Sample records for affect seed germination

  1. EASTERN DODDER (CUSCUTA MONOGYNA VAHL.) SEED GERMINATION AFFECTED BY SOME HERBACEOUS DISTILLATES.

    PubMed

    Movassaghi, M; Hassannejad, S

    2015-01-01

    Eastern dodder (Cuscuta monogyna Vahl.) is one of the noxious parasitic weeds that infected many ornamental trees in green spaces and gardens. Our purpose is to find natural inhibitors for prevention of its seed germination. In order to reach this aim, laboratory studies were conducted by using of herbaceous distillates of Dracocephalum moldavica, Nasturtium officinalis, Malva neglecta, Mentha piperita, Mentha pulegium, Rosa damascene, Ziziphora tenuior, and Urtica dioica on seed germination of C. monogyna. Z. tenuior distillate stimulated C. monogyna seed germination, whereas others reduced this parasitic weed's seed germination. D. moldavica caused maximum inhibition on weed seed germination. Seedling growth of C. monogyna was more affected than its seed germination. All of these herbaceous distillates reduced C. monogyna seedling length so that the latter decreased from 28.2 mm in distilled water to 4.5, 3.97, 3.85, 3.67, 3.1, 2.87, 2.57, 1.9, and 1.17 in M. pulegium, M. piperita, F. officinalis, Z. tenuior, N. officinalis, M. neglecta, R. damascene, U. dioica and D. moldavica, respectively. By using these medicinal plants distillates instead of herbicides, the parasitic weed seedling length and host plant infection will reduce.

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

    PubMed Central

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

    2017-01-01

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

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

    PubMed

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

    2017-01-01

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

  4. Proteomic analysis of tree peony (Paeonia ostii 'Feng Dan') seed germination affected by low temperature.

    PubMed

    Ren, Xiu-Xia; Xue, Jing-Qi; Wang, Shun-Li; Xue, Yu-Qian; Zhang, Ping; Jiang, Hai-Dong; Zhang, Xiu-Xin

    Seed germination is a critical process that is influenced by various factors. In the present study, the effect of low temperature (4 °C) on tree peony seed germination was investigated. Compared to seeds maintained at 25 °C, germination was inhibited when seeds were kept at 4 °C. Furthermore, low-temperature exposure of seeds resulted in a delay in water uptake, starch degradation, and soluble sugar consumption and a subsequent increase in soluble protein levels. Two-dimensional gel electrophoresis (2-DE) proteomic analysis identified 100 protein spots. Comparative analysis indicated that low-temperature exposure apparently mainly affected glycolysis and the tricarboxylic acid (TCA) cycle, while also significantly affecting proteometabolism-related factors. Moreover, low-temperature exposure led to the induction of abscisic acid, whereas the gibberellin pathway was not affected. Further comparison of the two temperature conditions showed that low-temperature exposure delays carbohydrate metabolism, adenosine triphosphate (ATP) production, respiration, and proteolysis and increases defense response factors. To further examine the obtained proteomic findings, four genes were evaluated by quantitative polymerase chain reaction (qPCR). The obtained transcriptional results for the GAPC gene coincided with the translational results, thus further suggesting that the delay in glycolysis may play a key role in low-temperature-induced inhibition of seed germination. However, the other three genes examined, which included FPP synthase, PCNT115, and endochitinase, showed non-correlative transcriptional and translational profiles. Our results suggest that the exposure of tree peony seeds to low temperature results in a delay in the degradation of starch and other metabolites, which in turn affects glycolysis and some other processes, thereby ultimately inhibiting seed germination. Copyright © 2017. Published by Elsevier GmbH.

  5. Optimization of chitosan treatments for managing microflora in lettuce seeds without affecting germination.

    PubMed

    Goñi, M G; Moreira, M R; Viacava, G E; Roura, S I

    2013-01-30

    Many studies have focused on seed decontamination but no one has been capable of eliminating all pathogenic bacteria. Two objectives were followed. First, to assess the in vitro antimicrobial activity of chitosan against: (a) Escherichia coli O157:H7, (b) native microflora of lettuce and (c) native microflora of lettuce seeds. Second, to evaluate the efficiency of chitosan on reducing microflora on lettuce seeds. The overall goal was to find a combination of contact time and chitosan concentration that reduces the microflora of lettuce seeds, without affecting germination. After treatment lettuce seeds presented no detectable microbial counts (<10(2)CFU/50 seeds) for all populations. Moreover, chitosan eliminated E. coli. Regardless of the reduction in the microbial load, a 90% reduction on germination makes imbibition with chitosan, uneconomical. Subsequent treatments identified the optimal treatment as 10 min contact with a 10 g/L chitosan solution, which maintained the highest germination percentage. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. Moisture stress affects germination of longleaf and slash pine seeds

    Treesearch

    James P. Barnett

    1969-01-01

    Osmotic stresses greater than 8 atm markedly reduced germination of both Pinus palustris Mill. P. elliotii Engelm. seeds. At stresses of 18 or more atm, no germination occurred. Moisture content at the onset of germination was twice as high in longleaf as in slash pine seeds.

  7. The Anthelmintic Ingredient Moxidectin Negatively Affects Seed Germination of Three Temperate Grassland Species

    PubMed Central

    Eichberg, Carsten; Wohde, Manuel; Müller, Kerstin; Rausch, Anja; Scherrmann, Christina; Scheuren, Theresa; Düring, Rolf-Alexander; Donath, Tobias W.

    2016-01-01

    In animal farming, anthelmintics are regularly applied to control gastrointestinal nematodes. There is plenty of evidence that also non-target organisms, such as dung beetles, are negatively affected by residues of anthelmintics in faeces of domestic ungulates. By contrast, knowledge about possible effects on wild plants is scarce. To bridge this gap of knowledge, we tested for effects of the common anthelmintic formulation Cydectin and its active ingredient moxidectin on seed germination. We conducted a feeding experiment with sheep and germination experiments in a climate chamber. Three wide-spread plant species of temperate grasslands (Centaurea jacea, Galium verum, Plantago lanceolata) were studied. We found significant influences of both, Cydectin and moxidectin, on germination of the tested species. Across species, both formulation and active ingredient solely led to a decrease in germination percentage and synchrony of germination and an increase in mean germination time with the formulation showing a more pronounced response pattern. Our study shows for the first time that anthelmintics have the potential to negatively affect plant regeneration. This has practical implications for nature conservation since our results suggest that treatments of livestock with anthelmintics should be carefully timed to not impede endozoochorous seed exchange between plant populations. PMID:27846249

  8. Seed colour affects light and temperature requirements during germination in two Lotus species (Fabaceae) of the Arabian subtropical deserts.

    PubMed

    Bhatt, Arvind; Gairola, Sanjay; El-Keblawy, Ali A

    2016-06-01

    Heterogeneity in seeds mostly occurs due to physiological, environmental and genetic factors, and these could affect seed dormancy and germination. Therefore, the aim of our study was to assess the effect of seed colour on germination behavior. For this, both light and temperature requirements were assessed in Lotus glinoides and Lotus halophilus (Fabaceae) from the hyper-arid deserts of the United Arab Emirates. Germination was assessed in terms of both final germination level (percentage) and germination rate, as expressed by Timson’s germination velocity index. Lotus glinoides produces black and yellow-colored seeds, and L. halophilus produces green and yellow seeds. Different seed lots were germinated in both light and darkness at different temperatures. Yellow seeds of the two species attained significantly lower germination, compared to black and green seeds. There was no specific light or temperature requirements for the germination of the two coloured seeds of L. glinoides; the effect of interactions between seed colour and both light and incubation temperature, were not significant on the final germination percentage. In L. halophilus, green seeds germinated significantly more in both light and darkness at lower temperatures (15/25 °C) and in light at higher temperatures (25/35 °C), compared to yellow seeds. Yellow seeds germinated faster, compared to black at 15/25 °C in L. glinoides and compared to green seeds at 15/25 °C and 25/35 °C in L. halophilus. Seed colour variation, at least in L. halophilus, could be a survival strategy that would determine the time of germination throughout the year in the unpredictable desert environment.

  9. Germination season and watering regime, but not seed morph, affect life history traits in a cold desert diaspore-heteromorphic annual.

    PubMed

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

    2014-01-01

    Seed morph, abiotic conditions and time of germination can affect plant fitness, but few studies have tested their combined effects on plasticity of plant life history traits. Thus, we tested the hypothesis that seed morph, germination season and watering regime influence phenotypic expression of post-germination life history traits in the diaspore-heteromorphic cold desert winter annual/spring ephemeral Diptychocarpus strictus. The two seed morphs were sown in watered and non-watered plots in late summer, and plants derived from them were watered or not-watered throughout the study. Seed morph did not affect phenology, growth and morphology, survival, dry mass accumulation and allocation or silique and seed production. Seeds in watered plots germinated in autumn (AW) and spring (SW) but only in spring for non-watered plots (SNW). A high percentage of AW, SW and SNW plants survived and reproduced, but flowering date and flowering period of autumn- vs. spring-germinated plants differed. Dry mass also differed with germination season/watering regime (AW > SW > SNW). Number of siliques and seeds increased with plant size (AW > SW > SNW), whereas percent dry mass allocated to reproduction was higher in small plants: SNW > SW > AW. Thus, although seed morph did not affect the expression of life history traits, germination season and watering regime significantly affected phenology, plant size and accumulation and allocation of biomass to reproduction. Flexibility throughout the life cycle of D. strictus is an adaptation to the variation in timing and amount of rainfall in its cold desert habitat.

  10. Disruptions in valine degradation affect seed development and germination in Arabidopsis.

    PubMed

    Gipson, Andrew B; Morton, Kyla J; Rhee, Rachel J; Simo, Szabolcs; Clayton, Jack A; Perrett, Morgan E; Binkley, Christiana G; Jensen, Erika L; Oakes, Dana L; Rouhier, Matthew F; Rouhier, Kerry A

    2017-06-01

    We have functionally characterized the role of two putative mitochondrial enzymes in valine degradation using insertional mutants. Prior to this study, the relationship between branched-chain amino acid degradation (named for leucine, valine and isoleucine) and seed development was limited to leucine catabolism. Using a reverse genetics approach, we show that disruptions in the mitochondrial valine degradation pathway affect seed development and germination in Arabidopsis thaliana. A null mutant of 3-hydroxyisobutyryl-CoA hydrolase (CHY4, At4g31810) resulted in an embryo lethal phenotype, while a null mutant of methylmalonate semialdehyde dehydrogenase (MMSD, At2g14170) resulted in seeds with wrinkled coats, decreased storage reserves, elevated valine and leucine, and reduced germination rates. These data highlight the unique contributions CHY4 and MMSD make to the overall growth and viability of plants. It also increases our knowledge of the role branched-chain amino acid catabolism plays in seed development and amino acid homeostasis. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

  11. Biorhythms in conifer seed germination during extended storage

    Treesearch

    James P. Barnett; N.I. Marnonov

    1989-01-01

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

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

    PubMed

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

    2012-05-01

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

  13. Wheat miR9678 Affects Seed Germination by Generating Phased siRNAs and Modulating Abscisic Acid/Gibberellin Signaling[OPEN

    PubMed Central

    Sun, Fenglong; Cao, Jie; Huo, Na; Wuda, Bala; Du, Jinkun; Peng, Huiru; Ni, Zhongfu; Sun, Qixin

    2018-01-01

    Seed germination is important for grain yield and quality and rapid, near-simultaneous germination helps in cultivation; however, cultivars that germinate too readily can undergo preharvest sprouting (PHS), which causes substantial losses in areas that tend to get rain around harvest time. Moreover, our knowledge of mechanisms regulating seed germination in wheat (Triticum aestivum) remains limited. In this study, we analyzed function of a wheat-specific microRNA 9678 (miR9678), which is specifically expressed in the scutellum of developing and germinating seeds. Overexpression of miR9678 delayed germination and improved resistance to PHS in wheat through reducing bioactive gibberellin (GA) levels; miR9678 silencing enhanced germination rates. We provide evidence that miR9678 targets a long noncoding RNA (WSGAR) and triggers the generation of phased small interfering RNAs that play a role in the delay of seed germination. Finally, we found that abscisic acid (ABA) signaling proteins bind the promoter of miR9678 precursor and activate its expression, indicating that miR9678 affects germination by modulating the GA/ABA signaling. PMID:29567662

  14. Phytochrome and Seed Germination. V. Changes of Phytochrome Content During the Germination of Cucumber Seeds 1

    PubMed Central

    Mancinelli, Alberto L.; Tolkowsky, Abby

    1968-01-01

    Cucumber seeds are light-sensitive, dark-germinating seeds. Inhibition of germination can be induced by prolonged exposure to continuous or intermittent FR. The dark germination process and the response to FR are phytochrome controlled. Phytochrome can be detected in these seeds by differential spectrophotometry in vivo. Spectrophotometrically measurable phytochrome increases during dark germination. The rate of increase is temperature dependent. Light treatments which are inhibitory for germination result in phytochrome contents lower than those of the seeds germinating in darkness. Treatments which restore germination also restore phytochrome formation. PMID:16656797

  15. Intra-specific downsizing of frugivores affects seed germination of fleshy-fruited plant species

    NASA Astrophysics Data System (ADS)

    Pérez-Méndez, Néstor; Rodríguez, Airam; Nogales, Manuel

    2018-01-01

    The loss of largest-bodied individuals within species of frugivorous animals is one of the major consequences of defaunation. The gradual disappearance of large-bodied frugivores is expected to entail a parallel deterioration in seed dispersal functionality if the remaining smaller-sized individuals are not so effective as seed dispersers. While the multiple impacts of the extinction of large bodied species have been relatively well studied, the impact of intraspecific downsizing (i.e. the extinction of large individuals within species) on seed dispersal has rarely been evaluated. Here we experimentally assessed the impact of body-size reduction in the frugivorous lizard Gallotia galloti (Lacertidae), an endemic species of the Canary Islands, on the seed germination patterns of two fleshy-fruited plant species (Rubia fruticosa and Withania aristata). Seed germination curves and the proportions of germinated seeds were compared for both plant species after being defecated by large-sized individuals and small-sized individuals. The data show that seeds of W. aristata defecated by larger-sized lizards germinated faster and in a higher percentage than those defecated by small-sized lizards, while no differences were found for R. fruticosa seeds. Our results suggest that disappearance of the largest individuals of frugivorous species may impair recruitment of some plant species by worsening seed germination. They also warn us of a potential cryptic loss of seed dispersal functionality on defaunated ecosystems, even when frugivorous species remain abundant.

  16. Different Modes of Hydrogen Peroxide Action During Seed Germination

    PubMed Central

    Wojtyla, Łukasz; Lechowska, Katarzyna; Kubala, Szymon; Garnczarska, Małgorzata

    2016-01-01

    Hydrogen peroxide was initially recognized as a toxic molecule that causes damage at different levels of cell organization and thus losses in cell viability. From the 1990s, the role of hydrogen peroxide as a signaling molecule in plants has also been discussed. The beneficial role of H2O2 as a central hub integrating signaling network in response to biotic and abiotic stress and during developmental processes is now well established. Seed germination is the most pivotal phase of the plant life cycle, affecting plant growth and productivity. The function of hydrogen peroxide in seed germination and seed aging has been illustrated in numerous studies; however, the exact role of this molecule remains unknown. This review evaluates evidence that shows that H2O2 functions as a signaling molecule in seed physiology in accordance with the known biology and biochemistry of H2O2. The importance of crosstalk between hydrogen peroxide and a number of signaling molecules, including plant phytohormones such as abscisic acid, gibberellins, and ethylene, and reactive molecules such as nitric oxide and hydrogen sulfide acting on cell communication and signaling during seed germination, is highlighted. The current study also focuses on the detrimental effects of H2O2 on seed biology, i.e., seed aging that leads to a loss of germination efficiency. The dual nature of hydrogen peroxide as a toxic molecule on one hand and as a signal molecule on the other is made possible through the precise spatial and temporal control of its production and degradation. Levels of hydrogen peroxide in germinating seeds and young seedlings can be modulated via pre-sowing seed priming/conditioning. This rather simple method is shown to be a valuable tool for improving seed quality and for enhancing seed stress tolerance during post-priming germination. In this review, we outline how seed priming/conditioning affects the integrative role of hydrogen peroxide in seed germination and aging. PMID:26870076

  17. Smoke-induced seed germination in California chaparral

    USGS Publications Warehouse

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

    1998-01-01

    smoke. While the mechanism behind smoke-induced germination is not known, it appears that smoke may be involved in overcoming different blocks to germination in different species. For example, in Emmenanthe penduliflora, NO2 in smoke was sufficient to induce germination, and most forms of physical or chemical scarification also induced germination. For Romneya coulteri, NO2 alone failed to induce germination, and scarified seeds required addition of gibberellic acid. In Dicentra chrysantha, none of these treatments, nor smoke alone, induced germination, but germination was triggered by a combination of soil burial followed by smoke treatment. Smoke-stimulated species differed substantially in the duration of smoke exposure required to induce germination, and this was inversely correlated with tolerance to smoke exposure. We suggest that such differences in response may affect postfire community structure.

  18. Internal dispersal of seeds by waterfowl: effect of seed size on gut passage time and germination patterns

    NASA Astrophysics Data System (ADS)

    Figuerola, Jordi; Charalambidou, Iris; Santamaria, Luis; Green, Andy J.

    2010-06-01

    Long distance dispersal may have important consequences for gene flow and community structure. The dispersal of many plants depends on transport by vertebrate seed dispersers. The shapes of seed shadows produced by vertebrates depend both on movement patterns of the dispersers and on the dynamics and effects of passage through the disperser’s gut (i.e. the retention time, survival and germination of ingested seeds). A combination of experiments with captive waterbirds and aquatic plant seeds was used to analyse the following: (a) the effects of inter- and intra-specific variation in seed size and duck species on seed retention time in the gut and (b) the relationship between retention time and the percent germination and germination rates of seeds. Among the three Scirpus species used, those with smaller seeds showed higher survival after ingestion by birds and longer retention times inside their guts than those with larger seeds. For Potamogeton pectinatus, only seeds from the smaller size class (<8 mg) survived ingestion. Retention time affected the percent germination and germination rate of Scirpus seeds but in a manner that varied for the different plant and bird species studied. We recorded both linear and non-linear effects of retention time on percent germination. In addition, germination rate was positively correlated with retention time in Scirpus litoralis but negatively correlated in Scirpus lacustris. Small seed size can favour dispersal over larger distances. However, the effects of retention time on percent germination can modify the seed shadows produced by birds due to higher percent germination of seeds retained for short or intermediate periods. The changes in dispersal quality associated with dispersal distance (which is expected to be positively related to retention time) will affect the probability of seedling establishment over longer distances and, thus, the spatial characteristics of the effective seed shadow.

  19. [The research of Valeriana amurensis seed germination characteristics].

    PubMed

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

    2011-10-01

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

  20. Oxygen requirement of germinating flax seeds

    NASA Astrophysics Data System (ADS)

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

    2003-05-01

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

  1. Oxygen requirement of germinating flax seeds.

    PubMed

    Kuznetsov, Oleg A; Hasenstein, K H

    2003-01-01

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

  2. Oxygen requirement of germinating flax seeds

    NASA Technical Reports Server (NTRS)

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

    2003-01-01

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

  3. Chapter 26. Seed germination

    Treesearch

    Kent R. Jorgensen; G. Richard Wilson

    2004-01-01

    Seed germination represents the means for survival and spread of many plants (McDonough 1977). Germination consists of three overlapping processes: (1) absorption of water, mainly by imbibition, causing swelling of the seed; (2) concurrent enzymatic activity and increased respiration and assimilation rates; and (3) cell enlargement and divisions resulting in emergence...

  4. Effect of atmospheric plasma treatment on seed germination of rice (Oryza sativa L.)

    NASA Astrophysics Data System (ADS)

    Penado, Keith Nealson M.; Mahinay, Christian Lorenz S.; Culaba, Ivan B.

    2018-01-01

    Multiple methods of improving plant development have been utilized over the past decades. Despite these improvements, there still exists a need for better planting methods due to the increasing population of a global community. Studies have reported that plasma treatment affects the growth and germination of a variety of plant species, including a multitude of grains which often takes the bulk in the diet of the average human being. This study explores the effect of atmospheric air plasma jet treatment on the seed germination of rice (Oryza sativa L.). The seeds were treated using an atmospheric air plasma jet for 1, 2, and 3 s. The effect of plasma exposure shows a reduction of trichomes on the surface of the seed. This caused a possible increase in wettability which significantly affected the seed germ length but did not affect the seed germination count after the germination period of 72 h.

  5. [Study on influence factors of seed germination and seeding growth of Lonicera macranthoides].

    PubMed

    Xu, Jin; Zhang, Ying; Cui, Guang-Lin; She, Yue-Hui; Li, Long-Yun

    2016-01-01

    In order to improve reproductive efficiency and quality standard, the influence factors of seed germination and seeding growth of Lonicera macranthoides werew studied. The fruit and seed morphological characteristics of L. macranthoides were observed, the seed water absorbing capacity was determined, and different wet sand stratification time, temperature and germination bed treatment were set up. The effects of the parameters on seed germination and seedling growth were analysed. There was no obstacles of water absorption on L. macranthoides seed, quantity for 22 h water absorption was close to saturation. In the first 80 d, with the increase of the stratification time, seed initial germination time was shortened, germination rate and germination potential was improved. Stratification for 100 d, germination rate decreased. At 15 ℃, seed germination and seedling growth indicators were the best. The seedling cotyledon width in light was significantly higher than that in dark. Seeds on the top of paper and top of sand germination rate, germination potential, and germination index was significantly higher than that of other germination bed and mildew rate is low. The optimal conditions of seeds germination test was stratified in 4 ℃ wet sand for 80 d, 15 ℃ illuminate culture on the top of paper or top of sand. The first seeding counting time was the 4th day after beginning the test, the final time was the 23th day. The germination potential statistical time was the 13th day after beginning the test. Copyright© by the Chinese Pharmaceutical Association.

  6. [Viability and germination of Hechtia perotensis (Bromeliaceae) seed].

    PubMed

    Elizalde, Violeta; García, José Rodolfo; Peña-Valdivia, Cecilia Beatriz; Ybarra, Ma Carmen; Leyva, Otto Raúl; Trejo, Carlos

    2017-03-01

    Endemic populations of Hechtia perotensis have been described in Puebla and Veracruz, Mexico. Good quality seed collections can be used in conservation, research and ecological restoration. To evaluate seed quality of wild and endemic species, some compounds are used as effective promoters of germination, such as potassium nitrate (KNO3) and gibberellic acid (AG3), because they increase seed germination capacity and reduce latency. The triphenyl tetrazolium chloride (tetrazolium) test correlates seed viability because it is based on the activity of dehydrogenases in live tissues that catalyze mitochondrial respiration. The objective of this study was to obtain information on size and weight of capsules and seeds and seed germination and viability of H. perotensis, collected in Veracruz in the year 2012 and 2015. The hypotheses were 1) that seed germination and viability are independent of the year of collection, 2) that there is a tetrazolium concentration that can identify seed viability better than others, and 3) that pretreatment with KNO3 or AG3 improves seed germination. Seed germination was assessed using a completely randomized design with three treatments (control and the germination promoters 0.2 % KNO3 and 500 mg/L AG3), four treatments for the viability test (control, 0.2, 0.5 and 1.0 % of tetrazolium) and six replicates for each treatment. A total of one hundred seeds for germination experiments, and 25 seeds for the viability test were used. The results between and within years were analyzed with ANOVA and multiple comparison with the Tukey test. The proportion of non-germinated seeds was quantified along with the number of normal and abnormal seedlings, seeds with viable embryo, seeds without embryo, and seeds with low or no viability. On average, for the 2012 collected sample, 36 % had viable embryos, 7 % had low viability, 24 % were not viable and 33 % had no embryo. This result was significantly different from the 2015 sample, for which 87 % of

  7. Seed storage conditions change the germination pattern of clonal growth plants in Mediterranean salt marshes

    USGS Publications Warehouse

    Espinar, J.L.; Garcia, L.V.; Clemente, L.

    2005-01-01

    The effect of salinity level and extended exposure to different salinity and flooding conditions on germination patterns of three saltmarsh clonal growth plants (Juncus subulatus, Scirpus litoralis, and S. maritimus) was studied. Seed exposure to extended flooding and saline conditions significantly affected the outcome of the germination process in a different, though predictable, way for each species, after favorable conditions for germination were restored. Tolerance of the germination process was related to the average salinity level measured during the growth/germination season at sites where established individuals of each species dominated the species cover. No relationship was found between salinity tolerance of the germination process and seed response to extended exposure to flooding and salinity conditions. The salinity response was significantly related to the conditions prevailing in the habitats of the respective species during the unfavorable (nongrowth/nongermination) season. Our results indicate that changes in salinity and hydrology while seeds are dormant affect the outcome of the seed-bank response, even when conditions at germination are identical. Because these environmental-history-dependent responses differentially affect seed germination, seedling density, and probably sexual recruitment in the studied and related species, these influences should be considered for wetland restoration and management.

  8. Mitochondrial Proteome Studies in Seeds during Germination

    PubMed Central

    Czarna, Malgorzata; Kolodziejczak, Marta; Janska, Hanna

    2016-01-01

    Seed germination is considered to be one of the most critical phases in the plant life cycle, establishing the next generation of a plant species. It is an energy-demanding process that requires functioning mitochondria. One of the earliest events of seed germination is progressive development of structurally simple and metabolically quiescent promitochondria into fully active and cristae-containing mitochondria, known as mitochondrial biogenesis. This is a complex and tightly regulated process, which is accompanied by sequential and dynamic gene expression, protein synthesis, and post-translational modifications. The aim of this review is to give a comprehensive summary of seed mitochondrial proteome studies during germination of various plant model organisms. We describe different gel-based and gel-free proteomic approaches used to characterize mitochondrial proteomes of germinating seeds as well as challenges and limitations of these proteomic studies. Furthermore, the dynamic changes in the abundance of the mitochondrial proteomes of germinating seeds are illustrated, highlighting numerous mitochondrial proteins involved in respiration, tricarboxycylic acid (TCA) cycle, metabolism, import, and stress response as potentially important for seed germination. We then review seed mitochondrial protein carbonylation, phosphorylation, and S-nitrosylation as well as discuss the possible link between these post-translational modifications (PTMs) and the regulation of seed germination. PMID:28248229

  9. Comparison of gamma and electron beam irradiation in reducing populations of E. coli artificially inoculated on mung bean, clover and fenugreek seeds, and affecting germination and growth of seeds

    NASA Astrophysics Data System (ADS)

    Fan, Xuetong; Sokorai, Kimberly; Weidauer, André; Gotzmann, Gaby; Rögner, Frank-Holm; Koch, Eckhard

    2017-01-01

    Sprouts have frequently been implicated in outbreaks of foodborne illnesses, mostly due to contaminated seeds. Intervention technologies to decontaminate seeds without affecting sprout yield are needed. In the present study, we compared gamma rays with electron beam in inactivating E. coli artificially inoculated on three seeds (fenugreek, clover and mung bean) that differed in size and surface morphology. Furthermore, the germination and growth of irradiated seeds were evaluated. Results showed that the D10 values (dose required to achieve 1 log reduction) for E. coli K12 on mung bean, clover, and fenugreek were 1.11, 1.21 and 1.40 kGy, respectively. To achieve a minimum 5-log reduction of E. coli, higher doses were needed on fenugreek than on mung bean or clover. Electron beam treatment at doses up to 12 kGy could not completely inactivate E. coli inoculated on all seeds even though most of the seeds were E. coli-free after 4-12 kGy irradiation. Gamma irradiation at doses up to 6 kGy did not significantly affect the germination rate of clover and fenugreek seeds but reduced the germination rate of mung bean seeds. Doses of 2 kGy gamma irradiation did not influence the growth of seeds while higher doses of gamma irradiation reduced the growth rate. Electron beam treatment at doses up to 12 kGy did not have any significant effect on germination or growth of the seeds. SEM imaging indicated there were differences in surface morphology among the three seeds, and E. coli resided in cracks and openings of seeds, making surface decontamination of seeds with low energy electron beam a challenge due to the low penetration ability. Overall, our results suggested that gamma rays and electron beam had different effects on E. coli inactivation and germination or growth of seeds. Future efforts should focus on optimization of electron bean parameters to increase penetration to inactivate E. coli without causing damage to the seeds.

  10. [Effects of illumination and seed-soaking reagent on seed germination of Solanum nigrum].

    PubMed

    Yang, Chuan-Jie; Wei, Shu-He; Zhou, Qi-Xing; Hu, Ya-Hu; Niu, Rong-Cheng

    2009-05-01

    To explore a rapid seed germination method for hyperaccumulator Solanum nigrum, a germination experiment with different illumination and seed-soaking treatments was conducted in constant temperature box and greenhouse, with filter as burgeon base. Under illumination, the germination rate was about 5 times high of that without illumination (P < 0.05), indicating that illumination was one of the prerequisites for the seed germination of S. nigrum. All test seed-soaking reagents could significantly improve the germination rate of S. nigrum (P < 0.05), with the best effect of H2O2. The seeds treated with H2O2 had the shortest germination time. The germination rate of seeds soaked but without cleaning was 2-3 times as high as that of seeds soaked and cleaned with water.

  11. The oxygen requirement of germinating flax seeds

    NASA Astrophysics Data System (ADS)

    Kuznetsov, O.; Hasenstein, K.

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

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

    PubMed

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

    2017-06-06

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

  13. Freezing tolerance of conifer seeds and germinants.

    PubMed

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

    2003-12-01

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

  14. Seed germination of three Ulmus species from Turkey as influenced by temperature and light.

    PubMed

    Cicek, Emrah; Tilki, Fahrettin

    2007-04-01

    The effect of temperature and light on the germination performance of Ulmus minor, Ulmus glabra and Ulmus laevis were studied in this research. Seeds were germinated under constant temperatures of 20 and 25 degrees C and alternating temperatures of 25/15 and 30/20 degrees C. Within each temperature regime, seeds were subjected daily to the following photoperiods: total darkness and 8 hr photoperiod. Temperature and light affected seed germination percentage (GP) and germination rate expressed as peak value (PV) in Ulmus minor and 25 and 30/20 degrees C under light gave the highest GP (>95%) and PV (>23). The temperatures of 25/15 and 30/20 degrees C gave the highest GP (>89%) in Ulmus glabra and light did not significantly affect GP. But the highest PV in Ulmus glabra was found at these temperatures under light. Germination percentage of Ulmus laevis was not affected by temperature and light, but the alternating temperature of 30/20 degrees C produced the highest germination rate under darkness.

  15. [Study on conditions of seed germination of Cistanche].

    PubMed

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

    2007-09-01

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

  16. Can heavy metal pollution defend seed germination against heat stress? Effect of heavy metals (Cu(2+), Cd(2+) and Hg(2+)) on maize seed germination under high temperature.

    PubMed

    Deng, Benliang; Yang, Kejun; Zhang, Yifei; Li, Zuotong

    2016-09-01

    Heavy metal pollution, as well as greenhouse effect, has become a serious threat today. Both heavy metal and heat stresses can arrest seed germination. What response can be expected for seed germination under both stress conditions? Here, the effects of heavy metals (Cu(2+), Cd(2+) and Hg(2+)) on maize seed germination were investigated at 20 °C and 40 °C. Compared with 20 °C, heat stress induced thermodormancy. However, this thermodormancy could be significantly alleviated by the addition of a low concentration of heavy metals. Heavy metals, as well as heat stress induced H2O2 accumulation in germinating seeds. Interestingly, this low concentration of heavy metal that promoted seed germination could be partly blocked by DMTU (a specific ROS scavenger), irrespective of temperature. Accordingly, H2O2 addition reinforced this promoting effect on seed germination, which was induced by a low concentration of heavy metal. Furthermore, we found that the NADPH oxidase derived ROS was required for seed germination promoted by the heavy metals. Subsequently, treatment of seeds with fluridone (a specific inhibitor of ABA) or ABA significantly alleviated or aggravated thermodormancy, respectively. However, this alleviation or aggravation could be partly attenuated by a low concentration of heavy metals. In addition, germination that was inhibited by high concentrations of heavy metals was also partly reversed by fluridone. The obtained results support the idea that heavy metal-mediated ROS and hormone interaction can finally affect the thermodormancy release or not. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Germinating pokeberry seed (Phytolacca americana L.)

    Treesearch

    Arnold Krochmal

    1970-01-01

    The seeds of pokeberry (Phytolacca americana L.) can be germinated successfully by storing them dry over winter and then nicking them with a needle to break the seed coat, followed by germination treatment at about 75ºF.

  18. Seed dormancy and germination in Jeffersonia dubia (Berberidaceae) as affected by temperature and gibberellic acid.

    PubMed

    Rhie, Y H; Lee, S Y; Kim, K S

    2015-03-01

    The genus Jeffersonia, which contains only two species, has a trans-Atlantic disjunct distribution. The aims of this study were to determine the requirements for breaking dormancy and germination of J. dubia seeds and to compare its dormancy characteristics with those of the congener in eastern North America. Ripe seeds of J. dubia contain an underdeveloped embryo and were permeable to water. In nature, seeds were dispersed in May, while embryos began to grow in September, and were fully elongated by late November. Germination started in March of the next year, and seeds emerged as seedlings soon after germination. In laboratory experiments, incubation at high temperatures (25 °C, 25/15 °C) for at least 8 weeks was required to initiate embryo growth, while a transfer to moderate temperatures (20/10 °C, 15/6 °C) was needed for the completion of embryo growth. At least 8 weeks at 5 °C was effective in overcoming physiological dormancy and for germination in seeds after the embryos had fully elongated. Thus, both high and low temperatures were essential to break dormancy. Gibberellic acid (GA3 ) treatment could substitute for the high temperature requirement, but not for the low temperature requirement. Based on the dormancy-breaking requirements, it is confirmed that the seeds have deep simple morphophysiological dormancy. This dormancy type is similar to that of seeds of the eastern North American species J. diphylla. Although seeds require 10-11 months from seed dispersal to germination in nature, under controlled conditions they required only 3 months after treatment with 1000 mg·l(-1) GA3 , followed by incubation at 15/6 °C. This represents practical knowledge for propagation of these plants from seed. © 2014 German Botanical Society and The Royal Botanical Society of the Netherlands.

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

    NASA Astrophysics Data System (ADS)

    Pineda-Mejia, Renan

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

  20. 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.

  1. Chickpea seeds germination rational parameters optimization

    NASA Astrophysics Data System (ADS)

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

    2018-05-01

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

  2. Abscisic acid regulates seed germination of Vellozia species in response to temperature.

    PubMed

    Vieira, B C; Bicalho, E M; Munné-Bosch, S; Garcia, Q S

    2017-03-01

    The relationship between the phytohormones, gibberellin (GA) and abscisic acid (ABA) and light and temperature on seed germination is still not well understood. We aimed to investigate the role of the ABA and GA on seed germination of Vellozia caruncularis, V. intermedia and V. alutacea in response to light/dark conditions on different temperature. Seeds were incubated in GA (GA 3 or GA 4 ) or ABA and their respective biosynthesis inhibitors (paclobutrazol - PAC, and fluridone - FLU) solutions at two contrasting temperatures (25 and 40 °C). Furthermore, endogenous concentrations of active GAs and those of ABA were measured in seeds of V. intermedia and V. alutacea during imbibition/germination. Exogenous ABA inhibited the germination of Vellozia species under all conditions tested. GA, FLU and FLU + GA 3 stimulated germination in the dark at 25 °C (GA 4 being more effective than GA 3 ). PAC reduced seed germination in V. caruncularis and V. alutacea, but did not affect germination of V. intermedia at 40 °C either under light or dark conditions. During imbibition in the dark, levels of active GAs decreased in the seeds of V. intermedia, but were not altered in those of V. alutacea. Incubation at 40 °C decreased ABA levels during imbibition in both V. caruncularis and V. alutacea. We conclude that the seeds of Vellozia species studied here require light or high temperature to germinate and ABA has a major role in the regulation of Vellozia seed germination in response to light and temperature. © 2016 German Botanical Society and The Royal Botanical Society of the Netherlands.

  3. [Seed vigor evaluation based on adversity resistance index of wheat seed germination under stress conditions.

    PubMed

    Chen, Lei Tai; Sun, Ai Qing; Yang, Min; Chen, Lu Lu; Ma, Xue Li; Li, Mei Ling; Yin, Yan Ping

    2016-09-01

    A total of 16 wheat cultivars were selected to detect seed vigor of different genotypes using standard germination test, seed germination test under stress conditions and field emergence test. The adversity resistance indices of seed vigor indices and field emergence percentage under different germination conditions were used as the indices to evaluate adversity resistance. Principal component analysis and cluster analysis were used for the comprehensive evaluation of seed vigor. Results showed that drought stress, artificial aging and cold soaking treatments affected seed vigor to some extent. The adversity resistance indices of the artificial aging and cold soaking tests were significantly positively correlated with the field emergence percentage, while the adversity resistance index of drought stress test had no significant correlation with the field emergence percentage. 16 wheat cultivars were classified as three groups based on the principal component analysis and cluster analysis. Yunong 949, Yumai 49-198, Luyuan 502, Zhengyumai 9987, Shimai 21, Shannong 23, and Shixin 828 belonged to high vigor seeds. Xunong 5, Yunong 982, Tangmai 8, Jimai 20, Jimai 22, Jinan 17, and Shannong 20 belonged to medium vigor seeds. The other two cultivars, Chang 4738 and Lunxuan 061, belonged to low vigor seeds.

  4. Seed size variation in the palm Euterpe edulis and the effects of seed predators on germination and seedling survival

    NASA Astrophysics Data System (ADS)

    Pizo, Marco A.; Von Allmen, Christiane; Morellato, L. Patricia C.

    2006-05-01

    Intraspecific variation in seed size is common in wild plant populations and has important consequences for the reproductive success of individual plants. Multiple, often conflicting evolutionary forces mediated by biotic as well as abiotic agents may maintain such a variation. In this paper we assessed seed size variation in a population of the threatened, commercially important palm Euterpe edulis in southeast Brazil. We investigated (i) how this variation affects the probability of attack by vertebrate and invertebrate post-dispersal seed predators, and (ii) if seed size influences the outcome of seeds damaged by beetles in terms of seed germination and early survival of seedlings. Euterpe edulis seeds varied in diameter from 8.3 to 14.1 mm. Neither insects nor rodents selected the seeds they preyed upon based on seed size. Seed germination and total, shoot and root biomasses of one-year seedlings were significantly and positively affected by seed size. Root biomass and seedling survival were negatively affected by seed damage caused by a scolytid beetle ( Coccotrypes palmarum) whose adults bore into seeds to consume part of the endosperm, but do not oviposit on them. Seed size had a marginally significant effect on seedling survival. Therefore, if any advantage is accrued by E. edulis individuals producing large seeds, this is because of greater seed germination success and seedling vigor. If this is so, even a relatively narrow range of variation in seed size as observed in the E. edulis population studied may translate into differential success of individual plants.

  5. Seed and Germination Characteristics of 20 Amazonian Liana Species

    PubMed Central

    Roeder, Mareike; Ferraz, Isolde D. K.; Hölscher, Dirk

    2013-01-01

    Lianas are an important component of tropical forests, and may reach their highest densities in disturbed areas. However, information on seed and germination characteristics is scarce. Twenty Amazon liana species were screened for their germination characteristics, including light dependence, tolerance of desiccation and of alternating temperatures; these characteristics are considered important for the germination success in areas with relatively open canopies. Between 31–1,420 seeds per species were available, as 15 species seeds came from one mother plant. We studied seed biometry and conducted germination trials with fresh seeds (12 h light daily, or dark) and desiccated seeds at 25 °C. Germination at alternating temperatures (20/30 °C, 15/35 °C) was analyzed for nine species. Of the 20 species, eight species with the largest seeds had desiccation sensitive seeds; this is the first record for species of four genera and one family, where only desiccation tolerant seeds are otherwise recorded. Light-dependent germination was found in three species (0.01–0.015 g) and is the first record for two; however, results were based on seeds from one plant per species. Alternating temperatures of 15/35 °C decreased final germination of four out of nine species, and response to 20/30 °C cycles varied compared to constant 25 °C. Seed and germination characteristics of the species ranged from pioneer to climax traits indicating that establishment of lianas from seeds may be confined to species specific niches. PMID:27137363

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

    PubMed

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

    2017-10-01

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

  7. Arabidopsis ABI5 plays a role in regulating ROS homeostasis by activating CATALASE 1 transcription in seed germination.

    PubMed

    Bi, Chao; Ma, Yu; Wu, Zhen; Yu, Yong-Tao; Liang, Shan; Lu, Kai; Wang, Xiao-Fang

    2017-05-01

    It has been known that ABA INSENSITIVE 5 (ABI5) plays a vital role in regulating seed germination. In the present study, we showed that inhibition of the catalase activity with 3-amino-1,2,4-triazole (3-AT) inhibits seed germination of Col-0, abi5 mutants and ABI5-overexpression transgenic lines. Compared with Col-0, the seeds of abi5 mutants showed more sensitive to 3-AT during seed germination, while the seeds of ABI5-overexpression transgenic lines showed more insensitive. H 2 O 2 showed the same effect on seed germination of Col-0, abi5 mutants and ABI5-overexpression transgenic lines as 3-AT. These results suggest that ROS is involved in the seed germination mediated by ABI5. Further, we observed that T-DNA insertion mutants of the three catalase members in Arabidopsis displayed 3-AT-insensitive or -hypersensitive phenotypes during seed germination, suggesting that these catalase members regulate ROS homeostasis in a highly complex way. ABI5 affects reactive oxygen species (ROS) homeostasis by affecting CATALASE expression and catalase activity. Furthermore, we showed that ABI5 directly binds to the CAT1 promoter and activates CAT1 expression. Genetic evidence supports the idea that CAT1 functions downstream of ABI5 in ROS signaling during seed germination. RNA-sequencing analysis indicates that the transcription of the genes involved in ROS metabolic process or genes responsive to ROS stress is impaired in abi5-1 seeds. Additionally, expression changes in some genes correlative to seed germination were showed due to the change in ABI5 expression under 3-AT treatment. Together, all the findings suggest that ABI5 regulates seed germination at least partly by affecting ROS homeostasis.

  8. Involvement of Alternative Splicing in Barley Seed Germination

    PubMed Central

    Zhang, Qisen; Zhang, Xiaoqi; Wang, Songbo; Tan, Cong; Zhou, Gaofeng; Li, Chengdao

    2016-01-01

    Seed germination activates many new biological processes including DNA, membrane and mitochondrial repairs and requires active protein synthesis and sufficient energy supply. Alternative splicing (AS) regulates many cellular processes including cell differentiation and environmental adaptations. However, limited information is available on the regulation of seed germination at post-transcriptional levels. We have conducted RNA-sequencing experiments to dissect AS events in barley seed germination. We identified between 552 and 669 common AS transcripts in germinating barley embryos from four barley varieties (Hordeum vulgare L. Bass, Baudin, Harrington and Stirling). Alternative 3’ splicing (34%-45%), intron retention (32%-34%) and alternative 5’ splicing (16%-21%) were three major AS events in germinating embryos. The AS transcripts were predominantly mapped onto ribosome, RNA transport machineries, spliceosome, plant hormone signal transduction, glycolysis, sugar and carbon metabolism pathways. Transcripts of these genes were also very abundant in the early stage of seed germination. Correlation analysis of gene expression showed that AS hormone responsive transcripts could also be co-expressed with genes responsible for protein biosynthesis and sugar metabolisms. Our RNA-sequencing data revealed that AS could play important roles in barley seed germination. PMID:27031341

  9. Seed germination of Sierra Nevada postfire chaparral species

    USGS Publications Warehouse

    Keeley, Jon E.; McGinnis, Thomas W.; Bollens, Kim A.

    2005-01-01

    The California chaparral community has a rich flora of species with different mechanisms for cuing germination to postfire conditions. Here we report further germination experiments that elucidate the response of several widespread shrub species whose germination response was not clear and include other species from the Sierra Nevada, which have not previously been included in germination studies. The shrubs Adenostoma fasciculatum and Eriodictyon crassifolium and the postfire annualMentzelia dispersa exhibited highly significant germination in response to smoke treatments, with some enhanced germination in response to heating as well. The shrubs Fremontodendron californicum and Malacothamnus fremontii were stimulated only by heat-shock treatments. Seeds buried in the soil for one year exhibited substantially higher germination for controls and most treatments. In the case of two postfire annuals, Mimulus bolanderi and M. gracilipes, germination of fresh seed was significantly greater with smoke or heating but after soil storage, over two-thirds of the control seeds germinated and treatment effects were not significant. These two annuals are generally restricted to postfire conditions and it is suggested that control germination of soil-stored seed may be a light-response (which was not tested here) as previously reported for another chaparral species in that genus.

  10. Karrikins delay soybean seed germination by mediating abscisic acid and gibberellin biogenesis under shaded conditions

    PubMed Central

    Meng, Yongjie; Chen, Feng; Shuai, Haiwei; Luo, Xiaofeng; Ding, Jun; Tang, Shengwen; Xu, Shuanshuan; Liu, Jianwei; Liu, Weiguo; Du, Junbo; Liu, Jiang; Yang, Feng; Sun, Xin; Yong, Taiwen; Wang, Xiaochun; Feng, Yuqi; Shu, Kai; Yang, Wenyu

    2016-01-01

    Karrikins (KAR) are a class of signal compounds, discovered in wildfire smoke, which affect seed germination. Currently, numerous studies have focused on the model plant Arabidopsis in the KAR research field, rather than on crops. Thus the regulatory mechanisms underlying KAR regulation of crop seed germination are largely unknown. Here, we report that KAR delayed soybean seed germination through enhancing abscisic acid (ABA) biosynthesis, while impairing gibberellin (GA) biogenesis. Interestingly, KAR only retarded soybean seed germination under shaded conditions, rather than under dark and white light conditions, which differs from in Arabidopsis. Phytohormone quantification showed that KAR enhanced ABA biogenesis while impairing GA biosynthesis during the seed imbibition process, and subsequently, the ratio of active GA4 to ABA was significantly reduced. Further qRT-PCR analysis showed that the transcription pattern of genes involved in ABA and GA metabolic pathways are consistent with the hormonal measurements. Finally, fluridone, an ABA biogenesis inhibitor, remarkably rescued the delayed-germination phenotype of KAR-treatment; and paclobutrazol, a GA biosynthesis inhibitor, inhibited soybean seed germination. Taken together, these evidences suggest that KAR inhibit soybean seed germination by mediating the ratio between GA and ABA biogenesis. PMID:26902640

  11. Karrikins delay soybean seed germination by mediating abscisic acid and gibberellin biogenesis under shaded conditions.

    PubMed

    Meng, Yongjie; Chen, Feng; Shuai, Haiwei; Luo, Xiaofeng; Ding, Jun; Tang, Shengwen; Xu, Shuanshuan; Liu, Jianwei; Liu, Weiguo; Du, Junbo; Liu, Jiang; Yang, Feng; Sun, Xin; Yong, Taiwen; Wang, Xiaochun; Feng, Yuqi; Shu, Kai; Yang, Wenyu

    2016-02-23

    Karrikins (KAR) are a class of signal compounds, discovered in wildfire smoke, which affect seed germination. Currently, numerous studies have focused on the model plant Arabidopsis in the KAR research field, rather than on crops. Thus the regulatory mechanisms underlying KAR regulation of crop seed germination are largely unknown. Here, we report that KAR delayed soybean seed germination through enhancing abscisic acid (ABA) biosynthesis, while impairing gibberellin (GA) biogenesis. Interestingly, KAR only retarded soybean seed germination under shaded conditions, rather than under dark and white light conditions, which differs from in Arabidopsis. Phytohormone quantification showed that KAR enhanced ABA biogenesis while impairing GA biosynthesis during the seed imbibition process, and subsequently, the ratio of active GA4 to ABA was significantly reduced. Further qRT-PCR analysis showed that the transcription pattern of genes involved in ABA and GA metabolic pathways are consistent with the hormonal measurements. Finally, fluridone, an ABA biogenesis inhibitor, remarkably rescued the delayed-germination phenotype of KAR-treatment; and paclobutrazol, a GA biosynthesis inhibitor, inhibited soybean seed germination. Taken together, these evidences suggest that KAR inhibit soybean seed germination by mediating the ratio between GA and ABA biogenesis.

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

    PubMed Central

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

    2015-01-01

    Germination and thermoinhibition in lettuce (Lactuca sativa ‘Jianyexianfeng No. 1’) seeds were investigated by a proteomic comparison among dry seeds, germinated seeds at 15°C, at 15°C after imbibition at 25°C for 48 h, or at 25°C in KNO3 (all sampled individually at germination), and ungerminated seeds at 25°C, a thermoinhibitory temperature. Before two-dimensional gel electrophoresis analysis, storage proteins (greater than 50% of total extractable protein) were removed by polyethylene glycol precipitation, which significantly improved the detection of less abundant proteins on two-dimensional gels. A total of 108 protein spots were identified to change more than 2-fold (P < 0.05) in abundance in at least one germination treatment. Nineteen proteins increasing and one protein decreasing in abundance during germination had higher abundance in germinated 15°C, 15°C after imbibition at 25°C for 48 h, and 25°C in KNO3 seeds than in ungerminated 25°C seeds. Gene expression of 12 of those proteins correlated well with the protein accumulation. Methionine metabolism, ethylene production, lipid mobilization, cell elongation, and detoxification of aldehydes were revealed to be potentially related to lettuce seed germination and thermoinhibition. Accumulation of three proteins and expression of five genes participating in the mevalonate (MVA) pathway of isoprenoid biosynthesis correlated positively with seed germinability. Inhibition of this pathway by lovastatin delayed seed germination and increased the sensitivity of germination to abscisic acid. MVA pathway-derived products, cytokinins, partially reversed the lovastatin inhibition of germination and released seed thermoinhibition at 25°C. We conclude that the MVA pathway for isoprenoid biosynthesis is involved in lettuce seed germination and thermoinhibition. PMID:25736209

  13. Effects of germination time on seed morph ratio in a seed-dimorphic species and possible ecological significance

    PubMed Central

    Yang, Fan; Baskin, Jerry M.; Baskin, Carol C.; Yang, Xuejun; Cao, Dechang; Huang, Zhenying

    2015-01-01

    Background and Aims Diaspores of heteromorphic species may germinate at different times due to distinct dormancy-breaking and germination requirements, and this difference can influence life history traits. The primary aim of this study was to determine the effect of germination time of the two seed morphs of Suaeda corniculata subsp. mongolica on life history traits of the offspring. Methods Germinated brown and black seeds were sown on the 20th of each month from April to September in a simulated but near-natural habitat of the species. Phenological and vegetative traits of the maternal plants, and number, size and germination percentage of the offspring were determined. Key Results Germinated seeds sown late in the year produced smaller plants that had a higher proportion of non-dormant brown than dormant black seeds, and these brown seeds were larger than those produced by germinated seeds sown early in the year. The length of the seedling stage for brown seeds was shorter than that for black seeds, and the root/shoot ratio and reproductive allocation of plants from brown seeds were more variable than they were for plants from black seeds. Late-germinating brown seeds produced larger plants than late-germinating black seeds. Conclusions Altering the proportion of the two seed types in response to germination timing can help alleviate the adverse effects of delayed germination. The flexible strategy of a species, such as S. corniculata, that produces different proportions of dimorphic seeds in response to variation in germination timing may favour the maintenance and regeneration of the population in its unpredictable environment. PMID:25395107

  14. Nitrate affects sensu-stricto germination of after-ripened Sisymbrium officinale seeds by modifying expression of SoNCED5, SoCYP707A2 and SoGA3ox2 genes.

    PubMed

    Carrillo-Barral, Néstor; Matilla, Angel J; Rodríguez-Gacio, María del Carmen; Iglesias-Fernández, Raquel

    2014-03-01

    The influence of nitrate upon the germination of Sisymbrium officinale seeds is not entirely controlled by after-ripening (AR), a process clearly influenced by nitrate. Recently, we have reported that nitrate affects sensu-stricto germination of non-AR (AR0) seeds by modifying the expression of crucial genes involved in the metabolism of GA and ABA. In this study, we demonstrate that nitrate affects also the germination of AR seeds because: (i) the AR negatively alters the ABA sensitivity being the seed more ABA-sensible as the AR is farthest from optimal (AR0 and AR20 versus AR7); in the presence of diniconazole (DZ), a competitive inhibitor of ABA 8'-hydroxylase, testa rupture is affected while the endosperm rupture is not. (ii) AR7 seed-coat rupture is not inhibited by paclobutrazol (PBZ) suggesting that nitrate can act by a mechanism GA-independent. (iii) The germination process is accelerated by nitrate, most probably by the increase in the expression of SoNCED5, SoCYP707A2 and SoGA3ox2 genes. Taken together, these and previous results demonstrate that nitrate promotes germination of AR and non-AR seeds through transcriptional changes of different genes involved in ABA and GA metabolism. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

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

    NASA Astrophysics Data System (ADS)

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

    2014-02-01

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

  16. Seed Coating Increases Seed Moisture Uptake and Restricts Embryonic Oxygen Availability in Germinating Cereal Seeds.

    PubMed

    Gorim, Linda; Asch, Folkard

    2017-05-24

    Seed coating is a technology to improve germination and homogenize stand establishment. Although coating often results in lower germination rates, seeds that do germinate grow more vigorously and show strongly reduced respiratory losses during reserve mobilization. We hypothesize that the higher mobilization efficiency is due to a shift in the enzymatic cleavage of sucrose from invertase to sucrose synthase in the embryonic tissue caused by a reduced oxygen availability induced by oversaturation with water caused by the coating during early germination. We investigated the effect of coating on barley, rye, and wheat seed imbibition during the first 30 h after seeds were placed in moisture. We profiled oxygen in the embryos and measured sucrose and acid invertase levels as imbibition progressed. We found that seeds within coatings absorbed significantly more moisture than uncoated seeds. Coating resulted in near anoxic oxygen concentrations in the developing embryonic tissues in all three species. In barley, sucrose was not cleaved via the invertase pathway, despite the fact that invertase activity in coated seeds was increased. In rye and wheat, invertase activities were significantly lower in embryos from coated seeds without significantly changing the sugar composition.

  17. Seed Coating Increases Seed Moisture Uptake and Restricts Embryonic Oxygen Availability in Germinating Cereal Seeds

    PubMed Central

    Gorim, Linda; Asch, Folkard

    2017-01-01

    Seed coating is a technology to improve germination and homogenize stand establishment. Although coating often results in lower germination rates, seeds that do germinate grow more vigorously and show strongly reduced respiratory losses during reserve mobilization. We hypothesize that the higher mobilization efficiency is due to a shift in the enzymatic cleavage of sucrose from invertase to sucrose synthase in the embryonic tissue caused by a reduced oxygen availability induced by oversaturation with water caused by the coating during early germination. We investigated the effect of coating on barley, rye, and wheat seed imbibition during the first 30 h after seeds were placed in moisture. We profiled oxygen in the embryos and measured sucrose and acid invertase levels as imbibition progressed. We found that seeds within coatings absorbed significantly more moisture than uncoated seeds. Coating resulted in near anoxic oxygen concentrations in the developing embryonic tissues in all three species. In barley, sucrose was not cleaved via the invertase pathway, despite the fact that invertase activity in coated seeds was increased. In rye and wheat, invertase activities were significantly lower in embryos from coated seeds without significantly changing the sugar composition. PMID:28538658

  18. Seed germination in response to chemicals: effect of nitrogen and pH in the media.

    PubMed

    Pérez-Fernández, M A; Calvo-Magro, E; Montanero-Fernández, J; Oyola-Velasco, J A

    2006-01-01

    Seed germination generally presents a peak in the next growing season after a fire. Among other factors associated with fire are the increase of soil nitrogen and changes in the pH of the soil. In this study, we addressed the question, whether or not the germination response of eight species is linked with the increase in pH and nitrogenous compounds in the germination media? We assessed the separate and combined effects of nitrogenous compounds and pH on the percentage and rate of germination of seeds of Medicago arabica (L.) Hudson, Epilobium hirsutum L., Foeniculum vulgare Miller, Daucus carota L., Thapsia villosa L., Cynosurus cristatus L., Dactylis glomerata L. and Rumex crispus L. All these species are well represented in the Mediterranean ecosystems of the central-west Spain. Water and CaCl2 were used as controls. Nitrogenous compounds increased percent germination (level) and rate in three of the species studied. High pH negatively affected the germination rate of seeds from most species, but had no effect on the per cent germination of any of the species. The higher concentration of the nutritious solutions affected negatively the germination level and rate. The different germination responses of seeds of the studied species could not be exclusively attributed to pH values in the media, whereas the amount and form of Nitrogen in the media has a greater effect on it. These differences in germination are species dependent.

  19. The effects of soak temperature on sugar maple seed germination

    Treesearch

    Carol A. Janerette

    1978-01-01

    The temperature at which sugar maple seeds were soaked before stratification significantly influenced their germination. Maximal germination was obtained when seeds were soaked at 4?C, but if seeds were soaked at 25?C, germination decreased and the stratification requirement increased.

  20. Fluridone and norflurazon, carotenoid-biosynthesis inhibitors, promote seed conditioning and germination of the holoparasite Orobanche minor.

    PubMed

    Chae, Sang Heon; Yoneyama, Koichi; Takeuchi, Yasutomo; Joel, Daniel M.

    2004-02-01

    Fluridone and norflurazon, two carotenoid-biosynthesis inhibitors, shortened the conditioning period required by seeds of Orobanche minor in order to respond to the germination stimulant strigol. Neither fluridone nor norflurazon alone induced seed germination of O. minor, they promoted strigol-induced germination. In addition, these compounds restored the conditioning and germination of seeds at a supraoptimal temperature (30 degrees C) as well as in the light. Gibberellic acid (GA(3)) showed similar promotive and protective effects on the conditioning and germination of O. minor seeds. Although fluridone and norflurazon are known to prevent abscisic acid (ABA)-biosynthesis, and stresses such as supraoptimal temperatures have been reported to induce ABA accumulation in plants, the amount of ABA in the seeds or that released from the seeds into the conditioning media was not affected by the fluridone treatment and by exposure to the supraoptimal temperature. These results indicate that the promotive and protective effects of fluridone and norflurazon on the conditioning and germination of O. minor seeds would be attributed to other perturbations rather than the inhibition of ABA-biosynthesis.

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

    PubMed

    Varga, Sandra

    2015-03-01

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

  2. Germination of Ocotea pulchella (Nees) Mez (Lauraceae) seeds in laboratory and natural restinga environment conditions.

    PubMed

    Pires, L A; Cardoso, V J M; Joly, C A; Rodrigues, R R

    2009-08-01

    The germination response of Ocotea pulchella (Nees) Mez seeds to light, temperature, water level and pulp presence is introduced. The laboratory assays were carried out in germination chambers and thermal-gradient apparatus, whereas the field assays were performed in environments with distinct light, temperature and soil moisture conditions within a permanent parcel of Restinga forest of the Parque Estadual da Ilha do Cardoso, Cananéia, São Paulo. The seeds do not exhibit dormancy, they are non photoblastic, and a loss of viability in dry stored seeds can be related to a decrease in water content of the seed. The presence of the pulp and the flooded substratum influenced negatively the germination of O. pulchella seeds tested in the laboratory. Otherwise, light and temperature probably are not limiting factors of the germination of O. pulchella seeds in the natural environment of Restinga. The optimum temperature range for germination of Ocotea pulchella seeds was 20 to 32 degrees C, the minimum or base temperature estimated was 11 degrees C and the maximum ranged between 33 and 42 degrees C. The isotherms exhibited a sigmoidal pattern well described by the Weibull model in the sub-optimal temperature range. The germinability of O. pulchella seeds in the understorey, both in wet and dry soil, was higher than in gaps. Germination was not affected by fluctuations in soil moisture content in the understorey environment, whereas in gaps, germination was higher in wet soils. Thus, the germination of this species involves the interaction of two or more factors and it cannot be explained by a single factor.

  3. Raffinose and stachyose metabolism are not required for efficient soybean seed germination.

    PubMed

    Dierking, Emily C; Bilyeu, Kristin D

    2009-08-15

    Raffinose family oligosaccharides (RFOs), which include raffinose and stachyose, are thought to be an important source of energy during seed germination. In contrast to their potential for promoting germination, RFOs represent anti-nutritional units for monogastric animals when consumed as a component of feed. The exact role for RFOs during soybean seed development and germination has not been experimentally determined; but it has been hypothesized that RFOs are required for successful germination. Previously, inhibition of RFO breakdown during imbibition and germination was shown to significantly delay germination in pea seeds. The objective of this study was to compare the germination potential for soybean seeds with either wild-type (WT) or low RFO levels and to examine the role of RFO breakdown in germination of soybean seeds. There was no significant difference in germination between normal and low RFO soybean seeds when imbibed/germinated in water. Similar to the situation in pea, soybean seeds of wild-type carbohydrate composition experienced a delay in germination when treated with a chemical inhibitor of alpha-galactosidase activity (1-deoxygalactonojirimycin or DGJ) during imbibition. However, low RFO soybean seed germination was not significantly delayed or reduced when treated with DGJ. In contrast to the situation in pea, the inhibitor-induced germination delay in wild-type soybean seeds was not partially overcome by the addition of galactose or sucrose. We conclude that RFOs are not an essential source of energy during soybean seed germination.

  4. Effect of day length on germination of seeds collected in Alaska

    USGS Publications Warehouse

    Densmore, R.V.

    1997-01-01

    Day length control can effectively limit seed germination to favorable seasons, but this phenomenon has been studied in relatively few wild plants. I tested species from interior Alaska for day length control of germination under controlled conditions, and I also monitored germination phenology in natural habitats. Unstratified and cold-stratified seeds were germinated on short (13 h) and long (22 h) day length and in the dark at constant and alternating temperatures. On long day length, unstratified Ledum decumbens and Saxifraga tricuspidata seeds germinated from 5??C to 20??C, but on short day length few or no seeds germinated at 5??C and 10??C and germination was reduced at higher temperatures. Unstratified seeds of Diapensia lapponica and Chamaedaphne calyculata germinated only at 15??C and 20??C on long day length, and short day length completely inhibited germination. Cold stratification widened the temperature range for germination on both long and short day lengths, but germination was still lower on short than long day length. Germination phenology in natural habitats was consistent with germination in controlled conditions. In these species, short day length and low temperatures interact to inhibit germination in the fall. After overwintering, seeds germinate in the spring at low temperatures and on long day lengths. The inhibitory effect of short day length is not important in the spring because day length is already long at snowmelt.

  5. Omethoate treatment mitigates high salt stress inhibited maize seed germination.

    PubMed

    Yang, Kejun; Zhang, Yifei; Zhu, Lianhua; Li, Zuotong; Deng, Benliang

    2018-01-01

    Omethoate (OM) is a highly toxic organophophate insecticide, which is resistant to biodegradation in the environment and is widely used for pest control in agriculture. The effect of OM on maize seed germination was evaluated under salt stress. Salt (800mM) greatly reduced germination of maize seed and this could be reversed by OM. Additionally, H 2 O 2 treatment further improved the effect of OM on seed germination. Higher H 2 O 2 content was measured in OM treated seed compared to those with salt stress alone. Dimethylthiourea (DTMU), a specific scavenger of reactive oxygen species (ROS), inhibited the effect of OM on seed germination, as did IMZ (imidazole), an inhibitor of NADPH oxidase. Abscisic acid (ABA) inhibited the effect of OM on seed germination, whereas fluridone, a specific inhibitor of ABA biosynthesis, enhanced the effect of OM. Taken together, these findings suggest a role of ROS and ABA in the promotion of maize seed germination by OM under salt stress. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. A high-throughput seed germination assay for root parasitic plants

    PubMed Central

    2013-01-01

    Background Some root-parasitic plants belonging to the Orobanche, Phelipanche or Striga genus represent one of the most destructive and intractable weed problems to agricultural production in both developed and developing countries. Compared with most of the other weeds, parasitic weeds are difficult to control by conventional methods because of their life style. The main difficulties that currently limit the development of successful control methods are the ability of the parasite to produce a tremendous number of tiny seeds that may remain viable in the soil for more than 15 years. Seed germination requires induction by stimulants present in root exudates of host plants. Researches performed on these minute seeds are until now tedious and time-consuming because germination rate is usually evaluated in Petri-dish by counting germinated seeds under a binocular microscope. Results We developed an easy and fast method for germination rate determination based on a standardized 96-well plate test coupled with spectrophotometric reading of tetrazolium salt (MTT) reduction. We adapted the Mosmann’s protocol for cell cultures to germinating seeds and determined the conditions of seed stimulation and germination, MTT staining and formazan salt solubilization required to obtain a linear relationship between absorbance and germination rate. Dose–response analyses were presented as applications of interest for assessing half maximal effective or inhibitory concentrations of germination stimulants (strigolactones) or inhibitors (ABA), respectively, using four parameter logistic curves. Conclusion The developed MTT system is simple and accurate. It yields reproducible results for germination bioassays of parasitic plant seeds. This method is adapted to high-throughput screenings of allelochemicals (stimulants, inhibitors) or biological extracts on parasitic plant seed germination, and strengthens the investigations of distinctive features of parasitic plant germination

  7. Seed germination strategies: an evolutionary trajectory independent of vegetative functional traits

    PubMed Central

    Hoyle, Gemma L.; Steadman, Kathryn J.; Good, Roger B.; McIntosh, Emma J.; Galea, Lucy M. E.; Nicotra, Adrienne B.

    2015-01-01

    Seed germination strategies vary dramatically among species but relatively little is known about how germination traits correlate with other elements of plant strategy systems. Understanding drivers of germination strategy is critical to our understanding of the evolutionary biology of plant reproduction.We present a novel assessment of seed germination strategies focussing on Australian alpine species as a case study. We describe the distribution of germination strategies and ask whether these are correlated with, or form an independent axis to, other plant functional traits. Our approach to describing germination strategy mimicked realistic temperatures that seeds experience in situ following dispersal. Strategies were subsequently assigned using an objective clustering approach. We hypothesized that two main strategies would emerge, involving dormant or non-dormant seeds, and that while these strategies would be correlated with seed traits (e.g., mass or endospermy) they would be largely independent of vegetative traits when analysed in a phylogenetically structured manner.Across all species, three germination strategies emerged. The majority of species postponed germination until after a period of cold, winter-like temperatures indicating physiological and/or morphological dormancy mechanisms. Other species exhibited immediate germination at temperatures representative of those at dispersal. Interestingly, seeds of an additional 13 species “staggered” germination over time. Germination strategies were generally conserved within families. Across a broad range of ecological traits only seed mass and endospermy showed any correlation with germination strategy when phylogenetic relatedness was accounted for; vegetative traits showed no significant correlations with germination strategy. The results indicate that germination traits correlate with other aspects of seed ecology but form an independent axis relative to vegetative traits. PMID:26528294

  8. Morpho-colorimetric analysis and seed germination of Brassica insularis Moris (Brassicaceae) populations.

    PubMed

    Santo, A; Mattana, E; Grillo, O; Bacchetta, G

    2015-03-01

    Brassica insularis is a perennial plant growing on both coastal and inland cliffs. Three seed lots from Sardinia were analysed using an image analysis system to detect differences in seed morphology, both within and among populations. Germination requirements at constant (5-25 °C) and alternating temperatures (25/10 °C), both in light and in darkness, were evaluated for all populations. In addition, the effect of a dry after-ripening period (90 days at 25 °C) was also investigated. Morpho-colorimetric analysis clearly identified seeds from different populations and discriminated three chromatic categories for seeds belonging to the Isola dei Cavoli coastal population, but not for the inland Masùa and the coastal Planu Sartu. Inter-population variability was also observed in germination behaviour. B. insularis seeds germinated, with percentages up to 60%, in a wide range of temperatures (5-25 °C), and neither light nor dry after-ripening affected final germination percentages. Moisture content measurements were made for seeds of each colour, but there were no particular differences among colours. Inter-populational variability in germination behaviour may be a survival strategy for species growing under unpredictable environmental conditions, such as under Mediterranean climate, while heteromorphy may be due to independent evolutionary divergence processes of the Isola dei Cavoli population. © 2014 German Botanical Society and The Royal Botanical Society of the Netherlands.

  9. Effects of environmental variation during seed production on seed dormancy and germination.

    PubMed

    Penfield, Steven; MacGregor, Dana R

    2017-02-01

    The environment during seed production has major impacts on the behaviour of progeny seeds. It can be shown that for annual plants temperature perception over the whole life history of the mother can affect the germination rate of progeny, and instances have been documented where these affects cross whole generations. Here we discuss the current state of knowledge of signal transduction pathways controlling environmental responses during seed production, focusing both on events that take place in the mother plant and those that occur directly as a result of environmental responses in the developing zygote. We show that seed production environment effects are complex, involving overlapping gene networks active independently in fruit, seed coat, and zygotic tissues that can be deconstructed using careful physiology alongside molecular and genetic experiments. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  10. Response of soybean seed germination to cadmium and acid rain.

    PubMed

    Liu, Ting Ting; Wu, Peng; Wang, Li Hong; Zhou, Qing

    2011-12-01

    Cadmium (Cd) pollution and acid rain are the main environmental issues, and they often occur in the same agricultural region. Nevertheless, up to now, little information on the combined pollution of Cd(2+) and acid rain action on crops were presented. Here, we investigated the combined effect of Cd(2+) and acid rain on the seed germination of soybean. The results indicated that the single treatment with the low level of Cd(2+) (0.18, 1.0, 3.0 mg L(-1)) or acid rain (pH ≥3.0) could not affect the seed germination of soybean, which was resulted in the increased activities of peroxidase and catalase. The single treatment with the high concentration of Cd(2+) (>6 mg L(-1)) or acid rain at pH 2.5 decreased the activities of peroxidase and catalase, damaged the cell membrane and then decreased the seed germination of soybean. Meanwhile, the same toxic effect was observed in the combined treatment with Cd(2+) and acid rain, and the combined treatment had more toxic effect than the single treatment with Cd(2+) or acid rain. Thus, the combined pollution of Cd(2+) and acid rain had more potential threat to the seed germination of soybean than the single pollution of Cd(2+) or acid rain.

  11. [Study on physiological and germination characteristics of Tulipa edulis seed].

    PubMed

    Wu, Zhengjun; Zhu, Zaibiao; Guo, Qiaosheng; Ma, Hongliang; Xu, Hongjian; Miao, Yuanyuan

    2012-03-01

    Current study was conducted to investigate the seed physiological characteristics of Tulipa edulis and improve germination rate. Anatomical characteristics was observed. Seed water absorption curve was tested by soaking method. Dynamic of embryo development and germination rate as well as germination index under different conditions were recorded. And the biological test of cabbage seed was used for detecting the germination inhibitors. The embryo rate of newly matured seeds was about 10%, and there was no obstacle of water absorption on testa of T. edulis. The optimum method for embryo development was exposure to 300 mg x L(-1) gibberellin solution for 24 hours, and stratification at 25 degrees C for 70 days followed by stratification at 5 degrees C for 40 days. The germintion rate and germination index of dormancy-broken seeds under the dark environment at 10 degrees C and 15 degrees C were significantly higher than those under other conditions. Additionally, there were some germination inhibitory substances in dry seeds. The seed of T. edulis can be classified as having complex morphophysiological dormancy, and the morphological embryo dormancy played a leading role. Warm and cold stratification resulted in a fast dormancy breaking effect, and a high germination rate more than 90% could be obtained under the optimum conditions.

  12. The role of fleshy pericarp in seed germination and dispersal under flooded conditions in three wetland forest species

    NASA Astrophysics Data System (ADS)

    Mora, Juan P.; Smith-Ramírez, Cecilia; Zúñiga-Feest, Alejandra

    2013-01-01

    In flooded habitats, inundations affect important forest regeneration processes, such as seed dispersal and germination. The main seed dispersal mechanism used by species in Austral South American temperate swamp and riparian forests is endozoochory, which releases seeds from the fleshy pericarp. Endozoochory could be favorable or unfavorable in wetland habitats, since this mechanism exposes seeds directly to water and can, in some cases, be detrimental to germination. In this study, we studied whether or not the fleshy pericarp favors germination after the flooding period's end. Furthermore, we quantified if the number of days which the fruit was found to be floating related to its germination success. We used the seeds of three common fleshy fruit species of flooded habitats from southern Chile, the trees Luma apiculata and Rhaphithamnus spinosus, and the vine Luzuriaga radicans. We simulated flooding periods of 7, 15, 30 and 45 days submerging seeds, with and without pericarps, in water. We found that the pericarp's presence significantly increased Luma's germination success and significantly decreased that of Luzuriaga. The germination of Rhaphithamnus was low after periods of flooding in both seed treatments, with no significant differences found between them. The fruits could float for an average of one to four weeks, depending on the species, which did not relate to their germination success. These results show that germination was affected by the presence of fleshy pericarps in flooded conditions and furthermore, that flotation allows for hydrochory from one week to one month. We suggest that in swamp forests multiple seed dispersal mechanisms are advantageous, especially for fleshy-fruited species.

  13. Phytotoxic effects of Sicyos deppei (Cucurbitaceae) in germinating tomato seeds.

    PubMed

    Lara-Núñez, Aurora; Sánchez-Nieto, Sobeida; Luisa Anaya, Ana; Cruz-Ortega, Rocio

    2009-06-01

    The phytotoxic effect of allelochemicals is referred to as allelochemical stress and it is considered a biotic stress. Sicyos deppei G. Don (Cucurbitaceae) is an allelopathic weed that causes phytotoxicity in Lycopersicon esculentum, delaying seed germination and severely inhibiting radicle growth. This paper reports in in vitro conditions, the effects of the aqueous leachate of S. deppei-throughout tomato germination times-on (1) the dynamics of starch and sugars metabolism, (2) activity and expression of the cell wall enzymes involved in endosperm weakening that allows the protrusion of the radicle, and (3) whether abscisic acid (ABA) is involved in this altered metabolic processes. Results showed that S. deppei leachate on tomato seed germination mainly caused: (1) delay in starch degradation as well as in sucrose hydrolysis; (2) lower activity of sucrose phosphate synthase, cell wall invertase, and alpha-amylase; being sucrose phosphate synthase (SPS) gene expression down-regulated, and the last two up regulated; (3) also, lower activity of endo beta-mannanase, beta-1,3 glucanase, alpha-galactosidase, and exo-polygalacturonase with altered gene expression; and (4) higher content of ABA during all times of germination. The phytotoxic effect of S. deppei aqueous leachate is because of the sum of many metabolic processes affected during tomato seed germination that finally is evidenced by a strong inhibition of radicle growth.

  14. Campanulaceae: a family with small seeds that require light for germination

    PubMed Central

    Koutsovoulou, Katerina; Daws, Matthew I.; Thanos, Costas A.

    2014-01-01

    Background and Aims The Campanulaceae is a large cosmopolitan family, but is understudied in terms of germination, and seed biology in general. Small seed mass (usually in the range 10–200 µg) is a noteworthy trait of the family, and having small seeds is commonly associated with a light requirement. Thus, the purpose of this study was to investigate the effect of light on germination in 131 taxa of the Campanulaceae family, from all five continents of its distribution. Methods For all taxa, seed germination was tested in light (8 or 12 h photoperiod) and continuous darkness under constant and alternating temperatures. For four taxa, the effect of light on germination was examined over a wide range of temperatures on a thermogradient plate, and the possible substitution of the light requirement by gibberellic acid and nitrate was examined in ten taxa. Key Results For all 131 taxa, seed germination was higher in light than in darkness for every temperature tested. Across species, the light requirement decreased significantly with increasing seed mass. For larger seeded species, germination in the dark reached higher levels under alternating than under constant temperatures. Gibberellic acid promoted germination in darkness whereas nitrates partially substituted for a light requirement only in species showing some dark germination. Conclusions A light requirement for germination, observed in virtually all taxa examined, constitutes a collective characteristic of the family. It is postulated that smaller seeded taxa might germinate only on the soil surface or at shallow depths, while larger seeded species might additionally germinate when buried in the soil if cued to do so by fluctuating temperatures. PMID:24232382

  15. Effect of fungicides on Wyoming big sagebrush seed germination

    Treesearch

    Robert D. Cox; Lance H. Kosberg; Nancy L. Shaw; Stuart P. Hardegree

    2011-01-01

    Germination tests of Wyoming big sagebrush (Artemisia tridentata Nutt. ssp. wyomingensis Beetle & Young [Asteraceae]) seeds often exhibit fungal contamination, but the use of fungicides should be avoided because fungicides may artificially inhibit germination. We tested the effect of seed-applied fungicides on germination of Wyoming big sagebrush at 2 different...

  16. Modeling the Effect of Density-Dependent Chemical Interference Upon Seed Germination

    PubMed Central

    Sinkkonen, Aki

    2005-01-01

    A mathematical model is presented to estimate the effects of phytochemicals on seed germination. According to the model, phytochemicals tend to prevent germination at low seed densities. The model predicts that at high seed densities they may increase the probability of seed germination and the number of germinating seeds. Hence, the effects are reminiscent of the density-dependent effects of allelochemicals on plant growth, but the involved variables are germination probability and seedling number. The results imply that it should be possible to bypass inhibitory effects of allelopathy in certain agricultural practices and to increase the efficiency of nature conservation in several plant communities. PMID:19330163

  17. Modeling the Effect of Density-Dependent Chemical Interference upon Seed Germination

    PubMed Central

    Sinkkonen, Aki

    2006-01-01

    A mathematical model is presented to estimate the effects of phytochemicals on seed germination. According to the model, phytochemicals tend to prevent germination at low seed densities. The model predicts that at high seed densities they may increase the probability of seed germination and the number of germinating seeds. Hence, the effects are reminiscent of the density-dependent effects of allelochemicals on plant growth, but the involved variables are germination probability and seedling number. The results imply that it should be possible to bypass inhibitory effects of allelopathy in certain agricultural practices and to increase the efficiency of nature conservation in several plant communities. PMID:18648596

  18. Comparison of Germination and Viability Tests for Southern Hardwood Seed

    Treesearch

    F. T. Bonner; J. L. Gammage

    1967-01-01

    This paper summarizes a 3-year evaluation of 10 methods for testing germinability and viability of the seed of six species of southern hardwood. In five of the methods, the seeds were germinated. In the others, visual, biochemical, or physical properties were the criteria. Cutting tests were best for sweetgum and Nuttall oak seed, while cutting or water germination...

  19. 7 CFR 201.54 - Number of seeds for germination.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 3 2012-01-01 2012-01-01 false Number of seeds for germination. 201.54 Section 201.54 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Germination Tests...

  20. 7 CFR 201.53 - Source of seeds for germination.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Source of seeds for germination. 201.53 Section 201.53 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Germination Tests...

  1. 7 CFR 201.53 - Source of seeds for germination.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 3 2012-01-01 2012-01-01 false Source of seeds for germination. 201.53 Section 201.53 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Germination Tests...

  2. 7 CFR 201.54 - Number of seeds for germination.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Number of seeds for germination. 201.54 Section 201.54 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Germination Tests...

  3. 7 CFR 201.53 - Source of seeds for germination.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 3 2014-01-01 2014-01-01 false Source of seeds for germination. 201.53 Section 201.53 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Germination Tests...

  4. 7 CFR 201.54 - Number of seeds for germination.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 3 2014-01-01 2014-01-01 false Number of seeds for germination. 201.54 Section 201.54 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Germination Tests...

  5. 7 CFR 201.54 - Number of seeds for germination.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false Number of seeds for germination. 201.54 Section 201.54 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Germination Tests...

  6. 7 CFR 201.54 - Number of seeds for germination.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Number of seeds for germination. 201.54 Section 201.54 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Germination Tests...

  7. The roles of auxin in seed dormancy and germination.

    PubMed

    Shuai, Hai-wei; Meng, Yong-jie; Luo, Xiao-feng; Chen, Feng; Qi, Ying; Yang, Wen-yu; Shu, Kai

    2016-04-01

    Seed dormancy and germination are attractive topics in the fields of plant molecular biology as they are key stages during plant growth and development. Seed dormancy is intricately regulated by complex networks of phytohormones and numerous key genes, combined with diverse environmental cues. The transition from dormancy to germination is a very important biological process, and extensive studies have demonstrated that phytohormones abscisic acid (ABA) and gibberellin acid (GA) are major determinants. Consequently, the precise balance between ABA and GA can ensure that the seeds remain dormant under stress conditions and germinate at optimal times. Here we review the role of auxin in seed dormancy and germination. Auxin is one of the classic phytohormones effective during tropism growth and tissue differentiation. Recent studies, however, show that auxin possesses positive effects on seed dormancy, which suggests that auxin is the second phytohormone that induces seed dormancy, besides ABA. We will focus on the synthetic effects in detail between auxin and ABA pathways on seed dormancy and propose future research directions.

  8. Measuring effects of music, noise, and healing energy using a seed germination bioassay.

    PubMed

    Creath, Katherine; Schwartz, Gary E

    2004-02-01

    To measure biologic effects of music, noise, and healing energy without human preferences or placebo effects using seed germination as an objective biomarker. A series of five experiments were performed utilizing okra and zucchini seeds germinated in acoustically shielded, thermally insulated, dark, humid growth chambers. Conditions compared were an untreated control, musical sound, pink noise, and healing energy. Healing energy was administered for 15-20 minutes every 12 hours with the intention that the treated seeds would germinate faster than the untreated seeds. The objective marker was the number of seeds sprouted out of groups of 25 seeds counted at 12-hour intervals over a 72-hour growing period. Temperature and relative humidity were monitored every 15 minutes inside the seed germination containers. A total of 14 trials were run testing a total of 4600 seeds. Musical sound had a highly statistically significant effect on the number of seeds sprouted compared to the untreated control over all five experiments for the main condition (p < 0.002) and over time (p < 0.000002). This effect was independent of temperature, seed type, position in room, specific petri dish, and person doing the scoring. Musical sound had a significant effect compared to noise and an untreated control as a function of time (p < 0.03) while there was no significant difference between seeds exposed to noise and an untreated control. Healing energy also had a significant effect compared to an untreated control (main condition, p < 0.0006) and over time (p < 0.0001) with a magnitude of effect comparable to that of musical sound. This study suggests that sound vibrations (music and noise) as well as biofields (bioelectromagnetic and healing intention) both directly affect living biologic systems, and that a seed germination bioassay has the sensitivity to enable detection of effects caused by various applied energetic conditions.

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

    PubMed

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

    2010-04-01

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

  10. Seed germination and sowing options [Chapter 8

    Treesearch

    Tara Luna; Kim Wilkinson; R. Kasten Dumroese

    2009-01-01

    Seeds of many native species are challenging to germinate. One important thing a grower can do is learn as much as possible about the life history, ecology, and habitat of the species they wish to grow.What processes do seeds of this species go through in nature? Any observations will be valuable when trying to germinate and grow species that have little or no...

  11. Seed germination and sowing options [Chapter 9

    Treesearch

    Tara Luna; Kim M. Wilkinson; R. Kasten Dumroese

    2014-01-01

    Seeds of many native species are challenging to germinate. One important thing a grower can do is to learn as much as possible about the life history, ecology, and habitat of the species he or she wishes to grow to understand the processes seeds from each target species go through in nature. Any observations will be valuable when trying to germinate and grow species...

  12. Investigating the Influence of Karrikins on Seed Germination

    ERIC Educational Resources Information Center

    de Beer, Josef

    2012-01-01

    Recent research has identified a karrikin (a butenolide derative) known as 3-methyl-2H-furo[2,3-c]pyran-2-one, formed from burning cellulose, that stimulates seed germination. Here, I present ideas on how to investigate the influence of karrikins on seed germination in the laboratory.

  13. Dynamic DNA methylation reconfiguration during seed development and germination.

    PubMed

    Kawakatsu, Taiji; Nery, Joseph R; Castanon, Rosa; Ecker, Joseph R

    2017-09-15

    Unlike animals, plants can pause their life cycle as dormant seeds. In both plants and animals, DNA methylation is involved in the regulation of gene expression and genome integrity. In animals, reprogramming erases and re-establishes DNA methylation during development. However, knowledge of reprogramming or reconfiguration in plants has been limited to pollen and the central cell. To better understand epigenetic reconfiguration in the embryo, which forms the plant body, we compared time-series methylomes of dry and germinating seeds to publicly available seed development methylomes. Time-series whole genome bisulfite sequencing reveals extensive gain of CHH methylation during seed development and drastic loss of CHH methylation during germination. These dynamic changes in methylation mainly occur within transposable elements. Active DNA methylation during seed development depends on both RNA-directed DNA methylation and heterochromatin formation pathways, whereas global demethylation during germination occurs in a passive manner. However, an active DNA demethylation pathway is initiated during late seed development. This study provides new insights into dynamic DNA methylation reprogramming events during seed development and germination and suggests possible mechanisms of regulation. The observed sequential methylation/demethylation cycle suggests an important role of DNA methylation in seed dormancy.

  14. Water uptake mechanism and germination of Erythrina velutina seeds treated with atmospheric plasma

    NASA Astrophysics Data System (ADS)

    Alves Junior, Clodomiro; de Oliveira Vitoriano, Jussier; da Silva, Dinnara Layza Souza; de Lima Farias, Mikelly; de Lima Dantas, Nadjamara Bandeira

    2016-09-01

    The effect of plasma applied to mulungu (Erythrina velutina) seeds was studied to verify its influence on the germination, water absorption, wettability and structure of the seeds. The plasma jet used in this study was produced by dielectric barrier discharge (DBD) in a helium gas flow of 0.03 L/s at a distance of 13 mm for 60 s. The plasma treatment significantly affected the seed germination rate, which was approximately 5% higher than that of the untreated group. Micropyle and hilum contributed a greater proportion to uptake. When sealed in the hilar or micropyle regions the amount of water absorbed into the seed decreased approximately 75% compared to the unsealed seed. This difference suggests that these two regions together act cooperatively in the water absorption. However, when plasma treated seed was blocked in the micropyle region, water absorption was higher higher than in seeds blocked hilum. This difference suggests that the plasma treatment changed the wettability of the hilum more effectively than it changed the micropyle. These results indicate that plasma can significantly change the hydrophilicity, water absorption and percentage of seed germination in E. velutina.

  15. 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

  16. Germination of dimorphic seeds of Suaeda aralocaspica in response to light and salinity conditions during and after cold stratification

    PubMed Central

    Wang, Hong-Ling; Tian, Chang-Yan

    2017-01-01

    Cold stratification is a requirement for seed dormancy breaking in many species, and thus it is one of the important factors for the regulation of timing of germination. However, few studies have examined the influence of various environmental conditions during cold stratification on subsequent germination, and no study has compared such effects on the performance of dormant versus non-dormant seeds. Seeds of halophytes in the cold desert might experience different light and salinity conditions during and after cold stratification. As such, dimorphic seeds (non-dormant brown seeds and black seeds with non-deep physiological dormancy) of Suaeda aralocaspica were cold stratified under different light (12 h light–12 h darkness photoperiod or continuous darkness) or salinity (0, 200 or 1,000 mmol L-1 NaCl) conditions for 20 or 40 days. Then stratified seeds were incubated under different light or salinity conditions at daily (12/12 h) temperature regime of 10:25 °C for 20 days. For brown seeds, cold stratification was also part of the germination period. In contrast, almost no black seeds germinated during cold stratification. The longer the cold stratification, the better the subsequent germination of black seeds, regardless of light or salinity conditions. Light did not influence germination of brown seeds. Germination of cold-stratified black seeds was inhibited by darkness, especially when they were stratified in darkness. With an increase in salinity at the stage of cold stratification or germination, germination percentages of both seed morphs decreased. Combinational pre-treatments of cold stratification and salinity did not increase salt tolerance of dimorphic seeds in germination phase. Thus, light and salinity conditions during cold stratification partly interact with these conditions during germination stage and differentially affect germination of dimorphic seeds of S. aralocaspica. PMID:28828266

  17. The effects of Fusarium oxysporum on broomrape (Orobanche egyptiaca) seed germination.

    PubMed

    Hasannejad, S; Zad, S Javad; Alizade, H Mohamad; Rahymian, H

    2006-01-01

    Broomrape (Orobanche aegyptiaca L.), one of the most important parasitic weeds in Iran, is a root parasitic plant that can attack several crops such as tobacco, sunflower, tomato and etc. Several methods were used for Orobanche control, however these methods are inefficient and very costly. Biological control is an additional recent tool for the control of parasitic weeds. In order to study of the fungus Fusarium oxysporum (biocontrol agent) effects on broomrape seed germination, two laboratory studies were conducted in Tehran University. In the first experiment, different concentration of GR60 (0, 1, 2 and 5 ppm) as stimulation factor for Orobanche seeds germination were experimented. Results showed that concentrations of GR60 had a significant effect on seed germination. The highest seed germination percent was obtained in 1 ppm. In the second experiment, the effect of Fusarium oxysporum was tested on O. aegyptiaca seeds germination. The fungus Fusarium oxysporum were isolated from infested and juvenile O. aegyptiaca ower stalks in tomato field in karaj. Fungus spores suspension in different concentrations (0 (Control), 10(5) (T1), 10(6) (T2), 10(7) (T3) and 3 x 10(7) (T4)) from potato dextrose agar (PDA) prepared and together with 1ppm of GR60 concentration were tested on O. aegyptiaca seeds. Results show that the highest inhibition of seed germination obtained in 10(5) spores/ml. With increasing of suspension concentrations, inhibition percent was reduced and mortality of seeds germ tube was increased. In this investigation, Fusarium oxysporum can be used to inhibit seed germination, stimulate the "suicidal germination" of seeds and reduce the Orobanche seed bank.

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

    NASA Astrophysics Data System (ADS)

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

    2013-11-01

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

  19. Release of Esterase Following Germination of Lettuce Seed (Lactuca sativa L.)

    PubMed Central

    Chandra, G. Ram; Toole, Vivian K.

    1977-01-01

    Light-insensitive lettuce seeds, Lactuca sativa L. cv. Great Lakes, release esterases for a period following radicle protrusion. Very little or no enzymes are released prior to 24 hours or after 48 hours of germination. As compared to intact seeds, half-seeds readily release esterases and the release is not affected by far red irradiation. Bulk of the released esterases are derived from the endosperm tissue and presumably exists in the intact seed as a component of the extraembryonic fluid. PMID:16659992

  20. Seed germination, seedling traits, and seed bank of the tree Moringa peregrina (Moringaceae) in a hyper-arid environment.

    PubMed

    Gomaa, Nasr H; Picó, F Xavier

    2011-06-01

    Water-limited hot environments are good examples of hyper-aridity. Trees are scarce in these environments but some manage to survive, such as the tree Moringa peregrina. Understanding how trees maintain viable populations in extremely arid environments may provide insight into the adaptive mechanisms by which trees cope with extremely arid weather conditions. This understanding is relevant to the current increasing aridity in several regions of the world. Seed germination experiments were conducted to assess variation in seed mass, seed germination, and seedling traits of Moringa peregrina plants and the correlations among these traits. A seed burial experiment was also designed to study the fate of M. peregrina seeds buried at two depths in the soil for two time periods. On average, seeds germinated in three days and seedling shoots grew 0.7 cm per day over three weeks. Larger seeds decreased germination time and increased seedling growth rates relative to smaller seeds. Seeds remained quiescent in the soil and germination was very high at both depths and burial times. The after-ripening time of Moringa peregrina seeds is short and seeds germinate quickly after imbibition. Plants of M. peregrina may increase in hyper-arid environments from seeds with larger mass, shorter germination times, and faster seedling growth rates. The results also illustrate the adjustment in allocation to seed biomass and correlations among seed and seedling traits that allows M. peregrina to be successful in coping with aridity in its environment.

  1. Thermal niche for in situ seed germination by Mediterranean mountain streams: model prediction and validation for Rhamnus persicifolia seeds

    PubMed Central

    Porceddu, Marco; Mattana, Efisio; Pritchard, Hugh W.; Bacchetta, Gianluigi

    2013-01-01

    Background and Aims Mediterranean mountain species face exacting ecological conditions of rainy, cold winters and arid, hot summers, which affect seed germination phenology. In this study, a soil heat sum model was used to predict field emergence of Rhamnus persicifolia, an endemic tree species living at the edge of mountain streams of central eastern Sardinia. Methods Seeds were incubated in the light at a range of temperatures (10–25 and 25/10 °C) after different periods (up to 3 months) of cold stratification at 5 °C. Base temperatures (Tb), and thermal times for 50 % germination (θ50) were calculated. Seeds were also buried in the soil in two natural populations (Rio Correboi and Rio Olai), both underneath and outside the tree canopy, and exhumed at regular intervals. Soil temperatures were recorded using data loggers and soil heat sum (°Cd) was calculated on the basis of the estimated Tb and soil temperatures. Key Results Cold stratification released physiological dormancy (PD), increasing final germination and widening the range of germination temperatures, indicative of a Type 2 non-deep PD. Tb was reduced from 10·5 °C for non-stratified seeds to 2·7 °C for seeds cold stratified for 3 months. The best thermal time model was obtained by fitting probit germination against log °Cd. θ50 was 2·6 log °Cd for untreated seeds and 2·17–2·19 log °Cd for stratified seeds. When θ50 values were integrated with soil heat sum estimates, field emergence was predicted from March to April and confirmed through field observations. Conclusions Tb and θ50 values facilitated model development of the thermal niche for in situ germination of R. persicifolia. These experimental approaches may be applied to model the natural regeneration patterns of other species growing on Mediterranean mountain waterways and of physiologically dormant species, with overwintering cold stratification requirement and spring germination. PMID:24201139

  2. Effects of glyphosate acid and the glyphosate-commercial formulation (Roundup) on Dimorphandra wilsonii seed germination: Interference of seed respiratory metabolism.

    PubMed

    Gomes, Marcelo Pedrosa; da Silva Cruz, Fernanda Vieira; Bicalho, Elisa Monteze; Borges, Felipe Viègas; Fonseca, Marcia Bacelar; Juneau, Philippe; Garcia, Queila Souza

    2017-01-01

    Glyphosate-formulations are widely used in the Brazilian Cerrado (neotropical savanna) with little or no control, threatening population of the endangered species Dimorphandra wilsonii. We investigated the toxicity of different concentrations (0, 5, 25 and 50 mg l -1 ) of glyphosate acid and one of its formulations (Roundup ® ) on seed germination in D. wilsonii. Glyphosate acid and Roundup drastically decreased seed germination by decreasing seed respiration rates. The activation of antioxidant enzymes, ascorbate peroxidase and catalase assure no hydrogen peroxide accumulation in exposed seeds. Glyphosate acid and the Roundup-formulation negatively affected the activities of enzymes associated with the mitochondrial electron transport chain (ETC), with Complex III as its precise target. The toxicity of Roundup-formulation was greater than that of glyphosate acid due to its greater effects on respiration. The herbicide glyphosate must impair D. wilsonii seed germination by disrupting the mitochondrial ETC, resulting in decreased energy (ATP) production. Our results therefore indicate the importance of avoiding (or closely regulating) the use of glyphosate-based herbicides in natural Cerrado habitats of D. wilsonni as they are toxic to seed germination and therefore threaten conservation efforts. It will likewise be important to investigate the effects of glyphosate on the seeds of other species and to investigate the impacts of these pesticides elsewhere in the world. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Effects of Autumn and Spring Heat Waves on Seed Germination of High Mountain Plants.

    PubMed

    Orsenigo, Simone; Abeli, Thomas; Rossi, Graziano; Bonasoni, Paolo; Pasquaretta, Cristian; Gandini, Maurizia; Mondoni, Andrea

    2015-01-01

    Alpine plants are considered to be particularly vulnerable to climate change and related extreme episodes, such as heat waves. Despite growing interest in the impact of heat waves on alpine plants, knowledge about their effects on regeneration is still fragmentary. Recruitment from seeds will be crucial for the successful migration and survival of these species and will play a key role in their future adaptation to climate change. In this study, we assessed the impacts of heat waves on the seed germination of 53 high mountain plants from the Northern Apennines (Italy). The seeds were exposed to laboratory simulations of three seasonal temperature treatments, derived from real data recorded at a meteorological station near the species growing site, which included two heat wave episodes that occurred both in spring 2003 and in autumn 2011. Moreover, to consider the effect of increasing drought conditions related to heat waves, seed germination was also investigated under four different water potentials. In the absence of heat waves, seed germination mainly occurred in spring, after seeds had experienced autumn and winter seasons. However, heat waves resulted in a significant increase of spring germination in c. 30% of the species and elicited autumn germination in 50%. When heat waves were coupled with drought, seed germination decreased in all species, but did not stop completely. Our results suggest that in the future, heat waves will affect the germination phenology of alpine plants, especially conditionally dormant and strictly cold-adapted chorotypes, by shifting the emergence time from spring to autumn and by increasing the proportion of emerged seedlings. The detrimental effects of heat waves on recruitment success is less likely to be due to the inhibition of seed germination per se, but rather due to seedling survival in seasons, and temperature and water conditions that they are not used to experiencing. Changes in the proportion and timing of emergence

  4. Effects of Autumn and Spring Heat Waves on Seed Germination of High Mountain Plants

    PubMed Central

    Orsenigo, Simone; Abeli, Thomas; Rossi, Graziano; Bonasoni, Paolo; Pasquaretta, Cristian; Gandini, Maurizia; Mondoni, Andrea

    2015-01-01

    Alpine plants are considered to be particularly vulnerable to climate change and related extreme episodes, such as heat waves. Despite growing interest in the impact of heat waves on alpine plants, knowledge about their effects on regeneration is still fragmentary. Recruitment from seeds will be crucial for the successful migration and survival of these species and will play a key role in their future adaptation to climate change. In this study, we assessed the impacts of heat waves on the seed germination of 53 high mountain plants from the Northern Apennines (Italy). The seeds were exposed to laboratory simulations of three seasonal temperature treatments, derived from real data recorded at a meteorological station near the species growing site, which included two heat wave episodes that occurred both in spring 2003 and in autumn 2011. Moreover, to consider the effect of increasing drought conditions related to heat waves, seed germination was also investigated under four different water potentials. In the absence of heat waves, seed germination mainly occurred in spring, after seeds had experienced autumn and winter seasons. However, heat waves resulted in a significant increase of spring germination in c. 30% of the species and elicited autumn germination in 50%. When heat waves were coupled with drought, seed germination decreased in all species, but did not stop completely. Our results suggest that in the future, heat waves will affect the germination phenology of alpine plants, especially conditionally dormant and strictly cold-adapted chorotypes, by shifting the emergence time from spring to autumn and by increasing the proportion of emerged seedlings. The detrimental effects of heat waves on recruitment success is less likely to be due to the inhibition of seed germination per se, but rather due to seedling survival in seasons, and temperature and water conditions that they are not used to experiencing. Changes in the proportion and timing of emergence

  5. Effects of fruit collection date on Phillyrea latifolia L. seed germination.

    PubMed

    Yücedağ, Cengiz; Gültekin, H Cemal

    2011-08-01

    This study was conducted to determine the effects of date of fruit collection on the germination of Phillyrea latifolia L. Fruits were collected between September and December of 2007, in Egirdir, Turkey. It was found that the one thousand seed weight for the species seeds was 400 g, with significant differences among dates of fruit collection. The highest germination percentage of 58% was obtained from the seeds collected on the ground from previous years on the 1st of September 2007. The seeds from crown on the 1st of September 2007 had a germination percentage of 42%. Moreover, seeds from crown on the 1st of November and December 2007 and 15th of October and November 2007 did not germinate. In conclusion, P. latifolia seeds collected on the ground from previous years could be sown in early autumn to obtain a high germination rate.

  6. The biomechanics of seed germination.

    PubMed

    Steinbrecher, Tina; Leubner-Metzger, Gerhard

    2017-02-01

    From a biomechanical perspective, the completion of seed (and fruit) germination depends on the balance of two opposing forces: the growth potential of the embryonic axis (radicle-hypocotyl growth zone) and the restraint of the seed-covering layers (endosperm, testa, and pericarp). The diverse seed tissues are composite materials which differ in their dynamic properties based on their distinct cell wall composition and water uptake capacities. The biomechanics of embryo cell growth during seed germination depend on irreversible cell wall loosening followed by water uptake due to the decreasing turgor, and this leads to embryo elongation and eventually radicle emergence. Endosperm weakening as a prerequisite for radicle emergence is a widespread phenomenon among angiosperms. Research into the biochemistry and biomechanics of endosperm weakening has demonstrated that the reduction in puncture force of a seed's micropylar endosperm is environmentally and hormonally regulated and involves tissue-specific expression of cell wall remodelling proteins such as expansins, diverse hydrolases, and the production of directly acting apoplastic reactive oxygen. The endosperm-weakening biomechanics and its underlying cell wall biochemistry differ between the micropylar (ME) and chalazal (CE) endosperm domains. In the ME, they involve cell wall loosening, cell separation, and programmed cell death to provide decreased and localized ME tissue resistance, autolysis, and finally the formation of an ME hole required for radicle emergence. Future work will further unravel the molecular mechanisms, environmental regulation, and evolution of the diverse biomechanical cell wall changes underpinning the control of germination by endosperm weakening. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  7. Responses of seed germination, seedling growth, and seed yield traits to seed pretreatment in maize (Zea mays L.).

    PubMed

    Tian, Yu; Guan, Bo; Zhou, Daowei; Yu, Junbao; Li, Guangdi; Lou, Yujie

    2014-01-01

    A series of seed priming experiments were conducted to test the effects of different pretreatment methods to seed germination, seedling growth, and seed yield traits in maize (Zea mays L.). Results indicated that the seeds primed by gibberellins (GA), NaCl, and polyethylene glycol (PEG) reagents showed a higher imbibitions rate compared to those primed with water. The final germination percentage and germination rate varied with different reagents significantly (P < 0.05). The recommended prime reagents were GA at 10 mg/L, NaCl at 50 mM, and PEG at 15% on account of germination experiment. 15% PEG priming reagent increased shoot and root biomass of maize seedling. The shoot biomass of seedlings after presoaking the seeds with NaCl reagent was significantly higher than the seedlings without priming treatment. No significant differences of plant height, leaf number, and hundred-grain weight were observed between control group and priming treatments. Presoaking with water, NaCl (50 mM), or PEG (15%) significantly increased the hundred-grain weight of maize. Therefore, seed pretreatment is proved to be an effective technique to improve the germination performance, seedling growth, and seed yield of maize. However, when compared with the two methods, if immediate sowing is possible, presoaking is recommended to harvest better benefits compared to priming method.

  8. Improving the seed germination of little bluestem with selection

    USDA-ARS?s Scientific Manuscript database

    Rapid seed germination is an important characteristic when it comes to plant stand establishment under variable environmental conditions. This research was designed to improve the seed germination of six experimental Syn-0 lines of little bluestem [Schizachyrium scoparium (Michx.) Nash]. Two cycle...

  9. Expression and inhibition of aquaporins in germinating Arabidopsis seeds.

    PubMed

    Vander Willigen, Clare; Postaire, Olivier; Tournaire-Roux, Colette; Boursiac, Yann; Maurel, Christophe

    2006-09-01

    Extensive and kinetically well-defined water exchanges occur during germination of seeds. A putative role for aquaporins in this process was investigated in Arabidopsis. Macro-arrays carrying aquaporin gene-specific tags and antibodies raised against aquaporin subclasses revealed two distinct aquaporin expression programs between dry seeds and young seedlings. High expression levels of a restricted number of tonoplast intrinsic protein (TIP) isoforms (TIP3;1 and/or TIP3;2, and TIP5;1) together with a low expression of all 13 plasma membrane aquaporin (PIP) isoforms was observed in dry and germinating materials. In contrast, prevalent expression of aquaporins of the TIP1, TIP2 and PIP subgroups was induced during seedling establishment. Mercury (5 microM HgCl(2)), a general blocker of aquaporins in various organisms, reduced the speed of seed germination and induced a true delay in maternal seed coat (testa) rupture and radicle emergence, by 8-9 and 25-30 h, respectively. Most importantly, mercury did not alter seed lot homogeneity nor the seed germination developmental sequence, and its effects were largely reversed by addition of 2 mM dithiothreitol, suggesting that these effects were primarily due to oxidation of cell components, possibly aquaporins, without irreversible alteration of cell integrity. Measurements of water uptake in control and mercury-treated seeds suggested that aquaporin functions are not involved in early seed imbibition (phase I) but would rather be associated with a delayed initiation of phase III, i.e. water uptake accompanying expansion and growth of the embryo. A possible role for aquaporins in germinating seeds and more generally in plant tissue growth is discussed.

  10. Dormancy and germination: How does the crop seed decide?

    PubMed

    Shu, K; Meng, Y J; Shuai, H W; Liu, W G; Du, J B; Liu, J; Yang, W Y

    2015-11-01

    Whether seeds germinate or maintain dormancy is decided upon through very intricate physiological processes. Correct timing of these processes is most important for the plants life cycle. If moist conditions are encountered, a low dormancy level causes pre-harvest sprouting in various crop species, such as wheat, corn and rice, this decreases crop yield and negatively impacts downstream industrial processing. In contrast, a deep level of seed dormancy prevents normal germination even under favourable conditions, resulting in a low emergence rate during agricultural production. Therefore, an optimal seed dormancy level is valuable for modern mechanised agricultural systems. Over the past several years, numerous studies have demonstrated that diverse endogenous and environmental factors regulate the balance between dormancy and germination, such as light, temperature, water status and bacteria in soil, and phytohormones such as ABA (abscisic acid) and GA (gibberellic acid). In this updated review, we highlight recent advances regarding the molecular mechanisms underlying regulation of seed dormancy and germination processes, including the external environmental and internal hormonal cues, and primarily focusing on the staple crop species. Furthermore, future challenges and research directions for developing a full understanding of crop seed dormancy and germination are also discussed. © 2015 German Botanical Society and The Royal Botanical Society of the Netherlands.

  11. Interactions between seed traits and digestive processes determine the germinability of bird-dispersed seeds

    PubMed Central

    Soons, Merel B.

    2018-01-01

    Waterbirds disperse a wide range of plant seeds via their guts, promoting biotic connectivity between isolated habitat patches. However, the intensity of digestive forces encountered by seeds, and therefore their potential to survive digestive tract passage, varies within and between waterbird species. Here, we investigate under controlled conditions how the interaction between seed traits and digestive strategies affect the germinability of seeds following waterbird-mediated dispersal. We exposed seeds of 30 wetland plant species to the main digestive processes in the dabbling duck digestive system: mechanical, chemical and intestinal digestion. These were simulated by 1) a pressure test and scarification treatment, 2) incubation in simulated gastric juice, and 3) incubation in intestinal contents of culled mallards (Anas platyrhynchos). We evaluated their separate and combined effects on seed germination, and identified the role of seed size and seed coat traits in resisting the digestive forces. Seeds were generally resistant to separate digestive processes, but highly sensitive to a combination. Resistance to mechanical break-down was reduced by up to 80% by chemical pre-treatment, especially for seeds with permeable coats. Scarified seeds were 12–17% more vulnerable to chemical and intestinal digestive processes than undamaged seeds. Large seeds and seeds with thin, permeable coats were particularly sensitive to chemical and intestinal digestion. These results indicate that efficient digestion of seeds requires multiple digestive processes. The gizzard, responsible for mechanical digestion, plays a key role in seed survival. Omnivorous birds, which have relatively light gizzards compared to pure herbivores or granivores, are thus most likely to disperse seeds successfully. Regardless of digestive strategy, small seeds with tough seed coats are most resistant to digestion and may be adapted to endozoochorous dispersal by waterbirds. PMID:29614085

  12. Interactions between seed traits and digestive processes determine the germinability of bird-dispersed seeds.

    PubMed

    Kleyheeg, Erik; Claessens, Mascha; Soons, Merel B

    2018-01-01

    Waterbirds disperse a wide range of plant seeds via their guts, promoting biotic connectivity between isolated habitat patches. However, the intensity of digestive forces encountered by seeds, and therefore their potential to survive digestive tract passage, varies within and between waterbird species. Here, we investigate under controlled conditions how the interaction between seed traits and digestive strategies affect the germinability of seeds following waterbird-mediated dispersal. We exposed seeds of 30 wetland plant species to the main digestive processes in the dabbling duck digestive system: mechanical, chemical and intestinal digestion. These were simulated by 1) a pressure test and scarification treatment, 2) incubation in simulated gastric juice, and 3) incubation in intestinal contents of culled mallards (Anas platyrhynchos). We evaluated their separate and combined effects on seed germination, and identified the role of seed size and seed coat traits in resisting the digestive forces. Seeds were generally resistant to separate digestive processes, but highly sensitive to a combination. Resistance to mechanical break-down was reduced by up to 80% by chemical pre-treatment, especially for seeds with permeable coats. Scarified seeds were 12-17% more vulnerable to chemical and intestinal digestive processes than undamaged seeds. Large seeds and seeds with thin, permeable coats were particularly sensitive to chemical and intestinal digestion. These results indicate that efficient digestion of seeds requires multiple digestive processes. The gizzard, responsible for mechanical digestion, plays a key role in seed survival. Omnivorous birds, which have relatively light gizzards compared to pure herbivores or granivores, are thus most likely to disperse seeds successfully. Regardless of digestive strategy, small seeds with tough seed coats are most resistant to digestion and may be adapted to endozoochorous dispersal by waterbirds.

  13. Abscisic acid in the thermoinhibition of lettuce seed germination and enhancement of its catabolism by gibberellin.

    PubMed

    Gonai, Takeru; Kawahara, Shusuke; Tougou, Makoto; Satoh, Shigeru; Hashiba, Teruyoshi; Hirai, Nobuhiro; Kawaide, Hiroshi; Kamiya, Yuji; Yoshioka, Toshihito

    2004-01-01

    Germination of lettuce (Lactuca sativa L. cv. 'Grand Rapids') seeds was inhibited at high temperatures (thermoinhibition). Thermoinhibition at 28 degrees C was prevented by the application of fluridone, an inhibitor of abscisic acid (ABA) biosynthesis. At 33 degrees C, the sensitivity of the seeds to ABA increased, and fluridone on its own was no longer effective. However, a combined application of fluridone and gibberellic acid (GA3) was able to restore the germination. Exogenous GA3 lowered endogenous ABA content in the seeds, enhancing catabolism of ABA and export of the catabolites from the intact seeds. The fluridone application also decreased the ABA content. Consequently, the combined application of fluridone and GA3 decreased the ABA content to a sufficiently low level to allow germination at 33 degrees C. There was no significant temperature-dependent change in endogenous GA1 contents. It is concluded that ABA is an important factor in the regulation of thermoinhibition of lettuce seed germination, and that GA affects the temperature responsiveness of the seeds through ABA metabolism.

  14. Influence of the Testa on Seed Dormancy, Germination, and Longevity in Arabidopsis1

    PubMed Central

    Debeaujon, Isabelle; Léon-Kloosterziel, Karen M.; Koornneef, Maarten

    2000-01-01

    The testa of higher plant seeds protects the embryo against adverse environmental conditions. Its role is assumed mainly by controlling germination through dormancy imposition and by limiting the detrimental activity of physical and biological agents during seed storage. To analyze the function of the testa in the model plant Arabidopsis, we compared mutants affected in testa pigmentation and/or structure for dormancy, germination, and storability. The seeds of most mutants exhibited reduced dormancy. Moreover, unlike wild-type testas, mutant testas were permeable to tetrazolium salts. These altered dormancy and tetrazolium uptake properties were related to defects in the pigmentation of the endothelium and its neighboring crushed parenchymatic layers, as determined by vanillin staining and microscopic observations. Structural aberrations such as missing layers or a modified epidermal layer in specific mutants also affected dormancy levels and permeability to tetrazolium. Both structural and pigmentation mutants deteriorated faster than the wild types during natural aging at room temperature, with structural mutants being the most strongly affected. PMID:10677433

  15. Red fox ( Vulpes vulpes L.) favour seed dispersal, germination and seedling survival of Mediterranean Hackberry ( Celtis australis L.)

    NASA Astrophysics Data System (ADS)

    Juan, Traba; Sagrario, Arrieta; Jesús, Herranz; Cristina, Clamagirand M.

    2006-07-01

    Seeds of the Mediterranean Hackberry Celtis australis are often encountered in fox faeces. In order to evaluate the effect of gut transit on the size of seeds selected, the rates and speed of germination and on the survival of the seedlings, Mediterranean Hackberry seeds from fox faeces were germinated in a greenhouse. The results were compared with those of seeds taken from ripe, uneaten fruits. Fox-dispersed seeds were smaller and lighter than the control ones and had higher (74% vs. 57%) and more rapid germination (74.5 days vs. 99.2 days). Seedlings from fox-dispersed seeds showed significantly greater survival by the end of the study period (74.1% vs. 43.6%) than the control ones. Survival in seedlings from fox-dispersed seeds was related to germination date, late seedlings showing poorer survival. This relationship was not observed away in the control seedlings. Seed mass did not affect seedling survival. Seedling arising from fox-dispersed seeds grew faster than control ones. These results suggest that fox can play a relevant role as seed disperser of Mediterranean Hackberry.

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

    PubMed Central

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

    2016-01-01

    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. PMID:27503884

  17. 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.

  18. The effect of altitude on breaking seed dormancy and stimulation of seed germination of Persian hogweed (Heracleum persicum).

    PubMed

    Salehani, M Khajavi; Mahmoudi, J; Mahdavi, S Kh; Habibzadeh, R

    2013-01-01

    Persian hogweed is a perennial herb and aromatic plant which has pharmaceutical and fodder values, and the main propagation method of this species is seed. The goal of this study was to investigate the effect of altitude on breaking dormancy and stimulate seed germination of this species. The study was designed and carried out using the test of seed analysis. For our purpose, seeds were collected from three different altitudes (1700, 2200, 2700 masl) in Kojoor area. After initial purification, germination percent (GP) and speed (GS) of each elevation were determined by cold stratification compared to control. According to results, control seeds did not germinate, showing that the seeds of this species need to be treated. Statistical analysis of results showed that there are significant differences between GP and GS of each elevation, as seeds of higher elevation had slower and less germination in longer periods. So, changes in elevation are an effective factor on seed germination characteristics of this species and this factor has to be considered in seed preparation and restoration with this species.

  19. Seed Germination and Cuttings Growth of Piper Aduncum

    NASA Astrophysics Data System (ADS)

    Susanto, D.; Sudrajat; Suwinarti, W.; Amirta, R.

    2018-04-01

    Sirih hutan (Piper aduncum L) is one of group shurbs tropical species, has potential to be developed as raw material of biomass based electricity. The aim of this research was to know seed germination and cuttings growth of P. aduncum plant as the first step in cultivation of this plant. Observation of flowers and fruits were done in secondary forest, while seed germination and growth of shoot cuttings were done in the laboratory. The results showed that P. aduncum seeds can be germinated in a relatively short time of 17 to 25 days with a fairly high germination percentage of 90 ± 8.16% and germination rate of 4.7 ± 0.34%. The growth of seedlings at 2 months old was 4.78 ± 0.42 cm, plant height 3.97 ± 0.27 cm, and relative growth rate 0.33 ± 0.14%. The treatment of synthetic growth regulator had significant effect on shoot growth and root number on the plant stem cuttings. Preparation of seedlings ready to plant in a generative and vegetative for cultivation of these plants in the experimental plot.

  20. Effects of gut passage, feces, and seed handling on latency and rate of germination in seeds consumed by capuchins (Cebus capucinus).

    PubMed

    Valenta, Kim; Fedigan, Linda M

    2009-04-01

    One of the key measures of the effectiveness of primary seed dispersal by animals is the quality of seed dispersal (Schupp: Plant Ecol 107/108 [1993] 15-29). We present data on quality of seed dispersal by two groups of white-faced capuchins (Cebus capucinus) in Costa Rica to test the hypothesis that capuchin seed handling results in effective primary dispersal for some fruit species they consume. We examined seed handling for 27 plant species, and germination rates of 18 species consumed by capuchins. For five of the most commonly swallowed seed species, we determined germination rates and average time to germination (latency) for seeds ingested and defecated by capuchins and compared these to seeds removed directly from fruit and planted. For the same five species, we compared germination rates and latency for passed seeds planted in capuchin feces to those cleaned of feces and planted in soil. For three of five species, differences in proportion of germinated seeds were significantly higher for gut passed seeds than for controls. For four of five species, germination latency was significantly faster for gut passed seeds than for controls. Feces had either no effect on seed germination rate or precluded germination. Data presented here support the hypothesis that white-faced capuchins are effective primary dispersers.

  1. Chcanges in Germinability and Activities of Polyphenol Oxidase and Peroxidase in Seeds of Pentaclethramacrophylla During Lowtemperature Treatment

    NASA Astrophysics Data System (ADS)

    Udosen, I. R.; Nkang, A. E.; Sam, S. M.

    2012-07-01

    Activities of peroxidase (POD) and polyphenol Oxidase (PPO) were investigated in seeds of Pentaclethramacrophylla during low temperature treatment. The seeds from the small-sized fruits (variety A) and those of the big-sized fruits (variety B) showed high germination, with maximum germination values ranging between 60 ñ 90%. Low temperature treatment did not significantly (P< 0.5) affect maximum germination values. Activities of POD and PPO increased initially (2-4 days) but declined with prolonged (6ñ8 days) low temperature treatment.

  2. The Florida Harvester Ant, Pogonomyrmex badius, Relies on Germination to Consume Large Seeds

    PubMed Central

    Kwapich, Christina L.

    2016-01-01

    The Florida harvester ant, Pogonomyrmex badius, is one of many ant species and genera that stores large numbers of seeds in damp, underground chambers for later consumption. A comparison of the sizes of seeds recovered from storage chambers with those of seed husks discarded following consumption revealed that the used seeds are far smaller than stored seeds. This difference in use-rate was confirmed in field and laboratory colonies by offering marked seeds of various sizes and monitoring the appearance of size-specific chaff. Because foragers collect a range of seed sizes but only open small seeds, large seeds accumulate, forming 70% or more of the weight of seed stores. Major workers increase the rates at which small and medium seeds are opened, but do not increase the size range of opened seeds. Experiments limiting ant access to portions of natural seed chambers showed that seeds germinate during storage, but that the ants rapidly remove them. When offered alongside non germinating seeds, germinating seeds were preferentially fed to larvae. The rate of germination during the annual cycle was determined by both burial in artificial chambers at various depths and under four laboratory temperatures. The germination rate depends upon the species of seed, the soil/laboratory temperature and/or the elapsed time. The seasonal soil temperature cycle generated germination patterns that vary with the mix of locally-available seeds. Taken together, exploitation of germination greatly increases the resources available to the ants in space and time. While the largest seeds may have the nutritional value of 15 small seeds, the inability of workers to open large seeds at will precludes them from rapid use during catastrophic events. The harvester ant’s approach to seed harvesting is therefore two-pronged, with both immediate and delayed payoffs arising from the tendency to forage for a wide variety of seeds sizes. PMID:27893844

  3. The Florida Harvester Ant, Pogonomyrmex badius, Relies on Germination to Consume Large Seeds.

    PubMed

    Tschinkel, Walter R; Kwapich, Christina L

    2016-01-01

    The Florida harvester ant, Pogonomyrmex badius, is one of many ant species and genera that stores large numbers of seeds in damp, underground chambers for later consumption. A comparison of the sizes of seeds recovered from storage chambers with those of seed husks discarded following consumption revealed that the used seeds are far smaller than stored seeds. This difference in use-rate was confirmed in field and laboratory colonies by offering marked seeds of various sizes and monitoring the appearance of size-specific chaff. Because foragers collect a range of seed sizes but only open small seeds, large seeds accumulate, forming 70% or more of the weight of seed stores. Major workers increase the rates at which small and medium seeds are opened, but do not increase the size range of opened seeds. Experiments limiting ant access to portions of natural seed chambers showed that seeds germinate during storage, but that the ants rapidly remove them. When offered alongside non germinating seeds, germinating seeds were preferentially fed to larvae. The rate of germination during the annual cycle was determined by both burial in artificial chambers at various depths and under four laboratory temperatures. The germination rate depends upon the species of seed, the soil/laboratory temperature and/or the elapsed time. The seasonal soil temperature cycle generated germination patterns that vary with the mix of locally-available seeds. Taken together, exploitation of germination greatly increases the resources available to the ants in space and time. While the largest seeds may have the nutritional value of 15 small seeds, the inability of workers to open large seeds at will precludes them from rapid use during catastrophic events. The harvester ant's approach to seed harvesting is therefore two-pronged, with both immediate and delayed payoffs arising from the tendency to forage for a wide variety of seeds sizes.

  4. Effects of hypobaria and hypoxia on seed germination of six plant species

    NASA Astrophysics Data System (ADS)

    Tang, Yongkang; Gao, Feng; Guo, Shuangsheng; Li, Fang

    2014-10-01

    Hypobaria (low pressure) is typically associated with hypoxia (low oxygen partial pressure). There are several advantages of growing higher plants under hypobaria in the moon or mars habitat. The objectives of this research were to investigate the seed germination of six plant species under hypobaric and ambient total pressure conditions. Seeds were sown and germinated under three levels of total atmospheric pressure (101, 30 and 10 kPa) and three levels of oxygen partial pressures (21, 6 and 2 kPa) in an 8-day study. Hypoxia (6 or 2 kPa) significantly inhibited all seed germination under three levels of total atmospheric pressure by increasing the electrical conductivity and the optical density, decreasing the seed germination percentage and seed dehydrogenase activity and inhibiting the growth of the shoots and roots. Hypobaria (30 or 10 kPa) markedly improved seed germination and root growth by enhancing the oxygen diffusion rate under hypoxic conditions (6 or 2 kPa). The seeds of three dicot plants (lettuce, Chinese cabbage and cucumber) were more sensitive to hypoxia caused by hypobaria than were those of three monocot plants (maize, wheat and rice); lettuce and cucumber seeds had the highest sensitivity, whereas rice seeds had the lowest sensitivity. This research demonstrates that six experimental seeds can germinate normally under hypobaria (30 kPa), but the oxygen partial pressure should not be less than 6 kPa.

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

    PubMed

    Milotić, T; Hoffmann, M

    2016-11-01

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

  6. Seed reserve composition in 19 tree species of a tropical deciduous forest in Mexico and its relationship to seed germination and seedling growth

    PubMed Central

    Soriano, Diana; Orozco-Segovia, Alma; Márquez-Guzmán, Judith; Kitajima, Kaoru; Gamboa-de Buen, Alicia; Huante, Pilar

    2011-01-01

    Background and Aims The size and composition of seed reserves may reflect the ecological strategy and evolutionary history of a species and also temporal variation in resource availability. The seed mass and composition of seed reserves of 19 co-existing tree species were studied, and we examined how they varied among species in relation to germination and seedling growth rates, as well as between two years with contrasting precipitation (652 and 384 mm). Methods Seeds were collected from a tropical deciduous forest in the northwest of Mexico (Chamela Biological Station). The seed dry mass, with and without the seed coat, and the concentrations of lipids, nitrogen and non-structural carbohydrates for the seed minus seed coat were determined. The anatomical localization of these reserves was examined using histochemical analysis. The germination capacity, rate and lag time were determined. The correlations among these variables, and their relationship to previously reported seedling relative growth rates, were evaluated with and without phylogenetic consideration. Key Results There were interannual differences in seed mass and reserve composition. Seed was significantly heavier after the drier year in five species. Nitrogen concentration was positively correlated with seed coat fraction, and was significantly higher after the drier year in 12 species. The rate and lag time of germination were negatively correlated with each other. These trait correlations were also supported for phylogenetic independent contrasts. Principal component analysis supported these correlations, and indicated a negative association of seedling relative growth rate with seed size, and a positive association of germination rate with nitrogen and lipid concentrations. Conclusions Nitrogen concentration tended to be higher after the drier year and, while interannual variations in seed size and reserve composition were not sufficient to affect interspecific correlations among seed and seedling

  7. The effects of smoke derivatives on in vitro seed germination and development of the leopard orchid Ansellia africana.

    PubMed

    Papenfus, H B; Naidoo, D; Pošta, M; Finnie, J F; Van Staden, J

    2016-03-01

    Plant-derived smoke and smoke-isolated compounds stimulate germination in seeds from over 80 genera. It has also been reported that smoke affects overall plant vigour and has a stimulatory effect on pollen growth. The effect of smoke on orchid seeds, however, has not been assessed. In South Africa, orchid seeds from several genera may be exposed to smoke when they are released from their seedpods. It is therefore possible that smoke may affect their germination and growth. Therefore, the effects of smoke [applied as smoke-water (SW)] and two smoke-derived compounds, karrikinolide (KAR1 ) and trimethylbutenolide (TMB), were investigated on the germination and growth of orchid seeds in vitro. The effect of SW, KAR1 and TMB were investigated on the endangered epiphytic orchid, Ansellia africana, which is indigenous to tropical areas of Africa. Smoke-water, KAR1 and TMB were infused in half-strength MS medium. The number of germinated seeds and number of seeds and protocorm bodies to reach predetermined developmental stages were recorded on a weekly basis using a dissecting microscope for a 13-week period. Infusing SW 1:250 (v:v) into half-strength MS medium significantly increased the germination rate index (GRI) and the development rate index (DRI) of the A. africana seeds. All the SW treatments significantly increased the number of large protocorm bodies at the final stage of development. Infusing KAR1 into the growing medium had no significant effect on germination or development of the seeds. The TMB treatment, however, significantly reduced the GRI and DRI of A. africana seeds. © 2015 German Botanical Society and The Royal Botanical Society of the Netherlands.

  8. Karrikins discovered in smoke trigger Arabidopsis seed germination by a mechanism requiring gibberellic acid synthesis and light.

    PubMed

    Nelson, David C; Riseborough, Julie-Anne; Flematti, Gavin R; Stevens, Jason; Ghisalberti, Emilio L; Dixon, Kingsley W; Smith, Steven M

    2009-02-01

    Discovery of the primary seed germination stimulant in smoke, 3-methyl-2H-furo[2,3-c]pyran-2-one (KAR1), has resulted in identification of a family of structurally related plant growth regulators, karrikins. KAR1 acts as a key germination trigger for many species from fire-prone, Mediterranean climates, but a molecular mechanism for this response remains unknown. We demonstrate that Arabidopsis (Arabidopsis thaliana), an ephemeral of the temperate northern hemisphere that has never, to our knowledge, been reported to be responsive to fire or smoke, rapidly and sensitively perceives karrikins. Thus, these signaling molecules may have greater significance among angiosperms than previously realized. Karrikins can trigger germination of primary dormant Arabidopsis seeds far more effectively than known phytohormones or the structurally related strigolactone GR-24. Natural variation and depth of seed dormancy affect the degree of KAR1 stimulation. Analysis of phytohormone mutant germination reveals suppression of KAR1 responses by abscisic acid and a requirement for gibberellin (GA) synthesis. The reduced germination of sleepy1 mutants is partially recovered by KAR1, which suggests that germination enhancement by karrikin is only partly DELLA dependent. While KAR1 has little effect on sensitivity to exogenous GA, it enhances expression of the GA biosynthetic genes GA3ox1 and GA3ox2 during seed imbibition. Neither abscisic acid nor GA levels in seed are appreciably affected by KAR1 treatment prior to radicle emergence, despite marked differences in germination outcome. KAR1 stimulation of Arabidopsis germination is light-dependent and reversible by far-red exposure, although limited induction of GA3ox1 still occurs in the dark. The observed requirements for light and GA biosynthesis provide the first insights into the karrikin mode of action.

  9. Seed germination of seven desert plants and implications for vegetation restoration

    PubMed Central

    Lai, Liming; Chen, Lijun; Jiang, Lianhe; Zhou, Jihua; Zheng, Yuanrun; Shimizu, Hideyuki

    2016-01-01

    Germination cues reflect the conditions under which a species is likely to succeed in recruitment. Therefore, knowledge of the seed germination characteristics of key plant species in desertified areas is essential for restoration. The aims of this study were to evaluate the seed germination responses of seven native species, and to explore the implications for vegetation restoration. Seeds of seven desert species were sown in Petri dishes and subjected to various temperature and light conditions. The seeds germinated well at day/night temperatures of 25/15 °C and 30/20 °C but poorly at 35/25 °C. Seeds germinated best in the dark, and final germination percentages of all species were strongly inhibited at a photon irradiance of 1000 µmol m−2 s−1. Based on these results and the environmental conditions of their natural habitat, Agropyron cristatum and Artemisia halodendron are best adapted to shifting sand dunes: Elymus dahuricus, Caragana korshinskii and C. microphylla for semi-fixed sand dunes: and Medicago sativa and Melilotus suaveolen for fixed sand dunes. If seeds are sown in early May, they will likely be buried in sand, and the precipitation and temperature conditions will be suitable for seedling survival. PMID:27179541

  10. Seed Hydropriming and Smoke Water Significantly Improve Low-Temperature Germination of Lupinus angustifolius L.

    PubMed

    Płażek, Agnieszka; Dubert, Franciszek; Kopeć, Przemysław; Dziurka, Michał; Kalandyk, Agnieszka; Pastuszak, Jakub; Wolko, Bogdan

    2018-03-26

    Seed imbibition under cold temperature is dangerous when dry seeds have relatively low water content. The aim of this study was to investigate germination of 20 lines/cultivars of narrow-leaf lupine at 7 °C (cold) and 13 °C (control) under the influence of smoke water and following seed hydropriming for 3 h at 20 °C. The efficacy of individual treatments was examined with regard to seed protection during low-temperature germination. Based on seed germination, vigour at cold was evaluated four days after sowing by means of hypocotyl length, the studied lines/cultivars were divided into three groups with low, high and very high germination rates. Germination vigour correlated with cell membrane permeability, dehydrogenase activity and abscisic acid (ABA) content and was analysed in the seeds one day after sowing. Gibberellin content did not correlate with germination vigour. The seeds of weakly germinating lines/cultivars had the highest cell permeability and ABA content as well as the lowest amylolytic activity at both studied temperatures. Additionally, the vigour of weakly germinating seeds at 7 °C correlated with dehydrogenase activity. Three-hour hydropriming was the most effective for seed germination under cold due to reduced cell membrane permeability and ABA level. Stimulating effects of smoke water on germination under cold could be explained by enhanced dehydrogenase activity.

  11. Using hyperspectral imaging to determine germination of native Australian plant seeds.

    PubMed

    Nansen, Christian; Zhao, Genpin; Dakin, Nicole; Zhao, Chunhui; Turner, Shane R

    2015-04-01

    We investigated the ability to accurately and non-destructively determine the germination of three native Australian tree species, Acacia cowleana Tate (Fabaceae), Banksia prionotes L.F. (Proteaceae), and Corymbia calophylla (Lindl.) K.D. Hill & L.A.S. Johnson (Myrtaceae) based on hyperspectral imaging data. While similar studies have been conducted on agricultural and horticultural seeds, we are unaware of any published studies involving reflectance-based assessments of the germination of tree seeds. Hyperspectral imaging data (110 narrow spectral bands from 423.6nm to 878.9nm) were acquired of individual seeds after 0, 1, 2, 5, 10, 20, 30, and 50days of standardized rapid ageing. At each time point, seeds were subjected to hyperspectral imaging to obtain reflectance profiles from individual seeds. A standard germination test was performed, and we predicted that loss of germination was associated with a significant change in seed coat reflectance profiles. Forward linear discriminant analysis (LDA) was used to select the 10 spectral bands with the highest contribution to classifications of the three species. In all species, germination decreased from over 90% to below 20% in about 10-30days of experimental ageing. P50 values (equal to 50% germination) for each species were 19.3 (A. cowleana), 7.0 (B. prionotes) and 22.9 (C. calophylla) days. Based on independent validation of classifications of hyperspectral imaging data, we found that germination of Acacia and Corymbia seeds could be classified with over 85% accuracy, while it was about 80% for Banksia seeds. The selected spectral bands in each LDA-based classification were located near known pigment peaks involved in photosynthesis and/or near spectral bands used in published indices to predict chlorophyll or nitrogen content in leaves. The results suggested that seed germination may be successfully classified (predicted) based on reflectance in narrow spectral bands associated with the primary metabolism

  12. Effect of Radiation on Seed Germinating Ability Ofwild-Growing and Cultivated Plants, Sources of Bioactive Substances

    NASA Astrophysics Data System (ADS)

    Shabanov, Aleksandr; Tirranen, Lyalya; Zykova, Irina; Bondarenko, Gennadiy

    2016-07-01

    In the above-ground parts of common chickweed (Stellaria media) the content of vitamin C was experimentally quantified, which (in terms of dry matter) was 81.55 mg/100 g; 133 mg/100 g and 161.76 mg/100 g depending on the growing site. 52 components were detected in the essential oil of the above-ground parts of common chickweed (Stellaria media). Chamazulene, neophytodien and phytol are the major components of whole oil. A wide range of elements was identified in the plants and seeds of common chickweed (Stellaria media), and in the seeds of carrots, parsley and lettuce. It was established that UV irradiation (lamp with a wavelength of 254 nm and 283 nm) of chickweed seeds (Stellaria media) for 15 sec. and 100 sec. in a microbiological box on a table at a distance from the object didn't affect their germinating ability. The germinating ability of the experimental seeds was identical to the control (no irradiation) seeds. With the help of an X-ray fluorescence spectrometer Renger 2 (Germany) at a voltage of 1.6 kV during 15 sec. the effect of "soft" radiation on the seed germinating ability of chickweed, carrot, parsley and lettuce seeds was studied.Under the effect of "soft" radiation during 15 sec. all the experimental chickweed seeds sprouted, like in the control. The germinating ability of the exposed lettuce seeds was 100% after one day, while only 45% of the exposed parsley seeds grew after 21 days. The exposed carrot seeds (70%) grew after 18 days. The effect of "hard" radiation on the germinating ability of common chickweed seeds was investigated using an X-ray fluorescence spectrometer S4 Pioneer (Germany) at a voltage of 60 kV for 15 sec and 100 sec. Under the effect of "hard" radiation and during 15 seconds of exposure, where the distance (L) from the focus of the X-ray tube to the seeds of chickweed was 20 mm, the germinating ability of the experimental chickweed seeds was 30 %. At a voltage of 60 kV and 100-second exposure the germinating ability of the

  13. Effect of fungicide on Wyoming big sagebrush seed germination

    USDA-ARS?s Scientific Manuscript database

    Because fungal infection may complicate both the logistics and the interpretation of germination tests, seeds are sometimes treated with chemical fungicides. Fungicides may reduce the germination rate and/or germination percentage, and should be avoided unless fungal contamination is severe enough ...

  14. Winery wastewater inhibits seed germination and vegetative growth of common crop species.

    PubMed

    Mosse, Kim P M; Patti, Antonio F; Christen, Evan W; Cavagnaro, Timothy R

    2010-08-15

    The ability to reuse winery wastewater would be of significant benefit to the wine industry, as it could potentially be a cost-effective method of wastewater management, whilst at the same time providing a valuable water resource. This study investigated the effects of different dilutions of a semi-synthetic winery wastewater on the growth and germination of four common crop species in a glasshouse study; barley (Hordeum vulgare), millet (Pennisetum glaucum), lucerne (Medicago sativa) and phalaris (Phalaris aquatica). The wastewater caused a significant delay in the germination of lucerne, millet and phalaris, although overall germination percentage of all species was not affected. Vegetative growth was significantly reduced in all species, with millet being the most severely affected. The germination index of barley correlated very highly (r(2)=0.99) with barley biomass, indicating that barley seed germination bioassays are highly relevant to plant growth, and therefore may be of use as a bioassay for winery wastewater toxicity. Copyright 2010 Elsevier B.V. All rights reserved.

  15. Proteomic investigation of the effect of salicylic acid on Arabidopsis seed germination and establishment of early defense mechanisms.

    PubMed

    Rajjou, Loïc; Belghazi, Maya; Huguet, Romain; Robin, Caroline; Moreau, Adrien; Job, Claudette; Job, Dominique

    2006-07-01

    The influence of salicylic acid (SA) on elicitation of defense mechanisms in Arabidopsis (Arabidopsis thaliana) seeds and seedlings was assessed by physiological measurements combined with global expression profiling (proteomics). Parallel experiments were carried out using the NahG transgenic plants expressing the bacterial gene encoding SA hydroxylase, which cannot accumulate the active form of this plant defense elicitor. SA markedly improved germination under salt stress. Proteomic analyses disclosed a specific accumulation of protein spots regulated by SA as inferred by silver-nitrate staining of two-dimensional gels, detection of carbonylated (oxidized) proteins, and neosynthesized proteins with [35S]-methionine. The combined results revealed several processes potentially affected by SA. This molecule enhanced the reinduction of the late maturation program during early stages of germination, thereby allowing the germinating seeds to reinforce their capacity to mount adaptive responses in environmental water stress. Other processes affected by SA concerned the quality of protein translation, the priming of seed metabolism, the synthesis of antioxidant enzymes, and the mobilization of seed storage proteins. All the observed effects are likely to improve seed vigor. Another aspect revealed by this study concerned the oxidative stress entailed by SA in germinating seeds, as inferred from a characterization of the carbonylated (oxidized) proteome. Finally, the proteomic data revealed a close interplay between abscisic signaling and SA elicitation of seed vigor.

  16. 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

  17. [Effect of Astragalus membranaceus var. mongholicus seed extracts on seed germination and seedling growth of different Codonopsis pilosula caltiver].

    PubMed

    Guo, Feng-Xia; Wu, Zhi-Jiang; Chen, Yuan; Xi, Zhuo-Xia; Zhang, Xiao-Hu; Yao, Li-Rong; Chen, Xiang

    2012-11-01

    To reveal the allelopathy effect of Astragalus membranaceus var. mongholicus seeds and provide information for the intercrop production. The A. membranaceus. var. mongholicus seeds were soaked in distilled water for different time (12, 24, 36, 48, 60 h) , and then the seed extracts were used to study their effects on the seed germination, seedling growth and development of two Codonopsis pilosula. The A. membranaceus var. mongholicus seeds contained some allelopathy compounds. Their soaked liquid had significantly influence on the seed germination and seedling growth of C. pilosula. The seed germination rate, germination power, germination index and vigor index of two C. pilosula calrivar were improved and then inhabited with soaking time elongation. The extract soaking for 24 h significantly improved the germination traits but the extract for 60 h appeared different degrees of inhibiting vigor. The seed extracts soaking ranging between 12 and 60 h all significantly improved the above plant growth of C. pilosula but significant inhibited their radicle growth in length. And with the soaking time elongation the facilitation effect weakened and the inhibiting effect enhanced, especially more significant in the C. pilosula caltivar (Baitiaodangshen). The A. membranaceus var. mongholicus seeds have allelopathic compounds and the endogenous inhibitor can be extracted when soaked for more than 24 h in water with intact seeds, resulting in improvement of seed germination rate. The C. pilosula could be intercropped in A. membranaceus var. mongholicus field, however, when intercroped it should notice that the intercrop proportion should vary with the caltivar.

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

    PubMed

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

    2015-10-01

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

  19. Ecological niche and bet-hedging strategies for Triodia (R.Br.) seed germination.

    PubMed

    Lewandrowski, Wolfgang; Erickson, Todd E; Dalziell, Emma L; Stevens, Jason C

    2018-02-12

    Regeneration dynamics in many arid zone grass species are regulated by innate seed dormancy mechanisms and environmental cues (temperature, moisture and fire) that result in infrequent germination following rainfall. This study investigated bet-hedging strategies associated with dormancy and germination in arid zone Triodia species from north-west Australia, by assessing (1) the effects of the mechanical restriction imposed by the indehiscent floral bracts (i.e. floret) covering the seed and (2) the impact of dormancy alleviation on florets and cleaned seeds (i.e. florets removed) when germinated under water stress. The initial dormancy status and germination for six species were tested on intact florets and cleaned seeds, across temperatures (10-40 °C) with and without the fire-related stimulant karrikinolide (KAR1), and under alternating light or constant dark conditions. Physiological dormancy alleviation was assessed by wet/dry cycling florets over a period of 10 weeks, and germination was compared against untreated florets, and cleaned seeds across a water potential gradient between 0 and -1.5 MPa. Florets restricted germination (<45 %) at all temperatures and, despite partial alleviation of physiological dormancy (wet/dry cycling for 8 weeks), intact florets germinated only at high water potentials. Cleaned seeds showed the highest germination (40-90 %) across temperatures when treated with KAR1, and germinated at much lower water potentials (-0.4 and -0.9 MPa). Triodia pungens was the most responsive to KAR1, with both seeds and florets responding, while for the remaining five species, KAR1 had a positive effect for seeds only. Only after seed dormancy was alleviated by removing florets and when KAR1 was applied did germination under water stress increase. This suggests that seeds of these Triodia species are cued to recruit following fire and during periods of high precipitation. Climate change, driven by large shifts in rainfall patterns, is likely to

  20. Transcription factor AtTCP14 regulates embryonic growth potential during seed germination in Arabidopsis thaliana.

    PubMed

    Tatematsu, Kiyoshi; Nakabayashi, Kazumi; Kamiya, Yuji; Nambara, Eiji

    2008-01-01

    To understand the molecular mechanisms underlying regulation of seed germination, we searched enriched cis elements in the upstream regions of Arabidopsis genes whose transcript levels increased during seed germination. Using available published microarray data, we found that two cis elements, Up1 or Up2, which regulate outgrowth of Arabidopsis axillary shoots, were significantly over-represented. Classification of Up1- and Up2-containing genes by gene ontology revealed that protein synthesis-related genes, especially ribosomal protein genes, were highly over-represented. Expression analysis using a reporter gene driven by a synthetic promoter regulated by these elements showed that the Up1 is necessary and sufficient for germination-associated gene induction, whereas Up2 acts as an enhancer of Up1. Up1-mediated gene expression was suppressed by treatments that blocked germination. Up1 is almost identical to the site II motif, which is the predicted target of TCP transcription factors. Of 24 AtTCP genes, AtTCP14, which showed the highest transcript level just prior to germination, was functionally characterized to test its involvement in the regulation of seed germination. Transposon-tagged lines for AtTCP14 showed delayed germination. In addition, germination of attcp14 mutants exhibited hypersensitivity to exogenously applied abscisic acid and paclobutrazol, an inhibitor of gibberellin biosynthesis. AtTCP14 was predominantly expressed in the vascular tissues of the embryo, and affected gene expression in radicles in a non-cell-autonomous manner. Taken together, these results indicate that AtTCP14 regulates the activation of embryonic growth potential in Arabidopsis seeds.

  1. Seed dormancy and germination of Ficus lundellii and tropical forest restoration.

    PubMed

    Garcia, Ximena; Hong, Tran D; Ellis, Richard H

    2006-01-01

    We investigated seed dormancy and germination in Ficus lundellii Standl. (Moraceae), a native species of Mexico's Los Tuxtlas tropical rain forest. In an 8-h photoperiod at an alternating diurnal (16/8 h) temperature of 20/30 degrees C, germination was essentially complete (96%) within 28 days, whereas in darkness, all seeds remained dormant. Neither potassium nitrate (0.05-0.2%) applied continuously nor gibberellic acid applied either continuously (10-200 ppm) or as a 24 hour pretreatment (2000 ppm) induced germination in the dark. Germination in the light was not reduced by a 24-h hydrochloric acid (0.1-1%) pretreatment, but it was reduced both by a 24-h pretreatment with either H(2)O(2) (0.1-5 M) or 5% HCl, or by more than 5 days of storage at 40 degrees C (4.5% seed water content). In a study with a 2-dimensional temperature gradient plate, seeds germinated fully and rapidly in the light at a constant temperature of 30 degrees C, and fully but less rapidly in the light at alternating temperatures with low amplitudes (< 12 degrees C) about the optimal constant temperature. The base, optimal and ceiling temperatures for rate of germination were estimated as 13.8, 30.1 and 41.1 degrees C, respectively. In all temperature regimes, light was essential for the germination of F. lundellii seeds.

  2. Greenhouse germination trials of pelletized western redcedar and red alder seeds

    Treesearch

    Nabil Khadduri

    2007-01-01

    Pelletized western redcedar (Thuja plicata Donn ex D. Don) and red alder (Alnus rubra Bong.) seeds exhibited lower total germination and delayed germination speed (G50 or days to 50% germination) when compared to non-pelletized “raw” seeds in greenhouse trials. Averaged across two lots of western redcedar, pelletizing decreased...

  3. Effect of population, collection year, after-ripening and incubation condition on seed germination of Stipa bungeana.

    PubMed

    Zhang, Rui; Baskin, J M; Baskin, C C; Mo, Qing; Chen, Lijun; Hu, Xiaowen; Wang, Yanrong

    2017-10-24

    Knowledge of the germination behavior of different populations of a species can be useful in the selection of appropriate seed sources for restoration. The aim of this study was to test the effect of seed population, collection year, after-ripening and incubation conditions on seed dormancy and germination of Stipa bungeana, a perennial grass used for revegetation of degraded grasslands on the Loess Plateau, China. Fresh S. bungeana seeds were collected from eight locally-adapted populations in 2015 and 2016. Dormancy and germination characteristics of fresh and 6-month-old dry-stored seeds were determined by incubating them over a range of alternating temperature regimes in light. Effect of water stress on germination was tested for fresh and 6-month-old dry-stored seeds. Seed dormancy and germination of S. bungeana differed with population and collection year. Six months of dry storage broke seed dormancy, broadened the temperature range for germination and increased among-population differences in germination percentage. The rank order of germination was not consistent in all germination tests, and it varied among populations. Thus, studies on comparing seed dormancy and germination among populations must consider year of collection, seed dormancy states and germination test conditions when selecting seeds for grassland restoration and management.

  4. Seed dormancy and germination of Halophila ovalis mediated by simulated seasonal temperature changes

    NASA Astrophysics Data System (ADS)

    Statton, John; Sellers, Robert; Dixon, Kingsley W.; Kilminster, Kieryn; Merritt, David J.; Kendrick, Gary A.

    2017-11-01

    The seagrass, Halophila ovalis plays an important ecological and sediment stability role in estuarine systems in Australia with the species in decline in many sites. Halophila ovalis is a facultative annual, relying mainly on recruitment from the sediment seed bank for the annual regeneration of meadows. Despite this, there is little understanding of seed dormancy releasing mechanisms and germination cues. Using H. ovalis seed from the warm temperate Swan River Estuary in Western Australia, the germination ecology of H. ovalis was investigated by simulating the natural seasonal variation in water temperatures. The proportion of germinating seeds was found to be significantly different among temperature treatments (p < 0.001). The treatment with the longest period of cold exposure at 15 °C followed by an increase in temperature to 20-25 °C (i.e. cold stratification) had the highest final mean germination of 32% and the fastest germination rate. Seeds exposed to constant mean winter temperatures of 15 °C had the slowest germination rate with less than two seeds germinating over 118 days. Thus temperature is a key germination cue for H. ovalis seeds and these data infer that cold stratification is an important dormancy releasing mechanism. This finding has implications for recruitment in facultative annual species like H. ovalis under global warming since the trend for increasing water temperatures in the region may limit seed-based recruitment in the future.

  5. [Study on morphology, quality and germination characteristics of Acanthopanax trifoliatus seeds under different habitats].

    PubMed

    Xiao, Juan

    2014-05-01

    To preliminary explore the difference of the morphological, quality and germinal characteristics of Acanthopanax trifoliatus seeds under different habitats. Collect the wild seeds from different habitats in West Mountain, and then observe their external appearances and internal structure, and test the thousand seeds weight,water content and seed vigor. What's more, the influence to germination rates of the seeds from different temperatures and light intensities in artificial bioclimatic chamber was studied. Orthogonal test in experimental plots was carried out to screen the different sowing dates, matrix types and soil depths which may influence germination rate. The external appearances and quality characteristics of wild seeds from three habitats were different. Seeds could germinate in the both light and dark, the germination rate of the habitat II was as high as 70.5% at the optimum temperature 20 degrees C in artificial bioclimatic chamber. The optimal combination A1, B1, C1 was screened out through orthogonal test, namely, the germination rate would be the highest when the seeds sowed in autumn covering with 2 cm depth of matrix type which component of the ratio of soil, sand and organic fertilizer was 6: 3: 1. There was significant difference in the morphology and germination rate of the three habitats seeds. The habitat II seeds were the optimal choice when culture seedling. The influences of different temperatures on germination rate were different, and the dried seeds should sow in current autumn, better than the next spring.

  6. Phylogeny and source climate impact seed dormancy and germination of restoration-relevant forb species

    PubMed Central

    Williams, Evelyn; Bilge, Arman; Kramer, Andrea T.

    2018-01-01

    For many species and seed sources used in restoration activities, specific seed germination requirements are often unknown. Because seed dormancy and germination traits can be constrained by phylogenetic history, related species are often assumed to have similar traits. However, significant variation in these traits is also present within species as a result of adaptation to local climatic conditions. A growing number of studies have attempted to disentangle how phylogeny and climate influence seed dormancy and germination traits, but they have focused primarily on species-level effects, ignoring potential population-level variation. We examined the relationships between phylogeny, climate, and seed dormancy and germination traits for 24 populations of eight native, restoration-relevant forb species found in a wide range of climatic conditions in the Southwest United States. The seeds were exposed to eight temperature and stratification length regimes designed to mimic regional climatic conditions. Phylogenetic relatedness, overall climatic conditions, and temperature conditions at the site were all significantly correlated with final germination response, with significant among-population variation in germination response across incubation treatments for seven of our eight study species. Notably, germination during stratification was significantly predicted by precipitation seasonality and differed significantly among populations for seven species. While previous studies have not examined germination during stratification as a potential trait influencing overall germination response, our results suggest that this trait should be included in germination studies as well as seed sourcing decisions. Results of this study deepen our understanding of the relationships between source climate, species identity, and germination, leading to improved seed sourcing decisions for restorations. PMID:29401470

  7. Mycoheterotrophic germination of Pyrola asarifolia dust seeds reveals convergences with germination in orchids.

    PubMed

    Hashimoto, Yasushi; Fukukawa, Satoru; Kunishi, Ayako; Suga, Haruhisa; Richard, Franck; Sauve, Mathieu; Selosse, Marc-André

    2012-08-01

    Dust seeds that germinate by obtaining nutrients from symbiotic fungi have evolved independently in orchids and 11 other plant lineages. The fungi involved in this 'mycoheterotrophic' germination have been identified in some orchids and non-photosynthetic Ericaceae, and proved identical to mycorrhizal fungi of adult plants. We investigated a third lineage, the Pyroleae, chlorophyllous Ericaceae species whose partial mycoheterotrophy at adulthood has recently attracted much attention. We observed experimental Pyrola asarifolia germination at four Japanese sites and investigated the germination pattern and symbiotic fungi, which we compared to mycorrhizal fungi of adult plants. Adult P. asarifolia, like other Pyroleae, associated with diverse fungal species that were a subset of those mycorrhizal on surrounding trees. Conversely, seedlings specifically associated with a lineage of Sebacinales clade B (endophytic Basidiomycetes) revealed an intriguing evolutionary convergence with orchids, some of which also germinate with Sebacinales clade B. Congruently, seedlings clustered spatially together, but not with adults. This unexpected transition in specificity and ecology of partners could support the developmental transition from full to partial mycoheterotrophy, but probably challenges survival and distribution during development. We discuss the physiological and ecological traits that predisposed to the repeated recruitment of Sebacinales clade B for dust seed germination. © 2012 The Authors. New Phytologist © 2012 New Phytologist Trust.

  8. Sodium chloride effects on lipase activity in germinating rape seeds.

    PubMed

    Ben Miled, D D; Zarrouk, M; Chérif, A

    2000-12-01

    Seeds of rape (Brassica napus L.) were germinated at various NaCl concentrations up to 200 mM. Germinating levels, seedling growth, triacylglycerol mobilization and lipase activity were investigated. High salt concentrations resulted in retardation of seed germination. Seedling growth as measured by radicle length was severely reduced by NaCl doses higher than 50 mM. Moreover, the mobilization of storage oil in control rapeseed seedlings, started about 24 h after imbibition. As for germination and growth, elevated salt concentrations are found to delay triacylglycerol degradation. Experiments using triolein as substrate indicated clearly that lipase activity was inhibited by salt treatment.

  9. Methods to Promote Germination of Dormant Setaria viridis Seeds

    PubMed Central

    Sebastian, Jose; Wong, Mandy Ka; Tang, Evan; Dinneny, José R.

    2014-01-01

    Setaria viridis has recently emerged as a promising genetic model system to study diverse aspects of monocot biology. While the post-germination life cycle of S. viridis is approximately 8 weeks long, the prolonged dormancy of freshly harvested seeds can more than double the total time required between successive generations. Here we describe methods that promote seed germination in S. viridis. Our results demonstrate that treating S. viridis seeds with liquid smoke or a GA3 and KNO3 solution improves germination rates to 90% or higher even in seeds that are 6 days post-harvest with similar results obtained whether seeds are planted in soil or on gel-based media. Importantly, we show that these treatments have no significant effect on the growth of the adult plant. We have tested these treatments on diverse S. viridis accessions and show variation in their response. The methods described here will help advance research using this model grass species by increasing the pace at which successive generations of plants can be analyzed. PMID:24748008

  10. Expression of a Polygalacturonase Associated with Tomato Seed Germination1

    PubMed Central

    Sitrit, Yaron; Hadfield, Kristen A.; Bennett, Alan B.; Bradford, Kent J.; Downie, A. Bruce

    1999-01-01

    Radicle protrusion from tomato (Lycopersicon esculentum Mill.) seeds to complete germination requires weakening of the endosperm tissue opposite the radicle tip. In common with other cell wall disassembly processes in plants, polygalacturonases (PGs) may be involved. Only calcium-dependent exo-PG activity was detected in tomato seed protein extracts. Chromatographic profiles of a partially acid-hydrolyzed fraction of polygalacturonic acid further digested with seed extract were consistent with the presence of only calcium-dependent exo-PG activity. In addition, a transcript encoding a previously unknown PG was detected prior to the completion of germination. The mRNA, produced from a gene (LeXPG1) estimated by Southern analysis to be represented once in the genome, was also present in flowers (anthers) and in lower amounts in roots and stems. LeXPG1 mRNA abundance was low during seed development, increased during imbibition, and was even greater in seeds that had completed germination. Expression of LeXPG1 during germination predominates in the endosperm cap and radicle tip, and in the radicle appears as a distinct band possibly associated with vascular tissue differentiation. We suggest that PG is involved in cell wall loosening of the endosperm necessary for radicle protrusion from tomato seeds and in subsequent embryo and seedling growth. PMID:10517833

  11. Software Tools for Weed Seed Germination Modeling

    USDA-ARS?s Scientific Manuscript database

    The next generation of weed seed germination models will need to account for variable soil microclimate conditions. In order to predict this microclimate environment we have developed a suite of individual tools (models) that can be used in conjunction with the next generation of weed seed germinati...

  12. Temporal changes in fungal communities from buckwheat seeds and their effects on seed germination and seedling secondary metabolism.

    PubMed

    Kovačec, Eva; Likar, Matevž; Regvar, Marjana

    2016-05-01

    Seed-associated fungal communities affect multiple parameters of seed quality at all stages of production, from seed development to post-harvest storage and germination. We therefore investigated the diversity and dynamics of fungal communities in the seeds of common buckwheat (Fagopyrum esculentum) and Tartary buckwheat (F. tataricum) from harvest to 1 y of storage. Fungal populations in seeds were relatively stable, comprised mainly of field fungi. Incidence of fungi was most likely determined by fungal interspecies direct interactions, as well as by their synthesis of volatile organic compounds. Most prominent antagonistic interactions were seen for two plant pathogens, Alternaria alternata on Botrytis cinerea. Detrimental effects of the fungi on seed germination and seedling development were related to fungal extracellular enzyme activity, and in particular to amylase, cellulase and, polyphenol oxidase. Polyphenol and tannin concentrations in buckwheat seedlings were related to fungal growth rate and intensity of fungal cellulase activity, respectively, which suggests that physical penetration of the fungi through the host tissues is probably the stimulus for the activation of plant defence reactions in these seedlings. Copyright © 2016 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

  13. Small Heat Shock Proteins Can Release Light Dependence of Tobacco Seed during Germination1[OPEN

    PubMed Central

    Koo, Hyun Jo; Park, Soo Min; Kim, Keun Pill; Suh, Mi Chung; Lee, Mi Ok; Lee, Seong-Kon; Xinli, Xia

    2015-01-01

    Small heat shock proteins (sHSPs) function as ATP-independent molecular chaperones, and although the production and function of sHSPs have often been described under heat stress, the expression and function of sHSPs in fundamental developmental processes, such as pollen and seed development, have also been confirmed. Seed germination involves the breaking of dormancy and the resumption of embryo growth that accompany global changes in transcription, translation, and metabolism. In many plants, germination is triggered simply by imbibition of water; however, different seeds require different conditions in addition to water. For small-seeded plants, like Arabidopsis (Arabidopsis thaliana), lettuce (Lactuca sativa), tomato (Solanum lycopersicum), and tobacco (Nicotiana tabacum), light is an important regulator of seed germination. The facts that sHSPs accumulate during seed development, sHSPs interact with various client proteins, and seed germination accompanies synthesis and/or activation of diverse proteins led us to investigate the role of sHSPs in seed germination, especially in the context of light dependence. In this study, we have built transgenic tobacco plants that ectopically express sHSP, and the effect was germination of the seeds in the dark. Administering heat shock to the seeds also resulted in the alleviation of light dependence during seed germination. Subcellular localization of ectopically expressed sHSP was mainly observed in the cytoplasm, whereas heat shock-induced sHSPs were transported to the nucleus. We hypothesize that ectopically expressed sHSPs in the cytoplasm led the status of cytoplasmic proteins involved in seed germination to function during germination without additional stimulus and that heat shock can be another signal that induces seed germination. PMID:25604531

  14. Allelopathic effects of weeds extracts against seed germination of some plants.

    PubMed

    Kadioglu, Izzet; Yanar, Yusuf; Asav, Unal

    2005-04-01

    This study investigated the allelopathic effects of various weeds extracts on seed germination of 11 crop species. Most of the weed extracts tested had inhibitory effects on seed germination of common bean, tomato, pepper, squash, onion, barley, wheat, and corn at different application rates as compared with the 10% acetone control. Chickpea seed germination was inhibited by extracts of Solanum nigrum L., Chenopodium album L., and Matricaria chamomilla L. (10%, 20% and 22.5%, respectively) at the end of 21 day incubation period. However, Glycyrrhiza glabra L., Sorghum halepense (L.) Pers., and Reseda lutea L. extracts stimulated chickpea seed germination at the rates of 95%, 94%, and 93%, respectively, compared to control. It was concluded that some of the weed extracts tested in this study could be used as inhibitor while others could be used as stimulator for the crops.

  15. S-nitrosylation triggers ABI5 degradation to promote seed germination and seedling growth

    PubMed Central

    Albertos, Pablo; Romero-Puertas, María C.; Tatematsu, Kiyoshi; Mateos, Isabel; Sánchez-Vicente, Inmaculada; Nambara, Eiji; Lorenzo, Oscar

    2015-01-01

    Plant survival depends on seed germination and progression through post-germinative developmental checkpoints. These processes are controlled by the stress phytohormone abscisic acid (ABA). ABA regulates the basic leucine zipper transcriptional factor ABI5, a central hub of growth repression, while the reactive nitrogen molecule nitric oxide (NO) counteracts ABA during seed germination. However, the molecular mechanisms by which seeds sense more favourable conditions and start germinating have remained elusive. Here we show that ABI5 promotes growth via NO, and that ABI5 accumulation is altered in genetic backgrounds with impaired NO homeostasis. S-nitrosylation of ABI5 at cysteine-153 facilitates its degradation through CULLIN4-based and KEEP ON GOING E3 ligases, and promotes seed germination. Conversely, mutation of ABI5 at cysteine-153 deregulates protein stability and inhibition of seed germination by NO depletion. These findings suggest an inverse molecular link between NO and ABA hormone signalling through distinct posttranslational modifications of ABI5 during early seedling development. PMID:26493030

  16. In Vivo Effects of Barbituates on Seed Germination and Seedling Growth.

    ERIC Educational Resources Information Center

    Kordan, H. A.

    1984-01-01

    A simple, low-cost experimental system can be used to demonstrate the "in vivo" effects of barbituates on seed germination and seedling growth behavior in different plant species. Lipid solubility and concentration of individual barbituates both affect the response. List of materials needed, procedures used, and typical results obtained are…

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

    PubMed

    Graeber, Kai; Linkies, Ada; Steinbrecher, Tina; Mummenhoff, Klaus; Tarkowská, Danuše; Turečková, Veronika; Ignatz, Michael; Sperber, Katja; Voegele, Antje; de Jong, Hans; Urbanová, Terezie; Strnad, Miroslav; Leubner-Metzger, Gerhard

    2014-08-26

    Seed germination is an important life-cycle transition because it determines subsequent plant survival and reproductive success. To detect optimal spatiotemporal conditions for germination, seeds act as sophisticated environmental sensors integrating information such as ambient temperature. Here we show that the delay of germination 1 (DOG1) gene, known for providing dormancy adaptation to distinct environments, determines the optimal temperature for seed germination. By reciprocal gene-swapping experiments between Brassicaceae species we show that the DOG1-mediated dormancy mechanism is conserved. Biomechanical analyses show that this mechanism regulates the material properties of the endosperm, a seed tissue layer acting as germination barrier to control coat dormancy. We found that DOG1 inhibits the expression of gibberellin (GA)-regulated genes encoding cell-wall remodeling proteins in a temperature-dependent manner. Furthermore we demonstrate that DOG1 causes temperature-dependent alterations in the seed GA metabolism. These alterations in hormone metabolism are brought about by the temperature-dependent differential expression of genes encoding key enzymes of the GA biosynthetic pathway. These effects of DOG1 lead to a temperature-dependent control of endosperm weakening and determine the optimal temperature for germination. The conserved DOG1-mediated coat-dormancy mechanism provides a highly adaptable temperature-sensing mechanism to control the timing of germination.

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

    PubMed Central

    Graeber, Kai; Linkies, Ada; Steinbrecher, Tina; Mummenhoff, Klaus; Tarkowská, Danuše; Turečková, Veronika; Ignatz, Michael; Sperber, Katja; Voegele, Antje; de Jong, Hans; Urbanová, Terezie; Strnad, Miroslav; Leubner-Metzger, Gerhard

    2014-01-01

    Seed germination is an important life-cycle transition because it determines subsequent plant survival and reproductive success. To detect optimal spatiotemporal conditions for germination, seeds act as sophisticated environmental sensors integrating information such as ambient temperature. Here we show that the DELAY OF GERMINATION 1 (DOG1) gene, known for providing dormancy adaptation to distinct environments, determines the optimal temperature for seed germination. By reciprocal gene-swapping experiments between Brassicaceae species we show that the DOG1-mediated dormancy mechanism is conserved. Biomechanical analyses show that this mechanism regulates the material properties of the endosperm, a seed tissue layer acting as germination barrier to control coat dormancy. We found that DOG1 inhibits the expression of gibberellin (GA)-regulated genes encoding cell-wall remodeling proteins in a temperature-dependent manner. Furthermore we demonstrate that DOG1 causes temperature-dependent alterations in the seed GA metabolism. These alterations in hormone metabolism are brought about by the temperature-dependent differential expression of genes encoding key enzymes of the GA biosynthetic pathway. These effects of DOG1 lead to a temperature-dependent control of endosperm weakening and determine the optimal temperature for germination. The conserved DOG1-mediated coat-dormancy mechanism provides a highly adaptable temperature-sensing mechanism to control the timing of germination. PMID:25114251

  19. iTRAQ Protein Profile Differential Analysis of Dormant and Germinated Grassbur Twin Seeds Reveals that Ribosomal Synthesis and Carbohydrate Metabolism Promote Germination Possibly Through the PI3K Pathway.

    PubMed

    Zhang, Guo-Liang; Zhu, Yue; Fu, Wei-Dong; Wang, Peng; Zhang, Rui-Hai; Zhang, Yan-Lei; Song, Zhen; Xia, Gui-Xian; Wu, Jia-He

    2016-06-01

    Grassbur is a destructive and invasive weed in pastures, and its burs can cause gastric damage to animals. The strong adaptability and reproductive potential of grassbur are partly due to a unique germination mechanism whereby twin seeds develop in a single bur: one seed germinates, but the other remains dormant. To investigate the molecular mechanism of seed germination in twin seeds, we used isobaric tags for relative and absolute quantitation (iTRAQ) to perform a dynamic proteomic analysis of germination and dormancy. A total of 1,984 proteins were identified, 161 of which were considered to be differentially accumulated. The differentially accumulated proteins comprised 102 up-regulated and 59 down-regulated proteins. These proteins were grouped into seven functional categories, ribosomal proteins being the predominant group. The authenticity and accuracy of the results were confirmed by enzyme-linked immunosorbent assay (ELISA) and quantitative real-time reverse transcription-PCR (qPCR). A dynamic proteomic analysis revealed that ribosome synthesis and carbohydrate metabolism affect seed germination possibly through the phosphoinositide 3-kinase (PI3K) pathway. As the PI3K pathway is generally activated by insulin, analyses of seeds treated with exogenous insulin by qPCR, ELISA and iTRAQ confirmed that the PI3K pathway can be activated, which suppresses dormancy and promotes germination in twin grassbur seeds. Together, these results show that the PI3K pathway may play roles in stimulating seed germination in grassbur by modulating ribosomal synthesis and carbohydrate metabolism. © The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  20. Sycamore Seed Germination: The Effects of Provenance, Stratification, Temperature, and Parent Tree

    Treesearch

    Charles D. Webb; Robert E. Farmer

    1968-01-01

    Various stratification periods and germination temperatures were applied to sycamore seed collected along the Chattahoochee River from north Georgia to west Florida. Results showed that percent and speed of germination were greater for seed from southern than from northern provenances. Percent and speed of germination increased as temperature increased. The...

  1. Proteolytic and Trypsin Inhibitor Activity in Germinating Jojoba Seeds (Simmondsia chinensis).

    PubMed

    Samac, D; Storey, R

    1981-12-01

    Changes in proteolytic activity (aminopeptidase, carboxypeptidase, endopeptidase) were followed during germination (imbibition through seedling development) in extracts from cotyledons of jojoba seeds (Simmondsia chinensis). After imbibition, the cotyledons contained high levels of sulfhydryl aminopeptidase activity (APA) but low levels of serine carboxypeptidase activity (CPA). CPA increased with germination through the apparent loss of a CPA inhibitor substance in the seed. Curves showing changes in endopeptidase activity (EPA) assayed at pH 4, 5, 6, 7, and 8 during germination were distinctly different. EPA at pH 4, 5, 6, and 7 showed characteristics of sulfhydryl enzymes while activity at pH 8 was probably due to a serine type enzyme. EPA at pH 6 was inhibited early in germination by one or more substances in the seed. Activities at pH 5 and later at pH 6 were the highest of all EPA throughout germination and increases in these activities were associated with a rapid loss of protein from the cotyledons of the developing seedling.Jojoba cotyledonary extracts were found to inhibit the enzymic activity of trypsin, chymotrypsin, and pepsin but not the protease from Aspergillus saotoi. The heat-labile trypsin inhibitor substance(s) was found in commercially processed jojoba seed meal and the albumin fraction of seed proteins. Trypsin inhibitor activity decreased with germination.

  2. Stratification requirements for germination of western larch (Larix occidentalis Nutt.) seed.

    Treesearch

    Frank C. Sorenson

    1990-01-01

    A northeast Washington collection of western larch seeds was stratified for 0,10, 20, 40, and 80 days and incubated at 55, 64, and 73 °F. The germination percentage of filled seeds and speed and uniformity of germination were improved by long stratification, particularly at the lowest incubation temperature. Stratified seeds were also nursery sown in early April and...

  3. Recurrent selection increases the seed germination of little bluestem (Schizachyrium scoparium)

    USDA-ARS?s Scientific Manuscript database

    Rainfall is often inadequate for satisfactory seed germination and emergence under field conditions. This research was designed to improve the seed germination of six experimental lines of little bluestem [Schizachyrium scoparium (Michx.) Nash]. Two cycle of recurrent selection were used to develo...

  4. Linking seed germination and plant height: a case study of a wetland community on the eastern Tibet Plateau.

    PubMed

    Liu, Kun; Cao, Suzhen; Du, Guozhen; Baskin, Jerry M; Baskin, Carol C; Bu, Haiyan; Qi, Wei; Liang, Ting

    2018-05-20

    Seed germination is the earliest trait expressed in a plant's life history, and it can directly affect the expression of post germination traits. Plant height is central to plant ecological strategies, because it is a major determinant of the ability of a species to compete for light. Thus, linking seed germination and plant height at the community level is very important to understanding plant fitness and community structure. Here, we tested storage condition and temperature requirements for germination of 31 species from a wetland plant community on the eastern Tibet Plateau, and analyzed correlation of germination traits with plant height in relation to storage condition. Germination percentage was positively related to plant height, and this relationship disappeared when seeds were incubated at a low temperature (i.e. 5°C) or after they were stored under wet-cold conditions. The response of seeds to dry+wet-cold storage was negatively related to plant height. Based on the scores of each species on the first two principal components derived from PCA, species were classified into two categories by Hierarchical Clustering, and there was a significant difference between germination and plant height of species in these two categories. These results suggest that the requirements for seed germination together with seasonal change in environmental conditions determine the window for germination and in turn plant growth season and resource utilization and ultimately plant height. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  5. Retarded germination of Nicotiana tabacum seeds following insertion of exogenous DNA mimics the seed persistent behavior

    PubMed Central

    Gagliardi, Assunta; Zaninelli, Mauro; Bini, Luca; Baldi, Antonella; Caccianiga, Marco; Reggi, Serena; Rossi, Luciana

    2017-01-01

    Tobacco seeds show a coat-imposed dormancy in which the seed envelope tissues (testa and endosperm) impose a physical constraint on the radicle protrusion. The germination-limiting process is represented by the endosperm rupture which is induced by cell-wall weakening. Transgenic tobacco seeds, obtained by insertion of exogenous genes codifying for seed-based oral vaccines (F18 and VT2eB), showed retarded germination with respect to the wild type and modified the expression of endogenous proteins. Morphological and proteomic analyses of wild type and transgenic seeds revealed new insights into factors influencing seed germination. Our data showed that the interference of exogenous DNA influences the germination rather than the dormancy release, by modifying the maturation process. Dry seeds of F18 and VT2eB transgenic lines accumulated a higher amount of reserve and stress–related proteins with respect to the wild type. Moreover, the storage proteins accumulated in tobacco F18 and VT2eB dry seeds have structural properties that do not enable the early limited proteolysis observed in the wild type. Morphological observations by electron and light microscopy revealed a retarded mobilization of the storage material from protein and lipid bodies in transgenic seeds, thus impairing water imbibition and embryo elongation. In addition, both F18 and VT2eB dry seeds are more rounded than the wild type. Both the morphological and biochemical characteristics of transgenic seeds mimic the seed persistent profile, in which their roundness enables them to be buried in the soil, while the higher content of storage material enables the hypocotyl to elongate more and the cotyledons to emerge. PMID:29216220

  6. Retarded germination of Nicotiana tabacum seeds following insertion of exogenous DNA mimics the seed persistent behavior.

    PubMed

    Onelli, Elisabetta; Moscatelli, Alessandra; Gagliardi, Assunta; Zaninelli, Mauro; Bini, Luca; Baldi, Antonella; Caccianiga, Marco; Reggi, Serena; Rossi, Luciana

    2017-01-01

    Tobacco seeds show a coat-imposed dormancy in which the seed envelope tissues (testa and endosperm) impose a physical constraint on the radicle protrusion. The germination-limiting process is represented by the endosperm rupture which is induced by cell-wall weakening. Transgenic tobacco seeds, obtained by insertion of exogenous genes codifying for seed-based oral vaccines (F18 and VT2eB), showed retarded germination with respect to the wild type and modified the expression of endogenous proteins. Morphological and proteomic analyses of wild type and transgenic seeds revealed new insights into factors influencing seed germination. Our data showed that the interference of exogenous DNA influences the germination rather than the dormancy release, by modifying the maturation process. Dry seeds of F18 and VT2eB transgenic lines accumulated a higher amount of reserve and stress-related proteins with respect to the wild type. Moreover, the storage proteins accumulated in tobacco F18 and VT2eB dry seeds have structural properties that do not enable the early limited proteolysis observed in the wild type. Morphological observations by electron and light microscopy revealed a retarded mobilization of the storage material from protein and lipid bodies in transgenic seeds, thus impairing water imbibition and embryo elongation. In addition, both F18 and VT2eB dry seeds are more rounded than the wild type. Both the morphological and biochemical characteristics of transgenic seeds mimic the seed persistent profile, in which their roundness enables them to be buried in the soil, while the higher content of storage material enables the hypocotyl to elongate more and the cotyledons to emerge.

  7. Survival and germination of Mediterranean grassland species after simulated sheep ingestion: ecological correlates with seed traits

    NASA Astrophysics Data System (ADS)

    Peco, B.; Lopez-Merino, L.; Alvir, M.

    2006-09-01

    Large amounts of viable seeds from Mediterranean grassland species have been found in herbivore dung; however which species produce seeds that can survive and germinate after ingestion by herbivores is still not well understood. This paper evaluates the importance of seed size, shape and coat impermeability in the endozoochorous dispersal process of 20 abundant species from central Iberian rangelands. Seed survival, germination percentages and germination speed were analysed in controlled experiments on the chewing and gut passage process by inserting seeds in the rumen of fistulated sheep, followed by simulated acid-pepsin digestion. Higher germination percentages in the control than the simulated sheep ingestion treatment were found in 75% of seeds. All species showed lower survival following the treatment, two species had a higher germination speed and five had a lower rate. Large-seeded species generally had higher survival percentages than small-seeded species. Species with impermeable seed coats had higher germination percentages following treatment although no significant differences were noted for either seed survival or germination speed.

  8. Seed development and viviparous germination in one accession of a tomato rin mutant

    PubMed Central

    Wang, Xu; Zhang, Lili; Xu, Xiaochun; Qu, Wei; Li, Jingfu; Xu, Xiangyang; Wang, Aoxue

    2016-01-01

    In an experimental field, seed vivipary occurred in one accession of tomato rin mutant fruit at approximately 45–50 days after pollination (DAP). In this study, the possible contributory factors to this viviparous germination were investigated. Firstly, developing seeds were freshly excised from the fruit tissue every 5 days from 25–60 DAP. Germination occurred when isolated seeds were incubated on water, but was inhibited when they remained ex situ in fruit mucilage gel. The effect of abscisic acid (ABA) and osmoticum, separate and together, on germination of developing seeds was investigated. Additionally, ABA content in the seed and mucilage gel, as well as fruit osmolality were measured. The results showed that ABA concentrations in seeds were low during early development and increased later, peaking at about 50 DAP. ABA concentrations in rin accession were similar to those of the control cultivar and thus are not directly associated with the occurrence of vivipary. Developing seeds of rin accession are more sensitive than control seeds to all inhibitory compounds. However, osmolality in rin fruit at later developmental stages becomes less negative that is required to permit germination of developing seeds. Hence, hypo-osmolality in rin fruit may be an important factor in permitting limited viviparous germination. PMID:27436947

  9. 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

  10. [Effects of seed priming on physiology of seed germination and seeding growth of Marsdenia tenacissima under NaCl stress].

    PubMed

    Xiao, Xue-feng; Liu, Li; Guo, Qiao-sheng; Li, Chao; Wang, Ping-li; Yang, Sheng-chao; Hang, Yue-yu

    2015-01-01

    To offer the reference and method for salt damage in the cultivation of Marsdenia tenacissima, the seeds of M. tenacissima collected from Maguan city ( Yunnan province) were taken as the test materials to study the effects of different priming materials on improving germination and growth under high-level salt stress condition. Four different treatments, which were GA3, KNO3-KH2PO4, PEG-6000, NaCl, combined with ANOVA were applied to test the performance of germination energy, germination percentage, germination index, MDA, SOD, and CAT. The results showed that the seed germination was obviously inhibited under salt stress and the soaked seeds with different priming materials could alleviate the damage of salt stress. Under these treatments, the activities of SOD, CAT the content of soluble protein significantly increased. While the content of MDA significantly decreased. The maximum index was obtained when treated with 1.20% KNO3-KH2PO4, the germination percentage increased from 52.67% to 87.33% and the activity of SOD increased from 138.01 to 219.44 respectively. Comparing with the treatment of 1.20% KNO3-KH2PO4, the germination percentage of treating with 300 mg x L(-1) GA3 increased from 52.67% to 80.67%, while the activity of SOD increased from 138.01 to 444.61.

  11. The effects of selected pre-treatments on germination of seeds of Oriental hornbeam (Carpinus orientalis).

    PubMed

    Ozel, Halil Bariş

    2016-07-01

    In the present study, the effect of some pre-treatments implemented on seeds of Oriental hornbeam (Carpinus orientalis), which has wide geographical variation along Turkey on germination percentage values were investigated. For this purpose, 13 different pre-treatments were implemented to seeds obtained from 17 different populations. According to the obtained results (except control seeds), pre-treatments leading to lowest germination percentage value (8.1%) in Oriental hornbeam seeds was PT10: Keeping seeds for 90 min in sulfuric acid, while highest germination percentage (86.58%) has been obtained with pre-treatment PT13: Implementation of 40% dose of Baikal EM1 + Biohoumous mixture to the seeds, while lowest germination percentage (40.50%) was observed on seeds collected from P7 (Bartin-Kozcağiz) population, highest germination percentage was observed in seeds obtained from P17 (Artvin-Hopa) population.

  12. Effects of Ethylene on Seed Germination of Halophyte Plants Under Salt Stress.

    PubMed

    Li, Weiqiang; Tran, Lam-Son Phan

    2017-01-01

    Halophyte plant species are those that can finish their life cycle in the presence of 50% or more seawater concentration. Ethylene, as a natural plant hormone produced at later stages of seed germination, plays an important role in regulating seed germination. However, its regulatory role in seed dormancy and germination of halophyte plants under salt stress is still not well understood. In this chapter, we describe methods used for applications of two ethylene donors, ethephon and 1-aminocyclopropane-1-carboxylic acid, in studies aimed at examining the effects of ethylene on seed germination of a representative halophyte plant Suaeda salsa under high salinity. Similar approaches can be applied to the study of ethylene and salt interactions in other plant species, when taking into account that salt sensitivities may differ.

  13. Seed dormancy and germination changes of snowbed species under climate warming: the role of pre- and post-dispersal temperatures.

    PubMed

    Bernareggi, Giulietta; Carbognani, Michele; Mondoni, Andrea; Petraglia, Alessandro

    2016-09-01

    Climate warming has major impacts on seed germination of several alpine species, hence on their regeneration capacity. Most studies have investigated the effects of warming after seed dispersal, and little is known about the effects a warmer parental environment may have on germination and dormancy of the seed progeny. Nevertheless, temperatures during seed development and maturation could alter the state of dormancy, affecting the timing of emergence and seedling survival. Here, the interplay between pre- and post-dispersal temperatures driving seed dormancy release and germination requirements of alpine plants were investigated. Three plant species inhabiting alpine snowbeds were exposed to an artificial warming treatment (i.e. +1·5 K) and to natural conditions in the field. Seeds produced were exposed to six different periods of cold stratification (0, 2, 4, 8, 12 and 20 weeks at 0 °C), followed by four incubation temperatures (5, 10, 15 and 20 °C) for germination testing. A warmer parental environment produced either no or a significant increase in germination, depending on the duration of cold stratification, incubation temperatures and their interaction. In contrast, the speed of germination was less sensitive to changes in the parental environment. Moreover, the effects of warming appeared to be linked to the level of (physiological) seed dormancy, with deeper dormant species showing major changes in response to incubation temperatures and less dormant species in response to cold stratification periods. Plants developed under warmer climates will produce seeds with changed germination responses to temperature and/or cold stratification, but the extent of these changes across species could be driven by seed dormancy traits. Transgenerational plastic adjustments of seed germination and dormancy shown here may result from increased seed viability, reduced primary and secondary dormancy state, or both, and may play a crucial role in future plant adaptation

  14. Seed dormancy and germination changes of snowbed species under climate warming: the role of pre- and post-dispersal temperatures

    PubMed Central

    Bernareggi, Giulietta; Carbognani, Michele; Mondoni, Andrea; Petraglia, Alessandro

    2016-01-01

    Background and Aims Climate warming has major impacts on seed germination of several alpine species, hence on their regeneration capacity. Most studies have investigated the effects of warming after seed dispersal, and little is known about the effects a warmer parental environment may have on germination and dormancy of the seed progeny. Nevertheless, temperatures during seed development and maturation could alter the state of dormancy, affecting the timing of emergence and seedling survival. Here, the interplay between pre- and post-dispersal temperatures driving seed dormancy release and germination requirements of alpine plants were investigated. Methods Three plant species inhabiting alpine snowbeds were exposed to an artificial warming treatment (i.e. +1·5 K) and to natural conditions in the field. Seeds produced were exposed to six different periods of cold stratification (0, 2, 4, 8, 12 and 20 weeks at 0 °C), followed by four incubation temperatures (5, 10, 15 and 20 °C) for germination testing. Key Results A warmer parental environment produced either no or a significant increase in germination, depending on the duration of cold stratification, incubation temperatures and their interaction. In contrast, the speed of germination was less sensitive to changes in the parental environment. Moreover, the effects of warming appeared to be linked to the level of (physiological) seed dormancy, with deeper dormant species showing major changes in response to incubation temperatures and less dormant species in response to cold stratification periods. Conclusions Plants developed under warmer climates will produce seeds with changed germination responses to temperature and/or cold stratification, but the extent of these changes across species could be driven by seed dormancy traits. Transgenerational plastic adjustments of seed germination and dormancy shown here may result from increased seed viability, reduced primary and secondary dormancy state, or both, and

  15. Temperature regulates positively photoblastic seed germination in four ficus (moraceae) tree species from contrasting habitats in a seasonal tropical rainforest.

    PubMed

    Chen, Hui; Cao, Min; Baskin, Jerry M; Baskin, Carol C

    2013-08-01

    Differences in seed germination responses of trees in tropical forests to temperature and light quality may contribute to their coexistence. We investigated the effects of temperature and red:far-red light (R:FR ratio) on seed germination of two gap-demanding species (Ficus hispida and F. racemosa) and two shade-tolerant species (F. altissima and F. auriculata) in a tropical seasonal rainforest in southwest China. A R:FR ratio gradient was created by filtering fluorescent light through polyester filters. Four temperature treatments were used to test the effect of temperature on seed germination of the four Ficus tree species across the R:FR gradient. Seeds of the four Ficus species were positively photoblastic. Seed germination of F. hispida and F. racemosa was not affected across the R:FR ratio gradient (0.25-1.19) at 25/35°C, but it was inhibited under low R:FR at 22/23°C. By contrast, germination percentages of F. altissima and F. auriculata were not inhibited along the entire light gradient in all temperature treatments. Differences in germination responses of Ficus species might contribute to differences in their habitat preferences. The inhibitory effect of understory temperatures in the forest might be a new mechanism that prevents positively photoblastic seeds of the gap-demanding species such as F. hispida and F. racemosa from germinating in the understory and in small canopy gaps.

  16. Allelochemical regulation of reproduction and seed germination of two BrazilianBaccharis species by phytotoxic trichothecenes.

    PubMed

    Kuti, J O; Jarvis, B B; Mokhtari-Rejali, N; Bean, G A

    1990-12-01

    The potent phytotoxic trichothecene roridins and baccharinoids occur naturally in the Brazilian plants,Baccharis coridifolia andB. megapotamica. Biosynthesis of roridins inB. coridifolia appears to be linked to pollination, and the phytotoxins then accumulate in the seed. The roles of the phytotoxins in pollination, seed maturation, and germination of theBaccharis species were investigated. The high production of roridins occurred only in seeds resulting from intraspecific pollination, and the concentration of the toxins in the seeds generally increased with seed maturity. Removal of seed coats from trichothecene-producing BrazilianBaccharis species (B. coridifolia andB. megapotamica) and non-trichothecene-producing AmericanBaccharis species (B. halimifolia andB. glutinosa) resulted in improved seed germination ofB. halimifolia andB. glutinosa but complete inhibition of seed germination ofB. coridifolia andB. megapotamica. Addition of seed coat extracts of the BrazilianBaccharis species of dilute solutions (10(-6)μg/ml) of roridins or baccharinoids to the decoated seeds ofB. coridifolia andB. megapotamica resulted in germination, while seeds ofB. halimifolia andB. glutinosa were killed by the phytotoxins. Roridins interacted with gibberellic acid, a germination promoter, but not with abscisic acid, a germination inhibitor. The results from this study suggest that macrocyclic trichothecenes have a regulatory role(s) on reproduction and germination of BrazilianBaccharis species in their natural habitat.

  17. Variation in Seed Germination of 134 Common Species on the Eastern Tibetan Plateau: Phylogenetic, Life History and Environmental Correlates

    PubMed Central

    Xu, Jing; Li, Wenlong; Zhang, Chunhui; Liu, Wei; Du, Guozhen

    2014-01-01

    Seed germination is a crucial stage in the life history of a species because it represents the pathway from adult to offspring, and it can affect the distribution and abundance of species in communities. In this study, we examined the effects of phylogenetic, life history and environmental factors on seed germination of 134 common species from an alpine/subalpine meadow on the eastern Tibetan Plateau. In one-way ANOVAs, phylogenetic groups (at or above order) explained 13.0% and 25.9% of the variance in germination percentage and mean germination time, respectively; life history attributes, such as seed size, dispersal mode, explained 3.7%, 2.1% of the variance in germination percentage and 6.3%, 8.7% of the variance in mean germination time, respectively; the environmental factors temperature and habitat explained 4.7%, 1.0% of the variance in germination percentage and 13.5%, 1.7% of the variance in mean germination time, respectively. Our results demonstrated that elevated temperature would lead to a significant increase in germination percentage and an accelerated germination. Multi-factorial ANOVAs showed that the three major factors contributing to differences in germination percentage and mean germination time in this alpine/subalpine meadow were phylogenetic attributes, temperature and seed size (explained 10.5%, 4.7% and 1.4% of the variance in germination percentage independently, respectively; and explained 14.9%, 13.5% and 2.7% of the variance in mean germination time independently, respectively). In addition, there were strong associations between phylogenetic group and life history attributes, and between life history attributes and environmental factors. Therefore, germination variation are constrained mainly by phylogenetic inertia in a community, and seed germination variation correlated with phylogeny is also associated with life history attributes, suggesting a role of niche adaptation in the conservation of germination variation within lineages

  18. Optimum storage and germination conditions for seeds of pickerelweed (Pontetieria cordata L.) from Florida

    Treesearch

    Lyn A. Gettys; R. Kasten Dumroese

    2009-01-01

    Clean seeds of pickerelweed (Pontederia cordata L. [Pontederiaceae]) germinated best (84 to 94%) under water, even after being stored dry up to 6 mo at about 25 °C (77 °F), but germination of clean seeds under water was reduced to 43% when seeds were stored at 4 °C (39 3 F) for 6 mo. Underwater germination of seeds enclosed in fruits was less...

  19. [Impact of priming on seed germination and seedling growth of Oldenlandia diffusa under drought stress].

    PubMed

    Zhu, Zai-Biao; Lu, Wei-Wei; Guo, Qiao-Sheng; Cao, Ya-Yue; Feng, Shan; Ning, Zi-Jun

    2014-04-01

    Current study was carried out to optimize the priming condition of Oldenlandia diffusa seeds, and improve germination rate and seed vigor of 0. diffusa seeds under drought conditions. Uniform design was used to optimize the concentration and priming time of three priming materials (PEG, KNO3, GA3). Different concentrations of polyethylene glycol (PEG) was used to simulate drought stress. The seedling was cultured in 1/4 Hoagland medium for 30 d. The results showed that seed priming treatment with 366 mg x kg(-1) GA3 for 1h resulted in significant increase in germination rate, germination index, vigor, root length, plant height and biomass of O. diffusa seeds under drought stress (15% PEG), while seed priming with 3.0% KNO3 for 1 h showed little effect on germination and growth of O. diffusa seeds under drought stress. Seed priming treatment with appropriate GA3 concentration and priming time could enhance seed germination and drought resistance of O. diffusa in seedling stage.

  20. Mitochondrial AtTrxo1 is transcriptionally regulated by AtbZIP9 and AtAZF2 and affects seed germination under saline conditions

    PubMed Central

    Ortiz-Espín, Ana; Iglesias-Fernández, Raquel; Calderón, Aingeru; Carbonero, Pilar; Sevilla, Francisca

    2017-01-01

    Abstract Mitochondrial thioredoxin-o (AtTrxo1) was characterized and its expression examined in different organs of Arabidopsis thaliana. AtTrxo1 transcript levels were particularly high in dry seeds and cotyledons where they reached a maximum 36 h after imbibition with water, coinciding with 50% germination. Expression was lower in seeds germinating in 100 mM NaCl. To gain insight into the transcriptional regulation of the AtTrxo1 gene, a phylogenomic analysis was coupled with the screening of an arrayed library of Arabidopsis transcription factors in yeast. The basic leucine zipper AtbZIP9 and the zinc finger protein AZF2 were identified as putative transcriptional regulators. Transcript regulation of AtbZIP9 and AtAFZ2 during germination was compatible with the proposed role in transcriptional regulation of AtTrxo1. Transient over-expression of AtbZIP9 and AtAZF2 in Nicotiana benthamiana leaves demonstrated an activation effect of AtbZIP9 and a repressor effect of AtAZF2 on AtTrxo1 promoter-driven reporter expression. Although moderate concentrations of salt delayed germination in Arabidopsis wild-type seeds, those of two different AtTrxo1 knock-out mutants germinated faster and accumulated higher H2O2 levels than the wild-type. All these data indicate that AtTrxo1 has a role in redox homeostasis during seed germination under salt conditions. PMID:28184497

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

    PubMed Central

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

    2018-01-01

    Since seed reserves can influence seed germination, the quantitative and qualitative differences in seed reserves may relate to the germination characteristics of species. The purpose of our study was to evaluate the correlation between germination and seed reserves, as well as their mobilization during germination of six grassland species (Chloris virgata, Kochia scoparia, Lespedeza hedysaroides, Astragalus adsurgens, Leonurus artemisia, and Dracocephalum moldavica) and compare the results with domesticated species. We measured starch, protein, and fat content in dry seeds and the initial absorption of water during imbibition. Starch, soluble protein, fat, and soluble sugar content also were determined at five stages during germination. Starch, protein, and fat reserves in dry seeds were not significantly correlated with germination percentage and rate (speed), but soluble sugar and soluble protein contents at different germination stages were positively significantly correlated with germination rate for the six species. Starch was mainly used during seed imbibition, and soluble protein was used from the imbibition stage to the highest germination stage. Fat content for all species remained relatively constant throughout germination for six species, regardless of the proportion of other seed reserves in the seeds. Our results for fat utilization differ from those obtained for cultivated grasses and legumes. These results provide new insight on the role of seed reserves as energy resources in germination for wild species. PMID:29535748

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

    PubMed

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

    2018-01-01

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

  3. Comparison of germination and seed bank dynamics of dimorphic seeds of the cold desert halophyte Suaeda corniculata subsp. mongolica

    PubMed Central

    Cao, Dechang; Baskin, Carol C.; Baskin, Jerry M.; Yang, Fan; Huang, Zhenying

    2012-01-01

    Background and Aims Differences in dormancy and germination requirements have been documented in heteromorphic seeds of many species, but it is unknown how this difference contributes to maintenance and regeneration of populations. The primary aim of this study was to compare the seed bank dynamics, including dormancy cycling, of the two seed morphs (black and brown) of the cold desert halophyte Suaeda corniculata and, if differences were found, to determine their influence on regeneration of the species. Method Seeds of the two seed morphs were buried, exhumed and tested monthly for 24 months over a range of temperatures and salinities, and germination recovery and viability were determined after exposure to salinity and water stress. Seedling emergence and dynamics of the soil seed bank were also investigated for the two morphs. Key Results Black seeds had an annual dormancy/non-dormancy cycle, while brown seeds, which were non-dormant at maturity, remained non-dormant. Black seeds also exhibited an annual cycle in sensitivity of germination to salinity. Seedlings derived from black seeds emerged in July and August and those from brown seeds in May. Seedlings were recruited from 2·6 % of the black seeds and from 2·8 % of the brown seeds in the soil, and only 0·5 % and 0·4 % of the total number of black and brown seeds in the soil, respectively, gave rise to seedlings that survived to produce seeds. Salinity and water stress induced dormancy in black seeds and decreased viability of brown seeds. Brown seeds formed only a transient soil seed bank and black seeds a persistent seed bank. Conclusions The presence of a dormancy cycle in black but not in brown seeds of S. corniculata and differences in germination requirements of the two morphs cause them to differ in their germination dynamics. The study contributes to our limited knowledge of dormancy cycling and seed bank formation in species producing heteromorphic seeds. PMID:22975287

  4. Comparison of germination and seed bank dynamics of dimorphic seeds of the cold desert halophyte Suaeda corniculata subsp. mongolica.

    PubMed

    Cao, Dechang; Baskin, Carol C; Baskin, Jerry M; Yang, Fan; Huang, Zhenying

    2012-12-01

    Differences in dormancy and germination requirements have been documented in heteromorphic seeds of many species, but it is unknown how this difference contributes to maintenance and regeneration of populations. The primary aim of this study was to compare the seed bank dynamics, including dormancy cycling, of the two seed morphs (black and brown) of the cold desert halophyte Suaeda corniculata and, if differences were found, to determine their influence on regeneration of the species. Seeds of the two seed morphs were buried, exhumed and tested monthly for 24 months over a range of temperatures and salinities, and germination recovery and viability were determined after exposure to salinity and water stress. Seedling emergence and dynamics of the soil seed bank were also investigated for the two morphs. Black seeds had an annual dormancy/non-dormancy cycle, while brown seeds, which were non-dormant at maturity, remained non-dormant. Black seeds also exhibited an annual cycle in sensitivity of germination to salinity. Seedlings derived from black seeds emerged in July and August and those from brown seeds in May. Seedlings were recruited from 2·6 % of the black seeds and from 2·8 % of the brown seeds in the soil, and only 0·5 % and 0·4 % of the total number of black and brown seeds in the soil, respectively, gave rise to seedlings that survived to produce seeds. Salinity and water stress induced dormancy in black seeds and decreased viability of brown seeds. Brown seeds formed only a transient soil seed bank and black seeds a persistent seed bank. The presence of a dormancy cycle in black but not in brown seeds of S. corniculata and differences in germination requirements of the two morphs cause them to differ in their germination dynamics. The study contributes to our limited knowledge of dormancy cycling and seed bank formation in species producing heteromorphic seeds.

  5. 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 (GA 3 ≥250 µM) overcame the requirement for HS to initiate germination. However, HS did not sensitise seeds to GA 3 , 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. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  6. [Study on method and its optimization of improving seed germination of Astragalus membranaceus as gansu traditional medicinal herb].

    PubMed

    Shi, Li-Ping; Ou, Qiao-Ming; Cui, Wen-Juan; Chen, Yu-Liang

    2014-04-01

    To break the hard testa and improve seed germination situation of Astragalus membranaceus var. mongholicus, in order to solve the problems of low success rate of seed germination and seedling. Longxi Astragalus membranaceus var. mongholicus seed was treated by soaking seed with 75% alcohol and concentrated sulfuric acid, warm-water incubating, grinding and comprehensive treating with warm-water incubating, grinding and sand culture. Its seed germination situation was evaluated by germination potential, germination rate and germination index. Different processing methods significantly improved seed germination with different effect. Comprehensive treatment with warm-water incubating, grinding and sand culture was the best one on Astragalus membranaceus var. mongholicus seed germination. Its germination potential, germination rate and germination index was 66.04%, 87.70% and 1.34,respectively. Comprehensive treatment with warm-water incubating, grinding and sand culture is an economic and effective processing method, which is suitable for actual production.

  7. Protein Mobilization in Germinating Mung Bean Seeds Involves Vacuolar Sorting Receptors and Multivesicular Bodies1[W][OA

    PubMed Central

    Wang, Junqi; Li, Yubing; Lo, Sze Wan; Hillmer, Stefan; Sun, Samuel S.M.; Robinson, David G.; Jiang, Liwen

    2007-01-01

    Plants accumulate and store proteins in protein storage vacuoles (PSVs) during seed development and maturation. Upon seed germination, these storage proteins are mobilized to provide nutrients for seedling growth. However, little is known about the molecular mechanisms of protein degradation during seed germination. Here we test the hypothesis that vacuolar sorting receptor (VSR) proteins play a role in mediating protein degradation in germinating seeds. We demonstrate that both VSR proteins and hydrolytic enzymes are synthesized de novo during mung bean (Vigna radiata) seed germination. Immunogold electron microscopy with VSR antibodies demonstrate that VSRs mainly locate to the peripheral membrane of multivesicular bodies (MVBs), presumably as recycling receptors in day 1 germinating seeds, but become internalized to the MVB lumen, presumably for degradation at day 3 germination. Chemical cross-linking and immunoprecipitation with VSR antibodies have identified the cysteine protease aleurain as a specific VSR-interacting protein in germinating seeds. Further confocal immunofluorescence and immunogold electron microscopy studies demonstrate that VSR and aleurain colocalize to MVBs as well as PSVs in germinating seeds. Thus, MVBs in germinating seeds exercise dual functions: as a storage compartment for proteases that are physically separated from PSVs in the mature seed and as an intermediate compartment for VSR-mediated delivery of proteases from the Golgi apparatus to the PSV for protein degradation during seed germination. PMID:17322331

  8. Effects of treatment and seed source on germination of eastern redcedar seed

    Treesearch

    David F. Van Haverbeke; C. W. Comer

    1985-01-01

    Germination of eastern redcedar (Juniperus virginiana L.) seeds was best with a 96-hour soak in citric acid (10,000 ppm), with 6 weeks of moist-warm (24° C) stratification, and 10 weeks of moist-cold (5° C) stratification. Geographic seed sources responded differently to treatment. Use of fresh seeds could reduce the time in moist-warm stratification, would improve...

  9. Karrikins Discovered in Smoke Trigger Arabidopsis Seed Germination by a Mechanism Requiring Gibberellic Acid Synthesis and Light1[W][OA

    PubMed Central

    Nelson, David C.; Riseborough, Julie-Anne; Flematti, Gavin R.; Stevens, Jason; Ghisalberti, Emilio L.; Dixon, Kingsley W.; Smith, Steven M.

    2009-01-01

    Discovery of the primary seed germination stimulant in smoke, 3-methyl-2H-furo[2,3-c]pyran-2-one (KAR1), has resulted in identification of a family of structurally related plant growth regulators, karrikins. KAR1 acts as a key germination trigger for many species from fire-prone, Mediterranean climates, but a molecular mechanism for this response remains unknown. We demonstrate that Arabidopsis (Arabidopsis thaliana), an ephemeral of the temperate northern hemisphere that has never, to our knowledge, been reported to be responsive to fire or smoke, rapidly and sensitively perceives karrikins. Thus, these signaling molecules may have greater significance among angiosperms than previously realized. Karrikins can trigger germination of primary dormant Arabidopsis seeds far more effectively than known phytohormones or the structurally related strigolactone GR-24. Natural variation and depth of seed dormancy affect the degree of KAR1 stimulation. Analysis of phytohormone mutant germination reveals suppression of KAR1 responses by abscisic acid and a requirement for gibberellin (GA) synthesis. The reduced germination of sleepy1 mutants is partially recovered by KAR1, which suggests that germination enhancement by karrikin is only partly DELLA dependent. While KAR1 has little effect on sensitivity to exogenous GA, it enhances expression of the GA biosynthetic genes GA3ox1 and GA3ox2 during seed imbibition. Neither abscisic acid nor GA levels in seed are appreciably affected by KAR1 treatment prior to radicle emergence, despite marked differences in germination outcome. KAR1 stimulation of Arabidopsis germination is light-dependent and reversible by far-red exposure, although limited induction of GA3ox1 still occurs in the dark. The observed requirements for light and GA biosynthesis provide the first insights into the karrikin mode of action. PMID:19074625

  10. A systematic proteomic analysis of NaCl-stressed germinating maize seeds.

    PubMed

    Meng, Ling-Bo; Chen, Yi-Bo; Lu, Tian-Cong; Wang, Yue-Feng; Qian, Chun-Rong; Yu, Yang; Ge, Xuan-Liang; Li, Xiao-Hui; Wang, Bai-Chen

    2014-05-01

    Salt (NaCl) is a common physiological stressor of plants. To better understand how germinating seeds respond to salt stress, we examined the changes that occurred in the proteome of maize seeds during NaCl-treated germination. Phenotypically, salt concentrations less than 0.2 M appear to delay germination, while higher concentrations disrupt development completely, leading to seed death. The identities of 96 proteins with expression levels altered by NaCl-incubation were established using 2-DE-MALDI-TOF-MS and 2-DE-MALDI-TOF-MS/MS. Of these 96 proteins, 79 were altered greater than twofold when incubated with a 0.2 M salt solution, while 51 were altered when incubated with a 0.1 M salt solution. According to their functional annotations in the Swiss-Prot protein-sequence databases, these proteins are mainly involved in seed storage, energy metabolism, stress response, and protein metabolism. Notably, the expression of proteins that respond to abscisic acid signals increased in response to salt stress. The results of this study provide important clues as to how NaCl stresses the physiology of germinating maize seeds.

  11. Recurrent selection for increased seed germination in sand bluestem (Andropogon hallii)

    USDA-ARS?s Scientific Manuscript database

    Water is essential for plant growth and under field conditions is often inadequate for satisfactory seed germination and seedling growth. The objective of this research was to improve the seed germination of sand bluestem (Andropogon hallii Hack.) lines ‘AB-medium Syn-0’ and ‘CD-tall Syn-0’ at low ...

  12. Proteolytic and Trypsin Inhibitor Activity in Germinating Jojoba Seeds (Simmondsia chinensis) 1

    PubMed Central

    Samac, Deborah; Storey, Richard

    1981-01-01

    Changes in proteolytic activity (aminopeptidase, carboxypeptidase, endopeptidase) were followed during germination (imbibition through seedling development) in extracts from cotyledons of jojoba seeds (Simmondsia chinensis). After imbibition, the cotyledons contained high levels of sulfhydryl aminopeptidase activity (APA) but low levels of serine carboxypeptidase activity (CPA). CPA increased with germination through the apparent loss of a CPA inhibitor substance in the seed. Curves showing changes in endopeptidase activity (EPA) assayed at pH 4, 5, 6, 7, and 8 during germination were distinctly different. EPA at pH 4, 5, 6, and 7 showed characteristics of sulfhydryl enzymes while activity at pH 8 was probably due to a serine type enzyme. EPA at pH 6 was inhibited early in germination by one or more substances in the seed. Activities at pH 5 and later at pH 6 were the highest of all EPA throughout germination and increases in these activities were associated with a rapid loss of protein from the cotyledons of the developing seedling. Jojoba cotyledonary extracts were found to inhibit the enzymic activity of trypsin, chymotrypsin, and pepsin but not the protease from Aspergillus saotoi. The heat-labile trypsin inhibitor substance(s) was found in commercially processed jojoba seed meal and the albumin fraction of seed proteins. Trypsin inhibitor activity decreased with germination. PMID:16662104

  13. Effects of hormonal priming on seed germination of pigeon pea under cadmium stress.

    PubMed

    Sneideris, Larissa C; Gavassi, Marina A; Campos, Marcelo L; D'Amico-Damião, Victor; Carvalho, Rogério F

    2015-09-01

    In this work we investigated whether priming with auxin, cytokinin, gibberellin, abscisic acid and ethylene, alters the physiological responses of seeds of pigeon pea germinated under water and cadmium stress. Seeds treated with water or non-treated seeds were used as control. Although compared to non-treated seeds we found that the hormone treatments improve the germination of pigeon pea under cadmium stress, however, these treatments did not differ from water. However, we also observed a trend of tolerance to the effects of cadmium in the presence of ethylene, suggesting that the use of this hormone may be an efficient method to overcome seed germination under metal stress.

  14. [Changes in Properties of Water during Germination of Zucchini Seed in Water Used].

    PubMed

    Novikov, S N; Novikov, L N; Ermolaeva, A I; Timoshenkov, S P; Goryunova, E P

    2015-01-01

    In this research the changes in the supramolecular structure of distilled water during germination of the seed in this water were studied. We used three methods: gravimetry, precision thermal analysis, electron work function measurements. In the first stage of seed germination--seed swelling--the seed extracts coherent domains in the water, herewith due to the transition of coherent domains adsorbed in nanofields into a stable state the flow of electromagnetic energy appears. In the second stage of the experiment--germ growing--the flow of biophotons occurs. This is evidenced by the increased water electron work function. A hypothetical model of the process of zucchini seed germination is suggested.

  15. Striga seed-germination activity of root exudates and compounds present in stems of Striga host and nonhost (trap crop) plants is reduced due to root colonization by arbuscular mycorrhizal fungi.

    PubMed

    Lendzemo, V; Kuyper, T W; Vierheilig, H

    2009-06-01

    Root colonization by arbuscular mycorrhizal (AM) fungi reduces stimulation of seed germination of the plant parasite Striga (Orobanchaceae). This reduction can affect not only host plants for Striga, resulting in a lower parasite incidence, but also false hosts or trap crops, which induce suicidal Striga seed germination, thereby diminishing their effectiveness. In order to better understand these AM-induced effects, we tested the influence of root colonization by different AM fungi on the seed-germination activity of root exudates of the Striga hermonthica nonhost plants cowpea and cotton on S. hermonthica. We also tested the effect of AM fungi on the seed-germination activity of the Striga gesnerioides host plant cowpea on S. gesnerioides. Moreover, we studied whether mycorrhization affects the transport of seed-germination activity to above-ground plant parts. Mycorrhization not only resulted in a lower seed germination of S. gesnerioides in the presence of root exudates of the S. gesnerioides host cowpea but also seed germination of S. hermonthica was also lower in the presence of root exudates of the S. hermonthica nonhosts cowpea and cotton. Downregulation of the Striga seed-germination activity occurs not only in root exudates upon root colonization by different AM fungi but also in the compounds produced by stems. The lowered seed-germination activity does not appear to depend on the presence of seed germination inhibitors in the root exudates of mycorrhizal plants. The implication for Striga control in the field is discussed.

  16. Seed flotation and germination of salt marsh plants: The effects of stratification, salinity, and/or inundation regime

    USGS Publications Warehouse

    Elsey-Quirk, T.; Middleton, B.A.; Proffitt, C.E.

    2009-01-01

    We examined the effects of cold stratification and salinity on seed flotation of eight salt marsh species. Four of the eight species were tested for germination success under different stratification, salinity, and flooding conditions. Species were separated into two groups, four species received wet stratification and four dry stratification and fresh seeds of all species were tested for flotation and germination. Fresh seeds of seven out of eight species had flotation times independent of salinity, six of which had average flotation times of at least 50 d. Seeds of Spartina alterniflora and Spartina patens had the shortest flotation times, averaging 24 and 26 d, respectively. Following wet stratification, the flotation time of S. alterniflora seeds in higher salinity water (15 and 36 ppt) was reduced by over 75% and germination declined by more than 90%. Wet stratification reduced the flotation time of Distichlis spicata seeds in fresh water but increased seed germination from 2 to 16% in a fluctuating inundation regime. Fresh seeds of Iva frutescens and S. alternflora were capable of germination and therefore are non-dormant during dispersal. Fresh seeds of I. frutescens had similar germination to dry stratified seeds ranging 25-30%. Salinity reduced seed germination for all species except for S. alterniflora. A fluctuating inundation regime was important for seed germination of the low marsh species and for germination following cold stratification. The conditions that resulted in seeds sinking faster were similar to the conditions that resulted in higher germination for two of four species. ?? 2009 Elsevier B.V.

  17. bZIP17 regulates the expression of genes related to seed storage and germination, reducing seed susceptibility to osmotic stress.

    PubMed

    Cifuentes-Esquivel, Nicolás; Celiz-Balboa, Jonathan; Henriquez-Valencia, Carlos; Mitina, Irina; Arraño-Salinas, Paulina; Moreno, Adrián A; Meneses, Claudio; Blanco-Herrera, Francisca; Orellana, Ariel

    2018-04-25

    Low temperatures, salinity, and drought cause significant crop losses. These conditions involve osmotic stress, triggering transcriptional remodeling, and consequently, the restitution of cellular homeostasis and growth recovery. Protein transcription factors regulate target genes, thereby mediating plant responses to stress. bZIP17 is a transcription factor involved in cellular responses to salinity and the unfolded protein response. Because salinity can also produce osmotic stress, the role of bZIP17 in response to osmotic stress was assessed. Mannitol treatments induced the transcript accumulation and protein processing of bZIP17. Transcriptomic analyses showed that several genes associated with seed storage and germination showed lower expression in bzip17 mutants than in wild-type plants. Interestingly, bZIP17 transcript was more abundant in seeds, and germination analyses revealed that wild-type plants germinated later than bzip17 mutants in the presence of mannitol, but no effects were observed when the seeds were exposed to ABA. Finally, the transcript levels of bZIP17 target genes that control seed storage and germination were assessed in seeds exposed to mannitol treatments, which showed lower expression levels in bzip17 mutants compared to the wild-type seeds. These results suggest that bZIP17 plays a role in osmotic stress, acting as a negative regulator of germination through the regulation of genes involved in seed storage and germination. © 2018 Wiley Periodicals, Inc.

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

    NASA Astrophysics Data System (ADS)

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

    2018-04-01

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

  19. Roles of Gibberellins and Abscisic Acid in Regulating Germination of Suaeda salsa Dimorphic Seeds Under Salt Stress

    PubMed Central

    Li, Weiqiang; Yamaguchi, Shinjiro; Khan, M. Ajmal; An, Ping; Liu, Xiaojing; Tran, Lam-Son P.

    2016-01-01

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

  20. Soil reaction and germination of Douglas-fir seed.

    Treesearch

    Robert F. Tarrant

    1954-01-01

    Wood ash and its accompanying alkalinity have sometimes been cited as being harmful to germination of tree seed on slash-burned forest land. Unasylva, the United Nations forestry publication, recently carried a report of research in British Columbia on the effect of slash burning on germination and initial survival of lodgepole pine and Douglas-fir. One finding was...

  1. Effect of saline water on seed germination and early seedling growth of the halophyte quinoa

    PubMed Central

    Panuccio, M. R.; Jacobsen, S. E.; Akhtar, S. S.; Muscolo, A.

    2014-01-01

    Salinization is increasing on a global scale, decreasing average yields for most major crop plants. Investigations into salt resistance have, unfortunately, mainly been focused on conventional crops, with few studies screening the potential of available halophytes as new crops. This study has been carried out to investigate the mechanisms used by quinoa, a facultative halophytic species, in order to cope with high salt levels at various stages of its development. Quinoa is regarded as one of the crops that might sustain food security in this century, grown primarily for its edible seeds with their high protein content and unique amino acid composition. Although the species has been described as a facultative halophyte, and its tolerance to salt stress has been investigated, its physiological and molecular responses to seawater (SW) and other salts have not been studied. We evaluated the effects of SW and different salts on seed germination, seedling emergence and the antioxidative pathway of quinoa. Seeds were germinated in Petri dishes and seedlings grown in pots with SW solutions (25, 50, 75 and 100 %) and NaCl, CaCl2, KCl and MgCl2 individually, at the concentrations in which they are present in SW. Our results demonstrated that all salts, at lower concentrations, increased the germination rate but not the germination percentages, compared with control (pure water). Conversely, seedlings were differently affected by treatments in respect to salt type and concentration. Growth parameters affected were root and shoot length, root morphology, fresh and dry weight, and water content. An efficient antioxidant mechanism was present in quinoa, activated by salts during germination and early seedling growth, as shown by the activities of antioxidant enzymes. Total antioxidant capacity was always higher under salt stress than in water. Moreover, osmotic and ionic stress factors had different degrees of influence on germination and development. PMID:25139769

  2. Effect of adding wood vinegar on cucumber (Cucumis sativus L) seed germination

    NASA Astrophysics Data System (ADS)

    Lei, Ming; Liu, Bingjie; Wang, Xiao

    2018-03-01

    Wood vinegar, a liquid by-product that was obtained from the condensed vapor generated during the biomass pyrolysis, had been reported as plant growth promotor, but the impact on the plant seeds was still not clear. Thus, we investigated the effects of wood vinegar on the germination and seedling growth of cucumber seeds through the germination experiments. The results showed that the different diluted wood vinegar addition showed no significant difference in the germination rates of cucumber seeds compared to those of the CK treatment (P > 0.05). However, the added wood vinegar at the 10000-time dilution significantly increased the root length and dry biomass of cucumber by 20.9 % and 5.92 %, respectively (P < 0.05). Therefore, the wood vinegar at an optimal time of dilution could be used a promising soaking agent for the seeds germination, and further enhance crop yields.

  3. Roles of gibberellins and abscisic acid in dormancy and germination of red bayberry (Myrica rubra) seeds.

    PubMed

    Chen, Shun-Ying; Kuo, Shing-Rong; Chien, Ching-Te

    2008-09-01

    Intact seeds from freshly harvested fruits of Myrica rubra (Sieb et Zucc.) were dormant and required 8 weeks of warm stratification followed by 12 weeks of cold stratification for germination. Exogenous application of gibberellic acid (GA(3)) to intact fresh seeds was effective in breaking dormancy, with > 70% of seeds germinating when treated with 5.2 mM GA(3) and incubated at a day/night temperature of 30/20 degrees C for 20 weeks. Removing the hard endocarp or endocarp plus seed coat of fresh seeds promoted germination, and addition of GA(3) to the embryo accelerated germination. The gibberellins GA(1) and GA(4) were more effective than GA(3) in promoting germination of seeds with the endocarp removed. Endogenous contents of GA(1), GA(3), GA(4), GA(7) and GA(20) were quantified by gas chromatography-mass spectrometry-selected ion monitoring in the endocarps, seed coats and embryos of fresh seeds treated with 5.2 mM GA(3). The content of GA(3) decreased in the endocarp during incubation, whereas GA(1) contents increased in the endocarp and seed coat. A high GA(1) content was detected in the endocarps and embryos of newly germinated seeds. We speculate that GA(3) was converted to GA(1) during incubation and that GA(1) is involved in seed germination. Endogenous abscisic acid (ABA) contents were measured in fresh seeds and in warm and cold stratified seeds. The ABA content in fresh seeds was distributed in the order endocarp > seed coat > embryo, with the content in the endocarp being about 132-fold higher than in the seed coat and embryo. Total ABA content of seeds subjected to warm or cold stratification, or both, was 8.7- to 14.0-fold lower than that of fresh seeds. Low contents of endogenous GA(1), GA(3), GA(7) and GA(20), but elevated contents of GA(4), were found in the seed coats and endocarps of warm plus cold stratified seeds and in the seed coats and embryos of newly germinated seeds. These observations, coupled with the finding that GA stimulated

  4. Influence of Light Intensity and Photoperiod on the Seed Germination of Four Rhododendron Species in Taiwan.

    PubMed

    Lin, Lei-Chen; Wang, Chang-Sheng

    2017-01-01

    There are 15 native Rhododendron species in Taiwan, among which 11 species are endemic and compose 73% of these native species. Although researchers predominantly use cuttings to propagate Rhododendron shrubs, there are no studies on the seed germination of Rhododendron species. The objective of this study was to evaluate the seed germination of four Rhododendron species in Taiwan under different light intensities and photoperiods. Two experiments on the seed germination percentage of R. breviperulatum, R. kanehirai, R. ovatum and R. simsii were conducted in this study. The first experiment was to identify the seed germination percentage of these four Rhododendron species using different light intensities (0, 700, 1400 and 3200 lux). The second experiment was to clarify the seed germination percentage of these four Rhododendron species using different photoperiods (0, 1, 4 and 16 h). All statistical analyses were performed using Statistical Package for the Social Science (SPSS12.0) for Windows software program. The data were analyzed using Tukey's multiple range test at the p<0.05 significance level. After 30 days, no seed germination occurred in darkness. The highest average seed germination percentages were all observed at 700 lux: R. breviperulatum (83.3%), R. kanehirai (68.9%), R. ovatum (85.6%) and R. simsii (92.2%). The highest average germination percentages of seeds were observed in R. breviperulatum at 16 h (83.3%), R. kanehirai at 1 h (60.0%), R. ovatum at 16 h (84.4%) and R. simsii at 16 h (85.6%). According to the results, these four Rhododendron species required light for germination. There were significant differences (p<0.05) in the seed germination of these four Rhododendron species for light intensity greater than 700 lux. Similar results were observed with photoperiods. The seed germination percentage of R. breviperulatum, R. ovatum and R. simsii increased with increasing photoperiod.

  5. [Eco-physiological studies on desert plants : V. Influence of soaking and redrying on the germination of Zygophyllum coccineum seeds and the possible contribution of an inhibitor to the effect].

    PubMed

    Batanouny, K H; Ziegler, H

    1971-06-01

    1. The rate and percentage of germination of soaked and redried seeds are higher than those of untreated seeds. The promoting effect of soaking and redryring of seeds on germination increases with the duration of soaking. Seeds that germinated during soaking are unable to tolerate drying. 2. Exposure of the seeds to light after the first 8 hours of soaking inhibits germination of the seeds after drying. 3. Washing the seeds with water has no effect on germination in the dark at 25°C, while it promotes germination in light at 25°C and in the dark at 10°C. 4. The leachate of Zygophyllum coccineum seeds has no significant effect on the dark germination of these seeds. On the other hand, it inhibits the light germination. Germination of Lepidium sativum seeds is not affected by the leachate of Zygophyllum seeds, either in the dark or in light. 5. When the washed seeds of Zygophyllum coccineum are germinated, their radicles are longer and the hypocotyls shorter than in the controls. The leachate promotes hypocotyl growth and inhibits that of the radicle. 6. A hypothesis is suggested to interpret the results based on the assumed interaction between seeds, light and an inhibitor.

  6. Reassessment of an Arabidopsis cell wall invertase inhibitor AtCIF1 reveals its role in seed germination and early seedling growth.

    PubMed

    Su, Tao; Wolf, Sebastian; Han, Mei; Zhao, Hongbo; Wei, Hongbin; Greiner, Steffen; Rausch, Thomas

    2016-01-01

    In higher plants, cell wall invertase (CWI) and vacuolar invertase (VI) are recognized as essential players in sugar metabolism and sugar signaling, thereby affecting source-sink interactions, plant development and responses to environmental cues. CWI and VI expression levels are transcriptionally controlled; however, both enzymes are also subject to posttranslational control by invertase inhibitor proteins. The physiological significances of inhibitor proteins during seed germination and early seedling development are not yet fully understood. Here, we demonstrate that the inhibitor isoform AtCIF1 impacted on seed germination and early seedling growth in Arabidopsis. The primary target of AtCIF1 was shown to be localized to the apoplast after expressing an AtCIF1 YFP-fusion construct in tobacco epidermis and transgenic Arabidopsis root. The analysis of expression patterns showed that AtCWI1 was co-expressed spatiotemporally with AtCIF1 within the early germinating seeds. Seed germination was observed to be accelerated independently of exogenous abscisic acid (ABA) in the AtCIF1 loss-of-function mutant cif1-1. This effect coincided with a drastic increase of CWI activity in cif1-1 mutant seeds by 24 h after the onset of germination, both in vitro and in planta. Accordingly, quantification of sugar content showed that hexose levels were significantly boosted in germinating seeds of the cif1-1 mutant. Further investigation of AtCIF1 overexpressors in Arabidopsis revealed a markedly suppressed CWI activity as well as delayed seed germination. Thus, we conclude that the posttranslational modulation of CWI activity by AtCIF1 helps to orchestrate seed germination and early seedling growth via fine-tuning sucrose hydrolysis and, possibly, sugar signaling.

  7. Seed germination of cirsium arvense and Lepidium latifolium: Implications for management of montane wetlands

    USGS Publications Warehouse

    Laubhan, M.K.; Shaffer, T.L.

    2006-01-01

    Cirsium arvense and Lepidium latifolium are species that can aggressively invade wetland margins and potentially reduce biodiversity and alter ecosystem function. Although expansion of these species primarily occurs via rhizomatous growth, seeds are thought to be important in initial establishment. We conducted this study to investigate differences in seed germination of C. arvense and L. latifolium in montane wetlands of Colorado and Wyoming, USA. We used germination chambers to simulate environmental conditions (photoperiod, day/night temperature) during three periods of the growing season at each site and evaluated seed germination in relation to three soil moisture levels and two soil depths. A combination of shallow (<1 cm) seed burial and wet conditions resulted in the greatest germination probability of C. arvense (x = 63.0%), 95% CI = 41.2-80.5%), whereas deep (2-3 cm) seed burial and saturated moisture conditions resulted in almost no germination (x?? = 0.3%, 95% CI = 0.1-1.3%). The maximum germination probability of 44.0% (CI = 28.1-61.4%) for L. latifolium also occurred in the shallow burial and wet treatment; however, only effects of seed burial were significant (P < 0.05). The estimated mean germination probability of deeply buried seeds was <1.0% (CI = 0.3-1.4%) compared to 32% (CI = 19.7-47.9%) for shallowly buried seeds. Our results suggest that each species has the ability to germinate at similar rates throughout the growing season and across a large portion of the moisture gradient. This suggests that management actions, including water-level manipulations, at any time during the growing season may stimulate germination. Although burial of seed to depths of 2-3 cm reduced the germination potential of both species, the use of mechanical implements may be problematic in established stands because new plants of both species easily sprout from root buds. Further, disturbance resulting from such actions diminishes the density and vigor of other plants

  8. OsLOX2, a rice type I lipoxygenase, confers opposite effects on seed germination and longevity.

    PubMed

    Huang, Jiexue; Cai, Maohong; Long, Qizhang; Liu, Linglong; Lin, Qiuyun; Jiang, Ling; Chen, Saihua; Wan, Jianmin

    2014-08-01

    Rice production and seed storage are confronted with grain deterioration and loss of seed viability. Some members of the lipoxygenase (LOX) family function in degradation of storage lipids during the seed germination, but little is known about their influence on seed longevity during storage. We characterized the role of rice OsLOX2 gene in seed germination and longevity via over-expression and knock-down approaches. Abundant expression of OsLOX2 was detected in panicles, roots, and stems, but not in leaves. Moreover, OsLOX2 was highly induced during germination. OsLOX2 protein, located in the cytoplasm, showed a wide range of temperature adaptation (20-50 °C) and a substrate preference to linoleic acid. Lines over-expressing OsLOX2 showed accelerated seed germination under normal condition and lower seed viability after accelerated aging. RNA interference (RNAi) of OsLOX2 caused delayed germination and enhanced seed longevity. RNAi lines with strongly repressed OsLOX2 activity completely lost the capability of germination after accelerated aging. More lipid hydroperoxide were found in OE15 than the control, but less in RNAi lines than in the WT Nipponbare. Therefore, OsLOX2 acts in opposite directions during seed germination and longevity during storage. Appropriate repression of the OsLOX2 gene may delay the aging process during the storage without compromising germination under normal conditions.

  9. Effects of seed cryopreservation, stratification and scarification on germination for five rare species of pitcher plants.

    PubMed

    Khanna, Sruti; Jenkins, Heather; Bucalo, Kylie; Determann, Ron O; Cruse-Sanders, Jennifer M; Pullman, Gerald S

    2014-01-01

    Habitat loss and over collection have caused North American pitcher plants to become rare, including U.S. federally endangered Sarracenia alabamensis and S. oreophila, and S. leucophylla, S. psittacina and S. purpurea spp. venosa, endangered in several states. To develop reliable seed cryopreservation protocols for endangered Sarracenia species enabling similar germination percentages before and after storage in liquid nitrogen (LN) either in vivo or using in vitro tools. Seed germination pre- and post-cryopreservation were compared following seed drying with germination in soil, aseptic environment with wet filter paper or enriched medium, and using scarification or stratification for dormancy removal. After cryostorage, germination in vitro (1/6- or 1/3-strength MS medium) increased compared to germination on peat moss. Germination pre- and post-cryopreservation was similar for S. alabamensis and S. oreophila when seeds were stratified and grown in vitro. S. leucophylla and S. psittacina also showed high germination after cryopreservation when germinated on medium following stratification. Rapid liquid nitrogen exposure and rewarming induced seed coat cracking that damaged seeds, likely allowing internal damage during acid scarification and microbial entry during germination in non-sterile environments.

  10. Transcriptome Analysis of the Effects of Shell Removal and Exogenous Gibberellin on Germination of Zanthoxylum Seeds.

    PubMed

    Sun, Jikang; Wang, Ping; Zhou, Tao; Rong, Jian; Jia, Hao; Liu, Zhiming

    2017-08-17

    The zanthoxylum seeds are oil-rich and have a very thick, dense and oily shell. In the natural conditions the seeds have a very low germination rate. Prior to treatment with GAs to promote germination, the seeds were usually soaked in sulfuric acid to remove shells easily. A high-throughput sequencing of mRNAs was performed to investigate the effects of the above treatments on the germination of zanthoxylum seeds. Seven libraries were assembled into 100,982 unigenes and 59,509 unigenes were annotated. We focused on the expression profiles of the key genes related to the oil metabolisms and hormone regulations during seed germination. Our data indicated the endogenous ABA of seeds was rich. The effects that the exogenous GAs promoted germination were apparent in the secong day of germination. Especially, for the first time our results indicated the exogenous GAs lowered the aerobic metabolism including the oil metabolisms during imbibition. We inferred that the exogenous GAs had inhibitory effects on the oil metabolisms to avoide oxidative damages to the imbibed seeds, and the seed shell played the role similiar to the exogenous GAs in the initial stage of germination in the natural conditions.

  11. Thioredoxin-Linked Proteins Are Reduced during Germination of Medicago truncatula Seeds1[W][OA

    PubMed Central

    Alkhalfioui, Fatima; Renard, Michelle; Vensel, William H.; Wong, Joshua; Tanaka, Charlene K.; Hurkman, William J.; Buchanan, Bob B.; Montrichard, Françoise

    2007-01-01

    Germination of cereals is accompanied by extensive change in the redox state of seed proteins. Proteins present in oxidized form in dry seeds are converted to the reduced state following imbibition. Thioredoxin (Trx) appears to play a role in this transition in cereals. It is not known, however, whether Trx-linked redox changes are restricted to cereals or whether they take place more broadly in germinating seeds. To gain information on this point, we have investigated a model legume, Medicago truncatula. Two complementary gel-based proteomic approaches were followed to identify Trx targets in seeds: Proteins were (1) labeled with a thiol-specific probe, monobromobimane (mBBr), following in vitro reduction by an NADP/Trx system, or (2) isolated on a mutant Trx affinity column. Altogether, 111 Trx-linked proteins were identified with few differences between axes and cotyledons. Fifty nine were new, 34 found previously in cereal or peanut seeds, and 18 in other plants or photosynthetic organisms. In parallel, the redox state of proteins assessed in germinating seeds using mBBr revealed that a substantial number of proteins that are oxidized or partly reduced in dry seeds became more reduced upon germination. The patterns were similar for proteins reduced in vivo during germination or in vitro by Trx. In contrast, glutathione and glutaredoxin were less effective as reductants in vitro. Overall, more than half of the potential targets identified with the mBBr labeling procedure were reduced during germination. The results provide evidence that Trx functions in the germination of seeds of dicotyledons as well as monocotyledons. PMID:17513483

  12. Effects of reduced winter duration on seed dormancy and germination in six populations of the alpine herb Aciphyllya glacialis (Apiaceae)

    PubMed Central

    Hoyle, G. L.; Cordiner, H.; Good, R. B.; Nicotra, A. B.

    2014-01-01

    The life stages of seed germination and seedling establishment play a vital role in maintaining plant populations and determining range dynamics of species. Thus, it is not surprising that specific germination requirements and dormancy mechanisms have evolved in all major angiosperm clades. In a rapidly changing climate, we face growing pressure to manage, conserve and restore native plant species and communities. To achieve these aims, we require solid knowledge of whether and how seed germination requirements and dormancy status vary between different populations of a given species and how germination strategies may be affected by warming climatic conditions. We assessed the effect of decreasing durations of cold stratification (i.e. conditions representing a shortened winter as predicted under climate change) on germination and dormancy of the alpine herb Aciphylla glacialis. Our results confirmed previous research showing that A. glacialis seeds possess physiological dormancy that can be alleviated by cold stratification. In addition, the results demonstrated that A. glacialis seeds have underdeveloped embryos at dispersal; these grow to germinable size following 4–9 weeks at both constant 5°C and 10–5°C (day–night) temperatures. We conclude that A. glacialis exhibits morphophysiological dormancy. Furthermore, we found that the final percentage germination and dormancy status varied significantly among natural populations and that this variation did not correlate with elevation at the site of seed origin. Seeds germinated following 6–8 weeks of cold stratification, and seedlings showed no detrimental effects as a result of shorter stratification periods. Together, these results suggest that reduced duration of winter is unlikely to have direct negative impacts on germination or early seedling growth in A. glacialis. The causes and implications of the population variation in germination traits are discussed. PMID:27293636

  13. EFFECTS OF COLD STRATIFICATION AND GA3 ON GERMINATION OF ARBUTUS UNEDO SEEDS OF THREE PROVENANCES.

    PubMed

    Pipinis, Elias; Stampoulidis, Athanasios; Milios, Elias; Kitikidou, Kyriaki; Radoglou, Kalliopi

    2017-01-01

    Arbutus unedo is a valuable Mediterranean shrub as an ornamental plant as well as fruit tree. Fresh fruits of A. unedo are a good source of antioxidants, of vitamins C, E and carotenoids and also are characterized by the high content of mineral elements. The effects of gibberellic acid (GA 3 ) and cold stratification (CS) on seed germination performance were investigated in A. unedo seeds collected from three provenances in the Northern part of Greece. Seeds of each provenance were soaked in solutions of GA 3 (500, 1000 or 2000 ppm) for 24 h and subsequently were subjected to CS at 3 - 5°C for 0, 1, 2, and 3 months. Non-stratified seeds of the three A. unedo provenances which were not treated with GA 3 solutions exhibited very low germination. However, seed germination was significantly improved after a one-month period of CS. Similarly, the non-stratified seeds of all three provenances became non-dormant after the treatment with 2000 ppm GA 3 and they germinated at high percentages. However, in untreated seeds with GA3, after a one-month CS period the seeds of the Pieria provenance exhibited higher germination percentage than that of Rodopi provenance seeds. Furthermore, in non-stratified seeds, the Pieria provenance seeds treated with GA3 germinated at higher percentages and more rapidly than those of the other two provenances. The results indicated that untreated seeds exhibited very low germination at 20/25°C. However, in all three provenances seed germinability was significantly improved by a one-month period of CS or treatment of seeds with 2000 ppm GA3. Furthermore, there was a considerable variability among seed provenances in response to the treatments which were applied.

  14. Novel hydrated graphene ribbon unexpectedly promotes aged seed germination and root differentiation

    NASA Astrophysics Data System (ADS)

    Hu, Xiangang; Zhou, Qixing

    2014-01-01

    It is well known that graphene (G) induces nanotoxicity towards living organisms. Here, a novel and biocompatible hydrated graphene ribbon (HGR) unexpectedly promoted aged (two years) seed germination. HGR formed at the normal temperature and pressure (120 days hydration), presented 17.1% oxygen, 0.9% nitrogen groups, disorder-layer structure, with 0.38 nm thickness ribbon morphology. Interestingly, there were bulges around the edges of HGR. Compared to G and graphene oxide (GO), HGR increased seed germination by 15% root differentiation between 52 and 59% and enhanced resistance to oxidative stress. The metabonomics analysis discovered that HGR upregulated carbohydrate, amino acid, and fatty acids metabolism that determined secondary metabolism, nitrogen sequestration, cell membrane integrity, permeability, and oxidation resistance. Hexadecanoic acid as a biomarker promoted root differentiation and increased the germination rate. Our discovery is a novel HGR that promotes aged seed germination, illustrates metabolic specificity among graphene-based materials, and inspires innovative concepts in the regulation of seed development.

  15. Hydrothermal time models for conidial germination and mycelial growth of the seed pathogen Pyrenophora semeniperda

    Treesearch

    Connor W. Barth; Susan E. Meyer; Julie Beckstead; Phil S. Allen

    2015-01-01

    Population-based threshold models using hydrothermal time (HTT) have been widely used to model seed germination. We used HTT to model conidial germination and mycelial growth for the seed pathogen Pyrenophora semeniperda in a novel approach to understanding its interactions with host seeds. Germination time courses and mycelial growth rates for P.semeniperda were...

  16. Germination traits explain soil seed persistence across species: the case of Mediterranean annual plants in cereal fields

    PubMed Central

    Saatkamp, Arne; Affre, Laurence; Dutoit, Thierry; Poschlod, Peter

    2011-01-01

    Background and Aims Seed persistence in the soil under field conditions is an important issue for the maintenance of local plant populations and the restoration of plant communities, increasingly so in the light of rapidly changing land use and climate change. Whereas processes important for dispersal in space are well known, knowledge of processes governing dispersal in time is still limited. Data for morphological seed traits such as size have given contradictory results for prediction of soil seed persistence or cover only a few species. There have been few experimental studies on the role of germination traits in determining soil seed persistence, while none has studied their predictive value consistently across species. Delayed germination, as well as light requirements for germination, have been suggested to contribute to the formation of persistent seed banks. Moreover, diurnally fluctuating temperatures can influence the timing of germination and are therefore linked to seed bank persistence. Methods The role of germination speed measured by T50 (days to germination of 50 % of all germinated seeds), light requirement and reaction to diurnally fluctuating temperatures in determining seed persistence in the soil was evaluated using an experimental comparative data set of 25 annual cereal weed species. Key Results It is shown that light requirements and slow germination are important features to maintain seeds ungerminated just after entering the soil, and hence influence survival of seeds in the soil. However, the detection of low diurnally fluctuating temperatures enhances soil seed bank persistence by limiting germination. Our data further suggest that the effect of diurnally fluctuating temperatures, as measured on seeds after dispersal and dry storage, is increasingly important to prevent fatal germination after longer burial periods. Conclusions These results underline the functional role of delayed germination and light for survival of seeds in the soil

  17. Analysis of how ant behaviors affect germination in a tropical myrmecochore Calathea microcephala (P. & E.) Koernicke (Marantaceae): Microsite selection and aril removal by neotropical ants, Odontomachus, Pachycondyla, and Solenopsis (Formicidae).

    PubMed

    Horvitz, C C

    1981-10-01

    The evolutionary effects of a tropical ant-seed interaction are examined by posing questions about the fate of Calathea seeds carried by neotropical ants. Where do ants take seeds and what do they do with them? How do ant behaviors affect seed germination? Treatment of seeds by ants is determined by a series of seed-fate trials in captive colonies. There is no evidence of seed predation by ants. Odontomachus laticeps, Pachycondyla spp, and Solenopsis geminata rapidly displace seeds to ant nests, determine the microsites of seeds, and remove the seed arils for food. The seed arils are rich in lipids. The effects on germination of microsite selection and aril removal are quantitatively evaluated. Seeds which are immediately taken to a consistently moist spot germinate readily; 72% germinate, with a mean germination speed of 29 days. For such seeds aril removal does not significantly affect germination. In contrast, seeds which experience a delay before encountering appropriate germination conditions seem to exhibit an induced dormancy (sensu, Harper 1977) and a lower germination percentage. They take longer to germinate (up to 85 days) even after conditions become appropriate. It appears that their germination is enhanced by aril removal, which may act as an environmental cue to break dormancy. Such a mechanism would indicate that ant-handling of seeds is predictive of favorable conditions for seedling growth and establishment. The exact nature of such conditions and the effects on plant population dynamics remain to be seen.

  18. ABA, GA(3), and nitrate may control seed germination of Crithmum maritimum (Apiaceae) under saline conditions.

    PubMed

    Atia, Abdallah; Debez, Ahmed; Barhoumi, Zouhaier; Smaoui, Abderrazak; Abdelly, Chedly

    2009-08-01

    Impaired germination is common among halophyte seeds exposed to salt stress, partly resulting from the salt-induced reduction of the growth regulator contents in seeds. Thus, the understanding of hormonal regulation during the germination process is a main key: (i) to overcome the mechanisms by which NaCl-salinity inhibit germination; and (ii) to improve the germination of these species when challenged with NaCl. In the present investigation, the effects of ABA, GA(3), NO(-)(3), and NH(+)(4) on the germination of the oilseed halophyte Crithmum maritimum (Apiaceae) were assessed under NaCl-salinity (up to 200 mM NaCl). Seeds were collected from Tabarka rocky coasts (N-W of Tunisia). The exogenous application of GA(3), nitrate (either as NaNO(3) or KNO(3)), and NH(4)Cl enhanced germination under NaCl salinity. The beneficial impact of KNO(3) on germination upon seed exposure to NaCl salinity was rather due to NO(-)(3) than to K(+), since KCl failed to significantly stimulate germination. Under optimal conditions for germination (0 mM NaCl), ABA inhibited germination over time in a dose dependent manner, but KNO(3) completely restored the germination parameters. Under NaCl salinity, the application of fluridone (FLU) an inhibitor of ABA biosynthesis, stimulated substantially seed germination. Taken together, our results point out that NO(-)(3) and GA(3) mitigate the NaCl-induced reduction of seed germination, and that NO(-)(3) counteracts the inhibitory effect of ABA on germination of C. maritimum.

  19. Effects of lanthanum and acid rain stress on the bio-sequestration of lanthanum in phytoliths in germinated rice seeds

    PubMed Central

    Si, Yong; Wang, Lihong; Huang, Xiaohua

    2018-01-01

    REEs in the environment can be absorbed by plants and sequestered by plant phytoliths. Acid rain can directly or indirectly affect plant physiological functions. Currently, the effects of REEs and acid rain on phytolith-REEs complex in plants are not yet fully understood. In this study, a high-silicon accumulation crop, rice (Oryza sativa L.), was selected as a representative of plants, and orthogonal experiments were conducted under various levels of lanthanum [La(III)] and pH. The results showed that various La(III) concentrations could significantly improve the efficiency and sequestration of phytolith La(III) in germinated rice seeds. A pH of 4.5 promoted phytolith La(III) sequestration, while a pH of 3.5 inhibited sequestration. Compared with the single treatment with La(III), the combination of La(III) and acid rain inhibited the efficiency and sequestration of phytolith La(III). Correlation analysis showed that the efficiency of phytolith La(III) sequestration had no correlation with the production of phytolith but was closely correlated with the sequestration of phytolith La(III) and the physiological changes of germinated rice seeds. Phytolith morphology was an important factor affecting phytolith La(III) sequestration in germinated rice seeds, and the effect of tubes on sequestration was more significant than that of dumbbells. This study demonstrated that the formation of the phytolith and La(III) complex could be affected by exogenous La(III) and acid rain in germinated rice seeds. PMID:29763463

  20. In vitro seed germination of economically important edible bamboo Dendrocalamus membranaceus Munro.

    PubMed

    Brar, Jasmine; Anand, Manju; Sood, Anil

    2013-01-01

    An in vitro propagation protocol using mature seeds of D. membranaceus was successfully established. Scarcity of seeds in bamboos because of their long flowering periods and irregular seed set resulting in low viability and germination potential, motivated us to undertake the present study. The effects of sterilants, light conditions, exogenous application of plant growth regulators and temperature in overcoming germination barriers in ageing seeds of bamboo were studied. It was found that HgCl2 (0.1%) along with bleach (15%) was more effective in raising aseptic cultures. Dark conditions, high temperatures around 30 degrees C and soaking of seeds in GA3 solution (50 ppm) overnight stimulated high percent of seed germination with corresponding increase in shoot length (2.7 +/- 0.7 mm) and number of sprouts (2.1 +/- 0.7) per explants during culture initiation. 6-benzylaminopurine acted synergistically with kinetin to give optimum germination rate of 70 +/- 13.9% as compared to 63.13% when used individually. For prolonged maintenance of cultures, 2% sucrose was found to be suitable for promoting photomixotrophic micropropagation. Following this procedure, about 65% survival of plantlets could be achieved during hardening. Biochemically seeds consume starchy endosperm for emergence of radicle which is taken as a sign of germination as also evident from the present study. Loss of viability and vigour after a year was confirmed by Tetrazolium chloride test. Micropropagation protocol developed here will ensure regeneration of large number of plants in a relatively short time. Conclusively, in vitro propagation protocol developed in D. membranaceus using mature seeds as an explants is reported for the first time.

  1. Disturbance frequency and vertical distribution of seeds affect long-term population dynamics: a mechanistic seed bank model.

    PubMed

    Eager, Eric Alan; Haridas, Chirakkal V; Pilson, Diana; Rebarber, Richard; Tenhumberg, Brigitte

    2013-08-01

    Seed banks are critically important for disturbance specialist plants because seeds of these species germinate only in disturbed soil. Disturbance and seed depth affect the survival and germination probability of seeds in the seed bank, which in turn affect population dynamics. We develop a density-dependent stochastic integral projection model to evaluate the effect of stochastic soil disturbances on plant population dynamics with an emphasis on mimicking how disturbances vertically redistribute seeds within the seed bank. We perform a simulation analysis of the effect of the frequency and mean depth of disturbances on the population's quasi-extinction probability, as well as the long-term mean and variance of the total density of seeds in the seed bank. We show that increasing the frequency of disturbances increases the long-term viability of the population, but the relationship between the mean depth of disturbance and the long-term viability of the population are not necessarily monotonic for all parameter combinations. Specifically, an increase in the probability of disturbance increases the long-term viability of the total seed bank population. However, if the probability of disturbance is too low, a shallower mean depth of disturbance can increase long-term viability, a relationship that switches as the probability of disturbance increases. However, a shallow disturbance depth is beneficial only in scenarios with low survival in the seed bank.

  2. Sensitivity of Polygonum aviculare Seeds to Light as Affected by Soil Moisture Conditions

    PubMed Central

    Batlla, Diego; Nicoletta, Marcelo; Benech-Arnold, Roberto

    2007-01-01

    Background and Aims It has been hypothesized that soil moisture conditions could affect the dormancy status of buried weed seeds, and, consequently, their sensitivity to light stimuli. In this study, an investigation is made of the effect of different soil moisture conditions during cold-induced dormancy loss on changes in the sensitivity of Polygonum aviculare seeds to light. Methods Seeds buried in pots were stored under different constant and fluctuating soil moisture environments at dormancy-releasing temperatures. Seeds were exhumed at regular intervals during storage and were exposed to different light treatments. Changes in the germination response of seeds to light treatments during storage under the different moisture environments were compared in order to determine the effect of soil moisture on the sensitivity to light of P. aviculare seeds. Key Results Seed acquisition of low-fluence responses during dormancy release was not affected by either soil moisture fluctuations or different constant soil moisture contents. On the contrary, different soil moisture environments affected seed acquisition of very low fluence responses and the capacity of seeds to germinate in the dark. Conclusions The results indicate that under field conditions, the sensitivity to light of buried weed seeds could be affected by the soil moisture environment experienced during the dormancy release season, and this could affect their emergence pattern. PMID:17430979

  3. Molecular Mechanisms Underlying Abscisic Acid/Gibberellin Balance in the Control of Seed Dormancy and Germination in Cereals

    PubMed Central

    Tuan, Pham A.; Kumar, Rohit; Rehal, Pawanpuneet K.; Toora, Parneet K.; Ayele, Belay T.

    2018-01-01

    Seed dormancy is an adaptive trait that does not allow the germination of an intact viable seed under favorable environmental conditions. Non-dormant seeds or seeds with low level of dormancy can germinate readily under optimal environmental conditions, and such a trait leads to preharvest sprouting, germination of seeds on the mother plant prior to harvest, which significantly reduces the yield and quality of cereal crops. High level of dormancy, on the other hand, may lead to non-uniform germination and seedling establishment. Therefore, intermediate dormancy is considered to be a desirable trait as it prevents the problems of sprouting and allows uniformity of postharvest germination of seeds. Induction, maintenance, and release of seed dormancy are complex physiological processes that are influenced by a wide range of endogenous and environmental factors. Plant hormones, mainly abscisic acid (ABA) and gibberellin (GA), are the major endogenous factors that act antagonistically in the control of seed dormancy and germination; ABA positively regulates the induction and maintenance of dormancy, while GA enhances germination. Significant progress has been made in recent years in the elucidation of molecular mechanisms regulating ABA/GA balance and thereby dormancy and germination in cereal seeds, and this review summarizes the current state of knowledge on the topic. PMID:29875780

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

    PubMed

    Ellison, A M

    2001-03-01

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

  5. Proteome analysis of Norway maple (Acer platanoides L.) seeds dormancy breaking and germination: influence of abscisic and gibberellic acids

    PubMed Central

    Pawłowski, Tomasz A

    2009-01-01

    Background Seed dormancy is controlled by the physiological or structural properties of a seed and the external conditions. It is induced as part of the genetic program of seed development and maturation. Seeds with deep physiological embryo dormancy can be stimulated to germinate by a variety of treatments including cold stratification. Hormonal imbalance between germination inhibitors (e.g. abscisic acid) and growth promoters (e.g. gibberellins) is the main cause of seed dormancy breaking. Differences in the status of hormones would affect expression of genes required for germination. Proteomics offers the opportunity to examine simultaneous changes and to classify temporal patterns of protein accumulation occurring during seed dormancy breaking and germination. Analysis of the functions of the identified proteins and the related metabolic pathways, in conjunction with the plant hormones implicated in seed dormancy breaking, would expand our knowledge about this process. Results A proteomic approach was used to analyse the mechanism of dormancy breaking in Norway maple seeds caused by cold stratification, and the participation of the abscisic (ABA) and gibberellic (GA) acids. Forty-four proteins showing significant changes were identified by mass spectrometry. Of these, eight spots were identified as water-responsive, 18 spots were ABA- and nine GA-responsive and nine spots were regulated by both hormones. The classification of proteins showed that most of the proteins associated with dormancy breaking in water were involved in protein destination. Most of the ABA- and GA-responsive proteins were involved in protein destination and energy metabolism. Conclusion In this study, ABA was found to mostly down-regulate proteins whereas GA up-regulated proteins abundance. Most of the changes were observed at the end of stratification in the germinated seeds. This is the most active period of dormancy breaking when seeds pass from the quiescent state to germination. Seed

  6. Proteome analysis of Norway maple (Acer platanoides L.) seeds dormancy breaking and germination: influence of abscisic and gibberellic acids.

    PubMed

    Pawłowski, Tomasz A

    2009-05-04

    Seed dormancy is controlled by the physiological or structural properties of a seed and the external conditions. It is induced as part of the genetic program of seed development and maturation. Seeds with deep physiological embryo dormancy can be stimulated to germinate by a variety of treatments including cold stratification. Hormonal imbalance between germination inhibitors (e.g. abscisic acid) and growth promoters (e.g. gibberellins) is the main cause of seed dormancy breaking. Differences in the status of hormones would affect expression of genes required for germination. Proteomics offers the opportunity to examine simultaneous changes and to classify temporal patterns of protein accumulation occurring during seed dormancy breaking and germination. Analysis of the functions of the identified proteins and the related metabolic pathways, in conjunction with the plant hormones implicated in seed dormancy breaking, would expand our knowledge about this process. A proteomic approach was used to analyse the mechanism of dormancy breaking in Norway maple seeds caused by cold stratification, and the participation of the abscisic (ABA) and gibberellic (GA) acids. Forty-four proteins showing significant changes were identified by mass spectrometry. Of these, eight spots were identified as water-responsive, 18 spots were ABA- and nine GA-responsive and nine spots were regulated by both hormones. The classification of proteins showed that most of the proteins associated with dormancy breaking in water were involved in protein destination. Most of the ABA- and GA-responsive proteins were involved in protein destination and energy metabolism. In this study, ABA was found to mostly down-regulate proteins whereas GA up-regulated proteins abundance. Most of the changes were observed at the end of stratification in the germinated seeds. This is the most active period of dormancy breaking when seeds pass from the quiescent state to germination. Seed dormancy breaking involves

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

    PubMed Central

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

    2017-01-01

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

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

    PubMed

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

    2017-01-01

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

  9. α-Xylosidase plays essential roles in xyloglucan remodelling, maintenance of cell wall integrity, and seed germination in Arabidopsis thaliana

    PubMed Central

    Shigeyama, Takuma; Watanabe, Asuka; Tokuchi, Konatsu; Toh, Shigeo; Sakurai, Naoki; Shibuya, Naoto; Kawakami, Naoto

    2016-01-01

    Regulation and maintenance of cell wall physical properties are crucial for plant growth and environmental response. In the germination process, hypocotyl cell expansion and endosperm weakening are prerequisites for dicot seeds to complete germination. We have identified the Arabidopsis mutant thermoinhibition-resistant germination 1 (trg1), which has reduced seed dormancy and insensitivity to unfavourable conditions for germination owing to a loss-of-function mutation of TRG1/XYL1, which encodes an α-xylosidase. Compared to those of wild type, the elongating stem of trg1 showed significantly lower viscoelasticity, and the fruit epidermal cells were longitudinally shorter and horizontally enlarged. Actively growing tissues of trg1 over-accumulated free xyloglucan oligosaccharides (XGOs), and the seed cell wall had xyloglucan with a greatly reduced molecular weight. These observations suggest that XGOs reduce xyloglucan size by serving as an acceptor in transglycosylation and eventually enhancing cell wall loosening. TRG1/XYL1 gene expression was abundant in growing wild-type organs and tissues but relatively low in cells at most actively elongating part of the tissues, suggesting that α-xylosidase contributes to maintaining the mechanical integrity of the primary cell wall in the growing and pre-growing tissues. In germinating seeds of trg1, expression of genes encoding specific abscisic acid and gibberellin metabolism enzymes was altered in accordance with the aberrant germination phenotype. Thus, cell wall integrity could affect seed germination not only directly through the physical properties of the cell wall but also indirectly through the regulation of hormone gene expression. PMID:27605715

  10. Effects of origin, seasons and storage under different temperatures on germination of Senecio vulgaris (Asteraceae) seeds.

    PubMed

    Ndihokubwayo, Noel; Nguyen, Viet-Thang; Cheng, Dandan

    2016-01-01

    Invasive plants colonize new environments, become pests and cause biodiversity loss, economic loss and health damage. Senecio vulgaris L. (Common groundsel, Asteraceae), a widely distributing cosmopolitan weed in the temperate area, is reported with large populations in the north-eastern and south-western part, but not in southern, central, or north-western parts of China. We studied the germination behavior of S. vulgaris to explain the distribution and the biological invasion of this species in China. We used seeds originating from six native and six invasive populations to conduct germination experiments in a climate chamber and under outdoor condition. When incubated in a climate chamber (15 °C), seeds from the majority of the populations showed >90% germination percentage (GP) and the GP was equal for seeds with a native and invasive origin. The mean germination time (MGT) was significantly different among the populations. Under outdoor conditions, significant effects of origin, storage conditions (stored at 4 °C or ambient room temperature, ca. 27 °C) and seasons (in summer or autumn) were observed on the GP while the MGT was only affected by the season. In autumn, the GP (38.6%) was higher and the MGT was slightly longer than that in summer. In autumn, seeds stored at 4 °C showed higher GP than those stored at ambient room temperature (ca.27 °C), and seeds from invasive populations revealed higher GP than those from native populations. The results implied that the high temperature in summer has a negative impact on the germination and might cause viability loss or secondary dormancy to S. vulgaris seeds. Our study offers a clue to exploring what factor limits the distribution of S. vulgaris in China by explaining why, in the cities in South-East China and central China such as Wuhan, S. vulgaris cannot establish natural and viable populations.

  11. Comparison of germination and seed vigor of sunflower in two contaminated soils of different texture

    NASA Astrophysics Data System (ADS)

    Zhao, Xin; Han, Jaemaro; Lee, Jong Keun; Kim, Jae Young

    2014-05-01

    Phytoremediation as an emerging low-cost and ecologically friendly alternative to the conventional soil remediation technologies has gained a great deal of attention and into lots of research. As a kind of the methods that use of green plants to remediate heavy metals contaminated soils, the early growth status of plant seeds in the contaminated environmental directly affects the effect of phytoremediation. Germination test in the water (aqueous solution of heavy metal) is generally used for assessing heavy metal phytotoxicity and possibility of plant growth, but there is a limit. Because soil is commonly main target of phytoremediation, not the water. The bioavailability of heavy metals in the soil also depends on the texture. So soil texture is an important factor of phytoremediation effect. Sunflower is the representative species which have good tolerance to various heavy metals; furthermore, the seeds of sunflower can be used as the raw-material for producing bio-diesel. The objectives of this research were to investigate germination rate of sunflowers in various heavy metal contaminated soils and to compare the seedling vigor index (SVI) of sunflower in two contaminated soils of different texture. Sunflower (Helianthusannuus L.) seeds were obtained from a commercial market. In order to prove the soil texture effect on heavy metal contaminated soil, germination tests in soil were conducted with two different types of soil texture (i.e., loam soil and sandy loam soil) classified by soil textural triangle (defined by USDA) including representative soil texture of Korea. Germination tests in soil were conducted using KS I ISO 11260-1 (2005) for reference that sunflower seeds were incubated for 7 days in dark at 25 ± 1 Celsius degree. The target heavy metals are Nickel (Ni) and Zinc (Zn). The Ni and Zn concentrations were 0, 10, 50, 100, 200, 300, 500 mg-Ni/kg-dry soil, and 0, 10, 50, 100, 300, 500, 900 mg-Zn/kg-dry soil, respectively. After germination test for 7

  12. A role for fruit structure in seed survival and germination of Swartzia langsdorffii Raddi beyond dispersal.

    PubMed

    Vaz, T A A; Rodrigues-Junior, A G; Davide, A C; Nakamura, A T; Toorop, P E

    2018-03-01

    Diaspore structure has been hypothesised to play a role in seed viability and/or germination of recalcitrant seeds, especially for Swartzia langsdorffii. Thus, this work aims to (i) investigate the in situ contribution of pericarp and aril on seed viability and germination, and (ii) identify morphoanatomical traits of S. langsdorffii diaspores that allow its desiccation-sensitive seeds to remain viable. The role of the pericarp and aril in seed survival and germination was investigated by placing the whole fruit, whole seeds (arillate seed) and bare seeds (without aril) in soil in the forest understorey, assessing germination, emergence, dead, firm and predated seeds, and water content of pericarps, arils and seeds. Correlation analysis was performed between environmental variables and physiological parameters. Histochemical features of diaspores were also investigated. Pericarp water content fell after several months, while the aril maintained its water content. Seeds did not lose water even without the presence of the pericarp and aril. However, presence of the pericarp promoted seed water content, viability and germination long after dispersal. The embryo had a thickened outer periclinal cell wall. Pericarp and aril are not essential to prevent water loss in seeds, but do help to retain seed moisture, favouring viability maintenance and promoting germination during the rainy season. Morphoanatomical features of seeds are suggested as main factors that reduce water loss. Survival of these desiccation-sensitive seeds upon dispersal during the dry season appears to be facilitated by multiple diaspore features that prevent viability loss. © 2017 German Society for Plant Sciences and The Royal Botanical Society of the Netherlands.

  13. Exogenous auxin represses soybean seed germination through decreasing the gibberellin/abscisic acid (GA/ABA) ratio.

    PubMed

    Shuai, Haiwei; Meng, Yongjie; Luo, Xiaofeng; Chen, Feng; Zhou, Wenguan; Dai, Yujia; Qi, Ying; Du, Junbo; Yang, Feng; Liu, Jiang; Yang, Wenyu; Shu, Kai

    2017-10-03

    Auxin is an important phytohormone which mediates diverse development processes in plants. Published research has demonstrated that auxin induces seed dormancy. However, the precise mechanisms underlying the effect of auxin on seed germination need further investigation, especially the relationship between auxins and both abscisic acid (ABA) and gibberellins (GAs), the latter two phytohormones being the key regulators of seed germination. Here we report that exogenous auxin treatment represses soybean seed germination by enhancing ABA biosynthesis, while impairing GA biogenesis, and finally decreasing GA 1 /ABA and GA 4 /ABA ratios. Microscope observation showed that auxin treatment delayed rupture of the soybean seed coat and radicle protrusion. qPCR assay revealed that transcription of the genes involved in ABA biosynthetic pathway was up-regulated by application of auxin, while expression of genes involved in GA biosynthetic pathway was down-regulated. Accordingly, further phytohormone quantification shows that auxin significantly increased ABA content, whereas the active GA 1 and GA 4 levels were decreased, resulting insignificant decreases in the ratiosGA 1 /ABA and GA 4 /ABA.Consistent with this, ABA biosynthesis inhibitor fluridone reversed the delayed-germination phenotype associated with auxin treatment, while paclobutrazol, a GA biosynthesis inhibitor, inhibited soybean seed germination. Altogether, exogenous auxin represses soybean seed germination by mediating ABA and GA biosynthesis.

  14. Effect of Germination and Fermentation Process on the Antioxidant Compounds of Quinoa Seeds.

    PubMed

    Carciochi, Ramiro Ariel; Galván-D'Alessandro, Leandro; Vandendriessche, Pierre; Chollet, Sylvie

    2016-12-01

    Quinoa (Chenopodium quinoa) seed has gained a great interest in the last years, mainly due to its nutritional properties and its content of antioxidant substances with health-promoting properties in humans. In this work, the effect of germination time and fermentation on the levels of antioxidant compounds (ascorbic acid, tocopherol isomers and phenolic compounds) and antioxidant activity of quinoa seeds was evaluated. Fermentation was carried out naturally by the microorganisms present in the seeds or by inoculation with two Saccharomyces cerevisiae strains (used for baking and brewing). Ascorbic acid and total tocopherols were significantly increased (p ≤ 0.05) after 72 h of germination process in comparison with raw quinoa seeds, whilst fermentation caused a decrease in both types of compounds. Phenolic compounds and antioxidant capacity were improved using both bioprocesses, being this effect more noticeable for germination process (101 % of increase after three days of germination). Germination and fermentation proved to be desirable procedures for producing enriched ingredients with health-promoting antioxidant compounds in a natural way.

  15. A study of the effects of micro-gravity on seed germination

    NASA Technical Reports Server (NTRS)

    Klein, Lynn Suzanne; Mckibben, Mark; Brain, David A.; Johnson, Theodore C.; Dannenberg, Konrad K.

    1992-01-01

    This study will identify characteristics of seed germination dependent upon gravity. To accomplish this objective, four different seed types will be germinated in space and then be compared to a control group germinated on Earth. Both the experimental and control groups will be analyzed on the cellular level for the size of cells, structural anomalies, and gravitational effects. The experiment will be conducted in a Get Away Special Canister (GAS Can no. 608) owned by the U.S. Space and Rocket Center and designed for students. The GAS Can will remain in the cargo bay of the Space Shuttle with minimal astronaut interaction.

  16. ESTs Analysis Reveals Putative Genes Involved in Symbiotic Seed Germination in Dendrobium officinale

    PubMed Central

    Zhao, Ming-Ming; Zhang, Gang; Zhang, Da-Wei; Hsiao, Yu-Yun; Guo, Shun-Xing

    2013-01-01

    Dendrobium officinale (Orchidaceae) is one of the world’s most endangered plants with great medicinal value. In nature, D . officinale seeds must establish symbiotic relationships with fungi to germinate. However, the molecular events involved in the interaction between fungus and plant during this process are poorly understood. To isolate the genes involved in symbiotic germination, a suppression subtractive hybridization (SSH) cDNA library of symbiotically germinated D . officinale seeds was constructed. From this library, 1437 expressed sequence tags (ESTs) were clustered to 1074 Unigenes (including 902 singletons and 172 contigs), which were searched against the NCBI non-redundant (NR) protein database (E-value cutoff, e-5). Based on sequence similarity with known proteins, 579 differentially expressed genes in D . officinale were identified and classified into different functional categories by Gene Ontology (GO), Clusters of orthologous Groups of proteins (COGs) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. The expression levels of 15 selected genes emblematic of symbiotic germination were confirmed via real-time quantitative PCR. These genes were classified into various categories, including defense and stress response, metabolism, transcriptional regulation, transport process and signal transduction pathways. All transcripts were upregulated in the symbiotically germinated seeds (SGS). The functions of these genes in symbiotic germination were predicted. Furthermore, two fungus-induced calcium-dependent protein kinases (CDPKs), which were upregulated 6.76- and 26.69-fold in SGS compared with un-germinated seeds (UGS), were cloned from D . officinale and characterized for the first time. This study provides the first global overview of genes putatively involved in D . officinale symbiotic seed germination and provides a foundation for further functional research regarding symbiotic relationships in orchids. PMID:23967335

  17. ESTs analysis reveals putative genes involved in symbiotic seed germination in Dendrobium officinale.

    PubMed

    Zhao, Ming-Ming; Zhang, Gang; Zhang, Da-Wei; Hsiao, Yu-Yun; Guo, Shun-Xing

    2013-01-01

    Dendrobiumofficinale (Orchidaceae) is one of the world's most endangered plants with great medicinal value. In nature, D. officinale seeds must establish symbiotic relationships with fungi to germinate. However, the molecular events involved in the interaction between fungus and plant during this process are poorly understood. To isolate the genes involved in symbiotic germination, a suppression subtractive hybridization (SSH) cDNA library of symbiotically germinated D. officinale seeds was constructed. From this library, 1437 expressed sequence tags (ESTs) were clustered to 1074 Unigenes (including 902 singletons and 172 contigs), which were searched against the NCBI non-redundant (NR) protein database (E-value cutoff, e(-5)). Based on sequence similarity with known proteins, 579 differentially expressed genes in D. officinale were identified and classified into different functional categories by Gene Ontology (GO), Clusters of orthologous Groups of proteins (COGs) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. The expression levels of 15 selected genes emblematic of symbiotic germination were confirmed via real-time quantitative PCR. These genes were classified into various categories, including defense and stress response, metabolism, transcriptional regulation, transport process and signal transduction pathways. All transcripts were upregulated in the symbiotically germinated seeds (SGS). The functions of these genes in symbiotic germination were predicted. Furthermore, two fungus-induced calcium-dependent protein kinases (CDPKs), which were upregulated 6.76- and 26.69-fold in SGS compared with un-germinated seeds (UGS), were cloned from D. officinale and characterized for the first time. This study provides the first global overview of genes putatively involved in D. officinale symbiotic seed germination and provides a foundation for further functional research regarding symbiotic relationships in orchids.

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

    PubMed Central

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

    2016-01-01

    Phelipanche aegyptiaca is one of the most destructive root parasitic plants of Orobanchaceae. This plant has significant impacts on crop yields worldwide. Conditioned and host root stimulants, in particular, strigolactones, are needed for unique seed germination. However, no extensive study on this phenomenon has been conducted because of insufficient genomic information. Deep RNA sequencing, including de novo assembly and functional annotation was performed on P. aegyptiaca germinating seeds. The assembled transcriptome was used to analyze transcriptional dynamics during seed germination. Key gene categories involved were identified. A total of 274,964 transcripts were determined, and 53,921 unigenes were annotated according to the NR, GO, COG, KOG, and KEGG databases. Overall, 5324 differentially expressed genes among dormant, conditioned, and GR24-treated seeds were identified. GO and KEGG enrichment analyses demonstrated numerous DEGs related to DNA, RNA, and protein repair and biosynthesis, as well as carbohydrate and energy metabolism. Moreover, ABA and ethylene were found to play important roles in this process. GR24 application resulted in dramatic changes in ABA and ethylene-associated genes. Fluridone, a carotenoid biosynthesis inhibitor, alone could induce P. aegyptiaca seed germination. In addition, conditioning was probably not the indispensable stage for P. aegyptiaca, because the transcript level variation of MAX2 and KAI2 genes (relate to strigolactone signaling) was not up-regulated by conditioning treatment. PMID:27428962

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

    PubMed

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

    2016-07-15

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

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

    PubMed Central

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

    2012-01-01

    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. PMID:22200664

  1. A correlation between tocopherol content and antioxidant activity in seeds and germinating seeds of soybean cultivars.

    PubMed

    Lee, Yu Young; Park, Hyang Mi; Hwang, Tae Young; Kim, Sun Lim; Kim, Mi Jung; Lee, Seuk Ki; Seo, Min Jung; Kim, Kee Jong; Kwon, Young-Up; Lee, Sang Chul; Kim, Yul Ho

    2015-03-15

    Tocopherols are crucial lipid-soluble antioxidants and essential nutrients. There is increasing interest in the biofortification of crops with vitamin E for reducing micronutrient malnutrition. However, relatively little is known about the development of soybean cultivars with high levels of tocopherol through combined breeding. Tocopherol contents of seeds and germinating seeds of 28 Korean soybean cultivars were analyzed and evaluated for health-promoting activities. Total tocopherol concentrations ranged from 203.9 to 503.1 µg g⁻¹ in seeds and from 20.1 to 230.1 µg g⁻¹ in germinating seeds. The traditional landraces of HaNagari (HN, 503.1 µg g⁻¹), Orialtae (OL, 486.6 µg g⁻¹), SuMoktae (SM, 476.5 µg g⁻¹) and SoRitae (SR, 475.5 µg g⁻¹) showed high levels of tocopherol content. The contents of the four isomers of tocopherol in seeds and germinating seeds were correlated with lipid peroxidation. The γ- and δ-tocopherol contents in seeds were related to 1,1-diphenyl-2-picrylhydrazyl free radical scavenging activity (0.434; P < 0.01 and 0.373; P < 0.05). Total tocopherol content was higher in soybean landraces as compared with modern cultivars developed by cross-breeding. These results suggest that soybean breeding is necessary to increase tocopherol levels. © 2014 Society of Chemical Industry.

  2. Increased germination and growth rates of pea and Zucchini seed by FSG plasma

    NASA Astrophysics Data System (ADS)

    Khatami, Shohreh; Ahmadinia, Arash

    2018-04-01

    Recently, cold atmospheric plasma (CAP) with the unique bio-disinfection features is used in various fields of industry, medicine, and agriculture. The main objectives of this work were to design FSG plasma (a semi-automatic device) and investigate the effect of the cold plasma in the enhancement of the Pea and Zucchini seed germination. Plasma irradiation time was studied to obtain a proper condition for the germination enhancement of seeds. The growth rate was calculated by measuring length of root and stem and dry weight of plants treated by plasma. To investigate drought resistance of plants, all treated and untreated samples were kept in darkness without water for 48 h. From the experimental results, it could be confirmed both drought resistance and germination of seedlings increased after plasma was applied to seeds at 30 s, while seeds treated whiten 60 s showed a decrease in both germination rate and seedling growth.

  3. Within- and trans-generational plasticity: seed germination responses to light quantity and quality.

    PubMed

    Vayda, Katherine; Donohue, Kathleen; Auge, Gabriela Alejandra

    2018-06-01

    Plants respond not only to the environment in which they find themselves, but also to that of their parents. The combination of within- and trans-generational phenotypic plasticity regulates plant development. Plants use light as source of energy and also as a cue of competitive conditions, since the quality of light (ratio of red to far-red light, R:FR) indicates the presence of neighbouring plants. Light regulates many aspects of plant development, including seed germination. To understand how seeds integrate environmental cues experienced at different times, we quantified germination responses to changes in light quantity (irradiance) and quality (R:FR) experienced during seed maturation and seed imbibition in Arabidopsis thaliana genotypes that differ in their innate dormancy levels and after treatments that break or reinduce dormancy. In two of the genotypes tested, reduced irradiance as well as reduced R:FR during seed maturation induced higher germination; thus, the responses to light quantity and R:FR reinforced each other. In contrast, in a third genotype, reduced irradiance during seed maturation induced progeny germination, but response to reduced R:FR was in the opposite direction, leading to a very weak or no overall effect of a simulated canopy experienced by the mother plant. During seed imbibition, reduced irradiance and reduced R:FR caused lower germination in all genotypes. Therefore, responses to light experienced at different times (maturation vs. imbibition) can have opposite effects. In summary, seeds responded both to light resources (irradiance) and to cues of competition (R:FR), and trans-generational plasticity to light frequently opposed and was stronger than within-generation plasticity.

  4. Ethanol exposure can inhibit red spruce ( Picea rubens ) seed germination

    Treesearch

    John R. Butnor; Brittany M. Verrico; Victor Vankus; Stephen R. Keller

    2018-01-01

    Flotation of seeds in solvents is a common means of separating unfilled and filled seeds. While a few protocols for processing red spruce (Picea rubens) seeds recommend ethanol flotation, delayed and reduced germination have been reported. We conducted an ethanol bioassay on seeds previously stored at -20°C to quantify the concentration required to separate red spruce...

  5. The role of the Arabidopsis FUSCA3 transcription factor during inhibition of seed germination at high temperature

    PubMed Central

    2012-01-01

    Background Imbibed seeds integrate environmental and endogenous signals to break dormancy and initiate growth under optimal conditions. Seed maturation plays an important role in determining the survival of germinating seeds, for example one of the roles of dormancy is to stagger germination to prevent mass growth under suboptimal conditions. The B3-domain transcription factor FUSCA3 (FUS3) is a master regulator of seed development and an important node in hormonal interaction networks in Arabidopsis thaliana. Its function has been mainly characterized during embryonic development, where FUS3 is highly expressed to promote seed maturation and dormancy by regulating ABA/GA levels. Results In this study, we present evidence for a role of FUS3 in delaying seed germination at supraoptimal temperatures that would be lethal for the developing seedlings. During seed imbibition at supraoptimal temperature, the FUS3 promoter is reactivated and induces de novo synthesis of FUS3 mRNA, followed by FUS3 protein accumulation. Genetic analysis shows that FUS3 contributes to the delay of seed germination at high temperature. Unlike WT, seeds overexpressing FUS3 (ML1:FUS3-GFP) during imbibition are hypersensitive to high temperature and do not germinate, however, they can fully germinate after recovery at control temperature reaching 90% seedling survival. ML1:FUS3-GFP hypersensitivity to high temperature can be partly recovered in the presence of fluridone, an inhibitor of ABA biosynthesis, suggesting this hypersensitivity is due in part to higher ABA level in this mutant. Transcriptomic analysis shows that WT seeds imbibed at supraoptimal temperature activate seed-specific genes and ABA biosynthetic and signaling genes, while inhibiting genes that promote germination and growth, such as GA biosynthetic and signaling genes. Conclusion In this study, we have uncovered a novel function for the master regulator of seed maturation, FUS3, in delaying germination at supraoptimal

  6. Seed germination of five Poa species at negative water potentials

    USDA-ARS?s Scientific Manuscript database

    Under field conditions water is often inadequate for satisfactory seed germination. An experiment was conducted to determine the effects of simulated dry conditions on germination and seedling growth of five bluegrass (Poa) species including: Texas, P. arachnifera Torr.; annual, P. annua L.; mutto...

  7. Nitrogen fertilization stimulates germination of dormant pin cherry seed

    Treesearch

    L.R. Auchmoody

    1979-01-01

    Nitrogen fertilizers triggered germination of dormant Prunus pensylvanica L. seed naturally buried in the forest floor of 60-year-old Allegheny hardwood stands. Neither triple superphosphate nor muriate of potash applied with urea increased germination over that which occurred with urea alone. Rates as low as 56 kg/ha N from urea and calcium...

  8. A Quick-Test for Biochar Effects on Seed Germination ...

    EPA Pesticide Factsheets

    Biochar is being globally evaluated as a soil amendment to improve soil characteristics (e.g. soil water holding, nutrient exchange, microbiology, pesticides and chemical availability) to increase crop yields. Unfortunately, there are no quick tests to determine what biochar types are most effective at improving soil characteristics amenable for higher crop yields. Seed germination is a critical parameter for plant establishment and may be a quick indicator of biochar quality. We adapted Oregon State University Seed Laboratory procedures to develop a “quick-test” for screening the effects of biochar on seed germination. We used 11.0 cm rectangular x 3.5 cm deep containers fitted with blotter paper. The paper was premoistened with reverse-osmosis water, followed by placement of seeds (25 in a uniform 5 x 5 vacuum-assisted pattern, and biochar mixtures). A Norfolk and Coxville soil series from South Carolina were used. A total of 18 biochars were evaluated that were produced from 6 feedstocks (pine chips, poultry litter, swine solids, switchgrass, and two blends of pine chips and poultry litter); with biochar from each feedstock made by pyrolysis at 350, 500 and 700 ̊ C. Crops were cabbage, cucumber, onion, ryegrass and tomato. Preliminary results from the test indicated differences in seed germination due to soil type and possibly soil x biochar feedstock interactions. Other measurements including shoot dry weight per plate and pH of the soil+ biochar mixtur

  9. Morpho-anatomy, imbibition, viability and germination of the seed of Anadenanthera colubrina var. cebil (Fabaceae).

    PubMed

    Varela, Rodolfo Omar; Albornoz, Patricia Liliana

    2013-09-01

    Seed biology is a relevant aspect of tropical forests because it is central to the understanding of processes of plant establishment, succession and natural regeneration. Anadenanthera colubrina var. cebil is a timber tree from South America that produces large seeds with thin weak teguments, which is uncommon among legumes. This study describes the morphology and anatomy of the seed coat, the viability, imbibition, and germination in this species. Seeds used during the essays came from 10 trees that grow naturally in Horco Molle, province of Tucumán, Argentina. Seed morphology was described from a sample of 20 units. The seed coat surface was examined with a scanning electron microscope. Transverse sections of hydrated and non-hydrated seeds were employed to describe the histological structure of the seed coat. Hydration, viability and germination experiments were performed under laboratory controlled conditions; and the experimental design consisted of 10 replicas of 10 seeds each. Viability and germination tests were conducted using freshly fallen seeds and seeds stored for five months. Morphologically the seeds of A. colubrina var. cebil are circular to subcircular, laterally compressed, smooth, bright brown and have a horseshoe fissure line (= pleurogram) on both sides. The seed coat comprises five tissue layers and a double (external and internal) cuticle. The outer cuticle (on the epidermis) is smooth and interrupted by microcracks and pores of variable depth. The epidermis consists of macroesclereids with non-lignified secondary walls. This layer is separated from the underlying ones during seed hydration. The other layers of internal tissues are comprised of osteosclereids, parenchyma, osteosclereids, and macrosclereids. The percentage of viable seeds was 93%, decreasing to 75% in seeds with five months old. Seed mass increased 76% after the first eight hours of hydration. Germination percentage was 75% after 76 hours. Germination of seeds stored for five

  10. Polyamines, IAA and ABA during germination in two recalcitrant seeds: Araucaria angustifolia (Gymnosperm) and Ocotea odorifera (Angiosperm)

    PubMed Central

    Pieruzzi, Fernanda P.; Dias, Leonardo L. C.; Balbuena, Tiago S.; Santa-Catarina, Claudete; dos Santos, André L. W.; Floh, Eny I. S.

    2011-01-01

    Background and Aims Plant growth regulators play an important role in seed germination. However, much of the current knowledge about their function during seed germination was obtained using orthodox seeds as model systems, and there is a paucity of information about the role of plant growth regulators during germination of recalcitrant seeds. In the present work, two endangered woody species with recalcitrant seeds, Araucaria angustifolia (Gymnosperm) and Ocotea odorifera (Angiosperm), native to the Atlantic Rain Forest, Brazil, were used to study the mobilization of polyamines (PAs), indole-acetic acid (IAA) and abscisic acid (ABA) during seed germination. Methods Data were sampled from embryos of O. odorifera and embryos and megagametophytes of A. angustifolia throughout the germination process. Biochemical analyses were carried out in HPLC. Key Results During seed germination, an increase in the (Spd + Spm) : Put ratio was recorded in embryos in both species. An increase in IAA and PA levels was also observed during seed germination in both embryos, while ABA levels showed a decrease in O. odorifera and an increase in A. angustifolia embryos throughout the period studied. Conclusions The (Spd + Spm) : Put ratio could be used as a marker for germination completion. The increase in IAA levels, prior to germination, could be associated with variations in PA content. The ABA mobilization observed in the embryos could represent a greater resistance to this hormone in recalcitrant seeds, in comparison to orthodox seeds, opening a new perspective for studies on the effects of this regulator in recalcitrant seeds. The gymnosperm seed, though without a connective tissue between megagametophyte and embryo, seems to be able to maintain communication between the tissues, based on the likely transport of plant growth regulators. PMID:21685432

  11. Soil warming increases plant species richness but decreases germination from the alpine soil seed bank.

    PubMed

    Hoyle, Gemma L; Venn, Susanna E; Steadman, Kathryn J; Good, Roger B; McAuliffe, Edward J; Williams, Emlyn R; Nicotra, Adrienne B

    2013-05-01

    Global warming is occurring more rapidly above the treeline than at lower elevations and alpine areas are predicted to experience above average warming in the future. Temperature is a primary factor in stimulating seed germination and regulating changes in seed dormancy status. Thus, plant regeneration from seed will be crucial to the persistence, migration and post disturbance recruitment of alpine plants in future climates. Here, we present the first assessment of the impact of soil warming on germination from the persistent alpine soil seed bank. Contrary to expectations, soil warming lead to reduced overall germination from the soil seed bank. However, germination response to soil temperature was species specific such that total species richness actually increased by nine with soil warming. We further explored the system by assessing the prevalence of seed dormancy and germination response to soil disturbance, the frequency of which is predicted to increase under climate change. Seeds of a significant proportion of species demonstrated physiological dormancy mechanisms and germination of several species appeared to be intrinsically linked to soil disturbance. In addition, we found no evidence of subalpine species and little evidence of exotic weed species in the soil, suggesting that the soil seed bank will not facilitate their invasion of the alpine zone. In conclusion, changes in recruitment via the alpine soil seed bank can be expected under climate change, as a result of altered dormancy alleviation and germination cues. Furthermore, the alpine soil seed bank, and the species richness therein, has the potential to help maintain local species diversity, support species range shift and moderate species dominance. Implications for alpine management and areas for further study are also discussed. © 2013 Blackwell Publishing Ltd.

  12. Extra soil fertilization of mother plants increases botanical seed yield but not long-term germination in wild Solanum (potato) species

    USDA-ARS?s Scientific Manuscript database

    Potato has about 100 wild species relatives that are multiplied in the form of botanical seed populations by genebanks, and distributed for use in research and breeding, so factors that affect long term seed germination are of interest. In 1987 the US Potato Genebank conducted routine seed multiplic...

  13. Identification of a Soybean MOTHER OF FT AND TFL1 Homolog Involved in Regulation of Seed Germination

    PubMed Central

    Wang, Xu; Wu, Faqiang; Hu, Ruibo; Fu, Yongfu

    2014-01-01

    Seed germination is an important event in the life cycle of seed plants, and is controlled by complex and coordinated genetic networks. Many genes involved in the regulation of this process have been identified in different plant species so far. Recent studies in both Arabidopsis and wheat have uncovered a new role of MOTHER OF FT AND TFL1 (MFT) in seed germination. Here, we reported a homolog of MFT in soybean (GmMFT) which strongly expressed in seeds. Detailed expression analysis showed that the mRNA level of GmMFT increased with seed development but declined during seed germination. The transcription of GmMFT also responded to exogenous application of ABA and GA3. Ectopic expression of GmMFT CDS in Arabidopsis moderately inhibited seed germination. All these evidences suggest that GmMFT may be a negative regulator of seed germination. PMID:24932489

  14. A method for the imbibition and germination of wheat seeds in space

    NASA Technical Reports Server (NTRS)

    Levine, H. G.; Piastuch, W. C.; Sager, J. C. (Principal Investigator)

    1999-01-01

    A method was developed for the reliable germination in space of wheat seeds on porous tube nutrient delivery systems. Germination paper strips were loosely rolled into cylinders and two seeds inserted close to the outer edges of each cylinder. This configuration: 1) directed the emerging shoots upward and roots downward, 2) was efficient in wicking moisture from the porous tubes, and 3) provided open areas for oxygen diffusion. Cotton tufts were inserted into the bottom crevices of the cylinders to fix the seeds in a mid-level position and cylinders were then storable (indefinitely) prior to the preprogrammed (on-orbit) initiation of imbibition. This method extends both the upper and lower ends of acceptable moisture levels for successful seed germination, increasing the probability of success for spaceflight applications where moisture availability is more variable than on Earth.

  15. A race for survival: Can Bromus tectorum seeds escape Pyrenophora semeniperda-caused mortality by germinating quickly?

    Treesearch

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

    2007-01-01

    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...

  16. Dynamic proteomics emphasizes the importance of selective mRNA translation and protein turnover during Arabidopsis seed germination.

    PubMed

    Galland, Marc; Huguet, Romain; Arc, Erwann; Cueff, Gwendal; Job, Dominique; Rajjou, Loïc

    2014-01-01

    During seed germination, the transition from a quiescent metabolic state in a dry mature seed to a proliferative metabolic state in a vigorous seedling is crucial for plant propagation as well as for optimizing crop yield. This work provides a detailed description of the dynamics of protein synthesis during the time course of germination, demonstrating that mRNA translation is both sequential and selective during this process. The complete inhibition of the germination process in the presence of the translation inhibitor cycloheximide established that mRNA translation is critical for Arabidopsis seed germination. However, the dynamics of protein turnover and the selectivity of protein synthesis (mRNA translation) during Arabidopsis seed germination have not been addressed yet. Based on our detailed knowledge of the Arabidopsis seed proteome, we have deepened our understanding of seed mRNA translation during germination by combining two-dimensional gel-based proteomics with dynamic radiolabeled proteomics using a radiolabeled amino acid precursor, namely [(35)S]-methionine, in order to highlight de novo protein synthesis, stability, and turnover. Our data confirm that during early imbibition, the Arabidopsis translatome keeps reflecting an embryonic maturation program until a certain developmental checkpoint. Furthermore, by dividing the seed germination time lapse into discrete time windows, we highlight precise and specific patterns of protein synthesis. These data refine and deepen our knowledge of the three classical phases of seed germination based on seed water uptake during imbibition and reveal that selective mRNA translation is a key feature of seed germination. Beyond the quantitative control of translational activity, both the selectivity of mRNA translation and protein turnover appear as specific regulatory systems, critical for timing the molecular events leading to successful germination and seedling establishment.

  17. Dynamic Proteomics Emphasizes the Importance of Selective mRNA Translation and Protein Turnover during Arabidopsis Seed Germination*

    PubMed Central

    Galland, Marc; Huguet, Romain; Arc, Erwann; Cueff, Gwendal; Job, Dominique; Rajjou, Loïc

    2014-01-01

    During seed germination, the transition from a quiescent metabolic state in a dry mature seed to a proliferative metabolic state in a vigorous seedling is crucial for plant propagation as well as for optimizing crop yield. This work provides a detailed description of the dynamics of protein synthesis during the time course of germination, demonstrating that mRNA translation is both sequential and selective during this process. The complete inhibition of the germination process in the presence of the translation inhibitor cycloheximide established that mRNA translation is critical for Arabidopsis seed germination. However, the dynamics of protein turnover and the selectivity of protein synthesis (mRNA translation) during Arabidopsis seed germination have not been addressed yet. Based on our detailed knowledge of the Arabidopsis seed proteome, we have deepened our understanding of seed mRNA translation during germination by combining two-dimensional gel-based proteomics with dynamic radiolabeled proteomics using a radiolabeled amino acid precursor, namely [35S]-methionine, in order to highlight de novo protein synthesis, stability, and turnover. Our data confirm that during early imbibition, the Arabidopsis translatome keeps reflecting an embryonic maturation program until a certain developmental checkpoint. Furthermore, by dividing the seed germination time lapse into discrete time windows, we highlight precise and specific patterns of protein synthesis. These data refine and deepen our knowledge of the three classical phases of seed germination based on seed water uptake during imbibition and reveal that selective mRNA translation is a key feature of seed germination. Beyond the quantitative control of translational activity, both the selectivity of mRNA translation and protein turnover appear as specific regulatory systems, critical for timing the molecular events leading to successful germination and seedling establishment. PMID:24198433

  18. Phytochrome B and REVEILLE1/2-mediated signalling controls seed dormancy and germination in Arabidopsis.

    PubMed

    Jiang, Zhimin; Xu, Gang; Jing, Yanjun; Tang, Weijiang; Lin, Rongcheng

    2016-08-10

    Seeds maintain a dormant state to withstand adverse conditions and germinate when conditions become favourable to give rise to a new generation of flowering plants. Seed dormancy and germination are tightly controlled by internal and external signals. Although phytochrome photoreceptors are proposed to regulate primary seed dormancy, the underlying molecular mechanism remains elusive. Here we show that the REVEILLE1 (RVE1) and RVE2 transcription factors promote primary seed dormancy and repress red/far-red-light-reversible germination downstream of phytochrome B (phyB) in Arabidopsis thaliana. RVE1 and RVE2 expression is downregulated after imbibition and by phyB. RVE1 directly binds to the promoter of GIBBERELLIN 3-OXIDASE 2, inhibits its transcription and thus suppresses the biosynthesis of bioactive gibberellins. In addition, DELAY OF GERMINATION 1 also acts downstream of phyB. This study identifies a signalling pathway that integrates environmental light input with internal factors to control both seed dormancy and germination.

  19. Germinability of Cook pine (Araucaria columnaris) seeds under different storage conditions

    Treesearch

    Paul G. Scowcroft

    1988-01-01

    Up to 25 metric tonnes of seeds of Cook pine, raucaria columnaris (Forst. f.) Hook., are exported from Hawaii in abundant seed years. Excess seeds cannot be stored and used to fill orders in poor seed years because the seeds quickly lose their ability to germinate. The effects of storage temperature, seed moisture content, and nitrogen enrichment...

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

    PubMed Central

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

    2017-01-01

    Soybean is an important and staple oilseed crop worldwide. Salinity stress has adverse effects on soybean development periods, especially on seed germination and post-germinative growth. Improving seed germination and emergence will have positive effects under salt stress conditions on agricultural production. Here we report that NaCl delays soybean seed germination by negatively regulating gibberellin (GA) while positively mediating abscisic acid (ABA) biogenesis, which leads to a decrease in the GA/ABA ratio. This study suggests that fluridone (FLUN), an ABA biogenesis inhibitor, might be a potential plant growth regulator that can promote soybean seed germination under saline stress. Different soybean cultivars, which possessed distinct genetic backgrounds, showed a similar repressed phenotype during seed germination under exogenous NaCl application. Biochemical analysis revealed that NaCl treatment led to high MDA (malondialdehyde) level during germination and the post-germinative growth stages. Furthermore, catalase, superoxide dismutase, and peroxidase activities also changed after NaCl treatment. Subsequent quantitative Real-Time Polymerase Chain Reaction analysis showed that the transcription levels of ABA and GA biogenesis and signaling genes were altered after NaCl treatment. In line with this, phytohormone measurement also revealed that NaCl considerably down-regulated active GA1, GA3, and GA4 levels, whereas the ABA content was up-regulated; and therefore ratios, such as GA1/ABA, GA3/ABA, and GA4/ABA, are decreased. Consistent with the hormonal quantification, FLUN partially rescued the delayed-germination phenotype caused by NaCl-treatment. Altogether, these results demonstrate that NaCl stress inhibits soybean seed germination by decreasing the GA/ABA ratio, and that FLUN might be a potential plant growth regulator that could promote soybean seed germination under salinity stress. PMID:28848576

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

    PubMed

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

    2017-01-01

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

  2. Seed Heteromorphism and Effects of Light and Abiotic Stress on Germination of a Typical Annual Halophyte Salsola ferganica in Cold Desert

    PubMed Central

    Ma, Yali; Wang, Juan; Zhang, Jinghua; Zhang, Shiyue; Liu, Yanxia; Lan, Haiyan

    2018-01-01

    Seed heteromorphism is a common characteristic of halophyte and an adaptation to the spatial and temporal variations of natural habitats. Differences in dormancy and germination requirements have been documented in heteromorphic seeds of many species, but the mechanisms for maintenance between different status in various populations have not been well-understood. Salsola ferganica is a typical annual halophyte in Chenopodiaceae distributed in cold desert, in the present study, we found that it could produce three distinct types of seed according to the shape and size of winged perianth (WP), which differed in dispersal ability, dormancy and germination behaviors. Our further investigation revealed that light could significantly promote germination of heteromorphic seeds of S. ferganica, and WP inhibited while GA3 enhanced germination, which suggests that S. ferganica seeds possessed a photo-sensitive combined with morphological and non-deep physiological dormancy type, in which light was the dominant factor. Not like other desert plant species, the germinability of heteromorphic seeds of S. ferganica could not sustain for long (only 1–2 years), especially the small seeds, and was affected by storage time, temperature, salinity, even the environmental conditions of the maternal plant. Thus, the differences of characteristics existed among heteromorphic seeds and variations of heteromorphic ratio among different calendar years were presumed as diverse adaptation strategies integrated in the individual mother plant, and might apply important ecological significance for successful reproduction of the species in the unpredictable cold desert. PMID:29387073

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

    PubMed Central

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

    2016-01-01

    The maternal environment can influence the intensity of seed dormancy and thus seasonal germination timing and post-germination life history traits. We tested the hypotheses that germination season influences phenotypic expression of post-germination life history traits in the cold desert annual Isatis violascens and that plants from autumn- and spring-germinating seeds produce different proportions of seeds with nondeep and intermediate physiological dormancy (PD). Seeds were sown in summer and flexibility in various life history traits determined for plants that germinated in autumn and in spring. A higher percentage of spring- than of autumn-germinating plants survived the seedling stage, and all surviving plants reproduced. Number of silicles increased with plant size (autumn- > spring-germinating plants), whereas percent dry mass allocated to reproduction was higher in spring- than in autumn-germinating plants. Autumn-germinating plants produced proportionally more seeds with intermediate PD than spring-germinating plants, while spring-germinating plants produced proportionally more seeds with nondeep PD than autumn-germinating plants. Flexibility throughout the life history and transgenerational plasticity in seed dormancy are adaptations of I. violascens to its desert habitat. Our study is the first to demonstrate that autumn- and spring-germinating plants in a species population differ in proportion of seeds produced with different levels of PD. PMID:27117090

  4. Nanopriming technology for enhancing germination and starch metabolism of aged rice seeds using phytosynthesized silver nanoparticles.

    PubMed

    Mahakham, Wuttipong; Sarmah, Ajit K; Maensiri, Santi; Theerakulpisut, Piyada

    2017-08-15

    Application of nanomaterials for agriculture is relatively new as compared to their use in biomedical and industrial sectors. In order to promote sustainable nanoagriculture, biocompatible silver nanoparticles (AgNPs) have been synthesized through green route using kaffir lime leaf extract for use as nanopriming agent for enhancing seed germination of rice aged seeds. Results of various characterization techniques showed the successful formation of AgNPs which were capped with phytochemicals present in the plant extract. Rice aged seeds primed with phytosynthesized AgNPs at 5 and 10 ppm significantly improved germination performance and seedling vigor compared to unprimed control, AgNO 3 priming, and conventional hydropriming. Nanopriming could enhance α-amylase activity, resulting in higher soluble sugar content for supporting seedlings growth. Furthermore, nanopriming stimulated the up-regulation of aquaporin genes in germinating seeds. Meanwhile, more ROS production was observed in germinating seeds of nanopriming treatment compared to unprimed control and other priming treatments, suggesting that both ROS and aquaporins play important roles in enhancing seed germination. Different mechanisms underlying nanopriming-induced seed germination were proposed, including creation of nanopores for enhanced water uptake, rebooting ROS/antioxidant systems in seeds, generation of hydroxyl radicals for cell wall loosening, and nanocatalyst for fastening starch hydrolysis.

  5. Chemical modification of a phenoxyfuranone-type strigolactone mimic for selective effects on rice tillering or Striga hermonthica seed germination.

    PubMed

    Takahashi, Ikuo; Fukui, Kosuke; Asami, Tadao

    2016-11-01

    We previously reported that a series of phenoxyfuranone compounds, designated 'debranones', mimic strigolactone (SL) activity. 4-Bromodebranone (4BD) is a functionally selective SL mimic that reduces the number of shoot branches on rice more potently than GR24, a typical synthetic SL analogue, but does not induce seed germination in the root-parasitic plant Striga hermonthica. To enhance the selective activity of debranones in stimulating the seed germination of root-parasitic plants, we prepared several analogues of 4BD in which the chlorine atom was substituted with an H atom at the o-, m- or p-position on the phenyl ring (designated 2-, 3-, or 4-chlorodebranone, respectively) or had a bicyclic group instead of the phenyl ring. We evaluated the biological activities of the compounds with rice tillering assays and S. hermonthica seed germination assays. Both assays showed that the substituent position affected debranone efficiency, and among the monochlorodebranones, 2-chlorodebranone was more effective than the other two isomers in both assays. When the activities of the bicyclic debranones were compared in the same two assays, one was more active than GR24 in the rice tillering assay. This debranone also stimulated the germination of S. hermonthica seeds. Thus, some debranone derivatives induced the germination of S. hermonthica seeds, although their activities were still ∼1/20 that of GR24. These results strongly suggest that further and rigorous structure-activity relationship studies of the debranones will identify derivatives that more potently stimulate the suicidal germination of S. hermonthica seeds. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  6. α-Xylosidase plays essential roles in xyloglucan remodelling, maintenance of cell wall integrity, and seed germination in Arabidopsis thaliana.

    PubMed

    Shigeyama, Takuma; Watanabe, Asuka; Tokuchi, Konatsu; Toh, Shigeo; Sakurai, Naoki; Shibuya, Naoto; Kawakami, Naoto

    2016-10-01

    Regulation and maintenance of cell wall physical properties are crucial for plant growth and environmental response. In the germination process, hypocotyl cell expansion and endosperm weakening are prerequisites for dicot seeds to complete germination. We have identified the Arabidopsis mutant thermoinhibition-resistant germination 1 (trg1), which has reduced seed dormancy and insensitivity to unfavourable conditions for germination owing to a loss-of-function mutation of TRG1/XYL1, which encodes an α-xylosidase. Compared to those of wild type, the elongating stem of trg1 showed significantly lower viscoelasticity, and the fruit epidermal cells were longitudinally shorter and horizontally enlarged. Actively growing tissues of trg1 over-accumulated free xyloglucan oligosaccharides (XGOs), and the seed cell wall had xyloglucan with a greatly reduced molecular weight. These observations suggest that XGOs reduce xyloglucan size by serving as an acceptor in transglycosylation and eventually enhancing cell wall loosening. TRG1/XYL1 gene expression was abundant in growing wild-type organs and tissues but relatively low in cells at most actively elongating part of the tissues, suggesting that α-xylosidase contributes to maintaining the mechanical integrity of the primary cell wall in the growing and pre-growing tissues. In germinating seeds of trg1, expression of genes encoding specific abscisic acid and gibberellin metabolism enzymes was altered in accordance with the aberrant germination phenotype. Thus, cell wall integrity could affect seed germination not only directly through the physical properties of the cell wall but also indirectly through the regulation of hormone gene expression. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.

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

    PubMed Central

    Ye, Juan; Wen, Bin

    2017-01-01

    Both spiny and edible amaranths (Amaranthus spinosus and A. tricolor) are exotic annuals in China that produce numerous small seeds every year. Spiny amaranth has become a successful invader and a troublesome weed in Xishuangbanna, but edible amaranth has not, although it is widely grown as a vegetable there. As seed germination is one of the most important life-stages contributing to the ability of a plant to become invasive, we conducted experiments to compare the effects of high temperature and water stress on seed germination in two varieties each of spiny amaranth and edible amaranth. Overall, the seeds of both amaranth species exhibited adaptation to high temperature and water stress, including tolerance to ground temperatures of 70°C for air-dried seeds, which is consistent with their behavior in their native ranges in the tropics. As expected, the invasive spiny amaranth seeds exhibited higher tolerance to both continuous and daily periodic high-temperature treatment at 45°C, and to imbibition-desiccation treatment, compared to edible amaranth seeds. Unexpectedly, edible amaranth seeds exhibited higher germination at extreme temperatures (10°C, 15°C, and 40°C), and at lower water potential (below -0.6 MPa). It is likely that cultivation of edible amaranth has selected seed traits that include rapid germination and germination under stressful conditions, either of which, under natural conditions, may result in the death of most germinating edible amaranth seeds and prevent them from becoming invasive weeds in Xishuangbanna. This study suggests that rapid germination and high germination under stress conditions—excellent seed traits for crops and for many invasive species—might be a disadvantage under natural conditions if these traits are asynchronous with natural local conditions that support successful germination. PMID:28414779

  8. 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

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

    PubMed

    Yan, An; Chen, Zhong

    2017-05-01

    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.

  10. Seed germination test for toxicity evaluation of compost: Its roles, problems and prospects.

    PubMed

    Luo, Yuan; Liang, Jie; Zeng, Guangming; Chen, Ming; Mo, Dan; Li, Guoxue; Zhang, Difang

    2018-01-01

    Compost is commonly used for the growth of plants and the remediation of environmental pollution. It is important to evaluate the quality of compost and seed germination test is a powerful tool to examine the toxicity of compost, which is the most important aspect of the quality. Now the test is widely adopted, but the main problem is that the test results vary with different methods and seed species, which limits the development and application of it. The standardization of methods and the modelization of seeds can contribute to solving the problem. Additionally, according to the probabilistic theory of seed germination, the error caused by the analysis and judgment methods of the test results can be reduced. Here, we reviewed the roles, problems and prospects of the seed germination test in the studies of compost. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. A Role for the Surrounding Fruit Tissues in Preventing the Germination of Tomato (Lycopersicon esculentum) Seeds 1

    PubMed Central

    Berry, Tannis; Bewley, J. Derek

    1992-01-01

    During tomato seed development the endogenous abscisic acid (ABA) concentration peaks at about 50 d after pollination (DAP) and then declines at later stages (60-70 DAP) of maturation. The ABA concentration in the sheath tissue immediately surrounding the seed increases with time of development, whereas that of the locule declines. The water contents of the seed and fruit tissues are similar during early development (20-30 DAP), but decline in the seed tissues between 30 and 40 DAP. The water potential and the osmotic potential of the embryo are lower than that of the locular tissue after 35 DAP also. Seeds removed from the fruit at 30, 35, and 60 DAP and placed ex situ on 35 and 60 DAP sheath and locular tissue are prevented from germinating. Development of 30 DAP seeds is maintained or promoted by the ex situ fruit tissue with which they are in contact. Their germination is inhibited until subsequent transfer to water, and germination is normal, i.e. by radicle protrusion, and viable seedlings are produced, compared with 30 DAP seeds transferred directly to water; more of these seeds germinate, but by hypocotyl extension, and seedling viability is very poor. Isolated seeds at 35 and 60 DAP re-placed in contact with fruit tissues only germinate when transferred to water after 7 d. At 30 DAP, isolated seeds are insensitive to ABA at physiological concentrations in that they germinate as if on water, albeit by hypocotyl extension. At higher concentrations germination occurs by radicle protrusion. Osmoticum prevents germination, but there is some recovery upon subsequent transfer to water. Seeds at 35 DAP are very sensitive to ABA and exhibit little or no germination, even upon transfer to water. The response of the isolated seeds to osmoticum more closely approximates that to incubation on the ex situ fruit tissues than does their response to ABA. This is also the case for isolated 60 DAP seeds, whose germination is not prevented by ABA, but only by the osmoticum

  12. Marking tree seeds with spray paint for germination studies

    Treesearch

    R. Kasten Dumroese

    2003-01-01

    I evaluated the potential use of spray paint for marking conifer seeds for germination studies in forest nurseries. For bulk seedlots of large-seeded species like western white pine (Pinus monticola), ponderosa pine (Pinus ponderosa), and Douglas-fir (Pseudotsuga menziesii), paint had little or no effect on six...

  13. Birch seeds will germinate under a water-light treatment without pre-chilling

    Treesearch

    George Yelenosky

    1961-01-01

    The seed of yellow and paper birches, like that of many other species, often exhibits delayed germination, which apparently is due to embryo dormancy. Stratification is usually recommended for overcoming this dormancy before the seed is sown or before it is tested for germination. This involves a chilling treatment for 1 to 2 1/2 months, which is best done under...

  14. Effects of NaCl stress on seed germination and seedling development of Brassica insularis Moris (Brassicaceae).

    PubMed

    Santo, A; Mattana, E; Frigau, L; Marzo Pastor, A; Picher Morelló, M C; Bacchetta, G

    2017-05-01

    Brassica insularis is a protected plant that grows on both coastal and inland cliffs in the western Mediterranean Basin. The objective of this study was to test if any variability exists in the salt stress response during seed germination and seedling development in this species relative to its provenance habitat. Variability among three populations in the salt stress effects on seed germination and recovery under different temperatures was evaluated. The effect of nebulisation of a salt solution on seedling development was evaluated between populations growing at different distances from the sea. Seeds of B. insularis could germinate at NaCl concentrations up to 200 mm. Seed viability was negatively affected by salt, and recovery ability decreased with increasing temperature or salinity. Inter-population variability was detected in salt response during the seed germination phase, as well as in seedling salt spray tolerance. The inland population seedlings had drastically decreased survival and life span and failed to survive to the end of the experiment. In contrast, at least 90% of the coastal seedlings survived, even when sprayed at the highest frequency with salt solution. This study allowed investigation of two natural factors, soil salinity and marine aerosols, widely present in the B. insularis habitat, and provided the first insights into ecology of this protected species and its distribution in the Mediterranean. These results might be useful in understanding the actual distributions of other species with the same ecology that experience these same abiotic parameters. © 2017 German Botanical Society and The Royal Botanical Society of the Netherlands.

  15. Using In Situ Symbiotic Seed Germination to Restore Over-collected Medicinal Orchids in Southwest China

    PubMed Central

    Shao, Shi-Cheng; Burgess, Kevin S.; Cruse-Sanders, Jennifer M.; Liu, Qiang; Fan, Xu-Li; Huang, Hui; Gao, Jiang-Yun

    2017-01-01

    Due to increasing demand for medicinal and horticultural uses, the Orchidaceae is in urgent need of innovative and novel propagation techniques that address both market demand and conservation. Traditionally, restoration techniques have been centered on ex situ asymbiotic or symbiotic seed germination techniques that are not cost-effective, have limited genetic potential and often result in low survival rates in the field. Here, we propose a novel in situ advanced restoration-friendly program for the endangered epiphytic orchid species Dendrobium devonianum, in which a series of in situ symbiotic seed germination trials base on conspecific fungal isolates were conducted at two sites in Yunnan Province, China. We found that percentage germination varied among treatments and locations; control treatments (no inoculum) did not germinate at both sites. We found that the optimal treatment, having the highest in situ seed germination rate (0.94-1.44%) with no significant variation among sites, supported a warm, moist and fixed site that allowed for light penetration. When accounting for seed density, percentage germination was highest (2.78-2.35%) at low densities and did not vary among locations for the treatment that supported optimal conditions. Similarly for the same treatment, seed germination ranged from 0.24 to 5.87% among seasons but also did vary among sites. This study reports on the cultivation and restoration of an endangered epiphytic orchid species by in situ symbiotic seed germination and is likely to have broad application to the horticulture and conservation of the Orchidaceae. PMID:28638388

  16. Using In Situ Symbiotic Seed Germination to Restore Over-collected Medicinal Orchids in Southwest China.

    PubMed

    Shao, Shi-Cheng; Burgess, Kevin S; Cruse-Sanders, Jennifer M; Liu, Qiang; Fan, Xu-Li; Huang, Hui; Gao, Jiang-Yun

    2017-01-01

    Due to increasing demand for medicinal and horticultural uses, the Orchidaceae is in urgent need of innovative and novel propagation techniques that address both market demand and conservation. Traditionally, restoration techniques have been centered on ex situ asymbiotic or symbiotic seed germination techniques that are not cost-effective, have limited genetic potential and often result in low survival rates in the field. Here, we propose a novel in situ advanced restoration-friendly program for the endangered epiphytic orchid species Dendrobium devonianum , in which a series of in situ symbiotic seed germination trials base on conspecific fungal isolates were conducted at two sites in Yunnan Province, China. We found that percentage germination varied among treatments and locations; control treatments (no inoculum) did not germinate at both sites. We found that the optimal treatment, having the highest in situ seed germination rate (0.94-1.44%) with no significant variation among sites, supported a warm, moist and fixed site that allowed for light penetration. When accounting for seed density, percentage germination was highest (2.78-2.35%) at low densities and did not vary among locations for the treatment that supported optimal conditions. Similarly for the same treatment, seed germination ranged from 0.24 to 5.87% among seasons but also did vary among sites. This study reports on the cultivation and restoration of an endangered epiphytic orchid species by in situ symbiotic seed germination and is likely to have broad application to the horticulture and conservation of the Orchidaceae.

  17. Reactive Oxygen Species Generated by NADPH Oxidases Promote Radicle Protrusion and Root Elongation during Rice Seed Germination

    PubMed Central

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

    2017-01-01

    Seed germination is a complicated biological process that requires regulation through various enzymatic and non-enzymatic mechanisms. Although it has been recognized that reactive oxygen species (ROS) regulate radicle emergence and root elongation in a non-enzymatic manner during dicot seed germination, the role of ROS in monocot seed germination remains unknown. NADPH oxidases (NOXs) are the major ROS producers in plants; however, whether and how NOXs regulate rice seed germination through ROS generation remains unclear. Here, we report that diphenyleneiodinium (DPI), a specific NOX inhibitor, potently inhibited embryo and seedling growth—especially that of the radicle and of root elongation—in a dose-dependent manner. Notably, the DPI-mediated inhibition of radicle and root growth could be eliminated by transferring seedlings from DPI to water. Furthermore, ROS production/accumulation during rice seed germination was quantified via histochemistry. Superoxide radicals (O2−), hydrogen peroxide (H2O2) and hydroxyl radicals (•OH) accumulated steadily in the coleorhiza, radicle and seedling root of germinating rice seeds. Expression profiles of the nine typical NOX genes were also investigated. According to quantitative PCR, OsNOX5, 7 and 9 were expressed relatively higher. When seeds were incubated in water, OsNOX5 expression progressively increased in the embryo from 12 to 48 h, whereas OsNOX7 and 9 expressions increased from 12 to 24 h and decreased thereafter. As expected, DPI inhibits the expression at predetermined time points for each of these genes. Taken together, these results suggest that ROS produced by NOXs are involved in radicle and root elongation during rice seed germination, and OsNOX5, 7 and 9 could play crucial roles in rice seed germination. These findings will facilitate further studies of the roles of ROS generated by NOXs during seed germination and seedling establishment and also provide valuable information for the regulation of NOX

  18. Release of Reactive Oxygen Intermediates (Superoxide Radicals, Hydrogen Peroxide, and Hydroxyl Radicals) and Peroxidase in Germinating Radish Seeds Controlled by Light, Gibberellin, and Abscisic Acid1

    PubMed Central

    Schopfer, Peter; Plachy, Claudia; Frahry, Gitta

    2001-01-01

    Germination of radish (Raphanus sativus cv Eterna) seeds can be inhibited by far-red light (high-irradiance reaction of phytochrome) or abscisic acid (ABA). Gibberellic acid (GA3) restores full germination under far-red light. This experimental system was used to investigate the release of reactive oxygen intermediates (ROI) by seed coats and embryos during germination, utilizing the apoplastic oxidation of 2′,7′-dichlorofluorescin to fluorescent 2′,7′-dichlorofluorescein as an in vivo assay. Germination in darkness is accompanied by a steep rise in ROI release originating from the seed coat (living aleurone layer) as well as the embryo. At the same time as the inhibition of germination, far-red light and ABA inhibit ROI release in both seed parts and GA3 reverses this inhibition when initiating germination under far-red light. During the later stage of germination the seed coat also releases peroxidase with a time course affected by far-red light, ABA, and GA3. The participation of superoxide radicals, hydrogen peroxide, and hydroxyl radicals in ROI metabolism was demonstrated with specific in vivo assays. ROI production by germinating seeds represents an active, developmentally controlled physiological function, presumably for protecting the emerging seedling against attack by pathogens. PMID:11299341

  19. The role of the Arabidopsis FUSCA3 transcription factor during inhibition of seed germination at high temperature.

    PubMed

    Chiu, Rex S; Nahal, Hardeep; Provart, Nicholas J; Gazzarrini, Sonia

    2012-01-27

    Imbibed seeds integrate environmental and endogenous signals to break dormancy and initiate growth under optimal conditions. Seed maturation plays an important role in determining the survival of germinating seeds, for example one of the roles of dormancy is to stagger germination to prevent mass growth under suboptimal conditions. The B3-domain transcription factor FUSCA3 (FUS3) is a master regulator of seed development and an important node in hormonal interaction networks in Arabidopsis thaliana. Its function has been mainly characterized during embryonic development, where FUS3 is highly expressed to promote seed maturation and dormancy by regulating ABA/GA levels. In this study, we present evidence for a role of FUS3 in delaying seed germination at supraoptimal temperatures that would be lethal for the developing seedlings. During seed imbibition at supraoptimal temperature, the FUS3 promoter is reactivated and induces de novo synthesis of FUS3 mRNA, followed by FUS3 protein accumulation. Genetic analysis shows that FUS3 contributes to the delay of seed germination at high temperature. Unlike WT, seeds overexpressing FUS3 (ML1:FUS3-GFP) during imbibition are hypersensitive to high temperature and do not germinate, however, they can fully germinate after recovery at control temperature reaching 90% seedling survival. ML1:FUS3-GFP hypersensitivity to high temperature can be partly recovered in the presence of fluridone, an inhibitor of ABA biosynthesis, suggesting this hypersensitivity is due in part to higher ABA level in this mutant. Transcriptomic analysis shows that WT seeds imbibed at supraoptimal temperature activate seed-specific genes and ABA biosynthetic and signaling genes, while inhibiting genes that promote germination and growth, such as GA biosynthetic and signaling genes. In this study, we have uncovered a novel function for the master regulator of seed maturation, FUS3, in delaying germination at supraoptimal temperature. Physiologically, this is

  20. Seeds of Brassicaceae weeds have an inherent or inducible response to the germination stimulant karrikinolide

    PubMed Central

    Long, Rowena L.; Stevens, Jason C.; Griffiths, Erin M.; Adamek, Markus; Gorecki, Marta J.; Powles, Stephen B.; Merritt, David J.

    2011-01-01

    Background and Aims Karrikinolide (KAR1) is a smoke-derived chemical that can trigger seeds to germinate. A potential application for KAR1 is for synchronizing the germination of weed seeds, thereby enhancing the efficiency of weed control efforts. Yet not all species germinate readily with KAR1, and it is not known whether seemingly non-responsive species can be induced to respond. Here a major agronomic weed family, the Brassicaceae, is used to test the hypothesis that a stimulatory response to KAR1 may be present in physiologically dormant seeds but may not be expressed under all circumstances. Methods Seeds of eight Brassicaceae weed species (Brassica tournefortii, Raphanus raphanistrum, Sisymbrium orientale, S. erysimoides, Rapistrum rugosum, Lepidium africanum, Heliophila pusilla and Carrichtera annua) were tested for their response to 1 µm KAR1 when freshly collected and following simulated and natural dormancy alleviation, which included wet–dry cycling, dry after-ripening, cold and warm stratification and a 2 year seed burial trial. Key Results Seven of the eight Brassicaceae species tested were stimulated to germinate with KAR1 when the seeds were fresh, and the remaining species became responsive to KAR1 following wet–dry cycling and dry after-ripening. Light influenced the germination response of seeds to KAR1, with the majority of species germinating better in darkness. Germination with and without KAR1 fluctuated seasonally throughout the seed burial trial. Conclusions KAR1 responses are more complex than simply stating whether a species is responsive or non-responsive; light and temperature conditions, dormancy state and seed lot all influence the sensitivity of seeds to KAR1, and a response to KAR1 can be induced. Three response types for generalizing KAR1 responses are proposed, namely inherent, inducible and undetected. Given that responses to KAR1 were either inherent or inducible in all 15 seed lots included in this study, the Brassicaceae

  1. Seeds of Brassicaceae weeds have an inherent or inducible response to the germination stimulant karrikinolide.

    PubMed

    Long, Rowena L; Stevens, Jason C; Griffiths, Erin M; Adamek, Markus; Gorecki, Marta J; Powles, Stephen B; Merritt, David J

    2011-10-01

    Karrikinolide (KAR(1)) is a smoke-derived chemical that can trigger seeds to germinate. A potential application for KAR(1) is for synchronizing the germination of weed seeds, thereby enhancing the efficiency of weed control efforts. Yet not all species germinate readily with KAR(1), and it is not known whether seemingly non-responsive species can be induced to respond. Here a major agronomic weed family, the Brassicaceae, is used to test the hypothesis that a stimulatory response to KAR(1) may be present in physiologically dormant seeds but may not be expressed under all circumstances. Seeds of eight Brassicaceae weed species (Brassica tournefortii, Raphanus raphanistrum, Sisymbrium orientale, S. erysimoides, Rapistrum rugosum, Lepidium africanum, Heliophila pusilla and Carrichtera annua) were tested for their response to 1 µm KAR(1) when freshly collected and following simulated and natural dormancy alleviation, which included wet-dry cycling, dry after-ripening, cold and warm stratification and a 2 year seed burial trial. Seven of the eight Brassicaceae species tested were stimulated to germinate with KAR(1) when the seeds were fresh, and the remaining species became responsive to KAR(1) following wet-dry cycling and dry after-ripening. Light influenced the germination response of seeds to KAR(1), with the majority of species germinating better in darkness. Germination with and without KAR(1) fluctuated seasonally throughout the seed burial trial. KAR(1) responses are more complex than simply stating whether a species is responsive or non-responsive; light and temperature conditions, dormancy state and seed lot all influence the sensitivity of seeds to KAR(1), and a response to KAR(1) can be induced. Three response types for generalizing KAR(1) responses are proposed, namely inherent, inducible and undetected. Given that responses to KAR(1) were either inherent or inducible in all 15 seed lots included in this study, the Brassicaceae may be an ideal target for

  2. Toxicity Effect of Cr Stress on Seed Germination and Seedling Growth in Lactuca Sativa

    NASA Astrophysics Data System (ADS)

    Ma, Wan Zheng; Ma, Wan Min; Du, Ying Ying; Dan, Qiong Peng; Yin, Bing; Dai, Shan Shan; Hao, Xiang

    2018-03-01

    The impact of Cr6+ on the growth of lactuca sativa in Greenhouse Cucumber was investigated. The seeds of lacuna sativa Italian bolting resistance lettuce were treated by different Cr6+ concentration to study the effects on its seed germination and seedling growth. The results showed that the seed germination rate, vigor index of seedlings decreased with increment of Cr6+ concentration to varying degrees, and vigor germination, vigor index, raw weight, root length significantly lower. The absorption of lettuce seedlings on different nutrient elements is impacted by the concentration of Cr6+.

  3. Effect of sequential dry heat and hydrogen peroxide treatment on inactivation of Salmonella Typhimurium on alfalfa seeds and seeds germination.

    PubMed

    Hong, Eun-Jeong; Kang, Dong-Hyun

    2016-02-01

    The purpose of this study was to inactivate Salmonella Typhimurium on alfalfa seeds without having negative effect on seed germination. Inoculated alfalfa seeds were treated with dry heat at 60, 70 or 80 °C for 0, 12, 18 or 24 h followed by 2% hydrogen peroxide solution (10 min). Populations of Salmonella on alfalfa seeds treated with dry heat alone (60, 70 or 80 °C) for up to 24 h were reduced by 0.26-2.76 log CFU/g, and sequential treatment with dry heat and H2O2 reduced populations by 1.66-3.60 log CFU/g. The germination percentage of seeds subjected to sequential treatments was significantly enhanced to up to 97%, whereas that of untreated seeds was only 79.5%. This study suggests that sequential treatment with dry heat and hydrogen peroxide is applicable for reducing levels of Salmonella on seeds while simultaneously enhancing seeds germinability. Copyright © 2015. Published by Elsevier Ltd.

  4. Physiological, cellular and molecular aspects of the desiccation tolerance in Anadenanthera colubrina seeds during germination.

    PubMed

    Castro, L E; Guimarães, C C; Faria, J M R

    2017-11-01

    During germination, orthodox seeds become gradually intolerant to desiccation, and for this reason, they are a good model for recalcitrance studies. In the present work, physiological, biochemical, and ultrastructural aspects of the desiccation tolerance were characterized during the germination process of Anadenanthera colubrina seeds. The seeds were imbibed during zero (control), 2, 8, 12 (no germinated seeds), and 18 hours (germinated seeds with 1 mm protruded radicle); then they were dried for 72 hours, rehydrated and evaluated for survivorship. Along the imbibition, cytometric and ultrastructural analysis were performed, besides the extraction of the heat-stable proteins. Posteriorly to imbibition and drying, the evaluation of ultrastructural damages was performed. Desiccation tolerance was fully lost after root protrusion. There was no increase in 4C DNA content after the loss of desiccation tolerance. Ultrastructural characteristics of cells from 1mm roots resembled those found in the recalcitrant seeds, in both hydrated and dehydrated states. The loss of desiccation tolerance coincided with the reduction of heat-stable proteins.

  5. Effects of High Temperature and Water Stress on Seed Germination of the Invasive Species Mexican Sunflower

    PubMed Central

    Wen, Bin

    2015-01-01

    Mexican sunflower is native to Mexico and Central America and was introduced into China early last century. Now it has widely naturalized and is exhibiting increasing invasiveness in South China. As this species often dominates bare ground, a habitat characterized by extreme fluctuation in temperature and water, it is reasonable to hypothesize that it has special adaptations to high temperature and water stress. Using laboratory experiments to simulate these stresses, this study investigated the response of Mexican sunflower seed germination to temperature and water stress, and compared these responses with those previously reported for another invasive, bamboo piper, which is confined to relatively cool and moist habitats in Xishuangbanna. As expected, Mexican sunflower seeds exhibited higher tolerance to these stresses than bamboo piper. Germination of Mexican sunflower seeds was highest at 15–30°C, but significant numbers of seeds germinated and formed seedlings at 10°C and 35°C, at which no bamboo piper seeds formed seedlings, indicating a wider temperature range for germination than the latter. Roughly half the seeds survived 240 h continuous heat treatment and up to 15 h daily periodical heat treatment at 40°C, while bamboo piper seeds were mostly killed by these treatments. About 20% of Mexican sunflower but no bamboo piper seeds germinated after heat treatment for 30 min at 80°C. Germination was completely inhibited in bamboo piper seeds at -0.6 mPa, while 20–60% of Mexican sunflower seeds germinated depending on PEG or NaCl as osmoticum. This higher tolerance in Mexican sunflower seeds accords with its stronger invasiveness in this area. This comparison between two plant invaders demonstrates that invasiveness is not an all-or-nothing situation, and that adaptation to local habitats is a critical determinant of successful invasiveness for an alien plant. PMID:26509675

  6. Karrikins: Regulators Involved in Phytohormone Signaling Networks during Seed Germination and Seedling Development

    PubMed Central

    Meng, Yongjie; Shuai, Haiwei; Luo, Xiaofeng; Chen, Feng; Zhou, Wenguan; Yang, Wenyu; Shu, Kai

    2017-01-01

    Seed germination and early seedling establishment are critical stages during a plant’s life cycle. These stages are precisely regulated by multiple internal factors, including phytohormones and environmental cues such as light. As a family of small molecules discovered in wildfire smoke, karrikins (KARs) play a key role in various biological processes, including seed dormancy release, germination regulation, and seedling establishment. KARs show a high similarity with strigolactone (SL) in both chemical structure and signaling transduction pathways. Current evidence shows that KARs may regulate seed germination by mediating the biosynthesis and/or signaling transduction of abscisic acid (ABA), gibberellin (GA) and auxin [indoleacetic acid (IAA)]. Interestingly, KARs regulate seed germination differently in different species. Furthermore, the promotion effect on seedling establishment implies that KARs have a great potential application in alleviating shade avoidance response, which attracts more and more attention in plant molecular biology. In these processes, KARs may have complicated interactions with phytohormones, especially with IAA. In this updated review, we summarize the current understanding of the relationship between KARs and SL in the chemical structure, signaling pathway and the regulation of plant growth and development. Further, the crosstalk between KARs and phytohormones in regulating seed germination and seedling development and that between KARs and IAA during shade responses are discussed. Finally, future challenges and research directions for the KAR research field are suggested. PMID:28174573

  7. Germination of dimorphic seeds of the desert annual halophyte Suaeda aralocaspica (Chenopodiaceae), a C4 plant without Kranz anatomy.

    PubMed

    Wang, Lei; Huang, Zhenying; Baskin, Carol C; Baskin, Jerry M; Dong, Ming

    2008-11-01

    Suaeda aralocaspica is a C4 summer annual halophyte without Kranz anatomy that is restricted to the deserts of central Asia. It produces two distinct types of seeds that differ in colour, shape and size. The primary aims of the present study were to compare the dormancy and germination characteristics of dimorphic seeds of S. aralocaspica and to develop a conceptual model of their dynamics. Temperatures simulating those in the natural habitat of S. aralocaspica were used to test for primary dormancy and germination behaviour of fresh brown and black seeds. The effects of cold stratification, gibberellic acid, seed coat scarification, seed coat removal and dry storage on dormancy breaking were tested in black seeds. Germination percentage and recovery responses of brown seeds, non-treated black seeds and 8-week cold-stratified black seeds to salt stress were tested. Brown seeds were non-dormant, whereas black seeds had non-deep Type 2 physiological dormancy (PD). Germination percentage and rate of germination of brown seeds and of variously pretreated black seeds were significantly higher than those of non-pretreated black seeds. Exposure of seeds to various salinities had significant effects on germination, germination recovery and induction into secondary dormancy. A conceptual model is presented that ties these results together and puts them into an ecological context. The two seed morphs of S. aralocaspica exhibit distinct differences in dormancy and germination characteristics. Suaeda aralocaspica is the first cold desert halophyte for which non-deep Type 2 PD has been documented.

  8. Seed germination and life history syndromes in the California chaparral

    USGS Publications Warehouse

    Keeley, J.E.

    1991-01-01

    Syndromes are life history responses that are correlated to environmental regimes and are shared by a group of species (Stebbins, 1974). In the California chaparral there are two syndromes contrasted by the timing of seedling recruitment relative to wildfires. One syndrome, here called the fire-recruiter or refractory seed syndrome, includes species (both resprouting and non-resprouting) which share the feature that the timing of seedling establishment is specialized to the first rainy season after fire. Included are woody, suffrutescent and annual life forms but no geophytes have this syndrome. These species are linked by the characteristic that their seeds have a dormancy which is readily broken by environmental stimuli such as intense heat shock or chemicals leached from charred wood. Such seeds are referred to as “refractory” and dormancy, in some cases, is due to seed coat impermeability (such seeds are commonly called hardseeded), but in other cases the mechanism is unknown. Seeds of some may require cold stratification and/or light in addition to fire related stimuli. In the absence of fire related cues, a portion or all of a species’ seed pool remains dormant. Most have locally dispersed seeds that persist in the soil seed bank until the site burns. Dispersal of propagules is largely during spring and summer which facilitates the avoidance of flowering and fruiting during the summer and fall drought. Within a life form (e.g., shrub, suffrutescent, etc.), the seeds of these species have less mass than those of species with non-refractory seeds and this possibly reflects the environmental favorableness of the postfire environment for seedling establishment. Regardless of when fire occurs, germination is normally delayed until late winter or early spring. In the absence of fire, or other disturbance, opportunities for population expansion are largely lacking for species with this syndrome. The other syndrome, here called the fire-resister or non

  9. Effect of new organic supplement (Panchgavya) on seed germination and soil quality.

    PubMed

    Jain, Paras; Sharma, Ravi Chandra; Bhattacharyya, Pradip; Banik, Pabitra

    2014-04-01

    We studied the suitability of Panchgavya (five products of cow), new organic amendment, application on seed germination, plant growth, and soil health. After characterization, Panchgavya was mixed with water to form different concentration and was tested for seed germination, germination index, and root and shoot growth of different seedlings. Four percent solution of Panchgavya was applied to different plants to test its efficacy. Panchgavya and other two organic amendments were incorporated in soil to test the change of soil chemical and microbiological parameters. Panchgavya contained higher nutrients as compared to farm yard manure (FYM) and vermicompost. Its application on different seeds has positively influenced germination percentage, germination index, root and shoot length, and fresh and dry weight of the seedling. Water-soluble macronutrients including pH and metal were positively and negatively correlated with the growth parameters, respectively. Four percent solution of Panchgavya application on some plants showed superiority in terms of plant height and chlorophyll content. Panchgavya-applied soil had higher values of macro and micronutrients (zinc, copper, and manganese), microbial activity as compared to FYM, and vermicompost applied soils. Application of Panchgavya can be gainfully used as an alternative organic supplement in agriculture.

  10. Effects of a warmer climate on seed germination in the subarctic

    PubMed Central

    Milbau, Ann; Graae, Bente Jessen; Shevtsova, Anna; Nijs, Ivan

    2009-01-01

    Background and Aims In a future warmer subarctic climate, the soil temperatures experienced by dispersed seeds are likely to increase during summer but may decrease during winter due to expected changes in snow depth, duration and quality. Because little is known about the dormancy-breaking and germination requirements of subarctic species, how warming may influence the timing and level of germination in these species was examined. Methods Under controlled conditions, how colder winter and warmer summer soil temperatures influenced germination was tested in 23 subarctic species. The cold stratification and warm incubation temperatures were derived from real soil temperature measurements in subarctic tundra and the temperatures were gradually changed over time to simulate different months of the year. Key Results Moderate summer warming (+2·5 °C) substantially accelerated germination in all but four species but did not affect germination percentages. Optimum germination temperatures (20/10°C) further decreased germination time and increased germination percentages in three species. Colder winter soil temperatures delayed the germination in ten species and decreased the germination percentage in four species, whereas the opposite was found in Silene acaulis. In most species, the combined effect of a reduced snow cover and summer warming resulted in earlier germination and thus a longer first growing season, which improves the chance of seedling survival. In particular the recruitment of (dwarf) shrubs (Vaccinium myrtillus, V. vitis-idaea, Betula nana), trees (Alnus incana, Betula pubescens) and grasses (Calamagrostis lapponica, C. purpurea) is likely to benefit from a warmer subarctic climate. Conclusions Seedling establishment is expected to improve in a future warmer subarctic climate, mainly by considerably earlier germination. The magnitudes of the responses are species-specific, which should be taken into account when modelling population growth and migration

  11. Chemical investigation of Cyperus distans L. and inhibitory activity of scabequinone in seed germination and seedling growth bioassays.

    PubMed

    Vilhena, Karyme S S; Guilhon, Giselle Maria Skelding Pinheiro; Zoghbi, Maria das Graças B; Santos, Lourivaldo Silva; Souza Filho, Antonio Pedro Silva

    2014-01-01

    Chemical investigation of the rhizomes of Cyperus distans (Cyperaceae) led to the identification of α-ciperone, cyperotundone and scabequinone, besides other common constituents. Complete assignment of the (13)C NMR data of scabequinone is being published for the first time. The inhibitory effects of C. distans extracts and scabequinone on the seed germination and seedling growth of Mimosa pudica, Senna obtusifolia and Pueraria phaseoloides were evaluated. Seed germination inhibition bioassay revealed that S. obtusifolia (52-53%) was more sensitive to the hexane and the methanol extracts at 1% than M. pudica (0-10%). Scabequinone at 250 mg L⁻¹ displayed seed germination inhibitions more than 50% and radicle growth reduction of more than 35% of the test species S. obtusifolia and P. phaseoloides, while the hypocotyl growth of M. pudica was significantly affected (>50%) by the quinone at the same concentration. These results demonstrate that scabequinone contributes to the overall inhibitory activities of C. distans.

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

    PubMed

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

    2017-06-02

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

  13. Exogenous 5-aminolevulenic acid promotes seed germination in Elymus nutans against oxidative damage induced by cold stress.

    PubMed

    Fu, Juanjuan; Sun, Yongfang; Chu, Xitong; Xu, Yuefei; Hu, Tianming

    2014-01-01

    The protective effects of 5-aminolevulenic acid (ALA) on germination of Elymus nutans Griseb. seeds under cold stress were investigated. Seeds of E. nutans (Damxung, DX and Zhengdao, ZD) were pre-soaked with various concentrations (0, 0.1, 0.5, 1, 5, 10 and 25 mg l(-1)) of ALA for 24 h before germination under cold stress (5°C). Seeds of ZD were more susceptible to cold stress than DX seeds. Both seeds treated with ALA at low concentrations (0.1-1 mg l(-1)) had higher final germination percentage (FGP) and dry weight at 5°C than non-ALA-treated seeds, whereas exposure to higher ALA concentrations (5-25 mg l(-1)) brought about a dose dependent decrease. The highest FGP and dry weight of germinating seeds were obtained from seeds pre-soaked with 1 mg l(-1) ALA. After 5 d of cold stress, pretreatment with ALA provided significant protection against cold stress in the germinating seeds, significantly enhancing seed respiration rate and ATP synthesis. ALA pre-treatment also increased reduced glutathione (GSH), ascorbic acid (AsA), total glutathione, and total ascorbate concentrations, and the activities of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and glutathione reductase (GR), whereas decreased the contents of malondialdehyde (MDA) and hydrogen peroxide (H2O2), and superoxide radical (O2•-) release in both germinating seeds under cold stress. In addition, application of ALA increased H+-ATPase activity and endogenous ALA concentration compared with cold stress alone. Results indicate that ALA considered as an endogenous plant growth regulator could effectively protect E. nutans seeds from cold-induced oxidative damage during germination without any adverse effect.

  14. A strong conditional mutualism limits and enhances seed dispersal and germination of a tropical palm

    USGS Publications Warehouse

    Klinger, R.; Rejmanek, M.

    2010-01-01

    Seed predation and seed dispersal can have strong effects on early life history stages of plants. These processes have often been studied as individual effects, but the degree to which their relative importance co-varies with seed predator abundance and how this influences seed germination rates is poorly understood. Therefore, we used a combination of observations and field experiments to determine the degree to which germination rates of the palm Astrocaryum mexicanum varied with abundance of a small mammal seed predator/disperser, Heteromysdesmarestianus, in a lowland tropical forest. Patterns of abundance of the two species were strongly related; density of H. desmarestianus was low in sites with low density of A. mexicanum and vice versa. Rates of predation and dispersal of A. mexicanum seeds depended on abundance of H. desmarestianus; sites with high densities of H. desmarestianus had the highest rates of seed predation and lowest rates of seed germination, but a greater total number of seeds were dispersed and there was greater density of seedlings, saplings, and adults of A. mexicanum in these sites. When abundance of H. desmarestianus was experimentally reduced, rates of seed predation decreased, but so did dispersal of A. mexicanum seeds. Critically, rates of germination of dispersed seeds were 5 times greater than undispersed seeds. The results suggest that the relationship between A. mexicanum and H. desmarestianus is a conditional mutualism that results in a strong local effect on the abundance of each species. However, the magnitude and direction of these effects are determined by the relative strength of opposing, but related, mechanisms. A. mexicanum nuts provide H. desmarestianus with a critical food resource, and while seed predation on A. mexicanum nuts by H. desmarestianus is very intense, A. mexicanum ultimately benefits because of the relatively high germination rates of its seeds that are dispersed by H. desmarestianus. ?? The Author(s) 2010.

  15. Biogenic nanoparticle-mediated augmentation of seed germination, growth, and antioxidant level of Eruca sativa mill. varieties.

    PubMed

    Ushahra, Jyoti; Bhati-Kushwaha, Himakshi; Malik, C P

    2014-09-01

    A study was undertaken to examine the influence of biogenic nanoparticles synthesized from Tridax procumbens on different parameters of seed germination, seedling growth, and various biochemical parameters in four Eruca sativa varieties having low percentage of germination. Seeds were treated with different concentrations (30 and 40 ppm) of biogenic nanoparticles, of which 30 ppm was found to be the most effective and was therefore used for subsequent studies. Initially, the effect of biogenic nanoparticles on germination percentage, speed of germination, coefficient of germination, mean germination time, shoot and root length, fresh and dry matter, and vigor index was studied. From the experiments performed and the results obtained, it was evident that the treatment with biogenic nanoparticles decreased the electrolyte leakage and level of malondialdehyde as compared to control. The treatment with biogenic nanoparticles enhanced the levels of proline and ascorbic acid and stimulated the antioxidant enzyme activities resulting in the reduced level of reactive oxygen species. These activities were found to be variety-dependent. The possible involvement of biogenic nanoparticles in the production of new pores in seed coat during their penetration, resulting in the influx of the nutrients inside the seed, is suggested. This accelerated seed germination is followed by rapid seedling growth. The present findings indicated that biogenic nanoparticles promote seed germination in E. sativa by overcoming the detrimental effects of reactive oxygen species (ROS) and improving the antioxidative defense system which finally result in increased seedling growth.

  16. AtNG1 encodes a protein that is required for seed germination.

    PubMed

    Yang, Libo; Peng, Xiongbo; Sun, Meng-xiang

    2011-10-01

    The pentatricopeptide repeat (PPR) family of eukaryotic proteins has numerous members in plants and is important for plant development. In the present study, we cloned a novel PPR gene, designated AtNG1, and characterized the ng1 Arabidopsis mutant. Morphological and structural observation of an ng1 mutant revealed that its sexual reproduction and seed formation processes are essentially normal. The mature embryonic root of ng1 is fully developed and has a well-differentiated structure; however, ng1 seeds cannot germinate, even when supplied with supplemental hormones and nutrition. Further investigation showed that embryo expansion and root cell elongation fails to occur after water imbibitions. Transient gene expression analysis indicated that AtNG1 localizes in mitochondrion. This implies that the deficiency of mitochondrion function might be the reason for the failed seed germination. Thus, our finding confirmed that AtNG1 plays a critical role in the early process of seed germination. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  17. The regulator of G-protein signaling proteins involved in sugar and abscisic acid signaling in Arabidopsis seed germination.

    PubMed

    Chen, Yun; Ji, Fangfang; Xie, Hong; Liang, Jiansheng; Zhang, Jianhua

    2006-01-01

    The regulator of G-protein signaling (RGS) proteins, recently identified in Arabidopsis (Arabidopsis thaliana; named as AtRGS1), has a predicted seven-transmembrane structure as well as an RGS box with GTPase-accelerating activity and thus desensitizes the G-protein-mediated signaling. The roles of AtRGS1 proteins in Arabidopsis seed germination and their possible interactions with sugars and abscisic acid (ABA) were investigated in this study. Using seeds that carry a null mutation in the genes encoding RGS protein (AtRGS1) and the alpha-subunit (AtGPA1) of the G protein in Arabidopsis (named rgs1-2 and gpa1-3, respectively), our genetic evidence proved the involvement of the AtRGS1 protein in the modulation of seed germination. In contrast to wild-type Columbia-0 and gpa1-3, stratification was found not to be required and the after-ripening process had no effect on the rgs1-2 seed germination. In addition, rgs1-2 seed germination was insensitive to glucose (Glc) and sucrose. The insensitivities of rgs1-2 to Glc and sucrose were not due to a possible osmotic stress because the germination of rgs1-2 mutant seeds showed the same response as those of gpa1-3 mutants and wild type when treated with the same concentrations of mannitol and sorbitol. The gpa1-3 seed germination was hypersensitive while rgs1-2 was less sensitive to exogenous ABA. The different responses to ABA largely diminished and the inhibitory effects on seed germination by exogenous ABA and Glc were markedly alleviated when endogenous ABA biosynthesis was inhibited. Hypersensitive responses of seed germination to both Glc and ABA were also observed in the overexpressor of AtRGS1. Analysis of the active endogenous ABA levels and the expression of NCED3 and ABA2 genes showed that Glc significantly stimulated the ABA biosynthesis and increased the expression of NCED3 and ABA2 genes in germinating Columbia seeds, but not in rgs1-2 mutant seeds. These data suggest that AtRGS1 proteins are involved in the

  18. ABA-stimulated SoDOG1 expression is after-ripening inhibited during early imbibition of germinating Sisymbrium officinale seeds.

    PubMed

    Carrillo-Barral, Néstor; Matilla, Angel J; García-Ramas, Cristina; Rodríguez-Gacio, María Del Carmen

    2015-12-01

    DELAY OF GERMINATION 1 (AtDOG1) was the first gene identified as dormancy-associated, but its physiological role in germination is far from being understood. Here, an orthologue of AtDOG1 in Sisymbrium officinale (SoDOG1; KM009050) is being reported. Phylogenetically, the SoDOG1 gene is included into the dicotyledonous group together with DOG1 from Arabidopsis thaliana (EF028470), Brassica rapa (AC189537), Lepidium papillosum (JX512183, JX512185) and Lepidium sativum (GQ411192). The SoDOG1 expression peaked at the onset of the silique maturation stage and there was presence of SoDOG1-mRNA in the freshly collected viable dry seed (i.e. AR0). The SoDOG1 transcripts were also found in other organs, such as open and closed flowers and to a lesser degree in roots and stems. We have previously reported in S. officinale seeds in which sensu stricto germination is positively affected by nitrate and both testa and micropylar endosperm ruptures are temporally separated. In dry viable seeds, the SoDOG1-mRNA level in three different after-ripening (AR) status was AR0 ≈ AR7 (optimal AR) < AR27 (optimal AR was almost lost). The presence of nitrate in the AR0 seed imbibition medium markedly decreased the SoDOG1 expression during sensu stricto germination. However, the nitrate stimulated the SoDOG1 expression during imbibition of AR7 compared to AR0. At the early AR0 seed imbibition (3-6 h), exogenous ABA provoked a very strong stimulation of the SoDOG1 expression. AR inhibits ABA-induced SoDOG1 expression during early germination and gibberellins (GA) can partially mimic this AR effect. A view on the integration of all found results in the sensu stricto germination of S. officinale was conducted. © 2015 Scandinavian Plant Physiology Society.

  19. Development of a Threshold Model to Predict Germination of Populus tomentosa Seeds after Harvest and Storage under Ambient Condition

    PubMed Central

    Wang, Wei-Qing; Cheng, Hong-Yan; Song, Song-Quan

    2013-01-01

    Effects of temperature, storage time and their combination on germination of aspen (Populus tomentosa) seeds were investigated. Aspen seeds were germinated at 5 to 30°C at 5°C intervals after storage for a period of time under 28°C and 75% relative humidity. The effect of temperature on aspen seed germination could not be effectively described by the thermal time (TT) model, which underestimated the germination rate at 5°C and poorly predicted the time courses of germination at 10, 20, 25 and 30°C. A modified TT model (MTT) which assumed a two-phased linear relationship between germination rate and temperature was more accurate in predicting the germination rate and percentage and had a higher likelihood of being correct than the TT model. The maximum lifetime threshold (MLT) model accurately described the effect of storage time on seed germination across all the germination temperatures. An aging thermal time (ATT) model combining both the TT and MLT models was developed to describe the effect of both temperature and storage time on seed germination. When the ATT model was applied to germination data across all the temperatures and storage times, it produced a relatively poor fit. Adjusting the ATT model to separately fit germination data at low and high temperatures in the suboptimal range increased the models accuracy for predicting seed germination. Both the MLT and ATT models indicate that germination of aspen seeds have distinct physiological responses to temperature within a suboptimal range. PMID:23658654

  20. The effect of frequency-specific sound signals on the germination of maize seeds.

    PubMed

    Vicient, Carlos M

    2017-07-25

    The effects of sound treatments on the germination of maize seeds were determined. White noise and bass sounds (300 Hz) had a positive effect on the germination rate. Only 3 h treatment produced an increase of about 8%, and 5 h increased germination in about 10%. Fast-green staining shows that at least part of the effects of sound are due to a physical alteration in the integrity of the pericarp, increasing the porosity of the pericarp and facilitating oxygen availability and water and oxygen uptake. Accordingly, by removing the pericarp from the seeds the positive effect of the sound on the germination disappeared.

  1. Genotyping of Endosperms to Determine Seed Dormancy Genes Regulating Germination Through Embryonic, Endospermic, or Maternal Tissues in Rice

    PubMed Central

    Gu, Xing-You; Zhang, Jinfeng; Ye, Heng; Zhang, Lihua; Feng, Jiuhuan

    2014-01-01

    Seed dormancy is imposed by one or more of the embryo, endosperm, and maternal tissues that belong to two generations and represent two ploidy levels. Many quantitative trait loci (QTL) have been identified for seed dormancy as measured by gross effects on reduced germination rate or delayed germination in crop or model plants. This research developed an endosperm genotype−based genetic approach to determine specific tissues through which a mapped QTL regulates germination using rice as a model. This approach involves testing germination velocity for partially after-ripened seeds harvested from single plants heterozygous for a tested QTL and genotyping endosperms from individual germinated and nongerminated seeds with a codominant DNA marker located on the QTL peak region. Information collected about the QTL includes genotypic frequencies in germinated and/or nongerminated subpopulations; allelic frequency distributions during a germination period; endosperm or embryo genotypic differences in germination velocity; and genotypic frequencies for gametes involved in the double fertilization to form the sampled seeds. Using this approach, the seed dormancy loci SD12, SD1-2, and SD7-1 were determined to regulate germination through the embryo, endosperm, and maternal tissues, respectively; SD12 and SD1-2 acted additively on germination velocity in the offspring tissues; and SD12 also was associated with the preferential fertilization of male gametes in rice. This new genetic approach can be used to characterize mapped genes/QTL for tissue-specific functions in endospermic seeds and for marker-assisted selection of QTL alleles before or immediately after germination in crop breeding. PMID:25480961

  2. Preliminary studies on allelopatic effect of some woody plants on seed germination of rye-grass and tall fescue.

    PubMed

    Arouiee, H; Nazdar, T; Mousavi, A

    2010-11-01

    In order to investigation of allelopathic effects of some ornamental trees on seed germination of rye-grass (Lolium prenne) and tall fescue (Festuca arundinaceae), this experiment was conducted in a randomized complete block design with 3 replicates at the laboratory of Horticultural Sciences Department of Ferdowsi University of Mashhad, during 2008. In this research, we studied the effect of aqueous and hydro-alcoholic extracts of Afghanistan pine (Pinus eldarica), arizona cypress (Cupressus arizonica), black locust (Robinia psedue acacia) and box elder (Acer negundo) leaves that prepared in 1:5 ratio on seed germination percent and rate for two grasses. The results showed that all extracts decreased statistically seed germination in compared to control treatment. The highest germination percentage and germination rate of tested grass detected in control treatment. Hydro-alcoholic extracts of all woody plants (15, 30%) were completely inhibited seed germination of rye-grass and tall fescue. Also aqueous extract of arizona cypress was completely inhibited seed germination of tall fescue and had more inhibitory activity than other aqueous extracts on rye-grass. Between aqueous extracts, the highest and lowest seed germination of rye-grass was found in Afghanistan pine and arizona cypress, respectively.

  3. Allelopathy of the invasive plant Bidens frondosa on the seed germination of Geum japonicum var. chinense.

    PubMed

    Wang, X F; Hassani, D; Cheng, Z W; Wang, C Y; Wu, J

    2014-12-12

    Five gradient concentrations (0.02, 0.04, 0.06, 0.08, and 0.10 g/mL) of leaching liquors from the roots, stems, and leaves of the invasive plant Bidens frondosa were used as conditioning fluid to examine its influence on seed germination conditions of the native plant Geum japonicum var. chinense in Huangshan. All leaching liquors of organs suppressed the seed germination of Geum japonicum var. chinense and reduced the final germination percentage and rate, and increased the germination inhibition rate, with a bimodal dependence on concentration. The leaching liquor inhibited the seed germination significantly at the concentration of 0.02 g/mL respectively. The seed germination was also inhibited as the concentration reached to 0.04 g/mL and beyond. Hence the allelopathic effects of the organs were significantly enhanced respectively. This phenomenon represented the presence of allelopathy substances in the root, stem and leaf of Bidens frondosa.

  4. Spatial profiling of maytansine during the germination process of Maytenus senegalensis seeds.

    PubMed

    Eckelmann, Dennis; Kusari, Souvik; Spiteller, Michael

    2017-06-01

    The ecological role of maytansine, an important antineoplastic and antimicrobial compound with high cytotoxicity, particularly as a chemical defense compound has remained elusive since its discovery in the 1970s in Maytenus and Putterlickia plants. In the present study, we have used MALDI-imaging-HRMS to visualize the occurrence as well as spatial and temporal distribution of maytansine in a Maytenus senegalensis plant, seeds obtained from the mother plant during seeding stage, through the germination of the seeds, and finally up to the establishment of seedlings (or daughter plants). Although the mother plant was devoid of maytansine, the bioactive compound was found to be distributed in the cotyledons and the endosperm of the seeds with an augmented accretion towards the seed coat. Furthermore, maytansine was always detected in the emerging seedlings, particularly the cortex encompassing the radicle, hypocotyl, and epicotyl. The typical pattern of accumulation of maytansine not only in the seeds but also during germination provides a proof-of-concept that M. senegalensis is ecologically primed to trigger the production of maytansine in vulnerable tissues such as seeds during plant reproduction. By utilizing maytansine as chemical defense compound against predators and/or pathogens, the plant can ensure viability of the seeds and successful germination, thus leading to the next generation of daughter plants. Copyright © 2017 Elsevier B.V. All rights reserved.

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

    PubMed

    Ren, C; Kermode, A R

    2000-09-01

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

  6. Exogenous 5-Aminolevulenic Acid Promotes Seed Germination in Elymus nutans against Oxidative Damage Induced by Cold Stress

    PubMed Central

    Fu, Juanjuan; Sun, Yongfang; Chu, Xitong; Xu, Yuefei; Hu, Tianming

    2014-01-01

    The protective effects of 5-aminolevulenic acid (ALA) on germination of Elymus nutans Griseb. seeds under cold stress were investigated. Seeds of E. nutans (Damxung, DX and Zhengdao, ZD) were pre-soaked with various concentrations (0, 0.1, 0.5, 1, 5, 10 and 25 mg l−1) of ALA for 24 h before germination under cold stress (5°C). Seeds of ZD were more susceptible to cold stress than DX seeds. Both seeds treated with ALA at low concentrations (0.1–1 mg l−1) had higher final germination percentage (FGP) and dry weight at 5°C than non-ALA-treated seeds, whereas exposure to higher ALA concentrations (5–25 mg l−1) brought about a dose dependent decrease. The highest FGP and dry weight of germinating seeds were obtained from seeds pre-soaked with 1 mg l−1 ALA. After 5 d of cold stress, pretreatment with ALA provided significant protection against cold stress in the germinating seeds, significantly enhancing seed respiration rate and ATP synthesis. ALA pre-treatment also increased reduced glutathione (GSH), ascorbic acid (AsA), total glutathione, and total ascorbate concentrations, and the activities of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and glutathione reductase (GR), whereas decreased the contents of malondialdehyde (MDA) and hydrogen peroxide (H2O2), and superoxide radical (O2 •−) release in both germinating seeds under cold stress. In addition, application of ALA increased H+-ATPase activity and endogenous ALA concentration compared with cold stress alone. Results indicate that ALA considered as an endogenous plant growth regulator could effectively protect E. nutans seeds from cold-induced oxidative damage during germination without any adverse effect. PMID:25207651

  7. 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.

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

    PubMed Central

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

    2014-01-01

    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. PMID:24744430

  9. Seed dormancy and germination of the medicinal holoparasitic plant Cistanche deserticola from the cold desert of northwest China.

    PubMed

    Wang, Jia; Baskin, Jerry M; Baskin, Carol C; Liu, Guofang; Yang, Xuejun; Huang, Zhenying

    2017-06-01

    Cistanche deserticola is a holoparasitic plant with high medicinal value that reproduces only by seeds. However, the requirements for seed dormancy break and germination of this species remain unclear. The freshly matured dust-like seeds consist of a water-permeable seed coat and an undifferentiated oval-shaped embryo embedded in endosperm. No fresh seeds germinated in water or a 10 -5  M fluridone solution at any incubation temperature within 60 days. Length of embryos in seeds incubated in warm- and cold-started stratification sequences had increased 10.4 and 11.7% after 50 and 40 weeks, respectively. After 6 months, length of embryos in seeds stratified at 5 °C had increased by 12%. Germination of fresh seeds and of seeds stratified at 5 °C for 6 months and then incubated in mixed fluridone/gibberellic acid 3 (GA 3 ) solutions at 30/20 °C germinated to only 2.6 and 11.7%, respectively. Embryos of fresh seeds and of cold-stratified seeds had increased 29.4 and 15.8% in length, respectively, at the time of germination, but they never differentiated into organs. The highest germination (54.4%) was for seeds incubated in a 10 -5  M solution of fluridone in darkness in spring that had overwinter on the soil surface in the natural habitat. Our study indicates that breaking of physiological dormancy (PD) occurs first and then the embryo grows to a critical length (0.44 mm) without differentiation into organs prior to seed germination. Seeds for which PD had been broken were induced to germinate by fluridone and GA 3 at high temperature. Taken together, these results suggest that C. deserticola seeds have a specialized kind of morphophysiological dormancy. This study reveals possible ways to release seed dormancy that will be useful in propagating this medicinal species. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  10. Differential seed handling by two African primates affects seed fate and establishment of large-seeded trees

    NASA Astrophysics Data System (ADS)

    Gross-Camp, Nicole D.; Kaplin, Beth A.

    2011-11-01

    We examined the influence of seed handling by two semi-terrestrial African forest primates, chimpanzees ( Pan troglodytes) and l'Hoest's monkeys ( Cercopithecus lhoesti), on the fate of large-seeded tree species in an afromontane forest. Chimpanzees and l'Hoest's monkeys dispersed eleven seed species over one year, with quantity and quality of dispersal varying through time. Primates differed in their seed handling behaviors with chimpanzees defecating large seeds (>0.5 cm) significantly more than l'Hoest's. Furthermore, they exhibited different oral-processing techniques with chimpanzees discarding wadges containing many seeds and l'Hoest's monkeys spitting single seeds. A PCA examined the relationship between microhabitat characteristics and the site where primates deposited seeds. The first two components explained almost half of the observed variation. Microhabitat characteristics associated with sites where seeds were defecated had little overlap with those characteristics describing where spit seeds arrived, suggesting that seed handling in part determines the location where seeds are deposited. We monitored a total of 552 seed depositions through time, recording seed persistence, germination, and establishment. Defecations were deposited significantly farther from an adult conspecific than orally-discarded seeds where they experienced the greatest persistence but poorest establishment. In contrast, spit seeds were deposited closest to an adult conspecific but experienced the highest seed establishment rates. We used experimental plots to examine the relationship between seed handling, deposition site, and seed fate. We found a significant difference in seed handling and fate, with undispersed seeds in whole fruits experiencing the lowest establishment rates. Seed germination differed by habitat type with open forest experiencing the highest rates of germination. Our results highlight the relationship between primate seed handling and deposition site and seed

  11. In Vitro Seeds Germination and Seedling Growth of Bambara Groundnut (Vigna subterranea (L.) Verdc. (Fabaceae)).

    PubMed

    Koné, Mongomaké; Koné, Tchoa; Silué, Nakpalo; Soumahoro, André Brahima; Kouakou, Tanoh Hilaire

    2015-01-01

    Bambara groundnut (Vigna subterranea (L.) Verdc.) is an indigenous grain legume. It occupies a prominent place in the strategies to ensure food security in sub-Saharan Africa. Development of an efficient in vitro regeneration system, a prerequisite for genetic transformation application, requires the establishment of optimal conditions for seeds germination and plantlets development. Three types of seeds were inoculated on different basal media devoid of growth regulators. Various strengths of the medium of choice and the type and concentration of carbon source were also investigated. Responses to germination varied with the type of seed. Embryonic axis (EA) followed by seeds without coat (SWtC) germinated rapidly and expressed a high rate of germination. The growth performances of plantlets varied with the basal medium composition and the seeds type. The optimal growth performances of plants were displayed on half strength MS basal medium with SWtC and EA as source of seeds. Addition of 3% sucrose in the culture medium was more suitable for a maximum growth of plantlets derived from EA.

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

    PubMed

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

    2012-01-01

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

  13. The influence of light, substrate and seed origin on the germination and establishment of an ant-garden bromeliad.

    PubMed

    Leroy, C; Petitclerc, F; Orivel, J; Corbara, B; Carrias, J-F; Dejean, A; Céréghino, R

    2017-01-01

    Plant germination and development depend upon a seed's successful dispersal into a suitable habitat and its ability to grow and survive within the surrounding biotic and abiotic environment. The seeds of Aechmea mertensii, a tank-bromeliad species, are dispersed by either Camponotus femoratus or Neoponera goeldii, two ant species that initiate ant gardens (AGs). These two mutualistic ant species influence the vegetative and reproductive traits of the bromeliad through their divergent ecological preferences (i.e. light and substrate). We hypothesised that the seeds dispersed by these two ant species have underlying genetic differences affecting germination, growth and survival of A. mertensii seedlings in different ways. To test this, we used an experimental approach consisting of sowing seeds of A. mertensii: (i) taken from the two AG-ant associations (i.e. seed origin), (ii) in two contrasting light conditions, and (iii) on three different substrates. Light and substrate had significant effects on germination, survival and on eight key leaf traits reflecting plant performance. Seed origin had a significant effect only on germination and on two leaf traits (total dry mass and relative growth rate). Overall, this bromeliad performs better (i.e. high growth and survival rates) when growing both in the shade and in the carton nest developed by C. femoratus ants. These results suggest that the plasticity of the tank bromeliad A. mertensii is mainly due to environment but also to genetic differences related to seed origin, as some traits are heritable. Thus, these two ant species may play contrasting roles in shaping plant evolution and speciation. © 2016 German Botanical Society and The Royal Botanical Society of the Netherlands.

  14. Strategies for adaptation of Suaeda physophora, Haloxylon ammodendron and Haloxylon persicum to a saline environment during seed-germination stage.

    PubMed

    Song, Jie; Feng, Gu; Tian, Changyan; Zhang, Fusuo

    2005-09-01

    Germination is very important for plant establishment in arid regions. The strategies taken by halophytes during the seed germination stage to adapt to saline environments in an arid zone were investigated in Suaeda physophora (euhalophyte), Haloxylon ammodendron (xero-halophyte) and Haloxylon persicum (xerophyte). Seeds of S. physophora, H. ammodendron and H. persicum were exposed to a range of iso-osmotic NaCl and PEG solutions. Seed germination in, and recovery germination from, high NaCl were recorded. The effects of iso-osmotic NaCl and PEG on seed water uptake and changes in ion content were measured. In addition, the structure of seeds and Na+ distribution in the seed coat and embryos of dry seeds were investigated. The relative increase in fresh weight of germinating seeds was markedly reduced in -2.24 MPa PEG compared with that in -2.24 MPa NaCl, while the opposite trend was found in concentration of K+ during the initial 9 h for all species. Haloxylon ammodendron and S. physophora had a higher recovery germination from -3.13 MPa NaCl compared with H. persicum. Seeds of all species had no endosperm. More Na+ was compartmentalized in the seed coats of the two halophytic species compared with that in the xerophyte H. persicum. The effect of NaCl on seed germination was due to both osmotic stress and ion toxicity for the three species. High soil salinity and a high content of Na+ in seeds may induce more seeds to remain ungerminated in S. physophora and H. ammodendron. Morphological structure and adaptation to salinity during seed germination may determine the geographical distribution of H. ammodendron and S. physophora in certain saline regions.

  15. Seed viability of five wild Saudi Arabian species by germination and X-ray tests.

    PubMed

    Al-Hammad, B A; Al-Ammari, B S

    2017-09-01

    Our objective was to evaluate the usefulness of the germination vs. the X-ray test in determining the initial viability of seeds of five wild species ( Moringa peregrina , Abrus precatorius , Arthrocnemum macrostachyum , Acacia ehrenbergiana and Acacia tortilis ) from Saudi Arabia. Usually several days were required to determine the viability of all five species via germination tests. However, X-ray test will give immediate results on filled/viable seeds. Seeds of all species, except Acacia ehrenbergiana and Acacia tortilis showed high viability in both germination (96-72% at 25/15 °C, 94-70% at 35/25 °C) and X-ray (100-80%) test. Furthermore, there was a general agreement between the germination (19%, 14% at 25/15 °C and 17% and 12% at 35/25 °C) and X-ray (8%, 4%) tests in which seed viability of Acacia ehrenbergiana and Acacia tortilis was very low due to insect damaged embryo as shown in X-ray analysis. Seeds of Abruspreca torius have physical dormancy, which was broken by scarification in concentrated sulfuric acid (10 min), and they exhibited high viability in both the germination (83% at 25/15 °C and 81% at 35/25 °C) and X-ray (96%) tests. Most of the nongerminated seeds of the five species except those of Acacia ehrenbergiana and Acacia tortilis , were alive as judged by the tetrazolium test (TZ). Thus, for the five species examined, the X-ray test was proved to be a good and rapid predictor of seed viability.

  16. Genetic variation of transgenerational plasticity of offspring germination in response to salinity stress and the seed transcriptome of Medicago truncatula.

    PubMed

    Vu, Wendy T; Chang, Peter L; Moriuchi, Ken S; Friesen, Maren L

    2015-04-01

    Transgenerational plasticity provides phenotypic variation that contributes to adaptation. For plants, the timing of seed germination is critical for offspring survival in stressful environments, as germination timing can alter the environmental conditions a seedling experiences. Stored seed transcripts are important determinants of seed germination, but have not previously been linked with transgenerational plasticity of germination behavior. In this study we used RNAseq and growth chamber experiments of the model legume M. trucantula to test whether parental exposure to salinity stress influences the expression of stored seed transcripts and early offspring traits and test for genetic variation. We detected genotype-dependent parental environmental effects (transgenerational plasticity) on the expression levels of stored seed transcripts, seed size, and germination behavior of four M. truncatula genotypes. More than 50% of the transcripts detected in the mature, ungerminated seed transcriptome were annotated as regulating seed germination, some of which are involved in abiotic stress response and post-embryonic development. Some genotypes showed increased seed size in response to parental exposure to salinity stress, but no parental environmental influence on germination timing. In contrast, other genotypes showed no seed size differences across contrasting parental conditions but displayed transgenerational plasticity for germimation timing, with significantly delayed germination in saline conditions when parental plants were exposed to salinity. In genotypes that show significant transgenerational plastic germination response, we found significant coexpression networks derived from salt responsive transcripts involved in post-transcriptional regulation of the germination pathway. Consistent with the delayed germination response to saline conditions in these genotypes, we found genes associated with dormancy and up-regulation of abscisic acid (ABA). Our results

  17. Cryopreservation of lipid-rich seeds: effect of moisture content and cooling rate on germination.

    PubMed

    González-Benito, E M; Pérez-García, F

    2001-01-01

    The effect of fast and slow cooling on germination of seeds from two Brassicaceae species (Eruca vesicaria (L.) Cav., Brassica napus L. var. oleifera (Moench) DC cv. Bingo) and cypselas from three Compositae species (Onopordum nervosum Boiss., Onopordum acanthium L., Helianthus annuus L. cv. Viky) at different moisture contents was studied. Seed lipid content (dry weight basis) ranged from 15% (O. nervosum) to 41% (H. annuus). For each species, seeds with four moisture contents were cryopreserved either by direct immersion in liquid nitrogen or by previous cooling at 10 degrees C/min from room temperature to -50 degrees C. In three species (E. vesicaria, B. napus, and H. annuus) germination of air-dried (6.2-8.9% moisture content) seeds cooled by direct immersion in liquid nitrogen was not significantly different from germination of control seeds (air-dried, non-cooled). In the two Onorpordum species the best response among cooling treatments was observed when air-dried seeds were slowly cooled.

  18. Hydrothermal thresholds for seed germination in winter annual forbs from old-field Mediterranean landscapes.

    PubMed

    Frischie, Stephanie; Fernández-Pascual, Eduardo; Gálvez Ramirez, Cándido; Toorop, Peter; Matías González, Hernández; Jiménez-Alfaro, Borja

    2018-05-22

    Under Mediterranean climates with dry-hot summers and cool-wet winters, many forbs with potential for habitat restoration are winter annuals, but there is little information about their germination. We performed laboratory germination experiments on 13 ruderal dicots native to Andalusia (southern Spain). We measured the germination of recently harvested seeds from natural populations across nine temperature treatments (from 5 °C to 35 °C, constant and alternate); two storage periods; and eight water stress treatments (from 0 MPa to -1.0 MPa). We thencalculated the hydrothermal thresholds for seed germination. Final germination ranged from 0-100% and results were mixed in response to temperature. Base temperature was below 6 °C, optimal temperature was around 14 °C and the ceiling temperature around 23 °C. For five species, 10 months of storage improved total germination, indicating a dormancy-breaking effect, but the other species did not respond or had their germination reduced. All species were relatively tolerant to water stress, with base water potential ranging from -0.8 MPa to -1.8 MPa. Our results suggest that hydrothermal germination thresholds, rather than physiological dormancy, are the main drivers of germination phenology in annual forbs from Mediterranean semi-dry environments. The germination of these forb species differs from winter annual grasses, but their seeds are all suitable for being stored before restoration. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  19. Cold tolerance in rice germinating seeds revealed by deep RNAseq analysis of contrasting indica genotypes.

    PubMed

    Dametto, Andressa; Sperotto, Raul A; Adamski, Janete M; Blasi, Édina A R; Cargnelutti, Denise; de Oliveira, Luiz F V; Ricachenevsky, Felipe K; Fregonezi, Jeferson N; Mariath, Jorge E A; da Cruz, Renata P; Margis, Rogério; Fett, Janette P

    2015-09-01

    Rice productivity is largely affected by low temperature, which can be harmful throughout plant development, from germination to grain filling. Germination of indica rice cultivars under cold is slow and not uniform, resulting in irregular emergence and small plant population. To identify and characterize novel genes involved in cold tolerance during the germination stage, two indica rice genotypes (sister lines previously identified as cold-tolerant and cold-sensitive) were used in parallel transcriptomic analysis (RNAseq) under cold treatment (seeds germinating at 13 °C for 7 days). We detected 1,361 differentially expressed transcripts. Differences in gene expression found by RNAseq were confirmed for 11 selected genes using RT-qPCR. Biological processes enhanced in the cold-tolerant seedlings include: cell division and expansion (confirmed by anatomical sections of germinating seeds), cell wall integrity and extensibility, water uptake and membrane transport capacity, sucrose synthesis, generation of simple sugars, unsaturation of membrane fatty acids, wax biosynthesis, antioxidant capacity (confirmed by histochemical staining of H2O2), and hormone and Ca(2+)-signaling. The cold-sensitive seedlings respond to low temperature stress increasing synthesis of HSPs and dehydrins, along with enhanced ubiquitin/proteasome protein degradation pathway and polyamine biosynthesis. Our findings can be useful in future biotechnological approaches aiming to cold tolerance in indica rice. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  20. Seed germination ecology of Echinochloa glabrescens and its implication for management in rice (Oryza sativa L.).

    PubMed

    Opeña, Jhoana L; Chauhan, Bhagirath S; Baltazar, Aurora M

    2014-01-01

    Echinochloa glabrescens is a C4 grass weed that is very competitive with rice when left uncontrolled. The competitive ability of weeds is intensified in direct-seeded rice production systems. A better understanding is needed of factors affecting weed seed germination, which can be used as a component of integrated weed management in direct-seeded rice. This study was conducted to determine the effects of temperature, light, salt and osmotic stress, burial depth, crop residue, time and depth of flooding, and herbicide application on the emergence, survival, and growth of two populations [Nueva Ecija (NE) and Los Baños (IR)] of E. glabrescens. Seeds from both populations germinated at all temperatures. The NE population had a higher germination rate (88%) from light stimulation than did the IR population (34%). The salt concentration and osmotic potential required to inhibit 50% of germination were 313 mM and -0.24 MPa, respectively, for the NE population and 254 mM and -0.33 MPa, respectively, for the IR population. Emergence in the NE population was totally inhibited at 4-cm burial depth in the soil, whereas that of the IR population was inhibited at 8 cm. Compared with zero residue, the addition of 5 t ha(-1) of rice residue reduced emergence in the NE and IR populations by 38% and 9%, respectively. Early flooding (within 2 days after sowing) at 2-cm depth reduced shoot growth by 50% compared with non-flooded conditions. Pretilachlor applied at 0.075 kg ai ha(-1) followed by shallow flooding (2-cm depth) reduced seedling emergence by 94-96% compared with the nontreated flooded treatment. Application of postemergence herbicides at 4-leaf stage provided 85-100% control in both populations. Results suggest that integration of different strategies may enable sustainable management of this weed and of weeds with similar germination responses.

  1. Relationships Between Seed Weight, Germination Potential and Biochemical Reserves of Maritime Pine in Morocco: Elements for Tree Seedlings Improvement

    NASA Technical Reports Server (NTRS)

    Wahid, Nadya; Bounoua, Lahouari

    2011-01-01

    Selection of quality seeds in breeding programs can significantly improve seedling productivity. Germination and biochemical analyses on seeds from ten natural populations of maritime pine (Pinus pinaster Ait.) in Morocco reveals significant differences among populations in seed weight, germination characters and protein content in both dry seeds and megagametophytes. During germination, the mobilization of protein content in megagametophyte is significantly different among populations than sugar content. A strong positive correlation between the germination capacity and the protein content in both dry seeds and megagametophytes indicates that the best populations in term of germination capacity may also be the richest in protein content. The present study finds that seed weight is not a good indicator for quality seed selection, nor is it recommended to increase the degree of germinability. Our results suggest that the pine population in southern Morocco might have adapted to drought conditions as it is characterized by heavy seed weight and lower speed of protein content mobilization in megagametophyte compared to northern populations growing in temperate climate.

  2. Regulatory-associated protein of TOR (RAPTOR) alters the hormonal and metabolic composition of Arabidopsis seeds, controlling seed morphology, viability and germination potential.

    PubMed

    Salem, Mohamed A; Li, Yan; Wiszniewski, Andrew; Giavalisco, Patrick

    2017-11-01

    Target of Rapamycin (TOR) is a positive regulator of growth and development in all eukaryotes, which positively regulates anabolic processes like protein synthesis, while repressing catabolic processes, including autophagy. To better understand TOR function we decided to analyze its role in seed development and germination. We therefore performed a detailed phenotypic analysis using mutants of the REGULATORY-ASSOCIATED PROTEIN OF TOR 1B (RAPTOR1B), a conserved TOR interactor, acting as a scaffold protein, which recruits substrates for the TOR kinase. Our results show that raptor1b plants produced seeds that were delayed in germination and less resistant to stresses, leading to decreased viability. These physiological phenotypes were accompanied by morphological changes including decreased seed-coat pigmentation and reduced production of seed-coat mucilage. A detailed molecular analysis revealed that many of these morphological changes were associated with significant changes of the metabolic content of raptor1b seeds, including elevated levels of free amino acids, as well as reduced levels of protective secondary metabolites and storage proteins. Most of these observed changes were accompanied by significantly altered phytohormone levels in the raptor1b seeds, with increases in abscisic acid, auxin and jasmonic acid, which are known to inhibit germination. Delayed germination and seedling growth, observed in the raptor1b seeds, could be partially restored by the exogenous supply of gibberellic acid, indicating that TOR is at the center of a regulatory hub controlling seed metabolism, maturation and germination. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

  3. Ammonia Volatilization from Urea-Application Influenced Germination and Early Seedling Growth of Dry Direct-Seeded Rice

    PubMed Central

    Qi, Xiaoli; Wu, Wei; Shah, Farooq; Peng, Shaobing; Huang, Jianliang; Cui, Kehui; Liu, Hongyan; Nie, Lixiao

    2012-01-01

    Poor seed germination and early seedling growth associated with urea-induced soil ammonia volatilization are major constraints in the adoption of dry direct-seeded rice. To directly examine soil ammonia volatilization and its damage to seed germination and early seedling growth of dry direct-seeded rice when urea is applied at seeding, two Petri-dish incubation experiments and a field experiment were conducted. Ammonia volatilization due to urea application significantly reduced seed germination and early seedling growth of dry direct-seedling rice. NBPT significantly reduced ammonia volatilization following urea application. The application of ammonium sulfate, instead of urea at seeding, may mitigate poor crop establishment of dry direct-seeded rice. Root growth of dry direct-seeded rice was more seriously inhibited by soil ammonia volatilization than that of shoot. Results suggest that roots are more sensitive to soil ammonia toxicity than shoots in dry direct-seeded rice system when N is applied as urea at seeding. PMID:22454611

  4. Comparison of the effects of temperature and water potential on seed germination of Fabaceae species from desert and subalpine grassland.

    PubMed

    Hu, Xiao Wen; Fan, Yan; Baskin, Carol C; Baskin, Jerry M; Wang, Yan Rong

    2015-05-01

    Temperature and water potential for germination based on the thermal and hydrotime models have been successfully applied in predicting germination requirements of physiologically dormant seeds as well as nondormant seeds. However, comparative studies of the germination requirements of physically dormant seeds from different ecosystems have not been done. Germination of scarified seeds of four legume species collected from the Qing-Tibetan Plateau and of four collected in the Alax Desert in China was compared over a range of temperatures and water potentials based on thermal time and hydrotime models. Seeds of species from the Qing-Tibetan Plateau had a lower base temperature (T b) and optimal temperature (T o) for germination than those from the Alax Desert. Seeds of the four species from the Qing-Tibetan Plateau germinated to high percentages at 5°C, whereas none of the four desert species did so. Seeds of species from the Alax Desert germinated to a high percentage at 35°C or 40°C, while no seeds of species from the Qing-Tibetan Plateau germinated at 35°C or 40°C. The base median water potential [Ψ b(50)] differed among species but not between the two habitats. The thermal time and hydrotime models accurately predicted the germination time course of scarified seeds of most of the eight species in response to temperature and water potential; thus, they can be useful tools in comparative studies on germination of seeds with physical dormancy. Habitat temperatures but not rainfall is closely related to germination requirements of these species. © 2015 Botanical Society of America, Inc.

  5. The Regulator of G-Protein Signaling Proteins Involved in Sugar and Abscisic Acid Signaling in Arabidopsis Seed Germination1

    PubMed Central

    Chen, Yun; Ji, Fangfang; Xie, Hong; Liang, Jiansheng; Zhang, Jianhua

    2006-01-01

    The regulator of G-protein signaling (RGS) proteins, recently identified in Arabidopsis (Arabidopsis thaliana; named as AtRGS1), has a predicted seven-transmembrane structure as well as an RGS box with GTPase-accelerating activity and thus desensitizes the G-protein-mediated signaling. The roles of AtRGS1 proteins in Arabidopsis seed germination and their possible interactions with sugars and abscisic acid (ABA) were investigated in this study. Using seeds that carry a null mutation in the genes encoding RGS protein (AtRGS1) and the α-subunit (AtGPA1) of the G protein in Arabidopsis (named rgs1-2 and gpa1-3, respectively), our genetic evidence proved the involvement of the AtRGS1 protein in the modulation of seed germination. In contrast to wild-type Columbia-0 and gpa1-3, stratification was found not to be required and the after-ripening process had no effect on the rgs1-2 seed germination. In addition, rgs1-2 seed germination was insensitive to glucose (Glc) and sucrose. The insensitivities of rgs1-2 to Glc and sucrose were not due to a possible osmotic stress because the germination of rgs1-2 mutant seeds showed the same response as those of gpa1-3 mutants and wild type when treated with the same concentrations of mannitol and sorbitol. The gpa1-3 seed germination was hypersensitive while rgs1-2 was less sensitive to exogenous ABA. The different responses to ABA largely diminished and the inhibitory effects on seed germination by exogenous ABA and Glc were markedly alleviated when endogenous ABA biosynthesis was inhibited. Hypersensitive responses of seed germination to both Glc and ABA were also observed in the overexpressor of AtRGS1. Analysis of the active endogenous ABA levels and the expression of NCED3 and ABA2 genes showed that Glc significantly stimulated the ABA biosynthesis and increased the expression of NCED3 and ABA2 genes in germinating Columbia seeds, but not in rgs1-2 mutant seeds. These data suggest that AtRGS1 proteins are involved in the

  6. Fungal endophytes from seeds of invasive, non-native Phragmites australis and their potential role in germination and seedling growth

    USGS Publications Warehouse

    Shearin, Zackery R. C.; Filipek, Matthew; Desai, Rushvi; Bickford, Wesley A.; Kowalski, Kurt P.; Clay, Keith

    2018-01-01

    Background and aimsWe characterized fungal endophytes of seeds of invasive, non-native Phragmites from three sites in the Great Lakes region to determine if fungal symbiosis could contribute to invasiveness through their effects on seed germination and seedling growth.MethodsField-collected seeds were surface sterilized and plated on agar to culture endophytes for ITS sequencing. Prevalence of specific endophytes from germinated and non-germinated seeds, and from seedlings, was compared.ResultsOne-third of 740 seeds yielded endophyte isolates. Fifteen taxa were identified with Alternaria sp. representing 54% of all isolates followed by Phoma sp. (21%) and Penicillium corylophilum (12%). Overall germination of seeds producing an isolate (36%) was significantly higher than seeds not producing an isolate (20%). Penicillium in particular was strongly associated with increased germination of seeds from one site. Sixty-three isolates and 11 taxa were also obtained from 30 seedlings where Phoma, Penicillium and Alternaria respectively were most prevalent. There was a significant effect of isolating an endophyte from the seed on seedling growth.ConclusionsThese results suggest that many endophyte taxa are transmitted in seeds and can increase seed germination and seedling growth of invasive Phragmites. The role of fungal endophytes in host establishment, growth and invasiveness in nature requires further research.

  7. 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

  8. [Effect of decimeter polarized electromagnetic radiation on germinating capacity of seeds].

    PubMed

    Polevik, N D

    2013-01-01

    The effect of a polarization structure of electromagnetic radiation on the germinating capacity of seeds of such weeds as Green foxtail (Setaria viridis) and Green amaranth (Amaranthus retroflexus) has been studied. Seeds have been exposed to impulse electromagnetic radiation in a frequency of 896 MHz with linear, elliptical right-handed and elliptical left-handed polarizations at different power flux density levels. It is determined that the effect of the right-handed polarized electromagnetic radiation increases and the influence of the left-handed polarized one reduces the germinating capacity of seeds compared to the effect of the linearly polarized electromagnetic radiation. It is shown that the seeds have an amplitude polarization selectivity as evinced by the major effect of the right-handed polarized radiation on seeds. An electrodynamic model as the right-handed elliptically polarized antenna with the given quantity of the ellipticity of polarization is suggested to use in description of this selectivity.

  9. The fluxes of H2O2 and O2 can be used to evaluate seed germination and vigor of Caragana korshinskii.

    PubMed

    Li, Jiaguo; Wang, Yu; Pritchard, Hugh W; Wang, Xiaofeng

    2014-06-01

    Seed deterioration is detrimental to plant germplasm conservation, and predicting seed germination and vigor with reliability and sensitivity means is urgently needed for practical problems. We investigated the link between hydrogen peroxide (H2O2) flux, oxygen influx and seed vigor of Caragana korshinskii by the non-invasive micro-test technique (NMT). Some related physiological and biochemical changes in seeds were also determined to further explain the changes in the molecular fluxes. The results showed that there was a good linear relationship between germination and H2O2 flux, and that O2 influx was more suitable for assessing seed vigor. H2O2 flux changed relatively little initially, mainly affected by antioxidants (APX, CAT and GSH) and H2O2 content; afterward, the efflux increased more and more rapidly due to high membrane permeability. With the damage of mitochondrial respiration and membrane integrity, O2 influx was gradually reduced. We propose that monitoring H2O2 and O2 fluxes by NMT may be a reliable and sensitive method to evaluate seed germination and vigor.

  10. Successional Distance between the Source and Recipient Influence Seed Germination and Seedling Survival during Surface Soil Replacement in SW China

    PubMed Central

    Shen, You-xin; Gao, Lei; Xia, Xue; Li, Yuhui; Guan, Huilin

    2013-01-01

    Adding propagules (source) to a degraded site (recipient) is a common way of manipulating secondary succession to restore diversity and services formerly provided by forests. However, heretofore no study has considered the effect of “successional distance” between source and recipient site. Four sites in the Shilin karst area of SW China were treated as different states along a secondary successional sere: grass, shrub, young secondary forest, and primary forest. Ten 1 m ×1m soil quadrats in the grass, shrub and young forest sites were replaced with 10 cm deep soil sources from corresponding later successional stage(s) in January 2009. Woody plant seed germination was monitored in the first year and seedling survival was monitored until the end of the second year. At the end of 2010, 2097 seeds of woody plants belonging to 45 taxa had germinated, and 3.9% of the seedlings and 7.8% of the species survived. Germination of most species was sensitive to ambient light (red, far-red, R:FR ratios, photosynthetically active radiation). Soil source and recipient site had a significant effect on the total number of seeds and number of species that germinated, and on the percentage of seedlings that survived through the end of the second year. Closer successional stages between recipient site and soil source had higher seed germination and seedling-survival percentages. However, a transition threshold exists in the young forest state, where seeds can germinate but not survive the second year. Our results, although based on an unreplicated chronosequence, suggest that successional distance between soil sources and recipient sites affect forest recruitment and restoration in degraded karst of SW China. PMID:24223891

  11. Influence of pulsed magnetic field on soybean (Glycine max L.) seed germination, seedling growth and soil microbial population.

    PubMed

    Radhakrishnan, Ramalingam; Kumari, Bollipo Dyana Ranjitha

    2013-08-01

    The effects of pulsed magnetic field (PMF) treatment of soybean (Glycine max L. cv CO3) seeds were investigated on rate of seed germination, seedling growth, physico-chemical properties of seed leachates and soil microbial population under laboratory conditions. Seeds were exposed to PMF of 1500 nT at 0.1, 1.0 10.0 and 100.0 Hz for 5 h per day for 20 days, induced by enclosure coil systems. Non-treated seeds were considered as controls. All PMF treatments significantly increased the rate of seed germination, while 10 and 100 Hz PMFs showed the most effective response. The 1.0 and 10 Hz PMFs remarkably improved the fresh weight of shoots and roots, leaf area and plant height from seedlings from magnetically-exposed seeds compared to the control, while 10 Hz PMF increased the total soluble sugar, total protein and phenol contents. The leaf chlorophyll a, b and total chlorophyll were higher in PMF (10 and 100 Hz) pretreated plants, as compared to other treatments. In addition, activities of alpha-amylase, acid phosphatase, alkaline phosphatase, nitrate reductase, peroxidase and polyphenoloxidase were increased, while beta-amylase and protease activities were declined in PMF (10 Hz)-exposed soybean plants. Similarly, the capacity of absorbance of water by seeds and electrical conductivity of seed leachates were significantly enhanced by 10 Hz PMF exposure, whereas PMF (10 Hz) pretreated plants did not affect the microbial population in rhizosphere soil. The results suggested the potential of 10 Hz PMF treatment to enhance the germination and seedling growth of soybean.

  12. Modeling analysis on germination and seedling growth using ultrasound seed pretreatment in switchgrass.

    PubMed

    Wang, Quanzhen; Chen, Guo; Yersaiyiti, Hayixia; Liu, Yuan; Cui, Jian; Wu, Chunhui; Zhang, Yunwei; He, Xueqing

    2012-01-01

    Switchgrass is a perennial C4 plant with great potential as a bioenergy source and, thus, a high demand for establishment from seed. This research investigated the effects of ultrasound treatment on germination and seedling growth in switchgrass. Using an orthogonal matrix design, conditions for the ultrasound pretreatment in switchgrass seed, including sonication time (factor A), sonication temperature (factor B) and ultrasound output power (factor C), were optimized for germinating and stimulating seedling growth (indicated as plumular and radicular lengths) through modeling analysis. The results indicate that sonication temperature (B) was the most effective factor for germination, whereas output power (C) had the largest effect on seedling growth when ultrasound treatment was used. Combined with the analyses of range, variance and models, the final optimal ultrasonic treatment conditions were sonication for 22.5 min at 39.7°C and at an output power of 348 W, which provided the greatest germination percentage and best seedling growth. For this study, the orthogonal matrix design was an efficient method for optimizing the conditions of ultrasound seed treatment on switchgrass. The electrical conductivity of seed leachates in three experimental groups (control, soaked in water only, and ultrasound treatment) was determined to investigate the effects of ultrasound on seeds and eliminate the effect of water in the ultrasound treatments. The results showed that the electrical conductivity of seed leachates during either ultrasound treatment or water bath treatment was significantly higher than that of the control, and that the ultrasound treatment had positive effects on switchgrass seeds.

  13. Germination of vegetable seeds exposed to very high pressure

    NASA Astrophysics Data System (ADS)

    Mori, Y.; Yokota, S.; Ono, F.

    2012-07-01

    Effects of high hydrostatic pressure were investigated on vegetable seeds in the GPa range to examine the potentialities of breed improvement by high-pressure processing. Specimens of several seeds of broccoli (Brassica oleracea var. italica), Turnip leaf (Brassica rapa var. perviridis) and Potherb Mustard (Brassica rapa var. nipposinica) were put in a teflon capsule with liquid high pressure medium, fluorinate, and inserted into a pyrophillite cube. By using a cubic anvil press a hydrostatic pressure of 5.5 GP a was applied to these seeds for 15 minutes. After being brought back to ambient pressure, they were seeded on humid soil in a plant pot. Many of these vegetable seeds began to germinate within 6 days after seeded.

  14. The Transcriptional Coregulator LEUNIG_HOMOLOG Inhibits Light-Dependent Seed Germination in Arabidopsis

    PubMed Central

    Lee, Nayoung; Park, Jeongmoo; Kim, Keunhwa; Choi, Giltsu

    2015-01-01

    PHYTOCHROME-INTERACTING FACTOR1 (PIF1) is a basic helix-loop-helix transcription factor that inhibits light-dependent seed germination in Arabidopsis thaliana. However, it remains unclear whether PIF1 requires other factors to regulate its direct targets. Here, we demonstrate that LEUNIG_HOMOLOG (LUH), a Groucho family transcriptional corepressor, binds to PIF1 and coregulates its targets. Not only are the transcriptional profiles of the luh and pif1 mutants remarkably similar, more than 80% of the seeds of both genotypes germinate in the dark. We show by chromatin immunoprecipitation that LUH binds a subset of PIF1 targets in a partially PIF1-dependent manner. Unexpectedly, we found LUH binds and coregulates not only PIF1-activated targets but also PIF1-repressed targets. Together, our results indicate LUH functions with PIF1 as a transcriptional coregulator to inhibit seed germination. PMID:26276832

  15. Integration of Auxin and Salt Signals by the NAC Transcription Factor NTM2 during Seed Germination in Arabidopsis1[W

    PubMed Central

    Park, Jungmin; Kim, Youn-Sung; Kim, Sang-Gyu; Jung, Jae-Hoon; Woo, Je-Chang; Park, Chung-Mo

    2011-01-01

    Seed germination is regulated through elaborately interacting signaling networks that integrate diverse environmental cues into hormonal signaling pathways. Roles of gibberellic acid and abscisic acid in germination have been studied extensively using Arabidopsis (Arabidopsis thaliana) mutants having alterations in seed germination. Auxin has also been implicated in seed germination. However, how auxin influences germination is largely unknown. Here, we demonstrate that auxin is linked via the IAA30 gene with a salt signaling cascade mediated by the NAM-ATAF1/2-CUC2 transcription factor NTM2/Arabidopsis NAC domain-containing protein 69 (for NAC with Transmembrane Motif1) during seed germination. Germination of the NTM2-deficient ntm2-1 mutant seeds exhibited enhanced resistance to high salinity. However, the salt resistance disappeared in the ntm2-1 mutant overexpressing the IAA30 gene, which was induced by salt in a NTM2-dependent manner. Auxin exhibited no discernible effects on germination under normal growth conditions. Under high salinity, however, whereas exogenous application of auxin further suppressed the germination of control seeds, the auxin effects were reduced in the ntm2-1 mutant. Consistent with the inhibitory effects of auxin on germination, germination of YUCCA 3-overexpressing plants containing elevated levels of active auxin was more severely influenced by salt. These observations indicate that auxin delays seed germination under high salinity through cross talk with the NTM2-mediated salt signaling in Arabidopsis. PMID:21450938

  16. [Effects of light intensity on Quercus liaotungensis seed germination and seedling growth].

    PubMed

    Yan, Xing-fu; Wang, Jian-li; Zhou, Li-biao

    2011-07-01

    This paper studied the effects of different shading (55.4%, 18.9%, 5.5%, 2.2%, 0.5% , and 0.3% natural sunlight) on the seed germination and seedling growth of Quercus liaotungensis. The seed germination rate and germination index were the highest (72.5% and 0.22, respectively) at 55.4% natural sunlight, declined with decreasing light intensity, and were the lowest (42.5% and 0.11, respectively) at 0.3% natural sunlight. Strong light had definite delaying effect on the germination. The index of germination vigor increased with decreasing light intensity, being the maximum at 0.5% natural sunlight. The delay of seed germination under strong light could be the selective tradeoff on varied seed fates. Strong light benefited the basal stem diameter and root system growth and dry mass accumulation of Q. liaotunensis seedling, but resulted in the minimum seedlings height (6.06 cm). Greater morphological plasticity was observed for the seedlings under different shading, which lent support to the higher adaptability of the seedlings to light environment. For example, the specific leaf area, specific shoot length, specific root length, and chlorophyll b and total chlorophyll contents were the maximum at 0.5% natural sunlight, being 142.57 cm2 x g(-1), 156.86 cm x g(-1), 271.87 cm x g(-1), 0.07 g x cm(-2), and 0.24 g x cm(-2), respectively, and the minimum at 55.4% natural sunlight, being 44.89 cm2 x g(-1), 52.84 cm x g(-1), 101.98 cm x g(-1), 0.04 g x cm(-2), and 0.15 g x cm(-2), respectively. The variation of the root/shoot ratio of Q. liaotungensis seedlings under different shading could be the effects of the combination of light intensity and water availability.

  17. The COP9 Signalosome regulates seed germination by facilitating protein degradation of RGL2 and ABI5

    PubMed Central

    Li, Bosheng; Bücker, Birte; Keil, Philipp; Zhang, Shaoman; Li, Jigang; Kang, Dingming; Liu, Jie; Dong, Jie; Deng, Xing Wang; Irish, Vivian

    2018-01-01

    The control of seed germination and seed dormancy are critical for the successful propagation of plant species, and are important agricultural traits. Seed germination is tightly controlled by the balance of gibberellin (GA) and abscisic acid (ABA), and is influenced by environmental factors. The COP9 Signalosome (CSN) is a conserved multi-subunit protein complex that is best known as a regulator of the Cullin-RING family of ubiquitin E3 ligases (CRLs). Multiple viable mutants of the CSN showed poor germination, except for csn5b-1. Detailed analyses showed that csn1-10 has a stronger seed dormancy, while csn5a-1 mutants exhibit retarded seed germination in addition to hyperdormancy. Both csn5a-1 and csn1-10 plants show defects in the timely removal of the germination inhibitors: RGL2, a repressor of GA signaling, and ABI5, an effector of ABA responses. We provide genetic evidence to demonstrate that the germination phenotype of csn1-10 is caused by over-accumulation of RGL2, a substrate of the SCF (CRL1) ubiquitin E3 ligase, while the csn5a-1 phenotype is caused by over-accumulation of RGL2 as well as ABI5. The genetic data are consistent with the hypothesis that CSN5A regulates ABI5 by a mechanism that may not involve CSN1. Transcriptome analyses suggest that CSN1 has a more prominent role than CSN5A during seed maturation, but CSN5A plays a more important role than CSN1 during seed germination, further supporting the functional distinction of these two CSN genes. Our study delineates the molecular targets of the CSN complex in seed germination, and reveals that CSN5 has additional functions in regulating ABI5, thus the ABA signaling pathway. PMID:29462139

  18. Germination and seedling development

    USDA-ARS?s Scientific Manuscript database

    Cottonseed germination and seedling development are highly sensitive to the environment at planting and for several weeks after that. Major factors that affect germination and development are temperature, water availability, soil conditions such as compaction, rhizosphere gases, and seed and seedlin...

  19. Effect of Germination and Fermentation on Carbohydrate Composition of Australian Sweet Lupin and Soybean Seeds and Flours.

    PubMed

    Kaczmarska, Kornelia T; Chandra-Hioe, Maria V; Zabaras, Dimitrios; Frank, Damian; Arcot, Jayashree

    2017-11-22

    This study investigated the effect of germination and fermentation on the composition of carbohydrates in Australian sweet lupin. Specifically, the amount of sugars (sucrose, fructose, and glucose), starch, oligosaccharides (verbascose, stachyose, and raffinose), and dietary fiber were measured in germinated lupin seeds and fermented lupin flour, and compared with those in soy. High performance liquid chromatography coupled with refractive index was employed for quantitation of sugars, starch, and oligosaccharides, and gas chromatography coupled with a flame ionization detector was used for quantitation of simple sugars in total, and soluble, and insoluble dietary fiber. The enzyme activities of α-amylase and α-glucosidase were compared before and after germination or fermentation. The α-amylase activity in germinated lupin increased to  ∼17 nmol/mL/min/0.1 g and in germinated soy∼32; in fermented lupin, the activity increased to ∼52, while in fermented soy it decreased to ∼20. In general, germination or fermentation decreased the oligosaccharide content, and increased the total sugar in samples (p < 0.05). Total oligosaccharides in lupin after uncontrolled germination were reduced by 98% to 6 mg/g, and after controlled germination reduced by 44% to 86 mg/g. Fermentation with yogurt culture lowered the content of total oligosaccharides due to 94% decrease in stachyose. Total oligosaccharides in soy flour prior to fermentation were 180 mg/g and significantly decreased to ∼124 mg/g in fermented soy. Germination did not affect the starch content. There was no significant change in the amounts of total, soluble, and insoluble dietary fiber after germination or fermentation of lupin except for galactose, which was significantly reduced in germinated lupin seeds. Soluble dietary fiber in germinated soy significantly increased. Germination and fermentation are simple and effective techniques to reduce the oligosaccharides while maintaining the composition of

  20. Influences of Air, Oxygen, Nitrogen, and Carbon Dioxide Nanobubbles on Seed Germination and Plant Growth.

    PubMed

    Ahmed, Ahmed Khaled Abdella; Shi, Xiaonan; Hua, Likun; Manzueta, Leidy; Qing, Weihua; Marhaba, Taha; Zhang, Wen

    2018-05-23

    Nanobubbles (NBs) hold promise in green and sustainable engineering applications in diverse fields (e.g., water/wastewater treatment, food processing, medical applications, and agriculture). This study investigated the effects of four types of NBs on seed germination and plant growth. Air, oxygen, nitrogen, and carbon dioxide NBs were generated and dispersed in tap water. Different plants, including lettuce, carrot, fava bean, and tomato, were used in germination and growth tests. The seeds in water-containing NBs exhibited 6-25% higher germination rates. Especially, nitrogen NBs exhibited considerable effects in the seed germination, whereas air and carbon dioxide NBs did not significantly promote germination. The growth of stem length and diameter, leave number, and leave width were promoted by NBs (except air). Furthermore, the promotion effect was primarily ascribed to the generation of exogenous reactive oxygen species by NBs and higher efficiency of nutrient fixation or utilization.

  1. The community-level effect of light on germination timing in relation to seed mass: a source of regeneration niche differentiation.

    PubMed

    Zhang, Chunhui; Willis, Charles G; Burghardt, Liana T; Qi, Wei; Liu, Kun; Souza-Filho, Paulo Roberto de Moura; Ma, Zhen; Du, Guozhen

    2014-11-01

    Within a community, species may germinate at different times so as to mitigate competition and to take advantage of different aspects of the seasonal environment (temporal niche differentiation). We illustrated a hypothesis of the combined effects of abiotic and biotic competitive factors on germination timing and the subsequent upscale effects on community assembly. We estimated the germination timing (GT) for 476 angiosperm species of the eastern Tibetan Plateau grasslands under two light treatments in the field: high (i.e. natural) light and low light. We also measured the shift in germination timing (SGT) across treatments for all species. Furthermore, we used phylogenetic comparative methods to test if GT and SGT were associated with seed mass, an important factor in competitive interactions. We found a significant positive correlation between GT and seed mass in both light treatments. Additionally, small seeds (early germinating seeds) tended to germinate later and large seeds (late germinating seeds) tended to germinate earlier under low light vs high light conditions. Low light availability can reduce temporal niche differentiation by increasing the overlap in germination time between small and large seeds. In turn, reduced temporal niche differentiation may increase competition in the process of community assembly. © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.

  2. Seed Germination Ecology of the Cold Desert Annual Isatis violascens (Brassicaceae): Two Levels of Physiological Dormancy and Role of the Pericarp

    PubMed Central

    Tan, Dun Y.; Baskin, Carol C.; Baskin, Jerry M.

    2015-01-01

    The occurrence of various species of Brassicaceae with indehiscent fruits in the cold deserts of NW China suggests that there are adaptive advantages of this trait. We hypothesized that the pericarp of the single-seeded silicles of Isatis violascens restricts embryo expansion and thus prevents germination for 1 or more years. Thus, our aim was to investigate the role of the pericarp in seed dormancy and germination of this species. The effects of afterripening, treatment with gibberellic acid (GA3) and cold stratification on seed dormancy-break were tested using intact silicles and isolated seeds, and germination phenology was monitored in an experimental garden. The pericarp has a role in mechanically inhibiting germination of fresh seeds and promotes germination of nondormant seeds, but it does not facilitate formation of a persistent seed bank. Seeds in silicles in watered soil began to germinate earlier in autumn and germinated to higher percentages than isolated seeds. Sixty-two percent of seeds in the buried silicles germinated by the end of the first spring, and only 3% remained nongerminated and viable. Twenty to twenty-five percent of the seeds have nondeep physiological dormancy (PD) and 75–80% intermediate PD. Seeds with nondeep PD afterripen in summer and germinate inside the silicles in autumn if the soil is moist. Afterripening during summer significantly decreased the amount of cold stratification required to break intermediate PD. The presence of both nondeep and intermediate PD in the seed cohort may be a bet-hedging strategy. PMID:26513241

  3. Accumulation of long-lived mRNAs associated with germination in embryos during seed development of rice

    PubMed Central

    Sano, Naoto; Ono, Hanako; Murata, Kazumasa; Yamada, Tetsuya; Hirasawa, Tadashi; Kanekatsu, Motoki

    2015-01-01

    Mature dry seeds contain translatable mRNAs called long-lived mRNAs. Early studies have shown that protein synthesis during the initial phase of seed germination occurs from long-lived mRNAs, without de novo transcription. However, the gene expression systems that generate long-lived mRNAs in seeds are not well understood. To examine the accumulation of long-lived mRNAs in developing rice embryos, germination tests using the transcriptional inhibitor actinomycin D (Act D) were performed with the Japonica rice cultivar Nipponbare. Although over 70% of embryos at 10 days after flowering (DAF) germinated in the absence of the inhibitor, germination was remarkably impaired in embryos treated with Act D. In contrast, more than 70% of embryos at 20, 25, 30 and 40 DAF germinated in the presence of Act D. The same results were obtained when another cultivar, Koshihikari, was used, indicating that the long-lived mRNAs required for germination predominantly accumulate in embryos between 10 and 20 DAF during seed development. RNA-Seq identified 529 long-lived mRNA candidates, encoding proteins such as ABA, calcium ion and phospholipid signalling-related proteins, and HSP DNA J, increased from 10 to 20 DAF and were highly abundant in 40 DAF embryos of Nipponbare and Koshihikari. We also revealed that these long-lived mRNA candidates are clearly up-regulated in 10 DAF germinating embryos after imbibition, suggesting that the accumulation of these mRNAs in embryos is indispensable for the induction of germination. The findings presented here may facilitate in overcoming irregular seed germination or producing more vigorous seedlings. PMID:25941326

  4. Impact of sunflower (Helianthus annuus L.) extracts upon reserve mobilization and energy metabolism in germinating mustard (Sinapis alba L.) seeds.

    PubMed

    Kupidłowska, Ewa; Gniazdowska, Agnieszka; Stepień, Joanna; Corbineau, Francoise; Vinel, Dominique; Skoczowski, Andrzej; Janeczko, Anna; Bogatek, Renata

    2006-12-01

    One commonly observed effect of phytotoxic compounds is the inhibition or delay of germination of sensitive seeds. Mustard (Sinapis alba L.) seeds were incubated with aqueous extracts of sunflower (Helianthus annuus L.) leaves. Although sunflower phytotoxins did not influence seed viability, extracts completely inhibited seed germination. Inhibition of germination was associated with alterations in reserve mobilization and generation of energy in the catabolic phase of germination. Degradation of lipids was suppressed by sunflower foliar extracts resulting in insufficient carbohydrate supply. The lack of respiratory substrates and decrease in energy (ATP) generation resulted in suppression of the anabolic phase of seed germination and ultimately growth inhibition.

  5. Β-Amylase from Starchless Seeds of Trigonella Foenum-Graecum and Its Localization in Germinating Seeds

    PubMed Central

    Srivastava, Garima; Kayastha, Arvind M.

    2014-01-01

    Fenugreek (Trigonella foenum-graecum) seeds do not contain starch as carbohydrate reserve. Synthesis of starch is initiated after germination. A β-amylase from ungerminated fenugreek seeds was purified to apparent electrophoretic homogeneity. The enzyme was purified 210 fold with specific activity of 732.59 units/mg. Mr of the denatured enzyme as determined from SDS-PAGE was 58 kD while that of native enzyme calculated from size exclusion chromatography was 56 kD. Furthermore, its identity was confirmed to be β-amylase from MALDI-TOF analysis. The optimum pH and temperature was found to be 5.0 and 50°C, respectively. Starch was hydrolyzed at highest rate and enzyme showed a Km of 1.58 mg/mL with it. Antibodies against purified Fenugreek β-amylase were generated in rabbits. These antibodies were used for localization of enzyme in the cotyledon during different stages of germination using fluorescence and confocal microscopy. Fenugreek β-amylase was found to be the major starch degrading enzyme depending on the high amount of enzyme present as compared to α-amylase and also its localization at the periphery of amyloplasts. A new finding in terms of its association with protophloem was observed. Thus, this enzyme appears to be important for germination of seeds. PMID:24551136

  6. Evaluation of Exotically-Derived Soybean Breeding Lines for Seed Yield, Germination, Damage, and Composition under Dryland Production in the Midsouthern USA

    PubMed Central

    Bellaloui, Nacer; Smith, James R.; Mengistu, Alemu; Ray, Jeffery D.; Gillen, Anne M.

    2017-01-01

    Although the Early Soybean Production System (ESPS) in the Midsouthern USA increased seed yield under irrigated and non-irrigated conditions, heat stress and drought still lead to poor seed quality in heat sensitive soybean cultivars. Our breeding goal was to identify breeding lines that possess high germination, nutritional quality, and yield potential under high heat and dryland production conditions. Our hypothesis was that breeding lines derived from exotic germplasm might possess physiological and genetic traits allowing for higher seed germinability under high heat conditions. In a 2-year field experiment, breeding lines derived from exotic soybean accessions, previously selected for adaptability to the ESPS in maturity groups (MG) III and IV, were grown under non-irrigated conditions. Results showed that three exotic breeding lines had consistently superior germination across 2 years. These lines had a mean germination percentage of >80%. Two (25-1-1-4-1-1 and 34-3-1-2-4-1) out of the three lines with ≥80% germination in both years maintained high seed protein, oleic acid, N, P, K, B, Cu, and Mo in both years. Significant (P < 0.05) positive correlations were found between germination and oleic acid and with K and Cu in both years. Significant negative correlations were found between germination and linoleic acid, Ca, and hard seed in both years. There were positive correlations between germination and N, P, B, Mo, and palmitic acid only in 2013. A negative correlation was found between germination and green seed damage and linolenic acid in 2013 only. Seed wrinkling was significantly negatively correlated with germination in 2012 only. A lower content of Ca in the seed of high germinability genotypes may explain the lower rates of hard seed in those lines, which could lead to higher germination. Many of the differences in yield, germination, diseases, and seed composition between years are likely due to heat and rainfall differences between years. The

  7. Seed dimorphism, nutrients and salinity differentially affect seed traits of the desert halophyte Suaeda aralocaspica via multiple maternal effects.

    PubMed

    Wang, Lei; Baskin, Jerry M; Baskin, Carol C; Cornelissen, J Hans C; Dong, Ming; Huang, Zhenying

    2012-09-25

    Maternal effects may influence a range of seed traits simultaneously and are likely to be context-dependent. Disentangling the interactions of plant phenotype and growth environment on various seed traits is important for understanding regeneration and establishment of species in natural environments. Here, we used the seed-dimorphic plant Suaeda aralocaspica to test the hypothesis that seed traits are regulated by multiple maternal effects. Plants grown from brown seeds had a higher brown:black seed ratio than plants from black seeds, and germination percentage of brown seeds was higher than that of black seeds under all conditions tested. However, the coefficient of variation (CV) for size of black seeds was higher than that of brown seeds. Seeds had the smallest CV at low nutrient and high salinity for plants from brown seeds and at low nutrient and low salinity for plants from black seeds. Low levels of nutrients increased size and germinability of black seeds but did not change the seed morph ratio or size and germinability of brown seeds. High levels of salinity decreased seed size but did not change the seed morph ratio. Seeds from high-salinity maternal plants had a higher germination percentage regardless of level of germination salinity. Our study supports the multiple maternal effects hypothesis. Seed dimorphism, nutrient and salinity interacted in determining a range of seed traits of S. aralocaspica via bet-hedging and anticipatory maternal effects. This study highlights the importance of examining different maternal factors and various offspring traits in studies that estimate maternal effects on regeneration.

  8. Seed dimorphism, nutrients and salinity differentially affect seed traits of the desert halophyte Suaeda aralocaspica via multiple maternal effects

    PubMed Central

    2012-01-01

    Background Maternal effects may influence a range of seed traits simultaneously and are likely to be context-dependent. Disentangling the interactions of plant phenotype and growth environment on various seed traits is important for understanding regeneration and establishment of species in natural environments. Here, we used the seed-dimorphic plant Suaeda aralocaspica to test the hypothesis that seed traits are regulated by multiple maternal effects. Results Plants grown from brown seeds had a higher brown:black seed ratio than plants from black seeds, and germination percentage of brown seeds was higher than that of black seeds under all conditions tested. However, the coefficient of variation (CV) for size of black seeds was higher than that of brown seeds. Seeds had the smallest CV at low nutrient and high salinity for plants from brown seeds and at low nutrient and low salinity for plants from black seeds. Low levels of nutrients increased size and germinability of black seeds but did not change the seed morph ratio or size and germinability of brown seeds. High levels of salinity decreased seed size but did not change the seed morph ratio. Seeds from high-salinity maternal plants had a higher germination percentage regardless of level of germination salinity. Conclusions Our study supports the multiple maternal effects hypothesis. Seed dimorphism, nutrient and salinity interacted in determining a range of seed traits of S. aralocaspica via bet-hedging and anticipatory maternal effects. This study highlights the importance of examining different maternal factors and various offspring traits in studies that estimate maternal effects on regeneration. PMID:23006315

  9. Effects of cold plasma treatment on seed germination and seedling growth of soybean

    PubMed Central

    Ling, Li; Jiafeng, Jiang; Jiangang, Li; Minchong, Shen; Xin, He; Hanliang, Shao; Yuanhua, Dong

    2014-01-01

    Effects of cold plasma treatment on soybean (Glycine max L. Merr cv. Zhongdou 40) seed germination and seedling growth were studied. Seeds were pre-treated with 0, 60, 80, 100 and 120 W of cold plasma for 15 s. Results showed that plasma treatments had positive effects on seed germination and seedling growth, and treatment of 80 W had the highest stimulatory effect. Germination and vigor indices significantly increased by 14.66% and 63.33%, respectively. Seed's water uptake improved by 14.03%, and apparent contact angle decreased by 26.19%. Characteristics of seedling growth, including shoot length, shoot dry weight, root length and root dry weight, significantly increased by 13.77%, 21.95%, 21.42% and 27.51%, respectively, compared with control. The seed reserve utilization, including weight of the mobilized seed reserve, seed reserve depletion percentage and seed reserve utilization efficiency significantly improved by cold plasma treatment. In addition, soluble sugar and protein contents were 16.51% and 25.08% higher than those of the control. Compared to a 21.95% increase in shoot weight, the root weight increased by 27.51% after treatment, indicating that plasma treatment had a greater stimulatory effect on plant roots. These results indicated that cold plasma treatment might promote the growth even yield of soybean. PMID:25080862

  10. [Determination of benzopyrene in the seeds of plants before and after their germination].

    PubMed

    Vettig, K; Gel'bert, G; Shabad, L M; Khesina, A Ia

    1976-01-01

    The possibility of BP synthesis in plants was studied. Seeds of pea, lupine, rye, oats, garden-cress were investigated in hydroponic systems with substrates containing carbon and without it. The results indicated that the quantity of BP in the seeds increased in the course of germination in solutions with carbon from 1 to 7 mug/Kg of dry weight. No increase of BP was observed after germination in media without carbon.

  11. Salt Stress and Ethylene Antagonistically Regulate Nucleocytoplasmic Partitioning of COP1 to Control Seed Germination.

    PubMed

    Yu, Yanwen; Wang, Juan; Shi, Hui; Gu, Juntao; Dong, Jingao; Deng, Xing Wang; Huang, Rongfeng

    2016-04-01

    Seed germination, a critical stage initiating the life cycle of a plant, is severely affected by salt stress. However, the underlying mechanism of salt inhibition of seed germination (SSG) is unclear. Here, we report that the Arabidopsis (Arabidopsis thaliana) CONSTITUTIVE PHOTOMORPHOGENESIS1 (COP1) counteracts SSG Genetic assays provide evidence that SSG in loss of function of the COP1 mutant was stronger than this in the wild type. A GUS-COP1 fusion was constitutively localized to the nucleus in radicle cells. Salt treatment caused COP1 to be retained in the cytosol, but the addition of ethylene precursor 1-aminocyclopropane-1-carboxylate had the reverse effect on the translocation of COP1 to the nucleus, revealing that ethylene and salt exert opposite regulatory effects on the localization of COP1 in germinating seeds. However, loss of function of the ETHYLENE INSENSITIVE3 (EIN3) mutant impaired the ethylene-mediated rescue of the salt restriction of COP1 to the nucleus. Further research showed that the interaction between COP1 and LONG HYPOCOTYL5 (HY5) had a role in SSG Correspondingly, SSG in loss of function of HY5 was suppressed. Biochemical detection showed that salt promoted the stabilization of HY5, whereas ethylene restricted its accumulation. Furthermore, salt treatment stimulated and ethylene suppressed transcription of ABA INSENSITIVE5 (ABI5), which was directly transcriptionally regulated by HY5. Together, our results reveal that salt stress and ethylene antagonistically regulate nucleocytoplasmic partitioning of COP1, thereby controlling Arabidopsis seed germination via the COP1-mediated down-regulation of HY5 and ABI5. These findings enhance our understanding of the stress response and have great potential for application in agricultural production. © 2016 American Society of Plant Biologists. All Rights Reserved.

  12. Arabidopsis DET1 degrades HFR1 but stabilizes PIF1 to precisely regulate seed germination

    PubMed Central

    Shi, Hui; Wang, Xin; Mo, Xiaorong; Tang, Chao; Zhong, Shangwei; Deng, Xing Wang

    2015-01-01

    Seed is an essential propagation organ and a critical strategy adopted by terrestrial flowering plants to colonize the land. The ability of seeds to accurately respond to light is vital for plant survival. However, the underlying mechanism is largely unknown. In this study, we reveal a circuit of triple feed-forward loops adopted by Arabidopsis seeds to exclusively repress germination in dark conditions and precisely initiate germination under diverse light conditions. We identify that de-etiolated 1 (DET1), an evolutionarily conserved protein, is a central repressor of light-induced seed germination. Genetic analysis demonstrates that DET1 functions upstream of long hypocotyl in far-red 1 (HFR1) and phytochrome interacting factor 1 (PIF1), the key positive and negative transcription regulators in seed germination. We further find that DET1 and constitutive photomorphogenic 10 (COP10) target HFR1 for protein degradation by assembling a COP10–DET1–damaged DNA binding protein 1–cullin4 E3 ligase complex. Moreover, DET1 and COP10 directly interact with and promote the protein stability of PIF1. Computational modeling reveals that phytochrome B (phyB)–DET1–HFR1–PIF1 and phyB–DET1–Protease–PIF1 are new signaling pathways, independent of the previously identified phyB-PIF1 pathway, respectively mediating the rapid and time-lapse responses to light irradiation. The model-simulated results are highly consistent with their experimental validations, suggesting that our mathematical model captures the essence of Arabidopsis seed germination networks. Taken together, this study provides a comprehensive molecular framework for light-regulated seed germination, improving our understanding of how plants respond to changeable environments. PMID:25775589

  13. Does smoke promote seed germination in 10 Interior West Penstemon species?

    Treesearch

    Paula J. Fornwalt

    2015-01-01

    Recent research has shown that exposing seeds to smoke stimulates germination for a multitude of plant species, including several species in the genus Penstemon (Scrophulariaceae). I evaluated whether smoke, either alone or followed by 10 wk of stratification (moist prechilling), influenced germination for 10 Penstemon species native to the Interior West of North...

  14. In vitro propagation of the Garden Heliotrope, Valeriana officinalis L.: influence of pre-chilling and light on seed germination.

    PubMed

    Bhat, B; Sharma, V D

    2015-03-01

    Valeriana officinalis is an important medicinal herb commonly found in Kashmir valley. This study forms an important preliminary step for in-vitro micro propagation of V. officinalis from breaking the seed dormancy, inducing rapid seed germination and its subsequent micro propagation. We investigated the influence of pretreatment of V. officinalis seeds with reduced temperature and light on seed germination and in-vitro propagation. Culture of explants from cultivated seeds have demonstrated its potential for in vitro propagation and plantlet regeneration. Individual as well as combinations of treatments such as temperature and light availability influenced the germination of seeds variedly. Unchilled seeds of V. officinalis were given dip in GA3 (200 ppm) for 24, 48 and 120 h. Seeds treated with GA3 for 24 h and kept in darkness showed the best results, i.e. 48%. Seeds pretreated with GA3 for 120 h and incubated in dark showed 40% germination. Pre-chilling up to 72 h and kept in light showed maximum germination of 60% followed by 40% kept in darkness. Pre-chilling for 48 h resulted in 40 and 25% seed germination in light and darkness, respectively. GA3 pre-treatment for 72 h and 24 h pre chilling were most effective in inducing seed germination. Maximum shoot response was obtained on MS enriched with BAP (1 mg/L) + IAA (0.1 mg/L) combinations using shoot tips as explants. Multiple shoot regeneration from shoot apices was recorded on BAP (1 mg/L) and BAP (1 mg/L) + IAA (0.1 mg/L).

  15. HFR1 Sequesters PIF1 to Govern the Transcriptional Network Underlying Light-Initiated Seed Germination in Arabidopsis[C][W][OPEN

    PubMed Central

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

    2013-01-01

    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. PMID:24179122

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

    PubMed

    Yuan, Xia; Wen, Bin

    2018-01-01

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

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

    PubMed Central

    Yuan, Xia

    2018-01-01

    Crassocephalum crepidioides, Conyza canadensis, and Ageratum conyzoides are alien annuals naturalized in China, which produce a large number of viable seeds every year. They widely grow in Xishuangbanna, becoming troublesome weeds that compete with crops for water and nutrients. As seed germination is among the most important life-stages which contribute to plant distribution and invasiveness, its adaptation to temperature and water stress were investigated in these three species. Results showed that: (1) These three species have wide temperature ranges to allow seed germination, i.e., high germination and seedling percentages were achieved between 15°C and 30°C, but germination was seriously inhibited at 35°C; only A. conyzoides demonstrated relative preference for warmer temperatures with approximately 25% germination and seedling percentage at 35°C; (2) light was a vital germination prerequisite for C. crepidioides and A. conyzoides, whereas most C. canadensis seeds germinated in full darkness; (3) Although all three species have good adaptation to bare ground habitat characterized by high temperatures and water stress, including their tolerance to soil surface temperatures of 70°C in air-dried seeds, A. conyzoides seeds exhibited higher tolerance to both continuous and daily periodic high-temperature treatment at 40°C, and to water restriction (e.g., ca. 65% seeds germinated to -0.8 MPa created by NaCl), which is consistent with their field behavior in Xishuangbanna. This study suggests that seed high-temperature tolerance contributes to the weed attributes of these three species, and that adaptation to local micro-habitats is a critical determinant for invasiveness of an alien plant. PMID:29364942

  18. Seed priming with iron and zinc in bread wheat: effects in germination, mitosis and grain yield.

    PubMed

    Reis, Sara; Pavia, Ivo; Carvalho, Ana; Moutinho-Pereira, José; Correia, Carlos; Lima-Brito, José

    2018-07-01

    Currently, the biofortification of crops like wheat with micronutrients such as iron (Fe) and zinc (Zn) is extremely important due to the deficiencies of these micronutrients in the human diet and in soils. Agronomic biofortification with Fe and Zn can be done through different exogenous strategies such as soil application, foliar spraying, and seed priming. However, the excess of these micronutrients can be detrimental to the plants. Therefore, in the last decade, a high number of studies focused on the evaluation of their phytotoxic effects to define the best strategies for biofortification of bread wheat. In this study, we investigated the effects of seed priming with different dosages (1 mg L -1 to 8 mg L -1 ) of Fe and/or Zn in germination, mitosis and yield of bread wheat cv. 'Jordão' when compared with control. Overall, our results showed that: micronutrient dosages higher than 4 mg L -1 negatively affect the germination; Fe and/or Zn concentrations higher than 2 mg L -1 significantly decrease the mitotic index and increase the percentage of dividing cells with anomalies; treatments performed with 8 mg L -1 of Fe and/or 8 mg L -1 Zn caused negative effects in germination, mitosis and grain yield. Moreover, seed priming with 2 mg L -1 Fe + 2 mg L -1 Zn has been shown to be non-cytotoxic, ensuring a high rate of germination (80%) and normal dividing cells (90%) as well as improving tillering and grain yield. This work revealed that seed priming with Fe and Zn micronutrients constitutes a useful and alternative approach for the agronomic biofortification of bread wheat.

  19. [Effects of bryophytes in dark coniferous forest of Changbai Mountains on three conifers seed germination and seedling growth].

    PubMed

    Lin, Fei; Hao, Zhanqing; Ye, Ji; Jiang, Ping

    2006-08-01

    This paper studied the effects of Hylocomium splendens and Rhytidiadelphus triquetrus, the main bryophytes in dark coniferous forests of Changbai Mountains, on the seed germination and seedling growth of Pinus koraiensis, Picea koraiensis and Larix olgensis. The results indicated that at definite concentrations, the water extract of H. splendens inhibited Picea koraiensis seed germination, while that of R. triquetrus promoted it. Although the water extracts of the two bryophytes had no obvious effects on the seed germination of Picea koraiensis and Larix olgensis, they expedited the occurrence of the tree species' daily germination peak. The water extracts of test bryophytes inhibited the seedling growth of P. koraiensis and Picea koraiensis, but promoted that of Larix olgensis. The living shoots of the two bryophytes had no obvious effects on the seed germination of Picea koraiensis and Larix olgensis, but delayed the daily germination peak of Picea koraiensis while promoted that of Larix olgensis, andthe killed shoots inhibited the seed germination of all test tree species. Living shoots in larger amounts promoted the seedling growth of Picea koraiensis and Larix olgensis, but killed shoots were inadverse.

  20. Identification of HDA15-PIF1 as a key repression module directing the transcriptional network of seed germination in the dark

    PubMed Central

    Gu, Dachuan; Chen, Chia-Yang; Zhao, Minglei; Zhao, Linmao; Duan, Xuewu

    2017-01-01

    Abstract Light is a major external factor in regulating seed germination. Photoreceptor phytochrome B (PHYB) plays a predominant role in promoting seed germination in the initial phase after imbibition, partially by repressing phytochrome-interacting factor1 (PIF1). However, the mechanism underlying the PHYB-PIF1-mediated transcription regulation remains largely unclear. Here, we identified that histone deacetylase15 (HDA15) is a negative component of PHYB-dependent seed germination. Overexpression of HDA15 in Arabidopsis inhibits PHYB-dependent seed germination, whereas loss of function of HDA15 increases PHYB-dependent seed germination. Genetic evidence indicated that HDA15 acts downstream of PHYB and represses seed germination dependent on PIF1. Furthermore, HDA15 interacts with PIF1 both in vitro and in vivo. Genome-wide transcriptome analysis revealed that HDA15 and PIF1 co-regulate the transcription of the light-responsive genes involved in multiple hormonal signaling pathways and cellular processes in germinating seeds in the dark. In addition, PIF1 recruits HDA15 to the promoter regions of target genes and represses their expression by decreasing the histone H3 acetylation levels in the dark. Taken together, our analysis uncovered the role of histone deacetylation in the light-regulated seed germination process and identified that HDA15-PIF1 acts as a key repression module directing the transcription network of seed germination. PMID:28444370

  1. Seed reserve composition and mobilization during germination and early seedling establishment of Cereus jamacaru D.C. ssp. jamacaru (Cactaceae).

    PubMed

    Alencar, Nara L M; Innecco, Renato; Gomes-Filho, Enéas; Gallão, Maria Izabel; Alvarez-Pizarro, Juan C; Prisco, José T; Oliveira, Alexandre B De

    2012-09-01

    Cereus jamacaru, a Cactaceae found throughout northeast Brazil, is widely used as cattle food and as an ornamental and medicinal plant. However, there has been little information about the physiological and biochemical aspects involved in its germination. The aim of this study was to investigate its reserve mobilization during germination and early seedling growth. For this, C. jamacaru seeds were germinated in a growth chamber and collected at 0, 2, 4, 5, 6, 8 and 12 days after imbibition for morphological and biochemical analyses. Dry seeds had wrinkled seed coats and large, curved embryos. Lipids were the most abundant reserve, comprising approximately 55% and 65% of the dry mass for cotyledons and the hypocotylradicle axis, respectively. Soluble sugars and starch were the minor reserves, corresponding to approximately 2.2% of the cotyledons' dry mass, although their levels showed significant changes during germination. Soluble proteins corresponded to 40% of the cotyledons' dry mass, which was reduced by 81% at the final period of germination compared to dry seeds. C. jamacaru seed can be classified as an oil seed due to its high lipid content. Moreover, lipids were the main reserve mobilized during germination because their levels were strongly reduced after seed germination, while proteins were the second most utilized reserve in this process.

  2. Using atmospheric plasma to increase wettability, imbibition and germination of physically dormant seeds of Mimosa Caesalpiniafolia.

    PubMed

    da Silva, A R M; Farias, M L; da Silva, D L S; Vitoriano, J O; de Sousa, R C; Alves-Junior, C

    2017-09-01

    In this study, we analyzed seed wettability as well as imbibition and germination after treatment with atmospheric pressure cold plasma (APCP) using dielectric barrier discharge (DBD) in seeds that have very low germination rates. To aid industrial applications, several seeds were simultaneously treated with plasma within a space between two coaxial glass tubes sandwiched by two metal mesh screens that produced high-voltage pulses at 17.5kV with a frequency of 990Hz. Three treatment times (3min, 9min and 15min) as well as untreated seeds were used to conduct the wettability, imbibition and germination tests. The wettability and imbibition were found to be directly related to the treatment duration, but saturation of the imbibition was found for treatment durations greater than 9min. Plasma treatment was also effective in improving germination, but shorter treatment duration presented greater germination. This apparent contradiction is explained by the cell damage caused by the increased exposure to plasma, as observed in other studies. The results suggest that there must be an optimal wettability and imbibition condition that ensures that excessive moisture does not harm the germination process. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Germination and Seed Bank Studies of Macbridea alba (Lamiaceae), a Federally Theatened Plant

    Treesearch

    Dana Madsen Schulze; John L. Walker; Timothy P. Spira

    2002-01-01

    Macbridea alba (Lamiaceae) is a Federally threatened plant endemic to Florida. Seedlings are rarely observed in natural populations, but seed production has been documented. We assessed the germinability of dry-stored seeds and of experimentally buried seeds, and sampled soil to detect a persistent seed bank.More than 20% of recorded seeds...

  4. Gibberellic and kaurenoic hybrid strigolactone mimics for seed germination of parasitic weeds.

    PubMed

    Pereira, Rondinelle G; Cala, Antonio; Fernández-Aparicio, Mónica; Molinillo, José Mg; Boaventura, Maria Ad; Macías, Francisco A

    2017-12-01

    Parasitic weeds are widespread and cause significant losses in important crops. Their germination requires the detection of crop-derived molecules such as strigolactones. Strigolactone mimics are germination-inducing molecules with the potential to apply a suicidal germination strategy for seed bank control of parasitic weeds. The D-ring, which is instrumental in the germination process of seeds of parasitic weeds, was attached to gibberellin (GA 3 ) and kaurenoic acid as the scaffold. It was shown that indeed strigolactone mimics prepared from GA 3 and kaurenoic acid are active as stimulants when a D-ring is present; some of the mimics are as active as GR24. The starting molecules were plant hormones that had previous growth-regulating activity in other organisms and the products showed enhanced activity towards parasitic weeds. The information generated may contribute to a better understanding of the germination biochemistry of the weed species used. Further research is required in this area but it is clear that the results are promising. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  5. Analysis of proteome profile in germinating soybean seed, and its comparison with rice showing the styles of reserves mobilization in different crops.

    PubMed

    Han, Chao; Yin, Xiaojian; He, Dongli; Yang, Pingfang

    2013-01-01

    Seed germination is a complex physiological process during which mobilization of nutrient reserves happens. In different crops, this event might be mediated by different regulatory and metabolic pathways. Proteome profiling has been proved to be an efficient way that can help us to construct these pathways. However, no such studies have been performed in soybean germinating seeds up to date. Proteome profiling was conducted through one-dimensional gel electrophoresis followed by liquid chromatography and tandem mass spectrometry strategy in the germinating seeds of soybean (glycine max). Comprehensive comparisons were also carried out between rice and soybean germinating seeds. 764 proteins belonging to 14 functional groups were identified and metabolism related proteins were the largest group. Deep analyses of the proteins and pathways showed that lipids were degraded through lipoxygenase dependent pathway and proteins were degraded through both protease and 26S proteosome system, and the lipoxygenase could also help to remove the reactive oxygen species during the rapid mobilization of reserves of soybean germinating seeds. The differences between rice and soybean germinating seeds proteome profiles indicate that each crop species has distinct mechanism for reserves mobilization during germination. Different reserves could be converted into starches before they are totally utilized during the germination in different crops seeds. This study is the first comprehensive analysis of proteome profile in germinating soybean seeds to date. The data presented in this paper will improve our understanding of the physiological and biochemical status in the imbibed soybean seeds just prior to germination. Comparison of the protein profile with that of germinating rice seeds gives us new insights on mobilization of nutrient reserves during the germination of crops seeds.

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

    PubMed

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

    2015-05-22

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

  7. Abscisic acid (ABA) sensitivity regulates desiccation tolerance in germinated Arabidopsis seeds.

    PubMed

    Maia, Julio; Dekkers, Bas J W; Dolle, Miranda J; Ligterink, Wilco; Hilhorst, Henk W M

    2014-07-01

    During germination, orthodox seeds lose their desiccation tolerance (DT) and become sensitive to extreme drying. Yet, DT can be rescued, in a well-defined developmental window, by the application of a mild osmotic stress before dehydration. A role for abscisic acid (ABA) has been implicated in this stress response and in DT re-establishment. However, the path from the sensing of an osmotic cue and its signaling to DT re-establishment is still largely unknown. Analyses of DT, ABA sensitivity, ABA content and gene expression were performed in desiccation-sensitive (DS) and desiccation-tolerant Arabidopsis thaliana seeds. Furthermore, loss and re-establishment of DT in germinated Arabidopsis seeds was studied in ABA-deficient and ABA-insensitive mutants. We demonstrate that the developmental window in which DT can be re-established correlates strongly with the window in which ABA sensitivity is still present. Using ABA biosynthesis and signaling mutants, we show that this hormone plays a key role in DT re-establishment. Surprisingly, re-establishment of DT depends on the modulation of ABA sensitivity rather than enhanced ABA content. In addition, the evaluation of several ABA-insensitive mutants, which can still produce normal desiccation-tolerant seeds, but are impaired in the re-establishment of DT, shows that the acquisition of DT during seed development is genetically different from its re-establishment during germination. © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.

  8. Seed germination and seedling emergence of Scotch broom (Cytisus scoparius)

    Treesearch

    Timothy B. Harrington

    2009-01-01

    Scotch broom is a large, leguminous shrub that has invaded 27 U.S. states. The species produces seeds with a hard coat that remain viable in the soil for years. Growth-chamber studies were conducted to determine effects of temperature regime and cold-stratification period on seed germination. Seedling emergence, mortality, and biomass also were studied in response to...

  9. The Effect of Arsenate and Other Inhibitors on Early Events during the Germination of Lettuce Seeds (Lactuca sativa L.)

    PubMed Central

    Speer, Henry L.

    1973-01-01

    The effect of arsenate, arsenite, 2,4-dinitrophenol, and anaerobiosis on early events in seed germination was investigated using both intact and punched seeds of lettuce (Lactuca sativa L.). It was found that punching the seed removes penetration barriers to the entrance of inhibitors without an undue loss of germination or light responses. The kinetics of the action of germination inhibitors were established by 2-hour pulse experiments. Arsenate and 2, 4-dinitrophenol have very different kinetics. The inhibition of germination in punched seeds by arsenate given in conjunction with phosphate compared with the lack of inhibition of arsenate plus phosphate on the growing seedling, suggest a distinct metabolic change in the germinating embryo at some time between the onset of germination and subsequent seedling growth. Images PMID:16658515

  10. Seed germination of roundleaf buffaloberry (Shepherdia rotundifolia) and silver buffaloberry (Shepherdia argentea) in three substrates

    Treesearch

    Taun Beddes; Heidi A. Kratsch

    2009-01-01

    Many western native plant species occur in areas characterized by well-drained soils low in organic matter. Some drought-tolerant native plant species exhibit poor seed germination. It was hypothesized that traditional growing substrates high in organic matter may impede their germination; therefore, stratified seeds of roundleaf buffaloherry (Shepherdia rotundifolia)...

  11. [Effects of fluridone, gibberellin acid and germination temperature on dormancy-breaking for Epimedium wushanense].

    PubMed

    Su, He; Wang, Yue; Yang, Yang; Dong, Xue-Hui

    2016-07-01

    We introduced Epimedium wushanense seed which has been stratified for 90 days at 10/20 ℃ as experimental materials, with which we studied the effects of fluridone, gibberellin acid and temperature on E. wushanense germination. The results were suggested as shown below. ①Temperature, fluridone and gibberellin acid can both solely or jointly affect germination energy, germination rate significantly. Among those factors, fluridone affect germination rate and germination energy the most, followed by gibberellin acid and temperature. The highest germination rate under 4 ℃ and 10/20 ℃ stratification are 79.3%, 72.0% respectively, which resulted from treatment of F10GA300 and F20GA200 respectively. The highest germination energy under 4 ℃ and 10/20 ℃ stratification are 52.7%, 52.0%, respectively, which both resulted from F20GA200. ②Compared with 4 ℃ germination, seed could not germinate at 10/20 ℃ germination. Nontheless, application of fluridone can lead E. wushanense seeds to germinating.③The effects of gibberellin acid and interaction between gibberellin acid and fluridone significantly affect seed rotten rate during germination. In addition, soaking is another remarkable factor which increased seed rotten rate. As a result, it is feasible to promote E. wushanense dormancy releasing with gibberellin acid and fluridone associating with a proper germination temperature. Further, it is necessary taking actions to avoid seed rotten rate for saving E. wushanense nurseries'cost. Copyright© by the Chinese Pharmaceutical Association.

  12. Comparison of HeNe laser and sinusoidal non-uniform magnetic field seed pre-sowing treatment effect on Glycine max (Var 90-I) germination, growth and yield.

    PubMed

    Asghar, Tehseen; Iqbal, Munawar; Jamil, Yasir; Zia-Ul-Haq; Nisar, Jan; Shahid, Muhammad

    2017-01-01

    Recently, laser and magnetic field pre-sowing seed treatments attracted the attention of the scientific community in response to their positive effect on plant characteristics and the present study was exemplified for Glycine max Var 90-I. Seeds were exposed to laser (HeNe-wave length 632nm and density power of 1mW/cm 2 ) and magnetic field (sinusoidal non-uniform-50, 75 and 100mT for 3, 5min with exposure) and seed germination, seedling growth and yield attributes were compared. The germination (mean germination, germination percentage, emergence index, germination speed, relative germination coefficient, emergence coefficient of uniformity) growth (root dry weight, root length, shoot fresh weight and shoot dry weight, leaf dry & fresh weight, root fresh weight, leaf area, shoot length, plant total dry weight at different stages, stem diameter, number of leaves, vigor index I & II), biochemical (essential oil) and yield attributes (seed weight, count) were enhanced significantly in response to both laser and magnetic field treatments. However, magnetic field treatment furnished slightly higher response versus laser except relative water contents, whole plant weight and shoot length. Results revealed that both laser and magnetic field pre-sowing seed treatments affect the germination, seedling growth, and yield characteristics positively and could possibly be used to enhance Glycine max productivity. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Stimulation of Phenolics, Antioxidant and α-Glucosidase Inhibitory Activities During Barley (Hordeum vulgare L.) Seed Germination.

    PubMed

    Ha, K-S; Jo, S-H; Mannam, V; Kwon, Y-I; Apostolidis, E

    2016-06-01

    The rationale of this study was to enhance the nutritional quality of dry barley seeds. In this study we are evaluating the effect of germination on barley seeds relevant to total phenolic contents, antioxidant activity (in terms of DPPH free-radical scavenging) and the in vitro α-glucosidase inhibitory activities. Barley seeds were germinated for 18.5, 24, 30, 48, and 67 h and then extracted in water. The total phenolic contents, antioxidant activities and α-glucosidase inhibitory activities changed with germination time. More specifically, within the first 48 h of germination the total phenolic content increased from 1.1 mg/g fresh weight (0 h) to 3.4 mg/g fresh weight (48 h) and then slightly reduced by 67 h. Similarly, α-glucosidase inhibitory activity was significantly increased from an IC50 128.82 mg/mL (0 h) to an IC50 18.88 mg/mL (48 h) and then slightly reduced by 67 h. Significant maltase inhibitory activity was observed only with 48 h-germinated extract. Antioxidant activities increased continuously from an IC50 15.72 mg/mL at 0 h to and IC50 5.72 mg/mL after 48 h of germination. Based on our observations, barley seed germination was over after 48 h. During the progress of germination phenolic compounds are becoming available and are more easily extracted. After 48 h, lignification is initiated resulting to the decreased total phenolic content and observed antioxidant and carbohydrate hydrolyzing enzyme inhibition activities. The above results indicate the positive effect of germination in barley seeds for enhanced antioxidant and α-glucosidase inhibitory activities.

  14. Tomato Seed Coat Permeability to Selected Carbon Nanomaterials and Enhancement of Germination and Seedling Growth

    PubMed Central

    Ratnikova, Tatsiana A.; Rao, Apparao M.; Taylor, Alan G.

    2015-01-01

    Seed coat permeability was examined using a model that tested the effects of soaking tomato (Solanum lycopersicon) seeds in combination with carbon-based nanomaterials (CBNMs) and ultrasonic irradiation (US). Penetration of seed coats to the embryo by CBNMs, as well as CBNMs effects on seed germination and seedling growth, was examined. Two CBNMs, C60(OH)20 (fullerol) and multiwalled nanotubes (MWNTs), were applied at 50 mg/L, and treatment exposure ranged from 0 to 60 minutes. Bright field, fluorescence, and electron microscopy and micro-Raman spectroscopy provided corroborating evidence that neither CBNM was able to penetrate the seed coat. The restriction of nanomaterial (NM) uptake was attributed to the semipermeable layer located at the innermost layer of the seed coat adjacent to the endosperm. Seed treatments using US at 30 or 60 minutes in the presence of MWNTs physically disrupted the seed coat; however, the integrity of the semipermeable layer was not impaired. The germination percentage and seedling length and weight were enhanced in the presence of MWNTs but were not altered by C60(OH)20. The combined exposure of seeds to NMs and US provided insight into the nanoparticle-seed interaction and may serve as a delivery system for enhancing seed germination and early seedling growth. PMID:26495423

  15. Effect of date of cone collection and stratification period on germination and growth of Douglas-fir seeds and seedlings.

    Treesearch

    Frank C. Sorensen

    1980-01-01

    Low-elevation seeds collected 6 and 2 weeks before assumed natural seed fall were stratified 1, 2, 4, 8, 16, 32, 64, and 123 days and germinated in the laboratory. Germinated seeds from all stratification periods were sown at the same time in the nursery bed. Germination and seedling measurements were taken over two growing seasons.Early collection gave...

  16. Priming effects on seed germination in Tecoma stans (Bignoniaceae) and Cordia megalantha (Boraginaceae), two tropical deciduous tree species

    NASA Astrophysics Data System (ADS)

    Alvarado-López, Sandra; Soriano, Diana; Velázquez, Noé; Orozco-Segovia, Alma; Gamboa-deBuen, Alicia

    2014-11-01

    Successful revegetation necessarily requires the establishment of a vegetation cover and one of the challenges for this is the scarce knowledge about germination and seedling establishment of wild tree species. Priming treatments (seed hydration during a specific time followed by seed dehydration) could be an alternative germination pre-treatment to improve plant establishment. Natural priming (via seed burial) promotes rapid and synchronous germination as well as the mobilisation of storage reserves; consequently, it increases seedling vigour. These metabolic and physiological responses are similar to those occurring as a result of the laboratory seed priming treatments (osmopriming and matrix priming) applied successfully to agricultural species. In order to know if natural priming had a positive effect on germination of tropical species we tested the effects of natural priming on imbibition kinetics, germination parameters (mean germination time, lag time and germination rate and percentage) and reserve mobilisation in the seeds of two tree species from a tropical deciduous forest in south-eastern México: Tecoma stans (L Juss. Ex Kunth) and Cordia megalantha (S.F Blake). The wood of both trees are useful for furniture and T. stans is a pioneer tree that promotes soil retention in disturbed areas. We also compared the effect of natural priming with that of laboratory matrix priming (both in soil). Matrix priming improved germination of both studied species. Natural priming promoted the mobilisation of proteins and increased the amount of free amino acids and of lipid degradation in T. stans but not in C. megalantha. Our results suggest that the application of priming via the burial of seeds is an easy and inexpensive technique that can improve seed germination and seedling establishment of tropical trees with potential use in reforestation and restoration practices.

  17. The E3 SUMO ligase AtSIZ1 functions in seed germination in Arabidopsis.

    PubMed

    Kim, Sung-Il; Kwak, Jun Soo; Song, Jong Tae; Seo, Hak Soo

    2016-11-01

    Seed germination is an important stage in the lifecycle of a plant because it determines subsequent vegetative growth and reproduction. Here, we show that the E3 SUMO ligase AtSIZ1 regulates seed dormancy and germination. The germination rates of the siz1 mutants were less than 50%, even after a short period of ripening. However, their germination rates increased to wild-type levels after cold stratification or long periods of ripening. In addition, exogenous gibberellin (GA) application improved the germination rates of the siz1 mutants to the wild-type level. In transgenic plants, suppression of AtSIZ1 caused rapid post-translational decay of SLEEPY1 (SLY1), a positive regulator of GA signaling, during germination, and inducible AtSIZ1 overexpression led to increased SLY1 levels. In addition, overexpressing wild-type SLY1 in transgenic sly1 mutants increased their germination ratios to wild-type levels, whereas the germination ratio of transgenic sly1 mutants overexpressing mSLY1 was similar to that of sly1. The germination ratios of siz1 mutant seeds in immature developing siliques were much lower than those of the wild-type. Moreover, SLY1 and DELAY OF GERMINATION 1 (DOG1) transcript levels were reduced in the siz1 mutants, whereas the transcript levels of DELLA and ABSCISIC ACID INSENSITIVE 3 (ABI3) were higher than those of the wild-type. Taken together, these results indicate that the reduced germination of the siz1 mutants results from impaired GA signaling due to low SLY1 levels and activity, as well as hyperdormancy due to high levels of expression of dormancy-related genes including DOG1. © 2016 The Authors. Physiologia Plantarum published by John Wiley & Sons Ltd on behalf of Scandinavian Plant Physiology Society.

  18. 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

  19. Identification of HDA15-PIF1 as a key repression module directing the transcriptional network of seed germination in the dark.

    PubMed

    Gu, Dachuan; Chen, Chia-Yang; Zhao, Minglei; Zhao, Linmao; Duan, Xuewu; Duan, Jun; Wu, Keqiang; Liu, Xuncheng

    2017-07-07

    Light is a major external factor in regulating seed germination. Photoreceptor phytochrome B (PHYB) plays a predominant role in promoting seed germination in the initial phase after imbibition, partially by repressing phytochrome-interacting factor1 (PIF1). However, the mechanism underlying the PHYB-PIF1-mediated transcription regulation remains largely unclear. Here, we identified that histone deacetylase15 (HDA15) is a negative component of PHYB-dependent seed germination. Overexpression of HDA15 in Arabidopsis inhibits PHYB-dependent seed germination, whereas loss of function of HDA15 increases PHYB-dependent seed germination. Genetic evidence indicated that HDA15 acts downstream of PHYB and represses seed germination dependent on PIF1. Furthermore, HDA15 interacts with PIF1 both in vitro and in vivo. Genome-wide transcriptome analysis revealed that HDA15 and PIF1 co-regulate the transcription of the light-responsive genes involved in multiple hormonal signaling pathways and cellular processes in germinating seeds in the dark. In addition, PIF1 recruits HDA15 to the promoter regions of target genes and represses their expression by decreasing the histone H3 acetylation levels in the dark. Taken together, our analysis uncovered the role of histone deacetylation in the light-regulated seed germination process and identified that HDA15-PIF1 acts as a key repression module directing the transcription network of seed germination. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

  20. The Arabidopsis DELAY OF GERMINATION 1 gene affects ABSCISIC ACID INSENSITIVE 5 (ABI5) expression and genetically interacts with ABI3 during Arabidopsis seed development.

    PubMed

    Dekkers, Bas J W; He, Hanzi; Hanson, Johannes; Willems, Leo A J; Jamar, Diaan C L; Cueff, Gwendal; Rajjou, Loïc; Hilhorst, Henk W M; Bentsink, Leónie

    2016-02-01

    The seed expressed gene DELAY OF GERMINATION (DOG) 1 is absolutely required for the induction of dormancy. Next to a non-dormant phenotype, the dog1-1 mutant is also characterized by a reduced seed longevity suggesting that DOG1 may affect additional seed processes as well. This aspect however, has been hardly studied and is poorly understood. To uncover additional roles of DOG1 in seeds we performed a detailed analysis of the dog1 mutant using both transcriptomics and metabolomics to investigate the molecular consequences of a dysfunctional DOG1 gene. Further, we used a genetic approach taking advantage of the weak aba insensitive (abi) 3-1 allele as a sensitized genetic background in a cross with dog1-1. DOG1 affects the expression of hundreds of genes including LATE EMBRYOGENESIS ABUNDANT and HEAT SHOCK PROTEIN genes which are affected by DOG1 partly via control of ABI5 expression. Furthermore, the content of a subset of primary metabolites, which normally accumulate during seed maturation, was found to be affected in the dog1-1 mutant. Surprisingly, the abi3-1 dog1-1 double mutant produced green seeds which are highly ABA insensitive, phenocopying severe abi3 mutants, indicating that dog1-1 acts as an enhancer of the weak abi3-1 allele and thus revealing a genetic interaction between both genes. Analysis of the dog1 and dog1 abi3 mutants revealed additional seed phenotypes and therefore we hypothesize that DOG1 function is not limited to dormancy but that it is required for multiple aspects of seed maturation, in part by interfering with ABA signalling components. © 2016 The Authors The Plant Journal © 2016 John Wiley & Sons Ltd.

  1. 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

  2. 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.

  3. Methylglyoxal inhibits seed germination and root elongation and up-regulates transcription of stress-responsive genes in ABA-dependent pathway in Arabidopsis.

    PubMed

    Hoque, T S; Uraji, M; Tuya, A; Nakamura, Y; Murata, Y

    2012-09-01

    Methylglyoxal (MG) is a highly reactive metabolite derived from glycolysis. In this study, we examined the effect of MG on seed germination, root elongation, chlorosis and stress-responsive gene expression in Arabidopsis using an abscisic acid (ABA)-deficient mutant, aba2-2. In the wild type, 0.1 mm MG did not affect germination but delayed root elongation, whereas 1.0 mm MG inhibited germination and root elongation and induced chlorosis. MG increased transcription levels of RD29B and RAB18 in a dose-dependent manner but did not affect RD29A transcription level. In contrast, in the aba2-2 mutant, MG inhibition of seed germination at 1.0 mm and 10.0 mm and a delay of root elongation at 0.1 mm MG were mitigated, although there was no significant difference in chlorosis between the wild type and mutant. Moreover, the aba2-2 mutation impaired MG-induced RD29B and RAB18 gene expression. These observations suggest that MG not only directly inhibits germination and root elongation but also indirectly modulates these processes via endogenous ABA in Arabidopsis. © 2012 German Botanical Society and The Royal Botanical Society of the Netherlands.

  4. Scatter Hoarding of Seeds Confers Survival Advantages and Disadvantages to Large-Seeded Tropical Plants at Different Life Stages

    PubMed Central

    Kuprewicz, Erin K.

    2015-01-01

    Scatter hoarding of seeds by animals contributes significantly to forest-level processes, including plant recruitment and forest community composition. However, the potential positive and negative effects of caching on seed survival, germination success, and seedling survival have rarely been assessed through experimental studies. Here, I tested the hypothesis that seed burial mimicking caches made by scatter hoarding Central American agoutis (Dasyprocta punctate) enhances seed survival, germination, and growth by protecting seeds from seed predators and providing favorable microhabitats for germination. In a series of experiments, I used simulated agouti seed caches to assess how hoarding affects seed predation by ground-dwelling invertebrates and vertebrates for four plant species. I tracked germination and seedling growth of intact and beetle-infested seeds and, using exclosures, monitored the effects of mammals on seedling survival through time. All experiments were conducted over three years in a lowland wet forest in Costa Rica. The majority of hoarded palm seeds escaped predation by both invertebrates and vertebrates while exposed seeds suffered high levels of infestation and removal. Hoarding had no effect on infestation rates of D. panamensis, but burial negatively affected germination success by preventing endocarp dehiscence. Non-infested palm seeds had higher germination success and produced larger seedlings than infested seeds. Seedlings of A. alatum and I. deltoidea suffered high mortality by seed-eating mammals. Hoarding protected most seeds from predators and enhanced germination success (except for D. panamensis) and seedling growth, although mammals killed many seedlings of two plant species; all seedling deaths were due to seed removal from the plant base. Using experimental caches, this study shows that scatter hoarding is beneficial to most seeds and may positively affect plant propagation in tropical forests, although tradeoffs in seed

  5. Potential effects of arboreal and terrestrial avian dispersers on seed dormancy, seed germination and seedling establishment in Ormosia (Papilionoideae) species in Peru

    USGS Publications Warehouse

    Foster, Mercedes S.

    2008-01-01

    The relative effectiveness of arboreal or terrestrial birds at dispersing seeds of Ormosia macrocalyx and O. bopiensis (Fabaceae: Papilionoideae) were studied in south-eastern Peru. Seeds of both species were either scarified, to represent seed condition after dispersal by terrestrial birds, or left intact, to represent seed condition after dispersal by arboreal birds. Seeds were distributed along forest transects, and germination, seedling development and mortality were monitored to determine the successes of the two groups at producing seedlings. Scarified seeds germinated with the early rains of the dry-to-wet-season transition, when erratic rainfall was interspersed with long dry spells. Intact seeds germinated 30 d later when the rain was more plentiful and regular. Intact seeds of O. macrocalyx gave rise to significantly more seedlings (41.1% vs. 25.5%) than did scarified seeds, in part, because significantly more seedlings from scarified seeds (n = 20) than from intact seeds (n = 3) died from desiccation when their radicles failed to enter the dry ground present during the dry-to-wet-season transition. Also, seedlings from scarified seeds were neither larger nor more robust than those from intact seeds despite their longer growing period. Results are consistent with the hypothesis that dispersal effectiveness of arboreal birds, at least for O. macrocalyx, is greater than that of terrestrial birds. Screen-house experiments in which seedlings developed under different watering regimes supported this result. Numbers of seedlings developing from intact and scarified seeds of O. bopiensis did not differ significantly.

  6. Seed Germination Ecology of Echinochloa glabrescens and Its Implication for Management in Rice (Oryza sativa L.)

    PubMed Central

    Opeña, Jhoana L.; Chauhan, Bhagirath S.; Baltazar, Aurora M.

    2014-01-01

    Echinochloa glabrescens is a C4 grass weed that is very competitive with rice when left uncontrolled. The competitive ability of weeds is intensified in direct-seeded rice production systems. A better understanding is needed of factors affecting weed seed germination, which can be used as a component of integrated weed management in direct-seeded rice. This study was conducted to determine the effects of temperature, light, salt and osmotic stress, burial depth, crop residue, time and depth of flooding, and herbicide application on the emergence, survival, and growth of two populations [Nueva Ecija (NE) and Los Baños (IR)] of E. glabrescens. Seeds from both populations germinated at all temperatures. The NE population had a higher germination rate (88%) from light stimulation than did the IR population (34%). The salt concentration and osmotic potential required to inhibit 50% of germination were 313 mM and −0.24 MPa, respectively, for the NE population and 254 mM and −0.33 MPa, respectively, for the IR population. Emergence in the NE population was totally inhibited at 4-cm burial depth in the soil, whereas that of the IR population was inhibited at 8 cm. Compared with zero residue, the addition of 5 t ha−1 of rice residue reduced emergence in the NE and IR populations by 38% and 9%, respectively. Early flooding (within 2 days after sowing) at 2-cm depth reduced shoot growth by 50% compared with non-flooded conditions. Pretilachlor applied at 0.075 kg ai ha−1 followed by shallow flooding (2-cm depth) reduced seedling emergence by 94−96% compared with the nontreated flooded treatment. Application of postemergence herbicides at 4-leaf stage provided 85−100% control in both populations. Results suggest that integration of different strategies may enable sustainable management of this weed and of weeds with similar germination responses. PMID:24642568

  7. Using composting for control seed germination of invasive plant (water hyacinth) in Extremadura (Spain)

    NASA Astrophysics Data System (ADS)

    Labrador, Juana; Gordillo, Judit; Ruiz, Trinidad; Albano, Eva; Moreno, Marta M.

    2016-04-01

    The biotransformation of the invasive water hyacinth (Eichhornia crassipes) by composting has been showed as a viable alternative to offset the economic cost of eliminating an invasive plant giving a value to the by-product; however, as result of the propagative plant capacity, it was necessary to check if the composting process could eliminate the germination seed rate. Despite the high temperatures and the biochemical biotransformation processes of the composting components, in the case of seed water hyacinth, with a recovery rate of 100%, damage was observed in some parts of the seed anatomy such as in the outer teguments; however, other parts of the seed coat and the endosperm maintained their integrity. A microscopic analysis revealed that the embryo was noticeable and this was supported by the rate of seed germination observed (3.5 ± 0.96%). The results indicate that the use of water hyacinth for compost production is not completely safe from an environmental perspective. Keywords: Eichhornia crassipes, water hyacinth, invasive plant, seed anatomy, seed germination rate, compost. References: Ruiz T., Martín de Rodrigo E., Lorenzo G., Albano E., Morán R., Sánchez J.M. 2008. The Water Hyacinth, Eichhornia crassipes: an invasive plant in the Guadiana River Basin (Spain). Aquatic Invasions Volume 3, Issue 1:42-53.

  8. Antagonism between abscisic acid and gibberellins is partially mediated by ascorbic acid during seed germination in rice.

    PubMed

    Ye, Nenghui; Zhang, Jianhua

    2012-05-01

    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. In the associated study, we investigated the relationship among ABA, reactive oxygen species (ROS), ascorbic acid (ASC) and GA during rice seed germination. ROS production is reduced by ABA, which hence results in decreasing ASC accumulation during imbibition. GA accumulation was also suppressed by a reduced ROS and ASC level, whereas application of exogenous ASC can partially rescue seed germination from ABA treatment. Further results show that 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. These studies reveal a new role for ASC in mediating the antagonism between ABA and GA during seed germination in rice.

  9. Inter- and intra-variability of seed germination traits of Carpobrotus edulis N.E.Br. and its hybrid C. affine acinaciformis.

    PubMed

    Podda, Lina; Santo, Andrea; Mattana, Efisio; Mayoral, Olga; Bacchetta, Gianluigi

    2018-06-22

    Invasions by alien Carpobrotus spp. have been recognized as one of the most severe threats to Mediterranean-climate coastal ecosystems and Carpobrotus is considered one of the most widespread invasive alien genera in the Mediterranean Basin. The aims of this study were to characterize seed germination of both C. edulis and its hybrid C. affine acinaciformis, in terms of photoperiod, temperature and salinity. Inter- and intra-specific variability in the responses to photoperiod (12/12 h light and total darkness), constant temperatures (5, 10, 15, 20, 25°C) and an alternating temperature regime (25/10°C), salt stress (0, 125, 250, 500 mM NaCl) and the recovery of seed germination were evaluated for two seed lots of C. edulis and two of its hybrid C. affine acinaciformis. All the tested seed lots achieved higher germination percentages in the light, respect to total darkness. In relation to temperature, the two C. edulis seed lots did not show a preference, while the two C. affine acinaciformis seed lots differed in their germination response, one germinating more at the lowest temperatures (5 and 10°C) and one at the highest (20 and 25°C). For all the seed lots, highest germination occurred without NaCl (0 mM) and germination decreased with increasing salinity. Different germination requirements in saline substrate were not detected for C. edulis, while were observed for C. affine acinaciformis. Marked differences were detected in recovery responses between the two taxa. C. edulis demonstrated to have the ability to germinate in a wide time window during the year. This study identified significant differences in seed production, seed mass, germination requirements (temperature) and salinity tolerance for both C. edulis and C. affine acinaciformis. Our results indicated the extreme versatility of the hybrid forms to germinate in a wide range of natural conditions and habitats. This article is protected by copyright. All rights reserved. This article is protected

  10. Validation of reference genes for real-time quantitative PCR normalization in soybean developmental and germinating seeds.

    PubMed

    Li, Qing; Fan, Cheng-Ming; Zhang, Xiao-Mei; Fu, Yong-Fu

    2012-10-01

    Most of traditional reference genes chosen for real-time quantitative PCR normalization were assumed to be ubiquitously and constitutively expressed in vegetative tissues. However, seeds show distinct transcriptomes compared with the vegetative tissues. Therefore, there is a need for re-validation of reference genes in samples of seed development and germination, especially for soybean seeds. In this study, we aimed at identifying reference genes suitable for the quantification of gene expression level in soybean seeds. In order to identify the best reference genes for soybean seeds, 18 putative reference genes were tested with various methods in different seed samples. We combined the outputs of both geNorm and NormFinder to assess the expression stability of these genes. The reference genes identified as optimums for seed development were TUA5 and UKN2, whereas for seed germination they were novel reference genes Glyma05g37470 and Glyma08g28550. Furthermore, for total seed samples it was necessary to combine four genes of Glyma05g37470, Glyma08g28550, Glyma18g04130 and UKN2 [corrected] for normalization. Key message We identified several reference genes that stably expressed in soybean seed developmental and germinating processes.

  11. QTLs for Seed Vigor-Related Traits Identified in Maize Seeds Germinated under Artificial Aging Conditions

    PubMed Central

    Han, Zanping; Ku, Lixia; Zhang, Zhenzhen; Zhang, Jun; Guo, ShuLei; Liu, Haiying; Zhao, Ruifang; Ren, Zhenzhen; Zhang, Liangkun; Su, Huihui; Dong, Lei; Chen, Yanhui

    2014-01-01

    High seed vigor is important for agricultural production due to the associated potential for increased growth and productivity. However, a better understanding of the underlying molecular mechanisms is required because the genetic basis for seed vigor remains unknown. We used single-nucleotide polymorphism (SNP) markers to map quantitative trait loci (QTLs) for four seed vigor traits in two connected recombinant inbred line (RIL) maize populations under four treatment conditions during seed germination. Sixty-five QTLs distributed between the two populations were identified and a meta-analysis was used to integrate genetic maps. Sixty-one initially identified QTLs were integrated into 18 meta-QTLs (mQTLs). Initial QTLs with contribution to phenotypic variation values of R2>10% were integrated into mQTLs. Twenty-three candidate genes for association with seed vigor traits coincided with 13 mQTLs. The candidate genes had functions in the glycolytic pathway and in protein metabolism. QTLs with major effects (R2>10%) were identified under at least one treatment condition for mQTL2, mQTL3-2, and mQTL3-4. Candidate genes included a calcium-dependent protein kinase gene (302810918) involved in signal transduction that mapped in the mQTL3-2 interval associated with germination energy (GE) and germination percentage (GP), and an hsp20/alpha crystallin family protein gene (At5g51440) that mapped in the mQTL3-4 interval associated with GE and GP. Two initial QTLs with a major effect under at least two treatment conditions were identified for mQTL5-2. A cucumisin-like Ser protease gene (At5g67360) mapped in the mQTL5-2 interval associated with GP. The chromosome regions for mQTL2, mQTL3-2, mQTL3-4, and mQTL5-2 may be hot spots for QTLs related to seed vigor traits. The mQTLs and candidate genes identified in this study provide valuable information for the identification of additional quantitative trait genes. PMID:24651614

  12. QTLs for seed vigor-related traits identified in maize seeds germinated under artificial aging conditions.

    PubMed

    Han, Zanping; Ku, Lixia; Zhang, Zhenzhen; Zhang, Jun; Guo, Shulei; Liu, Haiying; Zhao, Ruifang; Ren, Zhenzhen; Zhang, Liangkun; Su, Huihui; Dong, Lei; Chen, Yanhui

    2014-01-01

    High seed vigor is important for agricultural production due to the associated potential for increased growth and productivity. However, a better understanding of the underlying molecular mechanisms is required because the genetic basis for seed vigor remains unknown. We used single-nucleotide polymorphism (SNP) markers to map quantitative trait loci (QTLs) for four seed vigor traits in two connected recombinant inbred line (RIL) maize populations under four treatment conditions during seed germination. Sixty-five QTLs distributed between the two populations were identified and a meta-analysis was used to integrate genetic maps. Sixty-one initially identified QTLs were integrated into 18 meta-QTLs (mQTLs). Initial QTLs with contribution to phenotypic variation values of R(2)>10% were integrated into mQTLs. Twenty-three candidate genes for association with seed vigor traits coincided with 13 mQTLs. The candidate genes had functions in the glycolytic pathway and in protein metabolism. QTLs with major effects (R(2)>10%) were identified under at least one treatment condition for mQTL2, mQTL3-2, and mQTL3-4. Candidate genes included a calcium-dependent protein kinase gene (302810918) involved in signal transduction that mapped in the mQTL3-2 interval associated with germination energy (GE) and germination percentage (GP), and an hsp20/alpha crystallin family protein gene (At5g51440) that mapped in the mQTL3-4 interval associated with GE and GP. Two initial QTLs with a major effect under at least two treatment conditions were identified for mQTL5-2. A cucumisin-like Ser protease gene (At5g67360) mapped in the mQTL5-2 interval associated with GP. The chromosome regions for mQTL2, mQTL3-2, mQTL3-4, and mQTL5-2 may be hot spots for QTLs related to seed vigor traits. The mQTLs and candidate genes identified in this study provide valuable information for the identification of additional quantitative trait genes.

  13. Increasing the stearate content in seed oil of Brassica juncea by heterologous expression of MlFatB affects lipid content and germination frequency of transgenic seeds.

    PubMed

    Bhattacharya, Surajit; Sinha, Saheli; Das, Natasha; Maiti, Mrinal K

    2015-11-01

    Fatty acids from dietary lipids can impart both beneficial and harmful health effects. The compositional balance between saturated and unsaturated fatty acids plays a decisive role in maintaining the physiological harmony, proper growth and development in the human system. In case of Brassica juncea seed oil, the level of saturated fatty acid, especially desirable stearate is very much lower than the recommended value, along with a high content of nutritionally undesirable erucic acid. Therefore, in order to shift the carbon flux towards the production of stearate at the expense of erucate, the MlFatB gene encoding a FatB thioesterase from Madhuca longifolia (latifolia) was expressed heterologously in seed tissues of B. juncea. The functional MlFatB competed with the highly active endogenous BjFatA thioesterase, and the transgenic B. juncea lines showed noteworthy changes in their seed fatty acid profiles. The proportion of stearate increased up to 16-fold, constituting almost 31% of the total fatty acids along with the production of arachidic acid in significant amount (up to ∼11%). Moreover, the content of erucate was reduced up to 71% in the seed oils of transgenic lines. Although a nutritionally desirable fatty acid profile was achieved, the transgenic seeds exhibit reduction or abolition of seed germination in addition to a decrease in seed lipid content. The findings of the present study revealing the stearoyl-ACP thioesterase-mediated enhancement of the stearate content that is associated with reduced germination frequency of transgenic B. juncea seeds, may explain why no natural or induced stearate-rich Brassica has been found or developed. Furthermore, this study also suggests that the newly characterized MlFatB is a potential candidate gene for refined metabolic engineering strategy in B. juncea or other plant species for increasing stearate content in seed oil. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  14. Karrikin-KAI2 signalling provides Arabidopsis seeds with tolerance to abiotic stress and inhibits germination under conditions unfavourable to seedling establishment.

    PubMed

    Wang, Lu; Waters, Mark T; Smith, Steven M

    2018-07-01

    The control of seed germination in response to environmental conditions is important for plant success. We investigated the role of the karrikin receptor KARRIKIN INSENSITIVE2 (KAI2) in the response of Arabidopsis seeds to osmotic stress, salinity and high temperature. Germination of the kai2 mutant was examined in response to NaCl, mannitol and elevated temperature. The effect of karrikin on germination of wild-type seeds, hypocotyl elongation and the expression of karrikin-responsive genes was also examined in response to such stresses. The kai2 seeds germinated less readily than wild-type seeds and germination was more sensitive to inhibition by abiotic stress. Karrikin-induced KAI2 signalling stimulated germination of wild-type seeds under favourable conditions, but, surprisingly, inhibited germination in the presence of osmolytes or at elevated temperature. By contrast, GA stimulated germination of wild-type seeds and mutants under all conditions. Karrikin induced expression of DLK2 and KUF1 genes and inhibited hypocotyl elongation independently of osmotic stress. Under mild osmotic stress, karrikin enhanced expression of DREB2A, WRKY33 and ERF5 genes, but not ABA signalling genes. Thus, the karrikin-KAI2 signalling system can protect against abiotic stress, first by providing stress tolerance, and second by inhibiting germination under conditions unfavourable to seedling establishment. © 2018 The Authors. New Phytologist © 2018 New Phytologist Trust.

  15. Seed predators exert selection on the subindividual variation of seed size.

    PubMed

    Sobral, M; Guitián, J; Guitián, P; Larrinaga, A R

    2014-07-01

    Subindividual variation among repeated organs in plants constitutes an overlooked level of variation in phenotypic selection studies, despite being a major component of phenotypic variation. Animals that interact with plants could be selective agents on subindividual variation. This study examines selective pressures exerted during post-dispersal seed predation and germination on the subindividual variation of seed size in hawthorn (Crataegus monogyna). With a seed offering experiment and a germination test, we estimated phenotypic selection differentials for average and subindividual variation of seed size due to seed predation and germination. Seed size affects germination, growth rate and the probability of an individual seed of escaping predation. Longer seeds showed higher germination rates, but this did not result in significant selection on phenotypes of the maternal trees. On the other hand, seed predators avoided wider seeds, and by doing so exerted phenotypic selection on adult average and subindividual variation of seed size. The detected selection on subindividual variation suggests that the levels of phenotypic variation within individual plants may be, at least partly, the adaptive consequence of animal-mediated selection. © 2013 German Botanical Society and The Royal Botanical Society of the Netherlands.

  16. Determination of seed viability of eight wild Saudi Arabian species by germination and X-ray tests.

    PubMed

    Al-Turki, Turki A; Baskin, Carol C

    2017-05-01

    Our purpose was to evaluate the usefulness of the germination vs. the X-ray test in determining the initial viability of seeds of eight wild species ( Salvia spinosa , Salvia aegyptiaca , Ochradenus baccatus , Ochradenus arabicus , Suaeda aegyptiaca , Suaeda vermiculata , Prosopisfarcta and Panicumturgidum ) from Saudi Arabia. Several days were required to determine viability of all eight species via germination tests, while immediate results on filled/viable seeds were obtained with the X-ray test. Seeds of all the species, except Sa.aegyptiaca , showed high viability in both the germination (98-70% at 25/15 °C, 93-66% at 35/25 °C) and X-ray (100-75%) test. Furthermore, there was general agreement between the germination (10% at 25/15 °C and 8% at 35/25 °C) and X-ray (5%) tests that seed viability of Sa.aegyptiaca was very low, and X-ray analysis revealed that this was due to poor embryo development. Seeds of P.farcta have physical dormancy, which was broken by scarification in concentrated sulfuric acid (10 min), and they exhibited high viability in both the germination (98% at 25/15 °C and 93% at 35/25 °C) and X-ray (98%) test. Most of the nongerminated seeds of the eight species except those of Sa.aegyptiaca were alive as judged by the tetrazolium test (TZ). Thus, for the eight species examined, the X-ray test was a good and rapid predictor of seed viability.

  17. Methane alleviates copper-induced seed germination inhibition and oxidative stress in Medicago sativa.

    PubMed

    Samma, Muhammad Kaleem; Zhou, Heng; Cui, Weiti; Zhu, Kaikai; Zhang, Jing; Shen, Wenbiao

    2017-02-01

    Recent results discovered the protective roles of methane (CH 4 ) against oxidative stress in animals. However, the possible physiological roles of CH 4 in plants are still unknown. By using physiological, histochemical and molecular approaches, the beneficial role of CH 4 in germinating alfalfa seeds upon copper (Cu) stress was evaluated. Endogenous production of CH 4 was significantly increased in Cu-stressed alfalfa seeds, which was mimicked by 0.39 mM CH 4 . The pretreatment with CH 4 significantly alleviated the inhibition of seed germination and seedling growth induced by Cu stress. Cu accumulation was obviously blocked as well. Meanwhile, α/β amylase activities and sugar contents were increased, all of which were consistent with the alleviation of seed germination inhibition triggered by CH 4 . The Cu-triggered oxidative stress was also mitigated, which was confirmed by the decrease of lipid peroxidation and reduction of Cu-induced loss of plasma membrane integrity in CH 4 -pretreated alfalfa seedlings. The results of antioxidant enzymes, including ascorbate peroxidase (APX), superoxide dismutase (SOD), catalase (CAT), and guaiacol peroxidase (POD) total or isozymatic activities, and corresponding transcripts (APX1/2, Cu/Zn SOD and Mn-SOD), indicated that CH 4 reestablished cellular redox homeostasis. Further, Cu-induced proline accumulation was partly impaired by CH 4 , which was supported by the alternation of proline metabolism. Together, these results indicated that CH 4 performs an advantageous effect on the alleviation of seed germination inhibition caused by Cu stress, and reestablishment of redox homeostasis mainly via increasing antioxidant defence.

  18. The allelopathic effects of invasive plant Solidago canadensis on seed germination and growth of Lactuca sativa enhanced by different types of acid deposition.

    PubMed

    Wang, Congyan; Xiao, Hongguang; Zhao, Lulu; Liu, Jun; Wang, Lei; Zhang, Fei; Shi, Yanchun; Du, Daolin

    2016-04-01

    acid deposition and S. canadensis on seed germination and growth of L. sativa. The ratio of SO4(2-) to NO3(-) in acid deposition was an important factor that profoundly affected the allelopathic effects of S. canadensis on the seed germination and growth of L. sativa possibly because the difference in exchange capacity with hydroxyl groups (OH(-)) between SO4(2-) and NO3(-) as well as the fertilizing effects triggered by nitric deposition. Thus, the allelopathic effects of invasive species on seed germination and growth of native plants might be enhanced under increased and diversified acid deposition.

  19. Seed dormancy and germination vary within and among species of milkweeds

    PubMed Central

    Kaye, Thomas N; Sandlin, Isaac J; Bahm, Matt A

    2018-01-01

    Abstract Pollinators in general and monarch butterflies in particular are in decline due to habitat loss. Efforts to restore habitats for insects that rely on specific plant groups as larvae or adults depend on the ability of practitioners to grow and produce these plants. Monarch larvae feed exclusively on milkweed species, primarily in the genus Asclepias, making propagation and restoration of these plants crucial for habitat restoration. Seed germination protocols for milkweeds are not well established, in part due to the large number of milkweed species and conflicting reports of seed dormancy in the genus. We tested for seed dormancy and the optimum period of cold stratification in 15 populations of A. speciosa and 1–2 populations of five additional species, including A. asperula, A. fascicularis, A. subulata, A. subverticillata and A. syriaca. We exposed seeds to cold (5 °C) moist conditions for 0, 2, 4, 6 and 8 weeks and then moved them to 15 °C/25 °C alternating temperatures. In A. speciosa, dormancy was detected in eight populations, and this dormancy was broken by 2–4 weeks of cold stratification. The remaining seven populations showed no dormancy. Seed dormancy was also detected in two populations of A. fascicularis (broken by 4–6 weeks of cold stratification) and a single population of A. syriaca (broken by 2 weeks of cold stratification). No dormancy was detected in A. asperula, A. subulata or A. subverticillata. Seed dormancy appears to be widespread in the genus (confirmed in 15 species) but can vary between populations even within the same species. Variation in seed dormancy and cold stratification requirements within and among Asclepias species suggests local adaptation and maternal environments may drive seedling ecology, and that growers should watch for low germination and use cold stratification as needed to maximize seed germination and retain genetic variability in restored populations. PMID:29593856

  20. HRS1 acts as a negative regulator of abscisic acid signaling to promote timely germination of Arabidopsis seeds.

    PubMed

    Wu, Chongming; Feng, Juanjuan; Wang, Ran; Liu, Hong; Yang, Huixia; Rodriguez, Pedro L; Qin, Huanju; Liu, Xin; Wang, Daowen

    2012-01-01

    In this work, we conducted functional analysis of Arabidopsis HRS1 gene in order to provide new insights into the mechanisms governing seed germination. Compared with wild type (WT) control, HRS1 knockout mutant (hrs1-1) exhibited significant germination delays on either normal medium or those supplemented with abscisic acid (ABA) or sodium chloride (NaCl), with the magnitude of the delay being substantially larger on the latter media. The hypersensitivity of hrs1-1 germination to ABA and NaCl required ABI3, ABI4 and ABI5, and was aggravated in the double mutant hrs1-1abi1-2 and triple mutant hrs1-1hab1-1abi1-2, indicating that HRS1 acts as a negative regulator of ABA signaling during seed germination. Consistent with this notion, HRS1 expression was found in the embryo axis, and was regulated both temporally and spatially, during seed germination. Further analysis showed that the delay of hrs1-1 germination under normal conditions was associated with reduction in the elongation of the cells located in the lower hypocotyl (LH) and transition zone (TZ) of embryo axis. Interestingly, the germination rate of hrs1-1 was more severely reduced by the inhibitor of cell elongation, and more significantly decreased by the suppressors of plasmalemma H(+)-ATPase activity, than that of WT control. The plasmalemma H(+)-ATPase activity in the germinating seeds of hrs1-1 was substantially lower than that exhibited by WT control, and fusicoccin, an activator of this pump, corrected the transient germination delay of hrs1-1. Together, our data suggest that HRS1 may be needed for suppressing ABA signaling in germinating embryo axis, which promotes the timely germination of Arabidopsis seeds probably by facilitating the proper function of plasmalemma H(+)-ATPase and the efficient elongation of LH and TZ cells.

  1. HRS1 Acts as a Negative Regulator of Abscisic Acid Signaling to Promote Timely Germination of Arabidopsis Seeds

    PubMed Central

    Wang, Ran; Liu, Hong; Yang, Huixia; Rodriguez, Pedro L.; Qin, Huanju; Liu, Xin; Wang, Daowen

    2012-01-01

    In this work, we conducted functional analysis of Arabidopsis HRS1 gene in order to provide new insights into the mechanisms governing seed germination. Compared with wild type (WT) control, HRS1 knockout mutant (hrs1-1) exhibited significant germination delays on either normal medium or those supplemented with abscisic acid (ABA) or sodium chloride (NaCl), with the magnitude of the delay being substantially larger on the latter media. The hypersensitivity of hrs1-1 germination to ABA and NaCl required ABI3, ABI4 and ABI5, and was aggravated in the double mutant hrs1-1abi1-2 and triple mutant hrs1-1hab1-1abi1-2, indicating that HRS1 acts as a negative regulator of ABA signaling during seed germination. Consistent with this notion, HRS1 expression was found in the embryo axis, and was regulated both temporally and spatially, during seed germination. Further analysis showed that the delay of hrs1-1 germination under normal conditions was associated with reduction in the elongation of the cells located in the lower hypocotyl (LH) and transition zone (TZ) of embryo axis. Interestingly, the germination rate of hrs1-1 was more severely reduced by the inhibitor of cell elongation, and more significantly decreased by the suppressors of plasmalemma H+-ATPase activity, than that of WT control. The plasmalemma H+-ATPase activity in the germinating seeds of hrs1-1 was substantially lower than that exhibited by WT control, and fusicoccin, an activator of this pump, corrected the transient germination delay of hrs1-1. Together, our data suggest that HRS1 may be needed for suppressing ABA signaling in germinating embryo axis, which promotes the timely germination of Arabidopsis seeds probably by facilitating the proper function of plasmalemma H+-ATPase and the efficient elongation of LH and TZ cells. PMID:22545134

  2. The Effect of Seed-borne Mycoflora from Sorghum and Foxtail Millet Seeds on Germination and Disease Transmission.

    PubMed

    Yago, Jonar I; Roh, Jae-Hwan; Bae, Soon-do; Yoon, Young-Nam; Kim, Hyun-Ju; Nam, Min-Hee

    2011-09-01

    The seed-borne mycoflora of sorghum and foxtail millet collected from different growing areas in South Korea were isolated and taxonomically identified using dry inspection, standard blotter and the agar plate method. We investigated the in vitro and in vivo germination rates of disinfected and non-disinfected seeds of sorghum and foxtail millet using sterilized and unsterilized soil. The percent recovery of seed-borne mycoflora from the seed components of sorghum and foxtail millet seeds was determined and an infection experiment using the dominant species was evaluated for seedling emergence and mortality. A higher number of seed-borne fungi was observed in sorghum compared to that of foxtail millet. Eighteen fungal genera with 34 fungal species were identified from the seeds of sorghum and 13 genera with 22 species were identified from the seeds of foxtail millet. Five dominant species such as Alternaria alternata, Aspergillus flavus, Curvularia lunata, Fusarium moniliforme and Phoma sp. were recorded as seed-borne mycoflora in sorghum and 4 dominant species (Alternaria alternata, Aspergillus flavus, Curvularia lunata, Fusarium moniliforme) were observed in foxtail millet. The in vitro and in vivo germination rates were higher using disinfected seeds and sterilized soil. More seed-borne fungi were recovered from the pericarp compared to the endosperm and seed embryo. The percent recovery of seed-borne fungi ranged from 2.22% to 60.0%, and Alternaria alternata, Curvularia lunata and 4 species of Fusarium were isolated from the endosperm and embryo of sorghum and foxtail millet. Inoculation of the dominant seed-borne fungi showed considerable mortality of seedlings. All the transmitted seed-borne fungi might well be a primary source of infection of sorghum and foxtail millet crops.

  3. The Arabidopsis MYB96 Transcription Factor Is a Positive Regulator of ABSCISIC ACID-INSENSITIVE4 in the Control of Seed Germination1

    PubMed Central

    Lee, Kyounghee; Lee, Hong Gil; Kim, Hyun Uk; Seo, Pil Joon

    2015-01-01

    Seed germination is a key developmental transition that initiates the plant life cycle. The timing of germination is determined by the coordinated action of two phytohormones, gibberellin and abscisic acid (ABA). In particular, ABA plays a key role in integrating environmental information and inhibiting the germination process. The utilization of embryonic lipid reserves contributes to seed germination by acting as an energy source, and ABA suppresses lipid degradation to modulate the germination process. Here, we report that the ABA-responsive R2R3-type MYB transcription factor MYB96, which is highly expressed in embryo, regulates seed germination by controlling the expression of ABSCISIC ACID-INSENSITIVE4 (ABI4) in Arabidopsis (Arabidopsis thaliana). In the presence of ABA, germination was accelerated in MYB96-deficient myb96-1 seeds, whereas the process was significantly delayed in MYB96-overexpressing activation-tagging myb96-ox seeds. Consistently, myb96-1 seeds degraded a larger extent of lipid reserves even in the presence of ABA, while reduced lipid mobilization was observed in myb96-ox seeds. MYB96 directly regulates ABI4, which acts as a repressor of lipid breakdown, to define its spatial and temporal expression. Genetic analysis further demonstrated that ABI4 is epistatic to MYB96 in the control of seed germination. Taken together, the MYB96-ABI4 module regulates lipid mobilization specifically in the embryo to ensure proper seed germination under suboptimal conditions. PMID:25869652

  4. Abscisic acid and ethephon regulation of cellulase in the endosperm cap and radicle during lettuce seed germination.

    PubMed

    Chen, Bingxian; Ma, Jun; Xu, Zhenjiang; Wang, Xiaofeng

    2016-10-01

    The purpose of this study was to investigate the role of cellulase in endosperm cap weakening and radicle elongation during lettuce (Lactuca sativa L.) seed germination. The application of abscisic acid (ABA) or ethephon inhibits or promotes germination, respectively, by affecting endosperm cap weakening and radicle elongation. Cellulase activities, and related protein and transcript abundances of two lettuce cellulase genes, LsCEL1 and LsCEL2, increase in the endosperm cap and radicle prior to radicle protrusion following imbibition in water. ABA or ethephon reduce or elevate, respectively, cellulase activity, and related protein and transcript abundances in the endosperm cap. Taken together, these observations suggest that cellulase plays a role in endosperm cap weakening and radicle elongation during lettuce seed germination, and that the regulation of cellulase in the endosperm cap by ABA and ethephon play a role in endosperm cap weakening. However, the influence of ABA and ethephon on radicle elongation may not be through their effects on cellulase. © 2016 Institute of Botany, Chinese Academy of Sciences.

  5. Genetic variation in salt tolerance during seed germination in a backcross inbred line population and advanced breeding lines derived from upland cotton x pima cotton

    USDA-ARS?s Scientific Manuscript database

    Seed germination is a crucial phase of the plant life cycle that affects its establishment and productivity. However, information on salt tolerance at this phase is limited. Pima cotton (Gossypium barbadense L.) may be more salt tolerant during germination than Upland cotton (G. hirsutum L.) based o...

  6. Lifting DELLA Repression of Arabidopsis Seed Germination by Nonproteolytic Gibberellin Signaling1[C][W][OPEN

    PubMed Central

    Ariizumi, Tohru; Hauvermale, Amber L.; Nelson, Sven K.; Hanada, Atsushi; Yamaguchi, Shinjiro; Steber, Camille M.

    2013-01-01

    DELLA repression of Arabidopsis (Arabidopsis thaliana) seed germination can be lifted either through DELLA proteolysis by the ubiquitin-proteasome pathway or through proteolysis-independent gibberellin (GA) hormone signaling. GA binding to the GIBBERELLIN-INSENSITIVE DWARF1 (GID1) GA receptors stimulates GID1-GA-DELLA complex formation, which in turn triggers DELLA protein ubiquitination and proteolysis via the SCFSLY1 E3 ubiquitin ligase and 26S proteasome. Although DELLA cannot be destroyed in the sleepy1-2 (sly1-2) F-box mutant, long dry after-ripening and GID1 overexpression can relieve the strong sly1-2 seed dormancy phenotype. It appears that sly1-2 seed dormancy results from abscisic acid (ABA) signaling downstream of DELLA, since dormant sly1-2 seeds accumulate high levels of ABA hormone and loss of ABA sensitivity rescues sly1-2 seed germination. DELLA positively regulates the expression of XERICO, an inducer of ABA biosynthesis. GID1b overexpression rescues sly1-2 germination through proteolysis-independent DELLA down-regulation associated with increased expression of GA-inducible genes and decreased ABA accumulation, apparently as a result of decreased XERICO messenger RNA levels. Higher levels of GID1 overexpression are associated with more efficient sly1 germination and increased GID1-GA-DELLA complex formation, suggesting that GID1 down-regulates DELLA through protein binding. After-ripening results in increased GA accumulation and GID1a-dependent GA signaling, suggesting that after-ripening triggers GA-stimulated GID1-GA-DELLA protein complex formation, which in turn blocks DELLA transcriptional activation of the XERICO inhibitor of seed germination. PMID:23818171

  7. Fate of Salmonella enterica and Enterohemorrhagic Escherichia coli Cells Artificially Internalized into Vegetable Seeds during Germination.

    PubMed

    Liu, Da; Cui, Yue; Walcott, Ronald; Chen, Jinru

    2018-01-01

    Vegetable seeds contaminated with bacterial pathogens have been linked to fresh-produce-associated outbreaks of gastrointestinal infections. This study was undertaken to observe the physiological behavior of Salmonella enterica and enterohemorrhagic Escherichia coli (EHEC) cells artificially internalized into vegetable seeds during the germination process. Surface-decontaminated seeds of alfalfa, fenugreek, lettuce, and tomato were vacuum-infiltrated with four individual strains of Salmonella or EHEC. Contaminated seeds were germinated at 25°C for 9 days, and different sprout/seedling tissues were microbiologically analyzed every other day. The internalization of Salmonella and EHEC cells into vegetable seeds was confirmed by the absence of pathogens in seed-rinsing water and the presence of pathogens in seed homogenates after postinternalization seed surface decontamination. Results show that 317 (62%) and 343 (67%) of the 512 collected sprout/seedling tissue samples were positive for Salmonella and EHEC, respectively. The average Salmonella populations were significantly larger ( P < 0.05) than the EHEC populations. Significantly larger Salmonella populations were recovered from the cotyledon and seed coat tissues, followed by the root tissues, but the mean EHEC populations from all sampled tissue sections were statistically similar, except in pregerminated seeds. Three Salmonella and two EHEC strains had significantly larger cell populations on sprout/seedling tissues than other strains used in the study. Salmonella and EHEC populations from fenugreek and alfalfa tissues were significantly larger than those from tomato and lettuce tissues. The study showed the fate of internalized human pathogens on germinating vegetable seeds and sprout/seedling tissues and emphasized the importance of using pathogen-free seeds for sprout production. IMPORTANCE The internalization of microorganisms into vegetable seeds could occur naturally and represents a possible pathway of

  8. Influence of Harvest Aid Herbicides on Seed Germination, Seedling Vigor and Milling Quality Traits of Red Lentil (Lens culinaris L.).

    PubMed

    Subedi, Maya; Willenborg, Christian J; Vandenberg, Albert

    2017-01-01

    Most red lentil produced worldwide is consumed in dehulled form, and post-harvest milling and splitting qualities are major concerns in the secondary processing industry. Lentil producers in northern temperate regions usually apply pre-harvest desiccants as harvest aids to accelerate the lentil crop drying process and facilitate harvesting operations. This paper reports on field studies conducted at Scott and Saskatoon, Saskatchewan, Canada in the 2012 and 2013 cropping seasons to evaluate whether herbicides applied as harvest aids alone or tank mixed with glyphosate affect seed germination, seedling vigor, milling, and splitting qualities. The site-year by desiccant treatment interaction for seed germination, vigor, and milling recovery yields was significant. Glyphosate applied alone or as tank mix with other herbicides (except diquat) reduced seed germination and seedling vigor at Saskatoon and Scott in 2012 only. Pyraflufen-ethyl (20 g ai ha -1 ) applied with glyphosate as well as saflufenacil (36 g ai ha -1 ) decreased dehulling efficiency, while saflufenacil and/or glufosinate with glyphosate reduced milling recovery and football recovery, although these effects were inconsistent. Application of diquat alone or in combination with glyphosate exhibited more consistent dehulling efficiency gains and increases in milling recovery yield. Significant but negative associations were observed between glyphosate residue in seeds and seed germination ( r = -0.84, p < 0.001), seed vigor ( r = -0.62, p < 0.001), dehulling efficiency ( r = -0.55, p < 0.001), and milling recovery ( r = -0.62, p < 0.001). These results indicate application of diquat alone or in combination with glyphosate may be a preferred option for lentil growers to improve milling recovery yield.

  9. Influence of Harvest Aid Herbicides on Seed Germination, Seedling Vigor and Milling Quality Traits of Red Lentil (Lens culinaris L.)

    PubMed Central

    Subedi, Maya; Willenborg, Christian J.; Vandenberg, Albert

    2017-01-01

    Most red lentil produced worldwide is consumed in dehulled form, and post-harvest milling and splitting qualities are major concerns in the secondary processing industry. Lentil producers in northern temperate regions usually apply pre-harvest desiccants as harvest aids to accelerate the lentil crop drying process and facilitate harvesting operations. This paper reports on field studies conducted at Scott and Saskatoon, Saskatchewan, Canada in the 2012 and 2013 cropping seasons to evaluate whether herbicides applied as harvest aids alone or tank mixed with glyphosate affect seed germination, seedling vigor, milling, and splitting qualities. The site-year by desiccant treatment interaction for seed germination, vigor, and milling recovery yields was significant. Glyphosate applied alone or as tank mix with other herbicides (except diquat) reduced seed germination and seedling vigor at Saskatoon and Scott in 2012 only. Pyraflufen-ethyl (20 g ai ha−1) applied with glyphosate as well as saflufenacil (36 g ai ha−1) decreased dehulling efficiency, while saflufenacil and/or glufosinate with glyphosate reduced milling recovery and football recovery, although these effects were inconsistent. Application of diquat alone or in combination with glyphosate exhibited more consistent dehulling efficiency gains and increases in milling recovery yield. Significant but negative associations were observed between glyphosate residue in seeds and seed germination (r = −0.84, p < 0.001), seed vigor (r = −0.62, p < 0.001), dehulling efficiency (r = −0.55, p < 0.001), and milling recovery (r = −0.62, p < 0.001). These results indicate application of diquat alone or in combination with glyphosate may be a preferred option for lentil growers to improve milling recovery yield. PMID:28352275

  10. Metal Tolerance Protein 8 Mediates Manganese Homeostasis and Iron Reallocation during Seed Development and Germination.

    PubMed

    Eroglu, Seckin; Giehl, Ricardo F H; Meier, Bastian; Takahashi, Michiko; Terada, Yasuko; Ignatyev, Konstantin; Andresen, Elisa; Küpper, Hendrik; Peiter, Edgar; von Wirén, Nicolaus

    2017-07-01

    Metal accumulation in seeds is a prerequisite for germination and establishment of plants but also for micronutrient delivery to humans. To investigate metal transport processes and their interactions in seeds, we focused on METAL TOLERANCE PROTEIN8 (MTP8), a tonoplast transporter of the manganese (Mn) subclade of cation diffusion facilitators, which in Arabidopsis ( Arabidopsis thaliana ) is expressed in embryos of seeds. The x-ray fluorescence imaging showed that expression of MTP8 was responsible for Mn localization in subepidermal cells on the abaxial side of the cotyledons and in cortical cells of the hypocotyl. Accordingly, under low Mn availability, MTP8 increased seed stores of Mn, required for efficient seed germination. In mutant embryos lacking expression of VACUOLAR IRON TRANSPORTER1 ( VIT1 ), MTP8 built up iron (Fe) hotspots in MTP8 -expressing cells types, suggesting that MTP8 transports Fe in addition to Mn. In mtp8 vit1 double mutant seeds, Mn and Fe were distributed in all cell types of the embryo. An Fe transport function of MTP8 was confirmed by its ability to complement Fe hypersensitivity of a yeast mutant defective in vacuolar Fe transport. Imbibing mtp8-1 mutant seeds in the presence of Mn or subjecting seeds to wet-dry cycles showed that MTP8 conferred Mn tolerance. During germination, MTP8 promoted reallocation of Fe from the vasculature. These results indicate that cell type-specific accumulation of Mn and Fe in seeds depends on MTP8 and that this transporter plays an important role in the generation of seed metal stores as well as for metal homeostasis and germination efficiency under challenging environmental conditions. © 2017 American Society of Plant Biologists. All Rights Reserved.

  11. Glyoxysomes in Megagamethophyte of Germinating Ponderosa Pine Seeds 12

    PubMed Central

    Ching, Te May

    1970-01-01

    Decoated ponderosa pine (Pinus ponderosa Laws) seeds contained 40% lipids, which were mainly stored in megagametophytic tissue and were utilized or converted to sugars via the glyoxylate cycle during germination. Mitochondria and glyoxysomes were isolated from the tissue by sucrose density gradient centrifugation at different stages of germination. It was found that isocitrate lyase, malate synthase, and catalase were mainly bound in glyoxysomes. Aconitase and fumarase were chiefly localized in mitochondria, whereas citrate synthase was common for both. Both organelles increased in quantity and specific activity of their respective marker enzymes with the advancement of germination. When the megagametophyte was exhausted at the end of germination, the quantity of these organelles and the activity of their marker enzymes decreased abruptly. At the stage of highest lipolysis, the isolated mitochondria and glyoxysomes were able to synthesize protein from labeled amino acids. Both organellar fractions contained RNA and DNA. Some degree of autonomy in glyoxysomes is indicated. Images PMID:16657489

  12. Increasing the antioxidant activity, total phenolic and flavonoid contents by optimizing the germination conditions of amaranth seeds.

    PubMed

    Perales-Sánchez, Janitzio X K; Reyes-Moreno, Cuauhtémoc; Gómez-Favela, Mario A; Milán-Carrillo, Jorge; Cuevas-Rodríguez, Edith O; Valdez-Ortiz, Angel; Gutiérrez-Dorado, Roberto

    2014-09-01

    The aim of this study was to optimize the germination conditions of amaranth seeds that would maximize the antioxidant activity (AoxA), total phenolic (TPC), and flavonoid (TFC) contents. To optimize the germination bioprocess, response surface methodology was applied over three response variables (AoxA, TPC, TFC). A central composite rotable experimental design with two factors [germination temperature (GT), 20-45 ºC; germination time (Gt), 14-120 h] in five levels was used; 13 treatments were generated. The amaranth seeds were soaked in distilled water (25 °C/6 h) before germination. The sprouts from each treatment were dried (50 °C/8 h), cooled, and ground to obtain germinated amaranth flours (GAF). The best combination of germination bioprocess variables for producing optimized GAF with the highest AoxA [21.56 mmol trolox equivalent (TE)/100 g sample, dw], TPC [247.63 mg gallic acid equivalent (GAE)/100 g sample, dw], and TFC [81.39 mg catechin equivalent (CAE)/100 g sample, dw] was GT = 30 ºC/Gt = 78 h. The germination bioprocess increased AoxA, TPC, and TFC in 300-470, 829, and 213%, respectively. The germination is an effective strategy to increase the TPC and TFC of amaranth seeds for enhancing functionality with improved antioxidant activity.

  13. Effect of some light rare earth elements on seed germination, seedling growth and antioxidant metabolism in Triticum durum.

    PubMed

    d'Aquino, Luigi; de Pinto, Maria Concetta; Nardi, Luca; Morgana, Massimo; Tommasi, Franca

    2009-05-01

    Rare earth elements (REEs) enriched fertilizers have been commonly used in China since the 1980s, thus inducing a growing concern about their environmental impact in agriculture. In this work, the effect of some light REEs nitrate mixture and La(3+) nitrate on seed germination, seedling growth and antioxidant metabolism in Triticum durum was investigated with the aim of clarifying the potential benefits or damages of REEs on plants. Seed pre-soaking for 8 h with La(3+) and REEs nitrate inhibited seed germination at low concentrations (0.01 mM and 0.1 mM), while pre-soaking for 2 and 4 h already inhibited seed germination when higher concentrations (1 mM and 10 mM) of La(3+) and REEs nitrate were used. La(3+) and REEs nitrate treatment also affected seedling growth. Root growth was enhanced and inhibited at low and high concentrations, respectively. Shoot growth was inhibited by La(3+) and REEs nitrate at all tested concentrations after 12 d of treatments. Enzymatic and non enzymatic antioxidants were differently affected by La(3+) and REEs nitrate and their behaviour changed also depending on the plant organ. In roots La(3+) and REEs nitrate treatments induced an increase in ascorbate (ASC) and glutathione (GSH) contents. In shoots only La(3+) nitrate induced an increase in the ASC content whereas GSH decreased following both La(3+) and REEs nitrate treatments. An increase in ASC peroxidase activity was observed in shoots and roots, while catalase did not change in roots and slightly decreased in shoots. The possible role of the increase in some antioxidants as indicators of stress caused by lanthanide treatments is discussed.

  14. Submergence Tolerance and Germination Dynamics of Roegneria nutans Seeds in Water-Level Fluctuation Zones with Different Water Rhythms in the Three Gorges Reservoir

    PubMed Central

    Zeng, Bo; Pan, Xiaojiao; Su, Xiaolei

    2016-01-01

    The Three Gorges Dam features two water-level fluctuation zones (WLFZs): the preupland drawdown zone (PU-DZ) and the preriparian drawdown zone (PR-DZ). To investigate the vegetation potential of Roegneria nutans in WLFZs, we compared the submergence tolerance and germination dynamics in the natural riparian zone (NRZ), PU-DZ and PR-DZ. We found that the NRZ seeds maintained an 81.3% intactness rate and >91% germination rate. The final seed germination rate and germination dynamics were consistent with those of the controls. Meanwhile, the PU-DZ seeds submerged at 5 m, 10 m, 15 m, and 20 m exhibited intactness rates of 70.5%, 79.95%, 40.75%, and 39.87%, respectively, and >75% germination. Furthermore, the PR-DZ seeds exhibited intactness rates of 22.44%, 61.13%, 81.87%, and 15.36% at 5 m, 10 m, 15 m, and 17 m, respectively, and 80% germination. The germination rates of the intact seeds submerged >10 m were >80%. Finally, the intact seeds germinated quickly in all WLFZs. The high proportion of intact seeds, rapid germination capacity, and high germination rate permit R. nutans seeds to adapt to the complicated water rhythms of the PU-DZ and PR-DZ and indicate the potential for their use in vegetation restoration and recovery. Thus, perennial seeds can be used for vegetation restoration in the WLFZs of large reservoirs and in other regions with water rhythms similar to the Three Gorges Reservoir. PMID:27031104

  15. Delayed dehiscence of the pericarp: role in germination and retention of viability of seeds of two cold desert annual Brassicaceae species.

    PubMed

    Lu, J J; Tan, D Y; Baskin, C C; Baskin, J M

    2017-01-01

    Considerable variation occurs in post-maturity timing of dehiscence in fruits of Brassicaceae species, and several studies have shown that the pericarp plays an important role in seed germination and retention of viability in species with indehiscent fruits. However, little is known about the significance to seed biology of delay in pericarp dehiscence for <1 year in the field. Thus, we determined the role of the pericarps of Leptaleum filifolium and Neotorularia korolkovii, which open in <1 year after fruit maturity and dispersal, in seed germination and retention of seed viability. We compared dormancy-break via after-ripening in the laboratory and germination phenology and retention of seed viability in intact siliques and isolated seeds buried in an experimental garden. Seeds of both species have Type 6 non-deep physiological dormancy, which is enhanced by the pericarp. Seeds of both species after-ripened during summer 2013, and some of them germinated in autumn and some in the following spring in watered and non-watered soil. Germination percentages of seeds in siliques increased in soil in spring 2014, after the pericarps had opened. Most isolated seeds of L. filifolium and N. korolkovii had germinated or were dead by spring 2014 and summer 2015, respectively, whereas 60% of the seeds of both species in the (opened) pericarps were viable after 24 months. Thus, although the pericarp opened 9-10 months after burial, its presence had a significant effect on seed dormancy, germination phenology and retention of viability of seeds of L. filifolium and N. korolkovii. © 2016 German Botanical Society and The Royal Botanical Society of the Netherlands.

  16. Seed dormancy responses to temperature relate to Nothofagus species distribution and determine temporal patterns of germination across altitudes in Patagonia.

    PubMed

    Arana, María V; Gonzalez-Polo, Marina; Martinez-Meier, Alejandro; Gallo, Leonardo A; Benech-Arnold, Roberto L; Sánchez, Rodolfo A; Batlla, Diego

    2016-01-01

    Seeds integrate environmental cues that modulate their dormancy and germination. Although many mechanisms have been identified in laboratory experiments, their contribution to germination dynamics in existing communities and their involvement in defining species habitats remain elusive. By coupling mathematical models with ecological data we investigated the contribution of seed temperature responses to the dynamics of germination of three Nothofagus species that are sharply distributed across different altitudes in the Patagonian Andes. Seed responsiveness to temperature of the three Nothofagus species was linked to the thermal characteristics of their preferred ecological niche. In their natural distribution range, there was overlap in the timing of germination of the species, which was restricted to mid-spring. By contrast, outside their species distribution range, germination was temporally uncoupled with altitude. This phenomenon was described mathematically by the interplay between interspecific differences in seed population thermal parameters and the range in soil thermic environments across different altitudes. The observed interspecific variations in seed responsiveness to temperature and its environmental regulation, constitute a major determinant of the dynamics of Nothofagus germination across elevations. This phenomenon likely contributes to the maintenance of patterns of species abundance across altitude by placing germinated seeds in a favorable environment for plant growth. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  17. Relationship of seed microsite to germination and survival of lodgepole pine on high-elevation clearcuts in northeastern Utah

    Treesearch

    Deborah S. Page-Dumroese; R. Kasten Dumroese; Connie M. Carpenter; David L. Wenny

    2002-01-01

    On two high-elevation sites (~3,000 m) in northeastern Utah, lodgepole pine (Pinus contorta var. latifolia) seeds germinated best (53 percent) on large mineral microsites (5 x 5 m), and percentage survival of germinating seeds was best on microsites covered with forest floor material. Seed predation was severe at both study sites;...

  18. Chaparral & Fire Ecology: Role of Fire in Seed Germination.

    ERIC Educational Resources Information Center

    Steele, Nancy L. C.; Keeley, Jon E.

    1991-01-01

    An activity that incorporates the concepts of plant structure and function and ecology is described. Students investigate the reasons why some California chaparral seeds germinate only after a fire has burned the surrounding chaparral. The procedure, discussion and analysis questions, expected results, potential problems, and additional activities…

  19. [Biotic and abiotic factors that affect the quality of Schinopsis balansae Engl. and Aspidosperma quebracho-blanco Schltdl. seeds].

    PubMed

    Alzugaray, Claudia; Carnevale, Nélida J; Salinas, Adriana R; Pioli, Rosanna

    2007-06-01

    Aspidosperma quebracho-blanco (white quebracho) and Schinopsis balansae (red quebracho) are distinctive trees of the South American Park in Argentina. Quebrachos are found in forests that have been exploited very intensively. The object of this work was the identification of biotic and abiotic factors specially fungal pathogen that affect the quality of both species and its relation with germination. Seeds where evaluated through germination test and the percentage of the incidence of fungal agents in two different years of harvest was determined. In S. balansae the germination rate was 77% and of 27% in 2000 and 2001 harvests, respectively. Associations fungi-germination were found in 2001 for Alternaria spp., Curvularia spp., and Fusarium spp., showing an coefficient of correlation = -0.84; -0.85 and -0.73 (p < 0.00004), respectively. A high percentage of vane seeds (55%) was also found in 2001 harvest, due to adverse environmental factors, specifically higher precipitations during flowering. In A. quebracho-blanco seeds, the germination rate was 50% and 90% in 2000 and 2003 respectively, with a 42% of immature seeds in 2000 harvest that was associated to high precipitations and high temperatures during flowering and ripping of fruits. The incidence of pathogens was low and did not have association to germination.

  20. Co-exposure to titanium dioxide nanoparticles does not affect cadmium toxicity in radish seeds (Raphanus sativus).

    PubMed

    Manesh, R Roshan; Grassi, G; Bergami, E; Marques-Santos, L F; Faleri, C; Liberatori, G; Corsi, I

    2018-02-01

    Recent developments on environmental fate models indicate that as nano waste, engineered nanomaterials (ENMs) could reach terrestrial ecosystems thus potentially affecting environmental and human health. Plants can be therefore exposed to ENMs but controversial data in terms of fate and toxicity are currently available. Furthermore, there is a current lack of information on complex interactions/transformations to which ENMs undergo in the natural environment as for instance interacting with existing toxic compounds. The aim of the present study was to assess the behavior and biological effects of titanium dioxide nanoparticles (n-TiO 2 ) (Aeroxide P25, Degussa Evonik) and its interaction with cadmium (CdCl 2 ) in plants using radish seeds (Raphanus sativus L. Parvus) as model species. Radish seeds were exposed to n-TiO 2 (1-1000mg/L) and CdCl 2 (1-250mg/L) alone and in combination using a seed germination and seedling growth toxicity test OECD 208. Percentage of seed germination, germination index (GI) and root elongation were calculated. Cell morphology and oxidative stress parameters as glutathione-S-transferase (GST) and catalase activities (CAT) were measured in radish seeds after 5 days of exposure. Z-Average, PdI and Z-potential of n-TiO 2 in Milli-Q water as exposure medium were also determined. DLS analysis showed small aggregates of n-TiO 2 , negative Z-potential and stable PdI in seed's exposure media. Germination percentage, GI and root length resulted affected by n-TiO 2 exposure compared to controls. In particular, n-TiO 2 at 1mg/L and 100mg/L did not affect radish seeds germination (100%) while at concentration of 10mg/L, 200mg/L, 500mg/L, and 1000mg/L a slight but not significant decrease of germination % was observed. Similarly root length and GI resulted significantly higher in seeds exposed to 10mg/L and 200mg/L compared to 1mg/L, 100mg/L, 500mg/L, 1000mg/L and control (p < 0.05). On the opposite, CdCl 2 significantly abolished germination % and

  1. Germination, genetics, and growth of an ancient date seed.

    PubMed

    Sallon, Sarah; Solowey, Elaine; Cohen, Yuval; Korchinsky, Raia; Egli, Markus; Woodhatch, Ivan; Simchoni, Orit; Kislev, Mordechai

    2008-06-13

    An ancient date seed (Phoenix dactylifera L.) excavated from Masada and radiocarbon-dated to the first century Common Era was germinated. Climatic conditions at the Dead Sea may have contributed to the longevity of this oldest, directly dated, viable seed. Growth and development of the seedling over 26 months was compatible with normal date seedlings propagated from modern seeds. Preliminary molecular characterization demonstrated high levels of genetic variation in comparison to modern, elite date cultivars currently growing in Israel. As a representative of an extinct date palm population, this seedling can provide insights into the historic date culture of the Dead Sea region. It also has importance for seed banking and conservation and may be of relevance to modern date palm cultivation.

  2. Effect of temperature, light and salinity on seed germination and radicle growth of the geographically widespread halophyte shrub Halocnemum strobilaceum.

    PubMed

    Qu, Xiao-Xia; Huang, Zhen-Ying; Baskin, Jerry M; Baskin, Carol C

    2008-01-01

    The small leafy succulent shrub Halocnemum strobilaceum occurs in saline habitats from northern Africa and Mediterranean Europe to western Asia, and it is a dominant species in salt deserts such as those of north-west China. The effects of temperature, light/darkness and NaCl salinity were tested on seed germination, and the effects of salinity were tested on seed germination recovery, radicle growth and radicle elongation recovery, using seeds from north-west China; the results were compared with those previously reported on this species from 'salt steppes' in the Mediterranean region of Spain. Seed germination was tested over a range of temperatures in light and in darkness and over a range of salinities at 25 degrees C in the light. Seeds that did not germinate in the NaCl solutions were tested for germination in deionized water. Seeds from which radicles had barely emerged in deionized water were transferred to NaCl solutions for 10 d and then back to deionized water for 10 d to test for radicle growth and recovery. Seeds germinated to higher percentages in light than in darkness and at high than at low temperatures. Germination percentages decreased with an increase in salinity from 0.1 to 0.75 M NaCl. Seeds that did not germinate in NaCl solutions did so after transfer to deionized water. Radicle elongation was increased by low salinity, and then it decreased with an increase in salinity, being completely inhibited by > or = 2.0 M NaCl. Elongation of radicles from salt solutions < 3.0 M resumed after seedlings were transferred to deionized water. The seed and early seedling growth stages of the life cycle of H. strobilaceum are very salt tolerant, and their physiological responses differ somewhat between the Mediterranean 'salt steppe' of Spain and the inland cold salt desert of north-west China.

  3. Predicting seed dormancy loss and germination timing for Bromus tectorum in a semi-arid environment using hydrothermal time models

    Treesearch

    Susan E. Meyer; Phil S. Allen

    2009-01-01

    A principal goal of seed germination modelling for wild species is to predict germination timing under fluctuating field conditions. We coupled our previously developed hydrothermal time, thermal and hydrothermal afterripening time, and hydration-dehydration models for dormancy loss and germination with field seed zone temperature and water potential measurements from...

  4. Germination Potential of Dormant and Nondormant Arabidopsis Seeds Is Driven by Distinct Recruitment of Messenger RNAs to Polysomes

    PubMed Central

    Basbouss-Serhal, Isabelle; Soubigou-Taconnat, Ludivine; Bailly, Christophe; Leymarie, Juliette

    2015-01-01

    Dormancy is a complex evolutionary trait that temporally prevents seed germination, thus allowing seedling growth at a favorable season. High-throughput analyses of transcriptomes have led to significant progress in understanding the molecular regulation of this process, but the role of posttranscriptional mechanisms has received little attention. In this work, we have studied the dynamics of messenger RNA association with polysomes and compared the transcriptome with the translatome in dormant and nondormant seeds of Arabidopsis (Arabidopsis thaliana) during their imbibition at 25°C in darkness, a temperature preventing germination of dormant seeds only. DNA microarray analysis revealed that 4,670 and 7,028 transcripts were differentially abundant in dormant and nondormant seeds in the transcriptome and the translatome, respectively. We show that there is no correlation between transcriptome and translatome and that germination regulation is also largely translational, implying a selective and dynamic recruitment of messenger RNAs to polysomes in both dormant and nondormant seeds. The study of 5′ untranslated region features revealed that GC content and the number of upstream open reading frames could play a role in selective translation occurring during germination. Gene Ontology clustering showed that the functions of polysome-associated transcripts differed between dormant and nondormant seeds and revealed actors in seed dormancy and germination. In conclusion, our results demonstrate the essential role of selective polysome loading in this biological process. PMID:26019300

  5. A rice lectin receptor-like kinase that is involved in innate immune responses also contributes to seed germination

    PubMed Central

    Cheng, Xiaoyan; Wu, Yan; Guo, Jianping; Du, Bo; Chen, Rongzhi; Zhu, Lili; He, Guangcun

    2013-01-01

    Seed germination and innate immunity both have significant effects on plant life spans because they control the plant's entry into the ecosystem and provide defenses against various external stresses, respectively. Much ecological evidence has shown that seeds with high vigor are generally more tolerant of various environmental stimuli in the field than those with low vigor. However, there is little genetic evidence linking germination and immunity in plants. Here, we show that the rice lectin receptor-like kinase OslecRK contributes to both seed germination and plant innate immunity. We demonstrate that knocking down the OslecRK gene depresses the expression of α–amylase genes, reducing seed viability and thereby decreasing the rate of seed germination. Moreover, it also inhibits the expression of defense genes, and so reduces the resistance of rice plants to fungal and bacterial pathogens as well as herbivorous insects. Yeast two-hybrid and co-immunoprecipitation experiments revealed that OslecRK interacts with an actin-depolymerizing factor (ADF) in vivo via its kinase domain. Moreover, the rice adf mutant exhibited a reduced seed germination rate due to the suppression of α–amylase gene expression. This mutant also exhibited depressed immune responses and reduced resistance to biotic stresses. Our results thus provide direct genetic evidence for a common physiological pathway connecting germination and immunity in plants. They also partially explain the common observation that high-vigor seeds often perform well in the field. The dual effects of OslecRK may be indicative of progressive adaptive evolution in rice. PMID:24033867

  6. Physical characterization of Rhipsalis (Cactaceae) fruits and seeds germination in different temperatures and light regimes.

    PubMed

    Lone, A B; Colombo, R C; Andrade, B L G; Takahashi, L S A; Faria, R T

    2016-06-01

    The germination characteristics of the native cactus species are poorly known, being the temperature and the light the factors that the most interferes in that process. Thus, the objective of the present work was to characterize the fruits and evaluate the influence of the temperature and the light in the seed germination of Rhipsalis floccosa, Rhipsalis pilocarpa and Rhipsalis teres. The tested constant temperatures were 15, 20, 25, 30 and 35 °C and the alternate of 20-30 °C and 25-35 °C in a photoperiod of 10 hours, and with determination of the most appropriate temperature, the germination was tested in light absence. The germination percentage, the index of germination speed and medium time of germination were evaluated. For R. floccosa, the highest germination percentage was at 20 °C. For R. pilocarpa and R. teres, the highest germination percentages occurred in 15 °C and 20 °C. There was correlation to germination percentage between the three species, indicating that they had similar germination behavior. Total absence of germination was verified for the three species in condition of light absence. In conclusion, the temperature of 20 °C is the most suitable for the seed germination of R. floccosa. For the species R. pilocarpa and R. teres, the temperatures of 15 and 20 °C are the most suitable.

  7. The Effect of Seed-borne Mycoflora from Sorghum and Foxtail Millet Seeds on Germination and Disease Transmission

    PubMed Central

    Yago, Jonar I.; Bae, Soon-do; Yoon, Young-Nam; Kim, Hyun-Ju; Nam, Min-hee

    2011-01-01

    The seed-borne mycoflora of sorghum and foxtail millet collected from different growing areas in South Korea were isolated and taxonomically identified using dry inspection, standard blotter and the agar plate method. We investigated the in vitro and in vivo germination rates of disinfected and non-disinfected seeds of sorghum and foxtail millet using sterilized and unsterilized soil. The percent recovery of seed-borne mycoflora from the seed components of sorghum and foxtail millet seeds was determined and an infection experiment using the dominant species was evaluated for seedling emergence and mortality. A higher number of seed-borne fungi was observed in sorghum compared to that of foxtail millet. Eighteen fungal genera with 34 fungal species were identified from the seeds of sorghum and 13 genera with 22 species were identified from the seeds of foxtail millet. Five dominant species such as Alternaria alternata, Aspergillus flavus, Curvularia lunata, Fusarium moniliforme and Phoma sp. were recorded as seed-borne mycoflora in sorghum and 4 dominant species (Alternaria alternata, Aspergillus flavus, Curvularia lunata, Fusarium moniliforme) were observed in foxtail millet. The in vitro and in vivo germination rates were higher using disinfected seeds and sterilized soil. More seed-borne fungi were recovered from the pericarp compared to the endosperm and seed embryo. The percent recovery of seed-borne fungi ranged from 2.22% to 60.0%, and Alternaria alternata, Curvularia lunata and 4 species of Fusarium were isolated from the endosperm and embryo of sorghum and foxtail millet. Inoculation of the dominant seed-borne fungi showed considerable mortality of seedlings. All the transmitted seed-borne fungi might well be a primary source of infection of sorghum and foxtail millet crops. PMID:22783105

  8. Effects of Atmospheric Pressure Air Plasma Pretreatment on the Seed Germination and Early Growth of Andrographis paniculata

    NASA Astrophysics Data System (ADS)

    Tong, Jiayun; He, Rui; Zhang, Xiaoli; Zhan, Ruoting; Chen, Weiwen; Yang, Size

    2014-03-01

    The objective of this paper is to demonstrate whether air plasma can change the seed germination characteristics, seedling emergence, as well as biochemical reactivity, in Andrographis paniculata (A. paniculata) seedlings by modifying the seed coat and finding a beneficial treatment dose. Eight treatment doses and one control were used to conduct electrical conductivity determination, a germination test, a seedling emergence test and a biochemical assay. The results showed that after being treated with air plasma excited at 5950 V for 10 s, the permeability of the seeds was improved significantly, resulting in the acceleration of seed germination and seedling emergence. In the meantime, the catalase activity and catalase isoenzyme expression were also improved, while the malondialdehyde content in the seedlings was decreased (which means greater counteraction with environmental stress). After being treated with 4250 V for 10 s and 5950 V for 20 s, the seed germination was enhanced, but without an obvious change in seedling emergence. However, after treatment with 3400 V for 20 s and 5100 V for 10 s, the permeability of the seeds was decreased, resulting in a delay in seedling emergence. These results indicate that air plasma can change the physiological and biochemical characteristics of Andrographis paniculata seeds by modifying the seed coat, combined with the effects of the active plasma species, and that different treating doses have different effects.

  9. Improvement of Chia Seeds with Antioxidant Activity, GABA, Essential Amino Acids, and Dietary Fiber by Controlled Germination Bioprocess.

    PubMed

    Gómez-Favela, Mario Armando; Gutiérrez-Dorado, Roberto; Cuevas-Rodríguez, Edith Oliva; Canizalez-Román, Vicente Adrián; Del Rosario León-Sicairos, Claudia; Milán-Carrillo, Jorge; Reyes-Moreno, Cuauhtémoc

    2017-12-01

    Chia (Salvia hispanica L.) plant is native from southern Mexico and northern Guatemala. Their seeds are a rich source of bioactive compounds which protect consumers against chronic diseases. Germination improves functionality of the seeds due to the increase in the bioactive compounds and associated antioxidant activity. The purpose of this study was to obtain functional flour from germinated chia seeds under optimized conditions with increased antioxidant activity, phenolic compounds, GABA, essential amino acids, and dietary fiber with respect to un-germinated chia seeds. The effect of germination temperature and time (GT = 20-35 °C, Gt = 10-300 h) on protein, lipid, and total phenolic contents (PC, LC, TPC, respectively), and antioxidant activity (AoxA) was analyzed by response surface methodology as optimization tool. Chia seeds were germinated inside plastic trays with absorbent paper moisturized with 50 mL of 100 ppm sodium hypochlorite dissolution. The sprouts were dried (50 °C/8 h) and ground to obtain germinated chia flours (GCF). The prediction models developed for PC, LC, TPC, and AoxA showed high coefficients of determination, demonstrating their adequacy to explain the variations in experimental data. The highest values of PC, LC, TPC, and AoxA were obtained at two different optimal conditions (GT = 21 °C/Gt = 157 h; GT = 33 °C/Gt = 126 h). Optimized germinated chia flours (OGCF) had higher PC, TPC, AoxA, GABA, essential amino acids, calculated protein efficiency ratio (C-PER), and total dietary fiber (TDF) than un-germinated chia seed flour. The OGCF could be utilized as a natural source of proteins, dietary fiber, GABA, and antioxidants in the development of new functional beverages and foods.

  10. A sunflower WRKY transcription factor stimulates the mobilization of seed-stored reserves during germination and post-germination growth.

    PubMed

    Raineri, Jesica; Hartman, Matías D; Chan, Raquel L; Iglesias, Alberto A; Ribichich, Karina F

    2016-09-01

    The sunflower transcription factor HaWRKY10 stimulates reserves mobilization in Arabidopsis. Gene expression and enzymes activity assays indicated that lipolysis and gluconeogenesis were increased. Microarray results suggested a parallelism in sunflower. Germinating oilseeds converts stored lipids into sugars, and thereafter in metabolic energy that is used in seedling growth and establishment. During germination, the induced lipolysis linked to the glyoxylate pathway and gluconeogenesis produces sucrose, which is then transported to the embryo and driven through catabolic routes. Herein, we report that the sunflower transcription factor HaWRKY10 regulates carbon partitioning by reducing carbohydrate catabolism and increasing lipolysis and gluconeogenesis. HaWRKY10 was regulated by abscisic acid and gibberellins in the embryo leaves 48 h after seed imbibition and highly expressed during sunflower seed germination and seedling growth, concomitantly with lipid mobilization. Sunflower leaf disks overexpressing HaWRKY10 showed repressed expression of genes related to sucrose cleavage and glycolysis compared with controls. Moreover, HaWRKY10 constitutive expression in Arabidopsis seeds produced higher decrease in lipid reserves, whereas starch and sucrose were more preserved compared with wild type. Gene transcripts abundance and enzyme activities involved in stored lipid mobilization and gluconeogenesis increased more in transgenic than in wild type seeds 36 h after imbibition, whereas the negative regulator of lipid mobilization, ABI4, was repressed. Altogether, the results point out a functional parallelism between tissues and plant species, and reveal HaWRKY10 as a positive regulator of storage reserve mobilization in sunflower.

  11. Salt Stress and Ethylene Antagonistically Regulate Nucleocytoplasmic Partitioning of COP1 to Control Seed Germination1[OPEN

    PubMed Central

    Shi, Hui; Gu, Juntao; Dong, Jingao; Deng, Xing Wang

    2016-01-01

    Seed germination, a critical stage initiating the life cycle of a plant, is severely affected by salt stress. However, the underlying mechanism of salt inhibition of seed germination (SSG) is unclear. Here, we report that the Arabidopsis (Arabidopsis thaliana) CONSTITUTIVE PHOTOMORPHOGENESIS1 (COP1) counteracts SSG. Genetic assays provide evidence that SSG in loss of function of the COP1 mutant was stronger than this in the wild type. A GUS-COP1 fusion was constitutively localized to the nucleus in radicle cells. Salt treatment caused COP1 to be retained in the cytosol, but the addition of ethylene precursor 1-aminocyclopropane-1-carboxylate had the reverse effect on the translocation of COP1 to the nucleus, revealing that ethylene and salt exert opposite regulatory effects on the localization of COP1 in germinating seeds. However, loss of function of the ETHYLENE INSENSITIVE3 (EIN3) mutant impaired the ethylene-mediated rescue of the salt restriction of COP1 to the nucleus. Further research showed that the interaction between COP1 and LONG HYPOCOTYL5 (HY5) had a role in SSG. Correspondingly, SSG in loss of function of HY5 was suppressed. Biochemical detection showed that salt promoted the stabilization of HY5, whereas ethylene restricted its accumulation. Furthermore, salt treatment stimulated and ethylene suppressed transcription of ABA INSENSITIVE5 (ABI5), which was directly transcriptionally regulated by HY5. Together, our results reveal that salt stress and ethylene antagonistically regulate nucleocytoplasmic partitioning of COP1, thereby controlling Arabidopsis seed germination via the COP1-mediated down-regulation of HY5 and ABI5. These findings enhance our understanding of the stress response and have great potential for application in agricultural production. PMID:26850275

  12. Low power continuous wave-laser seed irradiation effect on Moringa oleifera germination, seedling growth and biochemical attributes.

    PubMed

    Urva; Shafique, Hina; Jamil, Yasir; Haq, Zia Ul; Mujahid, Tamveel; Khan, Aman Ullah; Iqbal, Munawar; Abbas, Mazhar

    2017-05-01

    Recently, laser application in agriculture has gained much attention since plant characteristics were improved significantly in response of pre-sowing seed treatment. Pre-sowing laser seed treatment effects on germination, seedling growth and mineral profile were studied in Moringa olifera. M. olifera healthy seeds were exposed to 25, 50, 75mJ low power continuous wave laser light and grown under greenhouse conditions. The seedling growth and biochemical attributes were evaluated from 10-day-old seedlings. The germination parameters (percentage, mean germination time), vigor index, seedling growth (root length, seedling length, shoot fresh weight, root fresh weight, shoot dry weight, root dry weight) enhanced considerably. The laser energy levels used for seed irradiation showed variable effects on germination, seedling growth and mineral profile. The mineral contents were recorded to be higher in seedling raised from laser treated seeds, which were higher in roots versus shoots and leaves. The effect of laser treatment on seedling fat, nitrogen and protein content was insignificant and at higher energy level both nitrogen and protein contents decreased versus control. Results revealed that M. olifera germination, seedling growth and mineral contents were enhanced and optimum laser energy level has more acceleratory effect since at three laser energy levels the responses were significantly different. Overall the laser energy levels effect on germination and seedling growth was found in following order; 75mJ>50mJ>25mJ, where as in case of fat, protein and nitrogen contents the trend was as; 25mJ>50mJ and 75mJ. However, this technique could possibly be used to improve the M. olifera germination, seedling growth, and minerals contents where germination is low due to unfavorable conditions. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. [Plant biomorphology and seed germination of pioneer species of the Kamchatka volcanoes].

    PubMed

    Voronkova, N M; Kholina, A B; Verkholat, V P

    2008-01-01

    Biomorphology, quantitative characters and seed germination of 17 pioneer plant species friable materials of volcanic eruptions (Kamchatka Peninsula) were studied. Adaptive trends in survival stress conditions are discussed. To evaluate a possibility of the cryogenic seed storage, their response to ultra low temperatures (-196 degrees C) was determine.

  14. Germination responses of the invasive Calotropis procera (Ait.) R. Br. (Apocynaceae): comparisons with seeds from two ecosystems in Northeastern Brazil.

    PubMed

    Leal, Laura C; Meiado, Marcos V; Lopes, Ariadna V; Leal, Inara R

    2013-09-01

    Life history traits are considered key indicators of plant invasibility. Among them, the germination behavior of seeds is of major relevance because it is influenced by environmental factors of invaded ecosystem. Here, we investigated how seed traits and seed tolerance to environmental factors on seed germination of Calotropis procera vary depending on the invaded ecosystems in northeastern Brazil. We have tested seeds from two vegetation types - Caatinga and Restinga - to different levels of light intensity, salinity, and water stress. Previous to those experiments, seed-set and morphometric analysis were carried out for both studied populations. We have observed a higher seed-set in Caatinga. Seeds produced in this ecosystem had lower seed moisture content. Seeds from Restinga showed lower germination time when light intensity decreased. We observed a reduction in both the germinability and the synchronization index with decreasing osmotic potential and increasing salinity. Nevertheless, both populations exhibited changes in photoblastism when seeds were submitted to water and saline stress. In conclusion, C. procera seeds are tolerant to environmental factors assessed. That characteristic ensures the colonization success and wide distribution of this plant species in the studied ecosystems.

  15. Role of thioproline on seed germination: interaction ROS-ABA and effects on antioxidative metabolism.

    PubMed

    Barba-Espin, Gregorio; Nicolas, Eduardo; Almansa, Maria Soledad; Cantero-Navarro, Elena; Albacete, Alfonso; Hernández, José Antonio; Díaz-Vivancos, Pedro

    2012-10-01

    In this work we investigate the effect of the imbibition of pea seeds with different thioproline (TP) concentrations on the germination percentage and the early growth of the seedlings. The interaction between TP and hydrogen peroxide (H₂O₂) treatments is also analysed in order to test if any synergy in germination and growth occurs. Although the imbibition of pea seeds in the presence of TP did not significantly improve the germination percentage, TP and/or H₂O₂ pre-treatments increased seedlings growth. This increase in seedling growth was reduced by abscisic acid (ABA) addition. Imbibition of pea seeds in the presence of ABA also reduced the endogenous H₂O₂ contents of pea seedlings in control and TP-treated seeds. The incubation of pea seeds with TP and/or H₂O₂ in presence or absence of ABA decreased the activity of H₂O₂-scavenging enzymes. The increase of the endogenous H₂O₂ contents observed in TP and/or H₂O₂ treatments in absence of ABA could be correlated with the decrease in these activities. Finally, the hormone profile of pea seedlings was investigated. The results show that the increase in seedling growth is correlated with a decrease in ABA in samples pre-treated with H₂O₂ and TP + H₂O₂. Nevertheless, no significant differences in endogenous ABA concentration were observed with the TP pre-treatment. This paper suggests a relationship between endogenous H₂O₂ contents and plant growth, so reinforcing the intricate crosstalk between reactive oxygen species (ROS) and plant hormones in seed germination signalling and early seedling development. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  16. Hormonal profile and the role of cell expansion in the germination control of Cerrado biome palm seeds.

    PubMed

    Dias, Daiane Souza; Ribeiro, Leonardo Monteiro; Lopes, Paulo Sérgio Nascimento; Munné-Bosch, Sergi; Garcia, Queila Souza

    2017-09-01

    Little information is currently available concerning the mechanisms controlling palm seed germination. We compared the anatomical and physiological aspects of seeds of two neotropical palm species showing different levels of dormancy. The seeds of Attalea vitrivir and Butia capitata were evaluated for the endogenous contents of hormones (ABA, GAs, CKs, BRs, IAA, JA, SA and the ethylene precursor ACC) in their cotyledonary petiole and operculum (structures involved in germination control), the force necessary to displace the operculum, endo-β-mannanase activities, and embryo cell elongation. The analyses were carried out on with intact dry and imbibed seeds as well as with seeds with the operculum mechanically removed, 2, 5 and 10 days after sowing. The germinabilities of the intact seeds of A. vitrivir and B. capitata were 68% and 3%, respectively; the removal of the operculum increased germination to more than 90% in both species. Reductions of ABA and increases in GAs contents coincided with cell elongation, although there is no evidence that hormonal balance and endo-β-mannanase activity are involved in operculum weakening. The ratio between the embryo length and the force required for operculum displacement (EL/OF) was found to be 1.9 times greater in A. vitrivir than in B. capitata, which means that very small elongations in each cell would be sufficient to promote germination, resulting in a lower level of dormancy in the former species. EL/OF and cell growth control are therefore important for defining dormancy level in palm seeds. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  17. Interchangeable effects of gibberellic acid and temperature on embryo growth, seed germination and epicotyl emergence in Ribes multiflorum ssp. sandalioticum (Grossulariaceae).

    PubMed

    Mattana, E; Pritchard, H W; Porceddu, M; Stuppy, W H; Bacchetta, G

    2012-01-01

    Morphophysiological dormancy was investigated in seeds of Ribes multiflorum Kit ex Roem et Schult. ssp. sandalioticum Arrigoni, a rare mountain species endemic to Sardinia (Italy). There were no differences in imbibition rates between intact and scarified seeds, suggesting a lack of physical dormancy, while methylene blue solution (0.5%) highlighted a preferential pathway for solution entrance through the raphe. Embryos were small at seed dispersal, with an initial embryo:seed ratio (E:S) of ca. 0.2 (embryo length, ca. 0.5 mm), whereas the critical E:S ratio for germination was three times longer (ca. 0.6). Gibberellic acid (GA(3), 250 mg · l(-1)) and warm stratification (25 °C for 3 months) followed by low temperature (<15 °C) enhanced embryo growth rate (maximum of ca. 0.04 mm · day(-1) at 10 °C) and subsequent seed germination (radicle emergence; ca. 80% at 10 °C). Low germination occurred at warmer temperatures, and cold stratification (5 °C for 3 months) induced secondary dormancy. After radicle emergence, epicotyl emergence was delayed for ca. 2 months for seeds from three different populations. Mean time of epicotyl emergence was affected by GA(3) . Seeds of this species showed non-deep simple (root) - non-deep simple (epicotyl) morphophysiological dormancy, highlighting a high synchronisation with Mediterranean seasonality in all the investigated populations. © 2011 German Botanical Society and The Royal Botanical Society of the Netherlands.

  18. A role for caleosin in degradation of oil-body storage lipid during seed germination.

    PubMed

    Poxleitner, Marianne; Rogers, Sally W; Lacey Samuels, A; Browse, John; Rogers, John C

    2006-09-01

    Caleosin is a Ca(2+)-binding oil-body surface protein. To assess its role in the degradation of oil-bodies, two independent insertion mutants lacking caleosin were studied. Both mutants demonstrated significant delay of breakdown of the 20:1 storage lipid at 48 and 60 h of germination. Additionally, although germination rates for seeds were not affected by the mutations, mutant seedlings grew more slowly than wild type when measured at 48 h of germination, a defect that was corrected with continued growth for 72 and 96 h in the light. After 48 h of germination, wild-type central vacuoles had smooth contours and demonstrated internalization of oil bodies and of membrane containing alpha- and delta-tonoplast intrinsic proteins (TIPs), markers for protein storage vacuoles. In contrast, mutant central vacuoles had distorted limiting membranes displaying domains with clumps of the two TIPs, and they contained fewer oil bodies. Thus, during germination caleosin plays a role in the degradation of storage lipid in oil bodies. Its role involves both the normal modification of storage vacuole membrane and the interaction of oil bodies with vacuoles. The results indicate that interaction of oil bodies with vacuoles is one mechanism that contributes to the degradation of storage lipid.

  19. Seed germination biology of Intermountain populations of fourwing saltbush (Atriplex canescens: Chenopodiaceae)

    Treesearch

    Susan E. Meyer; Stephanie L. Carlson

    2007-01-01

    Fourwing saltbush (Atriplex canescens) is a widely distributed shrub of semiarid western North America. We studied viability and germinability of fourwing saltbush seeds over 10 years for collections from 23 Intermountain populations. Fruit fill averaged 53 percent, and 96 percent of filled fruits contained viable seeds even after 6 years of...

  20. Vacuolar H+-ATPase Is Expressed in Response to Gibberellin during Tomato Seed Germination1

    PubMed Central

    Cooley, Michael B.; Yang, Hong; Dahal, Peetambar; Mella, R. Alejandra; Downie, A. Bruce; Haigh, Anthony M.; Bradford, Kent J.

    1999-01-01

    Completion of germination (radicle emergence) by gibberellin (GA)-deficient (gib-1) mutant tomato (Lycopersicon esculentum Mill.) seeds is dependent upon exogenous GA, because weakening of the endosperm tissue enclosing the radicle tip requires GA. To investigate genes that may be involved in endosperm weakening or embryo growth, differential cDNA display was used to identify mRNAs differentially expressed in gib-1 seeds imbibed in the presence or absence of GA4+7. Among these was a GA-responsive mRNA encoding the 16-kD hydrophobic subunit c of the V0 membrane sector of vacuolar H+-translocating ATPases (V-ATPase), which we termed LVA-P1. LVA-P1 mRNA expression in gib-1 seeds was dependent on GA and was particularly abundant in the micropylar region prior to radicle emergence. Both GA dependence and tissue localization of LVA-P1 mRNA expression were confirmed directly in individual gib-1 seeds using tissue printing. LVA-P1 mRNA was also expressed in wild-type seeds during development and germination, independent of exogenous GA. Specific antisera detected protein subunits A and B of the cytoplasmic V1 sector of the V-ATPase holoenzyme complex in gib-1 seeds only in the presence of GA, and expression was localized to the micropylar region. The results suggest that V-ATPase plays a role in GA-regulated germination of tomato seeds. PMID:10594121

  1. Serine carboxypeptidase 46 Regulates Grain Filling and Seed Germination in Rice (Oryza sativa L.)

    PubMed Central

    Li, Zhiyong; Tang, Liqun; Qiu, Jiehua; Zhang, Wen; Wang, Yifeng; Tong, Xiaohong; Wei, Xiangjin; Hou, Yuxuan

    2016-01-01

    Serine carboxypeptidase (SCP) is one of the largest groups of enzymes catalyzing proteolysis for functional protein maturation. To date, little is known about the function of SCPs in rice. In this study, we present a comprehensive analysis of the gene structure and expression profile of 59 rice SCPs. SCP46 is dominantly expressed in developing seeds, particularly in embryo, endosperm and aleurone layers, and could be induced by ABA. Functional characterization revealed that knock-down of SCP46 resulted in smaller grain size and enhanced seed germination. Furthermore, scp46 seed germination became less sensitive to the ABA inhibition than the Wild-type did; suggesting SCP46 is involved in ABA signaling. As indicated by RNA-seq and qRT-PCR analysis, numerous grain filling and seed dormancy related genes, such as SP, VP1 and AGPs were down-regulated in scp46. Yeast-two-hybrid assay also showed that SCP46 interacts with another ABA-inducible protein DI19-1. Taken together, we suggested that SCP46 is a master regulator of grain filling and seed germination, possibly via participating in the ABA signaling. The results of this study shed novel light into the roles of SCPs in rice. PMID:27448032

  2. Serine carboxypeptidase 46 Regulates Grain Filling and Seed Germination in Rice (Oryza sativa L.).

    PubMed

    Li, Zhiyong; Tang, Liqun; Qiu, Jiehua; Zhang, Wen; Wang, Yifeng; Tong, Xiaohong; Wei, Xiangjin; Hou, Yuxuan; Zhang, Jian

    2016-01-01

    Serine carboxypeptidase (SCP) is one of the largest groups of enzymes catalyzing proteolysis for functional protein maturation. To date, little is known about the function of SCPs in rice. In this study, we present a comprehensive analysis of the gene structure and expression profile of 59 rice SCPs. SCP46 is dominantly expressed in developing seeds, particularly in embryo, endosperm and aleurone layers, and could be induced by ABA. Functional characterization revealed that knock-down of SCP46 resulted in smaller grain size and enhanced seed germination. Furthermore, scp46 seed germination became less sensitive to the ABA inhibition than the Wild-type did; suggesting SCP46 is involved in ABA signaling. As indicated by RNA-seq and qRT-PCR analysis, numerous grain filling and seed dormancy related genes, such as SP, VP1 and AGPs were down-regulated in scp46. Yeast-two-hybrid assay also showed that SCP46 interacts with another ABA-inducible protein DI19-1. Taken together, we suggested that SCP46 is a master regulator of grain filling and seed germination, possibly via participating in the ABA signaling. The results of this study shed novel light into the roles of SCPs in rice.

  3. Mannans and endo-β-mannanase transcripts are located in different seed compartments during Brassicaceae germination.

    PubMed

    Carrillo-Barral, Néstor; Matilla, Angel J; Rodríguez-Gacio, María Del Carmen; Iglesias-Fernández, Raquel

    2018-03-01

    Mannans but not endo-β-mannanases are mainly found in the mucilage layer of two Brassicaceae seeds. Nonetheless, mannanase mobilization from inner to outer seed layers cannot be ruled out. The contribution of endo-β-mannanase (MAN) genes to the germination of the wild-type Sisymbrium officinale and cultivated Brassica rapa (Brassicaceae) species has been explored. In both species, mannans have been localized to the imbibed external seed coat layer (mucilage) by fluorescence immunolocalization and MAN enzymatic activity increases in seeds as imbibition progresses, reaching a peak before 100% germination is achieved. The MAN gene families have been annotated and the expression of their members analyzed in vegetative and reproductive organs. In S. officinale and B. rapa, MAN2, MAN5, MAN6, and MAN7 transcripts accumulate upon seed imbibition. SoMAN7 is the most expressed MAN gene in S. officinale germinating seeds, as occurs with its ortholog in Arabidopsis thaliana, but in B. rapa, the most abundant transcripts are BrMAN2 and BrMAN5. These genes (MAN2, MAN5, MAN6, and MAN7) are localized, by mRNA in situ hybridization, to the micropylar at the endosperm layer and to the radicle in S. officinale, but in B. rapa, these mRNAs are faintly found to the micropylar living seed coat layer and are mainly present at the radicle tip and the vascular bundles. If the domestication process undergone by B. rapa is responsible for these different MAN expression patterns, upon germination remains to be elucidated. Since mannans and MAN genes are not spatially distributed in the same seed tissues, a movement of MAN enzymes that are synthesized with typical signal peptides from the embryo tissues to the mucilage layer (via apoplastic space) is necessary for the mannans to be hydrolyzed.

  4. Systems biology of seeds: deciphering the molecular mechanisms of seed storage, dormancy and onset of germination.

    PubMed

    Sreenivasulu, Nese

    2017-05-01

    Seeds are heterogeneous storage reserves with wide array of storage compounds that include various soluble carbohydrates, starch polymer, storage proteins and lipids. These stored reserves comprise 70% of the world's caloric intake in the form of food and animal feed produced through sustainable agriculture, which contributes to food and nutritional security. Seed systems biology remains an enigmatic subject in understanding seed storage processes, maturation and pre-germinative metabolism. The reviews and research articles covered in this special issue of Plant Cell Reports highlight recent advances made in the area of seed biology that cover various systems biology applications such as gene regulatory networks, metabolomics, epigenetics and the role of micro-RNA in seed development.

  5. Effects of Atmospheric-Pressure N2, He, Air, and O2 Microplasmas on Mung Bean Seed Germination and Seedling Growth

    NASA Astrophysics Data System (ADS)

    Zhou, Renwu; Zhou, Rusen; Zhang, Xianhui; Zhuang, Jinxing; Yang, Size; Bazaka, Kateryna; (Ken) Ostrikov, Kostya

    2016-09-01

    Atmospheric-pressure N2, He, air, and O2 microplasma arrays have been used to investigate the effects of plasma treatment on seed germination and seedling growth of mung bean in aqueous solution. Seed germination and growth of mung bean were found to strongly depend on the feed gases used to generate plasma and plasma treatment time. Compared to the treatment with atmospheric-pressure O2, N2 and He microplasma arrays, treatment with air microplasma arrays was shown to be more efficient in improving both the seed germination rate and seedling growth, the effect attributed to solution acidification and interactions with plasma-generated reactive oxygen and nitrogen species. Acidic environment caused by air discharge in water may promote leathering of seed chaps, thus enhancing the germination rate of mung bean, and stimulating the growth of hypocotyl and radicle. The interactions between plasma-generated reactive species, such as hydrogen peroxide (H2O2) and nitrogen compounds, and seeds led to a significant acceleration of seed germination and an increase in seedling length of mung bean. Electrolyte leakage rate of mung bean seeds soaked in solution activated using air microplasma was the lowest, while the catalase activity of thus-treated mung bean seeds was the highest compared to other types of microplasma.

  6. Effects of Atmospheric-Pressure N2, He, Air, and O2 Microplasmas on Mung Bean Seed Germination and Seedling Growth.

    PubMed

    Zhou, Renwu; Zhou, Rusen; Zhang, Xianhui; Zhuang, Jinxing; Yang, Size; Bazaka, Kateryna; Ken Ostrikov, Kostya

    2016-09-01

    Atmospheric-pressure N2, He, air, and O2 microplasma arrays have been used to investigate the effects of plasma treatment on seed germination and seedling growth of mung bean in aqueous solution. Seed germination and growth of mung bean were found to strongly depend on the feed gases used to generate plasma and plasma treatment time. Compared to the treatment with atmospheric-pressure O2, N2 and He microplasma arrays, treatment with air microplasma arrays was shown to be more efficient in improving both the seed germination rate and seedling growth, the effect attributed to solution acidification and interactions with plasma-generated reactive oxygen and nitrogen species. Acidic environment caused by air discharge in water may promote leathering of seed chaps, thus enhancing the germination rate of mung bean, and stimulating the growth of hypocotyl and radicle. The interactions between plasma-generated reactive species, such as hydrogen peroxide (H2O2) and nitrogen compounds, and seeds led to a significant acceleration of seed germination and an increase in seedling length of mung bean. Electrolyte leakage rate of mung bean seeds soaked in solution activated using air microplasma was the lowest, while the catalase activity of thus-treated mung bean seeds was the highest compared to other types of microplasma.

  7. Evaluation of water binding, seed coat permeability and germination characteristics of wheat seeds equilibrated at different relative humidities.

    PubMed

    Chatterjee, Nabamita; Nagarajan, Shantha

    2006-08-01

    The relative binding of seed water and seed coat membrane stability were measured in two contrasting wheat (Triticum aestivum L) varieties, HDR 77 (drought-tolerant) and HD 2009 (susceptible) using seed water sorption isotherms, electrical conductivity (EC) of leachates and desorption-absorption isotherms. Analysis of sorption isotherm at 25 degrees C showed that the seeds of HDR 77 had significantly higher number of strong binding sites, with correspondingly greater amount of seed water as strongly bound water, as compared to HD 2009. Total number of binding sites was also higher in HDR 77 than HD 2009, which explained the better desiccation tolerance and higher capacity to bind water in seeds of HDR 77. EC of seed leachate in both varieties did not change with respect to change in equilibrium relative humidity (RII), indicating the general seed coat membrane stability of wheat seeds. However, absolute conductivity values were higher for HD 2009. showing its relatively porous seed coat membrane. Significantly lower area enclosed by the desorption-absorption isotherm loop in HDR 77, as compared to HD 2009 also indicated the greater membrane integrity of HDR 77. Germination and seedling vigour of HD 2009 were reduced when equilibrated over very low and very high RH. In contrast, germination and vigour in HDR 77 were maintained high, except at very high RH, indicating again its desiccation tolerance. Thus, the study demonstrated the relative drought tolerance of HDR 77, on the basis of seed water-binding characteristics and seed membrane stability. Seed membrane stability as measured by seed leachate conductivity or as area under dehydration-rehydration loop may be used as a preliminary screening test for drought tolerance in wheat.

  8. Is induction ability of seed germination of Phelipanche ramosa phylogenetically structured among hosts? A case study on Fabaceae species.

    PubMed

    Perronne, Rémi; Gibot-Leclerc, Stéphanie; Dessaint, Fabrice; Reibel, Carole; Le Corre, Valérie

    2017-12-01

    Phelipanche ramosa is a major root-holoparasitic damaging weed characterized by a broad host range, including numerous Fabaceae species. In France, the agricultural threat posed by P. ramosa has increased over two decades due to the appearance of a genetically differentiated pathovar presenting a clear host specificity for oilseed rape. The new pathovar has led to a massive expansion of P. ramosa in oilseed rape fields. The germination rate of P. ramosa seeds is currently known to vary among P. ramosa pathovars and host species. However, only a few studies have investigated whether phylogenetic relatedness among potential host species is a predictor of the ability of these species to induce the seed germination of parasitic weeds by testing for phylogenetic signal. We focused on a set of 12 Fabaceae species and we assessed the rate of induction of seed germination by these species for two pathovars based on in vitro co-cultivation experiments. All Fabaceae species tested induced the germination of P. ramosa seeds. The germination rate of P. ramosa seeds varied between Fabaceae species and tribes studied, while pathovars appeared non-influential. Considering oilseed rape as a reference species, we also highlighted a significant phylogenetic signal. Phylogenetically related species therefore showed more similar rates of induction of seed germination than species drawn at random from a phylogenetic tree. In in vitro conditions, only Lotus corniculatus induced a significantly higher germination rate than oilseed rape, and could potentially be used as a catch crop after confirmation of these results under field conditions.

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

    PubMed

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

    2018-03-21

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

  10. [Effect of smoke water and distillation liquid on the seed germination and seedling growth of Trichosathes kirilowii].

    PubMed

    Zhou, Jie; Bian, Li-hua; Zou, Lin; Zhou, Bin-qian; Liu, Wei; Wang, Xiao

    2015-10-01

    Smoke water and distillation liquid were used to treat the seeds of Trichosathes kirilowii and to study the effects of smoke water and distillation liquid on the seed germination and seedling growth of T. kirilowii. The results showed that germination rate, germination index and germination vigor of T. kirilowii all were significantly improved with the treatment of SW and DL treatment. The activity of α-amylase were significantly increased with the treatment of SW and DL at 1:2,000. SW and DL treatment showed no significant effects on the activity of SOD. The activity of POD were markedly enhanced under the treatment of SW (1:000) and DL (1:2,000). CAT activity were increased with the treatment of SW and DL at 1:2,000 while were inhibited by SW and DL at 1:500. Seedling height and root length were increased with the treatment of SW and DL (1:1,000, 1:2,000). SW and DL treaments improved the content of chlorophyll, and moreover with the concentration of SW and DL, the stimulatory were also increased. This work demonstrated that smoke water and diatillation liquid at 1:2,000 could stimulate the seed germination and seedling growth of T. kirilowii, and it provided the references for the study of seed germination technology.

  11. Arabidopsis Glutamate Receptor Homolog3.5 Modulates Cytosolic Ca2+ Level to Counteract Effect of Abscisic Acid in Seed Germination1[OPEN

    PubMed Central

    Kong, Dongdong; Ju, Chuanli; Parihar, Aisha; Kim, So; Cho, Daeshik; Kwak, June M.

    2015-01-01

    Seed germination is a critical step in a plant’s life cycle that allows successful propagation and is therefore strictly controlled by endogenous and environmental signals. However, the molecular mechanisms underlying germination control remain elusive. Here, we report that the Arabidopsis (Arabidopsis thaliana) glutamate receptor homolog3.5 (AtGLR3.5) is predominantly expressed in germinating seeds and increases cytosolic Ca2+ concentration that counteracts the effect of abscisic acid (ABA) to promote germination. Repression of AtGLR3.5 impairs cytosolic Ca2+ concentration elevation, significantly delays germination, and enhances ABA sensitivity in seeds, whereas overexpression of AtGLR3.5 results in earlier germination and reduced seed sensitivity to ABA. Furthermore, we show that Ca2+ suppresses the expression of ABSCISIC ACID INSENSITIVE4 (ABI4), a key transcription factor involved in ABA response in seeds, and that ABI4 plays a fundamental role in modulation of Ca2+-dependent germination. Taken together, our results provide molecular genetic evidence that AtGLR3.5-mediated Ca2+ influx stimulates seed germination by antagonizing the inhibitory effects of ABA through suppression of ABI4. These findings establish, to our knowledge, a new and pivotal role of the plant glutamate receptor homolog and Ca2+ signaling in germination control and uncover the orchestrated modulation of the AtGLR3.5-mediated Ca2+ signal and ABA signaling via ABI4 to fine-tune the crucial developmental process, germination, in Arabidopsis. PMID:25681329

  12. The NF-YC–RGL2 module integrates GA and ABA signalling to regulate seed germination in Arabidopsis

    PubMed Central

    Liu, Xu; Hu, Pengwei; Huang, Mingkun; Tang, Yang; Li, Yuge; Li, Ling; Hou, Xingliang

    2016-01-01

    The antagonistic crosstalk between gibberellic acid (GA) and abscisic acid (ABA) plays a pivotal role in the modulation of seed germination. However, the molecular mechanism of such phytohormone interaction remains largely elusive. Here we show that three Arabidopsis NUCLEAR FACTOR-Y C (NF-YC) homologues NF-YC3, NF-YC4 and NF-YC9 redundantly modulate GA- and ABA-mediated seed germination. These NF-YCs interact with the DELLA protein RGL2, a key repressor of GA signalling. The NF-YC–RGL2 module targets ABI5, a gene encoding a core component of ABA signalling, via specific CCAAT elements and collectively regulates a set of GA- and ABA-responsive genes, thus controlling germination. These results suggest that the NF-YC–RGL2–ABI5 module integrates GA and ABA signalling pathways during seed germination. PMID:27624486

  13. Effects of fungal elicitors on seed germination and tissue culture of Cymbidium goeringii

    NASA Astrophysics Data System (ADS)

    Gong, Mingfu; Guan, Qinlan; Lin, Tianxing; Lan, Juming; Liu, Si

    2018-04-01

    The endophytic fungi were isolated from the roots of Cymbidium goeringii and Cymbidium faberi and were made into liquid fungal elicitors used to co-fungus germination of seeds of C. goeringii and C. faberi. The results showed that the germination rate of the seeds of C. goeringii was increased 15% to 30% by inoculating the mixed fungal elicitors of C. goeringii and was no significant change by inoculating the mixed fungal elicitors of C. faberi. Mixed fungal elicitor promoted the acclimation of tissue culture seedlings. Mixed fungal elicitor prepared mycorrhizal inoculant made new seedlings easier to survive when transplanted.

  14. Seed morphology, germination phenology, and capacity to form a seed bank in six herbaceous layer apiaceae species of the eastern deciduous forest

    Treesearch

    Tracy S. Hawkins; Jerry M. Baskin; Carol C. Baskin

    2007-01-01

    We compared seed mass, seed morphology, and long-term germination phenology of three monocarpic (MI and three polycarpic (P) Apiaceae species of the herbaceous layer of the Eastern Deciduous Forest. Seeds (mericarps) of the six species differed considerably in mass, shape, and ornamentation. Mean seed masses were ranked Cryptotaenia canadensis (M)...

  15. Effect of Temperature, Light and Salinity on Seed Germination and Radicle Growth of the Geographically Widespread Halophyte Shrub Halocnemum strobilaceum

    PubMed Central

    Qu, Xiao-Xia; Huang, Zhen-Ying; Baskin, Jerry M.; Baskin, Carol C.

    2008-01-01

    Background and Aims The small leafy succulent shrub Halocnemum strobilaceum occurs in saline habitats from northern Africa and Mediterranean Europe to western Asia, and it is a dominant species in salt deserts such as those of north-west China. The effects of temperature, light/darkness and NaCl salinity were tested on seed germination, and the effects of salinity were tested on seed germination recovery, radicle growth and radicle elongation recovery, using seeds from north-west China; the results were compared with those previously reported on this species from ‘salt steppes’ in the Mediterranean region of Spain. Methods Seed germination was tested over a range of temperatures in light and in darkness and over a range of salinities at 25 °C in the light. Seeds that did not germinate in the NaCl solutions were tested for germination in deionized water. Seeds from which radicles had barely emerged in deionized water were transferred to NaCl solutions for 10 d and then back to deionized water for 10 d to test for radicle growth and recovery. Key Results Seeds germinated to higher percentages in light than in darkness and at high than at low temperatures. Germination percentages decreased with an increase in salinity from 0·1 to 0·75 m NaCl. Seeds that did not germinate in NaCl solutions did so after transfer to deionized water. Radicle elongation was increased by low salinity, and then it decreased with an increase in salinity, being completely inhibited by ≥2·0 m NaCl. Elongation of radicles from salt solutions <3·0 m resumed after seedlings were transferred to deionized water. Conclusions The seed and early seedling growth stages of the life cycle of H. strobilaceum are very salt tolerant, and their physiological responses differ somewhat between the Mediterranean ‘salt steppe’ of Spain and the inland cold salt desert of north-west China. PMID:17428834

  16. Growth of vegetative explant Moringa oleifera on different composition of auxin and cytokinin and its synthetic seed germination

    NASA Astrophysics Data System (ADS)

    Muslihatin, Wirdhatul; Jadid, Nurul; Puspitasari, Ika D.; Safitri, Chusnul E.

    2017-06-01

    The spread of Moringa oleifera is also rare for seed germination and viability or survival are low, and the lack of vegetative propagation method. The purpose of this study are to determine the effect of auxin and cytokinin on growth vegetative explants Moringa oleifera and its synthetic seed germination. The explants grown on MS medium with sucrose content of 30% and a range of additional hormone. Addition concentration and different types of hormone made in order to know the sensitivity and response explant growth on a variety of media to get a good callus and embryosomatic. The composition of the hormone given is MS + 2.4 D 3 ppm; MS + 2,4D 2 ppm + BAP 2 ppm; MS + NAA + 0.5 ppm kinetin 1 ppm; MS + NAA 1 ppm + kinetin 1 ppm; MS + NAA 1 ppm + 0.5 ppm kinetin. The explants were incubated at a temperature of 18-20 ° C with a photoperiod 16/8. Explants and MS medium is incubated to form embryonic callus. Seeds synthetic made from embryonic callus growing on medium 1 ppm kinetin + NAA 1 ppm with encapsulation method with sodium alginate 2%. Seed synthetic germinated in some kind of medium that medium ms0 solid (M1), ms0 liquid (M2), MS0 semi-solid (M3), MS solid NAA 1ppm + Kinetin 1 ppm (M4), MS liquid NAA 1 ppm + kinetin (M5), and semi-solid MS + NAA 1 ppm kinetin 1 ppm (M6). Synthetic seed viability was observed with the parameters of the fresh weight of synthetic seed, germination percentage and seedling. Chlorophyll content was measured by spectrophotometric method with solvent asseton. Best callus generated in this study are embryonic callus that grew on media NAA 1 ppm + kinetin 1 ppm. Embryonic callus on M6 + NAA 1 ppm kinetin 1 ppm capable of germination with an average weight of callus and sprouts of 40.38 mg. Of the entire amount of a synthetic seed on M6, just 5 seed germinate, so the percentage of germination of seeds is equal to 41.67%. with an average length of sprouts 1 cm with an average total chlorophyll content of 8.66 mg / g.

  17. The role of thioredoxin h in protein metabolism during wheat (Triticum aestivum L.) seed germination.

    PubMed

    Guo, Hongxiang; Wang, Shaoxin; Xu, Fangfang; Li, Yongchun; Ren, Jiangping; Wang, Xiang; Niu, Hongbin; Yin, Jun

    2013-06-01

    Thioredoxin h can regulate the redox environment in the cell and play an important role in the germination of cereals. In the present study, the thioredoxin s antisense transgenic wheat with down-regulation of thioredoxin h was used to study the role of thioredoxin h in protein metabolism during germination of wheat seeds, and to explore the mechanism of the thioredoxin s antisense transgenic wheat seeds having high resistance to pre-harvest sprouting. The qRT-PCR results showed that the expression of protein disulfide isomerase in the thioredoxin s antisense transgenic wheat was up-regulated, which induced easily forming glutenin macropolymers and the resistance of storage proteins to degradation. The expression of serine protease inhibitor was also up-regulated in transgenic wheat, which might be responsible for the decreased activity of thiocalsin during the germination. The expression of WRKY6 in transgenic wheat was down-regulated, which was consistent with the decreased activity of glutamine oxoglutarate aminotransferase. In transgenic wheat, the activities of glutamate dehydrogenase, glutamic pyruvic transaminase and glutamic oxaloacetic transaminase were down-regulated, indicating that the metabolism of amino acid was lower than that in wild-type wheat during seed germination. A putative model for the role of thioredoxin h in protein metabolism during wheat seed germination was proposed and discussed. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  18. Apparent seed digestibility and germination of seeds after passage through the digestive system of northern bobwhite

    USDA-ARS?s Scientific Manuscript database

    Limited information is available regarding the digestibility or germination of seed after the passage through the digestive system of northern bobwhites (Colinus virginianus), especially of plants associated with the sand sagebrush (Artemisia filifolia)-mixed prairie community. Thus, our objectives...

  19. Metal Tolerance Protein 8 Mediates Manganese Homeostasis and Iron Reallocation during Seed Development and Germination1[OPEN

    PubMed Central

    Takahashi, Michiko; Terada, Yasuko

    2017-01-01

    Metal accumulation in seeds is a prerequisite for germination and establishment of plants but also for micronutrient delivery to humans. To investigate metal transport processes and their interactions in seeds, we focused on METAL TOLERANCE PROTEIN8 (MTP8), a tonoplast transporter of the manganese (Mn) subclade of cation diffusion facilitators, which in Arabidopsis (Arabidopsis thaliana) is expressed in embryos of seeds. The x-ray fluorescence imaging showed that expression of MTP8 was responsible for Mn localization in subepidermal cells on the abaxial side of the cotyledons and in cortical cells of the hypocotyl. Accordingly, under low Mn availability, MTP8 increased seed stores of Mn, required for efficient seed germination. In mutant embryos lacking expression of VACUOLAR IRON TRANSPORTER1 (VIT1), MTP8 built up iron (Fe) hotspots in MTP8-expressing cells types, suggesting that MTP8 transports Fe in addition to Mn. In mtp8 vit1 double mutant seeds, Mn and Fe were distributed in all cell types of the embryo. An Fe transport function of MTP8 was confirmed by its ability to complement Fe hypersensitivity of a yeast mutant defective in vacuolar Fe transport. Imbibing mtp8-1 mutant seeds in the presence of Mn or subjecting seeds to wet-dry cycles showed that MTP8 conferred Mn tolerance. During germination, MTP8 promoted reallocation of Fe from the vasculature. These results indicate that cell type-specific accumulation of Mn and Fe in seeds depends on MTP8 and that this transporter plays an important role in the generation of seed metal stores as well as for metal homeostasis and germination efficiency under challenging environmental conditions. PMID:28461400

  20. Study on the seed production and germination dynamic of common milkweed (Asclepias syriaca L.).

    PubMed

    Sárkány, S E; Lehoczky, E; Nagy, P

    2008-01-01

    The common milkweed causes considerable damages on the agricultural and nature conservation areas. The area occupied by this weed is continuously bigger. The common milkweed is spread over North-America between the 35th and 50th degree of western Latitude and 60th 103rd degree of longitude. Millions of hectares are polluted by this weed in the United States. Important is its spread also in Asia (Iraq), in Europe (Carpathian Basin, Poland, Bulgaria, Switzerland, France, Austria, Germany), as well as in the area of the former Soviet Union (Belorussia, The Baltic Countries, Caucasus, and the Ukraine). Though the basic biological characters of this plant are well known, still its control is a significant problem, the damages increase on the areas occupied by this weed. We collect seed samples from several Hungarian areas in 2007. After the sampling we determined the average sprout length and the number of follicle as well as the average seed numbers in the follicle. We determined also the weight of thousand seeds of the resultant seed samples. At natural circumstances the seedlings appear at a soil temperature of 15 degrees C during the end of April and first week of May. Under Laboratory circumstances the dormancy of the seeds ceases continuously from November on, germinate at a temperature of 20-30 degrees C, the maximum germination can be achieved in the first part of April. At January we started germination examinations with the seeds in Petri dish, among laboratory condition.

  1. Identification of QTLs for seed germination capability after various storage periods using two RIL populations in rice.

    PubMed

    Jiang, Wenzhu; Lee, Joohyun; Jin, Yong-Mei; Qiao, Yongli; Piao, Rihua; Jang, Sun Mi; Woo, Mi-Ok; Kwon, Soon-Wook; Liu, Xianhu; Pan, Hong-Yu; Du, Xinglin; Koh, Hee-Jong

    2011-04-01

    Seed germination capability of rice is one of the important traits in the production and storage of seeds. Quantitative trait loci (QTL) associated with seed germination capability in various storage periods was identified using two sets of recombinant inbred lines (RILs) which derived from crosses between Milyang 23 and Tong 88-7 (MT-RILs) and between Dasanbyeo and TR22183 (DT-RILs). A total of five and three main additive effects (QTLs) associated with seed germination capability were identified in MT-RILs and DT-RILs, respectively. Among them, six QTLs were identified repeatedly in various seed storage periods designated as qMT-SGC5.1, qMT-SGC7.2, and qMT-SGC9.1 on chromosomes 5, 7, and 9 in MT-RILs, and qDT-SGC2.1, qDT-SGC3.1, and qDT-SGC9.1 on chromosomes 2, 3, and 9 in DT-RILs, respectively. The QTL on chromosome 9 was identified in both RIL populations under all three storage periods, explaining up to 40% of the phenotypic variation. Eight and eighteen pairs additive × additive epistatic effect (epistatic QTL) were identified in MT-RILs and DT-RILs, respectively. In addition, several near isogenic lines (NILs) were developed to confirm six repeatable QTL effects using controlled deterioration test (CDT). The identified QTLs will be further studied to elucidate the mechanisms controlling seed germination capability, which have important implications for long-term seed storage.

  2. Dry matter, lipids, and proteins of canola seeds as affected by germination and seedling growth under illuminated and dark environments.

    PubMed

    Zhang, Haiyan; Vasanthan, Thava; Wettasinghe, Mahinda

    2004-12-29

    The effect of germination and growth under illuminated and dark environments on canola seed reserves was investigated. Depletion of proteins and lipids in whole seedlings and their top (leaf/cotyledons) and bottom parts (stem/roots/seed coat) was independent of light, whereas the protein solubility increased at a faster rate under an illuminated environment than in the dark. A rapid increase in free fatty acids but a net decrease of dry matter content in seedlings grown in the dark environment was observed. The dry matter content of seedlings grown in the illuminated environment increased due to photosynthetic biomass accumulation.

  3. Insecticide use in hybrid onion seed production affects pre- and postpollination processes.

    PubMed

    Gillespie, Sandra; Long, Rachael; Seitz, Nicola; Williams, Neal

    2014-02-01

    Research on threats to pollination service in agro-ecosystems has focused primarily on the negative impacts of land use change and agricultural practices such as insecticide use on pollinator populations. Insecticide use could also affect the pollination process, through nonlethal impacts on pollinator attraction and postpollination processes such as pollen viability or pollen tube growth. Hybrid onion seed (Allium cepa L., Alliaceae) is an important pollinator-dependent crop that has suffered yield declines in California, concurrent with increased insecticide use. Field studies suggest that insecticide use reduces pollination service in this system. We conducted a field experiment manipulating insecticide use to examine the impacts of insecticides on 1) pollinator attraction, 2) pollen/stigma interactions, and 3) seed set and seed quality. Select insecticides had negative impacts on pollinator attraction and pollen/stigma interactions, with certain products dramatically reducing pollen germination and pollen tube growth. Decreased pollen germination was not associated with reduced seed set; however, reduced pollinator attraction was associated with lower seed set and seed quality, for one of the two female lines examined. Our results highlight the importance of pesticide effects on the pollination process. Overuse may lead to yield reductions through impacts on pollinator behavior and postpollination processes. Overall, in hybrid onion seed production, moderation in insecticide use is advised when controlling onion thrips, Thrips tabaci, on commercial fields.

  4. Germination response of Hylocereus setaceus (Salm-Dyck ex DC: ) Ralf Bauer (Cactaceae) seeds to temperature and reduced water potentials.

    PubMed

    Simão, E; Takaki, M; Cardoso, V J M

    2010-02-01

    The germination response of Hylocereus setaceus seeds to isothermic incubation at different water potentials was analysed by using the thermal time and hydrotime models, aiming to describe some germination parameters of the population and to test the validity of the models to describe the response of the seeds to temperature and water potential. Hylocereus setaceus seeds germinated relatively well in a wide range of temperatures and the germination was rate limited from 11 to 20 degrees C interval and beyond 30 degrees C until 40 degrees C, in which the germination rate respectively shifts positively and negatively with temperature. The minimum or base temperature (T(b)) for the germination of H. setaceus was 7 degrees C, and the ceiling temperature varied nearly from 43.5 to 59 degrees C depending on the percent fraction, with median set on 49.8 degrees C. The number of degrees day necessary for 50% of the seeds to germinate in the infra-optimum temperature range was 39.3 degrees C day, whereas at the supra-optimum interval the value of theta = 77 was assumed to be constant throughout. Germination was sensitive to decreasing values of psi in the medium, and both the germinability and the germination rate shift negatively with the reduction of psi, but the rate of reduction changed with temperature. The values of base water potential (psi(b)) shift to zero with increasing temperatures and such variation reflects in the relatively greater effect of low psi on germination in supra optimum range of T. In general, the model described better the germination time courses at lower than at higher water potentials. The analysis also suggest that Tb may not be independent of psi and that psi(b(g)) may change as a function of temperature at the infra-otimum temperature range.

  5. Biological effects of low energy nitrogen ion implantation on Jatropha curcas L. seed germination

    NASA Astrophysics Data System (ADS)

    Xu, Gang; Wang, Xiao-teng; Gan, Cai-ling; Fang, Yan-qiong; Zhang, Meng

    2012-09-01

    To explore the biological effects of nitrogen ion beam implantation on dry Jatropha curcas seed, a beam of N+ with energy of 25 keV was applied to treat the dry seed at six different doses. N+ beam implantation greatly decreased germination rate and seedling survival rate. The doses within the range of 12 × 1016 to 15 × 1016 ions cm-2 severely damaged the seeds: total antioxidant capacity (TAC), germination rate, seedling survival rate, reduced ascorbate acid (HAsA) and reduced glutathione (GSH) contents, and most of the tested antioxidases activity (i.e. catalase (CAT), ascorbate peroxidase (APX) and superoxide dismutase (SOD)) reached their lowest levels. At a dose of 18 × 1016 ion cm-2, biological repair took place: moderate increases were found in TAC, germination rate, seedling survival rate, HAsA and GSH contents, and some antioxidant enzyme activities (i.e. CAT, APX, SOD and GPX). The dose of 18 × 1016 ions cm-2 may be the optimum dose for use in dry J. curcas seed mutation breeding. CAT, HAsA and GSH contributed to the increase of TAC, but CAT was the most important. POD performed its important role as seed was severely damaged. The main role of the HAsA-GSH cycle appeared to be for regeneration of HAsA.

  6. Effects of irrigation frequency and grit color on the germination of lodgepole pine seeds

    Treesearch

    Jeremy R. Pinto; R. Kasten Dumroese; Douglas R. Cobos

    2009-01-01

    Nursery cultural practices during germination can be highly variable between existing production facilities. Although nursery guidebooks suggest keeping seeds moist, there are no known scientific answers indicating what sufficient moisture levels are. This study objective was to characterize differing irrigation regimes and grit color choices on different germination...

  7. Effects of moist cold stratification on germination, plant growth regulators, metabolites and embryo ultrastructure in seeds of Acer morrisonense (Sapindaceae).

    PubMed

    Chen, Shun-Ying; Chou, Shih-Han; Tsai, Ching-Chu; Hsu, Wen-Yu; Baskin, Carol C; Baskin, Jerry M; Chien, Ching-Te; Kuo-Huang, Ling-Long

    2015-09-01

    Breaking of seed dormancy by moist cold stratification involves complex interactions in cells. To assess the effect of moist cold stratification on dormancy break in seeds of Acer morrisonense, we monitored percentages and rates of germination and changes in plant growth regulators, sugars, amino acids and embryo ultrastructure after various periods of cold stratification. Fresh seeds incubated at 25/15 °C for 24 weeks germinated to 61%, while those cold stratified at 5 °C for 12 weeks germinated to 87% in 1 week. Neither exogenous GA3 nor GA4 pretreatment significantly increased final seed germination percentage. Total ABA content of seeds cold stratified for 12 weeks was reduced about 3.3-fold, to a concentration similar to that in germinated seeds (radicle emergence). Endogenous GA3 and GA7 were detected in 8-week and 12-week cold stratified seeds but not in fresh seeds. Numerous protein and lipid bodies were present in the plumule, first true leaves and cotyledons of fresh seeds. Protein and lipid bodies decreased greatly during cold stratification, and concentrations of total soluble sugars and amino acids increased. The major non-polar sugars in fresh seeds were sucrose and fructose, but sucrose increased and fructose decreased significantly during cold stratification. The major free amino acids were proline and tryptophan in fresh seeds, and proline increased and tryptophan decreased during cold stratification. Thus, as dormancy break occurs during cold stratification seeds of A. morrisonense undergo changes in plant growth regulators, proteins, lipids, sugars, amino acids and cell ultrastructure. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  8. Mycorrhizal fungi of Vanilla: diversity, specificity and effects on seed germination and plant growth.

    PubMed

    Porras-Alfaro, Andrea; Bayman, Paul

    2007-01-01

    Mycorrhizal fungi are essential for the germination of orchid seeds. However, the specificity of orchids for their mycorrhizal fungi and the effects of the fungi on orchid growth are controversial. Mycorrhizal fungi have been studied in some temperate and tropical, epiphytic orchids, but the symbionts of tropical, terrestrial orchids are still unknown. Here we study diversity, specificity and function of mycorrhizal fungi in Vanilla, a pantropical genus that is both terrestrial and epiphytic. Mycorrhizal roots were collected from four Vanilla species in Puerto Rico, Costa Rica and Cuba. Cultured and uncultured mycorrhizal fungi were identified by sequencing the internal transcribed spacer region of nuclear rDNA (nrITS) and part of the mitochondrial ribosomal large subunit (mtLSU), and by counting number of nuclei in hyphae. Vanilla spp. were associated with a wide range of mycorrhizal fungi: Ceratobasidium, Thanatephorus and Tulasnella. Related fungi were found in different species of Vanilla, although at different relative frequencies. Ceratobasidium was more common in roots in soil and Tulasnella was more common in roots on tree bark, but several clades of fungi included strains from both substrates. Relative frequencies of genera of mycorrhizal fungi differed significantly between cultured fungi and those detected by direct amplification. Ceratobasidium and Tulasnella were tested for effects on seed germination of Vanilla and effects on growth of Vanilla and Dendrobium plants. We found significant differences among fungi in effects on seed germination and plant growth. Effects of mycorrhizal fungi on Vanilla and Dendrobium were similar: a clade of Ceratobasidium had a consistently positive effect on plant growth and seed germination. This clade has potential use in germination and propagation of orchids. Results confirmed that a single orchid species can be associated with several mycorrhizal fungi with different functional consequences for the plant.

  9. Flying foxes create extensive seed shadows and enhance germination success of pioneer plant species in deforested Madagascan landscapes

    PubMed Central

    Oleksy, Ryszard; Giuggioli, Luca; McKetterick, Thomas J.; Racey, Paul A.

    2017-01-01

    Seed dispersal plays a significant role in forest regeneration and maintenance. Flying foxes are often posited as effective long-distance seed dispersers due to their large home ranges and ability to disperse seeds when flying. We evaluate the importance of the Madagascan flying fox Pteropus rufus in the maintenance and regeneration of forests in one of the world’s priority conservation areas. We tested germination success of over 20,000 seeds from the figs Ficus polita, F. grevei and F. lutea extracted from bat faeces and ripe fruits under progressively more natural conditions, ranging from petri-dishes to outdoor environments. Seeds from all fig species showed increased germination success after passing through the bats’ digestive tracts. Outside, germination success in F. polita was highest in faecal seeds grown under semi-shaded conditions, and seeds that passed through bats showed increased seedling establishment success. We used data from feeding trials and GPS tracking to construct seed shadow maps to visualize seed dispersal patterns. The models use Gaussian probability density functions to predict the likelihood of defecation events occurring after feeding. In captivity, bats had short gut retention times (often < 30 mins), but were sometimes able to retain seeds for over 24h. In the wild, bats travelled 3–5 km within 24–280 min after feeding, when defecation of ingested seeds is very likely. They produced extensive seed shadows (11 bats potentially dispersing seeds over 58,000 ha over 45 total days of tracking) when feeding on figs within their large foraging areas and dispersed the seeds in habitats that were often partially shaded and hence would facilitate germination up to 20 km from the feeding tree. Because figs are important pioneer species, P. rufus is an important dispersal vector that makes a vital contribution to the regeneration and maintenance of highly fragmented forest patches in Madagascar. PMID:28877248

  10. 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

  11. Evaluation of phytotoxicity effect of olive mill wastewater treated by different technologies on seed germination of barley (Hordeum vulgare L.).

    PubMed

    Rusan, Munir J M; Albalasmeh, Ammar A; Zuraiqi, Said; Bashabsheh, Mohammad

    2015-06-01

    Olive-mill wastewater (OMW) is a by-product effluent of olive oil extraction process that is produced in large amount in the Mediterranean region. OMW is believed to induce phytotoxic effect on organisms including seed germination and plant growth. The objective of this study was to evaluate the impact of untreated and treated OMW with different techniques on seed germination of barley (Hordeum vulgare L.). The following treatments were investigated: (1) tap water (control); (2) OMW treated by aerobic biological technology in a Jacto Reactor (JR); (3) OMW treated by solar fenton oxidation (SFO); (4) OMW treated by microfiltration followed by nanofiltration (MF+NF); (5) OMW treated by microfiltration followed by reverse osmosis (MF+RO) process; (6) diluted OMW with tap water (25 % OMW); (7) diluted OMW with tap water (50 % OMW); (8) diluted OMW with tap water (75 % OMW); and (9) untreated OMW (100 % OMW). A germination test was conducted in an incubator at temperature of 23 (∘)C. In each petri dish, a filter paper was mounted and ten seeds of barley were placed on the filter paper. Five milliliter of water were added to each petri dish. The seed germination was determined by counting the number of germinated seeds to calculate the percentage of germination (G %). Germination rate index (GRI), seed vigor index (SVI), and phytotoxicity index (PI) were also calculated. Then, the dry weights and lengths of the shoots and the roots of the germinated seeds were measured. The results show that 100, 75, and 50 %OMW were very phytotoxic and completely prohibited seed germination. However, phytotoxicity decreased significantly following treatments of OMW with all techniques investigated and by the 25 % OMW dilution, as results of removing the phenols and other phytotoxic organic compounds from the OMW or by diluting it. This was evidenced by relative enhancement of the dry weights and lengths of shoot and root as well as the G %, GRI, SVG, and PI. It was concluded that if

  12. Development of an Automated Seed Sowing and Induced Germination System for Space Flight Application

    NASA Technical Reports Server (NTRS)

    Heyenga, A. G.; Kliss, Mark

    1995-01-01

    The successful utilization of higher plants in space flight is likely to require the effective transition of plants through all phases of growth and development. A particularly sensitive and critical stage in this cycle is seed germination. The present inflight capability to manipulate seed from a state of dormancy to germination and the performance of such activity under aseptic conditions is extremely limited. An Automated Sowing Mechanism (ASM) has been designed to address this area of science and technology. The self-contained system is readily compatible with the existing Shuttle middeck locker Plant Growth Unit (PGU) and planned Plant Growth Facility (PGF), presenting an opportunity to extend the experimental capability of these systems. The ASM design encompasses the controlled transition of seed from a dry to hydrated state utilizing solid media substrate as the source of water and nutrient support. System activation has been achieved with both photo and timing mechanisms. Controlled induced germination and development of various plant species has been achieved in ground-based trials. The system is presently being prepared for a KC-135 flight test.

  13. Seed germination ecology of feather lovegrass [Eragrostis tenella (L.) Beauv. Ex Roemer & J.A. Schultes].

    PubMed

    Chauhan, Bhagirath S

    2013-01-01

    Feather lovegrass [Eragrostis tenella (L.) Beauv. Ex Roemer & J.A. Schultes] is a C4 grass weed that has the ability to grow in both lowland and upland conditions. Experiments were conducted in the laboratory and screenhouse to evaluate the effect of environmental factors on germination, emergence, and growth of this weed species. Germination in the light/dark regime was higher at alternating day/night temperatures of 30/20 °C (98%) than at 35/25 °C (83%) or 25/15 °C (62%). Germination was completely inhibited by darkness. The osmotic potential and sodium chloride concentrations required for 50% inhibition of maximum germination were -0.7 MPa and 76 mM, respectively. The highest seedling emergence (69%) was observed from the seeds sown on the soil surface and no seedlings emerged from seeds buried at depths of 0.5 cm or more. The use of residue as mulches significantly reduced the emergence and biomass of feather lovegrass seedlings. A residue amount of 0.5 t ha(-1) was needed to suppress 50% of the maximum seedlings. Because germination was strongly stimulated by light and seedling emergence was the highest for the seeds sown on the soil surface, feather lovegrass is likely to become a problematic weed in zero-till systems. The knowledge gained from this study could help in developing effective and sustainable weed management strategies.

  14. Differential Activity of Striga hermonthica Seed Germination Stimulants and Gigaspora rosea Hyphal Branching Factors in Rice and Their Contribution to Underground Communication

    PubMed Central

    Cardoso, Catarina; Charnikhova, Tatsiana; Jamil, Muhammad; Delaux, Pierre-Marc; Verstappen, Francel; Amini, Maryam; Lauressergues, Dominique; Ruyter-Spira, Carolien; Bouwmeester, Harro

    2014-01-01

    Strigolactones (SLs) trigger germination of parasitic plant seeds and hyphal branching of symbiotic arbuscular mycorrhizal (AM) fungi. There is extensive structural variation in SLs and plants usually produce blends of different SLs. The structural variation among natural SLs has been shown to impact their biological activity as hyphal branching and parasitic plant seed germination stimulants. In this study, rice root exudates were fractioned by HPLC. The resulting fractions were analyzed by MRM-LC-MS to investigate the presence of SLs and tested using bioassays to assess their Striga hermonthica seed germination and Gigaspora rosea hyphal branching stimulatory activities. A substantial number of active fractions were revealed often with very different effect on seed germination and hyphal branching. Fractions containing (−)−orobanchol and ent-2'-epi-5-deoxystrigol contributed little to the induction of S. hermonthica seed germination but strongly stimulated AM fungal hyphal branching. Three SLs in one fraction, putative methoxy-5-deoxystrigol isomers, had moderate seed germination and hyphal branching inducing activity. Two fractions contained strong germination stimulants but displayed only modest hyphal branching activity. We provide evidence that these stimulants are likely SLs although no SL-representative masses could be detected using MRM-LC-MS. Our results show that seed germination and hyphal branching are induced to very different extents by the various SLs (or other stimulants) present in rice root exudates. We propose that the development of rice varieties with different SL composition is a promising strategy to reduce parasitic plant infestation while maintaining symbiosis with AM fungi. PMID:25126953

  15. Germination parameterization and development of an after-ripening thermal-time model for primary dormancy release of Lithospermum arvense seeds.

    PubMed

    Chantre, Guillermo R; Batlla, Diego; Sabbatini, Mario R; Orioli, Gustavo

    2009-06-01

    Models based on thermal-time approaches have been a useful tool for characterizing and predicting seed germination and dormancy release in relation to time and temperature. The aims of the present work were to evaluate the relative accuracy of different thermal-time approaches for the description of germination in Lithospermum arvense and to develop an after-ripening thermal-time model for predicting seed dormancy release. Seeds were dry-stored at constant temperatures of 5, 15 or 24 degrees C for up to 210 d. After different storage periods, batches of 50 seeds were incubated at eight constant temperature regimes of 5, 8, 10, 13, 15, 17, 20 or 25 degrees C. Experimentally obtained cumulative-germination curves were analysed using a non-linear regression procedure to obtain optimal population thermal parameters for L. arvense. Changes in these parameters were described as a function of after-ripening thermal-time and storage temperature. The most accurate approach for simulating the thermal-germination response of L. arvense was achieved by assuming a normal distribution of both base and maximum germination temperatures. The results contradict the widely accepted assumption of a single T(b) value for the entire seed population. The after-ripening process was characterized by a progressive increase in the mean maximum germination temperature and a reduction in the thermal-time requirements for germination at sub-optimal temperatures. The after-ripening thermal-time model developed here gave an acceptable description of the observed field emergence patterns, thus indicating its usefulness as a predictive tool to enhance weed management tactics.

  16. Mycorrhizal compatibility and symbiotic seed germination of orchids from the Coastal Range and Andes in south central Chile.

    PubMed

    Herrera, Hector; Valadares, Rafael; Contreras, Domingo; Bashan, Yoav; Arriagada, Cesar

    2017-04-01

    Little is known about Orchidaceae plants in Chile and their mycorrhizal associations, a key issue for designing protective actions for endangered species. We investigated root fungi from seven terrestrial orchid species to identify potential mycorrhizal fungi. The main characteristics of Rhizoctonia-like fungi were observed under light microscopy, and isolates were identified through PCR-ITS sequencing. Molecular identification of fungal sequences showed a high diversity of fungi colonizing roots. Fungal ability to germinate seeds of different orchids was determined in symbiotic germination tests; 24 fungal groups were isolated, belonging to the genera Tulasnella, Ceratobasidium, and Thanatephorus. Furthermore, dark septate and other endophytic fungi were identified. The high number of Rhizoctonia-like fungi obtained from adult orchids from the Coastal mountain range suggests that, after germination, these orchids may complement their nutritional demands through mycoheterotrophy. Nonetheless, beneficial associations with other endophytic fungi may also co-exist. In this study, isolated mycorrhizal fungi had the ability to induce seed germination at different efficiencies and with low specificity. Germin ation rates were low, but protocorms continued to develop for 60 days. A Tulasnella sp. isolated from Chloraea gavilu was most effective to induce seed germination of different species. The dark septate endophytic (DSE) fungi did not show any effect on seed development; however, their widespread occurrence in some orchids suggests a putative role in plant establishment.

  17. Germination Ecology and Seed Dispersal of a Critically Endangered Plant: A Case Study of Pomaderris vacciniifolia (Round-Leaf Pomaderris)

    PubMed Central

    Dell, Matthew; Gibson, Maria

    2016-01-01

    Change in ecosystem disturbance regimes from human land-use poses a worldwide problem for management of rare species. Two important types of disturbance influencing the persistence of species in Australian ecosystems are habitat fragmentation and fire. In this study, seed dispersal and the germination ecology of Pomaderris vacciniifolia—a critically endangered, rare endemic Australian shrub—were examined to identify likely influences of fire and fragmentation on the decline of populations. The response of seed germination to simulated effects of wildfire and canopy openings was investigated, as was the unaided dispersal capability of seeds from parent plants. A significant increase in germination rate was observed following 100°C heat treatment to seeds, while smoke and light exposure had little influence. Seed imbibition was strongly influenced by heat treatment. The findings indicate a likely positive post-fire germination response, with implications for recruitment success determined by moisture availability following fire. Unaided seed dispersal was limited, which partly explains the apparent decline of populations. Understanding disturbance requirements for threatened species, and subsequent management of landscapes for disturbance, will aid conservation of rare species throughout the world. PMID:27557152

  18. Hydroquinone; A novel bioactive compound from plant-derived smoke can cue seed germination of lettuce

    NASA Astrophysics Data System (ADS)

    Kamran, Muhammad; Khan, Abdul L.; Ali, Liaqat; Hussain, Javid; Waqas, Muhammad; Al-Harrasi, Ahmed; Imran, Qari M.; Kim, Yoon-Ha; Kang, Sang-Mo; Yun, Byung-Wook; Lee, In-Jung

    2017-05-01

    Plant-derived smoke has been known to play an important role in distribution and growth of vegetation. Using a proficiently designed furnace, we extracted smoke from the leaves of four plant viz. Helianthus annuus, Aloe vera, Ginkgo biloba, and Cymbopogon jwarancusa. Smoke dilutions obtained from these plants were obtained in different concentrations to identify potential lettuce growth promoting smoke solution. Results revealed that smoke obtained from Ginkgo biloba significantly enhanced the lettuce seed germination. This solution was then partitioned into ethyl acetate, dichloromethane, n-hexane, chloroform and ether fractions. Ethyl acetate fraction was found to be potent to enhance seed germination. This fraction was subjected to column chromatography and spectroscopic techniques to obtain compound 1. This compound was identified as hydroquinone using 1D and 2D NMR techniques. At low concentrations (5, 10 and 20 ppm), compound 1 enhanced the lettuce seed germination; however, higher concentrations inhibited its growth as compared to control.

  19. Hydroquinone; A Novel Bioactive Compound from Plant-Derived Smoke Can Cue Seed Germination of Lettuce

    PubMed Central

    Kamran, Muhammad; Khan, Abdul L.; Ali, Liaqat; Hussain, Javid; Waqas, Muhammad; Al-Harrasi, Ahmed; Imran, Qari M.; Kim, Yoon-Ha; Kang, Sang-Mo; Yun, Byung-Wook; Lee, In-Jung

    2017-01-01

    Plant-derived smoke has been known to play an important role in distribution and growth of vegetation. Using a proficiently designed furnace, we extracted smoke from the leaves of four plant viz. Helianthus annuus,Aloe vera,Ginkgo biloba, and Cymbopogon jwarancusa. Smoke dilutions obtained from these plants were obtained in different concentrations to identify potential lettuce growth promoting smoke solution. Results revealed that smoke obtained from G. biloba significantly enhanced the lettuce seed germination. This solution was then partitioned into ethyl acetate, dichloromethane, n-hexane, chloroform and ether fractions. Ethyl acetate fraction was found to be potent to enhance seed germination. This fraction was subjected to column chromatography and spectroscopic techniques to obtain compound 1. This compound was identified as hydroquinone using 1D and 2D NMR techniques. At low concentrations (5, 10, and 20 ppm), compound 1 enhanced the lettuce seed germination; however, higher concentrations inhibited its growth as compared to control. PMID:28553632

  20. Hydroquinone; A Novel Bioactive Compound from Plant-Derived Smoke Can Cue Seed Germination of Lettuce.

    PubMed

    Kamran, Muhammad; Khan, Abdul L; Ali, Liaqat; Hussain, Javid; Waqas, Muhammad; Al-Harrasi, Ahmed; Imran, Qari M; Kim, Yoon-Ha; Kang, Sang-Mo; Yun, Byung-Wook; Lee, In-Jung

    2017-01-01

    Plant-derived smoke has been known to play an important role in distribution and growth of vegetation. Using a proficiently designed furnace, we extracted smoke from the leaves of four plant viz. Helianthus annuus , Aloe vera , Ginkgo biloba , and Cymbopogon jwarancusa . Smoke dilutions obtained from these plants were obtained in different concentrations to identify potential lettuce growth promoting smoke solution. Results revealed that smoke obtained from G. biloba significantly enhanced the lettuce seed germination. This solution was then partitioned into ethyl acetate, dichloromethane, n -hexane, chloroform and ether fractions. Ethyl acetate fraction was found to be potent to enhance seed germination. This fraction was subjected to column chromatography and spectroscopic techniques to obtain compound 1 . This compound was identified as hydroquinone using 1D and 2D NMR techniques. At low concentrations (5, 10, and 20 ppm), compound 1 enhanced the lettuce seed germination; however, higher concentrations inhibited its growth as compared to control.

  1. Respiratory metabolism in the embryonic axis of germinating pea seed exposed to cadmium.

    PubMed

    Smiri, Moêz; Chaoui, Abdelilah; El Ferjani, Ezzedine

    2009-02-15

    Seeds of pea (Pisum sativum L.) were germinated for 5d by soaking in distilled water or 5mM cadmium nitrate. The relationships among cadmium stress, germination rate, changes in respiratory enzyme activities and carbohydrates mobilization were studied. Two cell fractions were obtained from embryonic axis: (1) mitochondria, used to determine enzyme activities of citric acid cycle and electron transport chain, and (2) soluble, to measure some enzyme activities involved in fermentation and pentose phosphate pathway. Activities of malate- and succinate-dehydrogenases (MDH, SDH) and NADH- and succinate-cytochrome c reductases (NCCR, SCCR) were rapidly inhibited, while cytochrome c oxidase (CCO) was unaltered by cadmium treatment. However, this stimulated the NADPH-generating enzyme activities of the pentose phosphate pathway, glucose-6-phosphate- and 6-phosphogluconate-dehydrogenases (G6PDH, 6PGDH), as well as enzyme activity of fermentation, alcohol dehydrogenase (ADH), with concomitant inhibition in the capacity of enzyme inactivator (INADH). Moreover, Cd restricted carbohydrate mobilization in the embryonic axis. Almost no glucose and less than 7% of control fructose and total soluble sugars were available in the embryo tissues after 5d of exposure to cadmium. Cotyledonary invertase isoenzyme activity was also inhibited by Cd. The results indicate that cadmium induces disorder in the resumption of respiration in germinating pea seeds. The contribution of Cd-stimulated alternative metabolic pathways to compensate for the failure in mitochondrial respiration is discussed in relation to the delay in seed germination and embryonic axis growth.

  2. Systems biology and genome-wide approaches to unveil the molecular players involved in the pre-germinative metabolism: implications on seed technology traits.

    PubMed

    Macovei, Anca; Pagano, Andrea; Leonetti, Paola; Carbonera, Daniela; Balestrazzi, Alma; Araújo, Susana S

    2017-05-01

    The pre-germinative metabolism is among the most fascinating aspects of seed biology. The early seed germination phase, or pre-germination, is characterized by rapid water uptake (imbibition), which directs a series of dynamic biochemical events. Among those are enzyme activation, DNA damage and repair, and use of reserve storage compounds, such as lipids, carbohydrates and proteins. Industrial seedling production and intensive agricultural production systems require seed stocks with high rate of synchronized germination and low dormancy. Consequently, seed dormancy, a quantitative trait related to the activation of the pre-germinative metabolism, is probably the most studied seed trait in model species and crops. Single omics, systems biology, QTLs and GWAS mapping approaches have unveiled a list of molecules and regulatory mechanisms acting at transcriptional, post-transcriptional and post-translational levels. Most of the identified candidate genes encode for regulatory proteins targeting ROS, phytohormone and primary metabolisms, corroborating the data obtained from simple molecular biology approaches. Emerging evidences show that epigenetic regulation plays a crucial role in the regulation of these mentioned processes, constituting a still unexploited strategy to modulate seed traits. The present review will provide an up-date of the current knowledge on seed pre-germinative metabolism, gathering the most relevant results from physiological, genetics, and omics studies conducted in model and crop plants. The effects exerted by the biotic and abiotic stresses and priming are also addressed. The possible implications derived from the modulation of pre-germinative metabolism will be discussed from the point of view of seed quality and technology.

  3. Effects of stratification and temperature on seed germination speed and uniformity in central Oregon ponderosa pine (Pinus ponderosa Dougl. ex Laws.).

    Treesearch

    John C. Weber; Frank C. Sorensen

    1990-01-01

    Effects of stratification period and incubation temperature on seed germination speed and uniformity were investigated in a bulked seed lot of 200 ponderosa pine trees (Pinus ponderosa Dougl. ex Laws.) sampled from 149 locations in central Oregon. Mean rate of embryo development towards germination (l/days to 50 percent germination) and standard...

  4. Effect of essential oil of Origanum rotundifolium on some plant pathogenic bacteria, seed germination and plant growth of tomato

    NASA Astrophysics Data System (ADS)

    Dadaşoǧlu, Fatih; Kotan, Recep; Karagöz, Kenan; Dikbaş, Neslihan; Ćakmakçi, Ramazan; Ćakir, Ahmet; Kordali, Şaban; Özer, Hakan

    2016-04-01

    The aim of this study is to determine effect of Origanum rotundifolium's essential oil on some plant pathogenic bacterias, seed germination and plant growth of tomato. Xanthomonas axanopodis pv. vesicatoria strain (Xcv-761) and Clavibacter michiganensis ssp. michiganensis strain (Cmm) inoculated to tomato seed. The seeds were tested for germination in vitro and disease severity and some plant growth parameters in vivo. In vitro assay, maximum seed germination was observed at 62,5 µl/ml essential oil treatment in seeds inoculated with Xcv-761 and at 62,5 µl/ml essential oil and streptomycin treatment in seeds inoculated with Cmm. The least infected cotiledon number was observed at 500 µg/ml streptomycin treatment in seeds inoculated with Cmm. In vivo assay, maximum seed germination was observed at 250 µl/ml essential oil teratment in tomato inoculated with Cmm. Lowest disease severity, is seen in the CMM infected seeds with 250 µl/ml essential oil application these results were statistically significant when compared with pathogen infected seeds. Similarly, in application conducted with XCV-761 infected seed, the lowest disease severity was observed for seeds as a result of 250 µl/ml essential oil application. Also according to the results obtained from essential oil application of CMM infected seeds conducted with 62,5 µl/ml dose; while disease severity was found statistically insignificant compared to 250 µl/ml to essential oil application, ıt was found statistically significant compared to pathogen infected seeds. The results showed that essential oil of O. rotundifolium has a potential for some suppressed plant disease when it is used in appropriate dose.

  5. Gibberellic Acid-Stimulated Arabidopsis6 Serves as an Integrator of Gibberellin, Abscisic Acid, and Glucose Signaling during Seed Germination in Arabidopsis.

    PubMed

    Zhong, Chunmei; Xu, Hao; Ye, Siting; Wang, Shiyi; Li, Lingfei; Zhang, Shengchun; Wang, Xiaojing

    2015-11-01

    The DELLA protein REPRESSOR OF ga1-3-LIKE2 (RGL2) plays an important role in seed germination under different conditions through a number of transcription factors. However, the functions of the structural genes associated with RGL2-regulated germination are less defined. Here, we report the role of an Arabidopsis (Arabidopsis thaliana) cell wall-localized protein, Gibberellic Acid-Stimulated Arabidopsis6 (AtGASA6), in functionally linking RGL2 and a cell wall loosening expansin protein (Arabidopsis expansin A1 [AtEXPA1]), resulting in the control of embryonic axis elongation and seed germination. AtGASA6-overexpressing seeds showed precocious germination, whereas transfer DNA and RNA interference mutant seeds displayed delayed seed germination under abscisic acid, paclobutrazol, and glucose (Glc) stress conditions. The differences in germination rates resulted from corresponding variation in cell elongation in the hypocotyl-radicle transition region of the embryonic axis. AtGASA6 was down-regulated by RGL2, GLUCOSE INSENSITIVE2, and ABSCISIC ACID-INSENSITIVE5 genes, and loss of AtGASA6 expression in the gasa6 mutant reversed the insensitivity shown by the rgl2 mutant to paclobutrazol and the gin2 mutant to Glc-induced stress, suggesting that it is involved in regulating both the gibberellin and Glc signaling pathways. Furthermore, it was found that the promotion of seed germination and length of embryonic axis by AtGASA6 resulted from a promotion of cell elongation at the embryonic axis mediated by AtEXPA1. Taken together, the data indicate that AtGASA6 links RGL2 and AtEXPA1 functions and plays a role as an integrator of gibberellin, abscisic acid, and Glc signaling, resulting in the regulation of seed germination through a promotion of cell elongation. © 2015 American Society of Plant Biologists. All Rights Reserved.

  6. Low-dose ionizing radiation limitations to seed germination: Results from a model linking physiological characteristics and developmental-dynamics simulation strategy.

    PubMed

    Liu, Hui; Hu, Dawei; Dong, Chen; Fu, Yuming; Liu, Guanghui; Qin, Youcai; Sun, Yi; Liu, Dianlei; Li, Lei; Liu, Hong

    2017-08-01

    There is much uncertainty about the risks of seed germination after repeated or protracted environmental low-dose ionizing radiation exposure. The purpose of this study is to explore the influence mechanism of low-dose ionizing radiation on wheat seed germination using a model linking physiological characteristics and developmental-dynamics simulation. A low-dose ionizing radiation environment simulator was built to investigate wheat (Triticum aestivum L.) seeds germination process and then a kinetic model expressing the relationship between wheat seed germination dynamics and low-dose ionizing radiation intensity variations was developed by experimental data, plant physiology, relevant hypotheses and system dynamics, and sufficiently validated and accredited by computer simulation. Germination percentages were showing no differences in response to different dose rates. However, root and shoot lengths were reduced significantly. Plasma governing equations were set up and the finite element analysis demonstrated H 2 O, CO 2 , O 2 as well as the seed physiological responses to the low-dose ionizing radiation. The kinetic model was highly valid, and simultaneously the related influence mechanism of low-dose ionizing radiation on wheat seed germination proposed in the modeling process was also adequately verified. Collectively these data demonstrate that low-dose ionizing radiation has an important effect on absorbing water, consuming O 2 and releasing CO 2 , which means the risk for embryo and endosperm development was higher. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Effects of some pretreatments on germination of bladder-senna (Colutea armena Boiss. and Huet.) and smoke-tree (Cotinus coggygria Scop.) seeds.

    PubMed

    Olmez, Zafer; Yahyaoglu, Zeki; Temel, Fatih; Gokturk, Askin

    2008-05-01

    This study was carried out to determine effects of pre-treatments including floating in hot water(100 degrees C) followed by continual cooling for 24 hr in the same water floating in tap water for 24 hr submersion in concentrate (98%) sulphuric acid (H2SO4) and cold stratification for different durations (20, 40 and 60 days) and their combinations on seed germination and to investigate how to overcome dormancy of seeds of Colutea armena Boiss. and Huet. and Cotinus coggygria Scop. The seeds were sown in polyethylene pots in the greenhouse and on seedbeds under open field conditions. The statistical design was a randomized complete block design with three replications. The highest germination percentage (77.19%), the best germination rate (16 days) and the highest growth rate (69.01%) were obtained from Colutea armena seeds that were submersed in sulphuric acid for 30 min and sown in the greenhouse. The pre-treatment of submersion in sulphuric acid for 20 min with cold stratification for 60 days gave the highest germination percentage (82.77%) and the highest growth rate (79.37%) in the greenhouse for Cotinus coggygria seeds. On the other hand, the best germination rate (9 days) was obtained from smoketree seeds that were cold stratified 60 days and sown under open field conditions. It can be stated that there is an affirmative effect of the greenhouse condition on germination percentage and growth rate values of the seeds used in this study

  8. Phthalimide-derived strigolactone mimics as germinating agents for seeds of parasitic weeds.

    PubMed

    Cala, Antonio; Ghooray, Kala; Fernández-Aparicio, Mónica; Molinillo, José Mg; Galindo, Juan Cg; Rubiales, Diego; Macías, Francisco A

    2016-11-01

    Broomrapes attack important crops, cause severe yield losses and are difficult to eliminate because their seed bank is virtually indestructible. In the absence of a host, the induction of seed germination leads to inevitable death due to nutrient starvation. Synthetic analogues of germination-inducing factors may constitute a cheap and feasible strategy to control the seed bank. These compounds should be easy and cheap to synthesise, as this will allow their mass production. The aim of this work is to obtain new synthethic germinating agents. Nineteen N-substituted phthalimides containing a butenolide ring and different substituents in the aromatic ring were synthesised. The synthesis started with commercially available phthalimides. The complete collection was assayed against the parasitic weeds Orobanche minor, O. cumana, Phelipanche ramosa and P. aegyptiaca, with the synthetic strigolactone analogue GR24 used as a positive control. These compounds offered low EC 50 values: O. cumana 38.3 μM, O. minor 3.77 μM, P. aegyptiaca 1.35 μM and P. ramosa 1.49 μM. The synthesis was carried out in a few steps and provided the target compounds in good yields. The compounds tested showed great selectivity, and low EC 50 values were obtained for structures that were simpler than GR24. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  9. 7 CFR 201.63 - Germination.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... germination and also to the sum of the germination plus the hard seed when 400 or more seeds are tested. Mean... 7 Agriculture 3 2010-01-01 2010-01-01 false Germination. 201.63 Section 201.63 Agriculture..., Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT...

  10. 7 CFR 201.63 - Germination.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... germination and also to the sum of the germination plus the hard seed when 400 or more seeds are tested. Mean... 7 Agriculture 3 2011-01-01 2011-01-01 false Germination. 201.63 Section 201.63 Agriculture..., Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT...

  11. Dough performance, quality and shelf life of flat bread supplemented with fractions of germinated date seed.

    PubMed

    Hejri-Zarifi, Sudiyeh; Ahmadian-Kouchaksaraei, Zahra; Pourfarzad, Amir; Khodaparast, Mohammad Hossein Haddad

    2014-12-01

    Germinated palm date seeds were milled into two fractions: germ and residue. Dough rheological characteristics, baking (specific volume and sensory evaluation), and textural properties (at first day and during storage for 5 days) were determined in Barbari flat bread. Germ and residue fractions were incorporated at various levels ranged in 0.5-3 g/100 g of wheat flour. Water absorption, arrival time and gelatination temperature were decreased by germ fraction but accompanied by an increasing effect on the mixing tolerance index and degree of softening in most levels. Although improvement in dough stability was monitored but specific volume of bread was not affected by both fractions. Texture analysis of bread samples during 5 days of storage indicated that both fractions of germinated date seeds were able to diminish bread staling. Avrami non-linear regression equation was chosen as useful mathematical model to properly study bread hardening kinetics. In addition, principal component analysis (PCA) allowed discriminating among dough and bread specialties. Partial least squares regression (PLSR) models were applied to determine the relationships between sensory and instrumental data.

  12. Soilborne fungi have host affinity and host-specific effects on seed germination and survival in a lowland tropical forest.

    PubMed

    Sarmiento, Carolina; Zalamea, Paul-Camilo; Dalling, James W; Davis, Adam S; Stump, Simon M; U'Ren, Jana M; Arnold, A Elizabeth

    2017-10-24

    The Janzen-Connell (JC) hypothesis provides a conceptual framework for explaining the maintenance of tree diversity in tropical forests. Its central tenet-that recruits experience high mortality near conspecifics and at high densities-assumes a degree of host specialization in interactions between plants and natural enemies. Studies confirming JC effects have focused primarily on spatial distributions of seedlings and saplings, leaving major knowledge gaps regarding the fate of seeds in soil and the specificity of the soilborne fungi that are their most important antagonists. Here we use a common garden experiment in a lowland tropical forest in Panama to show that communities of seed-infecting fungi are structured predominantly by plant species, with only minor influences of factors such as local soil type, forest characteristics, or time in soil (1-12 months). Inoculation experiments confirmed that fungi affected seed viability and germination in a host-specific manner and that effects on seed viability preceded seedling emergence. Seeds are critical components of reproduction for tropical trees, and the factors influencing their persistence, survival, and germination shape the populations of seedlings and saplings on which current perspectives regarding forest dynamics are based. Together these findings bring seed dynamics to light in the context of the JC hypothesis, implicating them directly in the processes that have emerged as critical for diversity maintenance in species-rich tropical forests.

  13. Soilborne fungi have host affinity and host-specific effects on seed germination and survival in a lowland tropical forest

    PubMed Central

    Dalling, James W.; Stump, Simon M.; U’Ren, Jana M.; Arnold, A. Elizabeth

    2017-01-01

    The Janzen–Connell (JC) hypothesis provides a conceptual framework for explaining the maintenance of tree diversity in tropical forests. Its central tenet—that recruits experience high mortality near conspecifics and at high densities—assumes a degree of host specialization in interactions between plants and natural enemies. Studies confirming JC effects have focused primarily on spatial distributions of seedlings and saplings, leaving major knowledge gaps regarding the fate of seeds in soil and the specificity of the soilborne fungi that are their most important antagonists. Here we use a common garden experiment in a lowland tropical forest in Panama to show that communities of seed-infecting fungi are structured predominantly by plant species, with only minor influences of factors such as local soil type, forest characteristics, or time in soil (1–12 months). Inoculation experiments confirmed that fungi affected seed viability and germination in a host-specific manner and that effects on seed viability preceded seedling emergence. Seeds are critical components of reproduction for tropical trees, and the factors influencing their persistence, survival, and germination shape the populations of seedlings and saplings on which current perspectives regarding forest dynamics are based. Together these findings bring seed dynamics to light in the context of the JC hypothesis, implicating them directly in the processes that have emerged as critical for diversity maintenance in species-rich tropical forests. PMID:28973927

  14. Cross-species approaches to seed dormancy and germination: conservation and biodiversity of ABA-regulated mechanisms and the Brassicaceae DOG1 genes.

    PubMed

    Graeber, Kai; Linkies, Ada; Müller, Kerstin; Wunchova, Andrea; Rott, Anita; Leubner-Metzger, Gerhard

    2010-05-01

    Seed dormancy is genetically determined with substantial environmental influence mediated, at least in part, by the plant hormone abscisic acid (ABA). The ABA-related transcription factor ABI3/VP1 (ABA INSENSITIVE3/VIVIPAROUS1) is widespread among green plants. Alternative splicing of its transcripts appears to be involved in regulating seed dormancy, but the role of ABI3/VP1 goes beyond seeds and dormancy. In contrast, DOG1 (DELAY OF GERMINATION 1), a major quantitative trait gene more specifically involved in seed dormancy, was so far only known from Arabidopsis thaliana (AtDOG1) and whether it also has roles during the germination of non-dormant seeds was not known. Seed germination of Lepidium sativum ('garden cress') is controlled by ABA and its antagonists gibberellins and ethylene and involves the production of apoplastic hydroxyl radicals. We found orthologs of AtDOG1 in the Brassicaceae relatives L. sativum (LesaDOG1) and Brassica rapa (BrDOG1) and compared their gene structure and the sequences of their transcripts expressed in seeds. Tissue-specific analysis of LesaDOG1 transcript levels in L. sativum seeds showed that they are degraded upon imbibition in the radicle and the micropylar endosperm. ABA inhibits germination in that it delays radicle protrusion and endosperm weakening and it increased LesaDOG1 transcript levels during early germination due to enhanced transcription and/or inhibited degradation. A reduced decrease in LesaDOG1 transcript levels upon ABA treatment is evident in the late germination phase in both tissues. This temporal and ABA-related transcript expression pattern suggests a role for LesaDOG1 in the control of germination timing of non-dormant L. sativum seeds. The possible involvement of the ABA-related transcription factors ABI3 and ABI5 in the regulation of DOG1 transcript expression is discussed. Other species of the monophyletic genus Lepidium showed coat or embryo dormancy and are therefore highly suited for comparative

  15. Germination biology of Hibiscus tridactylites in Australia and the implications for weed management

    PubMed Central

    Chauhan, Bhagirath Singh

    2016-01-01

    Hibiscus tridactylites is a problematic broadleaf weed in many crops in Australia; however, very limited information is available on seed germination biology of Australian populations. Experiments were conducted to evaluate the effect of environmental factors on germination and emergence of H. tridactylites. Germination was stimulated by seed scarification, suggesting the inhibition of germination in this species is mainly due to the hard seed coat. Germination was not affected by light conditions, suggesting that seeds of this species are not photoblastic. Germination was higher at alternating day/night temperatures of 30/20 °C (74%) and 35/25 °C (69%) than at 25/15 °C (63%). Moderate salinity and water stress did not inhibit germination of H. tridactylites. Seedling emergence of H. tridactylites was highest (57%) for the seeds buried at a 2 cm depth in the soil; 18% of seedlings emerged from seeds buried at 8 cm but no seedlings emerged below this depth. Soil inversion by tillage to bury weed seeds below their maximum depth of emergence could serve an important tool for managing H. tridactylites. PMID:27174752

  16. Germination biology of Hibiscus tridactylites in Australia and the implications for weed management

    NASA Astrophysics Data System (ADS)

    Chauhan, Bhagirath Singh

    2016-05-01

    Hibiscus tridactylites is a problematic broadleaf weed in many crops in Australia; however, very limited information is available on seed germination biology of Australian populations. Experiments were conducted to evaluate the effect of environmental factors on germination and emergence of H. tridactylites. Germination was stimulated by seed scarification, suggesting the inhibition of germination in this species is mainly due to the hard seed coat. Germination was not affected by light conditions, suggesting that seeds of this species are not photoblastic. Germination was higher at alternating day/night temperatures of 30/20 °C (74%) and 35/25 °C (69%) than at 25/15 °C (63%). Moderate salinity and water stress did not inhibit germination of H. tridactylites. Seedling emergence of H. tridactylites was highest (57%) for the seeds buried at a 2 cm depth in the soil; 18% of seedlings emerged from seeds buried at 8 cm but no seedlings emerged below this depth. Soil inversion by tillage to bury weed seeds below their maximum depth of emergence could serve an important tool for managing H. tridactylites.

  17. Effects of various treatments on seed germination and growth of carob (Ceratonia siliqua L.)

    USDA-ARS?s Scientific Manuscript database

    Carob (Ceratonia siliqua L.) plays an important role in Mediterranean landscape. It is commercially propagated by grafting which requires the generation of seedlings. However, its seeds are very recalcitrant and need pretreatment for germination. In this study, carob seeds harvested from both wild a...

  18. 7 CFR 201.29 - Germination of vegetable seed in containers of 1 pound or less.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false Germination of vegetable seed in containers of 1 pound or less. 201.29 Section 201.29 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED AC...

  19. 7 CFR 201.29 - Germination of vegetable seed in containers of 1 pound or less.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 3 2012-01-01 2012-01-01 false Germination of vegetable seed in containers of 1 pound or less. 201.29 Section 201.29 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED AC...

  20. 7 CFR 201.29 - Germination of vegetable seed in containers of 1 pound or less.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Germination of vegetable seed in containers of 1 pound or less. 201.29 Section 201.29 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED AC...