMed Central

    Zhang, Yan-Yan; Wu, Kun-Lin; Zhang, Jian-Xia; Deng, Ru-Fang; Duan, Jun; Teixeira da Silva, Jaime A.; Huang, Wei-Chang; Zeng, Song-Jun

    2015-01-01

    This paper documents the key anatomical features during the development of P. armeniacum zygotic embryos and their ability to germinate asymbiotically in vitro. This study also examines the effect of media and seed pretreatments on seed germination and subsequent seedling growth. Seeds collected from pods 45 days after pollination (DAP) did not germinate while 95 DAP seeds displayed the highest seed germination percentage (96.2%). Most seedlings (50%) developed to stage 5 from 110 DAP seeds whose compact testa had not yet fully formed. Suspensor cells were vacuolated, which enabled the functional uptake of nutrients. The optimum basal medium for seed germination and subsequent protocorm development was eighth-strength Murashige and Skoog (1/8MS) for 95 DAP seeds and ¼MS for 110 DAP seeds. Poor germination was displayed by 140 DAP seeds with a compact testa. Pretreatment of dry mature seeds (180 DAP) with 1.0% sodium hypochlorite solution for 90 min or 40 kHz of ultrasound for 8 min improved germination percentage from 0 to 29.2% or to 19.7%, respectively. Plantlets that were at least 5 cm in height were transplanted to a Zhijing stone substrate for orchids, and 85.3% of plantlets survived 180 days after transplanting. PMID:26559888

  6. Effects of abscisic acid, ethylene and sugars on the mobilization of storage proteins and carbohydrates in seeds of the tropical tree Sesbania virgata (Leguminosae)

    PubMed Central

    Tonini, Patricia Pinho; Purgatto, Eduardo; Buckeridge, Marcos Silveira

    2010-01-01

    Background and Aims Endospermic legumes are abundant in tropical forests and their establishment is closely related to the mobilization of cell-wall storage polysaccharides. Endosperm cells also store large numbers of protein bodies that play an important role as a nitrogen reserve in this seed. In this work, a systems approach was adopted to evaluate some of the changes in carbohydrates and hormones during the development of seedlings of the rain forest tree Sesbania virgata during the period of establishment. Methods Seeds imbibed abscisic acid (ABA), glucose and sucrose in an atmosphere of ethylene, and the effects of these compounds on the protein contents, α-galactosidase activity and endogenous production of ABA and ethylene by the seeds were observed. Key Results The presence of exogenous ABA retarded the degradation of storage protein in the endosperm and decreased α-galactosidase activity in the same tissue during galactomannan degradation, suggesting that ABA represses enzyme action. On the other hand, exogenous ethylene increased α-galactosidase activity in both the endosperm and testa during galactomannan degradation, suggesting an inducing effect of this hormone on the hydrolytic enzymes. Furthermore, the detection of endogenous ABA and ethylene production during the period of storage mobilization and the changes observed in the production of these endogenous hormones in the presence of glucose and sucrose, suggested a correlation between the signalling pathway of these hormones and the sugars. Conclusions These findings suggest that ABA, ethylene and sugars play a role in the control of the hydrolytic enzyme activities in seeds of S. virgata, controlling the process of storage degradation. This is thought to ensure a balanced flow of the carbon and nitrogen for seedling development. PMID:20705626

  7. Enviromental Effects on Oleic Acid in Soybean Seed Oil of Plant Introductions with Elevated Oleic Concentration

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soybean [Glycine max (L.) Merr.] oil with oleic acid content >500 g per kg is desirable for a broader role in food and industrial uses. Seed oil in commercially grown soybean genotypes averages about 230 g per kg oleic acid (18:1). Some maturity group (MG) II to V plant introductions (PIs) have el...

  8. A simulation model for epidemics of stem rust in ryegrass seed crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A simulation model (STEMRUST_G, named for stem rust of grasses) was created for stem rust (caused by Puccinia graminis subsp. graminicola) in perennial ryegrass grown to maturity as a seed crop. The model has a daily time step and is driven by weather data and an initial input of disease severity fr...

  9. Seed production from Aeschynomene genetic resources rescued and regenerated using aeroponics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Jointvetch (Aeschynomene americana L. or A. americana L. var. americana) and A. villosa Poir. var. villosa are legumes used for cover cropping and forage. These accessions require a very long growing season and do not produce mature seed before the first hard freezes in Griffin, GA. This study was c...

  10. Optimizing IV and V for Mature Organizations

    NASA Technical Reports Server (NTRS)

    Fuhman, Christopher

    2003-01-01

    NASA is intending for its future software development agencies to have at least a Level 3 rating in the Carnegie Mellon University Capability Maturity Model (CMM). The CMM has built-in Verification and Validation (V&V) processes that support higher software quality. Independent Verification and Validation (IV&V) of software developed by mature agencies can be therefore more effective than for software developed by less mature organizations. How is Independent V&V different with respect to the maturity of an organization? Knowing a priori the maturity of an organization's processes, how can IV&V planners better identify areas of need choose IV&V activities, etc? The objective of this research is to provide a complementary set of guidelines and criteria to assist the planning of IV&V activities on a project using a priori knowledge of the measurable levels of maturity of the organization developing the software.

  11. Seed priming to alleviate salinity stress in germinating seeds.

    PubMed

    Ibrahim, Ehab A

    2016-03-15

    Salinity is one of the major abiotic stresses that affect crop production in arid and semiarid areas. Seed germination and seedling growth are the stages most sensitive to salinity. Salt stress causes adverse physiological and biochemical changes in germinating seeds. It can affect the seed germination and stand establishment through osmotic stress, ion-specific effects and oxidative stress. The salinity delays or prevents the seed germination through various factors, such as a reduction in water availability, changes in the mobilization of stored reserves and affecting the structural organization of proteins. Various techniques can improve emergence and stand establishment under salt conditions. One of the most frequently utilized is seed priming. The process of seed priming involves prior exposure to an abiotic stress, making a seed more resistant to future exposure. Seed priming stimulates the pre-germination metabolic processes and makes the seed ready for radicle protrusion. It increases the antioxidant system activity and the repair of membranes. These changes promote seed vigor during germination and emergence under salinity stress. The aim of this paper is to review the recent literature on the response of plants to seed priming under salinity stress. The mechanism of the effect of salinity on seed germination is discussed and the seed priming process is summarized. Physiological, biochemical and molecular changes induced by priming that lead to seed enhancement are covered. Plants' responses to some priming agents under salinity stress are reported based on the best available data. For a great number of crops, little information exists and further research is needed.

  12. [Grain filling dynamics and germination characteristics of Bupleurum chinense seeds].

    PubMed

    Jin, Xin; Ren, Bing; Cao, Ai-Nong; Jin, Xiao-Jun

    2014-10-01

    Bupleurum chinense used in the study were cultivated in the experimental fields of Gansu agricultural University for three years. The seeds of B. chinense were collected every 3 days 10 d after the blossom. The result showed that the 1 000-grain fresh weight reached the maximum 43 d after the blossom and then decreased rapidly, at the mature period the fresh weight of seeds were falling to the same level of the dry weight. The dynamic change of the grain dry matter accumulation showed as an S-shape curve, the rapid increase stage was 25-34 d following the flower, and the grain filling was ended 46 d after blossom. Grain filling rate was under the law "fast-slow-fast-slow". And there were two peaks of grain filling rate appeared, after reached the second peak 28 d after the flower the filling rate decreased rapidly and stayed steadily 43 d after flowering. The dehydration rate was also measured at its maximum 43 d following flower. The indexes of seeds all reached the top 52 days following the blossom, when the germination rate reached the peak (34.33%) and water content of seeds was near 10%. The rate of germination and the 1 000-graid weight of seed showed significant positive correlation, while the water content of seeds was found significant negatively correlation with germination percentage. So the best time for harvest should be 52 d after flowering (9 month), the seeds collected at that time showed both high quality and germination rate.

  13. Crop protection by seed coating.

    PubMed

    Ehsanfar, S; Modarres-Sanavy, S A M

    2005-01-01

    Providence of sufficient and healthy food for increasing human population clears the importance of notice to increasing crop production in company with environmental loss reduction. Growth and yield of every plant with sexual reproduction, depends on germination & emergence of sown seeds. Seed is a small alive plant that its biological function is protection and nutrition of embryo. Biological, chemical and physiological characteristics of seed, affect on plant performance & its resistance to undesirable environmental conditions, and even on its total yield. So attention to seed and try to increase its performance is so important. One of the factors that cause reduction in germination percentage and seedling establishment, is seed disease. It's possible to control these diseases by treating the seed before planting it. Coating the seed with pesticides, is one of the ways to gain this goal. Seed coating is a technique in which several material as fertilizers, nutritional elements, moisture attractive or repulsive agents, plant growth regulators, rhizobium inocolum, chemical & pesticide etc, add to seed by adhesive agents and cause to increase seed performance and germination. Seed coating, leads to increase benefits in seed industry, because seeds can use all of their genetic vigor. This technique is used for seeds of many garden plants, valuable crops (such as corn, sunflower, canola, alfalfa,...) and some of the grasses. In this technique that was first used in coating cereal seeds in 1930, a thin and permeable layer of pesticide is stuck on seed surface and prevent damage of seedborn pathogens. This layer is melted or splited after absorption of moisture and suitable temperature by seed, and let the radical to exit the seed. In this approach materials are used accurately with seed, evaporation & leakage of pesticide and also adverse effects of some pesticides on seeds are diminished, and these factors cause to increase the accuracy and performance of pesticide

  14. A Genome-wide Combinatorial Strategy Dissects Complex Genetic Architecture of Seed Coat Color in Chickpea

    PubMed Central

    Bajaj, Deepak; Das, Shouvik; Upadhyaya, Hari D.; Ranjan, Rajeev; Badoni, Saurabh; Kumar, Vinod; Tripathi, Shailesh; Gowda, C. L. Laxmipathi; Sharma, Shivali; Singh, Sube; Tyagi, Akhilesh K.; Parida, Swarup K.

    2015-01-01

    The study identified 9045 high-quality SNPs employing both genome-wide GBS- and candidate gene-based SNP genotyping assays in 172, including 93 cultivated (desi and kabuli) and 79 wild chickpea accessions. The GWAS in a structured population of 93 sequenced accessions detected 15 major genomic loci exhibiting significant association with seed coat color. Five seed color-associated major genomic loci underlying robust QTLs mapped on a high-density intra-specific genetic linkage map were validated by QTL mapping. The integration of association and QTL mapping with gene haplotype-specific LD mapping and transcript profiling identified novel allelic variants (non-synonymous SNPs) and haplotypes in a MATE secondary transporter gene regulating light/yellow brown and beige seed coat color differentiation in chickpea. The down-regulation and decreased transcript expression of beige seed coat color-associated MATE gene haplotype was correlated with reduced proanthocyanidins accumulation in the mature seed coats of beige than light/yellow brown seed colored desi and kabuli accessions for their coloration/pigmentation. This seed color-regulating MATE gene revealed strong purifying selection pressure primarily in LB/YB seed colored desi and wild Cicer reticulatum accessions compared with the BE seed colored kabuli accessions. The functionally relevant molecular tags identified have potential to decipher the complex transcriptional regulatory gene function of seed coat coloration and for understanding the selective sweep-based seed color trait evolutionary pattern in cultivated and wild accessions during chickpea domestication. The genome-wide integrated approach employed will expedite marker-assisted genetic enhancement for developing cultivars with desirable seed coat color types in chickpea. PMID:26635822

  15. 7 CFR 201.33 - Seed in bulk or large quantities; seed for cleaning or processing.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Seed in bulk or large quantities; seed for cleaning or... (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling in General § 201.33 Seed in bulk or large quantities; seed for cleaning or processing. (a) In the case of seed in bulk, the information required...

  16. Skeletal maturation determined by cervical vertebrae development.

    PubMed

    San Román, Paloma; Palma, Juan Carlos; Oteo, M Dolores; Nevado, Esther

    2002-06-01

    The aim of this study was to determine the validity of cervical vertebrae radiographic assessment to predict skeletal maturation. Left hand-wrist and lateral cephalometric radiographs of 958 Spanish children from 5 to 18 years of age were measured. On the left hand-wrist radiographs the classification of Grave and Brown was used to assess skeletal maturation. Cervical vertebrae maturation was evaluated with lateral cephalometric radiographs using the stages described by Lamparski and by Hassel and Farman. A new method to evaluate the cervical maturation by studying the changes in the concavity of the lower border, height, and shape of the vertebral body was created. Correlation coefficients were calculated to establish the relationship between skeletal maturation values obtained by the three classifications of vertebral and skeletal maturation measured at the wrist. All correlation values obtained were statistically significant (P < 0.001). The results suggest that this new method to determine skeletal maturation is very reliable. A simple method based on morphological characteristics of the cervical vertebral bodies to evaluate the maturation stage has been designed. In the population investigated, this method is as accurate as the Hassel and Farman classification and superior to the Lamparski classification. The morphological vertebral parameter best able to estimate the maturation is the concavity of the lower border of the body.

  17. 7 CFR 51.1865 - Mature.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF 1946... contents of two or more seed cavities have developed a jelly-like consistency and the seeds are...

  18. 7 CFR 51.1865 - Mature.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF 1946... contents of two or more seed cavities have developed a jelly-like consistency and the seeds are...

  19. European marketable grain legume seeds: Further insight into phenolic compounds profiles.

    PubMed

    Magalhães, Sara C Q; Taveira, Marcos; Cabrita, Ana R J; Fonseca, António J M; Valentão, Patrícia; Andrade, Paula B

    2017-01-15

    Twenty-nine mature raw varieties of grain legume seeds (chickpeas, field peas, faba beans, common vetch and lupins) produced in Europe were investigated for their phenolic profile by means of high performance liquid chromatography coupled to diode array detection (HPLC-DAD). To the best of our knowledge, this study reported for the first time the phenolic composition of mature raw seeds of chickpea type Desi, field pea and common vetch. Phenolic acids were predominant compounds in chickpeas, field peas and common vetch compared to flavonoids, whereas the opposite was observed for lupin seeds. Yellow lupins presented the highest levels of total phenolic compounds followed by narrow-leafed lupins (in average 960 and 679mg/kg, dry basis, respectively), whereas Kabuli chickpeas got the lowest ones (in average 47mg/kg, dry basis). Principal component analysis revealed that flavones and total levels of phenolic compounds were responsible for nearly 51% of total data variability.

  20. Empty seeds are not always bad: simultaneous effect of seed emptiness and masting on animal seed predation.

    PubMed

    Perea, Ramón; Venturas, Martin; Gil, Luis

    2013-01-01

    Seed masting and production of empty seeds have often been considered independently as different strategies to reduce seed predation by animals. Here, we integrate both phenomena within the whole assemblage of seed predators (both pre and post-dispersal) and in two contrasting microsites (open vs. sheltered) to improve our understanding of the factors controlling seed predation in a wind-dispersed tree (Ulmus laevis). In years with larger crop sizes more avian seed predators were attracted with an increase in the proportion of full seeds predated on the ground. However, for abundant crops, the presence of empty seeds decreased the proportion of full seeds predated. Empty seeds remained for a very long period in the tree, making location of full seeds more difficult for pre-dispersal predators and expanding the overall seed drop period at a very low cost (in dry biomass and allocation of C, N and P). Parthenocarpy (non-fertilized seeds) was the main cause of seed emptiness whereas seed abortion was produced in low quantity. These aborted seeds fell prematurely and, thus, could not work as deceptive seeds. A proportion of 50% empty seeds significantly reduced ground seed predation by 26%. However, a high rate of parthenocarpy (beyond 50% empty seeds) did not significantly reduce seed predation in comparison to 50% empty seeds. We also found a high variability and unpredictability in the production of empty seeds, both at tree and population level, making predator deception more effective. Open areas were especially important to facilitate seed survival since rodents (the main post-dispersal predators) consumed seeds mostly under shrub cover. In elm trees parthenocarpy is a common event that might work as an adaptive strategy to reduce seed predation. Masting per se did not apparently reduce the overall proportion of seeds predated in this wind-dispersed tree, but kept great numbers of seeds unconsumed.

  1. Empty Seeds Are Not Always Bad: Simultaneous Effect of Seed Emptiness and Masting on Animal Seed Predation

    PubMed Central

    Perea, Ramón; Venturas, Martin; Gil, Luis

    2013-01-01

    Seed masting and production of empty seeds have often been considered independently as different strategies to reduce seed predation by animals. Here, we integrate both phenomena within the whole assemblage of seed predators (both pre and post-dispersal) and in two contrasting microsites (open vs. sheltered) to improve our understanding of the factors controlling seed predation in a wind-dispersed tree (Ulmus laevis). In years with larger crop sizes more avian seed predators were attracted with an increase in the proportion of full seeds predated on the ground. However, for abundant crops, the presence of empty seeds decreased the proportion of full seeds predated. Empty seeds remained for a very long period in the tree, making location of full seeds more difficult for pre-dispersal predators and expanding the overall seed drop period at a very low cost (in dry biomass and allocation of C, N and P). Parthenocarpy (non-fertilized seeds) was the main cause of seed emptiness whereas seed abortion was produced in low quantity. These aborted seeds fell prematurely and, thus, could not work as deceptive seeds. A proportion of 50% empty seeds significantly reduced ground seed predation by 26%. However, a high rate of parthenocarpy (beyond 50% empty seeds) did not significantly reduce seed predation in comparison to 50% empty seeds. We also found a high variability and unpredictability in the production of empty seeds, both at tree and population level, making predator deception more effective. Open areas were especially important to facilitate seed survival since rodents (the main post-dispersal predators) consumed seeds mostly under shrub cover. In elm trees parthenocarpy is a common event that might work as an adaptive strategy to reduce seed predation. Masting per se did not apparently reduce the overall proportion of seeds predated in this wind-dispersed tree, but kept great numbers of seeds unconsumed. PMID:23776503

  2. Dynamics of exogenous nitrogen partitioning and nitrogen remobilization from vegetative organs in pea revealed by 15N in vivo labeling throughout seed filling.

    PubMed

    Schiltz, Séverine; Munier-Jolain, Nathalie; Jeudy, Christian; Burstin, Judith; Salon, Christophe

    2005-04-01

    The fluxes of (1) exogenous nitrogen (N) assimilation and (2) remobilization of endogenous N from vegetative plant compartments were measured by 15N labeling during the seed-filling period in pea (Pisum sativum L. cv Cameor), to better understand the mechanism of N remobilization. While the majority (86%) of exogenous N was allocated to the vegetative organs before the beginning of seed filling, this fraction decreased to 45% at the onset of seed filling, the remainder being directed to seeds. Nitrogen remobilization from vegetative parts contributed to 71% of the total N in mature seeds borne on the first two nodes (first stratum). The contribution of remobilized N to total seed N varied, with the highest proportion at the beginning of filling; it was independent of the developmental stage of each stratum of seeds, suggesting that remobilized N forms a unique pool, managed at the whole-plant level and supplied to all filling seeds whatever their position on the plant. Once seed filling starts, N is remobilized from all vegetative organs: 30% of the total N accumulated in seeds was remobilized from leaves, 20% from pod walls, 11% from roots, and 10% from stems. The rate of N remobilization was maximal when seeds of all the different strata were filling, consistent with regulation according to the N demand of seeds. At later stages of seed filling, the rate of remobilization decreases and may become controlled by the amount of residual N in vegetative tissues.

  3. Dynamics of Exogenous Nitrogen Partitioning and Nitrogen Remobilization from Vegetative Organs in Pea Revealed by 15N in Vivo Labeling throughout Seed Filling1

    PubMed Central

    Schiltz, Séverine; Munier-Jolain, Nathalie; Jeudy, Christian; Burstin, Judith; Salon, Christophe

    2005-01-01

    The fluxes of (1) exogenous nitrogen (N) assimilation and (2) remobilization of endogenous N from vegetative plant compartments were measured by 15N labeling during the seed-filling period in pea (Pisum sativum L. cv Caméor), to better understand the mechanism of N remobilization. While the majority (86%) of exogenous N was allocated to the vegetative organs before the beginning of seed filling, this fraction decreased to 45% at the onset of seed filling, the remainder being directed to seeds. Nitrogen remobilization from vegetative parts contributed to 71% of the total N in mature seeds borne on the first two nodes (first stratum). The contribution of remobilized N to total seed N varied, with the highest proportion at the beginning of filling; it was independent of the developmental stage of each stratum of seeds, suggesting that remobilized N forms a unique pool, managed at the whole-plant level and supplied to all filling seeds whatever their position on the plant. Once seed filling starts, N is remobilized from all vegetative organs: 30% of the total N accumulated in seeds was remobilized from leaves, 20% from pod walls, 11% from roots, and 10% from stems. The rate of N remobilization was maximal when seeds of all the different strata were filling, consistent with regulation according to the N demand of seeds. At later stages of seed filling, the rate of remobilization decreases and may become controlled by the amount of residual N in vegetative tissues. PMID:15793068

  4. The Effect of TRANSPARENT TESTA2 on Seed Fatty Acid Biosynthesis and Tolerance to Environmental Stresses during Young Seedling Establishment in Arabidopsis1[W][OA

    PubMed Central

    Chen, Mingxun; Wang, Zhong; Zhu, Yana; Li, Zhilan; Hussain, Nazim; Xuan, Lijie; Guo, Wanli; Zhang, Guoping; Jiang, Lixi

    2012-01-01

    In plants, fatty acids (FAs) and FA-derived complex lipids are major carbon and energy reserves in seeds. They are essential components of cellular membranes and cellular signal or hormone molecules. Although TRANSPARENT TESTA2 (TT2) is well studied for its function in regulating proanthocyanidin biosynthesis in the seed coat, little attention has been given to its role in affecting seed FA accumulation and tolerance to environmental stresses. We demonstrate that the tt2 mutation remarkably increased the seed FA content, decreased seed weight, and altered the FA composition. The increase in FA content in the tt2 seeds was due to the relative decrease of seed coat proportion as well as the more efficient FA synthesis in the tt2 embryo. Microarray analysis revealed that tt2 mutation up-regulated a group of genes critical to FA biosynthesis and embryonic development. The mutation also altered the gene expressions that respond to stress. The microarray analysis discovered that the increase in FA accumulation of the tt2 seeds were accompanied by the significant up-regulation of FUSCA3, a transcriptional factor for embryonic development and FATTY ACID ELONGASE1, which catalyzes the elongation of FA chains. Moreover, lower seed protein accumulation during seed maturation also contributed to the increased seed FA accumulation in tt2 mutants. This study advances the understanding of the TT2 gene in seed FA accumulation and abiotic stresses during seed germination and seedling establishment. PMID:22879396

  5. Smart Grid Interoperability Maturity Model

    SciTech Connect

    Widergren, Steven E.; Levinson, Alex; Mater, J.; Drummond, R.

    2010-04-28

    The integration of automation associated with electricity resources (including transmission and distribution automation and demand-side resources operated by end-users) is key to supporting greater efficiencies and incorporating variable renewable resources and electric vehicles into the power system. The integration problems faced by this community are analogous to those faced in the health industry, emergency services, and other complex communities with many stakeholders. To highlight this issue and encourage communication and the development of a smart grid interoperability community, the GridWise Architecture Council (GWAC) created an Interoperability Context-Setting Framework. This "conceptual model" has been helpful to explain the importance of organizational alignment in addition to technical and informational interface specifications for "smart grid" devices and systems. As a next step to building a community sensitive to interoperability, the GWAC is investigating an interoperability maturity model (IMM) based on work done by others to address similar circumstances. The objective is to create a tool or set of tools that encourages a culture of interoperability in this emerging community. The tools would measure status and progress, analyze gaps, and prioritize efforts to improve the situation.

  6. Seed-to-seed-to-seed growth and development of Arabidopsis in microgravity.

    PubMed

    Link, Bruce M; Busse, James S; Stankovic, Bratislav

    2014-10-01

    Arabidopsis thaliana was grown from seed to seed wholly in microgravity on the International Space Station. Arabidopsis plants were germinated, grown, and maintained inside a growth chamber prior to returning to Earth. Some of these seeds were used in a subsequent experiment to successfully produce a second (back-to-back) generation of microgravity-grown Arabidopsis. In general, plant growth and development in microgravity proceeded similarly to those of the ground controls, which were grown in an identical chamber. Morphologically, the most striking feature of space-grown Arabidopsis was that the secondary inflorescence branches and siliques formed nearly perpendicular angles to the inflorescence stems. The branches grew out perpendicularly to the main inflorescence stem, indicating that gravity was the key determinant of branch and silique angle and that light had either no role or a secondary role in Arabidopsis branch and silique orientation. Seed protein bodies were 55% smaller in space seed than in controls, but protein assays showed only a 9% reduction in seed protein content. Germination rates for space-produced seed were 92%, indicating that the seeds developed in microgravity were healthy and viable. Gravity is not necessary for seed-to-seed growth of plants, though it plays a direct role in plant form and may influence seed reserves.

  7. Seed-to-Seed-to-Seed Growth and Development of Arabidopsis in Microgravity

    PubMed Central

    Link, Bruce M.; Busse, James S.

    2014-01-01

    Abstract Arabidopsis thaliana was grown from seed to seed wholly in microgravity on the International Space Station. Arabidopsis plants were germinated, grown, and maintained inside a growth chamber prior to returning to Earth. Some of these seeds were used in a subsequent experiment to successfully produce a second (back-to-back) generation of microgravity-grown Arabidopsis. In general, plant growth and development in microgravity proceeded similarly to those of the ground controls, which were grown in an identical chamber. Morphologically, the most striking feature of space-grown Arabidopsis was that the secondary inflorescence branches and siliques formed nearly perpendicular angles to the inflorescence stems. The branches grew out perpendicularly to the main inflorescence stem, indicating that gravity was the key determinant of branch and silique angle and that light had either no role or a secondary role in Arabidopsis branch and silique orientation. Seed protein bodies were 55% smaller in space seed than in controls, but protein assays showed only a 9% reduction in seed protein content. Germination rates for space-produced seed were 92%, indicating that the seeds developed in microgravity were healthy and viable. Gravity is not necessary for seed-to-seed growth of plants, though it plays a direct role in plant form and may influence seed reserves. Key Words: Arabidopsis—Branch—Inflorescence—Microgravity—Morphology—Seed—Space. Astrobiology 14, 866–875. PMID:25317938

  8. Correct Targeting of the Bean Storage Protein Phaseolin in the Seeds of Transformed Tobacco 1

    PubMed Central

    Greenwood, John S.; Chrispeels, Maarten J.

    1985-01-01

    The storage protein phaseolin accumulates during seed development in protein bodies in cotyledons of the common bean Phaseolus vulgaris. Hall et al. (In L Van Vloten-Doting, TC Hall, eds, Molecular Form and Function of the Plant Genome, 1985 Plenum Press, In press) recently reported the expression of a gene coding for phaseolin and the accumulation of phaseolin protein in developing seeds of tobacco plants regenerated from transformed callus cells. The protein did not accumulate in other organs of the plants. Mature seeds from normal and transformed tobacco plants were obtained and the subcellular distribution of phaseolin in the seeds was examined using both light and electron microscopic immunocytochemical methods. Phaseolin was found in six of seven transformed tobacco embryos examined, but was present in only one endosperm of five. When present, phaseolin was located exclusively in the protein bodies of the embryonic and endospermic cells. Furthermore, phaseolin was restricted solely to the amorphous matrix of the protein bodies and was excluded from the globoid and proteinaceous crystalloid components of these organelles. The subcellular location of phaseolin in seeds from transformed tobacco plants is similar to that seen in mature seeds of the common bean indicating that in the transformed cells the protein is targeted to the right subcellular compartment. Images Fig. 1 Fig. 2 Fig. 3 PMID:16664403

  9. Aflatoxin contamination of pearl millet during field and storage conditions with reference to stage of grain maturation and insect damage.

    PubMed

    Raghavender, C R; Reddy, B N; Shobharani, G

    2007-12-01

    Aflatoxin contamination in five varieties of pearl millet (ICMH-451, ICMP-50I, ICTP-8203, WCC-75 and ICMV-155) was studied from field and storage conditions in three districts of Andhra Pradesh State, India and the inter-relationships between various parameters such as stage of grain maturation in the field and insect pest infestation in storage in relation to aflatoxin production were evaluated. Aflatoxin contamination was more frequent in the seed samples collected from the fields during rainy season than winter season. All major aflatoxins were isolated from one or the other varieties of pearl millet, whereas aflatoxin G2 was not commonly observed in the seed samples collected during winter. Among all the varieties tested, ICMH-451 was vulnerable to aflatoxin contamination whereas ICMV-155 was the least susceptible variety. The higher amount of aflatoxins was observed in the matured seed samples followed by pre-matured and milky stage. Among all the toxins reported in the field, aflatoxin B1 was found in higher concentration (185 (μg/kg) followed by B2 (105 μg/kg). The four major types of aflatoxins with higher levels (35, 40, 140, 190 μg/kg of G1, G2, B2, B1 were reported in the rainy season seed samples after six months of storage, whereas aflatoxin G1 was not observed in any variety of stored seed sample from winter. Statistical analysis revealed that the aflatoxin incidence in relation to different parameters studied was significantly different for each factor. The relationship between aflatoxin contamination and insect damaged-grain clearly indicated that the seed samples with 16-40% of insect damage contained higher amounts of aflatoxins (758 μg/kg).

  10. Seed Dormancy in Red Rice (Oryza sativa) (IX. Embryo Fructose-2,6-Bisphosphate during Dormancy Breaking and Subsequent Germination).

    PubMed Central

    Footitt, S.; Cohn, M. A.

    1995-01-01

    Fructose-2,6-bisphosphate (Fru-2,6-bisP) was evaluated as a potential marker for the dormancy-breaking phase or the germination phase before pericarp splitting in red rice (Oryza sativa). During 4 h of imbibition at 30[deg]C, Fru-2,6-bisP of dehulled dormant and nondormant seeds increased to 0.26 and 0.38 pmol embryo-1, respectively. In nondormant seeds, embryo Fru-2,6-bisP content remained stable until the onset of pericarp splitting (12 h) and increased rapidly thereafter. In dormant seeds, Fru-2,6-bisP declined to 0.09 pmol embryo-1 at 24 h. Embryo Fru-2,6-bisP was correlated with O2 uptake of dormant and nondormant seeds. A 24-h exposure of dehulled, water-imbibed, dormant seeds to treatments yielding >90% germination (sodium nitrite [4 mM], propionic acid [22 mM], methyl propionate [32 mM], propanol [75 mM], and propionaldehyde [40 mM]) led to changes in embryo Fru-2,6-bisP that were unrelated to the final germination percentages. Furthermore, a 2-h pulse of propionaldehyde increased Fru-2,6-bisP 4-fold but did not break dormancy. Whereas nitrite and propionaldehyde increased Fru-2,6-bisP to 0.33 pmol embryo-1 after 2 h of contact, propionic acid and methyl propionate did not increase Fru-2,6-bisP above the untreated control. In all cases, further increases in Fru-2,6-bisP occurred after pericarp splitting. However, the plateau Fru-2,6-bisP attained during chemical contact was inversely correlated with elapsed time to 30% germination (r = -0.978). Therefore, although Fru-2,6-bisP is not a universal marker for dormancy release, its rapid increase during nitrite and propionaldehyde treatments suggests that events associated with dormancy breaking can occur within 2 h of chemical treatment. PMID:12228440

  11. 7 CFR 51.312 - Mature.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ..., CERTIFICATION, AND STANDARDS) United States Standards for Grades of Apples Definitions § 51.312 Mature. “Mature” means that the apples have reached the stage of development which will insure the proper completion of the ripening process. Before a mature apple becomes overripe it will show varying degrees of...

  12. 7 CFR 51.312 - Mature.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ..., CERTIFICATION, AND STANDARDS) United States Standards for Grades of Apples Definitions § 51.312 Mature. “Mature” means that the apples have reached the stage of development which will insure the proper completion of the ripening process. Before a mature apple becomes overripe it will show varying degrees of...

  13. The Mature Woman and the Community College

    ERIC Educational Resources Information Center

    Elliot, Jeffrey M.; Mantz, Concetta M.

    1976-01-01

    The factors and motivations contributing to the presence of increasing numbers of mature women in college are examined, and seven proposals are offered, representing an attempt to develop a total community college program which will meet the needs of mature women students. (NHM)

  14. Quantifying Semantic Linguistic Maturity in Children

    ERIC Educational Resources Information Center

    Hansson, Kristina; Bååth, Rasmus; Löhndorf, Simone; Sahlén, Birgitta; Sikström, Sverker

    2016-01-01

    We propose a method to quantify "semantic linguistic maturity" (SELMA) based on a high dimensional semantic representation of words created from the co-occurrence of words in a large text corpus. The method was applied to oral narratives from 108 children aged 4;0-12;10. By comparing the SELMA measure with maturity ratings made by human…

  15. 7 CFR 29.6026 - Maturity.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Maturity. 29.6026 Section 29.6026 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... INSPECTION Standards Definitions § 29.6026 Maturity. The degree of ripeness. (See chart.)...

  16. New definitions for cotton fiber maturity ratio

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cotton fiber maturity affects fiber physical, mechanical, and chemical properties, as well as the processability and qualities of yarn and fabrics. New definitions of cotton fiber maturity ratio are introduced. The influences of sampling, sample preparation, measurement method, and correlations am...

  17. Thinned Mature Deciduous Forest Silvopastures for Appalachia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Little information is available on effective management and utilization of silvopastures developed from the ubiquitous mature woodlots which comprise 40-50% of small Appalachian farm acreage. We thinned a white oak dominated mature second growth forested area establishing two 0.5 ha, eight-paddock,...

  18. Canopy temperature and maturity in cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Heat units are a widely used indicator of maturity in cotton. It is generally assumed that it takes approximately 2200°F (1222°C) heat units for a cotton plant on the South High Plains of Texas to mature. This value is based on a typical planting date of May 15 with ample irrigation. As water for c...

  19. Motivation and Maturity Patterns in Marital Success.

    ERIC Educational Resources Information Center

    McClelland, David C.; And Others

    1978-01-01

    Married couples rated their marital satisfaction and played interpersonal competitive games which revealed the success with which they interacted. Younger husbands who scored more maturely on the Stewart measure of psychosocial maturity belonged to more successful marriages, as did college-educated wives who showed less immaturity and more phallic…

  20. 24 CFR 200.82 - Maturity.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... GENERAL INTRODUCTION TO FHA PROGRAMS Requirements for Application, Commitment, and Endorsement Generally... Requirements for Existing Projects Mortgage Provisions § 200.82 Maturity. The mortgage shall have a maturity... included under the applicable section of the Act. (2) Thirty-five years for existing projects, except...

  1. 24 CFR 200.82 - Maturity.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... GENERAL INTRODUCTION TO FHA PROGRAMS Requirements for Application, Commitment, and Endorsement Generally... Requirements for Existing Projects Mortgage Provisions § 200.82 Maturity. The mortgage shall have a maturity... included under the applicable section of the Act. (2) Thirty-five years for existing projects, except...

  2. Toward the Measurement of Psychosocial Maturity.

    ERIC Educational Resources Information Center

    Greenberger, Ellen; And Others

    The concept of psychosocial maturity is reviewed in preparation for the exploration of the feasibility of constructing a scale that measures maturity. Investigation produced a preliminary 54-item scale with high reliability and moderate validity, which is appended. A factor analysis of the scale supports the a priori structure by the theoretical…

  3. The FMI: Dimensions of Follower Maturity

    ERIC Educational Resources Information Center

    Moore, Loren I.

    1976-01-01

    The Follower Maturity Index (FMI) is an instrument derived from leadership theory and based on observations of verbal and nonverbal behavior of followers in task groups. Dimensions of follower maturity--achievement, responsibility, experience, activity, dependence, variety, interests, perspective, position, and awareness--are discussed. For…

  4. 7 CFR 1421.101 - Maturity dates.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS GRAINS AND SIMILARLY HANDLED COMMODITIES-MARKETING ASSISTANCE LOANS AND LOAN DEFICIENCY PAYMENTS FOR 2008 THROUGH 2012 Marketing Assistance Loans § 1421.101 Maturity dates. (a)(1) All marketing assistance loans shall mature on demand by CCC and no later than...

  5. 7 CFR 1421.101 - Maturity dates.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS GRAINS AND SIMILARLY HANDLED COMMODITIES-MARKETING ASSISTANCE LOANS AND LOAN DEFICIENCY PAYMENTS FOR 2008 THROUGH 2012 Marketing Assistance Loans § 1421.101 Maturity dates. (a)(1) All marketing assistance loans shall mature on demand by CCC and no later than...

  6. 7 CFR 1421.101 - Maturity dates.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS GRAINS AND SIMILARLY HANDLED COMMODITIES-MARKETING ASSISTANCE LOANS AND LOAN DEFICIENCY PAYMENTS FOR 2008 THROUGH 2012 Marketing Assistance Loans § 1421.101 Maturity dates. (a)(1) All marketing assistance loans shall mature on demand by CCC and no later than...

  7. 7 CFR 1421.101 - Maturity dates.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS GRAINS AND SIMILARLY HANDLED COMMODITIES-MARKETING ASSISTANCE LOANS AND LOAN DEFICIENCY PAYMENTS FOR 2008 THROUGH 2012 Marketing Assistance Loans § 1421.101 Maturity dates. (a)(1) All marketing assistance loans shall mature on demand by CCC and no later than...

  8. 24 CFR 201.11 - Loan maturities.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Loan maturities. 201.11 Section 201... DEVELOPMENT MORTGAGE AND LOAN INSURANCE PROGRAMS UNDER NATIONAL HOUSING ACT AND OTHER AUTHORITIES TITLE I PROPERTY IMPROVEMENT AND MANUFACTURED HOME LOANS Loan and Note Provisions § 201.11 Loan maturities....

  9. 24 CFR 201.11 - Loan maturities.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 24 Housing and Urban Development 2 2013-04-01 2013-04-01 false Loan maturities. 201.11 Section 201... DEVELOPMENT MORTGAGE AND LOAN INSURANCE PROGRAMS UNDER NATIONAL HOUSING ACT AND OTHER AUTHORITIES TITLE I PROPERTY IMPROVEMENT AND MANUFACTURED HOME LOANS Loan and Note Provisions § 201.11 Loan maturities....

  10. 24 CFR 201.11 - Loan maturities.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 24 Housing and Urban Development 2 2012-04-01 2012-04-01 false Loan maturities. 201.11 Section 201... DEVELOPMENT MORTGAGE AND LOAN INSURANCE PROGRAMS UNDER NATIONAL HOUSING ACT AND OTHER AUTHORITIES TITLE I PROPERTY IMPROVEMENT AND MANUFACTURED HOME LOANS Loan and Note Provisions § 201.11 Loan maturities....

  11. 24 CFR 201.11 - Loan maturities.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 24 Housing and Urban Development 2 2014-04-01 2014-04-01 false Loan maturities. 201.11 Section 201... DEVELOPMENT MORTGAGE AND LOAN INSURANCE PROGRAMS UNDER NATIONAL HOUSING ACT AND OTHER AUTHORITIES TITLE I PROPERTY IMPROVEMENT AND MANUFACTURED HOME LOANS Loan and Note Provisions § 201.11 Loan maturities....

  12. 7 CFR 51.1238 - Mature.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF 1946... Standards for Cleaned Virginia Type Peanuts in the Shell Definitions § 51.1238 Mature. Mature means that...

  13. Deciphering Transcriptional Programming during Pod and Seed Development Using RNA-Seq in Pigeonpea (Cajanus cajan)

    PubMed Central

    Pazhamala, Lekha T.; Agarwal, Gaurav; Bajaj, Prasad; Kumar, Vinay; Kulshreshtha, Akanksha; Saxena, Rachit K.; Varshney, Rajeev K.

    2016-01-01

    Seed development is an important event in plant life cycle that has interested humankind since ages, especially in crops of economic importance. Pigeonpea is an important grain legume of the semi-arid tropics, used mainly for its protein rich seeds. In order to understand the transcriptional programming during the pod and seed development, RNA-seq data was generated from embryo sac from the day of anthesis (0 DAA), seed and pod wall (5, 10, 20 and 30 DAA) of pigeonpea variety “Asha” (ICPL 87119) using Illumina HiSeq 2500. About 684 million sequencing reads have been generated from nine samples, which resulted in the identification of 27,441 expressed genes after sequence analysis. These genes have been studied for their differentially expression, co-expression, temporal and spatial gene expression. We have also used the RNA-seq data to identify important seed-specific transcription factors, biological processes and associated pathways during seed development process in pigeonpea. The comprehensive gene expression study from flowering to mature pod development in pigeonpea would be crucial in identifying candidate genes involved in seed traits directly or indirectly related to yield and quality. The dataset will serve as an important resource for gene discovery and deciphering the molecular mechanisms underlying various seed related traits. PMID:27760186

  14. Modification of AtGRDP1 gene expression affects silique and seed development in Arabidopsis thaliana.

    PubMed

    Rodríguez-Hernández, Aída Araceli; Muro-Medina, Carlos Vladimir; Ramírez-Alonso, Jocelin Itzel; Jiménez-Bremont, Juan Francisco

    2017-03-08

    Glycine Rich Proteins (GRPs) are induced at different developmental stages and in specific plant tissues. Recently, we described a novel Arabidopsis gene encoding a short glycine-rich domain protein (AtGRDP1). This gene is involved in abiotic stress responsiveness; the Atgrdp1-null mutant seeds were more sensitive to stress, while the opposite phenotype was achieved by AtGRDP1 overexpression. In this study, we analyzed the phenotype of the fruits produced by Arabidopsis Atgrdp1 mutants and 35S::AtGRDP1 overexpression lines. Our analyses revealed important changes in silique length, seed number, seed weight and morphology in the analyzed lines. In particular, Atgrdp1 mutant lines exhibited several defects including short siliques, a diminished number of seeds per silique, and reduction in seed size and weight as compared to Col-0. The overexpression of the AtGRDP1 gene also generated phenotypes with alterations in size of silique, number of seeds per silique, and size and weight of seed. In addition, the expression analysis of AtGRDP1 gene showed that it was expressed in floral and fruit organs, with the highest expression level in mature siliques. The alterations in the siliques and seeds traits in the Atgrdp1 mutant line, as well as the phenotypes observed in AtGRDP1 overexpression lines, suggest a role of the AtGRDP1 gene in the Arabidopsis fruit development.

  15. Local climate explains degree of seed dormancy in Hypericum elodes L. (Hypericaceae).

    PubMed

    Carta, A; Probert, R; Puglia, G; Peruzzi, L; Bedini, G

    2016-01-01

    Seed dormancy and germination characteristics may vary within species in response to several factors. Knowledge of such variation is crucial to understand plant evolution and adaptation to environmental changes. We examined the correlation of climate and population genetic differentiation (ISSR) with primary seed dormancy and germination behaviour in populations of the Atlantic-European soft-water pool specialist Hypericum elodes. Primary dormancy was measured by analysing seed germination response of fresh seeds and after various periods of cold stratification. Laboratory germination experiments revealed that the single most important factor for promoting germination was cold stratification prior to placing at the germination temperature. However, in agreement with their weaker primary dormancy, the seeds germinated well when fresh, and the benefit of cold stratification was more relaxed for the southern populations. Seeds of all populations demonstrated a near absolute requirement for a light and alternating temperature regime in order to germinate. The promoting effect of alternating temperatures was particularly effective at warm temperatures (mean 20 °C) but not at cool temperatures. Whilst seed germination requirements were similar among populations, the degree of primary dormancy varied considerably and was not associated with population genetic differentiation. Primary dormancy degree was instead associated with local climate: higher temperature in summer and rainfall in winter predicted weak and rapid loss of dormancy. These results suggest that seed maturation environment may play a substantial role in explaining the degree of dormancy in H. elodes, highlighting that physiological dormancy can be modulated by local climate.

  16. Proteomic Dissection of Seed Germination and Seedling Establishment in Brassica napus.

    PubMed

    Gu, Jianwei; Chao, Hongbo; Gan, Lu; Guo, Liangxing; Zhang, Kai; Li, Yonghong; Wang, Hao; Raboanatahiry, Nadia; Li, Maoteng

    2016-01-01

    The success of seed germination and establishment of a normal seedling are key determinants of plant species propagation. At present, only a few studies have focused on the genetic control of seed germination by using a proteomic approach in Brassica napus. In the present study, the protein expression pattern of seed germination was investigated using differential fluorescence two-dimensional gel electrophoresis in B. napus. One hundred and thirteen differentially expressed proteins (DEPs) that were mainly involved in storage (23.4%), energy metabolism (18.9%), protein metabolism (16.2%), defense/disease (12.6%), seed maturation (11.7%), carbohydrate metabolism (4.5%), lipid metabolism (4.5%), amino acids metabolism (3.6%), cell growth/division (3.6%), and some unclear functions (2.7%) were observed by proteomic analysis. Seventeen genes corresponding to 11 DEPs were identified within or near the associated linkage disequilibrium regions related to seed germination and vigor quantitative traits reported in B. napus in previous studies. The expression pattern of proteins showed that heterotrophic metabolism could be activated in the process of seed germination and that the onset of defense mechanisms might start during seed germination. These findings will help generate a more in-depth understanding of the mobilization of seed storage reserves and regulation mechanisms of the germination process in B. napus.

  17. Proteomic Dissection of Seed Germination and Seedling Establishment in Brassica napus

    PubMed Central

    Gu, Jianwei; Chao, Hongbo; Gan, Lu; Guo, Liangxing; Zhang, Kai; Li, Yonghong; Wang, Hao; Raboanatahiry, Nadia; Li, Maoteng

    2016-01-01

    The success of seed germination and establishment of a normal seedling are key determinants of plant species propagation. At present, only a few studies have focused on the genetic control of seed germination by using a proteomic approach in Brassica napus. In the present study, the protein expression pattern of seed germination was investigated using differential fluorescence two-dimensional gel electrophoresis in B. napus. One hundred and thirteen differentially expressed proteins (DEPs) that were mainly involved in storage (23.4%), energy metabolism (18.9%), protein metabolism (16.2%), defense/disease (12.6%), seed maturation (11.7%), carbohydrate metabolism (4.5%), lipid metabolism (4.5%), amino acids metabolism (3.6%), cell growth/division (3.6%), and some unclear functions (2.7%) were observed by proteomic analysis. Seventeen genes corresponding to 11 DEPs were identified within or near the associated linkage disequilibrium regions related to seed germination and vigor quantitative traits reported in B. napus in previous studies. The expression pattern of proteins showed that heterotrophic metabolism could be activated in the process of seed germination and that the onset of defense mechanisms might start during seed germination. These findings will help generate a more in-depth understanding of the mobilization of seed storage reserves and regulation mechanisms of the germination process in B. napus. PMID:27822216

  18. Legume adaptation to sulfur deficiency revealed by comparing nutrient allocation and seed traits in Medicago truncatula.

    PubMed

    Zuber, Hélène; Poignavent, Germain; Le Signor, Christine; Aimé, Delphine; Vieren, Eric; Tadla, Charlène; Lugan, Raphaël; Belghazi, Maya; Labas, Valérie; Santoni, Anne-Lise; Wipf, Daniel; Buitink, Julia; Avice, Jean-Christophe; Salon, Christophe; Gallardo, Karine

    2013-12-01

    Reductions in sulfur dioxide emissions and the use of sulfur-free mineral fertilizers are decreasing soil sulfur levels and threaten the adequate fertilization of most crops. To provide knowledge regarding legume adaptation to sulfur restriction, we subjected Medicago truncatula, a model legume species, to sulfur deficiency at various developmental stages, and compared the yield, nutrient allocation and seed traits. This comparative analysis revealed that sulfur deficiency at the mid-vegetative stage decreased yield and altered the allocation of nitrogen and carbon to seeds, leading to reduced levels of major oligosaccharides in mature seeds, whose germination was dramatically affected. In contrast, during the reproductive period, sulfur deficiency had little influence on yield and nutrient allocation, but the seeds germinated slowly and were characterized by low levels of a biotinylated protein, a putative indicator of germination vigor that has not been previously related to sulfur nutrition. Significantly, plants deprived of sulfur at an intermediary stage (flowering) adapted well by remobilizing nutrients from source organs to seeds, ensuring adequate quantities of carbon and nitrogen in seeds. This efficient remobilization of photosynthates may be explained by vacuolar sulfate efflux to maintain leaf metabolism throughout reproductive growth, as suggested by transcript and metabolite profiling. The seeds from these plants, deprived of sulfur at the floral transition, contained normal levels of major oligosaccharides but their germination was delayed, consistent with low levels of sucrose and the glycolytic enzymes required to restart seed metabolism during imbibition. Overall, our findings provide an integrative view of the legume response to sulfur deficiency.

  19. Two Faces of One Seed: Hormonal Regulation of Dormancy and Germination.

    PubMed

    Shu, Kai; Liu, Xiao-dong; Xie, Qi; He, Zu-hua

    2016-01-04

    Seed plants have evolved to maintain the dormancy of freshly matured seeds until the appropriate time for germination. Seed dormancy and germination are distinct physiological processes, and the transition from dormancy to germination is not only a critical developmental step in the life cycle of plants but is also important for agricultural production. These processes are precisely regulated by diverse endogenous hormones and environmental cues. Although ABA (abscisic acid) and GAs (gibberellins) are known to be the primary phytohormones that antagonistically regulate seed dormancy, recent findings demonstrate that another phytohormone, auxin, is also critical for inducing and maintaining seed dormancy, and therefore might act as a key protector of seed dormancy. In this review, we summarize our current understanding of the sophisticated molecular networks involving the critical roles of phytohormones in regulating seed dormancy and germination, in which AP2-domain-containing transcription factors play key roles. We also discuss the interactions (crosstalk) of diverse hormonal signals in seed dormancy and germination, focusing on the ABA/GA balance that constitutes the central node.

  20. Expression of 9-cis-EPOXYCAROTENOID DIOXYGENASE4 Is Essential for Thermoinhibition of Lettuce Seed Germination but Not for Seed Development or Stress Tolerance[C][W

    PubMed Central

    Huo, Heqiang; Dahal, Peetambar; Kunusoth, Keshavulu; McCallum, Claire M.; Bradford, Kent J.

    2013-01-01

    Thermoinhibition, or failure of seeds to germinate at warm temperatures, is common in lettuce (Lactuca sativa) cultivars. Using a recombinant inbred line population developed from a lettuce cultivar (Salinas) and thermotolerant Lactuca serriola accession UC96US23 (UC), we previously mapped a quantitative trait locus associated with thermoinhibition of germination to a genomic region containing a gene encoding a key regulated enzyme in abscisic acid (ABA) biosynthesis, 9-cis-EPOXYCAROTENOID DIOXYGENASE4 (NCED4). NCED4 from either Salinas or UC complements seeds of the Arabidopsis thaliana nced6-1 nced9-1 double mutant by restoring germination thermosensitivity, indicating that both NCED4 genes encode functional proteins. Transgenic expression of Salinas NCED4 in UC seeds resulted in thermoinhibition, whereas silencing of NCED4 in Salinas seeds led to loss of thermoinhibition. Mutations in NCED4 also alleviated thermoinhibition. NCED4 expression was elevated during late seed development but was not required for seed maturation. Heat but not water stress elevated NCED4 expression in leaves, while NCED2 and NCED3 exhibited the opposite responses. Silencing of NCED4 altered the expression of genes involved in ABA, gibberellin, and ethylene biosynthesis and signaling pathways. Together, these data demonstrate that NCED4 expression is required for thermoinhibition of lettuce seeds and that it may play additional roles in plant responses to elevated temperature. PMID:23503626

  1. Porosity and Cell Preseeding Influence Electrospun Scaffold Maturation and Meniscus Integration In Vitro

    PubMed Central

    Ionescu, Lara C.

    2013-01-01

    Electrospinning generates fibrous scaffolds ideal for engineering soft orthopedic tissues. By modifying the electrospinning process, scaffolds with different structural organization and content can be generated. For example, fibers can be aligned in a single direction, or the porosity of the scaffold can be modified through the use of multi-jet electrospinning and the removal of sacrificial fibers. In this work, we investigated the role of fiber alignment and scaffold porosity on construct maturation and integration within in vitro meniscus defects. Further, we explored the effect of preseeding expanded meniscus fibrochondrocytes (MFCs) onto the scaffold at a high density before in vitro repair. Our results demonstrate that highly porous electropun scaffolds integrate better with a native tissue and mature to a greater extent than low-porosity scaffolds, while scaffold alignment does not influence integration or maturation. The addition of expanded MFCs to scaffolds before in vitro repair improved integration with the native tissue, but did not influence maturation. In contrast, preculture of these same scaffolds for 1 month before repair decreased integration with the native tissue, but resulted in a more mature scaffold compared to implantation of cellular scaffolds or acellular scaffolds. This work will inform scaffold selection in future in vivo studies by identifying the ideal scaffold and seeding methods for meniscus tissue engineering. PMID:22994398

  2. Protein repair L-isoaspartyl methyltransferase in plants. Phylogenetic distribution and the accumulation of substrate proteins in aged barley seeds.

    PubMed Central

    Mudgett, M B; Lowenson, J D; Clarke, S

    1997-01-01

    Protein L-isoaspartate (D-aspartate) O-methyltransferases (MTs; EC 2.1.1.77) can initiate the conversion of detrimental L-isoaspartyl residues in spontaneously damaged proteins to normal L-aspartyl residues. We detected this enzyme in 45 species from 23 families repres