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Sample records for cell growth plant

  1. Thermodynamics of irreversible plant cell growth

    Directory of Open Access Journals (Sweden)

    Mariusz Pietruszka

    2011-04-01

    Full Text Available The time-irreversible cell enlargement of plant cells at a constant temperature results from two independent physical processes, e.g. water absorption and cell wall yielding. In such a model cell growth starts with reduction in wall stress because of irreversible extension of the wall. The water absorption and physical expansion are spontaneous consequences of this initial modification of the cell wall (the juvenile cell vacuolate, takes up water and expands. In this model the irreversible aspect of growth arises from the extension of the cell wall. Such theory expressed quantitatively by time-dependent growth equation was elaborated by Lockhart in the 60's.The growth equation omit however a very important factor, namely the environmental temperature at which the plant cells grow. In this paper we put forward a simple phenomenological model which introduces into the growth equation the notion of temperature. Moreover, we introduce into the modified growth equation the possible influence of external growth stimulator or inhibitor (phytohormones or abiotic factors. In the presence of such external perturbations two possible theoretical solutions have been found: the linear reaction to the application of growth hormones/abiotic factors and the non-linear one. Both solutions reflect and predict two different experimental conditions, respectively (growth at constant or increasing concentration of stimulator/inhibitor. The non-linear solution reflects a common situation interesting from an environmental pollution point of view e.g. the influence of increasing (with time concentration of toxins on plant growth. Having obtained temperature modified growth equations we can draw further qualitative and, especially, quantitative conclusions about the mechanical properties of the cell wall itself. This also concerns a new and interesting result obtained in our model: We have calculated the magnitude of the cell wall yielding coefficient (T [m3 J-1•s-1] in

  2. Cloning and analysis of genes regulating plant cell growth

    International Nuclear Information System (INIS)

    The aims of this work are to identify, clone and analyze genes involved in the regulation of plant cell growth. To do this, we have induced tumors on Arabidopsis thaliana by exposing seed or germinating seedlings to ionizing radiation. The tumors which developed on the plants derived from these seed were excised and established in culture. Unlike normal tissue explants, the tumors are able to grow on hormone-free medium suggesting changes in growth control (either hormonal or other) induced by the radiation exposure. This progress report describes work aimed at characterizing these tumors at the physiological and cellular levels and at determining the molecular basis of the changes leading to the tumorous phenotype

  3. Aspects of plant cell growth and the actin cytoskeleton: lessons from root hairs

    NARCIS (Netherlands)

    Ruijter, de N.C.A.

    1999-01-01

    The main topic the thesis addresses is the role of the actin cytoskeleton in the growth process of plant cells. Plant growth implies a combination of cell division and cell expansion. The cytoskeleton, which exists of microtubules and actin filaments, plays a major role in both processes. Before cel

  4. Morphological Transformation of Plant Cells in vitro and Its Effect on Plant Growth

    Institute of Scientific and Technical Information of China (English)

    GUO Zhigang; ZENG Zhaolin; LIU Ruizhi; DENG Ying

    2005-01-01

    Enhancement of cell growth in suspension cultures is urgently needed in plant cell culture engineering. This study investigates the relationship between morphological transformation and cell growth in callus and suspension cultures of saffron cells belonging to the cell line C96 induced from Crocus sativus L. In the suspension culture, an unbalanced osmotic pressure between the intracell and extracell regions induced a large morphological transformation which affected normal division of the saffron cells. An increase in osmotic pressure caused by the addition of sucrose inhibits the vacuolation and shrinkage of cytoplasm in the cells. As the sucrose concentration increases, the total amount of accumulated biomass also increases. Besides the sucrose concentration, increased ionic strength and inoculation ratio also help restrain to a large extent the vacuolation and shrinkage of the cytoplasm in the suspended cells, which results in increased biomass. The conditions for optimal biomass are: Murashige and Skoog's (MS) medium with 40 g/L sucrose and 60% (v/v) inoculation ratio.

  5. [Plant hormones, plant growth regulators].

    Science.gov (United States)

    Végvári, György; Vidéki, Edina

    2014-06-29

    Plants seem to be rather defenceless, they are unable to do motion, have no nervous system or immune system unlike animals. Besides this, plants do have hormones, though these substances are produced not in glands. In view of their complexity they lagged behind animals, however, plant organisms show large scale integration in their structure and function. In higher plants, such as in animals, the intercellular communication is fulfilled through chemical messengers. These specific compounds in plants are called phytohormones, or in a wide sense, bioregulators. Even a small quantity of these endogenous organic compounds are able to regulate the operation, growth and development of higher plants, and keep the connection between cells, tissues and synergy between organs. Since they do not have nervous and immume systems, phytohormones play essential role in plants' life.

  6. Wall extensibility: its nature, measurement and relationship to plant cell growth

    Science.gov (United States)

    Cosgrove, D. J.

    1993-01-01

    Expansive growth of plant cells is controlled principally by processes that loosen the wall and enable it to expand irreversibly. The central role of wall relaxation for cell expansion is reviewed. The most common methods for assessing the extension properties of plant cell walls ( wall extensibility') are described, categorized and assessed critically. What emerges are three fundamentally different approaches which test growing cells for their ability (a) to enlarge at different values of turgor, (b) to induce wall relaxation, and (c) to deform elastically or plastically in response to an applied tensile force. Analogous methods with isolated walls are similarly reviewed. The results of these different assays are related to the nature of plant cell growth and pertinent biophysical theory. I argue that the extensibilities' measured by these assays are fundamentally different from one another and that some are more pertinent to growth than others.

  7. Reversal of an immunity associated plant cell death program by the growth regulator auxin

    Directory of Open Access Journals (Sweden)

    Gopalan Suresh

    2008-12-01

    Full Text Available Abstract Background One form of plant immunity against pathogens involves a rapid host programmed cell death at the site of infection accompanied by the activation of local and systemic resistance to pathogens, termed the hypersensitive response (HR. In this work it was tested (i if the plant growth regulator auxin can inhibit the cell death elicited by a purified proteinaceous HR elicitor, (ii how far down the process this inhibition can be achieved, and (iii if the inhibition affects reporters of immune response. The effect of constitutive modulation of endogenous auxin levels in transgenic plants on this cell death program was also evaluated. Results The HR programmed cell death initiated by a bacterial type III secretion system dependent proteinaceous elicitor harpin (from Erwinia amylovora can be reversed till very late in the process by the plant growth regulator auxin. Early inhibition or late reversal of this cell death program does not affect marker genes correlated with local and systemic resistance. Transgenic plants constitutively modulated in endogenous levels of auxin are not affected in ability or timing of cell death initiated by harpin. Conclusion These data indicate that the cell death program initiated by harpin can be reversed till late in the process without effect on markers strongly correlated with local and systemic immunity. The constitutive modulation of endogenous auxin does not affect equivalent signaling processes affecting cell death or buffers these signals. The concept and its further study has utility in choosing better strategies for treating mammalian and agricultural diseases.

  8. Targeting and Regulation of Cell Wall Synthesis During Tip Growth in Plants

    Institute of Scientific and Technical Information of China (English)

    Fangwei Gu; Erik Nielsen

    2013-01-01

    Root hairs and pollen tubes are formed through tip growth, a process requiring synthesis of new cell wall material and the precise targeting and integration of these components to a selected apical plasma membrane domain in the growing tips of these cells. Presence of a tip-focused calcium gradient, control of actin cytoskeleton dynamics, and formation and targeting of secretory vesicles are essential to tip growth. Similar to cells undergoing diffuse growth, cellulose, hemi-celluloses, and pectins are also deposited in the growing apices of tip-growing cells. However, differences in the manner in which these cell wall components are targeted and inserted in the expanding portion of tip-growing cells is reflected by the identification of elements of the plant cell wall synthesis machinery which have been shown to play unique roles in tip-growing cells. In this review, we summarize our current understanding of the tip growth process, with a particular focus on the subcellular targeting of newly synthesized cell wall components, and their roles in this form of plant cell expansion.

  9. Turning a plant tissue into a living cell froth through isotropic growth.

    Science.gov (United States)

    Corson, Francis; Hamant, Olivier; Bohn, Steffen; Traas, Jan; Boudaoud, Arezki; Couder, Yves

    2009-05-26

    The forms resulting from growth processes are highly sensitive to the nature of the driving impetus, and to the local properties of the medium, in particular, its isotropy or anisotropy. In turn, these local properties can be organized by growth. Here, we consider a growing plant tissue, the shoot apical meristem of Arabidopsis thaliana. In plants, the resistance of the cell wall to the growing internal turgor pressure is the main factor shaping the cells and the tissues. It is well established that the physical properties of the walls depend on the oriented deposition of the cellulose microfibrils in the extracellular matrix or cell wall; this order is correlated to the highly oriented cortical array of microtubules attached to the inner side of the plasma membrane. We used oryzalin to depolymerize microtubules and analyzed its influence on the growing meristem. This had no short-term effect, but it had a profound impact on the cell anisotropy and the resulting tissue growth. The geometry of the cells became similar to that of bubbles in a soap froth. At a multicellular scale, this switch to a local isotropy induced growth into spherical structures. A theoretical model is presented in which a cellular structure grows through the plastic yielding of its walls under turgor pressure. The simulations reproduce the geometrical properties of a normal tissue if cell division is included. If not, a "cell froth" very similar to that observed experimentally is obtained. Our results suggest strong physical constraints on the mechanisms of growth regulation. PMID:19423667

  10. Multiwalled carbon nanotubes enter broccoli cells enhancing growth and water uptake of plants exposed to salinity

    OpenAIRE

    Martínez-Ballesta, Mª Carmen; Zapata, Lavinia; Chalbi, Najla; Carvajal, Micaela

    2016-01-01

    Background Carbon nanotubes have been shown to improve the germination and growth of some plant species, extending the applicability of the emerging nano-biotechnology field to crop science. Results In this work, exploitation of commercial multiwalled carbon nanotubes (MWCNTs) in control and 100 mM NaCl-treated broccoli was performed. Transmission electron microscopy demonstrated that MWCNTs can enter the cells in adult plants with higher accumulation under salt stress. Positive effect of MWC...

  11. Direct Image-Based Enumeration of Clostridium phytofermentans Cells on Insoluble Plant Biomass Growth Substrates.

    Science.gov (United States)

    Alvelo-Maurosa, Jesús G; Lee, Scott J; Hazen, Samuel P; Leschine, Susan B

    2016-02-01

    A dual-fluorescent-dye protocol to visualize and quantify Clostridium phytofermentans ISDg (ATCC 700394) cells growing on insoluble cellulosic substrates was developed by combining calcofluor white staining of the growth substrate with cell staining using the nucleic acid dye Syto 9. Cell growth, cell substrate attachment, and fermentation product formation were investigated in cultures containing either Whatman no. 1 filter paper, wild-type Sorghum bicolor, or a reduced-lignin S. bicolor double mutant (bmr-6 bmr-12 double mutant) as the growth substrate. After 3 days of growth, cell numbers in cultures grown on filter paper as the substrate were 6.0- and 2.2-fold higher than cell numbers in cultures with wild-type sorghum and double mutant sorghum, respectively. However, cells produced more ethanol per cell when grown with either sorghum substrate than with filter paper as the substrate. Ethanol yields of cultures were significantly higher with double mutant sorghum than with wild-type sorghum or filter paper as the substrate. Moreover, ethanol production correlated with cell attachment in sorghum cultures: 90% of cells were directly attached to the double mutant sorghum substrate, while only 76% of cells were attached to wild-type sorghum substrate. With filter paper as the growth substrate, ethanol production was correlated with cell number; however, with either wild-type or mutant sorghum, ethanol production did not correlate with cell number, suggesting that only a portion of the microbial cell population was active during growth on sorghum. The dual-staining procedure described here may be used to visualize and enumerate cells directly on insoluble cellulosic substrates, enabling in-depth studies of interactions of microbes with plant biomass. PMID:26637592

  12. The biochemical control of the cell cycle by growth regulators in higher plants

    Institute of Scientific and Technical Information of China (English)

    TANGWei; LatoyaHarris; RonaldJ.Newton

    2004-01-01

    The cell cycle is an important research field in cell biology and it is genetically and developmentally regulated in animals and plants. The aim of this study was to review knowledge about the biochemical regulation of the cell cycle by plant growth regulators through molecular checkpoints that regulate the transition from G0-G1-S-phase and G2-M in higher plants.Recent research has shown that zeatin treatment led to the up-regulation of CycD3 in Arabidopsis. Benzyladenine treatment can also shorten the duration of S-phase through recruitment of latent origins of DNA replication. Kinetin is involved in the phosphoregulation of the G2-M checkpoint; the major cyclin-dependent kinase (Cdk) at this checkpoint has recently shown to be dephosphorylated as a result of cytokinin treatment, an effect that can also be mimicked by the fission yeast Cdc25 phosphatase. Gibberellic acid (GA) treatment induces internode elongation in deepwater rice, this response is mediated by a GA-induced up-regulation of a cyclin-Cdk at the G2-M checkpoint. Recent evidence has also linked abscisic acid to a cyclin-dependent kinase inhibitor. A new D-type cyclin, recently discovered in Arabidopsis may have a key role in this process. A brief review on plant growth regulator-cell cycle interfacing during development and a cytokinin-induced continuum of cell cycle activation through the up-regulation of a plant D-type cyclin at the G1 checkpoint and the phosphoregulation of the Cdk at the G2/M checkpoint had been concluded. This review could be valuable to research on cell and developmental biology in plants.

  13. Plant Growth Regulators.

    Science.gov (United States)

    Nickell, Louis G.

    1978-01-01

    Describes the effect of "plant growth regulators" on plants, such as controlling the flowering, fruit development, plant size, and increasing crop yields. Provides a list of plant growth regulators which includes their chemical, common, and trade names, as well as their different use(s). (GA)

  14. Boron Plays an Important Role in the Regulation of Plant Cell Growth

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Boron is an essential nutrition for higher plants.However, the primary function of boron remains a matter of discussion.Boron may function by forming complexes with compounds having cis-hydroxyl groups(diols), e.g., pectic materials in cell walls, glycoproteins or glycolipids in membranes and o-diphenols.The well-defined functions of boron are its involvement in maintaining cell wall structure and both the structural and the functional integrity of plasma membrane.Lack of boron causes an increase in the leakage of ions and compounds which reflects the impairment of plasma membrane.Boron is functionally important in forming a pectic network in cell wall which is responsible for the extensibility of cell wall and consequently regulates cell growth.

  15. Enterococcus faecium LKE12 Cell-Free Extract Accelerates Host Plant Growth via Gibberellin and Indole-3-Acetic Acid Secretion.

    Science.gov (United States)

    Lee, Ko-Eun; Radhakrishnan, Ramalingam; Kang, Sang-Mo; You, Young-Hyun; Joo, Gil-Jae; Lee, In-Jung; Ko, Jae-Hwan; Kim, Jin-Ho

    2015-09-01

    The use of microbial extracts containing plant hormones is a promising technique to improve crop growth. Little is known about the effect of bacterial cell-free extracts on plant growth promotion. This study, based on phytohormonal analyses, aimed at exploring the potential mechanisms by which Enterococcus faecium LKE12 enhances plant growth in oriental melon. A bacterial strain, LKE12, was isolated from soil, and further identified as E. faecium by 16S rDNA sequencing and phylogenetic analysis. The plant growth-promoting ability of an LKE12 bacterial culture was tested in a gibberellin (GA)-deficient rice dwarf mutant (waito-C) and a normal GA biosynthesis rice cultivar (Hwayongbyeo). E. faecium LKE12 significantly improved the length and biomass of rice shoots in both normal and dwarf cultivars through the secretion of an array of gibberellins (GA1, GA3, GA7, GA8, GA9, GA12, GA19, GA20, GA24, and GA53), as well as indole-3-acetic acid (IAA). To the best of our knowledge, this is the first study indicating that E. faecium can produce GAs. Increases in shoot and root lengths, plant fresh weight, and chlorophyll content promoted by E. faecium LKE12 and its cell-free extract inoculated in oriental melon plants revealed a favorable interaction of E. faecium LKE12 with plants. Higher plant growth rates and nutrient contents of magnesium, calcium, sodium, iron, manganese, silicon, zinc, and nitrogen were found in cell-free extract-treated plants than in control plants. The results of the current study suggest that E. faecium LKE12 promotes plant growth by producing GAs and IAA; interestingly, the exogenous application of its cell-free culture extract can be a potential strategy to accelerate plant growth.

  16. Enterococcus faecium LKE12 Cell-Free Extract Accelerates Host Plant Growth via Gibberellin and Indole-3-Acetic Acid Secretion.

    Science.gov (United States)

    Lee, Ko-Eun; Radhakrishnan, Ramalingam; Kang, Sang-Mo; You, Young-Hyun; Joo, Gil-Jae; Lee, In-Jung; Ko, Jae-Hwan; Kim, Jin-Ho

    2015-09-01

    The use of microbial extracts containing plant hormones is a promising technique to improve crop growth. Little is known about the effect of bacterial cell-free extracts on plant growth promotion. This study, based on phytohormonal analyses, aimed at exploring the potential mechanisms by which Enterococcus faecium LKE12 enhances plant growth in oriental melon. A bacterial strain, LKE12, was isolated from soil, and further identified as E. faecium by 16S rDNA sequencing and phylogenetic analysis. The plant growth-promoting ability of an LKE12 bacterial culture was tested in a gibberellin (GA)-deficient rice dwarf mutant (waito-C) and a normal GA biosynthesis rice cultivar (Hwayongbyeo). E. faecium LKE12 significantly improved the length and biomass of rice shoots in both normal and dwarf cultivars through the secretion of an array of gibberellins (GA1, GA3, GA7, GA8, GA9, GA12, GA19, GA20, GA24, and GA53), as well as indole-3-acetic acid (IAA). To the best of our knowledge, this is the first study indicating that E. faecium can produce GAs. Increases in shoot and root lengths, plant fresh weight, and chlorophyll content promoted by E. faecium LKE12 and its cell-free extract inoculated in oriental melon plants revealed a favorable interaction of E. faecium LKE12 with plants. Higher plant growth rates and nutrient contents of magnesium, calcium, sodium, iron, manganese, silicon, zinc, and nitrogen were found in cell-free extract-treated plants than in control plants. The results of the current study suggest that E. faecium LKE12 promotes plant growth by producing GAs and IAA; interestingly, the exogenous application of its cell-free culture extract can be a potential strategy to accelerate plant growth. PMID:25907061

  17. Influences of Plant Growth Regulators,Basal Media and Carbohydrate Levels on Cell Suspension Culture of Panax ginseng

    Institute of Scientific and Technical Information of China (English)

    TangWei; WuJiongyuan; 等

    1995-01-01

    A cell suspension culture of Panax ginseng which may be continuously subcultured has been established.Embryogenic callus derived from clutured young leaves was used to initiate the culture,Plant growth regulators,basal medium formula and carbohydrate levels were examined to determine their various effects on suspension culture cell growth and development ,The best selection of plant growth regulator,basal medium and carbohydrate level is 2mg/L 2,4-D:0.5mg/L KT,MS and 3% sucrose respectively.

  18. Plant growth and cultivation.

    Science.gov (United States)

    Podar, Dorina

    2013-01-01

    There is a variety of methods used for growing plants indoor for laboratory research. In most cases plant research requires germination and growth of plants. Often, people have adapted plant cultivation protocols to the conditions and materials at hand in their own laboratory and growth facilities. Here I will provide a guide for growing some of the most frequently used plant species for research, i.e., Arabidopsis thaliana, barley (Hordeum vulgare) and rice (Oryza sativa). However, the methods presented can be used for other plant species as well, especially if they are related to the above-mentioned species. The presented methods include growing plants in soil, hydroponics, and in vitro on plates. This guide is intended as a starting point for those who are just beginning to work on any of the above-mentioned plant species. Methods presented are to be taken as suggestive and modification can be made according to the conditions existing in the host laboratory. PMID:23073874

  19. Plant growth promoting rhizobacterium

    Energy Technology Data Exchange (ETDEWEB)

    Doktycz, Mitchel John; Pelletier, Dale A.; Schadt, Christopher Warren; Tuskan, Gerald A.; Weston, David

    2015-08-11

    The present invention is directed to the Pseudomonas fluorescens strain GM30 deposited under ATCC Accession No. PTA-13340, compositions containing the GM30 strain, and methods of using the GM30 strain to enhance plant growth and/or enhance plant resistance to pathogens.

  20. Growing Out of Stress: The Role of Cell- and Organ-Scale Growth Control in Plant Water-Stress Responses.

    Science.gov (United States)

    Feng, Wei; Lindner, Heike; Robbins, Neil E; Dinneny, José R

    2016-08-01

    Water is the most limiting resource on land for plant growth, and its uptake by plants is affected by many abiotic stresses, such as salinity, cold, heat, and drought. While much research has focused on exploring the molecular mechanisms underlying the cellular signaling events governing water-stress responses, it is also important to consider the role organismal structure plays as a context for such responses. The regulation of growth in plants occurs at two spatial scales: the cell and the organ. In this review, we focus on how the regulation of growth at these different spatial scales enables plants to acclimate to water-deficit stress. The cell wall is discussed with respect to how the physical properties of this structure affect water loss and how regulatory mechanisms that affect wall extensibility maintain growth under water deficit. At a higher spatial scale, the architecture of the root system represents a highly dynamic physical network that facilitates access of the plant to a heterogeneous distribution of water in soil. We discuss the role differential growth plays in shaping the structure of this system and the physiological implications of such changes. PMID:27503468

  1. Flooding and Plant Growth

    OpenAIRE

    Visser, E.J.W.; Voesenek, L.A.C.J.; VARTAPETIAN, B. B.; Jackson, M B

    2003-01-01

    This Special Issue is based on the 7th Conference of the International Society for Plant Anaerobiosis (ISPA), held in Nijmegen, The Netherlands, 12–16 June 2001. The papers describe and analyse many of the responses that plants display when subjected to waterlogging of the soil or deeper submergence. These responses may be injurious or adaptive, and are discussed at various levels of organizational complexity ranging from ecosystem processes, through individual plants to single cells. The res...

  2. Overexpression of the carbohydrate binding module of strawberry expansin2 in Arabidopsis thaliana modifies plant growth and cell wall metabolism.

    Science.gov (United States)

    Nardi, Cristina F; Villarreal, Natalia M; Rossi, Franco R; Martínez, Santiago; Martínez, Gustavo A; Civello, Pedro M

    2015-05-01

    Several cell wall enzymes are carbohydrate active enzymes that contain a putative Carbohydrate Binding Module (CBM) in their structures. The main function of these non-catalitic modules is to facilitate the interaction between the enzyme and its substrate. Expansins are non-hydrolytic proteins present in the cell wall, and their structure includes a CBM in the C-terminal that bind to cell wall polymers such as cellulose, hemicelluloses and pectins. We studied the ability of the Expansin2 CBM (CBMFaEXP2) from strawberry (Fragaria x ananassa, Duch) to modify the cell wall of Arabidopsis thaliana. Plants overexpressing CBMFaEXP2 were characterized phenotypically and biochemically. Transgenic plants were taller than wild type, possibly owing to a faster growth of the main stem. Cell walls of CBMFaEXP2-expressing plants were thicker and contained higher amount of pectins. Lower activity of a set of enzymes involved in cell wall degradation (PG, β-Gal, β-Xyl) was found, and the expression of the corresponding genes (AtPG, Atβ-Gal, Atβ-Xyl5) was reduced also. In addition, a decrease in the expression of two A. thaliana Expansin genes (AtEXP5 and AtEXP8) was observed. Transgenic plants were more resistant to Botrytis cinerea infection than wild type, possibly as a consequence of higher cell wall integrity. Our results support the hypothesis that the overexpression of a putative CBM is able to modify plant cell wall structure leading to modulation of wall loosening and plant growth. These findings might offer a tool to controlling physiological processes where cell wall disassembly is relevant, such as fruit softening. PMID:25837738

  3. Possible dual regulatory circuits involving AtS6K1 in the regulation of plant cell cycle and growth.

    Science.gov (United States)

    Shin, Yun-jeong; Kim, Sunghan; Du, Hui; Choi, Soonyoung; Verma, Desh Pal S; Cheon, Choong-Ill

    2012-05-01

    The role of Arabidopsis S6 Kinase 1 (AtS6K1), a downstream target of TOR kinase, in controlling plant growth and ribosome biogenesis was characterized after generating transgenic plants expressing AtS6K1 under auxin-inducible promoter. Down regulation of selected cell cycle regulatory genes upon auxin treatment was observed in the transgenic plants, confirming the negative regulatory role of AtS6K1 in the plant cell cycle progression reported earlier. Callus tissues established from these transgenic plants grew to larger cell masses with more number of enlarged cells than untransformed control, demonstrating functional implication of AtS6K1 in the control of plant cell size. The observed negative correlation between the expression of AtS6K1 and the cell cycle regulatory genes, however, was completely reversed in protoplasts generated from the transgenic plants expressing AtS6K1, suggesting a possible existence of dual regulatory mechanism of the plant cell cycle regulation mediated by AtS6K1. An alternative method of kinase assay, termed "substrate-mediated kinase pull down", was employed to examine the additional phosphorylation on other domains of AtS6K1 and verified the phosphorylation of both amino- and carboxy-terminal domains, which is a novel finding regarding the phosphorylation target sites on plant S6Ks by upstream regulatory kinases. In addition, this kinase assay under the stress conditions revealed the salt- and sugar-dependencies of AtS6K1 phosphorylations.

  4. Root exudate-induced alterations in Bacillus cereus cell wall contribute to root colonization and plant growth promotion.

    Directory of Open Access Journals (Sweden)

    Swarnalee Dutta

    Full Text Available The outcome of an interaction between plant growth promoting rhizobacteria and plants may depend on the chemical composition of root exudates (REs. We report the colonization of tobacco, and not groundnut, roots by a non-rhizospheric Bacillus cereus (MTCC 430. There was a differential alteration in the cell wall components of B. cereus in response to the REs from tobacco and groundnut. Attenuated total reflectance infrared spectroscopy revealed a split in amide I region of B. cereus cells exposed to tobacco-root exudates (TRE, compared to those exposed to groundnut-root exudates (GRE. In addition, changes in exopolysaccharides and lipid-packing were observed in B. cereus grown in TRE-amended minimal media that were not detectable in GRE-amended media. Cell-wall proteome analyses revealed upregulation of oxidative stress-related alkyl hydroperoxide reductase, and DNA-protecting protein chain (Dlp-2, in response to GRE and TRE, respectively. Metabolism-related enzymes like 2-amino-3-ketobutyrate coenzyme A ligase and 2-methylcitrate dehydratase and a 60 kDa chaperonin were up-regulated in response to TRE and GRE. In response to B. cereus, the plant roots altered their exudate-chemodiversity with respect to carbohydrates, organic acids, alkanes, and polyols. TRE-induced changes in surface components of B. cereus may contribute to successful root colonization and subsequent plant growth promotion.

  5. The Utilization of Plant Facilities on the International Space Station—The Composition, Growth, and Development of Plant Cell Walls under Microgravity Conditions

    Directory of Open Access Journals (Sweden)

    Ann-Iren Kittang Jost

    2015-01-01

    Full Text Available In the preparation for missions to Mars, basic knowledge of the mechanisms of growth and development of living plants under microgravity (micro-g conditions is essential. Focus has centered on the g-effects on rigidity, including mechanisms of signal perception, transduction, and response in gravity resistance. These components of gravity resistance are linked to the evolution and acquisition of responses to various mechanical stresses. An overview is given both on the basic effect of hypergravity as well as of micro-g conditions in the cell wall changes. The review includes plant experiments in the US Space Shuttle and the effect of short space stays (8–14 days on single cells (plant protoplasts. Regeneration of protoplasts is dependent on cortical microtubules to orient the nascent cellulose microfibrils in the cell wall. The space protoplast experiments demonstrated that the regeneration capacity of protoplasts was retarded. Two critical factors are the basis for longer space experiments: a. the effects of gravity on the molecular mechanisms for cell wall development, b. the availability of facilities and hardware for performing cell wall experiments in space and return of RNA/DNA back to the Earth. Linked to these aspects is a description of existing hardware functioning on the International Space Station.

  6. The Utilization of Plant Facilities on the International Space Station-The Composition, Growth, and Development of Plant Cell Walls under Microgravity Conditions.

    Science.gov (United States)

    Jost, Ann-Iren Kittang; Hoson, Takayuki; Iversen, Tor-Henning

    2015-01-20

    In the preparation for missions to Mars, basic knowledge of the mechanisms of growth and development of living plants under microgravity (micro-g) conditions is essential. Focus has centered on the g-effects on rigidity, including mechanisms of signal perception, transduction, and response in gravity resistance. These components of gravity resistance are linked to the evolution and acquisition of responses to various mechanical stresses. An overview is given both on the basic effect of hypergravity as well as of micro-g conditions in the cell wall changes. The review includes plant experiments in the US Space Shuttle and the effect of short space stays (8-14 days) on single cells (plant protoplasts). Regeneration of protoplasts is dependent on cortical microtubules to orient the nascent cellulose microfibrils in the cell wall. The space protoplast experiments demonstrated that the regeneration capacity of protoplasts was retarded. Two critical factors are the basis for longer space experiments: a. the effects of gravity on the molecular mechanisms for cell wall development, b. the availability of facilities and hardware for performing cell wall experiments in space and return of RNA/DNA back to the Earth. Linked to these aspects is a description of existing hardware functioning on the International Space Station.

  7. Effect of Plant Growth Regulators on Calcium-stimulated Serine Transport into Tobacco Cells

    Science.gov (United States)

    Smith, Ivan K.

    1978-01-01

    The transport of serine into tobacco cells (Nicotiana tabacum L.) cultured in liquid medium was examined. Transport was inhibited approximately 50% by 2,4-dichlorophenoxyacetic acid, indoleacetic acid, α-naphthalene acetic acid, and kinetin at a concentration of 10 micrograms per milliliter. Transport was not inhibited by 2,6-dichlorophenoxyacetic acid and inhibited less than 25% by p-chlorophenoxyacetic acid at this concentration. Removal of 2,4-dichlorophenoxyacetic acid from the transport medium resulted in an alleviation of inhibition. Gibberellic acid at concentrations from 2 to 20 micrograms per milliliter stimulated transport. It was previously shown that inhibition of transport by La3+ was due to removal of Ca2+ from surface sites and inhibition of Ca2+ uptake by cells. None of the growth regulators tested had any significant effect on Ca2+ binding and/or transport. A contributing factor to the low transport rates in the absence of Ca2+ is the increased rate of serine efflux. None of the growth regulators tested had any significant effect on the rate of serine efflux. PMID:16660646

  8. Compositional changes in cell wall polysaccharides from apple fruit callus cultures modulated by different plant growth regulators.

    Science.gov (United States)

    Alayón-Luaces, Paula; Ponce, Nora M A; Mroginski, Luis A; Stortz, Carlos A; Sozzi, Gabriel O

    2012-04-01

    The cell wall composition of apples callus cultures showed changes in the presence of 5 mg l(-1) of three different plant growth regulators (PGRs), namely picloram, abscisic acid and gibberellic acid. Although the structural functions of cell walls do not generally allow for pronounced variations of the total pectin and matrix glycan content, this work provides evidence that the addition of these plant growth regulators can rule, at least partly, cell wall metabolism in apple callus cultures. The chelator- and carbonate-extracts always had the analytical characteristics of pectins, with high proportions of uronic acids, arabinose and galactose as the main monosaccharides, and a significant proportion of rhamnose, but the cross-linking glycan fractions were still rich in RG-I-like material. The application of PGRs produced shifts of uronic acid and neutral sugars between fractions. Arabinose was the neutral sugar exhibiting more variations in apple callus cell wall. Picloram and abscisic acid produced an increase of the uronic acid contents of the cell walls. The AIRs obtained from calluses treated with different PGRs did not show large amounts of high molecular weight products, as determined by size-exclusion chromatography. For the carbonate-extract only the callus treated with picloram displayed two separated peaks for products of different molecular weights. The chromatographic profiles for the 4% KOH-extract displayed two peaks for all the treatments, one very sharp with high molecular weight, and another one wider of smaller molecular weight, whereas the difference between treatments can only be appraised through the areas of the peaks. This is the first report on cell wall composition from fruit calluses supplemented with different PGRs.

  9. Two parametric cell cycle analyses of plant cell suspension cultures with fragile, isolated nuclei to investigate heterogeneity in growth of batch cultivations.

    Science.gov (United States)

    Haas, Christiane; Hegner, Richard; Helbig, Karsten; Bartels, Kristin; Bley, Thomas; Weber, Jost

    2016-06-01

    Plant cell suspensions are frequently considered to be heterogeneous with respect to growth in terms of progression of the cells through the cell cycle and biomass accumulation. Thus, segregated data of fractions in different cycle phases during cultivation is needed to develop robust production processes. Bromodeoxyuridine (BrdU) incorporation and BrdU-antibodies or 5-ethynyl-2'-deoxyuridine (EdU) click-it chemistry are frequently used to acquire such information. However, their use requires centrifugation steps that cannot be readily applied to sensitive cells, particularly if nuclei have to be extracted from the protective cellular milieu and envelopes for DNA analysis. Therefore, we have established a BrdU-Hoechst stain quenching protocol for analyzing nuclei directly isolated from delicate plant cell suspension cultures. After adding BrdU to test Harpagophytum procumbens cell suspension cultures the cell cycle distribution could be adequately resolved using its incorporation for the following 72 h (after which BrdU slowed biomass accumulation). Despite this limitation, the protocol allows resolution of the cell cycle distribution of cultures that cannot be analyzed using commonly applied methods due to the cells' fragility. The presented protocol enabled analysis of cycling heterogeneities in H. procumbens batch cultivations, and thus should facilitate process control of secondary metabolite production from fragile plant in vitro cultures. Biotechnol. Bioeng. 2016;113: 1244-1250. © 2015 Wiley Periodicals, Inc. PMID:26614913

  10. Chemical Control of Plant Growth.

    Science.gov (United States)

    Agricultural Research Center (USDA), Beltsville, MD.

    Seven experiments are presented in this Science Study Aid to help students investigate the control of plant growth with chemicals. Plant growth regulators, weed control, and chemical pruning are the topics studied in the experiments which are based on investigations that have been and are being conducted at the U. S. Agricultural Research Center,…

  11. Rapid burst of H2O2 by plant growth regulators increases intracellular Ca2+ amounts and modulates CD4+ T cell activation.

    Science.gov (United States)

    Ahmed, Asma; Mukherjee, Sambuddho; Deobagkar, Mukta; Naik, Tanushree; Nandi, Dipankar

    2010-11-01

    The identification of small molecules that affect T cell activation is an important area of research. Three molecules that regulate plant growth and differentiation, but not their structurally similar analogs, were identified to enhance primary mouse CD4(+) T cell activation in conjunction with soluble anti-CD3 stimulation: Indoleacetic acid (natural plant auxin), 1-Napthaleneacetic acid (synthetic plant auxin) and 2,4-Dichlorophenoxyacetic acid (synthetic plant auxin and herbicide). These effects are distinct in comparison to Curcumin, the well known phenolic immunomodulator, which lowers T cell activation. An investigation into the mechanisms of action of the three plant growth regulators revealed a rapid induction of reactive oxygen species (ROS), mainly comprising H(2)O(2). In addition, these three molecules synergize with soluble anti-CD3 signaling to enhance intracellular Ca(2+) concentrations [Ca(2+)](i), leading to greater T cell activation, e.g. induction of CD25 and IL-2. Enhanced production of TNFα and IFNγ by CD4(+) T cells is also observed upon plant growth regulator treatment with soluble anti-CD3. Interestingly, maximal IL-2 production and CD4(+) T cell cycle progression are observed upon activation with soluble anti-CD3 and phorbol 12-myristate 13-acetate (PMA), a phorbol ester. Additionally, stimulation with PMA and Ionomcyin (a Ca(2+) ionophore), which activates T cells by circumventing the TCR, and plant growth regulators also demonstrated the role of the strength of signal (SOS): T cell cycle progression is enhanced with gentle activation conditions but decreased with strong activation conditions. This study demonstrates the direct effects of three plant growth regulators on CD4(+) T cell activation and cycling.

  12. Effect of microgravity environment on cell wall regeneration, cell divisions, growth, and differentiation of plants from protoplasts (7-IML-1)

    Science.gov (United States)

    Rasmussen, Ole

    1992-01-01

    The primary goal of this project is to investigate if microgravity has any influence on growth and differentiation of protoplasts. Formation of new cell walls on rapeseed protoplasts takes place within the first 24 hours after isolation. Cell division can be observed after 2-4 days and formation of cell aggregates after 5-7 days. Therefore, it is possible during the 7 day IML-1 Mission to investigate if cell wall formation, cell division, and cell differentiation are influenced by microgravity. Protoplasts of rapeseeds and carrot will be prepared shortly before launch and injected into 0.6 ml polyethylene bags. Eight bags are placed in an aluminum block inside the ESA Type 1 container. The containers are placed at 4 C in PTCU's and transferred to orbiter mid-deck. At 4 C all cell processes are slowed down, including cell wall formation. Latest access to the shuttle will be 12 hours before launch. In orbit the containers will be transferred from the PTC box to the 22 C Biorack incubator. The installation of a 1 g centrifuge in Biorack will make it possible to distinguish between effects of near weightlessness and effects caused by cosmic radiation and other space flight factors including vibrations. Parallel control experiments will be carried out on the ground. Other aspects of the experiment are discussed.

  13. Spatio-temporal changes in cell division, endoreduplication and expression of cell cycle-related genes in pollinated and plant growth substances-treated ovaries of cucumber.

    Science.gov (United States)

    Fu, F Q; Mao, W H; Shi, K; Zhou, Y H; Yu, J Q

    2010-01-01

    We investigated the temporal and spatial changes in cell division, endoreduplication and expression of cell cycle-related genes in developing cucumber fruits at 0-20 days after anthesis (DAA). Cell division was intense at 0-4 DAA and then decreased until to 8 DAA. Meanwhile, endoreduplication started at 4 DAA and increased gradually to 20 DAA, accompanied by an increase in fruit weight. Cell division was mainly observed in the exocarp, while endoreduplication occurred mostly in the endocarp and pulp. Among the six cell cycle-related genes examined, two mitotic cyclin genes (CycA and CycB) and CDKB had the highest transcript levels within 2 DAA, while transcripts of two CycD3 genes and CDKA peaked at 4 DAA and 20 DAA, respectively. Naphthaleneacetic acid (NAA), N-(2-chloro-4-pyridyl)-N'-phenylurea (CPPU) and 24-epibrassinolide (EBR) all induced parthenocarpic growth as well as active cell division, and enhanced transcripts of cell cycle-related genes. In comparison, gibberellic acid (GA(3)) had little effect on the induction of parthenocarpy and transcripts of cell cycle-related genes. These results provide evidence for the important roles of cell division and endoreduplication during cucumber fruit development, and suggest the essential roles of cell cycle-related genes and plant growth substances in fruit development. PMID:20653892

  14. Effects of potentially acidic air pollutants on the intracellular distribution and transport of plant growth regulators in mesophyll cells of leaves. Consequences on stress- and developmental physiology

    Energy Technology Data Exchange (ETDEWEB)

    Kremer, H.; Pfanz, H.; Hartung, W.

    1987-07-11

    The influence of SO/sub 2/ on the intracellular distribution of abscisic acid (ABA) and indole-acetic acid (IAA) in mesophyll cells of Picea abies, Tsuga americana and Hordeum vulgare was investigated. The compartmentation of ABA and IAA depends on intracellular pH-gradients. The hydrophilic anions ABA and IAA are accumulated in the alkaline cell compartments cytosol and chloroplasts, which act as anion traps for weak acids. Uptake of sulfur dioxide into leaves leads to an acidification of alkaline cell compartments, thus decreasing intracellular pH-gradients. Consequently this results in an increased release of plant growth regulators from the cell interior into the apoplast. Therefore the target cells of plant hormones i.e. meristems and stomates are exposed to altered hormone concentrations. Obviously this influences the regulation of cellular metabolism plant development and growth.

  15. Celebrating Plant Cells: A Special Issue on Plant Cell Biology

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ A special issue on plant cell biology is long overdue for JIPB! In the last two decades or so, the plant biology community has been thrilled by explosive discoveries regarding the molecular and genetic basis of plant growth, development, and responses to the environment, largely owing to recent maturation of model systems like Arabidopsis thaliana and the rice Oryza sativa, as well as the rapid development of high throughput technologies associated with genomics and proteomics.

  16. Arabidopsis CAP1-mediated ammonium sensing required reactive oxygen species in plant cell growth.

    Science.gov (United States)

    Bai, Ling; Zhou, Yun; Ma, Xiaonan; Gao, Lijie; Song, Chun-Peng

    2014-06-18

    [Ca (2+)]cyt-associated protein kinase (CAP) gene 1 is a receptor-like kinase that belongs to CrRLK1L (Catharanthus roseus Receptor like kinase) subfamily. CAP1 has been identified as a novel modulator of NH 4(+) in the tonoplast, which regulates root hair growth by maintaining the cytoplasmic Ca (2+) gradients. Different expression pattern of tonoplast intrinsic protein (TIP2;3) in the CAP1 knock out mutant and wild type on Murashige and Skoog (MS) medium suggested that CAP1 influences transport activity to regulate the compartmentalization of NH 4(+) into vacuole. Lower expression level of Oxidative Signal-Inducible1(OXI1) in the cap1-1 root and the abnormal reactive oxygen species (ROS) gradient in root hair of cap1-1 on MS medium indicated that ROS signaling involve in CAP1-regulated root hair growth. Wild-type-like ROS distribution pattern in the cap1-1 root hair can be reestablished in seedlings grown on NH 4(+) deficient medium, which indicated that CAP1 functions as a sensor for NH 4(+) signaling in maintaining tip-focused ROS gradient in root hairs polar growth. PMID:24940875

  17. Growing Out of Stress: The Role of Cell- and Organ-Scale Growth Control in Plant Water-Stress Responses[OPEN

    Science.gov (United States)

    Robbins, Neil E.

    2016-01-01

    Water is the most limiting resource on land for plant growth, and its uptake by plants is affected by many abiotic stresses, such as salinity, cold, heat, and drought. While much research has focused on exploring the molecular mechanisms underlying the cellular signaling events governing water-stress responses, it is also important to consider the role organismal structure plays as a context for such responses. The regulation of growth in plants occurs at two spatial scales: the cell and the organ. In this review, we focus on how the regulation of growth at these different spatial scales enables plants to acclimate to water-deficit stress. The cell wall is discussed with respect to how the physical properties of this structure affect water loss and how regulatory mechanisms that affect wall extensibility maintain growth under water deficit. At a higher spatial scale, the architecture of the root system represents a highly dynamic physical network that facilitates access of the plant to a heterogeneous distribution of water in soil. We discuss the role differential growth plays in shaping the structure of this system and the physiological implications of such changes. PMID:27503468

  18. Plant perceptions of plant growth-promoting Pseudomonas.

    OpenAIRE

    Preston, Gail M.

    2004-01-01

    Plant-associated Pseudomonas live as saprophytes and parasites on plant surfaces and inside plant tissues. Many plant-associated Pseudomonas promote plant growth by suppressing pathogenic micro-organisms, synthesizing growth-stimulating plant hormones and promoting increased plant disease resistance. Others inhibit plant growth and cause disease symptoms ranging from rot and necrosis through to developmental dystrophies such as galls. It is not easy to draw a clear distinction between pathoge...

  19. On size and growth of cells

    CERN Document Server

    Boudaoud, A

    2002-01-01

    Understanding how growth induces form is a longstanding biological question. Many studies concentrated on the shapes of plant cells, fungi or bacteria. Some others have shown the importance of the mechanical properties of bacterial walls and plant tissues in pattern formation. Here I sketch a simple physical picture of cell growth. The study is focussed on isolated cells that have walls. They are modeled as thin elastic shells containing a liquid, which pressure drives the growth as generally admitted for bacteria or plant cells. Requiring mechanical equilibrium leads to estimations of typical cell sizes, in quantitative agreement with compiled data including bacteria, cochlear outer hair, fungi, yeast, root hair and giant alga cells.

  20. A Nicotiana attenuata cell wall invertase inhibitor (NaCWII) reduces growth and increases secondary metabolite biosynthesis in herbivore-attacked plants.

    Science.gov (United States)

    Ferrieri, Abigail P; Arce, Carla C M; Machado, Ricardo A R; Meza-Canales, Ivan D; Lima, Eraldo; Baldwin, Ian T; Erb, Matthias

    2015-10-01

    Plant invertases are sucrolytic enzymes that are essential for the regulation of carbohydrate metabolism and source-sink relationships. While their activity has been well documented during abiotic and biotic stresses, the role of proteinaceous invertase inhibitors in regulating these changes is unknown. Here, we identify a putative Nicotiana attenuata cell wall invertase inhibitor (NaCWII) which is strongly up-regulated in a jasmonate (JA)-dependent manner following simulated attack by the specialist herbivore Manduca sexta. To understand the role of NaCWII in planta, we silenced its expression by RNA interference and measured changes in primary and secondary metabolism and plant growth following simulated herbivory. NaCWII-silenced plants displayed a stronger depletion of carbohydrates and a reduced capacity to increase secondary metabolite pools relative to their empty vector control counterparts. This coincided with the attenuation of herbivore-induced CWI inhibition and growth suppression characteristic of wild-type plants. Together our findings suggest that NaCWII may act as a regulatory switch located downstream of JA accumulation which fine-tunes the plant's balance between growth and defense metabolism under herbivore attack. Although carbohydrates are not typically viewed as key factors in plant growth and defense, our study shows that interfering with their catabolism strongly influences plant responses to herbivory. PMID:26017581

  1. Paradigm shift in plant growth control.

    Science.gov (United States)

    Körner, Christian

    2015-06-01

    For plants to grow they need resources and appropriate conditions that these resources are converted into biomass. While acknowledging the importance of co-drivers, the classical view is still that carbon, that is, photosynthetic CO2 uptake, ranks above any other drivers of plant growth. Hence, theory and modelling of growth traditionally is carbon centric. Here, I suggest that this view is not reflecting reality, but emerged from the availability of methods and process understanding at leaf level. In most cases, poorly understood processes of tissue formation and cell growth are governing carbon demand, and thus, CO2 uptake. Carbon can only be converted into biomass to the extent chemical elements other than carbon, temperature or cell turgor permit.

  2. Organelle Extensions in Plant Cells

    Institute of Scientific and Technical Information of China (English)

    Jaideep Mathur; Alena Mammone; Kiah A.Barton

    2012-01-01

    Cell walls lock each cell in a specific position within the supraorganization of a plant.Despite its fixed location,each cell must be able to sense alterations in its immediate environment and respond rapidly to ensure the optimal functioning,continued growth and development,and eventual long-term survival of the plant.The ultra-structural detail that underlies our present understanding of the plant cell has largely been acquired from fixed and processed material that does not allow an appreciation of the dynamic nature of sub-cellular events in the cell.In recent years,fluorescent proteinaided imaging of living plant cells has added to our understanding of the dynamic nature of the plant cell.One of the major outcomes of live imaging of plant cells is the growing appreciation that organelle shapes are not fixed,and many organelles extend their surface transiently in rapid response to environmental stimuli.In many cases,the extensions appear as tubules extending from the main organelle.Specific terms such as stromules from plastids,matrixules from mitochondria,and peroxules from peroxisomes have been coined to describe the extensions.Here,we review our present understanding of organelle extensions and discuss how they may play potential roles in maintaining cellular homeostasis in plant cells.

  3. Pharmacological activity in growth inhibition and apoptosis of cultured human leiomyomal cells of tropical plant Scutellaria barbata D. Don (Lamiaceae).

    Science.gov (United States)

    Lee, Tae-Kyun; Lee, Yun-Jeong; Kim, Dong-Il; Kim, Hyung-Min; Chang, Young-Chae; Kim, Cheorl-Ho

    2006-01-01

    Scutellaria barbata D. Don (Lamiaceae) (SB), which is known in traditional Korean medicine, has been used as an anti-inflammatory and antitumor agent. Since uterine leiomyoma is the most common benign smooth muscle cell tumor of the myometrium, we aimed to determine the growth inhibition and the induction of apoptotic cell death brought about by the herb SB in two different leiomyomal cells, named LM-1 and LM-2, and to clarify the mechanism of this apoptosis. Water-soluble ingredients of SB, and the leiomyomal cell lines of LM-1 and LM-2, were used in vitro. Growth inhibition, induction of cell death, morphological features, the presence of DNA ladders, increases in Caspase 3-like activity, the effects of a Caspase 3 inhibitor on apoptotic cell death, and the release of Cytochrome C by SB were analyzed. SB inhibited the growth and decreased the viability of the leiomyomal cells. The viability of normal myomatrial smooth muscle cells (SMC) in the presence of low concentrations of SB was higher than those of leiomyomal cells. Apoptotic bodies and DNA ladders were observed to be induced in leiomyomal cells of LM-1 and LM-2 by SB. The synthetic tetrapeptide Caspase 3 inhibitor, N-acetyl-Asp-Glu-Val-Asp-aldehyde (Ac-DEVD-CHO), inhibited the apoptotic cell death of leiomyomal cells induced by SB. The Caspase 3-like activity in leiomyomal cells LM-1 and LM-2 increased after the addition of SB. Cytochrome C was released from mitochondria into the cytosol 8h after the addition of SB, and reached a peak at 16h. The peak of Cytochrome C release was earlier than that of Caspase 3-like activity. We concluded that SB inhibited the growth of the leiomyomal cells and induced apoptosis. The apoptosis of leiomyomal cells induced by SB was associated with the release of Cytochrome C from the mitochondria, followed by an increase in Caspase 3-like activity.

  4. Calcium in plant cells

    Directory of Open Access Journals (Sweden)

    V. V. Schwartau

    2014-04-01

    Full Text Available The paper gives the review on the role of calcium in many physiological processes of plant organisms, including growth and development, protection from pathogenic influences, response to changing environmental factors, and many other aspects of plant physiology. Initial intake of calcium ions is carried out by Ca2+-channels of plasma membrane and they are further transported by the xylem owing to auxins’ attractive ability. The level of intake and selectivity of calcium transport to ove-ground parts of the plant is controlled by a symplast. Ca2+enters to the cytoplasm of endoderm cells through calcium channels on the cortical side of Kaspary bands, and is redistributed inside the stele by the symplast, with the use of Ca2+-АТPases and Ca2+/Н+-antiports. Owing to regulated expression and activity of these calcium transporters, calclum can be selectively delivered to the xylem. Important role in supporting calcium homeostasis is given to the vacuole which is the largest depo of calcium. Regulated quantity of calcium movement through the tonoplast is provided by a number of potential-, ligand-gated active transporters and channels, like Ca2+-ATPase and Ca2+/H+ exchanger. They are actively involved in the inactivation of the calcium signal by pumping Ca2+ to the depo of cells. Calcium ATPases are high affinity pumps that efficiently transfer calcium ions against the concentration gradient in their presence in the solution in nanomolar concentrations. Calcium exchangers are low affinity, high capacity Ca2+ transporters that are effectively transporting calcium after raising its concentration in the cell cytosol through the use of protons gradients. Maintaining constant concentration and participation in the response to stimuli of different types also involves EPR, plastids, mitochondria, and cell wall. Calcium binding proteins contain several conserved sequences that provide sensitivity to changes in the concentration of Ca2+ and when you

  5. Growth phase-dependent expression of proteins with decreased plant-specific N-glycans and immunogenicity in tobacco BY2 cells

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Plants possess some desirable characteristics to synthesize recombinant glycoproteins for pharma-ceutical application.However,the mammalian glycoproteins produced in plants are somewhat different from their natural counterparts in terms of N-glycoforms.The immunogenicity of plant-specific glyco-epitopes is the major concern in human therapy.Here,the distribution of N-glycans in different growth phases of tobacco BY2 cells and their immunogenicity in mice were determined.It was ob-served that the percentage of β1,2-xylose and α1,3-fucose in proteins of growing cells increased and the corresponding protein extracts caused accelerated immune response in mice.Based on this observation,the recombinant erythropoietin in BY2 cells was expressed and characterized,and Western blot analysis showed that the recombinant erythropoietin contained a relatively small amount of plant-specific glyco-epitopes in the early phase of culture growth.This study may provide a simple but effective strategy for the production of therapeutic glycoproteins with human-like N-glycan structures in plant hosts to avoid a great allergenic risk.

  6. Plant stem cell niches.

    Science.gov (United States)

    Aichinger, Ernst; Kornet, Noortje; Friedrich, Thomas; Laux, Thomas

    2012-01-01

    Multicellular organisms possess pluripotent stem cells to form new organs, replenish the daily loss of cells, or regenerate organs after injury. Stem cells are maintained in specific environments, the stem cell niches, that provide signals to block differentiation. In plants, stem cell niches are situated in the shoot, root, and vascular meristems-self-perpetuating units of organ formation. Plants' lifelong activity-which, as in the case of trees, can extend over more than a thousand years-requires that a robust regulatory network keep the balance between pluripotent stem cells and differentiating descendants. In this review, we focus on current models in plant stem cell research elaborated during the past two decades, mainly in the model plant Arabidopsis thaliana. We address the roles of mobile signals on transcriptional modules involved in balancing cell fates. In addition, we discuss shared features of and differences between the distinct stem cell niches of Arabidopsis.

  7. Multiscale models in the biomechanics of plant growth

    OpenAIRE

    Jensen, O.E. & Fozard, J.A.

    2015-01-01

    Plant growth occurs through the coordinated expansion of tightly adherent cells, driven by regulated softening of cell walls. It is an intrinsically multiscale process, with the integrated properties of multiple cell walls shaping the whole tissue. Multiscale models encode physical relationships to bring new understanding to plant physiology and development.

  8. Monitoring cell growth.

    Science.gov (United States)

    Strober, W

    2001-05-01

    This appendix provides two protocols for monitoring cell growth. Counting cells using a hemacytometer is tedious but it allows one to effectively distinguish live cells from dead cells (using Trypan Blue exclusion). In addition, this procedure is less subject to errors due to cell clumping or heterogeneity of cell size. The use of an electronic cell counter is quicker and easier than counting cells using a hemacytometer. However, an electronic cell counter as currently constructed does not distinguish live from dead cells in a reliable fashion and is subject to error due to the presence of cell clumps. Overall, the electronic cell counter is best reserved for repetitive and rapid counting of fresh peripheral blood cells and should be used with caution when counting cell populations derived from tissues. PMID:18432653

  9. SALT ACCLIMATION OF TRITICUM-AESTIVUM BY CHOLINE CHLORIDE - PLANT-GROWTH, MINERAL-CONTENT, AND CELL-PERMEABILITY

    NARCIS (Netherlands)

    MANSOUR, MM; STADELMANN, EJ; LEESTADELMANN, OY

    1993-01-01

    Seedlings of a salt sensitive line of Triticum aestivum were grown in Hoagland solution supplemented with 100 mM NaCl following a pretreatment with choline chloride (ChCl). Changes in growth, mineral content of roots and shoots, and passive permeability of the cell membrane were measured. Relative g

  10. Effect of Plant Growth Regulators on Callus, Cell Suspension and Cell Line Selection for Flavonoid Production from Pegaga (centella asiatica L. urban

    Directory of Open Access Journals (Sweden)

    Suat H. Tan

    2010-01-01

    Full Text Available Problem statement: Considering pegaga medicinal properties and over-exploitation, the requirement for a tissue culture technique as an alternative production system was crucial. Approach: Investigation of cell suspension culture response to different plant growth regulators (PRGs for flavonoid production from elite cell line was carried out. Callus cultures were initiated from the leaf explants of Centella asiatica on Murashige and Skoog (MS medium containing B5 vitamins and 30 g L−1 sucrose supplemented with different concentrations (0.5-2.5 mg L−1 of 2,4-D, NAA, Dicamba, Picloram and IBA supplied singly and in combination with different concentrations (0.5-1.5 mg L−1 of kinetin, BAP and TDZ. Results: Callus induction was observed for all the PGRs tested. The highest callus induction frequency (86.67% was observed in MS medium containing 2.0 mg L−1 2,4-D while the combination of 2.0 mg L−1 2,4-D and 1 mg L−1 kinetin in MS medium gave the highest biomass yield (0.27 g dry weight culture−1. This combination was also found to be best for callus proliferation for all the accessions investigated. Among the four accessions tested, UPM03 was found to have the highest biomass yield (0.041 g DW culture−1 and hydrolysed flavonoid content (10.75 mg g−1 DW after the 12th day of culture. The flavonoids present in the four accessions were quercetin, kaempherol, luteolin and rutin based on high performance liquid chromatography (HPLC analysis. These results indicated that C. asiatica accession UPM03 was the potential elite cell line in mass production of flavonoid, especially luteolin. Coclusions/Recommendations: In the establishment of cell suspension culture, 2 mg L−1 2,4-D and 1 mg L−1 kinetin were the best PGRs in supporting the cell growth and flavonoid production. This is the first report on the use of PRGs on the establishment of cell suspension cultures in flavonoid production of C. asiatica.

  11. LED Systems Target Plant Growth

    Science.gov (United States)

    2010-01-01

    To help develop technologies for growing edible biomass (food crops) in space, Kennedy Space Center partnered with Orbital Technologies Corporation (ORBITEC), of Madison, Wisconsin, through the Small Business Innovation Research (SBIR) program. One result of this research was the High Efficiency Lighting with Integrated Adaptive Control (HELIAC) system, components of which have been incorporated into a variety of agricultural greenhouse and consumer aquarium lighting features. The new lighting systems can be adapted to a specific plant species during a specific growth stage, allowing maximum efficiency in light absorption by all available photosynthetic tissues.

  12. Plant-derived SAC domain of PAR-4 (Prostate Apoptosis Response 4 exhibits growth inhibitory effects in prostate cancer cells

    Directory of Open Access Journals (Sweden)

    Shayan eSarkar

    2015-10-01

    Full Text Available The gene Par-4 (Prostate Apoptosis Response 4 was originally identified in prostate cancer cells undergoing apoptosis and its product Par-4 showed cancer specific pro-apoptotic activity. Particularly, the SAC domain of Par-4 (SAC-Par-4 selectively kills cancer cells leaving normal cells unaffected. The therapeutic significance of bioactive SAC-Par-4 is enormous in cancer biology; however, its large scale production is still a matter of concern. Here we report the production of SAC-Par-4-GFP fusion protein coupled to translational enhancer sequence (5′ AMV and apoplast signal peptide (aTP in transgenic Nicotiana tabacum cv. Samsun NN plants under the control of a unique recombinant promoter M24. Transgene integration was confirmed by genomic DNA PCR, Southern and Northern blotting, Real-time PCR and Nuclear run-on assays. Results of Western blot analysis and ELISA confirmed expression of recombinant SAC-Par-4-GFP protein and it was as high as 0.15% of total soluble protein. In addition, we found that targeting of plant recombinant SAC-Par-4-GFP to the apoplast and endoplasmic reticulum (ER was essential for the stability of plant recombinant protein in comparison to the bacterial derived SAC-Par-4. Deglycosylation analysis demonstrated that ER-targeted SAC-Par-4-GFP-SEKDEL undergoes O-linked glycosylation unlike apoplast-targeted SAC-Par-4-GFP. Furthermore, various in vitro studies like mammalian cells proliferation assay (MTT, apoptosis induction assays, and NF-κB suppression suggested the cytotoxic and apoptotic properties of plant-derived SAC-Par-4-GFP against multiple prostate cancer cell lines. Additionally, pre-treatment of MAT-LyLu prostate cancer cells with purified SAC-Par-4-GFP significantly delayed the onset of tumor in a syngeneic rat prostate cancer model. Taken altogether, we proclaim that plant made SAC-Par-4 may become a useful alternate therapy for effectively alleviating cancer in the new era.

  13. Monoclonal Antibodies to Plant Growth Regulators

    Science.gov (United States)

    Eberle, Joachim; Arnscheidt, Angelika; Klix, Dieter; Weiler, Elmar W.

    1986-01-01

    Four high affinity monoclonal antibodies, which recognize two plant growth regulators from the cytokinin group, namely trans-zeatin riboside and dihydrozeatin riboside and their derivatives are reported. Six hybridomas were produced from three independent fusions of Balb/c spleen cells with P3-NS1-Ag 4-1 (abbreviated NS1) or X63-Ag 8.653 (X63) myeloma cells. The mice had been hyperimmunized with zeatin riboside-bovine serum albumin conjugate or dihydrozeatin riboside-bovine serum albumin conjugate for 3 months. The hybridomas secrete antibodies of the IgG 1 or IgG 2b subclass and allow the detection of femtomole amounts of the free cytokinins, their ribosides, and ribotides in plant extracts. The use of these monoclonals in radio- and enzyme-linked immunosorbent assay is also discussed. PMID:16664848

  14. The Plant Cell Surface

    Institute of Scientific and Technical Information of China (English)

    Anne-Mie C.Emons; Kurt V.Fagerstedt

    2010-01-01

    @@ Multicellular organization and tissue construction has evolved along essentially different lines in plants and animals. Since plants do not run away, but are anchored in the soil, their tissues are more or less firm and stiff. This strength stems from the cell walls, which encase the fragile cytoplasm, and protect it.

  15. Auxin Transport and Ribosome Biogenesis Mutant/Reporter Lines to Study Plant Cell Growth and Proliferation under Altered Gravity

    Science.gov (United States)

    Valbuena, Miguel A.; Manzano, Ana I.; van Loon, Jack JWA.; Saez-Vasquez, Julio; Carnero-Diaz, Eugenie; Herranz, Raul; Medina, F. J.

    2013-02-01

    We tested different Arabidopsis thaliana strains to check their availability for space use in the International Space Station (ISS). We used mutants and reporter gene strains affecting factors of cell proliferation and cell growth, to check variations induced by an altered gravity vector. Seedlings were grown either in a Random Positioning Machine (RPM), under simulated microgravity (μg), or in a Large Diameter Centrifuge (LDC), under hypergravity (2g). A combination of the two devices (μgRPM+LDC) was also used. Under all gravity alterations, seedling roots were longer than in control 1g conditions, while the levels of the nucleolar protein nucleolin were depleted. Alterations in the pattern of expression of PIN2, an auxin transporter, and of cyclin B1, a cell cycle regulator, were shown. All these alterations are compatible with previous space data, so the use of these strains will be useful in the next experiments in ISS, under real microgravity.

  16. Pathological modifications of plant stem cell destiny

    Science.gov (United States)

    In higher plants, the shoot apex contains undifferentiated stem cells that give rise to various tissues and organs. The fate of these stem cells determines the pattern of plant growth as well as reproduction; and such fate is genetically preprogrammed. We found that a bacterial infection can derai...

  17. Versatile roles of plastids in plant growth and development.

    Science.gov (United States)

    Inaba, Takehito; Ito-Inaba, Yasuko

    2010-11-01

    Plastids, found in plants and some parasites, are of endosymbiotic origin. The best-characterized plastid is the plant cell chloroplast. Plastids provide essential metabolic and signaling functions, such as the photosynthetic process in chloroplasts. However, the role of plastids is not limited to production of metabolites. Plastids affect numerous aspects of plant growth and development through biogenesis, varying functional states and metabolic activities. Examples include, but are not limited to, embryogenesis, leaf development, gravitropism, temperature response and plant-microbe interactions. In this review, we summarize the versatile roles of plastids in plant growth and development.

  18. Plant growth conditions alter phytolith carbon

    Directory of Open Access Journals (Sweden)

    Kimberley L Gallagher

    2015-09-01

    Full Text Available Many plants, including grasses and some important human food sources, accumulate and precipitate silica in their cells to form opaline phytoliths. These phytoliths contain small amounts of organic matter (OM that are trapped during the process of silicification. Previous work has suggested that plant silica is associated with compounds such as proteins, lipids, lignin and carbohydrate complexes. It is not known whether these compounds are cellular components passively encapsulated as the cell silicifies, polymers actively involved in the precipitation process or random compounds assimilated by the plant and discarded into a glass wastebasket. Here, we used Raman spectroscopy to map the distribution of OM in phytoliths, and to analyze individual phytoliths isolated from Sorghum bicolor plants grown under different laboratory treatments. Using mapping, we showed that OM in phytoliths is distributed throughout the silica and is not related to dark spots visible in light microscopy, previously assumed to be the repository for phytolith OM. The Raman spectra exhibited common bands indicative of C-H stretching modes of general OM, and further more diagnostic bands consistent with carbohydrates, lignins and other OM. These Raman spectra exhibited variability of spectral signatures and of relative intensities between sample treatments indicating that differing growth conditions altered the phytolith carbon. This may have strong implications for understanding the mechanism of phytolith formation, and for use of phytolith carbon isotope values in dating or paleoclimate reconstruction.

  19. Gravitational effects on plant growth hormone concentration

    Science.gov (United States)

    Bandurski, R. S.; Schulze, A.

    1983-01-01

    Dolk's (1936) finding that more growth hormone diffuses from the lower side of a gravity-stimulated plant shoot than from the upper side is presently confirmed by means of both an isotope dilution assay and selected ion monitoring-gas chromatography-mass spectrometry, and it is established that the asymmetrically distributed hormone is indole-3-acetic acid (IAA). This is the first physicochemical demonstration that there is more IAA on the lower sides of a geostimulated plant shoot. It is also found that free IAA primarily occurs in the conductive vascular tissues of the shoot, while IAA esters predominate in the growing cortical cells. A highly sensitive gas chromatographic isotope dilution assay shows that the hormone asymmetry also occurs in the nonvascular tissue.

  20. Error estimation in plant growth analysis

    Directory of Open Access Journals (Sweden)

    Andrzej Gregorczyk

    2014-02-01

    Full Text Available The scheme is presented for calculation of errors of dry matter values which occur during approximation of data with growth curves, determined by the analytical method (logistic function and by the numerical method (Richards function. Further formulae are shown, which describe absolute errors of growth characteristics: Growth rate (GR, Relative growth rate (RGR, Unit leaf rate (ULR and Leaf area ratio (LAR. Calculation examples concerning the growth course of oats and maize plants are given. The critical analysis of the estimation of obtained results has been done. The purposefulness of joint application of statistical methods and error calculus in plant growth analysis has been ascertained.

  1. Phytotoxicity assessment on corn stover biochar, derived from fast pyrolysis, based on seed germination, early growth, and potential plant cell damage.

    Science.gov (United States)

    Li, Yang; Shen, Fei; Guo, Haiyan; Wang, Zhanghong; Yang, Gang; Wang, Lilin; Zhang, Yanzong; Zeng, Yongmei; Deng, Shihuai

    2015-06-01

    The potential phytotoxicity of water extractable toxicants in a typical corn stover biochar, the product of fast pyrolysis, was investigated using an aqueous biochar extract on a soil-less bioassay with tomato plants. The biochar dosage of 0.0-16.0 g beaker(-1) resulted in an inverted U-shaped dose-response relationship between biochar doasage and seed germination/seedling growth. This indicated that tomato growth was slightly stimulated by low dosages of biochar and inhibited with higher dosages of biochar. Additionally, antioxidant enzyme activities in the roots and leaves were enhanced at lower dosages, but rapidly decreased with higher dosages of biochar. With the increased dosages of biochar, the malondialdehyde content in the roots and leaves increased, in addition with the observed morphology of necrotic root cells, suggesting that serious damage to tomato seedlings occurred. EC50 of root length inhibition occurred with biochar dosages of 9.2 g beaker(-1) (3.5th day) and 16.7 g beaker(-1) (11th day) (equivalent to 82.8 and 150.3 t ha(-1), respectively), which implied that toxicity to the early growth of tomato can potentially be alleviated as the plant grows. PMID:25628114

  2. Different shades of JAZ during plant growth and defense

    NARCIS (Netherlands)

    Pieterse, C.M.J.; Pierik, R.; Van Wees, S.C.M.

    2014-01-01

    Ever since their discovery as key regulators of the jasmonate (JA) signaling pathway, repressor proteins of the JASMONATE ZIM-domain (JAZ) family are rising stars in research on hormonal regulation of plant growth and defense. In plant cells, JAZ repressor proteins interact with an E3 ubiquitin liga

  3. Differential growth inhibitory effects of highly oxygenated guaianolides isolated from the Middle Eastern indigenous plant Achillea falcata in HCT-116 colorectal cancer cells.

    Science.gov (United States)

    Tohme, Rita; Al Aaraj, Lamis; Ghaddar, Tarek; Gali-Muhtasib, Hala; Saliba, Najat A; Darwiche, Nadine

    2013-01-01

    Medicinal plants play a crucial role in traditional medicine and in the maintenance of human health worldwide. Sesquiterpene lactones represent an interesting group of plant-derived compounds that are currently being tested as lead drugs in cancer clinical trials. Achillea falcata is a medicinal plant indigenous to the Middle Eastern region and belongs to the Asteraceae family, which is known to be rich in sesquiterpene lactones. We subjected Achillea falcata extracts to bioassay-guided fractionation against the growth of HCT-116 colorectal cancer cells and identified four secotanapartholides, namely 3-β-methoxy-isosecotanapartholide (1), isosecotanapartholide (2), tanaphallin (3), and 8-hydroxy-3-methoxyisosecotanapartholide (4). Three highly oxygenated guaianolides were isolated for the first time from Achillea falcata, namely rupin A (5), chrysartemin B (6), and 1β, 2β-epoxy-3β,4α,10α-trihydroxyguaian-6α,12-olide (7). These sesquiterpene lactones showed no or minor cytotoxicity while exhibiting promising anticancer effects against HCT-116 cells. Further structure-activity relationship studies related the bioactivity of the tested compounds to their skeleton, their lipophilicity, and to the type of functional groups neighboring the main alkylating center of the molecule. PMID:23860275

  4. Differential Growth Inhibitory Effects of Highly Oxygenated Guaianolides Isolated from the Middle Eastern Indigenous Plant Achillea falcata in HCT-116 Colorectal Cancer Cells

    Directory of Open Access Journals (Sweden)

    Nadine Darwiche

    2013-07-01

    Full Text Available Medicinal plants play a crucial role in traditional medicine and in the maintenance of human health worldwide. Sesquiterpene lactones represent an interesting group of plant-derived compounds that are currently being tested as lead drugs in cancer clinical trials. Achillea falcata is a medicinal plant indigenous to the Middle Eastern region and belongs to the Asteraceae family, which is known to be rich in sesquiterpene lactones. We subjected Achillea falcata extracts to bioassay-guided fractionation against the growth of HCT-116 colorectal cancer cells and identified four secotanapartholides, namely 3-β-methoxy- isosecotanapartholide (1, isosecotanapartholide (2, tanaphallin (3, and 8-hydroxy-3-methoxyisosecotanapartholide (4. Three highly oxygenated guaianolides were isolated for the first time from Achillea falcata, namely rupin A (5, chrysartemin B (6, and 1β, 2β-epoxy- 3β,4α,10α-trihydroxyguaian- 6α,12-olide (7. These sesquiterpene lactones showed no or minor cytotoxicity while exhibiting promising anticancer effects against HCT-116 cells. Further structure-activity relationship studies related the bioactivity of the tested compounds to their skeleton, their lipophilicity, and to the type of functional groups neighboring the main alkylating center of the molecule.

  5. Plant Growth and Morphogenesis under Different Gravity Conditions: Relevance to Plant Life in Space.

    Science.gov (United States)

    Hoson, Takayuki

    2014-01-01

    The growth and morphogenesis of plants are entirely dependent on the gravitational acceleration of earth. Under microgravity conditions in space, these processes are greatly modified. Recent space experiments, in combination with ground-based studies, have shown that elongation growth is stimulated and lateral expansion suppressed in various shoot organs and roots under microgravity conditions. Plant organs also show automorphogenesis in space, which consists of altered growth direction and spontaneous curvature in the dorsiventral (back and front) directions. Changes in cell wall properties are responsible for these modifications of growth and morphogenesis under microgravity conditions. Plants live in space with interesting new sizes and forms. PMID:25370193

  6. Plant growth promotion and Penicillium citrinum

    OpenAIRE

    Choo Yeon-Sik; Lee In-Jung; Kim Jong-Myeong; Hwang Seon-Kap; Suh Seok-Jong; Kim Ho-Youn; Yoon Hyeokjun; Hamayun Muhammad; Khan Sumera; Yoon Ung-Han; Kong Won-Sik; Lee Byung-Moo; Kim Jong-Guk

    2008-01-01

    Abstract Background Endophytic fungi are known plant symbionts. They produce a variety of beneficial metabolites for plant growth and survival, as well as defend their hosts from attack of certain pathogens. Coastal dunes are nutrient deficient and offer harsh, saline environment for the existing flora and fauna. Endophytic fungi may play an important role in plant survival by enhancing nutrient uptake and producing growth-promoting metabolites such as gibberellins and auxins. We screened roo...

  7. Segetoside I, a plant-derived bisdesmosidic saponin, induces apoptosis in human hepatoma cells in vitro and inhibits tumor growth in vivo.

    Science.gov (United States)

    Firempong, Caleb Kesse; Zhang, Hui Yun; Wang, Yan; Chen, Jingjing; Cao, Xia; Deng, Wenwen; Zhou, Jie; Wang, Qiang; Tong, Shan-Shan; Yu, Jiangnan; Xu, Ximing

    2016-08-01

    Segetoside I is a plant-derived bisdesmosidic saponin from Vaccaria segetalis (Neck) with reported anticancer activities. This development has raised an interest in the therapeutic potential of segetoside I. Here, we report the in vitro and in vivo antitumor activities of segetoside I against some selected cancer cell lines (HepG2, human hepatoma; H22, mouse hepatoma; MCF-7, breast cancer; U251, gliocoma; BGC, HGC & SGC, gastric cancinoma; Lovo-1,colon cancer). MTT bioassay analysis showed that HepG2 cells were the most sensitive to segetoside I compared with other cancer cell lines, with lower toxicity in healthy mouse embryonic fibroblast cells. Segetoside I pretreatment of HepG2 resulted in apoptotic induction, dose-dependent DNA fragmentation, inhibition of cell migration, up-regulation of Bax and down-regulation of Bcl-2, which indicated that an apoptotic signaling event could have been initiated. The segetoside I also suppressed hepato-tumour growth in mice with virtually no cytotoxicity and prolonged animal survival, making it a strong oncology drug agent. These findings showed that segetoside I exhibited its antitumor activity via apoptotic induction and significantly support the possible application of the antitumor agent as a potential chemotherapeutic candidate worthy of further investigations. PMID:27180010

  8. Rice transformation with cell wall degrading enzyme genes from Trichoderma atroviride and its effect on plant growth and resistance to fungal pathogens

    Institute of Scientific and Technical Information of China (English)

    Liu Mei; Sun Zong-Xiu; Zhu Jie; Xu Tong; Gary E Harman; Matteo Lorito; Sheri Woo

    2004-01-01

    @@ Three genes encoding for fungal cell wall degrading enzymes (CWDE), ech42, nag70 and gluc78from the biocontrol fungus Trichoderma atroviride were inserted into the binary vector pCAMBIA1305. 2 singly and in all possible combinations. The coding sequences were placed downstream of the rice actin promoter and all vectors were used to transform rice plants. A total of more than 1,800 independently regenerated plantlets in seven different populations (for each of the three genes and each of the four gene combinations) were obtained. Expression in plant was obtained for all the fungal genes used singly or in combinations. The ech42 gene encoding for an endochitinase increased resistance to sheath blight caused by Rhizoctonia solani, while the exochitinase-encoding gene, nag70, had a lesser effect. The expression level of endochitinase but not of the exochitinase was correlated with disease resistance. Nevertheless, exochitinase enhanced the positive effect of endochitinase on disease resistance when two genes were co-expressed in transgenic rice. Improved resistance to Magnaporthe grisea was found in all types of regenerated plants, including those with the gluc78 gene alone, while a few lines expressing either ech42 or nag70 appeared to be immune to this pathogen. Transgenic plants expressing the gluc78 gene alone were stunted and only few of them survived, even though they showed resistance to M. grisea. However, combination with either one of the two other genes ( ech42, nag70 ) as included in the same T-DNA region, reduced the negative effect of gluc78 on plant growth. This is the first report of single or multiple of expression of transgens encoding CWDEs that results in resistance to blast and sheath blight in rice.

  9. Plant growth under high salinity

    NARCIS (Netherlands)

    Blom, M.; Brandenburg, W.A.

    2011-01-01

    Plants most suitable for growing under high saline or even seawater conditions are the ones naturally living under high saline circumstances. A series of tolerant or moderate salt tolerant plants are experimentally tested and described in literature. For many species of this group a threshold value

  10. Foreign acquisition, plant survival, and employment growth

    DEFF Research Database (Denmark)

    Bandick, Roger; Görg, Holger

    2010-01-01

    endogeneity of acquisition using IV and propensity score matching approaches suggest that acquisition by foreign owners increases the lifetime of the acquired plants only if the plant was an exporter. The effect is robust to controlling for domestic acquisitions and differs between horizontal and vertical...... acquisitions. We find robust positive employment growth effects only for exporters and only if the takeover is vertical.......This paper analyzes the effect of foreign acquisition on survival and employment growth of targets using data on Swedish manufacturing plants.We separate targeted plants into those within Swedish MNEs, Swedish exporting non-MNEs, and purely domestic firms. The results, controlling for possible...

  11. Effects of two plant growth regulators, indole-3-acetic acid and β-naphthoxyacetic acid, on genotoxicity in Drosophila SMART assay and on proliferation and viability of HEK293 cells from the perspective of carcinogenesis.

    Science.gov (United States)

    Karadeniz, Asuman; Kaya, Bülent; Savaş, Burhan; Topcuoğlu, Ş Fatih

    2011-10-01

    In this study, the mutagenic and recombinogenic effects of indole-3-acetic acid (IAA), a plant growth regulator naturally synthesized in plants but produced synthetically, and β-naphthoxyacetic acid (BNOA), a synthetic plant growth regulator widely used in agricultural regions, were investigated using the somatic mutation and recombination test (SMART) in Drosophila wings. The effect of the same plant growth regulators against the proliferation and viability of a human immortalized embryonic kidney HEK293 cells which is at the early stage of carcinogenesis were also examined with MTT and trypan-blue exclusion assays. For the SMART assay, two different crosses were used: a standard and a high-bioactivation (HB) cross, involving the flare-3 and the multiple wing hairs markers. The HB cross involved flies characterized by an increased cytochrome P-450-dependent bioactivation capacity, which permits the more efficient biotransformation of promutagens and procarcinogens. In both crosses, the wings of the two types of progeny, inversion-free marker heterozygotes and balancer heterozygotes, were analyzed. The results show that IAA and BNOA are not mutagenic or recombinogenic in the wing cells of Drosophila. Furthermore, neither plant growth regulator affected the proliferation rate of HEK293 cells; however, both of them induced cell death at high concentrations.

  12. Foreign acquisition, plant survival, and employment growth

    DEFF Research Database (Denmark)

    Bandick, Roger; Görg, Holger

    the lifetime of the acquired plants only if the plant was an exporter.  The effect differs depending on whether the acquisition is horizontal or vertical.  We also find robust positive employment growth effects only for exporters, and only if the takeover is vertical, not horizontal.......This paper analyses the effect of foreign acquisition on survival probability and employment growth of target plant using data on Swedish manufacturing plants during the period 1993-2002.  An improvement over previous studies is that we take into account firm level heterogeneity by separating...... the targeted plants into those within Swedish MNEs, Swedish exporting non-MNEs, and purely domestic firms before foreign takeover. The results, controlling for possible endogeneity of the acquisition dummy using an IV and propensity score matching approach suggest that acquisition by foreign owners increases...

  13. Transgenic plants with enhanced growth characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Unkefer, Pat J.; Anderson, Penelope S.; Knight, Thomas J.

    2016-09-06

    The invention relates to transgenic plants exhibiting dramatically enhanced growth rates, greater seed and fruit/pod yields, earlier and more productive flowering, more efficient nitrogen utilization, increased tolerance to high salt conditions, and increased biomass yields. In one embodiment, transgenic plants engineered to over-express both glutamine phenylpyruvate transaminase (GPT) and glutamine synthetase (GS) are provided. The GPT+GS double-transgenic plants of the invention consistently exhibit enhanced growth characteristics, with T0 generation lines showing an increase in biomass over wild type counterparts of between 50% and 300%. Generations that result from sexual crosses and/or selfing typically perform even better, with some of the double-transgenic plants achieving an astounding four-fold biomass increase over wild type plants.

  14. Inducible cell death in plant immunity

    DEFF Research Database (Denmark)

    Hofius, Daniel; Tsitsigiannis, Dimitrios I; Jones, Jonathan D G;

    2006-01-01

    Programmed cell death (PCD) occurs during vegetative and reproductive plant growth, as typified by autumnal leaf senescence and the terminal differentiation of the endosperm of cereals which provide our major source of food. PCD also occurs in response to environmental stress and pathogen attack......, and these inducible PCD forms are intensively studied due their experimental tractability. In general, evidence exists for plant cell death pathways which have similarities to the apoptotic, autophagic and necrotic forms described in yeast and metazoans. Recent research aiming to understand these pathways...... and their molecular components in plants are reviewed here....

  15. Plumbagin, a medicinal plant (Plumbago zeylanica) - derived 1,4-naphthoquinone, inhibits growth and metastasis of human prostate cancer PC-3M-luciferase cells in an orthotopic xenograft mouse model

    OpenAIRE

    Hafeez, Bilal Bin; Zhong, Weixiong; Fischer, Joseph W.; Mustafa, Ala; Shi, Xudong Daniel; Meske, Louise; Hong, Hao; Cai, Weibo; Havighurst, Thomas; Kim, KyungMann; Verma, Ajit K.

    2012-01-01

    We present here first time that Plumbagin (PL), a medicinal plant-derived 1,4-naphthoquinone, inhibits the growth and metastasis of prostate cancer (PCa) in an orthotopic xenograft mouse model. In this study, human PCa PC-3M-luciferase cells (2X106) were injected into the prostate of athymic nude mice. Three days post cell implantation, mice were treated with PL (2 mg/kg body wt. i.p five days in a week) for 8 weeks. Growth and metastasis of PC-3M-luciferase cells was examined weekly by biolu...

  16. Lunar base agriculture: Soils for plant growth

    Science.gov (United States)

    Ming, Douglas W. (Editor); Henninger, Donald L. (Editor)

    1989-01-01

    This work provides information on research and experimentation concerning various aspects of food production in space and particularly on the moon. Options for human settlement of the moon and Mars and strategies for a lunar base are discussed. The lunar environment, including the mineralogical and chemical properties of lunar regolith are investigated and chemical and physical considerations for a lunar-derived soil are considered. It is noted that biological considerations for such a soil include controlled-environment crop production, both hydroponic and lunar regolith-based; microorganisms and the growth of higher plants in lunar-derived soils; and the role of microbes to condition lunar regolith for plant cultivation. Current research in the controlled ecological life support system (CELSS) project is presented in detail and future research areas, such as the growth of higher research plants in CELSS are considered. Optimum plant and microbiological considerations for lunar derived soils are examined.

  17. Developmental Stages in Dynamic Plant Growth Models

    Science.gov (United States)

    Maclean, Heather; Dochain, Denis; Waters, Geoff; Stasiak, Michael; Dixon, Mike; Van Der Straeten, Dominique

    2011-09-01

    During the growth of red beet plants in a closed environment plant growth chamber, a change in metabolism was observed (decreasing photosynthetic quotient) which was not predicted by a previously developed simple dynamic model of photosynthesis and respiration reactions. The incorporation of developmental stages into the model allowed for the representation of this change in metabolism without adding unnecessary complexity. Developmental stages were implemented by dividing the model into two successive sub-models with independent yields. The transition between the phases was detected based on online measurements. Results showed an accurate prediction of carbon dioxide and oxygen fluxes.

  18. Modelling asymmetric growth in crowded plant communities

    DEFF Research Database (Denmark)

    Damgaard, Christian

    2010-01-01

    A class of models that may be used to quantify the effect of size-asymmetric competition in crowded plant communities by estimating a community specific degree of size-asymmetric growth for each species in the community is suggested. The model consists of two parts: an individual size-asymmetric ......A class of models that may be used to quantify the effect of size-asymmetric competition in crowded plant communities by estimating a community specific degree of size-asymmetric growth for each species in the community is suggested. The model consists of two parts: an individual size...

  19. Microtubule networks for plant cell division.

    Science.gov (United States)

    de Keijzer, Jeroen; Mulder, Bela M; Janson, Marcel E

    2014-09-01

    During cytokinesis the cytoplasm of a cell is divided to form two daughter cells. In animal cells, the existing plasma membrane is first constricted and then abscised to generate two individual plasma membranes. Plant cells on the other hand divide by forming an interior dividing wall, the so-called cell plate, which is constructed by localized deposition of membrane and cell wall material. Construction starts in the centre of the cell at the locus of the mitotic spindle and continues radially towards the existing plasma membrane. Finally the membrane of the cell plate and plasma membrane fuse to form two individual plasma membranes. Two microtubule-based cytoskeletal networks, the phragmoplast and the pre-prophase band (PPB), jointly control cytokinesis in plants. The bipolar microtubule array of the phragmoplast regulates cell plate deposition towards a cortical position that is templated by the ring-shaped microtubule array of the PPB. In contrast to most animal cells, plants do not use centrosomes as foci of microtubule growth initiation. Instead, plant microtubule networks are striking examples of self-organizing systems that emerge from physically constrained interactions of dispersed microtubules. Here we will discuss how microtubule-based activities including growth, shrinkage, severing, sliding, nucleation and bundling interrelate to jointly generate the required ordered structures. Evidence mounts that adapter proteins sense the local geometry of microtubules to locally modulate the activity of proteins involved in microtubule growth regulation and severing. Many of the proteins and mechanisms involved have roles in other microtubule assemblies as well, bestowing broader relevance to insights gained from plants. PMID:25136380

  20. Plant growth-promoting bacteria as inoculants in agricultural soils

    OpenAIRE

    Rocheli de Souza; Adriana Ambrosini; Passaglia, Luciane M. P.

    2015-01-01

    Abstract Plant-microbe interactions in the rhizosphere are the determinants of plant health, productivity and soil fertility. Plant growth-promoting bacteria (PGPB) are bacteria that can enhance plant growth and protect plants from disease and abiotic stresses through a wide variety of mechanisms; those that establish close associations with plants, such as the endophytes, could be more successful in plant growth promotion. Several important bacterial characteristics, such as biological nitro...

  1. Plant growth responses to polypropylene--biocontainers

    Science.gov (United States)

    The influence of bio-fillers incorporated into polypropylene (PP) on the growth of plants was evaluated. Biocontainers were created by injection molding of PP with 25-40% by weight of Osage orange tree, Paulownia tree, coffee tree wood or dried distillers grain and 5% by weight of maleated polypropy...

  2. Plant growth strategies are remodeled by spaceflight

    Directory of Open Access Journals (Sweden)

    Paul Anna-Lisa

    2012-12-01

    Full Text Available Abstract Background Arabidopsis plants were grown on the International Space Station within specialized hardware that combined a plant growth habitat with a camera system that can capture images at regular intervals of growth. The Imaging hardware delivers telemetric data from the ISS, specifically images received in real-time from experiments on orbit, providing science without sample return. Comparable Ground Controls were grown in a sister unit that is maintained in the Orbital Environment Simulator at Kennedy Space Center. One of many types of biological data that can be analyzed in this fashion is root morphology. Arabidopsis seeds were geminated on orbit on nutrient gel Petri plates in a configuration that encouraged growth along the surface of the gel. Photos were taken every six hours for the 15 days of the experiment. Results In the absence of gravity, but the presence of directional light, spaceflight roots remained strongly negatively phototropic and grew in the opposite direction of the shoot growth; however, cultivars WS and Col-0 displayed two distinct, marked differences in their growth patterns. First, cultivar WS skewed strongly to the right on orbit, while cultivar Col-0 grew with little deviation away from the light source. Second, the Spaceflight environment also impacted the rate of growth in Arabidopsis. The size of the Flight plants (as measured by primary root and hypocotyl length was uniformly smaller than comparably aged Ground Control plants in both cultivars. Conclusions Skewing and waving, thought to be gravity dependent phenomena, occur in spaceflight plants. In the presence of an orienting light source, phenotypic trends in skewing are gravity independent, and the general patterns of directional root growth typified by a given genotype in unit gravity are recapitulated on orbit, although overall growth patterns on orbit are less uniform. Skewing appears independent of axial orientation on the ISS – suggesting

  3. Pectin, a versatile polysaccharide present in plant cell walls

    NARCIS (Netherlands)

    Voragen, A.G.J.; Coenen, G.J.; Verhoef, R.P.; Schols, H.A.

    2009-01-01

    Pectin or pectic substances are collective names for a group of closely associated polysaccharides present in plant cell walls where they contribute to complex physiological processes like cell growth and cell differentiation and so determine the integrity and rigidity of plant tissue. They also pla

  4. Plant growth promotion and Penicillium citrinum

    Directory of Open Access Journals (Sweden)

    Choo Yeon-Sik

    2008-12-01

    Full Text Available Abstract Background Endophytic fungi are known plant symbionts. They produce a variety of beneficial metabolites for plant growth and survival, as well as defend their hosts from attack of certain pathogens. Coastal dunes are nutrient deficient and offer harsh, saline environment for the existing flora and fauna. Endophytic fungi may play an important role in plant survival by enhancing nutrient uptake and producing growth-promoting metabolites such as gibberellins and auxins. We screened roots of Ixeris repenes (L. A. Gray, a common dune plant, for the isolation of gibberellin secreting endophytic fungi. Results We isolated 15 endophytic fungi from the roots of Ixeris repenes and screened them for growth promoting secondary metabolites. The fungal isolate IR-3-3 gave maximum plant growth when applied to waito-c rice and Atriplex gemelinii seedlings. Analysis of the culture filtrate of IR-3-3 showed the presence of physiologically active gibberellins, GA1, GA3, GA4 and GA7 (1.95 ng/ml, 3.83 ng/ml, 6.03 ng/ml and 2.35 ng/ml, respectively along with other physiologically inactive GA5, GA9, GA12, GA15, GA19, GA20 and, GA24. The plant growth promotion and gibberellin producing capacity of IR-3-3 was much higher than the wild type Gibberella fujikuroi, which was taken as control during present study. GA5, a precursor of bioactive GA3 was reported for the first time in fungi. The fungal isolate IR-3-3 was identified as a new strain of Penicillium citrinum (named as P. citrinum KACC43900 through phylogenetic analysis of 18S rDNA sequence. Conclusion Isolation of new strain of Penicillium citrinum from the sand dune flora is interesting as information on the presence of Pencillium species in coastal sand dunes is limited. The plant growth promoting ability of this fungal strain may help in conservation and revegetation of the rapidly eroding sand dune flora. Penicillium citrinum is already known for producing mycotoxin citrinin and cellulose digesting

  5. Potential of plant growth promoting rhizobacteria and chemical fertilizers on soil enzymes and plant growth

    International Nuclear Information System (INIS)

    The present investigation deals with the role of Plant Growth Promoting Rhizobacteria and chemical fertilizers alone or in combination on urease, invertase and phosphatase activities of rhizospheric soil and also on general impact on growth of safflower cvv. Thori and Saif-32. The PGPR (Azospirillum brasilense and Azotobacter vinelandii) were applied at 10/sup 6/ cells/mL as seed inoculation prior to sowing. Chemical fertilizers were applied at full (Urea 60 Kg ha/sup -1/ and Diammonium phosphate (DAP) 30 Kg ha/sup -1/), half (Urea 30 Kg ha/sup -1/ and DAP 15 Kg ha/sup -1/) and quarter doses (Urea 15 Kg ha-1 and DAP 7.5 Kg ha/sup -1/) during sowing. The chemical fertilizers and PGPR enhanced urease and invertase activities of soil. Presence of PGPR in combination with quarter and half doses of chemical fertilizers further augmented their effect on soil enzymes activities. The soil phosphatase activity was greater in Azospirillum and Azotobacter in combination with half dose of chemical fertilizers. Maximum increase in leaf melondialdehyde content was recorded in full dose of chemical fertilizers whereas coinoculation treatment exhibited significant reduction in cv. Thori. Half and quarter dose of chemical fertilizers increased the shoot length of safflower whereas maximum increase in leaf protein was recorded in Azotobacter in combination with full dose of chemical fertilizers. Root length was improved by Azospirillum and Azotobacter in combination with quarter dose of chemical fertilizers. Leaf area and chlorophyll contents were significantly improved by Azotobacter in combination with half dose of chemical fertilizers. It is inferred that PGPR can supplement 50 % chemical fertilizers for better plant growth and soil health. (author)

  6. Circularly Polarized Light and Growth of Plants

    Science.gov (United States)

    Shibayev, Pavel; Pergolizzi, Robert

    2011-03-01

    The influence of linearly polarized light on the direction of plants growth has been recently demonstrated. The state of circularly polarized (CP) light can also change when it is reflected from the surface of leaves and stems. However, the role of light handedness in the development of plants and CP light interaction with the complexes of chlorophyll molecules have still not been studied enough. In this work, the role of left CP light in the accelerated growth of lentil and pea plants is revealed and studied. The mechanism of such an enhancement is discussed in terms of the model considering transmission, absorption, and scattering of CP light on micro and macro levels of leaf organization. Theoretical modeling of light interaction with the interior of the leaf was conducted for a number of recently proposed models of organization of chlorophyll molecules and chloroplasts. All the calculations were performed by employing a 4x4 matrix method in solving Maxwell equations. It is shown that left-handed chiral organization of chlorophyll molecules can greatly enhance the absorption of light and therefore lead to the enhanced growth of the whole plant under CP light.

  7. Klebsiella pneumoniae inoculants for enhancing plant growth

    Energy Technology Data Exchange (ETDEWEB)

    Triplett, Eric W. (Middleton, WI); Kaeppler, Shawn M. (Oregon, WI); Chelius, Marisa K. (Greeley, CO)

    2008-07-01

    A biological inoculant for enhancing the growth of plants is disclosed. The inoculant includes the bacterial strains Herbaspirillum seropedicae 2A, Pantoea agglomerans P101, Pantoea agglomerans P102, Klebsiella pneumoniae 342, Klebsiella pneumoniae zmvsy, Herbaspirillum seropedicae Z152, Gluconacetobacter diazotrophicus PA15, with or without a carrier. The inoculant also includes strains of the bacterium Pantoea agglomerans and K. pneumoniae which are able to enhance the growth of cereal grasses. Also disclosed are the novel bacterial strains Herbaspirillum seropedicae 2A, Pantoea agglomerans P101 and P102, and Klebsiella pneumoniae 342 and zmvsy.

  8. Clonal growth and plant species abundance

    Science.gov (United States)

    Herben, Tomáš; Nováková, Zuzana; Klimešová, Jitka

    2014-01-01

    Background and Aims Both regional and local plant abundances are driven by species' dispersal capacities and their abilities to exploit new habitats and persist there. These processes are affected by clonal growth, which is difficult to evaluate and compare across large numbers of species. This study assessed the influence of clonal reproduction on local and regional abundances of a large set of species and compared the predictive power of morphologically defined traits of clonal growth with data on actual clonal growth from a botanical garden. The role of clonal growth was compared with the effects of seed reproduction, habitat requirements and growth, proxied both by LHS (leaf–height–seed) traits and by actual performance in the botanical garden. Methods Morphological parameters of clonal growth, actual clonal reproduction in the garden and LHS traits (leaf-specific area – height – seed mass) were used as predictors of species abundance, both regional (number of species records in the Czech Republic) and local (mean species cover in vegetation records) for 836 perennial herbaceous species. Species differences in habitat requirements were accounted for by classifying the dataset by habitat type and also by using Ellenberg indicator values as covariates. Key Results After habitat differences were accounted for, clonal growth parameters explained an important part of variation in species abundance, both at regional and at local levels. At both levels, both greater vegetative growth in cultivation and greater lateral expansion trait values were correlated with higher abundance. Seed reproduction had weaker effects, being positive at the regional level and negative at the local level. Conclusions Morphologically defined traits are predictive of species abundance, and it is concluded that simultaneous investigation of several such traits can help develop hypotheses on specific processes (e.g. avoidance of self-competition, support of offspring) potentially

  9. Low dose radiation and plant growth

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sung Jae; Lee, Hae Youn; Park, Hong Sook

    2001-03-01

    Ionizing radiation includes cosmic radiation, earth radiation, radionuclides for the medical purpose and nuclear industry, fallout radiation. From the experimental results of various radiation effects on seeds or seedlings, it was found that germination rate, development, respiration rate, reproduction and blooming were accelerated compared with the control. In mammal, hormesis phenomenon manifested itself in increased disease resistance, lifespan, and decreased rate of tumor incidence. In plants, it was shown that germination, sprouting, growth, development, blooming and resistance to disease were accelerated.

  10. Low dose radiation and plant growth

    International Nuclear Information System (INIS)

    Ionizing radiation includes cosmic radiation, earth radiation, radionuclides for the medical purpose and nuclear industry, fallout radiation. From the experimental results of various radiation effects on seeds or seedlings, it was found that germination rate, development, respiration rate, reproduction and blooming were accelerated compared with the control. In mammal, hormesis phenomenon manifested itself in increased disease resistance, lifespan, and decreased rate of tumor incidence. In plants, it was shown that germination, sprouting, growth, development, blooming and resistance to disease were accelerated

  11. Plumbagin, a plant derived natural agent inhibits the growth of pancreatic cancer cells in in vitro and in vivo via targeting EGFR, Stat3 and NF-κB signaling pathways

    OpenAIRE

    Hafeez, Bilal Bin; Jamal, Mohammad Sarwar; Fischer, Joseph W.; Mustafa, Ala; Verma, Ajit Kumar

    2012-01-01

    Pancreatic cancer (PC) is the most aggressive malignant disease, ranks as the fourth most leading cause of cancer related death among men and women in the United States. We present here that plumbagin (PL), a quinoid constituent isolated from the roots of the medicinal plant Plumbago zeylanica L, inhibits the growth of PC cells both in vitro and in vivo model systems. PL treatment induces apoptosis and inhibits cell viability of PC cells (PANC1, BxPC3, and ASPC1). In addition, i.p administrat...

  12. Plant guard cell anion channel SLAC1 regulates stomatal closure

    OpenAIRE

    Vahisalu, Triin

    2010-01-01

    Plants are rooted to their growth place; therefore it is important that they react adequately to changes in environmental conditions. Stomatal pores, which are formed of a pair of guard cells in leaf epidermis, regulate plant gas-exchange. Importantly, guard cells protect the plant from desiccation in drought conditions by reducing the aperture of the stomatal pore. They serve also as the first barrier against the major air pollutant ozone, but the behaviour of guard cells during ozone expo...

  13. Plant Growth-Promoting Rhizobacteria Stimulate Vegetative Growth and Asexual Reproduction of Kalanchoe daigremontiana

    OpenAIRE

    Park, Yong-Soon; Park, Kyungseok; Kloepper, Joseph W.; Ryu, Choong-Min

    2015-01-01

    Certain bacterial species associate with plant roots in soil. The plant growth-promoting rhizobacteria (PGPR) stimulate plant growth and yield in greenhouse and field. Here, we examined whether application of known bacilli PGPR strains stimulated growth and asexual reproduction in the succulent plant Kalanchoe daigremontiana. Four PGPR strains B. amyloliquefaciens IN937a, B. cereus BS107, B. pumilus INR7, and B. subtilis GB03 were applied to young plantlets by soil-drenching, and plant growth...

  14. Agriculture on Mars: Soils for Plant Growth

    Science.gov (United States)

    Ming, D. W.

    2016-01-01

    Robotic rovers and landers have enabled the mineralogical, chemical, and physical characterization of loose, unconsolidated materials on the surface of Mars. Planetary scientists refer to the regolith material as "soil." NASA is currently planning to send humans to Mars in the mid 2030s. Early missions may rely on the use of onsite resources to enable exploration and self-sufficient outposts on Mars. The martian "soil" and surface environment contain all essential plant growth elements. The study of martian surface materials and how they might react as agricultural soils opens a new frontier for researchers in the soil science community. Other potential applications for surface "soils" include (i) sources for extraction of essential plant-growth nutrients, (ii) sources of O2, H2, CO2, and H2O, (iii) substrates for microbial populations in the degradation of wastes, and (iv) shielding materials surrounding outpost structures to protect humans, plants, and microorganisms from radiation. There are many challenges that will have to be addressed by soil scientists prior to human exploration over the next two decades.

  15. Dynamics and Regulation of Actin Cytoskeleton in Plant Cells

    Institute of Scientific and Technical Information of China (English)

    Ren Haiyun

    2007-01-01

    @@ The actin cytoskeleton constituted of globular actin (G-actin) is a ubiquitous component of eukaryotic cells and plays crucial roles in diverse physiological processes in plant cells, such as cytoplasmic streaming, organelle and nucleus positioning, cell morphogenesis, cell division, tip growth, etc.

  16. Hormone Signaling Pathways in Plants: The Role of Jasmonic Acid in Plant Cell Signaling

    OpenAIRE

    TİRYAKİ, İskender

    2004-01-01

    Plant growth and metabolism are affected by various biotic and abiotic stimuli including microorganisms and insects attack as well as light and environmental stresses. Such a diverse plant response requires a communication system that uses a group of chemical messengers called hormones. Hormones promote, inhibit, or qualitatively modify plant growth and development. This complex process requires a signal transduction that defines a specific information pathway within a cell that translat...

  17. Phosphorylation-dependent differential regulation of plant growth, cell death, and innate immunity by the regulatory receptor-like kinase BAK1

    DEFF Research Database (Denmark)

    Schwessinger, Benjamin; Roux, Milena; Kadota, Yasuhiro;

    2011-01-01

    Plants rely heavily on receptor-like kinases (RLKs) for perception and integration of external and internal stimuli. The Arabidopsis regulatory leucine-rich repeat RLK (LRR-RLK) BAK1 is involved in steroid hormone responses, innate immunity, and cell death control. Here, we describe the different......Plants rely heavily on receptor-like kinases (RLKs) for perception and integration of external and internal stimuli. The Arabidopsis regulatory leucine-rich repeat RLK (LRR-RLK) BAK1 is involved in steroid hormone responses, innate immunity, and cell death control. Here, we describe...... the differential regulation of three different BAK1-dependent signaling pathways by a novel allele of BAK1, bak1-5. Innate immune signaling mediated by the BAK1-dependent RKs FLS2 and EFR is severely compromised in bak1-5 mutant plants. However, bak1-5 mutants are not impaired in BR signaling or cell death control...... of FLS2 or EFR with BAK1 in planta, revealing another pathway specific mechanistic difference. The specific suppression of FLS2- and EFR-dependent signaling in bak1-5 is not due to a differential interaction of BAK1-5 with the respective ligand-binding RK but requires BAK1-5 kinase activity. Overall our...

  18. Short-term effects of plant hormones on membrane potential and membrane permeability of dwarf maize coleoptile cells (Zea mays L. d 1) in comparison with growth responses.

    Science.gov (United States)

    Nelles, A

    1977-01-01

    The membrane potential difference of dwarf maize coleoptile cells is increased by both 10(-5)moll(-1) gibberellic acid (GA3) and indoleacetic acid (IAA) a few minutes after application. A final level is reached after 10-20 min. The membrane permeability ratio P Na:P K is altered by both hormones during the first 15 min after application, indicating a rapid effect on the membrane. Elongation growth of coleoptile segments, however, is only stimulated by IAA. The auxin-induced growth as well as the auxin effect on membrane permeability depends on the calcium ion concentration of the medium. It is concluded that IAA acts via a proton extrusion pump that is electrically balanced by a potassium ion uptake, driven by the electromotive force of the pump. The mode of action of GA3 on elongation growth is assumed to involve a process that depends on the physiologic state of the tissue and/or metabolic energy. PMID:24420668

  19. Plant AGC protein kinases orient auxin-mediated differential growth and organogenesis

    NARCIS (Netherlands)

    Galván Ampudia, Carlos Samuel

    2009-01-01

    In view of their predominant sessile lifestyle, plants need to be able to adapt to changes in their environment. Environmental signals such as light and gravity modulate plant growth and architecture by redirecting polar cell-to-cell transport of auxin, thus causing changes in the distribution of th

  20. GRAMINEAE PLANTS GROWTH STIMULATION BY SURFACE-ACTIVE RHAMNOLIPIDS

    Directory of Open Access Journals (Sweden)

    O. V. Karpenko

    2013-12-01

    Full Text Available The effect of biogenic surfactants which were synthesized by the culture Pseudomonas sp. PS-17, particularly rhamnolipid biocomplex, on the growth of cereal plants — wheat and barley in the early stages of vegetation, as well as its effect on the activity of indole-3-acetic acid was studied. The effect of rhamnolipid biocomplex on the growth activity of winter wheat and spring barley was studied in vegetation (sand culture and field experiments with pre-sowing treatment of seeds with rhamnolipid biocomplex solutions of different concentrations. To investigate the action of surfaceactive rhamnolipid biocomplex on the extension growth of plant cells the specific biotest on sections of wheat coleoptiles was used. The stimulating effect of rhamnolipid biocomplex on the growth of cereal plants, as well as the optimal concentration for its use in pre-sowing treatment of seeds was established: for winter wheat — 10 mg/l, for spring barley — 50 mg/l (Р ? 0,05. The application of rhamnolipid biocomplex contributed to the increase of aboveground dry weight of wheat on 16%, of barley — on 18% compared to the control (Р ? 0,05. Rhamnolipid biocomplex effectiveness was also confirmed in the field experiment — after the treatment of spring barley seeds the vegetative mass was averagely 34% (Р ? 0,05 higher than in the control. The obtained results indicate the prospects of practical use of rhamnolipid surfactants as environmentally friendly growth stimulants for cereal plants for modern technologies in agriculture. They can be effective in creating complex preparations with indole-3-acetic acid and, possibly also with other phytohormones, that will allow the enhancement of their activity.

  1. Biomass Production System (BPS) Plant Growth Unit

    Science.gov (United States)

    Morrow, R. C.; Crabb, T. M.

    The Biomass Production System (BPS) was developed under the Small Business Innovative Research (SBIR) program to meet science, biotechnology and commercial plant growth needs in the Space Station era. The BPS is equivalent in size to a double middeck locker, but uses it's own custom enclosure with a slide out structure to which internal components mount. The BPS contains four internal growth chambers, each with a growing volume of more than 4 liters. Each of the growth chambers has active nutrient delivery, and independent control of temperature, humidity, lighting, and CO2 set-points. Temperature control is achieved using a thermoelectric heat exchanger system. Humidity control is achieved using a heat exchanger with a porous interface which can both humidify and dehumidify. The control software utilizes fuzzy logic for nonlinear, coupled temperature and humidity control. The fluorescent lighting system can be dimmed to provide a range of light levels. CO2 levels are controlled by injecting pure CO2 to the system based on input from an infrared gas analyzer. The unit currently does not scrub CO2, but has been designed to accept scrubber cartridges. In addition to providing environmental control, a number of features are included to facilitate science. The BPS chambers are sealed to allow CO2 and water vapor exchange measurements. The plant chambers can be removed to allow manipulation or sampling of specimens, and each chamber has gas/fluid sample ports. A video camera is provided for each chamber, and frame-grabs and complete environmental data for all science and hardware system sensors are stored on an internal hard drive. Data files can also be transferred to 3.5-inch disks using the front panel disk drive

  2. Growth analysis of soybean plants treated with plant growth regulators Marcelo Ferraz de Campos

    Directory of Open Access Journals (Sweden)

    João Domingos Rodrigues

    2008-09-01

    Full Text Available This work aimed to verify the effect of plant growth regulators on soybean plant growth and chlorophyll content. In an experiment carried out in a greenhouse, soybean plants were cultivated (Glycine max (L. Merrill cv. BRS-184 in 10-liter pots containing soil from the arable layer, corrected and fertilized according to the soil analysis. The treatments used were: control; GA3 100mg.L-1; BAP 100mg.L-1; IBA 100mg.L-1; Stimulate® (IBA, GA3 and kinetin 20mL.L-1; mepiquat chloride 100mg.L-1 and mepiquat chloride 100mg.L-1 + BAP 100mg.L-1 + IBA 100mg.L-1. Treatments were applied three times at 30-day intervals. Six samplings were taken at 13-day intervals. The results indicated that the highest total dry weight value resulted from the application of IBA and Stimulate®, and that the application of mepiquat chloride in association with IBA and BAP reduced total dry matter production. The leaf area was smaller than the control in most treatments. The chlorophyll content and growth rate were slightly influenced by the treatments. The cytokinin treatment alone or in association with other plant growth regulators retained the chlorophyll content. RGR and NAR decreased from 99 days after sowing with the application of mepiquat chloride.

  3. Peat soil composition as indicator of plants growth environment

    Science.gov (United States)

    Noormets, M.; Tonutare, T.; Kauer, K.; Szajdak, L.; Kolli, R.

    2009-04-01

    Exhausted milled peat areas have been left behind as a result of decades-lasting intensive peat production in Estonia and Europe. According to different data there in Estonia is 10 000 - 15 000 ha of exhausted milled peat areas that should be vegetated. Restoration using Sphagnum species is most advantageous, as it creates ecological conditions closest to the natural succession towards a natural bog area. It is also thought that the large scale translocation of vegetation from intact bogs, as used in some Canadian restoration trials, is not applicable in most of European sites due to limited availability of suitable donor areas. Another possibility to reduce the CO2 emission in these areas is their use for cultivation of species that requires minimum agrotechnical measures exploitation. It is found by experiments that it is possible to establish on Vaccinium species for revegetation of exhausted milled peat areas. Several physiological activity of the plant is regulated by the number of phytohormones. These substances in low quantities move within the plant from a site of production to a site of action. Phytohormone, indole-3-acetic acid (IAA) is formed in soils from tryptophane by enzymatic conversion. This compound seems to play an important function in nature as result to its influence in regulation of plant growth and development. A principal feature of IAA is its ability to affect growth, development and health of plants. This compound activates root morphology and metabolic changes in the host plant. The physiological impact of this substance is involved in cell elongation, apical dominance, root initiation, parthenocarpy, abscission, callus formation and the respiration. The investigation areas are located in the county of Tartu (58˚ 22' N, 26˚ 43' E), in the southern part of Estonia. The soil of the experimental fields belongs according to the WRB soil classification, to the soils subgroups of Fibri-Dystric Histosols. The investigation areas were

  4. Spatial Regulation of Root Growth: Placing the Plant TOR Pathway in a Developmental Perspective.

    Science.gov (United States)

    Barrada, Adam; Montané, Marie-Hélène; Robaglia, Christophe; Menand, Benoît

    2015-08-19

    Plant cells contain specialized structures, such as a cell wall and a large vacuole, which play a major role in cell growth. Roots follow an organized pattern of development, making them the organs of choice for studying the spatio-temporal regulation of cell proliferation and growth in plants. During root growth, cells originate from the initials surrounding the quiescent center, proliferate in the division zone of the meristem, and then increase in length in the elongation zone, reaching their final size and differentiation stage in the mature zone. Phytohormones, especially auxins and cytokinins, control the dynamic balance between cell division and differentiation and therefore organ size. Plant growth is also regulated by metabolites and nutrients, such as the sugars produced by photosynthesis or nitrate assimilated from the soil. Recent literature has shown that the conserved eukaryotic TOR (target of rapamycin) kinase pathway plays an important role in orchestrating plant growth. We will summarize how the regulation of cell proliferation and cell expansion by phytohormones are at the heart of root growth and then discuss recent data indicating that the TOR pathway integrates hormonal and nutritive signals to orchestrate root growth.

  5. Spatial Regulation of Root Growth: Placing the Plant TOR Pathway in a Developmental Perspective

    Directory of Open Access Journals (Sweden)

    Adam Barrada

    2015-08-01

    Full Text Available Plant cells contain specialized structures, such as a cell wall and a large vacuole, which play a major role in cell growth. Roots follow an organized pattern of development, making them the organs of choice for studying the spatio-temporal regulation of cell proliferation and growth in plants. During root growth, cells originate from the initials surrounding the quiescent center, proliferate in the division zone of the meristem, and then increase in length in the elongation zone, reaching their final size and differentiation stage in the mature zone. Phytohormones, especially auxins and cytokinins, control the dynamic balance between cell division and differentiation and therefore organ size. Plant growth is also regulated by metabolites and nutrients, such as the sugars produced by photosynthesis or nitrate assimilated from the soil. Recent literature has shown that the conserved eukaryotic TOR (target of rapamycin kinase pathway plays an important role in orchestrating plant growth. We will summarize how the regulation of cell proliferation and cell expansion by phytohormones are at the heart of root growth and then discuss recent data indicating that the TOR pathway integrates hormonal and nutritive signals to orchestrate root growth.

  6. Plant thin cell layers: update and perspectives

    Directory of Open Access Journals (Sweden)

    Teixeira da Silva Jaime A.

    2015-12-01

    Full Text Available Thin cell layers (TCLs are small and versatile explants for the in vitro culture of plants. At face value, their morphogenic productivity may appear to be less than conventional explants, but once the plant growth correction factor and geometric factor have been applied, the true (potential productivity exceeds that of a conventional explant. It is for this reason that for almost 45 years, TCLs have been applied to the in vitro culture of almost 90 species or hybrids, mainly ornamentals and orchids, but also to field and vegetable crops and medicinal plants. Focusing on 12 new studies that have emerged in the recent past (2013-2015, this paper brings promise to other horticultural species that could benefit from the use of TCLs.

  7. Mechanisms and applications of plant growth promoting rhizobacteria: Current perspective

    Directory of Open Access Journals (Sweden)

    Munees Ahemad

    2014-01-01

    Full Text Available Plant growth promoting rhizobacteria are the soil bacteria inhabiting around/on the root surface and are directly or indirectly involved in promoting plant growth and development via production and secretion of various regulatory chemicals in the vicinity of rhizosphere. Generally, plant growth promoting rhizobacteria facilitate the plant growth directly by either assisting in resource acquisition (nitrogen, phosphorus and essential minerals or modulating plant hormone levels, or indirectly by decreasing the inhibitory effects of various pathogens on plant growth and development in the forms of biocontrol agents. Various studies have documented the increased health and productivity of different plant species by the application of plant growth promoting rhizobacteria under both normal and stressed conditions. The plant-beneficial rhizobacteria may decrease the global dependence on hazardous agricultural chemicals which destabilize the agro-ecosystems. This review accentuates the perception of the rhizosphere and plant growth promoting rhizobacteria under the current perspectives. Further, explicit outlooks on the different mechanisms of rhizobacteria mediated plant growth promotion have been described in detail with the recent development and research. Finally, the latest paradigms of applicability of these beneficial rhizobacteria in different agro-ecosystems have been presented comprehensively under both normal and stress conditions to highlight the recent trends with the aim to develop future insights.

  8. Martian Soil Plant Growth Experiment: The Effects of Adding Nitrogen, Bacteria, and Fungi to Enhance Plant Growth

    Science.gov (United States)

    Kliman, D. M.; Cooper, J. B.; Anderson, R. C.

    2000-01-01

    Plant growth is enhanced by the presence of symbiotic soil microbes. In order to better understand how plants might prosper on Mars, we set up an experiment to test whether symbiotic microbes function to enhance plant growth in a Martian soil simulant.

  9. Plant growth-promoting rhizobacteria and root system functioning

    OpenAIRE

    Vacheron, Jordan; Desbrosses, Guilhem; Bouffaud, Marie-Lara; Touraine, Bruno; Moënne-Loccoz, Yvan; Muller, Daniel; Legendre, Laurent; Wisniewski-Dyé, Florence; Prigent-Combaret, Claire

    2013-01-01

    The rhizosphere supports the development and activity of a huge and diversified microbial community, including microorganisms capable to promote plant growth. Among the latter, plant growth-promoting rhizobacteria (PGPR) colonize roots of monocots and dicots, and enhance plant growth by direct and indirect mechanisms. Modification of root system architecture by PGPR implicates the production of phytohormones and other signals that lead, mostly, to enhanced lateral root branching and developme...

  10. Plant growth-promoting rhizobacteria and root system functioning

    OpenAIRE

    Jordan eVacheron; Guilhem eDesbrosses; Marie-Lara eBouffaud; Bruno eTouraine; Yvan eMoënne-Loccoz; Daniel eMuller; Laurent eLegendre; Florence eWisniewski-Dyé; Claire ePrigent-Combaret

    2013-01-01

    The rhizosphere supports the development and activity of a huge and diversified microbial community, including microorganisms capable to promote plant growth. Among the latter, Plant Growth-Promoting Rhizobacteria (PGPR) colonize roots of monocots and dicots, and enhance plant growth by direct and indirect mechanisms. Modification of root system architecture by PGPR implicates the production of phytohormones and other signals that lead, mostly, to enhanced lateral root branching and developme...

  11. Artificial Life of Soybean Plant Growth Modeling Using Intelligence Approaches

    OpenAIRE

    Atris Suyantohadi; Mochamad Hariadi; Mauridhi Hery Purnomo

    2010-01-01

    The natural process on plant growth system has a complex system and it has could be developed on characteristic studied using intelligent approaches conducting with artificial life system. The approaches on examining the natural process on soybean (Glycine Max L.Merr) plant growth have been analyzed and synthesized in these research through modeling using Artificial Neural Network (ANN) and Lindenmayer System (L-System) methods. Research aimed to design and to visualize plant growth modeling...

  12. Nuclear lamina in plant cells

    Institute of Scientific and Technical Information of China (English)

    汪健; 杨澄; 翟中和

    1996-01-01

    By using selective extraction and diethylene glycol distearate (DGD) embedment and embedment-free electron microscopy, the nuclear lamina was demonstrated in carrot and Ginkgo male generative cells. Western blotting revealed that the nuclear lamina was composed of A-type and B-type lamins which contained at least 66-ku and 84-ku or 66-ku and 86-ku polypeptides, respectively. These lamin proteins were localized at the nudear periphery as shown by immunogold-labelling. In situ hybridization for light microscope and electron microscope showed that plant cells have the homologous sequences of animal lamin cDNA. The sorting site of lamin mRNA is mainly distributed in the cytoplasm near the nudear envelope. The data have verified that there indeed exists nudear lamina in plant cells.

  13. The Role of Plant Hormones in Nematode Feeding Cell Formation

    NARCIS (Netherlands)

    Goverse, A.; Bird, D.

    2011-01-01

    In this Chapter, we discuss recent advances in the role of plant hormones in the molecular mechanisms underlying feeding cell formation both by cyst (CN) and root-knot nematodes (RKN). Phytohormones are small signalling molecules that regulate plant growth and development, including the formation of

  14. Plant growth promotion induced by phosphate solubilizing endophytic Pseudomonas isolates

    OpenAIRE

    Oteino, Nicholas; Lally, Richard D.; Kiwanuka, Samuel; Lloyd, Andrew; Ryan, David; Germaine, Kieran J.; Dowling, David N.

    2015-01-01

    The use of plant growth promoting bacterial inoculants as live microbial biofertilizers provides a promising alternative to chemical fertilizers and pesticides. Inorganic phosphate solubilization is one of the major mechanisms of plant growth promotion by plant associated bacteria. This involves bacteria releasing organic acids into the soil which solubilize the phosphate complexes converting them into ortho-phosphate which is available for plant up-take and utilization. The study presented h...

  15. Strigolactones as mediators of plant growth responses to environmental conditions

    OpenAIRE

    Koltai, Hinanit; Kapulnik, Yoram

    2011-01-01

    Strigolactones (SLs) have been recently identified as a new group of plant hormones or their derivatives thereof, shown to play a role in plant development. Evolutionary forces have driven the development of mechanisms in plants that allow adaptive adjustments to a variety of different habitats by employing plasticity in shoot and root growth and development. The ability of SLs to regulate both shoot and root development suggests a role in the plant's response to its growth environment. To pl...

  16. Virtual microstructural leaf tissue generation based on cell growth modeling

    NARCIS (Netherlands)

    Abera, M.K.; Retta, M.A.; Verboven, P.; Nicolai, B.M.; Berghuijs, H.; Struik, P.

    2016-01-01

    A cell growth algorithm for virtual leaf tissue generation is presented based on the biomechanics of plant cells in tissues. The algorithm can account for typical differences in epidermal layers, palisade mesophyll layer and spongy mesophyll layer which have characteristic differences in the shap

  17. Extracellular ATP signaling and homeostasis in plant cells

    OpenAIRE

    Sun, Jian; Zhang, Chunlan; Zhang, Xuan; Deng, Shurong; Zhao, Rui; Shen, Xin; Chen, Shaoliang

    2012-01-01

    Extracellular ATP (eATP) is now recognized as an important signaling agent in plant growth and defense response to environmental stimuli. eATP has dual functions in plant cell signaling, which is largely dependent on its concentration in the extracellular matrix (ECM). A lethal level of eATP (extremely low or high) causes cell death, whereas a moderate level of eATP benefits plant growth and development. Ecto-apyrases (Nucleoside Triphosphate-Diphosphohydrolase) help control the eATP concentr...

  18. A simple way to identify non-viable cells within living plant tissue using confocal microscopy

    OpenAIRE

    Truernit Elisabeth; Haseloff Jim

    2008-01-01

    Abstract Background Plant cell death is a normal process during plant development. Mutant plants may exhibit misregulation of this process, which can lead to severe growth defects. Simple ways of visualising cell death in living plant tissues can aid the study of plant development and physiology. Results Spectral variants of the fluorescent SYTOX dyes were tested for their usefulness for the detection of non-viable cells within plant embryos and roots using confocal laser-scanning microscopy....

  19. Exocytosis and polarity in plant cells: insights by studying cellulose synthase complexes and the exocyst

    NARCIS (Netherlands)

    Ying Zhang, Ying

    2012-01-01

    The work presented in this thesis covers aspects of exocytosis, plant cell growth and cell wall formation. These processes are strongly linked as cell growth and cell wall formation occur simultaneously and exocytosis is the process that delivers cell wall components to the existing cell wall and in

  20. Plant hormone cross-talk: the pivot of root growth.

    Science.gov (United States)

    Pacifici, Elena; Polverari, Laura; Sabatini, Sabrina

    2015-02-01

    Root indeterminate growth and its outstanding ability to produce new tissues continuously make this organ a highly dynamic structure able to respond promptly to external environmental stimuli. Developmental processes therefore need to be finely tuned, and hormonal cross-talk plays a pivotal role in the regulation of root growth. In contrast to what happens in animals, plant development is a post-embryonic process. A pool of stem cells, placed in a niche at the apex of the meristem, is a source of self-renewing cells that provides cells for tissue formation. During the first days post-germination, the meristem reaches its final size as a result of a balance between cell division and cell differentiation. A complex network of interactions between hormonal pathways co-ordinates such developmental inputs. In recent years, by means of molecular and computational approaches, many efforts have been made aiming to define the molecular components of these networks. In this review, we focus our attention on the molecular mechanisms at the basis of hormone cross-talk during root meristem size determination.

  1. Fluorescence activated cell sorting of plant protoplasts.

    Science.gov (United States)

    Bargmann, Bastiaan O R; Birnbaum, Kenneth D

    2010-02-18

    cell types (e.g. quiescent center cells). Lastly, a growth setup for Arabidopsis seedlings is demonstrated that enables uncomplicated treatment of the plants prior to cell sorting (e.g. for the cell type-specific analysis of biotic or abiotic stress responses). Potential supplementary uses for FACS of plant protoplasts are discussed.

  2. Pochonia chlamydosporia promotes the growth of tomato and lettuce plants

    Directory of Open Access Journals (Sweden)

    Rosangela Dallemole-Giaretta

    2015-10-01

    Full Text Available The fungus Pochonia chlamydosporia is one of the most studied biological agents used to control plant-parasitic nematodes. This study found that the isolates Pc-3, Pc-10 and Pc-19 of this fungus promote the growth of tomato and lettuce seedlings. The isolate Pc-19 colonized the rhizoplane of tomato seedlings in only 15 days and produced a large quantity of chlamydospores. This isolate was able to use cellulose as a carbon source, in addition to glucose and sucrose. Scanning electron microscopy (SEM revealed that hyphae of the P. chlamydosporia isolate Pc-10 penetrated the epidermal cells of the tomato roots. These three P. chlamydosporia isolates promote the growth of tomato and lettuce.

  3. Stem cells: a plant biology perspective

    NARCIS (Netherlands)

    Scheres, B.J.G.

    2005-01-01

    A recent meeting at the Juan March Foundation in Madrid, Spain brought together plant biologists to discuss the characteristics of plant stem cells that are unique and those that are shared by stem cells from the animal kingdom

  4. Molecular regulation of plant cell wall extensibility

    Science.gov (United States)

    Cosgrove, D. J.

    1998-01-01

    Gravity responses in plants often involve spatial and temporal changes in cell growth, which is regulated primarily by controlling the ability of the cell wall to extend. The wall is thought to be a cellulose-hemicellulose network embedded in a hydrated matrix of complex polysaccharides and a small amount of structural protein. The wall extends by a form of polymer creep, which is mediated by expansins, a novel group of wall-loosening proteins. Expansins were discovered during a molecular dissection of the "acid growth" behavior of cell walls. Expansin alters the rheology of plant walls in profound ways, yet its molecular mechanism of action is still uncertain. It lacks detectable hydrolytic activity against the major components of the wall, but it is able to disrupt noncovalent adhesion between wall polysaccharides. The discovery of a second family of expansins (beta-expansins) sheds light on the biological role of a major group of pollen allergens and implies that expansins have evolved for diverse developmental functions. Finally, the contribution of other processes to wall extensibility is briefly summarized.

  5. Effect of plant extracts used in folk medicine on cell growth and differentiation of Herpetomonas samuelpessoai (Kinetoplastida, Trypanosomatidae) cultivated in defined medium Efeito de extratos de plantas utilizadas na medicina popular no crescimento e diferenciação celular de Herpetomonas samuelpessoai (Kinetoplastida, Trypanosomatidae) cultivada em meio definido

    OpenAIRE

    Fabiola Barbieri Holetz; Tania Ueda Nakamura; Benedito Prado Dias Filho; Diogenes Aparicio Garcia Cortez; João Carlos Palazzo de Mello; Celso Vataru Nakamura

    2002-01-01

    This work reports the effect of 15 medicinal plants on cell growth and differentiation of Herpetomonas samuelpessoai, a non-pathogenic trypanosomatid, used as biological model for its similar antigens to Trypanosoma cruzi. Crude extracts (1,000 g/ml) or essential oil (250 g/ml) were added in a defined medium. Cell growth was estimated by counting in Neubauer’s chamber and cell differentiation was examined by light microscope. Ocimum gratissimum, Lippia alba, Piper regnellii, Stryphnodendron...

  6. 2003 Plant Cell Walls Gordon Conference

    Energy Technology Data Exchange (ETDEWEB)

    Daniel J. Cosgrove

    2004-09-21

    This conference will address recent progress in many aspects of cell wall biology. Molecular, genetic, and genomic approaches are yielding major advances in our understanding of the composition, synthesis, and architecture of plant cell walls and their dynamics during growth, and are identifying the genes that encode the machinery needed to make their biogenesis possible. This meeting will bring together international scientists from academia, industry and government labs to share the latest breakthroughs and perspectives on polysaccharide biosynthesis, wood formation, wall modification, expansion and interaction with other organisms, and genomic & evolutionary analyses of wall-related genes, as well as to discuss recent ''nanotechnological'' advances that take wall analysis to the level of a single cell.

  7. Regulation of Water in Plant Cells

    Science.gov (United States)

    Kowles, Richard V.

    2010-01-01

    Cell water relationships are important topics to be included in cell biology courses. Differences exist in the control of water relationships in plant cells relative to control in animal cells. One important reason for these differences is that turgor pressure is a consideration in plant cells. Diffusion and osmosis are the underlying factors…

  8. Productivity growth patterns in US dairy products manufacturing plants

    NARCIS (Netherlands)

    Geylani, P.C.; Stefanou, S.E.

    2011-01-01

    We analyse the productivity growth patterns in the US dairy products industry using the Census Bureau's plant-level data set. We decompose Total Factor Productivity (TFP) growth into the scale and technical change components and analyse variability of plants' productivity by constructing transition

  9. The research on Virtual Plants Growth Based on DLA Model

    Science.gov (United States)

    Zou, YunLan; Chai, Bencheng

    This article summarizes the separated Evolutionary Algorithm in fractal algorithm of Diffusion Limited Aggregation model (i.e. DLA model) and put forward the virtual plant growth realization in computer based on DLA model. The method is carried out in the VB6.0 environment to achieve and verify the plant growth based on DLA model.

  10. Artificial Life of Soybean Plant Growth Modeling Using Intelligence Approaches

    Directory of Open Access Journals (Sweden)

    Atris Suyantohadi

    2010-03-01

    Full Text Available The natural process on plant growth system has a complex system and it has could be developed on characteristic studied using intelligent approaches conducting with artificial life system. The approaches on examining the natural process on soybean (Glycine Max L.Merr plant growth have been analyzed and synthesized in these research through modeling using Artificial Neural Network (ANN and Lindenmayer System (L-System methods. Research aimed to design and to visualize plant growth modeling on the soybean varieties which these could help for studying botany of plant based on fertilizer compositions on plant growth with Nitrogen (N, Phosphor (P and Potassium (K. The soybean plant growth has been analyzed based on the treatments of plant fertilizer compositions in the experimental research to develop plant growth modeling. By using N, P, K fertilizer compositions, its capable result on the highest production 2.074 tons/hectares. Using these models, the simulation on artificial life for describing identification and visualization on the characteristic of soybean plant growth could be demonstrated and applied.

  11. Influence of calcium foliar fertilization on plant growth, nutrient concentrations, and fruit quality of papaya.

    Science.gov (United States)

    Calcium (Ca) is a major plant nutrient that affects cell wall and plasma membrane formation and plays a key role in plant growth and biomass production. It can be used to decrease fruit decay and increase firmness and shelf life. So far, little attention has been paid to investigate the effects of f...

  12. Plant growth-promoting bacteria as inoculants in agricultural soils

    Directory of Open Access Journals (Sweden)

    Rocheli de Souza

    2015-01-01

    Full Text Available AbstractPlant-microbe interactions in the rhizosphere are the determinants of plant health, productivity and soil fertility. Plant growth-promoting bacteria (PGPB are bacteria that can enhance plant growth and protect plants from disease and abiotic stresses through a wide variety of mechanisms; those that establish close associations with plants, such as the endophytes, could be more successful in plant growth promotion. Several important bacterial characteristics, such as biological nitrogen fixation, phosphate solubilization, ACC deaminase activity, and production of siderophores and phytohormones, can be assessed as plant growth promotion (PGP traits. Bacterial inoculants can contribute to increase agronomic efficiency by reducing production costs and environmental pollution, once the use of chemical fertilizers can be reduced or eliminated if the inoculants are efficient. For bacterial inoculants to obtain success in improving plant growth and productivity, several processes involved can influence the efficiency of inoculation, as for example the exudation by plant roots, the bacterial colonization in the roots, and soil health. This review presents an overview of the importance of soil-plant-microbe interactions to the development of efficient inoculants, once PGPB are extensively studied microorganisms, representing a very diverse group of easily accessible beneficial bacteria.

  13. Plant growth-promoting bacteria as inoculants in agricultural soils.

    Science.gov (United States)

    Souza, Rocheli de; Ambrosini, Adriana; Passaglia, Luciane M P

    2015-12-01

    Plant-microbe interactions in the rhizosphere are the determinants of plant health, productivity and soil fertility. Plant growth-promoting bacteria (PGPB) are bacteria that can enhance plant growth and protect plants from disease and abiotic stresses through a wide variety of mechanisms; those that establish close associations with plants, such as the endophytes, could be more successful in plant growth promotion. Several important bacterial characteristics, such as biological nitrogen fixation, phosphate solubilization, ACC deaminase activity, and production of siderophores and phytohormones, can be assessed as plant growth promotion (PGP) traits. Bacterial inoculants can contribute to increase agronomic efficiency by reducing production costs and environmental pollution, once the use of chemical fertilizers can be reduced or eliminated if the inoculants are efficient. For bacterial inoculants to obtain success in improving plant growth and productivity, several processes involved can influence the efficiency of inoculation, as for example the exudation by plant roots, the bacterial colonization in the roots, and soil health. This review presents an overview of the importance of soil-plant-microbe interactions to the development of efficient inoculants, once PGPB are extensively studied microorganisms, representing a very diverse group of easily accessible beneficial bacteria. PMID:26537605

  14. Visualized modeling platform for virtual plant growth and monitoring on the internet

    Science.gov (United States)

    Zhou, De-fu; Tian, Feng-qui; Ren, Ping

    2009-07-01

    Virtual plant growth is a key research topic in Agriculture Information Technique and Computer Graphics. It has been applied in botany, agronomy, environmental sciences, computre sciences and applied mathematics. Modeling leaf color dynamics in plant is of significant importance for realizing virtual plant growth. Using systematic analysis method and dynamic modeling technology, a SPAD-based leaf color dynamic model was developed to simulate time-course change characters of leaf SPAD on the plant. In addition, process of plant growth can be computer-stimulated using Virtual Reality Modeling Language (VRML) to establish a vivid and visible model, including shooting, rooting, blooming, as well as growth of the stems and leaves. In the resistance environment, e.g., lacking of water, air or nutrient substances, high salt or alkaline, freezing injury, high temperature, suffering from diseases and insect pests, the changes from the level of whole plant to organs, tissues and cells could be computer-stimulated. Changes from physiological and biochemistry could also be described. When a series of indexes were input by the costumers, direct view and microcosmic changes could be shown. Thus, the model has a good performance in predicting growth condition of the plant, laying a foundation for further constructing virtual plant growth system. The results revealed that realistic physiological and pathological processes of 3D virtual plants could be demonstrated by proper design and effectively realized in the internet.

  15. Water soluble carbon nano-onions from wood wool as growth promoters for gram plants

    Science.gov (United States)

    Sonkar, Sumit Kumar; Roy, Manas; Babar, Dipak Gorakh; Sarkar, Sabyasachi

    2012-11-01

    Water-soluble carbon nano-onions (wsCNOs) isolated from wood wool--a wood-based pyrolysis waste product of wood, can enhance the overall growth rate of gram (Cicer arietinum) plants. Treatment of plants with upto 30 μg mL-1 of wsCNOs for an initial 10 day period in laboratory conditions led to an increase in the overall growth of the plant biomass. In order to examine the growth stimulating effects of wsCNOs under natural conditions, 10 day-old plants treated with and without wsCNOs were transplanted into soil of standard carbon and nitrogen composition. We observed an enhanced growth rate of the wsCNOs pre-treated plants in soil, which finally led to an increased productivity of plants in terms of a larger number of grams. On analyzing the carbon, hydrogen, and nitrogen (CHN) content for the shoot and fruit sections of the plants treated with and without wsCNOs, only a minor difference in the composition was noticed. However, a slight increase in the percentage of carbon and hydrogen in shoots reflects the synthesis of more organic biomass in the case of treated plants. This work shows that wsCNOs are non-toxic to plant cells and can act as efficient growth stimulants which can be used as benign growth promoters.

  16. Carrageenans from red seaweeds as promoters of growth and elicitors of defense response in plants

    Directory of Open Access Journals (Sweden)

    Pushp Sheel Shukla

    2016-05-01

    Full Text Available Plants incessantly encounter abiotic and biotic stresses that limit their growth and productivity. However, conversely, plant growth can also be induced by treatments with various abiotic and biotic elicitors. Carrageenans are sulfated linear polysaccharides that represent major cellular constituents of seaweeds belonging to red algae (Rhodophyta. Recent research has unraveled the biological activity of carrageenans and of their oligomeric forms, the oligo carrageenans (OCs, as promoters of plant growth and as elicitors of defense responses against pests and diseases. In this review, we discuss the molecular mechanisms by which carrageenans and OCs mediate plant growth and plant defense responses. Carrageenans and OCs improve plant growth by regulating various metabolic processes such as photosynthesis and ancillary pathways, cell division, purine and pyrimidine synthetic pathways as well as metabolic pathways involved in nitrogen and sulfur assimilation. Carrageenans and OCs also induce plant defense responses against viroids, viruses, bacteria, fungi and insects by modulating the activity of different defense pathways, including salicylate, jasmonate and ethylene signaling pathways. Further studies will likely substantiate the beneficial effects of carrageenans and of OCs on plant growth and plant defense responses and open new avenues for their use in agriculture and horticultural industry.

  17. Plant growth and greenhouse effect. Plantengroei en broeikaseffect

    Energy Technology Data Exchange (ETDEWEB)

    Goudriaan, J. (Vakgroep Theoretische Produktie-ecologie, Landbouwuniversiteit Wageningen, Wageningen (Netherlands))

    1993-07-01

    Climatic change means a change in the growth of plants, of agriculture and finally of total ecosystems. The vegetation itself also has a considerable impact on the atmospheric composition and hence on the climate. The increase of the amount of CO[sub 2] in the air improves the plant growth. Attention is paid to the impact of plants on the climate and how to benefit from it. 6 figs., 9 ills.

  18. PEMANFAATAN PLANT GROWTH PROMOTING RHIZOBACTERIA UNTUK BIOSTIMULANTS DAN BIOPROTECTANTS

    Directory of Open Access Journals (Sweden)

    Khamdan Khalimi

    2012-11-01

    Full Text Available Various findings on the benefit of plant growth promoting rhizobacteria (PGPR for agriculture have been reported by many research institutional. The enthusiasm to commercialize these bacteria as a promising alternative technology is triggered mainly by the to develop environmentally benign agriculture by reducing the use of synthetically agrochemical inputs (fertilizers and pesticides. These result suggested that application of PGPR could promoted the plant growth and increase the resistance of plant against fungi pathogen.

  19. Plant growth and architectural modelling and its applications

    OpenAIRE

    Guo, Yan; Fourcaud, Thierry; Jaeger, Marc; Zhang, Xiaopeng; Li, Baoguo

    2011-01-01

    Over the last decade, a growing number of scientists around the world have invested in research on plant growth and architectural modelling and applications (often abbreviated to plant modelling and applications, PMA). By combining physical and biological processes, spatially explicit models have shown their ability to help in understanding plant–environment interactions. This Special Issue on plant growth modelling presents new information within this topic, which are summarized in this pref...

  20. Functions of Xyloglucan in Plant Cells

    Institute of Scientific and Technical Information of China (English)

    Takahisa Hayashi; Rumi Kaida

    2011-01-01

    While an increase in the number of xyloglucan tethers between the cellulose microfibrils in plant cell walls increases the walls' rigidity, the degradation of these tethers causes the walls to loosen. Degradation can occur either through the integration of xyloglucan oligosaccharides due to the action of xyloglucan endotransglucosylase or through direct hydrolysis due to the action of xyloglucanase. This is why the addition of xyloglucan and its fragment oligosac-charides causes plant tissue tension to increase and decrease so dramatically. Experiments involving the overexpression of xyloglucanase and cellulase have revealed the roles of xyloglucans in the walls. The degradation of wall xyloglucan in poplar by the transgenic expression of xyloglucanase, for example, not only accelerated stem elongation in the primary wall, but also blocked upright-stem gravitropism in the secondary wall. Overexpression of cellulase also reduced xyloglucan content in the walls as cellulose microfibrils were trimmed at their amorphous region, resulting in increased cell volume in Arabidopsis leaves and in sengon with disturbed leaf movements. The hemicellulose xyloglucan, in its function as a tether, plays a key role in the loosening and tightening of cellulose microfibrils: it enables the cell to change its shape in growth and differentiation zones and to retain its final shape after cell maturation.

  1. Cytokinins as key regulators in plant-microbe-insect interactions: connecting plant growth and defence

    NARCIS (Netherlands)

    Giron, D.; Frago, E.; Glevarec, G.; Pieterse, C.M.J.; Dicke, M.

    2013-01-01

    Plant hormones play important roles in regulating plant growth and defence by mediating developmental processes and signalling networks involved in plant responses to a wide range of parasitic and mutualistic biotic interactions. Plants are known to rapidly respond to pathogen and herbivore attack b

  2. Polynucleotide phosphorylase from plant cells.

    Science.gov (United States)

    Schumacher-Wittkopf, E; Richter, G; Schulze, S

    1984-06-01

    The isolation of polynucleotide phosphorylase (EC 2. 7. 7. 8) from suspension cultured plant cells of parsley (Petroselinum sativum) and from tomato seedlings (Lycopersicon esculentum) is described. The procedure includes an ultracentrifugation step, a glycerol density gradient centrifugation and preparative gel electrophoresis under nondenaturing conditions. Isoelectric focusing gives rise to a major component (pI ≈ 7.5) and to a minor one (pI ≈ 5). The enzyme contains five subunits with apparent Mr values of 160 000, 140 000, 70 000, 34 000 and 12 000, the 70 000-dalton one being a glycoprotein. PMID:24253429

  3. Endophytic bacteria affect sugarcane physiology without changing plant growth

    OpenAIRE

    Fernanda Castro Correia Marcos; Raquel de Paula Freitas Iório; Adriana Parada Dias da Silveira; Rafael Vasconcelos Ribeiro; Eduardo Caruso Machado; Ana Maria Magalhães Andrade Lagôa

    2015-01-01

    ABSTRACT The aim of this study was to evaluate if endophytic bacteria inoculants would be beneficial to the sugarcane varieties IACSP94-2094 and IACSP95-5000, promoting changes in photosynthesis and plant growth. The plants, obtained from mini stalks with one bud, were treated with two bacteria mixtures (inoculum I or II) or did not receive any inoculum (control plants). The inocula did not affect shoot and root dry matter accumulation as compared to the control condition (plants with native ...

  4. Magnetic fields: how is plant growth and development impacted?

    Science.gov (United States)

    da Silva, Jaime A Teixeira; Dobránszki, Judit

    2016-03-01

    This review provides detailed insight on the effects of magnetic fields on germination, growth, development, and yield of plants focusing on ex vitro growth and development and discussing the possible physiological and biochemical responses. The MFs considered in this review range from the nanoTesla (nT) to geomagnetic levels, up to very strong MFs greater than 15 Tesla (T) and also super-weak MFs (near 0 T). The theoretical bases of the action of MFs on plant growth, which are complex, are not discussed here and thus far, there is limited mathematical background about the action of MFs on plant growth. MFs can positively influence the morphogenesis of several plants which allows them to be used in practical situations. MFs have thus far been shown to modify seed germination and affect seedling growth and development in a wide range of plants, including field, fodder, and industrial crops; cereals and pseudo-cereals; grasses; herbs and medicinal plants; horticultural crops (vegetables, fruits, ornamentals); trees; and model crops. This is important since MFs may constitute a non-residual and non-toxic stimulus. In addition to presenting and summarizing the effects of MFs on plant growth and development, we also provide possible physiological and biochemical explanations for these responses including stress-related responses of plants, explanations based on dia-, para-, and ferromagnetism, oriented movements of substances, and cellular and molecular changes.

  5. Changes in alpine plant growth under future climate conditions

    Directory of Open Access Journals (Sweden)

    A. Rammig

    2010-06-01

    Full Text Available Alpine shrub- and grasslands are shaped by extreme climatic conditions such as a long-lasting snow cover and a short vegetation period. Such ecosystems are expected to be highly sensitive to global environmental change. Prolonged growing seasons and shifts in temperature and precipitation are likely to affect plant phenology and growth. In a unique experiment, climatology and plant growth was monitored for almost a decade at 17 snow meteorological stations in different alpine regions along the Swiss Alps. Regression analyses revealed highly significant correlations between mean air temperature in May/June and snow melt out, onset of plant growth, and plant height. These correlations were used to project plant growth phenology for future climate conditions based on the gridded output of a set of regional climate models runs. Melt out and onset of growth were projected to occur on average 17 days earlier by the end of the century than in the control period from 1971–2000 under the future climate conditions of the low resolution climate model ensemble. Plant height and biomass production were expected to increase by 77% and 45%, respectively. The earlier melt out and onset of growth will probably cause a considerable shift towards higher growing plants and thus increased biomass. Our results represent the first quantitative and spatially explicit estimates of climate change impacts on future growing season length and the respective productivity of alpine plant communities in the Swiss Alps.

  6. Plant Growth-Promoting Rhizobacteria Stimulate Vegetative Growth and Asexual Reproduction of Kalanchoe daigremontiana.

    Science.gov (United States)

    Park, Yong-Soon; Park, Kyungseok; Kloepper, Joseph W; Ryu, Choong-Min

    2015-09-01

    Certain bacterial species associate with plant roots in soil. The plant growth-promoting rhizobacteria (PGPR) stimulate plant growth and yield in greenhouse and field. Here, we examined whether application of known bacilli PGPR strains stimulated growth and asexual reproduction in the succulent plant Kalanchoe daigremontiana. Four PGPR strains B. amyloliquefaciens IN937a, B. cereus BS107, B. pumilus INR7, and B. subtilis GB03 were applied to young plantlets by soil-drenching, and plant growth and development was monitored for three months. Aerial growth was significantly stimulated in PGPR-inoculated plants, which was observed as increases in plant height, shoot weight, and stem width. The stimulated growth influenced plant development by increasing the total number of leaves per plant. Treatment with bacilli also increased the total root biomass compared with that of control plants, and led to a 2-fold increase in asexual reproduction and plantlet formation on the leaf. Collectively, our results firstly demonstrate that Bacillus spp. promote vegetative development of K. daigremontiana, and the enhanced growth stimulates asexual reproduction and plantlet formation. PMID:26361480

  7. Plant Growth-Promoting Rhizobacteria Stimulate Vegetative Growth and Asexual Reproduction of Kalanchoe daigremontiana

    Directory of Open Access Journals (Sweden)

    Yong-Soon Park

    2015-09-01

    Full Text Available Certain bacterial species associate with plant roots in soil. The plant growth-promoting rhizobacteria (PGPR stimulate plant growth and yield in greenhouse and field. Here, we examined whether application of known bacilli PGPR strains stimulated growth and asexual reproduction in the succulent plant Kalanchoe daigremontiana. Four PGPR strains B. amyloliquefaciens IN937a, B. cereus BS107, B. pumilus INR7, and B. subtilis GB03 were applied to young plantlets by soil-drenching, and plant growth and development was monitored for three months. Aerial growth was significantly stimulated in PGPR-inoculated plants, which was observed as increases in plant height, shoot weight, and stem width. The stimulated growth influenced plant development by increasing the total number of leaves per plant. Treatment with bacilli also increased the total root biomass compared with that of control plants, and led to a 2-fold increase in asexual reproduction and plantlet formation on the leaf. Collectively, our results firstly demonstrate that Bacillus spp. promote vegetative development of K. daigremontiana, and the enhanced growth stimulates asexual reproduction and plantlet formation.

  8. Plant Growth-Promoting Rhizobacteria Stimulate Vegetative Growth and Asexual Reproduction of Kalanchoe daigremontiana.

    Science.gov (United States)

    Park, Yong-Soon; Park, Kyungseok; Kloepper, Joseph W; Ryu, Choong-Min

    2015-09-01

    Certain bacterial species associate with plant roots in soil. The plant growth-promoting rhizobacteria (PGPR) stimulate plant growth and yield in greenhouse and field. Here, we examined whether application of known bacilli PGPR strains stimulated growth and asexual reproduction in the succulent plant Kalanchoe daigremontiana. Four PGPR strains B. amyloliquefaciens IN937a, B. cereus BS107, B. pumilus INR7, and B. subtilis GB03 were applied to young plantlets by soil-drenching, and plant growth and development was monitored for three months. Aerial growth was significantly stimulated in PGPR-inoculated plants, which was observed as increases in plant height, shoot weight, and stem width. The stimulated growth influenced plant development by increasing the total number of leaves per plant. Treatment with bacilli also increased the total root biomass compared with that of control plants, and led to a 2-fold increase in asexual reproduction and plantlet formation on the leaf. Collectively, our results firstly demonstrate that Bacillus spp. promote vegetative development of K. daigremontiana, and the enhanced growth stimulates asexual reproduction and plantlet formation.

  9. A dynamic model of tomato fruit growth integrating cell division, cell growth and endoreduplication

    NARCIS (Netherlands)

    Fanwoua, J.; Visser, de P.H.B.; Heuvelink, E.; Yin, X.; Struik, P.C.; Marcelis, L.F.M.

    2013-01-01

    In this study, we developed a model of tomato (Solanum lycopersicum L.) fruit growth integrating cell division, cell growth and endoreduplication. The fruit was considered as a population of cells grouped in cell classes differing in their initial cell age and cell mass. The model describes fruit gr

  10. Another brick in the cell wall: biosynthesis dependent growth model.

    Directory of Open Access Journals (Sweden)

    Adelin Barbacci

    Full Text Available Expansive growth of plant cell is conditioned by the cell wall ability to extend irreversibly. This process is possible if (i a tensile stress is developed in the cell wall due to the coupling effect between turgor pressure and the modulation of its mechanical properties through enzymatic and physicochemical reactions and if (ii new cell wall elements can be synthesized and assembled to the existing wall. In other words, expansive growth is the result of coupling effects between mechanical, thermal and chemical energy. To have a better understanding of this process, models must describe the interplay between physical or mechanical variable with biological events. In this paper we propose a general unified and theoretical framework to model growth in function of energy forms and their coupling. This framework is based on irreversible thermodynamics. It is then applied to model growth of the internodal cell of Chara corallina modulated by changes in pressure and temperature. The results describe accurately cell growth in term of length increment but also in term of cell pectate biosynthesis and incorporation to the expanding wall. Moreover, the classical growth model based on Lockhart's equation such as the one proposed by Ortega, appears as a particular and restrictive case of the more general growth equation developed in this paper.

  11. Plant growth regulators enhance gold uptake in Brassica juncea.

    Science.gov (United States)

    Kulkarni, Manoj G; Stirk, Wendy A; Southway, Colin; Papenfus, Heino B; Swart, Pierre A; Lux, Alexander; Vaculík, Marek; Martinka, Michal; Van Staden, Johannes

    2013-01-01

    The use of plant growth regulators is well established and they are used in many fields of plant science for enhancing growth. Brassica juncea plants were treated with 2.5, 5.0 and 7.5 microM auxin indole-3-butyric acid (IBA), which promotes rooting. The IBA-treated plants were also sprayed with 100 microM gibberellic acid (GA3) and kinetin (Kin) to increase leaf-foliage. Gold (I) chloride (AuCl) was added to the growth medium of plants to achieve required gold concentration. The solubilizing agent ammonium thiocyanate (1 g kg(-1)) (commonly used in mining industries to solubilize gold) was added to the nutrient solution after six weeks of growth and, two weeks later, plants were harvested. Plant growth regulators improved shoot and root dry biomass of B. juncea plants. Inductively Coupled Plasma Optical Emission Spectrometry analysis showed the highest Au uptake for plants treated with 5.0 microM IBA. The average recovery of Au with this treatment was significantly greater than the control treatment by 45.8 mg kg(-1) (155.7%). The other IBA concentrations (2.5 and 7.5 microM) also showed a significant increase in Au uptake compared to the control plants by 14.7 mg kg(-1) (50%) and 42.5 mg kg(-1) (144.5%) respectively. A similar trend of Au accumulation was recorded in the roots of B. juncea plants. This study conducted in solution culture suggests that plant growth regulators can play a significant role in improving phytoextraction of Au.

  12. On-line flaw growth monitoring in high temperature plant

    Energy Technology Data Exchange (ETDEWEB)

    Atkinson, I. (KANDE International Ltd, Knutsford (United Kingdom)); Kelly, S.; Lay, P. (Doosan Babcock, Renfrew (United Kingdom)); Brett, C. (E.ON Engineering, Nottingham (United Kingdom))

    2010-05-15

    The operating conditions experienced by power plants place high demands on plant components, and ensuring plant availability without compromising safety or plant integrity can be a significant challenge to operators. On-line measurement of known flaws in plant has the potential to provide plant operators with substantial savings in overall operating costs through the better management of inspection and repair activities. This is particularly true of high-temperature plant, where the preferred inspection techniques for measuring crack growth are unsuitable for on-line application and must be applied during plant shutdown, which can lead to low accuracy and substantial inspection costs, as well as loss of production. To address such problems, we have been working on the development of of in-situ, high-temperature ultrasonic crack growth measurement techniques for several years, and will this year proceed to a trial installation at a UK fossil-fuel plant. This paper reports the results of a laboratory trial to demonstrate the measurement of fatigue crack growth in a thick-walled ferritic steel pipe section at 615degC. This was part of a programme of tests performed to verify the viabilityof the transducers and crack-growth measurement techniques, prior to the trial on operational plant. (orig.)

  13. Tubular Membrane Plant-Growth Unit

    Science.gov (United States)

    Dreschel, Thomas W.

    1992-01-01

    Hydroponic system controls nutrient solution for growing crops in space. Pump draws nutrient solution along inside of tubular membrane in pipe from reservoir, maintaining negative pressure in pipe. Roots of plants in slot extract nutrient through membrane within pipe. Crop plants such as wheat, rice, lettuce, tomatoes, soybeans, and beans grown successfully with system.

  14. Plant growth promotion by Pseudomonas fluorescens

    NARCIS (Netherlands)

    Cheng, X.

    2016-01-01

    Pseudomonas fluorescens is a Gram-negative rod shaped bacterium that has a versatile metabolism and is widely spread in soil and water. P. fluorescens strain SBW25 (Pf.SBW25) is a well-known model strain to study bacterial evolution, plant colonization and biocontrol of plant diseases. It produces t

  15. Polar fluxes of calcium ions and growth of plant tissues

    International Nuclear Information System (INIS)

    The authors studied the action exerted by auxin transport inhibitors (2,3,5-triiodobenzoic acid, 10-4 M; 1-N-naphthylphthalamic acid, 10-4 M), inhibitors of membrane-bound ATPases (sodium orthovanadate, 10-4 M; diethylstilbestrol, 10-5 M), and a blocker of Ca-channels (verapamil, 1.3 x 10-4 M) on growth processes (lengthwise growth, the gravitropic response) and translocation of 45Ca in segments of corn (Zea mays L.) coleoptiles and pea (Pisum sativum L.) internodes. Calcium in vertically oriented and gravistimulated segments was polarly translocated in a direction opposite the vector of gravitational force. It is hypothesized that the polar fluxes of Ca2+ ions which arise in tissues with a change in position of the plant organism in space are capable of correcting the direction of active basipetal transport of IAA and thereby able to induce polarization of growth processes. In studying transport of Ca2+ ions on plasmalemma vesicles with the aid of chlorotetracycline, it was found that creation of a potassium diffusion potential on the membrane (as a results of valinomycin treatment) induces entry of calcium into the vesicles. Since this effect was removed by verapamil and ruthenium red, it is postulated that potential-dependent Ca-channels are present on the plasma membrane of corn coleoptile cells

  16. Expert System Control of Plant Growth in an Enclosed Space

    Science.gov (United States)

    May, George; Lanoue, Mark; Bathel, Matthew; Ryan, Robert E.

    2008-01-01

    The Expert System is an enclosed, controlled environment for growing plants, which incorporates a computerized, knowledge-based software program that is designed to capture the knowledge, experience, and problem-solving skills of one or more human experts in a particular discipline. The Expert System is trained to analyze crop/plant status, to monitor the condition of the plants and the environment, and to adjust operational parameters to optimize the plant-growth process. This system is intended to provide a way to remotely control plant growth with little or no human intervention. More specifically, the term control implies an autonomous method for detecting plant states such as health (biomass) or stress and then for recommending and implementing cultivation and/or remediation to optimize plant growth and to minimize consumption of energy and nutrients. Because of difficulties associated with delivering energy and nutrients remotely, a key feature of this Expert System is its ability to minimize this effort and to achieve optimum growth while taking into account the diverse range of environmental considerations that exist in an enclosed environment. The plant-growth environment for the Expert System could be made from a variety of structures, including a greenhouse, an underground cavern, or another enclosed chamber. Imaging equipment positioned within or around the chamber provides spatially distributed crop/plant-growth information. Sensors mounted in the chamber provide data and information pertaining to environmental conditions that could affect plant development. Lamps in the growth environment structure supply illumination, and other additional equipment in the chamber supplies essential nutrients and chemicals.

  17. Structural Studies of Complex Carbohydrates of Plant Cell Walls

    Energy Technology Data Exchange (ETDEWEB)

    Darvill, Alan [Univ. of Georgia, Athens, GA (United States); Hahn, Michael G. [Univ. of Georgia, Athens, GA (United States); O' Neill, Malcolm A. [Univ. of Georgia, Athens, GA (United States); York, William S. [Univ. of Georgia, Athens, GA (United States)

    2015-02-17

    Most of the solar energy captured by land plants is converted into the polysaccharides (cellulose, hemicellulose, and pectin) that are the predominant components of the cell wall. These walls, which account for the bulk of plant biomass, have numerous roles in the growth and development of plants. Moreover, these walls have a major impact on human life as they are a renewable source of biomass, a source of diverse commercially useful polymers, a major component of wood, and a source of nutrition for humans and livestock. Thus, understanding the molecular mechanisms that lead to wall assembly and how cell walls and their component polysaccharides contribute to plant growth and development is essential to improve and extend the productivity and value of plant materials. The proposed research will develop and apply advanced analytical and immunological techniques to study specific changes in the structures and interactions of the hemicellulosic and pectic polysaccharides that occur during differentiation and in response to genetic modification and chemical treatments that affect wall biosynthesis. These new techniques will make it possible to accurately characterize minute amounts of cell wall polysaccharides so that subtle changes in structure that occur in individual cell types can be identified and correlated to the physiological or developmental state of the plant. Successful implementation of this research will reveal fundamental relationships between polysaccharide structure, cell wall architecture, and cell wall functions.

  18. Plant growth-promoting rhizobacteria and root system functioning

    Directory of Open Access Journals (Sweden)

    Jordan eVacheron

    2013-09-01

    Full Text Available The rhizosphere supports the development and activity of a huge and diversified microbial community, including microorganisms capable to promote plant growth. Among the latter, Plant Growth-Promoting Rhizobacteria (PGPR colonize roots of monocots and dicots, and enhance plant growth by direct and indirect mechanisms. Modification of root system architecture by PGPR implicates the production of phytohormones and other signals that lead, mostly, to enhanced lateral root branching and development of root hairs. PGPR also modify root functioning, improve plant nutrition and influence the physiology of the whole plant. Recent results provided first clues as to how PGPR signals could trigger these plant responses. Whether local and/or systemic, the plant molecular pathways involved remain often unknown. From an ecological point of view, it emerged that PGPR form coherent functional groups, whose rhizosphere ecology is influenced by a myriad of abiotic and biotic factors in natural and agricultural soils, and these factors can in turn modulate PGPR effects on roots. In this paper, we address novel knowledge and gaps on PGPR modes of action and signals, and highlight recent progress on the links between plant morphological and physiological effects induced by PGPR. We also show the importance of taking into account the size, diversity and gene expression patterns of PGPR assemblages in the rhizosphere to better understand their impact on plant growth and functioning. Integrating mechanistic and ecological knowledge on PGPR populations in soil will be a prerequisite to develop novel management strategies for sustainable agriculture.

  19. Stochastic Gompertz model of tumour cell growth.

    Science.gov (United States)

    Lo, C F

    2007-09-21

    In this communication, based upon the deterministic Gompertz law of cell growth, a stochastic model in tumour growth is proposed. This model takes account of both cell fission and mortality too. The corresponding density function of the size of the tumour cells obeys a functional Fokker--Planck equation which can be solved analytically. It is found that the density function exhibits an interesting "multi-peak" structure generated by cell fission as time evolves. Within this framework the action of therapy is also examined by simply incorporating a therapy term into the deterministic cell growth term.

  20. [Protective properties of avermectine complex and plant growth regulators].

    Science.gov (United States)

    Iamborko, N A; Pindrus, A A

    2009-01-01

    Antimutagen properties of avermectine complex of Avercom synthesized by Streptomyces avermitilis UCM Ac-2161, and growth regulators of plants (GRP) of bioagrostim-extra, ivin and emistim-C have been revealed in experiments with test-cultures of Salmonella typhimurium TA 100, TA 98. Avercom and plant growth regulators neutralize by toxication 27-48% and mutagen action of pesticides on soil microbial associations by 19.0-30.0%.

  1. Multinationals as Stabilizers?: Economic Crisis and Plant Employment Growth

    OpenAIRE

    Álvarez Espinoza, Roberto; Görg, Holger

    2007-01-01

    This paper examines the link between multinational enterprises and employment growth at the plant-level. We investigate in detail the comparative response of multinationals and domestic firms to an economic crisis, using the empirical setting of a well defined case of economic slowdown in Chile as a natural experiment. In our empirical analysis we find that employment growth in manufacturing plants has been drastically reduced during the economic crisis. More importantly, we do not find evide...

  2. Plant Hormones Promote Growth in Lichen-Forming Fungi

    OpenAIRE

    Wang, Xin Yu; Wei, Xin Li; Luo, Heng; Kim, Jung A; Jeon, Hae Sook; Koh, Young Jin; Hur, Jae-Seoun

    2010-01-01

    The effect of plant hormones on the growth of lichen-forming fungi (LFF) was evaluated. The use of 2,3,5-triiodobenzoic acid and indole-3-butyric acid resulted in a 99% and 57% increase in dry weight of the lichen-forming fungus Nephromopsis ornata. The results suggest that some plant hormones can be used as inducers or stimulators of LFF growth for large-scale culture.

  3. Effects of different plant growth inhibitors on growth and flowering of narcissus

    Institute of Scientific and Technical Information of China (English)

    Ren Xuqin

    2003-01-01

    This study was conducted to determine effects of four plant growth inhibitors viz. PP333, Het, CCC and B9 with different concentrations on growth and flowering of narcissus. The results indicated that the narcissus treated with certain concentration inhibitors could grow shorter plants with shorter scapes of flower and smaller leaves than the check, and the compact, straight and coordinate plants improve the decorative value obviously.

  4. Refractive index of plant cell walls

    Science.gov (United States)

    Gausman, H. W.; Allen, W. A.; Escobar, D. E.

    1974-01-01

    Air was replaced with media of higher refractive indices by vacuum infiltration in leaves of cucumber, blackeye pea, tomato, and string bean plants, and reflectance of noninfiltrated and infiltrated leaves was spectrophotometrically measured. Infiltrated leaves reflected less light than noninfiltrated leaves over the 500-2500-nm wavelength interval because cell wall-air interfaces were partly eliminated. Minimal reflectance should occur when the average refractive index of plant cell walls was matched by the infiltrating fluid. Although refractive indices that resulted in minimal reflectance differed among the four plant genera, an average value of 1.425 approximates the refractive index of plant cell walls for the four plant genera.

  5. The microbiome of medicinal plants: diversity and importance for plant growth, quality and health.

    Science.gov (United States)

    Köberl, Martina; Schmidt, Ruth; Ramadan, Elshahat M; Bauer, Rudolf; Berg, Gabriele

    2013-01-01

    Past medicinal plant research primarily focused on bioactive phytochemicals, however, the focus is currently shifting due to the recognition that a significant number of phytotherapeutic compounds are actually produced by associated microbes or through interaction with their host. Medicinal plants provide an enormous bioresource of potential use in modern medicine and agriculture, yet their microbiome is largely unknown. The objective of this review is (i) to introduce novel insights into the plant microbiome with a focus on medicinal plants, (ii) to provide details about plant- and microbe-derived ingredients of medicinal plants, and (iii) to discuss possibilities for plant growth promotion and plant protection for commercial cultivation of medicinal plants. In addition, we also present a case study performed both to analyse the microbiome of three medicinal plants (Matricaria chamomilla L., Calendula officinalis L., and Solanum distichum Schumach. and Thonn.) cultivated on organically managed Egyptian desert farm and to develop biological control strategies. The soil microbiome of the desert ecosystem was comprised of a high abundance of Gram-positive bacteria of prime importance for pathogen suppression under arid soil conditions. For all three plants, we observed a clearly plant-specific selection of the microbes as well as highly specific diazotrophic communities that overall identify plant species as important drivers in structural and functional diversity. Lastly, native Bacillus spec. div. strains were able to promote plant growth and elevate the plants' flavonoid production. These results underline the numerous links between the plant-associated microbiome and the plant metabolome. PMID:24391634

  6. PLANT-MICROBIAL INTERACTIONS IN THE RHIZOSPHERE – STRATEGIES FOR PLANT GROWTH-PROMOTION

    Directory of Open Access Journals (Sweden)

    Marius Stefan

    2012-03-01

    Full Text Available Plant growth-promoting rhizobacteria (PGPR are a group of bacteria that can actively colonize plant rootsand enhance plant growth using different mechanisms: production of plant growth regulators like indoleacetic acid,gibberellic acid, cytokinins and ethylene(Zahir et al., 2003, providing the host plant with fixed nitrogen, solubilizationof soil phosphorus, enhance Fe uptake, biocontrol, reducing the concentration of heavy metals. PGPR are perfectcandidates to be used as biofertilizers – eco-friendly alternative to common applied chemical fertilizer in today’sagriculture. The most important benefit of PGPR usage is related to the reduction of environmental pollution in conditionof increasing crop yield. This review presents the main mechanisms involved in PGPR promotion of plant growth.

  7. Growth, Nitrogen Uptake and Flow in Maize Plants Affected by Root Growth Restriction

    Institute of Scientific and Technical Information of China (English)

    Liang-zheng Xu; Jun-fang Niu; Chun-jian Li; Fu-suo Zhang

    2009-01-01

    The objective of the present study was to investigate the influence of a reduced maize root-system size on root growth and nitrogen (N) uptake and flow within plants. Restriction of shoot-borne root growth caused a strong decrease in the absorption of root: shoot dry weight ratio and a reduction in shoot growth. On the other hand, compensatory growth and an increased N uptake rate in the remaining roots were observed. Despite the limited long-distance transport pathway in the mesocotyl with restriction of shoot-borne root growth, N cycling within these plants was higher than those in control plants, implying that xylem and phloem flow velocities via the mesocotyl were considerably higher than in plants with an intact root system. The removal of the seminal roots in addition to restricting shoot-borne root development did not affect whole plant growth and N uptake, except for the stronger compensatory growth of the primary roots. Our results suggest that an adequate N supply to maize plant is maintained by compensatory growth of the remaining roots, increased N uptake rate and flow velocities within the xylem and phloem via the mesocotyl, and reduction in the shoot growth rate.

  8. Effect of Silicon on Plant Growth and Drought Stress Tolerance

    OpenAIRE

    Janislampi, Kaerlek W.

    2012-01-01

    Silicon is not considered an essential nutrient, but it is typically abundant in soils and can be taken up in large amounts by plants. Silicon is known to have beneficial effects when added to rice and several other plants. These effects include disease and insect resistance, structural fortification, and regulation of the uptake of other ions. In this study, the effect of silicic acid fertilization on the growth and drought tolerance of four crop plants (corn, wheat, soybean, and rice) was a...

  9. Irrigation and planting density affect river red gum growth

    OpenAIRE

    Cockerham, Stephen T.

    2004-01-01

    In a 6-year study, production of river red gum, an excellent fuel-wood source, was evaluated for responses to three levels of irrigation, fertilization and planting density. Irrigation and planting density had the greatest influence on tree growth. Irrigation in the fifth and sixth years produced greater wood volume and weight per tree. Tree size was greatest in the wide spacing of the lower planting density. Fertilizer had no effect on any of the treatments. Per acre volume and weight yields...

  10. The microbiome of medicinal plants: diversity and importance for plant growth, quality and health

    Science.gov (United States)

    Köberl, Martina; Schmidt, Ruth; Ramadan, Elshahat M.; Bauer, Rudolf; Berg, Gabriele

    2013-01-01

    Past medicinal plant research primarily focused on bioactive phytochemicals, however, the focus is currently shifting due to the recognition that a significant number of phytotherapeutic compounds are actually produced by associated microbes or through interaction with their host. Medicinal plants provide an enormous bioresource of potential use in modern medicine and agriculture, yet their microbiome is largely unknown. The objective of this review is (i) to introduce novel insights into the plant microbiome with a focus on medicinal plants, (ii) to provide details about plant- and microbe-derived ingredients of medicinal plants, and (iii) to discuss possibilities for plant growth promotion and plant protection for commercial cultivation of medicinal plants. In addition, we also present a case study performed both to analyse the microbiome of three medicinal plants (Matricaria chamomilla L., Calendula officinalis L., and Solanum distichum Schumach. and Thonn.) cultivated on organically managed Egyptian desert farm and to develop biological control strategies. The soil microbiome of the desert ecosystem was comprised of a high abundance of Gram-positive bacteria of prime importance for pathogen suppression under arid soil conditions. For all three plants, we observed a clearly plant-specific selection of the microbes as well as highly specific diazotrophic communities that overall identify plant species as important drivers in structural and functional diversity. Lastly, native Bacillus spec. div. strains were able to promote plant growth and elevate the plants’ flavonoid production. These results underline the numerous links between the plant-associated microbiome and the plant metabolome. PMID:24391634

  11. Dynamical Riemannian Geometry and Plant Growth

    CERN Document Server

    Pulwicki, Julia

    2010-01-01

    A new model for biological growth is introduced that couples the geometry of an organism (or part of the organism) to the flow and deposition of material. The model has three dynamical variables (a) a Riemann metric tensor for the geometry, (b) a transport velocity of the material and (c) a material density. While the model was developed primarily to determine the effects of geometry (i.e. curvature and scale changes) in two-dimensional systems such as leaves and petals, it can be applied to any dimension. Results for one dimensional systems are presented and compared to measurements of growth made on blades of grass and corn roots. It is found that the model is able to reproduce many features associated with botanical growth.

  12. Material and methods to increase plant growth and yield

    Energy Technology Data Exchange (ETDEWEB)

    Kirst, Matias

    2015-09-15

    The present invention relates to materials and methods for modulating growth rates, yield, and/or resistance to drought conditions in plants. In one embodiment, a method of the invention comprises increasing expression of an hc1 gene (or a homolog thereof that provides for substantially the same activity), or increasing expression or activity of the protein encoded by an hc1 gene thereof, in a plant, wherein expression of the hc1 gene or expression or activity of the protein encoded by an hc1 gene results in increased growth rate, yield, and/or drought resistance in the plant.

  13. Design and construction of an inexpensive homemade plant growth chamber.

    Directory of Open Access Journals (Sweden)

    Fumiaki Katagiri

    Full Text Available Plant growth chambers produce controlled environments, which are crucial in making reproducible observations in experimental plant biology research. Commercial plant growth chambers can provide precise controls of environmental parameters, such as temperature, humidity, and light cycle, and the capability via complex programming to regulate these environmental parameters. But they are expensive. The high cost of maintaining a controlled growth environment is often a limiting factor when determining experiment size and feasibility. To overcome the limitation of commercial growth chambers, we designed and constructed an inexpensive plant growth chamber with consumer products for a material cost of $2,300. For a comparable growth space, a commercial plant growth chamber could cost $40,000 or more. Our plant growth chamber had outside dimensions of 1.5 m (W x 1.8 m (D x 2 m (H, providing a total growth area of 4.5 m2 with 40-cm high clearance. The dimensions of the growth area and height can be flexibly changed. Fluorescent lights with large reflectors provided a relatively spatially uniform photosynthetically active radiation intensity of 140-250 μmoles/m2/sec. A portable air conditioner provided an ample cooling capacity, and a cooling water mister acted as a powerful humidifier. Temperature, relative humidity, and light cycle inside the chamber were controlled via a z-wave home automation system, which allowed the environmental parameters to be monitored and programmed through the internet. In our setting, the temperature was tightly controlled: 22.2°C±0.8°C. The one-hour average relative humidity was maintained at 75%±7% with short spikes up to ±15%. Using the interaction between Arabidopsis and one of its bacterial pathogens as a test experimental system, we demonstrate that experimental results produced in our chamber were highly comparable to those obtained in a commercial growth chamber. In summary, our design of an inexpensive plant

  14. Design and construction of an inexpensive homemade plant growth chamber.

    Science.gov (United States)

    Katagiri, Fumiaki; Canelon-Suarez, Dario; Griffin, Kelsey; Petersen, John; Meyer, Rachel K; Siegle, Megan; Mase, Keisuke

    2015-01-01

    Plant growth chambers produce controlled environments, which are crucial in making reproducible observations in experimental plant biology research. Commercial plant growth chambers can provide precise controls of environmental parameters, such as temperature, humidity, and light cycle, and the capability via complex programming to regulate these environmental parameters. But they are expensive. The high cost of maintaining a controlled growth environment is often a limiting factor when determining experiment size and feasibility. To overcome the limitation of commercial growth chambers, we designed and constructed an inexpensive plant growth chamber with consumer products for a material cost of $2,300. For a comparable growth space, a commercial plant growth chamber could cost $40,000 or more. Our plant growth chamber had outside dimensions of 1.5 m (W) x 1.8 m (D) x 2 m (H), providing a total growth area of 4.5 m2 with 40-cm high clearance. The dimensions of the growth area and height can be flexibly changed. Fluorescent lights with large reflectors provided a relatively spatially uniform photosynthetically active radiation intensity of 140-250 μmoles/m2/sec. A portable air conditioner provided an ample cooling capacity, and a cooling water mister acted as a powerful humidifier. Temperature, relative humidity, and light cycle inside the chamber were controlled via a z-wave home automation system, which allowed the environmental parameters to be monitored and programmed through the internet. In our setting, the temperature was tightly controlled: 22.2°C±0.8°C. The one-hour average relative humidity was maintained at 75%±7% with short spikes up to ±15%. Using the interaction between Arabidopsis and one of its bacterial pathogens as a test experimental system, we demonstrate that experimental results produced in our chamber were highly comparable to those obtained in a commercial growth chamber. In summary, our design of an inexpensive plant growth chamber

  15. Design and construction of an inexpensive homemade plant growth chamber.

    Science.gov (United States)

    Katagiri, Fumiaki; Canelon-Suarez, Dario; Griffin, Kelsey; Petersen, John; Meyer, Rachel K; Siegle, Megan; Mase, Keisuke

    2015-01-01

    Plant growth chambers produce controlled environments, which are crucial in making reproducible observations in experimental plant biology research. Commercial plant growth chambers can provide precise controls of environmental parameters, such as temperature, humidity, and light cycle, and the capability via complex programming to regulate these environmental parameters. But they are expensive. The high cost of maintaining a controlled growth environment is often a limiting factor when determining experiment size and feasibility. To overcome the limitation of commercial growth chambers, we designed and constructed an inexpensive plant growth chamber with consumer products for a material cost of $2,300. For a comparable growth space, a commercial plant growth chamber could cost $40,000 or more. Our plant growth chamber had outside dimensions of 1.5 m (W) x 1.8 m (D) x 2 m (H), providing a total growth area of 4.5 m2 with 40-cm high clearance. The dimensions of the growth area and height can be flexibly changed. Fluorescent lights with large reflectors provided a relatively spatially uniform photosynthetically active radiation intensity of 140-250 μmoles/m2/sec. A portable air conditioner provided an ample cooling capacity, and a cooling water mister acted as a powerful humidifier. Temperature, relative humidity, and light cycle inside the chamber were controlled via a z-wave home automation system, which allowed the environmental parameters to be monitored and programmed through the internet. In our setting, the temperature was tightly controlled: 22.2°C±0.8°C. The one-hour average relative humidity was maintained at 75%±7% with short spikes up to ±15%. Using the interaction between Arabidopsis and one of its bacterial pathogens as a test experimental system, we demonstrate that experimental results produced in our chamber were highly comparable to those obtained in a commercial growth chamber. In summary, our design of an inexpensive plant growth chamber

  16. Morphological classification of plant cell deaths

    DEFF Research Database (Denmark)

    van Doorn, W.G.; Beers, E.P.; Dangl, J.L.;

    2011-01-01

    Programmed cell death (PCD) is an integral part of plant development and of responses to abiotic stress or pathogens. Although the morphology of plant PCD is, in some cases, well characterised and molecular mechanisms controlling plant PCD are beginning to emerge, there is still confusion about...... the classification of PCD in plants. Here we suggest a classification based on morphological criteria. According to this classification, the use of the term 'apoptosis' is not justified in plants, but at least two classes of PCD can be distinguished: vacuolar cell death and necrosis. During vacuolar cell death......, the cell contents are removed by a combination of autophagy-like process and release of hydrolases from collapsed lytic vacuoles. Necrosis is characterised by early rupture of the plasma membrane, shrinkage of the protoplast and absence of vacuolar cell death features. Vacuolar cell death is common during...

  17. Effect of plant-biostimulant on cassava initial growth

    Directory of Open Access Journals (Sweden)

    João Emílio de Souza Magalhães

    2016-04-01

    Full Text Available ABSTRACT Biostimulants are complex substances that promote hormonal balance in plants, favor the genetic potential expression, and enhance growth of shoots and root system. The use of these plant growth promoters in crops can increase quantitatively and qualitatively crop production. Therefore, the aim of this study was to evaluate the effect of a commercial biostimulant on the initial growth of cassava. The experiment was arranged in a 2 x 5 factorial design, corresponding to two cassava cultivars (Cacau-UFV and Coimbra and five biostimulant concentrations (0, 4, 8, 12 and 16 mL L-1. At 90 days after planting, the characteristics leaf area, plant height, stem diameter, leaf number, total dry matter and dry matter of roots, stems and leaves were evaluated. The biostimulant promoted linear increases in plant height, leaf number, leaf area, total dry matter, dry matter of stems, leaves and roots. The cultivar Cacau-UFV had a higher growth rate than the cultivar Coimbra. The growth promoter stimulated the early growth of the cassava crop.

  18. Manufactured soils for plant growth at a lunar base

    Science.gov (United States)

    Ming, Douglas W.

    1989-01-01

    Advantages and disadvantages of synthetic soils are discussed. It is pointed out that synthetic soils may provide the proper physical and chemical properties necessary to maximize plant growth, such as a toxic-free composition and cation exchange capacities. The importance of nutrient retention, aeration, moisture retention, and mechanical support as qualities for synthetic soils are stressed. Zeoponics, or the cultivation of plants in zeolite substrates that both contain essential plant-growth cations on their exchange sites and have minor amounts of mineral phases and/or anion-exchange resins that supply essential plant growth ions, is discussed. It is suggested that synthetic zeolites at lunar bases could provide adsorption media for separation of various gases, act as catalysts and as molecular sieves, and serve as cation exchangers in sewage-effluent treatment, radioactive-waste disposal, and pollution control. A flow chart of a potential zeoponics system illustrates this process.

  19. Plant Growth Promotion Induced by Phosphate Solubilizing Endophytic Pseudomonas Isolates

    Directory of Open Access Journals (Sweden)

    Nicholas eOtieno

    2015-07-01

    Full Text Available The use of plant growth promoting bacterial inoculants as live microbial biofertilisers provides a promising alternative to chemical fertilisers and pesticides. Inorganic phosphate solubilisation is one of the major mechanisms of plant growth promotion by plant associated bacteria. This involves bacteria releasing organic acids into the soil which solubilise the phosphate complexes converting them into ortho-phosphate which is available for plant up-take and utilisation. The study presented here describes the ability of endophytic bacterial isolates to produce gluconic acid, solubilise insoluble phosphate and stimulate the growth of Pea plants (Pisum sativum. This study also describes the genetic systems within three of these endophyte isolates thought to be responsible for their effective phosphate solubilising abilities. The results showed that many of the endophytic isolates produced gluconic acid (14-169 mM and have moderate to high phosphate solubilisation capacities (~ 400-1300 mg L-1. When inoculated to Pea plants grown in sand/soil under soluble phosphate limiting conditions, the endophyte isolates that produced medium to high levels of gluconic acid also displayed enhanced plant growth promotion effects.

  20. Long term effects on petrochemical activated sludge on plants and soil. Plant growth and metal absorption

    Energy Technology Data Exchange (ETDEWEB)

    Tedesco, M.J.; Gianello, C. [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil). Dept. de Solos; Ribas, P.I.F.; Carvalho, E.B. [CORSAN-SITEL, Triunfo, RS (Brazil). Polo Petroquimico do Sul. Dept. de Operacao e Manutencao

    1993-12-31

    An experiment to study the effects of several application rates of excess activated sludge on plants, soil and leached water was started in 1985. Sludge was applied for six years and increased plant growth due to its nitrogen and phosphorous contribution, even though the decomposition rate in soil is low. Plant zinc, cadmium and nickel content increased with sludge application, while liming decreased the amounts of these metals taken up by plants. 9 refs., 8 tabs.

  1. Confocal imaging of ionised calcium in living plant cells.

    Science.gov (United States)

    Williams, D A; Cody, S H; Gehring, C A; Parish, R W; Harris, P J

    1990-04-01

    Laser-scanning confocal microscopy has been used in conjunction with Fluo-3, a highly fluorescent visible wavelength probe for Ca2+, to visualize Ca2(+)-dynamics in the function of living plant cells. This combination has overcome many of the problems that have limited the use of fluorescence imaging techniques in the study of the role of cations (Ca2+ and H+) in plant cell physiology and enables these processes to be studied in single cells within intact plant tissue preparations. Maize coleoptiles respond to application of ionophores and plant growth hormones with elevations in cytosolic Ca2+ that can be resolved with a high degree of spatial resolution and can be interpreted quantitatively. PMID:2113832

  2. Straw gasification biochar increases plant available water capacity and plant growth in coarse sandy soil

    DEFF Research Database (Denmark)

    Hansen, Veronika; Hauggaard-Nielsen, Henrik; Petersen, Carsten Tilbæk;

    increase of plant biomass under both water regimes, most likely due to reduced mechanical impedance to root growth. No positive effects on plant growth were achieved by addition of WGB. Our results suggest that SGB has a great global potential to increase crop productivity on coarser soil types changing...... was conducted to investigate the effect of soil amendment of straw (SGB) and wood (WGB) GB on shoot and root growth under two levels of water supply in a temperate sandy loam and coarse sandy soil. In the sandy loam, the reduced water regime significantly affected plant growth and water consumption......, whereas the effect was less pronounced in the coarse sand. Independent of the soil type, both GBs increased AWC, with the highest absolute effect in the coarse sand. In the sandy loam, soil application of GB had no effect on plant growth, however, the addition of SGB to coarse sand led to a substantial...

  3. Plant Cell Cancer: May Natural Phenolic Compounds Prevent Onset and Development of Plant Cell Malignancy? A Literature Review.

    Science.gov (United States)

    Rasouli, Hassan; Farzaei, Mohammad Hosein; Mansouri, Kamran; Mohammadzadeh, Sara; Khodarahmi, Reza

    2016-01-01

    Phenolic compounds (PCs) are known as a chemically diverse category of secondary and reactive metabolites which are produced in plants via the shikimate-phenylpropanoid pathways. These compounds-ubiquitous in plants-are an essential part of the human diet, and are of considerable interest due to their antioxidant properties. Phenolic compounds are essential for plant functions, because they are involved in oxidative stress reactions, defensive systems, growth, and development. A large body of cellular and animal evidence carried out in recent decades has confirmed the anticancer role of PCs. Phytohormones-especially auxins and cytokinins-are key contributors to uncontrolled growth and tumor formation. Phenolic compounds can prevent plant growth by the endogenous regulation of auxin transport and enzymatic performance, resulting in the prevention of tumorigenesis. To conclude, polyphenols can reduce plant over-growth rate and the development of tumors in plant cells by regulating phytohormones. Future mechanistic studies are necessary to reveal intracellular transcription and transduction agents associated with the preventive role of phenolics versus plant pathological malignancy cascades. PMID:27563858

  4. Effect of intensive planting density on tree growth, wood density and fiber properties of maple (Acer velutinum Boiss.)

    OpenAIRE

    Naji HR; Nia MF; Kiaei M; Abdul-Hamid H; Soltani M; Faghihi A

    2016-01-01

    Planting density is a major factor in determining tree growth and wood quality. Although the effect of low planting density on the variation of tree and wood characteristics has been already reported, the effect of intensive initial densities in plantations has not been fully assessed yet. In this study, the effect of intensive planting densities on tree growth, wood density and fiber cell properties was investigated in the context of the development of densely-stocked maple plantations for w...

  5. Piriformospora indica enhances plant growth by transferring phosphate

    OpenAIRE

    Kumar, Manoj; Yadav, Vikas; Kumar, Hemant; Sharma, Ruby; Singh, Archana; Tuteja, Narendra; Johri, Atul Kumar

    2011-01-01

    Piriformospora indica is an endophytic fungus that colonized monocot as well as dicot. P. indica has been termed as plant probiotic because of its plant growth promoting activity and its role in enhancement of the tolerance of the host plants against abiotic and biotic stresses. In our recent study, we have characterized a high affinity phosphate transporter (PiPT) and by using RNAi approach, we have demonstrated the involvement of PiPT in P transfer to the host plant. When knockdown strains ...

  6. Microtubule networks for plant cell division

    NARCIS (Netherlands)

    Keijzer, de Jeroen; Mulder, B.M.; Janson, M.E.

    2014-01-01

    During cytokinesis the cytoplasm of a cell is divided to form two daughter cells. In animal cells, the existing plasma membrane is first constricted and then abscised to generate two individual plasma membranes. Plant cells on the other hand divide by forming an interior dividing wall, the so-called

  7. In vivo cell wall loosening by hydroxyl radicals during cress seed germination and elongation growth

    OpenAIRE

    Müller, Kerstin; Linkies, Ada; Vreeburg, Robert A. M.; Fry, Stephen C; Krieger-Liszkay, Anja; Leubner-Metzger, Gerhard

    2009-01-01

    Loosening of cell walls is an important developmental process in key stages of plant life cycles, including seed germination, elongation growth and fruit ripening. Here we report direct in vivo evidence for hydroxyl radical (•OH)-mediated cell wall loosening during plant seed germination and seedling growth. We used electron paramagnetic resonance (EPR)-spectroscopy to show that •OH is generated in the cell wall during radicle elongation and weakening of the endosperm of cress (Lepidium sativ...

  8. Auxin regulation of cell polarity in plants.

    Science.gov (United States)

    Pan, Xue; Chen, Jisheng; Yang, Zhenbiao

    2015-12-01

    Auxin is well known to control pattern formation and directional growth at the organ/tissue levels via the nuclear TIR1/AFB receptor-mediated transcriptional responses. Recent studies have expanded the arena of auxin actions as a trigger or key regulator of cell polarization and morphogenesis. These actions require non-transcriptional responses such as changes in the cytoskeleton and vesicular trafficking, which are commonly regulated by ROP/Rac GTPase-dependent pathways. These findings beg for the question about the nature of auxin receptors that regulate these responses and renew the interest in ABP1 as a cell surface auxin receptor, including the work showing auxin-binding protein 1 (ABP1) interacts with the extracellular domain of the transmembrane kinase (TMK) receptor-like kinases in an auxin-dependent manner, as well as the debate on this auxin binding protein discovered about 40 years ago. This review highlights recent work on the non-transcriptional auxin signaling mechanisms underscoring cell polarity and shape formation in plants. PMID:26599954

  9. Phase-segregated model for plant cell culture: The effect of cell volume fraction

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, W. [Univ. of Adelaide, Adelaide (Australia). Dept. of Chemical Engineering]|[Tokyo Univ. (Japan)hinese Academy of Sciences, Dalian (China). Dalian Inst. of Chemical Physics; Furusaki, S. [Tokyo Univ. (Japan)] Middelberg, A. [Univ. of Adelaide, Adelaide (Australia). Dept. of Chemical Engineering

    1998-06-01

    Plant cells are characterized by low water content, so the fraction of cell volume (volume fraction) in a vessel is large compared with other cell systems, even if the cell concentrations are the same. Therefore, concentration of plant cells should preferably be expressed by the liquid volume basis rather than by the total vessel volume basis. In this paper, a new model is proposed to analyze behavior of a plant cell culture by dividing the cell suspension into the biotic- and abiotic-phases. Using this model, we analyzed the cell-growth and the alkaloid production by Catharanthus roseus. Large errors in the simulated results were observed if the phase-segregation was not considered. 12 refs., 3 figs.

  10. Xanthine oxidase inhibitory triterpenoid and phloroglucinol from guttiferaceous plants inhibit growth and induced apoptosis in human NTUB1 cells through a ROS-dependent mechanism.

    Science.gov (United States)

    Lin, Kai-Wei; Huang, A-Mei; Tu, Huang-Yao; Lee, Ling-Yi; Wu, Chien-Chang; Hour, Tzyh-Chyuan; Yang, Shyh-Chyun; Pu, Yeong-Shiau; Lin, Chun-Nan

    2011-01-12

    A known triterpenoid, β-amyrin (1), and a known and a new phloroglucinol, cohulupone (2) and garcinielliptone P (3), were isolated from the pericarp and heartwood and seed of Garcinia subelliptica, respectively. A new xanthonolignoid, hyperielliptone HF (4), was isolated from the heartwood of Hypericum geminiflorum. The new compounds were established by analysis of their spectroscopic data. Compounds 1-3 showed an inhibitory effect on xanthine oxidase (XO). Treatment of NTUB1, a human bladder cancer cell, with 1 or 1 cotreated with cisplatin for 24 h resulted in a decreased viability of cells. Exposure of NTUB1 to 1 or 1 cotreated with cisplatin for 24 h significantly increased the level of production of reactive oxygen species (ROS). Flow cytometric analysis indicated that treatment of NTUB1 with 1 or 1 cotreated with cisplatin led to the cell cycle arrest, accompanied by an increase in the extent of apoptotic cell death in 1 or 1 combined with cisplatin-treated NTUB1 after 24 h. These data suggested that the presentation of cell cycle arrest and apoptosis in 1 or 1 combined with cisplatin-treated NTUB1 for 24 h was mediated through an increased amount of ROS in cells exposed to 1 or 1 cotreated with cisplatin. PMID:21158429

  11. L-Ascorbic Acid: A Multifunctional Molecule Supporting Plant Growth and Development

    OpenAIRE

    Gallie, Daniel R.

    2013-01-01

    L-Ascorbic acid (vitamin C) is as essential to plants as it is to animals. Ascorbic acid functions as a major redox buffer and as a cofactor for enzymes involved in regulating photosynthesis, hormone biosynthesis, and regenerating other antioxidants. Ascorbic acid regulates cell division and growth and is involved in signal transduction. In contrast to the single pathway responsible for ascorbic acid biosynthesis in animals, plants use multiple pathways to synthesize ascorbic acid, perhaps re...

  12. The biotoxicity of hydroxyapatite nanoparticles to the plant growth

    International Nuclear Information System (INIS)

    Highlights: • Mung bean sprouts were first used as the experimental model to research the cytotoxicity of the HAP nanomaterials. • The biotoxicity depends on the concentration and particle size of HAP nanomaterials. • The biotoxicity mechanism of HAP nanomaterials was discussed. - Abstract: In the present study, hydroxyapatite (HAP) nanoparticles of different particle sizes with high crystallinity and similiar structure were prepared by hydrothermal method. The crystal structure and particle size were characterized by X-ray diffraction pattern (XRD), transmission electron microscopy (TEM) and Fourier transform infrared (FT-IR) spectroscopy. Mung bean sprouts were first used as experimental models. Instead of by MTT assay, the cytoxicity of HAP nanoparticles were proved and evaluated by measuring the hypocotyle length of mung bean sprouts in the culture media. The result showed that the inhibition effect to the growth of mung bean sprouts enhanced when HAP nanoparticles existed. Culture media of HAP nanoparticles with different concentrations and particle sizes was prepared to investigate the level of inhibition effect to the growth of mung bean sprouts. The result found that hypocotyl length of mung bean sprouts were the shortest cultured in 5 mg/mL culture media in which the HAP nanoparticles were prepared by hydrothermal method for 24 h. It was concluded the inhibition effect depended on the amount of intracellular HAP nanoparticles. The nanostructure and Ca2+ concentration were considered as the main factors to cause cell apoptosis which was the reason of inhibition. The study provided a preliminary perspective about biotoxicity of HAP nanomaterials to the plant growth

  13. Reactive oxygen species mediate growth and death in submerged plants

    Directory of Open Access Journals (Sweden)

    Bianka eSteffens

    2013-06-01

    Full Text Available Aquatic and semi-aquatic plants are well adapted to survive partial or complete submergence which is commonly accompanied by oxygen deprivation. The gaseous hormone ethylene controls a number of adaptive responses to submergence including adventitious root growth and aerenchyma formation. Reactive oxygen species (ROS act as signaling intermediates in ethylene-controlled submergence adaptation and possibly also independent of ethylene. ROS levels are controlled by synthesis, enzymatic metabolism and nonenzymatic scavenging. While the actors are by and large known, we still have to learn about altered ROS at the subcellular level and how they are brought about, and the signaling cascades that trigger a specific response. This review briefly summarizes our knowledge on the contribution of ROS to submergence adaptation and describes spectrophotometrical, histochemical and live cell imaging detection methods that have been used to study changes in ROS abundance. Electron paramagnetic resonance (EPR spectroscopy is introduced as a method that allows identification and quantification of specific ROS in cell compartments. The use of advanced technologies such as EPR spectroscopy will be necessary to untangle the intricate and partially interwoven signaling networks of ethylene and ROS.

  14. Effects of plant growth regulators on survival and recovery growth following cryopreservation.

    Science.gov (United States)

    Turner, S R; Touchell, D H; Senaratna, T; Bunn, E; Tan, B; Dixon, K W

    2001-01-01

    Studies on the effects of plant growth regulators (PGRs) on survival, recovery and post-recovery growth of shoot apices following cryopreservation are limited. In this study, the effects of plant growth regulators in both the culture phase and the recovery phase of cryostorage were examined for the rare plant species, Anigozanthos viridis ssp terraspectans Hopper. Survival of shoot apices was not correlated to cytokinin or auxin treatments administered in culture media prior to cryostorage. In recovery media, the plant growth regulators, kinetin, zeatin (cytokinins), IAA, (auxin) and GA3 were examined for their effect following cryopreservation. It was found that the application of a combination of cytokinin and 0.5 microM GA3 from day zero was the most appropriate for obtaining vigorously growing plantlets following LN immersion. This combination proved to be more effective than basal medium, zeatin or kinetin treatments.

  15. Growth Characteristics of Rhizophagus clarus Strains and Their Effects on the Growth of Host Plants.

    Science.gov (United States)

    Lee, Eun-Hwa; Eom, Ahn-Heum

    2015-12-01

    Arbuscular mycorrhizal fungi (AMF) are ubiquitous in the rhizosphere and form symbiotic relationships with most terrestrial plant roots. In this study, four strains of Rhizophagus clarus were cultured and variations in their growth characteristics owing to functional diversity and resultant effects on host plant were investigated. Growth characteristics of the studied R. clarus strains varied significantly, suggesting that AMF retain high genetic variability at the intraspecies level despite asexual lineage. Furthermore, host plant growth response to the R. clarus strains showed that genetic variability in AMF could cause significant differences in the growth of the host plant, which prefers particular genetic types of fungal strains. These results suggest that the intraspecific genetic diversity of AMF could be result of similar selective pressure and may be expressed at a functional level. PMID:26839504

  16. Wound-induced endogenous jasmonates stunt plant growth by inhibiting mitosis.

    Directory of Open Access Journals (Sweden)

    Yi Zhang

    Full Text Available When plants are repeatedly injured their growth is stunted and the size of organs such as leaves is greatly reduced. The basis of this effect is not well-understood however, even though it reduces yield of crops injured by herbivory, and produces dramatic effects exemplified in ornamental bonsai plants. We have investigated the genetic and physiological basis of this "bonsai effect" by repeatedly wounding leaves of the model plant Arabidopsis. This treatment stunted growth by 50% and increased the endogenous content of jasmonate (JA, a growth inhibitor, by seven-fold. Significantly, repeated wounding did not stunt the growth of the leaves of mutants unable to synthesise JA, or unable to respond to JA including coi1, jai3, myc2, but not jar1. The stunted growth did not result from reduced cell size, but resulted instead from reduced cell number, and was associated with reduced expression of CycB1;2. Wounding caused systemic disappearance of constitutively expressed JAZ1::GUS. Wounding also activates plant immunity. We show that a gene, 12-oxo-phytodienoate reductase, which catalyses a step in JA biosynthesis, and which we confirm is not required for defence, is however required for wound-induced stunting. Our data suggest that intermediates in the JA biosynthetic pathway activate defence, but a primary function of wound-induced JA is to stunt growth through the suppression of mitosis.

  17. Gravity research on plants: use of single cell experimental models

    Directory of Open Access Journals (Sweden)

    Youssef eChebli

    2011-09-01

    Full Text Available Future space missions and implementation of permanent bases on Moon and Mars will greatly depend on the availability of ambient air and sustainable food supply. Therefore, understanding the effects of altered gravity conditions on plant metabolism and growth is vital for space missions and extra-terrestrial human existence. In this mini-review we summarize how plant cells are thought to perceive changes in magnitude and orientation of the gravity vector. The particular advantages of several single celled model systems for gravity research are explored and an overview over recent advancements and potential use of these systems is provided.

  18. Light-regulated plant growth and development.

    Science.gov (United States)

    Kami, Chitose; Lorrain, Séverine; Hornitschek, Patricia; Fankhauser, Christian

    2010-01-01

    Plants are sessile and photo-autotrophic; their entire life cycle is thus strongly influenced by the ever-changing light environment. In order to sense and respond to those fluctuating conditions higher plants possess several families of photoreceptors that can monitor light from UV-B to the near infrared (far-red). The molecular nature of UV-B sensors remains unknown, red (R) and far-red (FR) light is sensed by the phytochromes (phyA-phyE in Arabidopsis) while three classes of UV-A/blue photoreceptors have been identified: cryptochromes, phototropins, and members of the Zeitlupe family (cry1, cry2, phot1, phot2, ZTL, FKF1, and LKP2 in Arabidopsis). Functional specialization within photoreceptor families gave rise to members optimized for a wide range of light intensities. Genetic and photobiological studies performed in Arabidopsis have shown that these light sensors mediate numerous adaptive responses (e.g., phototropism and shade avoidance) and developmental transitions (e.g., germination and flowering). Some physiological responses are specifically triggered by a single photoreceptor but in many cases multiple light sensors ensure a coordinated response. Recent studies also provide examples of crosstalk between the responses of Arabidopsis to different external factors, in particular among light, temperature, and pathogens. Although the different photoreceptors are unrelated in structure, in many cases they trigger similar signaling mechanisms including light-regulated protein-protein interactions or light-regulated stability of several transcription factors. The breath and complexity of this topic forced us to concentrate on specific aspects of photomorphogenesis and we point the readers to recent reviews for some aspects of light-mediated signaling (e.g., transition to flowering).

  19. Growth regulation of cultured human nevus cells.

    Science.gov (United States)

    Mancianti, M L; Györfi, T; Shih, I M; Valyi-Nagy, I; Levengood, G; Menssen, H D; Halpern, A C; Elder, D E; Herlyn, M

    1993-03-01

    Cells isolated from congenital melanocytic nevi and cultured in vitro have growth characteristics that resemble their premalignant stage in situ. A serum-free, chemically defined medium has been developed that allows continuous growth of established nevus cultures for up to several months. Like primary melanoma cells, nevus cells in high-calcium-containing W489 medium require insulin for growth. In contrast to melanoma cells, nevus cells in serum-free medium require the presence of alpha-melanocyte-stimulating hormone, which enhanced intracellular levels of cyclic adenosine monophosphate. In contrast to the requirements of normal human melanocytes from newborn foreskin, congenital nevus cells grow with less dependency on basic fibroblast growth factor (bFGF). Nevus cultures contain bFGF-like activity, and they express bFGF mRNA. Nevic cells of compound nevi also express bFGF mRNA in situ but only in the junctional areas. These results indicate that bFGF plays an important growth regulatory role for nevus cells in vitro and in vivo. PMID:8440904

  20. Gravity sensing, a largely misunderstood trigger of plant orientated growth.

    Science.gov (United States)

    Lopez, David; Tocquard, Kévin; Venisse, Jean-Stéphane; Legué, Valerie; Roeckel-Drevet, Patricia

    2014-01-01

    Gravity is a crucial environmental factor regulating plant growth and development. Plants have the ability to sense a change in the direction of gravity, which leads to the re-orientation of their growth direction, so-called gravitropism. In general, plant stems grow upward (negative gravitropism), whereas roots grow downward (positive gravitropism). Models describing the gravitropic response following the tilting of plants are presented and highlight that gravitropic curvature involves both gravisensing and mechanosensing, thus allowing to revisit experimental data. We also discuss the challenge to set up experimental designs for discriminating between gravisensing and mechanosensing. We then present the cellular events and the molecular actors known to be specifically involved in gravity sensing.

  1. Gravity sensing, a largely misunderstood trigger of plant orientated growth

    Directory of Open Access Journals (Sweden)

    David eLopez

    2014-11-01

    Full Text Available Gravity is a crucial environmental factor regulating plant growth and development. Plants have the ability to sense a change in the direction of gravity, which leads to the re-orientation of their growth direction, so-called gravitropism. In general, plant stems grow upward (negative gravitropism, whereas roots grow downward (positive gravitropism. Models describing the gravitropic response following the tilting of plants are presented and highlight that gravitropic curvature involves both gravisensing and mechanosensing, thus allowing to revisit experimental data. We also discuss the challenge to set up experimental designs for discriminating between gravisensing and mechanosensing. We then present the cellular events and the molecular actors known to be specifically involved in gravity sensing.

  2. Symbiotic regulation of plant growth, development and reproduction

    Science.gov (United States)

    Rodriguez, R.J.; Freeman, D. Carl; McArthur, E.D.; Kim, Y.-O.; Redman, R.S.

    2009-01-01

    The growth and development of rice (Oryzae sativa) seedlings was shown to be regulated epigenetically by a fungal endophyte. In contrast to un-inoculated (nonsymbiotic) plants, endophyte colonized (symbiotic) plants preferentially allocated resources into root growth until root hairs were well established. During that time symbiotic roots expanded at five times the rate observed in nonsymbiotic plants. Endophytes also influenced sexual reproduction of mature big sagebrush (Artemisia tridentata) plants. Two spatially distinct big sagebrush subspecies and their hybrids were symbiotic with unique fungal endophytes, despite being separated by only 380 m distance and 60 m elevation. A double reciprocal transplant experiment of parental and hybrid plants, and soils across the hybrid zone showed that fungal endophytes interact with the soils and different plant genotypes to confer enhanced plant reproduction in soil native to the endophyte and reduced reproduction in soil alien to the endophyte. Moreover, the most prevalent endophyte of the hybrid zone reduced the fitness of both parental subspecies. Because these endophytes are passed to the next generation of plants on seed coats, this interaction provides a selective advantage, habitat specificity, and the means of restricting gene flow, thereby making the hybrid zone stable, narrow and potentially leading to speciation. ?? 2009 Landes Bioscience.

  3. Plant Cell Cancer: May Natural Phenolic Compounds Prevent Onset and Development of Plant Cell Malignancy? A Literature Review

    Directory of Open Access Journals (Sweden)

    Hassan Rasouli

    2016-08-01

    Full Text Available Phenolic compounds (PCs are known as a chemically diverse category of secondary and reactive metabolites which are produced in plants via the shikimate-phenylpropanoid pathways. These compounds—ubiquitous in plants—are an essential part of the human diet, and are of considerable interest due to their antioxidant properties. Phenolic compounds are essential for plant functions, because they are involved in oxidative stress reactions, defensive systems, growth, and development. A large body of cellular and animal evidence carried out in recent decades has confirmed the anticancer role of PCs. Phytohormones—especially auxins and cytokinins—are key contributors to uncontrolled growth and tumor formation. Phenolic compounds can prevent plant growth by the endogenous regulation of auxin transport and enzymatic performance, resulting in the prevention of tumorigenesis. To conclude, polyphenols can reduce plant over-growth rate and the development of tumors in plant cells by regulating phytohormones. Future mechanistic studies are necessary to reveal intracellular transcription and transduction agents associated with the preventive role of phenolics versus plant pathological malignancy cascades.

  4. Tomato fruit growth : integrating cell division, cell growth and endoreduplication by experimentation and modelling

    NARCIS (Netherlands)

    Fanwoua, J.

    2012-01-01

    Keywords: cell division, cell growth, cell endoreduplication, fruit growth, genotype, G×E interaction, model, tomato. Fruit size is a major component of fruit yield and quality of many crops. Variations in fruit size can be tremendous due to genotypic and environmental factors. The mechanisms

  5. System Studies of Fuel Cell Power Plants

    OpenAIRE

    Kivisaari, Timo

    2001-01-01

    This thesis concerns system studies of power plants wheredifferent types of fuel cells accomplish most of the energyconversion. Ever since William Grove observed the fuel cell effect inthe late 1830s fuel cells have been the subject or more or lessintense research and development. Especially in the USA theseactivities intensified during the second part of the 1950s,resulting in the development of the fuel cells used in theApollo-program. Swedish fuel cell activities started in themid-1960s, w...

  6. Ethylene production throughout growth and development of plants

    Science.gov (United States)

    Wheeler, Raymond M.; Peterson, Barbara V.; Stutte, Gary W.

    2004-01-01

    Ethylene production by 10 or 20 m2 stands of wheat, soybean, lettuce, potato, and tomato was monitored throughout growth and development in an atmospherically closed plant chamber. Chamber ethylene levels varied among species and rose during periods of canopy expansion and rapid growth for all species. Following this, ethylene levels either declined during seed fill and maturation for wheat and soybean, or remained relatively constant for potato and tomato (during flowering and early fruit development). Lettuce plants were harvested during rapid growth and peak ethylene production. Chamber ethylene levels increased rapidly during tomato ripening, reaching concentrations about 10 times that measured during vegetative growth. The highest ethylene production rates during vegetative growth ranged from 1.6 to 2.5 nmol m-2 d-1 during rapid growth of lettuce and wheat stands, or about 0.3 to 0.5 nmol g-1 fresh weight per hour. Estimates of stand ethylene production during tomato ripening showed that rates reached 43 nmol m-2 d-1 in one study and 93 nmol m-2 d-1 in a second study with higher lighting, or about 50x that of the rate during vegetative growth of tomato. In a related test with potato, the photoperiod was extended from 12 to 24 hours (continuous light) at 58 days after planting (to increase tuber yield), but this change in the environment caused a sharp increase in ethylene production from the basal rate of 0.4 to 6.2 nmol m-2 d-1. Following this, the photoperiod was changed back to 12 h at 61 days and ethylene levels decreased. The results suggest three separate categories of ethylene production were observed with whole stands of plants: 1) production during rapid vegetative growth, 2) production during climacteric fruit ripening, and 3) production from environmental stress.

  7. Dynamics of Plant Growth; A Theory Based on Riemannian Geometry

    CERN Document Server

    Pulwicki, Julia

    2016-01-01

    In this work, a new model for macroscopic plant tissue growth based on dynamical Riemannian geometry is presented. We treat 1D and 2D tissues as continuous, deformable, growing geometries for sizes larger than 1mm. The dynamics of the growing tissue are described by a set of coupled tensor equations in non-Euclidean (curved) space. These coupled equations represent a novel feedback mechanism between growth and curvature dynamics. For 1D growth, numerical simulations are compared to two measures of root growth. First, modular growth along the simulated root shows an elongation zone common to many species of plant roots. Second, the relative elemental growth rate (REGR) calculated in silico exhibits temporal dynamics recently characterized in high-resolution root growth studies but which thus far lack a biological hypothesis to explain them. Namely, the REGR can evolve from a single peak localized near the root tip to a double-peak structure. In our model, this is a direct consequence of considering growth as b...

  8. SPATULA links daytime temperature and plant growth rate.

    Science.gov (United States)

    Sidaway-Lee, Kate; Josse, Eve-Marie; Brown, Alanna; Gan, Yinbo; Halliday, Karen J; Graham, Ian A; Penfield, Steven

    2010-08-24

    Plants exhibit a wide variety of growth rates that are known to be determined by genetic and environmental factors, and different plants grow optimally at different temperatures, indicating that this is a genetically determined character. Moderate decreases in ambient temperature inhibit vegetative growth, but the mechanism is poorly understood, although a decrease in gibberellin (GA) levels is known to be required. Here we demonstrate that the basic helix-loop-helix transcription factor SPATULA (SPT), previously known to be a regulator of low temperature-responsive germination, mediates the repression of growth by cool daytime temperatures but has little or no growth-regulating role under warmer conditions. We show that only daytime temperatures affect vegetative growth and that SPT couples morning temperature to growth rate. In seedlings, warm temperatures inhibit the accumulation of the SPT protein, and SPT autoregulates its own transcript abundance in conjunction with diurnal effects. Genetic data show that repression of growth by SPT is independent of GA signaling and phytochrome B, as previously shown for PIF4. Our data suggest that SPT integrates time of day and temperature signaling to control vegetative growth rate.

  9. Interactive effects of above- and belowground herbivory and plant competition on plant growth and defence

    NARCIS (Netherlands)

    Jing, Jingying; Raaijmakers, Ciska; Kostenko, Olga; Kos, Martine; Mulder, P.P.J.; Bezemer, T. Martijn

    2015-01-01

    Competition and herbivory are two major factors that can influence plant growth and plant defence. Although these two factors are often studied separately, they do not operate independently. We examined how aboveground herbivory by beet armyworm larvae (Spodoptera exigua) and belowground herbivory b

  10. Shape of growth cells in directional solidification.

    Science.gov (United States)

    Pocheau, A; Georgelin, M

    2006-01-01

    The purpose of this study is to characterize experimentally the whole shape of the growth cells displayed in directional solidification and its evolution with respect to control parameters. A library of cells is first built up from observation of directional solidification of a succinonitrile alloy in a large range of pulling velocity, cell spacing, and thermal gradient. Cell boundaries are then extracted from these images and fitted by trial functions on their whole profile, from cell tip to cell grooves. A coherent evolution of the fit parameters with the control parameters is evidenced. It enables us to characterize the whole cell shape by a single function involving only two parameters which vary smoothly in the control parameter space. This, in particular, evidences a continuous evolution of the cell geometry at the cell to dendrite transition which denies the existence of a change of branch of solutions at the occurrence of sidebranching. More generally, this global determination of cell shape complemented with a previous determination of the position of cells in the thermal field (the cell tip undercooling) provides a complete characterization of growth solutions and of their evolutions in this system. It thus brings about a relevant framework for testing and improving theoretical and numerical understanding of cell shapes and cell stability in directional solidification.

  11. Effect of planting density on plant growth and camptothecin content of Camptotheca acuminata seedlings

    Institute of Scientific and Technical Information of China (English)

    WEIHuan-yong; WANGYang; WANGZhen-yue; YANXiu-feng

    2005-01-01

    C. acuminata seedlings cultivated in greenhouse were transplanted into the fields with 5 designed planting densities (11, 16, 25,44 and 100 plants·m-2) in May of 2004 and were harvested in the middle of September of 2004. The seedling growth indexes including plant height and crown width, biomass allocation, camptothecin (CPT) content and CPT yield of different organs (young leaf, old leaf, stem,and root) were studied. For the 5 selected planting densities, the plant biomass, height, crown width, and total leaf area of C. acuminata seedlings all showed highest values at the planting density of 25 plants ·m-2. CPT content in young leaves was higher than that in other organs of seedlings and presented an obvious change with the variation of planting densities and with the highest value at density of 100plants·m-2, while for other organs no significant variation in CPT content was found with change of planting density. The accumulation of CPT was enhanced significantly at the planting density of 25 plants·m-2. It is concluded that for the purpose to get raw materials with more CPT from C. acuminata, the optimal planting density of C. acuminata seedlings should be designed as 25 plants·m-2.

  12. Growth Chambers on the International Space Station for Large Plants

    Science.gov (United States)

    Massa, Gioia D.; Wheeler, Raymond M.; Morrow, Robert C.; Levine, Howard G.

    2016-01-01

    The International Space Station (ISS) now has platforms for conducting research on horticultural plant species under LED (Light Emitting Diodes) lighting, and those capabilities continue to expand. The Veggie vegetable production system was deployed to the ISS as an applied research platform for food production in space. Veggie is capable of growing a wide array of horticultural crops. It was designed for low power usage, low launch mass and stowage volume, and minimal crew time requirements. The Veggie flight hardware consists of a light cap containing red (630 nanometers), blue, (455 nanometers) and green (530 nanometers) LEDs. Interfacing with the light cap is an extendable bellowsbaseplate for enclosing the plant canopy. A second large plant growth chamber, the Advanced Plant Habitat (APH), is will fly to the ISS in 2017. APH will be a fully controllable environment for high-quality plant physiological research. APH will control light (quality, level, and timing), temperature, CO2, relative humidity, and irrigation, while scrubbing any cabin or plant-derived ethylene and other volatile organic compounds. Additional capabilities include sensing of leaf temperature and root zone moisture, root zone temperature, and oxygen concentration. The light cap will have red (630 nm), blue (450 nm), green (525 nm), far red (730 nm) and broad spectrum white LEDs (4100K). There will be several internal cameras (visible and IR) to monitor and record plant growth and operations. Veggie and APH are available for research proposals.

  13. A simple way to identify non-viable cells within living plant tissue using confocal microscopy

    Directory of Open Access Journals (Sweden)

    Truernit Elisabeth

    2008-06-01

    Full Text Available Abstract Background Plant cell death is a normal process during plant development. Mutant plants may exhibit misregulation of this process, which can lead to severe growth defects. Simple ways of visualising cell death in living plant tissues can aid the study of plant development and physiology. Results Spectral variants of the fluorescent SYTOX dyes were tested for their usefulness for the detection of non-viable cells within plant embryos and roots using confocal laser-scanning microscopy. The dyes were selective for non-viable cells and showed very little background staining in living cells. Simultaneous detection of SYTOX dye and fluorescent protein (e.g. GFP fluorescence was possible. Conclusion The fluorescent SYTOX dyes are useful for an easy and quick first assay of plant cell viability in living plant samples using fluorescence and confocal laser-scanning microscopy.

  14. Electron Tomography in Plant Cell Biology

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This review focuses on the contribution of electron tomography-based techniques to our understanding of cellular processes in plant cells. Electron microscopy techniques have evolved to provide better three-dimensional resolution and improved preservation of the subcellular components. In particular, the combination of cryofixation/freeze substitution and electron tomography have allowed plant cell biologists to image organelles and macromolecular complexes in their native cellular context with unprecedented three-dimensional resolution (4-7 nm). Until now, electron tomography has been applied in plant cell biology for the study of cytokinesis, Golgi structure and trafficking, formation of plant endosome/prevacuolar compartments, and organization of photosynthetic membranes. We discuss in this review the new insights that these tomographic studies have brought to the plant biology field.

  15. Influence of Plant Growth Regulators (PGRs) and Planting Method on Growth and Yield in Oil Pumpkin (Cucurbita pepo var. styriaca)

    OpenAIRE

    Shirzad SURE; Hosein AROOIE; Majid AZIZI

    2012-01-01

    The effect of plant growth regulators IBA (indole butyric acid), GA3 (gibberellin) and ethylene (as ethephon) in two methods of planting was investigated (each method was considered as a separate experiment) on morphological characters and yield of medicinal pumpkin. The experiments were carried out in a factorial trial based on completely randomized block design, with four replicates. The treatments were combined with priming and spraying with the above PGRs. The first seed priming with cont...

  16. Beta cell proliferation and growth factors

    DEFF Research Database (Denmark)

    Nielsen, Jens Høiriis; Svensson, C; Møldrup, Annette;

    1999-01-01

    Formation of new beta cells can take place by two pathways: replication of already differentiated beta cells or neogenesis from putative islet stem cells. Under physiological conditions both processes are most pronounced during the fetal and neonatal development of the pancreas. In adulthood little...... cloned a novel GH/PRL stimulated rat islet gene product, Pref-1 (preadipocyte factor-1). This protein contains six EGF-like motifs and may play a role both in embryonic pancreas differentiation and in beta cell growth and function. In summary, the increasing knowledge about the mechanisms involved...... increase in the beta cell number seems to occur. In pregnancy, however, a marked hyperplasia of the beta cells is observed both in rodents and man. Increased mitotic activity has been seen both in vivo and in vitro in islets exposed to placental lactogen (PL), prolactin (PRL) and growth hormone (GH...

  17. Climate change effects on plant growth, crop yield and livestock

    NARCIS (Netherlands)

    Rötter, R.P.; Geijn, van de S.C.

    1999-01-01

    A review is given of the state of knowledge in the field of assessing climate change impacts on agricultural crops and livestock. Starting from the basic processes controlling plant growth and development, the possible impacts and interactions of climatic and other biophysical variables in different

  18. Effects of Different Substrate Composition on Growth of Gesneriaceae Plants

    Institute of Scientific and Technical Information of China (English)

    Zhijing QIU; Chunqing ZOU; Zhengjun SHI; Yaoliang DAI; Ruixing XIE

    2014-01-01

    The cultivation experiment was carried out to investigate the effects of dif-ferent proportions of peat soil, perlite, vermiculite and yel ow mud on growth of Gesneriaceae species (Chirita gueilinensis, Sinningia speciosa, Lysionotus pauci-florus, Hemiboea henryi, Aeschynanthus acuminatus, Saintpaulia ionantha). The growth traits of each plant growing in 7 different matrix materials were investigated. The plant height, crown width and chlorophyl content of each plant were mea-sured. The results showed that the best substrate ratio was peat soil∶vermiculite=2∶1 for C. gueilinensis, L. pauciflorus and H. henryi; peat soil∶perlite∶vermiculite = 2∶1∶1 for S. ionantha; peat soil∶vermiculite∶yel ow mud=2∶1∶1 for S. speciosa; peat soil∶per-lite∶vermiculite∶yel ow mud=2∶1∶1∶1 for A. acuminatus.

  19. Regulation of cell division in higher plants

    Energy Technology Data Exchange (ETDEWEB)

    Jacobs, T.W.

    1992-01-01

    Cell division is arguably the most fundamental of all developmental processes. In higher plants, mitotic activity is largely confined to foci of patterned cell divisions called meristems. From these perpetually embryonic tissues arise the plant's essential organs of light capture, support, protection and reproduction. Once an adequate understanding of plant cell mitotic regulation is attained, unprecedented opportunities will ensue for analyzing and genetically controlling diverse aspects of development, including plant architecture, leaf shape, plant height, and root depth. The mitotic cycle in a variety of model eukaryotic systems in under the control of a regulatory network of striking evolutionary conservation. Homologues of the yeast cdc2 gene, its catalytic product, p34, and the cyclin regulatory subunits of the MPF complex have emerged as ubiquitous mitotic regulators. We have cloned cdc2-like and cyclin genes from pea. As in other eukaryotic model systems, p34 of Pisum sativum is a subunit of a high molecular weight complex which binds the fission yeast p13 protein and displays histone H1 kinase activity in vitro. Our primary objective in this study is to gain baseline information about the regulation of this higher plant cell division control complex in non-dividing, differentiated cells as well as in synchronous and asynchronous mitotic cells. We are investigating cdc2 and cyclin expression at the levels of protein abundance, protein phosphorylation and quaternary associations.

  20. Plant growth promoting bacteria from Crocus sativus rhizosphere.

    Science.gov (United States)

    Ambardar, Sheetal; Vakhlu, Jyoti

    2013-12-01

    Present study deals with the isolation of rhizobacteria and selection of plant growth promoting bacteria from Crocus sativus (Saffron) rhizosphere during its flowering period (October-November). Bacterial load was compared between rhizosphere and bulk soil by counting CFU/gm of roots and soil respectively, and was found to be ~40 times more in rhizosphere. In total 100 bacterial isolates were selected randomly from rhizosphere and bulk soil (50 each) and screened for in-vitro and in vivo plant growth promoting properties. The randomly isolated bacteria were identified by microscopy, biochemical tests and sequence homology of V1-V3 region of 16S rRNA gene. Polyphasic identification categorized Saffron rhizobacteria and bulk soil bacteria into sixteen different bacterial species with Bacillus aryabhattai (WRF5-rhizosphere; WBF3, WBF4A and WBF4B-bulk soil) common to both rhizosphere as well as bulk soil. Pseudomonas sp. in rhizosphere and Bacillus and Brevibacterium sp. in the bulk soil were the predominant genera respectively. The isolated rhizobacteria were screened for plant growth promotion activity like phosphate solubilization, siderophore and indole acetic acid production. 50 % produced siderophore and 33 % were able to solubilize phosphate whereas all the rhizobacterial isolates produced indole acetic acid. The six potential PGPR showing in vitro activities were used in pot trial to check their efficacy in vivo. These bacteria consortia demonstrated in vivo PGP activity and can be used as PGPR in Saffron as biofertilizers.This is the first report on the isolation of rhizobacteria from the Saffron rhizosphere, screening for plant growth promoting bacteria and their effect on the growth of Saffron plant.

  1. Influence of Plant Growth Regulators (PGRs and Planting Method on Growth and Yield in Oil Pumpkin (Cucurbita pepo var. styriaca

    Directory of Open Access Journals (Sweden)

    Shirzad SURE

    2012-05-01

    Full Text Available The effect of plant growth regulators IBA (indole butyric acid, GA3 (gibberellin and ethylene (as ethephon in two methods of planting was investigated (each method was considered as a separate experiment on morphological characters and yield of medicinal pumpkin. The experiments were carried out in a factorial trial based on completely randomized block design, with four replicates. The treatments were combined with priming and spraying with the above PGRs. The first seed priming with control (water, IBA 100 ppm, GA3 25 ppm and ethephon 200 ppm, and when seedling developed to 4 leaf stage sprayed there with control (water, IBA 100 ppm, GA3 25 ppm and ethephon 200 ppm for three times. In both planting methods, there were all of these treatments. The result showed that PGRs and planting method had significant effects on vegetative, flowering and yield characteristics including: leaf area %DM plant, number of male and female flowers per plant, number of fruit/plant, fruits fresh weight, seeds length and width, number of seed per fruit, seed yield, % seeds oil and oil yield. Hence spraying with GA3 25 ppm in four leaf stage at trellis method could be a suitable treatment for enhancing growth and yield of medicinal pumpkin.

  2. Differential responses of onion and garlic against plant growth regulators

    International Nuclear Information System (INIS)

    The effects of Gibberellic acid-GA3, Prohexadione-Calcium, and Ethephon pre-harvest application on yield, biomass production, photosynthetic function, lipid peroxidation and quality characteristics of onion (Allium cepa L.) and garlic (Allium sativum L.) plants were investigated. Shoot length and biomass of onion and garlic, expressed either in fresh or dry weight, increased significantly under GA3, while a progressive decrease under Prohex-Ca and Ethephon occurred. Higher MDA (lipid peroxidation) values were recorded after Prohex-Ca and Ethephon supply on onion and garlic plants; it seems that GA3 treatment prevents lipid peroxidation as measured with the help of the TBARS method. Plants treated with Prohex-Ca and Ethephon revealed higher peroxidase activity compared to control and GA3 treated plants. Considering the results of MDA content and peroxidase activities it can be assumed that GA3 treated plants are slightly protected from the natural course of oxidative stress, which occurs during ageing as observed for control samples. The fluctuations of chlorophyll fluorescence parameters represent a general decline in chloroplasts function after plant growth regulators exposure, whereas in combination to the suppressed chlorophyll content, structural malformations of photo systems may also occur. The production of ascorbic acid, glucose and fructose content seems to be enhanced under GA3 in both species, while their values were depressed under Prohex-Ca and Ethephon. Overall, only GA3 supply leads to a vigorous onion and garlic growth and yield. (author)

  3. Disposable Bioreactors for Plant Micropropagation and Mass Plant Cell Culture

    Science.gov (United States)

    Ducos, Jean-Paul; Terrier, Bénédicte; Courtois, Didier

    Different types of bioreactors are used at Nestlé R&D Centre - Tours for mass propagation of selected plant varieties by somatic embryogenesis and for large scale culture of plants cells to produce metabolites or recombinant proteins. Recent studies have been directed to cut down the production costs of these two processes by developing disposable cell culture systems. Vegetative propagation of elite plant varieties is achieved through somatic embryogenesis in liquid medium. A pilot scale process has recently been set up for the industrial propagation of Coffea canephora (Robusta coffee). The current production capacity is 3.0 million embryos per year. The pre-germination of the embryos was previously conducted by temporary immersion in liquid medium in 10-L glass bioreactors. An improved process has been developed using a 10-L disposable bioreactor consisting of a bag containing a rigid plastic box ('Box-in-Bag' bioreactor), insuring, amongst other advantages, a higher light transmittance to the biomass due to its horizontal design. For large scale cell culture, two novel flexible plastic-based disposable bioreactors have been developed from 10 to 100 L working volumes, validated with several plant species ('Wave and Undertow' and 'Slug Bubble' bioreactors). The advantages and the limits of these new types of bioreactor are discussed, based mainly on our own experience on coffee somatic embryogenesis and mass cell culture of soya and tobacco.

  4. Experiments on Growth and Variation of Spaceship Loaded Plant Seeds

    International Nuclear Information System (INIS)

    This educational experiment was designed (1)to obtain the basic information on the effects of the space environments on plant growth and mutagenesis, (2)to evaluate plant germination and seedling growth under the effect of microgravity and light conditions and (3)to improve a child's scientific mind through the real-time observations of a seedling growth for two plants conducted both in space and on earth. This project was implemented?as one of the missions in the Korean Astronaut Program. Seeds of eleven plant species (rice, soybean, rape, radish, hot pepper, perilla, arabidopsis, orchids, dandelion, hibiscus, cosmos) was vacuum-sealed in aluminium bags. Those seeds was loaded in the 'Progress' spaceship in Feb. 2008, traveled in the 'Progress', placed in the Russian Sector-International Space Station (RS-ISS), and then was brought by the Korean astronaut from the RS-ISS, and handed over to us at Korea Atomic Energy Research Institute(KAERI). The germination rate, plant growth and mutation type/frequency of the returned plants are under testing in the lab and field in KAERI now. The first Korean astronaut, Dr. So-Yeon Yi, who had returned to earth on April 19, 2008 after successfully completing her scientific mission for 12 days in Space, performed the experiment of plant germination and seedling growth in the International Space Station (ISS), and a similarly designed experiment kit was distributed to conduct the experiment by student and adult volunteers in Korea at the same time. The experiment was to observe the effects of microgravity and light on a seedling growth for soybean and radish. We designed a growth kit that was an all-in-one package consisting of seeds (12 seeds in each chamber) and rock wool as a growing medium filled in four polycarbonate growing chambers in a light proof textile bag or carton paper. The bottom of the chamber was filled with a tightly-fitted rock wool which can hold water and provide moisture during a seedling growth. The

  5. The pituitary growth hormone cell in space

    Science.gov (United States)

    Hymer, Wesley C.; Grindeland, R.

    1989-01-01

    Growth hormone (GH), produced and secreted from specialized cells in the pituitary gland, controls the metabolism of protein, fat, and carbohydrate. It is also probably involved in the regulation of proper function of bone, muscle and immune systems. The behavior of the GH cell system was studied by flying either isolated pituitary cells or live rats. In the latter case, pituitary GH cells are prepared on return to earth and then either transplanted into hypophysectomized rats or placed into cell culture so that function of GH cells in-vivo vs. in-vitro can be compared. The results from three flights to date (STS-8, 1983; SL-3, 1985; Cosmos 1887, 1987) established that the ability of GH cells to release hormone, on return to earth, is compromised. The mechanism(s) responsible for this attenuation response is unknown. However, the data are sufficiently positive to indicate that the nature of the secretory defect resides directly within the GH cells.

  6. Effect of intensive planting density on tree growth, wood density and fiber properties of maple (Acer velutinum Boiss.

    Directory of Open Access Journals (Sweden)

    Naji HR

    2016-04-01

    Full Text Available Planting density is a major factor in determining tree growth and wood quality. Although the effect of low planting density on the variation of tree and wood characteristics has been already reported, the effect of intensive initial densities in plantations has not been fully assessed yet. In this study, the effect of intensive planting densities on tree growth, wood density and fiber cell properties was investigated in the context of the development of densely-stocked maple plantations for wood production. The study was carried out in a 12-year-old Acer velutinum trial plantation in northern Iran, with initial densities of 10000, 4444, and 2500 trees ha-1 planted. The variation of diameter at breast height, annual ring width, stem taper, wood density, and fiber cell properties were examined. As expected, low planting densities showed trees with larger diameter at breast height and annual ring width. The largest trees at higher densities were smaller than those in lower planting densities. However, initial planting density had no significant effect on stem taper, wood density and fiber cell properties. In addition, no significant relationships between tree growth features and wood properties were detected, indicating similar wood properties at all planting densities. Therefore, stand/tree growth attributes under intensive planting densities could not be considered as reliable predictors of the wood properties.

  7. 15. international conference on plant growth substances: Program -- Abstracts

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-31

    Since the 14th Conference in Amsterdam in 1991, progress in plant hormone research and developmental plant biology has been truly astonishing. The five ``classical`` plant hormones, auxin, gibberellin, cytokinin, ethylene, and abscisic acid, have been joined by a number of new signal molecules, e.g., systemin, jasmonic acid, salicylic acid, whose biosynthesis and functions are being understood in ever greater detail. Molecular genetics has opened new vistas in an understanding of transduction pathways that regulate developmental processes in response to hormonal and environmental signals. The program of the 15th Conference includes accounts of this progress and brings together scientists whose work focuses on physiological, biochemical, and chemical aspects of plant growth regulation. This volume contains the abstracts of papers presented at this conference.

  8. Oral Delivery of Protein Drugs Bioencapsulated in Plant Cells.

    Science.gov (United States)

    Kwon, Kwang-Chul; Daniell, Henry

    2016-08-01

    Plants cells are now approved by the FDA for cost-effective production of protein drugs (PDs) in large-scale current Good Manufacturing Practice (cGMP) hydroponic growth facilities. In lyophilized plant cells, PDs are stable at ambient temperature for several years, maintaining their folding and efficacy. Upon oral delivery, PDs bioencapsulated in plant cells are protected in the stomach from acids and enzymes but are subsequently released into the gut lumen by microbes that digest the plant cell wall. The large mucosal area of the human intestine offers an ideal system for oral drug delivery. When tags (receptor-binding proteins or cell-penetrating peptides) are fused to PDs, they efficiently cross the intestinal epithelium and are delivered to the circulatory or immune system. Unique tags to deliver PDs to human immune or nonimmune cells have been developed recently. After crossing the epithelium, ubiquitous proteases cleave off tags at engineered sites. PDs are also delivered to the brain or retina by crossing the blood-brain or retinal barriers. This review highlights recent advances in PD delivery to treat Alzheimer's disease, diabetes, hypertension, Gaucher's or ocular diseases, as well as the development of affordable drugs by eliminating prohibitively expensive purification, cold chain and sterile delivery. PMID:27378236

  9. Getting the ecology into interactions between plants and the plant growth-promoting bacterium Pseudomonas fluorescens

    Directory of Open Access Journals (Sweden)

    W. H. Gera eHol

    2013-04-01

    Full Text Available Plant growth-promoting rhizobacteria (PGPR are increasingly appreciated for their contributions to primary productivity through promotion of growth and triggering of induced systemic resistance in plants. Here we focus on the beneficial effects of one particular species of PGPR (Pseudomonas fluorescens on plants through induced plant defence. This model organism has provided much understanding of the underlying molecular mechanisms of PGPR-induced plant defence. However, this knowledge can only be appreciated at full value once we know to what extent these mechanisms also occur under more realistic, species-diverse conditions as are occurring in the plant rhizosphere. To provide the necessary ecological context, we review the literature to compare the effect of P. fluorescens on induced plant defence when it is present as a single species or in combination with other soil dwelling species. Specifically, we discuss combinations with other plant mutualists (bacterial or fungal, plant pathogens (bacterial or fungal, bacterivores (nematode or protozoa and decomposers. Synergistic interactions between P. fluorescens and other plant mutualists are much more commonly reported than antagonistic interactions. Recent developments have enabled screenings of P. fluorescens genomes for defence traits and this could help with selection of strains with likely positive interactions on biocontrol. However, studies that examine the effects of multiple herbivores, pathogens, or herbivores and pathogens together on the effectiveness of PGPR to induce plant defences are underrepresented and we are not aware of any study that has examined interactions between P. fluorescens and bacterivores or decomposers. As co-occurring soil organisms can enhance but also reduce the effectiveness of PGPR, a better understanding of the biotic factors modulating P. fluorescens -plant interactions will improve the effectiveness of introducing P. fluorescens to enhance plant production

  10. Improvements in plant growth rate using underwater discharge

    International Nuclear Information System (INIS)

    The drainage water from plant pots was irradiated by plasma and then recycled to irrigate plants for improving the growth rate by supplying nutrients to plants and inactivating the bacteria in the bed-soil. Brassica rapa var. perviridis (Chinese cabbage; Brassica campestris) plants were cultivated in pots filled with artificial soil, which included the use of chicken droppings as a fertiliser. The water was recycled once per day from a drainage water pool and added to the bed-soil in the pots. A magnetic compression type pulsed power generator was used to produce underwater discharge with repetition rate of 250 pps. The plasma irradiation times were set as 10 and 20 minutes per day over 28 days of cultivation. The experimental results showed that the growth rate increased significantly with plasma irradiation into the drainage water. The growth rate increased with the plasma irradiation time. The nitrogen concentration of the leaves increased as a result of plasma irradiation based on chlorophyll content analysis. The bacteria in the drainage water were inactivated by the plasma irradiation.

  11. Plant-growth promoting effect of newly isolated rhizobacteria varies between two Arabidopsis ecotypes

    OpenAIRE

    Schwachtje, Jens; Karojet, Silke; Kunz, Sabine; Brouwer, Stephan; van Dongen, Joost T.

    2012-01-01

    Various rhizobacteria are known for their beneficial effects on plants, i. e. promotion of growth and induction of systemic resistance against pathogens. These bacteria are categorized as plant growth promoting rhizobacteria (PGPR) and are associated with plant roots. Knowledge of the underlying mechanisms of plant growth promotion in vivo is still very limited, but interference of bacteria with plant hormone metabolism is suggested to play a major role. To obtain new growth promoting bacteri...

  12. Growth of gold nanoparticles in human cells.

    Science.gov (United States)

    Anshup, Anshup; Venkataraman, J Sai; Subramaniam, Chandramouli; Kumar, R Rajeev; Priya, Suma; Kumar, T R Santhosh; Omkumar, R V; John, Annie; Pradeep, T

    2005-12-01

    Gold nanoparticles of 20-100 nm diameter were synthesized within HEK-293 (human embryonic kidney), HeLa (human cervical cancer), SiHa (human cervical cancer), and SKNSH (human neuroblastoma) cells. Incubation of 1 mM tetrachloroaurate solution, prepared in phosphate buffered saline (PBS), pH 7.4, with human cells grown to approximately 80% confluency yielded systematic growth of nanoparticles over a period of 96 h. The cells, stained due to nanoparticle growth, were adherent to the bottom of the wells of the tissue culture plates, with their morphology preserved, indicating that the cell membrane was intact. Transmission electron microscopy of ultrathin sections showed the presence of nanoparticles within the cytoplasm and in the nucleus, the latter being much smaller in dimension. Scanning near field microscopic images confirmed the growth of large particles within the cytoplasm. Normal cells gave UV-visible signatures of higher intensity than the cancer cells. Differences in the cellular metabolism of cancer and noncancer cells were manifested, presumably in their ability to carry out the reduction process. PMID:16316080

  13. Effects of New Plant Growth Regulators on Growth and Quality in Potato

    Directory of Open Access Journals (Sweden)

    Chen Weiyan

    2015-04-01

    Full Text Available This experiment aimed to explore the effects of new plant growth regulators on the growth and quality of potato, we conduct potato tubers with different concentrations of the regulators and cultivated in the seedling pot, with water as the control treatment. The results showed that sorbic amide (5%, sorbic amide quaternary ammonium salt (5%, Cinnamamide (5%, betaine Cinnamamide (5%, naphthalene dicarboxamide (5%, betaine naphthalenedicarboxamide (5% these 6 new regulators have good activity in improving and enhancing the content of chlorophyll, soluble protein, soluble sugar and free amino acids with 400 times dilution and 800 times dilution on potato seedling. At the same time, we compared the changes of the physiological indexes in different periods. As can be seen from the experiment, these 6 compounds have a strong role in promoting growth and improving the quality of the potato so that they can be called plant growth regulators.

  14. Plant growth-promoting traits of yeasts isolated from the phyllosphere and rhizosphere of Drosera spatulata Lab.

    Science.gov (United States)

    Fu, Shih-Feng; Sun, Pei-Feng; Lu, Hsueh-Yu; Wei, Jyuan-Yu; Xiao, Hong-Su; Fang, Wei-Ta; Cheng, Bai-You; Chou, Jui-Yu

    2016-03-01

    Microorganisms can promote plant growth through direct and indirect mechanisms. Compared with the use of bacteria and mycorrhizal fungi, the use of yeasts as plant growth-promoting (PGP) agents has not been extensively investigated. In this study, yeast isolates from the phyllosphere and rhizosphere of the medicinally important plant Drosera spatulata Lab. were assessed for their PGP traits. All isolates were tested for indole-3-acetic acid-, ammonia-, and polyamine-producing abilities, calcium phosphate and zinc oxide solubilizing ability, and catalase activity. Furthermore, the activities of siderophore, 1-aminocyclopropane-1-carboxylate deaminase, and fungal cell wall-degrading enzymes were assessed. The antagonistic action of yeasts against pathogenic Glomerella cingulata was evaluated. The cocultivation of Nicotiana benthamiana with yeast isolates enhanced plant growth, indicating a potential yeast-plant interaction. Our study results highlight the potential use of yeasts as plant biofertilizers under controlled and field conditions. PMID:26895872

  15. In Vitro and In Vivo Plant Growth Promoting Activities and DNA Fingerprinting of Antagonistic Endophytic Actinomycetes Associates with Medicinal Plants

    OpenAIRE

    Ajit Kumar Passari; Vineet Kumar Mishra; Vijai Kumar Gupta; Mukesh Kumar Yadav; Ratul Saikia; Bhim Pratap Singh

    2015-01-01

    Endophytic actinomycetes have shown unique plant growth promoting as well as antagonistic activity against fungal phytopathogens. In the present study forty-two endophytic actinomycetes recovered from medicinal plants were evaluated for their antagonistic potential and plant growth-promoting abilities. Twenty-two isolates which showed the inhibitory activity against at least one pathogen were subsequently tested for their plant-growth promoting activities and were compared genotypically using...

  16. Growth-promotion of plants with depolymerized alginates by irradiation

    Science.gov (United States)

    Hien, Nguyen Quoc; Nagasawa, Naotsugu; Tham, Le Xuan; Yoshii, Fumio; Dang, Vo Huy; Mitomo, Hiroshi; Makuuchi, Keizo; Kume, Tamikazu

    2000-07-01

    Alginate has been degraded by gamma-ray irradiation from a Co-60 source in liquid state (aqueous solution) and in solid state (powder form). The irradiated alginate with a molecular weight less than 10 4 shows a strong effect on the growth-promotion of rice and peanut. Low concentration of degraded alginate from 4% solution irradiated at 100 kGy is effective for the growth-promotion of plants and the suitable concentrations are ca 50 ppm for rice and ca 100 ppm for peanut.

  17. Study of creep cavity growth for power plant lifetime assessment

    Energy Technology Data Exchange (ETDEWEB)

    Wu Rui; Sandstroem, Rolf

    2001-01-01

    This report aims to the sub project lifetime assessment by creep (livslaengdspredikteringar vid kryp), which is involved in the project package strength in high temperature power plant, KME 708. The physical creep damage includes mainly cavities and their development. Wu and Sandstroem have observed that cavity size increases linearly with increasing creep strain in a 12%Cr steel. Sandstroem has showed that, based on the relations between the nucleation and growth of creep cavities with creep strain, the physical creep damage can be modelled as a function of creep strain. In the present paper the growth of creep cavity radius R in relation to time t and strain {epsilon} in low alloy and 12%Cr steels as well as a Type 347 steel has been studied. The results exhibit that the power law cavity radius with creep time (R-t) and with creep strain (R-{epsilon}) relations are found for these materials at various testing conditions. The power law R-t and R-{epsilon} relations are in most cases dependent and independent on testing conditions, respectively. The empirical power law R-{epsilon} relations give a description of cavity evolution, which can be used for lifetime assessment. Experimental data have also been compared to the estimations by the classical models for cavity growth, including the power law growth due to Hancock, the diffusion growth due to Speight and Harris, the constrained diffusion growths due to Dyson and due to Rice and the enhanced diffusion growth due to Beere. It appears that the constraint diffusion growth models give a reasonable estimation of R-{epsilon} relation in many cases. The diffusion growth model is only applicable for limited cases where the power over t in R-t relation takes about 1/3. The power law and the enhanced diffusion models are found in most cases to overestimate the cavity growth.

  18. Transcriptional responses to sucrose mimic the plant-associated life style of the plant growth promoting endophyte Enterobacter sp. 638.

    Directory of Open Access Journals (Sweden)

    Safiyh Taghavi

    Full Text Available Growth in sucrose medium was previously found to trigger the expression of functions involved in the plant associated life style of the endophytic bacterium Enterobacter sp. 638. Therefore, comparative transcriptome analysis between cultures grown in sucrose or lactate medium was used to gain insights in the expression levels of bacterial functions involved in the endophytic life style of strain 638. Growth on sucrose as a carbon source resulted in major changes in cell physiology, including a shift from a planktonic life style to the formation of bacterial aggregates. This shift was accompanied by a decrease in transcription of genes involved in motility (e.g., flagella biosynthesis and an increase in the transcription of genes involved in colonization, adhesion and biofilm formation. The transcription levels of functions previously suggested as being involved in endophytic behavior and functions responsible for plant growth promoting properties, including the synthesis of indole-acetic acid, acetoin and 2,3-butanediol, also increased significantly for cultures grown in sucrose medium. Interestingly, despite an abundance of essential nutrients transcription levels of functions related to uptake and processing of nitrogen and iron became increased for cultures grown on sucrose as sole carbon source. Transcriptome data were also used to analyze putative regulatory relationships. In addition to the small RNA csrABCD regulon, which seems to play a role in the physiological adaptation and possibly the shift between free-living and plant-associated endophytic life style of Enterobacter sp. 638, our results also pointed to the involvement of rcsAB in controlling responses by Enterobacter sp. 638 to a plant-associated life style. Targeted mutagenesis was used to confirm this role and showed that compared to wild-type Enterobacter sp. 638 a ΔrcsB mutant was affected in its plant growth promoting ability.

  19. Straw gasification biochar increases plant available water capacity and plant growth in coarse sandy soil

    DEFF Research Database (Denmark)

    Hansen, Veronika; Hauggaard-Nielsen, Henrik; Petersen, Carsten Tilbæk;

    Gasification biochar (GB) contains recalcitrant carbon that can contribute to soil carbon sequestration and soil quality improvement. However, the impact of GB on plant available water capacity (AWC) and plant growth in diverse soil types needs further reserach. A pot experiment with spring barle...... the characteristic low compressibility and high friction giving much better conditions for root penetration increasing yield potentials. Furthermore, risk of drought in dry periods, and nutrient losses in wet periods in coarser soil types is also reduced......Gasification biochar (GB) contains recalcitrant carbon that can contribute to soil carbon sequestration and soil quality improvement. However, the impact of GB on plant available water capacity (AWC) and plant growth in diverse soil types needs further reserach. A pot experiment with spring barley...... was conducted to investigate the effect of soil amendment of straw (SGB) and wood (WGB) GB on shoot and root growth under two levels of water supply in a temperate sandy loam and coarse sandy soil. In the sandy loam, the reduced water regime significantly affected plant growth and water consumption, whereas...

  20. Plant development in space: Observations on root formation and growth

    Science.gov (United States)

    Levine, H. G.; Kann, R. P.; Krikorian, Abraham D.

    1990-01-01

    Root growth in space is discussed and observations on root production from plants flown as part of the Chromex project that were defined as to their origin, stage of development and physiological status, are presented. Roots were generated from fully differentiated, aseptically maintained individuals of Haplopappus gracilis (Compositae) under spaceflight conditions. Results are compared for tissue culture generated plantlets and comparably sized seedling clone individuals, both of which had their roots trimmed on Earth before they were loaded into NASA's plant growth unit and subjected to a 5 day shuttle flight (STS-29). Asepsis was maintained throughout the experiment. Overall root production was 40 to 50 percent greater under spaceflight conditions than during ground control tests. However, root formation slowed down towards the end of the flight. This decrease in new roots did not occur in the ground controls that sought to simulate flight except for microgravity.

  1. Laser-mediated perforation of plant cells

    Science.gov (United States)

    Wehner, Martin; Jacobs, Philipp; Esser, Dominik; Schinkel, Helga; Schillberg, Stefan

    2007-07-01

    The functional analysis of plant cells at the cellular and subcellular levels requires novel technologies for the directed manipulation of individual cells. Lasers are increasingly exploited for the manipulation of plant cells, enabling the study of biological processes on a subcellular scale including transformation to generate genetically modified plants. In our setup either a picosecond laser operating at 1064 nm wavelength or a continuous wave laser diode emitting at 405 nm are coupled into an inverse microscope. The beams are focused to a spot size of about 1.5 μm and the tobacco cell protoplasts are irradiated. Optoporation is achieved when targeting the laser focal spot at the outermost edge of the plasma membrane. In case of the picosecond laser a single pulse with energy of about 0.4 μJ was sufficient to perforate the plasma membrane enabling the uptake of dye or DNA from the surrounding medium into the cytosol. When the ultraviolet laser diode at a power level of 17 mW is employed an irradiation time of 200 - 500 milliseconds is necessary to enable the uptake of macromolecules. In the presence of an EYFP encoding plasmid with a C-terminal peroxisomal signal sequence in the surrounding medium transient transformation of tobacco protoplasts could be achieved in up to 2% of the optoporated cells. Single cell perforation using this novel optoporation method shows that isolated plant cells can be permeabilized without direct manipulation. This is a valuable procedure for cell-specific applications, particularly where the import of specific molecules into plant cells is required for functional analysis.

  2. Increasing plant growth by modulating omega-amidase expression in plants

    Energy Technology Data Exchange (ETDEWEB)

    Unkefer, Pat J.; Anderson, Penelope S.; Knight, Thomas J.

    2015-06-30

    The present disclosure relates to compositions and methods for increasing the leaf-to-root ratio of the signal metabolite 2-oxoglutaramate and related proline molecules in plants by modulating levels of .omega.-amidase to increase nitrogen use efficiency, resulting in enhanced growth, faster growth rates, greater seed and fruit/pod yields, earlier and more productive flowering, increased tolerance to high salt conditions, and increased biomass yields.

  3. Aromatic fluorine compounds. VIII. Plant growth regulators and intermediates

    Science.gov (United States)

    Finger, G.C.; Gortatowski, M.J.; Shiley, R.H.; White, R.H.

    1959-01-01

    The preparation and properties of 41 fluorophenoxyacetic acids, 4 fluorophenoxypropionic acids, 2 fluorobenzoic acids, several indole derivatives, and a number of miscellaneous compounds are described. Data are given for many intermediates such as new fluorinated phenols, anisoles, anilines and nitrobenzenes. Most of the subject compounds are related to a number of well-known herbicides or plant growth regulators such as 2,4-D, 2,4,5-T and others.

  4. THERMAL RADIATION LOAD ON TEMPERATURE REGIMES IN PLANT GROWTH CHAMBERS

    OpenAIRE

    Hamasaki, T; Okada, Masumi

    2000-01-01

    In enclosed environments such as a plant growth chamber, thermal radiation plays an important role in determining heat balance and therefore the resultant temperature regimes. In artificially illuminated chambers, a significant level of thermal radiation is emitted from the lamps and/or the lamp house surface. Though there are both shortwave and longwave components in thermal radiation, our measurements in two different chamber designs, with and without thermal radiation filters, showed the l...

  5. [Effect of plant growth regulators on physiological activity of Bradyrhizobium japonicum ].

    Science.gov (United States)

    Leonova, N O; Tytova, L V; Tantsiurenko, O V; Antypchuk, A F

    2005-01-01

    Influence of plant growth regulators Ivin, Emistim C, Eney and Agrostimulin on the biomass production and exopolymers synthesis of soybean nodule bacteria, which have contrasting symbiotic properties, and glutamine synthetase activity of their cell-free extracts were studied. It was shown that the processes of the biomass and exopolymers accumulation had an opposite direction. Of all preparations only Ivin and Agrostimulin intensificol growth activity of the microorganisms under study. The level of glutamine synthetase activity and this enzymatic reaction specificity to the bivalent metal ions were determined by the special features of Bradyrhizobium strains and nature of the plant growth regulators. Only in the presence of Eney the increase of glutamine synthetase activity of both cultures of Bradyrhizobium japonicum was established.

  6. L-Ascorbic Acid: A Multifunctional Molecule Supporting Plant Growth and Development

    Directory of Open Access Journals (Sweden)

    Daniel R. Gallie

    2013-01-01

    Full Text Available L-Ascorbic acid (vitamin C is as essential to plants as it is to animals. Ascorbic acid functions as a major redox buffer and as a cofactor for enzymes involved in regulating photosynthesis, hormone biosynthesis, and regenerating other antioxidants. Ascorbic acid regulates cell division and growth and is involved in signal transduction. In contrast to the single pathway responsible for ascorbic acid biosynthesis in animals, plants use multiple pathways to synthesize ascorbic acid, perhaps reflecting the importance of this molecule to plant health. Given the importance of ascorbic acid to human nutrition, several technologies have been developed to increase the ascorbic acid content of plants through the manipulation of biosynthetic or recycling pathways. This paper provides an overview of these approaches as well as the consequences that changes in ascorbic acid content have on plant growth and function. Discussed is the capacity of plants to tolerate changes in ascorbic acid content. The many functions that ascorbic acid serves in plants, however, will require highly targeted approaches to improve their nutritional quality without compromising their health.

  7. Disease resistance or growth: the role of plant hormones in balancing immune responses and fitness costs

    OpenAIRE

    Denancé, Nicolas; Sánchez-Vallet, Andrea; Goffner, Deborah; Molina, Antonio

    2013-01-01

    Plant growth and response to environmental cues are largely governed by phytohormones. The plant hormones ethylene, jasmonic acid, and salicylic acid (SA) play a central role in the regulation of plant immune responses. In addition, other plant hormones, such as auxins, abscisic acid (ABA), cytokinins, gibberellins, and brassinosteroids, that have been thoroughly described to regulate plant development and growth, have recently emerged as key regulators of plant immunity. Plant hormones inter...

  8. Disease resistance or growth: the role of plant hormones in balancing immune responses and fitness costs

    OpenAIRE

    Nicolas eDenancé; Andrea eSánchez-Vallet; Deborah eGoffner; Antonio eMolina

    2013-01-01

    Plant growth and response to environmental cues are largely governed by phytohormones. The plant hormones ethylene, jasmonic acid and salicylic acid (SA) play a central role in the regulation of plant immune responses. In addition, other plant hormones, such as auxins, abscisic acid (ABA), cytokinins, gibberellins and brassinosteroids, that have been thoroughly described to regulate plant development and growth, have recently emerged as key regulators of plant immunity. Plant hormones interac...

  9. Characterization of Cellulose Synthesis in Plant Cells

    OpenAIRE

    Samaneh Sadat Maleki; Kourosh Mohammadi; Kong-shu Ji

    2016-01-01

    Cellulose is the most significant structural component of plant cell wall. Cellulose, polysaccharide containing repeated unbranched β (1-4) D-glucose units, is synthesized at the plasma membrane by the cellulose synthase complex (CSC) from bacteria to plants. The CSC is involved in biosynthesis of cellulose microfibrils containing 18 cellulose synthase (CesA) proteins. Macrofibrils can be formed with side by side arrangement of microfibrils. In addition, beside CesA, various proteins like the...

  10. UV-Induced Cell Death in Plants

    Directory of Open Access Journals (Sweden)

    Chang Ho Kang

    2013-01-01

    Full Text Available Plants are photosynthetic organisms that depend on sunlight for energy. Plants respond to light through different photoreceptors and show photomorphogenic development. Apart from Photosynthetically Active Radiation (PAR; 400–700 nm, plants are exposed to UV light, which is comprised of UV-C (below 280 nm, UV-B (280–320 nm and UV-A (320–390 nm. The atmospheric ozone layer protects UV-C radiation from reaching earth while the UVR8 protein acts as a receptor for UV-B radiation. Low levels of UV-B exposure initiate signaling through UVR8 and induce secondary metabolite genes involved in protection against UV while higher dosages are very detrimental to plants. It has also been reported that genes involved in MAPK cascade help the plant in providing tolerance against UV radiation. The important targets of UV radiation in plant cells are DNA, lipids and proteins and also vital processes such as photosynthesis. Recent studies showed that, in response to UV radiation, mitochondria and chloroplasts produce a reactive oxygen species (ROS. Arabidopsis metacaspase-8 (AtMC8 is induced in response to oxidative stress caused by ROS, which acts downstream of the radical induced cell death (AtRCD1 gene making plants vulnerable to cell death. The studies on salicylic and jasmonic acid signaling mutants revealed that SA and JA regulate the ROS level and antagonize ROS mediated cell death. Recently, molecular studies have revealed genes involved in response to UV exposure, with respect to programmed cell death (PCD.

  11. Osmosis in Poisoned Plant Cells.

    Science.gov (United States)

    Tatina, Robert

    1998-01-01

    Describes two simple laboratory exercises that allow students to test hypotheses concerning the requirement of cell energy for osmosis. The first exercise involves osmotically-caused changes in the length of potato tubers and requires detailed quantitative observations. The second exercise involves osmotically-caused changes in turgor of Elodea…

  12. Function of root border cells in plant health: pioneers in the rhizosphere.

    Science.gov (United States)

    Hawes, M C; Brigham, L A; Wen, F; Woo, H H; Zhu, Y

    1998-01-01

    Plants dedicate a large amount of energy to the regulated production of living cells programmed to separate from roots into the external environment. This unusual process may be worth the cost because it enables the plant to dictate which species will share its ecological niche. For example, border cells can rapidly attract and stimulate growth in some microorganisms and repel and inhibit the growth of others. Such specificity may provide a way to control the dynamics of adjacent microbial populations in the soil to foster beneficial associations and inhibit pathogenic invasion. Plant genes controlling the delivery of border cells and the expression of their unique properties provide tools to genetically engineer plants with altered border cell quality and quantity. Such variants are being used to test the hypothesis that the function of border cells is to protect plant health by controlling the ecology of the root system.

  13. Influence of growth regulators on plant growth, yield, and skin color of specialty potatoes

    Science.gov (United States)

    2,4-D has been used since the 1950’s to enhance color in red-skinned potatoes, but there is little research on the potential use of other plant growth regulators to improve tuber skin color in the wide range of specialty potatoes now available on the market. Field trials conducted at Parma, ID in 20...

  14. Key physiological properties contributing to rhizosphere adaptation and plant growth promotion abilities of Azospirillum brasilense.

    Science.gov (United States)

    Fibach-Paldi, Sharon; Burdman, Saul; Okon, Yaacov

    2012-01-01

    Azospirillum brasilense is a plant growth promoting rhizobacterium (PGPR) that is being increasingly used in agriculture in a commercial scale. Recent research has elucidated key properties of A. brasilense that contribute to its ability to adapt to the rhizosphere habitat and to promote plant growth. They include synthesis of the auxin indole-3-acetic acid, nitric oxide, carotenoids, and a range of cell surface components as well as the ability to undergo phenotypic variation. Storage and utilization of polybetahydroxyalkanoate polymers are important for the shelf life of the bacteria in production of inoculants, products containing bacterial cells in a suitable carrier for agricultural use. Azospirillum brasilense is able to fix nitrogen, but despite some controversy, as judging from most systems evaluated so far, contribution of fixed nitrogen by this bacterium does not seem to play a major role in plant growth promotion. In this review, we focus on recent advances in the understanding of physiological properties of A. brasilense that are important for rhizosphere performance and successful interactions with plant roots.

  15. Plant hydraulic traits govern forest water use and growth

    Science.gov (United States)

    Matheny, Ashley; Bohrer, Gil; Fiorella, Rich; Mirfenderesgi, Golnazalsadat

    2016-04-01

    Biophysical controls at the leaf, stem, and root levels govern plant water acquisition and use. Suites of sometimes co-varying traits afford plants the ability to manage water stress at each of these three levels. We studied the contrasting hydraulic strategies of red oaks (Q. rubra) and red maples (A. rubrum) in northern Michigan, USA. These two species differ in stomatal regulation strategy and xylem architecture, and are thought to root at different depths. Water use was monitored through sap flux, stem water storage, and leaf water potential measurements. Depth of water acquisition was determined on the basis of stable oxygen and hydrogen isotopes from xylem water samples taken from both species. Fifteen years of bole growth records were used to compare the influence of the trees' opposing hydraulic strategies on carbon acquisition and growth. During non-limiting soil moisture conditions, transpiration from red maples typically exceeded that of red oak. However, during a 20% soil dry down, transpiration from red maples decreased by more than 80%, while transpiration from red oaks only fell by 31%. Stem water storage in red maple also declined sharply, while storage in red oaks remained nearly constant. The more consistent isotopic compositions of xylem water samples indicated that oaks can draw upon a steady, deep supply of water which red maples cannot access. Additionally, red maple bole growth correlated strongly with mean annual soil moisture, while red oak bole growth did not. These results indicate that the deeper rooting strategy of red oaks allowed the species to continue transpiration and carbon uptake during periods of intense soil water limitation, when the shallow-rooted red maples ceased transpiration. The ability to root deeply could provide an additional buffer against drought-induced mortality, which may permit some anisohydric species, like red oak, to survive hydrologic conditions that would be expected to favor survival of more isohydric

  16. Isolation of plant growth promoting rhizobacteria of guava plants (Psidium guajava

    Directory of Open Access Journals (Sweden)

    Blanca Estela Gómez Luna

    2012-09-01

    Full Text Available Guava production for 2008 in the state of Guanajuato was 177 ha in area planted and the same number of area harvested, production in 1,130.80 Ton. In traditional farming practices have made excessive use of mineral fertilizers, which, if it is true, ensure a good production are expensive and come to cause imbalances in agroecosystems by contamination of soil, water, and food. In this work we evaluated the effect of Bacillus subtilis strains as plant growth promoter rhizobacteria in guava plants under greenhouse conditions. We used three strains were inoculated potted plant with guava. We measured the height, number of branches and leaves. Guava orchards of 2 then display of soil were taken for the isolation andcharacterization of rhizobacteria. Selective medium was used with 1 - carboxylic acid, -1 - aminocyclopropane and selecting bacteria with ACC desaminase activity. For the isolates were determined antibiotic resistance, confrontation with fungal pathogens, plant growth tests in vitro and BIOLOG metabolic profiles. We found 30 isolates with ACC activities, 7 have the effect of biological control and 5 had effect on root development in vitro. The use of growth promotingrhizobacteria are an excellent alternative for improving the production of guavas, growing very little is known of themicroflora associated with the rhizosphere and the ecological role they have in the ground.

  17. Effect of low doses of seed irradiation on plant growth

    International Nuclear Information System (INIS)

    The stimulation effect has often been discussed in research papers. There were the results of Russian work which showed greater yield after seed irradiation, and other research which showed no significant stimulating effect of seed irradiation on plant growth. These different results may be due to varying conditions like temperature, rainfall, variety, etc., under which the experiments were carried out. In the present work of this establishment the effect of radiation at different growing periods is being studied to obtain more information on the stimulating effect of small doses of radiation. These studies cover: (1) Germination speed. In these experiments the breakthrough of the primary root is investigated in relation to time and dose. (2) Development of young plants. After a growing period of 14 d the length of the plants and their dry and fresh weight are measured. (3) Radiation effect on yield. In pot and field experiments several agricultural plants, such as barley, wheat, potatoes and maize, are investigated at harvest time. The total yield, and the yield in grain and straw, are then determined separately. The first experiments have shown that the effect depends very much on the variety of plant, the growing temperature and the water content of the seeds at the time of irradiation. 10 figs, 1 tab

  18. Spectro-Microscopy of Living Plant Cells

    Institute of Scientific and Technical Information of China (English)

    Klaus Harter; Alfred J. Meixner; Frank Schleifenbaum

    2012-01-01

    Spectro-microscopy,a combination of fluorescence microscopy with spatially resolved spectroscopic techniques,provides new and exciting tools for functional cell biology in living organisms.This review focuses on recent developments in spectro-microscopic applications for the investigation of living plant cells in their native tissue context.The application of spectro-microscopic methods led to the recent discovery of a fast signal response pathway for the brassinosteroide receptor BRI1 in the plasma membrane of living plant cells.Moreover,the competence of different plant cell types to respond to environmental or endogenous stimuli was determined in vivo by correlation analysis of different optical and spectroscopic readouts such as fluorescence lifetime (FLT).Furthermore,a new spectro-microscopic technique,fluorescence intensity decay shape analysis microscopy (FIDSAM),has been developed.FIDSAM is capable of imaging lowexpressed fluorophore-tagged proteins at high spatial resolution and precludes the misinterpretation of autofluorescence artifacts.In addition,FIDSAM provides a very effective and sensitive tool on the basis of F(o)rster resonance energy transfer (FRET) for the qualitative and quantitative determination of protein-protein interaction.Finally,we report on the quantitative analysis of the photosystem Ⅰ and Ⅱ (PSⅠ/PSⅡ) ratio in the chloroplasts of living Arabidopsis plants at room temperature,using high-resolution,spatially resolved fluorescence spectroscopy.With this technique,it was not only possible to measure PSⅠ/PSⅡ ratios,but also to demonstrate the differential competence of wild-type and carbohydrate-deficient plants to adapt the PSⅠ/PSⅡ ratio to different light conditions.In summary,the information content of standard microscopic images is extended by several dimensions by the use of spectro-microscopic approaches.Therefore,novel cell physiological and molecular topics can be addressed and valuable insights into molecular and

  19. Biochar Treatment Resulted in a Combined Effect on Soybean Growth Promotion and a Shift in Plant Growth Promoting Rhizobacteria

    OpenAIRE

    EGAMBERDIEVA, Dilfuza; Wirth, Stephan; Behrendt, Undine; Abd_Allah, Elsayed F.; Berg, Gabriele

    2016-01-01

    The application of biochar to soil is considered to have the potential for long-term soil carbon sequestration, as well as for improving plant growth and suppressing soil pathogens. In our study we evaluated the effect of biochar on the plant growth of soybeans, as well as on the community composition of root-associated bacteria with plant growth promoting traits. Two types of biochar, namely, maize biochar (MBC), wood biochar (WBC), and hydrochar (HTC) were used for pot experiments to monito...

  20. POTENTIAL OF PLANT EXTRACTS AS GROWTH EXOGENOUS REGULATORS OF POTATO SEEDS

    OpenAIRE

    Fachirah Ulfa; Sengin, Enny Lisan; Baharuddin.

    2013-01-01

    Potato production in Indonesia has been declining while demand for potatoes remains increasing. One main reason of the decline is the lack of availability for good potato seedling. To optimize the growth of potato seedling, some plant extracts as exogenous growth regulators may be used. This experiment was aimed to select the best plant extract as exogenous growth regulator for potato seedling growth and study the underlying physiological process. Seven plant extracts as exogenous growth regu...

  1. A native plant growth promoting bacterium, Bacillus megaterium B55, rescues growth performance of an ethylene insensitive plant genotype in nature

    OpenAIRE

    Dorothea Gertrud Meldau; Hoang Hoa Long; Ian Thomas Baldwin

    2012-01-01

    Many plants have intimate relationships with soil microbes that through a variety of mechanisms improve the plant’s growth and fitness. Bacillus megaterium is a natural endophyte isolated from Nicotiana attenuata plant roots growing in native soils. A particular isolate (B55), was found to have dramatic plant growth promoting (PGP) effects on wild type (WT) and transgenic plants impaired in ethylene (ET) perception (35S-etr1), the genotype from which this bacteria was first isolated. B55 not ...

  2. Direct FuelCell/Turbine Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Hossein Ghezel-Ayagh

    2008-09-30

    This report summarizes the progress made in development of Direct FuelCell/Turbine (DFC/T{reg_sign}) power plants for generation of clean power at very high efficiencies. The DFC/T system employs an indirectly heated Turbine Generator to supplement fuel cell generated power. The concept extends the high efficiency of the fuel cell by utilizing the fuel cell's byproduct heat in a Brayton cycle. Features of the DFC/T system include: electrical efficiencies of up to 75% on natural gas, minimal emissions, reduced carbon dioxide release to the environment, simplicity in design, direct reforming internal to the fuel cell, and potential cost competitiveness with existing combined cycle power plants. Proof-of-concept tests using a sub-MW-class DFC/T power plant at FuelCell Energy's (FCE) Danbury facility were conducted to validate the feasibility of the concept and to measure its potential for electric power production. A 400 kW-class power plant test facility was designed and retrofitted to conduct the tests. The initial series of tests involved integration of a full-size (250 kW) Direct FuelCell stack with a 30 kW Capstone microturbine. The operational aspects of the hybrid system in relation to the integration of the microturbine with the fuel cell, process flow and thermal balances, and control strategies for power cycling of the system, were investigated. A subsequent series of tests included operation of the sub-MW Direct FuelCell/Turbine power plant with a Capstone C60 microturbine. The C60 microturbine extended the range of operation of the hybrid power plant to higher current densities (higher power) than achieved in initial tests using the 30kW microturbine. The proof-of-concept test results confirmed the stability and controllability of operating a fullsize (250 kW) fuel cell stack in combination with a microturbine. Thermal management of the system was confirmed and power plant operation, using the microturbine as the only source of fresh air supply

  3. Dynamics of Seed-Borne Rice Endophytes on Early Plant Growth Stages

    NARCIS (Netherlands)

    Hardoim, P.R.; Hardoim, C.C.P.; Overbeek, van L.S.; Elsas, van J.D.

    2012-01-01

    Bacterial endophytes are ubiquitous to virtually all terrestrial plants. With the increasing appreciation of studies that unravel the mutualistic interactions between plant and microbes, we increasingly value the beneficial functions of endophytes that improve plant growth and development. However,

  4. Minimising toxicity of cadmium in plants--role of plant growth regulators.

    Science.gov (United States)

    Asgher, Mohd; Khan, M Iqbal R; Anjum, Naser A; Khan, Nafees A

    2015-03-01

    A range of man-made activities promote the enrichment of world-wide agricultural soils with a myriad of chemical pollutants including cadmium (Cd). Owing to its significant toxic consequences in plants, Cd has been one of extensively studied metals. However, sustainable strategies for minimising Cd impacts in plants have been little explored. Plant growth regulators (PGRs) are known for their role in the regulation of numerous developmental processes. Among major PGRs, plant hormones (such as auxins, gibberellins, cytokinins, abscisic acid, jasmonic acid, ethylene and salicylic acid), nitric oxide (a gaseous signalling molecule), brassinosteroids (steroidal phytohormones) and polyamines (group of phytohormone-like aliphatic amine natural compounds with aliphatic nitrogen structure) have gained attention by agronomist and physiologist as a sustainable media to induce tolerance in abiotic-stressed plants. Considering recent literature, this paper: (a) overviews Cd status in soil and its toxicity in plants, (b) introduces major PGRs and overviews their signalling in Cd-exposed plants, (c) appraises mechanisms potentially involved in PGR-mediated enhanced plant tolerance to Cd and (d) highlights key aspects so far unexplored in the subject area.

  5. Budding yeast colony growth study based on circular granular cell

    Science.gov (United States)

    Aprianti, Devi; Khotimah, S. N.; Viridi, S.

    2016-08-01

    Yeast colony growth can be modelled by using circular granular cells, which can grow and produce buds. The bud growth angle can be set to regulate cell budding pattern. Cohesion force, contact force and Stokes force were adopted to accommodate the behaviour and interactions among cells. Simulation steps are divided into two steps, the explicit step is due to cell growing and implicit step for the cell rearrangement. Only in explicit step that time change was performed. In this study, we examine the influence of cell diameter growth time and reproduction time combination toward the growth of cell number and colony formation. We find a commutative relation between the cell diameter growth time and reproduction time to the specific growth rate. The greater value of the multiplication of the parameters, the smaller specific growth rate is obtained. It also shows a linear correlation between the specific growth rate and colony diameter growth rate.

  6. Integrating transcriptional controls for plant cell expansion

    OpenAIRE

    Mockaitis, Keithanne; Estelle, Mark

    2004-01-01

    The plant hormones auxin and brassinosteroid promote cell expansion by regulating gene expression. In addition to independent transcriptional responses generated by the two signals, recent microarray analyses indicate that auxin and brassinosteroid also coordinate the expression of a set of shared target genes.

  7. Plant microbial fuel cell applied in wetlands

    NARCIS (Netherlands)

    Wetser, Koen; Liu, Jia; Buisman, Cees; Strik, David

    2015-01-01

    The plant microbial fuel cell (PMFC) has to be applied in wetlands to be able to generate electricity on a large scale. The objective of this PMFC application research is to clarify the differences in electricity generation between a Spartina anglica salt marsh and Phragmites australis peat soil

  8. Bounds on bacterial cell growth rates

    CERN Document Server

    Landy, Jonathan

    2013-01-01

    Recent experiments have shown that rod-like bacteria in nutrient-rich media grow in length at an exponential rate. Here, I point out that it is the elongated shape of these bacteria that allows for this behavior. Further, I show that when a bacterium's growth is limited by some nutrient -- taken in by the cell through a diffusion-to-capture process -- its growth is suppressed: In three-dimensional geometries, the length $L$ is bounded by $\\log L \\lesssim t^{1/2}$, while in two dimensions the length is bounded by a power-law form. Fits of experimental growth curves to these predicted, sub-exponential forms could allow for direct measures of quantities relating to cellular metabolic rates.

  9. Micrasterias as a model system in plant cell biology

    Directory of Open Access Journals (Sweden)

    Ursula Luetz-Meindl

    2016-07-01

    Full Text Available The unicellular freshwater alga Micrasterias denticulata is an exceptional organism due to its extraordinary star-shaped, highly symmetric morphology and has thus attracted the interest of researchers for many decades. As a member of the Streptophyta, Micrasterias is not only genetically closely related to higher land plants but shares common features with them in many physiological and cell biological aspects. These facts, together with its considerable cell size of about 200 µm, its modest cultivation conditions and the uncomplicated accessibility particularly to any microscopic techniques, make Micrasterias a very well suited cell biological plant model system. The review focuses particularly on cell wall formation and composition, dictyosomal structure and function, cytoskeleton control of growth and morphogenesis as well as on ionic regulation and signal transduction. It has been also shown in the recent years that Micrasterias is a highly sensitive indicator for environmental stress impact such as heavy metals, high salinity, oxidative stress or starvation. Stress induced organelle degradation, autophagy, adaption and detoxification mechanisms have moved in the center of interest and have been investigated with modern microscopic techniques such as 3-D- and analytical electron microscopy as well as with biochemical, physiological and molecular approaches. This review is intended to summarize and discuss the most important results obtained in Micrasterias in the last 20 years and to compare the results to similar processes in higher plant cells.

  10. Micrasterias as a Model System in Plant Cell Biology

    Science.gov (United States)

    Lütz-Meindl, Ursula

    2016-01-01

    The unicellular freshwater alga Micrasterias denticulata is an exceptional organism due to its complex star-shaped, highly symmetric morphology and has thus attracted the interest of researchers for many decades. As a member of the Streptophyta, Micrasterias is not only genetically closely related to higher land plants but shares common features with them in many physiological and cell biological aspects. These facts, together with its considerable cell size of about 200 μm, its modest cultivation conditions and the uncomplicated accessibility particularly to any microscopic techniques, make Micrasterias a very well suited cell biological plant model system. The review focuses particularly on cell wall formation and composition, dictyosomal structure and function, cytoskeleton control of growth and morphogenesis as well as on ionic regulation and signal transduction. It has been also shown in the recent years that Micrasterias is a highly sensitive indicator for environmental stress impact such as heavy metals, high salinity, oxidative stress or starvation. Stress induced organelle degradation, autophagy, adaption and detoxification mechanisms have moved in the center of interest and have been investigated with modern microscopic techniques such as 3-D- and analytical electron microscopy as well as with biochemical, physiological and molecular approaches. This review is intended to summarize and discuss the most important results obtained in Micrasterias in the last 20 years and to compare the results to similar processes in higher plant cells. PMID:27462330

  11. Circadian rhythm and cell population growth

    CERN Document Server

    Clairambault, Jean; Lepoutre, Thomas

    2010-01-01

    Molecular circadian clocks, that are found in all nucleated cells of mammals, are known to dictate rhythms of approximately 24 hours (circa diem) to many physiological processes. This includes metabolism (e.g., temperature, hormonal blood levels) and cell proliferation. It has been observed in tumor-bearing laboratory rodents that a severe disruption of these physiological rhythms results in accelerated tumor growth. The question of accurately representing the control exerted by circadian clocks on healthy and tumour tissue proliferation to explain this phenomenon has given rise to mathematical developments, which we review. The main goal of these previous works was to examine the influence of a periodic control on the cell division cycle in physiologically structured cell populations, comparing the effects of periodic control with no control, and of different periodic controls between them. We state here a general convexity result that may give a theoretical justification to the concept of cancer chronothera...

  12. Light and Plants. A Series of Experiments Demonstrating Light Effects on Seed Germination, Plant Growth, and Plant Development.

    Science.gov (United States)

    Downs, R. J.; And Others

    A brief summary of the effects of light on plant germination, growth and development, including photoperiodism and pigment formation, introduces 18 experiments and demonstrations which illustrate aspects of these effects. Detailed procedures for each exercise are given, the expected results outlined, and possible sources of difficulty discussed.…

  13. Proanthocyanidin as a cytogenetic protective agent against adverse effects of plant growth regulators supplementation in rats.

    Science.gov (United States)

    Hassan, Hanaa A; El-Kholy, Wafaa M; Nour, Samar E

    2014-08-01

    The aim of the present study was to investigate the protective role of grape seed extract (containing proanthocyandin) against the adverse effects of plant growth regulators (GA3 (gibberellic acid) and IAA (indoleacetic acid)). The present data showed that the administration of either GA3 and IAA caused undesirable changes in both hepatic and testicular structure. This was evidenced by a disturbed hepatic strands, pyknotic nuclei, central vein with collapsed endothelium, dilatation in bile sinusoids, congested blood vessel, binucleatd hepatocytes, lymphocytic infiltration, vacuolation, giant hepatic cells, increased Kupffer cells and karyoryxis. Additionally, it was shown that degenerative changes in the testis, spermatogenic arrest, moderate tubular necrosis, Leydig cell degeneration and reduction in the number and size of the seminiferous tubules with some spermatogonia detached from the basement membrane. Concerning flow cytometric study of the liver a significant decrease in G0/1 % and a significant increase in S phase %, G2/M  %, P(53) % and apoptosis % (sub G1) were detected. However, in testis the data recorded a significant decrease in the percentage of mature sperm (percentage of haploid cells) and a significant increase in the percentage of spermatide, diploid cells, P(53) and of apoptotic cells. On the other hand, a distinct recovery of the mentioned hepatic and testicular histopathological and cytogenetic disorders was observed when proanthocyanidin was supplemented to rats administered either of the plant growth hormones (GA3 and IAA).

  14. Study the Effect of Triazophos as Plant Growth Regulator in Tissue Culture of Different Plants

    Directory of Open Access Journals (Sweden)

    Laith Ahmad Yaaqoub

    2012-09-01

    Full Text Available The present study was conducted to investigate the effect of triazophos in tissue cultures of three plants Catharanthus roseus, Zizyphus vulgaris and Eucalyptus globulus. Triazophos was compared with 2,4-D on Murashige and Skoog's (MS medium supplemented with different concentrations of them. Triazophos was tested for it is potential in callus induction and compared its activity with 2,4-D as plant growth regulator .There are no significant differences (p<0.05 in callus induction on leaf explants between Triazophos and 2,4-D of all plants. The best concentrations to initiation and maintenance callus were (0.1and 1 mg/L for Triazophos and 2,4-D respectively for all plants.

  15. Induction of drought tolerance in cucumber plants by a consortium of three plant growth-promoting rhizobacterium strains.

    Directory of Open Access Journals (Sweden)

    Chun-Juan Wang

    Full Text Available Our previous work showed that a consortium of three plant growth-promoting rhizobacterium (PGPR strains (Bacillus cereus AR156, Bacillus subtilis SM21, and Serratia sp. XY21, termed as BBS for short, was a promising biocontrol agent. The present study investigated its effect on drought tolerance in cucumber plants. After withholding watering for 13 days, BBS-treated cucumber plants had much darker green leaves and substantially lighter wilt symptoms than control plants. Compared to the control, the BBS treatment decreased the leaf monodehydroascorbate (MDA content and relative electrical conductivity by 40% and 15%, respectively; increased the leaf proline content and the root recovery intension by 3.45-fold and 50%, respectively; and also maintained the leaf chlorophyll content in cucumber plants under drought stress. Besides, in relation to the control, the BBS treatment significantly enhanced the superoxide dismutase (SOD activity and mitigated the drought-triggered down-regulation of the expression of the genes cAPX, rbcL, and rbcS encoding cytosolic ascorbate peroxidase, and ribulose-1,5-bisphosphate carboxy/oxygenase (Rubisco large and small subunits, respectively, in cucumber leaves. However, 1-aminocyclopropane-1-carboxylate (ACC deaminase activity was undetected in none of the culture solutions of three BBS constituent strains. These results indicated that BBS conferred induced systemic tolerance to drought stress in cucumber plants, by protecting plant cells, maintaining photosynthetic efficiency and root vigor and increasing some of antioxidase activities, without involving the action of ACC deaminase to lower plant ethylene levels.

  16. Isolation and characterization of plant growth-promoting rhizobacteria from wheat rhizosphere and their effect on plant growth promotion

    Directory of Open Access Journals (Sweden)

    M. Kaleem eABBASI

    2015-03-01

    Full Text Available AbstractThe present study was conducted to characterize the native plant growth promoting bacteria from wheat rhizosphere and root-endosphere in the Himalayan region of Rawalakot, Azad Jammu and Kashmir (AJK, Pakistan. Nine bacterial isolates were purified, screened in vitro for plant growth promoting (PGP characteristics and evaluated for their beneficial effects on the early growth of wheat (Triticum aestivum L.. Among nine bacterial isolates, seven were able to produce indole-3- acetic acid in tryptophan-supplemented medium; seven were nitrogen fixer, and four were able to solubilize inorganic phosphate in vitro. Four different morphotypes were genotypically identified based on IGS-RFLP fingerprinting and representative of each morphotype was identified by 16S rRNA gene sequencing analysis except Gram positive putative Bacillus sp. Based on 16S rRNA gene sequence analysis, bacterial isolates AJK–3 and AJK-9 showing multiple PGP-traits were identified as Stenotrophomonas spp. while AJK-7 showed equal homologies to Acetobacter pasteurianus and Stenotrophomonas specie. Plant inoculation studies indicated that these PGPR strains provided a significant increase in shoot and root length, and shoot and root biomass. A significant increase in shoot N contents (up to 76% and root N contents (up to 32% was observed over the un-inoculated control. The study indicates the potential of these PGPR for inoculums production or biofertilizers for enhancing growth and nutrient content of wheat and other crops under field conditions. The study is the first report of wheat associated bacterial diversity in the Himalayan region of Rawalakot, AJK.

  17. Hormone activities and the cell cycle machinery in immunity-triggered growth inhibition.

    Science.gov (United States)

    Reitz, M U; Gifford, M L; Schäfer, P

    2015-04-01

    Biotic stress and diseases caused by pathogen attack pose threats in crop production and significantly reduce crop yields. Enhancing immunity against pathogens is therefore of outstanding importance in crop breeding. However, this must be balanced, as immune activation inhibits plant growth. This immunity-coupled growth trade-off does not support resistance but is postulated to reflect the reallocation of resources to drive immunity. There is, however, increasing evidence that growth-immunity trade-offs are based on the reconfiguration of hormone pathways, shared by growth and immunity signalling. Studies in roots revealed the role of hormones in orchestrating growth across different cell types, with some hormones showing a defined cell type-specific activity. This is apparently highly relevant for the regulation of the cell cycle machinery and might be part of the growth-immunity cross-talk. Since plants are constantly exposed to Immuno-activating microbes under agricultural conditions, the transition from a growth to an immunity operating mode can significantly reduce crop yield and can conflict our efforts to generate next-generation crops with improved yield under climate change conditions. By focusing on roots, we outline the current knowledge of hormone signalling on the cell cycle machinery to explain growth trade-offs induced by immunity. By referring to abiotic stress studies, we further introduce how root cell type-specific hormone activities might contribute to growth under immunity and discuss the feasibility of uncoupling the growth-immunity cross-talk.

  18. Effect of crop development on biogenic emissions from plant populations grown in closed plant growth chambers

    Science.gov (United States)

    Batten, J. H.; Stutte, G. W.; Wheeler, R. M.

    1995-01-01

    The Biomass Production Chamber at John F. Kennedy Space Center is a closed plant growth chamber facility that can be used to monitor the level of biogenic emissions from large populations of plants throughout their entire growth cycle. The head space atmosphere of a 26-day-old lettuce (Lactuca sativa cv. Waldmann's Green) stand was repeatedly sampled and emissions identified and quantified using GC-mass spectrometry. Concentrations of dimethyl sulphide, carbon disulphide, alpha-pinene, furan and 2-methylfuran were not significantly different throughout the day; whereas, isoprene showed significant differences in concentration between samples collected in light and dark periods. Volatile organic compounds from the atmosphere of wheat (Triticum aestivum cv. Yecora Rojo) were analysed and quantified from planting to maturity. Volatile plant-derived compounds included 1-butanol, 2-ethyl-1-hexanol, nonanal, benzaldehyde, tetramethylurea, tetramethylthiourea, 2-methylfuran and 3-methylfuran. Concentrations of volatiles were determined during seedling establishment, vegetative growth, anthesis, grain fill and senescence and found to vary depending on the developmental stage. Atmospheric concentrations of benzaldehyde and nonanal were highest during anthesis, 2-methylfuran and 3-methylfuran concentrations were greatest during grain fill, and the concentration of the tetramethylurea peaked during senescence.

  19. Plant growth-promoting rhizobacteria improved growth, nutrient, and hormone content of cabbage (Brassica oleracea) seedlings

    OpenAIRE

    Turan, Metin; EKİNCİ, Melek; YILDIRIM, Ertan; GÜNEŞ, Adem; Karagöz, Kenan; KOTAN, Recep; Dursun, Atilla

    2014-01-01

    A greenhouse experiment was conducted to observe the effects of Bacillus megaterium strain TV-91C, Pantoea agglomerans strain RK-92, and B. subtilis strain TV-17C inoculation on the growth, nutrient, and hormone content of cabbage seedlings. The seeds of cabbage were incubated in flasks by shaking at 80 rpm for 2 h at 28 °C to coat the seeds with the rhizobacteria. Plant growth-promoting rhizobacteria (PGPR) treatments increased fresh and dry shoot and root weight, stem diameter, seedling hei...

  20. Weijia Zhou Inspects the Advanced Astroculture plant growth unit

    Science.gov (United States)

    2003-01-01

    Dr. Weijia Zhou, director of the Wisconsin Center for Space Automation and Robotics at the University of Wisconsin-Madison, inspects the Advanced Astroculture(tm) plant growth unit before its first flight last spring. Coating technology is used inside the miniature plant greenhouse to remove ethylene, a chemical produced by plant leaves that can cause plants to mature too quickly. This same coating technology is used in a new anthrax-killing device. The Space Station experiment is managed by the Space Product Development Program at NASA's Marshall Space Flight Center in Huntsville, Ala. DuPont is partnering with NASA and the Wisconsin Center for Space Automation and Robotics (WCSAR) at the University of Wisconsin-Madison to grow soybeans aboard the Space Station to find out if they have improved oil, protein, carbohydrates or secondary metabolites that could benefit farmers and consumers. Principal Investigators: Dr. Tom Corbin, Pioneer Hi-Bred International Inc., a Dupont Company, with headquarters in Des Moines, Iowa, and Dr. Weijia Zhou, Wisconsin Center for Space Automation and Robotics (WCSAR), University of Wisconsin-Madison.

  1. Plant cell walls: New insights from ancient species

    DEFF Research Database (Denmark)

    Sørensen, Iben; Willats, William George Tycho

    2008-01-01

    Cell walls are a defining feature of plants and have numerous crucial roles in growth and development. They are also the largest source of terrestrial biomass and have many important industrial applications - ranging from bulk products to functional food ingredients. There is considerable interest...... in the structure and functions of cell walls, and in the evolution of their remarkably complex polysaccharide structures. The grasses and cereals (order Poales), have long been regarded as being unique in that their cell walls contain an unbranched homopolymer, (1¿3)(1¿4)-ß-D-glucan, in which short blocks of (1...... in horsetails (Equisetales order) was therefore significant and has prompted a re-evaluation of some of the current views on cell wall evolution and structural diversity. Addendum to: Sørensen I, Pettolino FA, Wilson SM, Doblin MS, Johansen B, Bacic A, Willats WGT. Mixed-linkage (1¿3),(1¿4)-ß...

  2. Dwarfing effects of plant growth regulators on narcissi

    Institute of Scientific and Technical Information of China (English)

    RENXu-qin; LIANGHong-wei; CHENBo-qing; JIMei-yun

    2003-01-01

    The effects of four kinds of plant growth regulators with different concentrations on narcissi were studied in 2001.The results showed that the regulators could inhibit the growths of height and leaves of narcissi. Of the four regulators, the dwarfing effects of paclobatrazol (PP333) and uniconazole (S3307) on narcissi were better than those of chlorocholine (CCC) and dimethyl amino-sussinamic acid (B9). All of the regulators did not have significant effect on the root length. Moreover, the time of flowering was later for the narcissi treated with regulators than that of the control to a certain extent, and the range delayed was from 2 days to 19 days. The correlation analysis results showed that there was a significant correlation between the time of flowering and the concentrations of regulators. The ornament value of narcissi was obviously improved by using the regulators.

  3. mRNA Transcript abundance during plant growth and the influence of Li(+) exposure.

    Science.gov (United States)

    Duff, M C; Kuhne, W W; Halverson, N V; Chang, C-S; Kitamura, E; Hawthorn, L; Martinez, N E; Stafford, C; Milliken, C E; Caldwell, E F; Stieve-Caldwell, E

    2014-12-01

    Lithium (Li) toxicity in plants is, at a minimum, a function of Li(+) concentration, exposure time, species and growth conditions. Most plant studies with Li(+) focus on short-term acute exposures. This study examines short- and long-term effects of Li(+) exposure in Arabidopsis with Li(+) uptake studies and measured shoot mRNA transcript abundance levels in treated and control plants. Stress, pathogen-response and arabinogalactan protein genes were typically more up-regulated in older (chronic, low level) Li(+)-treatment plants and in the much younger plants from acute high-level exposures. The gene regulation behavior of high-level Li(+) resembled prior studies due to its influence on: inositol synthesis, 1-aminocyclopropane-1-carboxylate synthases and membrane ion transport. In contrast, chronically-exposed plants had gene regulation responses that were indicative of pathogen, cold, and heavy-metal stress, cell wall degradation, ethylene production, signal transduction, and calcium-release modulation. Acute Li(+) exposure phenocopies magnesium-deficiency symptoms and is associated with elevated expression of stress response genes that could lead to consumption of metabolic and transcriptional energy reserves and the dedication of more resources to cell development. In contrast, chronic Li(+) exposure increases expression signal transduction genes. The identification of new Li(+)-sensitive genes and a gene-based "response plan" for acute and chronic Li(+) exposure are delineated. PMID:25443852

  4. Distribution System Optimization Planning Based on Plant Growth Simulation Algorithm

    Institute of Scientific and Technical Information of China (English)

    WANG Chun; CHENG Hao-zhong; HU Ze-chun; WANG Yi

    2008-01-01

    An approach for the integrated optimization of the construction/expansion capacity of high-voltage/medium-voltage (HV/MV) substations and the configuration of MV radial distribution network was presented using plant growth simulation algorithm (PGSA). In the optimization process, fixed costs correspondent to the investment in lines and substations and the variable costs associated to the operation of the system were considered under the constraints of branch capacity, substation capacity and bus voltage. The optimization variables considerably reduce the dimension of variables and speed up the process of optimizing. The effectiveness of the proposed approach was tested by a distribution system planning.

  5. Microanalysis of Plant Cell Wall Polysaccharides

    Institute of Scientific and Technical Information of China (English)

    Nicolai Obel; Veronika Erben; Tatjana Schwarz; Stefan Kühne; Andrea Fodor; Markus Pauly

    2009-01-01

    Oligosaccharide Mass Profiling (OLIMP) allows a fast and sensitive assessment of cell wall polymer structure when coupled with Matrix Assisted Laser Desorption Ionisation Time Of Flight Mass Spectrometry (MALDI-TOF MS). The short time required for sample preparation and analysis makes possible the study of a wide range of plant organs, revealing a high degree of heterogeneity in the substitution pattern of wall polymers such as the cross-linking glycan xyloglucan and the pectic polysaccharide homogalacturonan. The high sensitivity of MALDI-TOF allows the use of small amounts of samples, thus making it possible to investigate the wall structure of single cell types when material is collected by such methods as laser micro-dissection. As an example, the analysis of the xyloglucan structure in the leaf cell types outer epidermis layer, entire epidermis cell layer, palisade mesophyll cells, and vascular bundles were investigated. OLIMP is amenable to in situ wall analysis, where wall polymers are analyzed on unprepared plant tissue itself without first iso-lating cell walls. In addition, OLIMP enables analysis of wall polymers in Golgi-enriched fractions, the location of nascent matrix polysaccharide biosynthesis, enabling separation of the processes of wall biosynthesis versus post-deposition apo-plastic metabolism. These new tools will make possible a semi-quantitative analysis of the cell wall at an unprecedented level.

  6. Response of Phaseolus vulgaris L. plants to low-let ionizing radiation: Growth and oxidative stress

    Science.gov (United States)

    Arena, C.; De Micco, V.; Aronne, G.; Pugliese, M.; Virzo De Santo, A.; De Maio, A.

    2013-10-01

    The scenarios for the long-term habitation of space platforms and planetary stations involve plants as fundamental part of Bioregenerative Life Support Systems (BLSS) to support the crew needs. Several constraints may limit plant growth in space: among them ionizing radiation is recognized to severely affect plant cell at morphological, physiological and biochemical level. In this work, plants of Phaseolus vulgaris L. were subjected to four different doses of X-rays (0.3, 10, 50 and 100 Gy) in order to assess the effects of ionizing radiation on this species and to analyze possible mechanisms carried out to overcome the radiation injuries. The effects of X-rays on plant growth were assessed by measuring stem elongation, number of internodes and leaf dry weight. The integrity of photosynthetic apparatus was evaluated by photosynthetic pigment composition and ribulose 1,5-bisphosphate carboxylase (Rubisco) activity, whereas changes in total antioxidant pool and glutathione S transferase activity (GST) were utilized as markers of oxidative stress. The distribution of phenolic compounds in leaf tissues as natural shielding against radiation was also determined. Irradiation of plants at 0.3 and 10 Gy did not determine differences in all considered parameters as compared to control. On the contrary, at 50 and 100 Gy a reduction of plant growth and a decrease in photosynthetic pigment content, as well as an increase in phenolic compounds and a decrease in total antioxidant content and GST activity were found. Only a slight reduction of Rubisco activity in leaves irradiated at 50 and 100 Gy was found. The overall results indicate P. vulgaris as a species with a good potential to face ionizing radiation and suggest its suitability for utilization in BLSSs.

  7. Mechanosensitive control of plant growth: Bearing the load, sensing, transducing and responding

    Directory of Open Access Journals (Sweden)

    Bruno eMoulia

    2015-02-01

    Full Text Available As land plants grow and develop, they encounter complex mechanical challenges, especially from winds and turgor pressure. Mechanosensitive control over growth and morphogenesis is an adaptive trait, reducing the risks of breakage or explosion. This control has been mostly studied through experiments with artificial mechanical loads, often focusing on cellular or molecular mechanotransduction pathway. However some important aspects of mechanosensing are often neglected. i What are the mechanical characteristics of different loads and how are loads distributed within different organs? ii What is the relevant mechanical stimulus in the cell? Is it stress, strain, or energy? iii How do mechanosensing cells signal to meristematic cells? Without answers to these questions we cannot make progress analyzing the mechanobiological effects of plant size, plant shape, tissue distribution and stiffness, or the magnitude of stimuli. This situation is rapidly changing however, as systems mechanobiology is being developed, using specific biomechanical and/or mechanobiological models. These models are instrumental in comparing loads and responses between experiments and make it possible to quantitatively test biological hypotheses describing the mechanotransduction networks. This review is designed for a general plant science audience and aims to help biologists master the models they need for mechanobiological studies. Analysis and modeling is broken down into four steps looking at how the structure bears the load, how the distributed load is sensed, how the mechanical signal is transduced, and then how the plant responds through growth. Throughout, two examples of adaptive responses are used to illustrate this approach: the thigmorphogenetic syndrome of plant shoots bending and the mechanosensitive control of shoot apical meristem morphogenesis. Overall this should provide a generic understanding of systems mechanobiology at work.

  8. Mechanosensitive control of plant growth: bearing the load, sensing, transducing, and responding.

    Science.gov (United States)

    Moulia, Bruno; Coutand, Catherine; Julien, Jean-Louis

    2015-01-01

    As land plants grow and develop, they encounter complex mechanical challenges, especially from winds and turgor pressure. Mechanosensitive control over growth and morphogenesis is an adaptive trait, reducing the risks of breakage or explosion. This control has been mostly studied through experiments with artificial mechanical loads, often focusing on cellular or molecular mechanotransduction pathway. However, some important aspects of mechanosensing are often neglected. (i) What are the mechanical characteristics of different loads and how are loads distributed within different organs? (ii) What is the relevant mechanical stimulus in the cell? Is it stress, strain, or energy? (iii) How do mechanosensing cells signal to meristematic cells? Without answers to these questions we cannot make progress analyzing the mechanobiological effects of plant size, plant shape, tissue distribution and stiffness, or the magnitude of stimuli. This situation is rapidly changing however, as systems mechanobiology is being developed, using specific biomechanical and/or mechanobiological models. These models are instrumental in comparing loads and responses between experiments and make it possible to quantitatively test biological hypotheses describing the mechanotransduction networks. This review is designed for a general plant science audience and aims to help biologists master the models they need for mechanobiological studies. Analysis and modeling is broken down into four steps looking at how the structure bears the load, how the distributed load is sensed, how the mechanical signal is transduced, and then how the plant responds through growth. Throughout, two examples of adaptive responses are used to illustrate this approach: the thigmorphogenetic syndrome of plant shoots bending and the mechanosensitive control of shoot apical meristem (SAM) morphogenesis. Overall this should provide a generic understanding of systems mechanobiology at work. PMID:25755656

  9. Mesenchymal stem cell like (MSCl) cells generated from human embryonic stem cells support pluripotent cell growth

    Energy Technology Data Exchange (ETDEWEB)

    Varga, Nora [Membrane Research Group of the Hungarian Academy of Sciences, Semmelweis University, Budapest (Hungary); Vereb, Zoltan; Rajnavoelgyi, Eva [Department of Immunology, Medical and Health Science Centre, University of Debrecen, Debrecen (Hungary); Nemet, Katalin; Uher, Ferenc; Sarkadi, Balazs [Membrane Research Group of the Hungarian Academy of Sciences, Semmelweis University, Budapest (Hungary); Apati, Agota, E-mail: apati@kkk.org.hu [Membrane Research Group of the Hungarian Academy of Sciences, Semmelweis University, Budapest (Hungary)

    2011-10-28

    Highlights: Black-Right-Pointing-Pointer MSC like cells were derived from hESC by a simple and reproducible method. Black-Right-Pointing-Pointer Differentiation and immunosuppressive features of MSCl cells were similar to bmMSC. Black-Right-Pointing-Pointer MSCl cells as feeder cells support the undifferentiated growth of hESC. -- Abstract: Mesenchymal stem cell like (MSCl) cells were generated from human embryonic stem cells (hESC) through embryoid body formation, and isolated by adherence to plastic surface. MSCl cell lines could be propagated without changes in morphological or functional characteristics for more than 15 passages. These cells, as well as their fluorescent protein expressing stable derivatives, efficiently supported the growth of undifferentiated human embryonic stem cells as feeder cells. The MSCl cells did not express the embryonic (Oct4, Nanog, ABCG2, PODXL, or SSEA4), or hematopoietic (CD34, CD45, CD14, CD133, HLA-DR) stem cell markers, while were positive for the characteristic cell surface markers of MSCs (CD44, CD73, CD90, CD105). MSCl cells could be differentiated toward osteogenic, chondrogenic or adipogenic directions and exhibited significant inhibition of mitogen-activated lymphocyte proliferation, and thus presented immunosuppressive features. We suggest that cultured MSCl cells can properly model human MSCs and be applied as efficient feeders in hESC cultures.

  10. The growth and survival of plants in urban green roofs in a dry climate.

    Science.gov (United States)

    Razzaghmanesh, M; Beecham, S; Kazemi, F

    2014-04-01

    Green roofs as one of the components of water-sensitive urban design have become widely used in recent years. This paper describes performance monitoring of four prototype-scale experimental green roofs in a northern suburb of Adelaide, South Australia, undertaken over a 1-year period. Four species of indigenous Australian ground cover and grass species comprising Carpobrotus rossii, Lomandra longifolia 'Tanika,' Dianella caerula 'Breeze' and Myoporum parvifolium were planted in extensive and intensive green roof configurations using two different growing media. The first medium consisted of crushed brick, scoria, coir fibre and composted organics while the second comprised scoria, composted pine bark and hydro-cell flakes. Plant growth indices including vertical and horizontal growth rate, leaf succulence, shoot and root biomasses, water use efficiency and irrigation regimes were studied during a 12-month period. The results showed that the succulent species, C. rossii, can best tolerate the hot, dry summer conditions of South Australia, and this species showed a 100% survival rate and had the maximum horizontal growth rate, leaf succulence, shoot biomass and water use efficiency. All of the plants in the intensive green roofs with the crushed brick mix media survived during the term of this study. It was shown that stormwater can be used as a source of irrigation water for green roofs during 8 months of the year in Adelaide. However, supplementary irrigation is required for some of the plants over a full annual cycle.

  11. The growth and survival of plants in urban green roofs in a dry climate.

    Science.gov (United States)

    Razzaghmanesh, M; Beecham, S; Kazemi, F

    2014-04-01

    Green roofs as one of the components of water-sensitive urban design have become widely used in recent years. This paper describes performance monitoring of four prototype-scale experimental green roofs in a northern suburb of Adelaide, South Australia, undertaken over a 1-year period. Four species of indigenous Australian ground cover and grass species comprising Carpobrotus rossii, Lomandra longifolia 'Tanika,' Dianella caerula 'Breeze' and Myoporum parvifolium were planted in extensive and intensive green roof configurations using two different growing media. The first medium consisted of crushed brick, scoria, coir fibre and composted organics while the second comprised scoria, composted pine bark and hydro-cell flakes. Plant growth indices including vertical and horizontal growth rate, leaf succulence, shoot and root biomasses, water use efficiency and irrigation regimes were studied during a 12-month period. The results showed that the succulent species, C. rossii, can best tolerate the hot, dry summer conditions of South Australia, and this species showed a 100% survival rate and had the maximum horizontal growth rate, leaf succulence, shoot biomass and water use efficiency. All of the plants in the intensive green roofs with the crushed brick mix media survived during the term of this study. It was shown that stormwater can be used as a source of irrigation water for green roofs during 8 months of the year in Adelaide. However, supplementary irrigation is required for some of the plants over a full annual cycle. PMID:24468503

  12. Noise and seasonal effects on the dynamics of plant-herbivore models with monotonic plant growth functions

    CERN Document Server

    Kang, Yun

    2011-01-01

    We formulate general plant-herbivore interaction models with monotone plant growth functions (rates). We study the impact of monotone plant growth functions in general plant-herbivore models on their dynamics. Our study shows that all monotone plant growth models generate a unique interior equilibrium and they are uniform persistent under certain range of {parameters} values. However, if the attacking rate of herbivore is too small or the quantity of plant is not enough, then herbivore goes extinct. Moreover, these models lead to noise sensitive bursting which can be identified as a dynamical mechanism for almost periodic outbreaks of the herbivore infestation. Monotone and non-monotone plant growth models are contrasted with respect to bistability and crises of chaotic attractors.

  13. Bacterial strains from floodplain soils perform different plant-growth promoting processes and enhance cowpea growth

    Directory of Open Access Journals (Sweden)

    Elaine Martins da Costa

    2016-08-01

    Full Text Available ABSTRACT Certain nodulating nitrogen-fixing bacteria in legumes and other nodule endophytes perform different plant-growth promoting processes. The objective of this study was to evaluate 26 bacterial strains isolated from cowpea nodules grown in floodplain soils in the Brazilian savannas, regarding performance of plant-growth promoting processes and ability to enhance cowpea growth. We also identified these strains by 16S rRNA sequencing. The following processes were evaluated: free-living biological nitrogen fixation (BNF, solubilization of calcium, aluminum and iron phosphates and production of indole-3-acetic acid (IAA. The abilities to nodulate and promote cowpea growth were evaluated in Leonard jars. Partial sequencing of the 16S rRNA gene identified 60 % of the strains as belonging to genus Paenibacillus. The following four genera were also identified: Bacillus, Bradyrhizobium, Enterobacter and Pseudomonas. None of the strains fixed N2 free-living. Among the strains, 80 % solubilized Ca phosphate and one solubilized Al phosphate and none solubilized Fe phosphate. The highest IAA concentrations (52.37, 51.52 and 51.00 μg mL−1 were obtained in the 79 medium with tryptophan by Enterobacter strains UFPI B5-7A, UFPI B5-4 and UFPI B5-6, respectively. Only eight strains nodulated cowpea, however, all increased production of total dry matter. The fact that the strains evaluated perform different biological processes to promote plant growth indicates that these strains have potential use in agricultural crops to increase production and environmental sustainability.

  14. Direct FuelCell/Turbine Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Hossein Ghezel-Ayagh

    2008-09-30

    This report summarizes the progress made in development of Direct FuelCell/Turbine (DFC/T{reg_sign}) power plants for generation of clean power at very high efficiencies. The DFC/T system employs an indirectly heated Turbine Generator to supplement fuel cell generated power. The concept extends the high efficiency of the fuel cell by utilizing the fuel cell's byproduct heat in a Brayton cycle. Features of the DFC/T system include: electrical efficiencies of up to 75% on natural gas, minimal emissions, reduced carbon dioxide release to the environment, simplicity in design, direct reforming internal to the fuel cell, and potential cost competitiveness with existing combined cycle power plants. Proof-of-concept tests using a sub-MW-class DFC/T power plant at FuelCell Energy's (FCE) Danbury facility were conducted to validate the feasibility of the concept and to measure its potential for electric power production. A 400 kW-class power plant test facility was designed and retrofitted to conduct the tests. The initial series of tests involved integration of a full-size (250 kW) Direct FuelCell stack with a 30 kW Capstone microturbine. The operational aspects of the hybrid system in relation to the integration of the microturbine with the fuel cell, process flow and thermal balances, and control strategies for power cycling of the system, were investigated. A subsequent series of tests included operation of the sub-MW Direct FuelCell/Turbine power plant with a Capstone C60 microturbine. The C60 microturbine extended the range of operation of the hybrid power plant to higher current densities (higher power) than achieved in initial tests using the 30kW microturbine. The proof-of-concept test results confirmed the stability and controllability of operating a fullsize (250 kW) fuel cell stack in combination with a microturbine. Thermal management of the system was confirmed and power plant operation, using the microturbine as the only source of fresh air supply

  15. Use of Plant Growth Regulators to Increase Branching of Clematis Spp.

    OpenAIRE

    Puglisi, Sadie Erica

    2002-01-01

    Clematis spp. L. is a twining vine covered in showy blooms. Typical growth of hybrids is from the main leader, producing a thin, unbranched plant with one cyme. Apical dominance is released by cutting back the vine during production. Cutting back, or pinching, of a plant is labor intensive and compromises bloom for vegetative growth at time of sales. The purpose of this project was to eliminate manual pinching by treating young plants with chemical plant growth regulators (PGRs) that enha...

  16. Programmed cell cycle arrest is required for infection of corn plants by the fungus Ustilago maydis.

    Science.gov (United States)

    Castanheira, Sónia; Mielnichuk, Natalia; Pérez-Martín, José

    2014-12-01

    Ustilago maydis is a plant pathogen that requires a specific structure called infective filament to penetrate the plant tissue. Although able to grow, this filament is cell cycle arrested on the plant surface. This cell cycle arrest is released once the filament penetrates the plant tissue. The reasons and mechanisms for this cell cycle arrest are unknown. Here, we have tried to address these questions. We reached three conclusions from our studies. First, the observed cell cycle arrest is the result of the cooperation of at least two distinct mechanisms: one involving the activation of the DNA damage response (DDR) cascade; and the other relying on the transcriptional downregulation of Hsl1, a kinase that modulates the G2/M transition. Second, a sustained cell cycle arrest during the infective filament step is necessary for the virulence in U. maydis, as a strain unable to arrest the cell cycle was severely impaired in its ability to infect corn plants. Third, production of the appressorium, a structure required for plant penetration, is incompatible with an active cell cycle. The inability to infect plants by strains defective in cell cycle arrest seems to be caused by their failure to induce the appressorium formation process. In summary, our findings uncover genetic circuits to arrest the cell cycle during the growth of this fungus on the plant surface, thus allowing the penetration into plant tissue.

  17. Natural genetic variation in Arabidopsis for responsiveness to plant growth-promoting rhizobacteria

    OpenAIRE

    Wintermans, P.C.A.; Bakker, P.A.H.M.; Pieterse, C.M.J.

    2016-01-01

    The plant growth-promoting rhizobacterium (PGPR) Pseudomonas simiae WCS417r stimulates lateral root formation and increases shoot growth in Arabidopsis thaliana (Arabidopsis). These plant growth-stimulating effects are partly caused by volatile organic compounds (VOCs) produced by the bacterium. Here, we performed a genome-wide association (GWA) study on natural genetic variation in Arabidopsis for the ability to profit from rhizobacteria-mediated plant growth-promotion. To this end, 302 Arab...

  18. Plant growth analysis and seed vigor expression: effects of soil waterlogging during rye plant development

    OpenAIRE

    Tiago Pedó; Emanuela Garbin Martinazzo; Tiago Zanatta Aumonde; Francisco Amaral Villela

    2015-01-01

    This study aimed to evaluate the growth, assimilate partitioning and seed vigor expression of rye seeds subjected to waterlogging during development. The experimental design was completely randomized with six replications and three treatments. The treatments involved different waterlogging periods: a) no waterlogging; b) single waterlogging of three days; and c) two soil waterlogging periods of three days. The plants were collected at regular intervals of 14 days after emergence until the end...

  19. Biochar treatment resulted in a combined effect on soybean growth promotion and a shift in plant growth promoting rhizobacteria

    OpenAIRE

    Dilfuza eEgamberdieva; Stephan eWirth; Undine eBehrendt; Elsayed eAbd_Allah; Gabriele eBerg

    2016-01-01

    The application of biochar to soil is considered to have the potential for long-term soil carbon sequestration, as well as for improving plant growth and suppressing soil pathogens. In our study we evaluated the effect of biochar on the plant growth of soybeans, as well as on the composition of root-associated bacteria with plant growth promoting traits. Two types of biochar, namely, maize biochar (MBC), wood biochar (WBC), and hydrochar (HTC) were used for pot experiments to monitor plant gr...

  20. Characterization of Cellulose Synthesis in Plant Cells

    Directory of Open Access Journals (Sweden)

    Samaneh Sadat Maleki

    2016-01-01

    Full Text Available Cellulose is the most significant structural component of plant cell wall. Cellulose, polysaccharide containing repeated unbranched β (1-4 D-glucose units, is synthesized at the plasma membrane by the cellulose synthase complex (CSC from bacteria to plants. The CSC is involved in biosynthesis of cellulose microfibrils containing 18 cellulose synthase (CesA proteins. Macrofibrils can be formed with side by side arrangement of microfibrils. In addition, beside CesA, various proteins like the KORRIGAN, sucrose synthase, cytoskeletal components, and COBRA-like proteins have been involved in cellulose biosynthesis. Understanding the mechanisms of cellulose biosynthesis is of great importance not only for improving wood production in economically important forest trees to mankind but also for plant development. This review article covers the current knowledge about the cellulose biosynthesis-related gene family.

  1. Characterization of Cellulose Synthesis in Plant Cells.

    Science.gov (United States)

    Maleki, Samaneh Sadat; Mohammadi, Kourosh; Ji, Kong-Shu

    2016-01-01

    Cellulose is the most significant structural component of plant cell wall. Cellulose, polysaccharide containing repeated unbranched β (1-4) D-glucose units, is synthesized at the plasma membrane by the cellulose synthase complex (CSC) from bacteria to plants. The CSC is involved in biosynthesis of cellulose microfibrils containing 18 cellulose synthase (CesA) proteins. Macrofibrils can be formed with side by side arrangement of microfibrils. In addition, beside CesA, various proteins like the KORRIGAN, sucrose synthase, cytoskeletal components, and COBRA-like proteins have been involved in cellulose biosynthesis. Understanding the mechanisms of cellulose biosynthesis is of great importance not only for improving wood production in economically important forest trees to mankind but also for plant development. This review article covers the current knowledge about the cellulose biosynthesis-related gene family. PMID:27314060

  2. Physiological, structural and molecular traits activated in strawberry plants after inoculation with the plant growth-promoting bacterium Azospirillum brasilense REC3.

    Science.gov (United States)

    Guerrero-Molina, M F; Lovaisa, N C; Salazar, S M; Martínez-Zamora, M G; Díaz-Ricci, J C; Pedraza, R O

    2015-05-01

    The plant growth-promoting strain REC3 of Azospirillum brasilense, isolated from strawberry roots, prompts growth promotion and systemic protection against anthracnose disease in this crop. Hence, we hypothesised that A. brasilense REC3 can induce different physiological, structural and molecular responses in strawberry plants. Therefore, the aim of this work was to study these traits activated in Azospirillum-colonised strawberry plants, which have not been assessed until now. Healthy, in vitro micropropagated plants were root-inoculated with REC3 under hydroponic conditions; root and leaf tissues were sampled at different times, and oxidative burst, phenolic compound content, malondialdehyde (MDA) concentration, callose deposition, cell wall fortification and gene expression were evaluated. Azospirillum inoculation enhanced levels of soluble phenolic compounds after 12 h post-inoculation (hpi), while amounts of cell wall bound phenolics were similar in inoculated and control plants. Other early responses activated by REC3 (at 24 hpi) were a decline of lipid peroxidation and up-regulation of strawberry genes involved in defence (FaPR1), bacterial recognition (FaFLS2) and H₂O₂ depuration (FaCAT and FaAPXc). The last may explain the apparent absence of oxidative burst in leaves after bacterial inoculation. Also, REC3 inoculation induced delayed structural responses such as callose deposition and cell wall fortification (at 72 hpi). Results showed that A. brasilense REC3 is capable of exerting beneficial effects on strawberry plants, reinforcing their physiological and cellular characteristics, which in turns contribute to improve plant performance.

  3. Mechanisms of pancreatic beta-cell growth and regeneration

    DEFF Research Database (Denmark)

    Nielsen, Jens Høiriis

    1989-01-01

    Information about the mechanism of beta-cell growth and regeneration may be obtained by studies of insulinoma cells. In the present study the growth and function of the rat insulinoma cell lines RINm5F and 5AH were evaluated by addition of serum, hormones, and growth factors. It was found...... that transferrin is the only obligatory factor whereas growth hormone, epidermal growth factor, fibroblast growth factor, and TRH had modulating effects. A heat-labile heparin binding serum factor which stimulated thymidine incorporation but not cell proliferation was demonstrated in human serum. Measurements...... of insulin mRNA content showed that the insulinoma cells only contained about 2% of that of normal rat beta-cells. These results are discussed in relation to the role of growth factors, oncogenes, and differentiation in the growth and regeneration of beta-cells....

  4. Plant polar growth in tobacco disturbed by y-tubulin gene silencing

    Institute of Scientific and Technical Information of China (English)

    Shuang Zhao; Kun Yang; Qian Ma; Qi Wang; Xiaodan Wang; Yanhong Li

    2009-01-01

    To further understand the functions of y-tubulin in plant cells, we conducted a study in which the y-tubulin gene was down-regulated in tobacco plants (obtained by the Agrobacterium-mediated method). This involved transforming the target fragments, in which the sense and antisense partial y-tubulin cDNA fragments were ligated together, into Nicotiana tabacum var. Samsun NN. The y-tubulin down-regulated transformants developed multiple meristems or branches with trumpet-shaped leaves; their root generation also appeared abnormal, with the taproots undeveloped, whereas lateral roots were developed. In addition, the content of indole-3-acetic acid (IAA) and expression of polarity transportation vector PGPI were aberrant. These results suggest that y-tubulin gene silencing disturbed the polar growth of tobacco plants, and that this phenomenon was probably correlated with the IAA content and the polar transpor-tation process.

  5. Seed biopriming with plant growth promoting rhizobacteria: a review.

    Science.gov (United States)

    Mahmood, Ahmad; Turgay, Oğuz Can; Farooq, Muhammad; Hayat, Rifat

    2016-08-01

    Beneficial microbes are applied to the soil and plant tissues directly or through seed inoculation, whereas soil application is preferred when there is risk of inhibitors or antagonistic microbes on the plant tissues. Insufficient survival of the microorganisms, hindrance in application of fungicides to the seeds and exposure to heat and sunlight in subsequent seed storage in conventional inoculation methods force to explore appropriate and efficient bacterial application method. Seed priming, where seeds are hydrated to activate metabolism without actual germination followed by drying, increases the germination, stand establishment and stress tolerance in different crops. Seed priming with living bacterial inoculum is termed as biopriming that involves the application of plant growth promoting rhizobacteria. It increases speed and uniformity of germination; also ensures rapid, uniform and high establishment of crops; and hence improves harvest quality and yield. Seed biopriming allows the bacteria to enter/adhere the seeds and also acclimatization of bacteria in the prevalent conditions. This review focuses on methods used for biopriming, and also the role in improving crop productivity and stress tolerance along with prospects of this technology. The comparison of methods being followed is also reviewed proposing biopriming as a promising technique for application of beneficial microbes to the seeds. PMID:27222220

  6. Plant cell technologies in space: Background, strategies and prospects

    Science.gov (United States)

    Kirkorian, A. D.; Scheld, H. W.

    1987-01-01

    An attempt is made to summarize work in plant cell technologies in space. The evolution of concepts and the general principles of plant tissue culture are discussed. The potential for production of high value secondary products by plant cells and differentiated tissue in automated, precisely controlled bioreactors is discussed. The general course of the development of the literature on plant tissue culture is highlighted.

  7. How do plant cell walls extend?

    Science.gov (United States)

    Cosgrove, D. J.

    1993-01-01

    This article briefly summarizes recent work that identifies the biophysical and biochemical processes that give rise to the extension of plant cell walls. I begin with the biophysical notion of stress relaxation of the wall and follow with recent studies of wall enzymes thought to catalyze wall extension and relaxation. Readers should refer to detailed reviews for more comprehensive discussion of earlier literature (Taiz, 1984; Carpita and Gibeaut, 1993; Cosgrove, 1993).

  8. Effect of plant growth-promoting bacteria on the growth and fructan production of Agave americana L.

    OpenAIRE

    De La Torre-Ruiz, Neyser; Ruiz-Valdiviezo, Víctor Manuel; Rincón-Molina, Clara Ivette; Rodríguez-Mendiola, Martha; Arias-Castro, Carlos; Gutiérrez-Miceli, Federico Antonio; Palomeque-Dominguez, Héctor; Rincón-Rosales, Reiner

    2016-01-01

    The effect of plant growth-promoting bacteria inoculation on plant growth and the sugar content in Agave americana was assessed. The bacterial strains ACO-34A, ACO-40, and ACO-140, isolated from the A. americana rhizosphere, were selected for this study to evaluate their phenotypic and genotypic characteristics. The three bacterial strains were evaluated via plant inoculation assays, and Azospirillum brasilense Cd served as a control strain. Phylogenetic analysis based on the 16S rRNA gene sh...

  9. Effect of vanadium on plant growth and its accumulation in plant tissues

    Directory of Open Access Journals (Sweden)

    Narumol Vachirapatama

    2011-06-01

    Full Text Available Hydroponic experiments were conducted to investigate vanadium uptake by Chinese green mustard and tomato plantsand its effect on their growth. Twenty-eight (Chinese green mustard and 79 days (tomato after germination, the plants wereexposed for a further seven days to a solution containing six different concentrations of ammonium metavanadate (0-80 mg/lNH4VO3. The vanadium accumulated in the plant tissues were determined by ion-interaction high performance liquid chromatography,with confirmation by magnetic sector ICP-MS.The results indicated that nutrient solution containing more than 40 mg/l NH4VO3 affected plant growth for bothChinese green mustard and tomato plant. Chinese green mustard grown in the solution containing NH4VO3 at the concentrationsof 40 and 80 mg/l had stem length, number of leaves, dry weight of leaf, stem and root significantly lower than those ofplants grown in the solution containing 0-20 mg/l NH4VO3. Tomato plants were observed to wilt after four days in contactwith the nutrient solutions containing 40 and 80 mg/l NH4VO3. As the vanadium concentrations increased, a resultantdecrease in the stem length, root fresh weight, and fruit fresh weight were noted. The accumulation of vanadium was higher inthe root compared with leaf, stem, or fruit. Measured levels of vanadium, from a nutrient solution containing 40 mg/l NH4VO3,were 328, 340, and 9.66x103 g/g in the leaf, stem and root for Chinese green mustard, and 4.04 and 4.01x103 g/g in the fruitand roots for tomato plants, respectively.

  10. Regulatory and functional interactions of plant growth regulators and plant glutathione S-transferases (GSTs).

    Science.gov (United States)

    Moons, Ann

    2005-01-01

    Plant glutathioneS-transferases (GSTs) are a heterogeneous superfamily of multifunctional proteins, grouped into six classes. The tau (GSTU) and phi (GSTF) class GSTs are the most represented ones and are plant-specific, whereas the smaller theta (GSTT) and zeta (GSTZ) classes are also found in animals. The lambda GSTs (GSTL) and the dehydroascorbate reductases (DHARs) are more distantly related. Plant GSTs perform a variety of pivotal catalytic and non-enzymatic functions in normal plant development and plant stress responses, roles that are only emerging. Catalytic functions include glutathione (GSH)-conjugation in the metabolic detoxification of herbicides and natural products. GSTs can also catalyze GSH-dependent peroxidase reactions that scavenge toxic organic hydroperoxides and protect from oxidative damage. GSTs can furthermore catalyze GSH-dependent isomerizations in endogenous metabolism, exhibit GSH-dependent thioltransferase safeguarding protein function from oxidative damage and DHAR activity functioning in redox homeostasis. Plant GSTs can also function as ligandins or binding proteins for phytohormones (i.e., auxins and cytokinins) or anthocyanins, thereby facilitating their distribution and transport. Finally, GSTs are also indirectly involved in the regulation of apoptosis and possibly also in stress signaling. Plant GST genes exhibit a diversity of expression patterns during biotic and abiotic stresses. Stress-induced plant growth regulators (i.e., jasmonic acid [JA], salicylic acid [SA], ethylene [ETH], and nitric oxide [NO] differentially activate GST gene expression. It is becoming increasingly evident that unique combinations of multiple, often interactive signaling pathways from various phytohormones and reactive oxygen species or antioxidants render the distinct transcriptional activation patterns of individual GSTs during stress. Underestimated post-transcriptional regulations of individual GSTs are becoming increasingly evident and roles

  11. Silver nanoparticle toxicity effect on growth and cellular viability of the aquatic plant Lemna gibba.

    Science.gov (United States)

    Oukarroum, Abdallah; Barhoumi, Lotfi; Pirastru, Laura; Dewez, David

    2013-04-01

    The toxicity effect of silver nanoparticles (AgNPs) on growth and cellular viability was investigated on the aquatic plant Lemna gibba exposed over 7 d to 0, 0.01, 0.1, 1, and 10 mg/L of AgNPs. Growth inhibition was demonstrated by a significant decrease of frond numbers dependent on AgNP concentration. Under these conditions, reduction in plant cellular viability was detected for 0.1, 1, and 10 mg/L of AgNPs within 7 d of AgNPs treatment. This effect was highly correlated with the production of intracellular reactive oxygen species (ROS). A significant increase of intracellular ROS formation was triggered by 1 and 10 mg/L of AgNP exposure. The induced oxidative stress was related to Ag accumulation within L. gibba plant cells and with the increasing concentration of AgNP exposure in the medium. The authors' results clearly suggested that AgNP suspension represented a potential source of toxicity for L. gibba plant cells. Due to the low release capacity of free soluble Ag from AgNP dissolution in the medium, it is most likely that the intracellular uptake of Ag was directly from AgNPs, triggering cellular oxidative stress that may be due to the release of free Ag inside plant cells. Therefore, the present study demonstrated that AgNP accumulation in an aquatic environment may represent a potential source of toxicity and a risk for the viability of duckweeds. PMID:23341248

  12. Bio-based composites that mimic the plant cell wall

    OpenAIRE

    Li, Zhuo

    2009-01-01

    Nature creates high performance materials under modest conditions, i.e., neutral pH and ambient temperature and pressure. One of the most significant materials is the plant cell wall. The plant cell wall is a composite of oriented cellulose microfibrils reinforcing a lignin/hemicellulose matrix. In principle, the plant cell wall composite is designed much like a synthetic fiber-reinforced polymer composite. Unlike synthetic composites, the plant cell wall has an excellent combination of h...

  13. Eduard Strasburger (1844-1912): founder of modern plant cell biology.

    Science.gov (United States)

    Volkmann, Dieter; Baluška, František; Menzel, Diedrik

    2012-10-01

    Eduard Strasburger, director of the Botany Institute and the Botanical Garden at the University of Bonn from 1881 to 1912, was one of the most admirable scientists in the field of plant biology, not just as the founder of modern plant cell biology but in addition as an excellent teacher who strongly believed in "education through science." He contributed to plant cell biology by discovering the discrete stages of karyokinesis and cytokinesis in algae and higher plants, describing cytoplasmic streaming in different systems, and reporting on the growth of the pollen tube into the embryo sac and guidance of the tube by synergides. Strasburger raised many problems which are hot spots in recent plant cell biology, e.g., structure and function of the plasmodesmata in relation to phloem loading (Strasburger cells) and signaling, mechanisms of cell plate formation, vesicle trafficking as a basis for most important developmental processes, and signaling related to fertilization.

  14. Biochar treatment resulted in a combined effect on soybean growth promotion and a shift in plant growth promoting rhizobacteria

    Directory of Open Access Journals (Sweden)

    Dilfuza eEgamberdieva

    2016-02-01

    Full Text Available The application of biochar to soil is considered to have the potential for long-term soil carbon sequestration, as well as for improving plant growth and suppressing soil pathogens. In our study we evaluated the effect of biochar on the plant growth of soybeans, as well as on the composition of root-associated bacteria with plant growth promoting traits. Two types of biochar, namely, maize biochar (MBC, wood biochar (WBC, and hydrochar (HTC were used for pot experiments to monitor plant growth. Soybean plants grown in soil amended with HTC char (2% showed the best performance and were collected for isolation and further characterization of root-associated bacteria for multiple plant growth promoting traits.Only HTC char amendment resulted in a statistically significant increase in the root and shoot dry weight of soybeans. Interestingly, rhizosphere isolates from HTC char amended soil showed higher diversity than the rhizosphere isolates from the control soil. In addition, a higher proportion of isolates from HTC char amended soil compared with control soil was found to express plant growth promoting properties and showed antagonistic activity against one or more phytopathogenic fungi. Our study provided evidence that improved plant growth by biochar incorporation into soil results from the combination of a direct effect that is dependent on the type of char and a microbiome shift in root-associated beneficial bacteria.

  15. Two endogenous proteins that induce cell wall extension in plants

    Science.gov (United States)

    McQueen-Mason, S.; Durachko, D. M.; Cosgrove, D. J.

    1992-01-01

    Plant cell enlargement is regulated by wall relaxation and yielding, which is thought to be catalyzed by elusive "wall-loosening" enzymes. By employing a reconstitution approach, we found that a crude protein extract from the cell walls of growing cucumber seedlings possessed the ability to induce the extension of isolated cell walls. This activity was restricted to the growing region of the stem and could induce the extension of isolated cell walls from various dicot stems and the leaves of amaryllidaceous monocots, but was less effective on grass coleoptile walls. Endogenous and reconstituted wall extension activities showed similar sensitivities to pH, metal ions, thiol reducing agents, proteases, and boiling in methanol or water. Sequential HPLC fractionation of the active wall extract revealed two proteins with molecular masses of 29 and 30 kD associated with the activity. Each protein, by itself, could induce wall extension without detectable hydrolytic breakdown of the wall. These proteins appear to mediate "acid growth" responses of isolated walls and may catalyze plant cell wall extension by a novel biochemical mechanism.

  16. [Stem cells and growth factors in wound healing].

    Science.gov (United States)

    Pikuła, Michał; Langa, Paulina; Kosikowska, Paulina; Trzonkowski, Piotr

    2015-01-01

    Wound healing is a complex process which depends on the presence of various types of cells, growth factors, cytokines and the elements of extracellular matrix. A wound is a portal of entry for numerous pathogens, therefore during the evolution wound healing process has formed very early, being critical for the survival of every individual. Stem cells, which give rise to their early descendants progenitor cells and subsequently differentiated cells, play a specific role in the process of wound healing. Among the most important cells which take part in wound healing the following cells need to be distinguished: epidermal stem cells, dermal precursor of fibroblasts, adipose-derived stem cells as well as bone marrow cells. The activity of these cells is strictly regulated by various growth factors, inter alia epidermal growth factor (EGF), fibroblast growth factor (FGF), platelet-derived growth factor (PDGF), transforming growth factor (TGF), vascular endothelial growth factor (VEGF). Any disorders in functioning of stem cells and biological activity of growth factors may lead to the defects in wound healing, for instance delayed wound healing or creation of hypertrophic scars. Therefore, knowledge concerning the mechanisms of wound healing is extremely essential from clinical point of view. In this review the current state of the knowledge of the role of stem cells and growth factors in the process of wound healing has been presented. Moreover, some clinical aspects of wound healing as well as the possibility of the therapy based on stem cells and growth factors have included.

  17. Constitutive expression of CaPLA1 conferred enhanced growth and grain yield in transgenic rice plants.

    Science.gov (United States)

    Park, Ki Youl; Kim, Eun Yu; Seo, Young Sam; Kim, Woo Taek

    2016-03-01

    Phospholipids are not only important components of cell membranes, but participate in diverse processes in higher plants. In this study, we generated Capsicum annuum phospholipiase A1 (CaPLA1) overexpressing transgenic rice (Oryza sativa L.) plants under the control of the maize ubiquitin promoter. The T4 CaPLA1-overexpressing rice plants (Ubi:CaPLA1) had a higher root:shoot mass ratio than the wild-type plants in the vegetative stage. Leaf epidermal cells from transgenic plants had more cells than wild-type plants. Genes that code for cyclin and lipid metabolic enzymes were up-regulated in the transgenic lines. When grown under typical paddy field conditions, the transgenic plants produced more tillers, longer panicles and more branches per panicle than the wild-type plants, all of which resulted in greater grain yield. Microarray analysis suggests that gene expressions that are related with cell proliferation, lipid metabolism, and redox state were widely altered in CaPLA1-overexpressing transgenic rice plants. Ubi:CaPLA1 plants had a reduced membrane peroxidation state, as determined by malondialdehyde and conjugated diene levels and higher peroxidase activity than wild-type rice plants. Furthermore, three isoprenoid synthetic genes encoding terpenoid synthase, hydroxysteroid dehydrogenase and 3-hydroxy-3-methyl-glutaryl-CoA reductase were up-regulated in CaPLA1-overexpressing plants. We suggest that constitutive expression of CaPLA1 conferred increased grain yield with enhanced growth in transgenic rice plants by alteration of gene activities related with cell proliferation, lipid metabolism, membrane peroxidation state and isoprenoid biosynthesis. PMID:26803502

  18. Genome Sequence of the Banana Plant Growth-Promoting Rhizobacterium Pseudomonas fluorescens PS006.

    Science.gov (United States)

    Gamez, Rocío M; Rodríguez, Fernando; Ramírez, Sandra; Gómez, Yolanda; Agarwala, Richa; Landsman, David; Mariño-Ramírez, Leonardo

    2016-05-05

    Pseudomonas fluorescens is a well-known plant growth-promoting rhizobacterium (PGPR). We report here the first whole-genome sequence of PGPR P. fluorescens evaluated in Colombian banana plants. The genome sequences contains genes involved in plant growth and defense, including bacteriocins, 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase, and genes that provide resistance to toxic compounds.

  19. Genome Sequence of the Banana Plant Growth-Promoting Rhizobacterium Pseudomonas fluorescens PS006.

    Science.gov (United States)

    Gamez, Rocío M; Rodríguez, Fernando; Ramírez, Sandra; Gómez, Yolanda; Agarwala, Richa; Landsman, David; Mariño-Ramírez, Leonardo

    2016-01-01

    Pseudomonas fluorescens is a well-known plant growth-promoting rhizobacterium (PGPR). We report here the first whole-genome sequence of PGPR P. fluorescens evaluated in Colombian banana plants. The genome sequences contains genes involved in plant growth and defense, including bacteriocins, 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase, and genes that provide resistance to toxic compounds. PMID:27151797

  20. Genome Sequence of the Banana Plant Growth-Promoting Rhizobacterium Pseudomonas fluorescens PS006

    OpenAIRE

    Gamez, Rocío M.; Rodríguez, Fernando; Ramírez, Sandra; Gómez, Yolanda; Agarwala, Richa; Landsman, David; Mariño-Ramírez, Leonardo

    2016-01-01

    Pseudomonas fluorescens is a well-known plant growth-promoting rhizobacterium (PGPR). We report here the first whole-genome sequence of PGPR P. fluorescens evaluated in Colombian banana plants. The genome sequences contains genes involved in plant growth and defense, including bacteriocins, 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase, and genes that provide resistance to toxic compounds.

  1. Trickle water and feeding system in plant culture and light-dark cycle effects on plant growth

    Science.gov (United States)

    Takano, T.; Inada, K.; Takanashi, J.

    1987-01-01

    Rockwool, as an inert medium covered or bagged with polyethylene film, can be effectively used for plant culture in space stations. The most important machine is the pump adjusting the dripping rate in the feeding system. Hydro-aeroponics may be adaptable to a space laboratory. The shortening of the light-dark cycles inhibits plant growth and induces an abnormal morphogenesis. A photoperiod of 12 hr dark may be needed for plant growth.

  2. Phytohormone profiles induced by Trichoderma isolates correspond with their biocontrol and plant growth-promoting activity on melon plants

    NARCIS (Netherlands)

    Martínez-Medina, Ainhoa; Del Mar Alguacil, Maria; Pascual, Jose A.; van Wees, Saskia C M

    2014-01-01

    The application of Trichoderma strains with biocontrol and plant growth-promoting capacities to plant substrates can help reduce the input of chemical pesticides and fertilizers in agriculture. Some Trichoderma isolates can directly affect plant pathogens, but they also are known to influence the ph

  3. Vegetative growth response of cotton plants due to growth regulator supply via seeds

    Directory of Open Access Journals (Sweden)

    João Vitor Ferrari

    2015-08-01

    Full Text Available The global cotton industry is distinguished by its numerous industrial uses of the plume as well as by high production costs. Excessive vegetative growth can interfere negatively with productivity, and thus, applying growth regulators is essential for the development of the cotton culture. The objective of this study was to evaluate the development and yield of the cotton cultivar FMT 701 with the application of mepiquat chloride to seeds and leaves. The experimental design used a randomized block design with four replications, arranged in bands.The treatments consisted of mepiquat chloride rates (MC (0, 4, 6, 8 and 10 g a.i. kg-1 of seeds applied directly to the cotton seeds and MC management by foliar spray using a 250 mL ha-1 rates that was administered under the following conditions: divided into four applications (35, 45, 55 and 65 days after emergence; as a single application at 70 days; and without the application of the product. The mepiquat chloride applied to cotton seeds controls the initial plant height and stem diameter, while foliar application reduces the height of the plants. After application to seed, foliar spraying MC promotes increase mass of 20 bolls, however no direct influence amount bolls per plant and yield of cotton seed. Higher cotton seed yield was obtained with a rate of 3.4 g a.i. MC kg-1 seeds.

  4. Multitrait plant growth promoting (PGP) rhizobacterial isolates from Brassica juncea rhizosphere : Keratin degradation and growth promotion.

    Science.gov (United States)

    Anwar, Mohmmad Shahbaz; Siddique, Mohammad Tahir; Verma, Amit; Rao, Yalaga Rama; Nailwal, Tapan; Ansari, Mohammad; Pande, Veena

    2014-01-01

    Plant growth promoting (PGP) rhizobacteria, a beneficial microbe colonizing plant roots, enhanced crop productivity and offers an attractive way to replace chemical fertilizers, pesticides, and supplements. The keratinous waste which comprises feathers, hairs, nails, skin and wool creates problem of solid waste management due to presence of highly recalcitrant keratin. The multi traits rhizobacteria effective to remove both keratine from the environment by producing keratinase enzyme and to eradicate the chemical fertilizer by providing different PGP activity is novel achievement. In the present study, the effective PM2 strain of PGPR was isolated from rhizospheric soil of mustard (Brassica juncea) field, Pantnagar and they were identified on the basis of different biochemical tests as belonging to Bacillus genera. Different plant growth promoting activity, feather degradation and keratinolytic activity was performed and found very effective toward all the parameters. Furthermore, the efficient strain PM2 was identified on the basis of 16s rRNA sequencing and confirmed as Bacillus cereus. The strain PM2 might be used efficiently for keratinous waste management and PGP activity. Therefore, the present study suggests that Bacillus cereus have multi traits activity which extremely useful for different PGP activity and biotechnological process involving keratin hydrolysis, feather biodegradation or in the leather industry. PMID:24778758

  5. Natural genetic variation in Arabidopsis for responsiveness to plant growth-promoting rhizobacteria

    NARCIS (Netherlands)

    Wintermans, P.C.A.; Bakker, P.A.H.M.; Pieterse, C.M.J.

    2016-01-01

    The plant growth-promoting rhizobacterium (PGPR) Pseudomonas simiae WCS417r stimulates lateral root formation and increases shoot growth in Arabidopsis thaliana (Arabidopsis). These plant growth-stimulating effects are partly caused by volatile organic compounds (VOCs) produced by the bacterium. Her

  6. The effect of Translationally Controlled Tumour Protein (TCTP) on programmed cell death in plants

    OpenAIRE

    Hoepflinger, Marion Christine; Reitsamer, Johannes; Geretschlaeger, Anja Maria; Mehlmer, Norbert; Tenhaken, Raimund

    2013-01-01

    Background: Translationally controlled tumour protein (TCTP), a well known protein of the animal kingdom, was shown to be a Ca2+-binding protein with important functions in many different cellular processes (e.g. protection against stress and apoptosis, cell growth, cell cycle progression, and microtubule organization). However, only little is known about TCTP in plants. Transcript and protein levels of plant TCTPs were shown to be altered by various stress conditions (e.g. cold, salt, draugh...

  7. Modes of Action and Functions of ERECTA-family Receptor-like Kinases in Plant Organ Growth and Development

    Energy Technology Data Exchange (ETDEWEB)

    TORII, Keiko U.

    2012-05-01

    Higher plants constitute the central resource for renewable lignocellulose biomass that can supplement for the world's depleting stores of fossil fuels. As such, understanding the molecular and genetic mechanisms of plant organ growth will provide key knowledge and genetic resources that enables manipulation of plant biomass feedstock for better growth and productivity. The goal of this proposal is to understand how cell proliferation and growth are coordinated during aboveground organ morphogenesis, and how cell-cell signaling mediated by a family of receptor kinases coordinates plant organogenesis. The well-established model plant Arabidopsis thaliana is used for our research to facilitate rapid progress. Specifically, we focus on how ERECTA-family leucine-rich repeat receptor kinases (LRR-RLKs) interact in a synergistic manner to promote organogenesis and pattern formation in Arabidopsis. This project was highly successful, resulted in fourteen publications including nine peer-reviewed original research articles. One provisional US patent has been filed through this DOE funding. We have addressed the critical roles for a family of receptor kinases in coordinating proliferation and differentiation of plants, and we successfully elucidated the downstream targets of this signaling pathway in specifying stomatal patterning.

  8. Plant growth promotion, metabolite production and metal tolerance of dark septate endophytes isolated from metal-polluted poplar phytomanagement sites.

    Science.gov (United States)

    Berthelot, Charlotte; Leyval, Corinne; Foulon, Julie; Chalot, Michel; Blaudez, Damien

    2016-10-01

    Numerous studies address the distribution and the diversity of dark septate endophytes (DSEs) in the literature, but little is known about their ecological role and their effect on host plants, especially in metal-polluted soils. Seven DSE strains belonging to Cadophora, Leptodontidium, Phialophora and Phialocephala were isolated from roots of poplar trees from metal-polluted sites. All strains developed on a wide range of carbohydrates, including cell-wall-related compounds. The strains evenly colonized birch, eucalyptus and ryegrass roots in re-synthesis experiments. Root and shoot growth promotion was observed and was both plant and strain dependent. Two Phialophora and Leptodontidium strains particularly improved plant growth. However, there was no correlation between the level of root colonization by DSEs and the intensity of growth promotion. All strains produced auxin and six also stimulated plant growth through the release of volatile organic compounds (VOCs). SPME-GC/MS analyses revealed four major VOCs emitted by Cadophora and Leptodontidium The strains exhibited growth at high concentrations of several metals. The ability of metal-resistant DSE strains to produce both soluble and volatile compounds for plant growth promotion indicates interesting microbial resources with high potential to support sustainable production of bioenergy crops within the context of the phytomanagement of metal-contaminated sites. PMID:27364359

  9. Effect of multiple metal resistant bacteria from contaminated lake sediments on metal accumulation and plant growth

    Energy Technology Data Exchange (ETDEWEB)

    Li, Kefeng [Department of Biological Sciences, Michigan Technological University, 1400 Townsend Drive, Houghton, MI 49931 (United States); Ramakrishna, Wusirika, E-mail: wusirika@mtu.edu [Department of Biological Sciences, Michigan Technological University, 1400 Townsend Drive, Houghton, MI 49931 (United States)

    2011-05-15

    Naturally occurring bacteria play an important role in bioremediation of heavy metal pollutants in soil and wastewater. This study identified high levels of resistance to zinc, cesium, lead, arsenate and mercury in eight copper resistant Pseudomonas strains previously isolated from Torch Lake sediment. These strains showed variable susceptibility to different antibiotics. Furthermore, these metal resistant strains were capable of bioaccumulation of multiple metals and solubilization of copper. Bacterial strains TLC 3-3.5-1 and TLC 6-6.5-1 showed high bioaccumulation ability of Zn (up to 15.9 mg/g dry cell) and Pb (80.7 mg/g dry cell), respectively. All the strains produced plant growth promoting indole-3-acetic acid (IAA), iron chelating siderophore and solubilized mineral phosphate and metals. The effect of bacterial inoculation on plant growth and copper uptake by maize (Zea mays) and sunflower (Helianthus annuus) was investigated using one of the isolates (Pseudomonas sp. TLC 6-6.5-4) with higher IAA production and phosphate and metal soubilization, which resulted in a significant increase in copper accumulation in maize and sunflower, and an increase in the total biomass of maize. The multiple metal-resistant bacterial isolates characterized in our study have potential applications for remediation of metal contaminated soils in combination with plants and metal contaminated water.

  10. A soil irrigation method for experimental plant growth

    Science.gov (United States)

    Pop, M. N.; Soran, M. L.

    2015-12-01

    An irrigation method developed in order to ensure periodic wetting of several batches of soil, for experimental plant growth, is proposed. An experimental irrigation installation, intended to perform real-time soil moisturizing, by adding known quantities (preset for a certain batch of soil) of aqueous solutions has been built and tested. The prototype installation comprises six miniature pumps for water dosage, each meant to moisturize a batch of soil. Each pump is actuated from the mains power supply, with zero-crossing synchronization. The administrated quantity of aqueous solution is a multiple of the minimum volume, 0.2±0.01 ml of fluid. Due to its structure, the system allows the administration of different aqueous solutions for each batch of soil. Due to its modular construction the experimental installation can be expanded in order to ensure water disposal over an increased number of soil batches and the method may be suited also for micro irrigation systems.

  11. Bacterial growth inhibition potential of annatto plant parts

    Institute of Scientific and Technical Information of China (English)

    Akshatha Venugopalan; Parvatam Giridhar

    2012-01-01

    Objective: To study the antibacterial efficacy of Bixa orellana leaves and deseeded fruit capsule extracts against both Gram positive and Gram negative bacteria. Methods: The antibacterial activity of the ethanolic, methanolic, acetone and dimethyl sulphoxide extracts of B. orellana were tested against Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Bacillus subtilis,Bacillus cereus and Staphylococus aureus by disc diffusion method. Results: The antibacterial activity of leaf was more pronounced even at low concentrations and fruit extracts exhibited the same at relatively higher concentrations. Only DMSO extract of seeds showed growth inhibition of S. aureus, B. subtilis, B. cereus, and P. aeruginosa. Conclusions: The present study suggested that the leaves and deseeded capsule extracts of B. orellana possess significant antibacterial activity thereby providing substantial support for the ethanobotanical applications of this plant.

  12. Chromium Resistant Bacteria: Impact on Plant Growth in Soil Microcosm

    Directory of Open Access Journals (Sweden)

    Sayel Hanane

    2014-07-01

    Full Text Available Three chromium resistant bacterial strains, Pseudomonas fluorescens PF28, Enterobacter amnigenus EA31 and Enterococcus gallinarum S34 isolated from tannery waste contaminated soil were used in this study. All strains could resist a high concentration of K2Cr2O7 that is up to 300 mg/L. The effect of these strains on clover plants (Trifolium campestre in the presence of two chromium salts CrCl3 and K2Cr2O7 was studied in soil microcosm. Application of chromium salts adversely affected seed germination, root and shoot length. Bacterial inoculation improved the growth parameters under chromate stress when compared with non inoculated respective controls. There was observed more than 50% reduction of Cr(VI in inoculated soil microcosms, as compared to the uninoculated soil under the same conditions. The results obtained in this study are significant for the bioremediation of chromate pollution.

  13. Characterization of the bioactive metabolites from a plant growth-promoting rhizobacteria and their exploitation as antimicrobial and plant growth-promoting agents.

    Science.gov (United States)

    George, Emrin; Kumar, S Nishanth; Jacob, Jubi; Bommasani, Bhaskara; Lankalapalli, Ravi S; Morang, P; Kumar, B S Dileep

    2015-05-01

    A plant growth-promoting bacterial strain, PM 105, isolated from a tea plantation soil from the North Eastern region of India was identified as Pseudomonas aeruginosa through classical and 16S ribosomal DNA (rDNA) gene sequencing. Further studies with this strain confirmed broad spectrum antifungal activity against ten human and plant pathogenic fungal pathogens viz. Aspergillus flavus, Aspergillus fumigatus, Aspergillus niger, Aspergillus tubingensis, Candida albicans, Colletotrichum gloeosporioides, Fusarium oxysporum, Pencillium expansum, Rhizoctonia solani, Trichophyton rubrum besides growth-promoting property in cowpea (Vigna unguiculata) and pigeon pea (Cajanus cajan). However, no antibacterial property was exhibited by this strain against the four test bacterial pathogens tested in agar overlay method. The crude bioactive metabolites produced by this strain were isolated with three different solvents that exhibited significant antimicrobial and plant growth-promoting activity. Chloroform extract recorded significant antimicrobial and plant growth-promoting activity. Three major compounds viz. 1-hydroxyphenazine, pyocyanin, and phenazine-1-carboxamide were purified and characterized from crude extracts of this strain by various spectral data. The purified compounds recorded prominent antimicrobial activity but failed to establish the plant growth promotion activity in test crop plants under gnotobiotic conditions. Pyocyanin recorded significant antimicrobial activity, and best activity was recorded against T. rubrum (29 mm), followed by P. expansum (28 mm). These results suggest the use of PM 105 as plant growth-promoting agent in crop plants after successful field trials. PMID:25832181

  14. Posteffect of calcium compounds on growth and evolution of irradiated cotton plants

    International Nuclear Information System (INIS)

    The aftereffect of calcium salts on the growth and development of radiated and non-radiated cotton plants was studied. It was found out that as a result of the application of calcium the first seed prosterity of radiated plants had almost none of the symptoms of the radiation injury, the growth, the development of cotton plants and crude cotton yields being restored. As a result of the treatment of seeds in the Ca(NO3)2 solution and the application of CaO to the soil the amount of long-chain fatty acids increased which is necessary for the regeneration of injured membranes in cells of radiated plants. For example, there were 75.2 per cent of fatty acids with long carbon chains in the control, i.e. without calcium; 85.9 per cent after the application of CaO to the soil and the treatment of seeds in the Ca(NO3)2 solution; 70.9 per cent in the variant with irradiation at the dose of 30 kr and 81.19 per cent of fatty acids with long carbon chains after the treatment of irradiated seeds in the Ca(NO3)2 solution and the application of CaO

  15. Pectinous cell wall thickenings formation - A common defense strategy of plants to cope with Pb.

    Science.gov (United States)

    Krzesłowska, Magdalena; Rabęda, Irena; Basińska, Aneta; Lewandowski, Michał; Mellerowicz, Ewa J; Napieralska, Anna; Samardakiewicz, Sławomir; Woźny, Adam

    2016-07-01

    Lead, one of the most abundant and hazardous trace metals affecting living organisms, has been commonly detected in plant cell walls including some tolerant plants, mining ecotypes and hyperaccumulators. We have previously shown that in tip growing Funaria sp. protonemata cell wall is remodeled in response to lead by formation of thickenings rich in low-methylesterified pectins (pectin epitope JIM5 - JIM5-P) able to bind metal ions, which accumulate large amounts of Pb. Hence, it leads to the increase of cell wall capacity for Pb compartmentalization. Here we show that diverse plant species belonging to different phyla (Arabidopsis, hybrid aspen, star duckweed), form similar cell wall thickenings in response to Pb. These thickenings are formed in tip growing cells such as the root hairs, and in diffuse growing cells such as meristematic and root cap columella cells of root apices in hybrid aspen and Arabidopsis and in mesophyll cells in star duckweed fronds. Notably, all analyzed cell wall thickenings were abundant in JIM5-P and accumulated high amounts of Pb. In addition, the co-localization of JIM5-P and Pb commonly occurred in these cells. Hence, cell wall thickenings formed the extra compartment for Pb accumulation. In this way plant cells increased cell wall capacity for compartmentalization of this toxic metal, protecting protoplast from its toxicity. As cell wall thickenings occurred in diverse plant species and cell types differing in the type of growth we may conclude that pectinous cell wall thickenings formation is a widespread defense strategy of plants to cope with Pb. Moreover, detection of natural defense strategy, increasing plant cell walls capacity for metal accumulation, reveals a promising direction for enhancing plant efficiency in phytoremediation. PMID:27107260

  16. Pectinous cell wall thickenings formation - A common defense strategy of plants to cope with Pb.

    Science.gov (United States)

    Krzesłowska, Magdalena; Rabęda, Irena; Basińska, Aneta; Lewandowski, Michał; Mellerowicz, Ewa J; Napieralska, Anna; Samardakiewicz, Sławomir; Woźny, Adam

    2016-07-01

    Lead, one of the most abundant and hazardous trace metals affecting living organisms, has been commonly detected in plant cell walls including some tolerant plants, mining ecotypes and hyperaccumulators. We have previously shown that in tip growing Funaria sp. protonemata cell wall is remodeled in response to lead by formation of thickenings rich in low-methylesterified pectins (pectin epitope JIM5 - JIM5-P) able to bind metal ions, which accumulate large amounts of Pb. Hence, it leads to the increase of cell wall capacity for Pb compartmentalization. Here we show that diverse plant species belonging to different phyla (Arabidopsis, hybrid aspen, star duckweed), form similar cell wall thickenings in response to Pb. These thickenings are formed in tip growing cells such as the root hairs, and in diffuse growing cells such as meristematic and root cap columella cells of root apices in hybrid aspen and Arabidopsis and in mesophyll cells in star duckweed fronds. Notably, all analyzed cell wall thickenings were abundant in JIM5-P and accumulated high amounts of Pb. In addition, the co-localization of JIM5-P and Pb commonly occurred in these cells. Hence, cell wall thickenings formed the extra compartment for Pb accumulation. In this way plant cells increased cell wall capacity for compartmentalization of this toxic metal, protecting protoplast from its toxicity. As cell wall thickenings occurred in diverse plant species and cell types differing in the type of growth we may conclude that pectinous cell wall thickenings formation is a widespread defense strategy of plants to cope with Pb. Moreover, detection of natural defense strategy, increasing plant cell walls capacity for metal accumulation, reveals a promising direction for enhancing plant efficiency in phytoremediation.

  17. Effect of various sucker sizes and planting times on growth and flower yield of chrysanthemum

    International Nuclear Information System (INIS)

    Small and large sized suckers of Chrysanthemum morifolium were planted on four different dates, i.e. 18th February, 18th April, 17th June and 16th August to find out their effect on growth and flower yield. Plants resulting from small sized suckers produced significantly higher number of primary and secondary branches and leaves plant/sup -1/. However, plant height, leaf area, number of suckers produced, biomass (fresh plant weight) and flower yield plant/sup -1/ were not affected by the sucker sizes. As the planting was delayed, plant growth and flower yield was reduced. Early plantings resulted in increased plant height, more number of branches and leaves plant/sup -1/, greater biomass, and higher flower yields but reduced leaf area as compared to late plantings. (author)

  18. The influence of simulated low-gravity environments on growth, development and metabolism of plants.

    Science.gov (United States)

    Dedolph, R R

    1967-01-01

    Low-gravity environments may be simulated through appropriate horizontal clinostat rotation. This simulation is accomplished through a biological nullification of the directional component of gravitational force. Measuring biologically effective gravity force by organ response, it is readily demonstrated that biologically active gravitational force may be treated as a two-dimensional vector. Though the magnitude dimension of this vector remains virtually constant anywhere on earth, the biologically effective direction dimension may be quantitatively altered by clinostat rotation, provided appropriate angular velocities and angles of inclination of clinostat axes are employed. Using oat seedlings, a rotation rate of 2 rpm, and a horizontal axis clinostat, a 'zero g' environment may be simulated. This simulated 'zero g' condition is attested by the inability of plants to perceive unidirectional gravitational force of sufficient magnitude to elicit directional growth. Under such conditions, plants will grow in the direction imparted by the initial orientation of the plants in the system. Geotropic curvature responses to subsequent geostimulation are, however, greater in seedlings grown under these conditions, nullifying the direction dimension of gravitational force, than in seedlings grown with rotation but with normal unidirectional gravity loads. Root growth under simulated 'zero' gravity conditions is likewise enhanced as compared to plants grown with rotation but normal unidirectional gravity. These differences in magnitude of growth and response to subsequent geostimulation are inexplicable on bases of modified auxin economy or production. Respiration rates are, however, materially enhanced by the simulated 'zero g' environments. This enhancement of respiration, as well as growth, quantitatively diminishes as the unidirectional gravity load is increased. These results imply that the primary effect of low-gravity environments is likely that of modifying the

  19. Differential growth stimulation response of potato towards inoculation with taxonomically diverse plant growth promoting rhizobacteria

    Directory of Open Access Journals (Sweden)

    Tahir eNaqqash

    2016-02-01

    Full Text Available Rhizosphere engineering with beneficial plant growth promoting bacteria offers great promise for sustainable crop yield. Potato is an important food commodity that needs large inputs of nitrogen and phosphorus fertilizers. To overcome high fertilizer demand (especially nitrogen, five bacteria, i.e. Azospirillum sp.TN10, Agrobacterium sp.TN14, Pseudomonas sp.TN36, Enterobactersp. TN38 and Rhizobium sp. TN42 were isolated from the potato rhizosphere on nitrogen-free malate medium and identified based on their 16S rRNA gene sequences. Three strains, i.e. TN10, TN38 and TN42, showed nitrogen fixation (92.67-134.54 nmol h-1mg-1protein, while all showed the production of indole acetic acid in the presence and/or absence of L-tryptophan. Azospirillum sp. TN10 produced the highest amount of IAA, as measured by spectrophotometry (312.14 µg mL-1 and HPLC (18.3 µg mL-1. Inoculation with these bacteria under axenic conditions resulted in differential growth responses of potato. Azospirillum sp. TN10 incited the highest increase in potato fresh and dry weight over control plants, along with increased N contents of shoot and roots. All strains were able to colonize and maintain their population densities in the potato rhizosphere for upto 60 days, with Azospirillum sp. and Rhizobium sp. showing the highest survival. Plant root colonization potential was analyzed by transmission electron microscopy of root sections inoculated with Azospirillum sp. TN10. Of the five test strains, Azospirillum sp. TN10 has the greatest potential to increase the growth and nitrogen uptake of potato. Hence, it is suggested as a good candidate for the production of potato biofertilizer for integrated nutrient management with potato.

  20. Phytohormone profiles induced by trichoderma isolates correspond with their biocontrol and plant growth-promoting activity on melon plants.

    Science.gov (United States)

    Martínez-Medina, Ainhoa; Del Mar Alguacil, Maria; Pascual, Jose A; Van Wees, Saskia C M

    2014-07-01

    The application of Trichoderma strains with biocontrol and plant growth-promoting capacities to plant substrates can help reduce the input of chemical pesticides and fertilizers in agriculture. Some Trichoderma isolates can directly affect plant pathogens, but they also are known to influence the phytohormonal network of their host plant, thus leading to an improvement of plant growth and stress tolerance. In this study, we tested whether alterations in the phytohormone signature induced by different Trichoderma isolates correspond with their ability for biocontrol and growth promotion. Four Trichoderma isolates were collected from agricultural soils and were identified as the species Trichoderma harzianum (two isolates), Trichoderma ghanense, and Trichoderma hamatum. Their antagonistic activity against the plant pathogen Fusarium oxysporum f. sp. melonis was tested in vitro, and their plant growth-promoting and biocontrol activity against Fusarium wilt on melon plants was examined in vivo, and compared to that of the commercial strain T. harzianum T-22. Several growth- and defense-related phytohormones were analyzed in the shoots of plants that were root-colonized by the different Trichoderma isolates. An increase in auxin and a decrease in cytokinins and abscisic acid content were induced by the isolates that promoted the plant growth. Principal component analysis (PCA) was used to evaluate the relationship between the plant phenotypic and hormonal variables. PCA pointed to a strong association of auxin induction with plant growth stimulation by Trichoderma. Furthermore, the disease-protectant ability of the Trichoderma strains against F. oxysporum infection seems to be more related to their induced alterations in the content of the hormones abscisic acid, ethylene, and the cytokinin trans-zeatin riboside than to the in vitro antagonism activity against F. oxysporum.

  1. Enhancement of the Initial Growth Rate of Agricultural Plants by Using Static Magnetic Fields.

    Science.gov (United States)

    Kim, Seung C; Mason, Alex; Im, Wooseok

    2016-01-01

    Electronic devices and high-voltage wires induce magnetic fields. A magnetic field of 1,300-2,500 Gauss (0.2 Tesla) was applied to Petri dishes containing seeds of Garden Balsam (Impatiens balsamina), Mizuna (Brassica rapa var. japonica), Komatsuna (Brassica rapa var. perviridis), and Mescluns (Lepidium sativum). We applied magnets under the culture dish. During the 4 days of application, we observed that the stem and root length increased. The group subjected to magnetic field treatment (n = 10) showed a 1.4 times faster rate of growth compared with the control group (n = 11) in a total of 8 days (p <0.0005). This rate is 20% higher than that reported in previous studies. The tubulin complex lines did not have connecting points, but connecting points occur upon the application of magnets. This shows complete difference from the control, which means abnormal arrangements. However, the exact cause remains unclear. These results of growth enhancement of applying magnets suggest that it is possible to enhance the growth rate, increase productivity, or control the speed of germination of plants by applying static magnetic fields. Also, magnetic fields can cause physiological changes in plant cells and can induce growth. Therefore, stimulation with a magnetic field can have possible effects that are similar to those of chemical fertilizers, which means that the use of fertilizers can be avoided. PMID:27500712

  2. Plant extracts used as growth promoters in broilers

    Directory of Open Access Journals (Sweden)

    MSR Barreto

    2008-06-01

    Full Text Available Two experiments were carried out to assess the efficacy of plant extracts as alternatives for antimicrobial growth promoters in broiler diets. The performance experiment included 1,200 male broilers raised from 1 to 42 days of age. The metabolism experiment used 96 male broilers in the grower phase housed in metabolic cages for total excreta collection. At the end of the metabolism experiment, 24 birds were sacrificed to assess organ morphometrics. In both experiments, the following treatments were applied: control diet (CD; CD + 10 ppm avilamycin; CD + 1000 ppm oregano extract; CD + 1000 ppm clove extract; CD + 1000 ppm cinnamon extract; and CD + 1000 ppm red pepper extract. The microencapsulated extracts contained 20% of essential oil. No significant differences (P>0.05 in the studied performance parameters were observed among treatments. The dietary supplementation of the extracts did not influence (P>0.05 nitrogen-corrected apparent metabolizable energy values. In general, organ morphometrics was not affected by the experimental treatments, but birds fed the control diet had higher liver relative weight (P<0.05 as compared to those fed the diet containing red pepper extract, which presented the lowest liver relative weight. These results showed that there was no effect of the tested plant extracts on live performance or in organ morphometrics.

  3. Roles of membrane trafficking in plant cell wall dynamics

    OpenAIRE

    Ebine, Kazuo; Ueda, Takashi

    2015-01-01

    The cell wall is one of the characteristic components of plant cells. The cell wall composition differs among cell types and is modified in response to various environmental conditions. To properly generate and modify the cell wall, many proteins are transported to the plasma membrane or extracellular space through membrane trafficking, which is one of the key protein transport mechanisms in eukaryotic cells. Given the diverse composition and functions of the cell wall in plants, the transpor...

  4. Computational insight into the chemical space of plant growth regulators.

    Science.gov (United States)

    Bushkov, Nikolay A; Veselov, Mark S; Chuprov-Netochin, Roman N; Marusich, Elena I; Majouga, Alexander G; Volynchuk, Polina B; Shumilina, Daria V; Leonov, Sergey V; Ivanenkov, Yan A

    2016-02-01

    An enormous technological progress has resulted in an explosive growth in the amount of biological and chemical data that is typically multivariate and tangled in structure. Therefore, several computational approaches have mainly focused on dimensionality reduction and convenient representation of high-dimensional datasets to elucidate the relationships between the observed activity (or effect) and calculated parameters commonly expressed in terms of molecular descriptors. We have collected the experimental data available in patent and scientific publications as well as specific databases for various agrochemicals. The resulting dataset was then thoroughly analyzed using Kohonen-based self-organizing technique. The overall aim of the presented study is to investigate whether the developed in silico model can be applied to predict the agrochemical activity of small molecule compounds and, at the same time, to offer further insights into the distinctive features of different agrochemical categories. The preliminary external validation with several plant growth regulators demonstrated a relatively high prediction power (67%) of the constructed model. This study is, actually, the first example of a large-scale modeling in the field of agrochemistry.

  5. Induction of Drought Tolerance in Cucumber Plants by a Consortium of Three Plant Growth-Promoting Rhizobacterium Strains

    OpenAIRE

    Chun-Juan Wang; Wei Yang; Chao Wang; Chun Gu; Dong-Dong Niu; Hong-Xia Liu; Yun-Peng Wang; Jian-Hua Guo

    2012-01-01

    Our previous work showed that a consortium of three plant growth-promoting rhizobacterium (PGPR) strains (Bacillus cereus AR156, Bacillus subtilis SM21, and Serratia sp. XY21), termed as BBS for short, was a promising biocontrol agent. The present study investigated its effect on drought tolerance in cucumber plants. After withholding watering for 13 days, BBS-treated cucumber plants had much darker green leaves and substantially lighter wilt symptoms than control plants. Compared to the cont...

  6. PRODUCTION OF PLANT GROWTH PROMOTING SUBSTANCES IN BACTERIAL ISOLATES FROM THE SEAGRASS RHIZOSPHERE

    Science.gov (United States)

    Plants and rhizosphere bacteria have evolved chemical signals that enable their mutual growth. These relationships have been well investigated with agriculturally important plants, but not in seagrasses, which are important to the stability of estuaries. Seagrasses are rooted in ...

  7. Antiphase light and temperature cycles disrupt rhythmic plant growth : the Arabidopsis jetlag

    NARCIS (Netherlands)

    Bours, R.M.E.H.

    2014-01-01

      Light and temperature are important determinants of plant growth and development. Plant elongation is stimulated by positively increasing differences between day and night temperature (+DIF, phased cycles). In contrast, a negative temperature difference (-DIF, antiphased cycles) reduces

  8. Different growth promoting effects of endophytic bacteria on invasive and native clonal plants

    OpenAIRE

    Zhi-Cong eDai; Wei eFu; Ling-Yun eWan; Hong-Hong eCai; Ning eWang; Shanshan eQi; Daolin eDu

    2016-01-01

    The role of the interactions between endophytes and alien plants has been unclear yet in plant invasion. We used a completely germ-free culture system to quantify the plant growth-promoting (PGP) effects of endophytic bacteria Bacillus sp. on aseptic seedlings of W. trilobata and of its native clonal congener W. chinensis. The endophytic bacteria did not affect the growth of W. chinensis, but they significantly promoted the growth of W. trilobata. With the PGP effects of endophytic bacteria,...

  9. Activity screening of plant growth promoting rhizobacteria isolated from alfalfa rhizosphere

    OpenAIRE

    shahla pashapour; Hossein besharati; Mahmoud rezazadeh; Ahmad Alimadadi; Nadergholi Ebrahimi

    2016-01-01

    Introduction: Some rhizobacteria by various mechanisms influence plant growth as they are called plant growth promoting rhizobacteria (PGPR). Scientists identified some PGPR characters involved in promoting plant growth, while all these characters are not able to study. The aim of this study was to evaluate PGP activities of bacterial isolates, (45 isolates belonged to rhizobium and 2 bacterial isolates belonged to Pseudomonas fluorescens), which were isolated from alfalfa (Medicago sativa) r...

  10. Influence Of Plant Growth Promoting Rhizobacteria (pgpr) On Thegrowth Of Maize (zea Mays L.)

    OpenAIRE

    T. Sheela; Usharani

    2013-01-01

    Plant Growth Promoting Rhizobacteria (PGPR) are beneficial bacteria that colonize plant roots and enhance plant growth by wide variety of mechanism these includes direct and indirect mechanisms like phosphate solubilization, phytohormone production, antifungal activity, etc. The bacteria, were successfully isolated and characterized by morphological and biochemical methods as P. polymyxa. Subsequently to investigate the effect of PGPR isolates on the growth of maize (zea mays L.), a pot cultu...

  11. Microflora inside closed modules with plant growth facility

    Science.gov (United States)

    Zyablova, Natalya V.; Berkovich, Yuliy A.; Shanturin, Nikolai; Deshevaya, Elena; Smolyanina, Svetlana O.

    Currently, plant growth facility (PGF) is included in the LSS in many scenarios of Martian expedition. A number of investigators assume growing of crops can accelerate microflora re-production in closed ecological system. To estimate experimentally the change of density of microbiological community in the isolated module, Chinese cabbage Brassica hinensis L., cv. Vesnyanka, has been grown in the closed climatic chambers in volume 0.07 m3, 3 m3 and 250 m3 under continuous illumination in the range of values of temperature and relative humidity of air 23 -270 and 30 -60%, respectively. There were no differences in growth and develop-ment of plants grown during 30 days on the test-beds in the laboratory room (control) and in the closed chamber by 0.07 m3 volume (test). The microbiological analysis of root zone has revealed the presence of exclusively saprophytic species -the typical representatives of the soil microbiota. Then the plants were growing during 45 days in the prototype of the conveyor space PGF "Phytocycle LED" placed inside the chamber of 3 m3 volume. Every 3 days 50 -60 cm3 of liquid imitator of air condensate (IAC) from inhabited module had been injected to the chamber to simulate air pollution. The content of colony-forming units of the micromycetes in the air of the chamber, on the inner surfaces of the climate chamber, internal and external surfaces of the PGF and the leaves did not exceed the permissible values. When the PGF has been installed during 14 days inside the inhabited module with volume of 250 m3, the representatives of saprophytic and conditioned-pathogenic species of micromycetes (Trichethe-cium rozeum, Trichoderma sp., Fuzarrium sp., Mucor sp., Penicillium sp.) have been found out exclusively on the open surfaces of artificial soil and water-saturated porous passage. The obtained data shows that PGF inside closed modules can assure microbiological safety when all wet surfaces are isolated from the gas environment.

  12. Disease resistance or growth: the role of plant hormones in balancing immune responses and fitness costs

    NARCIS (Netherlands)

    Denance, N.; Sanchez Vallet, A.; Goffner, D.; Molina, A.

    2013-01-01

    Plant growth and response to environmental cues are largely governed by phytohormones. The plant hormones ethylene, jasmonic acid, and salicylic acid (SA) play a central role in the regulation of plant immune responses. In addition, other plant hormones, such as auxins, abscisic acid (ABA), cytokini

  13. Cytokinins as key regulators in plant–microbe–insect interactions: connecting plant growth and defence

    NARCIS (Netherlands)

    Giron, D.; Frago, E.; Glevarec, G.; Pieterse, C.M.J.; Dicke, M.

    2013-01-01

    1. Plant hormones play important roles in regulating plant growth and defence by mediating developmental processes and signalling networks involved in plant responses to a wide range of parasitic and mutualistic biotic interactions. 2. Plants are known to rapidly respond to pathogen and herbivore at

  14. Plant and animal stem cells: similar yet different

    NARCIS (Netherlands)

    Heidstra, R.; Sabatini, S.

    2014-01-01

    The astonishingly long lives of plants and their regeneration capacity depend on the activity of plant stem cells. As in animals, stem cells reside in stem cell niches, which produce signals that regulate the balance between self-renewal and the generation of daughter cells that differentiate into n

  15. Utilization of {gamma}-irradiation technique on plant mutation breeding and plant growth regulation in Tokyo Metropolitan Isotope Research Center

    Energy Technology Data Exchange (ETDEWEB)

    Suda, Hirokatsu [Tokyo Metropolitan Isotope Research Center (Japan)

    1997-03-01

    During about 30-years, we have developed {gamma}-irradiation technique and breeding back pruning method for the study of mutation breeding of ornamental plants. As a result, we have made a wide variety of new mutant lines in chrysanthemum, narcissus, begonia rex, begonia iron cross, winter daphne, zelkova, sweet-scented oleander, abelia, kobus, and have obtained 7 plant patents. By the use of {gamma}-irradiation to plant mutation breeding, we often observed that plants irradiated by low dose of {gamma}-rays showed superior or inferior growth than the of non-irradiated plants. Now, we established the irradiation conditions of {gamma}-rays for mutation breeding and growth of regulation in narcissus, tulip, Enkianthus perulatus Schneid., komatsuna, moyashi, african violet. In most cases, irradiation dose rate is suggested to be a more important factor to induce plant growth regulators than irradiation dose. (author)

  16. Ceratopteris richardii (C-fern: A model for investigating adaptive modification of vascular plant cell walls

    Directory of Open Access Journals (Sweden)

    Olivier eLeroux

    2013-09-01

    Full Text Available Plant cell walls are essential for most aspects of plant growth, development, and survival, including cell division, expansive cell growth, cell-cell communication, biomechanical properties, and stress responses. Therefore, characterising cell wall diversity contributes to our overall understanding of plant evolution and development. Recent biochemical analyses, concomitantly with whole genome sequencing of plants located at pivotal points in plant phylogeny, have helped distinguish between homologous characters and those which might be more derived. Most plant lineages now have at least one fully sequenced representative and although genome sequences for fern species are in progress they not yet available this group. Ferns offer key advantages for the study of developmental processes leading to vascularisation and complex organs as well as the specific differences between diploid sporophyte tissues and haploid gametophyte tissues and the interplay between them. Ceratopteris richardii has been well investigated building a body of knowledge which combined with the genomic and biochemical information available for other plants will progress our understanding of wall diversity and its impact on evolution and development.

  17. Peniamidienone and penidilamine, plant growth regulators produced by the fungus Penicillium sp. No. 13.

    Science.gov (United States)

    Kimura, Y; Mizuno, T; Kawano, T; Okada, K; Shimada, A

    2000-04-01

    Peniamidienone and penidilamine were isolated from cultures of the fungus Penicillium sp. No. 13 as new plant growth regulators and their structures were established by NMR spectroscopic studies. Peniamidienone showed weak inhibition of lettuce seedling growth.

  18. Radiation Processed Carrageenan Improves Plant Growth, Physiological Activities, and Alkaloids Production in Catharanthus roseus L.

    OpenAIRE

    Naeem, M.; Mohd Idrees; Tariq Aftab; M. Masidur Alam; Khan, M. Masroor A.; Moin Uddin; Lalit Varshney

    2015-01-01

    Catharanthus roseus (L.) G. Don (Apocynaceae) is a medicinal plant that produces indole alkaloids used in cancer chemotherapy. Commercially important antineoplastic alkaloids, namely, vinblastine and vincristine, are mainly present in the leaves of C. roseus. Gamma-rays irradiated carrageenan (ICR) has been proven as plant growth promoting substance for a number of medicinal and agricultural plants. Considering the importance of ICR as a promoter of plant growth and alkaloids production in C....

  19. Fusarium oxysporum volatiles enhance plant growth via affecting auxin transport and signaling

    OpenAIRE

    Vasileios eBitas; Nathaniel eMcCartney; Ningxiao eLi; Jill eDemers; Jung-Eun eKim; Hye-Seon eKim; Kathleen eBrown; Seogchan eKang

    2015-01-01

    Volatile organic compounds (VOCs) have well-documented roles in plant-plant communication and directing animal behavior. In this study, we examine the less understood roles of VOCs in plant-fungal relationships. Phylogenetically and ecologically diverse strains of Fusarium oxysporum, a fungal species complex that often resides in the rhizosphere of assorted plants, produce volatile compounds that augment shoot and root growth of Arabidopsis thaliana and tobacco. Growth responses of A. thalia...

  20. Fusarium Oxysporum Volatiles Enhance Plant Growth Via Affecting Auxin Transport and Signaling

    OpenAIRE

    Bitas, Vasileios; McCartney, Nathaniel; Li, Ningxiao; Demers, Jill; Kim, Jung-Eun; Kim, Hye-Seon; Brown, Kathleen M.; Kang, Seogchan

    2015-01-01

    Volatile organic compounds (VOCs) have well-documented roles in plant-plant communication and directing animal behavior. In this study, we examine the less understood roles of VOCs in plant-fungal relationships. Phylogenetically and ecologically diverse strains of Fusarium oxysporum, a fungal species complex that often resides in the rhizosphere of assorted plants, produce volatile compounds that augment shoot and root growth of Arabidopsis thaliana and tobacco. Growth responses of A. thalian...

  1. The effects of exogenous plant growth regulators in the phytoextraction of heavy metals.

    Science.gov (United States)

    Tassi, Eliana; Pouget, Joël; Petruzzelli, Gianniantonio; Barbafieri, Meri

    2008-03-01

    The term "assisted phytoextraction" usually refers to the process of applying a chemical additive to contaminated soil in order to increase the metal uptake by crop plants. In this study three commercially available plant growth regulators (PGRs) based on cytokinins (CKs) were used to boost the assisted phytoextraction of Pb and Zn in contaminated soil collected from a former manufactured gas-plant site. The effects of EDTA treatment in soil and PGR treatment in leaves of Helianthus annuus were investigated in terms of dry weight biomass, Pb and Zn accumulation in the upper parts of the plants, Pb and Zn phytoextraction efficiency and transpiration rate. Metal solubility in soil and its subsequent accumulation in shoots were markedly enhanced by EDTA. The combined effects of EDTA and cytokine resulted in an increase in the Pb and Zn phytoextraction efficiency (up to 890% and 330%, respectively, compared to untreated plants) and up to a 50% increase in foliar transpiration. Our results indicate that exogenous PGRs based on CKs can positively assist the phytoextraction increasing the biomass production, the metal accumulation in shoots and the plant transpiration. The observed increase in biomass could be related to its action in stimulation of cell division and shoot initiation. On the other hand, the increase in metal accumulation in upper parts of plant could be related to both the role of PGRs in the enhancement of plant resistance to stress (as toxic metals) and the increase in transpiration rate, i.e. flux of water-soluble soil components and contaminants by the regulation of stomatal opening.

  2. Effect of plant growth regulators on indices of growth analysis for sweet passion fruit seedlings (Passiflora alata Curtis

    Directory of Open Access Journals (Sweden)

    Carmen Sílvia Fernandes Boaro

    2008-09-01

    Full Text Available The objective of this work was to investigate the effects of GA3 + IBA + cinetina on the growth of Passiflora alata Curtis plants through growth analysis. The experiment was carried out by completely randomized block design, with six treatments and four replications. The plant growth regulators, gibberellin (GA3, auxin (IBA and cytokinin (kinetin, were applied to leaves at concentrations of 0 (control, 25, 50, 75, 100, 125mL.L-1. The applications were performed at 48, 55, 52, 69, and 76 days after the emergence of the plants and the growths were evaluated five times at 7-day intervals. The first evaluations were accomplished 55 days after plant emergence. The leaf area ratio (RAF, specific leaf area (AFE, liquid assimilation rate (TCA, and relative growth rate (TCR were analyzed. The following data were also analyzed for P. alata Curtis plants: leaf area, leaf lamina dry mass and total leaves dry mass. The growth analysis, which employed the ANACRES computer program, indicated that the growth regulators increased plant productivity.

  3. Biological management of Sclerotinia sclerotiorum in pea using plant growth promoting microbial consortium.

    Science.gov (United States)

    Jain, Akansha; Singh, Akanksha; Singh, Surendra; Singh, Harikesh Bahadur

    2015-08-01

    The beneficial plant-microbe interactions play crucial roles in protection against large number of plant pathogens causing disease. The present study aims to investigate the growth promoting traits induced by beneficial microbes namely Pseudomonas aeruginosa PJHU15, Trichoderma harzianum TNHU27, and Bacillus subtilis BHHU100 treated singly and in combinations under greenhouse and field conditions to control Sclerotinia sclerotiorum. Plants treated with three microbe consortium enhanced plant growth maximally both in the presence and absence of the pathogen. Increase in plant length, total biomass, number of leaves, nodules and secondary roots, total chlorophyll and carotenoid content, and yield were recorded in plants treated with microbial consortia. Also, a decrease in plant mortality was observed in plants treated with microbial consortia in comparison to untreated control plants challenged with S. sclerotiorum. Furthermore, the decrease in disease of all the treatments can be associated with differential improvement of growth induced in pea. PMID:25727183

  4. Chemotactic response of plant-growth-promoting bacteria towards roots of vesicular-arbuscular mycorrhizal tomato plants.

    Science.gov (United States)

    Gupta Sood, Sushma

    2003-08-01

    The chemotactic responses of the plant-growth-promoting rhizobacteria Azotobacter chroococcum and Pseudomonas fluorescens to roots of vesicular-arbuscular mycorrhizal (Glomus fasciculatum) tomato plants were determined. A significantly (P=0.05) greater number of bacterial cells of wild strains were attracted towards vesicular-arbuscular mycorrhizal tomato roots compared to non-vesicular-arbuscular mycorrhizal tomato roots. Substances exuded by roots served as chemoattractants for these bacteria. P. fluorescens was strongly attracted towards citric and malic acids, which were predominant constituents in root exudates of tomato plants. A. chroococcum showed a stronger response towards sugars than amino acids, but the response was weakest towards organic acids. The effects of temperature, pH, and soil water matric potential on bacterial chemotaxis towards roots were also investigated. In general, significantly (P=0.05) greater chemotactic responses of bacteria were observed at higher water matric potentials (0, -1, and -5 kPa), slightly acidic to neutral pH (6, 6.5 and 7), and at 20-30 degrees C (depending on the bacterium) than in other environmental conditions. It is suggested that chemotaxis of P. fluorescens and A. chroococcum towards roots and their exudates is one of the several steps in the interaction process between bacteria and vesicular-arbuscular mycorrhizal roots. PMID:19719591

  5. Plant growth in Arabidopsis is assisted by compost soil-derived microbial communities.

    Science.gov (United States)

    Carvalhais, Lilia C; Muzzi, Frederico; Tan, Chin-Hong; Hsien-Choo, Jin; Schenk, Peer M

    2013-01-01

    Plants in natural and agricultural environments are continuously exposed to a plethora of diverse microorganisms resulting in microbial colonization of roots and the rhizosphere. This process is believed to be accompanied by an intricate network of ongoing simultaneous interactions. In this study, we examined Arabidopsis thaliana roots and shoots in the presence or absence of whole microbial communities extracted from compost soil. The results show a clear growth promoting effect on Arabidopsis shoots in the presence of soil microbes compared to plants grown in microbe-free soil under otherwise identical conditions. Element analyses showed that iron uptake was facilitated by these mixed microbial communities which also led to transcriptional downregulation of genes required for iron transport. In addition, soil microbial communities suppressed the expression of marker genes involved in nitrogen uptake, oxidative stress/redox signaling, and salicylic acid (SA)-mediated plant defense while upregulating jasmonate (JA) signaling, cell wall organization/biosynthesis and photosynthesis. Multi-species analyses such as simultaneous transcriptional profiling of plants and their interacting microorganisms (metatranscriptomics) coupled to metagenomics may further increase our understanding of the intricate networks underlying plant-microbe interactions. PMID:23847639

  6. Beyond growth: novel functions for bacterial cell wall hydrolases.

    Science.gov (United States)

    Wyckoff, Timna J; Taylor, Jennifer A; Salama, Nina R

    2012-11-01

    The peptidoglycan cell wall maintains turgor pressure and cell shape of most bacteria. Cell wall hydrolases are essential, together with synthases, for growth and daughter cell separation. Recent work in diverse organisms has uncovered new cell wall hydrolases that act autonomously or on neighboring cells to modulate invasion of prey cells, cell shape, innate immune detection, intercellular communication, and competitor lysis. The hydrolases involved in these processes catalyze the cleavage of bonds throughout the sugar and peptide moities of peptidoglycan. Phenotypes associated with these diverse hydrolases reveal new functions of the bacterial cell wall beyond growth and division.

  7. Exploration of plant growth and development using the European Modular Cultivation System facility on the International Space Station.

    Science.gov (United States)

    Kittang, A-I; Iversen, T-H; Fossum, K R; Mazars, C; Carnero-Diaz, E; Boucheron-Dubuisson, E; Le Disquet, I; Legué, V; Herranz, R; Pereda-Loth, V; Medina, F J

    2014-05-01

    Space experiments provide a unique opportunity to advance our knowledge of how plants respond to the space environment, and specifically to the absence of gravity. The European Modular Cultivation System (EMCS) has been designed as a dedicated facility to improve and standardise plant growth in the International Space Station (ISS). The EMCS is equipped with two centrifuges to perform experiments in microgravity and with variable gravity levels up to 2.0 g. Seven experiments have been performed since the EMCS was operational on the ISS. The objectives of these experiments aimed to elucidate phototropic responses (experiments TROPI-1 and -2), root gravitropic sensing (GRAVI-1), circumnutation (MULTIGEN-1), cell wall dynamics and gravity resistance (Cell wall/Resist wall), proteomic identification of signalling players (GENARA-A) and mechanism of InsP3 signalling (Plant signalling). The role of light in cell proliferation and plant development in the absence of gravity is being analysed in an on-going experiment (Seedling growth). Based on the lessons learned from the acquired experience, three preselected ISS experiments have been merged and implemented as a single project (Plant development) to study early phases of seedling development. A Topical Team initiated by European Space Agency (ESA), involving experienced scientists on Arabidopsis space research experiments, aims at establishing a coordinated, long-term scientific strategy to understand the role of gravity in Arabidopsis growth and development using already existing or planned new hardware.

  8. Dynamic simulation of a direct carbonate fuel cell power plant

    Energy Technology Data Exchange (ETDEWEB)

    Ernest, J.B. [Fluor Daniel, Inc., Irvine, CA (United States); Ghezel-Ayagh, H.; Kush, A.K. [Fuel Cell Engineering, Danbury, CT (United States)

    1996-12-31

    Fuel Cell Engineering Corporation (FCE) is commercializing a 2.85 MW Direct carbonate Fuel Cell (DFC) power plant. The commercialization sequence has already progressed through construction and operation of the first commercial-scale DFC power plant on a U.S. electric utility, the 2 MW Santa Clara Demonstration Project (SCDP), and the completion of the early phases of a Commercial Plant design. A 400 kW fuel cell stack Test Facility is being built at Energy Research Corporation (ERC), FCE`s parent company, which will be capable of testing commercial-sized fuel cell stacks in an integrated plant configuration. Fluor Daniel, Inc. provided engineering, procurement, and construction services for SCDP and has jointly developed the Commercial Plant design with FCE, focusing on the balance-of-plant (BOP) equipment outside of the fuel cell modules. This paper provides a brief orientation to the dynamic simulation of a fuel cell power plant and the benefits offered.

  9. Homogenization of a viscoelastic model for plant cell wall biomechanics

    OpenAIRE

    Ptashnyk, Mariya; Seguin, Brian

    2015-01-01

    The microscopic structure of a plant cell wall is given by cellulose microfibrils embedded in a cell wall matrix. In this paper we consider a microscopic model for interactions between viscoelastic deformations of a plant cell wall and chemical processes in the cell wall matrix. We consider elastic deformations of the cell wall microfibrils and viscoelastic Kelvin--Voigt type deformations of the cell wall matrix. Using homogenization techniques (two-scale convergence and periodic unfolding me...

  10. Different growth promoting effects of endophytic bacteria on invasive and native clonal plants

    Directory of Open Access Journals (Sweden)

    Zhi-Cong eDai

    2016-05-01

    Full Text Available The role of the interactions between endophytes and alien plants has been unclear yet in plant invasion. We used a completely germ-free culture system to quantify the plant growth-promoting (PGP effects of endophytic bacteria Bacillus sp. on aseptic seedlings of W. trilobata and of its native clonal congener W. chinensis. The endophytic bacteria did not affect the growth of W. chinensis, but they significantly promoted the growth of W. trilobata. With the PGP effects of endophytic bacteria, relative change ratios of the clonal traits and the ramets' growth traits of W. trilobata were significantly greater than those of W. chinensis. Our results indicate that the growth-promoting effects of endophytes may differ between invasive and native clonal plants, and the endophytes of invasive plant may be host-specific to facilitate plant invasion.

  11. Different Growth Promoting Effects of Endophytic Bacteria on Invasive and Native Clonal Plants

    Science.gov (United States)

    Dai, Zhi-Cong; Fu, Wei; Wan, Ling-Yun; Cai, Hong-Hong; Wang, Ning; Qi, Shan-Shan; Du, Dao-Lin

    2016-01-01

    The role of the interactions between endophytes and alien plants has been unclear yet in plant invasion. We used a completely germ-free culture system to quantify the plant growth-promoting (PGP) effects of endophytic bacteria Bacillus sp. on aseptic seedlings of Wedelia trilobata and of its native clonal congener W. chinensis. The endophytic bacteria did not affect the growth of W. chinensis, but they significantly promoted the growth of W. trilobata. With the PGP effects of endophytic bacteria, relative change ratios of the clonal traits and the ramets’ growth traits of W. trilobata were significantly greater than those of W. chinensis. Our results indicate that the growth-promoting effects of endophytes may differ between invasive and native clonal plants, and the endophytes of invasive plant may be host-specific to facilitate plant invasion. PMID:27252722

  12. Effect of plant growth-promoting bacteria on the growth and fructan production of Agave americana L.

    Science.gov (United States)

    De La Torre-Ruiz, Neyser; Ruiz-Valdiviezo, Víctor Manuel; Rincón-Molina, Clara Ivette; Rodríguez-Mendiola, Martha; Arias-Castro, Carlos; Gutiérrez-Miceli, Federico Antonio; Palomeque-Dominguez, Héctor; Rincón-Rosales, Reiner

    2016-01-01

    The effect of plant growth-promoting bacteria inoculation on plant growth and the sugar content in Agave americana was assessed. The bacterial strains ACO-34A, ACO-40, and ACO-140, isolated from the A. americana rhizosphere, were selected for this study to evaluate their phenotypic and genotypic characteristics. The three bacterial strains were evaluated via plant inoculation assays, and Azospirillum brasilense Cd served as a control strain. Phylogenetic analysis based on the 16S rRNA gene showed that strains ACO-34A, ACO-40 and ACO-140 were Rhizobium daejeonense, Acinetobacter calcoaceticus and Pseudomonas mosselii, respectively. All of the strains were able to synthesize indole-3-acetic acid (IAA), solubilize phosphate, and had nitrogenase activity. Inoculation using the plant growth-promoting bacteria strains had a significant effect (pagave plants with proper biological characteristics for agroindustrial and biotechnological use and to increase the sugar content in this agave species. PMID:27268113

  13. ESM Calculations for Hydroponic Plant and Fungi Growth Chambers, Biosolids Dewatering Plant System, and Tilapia Growth System--EAC Presentation 2004

    OpenAIRE

    Aydogan, Selen; Blau, Gary; Pekny, Joseph; Reklaitis, Gintaras

    2004-01-01

    In this work, preliminary Equivalent System Mass (ESM) estimations of the Hydroponic Plant and Fungi Growth Chambers, Biosolids Dewatering Plant and Tilapia Growth Systems are presented. ESM may be used to evaluate a system or technology based on its mass, volume, power, cooling and manpower requirements. This ESM analysis focuses on a hypothetical device, instead of the anticipated technology that is system flight proven in mission operations. We have examined the Evolved Mars Base mission, ...

  14. Plastids: dynamic components of plant cell development

    Science.gov (United States)

    Guikema, J. A.; Gallegos, G. L.; Spooner, B. S. (Principal Investigator)

    1992-01-01

    The gravitropic bending of maize roots, as a response to reorientation of the root within a gravitational field, was examined for sensitivity to exogenous applications of the cytoskeletal inhibitor, cytochalasin D. Agar blocks were impregnated with this inhibitor, and were applied either to the root cap or to the zone of root cell elongation. Root growth was normal with either treatment, if the roots were not repositioned with respect to the gravitational vector. When untreated roots were placed in a horizontal position with respect to gravity, a 40 degree bending response was observed within one hour. This bending also occurred when cytochalasin D was applied at high concentrations to the zone of root cell elongation. However, when cytochalasin D above 40 micrograms/ml was applied to the root cap, roots lost the ability of directional reorientation within the gravitational field, causing a random bending.

  15. Regeneration of Dioscorea floribunda plants from cryopreserved encapsulated shoot tips: effect of plant growth regulators.

    Science.gov (United States)

    Mandal, B B; Ahuja-Ghosh, Sangeeta

    2007-01-01

    The encapsulation-dehydration protocol for the cryopreservation of in vitro shoot tips of Dioscorea floribunda was optimized. Maximum survival of 87% was obtained when overnight pretreatment with 0.3 M sucrose was followed by encapsulation, preculture in 0.75 M sucrose for 4 d, dehydration in a laminar air flow for 5.5 h, quenching in liquid nitrogen and thawing at 40 degrees C. During recovery growth, 29% shoot formation was obtained when cryopreserved shoot tips were initially cultured for 25 d on a medium with 1.5 mg per liter (-1) BAP, 0.2 mg per liter(-1) NAA and 0.2 mg per liter(-1) GA3 followed by culturing for 15 d on a medium with reduced BAP (1 mg per liter(-1)) but increased NAA (0.5 mg per liter(-1)) and GA3 (0.3 mg per liter(-1)). Finally, transfer on to a medium with further reduced doses of BAP (0.05 mg per liter(-1)) and NAA (0.15 mg per liter(-1)) but without GA3 stimulated production of fully grown plantlets. All plants regenerated without callus formation. Modification of post-thaw culture media with plant growth regulators was essential for regrowth of shoot tips to plantlets.

  16. Plant Cell Wall Matrix Polysaccharide Biosynthesis

    Institute of Scientific and Technical Information of China (English)

    Ajay Pal S. Sandhu; Gursharn S. Randhawa; Kanwarpal S. Dhugga

    2009-01-01

    The wall of an expanding plant cell consists primarily of cellulose microfibrils embedded in a matrix of hemi-cellulosic and pectic polysaccharides along with small amounts of structural and enzymatic proteins. Matrix polysacchar-ides are synthesized in the Golgi and exported to the cell wall by exocytosis, where they intercalate among cellulose microfibrUs, which are made at the plasma membrane and directly deposited into the cell wall. Involvement of Golgi glucan synthesis in auxin-induced cell expansion has long been recognized; however, only recently have the genes corresponding to glucan synthases been identified. Biochemical purification was unsuccessful because of the labile nature and very low abundance of these enzymes. Mutational genetics also proved fruitless. Expression of candidate genes identified through gene expression profiling or comparative genomics in heterologous systems followed by functional characterization has been relatively successful. Several genes from the cellulose synthase-like (Cs/) family have been found to be involved in the synthesis of various hemicellulosic glycans. The usefulness of this approach, however, is limited to those enzymes that probably do not form complexes consisting of unrelated proteins. Nonconventional approaches will continue to incre-mentally unravel the mechanisms of Golgi polysaccharide biosynthesis.

  17. Dietary medicinal plant extracts improve growth, immune activity and survival of tilapia Oreochromis mossambicus.

    Science.gov (United States)

    Immanuel, G; Uma, R P; Iyapparaj, P; Citarasu, T; Peter, S M Punitha; Babu, M Michael; Palavesam, A

    2009-05-01

    The effects of supplementing diets with acetone extract (1% w/w) from four medicinal plants (Bermuda grass Cynodon dactylon, H(1), beal Aegle marmelos, H(2), winter cherry Withania somnifera, H(3) and ginger Zingiber officinale, H(4)) on growth, the non-specific immune response and ability to resist pathogen infection in tilapia Oreochromis mossambicus were assessed. In addition, the antimicrobial properties of the extract were assessed against Vibrio alginolyticus, Vibrioparahaemolyticus, Vibrio mimicus, Vibrio campbelli, Vibrio vulnificus, Vibrio harveyi and Photobacterium damselae. Oreochromis mossambicus were fed 5% of their body mass per day for 45 days, and those fed the experimental diets showed a greater increase in mass (111-139%) over the 45 days compared to those that received the control diet (98%). The specific growth rate of O. mossambicus fed the four diets was also significantly greater (1.66-1.93%) than control (1.52%) diet-fed fish. The blood plasma chemistry analysis revealed that protein, albumin, globulin, cholesterol, glucose and triglyceride levels of experimental fish were significantly higher than that of control fish. Packed cell volume of the blood samples of experimental diet-fed fish was also significantly higher (34.16-37.95%) than control fish (33.0%). Leucocrit value, phagocytic index and lysozyme activity were enhanced in fish fed the plant extract-supplemented diets. The acetone extract of the plants inhibited growth of Vibrio spp. and P. damselae with extracts from W. somnifera showing maximum growth inhibition. A challenge test with V. vulnificus showed 100% mortality in O. mossambicus fed the control diet by day 15, whereas the fish fed the experimental diets registered only 63-80% mortality at the end of challenge experiment (30 days). The cumulative mortality index for the control group was 12,000, which was equated to 1.0% mortality, and accordingly, the lowest mortality of 0.35% was registered in H(4)-diet-fed group. PMID

  18. Programmed cell death in plants and caspase-like activities

    NARCIS (Netherlands)

    Gaussand, Gwénael Martial Daniel Jean-Marie

    2007-01-01

    The development of multicellular organisms involves an important balance between cell growth, cell division and cell death. In animals, programmed cell death (PCD) plays a key role by forming and deleting structures, controlling cell numbers and eliminating abnormal damaged cells. Caspases were foun

  19. FUNCTION OF PHLOEM-BORNE INFORMATION MACROMOLECULES IN INTEGRATING PLANT GROWTH & DEVELOPMENT

    Energy Technology Data Exchange (ETDEWEB)

    William J. Lucas

    2012-11-12

    Studies on higher plants have revealed the operation of cell-to-cell and long-distance communication networks that mediate the transport of information macromolecules, such as proteins and RNA. Based on the findings from this DOE-funded project and results from other groups, it is now well established that the enucleate sieve tube system of the angiosperms contains a complex set of proteins including RNA binding proteins as well as a unique population of RNA molecules, comprised of both mRNA and small RNA species. Hetero-grafting experiments demonstrated that delivery of such RNA molecules, into the scion, is highly correlated with changes in developmental phenotypes. Furthermore, over the course of this project, our studies showed that plasmodesmata and the phloem are intimately involved in the local and systemic spread of sequence-specific signals that underlie gene silencing in plants. Major advances were also made in elucidating the underlying mechanisms that operate to mediate the selective entry and exit of proteins and RNA into and out of the phloem translocation stream. Our pioneering studies identified the first plant protein with the capacity to both bind specifically to small RNA molecules (si-RNA) and mediate in the cell-to-cell movement of such siRNA. Importantly, studies conducted with support from this DOE program also yielded a detailed characterization of the first phloem-mobile RNP complex isolated from pumpkin, namely the CmRBP50-RNP complex. This RNP complex was shown to bind, in a sequence-specific manner, to a set of transcripts encoding for transcription factors. The remarkable stability of this CmRBP50-RNP complex allows for long-distance delivery of bound transcripts from mature leaves into developing tissues and organs. Knowledge gained from this project can be used to exert control over the long-distance signaling networks used by plants to integrate their physiological and developmental programs at a whole plant level. Eventually, this

  20. Growth Response and Tolerance to Heavy Metals of two Swamp Species inoculated with a Plant Growth-Promoting Rhizobacteria

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez-Dorantes, A.; Labra-Cardon, D.; Guerrero-Zuniga, A.; Montes-Villafan, S.

    2009-07-01

    Due to the sensitivity and the sequestration ability of the microbial communities to heavy metals, microbes have been used for bioremediation. Recently the application of plant growth-promoting rhizobacteria (PGPR) for the bioremediation of this kind of contaminants has been done. This study evaluated the growth response and the tolerance to heavy metals of two swamp species. (Author)

  1. A simple and efficient method for the long-term preservation of plant cell suspension cultures

    Directory of Open Access Journals (Sweden)

    Boisson Anne-Marie

    2012-01-01

    Full Text Available Abstract Background The repeated weekly subculture of plant cell suspension is labour intensive and increases the risk of variation from parental cells lines. Most of the procedures to preserve cultures are based on controlled freezing/thawing and storage in liquid nitrogen. However, cells viability after unfreezing is uncertain. The long-term storage and regeneration of plant cell cultures remains a priority. Results Sycamore (Acer pseudoplatanus and Arabidopsis cell were preserved over six months as suspensions cultures in a phosphate-free nutrient medium at 5°C. The cell recovery monitored via gas exchange measurements and metabolic profiling using in vitro and in vivo 13C- and 31P-NMR took a couple of hours, and cell growth restarted without appreciable delay. No measurable cell death was observed. Conclusion We provide a simple method to preserve physiologically homogenous plant cell cultures without subculture over several months. The protocol based on the blockage of cell growth and low culture temperature is robust for heterotrophic and semi-autotrophic cells and should be adjustable to cell lines other than those utilised in this study. It requires no specialized equipment and is suitable for routine laboratory use.

  2. Fibroblast growth factor 8 increases breast cancer cell growth by promoting cell cycle progression and by protecting against cell death

    Energy Technology Data Exchange (ETDEWEB)

    Nilsson, Emeli M., E-mail: Emeli.Nilsson@med.lu.se [Department of Laboratory Medicine, Tumour Biology, Lund University, CRC, Building 91, Plan 10, Entrance 72, UMAS, 205 02 Malmoe (Sweden); Brokken, Leon J.S., E-mail: Leon.Brokken@med.lu.se [Department of Laboratory Medicine, Tumour Biology, Lund University, CRC, Building 91, Plan 10, Entrance 72, UMAS, 205 02 Malmoe (Sweden); Haerkoenen, Pirkko L., E-mail: Pirkko.Harkonen@med.lu.se [Department of Laboratory Medicine, Tumour Biology, Lund University, CRC, Building 91, Plan 10, Entrance 72, UMAS, 205 02 Malmoe (Sweden)

    2010-03-10

    Fibroblast growth factor 8 (FGF-8) is expressed in a large proportion of breast cancers, whereas its level in normal mammary gland epithelium is low. Previous studies have shown that FGF-8b stimulates breast cancer cell growth in vitro and in vivo. To explore the mechanisms by which FGF-8b promotes growth, we studied its effects on cell cycle regulatory proteins and signalling pathways in mouse S115 and human MCF-7 breast cancer cells. We also studied the effect of FGF-8b on cell survival. FGF-8b induced cell cycle progression and up-regulated particularly cyclin D1 mRNA and protein in S115 cells. Silencing cyclin D1 with siRNA inhibited most but not all FGF-8b-induced proliferation. Inhibition of the FGF-8b-activated ERK/MAPK pathway decreased FGF-8b-stimulated proliferation. Blocking the constitutively active PI3K/Akt and p38 MAPK pathways also lowered FGF-8b-induced cyclin D1 expression and proliferation. Corresponding results were obtained in MCF-7 cells. In S115 and MCF-7 mouse tumours, FGF-8b increased cyclin D1 and Ki67 levels. Moreover, FGF-8b opposed staurosporine-induced S115 cell death which effect was blocked by inhibiting the PI3K/Akt pathway but not the ERK/MAPK pathway. In conclusion, our results suggest that FGF-8b increases breast cancer cell growth both by stimulating cell cycle progression and by protecting against cell death.

  3. Estimating plant stem emerging points (PSEPs) of sugar of beets in early growth stages

    DEFF Research Database (Denmark)

    Midtiby, Henrik; Mosgaard Giselsson, Thomas; Jørgensen, Rasmus Nyholm

    2012-01-01

    Successful intra--row mechanical weed control of sugar beet 
(beta vulgaris) in early growth stages requires precise 
knowledge about location of crop plants.
A computer vision system for locating Plant Stem Emerging Point (PSEP) 
of sugar beet in early growth stages was developed and tested...

  4. Effect of the different timing of AMF inoculation on plant growth and flower quality of chrysanthemum

    NARCIS (Netherlands)

    Sohn, B.K.; Kim, K.Y.; Chung, S.J.; Kim, W.S.; Park, S.M.; Kang, J.G.; Rim, Y.S.; Cho, J.S.; Kim, T.H.; Lee, J.H.

    2003-01-01

    Plant growth and flower quality of an ornamental plant (Chrysanthemum morifolium Ramat) var. Baekgwang in response to the different timing of arbuscular mycorrhizal fungi (AMF) inoculation were examined. To evaluate the effects of AMF inoculation timing on growth of chrysanthemum cuttings, AMF was d

  5. Genome Sequence of Enterobacter radicincitans DSM16656T, a Plant Growth-Promoting Endophyte

    OpenAIRE

    Witzel, Katja; Gwinn-Giglio, Michelle; Nadendla, Suvarna; Shefchek, Kent; Ruppel, Silke

    2012-01-01

    Enterobacter radicincitans sp. nov. DSM16656T represents a new species of the genus Enterobacter which is a biological nitrogen-fixing endophytic bacterium with growth-promoting effects on a variety of crop and model plant species. The presence of genes for nitrogen fixation, phosphorous mobilization, and phytohormone production reflects this microbe's potential plant growth-promoting activity.

  6. Fusarium oxysporum volatiles enhance plant growth via affecting auxin transport and signaling

    Directory of Open Access Journals (Sweden)

    Vasileios eBitas

    2015-11-01

    Full Text Available Volatile organic compounds (VOCs have well-documented roles in plant-plant communication and directing animal behavior. In this study, we examine the less understood roles of VOCs in plant-fungal relationships. Phylogenetically and ecologically diverse strains of Fusarium oxysporum, a fungal species complex that often resides in the rhizosphere of assorted plants, produce volatile compounds that augment shoot and root growth of Arabidopsis thaliana and tobacco. Growth responses of A. thaliana hormone signaling mutants and expression patterns of a GUS reporter gene under the auxin-responsive DR5 promoter supported the involvement of auxin signaling in F. oxysporum volatile-mediated growth enhancement. In addition, 1-naphthylthalamic acid, an inhibitor of auxin efflux, negated F. oxysporum volatile-mediated growth enhancement in both plants. Comparison of the profiles of volatile compounds produced by F. oxysporum strains that differentially affected plant growth suggests that the relative compositions of both growth inhibitory and stimulatory compounds may determine the degree of plant growth enhancement. Volatile-mediated signaling between fungi and plants may represent a potentially conserved, yet mostly overlooked, mechanism underpinning plant-fungus interactions and fungal niche adaption.

  7. Fusarium Oxysporum Volatiles Enhance Plant Growth Via Affecting Auxin Transport and Signaling.

    Science.gov (United States)

    Bitas, Vasileios; McCartney, Nathaniel; Li, Ningxiao; Demers, Jill; Kim, Jung-Eun; Kim, Hye-Seon; Brown, Kathleen M; Kang, Seogchan

    2015-01-01

    Volatile organic compounds (VOCs) have well-documented roles in plant-plant communication and directing animal behavior. In this study, we examine the less understood roles of VOCs in plant-fungal relationships. Phylogenetically and ecologically diverse strains of Fusarium oxysporum, a fungal species complex that often resides in the rhizosphere of assorted plants, produce volatile compounds that augment shoot and root growth of Arabidopsis thaliana and tobacco. Growth responses of A. thaliana hormone signaling mutants and expression patterns of a GUS reporter gene under the auxin-responsive DR5 promoter supported the involvement of auxin signaling in F. oxysporum volatile-mediated growth enhancement. In addition, 1-naphthylthalamic acid, an inhibitor of auxin efflux, negated F. oxysporum volatile-mediated growth enhancement in both plants. Comparison of the profiles of volatile compounds produced by F. oxysporum strains that differentially affected plant growth suggests that the relative compositions of both growth inhibitory and stimulatory compounds may determine the degree of plant growth enhancement. Volatile-mediated signaling between fungi and plants may represent a potentially conserved, yet mostly overlooked, mechanism underpinning plant-fungus interactions and fungal niche adaption. PMID:26617587

  8. Tracer methods for investigating biosynthetic pathways and the metabolism of bioactive substances in plants. [Herbicides; Plant growth regulators

    Energy Technology Data Exchange (ETDEWEB)

    Schuette, H.R. (Akademie der Wissenschaften der DDR, Halle/Saale. Inst. fuer Biochemie der Pflanzen)

    1984-03-01

    Proceeding from the general terms of investigating the courses of reactions in plants by means of tracer methods, problems and possibilities of the methods are discussed on the basis of examples referring in particular to double labelling techniques and to the determination of the distribution of radioactivity in the resulting products. Examples of herbicides and plant growth regulators are used for describing metabolism studies.

  9. Effects of Plant Growth Hormones on Mucor indicus Growth and Chitosan and Ethanol Production

    OpenAIRE

    Zahra Safaei; Keikhosro Karimi; Poorandokht Golkar; Akram Zamani

    2015-01-01

    The objective of this study was to investigate the effects of indole-3-acetic acid (IAA) and kinetin (KIN) on Mucor indicus growth, cell wall composition, and ethanol production. A semi-synthetic medium, supplemented with 0–5 mg/L hormones, was used for the cultivations (at 32 °C for 48 h). By addition of 1 mg/L of each hormone, the biomass and ethanol yields were increased and decreased, respectively. At higher levels, however, an inverse trend was observed. The glucosamine fraction of the ...

  10. Cell growth characterization using multi-electrode bioimpedance spectroscopy

    International Nuclear Information System (INIS)

    Cell growth characterization during culturing is an important issue in a variety of biomedical applications. In this study an electrical bioimpedance spectroscopy-based multi-electrode culture monitoring system was developed to characterize cell growth. A PC12 cell line was cultured for the cell growth study. The bioimpedance variations for PC12 cell growth within the initial 12 h were measured over a range between 1 kHz and 4 MHz at three different medium concentrations. Within this frequency range, the largest bioimpedance value was 1.9 times the smallest bioimpedance value. The phase angle decreased over the range from 1 to 10 kHz when cells were growing. Then, the phase angle approached a constant over the frequency range between 10 kHz and 2 MHz. Thereafter, the phase angle increased rapidly from 20 to 52 degrees during cell culturing between 8 and 12 h at 4 MHz. The maximum cell number after culturing for 12 h increased by 25.8% for the control sites with poly-D-lysine (PDL) pastes. For the normal growth factor, the cell number increased up to 4.78 times from 8 to 12 h, but only 0.96 and 1.60 times for the other two medium growth factors. The correlation coefficients between impedance and cell number were 0.868 (coating with PDL), and 0.836 (without PDL) for the normal concentration medium. Thus, impedance may be used as an index for cell growth characterization. (paper)

  11. Cell growth characterization using multi-electrode bioimpedance spectroscopy

    Science.gov (United States)

    Lu, Yi-Yu; Huang, Ji-Jer; Huang, Yu-Jie; Cheng, Kuo-Sheng

    2013-03-01

    Cell growth characterization during culturing is an important issue in a variety of biomedical applications. In this study an electrical bioimpedance spectroscopy-based multi-electrode culture monitoring system was developed to characterize cell growth. A PC12 cell line was cultured for the cell growth study. The bioimpedance variations for PC12 cell growth within the initial 12 h were measured over a range between 1 kHz and 4 MHz at three different medium concentrations. Within this frequency range, the largest bioimpedance value was 1.9 times the smallest bioimpedance value. The phase angle decreased over the range from 1 to 10 kHz when cells were growing. Then, the phase angle approached a constant over the frequency range between 10 kHz and 2 MHz. Thereafter, the phase angle increased rapidly from 20 to 52 degrees during cell culturing between 8 and 12 h at 4 MHz. The maximum cell number after culturing for 12 h increased by 25.8% for the control sites with poly-D-lysine (PDL) pastes. For the normal growth factor, the cell number increased up to 4.78 times from 8 to 12 h, but only 0.96 and 1.60 times for the other two medium growth factors. The correlation coefficients between impedance and cell number were 0.868 (coating with PDL), and 0.836 (without PDL) for the normal concentration medium. Thus, impedance may be used as an index for cell growth characterization.

  12. Effect of Plant Growth-Promoting Rhizobacteria on Growth,Nodulation and Nutrient Accumulation of Lentil Under Controlled Conditions

    Institute of Scientific and Technical Information of China (English)

    M.ZAFAR; M.K.ABBASI; M.A.KHAN; A.KHALIQ; T.SULTAN; M.ASLAM

    2012-01-01

    Application of plant growth-promoting rhizobacteria (PGPR) has been shown to increase legume growth and development under field and controlled environmental conditions.The present study was conducted to isolate plant growth-promoting rhizobacteria (PGPR) from the root nodules of lentil (Lens culinaris Medik.) grown in arid/semi-arid region of Punjab,Pakistan and examined their plant growth-promoting abilities.Five bacterial isolates were isolated,screened in vitro for plant growth-promoting (PGP)characteristics and their effects on the growth of lentil were assessed under in vitro,hydroponic and greenhouse (pot experiment)conditions.All the isolates were Gram negative,rod-shaped and circular in form and exhibited the plant growth-promoting attributes of phosphate solubilization and auxin (indole acetic acid,IAA) production.The IAA production capacity ranged in 0.5-11.0 μgmL-1and P solubilization ranged in 3 16 mg L-1.When tested for their effects on plant growth,the isolated strains had a stimulatory effect on growth,nodulation and nitrogen (N) and phosphorus (P) uptake in plants on nutrient-deficient soil.In the greenhouse pot experiment,application of PGPR significantly increased shoot length,fresh weight and dry weight by 65%,43% and 63% and the increases in root length,fresh weight and dry weight were 74%,54% and 92%,respectively,as compared with the uninoculated control.The relative increases in growth characteristics under in vitro and hydroponic conditions were even higher.PGPR also increased the number of pods per plant,1000-grain weight,dry matter yield and grain yield by 50%,13%,28% and 29%,respectively,over the control.The number of nodules and nodule dry mass increased by 170% and 136%,respectively.After inoculation with effective bacterial strains,the shoot,root and seed N and P contents increased,thereby increasing both N and P uptake in plants. The root elongation showed a positive correlation (R2 =0.67) with the IAA

  13. Controlled ecological life support systems: Development of a plant growth module

    Science.gov (United States)

    Averner, Mel M.; Macelroy, Robert D.; Smernoff, David T.

    1987-01-01

    An effort was made to begin defining the scientific and technical requirements for the design and construction of a ground-based plant growth facility. In particular, science design criteria for the Plant Growth Module (PGM) of the Controlled Ecological Life Support System (CELSS) were determined in the following areas: (1) irradiation parameters and associated equipment affecting plant growth; (2) air flow; (3) planting, culture, and harvest techniques; (4) carbon dioxide; (5) temperature and relative humidity; (6) oxygen; (7) construction materials and access; (8) volatile compounds; (9) bacteria, sterilization, and filtration; (10) nutrient application systems; (11) nutrient monitoring; and (12) nutrient pH and conductivity.

  14. L-serine capped ZnS:Mn nanocrystals for plant cell biological studies and as a growth enhancing agent for micropropagation of Bacopa monnieri Linn. (Brahmi:Scrophulariaceae)

    Energy Technology Data Exchange (ETDEWEB)

    Augustine, M. Sajimol, E-mail: sajimollazar@gmail.com [Department of Physics, St.Teresa' s College , Kochi-11, Kerala (India); Mathew, Lizzy [Department of Botany, St.Teresa' s College , Kochi-11, Kerala (India); Alex, Roselin [Department of Biotechnology, Cochin University of Science and Technology, Kochi-22 (India); Deepa, G. D. [NCAAH, Cochin University of Science and Technology,Kochi-22, Kerala (India); Jayalekshmi, S., E-mail: jayalekshmi@cusat.ac.in [Department of Physics, Cochin University of Science and Technology, Kochi-22 (India)

    2014-01-28

    In the present work, the prospects of ZnS:Mn nanocrystals capped with L- serine, a bio-compatible amino acid, synthesized by wet chemical route, as efficient fluorescent probes for plant cell biological studies have been investigated. The present synthesis route using bio-compatible material is a low cost and easy to control method. The colloidal stability of the capped nano crystals is very good as they remain stable without settling down for long time. It is observed that L- serine significantly modifies the structural and optical characteristics of the ZnS:Mn nanocrystals and hence is suitable as a bio-compatible capping agent. The structural properties of L- serine capped nanocrystals were investigated by XRD technique. The size of the L- serine capped ZnS:Mn nanocrystals is found to be around 2 nm . The optical characterization of the nanocrystals was carried out on the basis of photoluminescence (PL) spectroscopic studies. The intense photoluminescence emission observed around 597nm for L-serine capped ZnS:Mn offers high prospects of applications in bio-imaging fields. The unique optical properties of nanoparticles make them appealing as in vivo and in vitro fluorophores in a variety of biological investigations. In the present study, L-serine capped ZnS:Mn nanocrystals were used as a staining dye in fluorescent microscope for observing cell division, cell structure etc. These nanocrystals were also incorporated into the culture media along with the normal auxin- cytokinin hormone combinations in Murashige and Skoog (MS) medium for micropropagation of Bacopa monnieri Linn. (Brahmi:Scrophulariaceae), an Ayurvedic medicine. The results suggest that L-serine capped ZnS:Mn nanocrystals can act as efficient enhancers towards quick callusing and shoot proliferation.

  15. L-serine capped ZnS:Mn nanocrystals for plant cell biological studies and as a growth enhancing agent for micropropagation of Bacopa monnieri Linn. (Brahmi:Scrophulariaceae)

    Science.gov (United States)

    Augustine, M. Sajimol; Mathew, Lizzy; Alex, Roselin; Deepa, G. D.; Jayalekshmi, S.

    2014-01-01

    In the present work, the prospects of ZnS:Mn nanocrystals capped with L- serine, a bio-compatible amino acid, synthesized by wet chemical route, as efficient fluorescent probes for plant cell biological studies have been investigated. The present synthesis route using bio-compatible material is a low cost and easy to control method. The colloidal stability of the capped nano crystals is very good as they remain stable without settling down for long time. It is observed that L- serine significantly modifies the structural and optical characteristics of the ZnS:Mn nanocrystals and hence is suitable as a bio-compatible capping agent. The structural properties of L- serine capped nanocrystals were investigated by XRD technique. The size of the L- serine capped ZnS:Mn nanocrystals is found to be around 2 nm . The optical characterization of the nanocrystals was carried out on the basis of photoluminescence (PL) spectroscopic studies. The intense photoluminescence emission observed around 597nm for L-serine capped ZnS:Mn offers high prospects of applications in bio-imaging fields. The unique optical properties of nanoparticles make them appealing as in vivo and in vitro fluorophores in a variety of biological investigations. In the present study, L-serine capped ZnS:Mn nanocrystals were used as a staining dye in fluorescent microscope for observing cell division, cell structure etc. These nanocrystals were also incorporated into the culture media along with the normal auxin- cytokinin hormone combinations in Murashige and Skoog (MS) medium for micropropagation of Bacopa monnieri Linn. (Brahmi:Scrophulariaceae), an Ayurvedic medicine. The results suggest that L-serine capped ZnS:Mn nanocrystals can act as efficient enhancers towards quick callusing and shoot proliferation.

  16. Relationship between plant growth and cytological effect in root apical meristem after exposure of wheat dry seeds to carbon ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Qingfang [Radiobiology Laboratory, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, Gansu Province 730000 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Wang, Zhuanzi; Zhou, Libin; Qu, Ying; Lu, Dong [Radiobiology Laboratory, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, Gansu Province 730000 (China); Yu, Lixia; Du, Yan [Radiobiology Laboratory, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, Gansu Province 730000 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Jin, Wenjie [Radiobiology Laboratory, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, Gansu Province 730000 (China); Li, Wenjian, E-mail: wjli@impcas.ac.cn [Radiobiology Laboratory, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, Gansu Province 730000 (China)

    2013-06-15

    In order to analyze the relationship between plant growth and cytological effects, wheat dry seeds were exposed to various doses of {sup 12}C{sup 6+} beams and the biological endpoints reflecting plant growth and root apical meristem (RAM) activities were investigated. The results showed that most of the seeds were able to germinate normally within all dose range, while the plant survival rate descended at higher doses. The seedling growth including root length and seedling height also decreased significantly at higher doses. Mitotic index (MI) in RAM had no changes at 10 and 20 Gy and decreased obviously at higher doses and the proportion of prophase cells had the same trend with MI. These data suggested that RAM cells experienced cell cycle arrest, which should be responsible for the inhibition of root growth after exposure to higher doses irradiation. Moreover, various types of chromosome aberrations (CAs) were observed in the mitotic cells. The frequencies of mitotic cells with lagging chromosomes and these with anaphase bridges peaked around 60 Gy, while the frequencies of these with fragments increased as the irradiation doses increased up to 200 Gy. The total frequencies of mitotic cells with CAs induced by irradiation increased significantly with the increasing doses. The serious damage of mitotic chromosomes maybe caused cell cycle arrest or cell death. These findings suggested that the influences of {sup 12}C{sup 6+} beams irradiation on plant growth were related to the alternation of mitotic activities and the chromosomal damages in RAM.

  17. Effects of microgravity on growth hormone concentration and distribution in plants

    Science.gov (United States)

    Schulze, Aga; Jensen, Philip; Desrosiers, Mark; Bandurski, Robert S.

    1989-01-01

    On earth, gravity affects the distribution of the plant growth hormone, indole-3-acetic acid (IAA), in a manner such that the plant grows into a normal vertical orientation (shoots up, roots down). How the plant controls the amount and distribution of IAA is only partially understood and is currently under investigation in this laboratory. The question to be answered in the flight experiment concerns the effect of gravity on the concentration, turn over, and distribution of the growth hormone. The answer to this question will aid in understanding the mechanism by which plants control the amount and distribution of growth hormone. Such knowledge of a plant's hormonal metabolism may aid in the growth of plants in space and will lead to agronomic advances.

  18. Atmospheric nitrogen dioxide at ambient levels stimulates growth and development of horticultural plants

    International Nuclear Information System (INIS)

    Studies have demonstrated that ambient levels of atmospheric nitrogen dioxide (NO2) can cause Nicotiana plumbaginifolia to double its biomass as well as its cell contents. This paper examined the influence of NO2 on lettuce, sunflower, cucumber, and pumpkin plants. Plants were grown in environments supplemented with stable isotope-labelled NO2 for approximately 6 weeks and irrigated with nitrates. Measured growth parameters included leaf number, internode number, stem length, number of flower buds, and root length. Results of the study demonstrated that the addition of NO2 doubled the aboveground and belowground biomass of sunflowers, while only the aboveground biomass of pumpkin, cucumbers, and lettuces was doubled. Levels of carbon (C), nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) were also doubled in the lettuce samples. A mass spectrometry analysis showed that only a small percentage of total plant N was derived from NO2. It was concluded that exogenous NO2 additions function as a signal rather than as a significant nutrient source in horticultural plants. 22 refs., 2 tabs., 1 fig

  19. Influence of Nitrogen Sources and Plant Growth-Promoting Rhizobacteria Inoculation on Growth, Crude Fiber and Nutrient Uptake in Squash (Cucurbita moschata Duchesne ex Poir. Plants

    Directory of Open Access Journals (Sweden)

    Alice I. TCHIAZE

    2016-06-01

    Full Text Available Plant growth promoting rhizobacteria (PGPR, B have immense potential application in sustainable agriculture as ecofriendly biofertilizers and biopesticides. In this study, the effects of three nitrogen (N sources (NO3-, NH4+ and NO3NH4 and PGPR on growth, crude fiber and nutrient uptake were investigated in squash plants. Some growth parameters [root dry weight (RDW, shoot dry weight (SDW, total plant dry weight (PDW, number of leaves (NL, shoot length (SL, stem diameter (SD and number of ramifications (NR], crude fiber (cellulose content and nutrient uptake (N, P, K, Ca, Mg, Na, Fe, Cu, Mn and Zn were determined. Application of NO3-,NH4+ or NO3NH4 singly or in combination with PGPR inoculation led to a significant increase in RDW, SDW, PDW, NL, SL, SD and NR. Na, Cu and Zn contents, on the contrary, decreased in inoculated treated plants while no significant differences were recorded in cellulose contents (CE of leaves except in plants fed with NO3-. The leaf CE content ranged from 12.58 to 13.67%. The plants supplied with NO3+B, NH4+B and NO3NH4+B showed significantly higher plant biomass and accumulation of N, P, K and Mn concentrations in leaves compared to all other treatments. These results suggest that specific combinations of PGPR with NO3-, NH4+ or NO3NH4 fertilizers can be considered as efficient alternative biofertilizers to improve significantly the squash growth and nutrient uptake.

  20. The influence of growth retardants and cytokinins on flowering of ornamental plants

    OpenAIRE

    Anna Pobudkiewicz

    2012-01-01

    Growth retardants are applied in order to obtain short and well compact plants. They usually inhibit stem elongation, but also can influence the flowering of plants. The aim of cytokinin application is to obtain well branched plants without removing the apical meristem. Cytokinins usually increase the number of axillary shoots but also can influence flowering. Growth retardants and cytokinins can affect flower size, pedicel length, number of flowers, flower longevity, abortion of flower buds ...

  1. Protocol: optimising hydroponic growth systems for nutritional and physiological analysis of Arabidopsis thaliana and other plants

    OpenAIRE

    Conn, Simon J; Hocking, Bradleigh; Dayod, Maclin; Xu, Bo; Athman, Asmini; Henderson, Sam; Aukett, Lucy; Conn, Vanessa; Shearer, Monique K; Fuentes, Sigfredo; TYERMAN, STEPHEN D.; Gilliham, Matthew

    2013-01-01

    Background Hydroponic growth systems are a convenient platform for studying whole plant physiology. However, we found through trialling systems as they are described in the literature that our experiments were frequently confounded by factors that affected plant growth, including algal contamination and hypoxia. We also found the way in which the plants were grown made them poorly amenable to a number of common physiological assays. Results The drivers for the development of this hydroponic s...

  2. Plant Growth-Promoting Rhizobacteria Enhance Salinity Stress Tolerance in Okra through ROS-Scavenging Enzymes

    OpenAIRE

    Sheikh Hasna Habib; Hossain Kausar; Halimi Mohd Saud

    2016-01-01

    Salinity is a major environmental stress that limits crop production worldwide. In this study, we characterized plant growth-promoting rhizobacteria (PGPR) containing 1-aminocyclopropane-1-carboxylate (ACC) deaminase and examined their effect on salinity stress tolerance in okra through the induction of ROS-scavenging enzyme activity. PGPR inoculated okra plants exhibited higher germination percentage, growth parameters, and chlorophyll content than control plants. Increased antioxidant enzym...

  3. Modulation of plant growth and metabolism in cadmium-enriched environments.

    Science.gov (United States)

    Qadir, Shaista; Jamshieed, Sumiya; Rasool, Saiema; Ashraf, Muhammad; Akram, Nudrat Aisha; Ahmad, Parvaiz

    2014-01-01

    Cadmium (Cd) is a water soluble metal pollutant that is not essential to plant growth.It has attracted attention from soil scientists and plant nutritionists in recent years because of its toxicity and mobility in the soil-plant continuum. Even low levels of Cd (0.1-1 J.!M) cause adverse effects on plant growth and metabolism. Cadmium is known to trigger the synthesis of reactive oxygen species, hinder utilization, uptake and transport of essential nutrients and water, and modify photosynthetic machinery,thereby resulting in plant tissue death. Although the effects of Cd are dose- as well as plant species-dependent, some plants show Cd tolerance through a wide range of cellular responses. Such tolerance results from synthesis of osmolytes,generation of enzymatic and non-enzymatic antioxidants and metal-detoxifying peptides, changes in gene expression, and metal ion homeostasis and compartmentalization of ligand-metal complexes. Cd toxicity in plants produces effects on chlorophyllbio synthesis, reduces photosynthesis, and upsets plant water relations and hormonal and/or nutritional balances. All of these effects on plants and on plant metabolism ultimately reduce growth and productivity.In this review, we describe the extent to which Cd affects underlying metabolic processes in plants and how such altered processes affect plant growth. We review the sources of Cd contamination, its uptake, transportation and bioavailability and accumulation in plants, and its antagonistic and synergistic effects with other metals and compounds. We further address the effects of Cd on plant genetics and metabolism,and how plants respond to mitigate the adverse effects of Cd exposure, as well as strategies(e.g., plant breeding) that can reduce the impact of Cd contamination on plants.

  4. Dual Effect of the Cubic Ag₃PO₄ Crystal on Pseudomonas syringae Growth and Plant Immunity

    Directory of Open Access Journals (Sweden)

    Mi Kyung Kim

    2016-04-01

    Full Text Available We previously found that the antibacterial activity of silver phosphate crystals on Escherichia coli depends on their structure. We here show that the cubic form of silver phosphate crystal (SPC can also be applied to inhibit the growth of a plant-pathogenic Pseudomonas syringae bacterium. SPC pretreatment resulted in reduced in planta multiplication of P. syringae. Induced expression of a plant defense marker gene PR1 by SPC alone is suggestive of its additional plant immunity-stimulating activity. Since SPC can simultaneously inhibit P. syringae growth and induce plant defense responses, it might be used as a more effective plant disease-controlling agent.

  5. Plant growth regulation in seed crops of perennial ryegrass (Lolium perenne L)

    DEFF Research Database (Denmark)

    Boelt, Birte; Lemaire, Charles; Abel, Simon;

    2016-01-01

    Seed yield components were recorded in plants of perennial ryegrass cv. Calibra a medium late, forage type (4n) in a two factorial block design with Nitrogen (N) and plant growth regulator (PGR) application in 2014 and 2015 at Aarhus University (AU), Flakkebjerg. For each plant, reproductive...

  6. The influence of Plant Growth Promoting Rhizobacteria (PGPR on the reduction of abiotic stresses in crops

    Directory of Open Access Journals (Sweden)

    Omid Alizadeh

    2011-12-01

    Full Text Available Plants are always subjected to biotic and abiotic stresses in the environment which haveinfluences on the growth and development of the plants. Beneficial free-living soil bacteria are usuallyreferred as Plant-Growth Promoting Rhizobacteria or PGPR. Different plant growth-promotingRhizosphere bacteria, including associative bacteria such as: Azospirillum, Bacillus, Pseudomonas andEnterobacter group have been used for their beneficial influences on plants. Typically, PGPRs areassociated with plants root and augment plant productivity and immunity; however, recent worksshowed that PGPRs not have just induced the systemic tolerance to abiotic stress such as salt anddrought, but also they have increased the nutrient uptake from soils, and as a result the hazardousaccumulation of nitrates and phosphates in the agricultural soils can be reduced by usage of them.

  7. Shoot growth restriction in dry matter partitioning andminituber production of potato plants

    OpenAIRE

    Dilson Antônio Bisognin; Jacso Dellai

    2015-01-01

    The aim of this research was to determine the effect of shoot growth restriction in the dry matter partitioning and minituber production of potato plants grown in a closed soilless system. Minitubers of the cultivars 'Macaca' and 'Asterix' were planted in the greenhouse in the density of 100 hills m-2, during autumn and spring growing seasons. Growth restriction levels were gotten by pruning shoots at 10, 20 and 30cm height or without pruning. The growth restriction levels were identified by ...

  8. Conserved V-ATPase c subunit plays a role in plant growth by influencing V-ATPase-dependent endosomal trafficking.

    Science.gov (United States)

    Zhou, Aimin; Bu, Yuanyuan; Takano, Tetsuo; Zhang, Xinxin; Liu, Shenkui

    2016-01-01

    In plant cells, the vacuolar-type H(+)-ATPases (V-ATPase) are localized in the tonoplast, Golgi, trans-Golgi network and endosome. However, little is known about how V-ATPase influences plant growth, particularly with regard to the V-ATPase c subunit (VHA-c). Here, we characterized the function of a VHA-c gene from Puccinellia tenuiflora (PutVHA-c) in plant growth. Compared to the wild-type, transgenic plants overexpressing PutVHA-c in Arabidopsis thaliana exhibit better growth phenotypes in root length, fresh weight, plant height and silique number under the normal and salt stress conditions due to noticeably higher V-ATPase activity. Consistently, the Arabidopsis atvha-c5 mutant shows reduced V-ATPase activity and retarded plant growth. Furthermore, confocal and immunogold electron microscopy assays demonstrate that PutVHA-c is mainly localized to endosomal compartments. The treatment of concanamycin A (ConcA), a specific inhibitor of V-ATPases, leads to obvious aggregation of the endosomal compartments labelled with PutVHA-c-GFP. Moreover, ConcA treatment results in the abnormal localization of two plasma membrane (PM) marker proteins Pinformed 1 (AtPIN1) and regulator of G protein signalling-1 (AtRGS1). These findings suggest that the decrease in V-ATPase activity blocks endosomal trafficking. Taken together, our results strongly suggest that the PutVHA-c plays an important role in plant growth by influencing V-ATPase-dependent endosomal trafficking.

  9. Effects of gasification biochar on plant-available water capacity and plant growth in two contrasting soil types

    DEFF Research Database (Denmark)

    Hansen, Veronika; Hauggaard-Nielsen, Henrik; Petersen, Carsten Tilbæk;

    2016-01-01

    Gasification biochar (GB) contains recalcitrant carbon that can contribute to soil carbon sequestration and soil quality improvement. However, the impact of GB on plant-available water capacity (AWC) and plant growth in diverse soil types still needs to be explored. A pot experiment with spring......, the reduced water regime significantly affected plant growth and water consumption, whereas the effect was less pronounced in the coarse sand. Irrespective of the soil type, both GBs increased AWC by 17-42%, with the highest absolute effect in the coarse sand. The addition of SGB to coarse sand led...... barley (Hordeum vulgare L.) was conducted to investigate the effect of soil amendment by 1 % straw and wood gasification biochar (SGB and WGB), respectively, on AWC and plant growth responses under two levels of water supply in a temperate sandy loam and a coarse sandy subsoil. In the sandy loam...

  10. Role of plant growth regulators as chemical signals in plant-microbe interactions: a double edged sword.

    Science.gov (United States)

    Spence, Carla; Bais, Harsh

    2015-10-01

    Growth regulators act not only as chemicals that modulate plant growth but they also act as signal molecules under various biotic and abiotic stresses. Of all growth regulators, abscisic acid (ABA) is long known for its role in modulating plants response against both biotic and abiotic stress. Although the genetic information for ABA biosynthesis in plants is well documented, the knowledge about ABA biosynthesis in other organisms is still in its infancy. It is known that various microbes including bacteria produce and secrete ABA, but the overall functional significance of why ABA is synthesized by microbes is not known. Here we discuss the functional involvement of ABA biosynthesis by a pathogenic fungus. Furthermore, we propose that ABA biosynthesis in plant pathogenic fungi could be targeted for novel fungicidal discovery.

  11. Effects of gasification biochar on plant-available water capacity and plant growth in two contrasting soil types

    DEFF Research Database (Denmark)

    Hansen, Veronika; Hauggaard-Nielsen, Henrik; Petersen, Carsten Tilbæk;

    2016-01-01

    Abstract Gasification biochar (GB) contains recalcitrant carbon that can contribute to soil carbon sequestration and soil quality improvement. However, the impact of GB on plant-available water capacity (AWC) and plant growth in diverse soil types still needs to be explored. A pot experiment...... with spring barley (Hordeum vulgare L.) was conducted to investigate the effect of soil amendment by 1% straw and wood gasification biochar (SGB and WGB), respectively, on AWC and plant growth responses under two levels of water supply in a temperate sandy loam and a coarse sandy subsoil. In the sandy loam......, the reduced water regime significantly affected plant growth and water consumption, whereas the effect was less pronounced in the coarse sand. Irrespective of the soil type, both GBs increased AWC by 17–42%, with the highest absolute effect in the coarse sand. The addition of SGB to coarse sand led...

  12. Effect of plant sterols and tannins on Phytophthora ramorum growth and sporulation

    Science.gov (United States)

    The acquisition of plant sterols, mediated via elicitins, is required for growth and sporulation of Phytophthora spp. In this paper, we looked at the interaction between elicitins, sterols, and tannins. When ground leaf tissue was added to growth media, P. ramorum growth and sporulation was greates...

  13. Bacteria with ACC deaminase can promote plant growth and help to feed the world.

    Science.gov (United States)

    Glick, Bernard R

    2014-01-20

    To feed all of the world's people, it is necessary to sustainably increase agricultural productivity. One way to do this is through the increased use of plant growth-promoting bacteria; recently, scientists have developed a more profound understanding of the mechanisms employed by these bacteria to facilitate plant growth. Here, it is argued that the ability of plant growth-promoting bacteria that produce 1-aminocyclopropane-1-carboxylate (ACC) deaminase to lower plant ethylene levels, often a result of various stresses, is a key component in the efficacious functioning of these bacteria. The optimal functioning of these bacteria includes the synergistic interaction between ACC deaminase and both plant and bacterial auxin, indole-3-acetic acid (IAA). These bacteria not only directly promote plant growth, they also protect plants against flooding, drought, salt, flower wilting, metals, organic contaminants, and both bacterial and fungal pathogens. While a considerable amount of both basic and applied work remains to be done before ACC deaminase-producing plant growth-promoting bacteria become a mainstay of plant agriculture, the evidence indicates that with the expected shift from chemicals to soil bacteria, the world is on the verge of a major paradigm shift in plant agriculture. PMID:24095256

  14. Efeito de extratos de plantas utilizadas na medicina popular no crescimento e diferenciação celular de Herpetomonas samuelpessoai (Kinetoplastida, Trypanosomatidae cultivada em meio definido Effect of plant extracts used in folk medicine on cell growth and differentiation of Herpetomonas samuelpessoai (Kinetoplastida, Trypanosomatidae cultivated in defined medium

    Directory of Open Access Journals (Sweden)

    Fabiola Barbieri Holetz

    2002-04-01

    Full Text Available Neste trabalho, verificou-se o efeito de 15 plantas medicinais no crescimento e diferenciação celular de Herpetomonas samuelpessoai, um tripanosomatídeo não patogênico utilizado como modelo biológico, que apresenta antígenos semelhantes aos do Trypanosoma cruzi. Extratos brutos (1.000 g/ml ou óleo essencial (250 µg/ml foram adicionados ao meio definido. O crescimento celular foi determinado pela contagem em câmara de Newbauer e a diferenciação celular examinada por microscopia ótica. Ocimum gratissimum, Lippia alba, Piper regnellii, Stryphnodendron adstringens, e Tanacetum vulgare mostraram atividade antiprotozoário, Psidium guajava e Punica granatum menor atividade e Achillea millefolium, Eugenia uniflora, Mikania glomerata, Plantago major, e Spilanthes acmella não apresentaram atividade. Por outro lado, Arctium lappa, Erythrina speciosa, e Sambucus canadensis estimularam o crescimento de H. samuelpessoai e L. alba e S. acmella a diferenciação celular deste flagelado. Estes resultados indicam que plantas medicinais possuem princípios ativos contra H. samuelpessoai, o qual parece ser útil como modelo para seleção de plantas que contém drogas tripanomicidasThis work reports the effect of 15 medicinal plants on cell growth and differentiation of Herpetomonas samuelpessoai, a non-pathogenic trypanosomatid, used as biological model for its similar antigens to Trypanosoma cruzi. Crude extracts (1,000 g/ml or essential oil (250 g/ml were added in a defined medium. Cell growth was estimated by counting in Neubauer’s chamber and cell differentiation was examined by light microscope. Ocimum gratissimum, Lippia alba, Piper regnellii, Stryphnodendron adstringens, and Tanacetum vulgare showed antiprotozoan activity, Psidium guajava and Punica granatum a lower activity and Achillea millefolium, Eugenia uniflora, Mikania glomerata, Plantago major, and Spilanthes acmella had no activity. In contrast, Arctium lappa, Erythrina

  15. Using Tissue Culture To Investigate Plant Cell Differentiation and Dedifferentiation.

    Science.gov (United States)

    Bozzone, Donna M.

    1997-01-01

    Describes an experimental project that uses plant tissue culture techniques to examine cell differentiation in the carrot. Allows students to gain experience in some important techniques and to explore fundamental questions about cell differentiation. (DDR)

  16. Advanced technologies for plant cell wall evolution and diversity

    DEFF Research Database (Denmark)

    Fangel, Jonatan Ulrik

    Plant cell walls consist of polysaccharides, glycoproteins and phenolic polymers interlinked together in a highly complex network. The detailed analysis of cell walls is challenging because of their inherent complexity and heterogeneity. Also, complex carbohydrates, unlike proteins and nucleotide...

  17. Formative cell divisions: principal determinants of plant morphogenesis.

    Science.gov (United States)

    Smolarkiewicz, Michalina; Dhonukshe, Pankaj

    2013-03-01

    Formative cell divisions utilizing precise rotations of cell division planes generate and spatially place asymmetric daughters to produce different cell layers. Therefore, by shaping tissues and organs, formative cell divisions dictate multicellular morphogenesis. In animal formative cell divisions, the orientation of the mitotic spindle and cell division planes relies on intrinsic and extrinsic cortical polarity cues. Plants lack known key players from animals, and cell division planes are determined prior to the mitotic spindle stage. Therefore, it appears that plants have evolved specialized mechanisms to execute formative cell divisions. Despite their profound influence on plant architecture, molecular players and cellular mechanisms regulating formative divisions in plants are not well understood. This is because formative cell divisions in plants have been difficult to track owing to their submerged positions and imprecise timings of occurrence. However, by identifying a spatiotemporally inducible cell division plane switch system applicable for advanced microscopy techniques, recent studies have begun to uncover molecular modules and mechanisms for formative cell divisions. The identified molecular modules comprise developmentally triggered transcriptional cascades feeding onto microtubule regulators that now allow dissection of the hierarchy of the events at better spatiotemporal resolutions. Here, we survey the current advances in understanding of formative cell divisions in plants in the context of embryogenesis, stem cell functionality and post-embryonic organ formation. PMID:23248201

  18. Genetic and phenotypic diversity of plant growth promoting rhizobacteria isolated from sugarcane plants growing in pakistan.

    Science.gov (United States)

    Mehnaz, Samina; Baig, Deeba Noreen; Lazarovits, George

    2010-12-01

    Bacteria were isolated from roots of sugarcane varieties grown in the fields of Punjab. They were identified by using API20E/NE bacterial identification kits and from sequences of 16S rRNA and amplicons of the cpn60 gene. The majority of bacteria were found to belong to the genera of Enterobacter, Pseudomonas, and Klebsiella, but members of genera Azospirillum, Rhizobium, Rahnella, Delftia, Caulobacter, Pannonibacter, Xanthomonas, and Stenotrophomonas were also found. The community, however, was dominated by members of the Pseudomonadaceae and Enterobacteriaceae, as representatives of these genera were found in samples from every variety and location examined. All isolates were tested for the presence of five enzymes and seven factors known to be associated with plant growth promotion. Ten isolates showed lipase activity and eight were positive for protease activity. Cellulase, chitinase, and pectinase were not detected in any strain. Nine strains showed nitrogen fixing ability (acetylene reduction assay) and 26 were capable of solubilizing phosphate. In the presence of 100 mg/l tryptophan, all strains except one produced indole acetic acid in the growth medium. All isolates were positive for ACC deaminase activity. Six strains produced homoserine lactones and three produced HCN and hexamate type siderophores. One isolate was capable of inhibiting the growth of 24 pathogenic fungal strains of Colletotrichum, Fusarium, Pythium, and Rhizoctonia spp. In tests of their abilities to grow under a range of temperature, pH, and NaCl concentrations, all isolates grew well on plates with 3% NaCl and most of them grew well at 4 to 41degrees C and at pH 11.

  19. Plant cell wall proteomics: the leadership of Arabidopsis thaliana

    OpenAIRE

    Albenne, Cécile; Canut, Hervé; Jamet, Elisabeth

    2013-01-01

    Plant cell wall proteins (CWPs) progressively emerged as crucial components of cell walls although present in minor amounts. Cell wall polysaccharides such as pectins, hemicelluloses, and cellulose represent more than 90% of primary cell wall mass, whereas hemicelluloses, cellulose, and lignins are the main components of lignified secondary walls. All these polymers provide mechanical properties to cell walls, participate in cell shape and prevent water loss in aerial organs. However, cell wa...

  20. Understanding CrRLK1L Function: Cell Walls and Growth Control.

    Science.gov (United States)

    Nissen, Karen S; Willats, William G T; Malinovsky, Frederikke G

    2016-06-01

    To develop successfully in an ever-changing environment, it is essential for plants to monitor and control their growth. Therefore, cell expansion is carefully regulated to establish correct cell shape and size. In this review, we explore the role of the Catharanthus roseus receptor-like kinase (CrRLK1L) subfamily as regulators of cell expansion. Recently, the downstream signalling events of individual CrRLK1L pathways were discovered, implicating known modulators of cell expansion, such as reactive oxygen species (ROS) production, Ca(2+) dynamics, and exocytosis of cell wall material. Based on these intriguing new insights, we propose a model for a common pathway of CrRLK1L signalling that enables spatial and temporal control of cell wall extensibility throughout the plant. PMID:26778775

  1. Cell Fate Switch during In Vitro Plant Organogenesis

    Institute of Scientific and Technical Information of China (English)

    Xiang Yu Zhao; Ying Hua Su; Zhi Juan Cheng; Xian Sheng Zhang

    2008-01-01

    Plant mature cells have the capability to reverse their state of differenUation and produce new organs under cultured conditions. Two phases, dedifferentiation and redifferentiation, are commonly characterized during in vitro organogenesis.In these processes, cells undergo fate switch several times regulated by both extrinsic and intrinsic factors, which are associated with reentry to the cell cycle, the balance between euchromatin and heterochromatin, reprogramming of gene expression, and so forth. This short article reviews the advances in the mechanism of organ regeneration from plant somatic cells in molecular, genomic and epigenetic aspects, aiming to provide important information on the mechanism underlying cell fate switch during in vitro plant organogenesis.

  2. Explaining tomato fruit growth by a multi-scale model on regulation of cell division, cell growth and carbohydrate dynamics

    NARCIS (Netherlands)

    Visser, de P.H.B.; Kromdijk, W.; Okello, R.C.; Fanwoua, J.; Struik, P.C.; Yin, X.; Heuvelink, E.; Marcelis, L.F.M.

    2012-01-01

    A multi-scale approach to model tomato fruit growth is proposed, in order to account for the interaction between gene functioning and growth conditions, and, ultimately, to explain the fruit phenotype of various genotypes in diverse growth environments. There is particular focus on: (I) cell divisio

  3. Transcriptional analysis of cell growth and morphogenesis in the unicellular green alga Micrasterias (Streptophyta), with emphasis on the role of expansin

    OpenAIRE

    Vannerum, K.; Huysman, M. J. J.; De Rycke, R.; Vuylsteke, M.; Leliaert, F.; Pollier, J.; Lütz-Meindl, U.; Gillard, J; De Veylder, L.; Goossens, A; Inzé, D; Vyverman, W.

    2011-01-01

    BackgroundStreptophyte green algae share several characteristics of cell growth and cell wall formation with their relatives, the embryophytic land plants. The multilobed cell wall of Micrasterias denticulata that rebuilds symmetrically after cell division and consists of pectin and cellulose, makes this unicellular streptophyte alga an interesting model system to study the molecular controls on cell shape and cell wall formation in green plants.ResultsGenome-wide transcript expression profil...

  4. Transcriptional analysis of cell growth and morphogenesis in the unicellular green alga Micrasterias (Streptophyta), with emphasis on the role of expansin

    OpenAIRE

    Leliaert Frederik; Vuylsteke Marnik; De Rycke Riet; Huysman Marie JJ; Vannerum Katrijn; Pollier Jacob; Lütz-Meindl Ursula; Gillard Jeroen; De Veylder Lieven; Goossens Alain; Inzé Dirk; Vyverman Wim

    2011-01-01

    Abstract Background Streptophyte green algae share several characteristics of cell growth and cell wall formation with their relatives, the embryophytic land plants. The multilobed cell wall of Micrasterias denticulata that rebuilds symmetrically after cell division and consists of pectin and cellulose, makes this unicellular streptophyte alga an interesting model system to study the molecular controls on cell shape and cell wall formation in green plants. Results Genome-wide transcript expre...

  5. Growth kinetics of Thiobacillus ferrooxidans in bioelectrochemical cell

    Institute of Scientific and Technical Information of China (English)

    李宏煦; 王淀佐; 邱冠周; 胡岳华

    2004-01-01

    Thiobacillus ferrooxidans might be the most important bacteria used in biometallurgy. The foundation way of its growth process is oxidizing ferrous in order to obtain energy needed for metabolism, but the variation of ferrous concentration and mixed potential of the culture media would have crucial effect on the bacteria growth.Based on the characteristics of Thiobacillus ferrooxidans growth and redox potential of ferric and ferrous, an electrochemical cell was designed conventionally to study growth rule and the relationship between redox potential and bacteria growth was built up, and some growth kinetics of Thiobacillus ferrooxidans were elucidated. It demonstrates that the variation of open potential of electrochemical cell △E shows the growth tendency of Thiobacillus ferrooxidans, at the initial growth stage, the value of △E increases slowly, when at logistic growth stage, it increases drastically, and the growth rate of bacteria is linear with the oxidation rate of ferrous. The bacteria growth kinetics model is proposed using Monod and Michealis-Menten equation, and the kinetics parameters are got. The consistence of the measured and the calculated results proves that it is proper to use the proposed kinetics model and the electrochemical cell method to describe the growth rule of Thiobacillus ferrooxidans.

  6. MHC class II molecules regulate growth in human T cells

    DEFF Research Database (Denmark)

    Nielsen, M; Odum, Niels; Bendtzen, K;

    1994-01-01

    modulate several T cell responses. Here, we studied further the role of class II molecules in the regulation of T cell growth. Costimulation of class II molecules by immobilized HLA-DR mAb significantly enhanced interleukin (IL)-2-supported T cell growth of the majority of CD4+, CD45RAlow, ROhigh T cell......-like) as well as T cells producing both cytokines (THO-like) responded to class II mAb. The costimulatory effect was not restricted to IL-2-driven T cell growth, since TCR/CD3-induced T cell activation was also enhanced by HLA-DR mAb. Moreover, class II costimulation potentiated CD28-mAb-induced T cell...

  7. Plant cell wall dynamics and wall-related susceptibility in plant-pathogen interactions

    OpenAIRE

    Daniela eBellincampi; Felice eCervone; Vincenzo eLionetti

    2014-01-01

    The cell wall is a dynamic structure that often determines the outcome of the interactions between plants and pathogens. It is a barrier that pathogens need to breach to colonize the plant tissue. While fungal necrotrophs extensively destroy the integrity of the cell wall through the combined action of degrading enzymes, biotrophic fungi require a more localized and controlled degradation of the cell wall in order to keep the host cells alive and utilize their feeding structures. Also bacteri...

  8. Leaf and Life History Traits Predict Plant Growth in a Green Roof Ecosystem

    OpenAIRE

    Jeremy Lundholm; Amy Heim; Stephanie Tran; Tyler Smith

    2014-01-01

    Green roof ecosystems are constructed to provide services such as stormwater retention and urban temperature reductions. Green roofs with shallow growing media represent stressful conditions for plant survival, thus plants that survive and grow are important for maximizing economic and ecological benefits. While field trials are essential for selecting appropriate green roof plants, we wanted to determine whether plant leaf traits could predict changes in abundance (growth) to provide a more ...

  9. Effects of Eichhornia crassipes Growth on Aquatic Plants in Dianchi Lake

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    [Objective] The aim was to study the effects of Eichhornia crassipes as an invasive plant on aquatic plants in Dianchi Lake. [Method] Based on the determination of chlorophyll content of phytoplankton and submerged plant (Potamogeton pectinatus) in Dianchi Lake in different months, the effects of E. crassipes on aquatic plants in Dianchi Lake were studied, and the allelopathy effect of root culture solution of E. crassipes on Microcystis aquaticum was discussed. [Result] The growth of E. crassipes in Dianch...

  10. Growth and Contaminant Removal Effect of Several Plants in Constructed Wetlands

    Institute of Scientific and Technical Information of China (English)

    Xiu-Yun Cheng; Ming-Qiu Liang; Wen-Yin Chen; Xu-Cheng Liu; Zhang-He Chen

    2009-01-01

    The aim of the present study is to probe the relation between plant growth and its decontamination effect in constructed wetlands.Four species were studied in the small-scale mono-cuitured constructed wetlands, which were fed with domestic wastewater. Plant growth indexes were correlated with contaminant removal performance of the constructed wetlands. Wetlands planted with Cyperus flabelliformis Rottb. showed the highest growth indexes such as shoot growth, biomass, root activity, root biomass increment, and the highest contaminant removal rates, whereas wetlands planted with Vetiveria zizanioides L. Nash had the lowest growth indexes and the lowest removal rates. Above-ground biomass and total biomass were significantly correlated with ammonia nitrogen removal, and below-ground biomass with soluble reactive phosphorus removal. Photosynthetic rate had higher correlation with nitrogen removal in these species. Root activity and root biomass increment was more correlated with 5 d biochemical oxygen demand removal.Chemical oxygen demand removal had lower correlations with plant growth indexes. All four species had higher removal rates in summer and autumn. The results suggest that the effect of plant growth on contaminant removal in constructed wetlands were different specifically in plants and contaminants.

  11. Isolation and biological activity of a new plant growth regulator of Vicia faba L

    International Nuclear Information System (INIS)

    Jasmonic acid was identified as a plant growth inhibitor of the pericarp of Vicia faba by means of gas-liquid chromatography, high resolution mass spectrometry as well as 1H and 13C NMR. The highest level of jasmonic acid was reached during intensive pericarp growth. Jasmonic acid is a plant growth inhibitor possessing a relative activity in the wheat seedling bioassay of 1-2.5 % compared to ABA (=100%). Contrary to ABA, jasmonic acid does not cause retardation of leaf emergence. In the dwarf rice gibberellin bioassay relative low concentrations of jasmonic acid inhibit both autonomous and GA3-stimulated growth. Jasmonic acid does not influence seed germination of Amaranthus caudatus. The possible physiological role of jasmonic acid in the Vicia pericarp and the distribution in plants of this new plant growth regulator type are discussed. (author)

  12. The First Observation on Plant Cell Fossils in China

    Institute of Scientific and Technical Information of China (English)

    WANG Xin; CUI Jinzhong

    2007-01-01

    For a long time, paleontologists have been focusing on hard parts of organisms during different geological periods while soft parts are rarely reported. Well-preserved plant cells, if found in fossils, are treated only as a rarity. Recent progress in research on fossil cytoplasm indicates that plant cytoplasm not only has excellent ultrastructures preserved but also may be a quite commonly seen fossil in strata. However, up to now there is no report of plant cell fossils in China yet. Here plant cell fossils are reported from Huolinhe Coal Mine (the early Cretaceous), Inner Mongolia, China. The presence of plant cytoplasm fossils in two cones on the same specimen not only provides further support for the recently proposed hypothesis on plant cytoplasm fossilization but also marks the first record of plant cytoplasm fossils in China, which suggests a great research potential in this new area.

  13. Progress and prospects for phosphoric acid fuel cell power plants

    Energy Technology Data Exchange (ETDEWEB)

    Bonville, L.J.; Scheffler, G.W.; Smith, M.J. [International Fuel Cells Corp., South Windsor, CT (United States)

    1996-12-31

    International Fuel Cells (IFC) has developed the fuel cell power plant as a new, on-site power generation source. IFC`s commercial fuel cell product is the 200-kW PC25{trademark} power plant. To date over 100 PC25 units have been manufactured. Fleet operating time is in excess of one million hours. Individual units of the initial power plant model, the PC25 A, have operated for more than 30,000 hours. The first model {open_quotes}C{close_quotes} power plant has over 10,000 hours of operation. The manufacturing, application and operation of this power plant fleet has established a firm base for design and technology development in terms of a clear understanding of the requirements for power plant reliability and durability. This fleet provides the benchmark against which power plant improvements must be measured.

  14. Plumbagin attenuates cancer cell growth and osteoclast formation in the bone microenvironment of mice

    OpenAIRE

    Yan, Wei; Wang, Ting-Yu; Fan, Qi-ming; Du, Lin; Xu, Jia-ke; Zhai, Zan-jing; Li, Hao-wei; Tang, Ting-ting

    2014-01-01

    Aim: To investigate the effects of plumbagin, a naphthoquinone derived from the medicinal plant Plumbago zeylanica, on human breast cancer cell growth and the cancer cell-induced osteolysis in the bone microenvironment of mice. Methods: Human breast cancer cell subline MDA-MB-231SA with the ability to spread and grow in the bone was tested. The cell proliferation was determined using the CCK-8 assay. Apoptosis was detected with Annexin V/PI double-labeled flow cytometry. Red fluorescent prote...

  15. Silica distribution in various bamboos species and its effects on plant growth

    Science.gov (United States)

    Collin, B.; Meunier, J.; Keller, C.; Doelsch, E.; Panfili, F.

    2010-12-01

    Bamboos are distributed throughout the world’s temperate, tropical and subtropical regions. They are widely used in industry, as fresh edible shoots, paper maker, building and even in medicine. Bamboos also play multiple ecologic functions such as soil and water conservation and erosion control. Bamboos have generally high silicon (Si) content. Silicon is known to have beneficial effects on plants and alleviate various stresses. The aim of this study is to quantify the Si uptake and distribution in various bamboos species and to investigate the effects of Si on the plant growth. Two complementary studies were carried out, one under natural conditions and one under controlled conditions. First of all, we performed an inventory of Si tissue content in 16 bamboos species growing in a non-polluted tropical soil at the Reunion Island (France, Indian ocean). We determined Si content in leaf and in stem tissues sampled at several heights for each plant. One of these species Gigantocloa sp « Malay Dwarf » was grown for 3 months in nutrient solution at five Si concentrations (0, 0.25, 0.75, 1.15, 1.5 mM Si). Silica deposition was examined in leaves using a cryo-SEM equipped with EDS. The Si concentration varies significantly between species, depending on rhizome morphology. Bamboos having leptomorph rhizomes show significantly higher leaf and stem Si content than that of species having pachymorph rhizomes. The distribution of Si in the plant has the same trends for all species. Leaves are the most concentrated organs (10.9 %), and within the stem Si concentration significantly increases from the bottom (0.32%) to the top of the plant (2.1%). Plant Si content increases with the Si supply. Leaves of Gigantocloa sp « Malay Dwarf » accumulate 15.2 % of Si under natural conditions and up to 24 % when exposed to the highest Si treatment. Unlike previous studies, our experiment shows that the concentration of Si had no significant effect on nutrient uptake and biomass

  16. Growth of children with Langerhans cell histiocytosis

    NARCIS (Netherlands)

    A.C.J. van den Hoek (A. C J); A. Karstens (A.); R.M. Egeler (Maarten); K. Hählen (Karel)

    1995-01-01

    textabstractConclusion: GH deficiency is not a common manifestation of LCH in childhood and GH provocation tests are only indicated when there is a poor or decelerating growth rate. In our patients the number of organs involved and/or the treatment modality did not influence the growth in all but on

  17. Chemical- and pathogen-induced programmed cell death in plants

    NARCIS (Netherlands)

    Iakimova, E.T.; Atanassov, A.; Woltering, E.J.

    2005-01-01

    This review focuses on recent update in the understanding of programmed cell death regarding the differences and similarities between the diverse types of cell death in animal and plant systems and describes the morphological and some biochemical determinants. The role of PCD in plant development an

  18. Dihydroartemisinin is an inhibitor of ovarian cancer cell growth

    Institute of Scientific and Technical Information of China (English)

    Yang JIAO; Chun-min GE; Qing-hui MENG; Jian-ping CAO; Jian TONG; Sai-jun FAN

    2007-01-01

    Aim: To investigate the anticancer activity of dihydroartemisinin (DHA), a deriva-tive of antimalaria drug artemisinin in a panel of human ovarian cancer cell lines. Methods: Cell growth was determined by the MTT viability assay. Apoptosis and cell cycle progression were evaluated by a DNA fragmentation gel electro-phoresis, flow cytometry assay, and TUNEL assay; protein and mRNA expression were analyzed by Western blotting and RT-PCR assay. Results: Artemisinin and its derivatives, including artesunate, arteether, artemether, arteannuin, and DHA, exhibit anticancer growth activities in human ovarian cancer cells. Among them, DHA is the most effective in inhibiting cell growth. Ovarian cancer cell lines are more sensitive (5-10-fold) to DHA treatment compared to normal ovarian cell lines. DHA at micromolar dose levels exhibits a dose- and time-dependent cyto-toxicity in ovarian cancer cell lines. Furthermore, DHA induced apoptosis and G2 cell cycle arrest, accompanied by a decrease of Bcl-xL and Bcl-2 and an increase of Bax and Bad. Conclusion: The promising results show for the first time that DHA inhibits the growth of human ovarian cancer cells. The selective inhibition of ovarian cancer cell growth, apoptosis induction, and G2 arrest provide in vitro evidence for further studies of DHA as a possible anticancer drug in the clinical treatment of ovarian cancer.

  19. Influence of Plant Population and Nitrogen-Fertilizer at Various Levels on Growth and Growth Efficiency of Maize

    Directory of Open Access Journals (Sweden)

    M. I. Tajul

    2013-01-01

    Full Text Available Field experiments were conducted to evaluate plant population and N-fertilizer effects on yield and yield components of maize (Zea mays L.. Three levels of plant populations (53000, 66000, and 800000 plants ha−1 corresponding to spacings of 75 × 25, 60 × 25, and 50 × 25 cm and 4 doses of N (100, 140, 180, and 220 kg ha−1 were the treatment variables. Results revealed that plant growth, light interception (LI, yield attributes, and grain yield varied significantly due to the variations in population density and N-rates. Crop growth rate (CGR was the highest with the population of 80,000 ha−1 receiving 220 kg N ha−1, while relative growth rate (RGR showed an opposite trend of CGR. Light absorption was maximum when most of densely populated plant received the highest amount of N (220 kg N ha−1. Response of soil-plant-analysis development (SPAD value as well as N-content to N-rates was found significant. Plant height was the maximum at the lowest plant density with the highest amount of N. Plants that received 180 kg N ha−1 with 80,000 plants ha−1 had larger foliage, greater SPAD value, and higher amount of grains cob−1 that contributed to the maximum yield (5.03 t ha−1 and the maximum harvest index (HI compared to the plants in other treatments.

  20. Influence of plant population and nitrogen-fertilizer at various levels on growth and growth efficiency of maize.

    Science.gov (United States)

    Tajul, M I; Alam, M M; Hossain, S M M; Naher, K; Rafii, M Y; Latif, M A

    2013-01-01

    Field experiments were conducted to evaluate plant population and N-fertilizer effects on yield and yield components of maize (Zea mays L.). Three levels of plant populations (53000, 66000, and 800,000 plants ha⁻¹ corresponding to spacings of 75 × 25, 60 × 25, and 50 × 25 cm) and 4 doses of N (100, 140, 180, and 220 kg ha⁻¹) were the treatment variables. Results revealed that plant growth, light interception (LI), yield attributes, and grain yield varied significantly due to the variations in population density and N-rates. Crop growth rate (CGR) was the highest with the population of 80,000 ha⁻¹ receiving 220 kg N ha⁻¹, while relative growth rate (RGR) showed an opposite trend of CGR. Light absorption was maximum when most of densely populated plant received the highest amount of N (220 kg N ha⁻¹). Response of soil-plant-analysis development (SPAD) value as well as N-content to N-rates was found significant. Plant height was the maximum at the lowest plant density with the highest amount of N. Plants that received 180 kg N ha⁻¹ with 80,000 plants ha⁻¹ had larger foliage, greater SPAD value, and higher amount of grains cob⁻¹ that contributed to the maximum yield (5.03 t ha⁻¹) and the maximum harvest index (HI) compared to the plants in other treatments.

  1. Growth chamber for the cultivation of woody plants in a radioactive carbon dioxide atmosphere

    International Nuclear Information System (INIS)

    A growth chamber is described, suited for the production of uniformly C14-labelled plant material. Temperature and humidity is automatically controlled. Radioactive 14CO2 is supplied by means of a manually operated bariumcarbonate-reactor. The cultivation of poplars (Populus tremula), larches (Larix Europea) and Scots pines (Pinus silvestris) as well as their growth experiences are described. Average specific activity of the plant material was 2 μCi/gC. This growth chamber is especially useful for labelling woody plants over long growing periods. (orig.)

  2. Stimulatory effects of arsenic-tolerant soil fungi on plant growth promotion and soil properties.

    Science.gov (United States)

    Srivastava, Pankaj Kumar; Shenoy, Belle Damodara; Gupta, Manjul; Vaish, Aradhana; Mannan, Shivee; Singh, Nandita; Tewari, Shri Krishna; Tripathi, Rudra Deo

    2012-01-01

    Fifteen fungi were obtained from arsenic-contaminated agricultural fields in West Bengal, India and examined for their arsenic tolerance and removal ability in our previous study. Of these, the four best arsenic-remediating isolates were tested for plant growth promotion effects on rice and pea in the present study. A greenhouse-based pot experiment was conducted using soil inocula of individual fungi. The results indicated a significant (PLasiodiplodia. These fungi improved soil nutrient content and enhanced plant growth. These fungi may be used as bioinoculants for plant growth promotion and improved soil properties in arsenic-contaminated agricultural soils. PMID:23047145

  3. Plant programmed cell death, ethylene and flower senescence

    NARCIS (Netherlands)

    Woltering, E.J.; Jong, de A.; Hoeberichts, F.A.; Iakimova, E.T.; Kapchina, V.

    2005-01-01

    Programmed cell death (PCD) applies to cell death that is part of the normal life of multicellular organisms. PCD is found throughout the animal and plant kingdoms; it is an active process in which a cell suicide pathway is activated resulting in controlled disassembly of the cell. Most cases of PCD

  4. The role of root border cells in plant defense.

    Science.gov (United States)

    Hawes, M C; Gunawardena, U; Miyasaka, S; Zhao, X

    2000-03-01

    The survival of a plant depends upon the capacity of root tips to sense and move towards water and other nutrients in the soil. Perhaps because of the root tip's vital role in plant health, it is ensheathed by large populations of detached somatic cells - root 'border' cells - which have the ability to engineer the chemical and physical properties of the external environment. Of particular significance, is the production by border cells of specific chemicals that can dramatically alter the behavior of populations of soilborne microflora. Molecular approaches are being used to identify and manipulate the expression of plant genes that control the production and the specialized properties of border cells in transgenic plants. Such plants can be used to test the hypothesis that these unusual cells act as a phalanx of biological 'goalies', which neutralize dangers to newly generated root tissue as the root tip makes its way through soil.

  5. Assembly and enlargement of the primary cell wall in plants

    Science.gov (United States)

    Cosgrove, D. J.

    1997-01-01

    Growing plant cells are shaped by an extensible wall that is a complex amalgam of cellulose microfibrils bonded noncovalently to a matrix of hemicelluloses, pectins, and structural proteins. Cellulose is synthesized by complexes in the plasma membrane and is extruded as a self-assembling microfibril, whereas the matrix polymers are secreted by the Golgi apparatus and become integrated into the wall network by poorly understood mechanisms. The growing wall is under high tensile stress from cell turgor and is able to enlarge by a combination of stress relaxation and polymer creep. A pH-dependent mechanism of wall loosening, known as acid growth, is characteristic of growing walls and is mediated by a group of unusual wall proteins called expansins. Expansins appear to disrupt the noncovalent bonding of matrix hemicelluloses to the microfibril, thereby allowing the wall to yield to the mechanical forces generated by cell turgor. Other wall enzymes, such as (1-->4) beta-glucanases and pectinases, may make the wall more responsive to expansin-mediated wall creep whereas pectin methylesterases and peroxidases may alter the wall so as to make it resistant to expansin-mediated creep.

  6. Effect of plant growth regulators on leaf anatomy of the has mutant of Arabidopsis thaliana.

    Science.gov (United States)

    Janosević, D; Uzelac, B; Budimir, S

    2008-12-01

    In this study, the effect of plant growth regulators on leaf morphogenesis of the recessive T-DNA insertion mutant of Arabidopsis thaliana was analyzed. The morpho-anatomical analysis revealed that leaves of the has mutant are small and narrow, with lobed blades and disrupted tissue organization. When has plants were grown on the medium supplied with plant growth regulators: benzylaminopurine (BAP) or ethylene precursor, 1-aminocyclopropane-1-carboxylic acid (ACC), the leaf anatomy was partially restored to the wild type, although plants still exhibited morphological abnormalities.

  7. ISOLATION AND CHARACTERIZATION OF RHIZOBIA AND PLANT GROWTH-PROMOTING RHIZOBACTERIA AND THEIR EFFECTS ON GROWTH OF RICE SEEDLINGS

    OpenAIRE

    K. Z. Tan; O. Radziah; Halimi, M. S.; A. R. Khairuddin; S. H. Habib; Shamsuddin, Z. H.

    2014-01-01

    Biofertilizer is a relatively safer, environmentally friendly and cost-effective approach as an alternative to reduce chemical fertilizer usage. The selection of bacterial strains with multiple beneficial characteristics are important to maximize the effectiveness on the host plant. Due to aforementioned interest, several Plant Growth-Promoting Rhizobacterial (PGPR) and rhizobial strains were isolated from rice and legume roots, respectively, at four locations in Malaysia namely Universiti Pu...

  8. Withaferin A inhibits in vivo growth of breast cancer cells accelerated by Notch2 knockdown.

    Science.gov (United States)

    Kim, Su-Hyeong; Hahm, Eun-Ryeong; Arlotti, Julie A; Samanta, Suman K; Moura, Michelle B; Thorne, Stephen H; Shuai, Yongli; Anderson, Carolyn J; White, Alexander G; Lokshin, Anna; Lee, Joomin; Singh, Shivendra V

    2016-05-01

    The present study offers novel insights into the molecular circuitry of accelerated in vivo tumor growth by Notch2 knockdown in triple-negative breast cancer (TNBC) cells. Therapeutic vulnerability of Notch2-altered growth to a small molecule (withaferin A, WA) is also demonstrated. MDA-MB-231 and SUM159 cells were used for the xenograft studies. A variety of technologies were deployed to elucidate the mechanisms underlying tumor growth augmentation by Notch2 knockdown and its reversal by WA, including Fluorescence Molecular Tomography for measurement of tumor angiogenesis in live mice, Seahorse Flux analyzer for ex vivo measurement of tumor metabolism, proteomics, and Luminex-based cytokine profiling. Stable knockdown of Notch2 resulted in accelerated in vivo tumor growth in both cells reflected by tumor volume and/or latency. For example, the wet tumor weight from mice bearing Notch2 knockdown MDA-MB-231 cells was about 7.1-fold higher compared with control (P medicinal plant. Molecular underpinnings for tumor growth intensification by Notch2 knockdown included compensatory increase in Notch1 activation, increased cellular proliferation and/or angiogenesis, and increased plasma or tumor levels of growth stimulatory cytokines. WA administration reversed many of these effects providing explanation for its remarkable anti-cancer efficacy. Notch2 functions as a tumor growth suppressor in TNBC and WA offers a novel therapeutic strategy for restoring this function. PMID:27097807

  9. Growth-stimulatory effect of resveratrol in human cancer cells.

    Science.gov (United States)

    Fukui, Masayuki; Yamabe, Noriko; Kang, Ki Sung; Zhu, Bao Ting

    2010-08-01

    Earlier studies have shown that resveratrol could induce death in several human cancer cell lines in culture. Here we report our observation that resveratrol can also promote the growth of certain human cancer cells when they are grown either in culture or in athymic nude mice as xenografts. At relatively low concentrations (cells, but this effect was not observed in several other human cell lines tested. Analysis of cell signaling molecules showed that resveratrol induced the activation of JNK, p38, Akt, and NF-kappaB signaling pathways in these cells. Further analysis using pharmacological inhibitors showed that only the NF-kappaB inhibitor (BAY11-7082) abrogated the growth-stimulatory effect of resveratrol in cultured cells. In athymic nude mice, resveratrol at 16.5 mg/kg body weight enhanced the growth of MDA-MB-435s xenografts compared to the control group, while resveratrol at the 33 mg/kg body weight dose did not have a similar effect. Additional analyses confirmed that resveratrol stimulated cancer cell growth in vivo through activation of the NF-kappaB signaling pathway. Taken together, these observations suggest that resveratrol at low concentrations could stimulate the growth of certain types of human cancer cells in vivo. This cell type-specific mitogenic effect of resveratrol may also partly contribute to the procarcinogenic effect of alcohol consumption (rich in resveratrol) in the development of certain human cancers.

  10. Cell wall integrity signaling and innate immunity in plants

    OpenAIRE

    Nühse, Thomas S.

    2012-01-01

    All plant pathogens and parasites have had to develop strategies to overcome cell walls in order to access the host’s cytoplasm. As a mechanically strong, multi-layered composite exoskeleton, the cell wall not only enables plants to grow tall but also protects them from such attacks. Many plant pathogens employ an arsenal of cell wall degrading enzymes, and it has long been thought that the detection of breaches in wall integrity contributes to the induction of defense. Cell wall fragments ar...

  11. The influence of humic acids derived from earthworm-processed organic wastes on plant growth

    Energy Technology Data Exchange (ETDEWEB)

    Atiyeh, R.M.; Lee, S.; Edwards, C.A.; Arancon, N.Q.; Metzger, J.D. [Ohio State University, Columbus, OH (United States). Soil Ecology Lab.

    2002-08-01

    Some effects of humic acids, formed during the breakdown of organic wastes by earthworms (vermicomposting), on plant growth were evaluated. In the first experiment, humic acids were extracted from pig manure vermicompost using the classic alkali/acid fractionation procedure and mixed with a soilless container medium (Metro-Mix 360), to provide a range of 0, 50, 100, 150, 200, 250, 500, 1000, 2000 and 4000 mg of humate per kg of dry weight of container medium, and tomato seedlings were grown in the mixtures. In the second experiment, humates extracted from pig manure and food wastes vermicomposts were mixed with vermiculite to provide a range of 0, 50, 125, 250, 500, 1000 and 4000 mg of humate per kg of dry weight of the container medium, and cucumber seedlings were grown in the mixtures. Both tomato and cucumber seedlings were watered daily with a solution containing all nutrients required to ensure that any differences in growth responses were not nutrient-mediated. The incorporation of both types of vermicompost-derived humic acids, into either type of soilless plant growth media, increased the growth of tomato and cucumber plants significantly, in terms of plant heights, leaf areas, shoot and root dry weights. Plant growth increased with increasing concentrations of humic acids incorporated into the medium up to a certain proportion, but this differed according to the plant species, the source of the vermicompost, and the nature of the container medium. Plant growth tended to be increased by treatments of the plants with 50-500 mg/kg humic acids, but often decreased significantly when the concentrations of humic acids derived in the container medium exceeded 500-1000 mg/kg. These growth responses were most probably due to hormone-like activity of humic acids from the vermicomposts or could have been due to plant growth hormones adsorbed onto the humates. (author)

  12. Effects of plant growth promoting bacteria (PGPB) on yield, growth and nutrient contents of organically grown strawberry

    OpenAIRE

    Ahmet ESITKEN; Yildiz, Hilal E.; Ercisli, Sezai; Donmez, M.Figen; Turan, Metin; Gunes, Adem

    2009-01-01

    The effects of plant growth promoting bacteria (PGPB) on the fruit yield, growth and nutrient element content of strawberry cv. Fern were investigated under organic growing conditions between 2006 and 2008. The experimental plot was a completely randomized design with 3 replicates. Three PGPB strains (Pseudomonas BA-8, Bacillus OSU-142 and Bacillus M-3) were used alone or in combination as biofertilizer agent in the experiment. Data through 3 years showed that the use of PGPB sign...

  13. Endothelial cell-derived interleukin-6 regulates tumor growth

    International Nuclear Information System (INIS)

    Endothelial cells play a complex role in the pathobiology of cancer. This role is not limited to the making of blood vessels to allow for influx of oxygen and nutrients required for the high metabolic demands of tumor cells. Indeed, it has been recently shown that tumor-associated endothelial cells secrete molecules that enhance tumor cell survival and cancer stem cell self-renewal. The hypothesis underlying this work is that specific disruption of endothelial cell-initiated signaling inhibits tumor growth. Conditioned medium from primary human dermal microvascular endothelial cells (HDMEC) stably transduced with silencing RNA for IL-6 (or controls) was used to evaluate the role of endothelial-derived IL-6 on the activation of key signaling pathways in tumor cells. In addition, these endothelial cells were co-transplanted with tumor cells into immunodefficient mice to determine the impact of endothelial cell-derived IL-6 on tumor growth and angiogenesis. We observed that tumor cells adjacent to blood vessels show strong phosphorylation of STAT3, a key mediator of tumor progression. In search for a possible mechanism for the activation of the STAT3 signaling pathway, we observed that silencing interleukin (IL)-6 in tumor-associated endothelial cells inhibited STAT3 phosphorylation in tumor cells. Notably, tumors vascularized with IL-6-silenced endothelial cells showed lower intratumoral microvessel density, lower tumor cell proliferation, and slower growth than tumors vascularized with control endothelial cells. Collectively, these results demonstrate that IL-6 secreted by endothelial cells enhance tumor growth, and suggest that cancer patients might benefit from targeted approaches that block signaling events initiated by endothelial cells

  14. Compost and vermicompost as nursery pot components: effects on tomato plant growth and morphology

    Energy Technology Data Exchange (ETDEWEB)

    Lazcano, C.; Arnold, J.; Tato, A.; Zaller, J. G.; Dominguez, J.

    2009-07-01

    Abstract Post transplant success after nursery stage is strongly influenced by plant morphology. Cultural practices strongly shape plant morphology, and substrate choice is one of the most determining factors. Peat is the most often used amendment in commercial potting substrates, involving the exploitation of non-renewable resources and the degradation of highly valuable peatland ecosystems and therefore alternative substrates are required. Here the feasibility of replacing peat by compost or vermicompost for the production of tomato plants in nurseries was investigated through the study of the effect of increasing proportions of these substrates (0%, 10%, 20%, 50%, 75% and 100%) in target plant growth and morphological features, indicators of adequate post-transplant growth and yield. Compost and vermicompost showed to be adequate substrates for tomato plant growth. Total replacement of peat by vermicompost was possible while doses of compost higher than 50% caused plant mortality. Low doses of compost (10 and 20%) and high doses of vermicompost produced significant increases in aerial and root biomass of the tomato plants. In addition these treatments improved significantly plant morphology (higher number of leaves and leaf area, and increased root volume and branching). The use of compost and vermicompost constitute an attractive alternative to the use of peat in plant nurseries due to the environmental benefits involved but also due to the observed improvement in plant quality. Additional key words: peat moss, plant nursery, soil-less substrate, Solanum lycopersicum L. (Author) 37 refs.

  15. Plant growth depressions in arbuscular mycorrhizal symbioses: not just caused by carbon drain?

    Science.gov (United States)

    Li, Huiying; Smith, F Andrew; Dickson, Sandy; Holloway, Robert E; Smith, Sally E

    2008-01-01

    * This study investigated effects of plant density and arbuscular mycorrhizal (AM) colonization on growth and phosphorus (P) nutrition of a cultivar of wheat (Triticum aestivum) that often shows early AM-induced growth depressions. * Two experiments were conducted. Expt 1 had three plant densities and one soil P concentration. Expt 2 had two plant densities and two P concentrations. Plants were grown in calcareous P-fixing soil, inoculated with Glomus intraradices or Gigaspora margarita, or noninoculated (nonmycorrhizal (NM)). Glomus intraradices colonized well and caused a growth depression only in Expt 1. Gigaspora margarita caused large growth depressions in both experiments even though it colonized poorly. * The results showed that growth depressions were mitigated by changes in relative competition for soil P by NM and AM plants, and probably by decreasing carbon costs of the fungi. * The different effects of the two fungi appear to be attributable to differences in the balance between P uptake by the fungal pathway and direct uptake via the roots. These differences may be important in other AM symbioses that result in growth depressions. The results show that mycorrhizal growth responses of plants grown singly may not apply at the population or community level.

  16. Exopolysaccharide-Producing Plant Growth-Promoting Rhizobacteria Under Salinity Condition

    Institute of Scientific and Technical Information of China (English)

    S. K. UPADHYAY; J. S. SINGH; D. P. SINGH

    2011-01-01

    Salt-tolerant plant growth-promoting rhizobacteria (PGPR) can play an important role in alleviating soil salinity stress during plant growth and bacterial exopolysaccharide (EPS) can also help to mitigate salinity stress by reducing the content of Na+ available for plant uptake. In this study, native bacterial strains of wheat rhizosphere in soils of Varanasi, India, were screened to identify the EPS-producing salt-tolerant rhizobacteria with plant growth-promoting traits. The various rhizobacteria strains were isolated and identified using 16S rDNA sequencing. The plant growth-promoting effect of inoculation of seedlings with these bacterial strains was evaluated under soil salinity conditions in a pot experiment. Eleven bacterial strains which initially showed tolerance up to 80 g L-1 NaCl also exhibited an EPS-producing potential. The results suggested that the isolated bacterial strains demonstrated some of the plant growth-promoting traits such as phosphate solubilizing ability and production of auxin, proline, reducing sugars, and total soluble sugars, Furthermore, the inoculated wheat plants had an increased biomass compared to the un-inoculated plants.

  17. The effect of Bt-transgene introgression on plant growth and reproduction in wild Brassica juncea.

    Science.gov (United States)

    Liu, Yong-Bo; Darmency, Henry; Stewart, C Neal; Wei, Wei; Tang, Zhi-Xi; Ma, Ke-Ping

    2015-06-01

    This study aims to investigate the relative plant growth and reproduction of insect-resistant and susceptible plants following the introgression of an insect-resistance Bt-transgene from Brassica napus, oilseed rape, to wild Brassica juncea. The second backcrossed generation (BC2) from a single backcross family was grown in pure and mixed stands of Bt-transgenic and non-transgenic siblings under two insect treatments. Various proportions of Bt-transgenic plants were employed in mixed stands to study the interaction between resistant and susceptible plants. In the pure stands, Bt-transgenic BC2 plants performed better than non-transgenic plants with or without insect treatments. In mixed stands, Bt-transgenic BC2 plants produced fewer seeds than their non-Bt counterparts at low proportions of Bt-transgenic BC2 plants in the absence of insects. Reproductive allocation of non-transgenic plants marginally increased with increasing proportions of Bt-transgenic plants under herbivore pressure, which resulted in increased total biomass and seed production per stand. The results showed that the growth of non-transgenic plants was protected by Bt-transgenic plants under herbivore pressure. The Bt-transgene might not be advantageous in mixed stands of backcrossed hybrids; thus transgene introgression would not be facilitated when herbivorous insects are not present. However, a relatively large initial population of Bt-transgenic plants might result in transgene persistence when target herbivores are present.

  18. Growth limitation of Lemna minor due to high plant density

    NARCIS (Netherlands)

    Driever, S.M.; Nes, van E.H.; Roijackers, R.M.M.

    2005-01-01

    The effect of high population densities on the growth rate of Lemna minor (L.) was studied under laboratory conditions at 23°C in a medium with sufficient nutrients. At high population densities, we found a non-linear decreasing growth rate with increasing L. minor density. Above a L. minor biomass

  19. Influence of water relations and growth rate on plant element uptake and distribution

    Energy Technology Data Exchange (ETDEWEB)

    Greger, Maria [Stockholm Univ. (Sweden). Dept. of Botany

    2006-02-15

    Plant uptake of Ni, Sr, Mo, Cs, La, Th, Se, Cl and I was examined to determine how plant water relations and growth rate influence the uptake and distribution of these elements in the studied plants. The specific questions were how water uptake and growth rate influenced the uptake of various nuclides and how transpiration influenced translocation to the shoot. The knowledge gained will be used in future modelling of radionuclide leakage from nuclear waste deposits entering the ecosystem via plants. The plant studied was willow, Salix viminalis, a common plant in the areas suggested for waste disposal; since there can be clone variation, two different clones having different uptake properties for several other heavy metals were used. The plants were grown in nutrient solution and the experiments on 3-month-old plants were run for 3 days. Polyethylene glycol was added to the medium to decrease the water uptake rate, a fan was used to increase the transpiration rate, and different light intensities were used to produce different growth rates. Element concentration was analysed in roots and shoots. The results show that both the uptake and distribution of various elements are influenced in different ways and to various extents by water flow and plant growth rate, and that it is not possible from the chemical properties of these elements to know how they will react. However, in most cases increased growth rate diluted the concentration of the element in the tissue, reduced water uptake reduced the element uptake, while transpiration had no effect on the translocation of elements to the shoot. The clones did not differ in terms of either the uptake or translocation of the elements, except that I was not taken up and translocated to the shoot in one of the clones when the plant water flow or growth rate was too low. Not all of the elements were found in the plant in the same proportions as they had been added to the nutrient solution.

  20. Influence of water relations and growth rate on plant element uptake and distribution

    International Nuclear Information System (INIS)

    Plant uptake of Ni, Sr, Mo, Cs, La, Th, Se, Cl and I was examined to determine how plant water relations and growth rate influence the uptake and distribution of these elements in the studied plants. The specific questions were how water uptake and growth rate influenced the uptake of various nuclides and how transpiration influenced translocation to the shoot. The knowledge gained will be used in future modelling of radionuclide leakage from nuclear waste deposits entering the ecosystem via plants. The plant studied was willow, Salix viminalis, a common plant in the areas suggested for waste disposal; since there can be clone variation, two different clones having different uptake properties for several other heavy metals were used. The plants were grown in nutrient solution and the experiments on 3-month-old plants were run for 3 days. Polyethylene glycol was added to the medium to decrease the water uptake rate, a fan was used to increase the transpiration rate, and different light intensities were used to produce different growth rates. Element concentration was analysed in roots and shoots. The results show that both the uptake and distribution of various elements are influenced in different ways and to various extents by water flow and plant growth rate, and that it is not possible from the chemical properties of these elements to know how they will react. However, in most cases increased growth rate diluted the concentration of the element in the tissue, reduced water uptake reduced the element uptake, while transpiration had no effect on the translocation of elements to the shoot. The clones did not differ in terms of either the uptake or translocation of the elements, except that I was not taken up and translocated to the shoot in one of the clones when the plant water flow or growth rate was too low. Not all of the elements were found in the plant in the same proportions as they had been added to the nutrient solution

  1. Functional compatibility in cucumber mycorrhizas in terms of plant growth performance and foliar nutrient composition.

    Science.gov (United States)

    Ravnskov, S; Larsen, J

    2016-09-01

    Functional compatibility in cucumber mycorrhizas in terms of plant and fungal growth, and foliar nutrient composition from all possible combinations of six cucumber varieties and three species of arbuscular mycorrhizal (AM) fungi was evaluated. Measurements of foliar nutrient composition included N, P, K, Mg, Ca, Na, Fe, Zn, Mn and Cu. Growth of AM fungi was measured in terms of root colonisation, as examined with microscopy and the AM fungus biomarker fatty acid 16:1ω5 from both phospholipids and neutral lipids. Different responses of plant growth and foliar nutrient profiles were observed for the different AM symbioses examined. The AM fungus Claroideoglomus claroideum caused growth depression in association with four out of six cucumber varieties; Rhizophagus irregularis caused growth promotion in one of six cucumber varieties; whereas Funneliformis mosseae had no effect on the growth performance of any of the cucumber varieties examined. All three AM fungi markedly altered host plant shoot nutrient composition, with the strongest contrast observed between cucumber-R. irregularis symbioses and non-mycorrhizal cucumber plants, independent of cucumber variety. On the other hand, AM fungal growth in roots differed between the three AM fungi, but was unaffected by host genotype. Strong build-up of storage lipids was observed for R. irregularis, which was more moderate in the two other AM fungi. In conclusion, strong differential responses of cucumber varieties to inoculation with different AM fungi in terms of growth and shoot nutrient composition revealed high functional diversity in AM symbioses in cucumber plants.

  2. The effects of invertebrate herbivores on plant population growth: a meta-regression analysis.

    Science.gov (United States)

    Katz, Daniel S W

    2016-09-01

    Over the last two decades, an increasing number of studies have quantified the effects of herbivory on plant populations using stage-structured population models and integral projection models, allowing for the calculation of plant population growth rates (λ) with and without herbivory. In this paper, I assembled 29 studies and conducted a meta-regression to determine the importance of invertebrate herbivores to population growth rates (λ) while accounting for missing data. I found that invertebrate herbivory often induced important reductions in plant population growth rates (with herbivory, λ was 1.08 ± 0.36; without herbivory, λ was 1.28 ± 0.58). This relationship tended to be weaker for seed predation than for other types of herbivory, except when seed predation rates were very high. Even so, the amount by which studies reduced herbivory was a poor predictor of differences in population growth rates-which strongly cautions against using measured herbivory rates as a proxy for the impact of herbivores. Herbivory reduced plant population growth rates significantly more when potential growth rates were high, which helps to explain why there was less variation in actual population growth rates than in potential population growth rates. The synthesis of these studies also shows the need for future studies to report variance in estimates of λ and to quantify how λ varies as a function of plant density.

  3. The effects of invertebrate herbivores on plant population growth: a meta-regression analysis.

    Science.gov (United States)

    Katz, Daniel S W

    2016-09-01

    Over the last two decades, an increasing number of studies have quantified the effects of herbivory on plant populations using stage-structured population models and integral projection models, allowing for the calculation of plant population growth rates (λ) with and without herbivory. In this paper, I assembled 29 studies and conducted a meta-regression to determine the importance of invertebrate herbivores to population growth rates (λ) while accounting for missing data. I found that invertebrate herbivory often induced important reductions in plant population growth rates (with herbivory, λ was 1.08 ± 0.36; without herbivory, λ was 1.28 ± 0.58). This relationship tended to be weaker for seed predation than for other types of herbivory, except when seed predation rates were very high. Even so, the amount by which studies reduced herbivory was a poor predictor of differences in population growth rates-which strongly cautions against using measured herbivory rates as a proxy for the impact of herbivores. Herbivory reduced plant population growth rates significantly more when potential growth rates were high, which helps to explain why there was less variation in actual population growth rates than in potential population growth rates. The synthesis of these studies also shows the need for future studies to report variance in estimates of λ and to quantify how λ varies as a function of plant density. PMID:27017603

  4. Cell wall assembly and intracellular trafficking in plant cells are directly affected by changes in the magnitude of gravitational acceleration.

    Directory of Open Access Journals (Sweden)

    Youssef Chebli

    Full Text Available Plants are able to sense the magnitude and direction of gravity. This capacity is thought to reside in selected cell types within the plant body that are equipped with specialized organelles called statoliths. However, most plant cells do not possess statoliths, yet they respond to changes in gravitational acceleration. To understand the effect of gravity on the metabolism and cellular functioning of non-specialized plant cells, we investigated a rapidly growing plant cell devoid of known statoliths and without gravitropic behavior, the pollen tube. The effects of hyper-gravity and omnidirectional exposure to gravity on intracellular trafficking and on cell wall assembly were assessed in Camellia pollen tubes, a model system with highly reproducible growth behavior in vitro. Using an epi-fluorescence microscope mounted on the Large Diameter Centrifuge at the European Space Agency, we were able to demonstrate that vesicular trafficking is reduced under hyper-gravity conditions. Immuno-cytochemistry confirmed that both in hyper and omnidirectional gravity conditions, the characteristic spatial profiles of cellulose and callose distribution in the pollen tube wall were altered, in accordance with a dose-dependent effect on pollen tube diameter. Our findings suggest that in response to gravity induced stress, the pollen tube responds by modifying cell wall assembly to compensate for the altered mechanical load. The effect was reversible within few minutes demonstrating that the pollen tube is able to quickly adapt to changing stress conditions.

  5. Super-resolution Microscopy in Plant Cell Imaging.

    Science.gov (United States)

    Komis, George; Šamajová, Olga; Ovečka, Miroslav; Šamaj, Jozef

    2015-12-01

    Although the development of super-resolution microscopy methods dates back to 1994, relevant applications in plant cell imaging only started to emerge in 2010. Since then, the principal super-resolution methods, including structured-illumination microscopy (SIM), photoactivation localization microscopy (PALM), stochastic optical reconstruction microscopy (STORM), and stimulated emission depletion microscopy (STED), have been implemented in plant cell research. However, progress has been limited due to the challenging properties of plant material. Here we summarize the basic principles of existing super-resolution methods and provide examples of applications in plant science. The limitations imposed by the nature of plant material are reviewed and the potential for future applications in plant cell imaging is highlighted.

  6. Fluorescent Probes for Exploring Plant Cell Wall Deconstruction: A Review

    Directory of Open Access Journals (Sweden)

    Gabriel Paës

    2014-07-01

    Full Text Available Plant biomass is a potential resource of chemicals, new materials and biofuels that could reduce our dependency on fossil carbon, thus decreasing the greenhouse effect. However, due to its chemical and structural complexity, plant biomass is recalcitrant to green biological transformation by enzymes, preventing the establishment of integrated bio-refineries. In order to gain more knowledge in the architecture of plant cell wall to facilitate their deconstruction, many fluorescent probes bearing various fluorophores have been devised and used successfully to reveal the changes in structural motifs during plant biomass deconstruction, and the molecular interactions between enzymes and plant cell wall polymers. Fluorescent probes are thus relevant tools to explore plant cell wall deconstruction.

  7. Programmed cell death: a way of life for plants.

    OpenAIRE

    Greenberg, J T

    1996-01-01

    Cell death in higher plants has been widely observed in predictable patterns throughout development and in response to pathogenic infection. Genetic, biochemical, and morphological evidence suggests that these cell deaths occur as active processes and can be defined formally as examples of programmed cell death (PCD). Intriguingly, plants have at least two types of PCD, an observation that is also true of PCD in animals [Schwartz, L. M., Smith, W.W., Jones, M. E. E. & Osborne, B. A. (1993) Pr...

  8. Integrated LED/Imaging Illumination Panels Demonstrated within a Small Plant Growth Chamber Project

    Data.gov (United States)

    National Aeronautics and Space Administration — LED light sources are ideal for plant growth systems. However, commercially available multi-color LED illumination panels are designed and manufactured to produce a...

  9. Screening of Pseudomonas sp. Isolated from Rhizosphere of Soybean Plant as Plant Growth Promoter and Biocontrol Agent

    Directory of Open Access Journals (Sweden)

    Aris T. Wahyudi

    2011-01-01

    Full Text Available Problem statement: Pseudomonas spesies are one of the rihizobacterial group that have an important role in plant growth promoter and plant health. To prepare them as inoculants, they must have a range of characters as growth promoter such as Indole Acetic Acid (IAA producers which can promote the growth of plants and solubilize phosphates. In addition, they must also have the various characters that act as biocontrol agents such as siderofor, chitinase and anti-fungal compound producers. Approach: Pseudomonas sp isolated from soybeans rhizospere and identified based on physiological reactions and 16S rRNA gene sequences. Various tests for the determination of the growth promoter were based on IAA production, phosphate solubilization and growth promoter of length of root and stems and number of lateral roots of soybean sprouts. Test of siderophore, chitinase, as well as anti anti-fungal compounds productions to inhibit the growth of Fusarium oxysporum, Rhizoctonia solani and Sclerotium rolfsii, were used as a biocontrol agent determination. Hypersensitivity test was used to screen for Pseudomonas sp classified as non-pathogenic rhizobacteria. Results: Fourteen isolates identified as a non-pathogenic Pseudomonas sp that produced IAA and Promoted enhancement of root length, shoot length, or number of lateral root. Among those 14 isolates, 8 isolates showed phosphate solubilizing activity, 12 isolates capable of producing siderophore and six isolates were observed to have chitinolytic activity. Only three isolates were able to inhibit the growth of Fusarium oxysporum in high level. While one and two isolates inhibited Sclerotium rolfsii and Rhizoctonia solani in high level, respectively. Conclusion: On the basis of excellent growth promoter and biocontrol activities, we recommended 5 isolates of Pseudomonas sp which were Crb-3, Crb-16, Crb-17, Crb-44 and Crb-94 as potential isolates of Pseudomonas sp that could be applied as

  10. Citric acid enhances the phytoextraction of manganese and plant growth by alleviating the ultrastructural damages in Juncus effusus L

    Energy Technology Data Exchange (ETDEWEB)

    Najeeb, U.; Xu, L.; Ali, Shafaqat [Institute of Crop Science, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310029 (China); Jilani, Ghulam, E-mail: jilani@uaar.edu.pk [Department of Soil Science, Pir Mehr Ali Shah Arid Agriculture University, Rawalpindi, Punjab 46300 (Pakistan); Gong, H.J. [Institute of Crop Science, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310029 (China); Shen, W.Q. [The University of Nottingham at Ningbo, Ningbo 315100 (China); Zhou, W.J., E-mail: wjzhou@zju.edu.cn [Institute of Crop Science, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310029 (China)

    2009-10-30

    Chelate-assisted phytoextraction by high biomass producing plant species enhances the removal of heavy metals from polluted environments. In this regard, Juncus effusus a wetland plant has great potential. This study evaluated the effects of elevated levels of manganese (Mn) on the vegetative growth, Mn uptake and antioxidant enzymes in J. effusus. We also studied the role of citric acid and EDTA on improving metal accumulation, plant growth and Mn toxicity stress alleviation. Three-week-old plantlets of J. effusus were subjected to various treatments in the hydroponics as: Mn (50, 100 and 500 {mu}M) alone, Mn (500 {mu}M) + citric acid (5 mM), and Mn (500 {mu}M) + EDTA (5 mM). After 2 weeks of treatment, higher Mn concentrations significantly reduced the plant biomass and height. Both citric acid and EDTA restored the plant height as it was reduced at the highest Mn level. Only the citric acid (but not EDTA) was able to recover the plant biomass weight, which was also obvious from the microscopic visualization of mesophyll cells. There was a concentration dependent increase in Mn uptake in J. effusus plants, and relatively more deposition in roots compared to aerial parts. Although both EDTA and citric acid caused significant increase in Mn accumulation; however, the Mn translocation was enhanced markedly by EDTA. Elevated levels of Mn augmented the oxidative stress, which was evident from changes in the activities of antioxidative enzymes in plant shoots. Raised levels of lipid peroxidation and variable changes in the activities of antioxidant enzymes were recorded under Mn stress. Electron microscopic images revealed several modifications in the plants at cellular and sub-cellular level due to the oxidative damage induced by Mn. Changes in cell shape and size, chloroplast swelling, increased number of plastoglobuli and disruption of thylakoid were noticed. However, these plants showed a high degree of tolerance against Mn toxicity stress, and it removed

  11. The effect of plant growth regulators on height control in potted Arundina graminifolia orchids (Growth regulators in Arundina graminifolia

    Directory of Open Access Journals (Sweden)

    Christina da Silva Wanderley

    2014-08-01

    Full Text Available Orchids have become an important portion of the international floriculture market.  Arundina graminifolia is a terrestrial orchid that produces attractive flowers, and, although the species could be a potential candidate for the floriculture market, its considerable height makes it difficult to transport and commercialize.  A number of plant growth regulators have been utilized to control plant height in ornamentals and other species.  Thus, the aim of this study was to evaluate the efficiency of growth regulators, paclobutrazol and chlormequat chloride on the vegetative development of containerized A. graminifolia orchid aiming at height control.  Paclobutrazol (Cultar was applied at 0, 5, 10, and 20 mg L-1, and CCC (Cycocel was applied at 0, 2000, 4000, and 6000 mg L-1. The plants were assessed monthly for the plant height and number of shoots per container. CCC had no effect on the final height of plants at the concentrations applied. In contrast, paclobutrazol was effective in controlling plant height at a concentration of 5 mg L-1, but higher concentrations (10 and 20 mg L-1 proved to be toxic to the plants, causing death to the new shoots. Paclobutrazol at lower concentrations offers a viable means for height control in A. graminifolia.

  12. Bromeliad-living spiders improve host plant nutrition and growth.

    Science.gov (United States)

    Romero, Gustavo Q; Mazzafera, Paulo; Vasconcellos-Neto, Joao; Trivelin, Paulo C O

    2006-04-01

    Although bromeliads are believed to obtain nutrients from debris deposited by animals in their rosettes, there is little evidence to support this assumption. Using stable isotope methods, we found that the Neotropical jumping spider Psecas chapoda (Salticidae), which lives strictly associated with the terrestrial bromeliad Bromelia balansae, contributed 18% of the total nitrogen of its host plant in a greenhouse experiment. In a one-year field experiment, plants with spiders produced leaves 15% longer than plants from which the spiders were excluded. This is the first study to show nutrient provisioning in a spider-plant system. Because several animal species live strictly associated with bromeliad rosettes, this type of facultative mutualism involving the Bromeliaceae may be more common than previously thought.

  13. Evaluation of absorption of radionuclides via roots of plants at different growth stages

    Energy Technology Data Exchange (ETDEWEB)

    Ambe, Shizuko [Institute of Physical and Chemical Research, Wako, Saitama (Japan)

    1999-03-01

    For the environmental risk assessment of radionuclides and toxic elements which were released by nuclear power plants and factories, the absorption of trace elements by plants has been studied by a multitracer technique. The selective absorption coefficient, which is a parameter of an uptake model of radionuclides by plants, was determined for various radionuclides. The selective absorption coefficients of some elements varied greatly in experimental runs. Therefore, the selective absorption coefficients of radionuclides by komatsuna at different growth stages were determined. Moreover, the soil-to-plant transfer of radionuclides in komatsuna at different growth stages was studied. Extraction of the radionuclides from the soil was carried out in order to study the correlation between the transfer factor and the aging effect of the radionuclides in soil. The effect of soil acidity on the absorption of radionuclides in soybean and tomato was studied using the plants at different growth stages. (author)

  14. Plant Growth-Promoting Rhizobacteria Enhance Salinity Stress Tolerance in Okra through ROS-Scavenging Enzymes.

    Science.gov (United States)

    Habib, Sheikh Hasna; Kausar, Hossain; Saud, Halimi Mohd

    2016-01-01

    Salinity is a major environmental stress that limits crop production worldwide. In this study, we characterized plant growth-promoting rhizobacteria (PGPR) containing 1-aminocyclopropane-1-carboxylate (ACC) deaminase and examined their effect on salinity stress tolerance in okra through the induction of ROS-scavenging enzyme activity. PGPR inoculated okra plants exhibited higher germination percentage, growth parameters, and chlorophyll content than control plants. Increased antioxidant enzyme activities (SOD, APX, and CAT) and upregulation of ROS pathway genes (CAT, APX, GR, and DHAR) were observed in PGPR inoculated okra plants under salinity stress. With some exceptions, inoculation with Enterobacter sp. UPMR18 had a significant influence on all tested parameters under salt stress, as compared to other treatments. Thus, the ACC deaminase-containing PGPR isolate Enterobacter sp. UPMR18 could be an effective bioresource for enhancing salt tolerance and growth of okra plants under salinity stress. PMID:26951880

  15. Isolation and identification of plant growth promoting rhizobacteria from cucumber rhizosphere and their effect on plant growth promotion and disease suppression

    Directory of Open Access Journals (Sweden)

    Shaikhul eIslam

    2016-02-01

    Full Text Available Plant growth promoting rhizobacteria (PGPR are the rhizosphere bacteria that may be utilized to augment plant growth and suppress plant diseases. The objectives of this study were to identify and characterize PGPR indigenous to cucumber rhizosphere in Bangladesh, and to evaluate their ability to suppress Phytophthora crown rot in cucumber. A total of sixty six isolates were isolated, out of which ten (PPB1, PPB2, PPB3, PPB4, PPB5, PPB8, PPB9, PPB10, PPB11 and PPB12 were selected based on their in vitro plant growth promoting attributes and antagonism of phytopathogens. Phylogenetic analysis of 16S rRNA sequences identified these isolates as new strains of Pseudomonas stutzeri, Bacillus subtilis, Stenotrophomonas maltophilia and B. amyloliquefaciens. The selected isolates produced high levels (26.78 to 51.28 μg mL−1 of indole-3-acetic acid, while significant acetylene reduction activities (1.79 to 4.9 µmole C2H4 mg-1 protein h-1 were observed in eight isolates. Cucumber plants grown from seeds that were treated with these PGPR strains displayed significantly higher levels of germination, seedling vigor, growth, and N content in root and shoot tissue compared to non-treated control plants. All selected isolates were able to successfully colonize the cucumber roots. Moreover, treating cucumber seeds with these isolates significantly suppressed Phytophthora crown rot caused by Phytophthora capsici, and characteristic morphological alterations in Ph. capsici hyphae that grew towards PGPR colonies were observed. Since these PGPR inoculants exhibited multiple traits beneficial to the host plants, they may be applied in the development of new, safe, and effective seed treatments as an alternative to chemical fungicides.

  16. Contrasting growth responses of dominant peatland plants to warming and vegetation composition.

    Science.gov (United States)

    Walker, Tom N; Ward, Susan E; Ostle, Nicholas J; Bardgett, Richard D

    2015-05-01

    There is growing recognition that changes in vegetation composition can strongly influence peatland carbon cycling, with potential feedbacks to future climate. Nevertheless, despite accelerated climate and vegetation change in this ecosystem, the growth responses of peatland plant species to combined warming and vegetation change are unknown. Here, we used a field warming and vegetation removal experiment to test the hypothesis that dominant species from the three plant functional types present (dwarf-shrubs: Calluna vulgaris; graminoids: Eriophorum vaginatum; bryophytes: Sphagnum capillifolium) contrast in their growth responses to warming and the presence or absence of other plant functional types. Warming was accomplished using open top chambers, which raised air temperature by approximately 0.35 °C, and we measured air and soil microclimate as potential mechanisms through which both experimental factors could influence growth. We found that only Calluna growth increased with experimental warming (by 20%), whereas the presence of dwarf-shrubs and bryophytes increased growth of Sphagnum (46%) and Eriophorum (20%), respectively. Sphagnum growth was also negatively related to soil temperature, which was lower when dwarf-shrubs were present. Dwarf-shrubs may therefore promote Sphagnum growth by cooling the peat surface. Conversely, the effect of bryophyte presence on Eriophorum growth was not related to any change in microclimate, suggesting other factors play a role. In conclusion, our findings reveal contrasting abiotic and biotic controls over dominant peatland plant growth, suggesting that community composition and carbon cycling could be modified by simultaneous climate and vegetation change. PMID:25687830

  17. Incorporation of mammalian actin into microfilaments in plant cell nucleus

    Directory of Open Access Journals (Sweden)

    Paves Heiti

    2004-04-01

    Full Text Available Abstract Background Actin is an ancient molecule that shows more than 90% amino acid homology between mammalian and plant actins. The regions of the actin molecule that are involved in F-actin assembly are largely conserved, and it is likely that mammalian actin is able to incorporate into microfilaments in plant cells but there is no experimental evidence until now. Results Visualization of microfilaments in onion bulb scale epidermis cells by different techniques revealed that rhodamine-phalloidin stained F-actin besides cytoplasm also in the nuclei whereas GFP-mouse talin hybrid protein did not enter the nuclei. Microinjection of fluorescently labeled actin was applied to study the presence of nuclear microfilaments in plant cells. Ratio imaging of injected fluorescent rabbit skeletal muscle actin and phalloidin staining of the microinjected cells showed that mammalian actin was able to incorporate into plant F-actin. The incorporation occurred preferentially in the nucleus and in the perinuclear region of plant cells whereas part of plant microfilaments, mostly in the periphery of cytoplasm, did not incorporate mammalian actin. Conclusions Microinjected mammalian actin is able to enter plant cell's nucleus, whereas incorporation of mammalian actin into plant F-actin occurs preferentially in the nucleus and perinuclear area.

  18. Different Degree in Proteasome Malfunction Has Various Effects on Root Growth Possibly through Preventing Cell Division and Promoting Autophagic Vacuolization

    OpenAIRE

    Xianyong Sheng; Qian Wei; Liping Jiang; Xue Li; Yuan Gao; Li Wang

    2012-01-01

    The ubiquitin/proteasome pathway plays a vital role in plant development. But the effects of proteasome malfunction on root growth, and the mechanism underlying this involvement remains unclear. In the present study, the effects of proteasome inhibitors on Arabidopsis root growth were studied through the analysis of the root length, and meristem size and cell length in maturation zone using FM4-64, and cell-division potential using GFP fusion cyclin B, and accumulation of ubiquitinated protei...

  19. Plant root growth and the marginal value theorem

    OpenAIRE

    McNickle, Gordon G.; Cahill, James F.

    2009-01-01

    All organisms must find and consume resources to live, and the strategies an organism uses when foraging can have significant impacts on their fitness. Models assuming optimality in foraging behavior, and which quantitatively account for the costs, benefits, and biological constraints of foraging, are common in the animal literature. Plant ecologists on the other hand have rarely adopted an explicit framework of optimality with respect to plant root foraging. Here, we show with a simple exper...

  20. PECULIARITIES OF SECONDARY METABOLITES BIOSYNTHESIS IN PLANT CELL CULTURES

    Directory of Open Access Journals (Sweden)

    A.M. NOSOV

    2014-06-01

    Full Text Available metabolites formation in plant cell cultures of Panax spp., (ginsenosides; Dioscorea deltoidea (steroid glycosides; Ajuga reptans, Serratula coronata, Rhaponticum carthamoides (ecdisteroids; Polyscias spp., (triterpene glycosides, Taxus spp. (taxoids, Stevia rebaudiana (diterpene steviol-glycosides, Stephania glabra (alkaloids. They are some regular trends of secondary metabolites synthesis in the plant cell culture:It can be noted the stable synthesis of the compound promoting cell proliferation. Indeed, cell cultures of Dioscorea deltoidea were demonstrated to accumulate only furostanol glycosides, which promoted cell division. Furostanol glycoside content of Dioscorea strain DM-0.5 was up to 6 - 12% by dry biomass.Panax ginseng and P. japonicus plant cell cultures synthesize as minimum seven triterpene glycosides (ginsenosides, the productivity of these compounds was up to 6.0 - 8.0% on dry biomass.By contrast, the detectable synthesis of diterpene steviol-glycosides in cultivated cells of Stevia rebaudiana initiated in the mixotrophic cultures during chloroplast formation only.Despite these differences, or mainly due to them, plant cell cultures have become an attractive source of phytochemicals in alternative to collecting wild plants. It provides a guideline to bioreactor-based production of isoprenoids using undifferentiated plant cell cultures. 

  1. Increasing cellulose production and transgenic plant growth in forest tree species

    Institute of Scientific and Technical Information of China (English)

    TANG Wei; Aaron Nelson; Emmanuel Johnson

    2005-01-01

    Cellulose is one of many important polymers in plants. Cellulose is made of repeat units of the monomer glucose. Cellulose is a major industrial biopolymer in the forest products, textile, and chemical industries. It also forms a large portion of the biomass useful in the generation of energy. Moreover, cellulose-based biomass is a renewable energy source that can be used for the generation of ethanol as a fuel. Cellulose is synthesized by a variety of living organisms such as plants and algae. It is the major component of plant cell walls with secondary cell walls having a much higher content of cellulose. The relationship between cellulose and lignin biosynthesis is complicated, but it is confirmed that inhibition of lignin biosynthesis in transgenic trees will increase cellulose biosynthesis and plant growth. Cellulose accumulation may be increased by down-regulating 4-coumarate:coenzyme A ligase (4CL, EC 6.2.1.12) as shown in transgenic aspen. There is no similar reports on down-regulating 4CL in transgenic conifers. Based on our established Agrobacterium tumefaciens-mediated transformation system in loblolly pine, we are able to produce antisense 4-CL transgenic loblolly pine which is predicted to have increasing cellulose accumulation. The overall objective of this project is to genetically engineer forest tree species such as loblolly pine with reduced amount of lignin and increased cellulose content. The research strategy includes: (1) isolate the 4-coumarate:coenzyme A ligase gene from loblolly pine seedlings by reverse transcription-polymerase chain reaction (RT-PCR) and Rapid Amplification of cDNA Ends-Polymerase Chain Reaction (RACE-PCR) techniques from the cDNA library; (2) construct binary expression vectors with antisense 4CL coding sequences and introduce antisense constructs of the 4-coumarate:coenzyme A ligase gene cloned from loblolly pine into the loblolly pine to down regulate the 4-coumarate:coenzyme A ligase gene expression; (3) study the

  2. [Transfer of T-DNA from agrobacteria into plant cells through cell walls and membranes].

    Science.gov (United States)

    Chumakov, M I

    2001-01-01

    Discusses probable routes of agrobacterial penetration through the plant integumental tissues, cell wall, and plant cell plasmodesma. Analyzes the contribution of extracellular structures of agrobacteria in penetration through barriers of a plant cell, primary contact (adhesion), and during DNA transfer from bacterial (E. coli, A. tumefaciens) to recipient (bacterial or plant) cells. Discusses the relationship between donor cell adhesion to recipient cell surface and the infectious and conjugation processes. Considers the probable role of piles in conjugative transfer of agrobacterial DNA through membranes of donor and recipient (bacterial and plant) cells. Analyzes the contribution of the plant cell cytoskeleton to T-DNA transfer. Suggests a model of transport of T-DNA-VirD2 complex and VirE2 proteins through independent channels consisting of vir-coded proteins. PMID:11236737

  3. Stem-Cell-Triggered Immunity Safeguards Cytokinin Enriched Plant Shoot Apexes from Pathogen Infection

    Directory of Open Access Journals (Sweden)

    Thomas eDandekar

    2014-10-01

    Full Text Available Intricate mechanisms discriminate between friends and foes in plants. Plant organs deploy overlapping and distinct protection strategies. Despite vulnerability to a plethora of pathogens, the growing tips of plants grow bacteria free. The shoot apical meristem (SAM is among three stem cells niches, a self-renewable reservoir for the future organogenesis of leaf, stem and flowers. How plants safeguard this high value growth target from infections was not known until now. Recent reports find the stem cell secreted 12-amino acid peptide CLV3p (CLAVATA3 peptide is perceived by FLS2 (FLAGELLIN SENSING 2 receptor and activates the transcription of immunity and defense marker genes. No infection in the SAM of wild type plants and bacterial infection in clv3 and fls2 mutants illustrate this natural protection against infections. Cytokinins are enriched in the SAM and regulate meristem activities by their involvement in stem cell signaling networks. Auxin mediates plant susceptibility to pathogen infections while cytokinins boost plant immunity. Here, in addition to the stem-cell-triggered immunity we also highlight a potential link between cytokinin signaling and CLV3p mediated immune response in the SAM.

  4. Role of Plant Growth Promoting Rhizobacteria in Agricultural Sustainability—A Review

    OpenAIRE

    Pravin Vejan; Rosazlin Abdullah; Tumirah Khadiran; Salmah Ismail; Amru Nasrulhaq Boyce

    2016-01-01

    Plant growth promoting rhizobacteria (PGPR) shows an important role in the sustainable agriculture industry. The increasing demand for crop production with a significant reduction of synthetic chemical fertilizers and pesticides use is a big challenge nowadays. The use of PGPR has been proven to be an environmentally sound way of increasing crop yields by facilitating plant growth through either a direct or indirect mechanism. The mechanisms of PGPR include regulating hormonal and nutritional...

  5. Carrageenans from red seaweeds as promoters of growth and elicitors of defense response in plants

    OpenAIRE

    Pushp Sheel Shukla; Tudor eBorza; Critchley, Alan T; Balakrishnan ePrithiviraj

    2016-01-01

    Plants incessantly encounter abiotic and biotic stresses that limit their growth and productivity. However, conversely, plant growth can also be induced by treatments with various abiotic and biotic elicitors. Carrageenans are sulfated linear polysaccharides that represent major cellular constituents of seaweeds belonging to red algae (Rhodophyta). Recent research has unraveled the biological activity of carrageenans and of their oligomeric forms, the oligo carrageenans (OCs), as promoters of...

  6. Effect of Pesticides on Growth or Rhizobia and Their Host Plants During Symbiosis

    Institute of Scientific and Technical Information of China (English)

    B.Madhavi; C.S.ANAND; 等

    1993-01-01

    Effect of various pesticides(insecticides,fungicides and herbicides)has been studied on growth and efficiency of symbiotic properties of 3 fast growing Rhizobuium sp.under green house conditions.The results reveales adverse effects on plant growth and nitrogen fixing capactity as measured by dry weight and totoal nitrogen content of plants infected with pesticide treated Rhizobium.Of the pesticides terbicides were found to be more effective on the above parameters than the insecticides and fungicides.

  7. Response of plant growth to low calcium concentration in the nutrient solution

    OpenAIRE

    Amor, del, F.M.; Marcelis, L.F.M.

    2005-01-01

    Many studies have indicated the importance of calcium in fruit disorders. This nutrient is often applied in the nutrient solution in relatively high amounts throughout the crop season, usually without taking into account the physiological stage of the plant. Our study aimed to determine the effect of calcium supply on growth of young, vegetative tomato plants. The experiment was carried out in a growth chamber under fully controlled climate conditions. Treatments consisted of four periods of ...

  8. Circadian rhythms of hydraulic conductance and growth are enhanced by drought and improve plant performance

    OpenAIRE

    Caldeira, Cecilio Frois; Jeanguenin, Linda; Chaumont, François; Tardieu, Francois

    2014-01-01

    Supplementary information available for this article at http://www.nature.com/ncomms/2014/141105/ncomms6365/suppinfo/ncomms6365_S1.html Circadian rhythms enable plants to anticipate daily environmental variations, resulting in growth oscillations under continuous light. Because plants daily transpire up to 200% of their water content, their water status oscillates from favourable during the night to unfavourable during the day. We show that rhythmic leaf growth under continuous light is ob...

  9. Evaluation of Phytase Producing Bacteria for Their Plant Growth Promoting Activities

    OpenAIRE

    Prashant Singh; Vinod Kumar; Sanjeev Agrawal

    2014-01-01

    Bacterial inoculants are known to possess plant growth promoting abilities and have potential as liquid biofertilizer application. Four phytase producing bacterial isolates (phytase activity in the range of 0.076–0.174 U/mL), identified as Advenella species (PB-05, PB-06, and PB-10) and Cellulosimicrobium sp. PB-09, were analyzed for their plant growth promoting activities like siderophore production, IAA production, HCN production, ammonia production, phosphate solubilization, and antifungal...

  10. Comparative genomic analysis of four representative plant growth-promoting rhizobacteria in Pseudomonas

    OpenAIRE

    Shen, Xuemei; Hu, Hongbo; Peng, Huasong; Wang, Wei; Zhang, Xuehong

    2013-01-01

    Background Some Pseudomonas strains function as predominant plant growth-promoting rhizobacteria (PGPR). Within this group, Pseudomonas chlororaphis and Pseudomonas fluorescens are non-pathogenic biocontrol agents, and some Pseudomonas aeruginosa and Pseudomonas stutzeri strains are PGPR. P. chlororaphis GP72 is a plant growth-promoting rhizobacterium with a fully sequenced genome. We conducted a genomic analysis comparing GP72 with three other pseudomonad PGPR: P. fluorescens Pf-5, P. aerugi...

  11. Foaming and cell flotation in suspended plant cell cultures and the effect of chemical antifoams.

    Science.gov (United States)

    Wongsamuth, R; Doran, P M

    1994-08-01

    Foam development and stability in Atropa belladonna suspensions were investigated as a function of culture conditions. Foaming was due mainly to properties of the cell-free broth and was correlated with protein content; effects due to presence of cells increased towards the end of batch culture. Highest foam levels were measured 11 days after inoculation. Air flow rate was of major importance in determining foam volume; foam volume and stability were also strongly dependent on pH. Foam flotation of plant cells was very effective. After 30 min foaming, ca. 55% of cells were found in the foam; this increased to ca. 75% after 90 min. Polypropylene glycol 1025 and 2025, Pluronic PE 6100, and Antifoam-C emulsion were tested as chemical antifoams. Polypropylene glycol 1025 and Antifoam C at concentrations up to 600 ppm had no adverse effect on growth in shake flasks; Pluronic PE 6100 has an inhibitory effect at all levels tested. Concentrations of polypropylene glycol 2025 and Pluronic PE 6100 as low as 20 ppm reduced foam volumes by a factor of ca. 10. Addition of antifoam reduced k(L)a values in bubble-column and stirred-tank bioreactors. After operation of a stirred reactor for 2 days using Antifoam C for foam control, cell production was limited by oxygen due to the effect of antifoam on mass transfer. Theoretical analysis showed that maximum cell concentrations and biomass levels decline with increasing reactors working volume due to greater consumption of antifoam to prevent foam overflow. The results indicate that when chemical foam control is used in plant cell cultures, head-space volume and tolerable foam levels must be considered to optimize biomass production. (c) 1994 John Wiley & Sons, Inc.

  12. Foaming and cell flotation in suspended plant cell cultures and the effect of chemical antifoams.

    Science.gov (United States)

    Wongsamuth, R; Doran, P M

    1994-08-01

    Foam development and stability in Atropa belladonna suspensions were investigated as a function of culture conditions. Foaming was due mainly to properties of the cell-free broth and was correlated with protein content; effects due to presence of cells increased towards the end of batch culture. Highest foam levels were measured 11 days after inoculation. Air flow rate was of major importance in determining foam volume; foam volume and stability were also strongly dependent on pH. Foam flotation of plant cells was very effective. After 30 min foaming, ca. 55% of cells were found in the foam; this increased to ca. 75% after 90 min. Polypropylene glycol 1025 and 2025, Pluronic PE 6100, and Antifoam-C emulsion were tested as chemical antifoams. Polypropylene glycol 1025 and Antifoam C at concentrations up to 600 ppm had no adverse effect on growth in shake flasks; Pluronic PE 6100 has an inhibitory effect at all levels tested. Concentrations of polypropylene glycol 2025 and Pluronic PE 6100 as low as 20 ppm reduced foam volumes by a factor of ca. 10. Addition of antifoam reduced k(L)a values in bubble-column and stirred-tank bioreactors. After operation of a stirred reactor for 2 days using Antifoam C for foam control, cell production was limited by oxygen due to the effect of antifoam on mass transfer. Theoretical analysis showed that maximum cell concentrations and biomass levels decline with increasing reactors working volume due to greater consumption of antifoam to prevent foam overflow. The results indicate that when chemical foam control is used in plant cell cultures, head-space volume and tolerable foam levels must be considered to optimize biomass production. (c) 1994 John Wiley & Sons, Inc. PMID:18618782

  13. Organ-specific regulation of growth-defense tradeoffs by plants.

    Science.gov (United States)

    Smakowska, Elwira; Kong, Jixiang; Busch, Wolfgang; Belkhadir, Youssef

    2016-02-01

    Plants grow while also defending themselves against phylogenetically unrelated pathogens. Because defense and growth are both costly programs, a plant's success in colonizing resource-scarce environments requires tradeoffs between the two. Here, we summarize efforts aimed at understanding how plants use iterative tradeoffs to modulate differential organ growth when defenses are elicited. First, we focus on shoots to illustrate how light, in conjunction with the growth hormone gibberellin (GA) and the defense hormone jasmonic acid (JA), act to finely regulate defense and growth programs in this organ. Second, we expand on the regulation of growth-defense trade-offs in the root, a less well-studied topic despite the critical role of this organ in acquiring resources in an environment deeply entrenched with disparate populations of microbes. PMID:26802804

  14. Influence of nutrient composition and plant growth regulators on callus induction and plant regeneration in glutinous rice (Oryza sativa L.).

    Science.gov (United States)

    Duangsee, K; Bunnag, S

    2014-01-01

    The potential for callus induction and regeneration depends on nutrient composition and plant growth regulators. The aim of the present study was to investigate the effect of nutrient composition and plant growth regulators on callus induction and plant regeneration in the glutinous rice cultivar Khunvang. The effect of 2,4-D concentrations (1, 2, 3, 4 and 5 mg L(-1)) on callus induction and growth were investigated. The results revealed that the highest percentage of callus induction (97%) was observed in MS medium supplemented with 5 mg L(-1) 2,4-D under 16 h Photoperiod. The effects of casein hydrolysate concentrations of casein hydrolysate (0, 300, 500, 700 and 900 mg L(-1)) and proline (0, 300, 500, 700 and 900 mg L(-1)) on callus induction and growth of Khunvang were also observed. The results indicated that the increasing casein hydrolysate and proline concentrations did not show a significant effect on callus growth. However, proline concentration of 900 mg L(-1) yielded 85.67% of callus growth.

  15. Effect of Plant Growth Regulators on Phytoremediation of Hexachlorocyclohexane-Contaminated Soil.

    Science.gov (United States)

    Chouychai, Waraporn; Kruatrachue, Maleeya; Lee, Hung

    2015-01-01

    The influence of three plant growth regulators, indolebutyric acid (IBA), thidiazuron (TDZ) and gibberellic acid (GA3), either individually or in pair-wise combinations, on the ability of waxy corn plant to remove hexachlorocyclohexane (HCH) from contaminated soil was studied. Waxy corn seeds were immersed for 3 h in solutions of 1.0 mg/l IBA, 0.01 mg/l TDZ, 0.1 mg/l GA3, or a mixture of two of the growth regulators, and then inoculated in soil contaminated with 46.8 mg/kg HCH for 30 days. Pretreatment of corn seeds with the plant growth regulators did not enhance corn growth when compared with those immersed in distilled water (control), but the pretreatment enhanced HCH removal significantly. On day 30, HCH concentration in the bulk soil planted with corn seeds pretreated with GA3 or TDZ+GA3 decreased by 97.4% and 98.4%, respectively. In comparison, HCH removal in soil planted with non-pretreated control waxy corn seeds was only 35.7%. The effect of several growth regulator application methods was tested with 0.01 mg/l TDZ. The results showed that none of the methods, which ranged from seed immersion, watering in soil, or spraying on shoots, affected HCH removal from soil. However, the method of applying the growth regulators may affect corn growth. Watering the corn plant with TDZ in soil led to higher root fresh weight (2.2 g) and higher root dried weight (0.57 g) than the other treatments (0.2-1.7 g root fresh weight and 0.02-0.43 g root dried weight) on day 30. Varying the concentrations of GA3 did not affect the enhancement of corn growth and HCH removal on day 30. The results showed that plant growth regulators may have potential for use to enhance HCH phytoremediation.

  16. Combined inoculation of Pseudomonas fluorescens and Trichoderma harzianum for enhancing plant growth of vanilla (Vanilla planifolia).

    Science.gov (United States)

    Sandheep, A R; Asok, A K; Jisha, M S

    2013-06-15

    This study was conducted to evaluate the plant growth promoting efficiency of combined inoculation of rhizobacteria on Vanilla plants. Based on the in vitro performance of indigenous Trichoderma spp. and Pseudomonas spp., four effective antagonists were selected and screened under greenhouse experiment for their growth enhancement potential. The maximum percentage of growth enhancement were observed in the combination of Trichoderma harzianum with Pseudomonas fluorescens treatment followed by Pseudomonas fluorescens, Trichoderma harzianum, Pseudomonas putida and Trichoderma virens, respectively in decreasing order. Combined inoculation of Trichoderma harzianum and Pseudomonas fluorescens registered the maximum length of vine (82.88 cm), highest number of leaves (26.67/plant), recorded the highest fresh weight of shoots (61.54 g plant(-1)), fresh weight of roots (4.46 g plant(-1)) and dry weight of shoot (4.56 g plant(-1)) where as the highest dry weight of roots (2.0806 g plant(-1)) were achieved with treatments of Pseudomonas fluorescens. Among the inoculated strains, combined inoculation of Trichoderma harzianum and Pseudomonas fluorescens recorded the maximum nitrogen uptake (61.28 mg plant(-1)) followed by the combined inoculation of Trichoderma harzianum (std) and Pseudomonas fluorescens (std) (55.03 mg plant(-1)) and the highest phosphorus uptake (38.80 mg plant(-1)) was recorded in dual inoculation of Trichoderma harzianum and Pseudomonas fluorescens.

  17. Targeting Btk with ibrutinib inhibit gastric carcinoma cells growth

    Science.gov (United States)

    Wang, Jin Dao; Chen, Xiao Ying; Ji, Ke Wei; Tao, Feng

    2016-01-01

    Bruton’s tyrosine kinase (Btk) is a member of the Tec-family non-receptor tyrosine kinases family. It has previously been reported to be expressed in B cells and has an important role in B-cell malignancies. While the roles of Btk in the pathogenesis of certain B-cell malignancies are well established, the functions of Btk in gastric carcinoma have never been investigated. Herein, we found that Btk is over-expressed in gastric carcinoma tissues and gastric cancer cells. Knockdown of Btk expression selectively inhibits the growth of gastric cancer cells, but not that of the normal gastric mucosa epithelial cell, which express very little Btk. Inhibition of Btk by its inhibitor ibrutinib has an additive inhibitory effect on gastric cancer cell growth. Treatment of gastric cancer cells, but not immortalized breast epithelial cells with ibrutinib results in effective cell killing, accompanied by the attenuation of Btk signals. Ibrutinib also induces apoptosis in gastric carcinoma cells as well as is a chemo-sensitizer for docetaxel (DTX), a standard of care for gastric carcinoma patients. Finally, ibrutinib markedly reduces tumor growth and increases tumor cell apoptosis in the tumors formed in mice inoculated with the gastric carcinoma cells. Given these promising preclinical results for ibrutinib in gastric carcinoma, a strategy combining Btk inhibitor warrants attention in gastric cancer. PMID:27508020

  18. Pre-sowing magnetic treatments of tomato seeds increase the growth and yield of plants.

    Science.gov (United States)

    De Souza, A; Garcí, D; Sueiro, L; Gilart, F; Porras, E; Licea, L

    2006-05-01

    The effects of pre-sowing magnetic treatments on growth and yield of tomato (cv Campbell-28) were investigated under field conditions. Tomato seeds were exposed to full-wave rectified sinusoidal non-uniform magnetic fields (MFs) induced by an electromagnet at 100 mT (rms) for 10 min and at 170 mT (rms) for 3 min. Non-treated seeds were considered as controls. Plants were grown in experimental plots (30.2 m(2)) and were cultivated according to standard agricultural practices. During the vegetative and generative growth stages, samples were collected at regular intervals for growth rate analyses, and the resistance of plants to geminivirus and early blight was evaluated. At physiological maturity, the plants were harvested from each plot and the yield and yield parameters were determined. In the vegetative stage, the treatments led to a significant increase in leaf area, leaf dry weight, and specific leaf area (SLA) per plant. Also, the leaf, stem, and root relative growth rates of plants derived from magnetically treated seeds were greater than those shown by the control plants. In the generative stage, leaf area per plant and relative growth rates of fruits from plants from magnetically exposed seeds were greater than those of the control plant fruits. At fruit maturity stage, all magnetic treatments increased significantly (P magnetically treated seeds than that of the controls. A significant delay in the appearance of first symptoms of geminivirus and early blight and a reduced infection rate of early blight were observed in the plants from exposed seeds to MFs. Pre-sowing magnetic treatments would enhance the growth and yield of tomato crop. PMID:16511881

  19. Catalase regulates cell growth in HL60 human promyelocytic cells: evidence for growth regulation by H(2)O(2).

    Science.gov (United States)

    Hachiya, Misao; Akashi, Makoto

    2005-03-01

    Reactive oxygen species (ROS) including hydrogen peroxide (H(2)O(2)) are generated constitutively in mammalian cells. Because of its relatively long life and high permeability across membranes, H(2)O(2) is thought to be an important second messenger. Generation of H(2)O(2) is increased in response to external insults, including radiation. Catalase is located at the peroxisome and scavenges H(2)O(2). In this study, we investigated the role of catalase in cell growth using the H(2)O(2)-resistant variant HP100-1 of human promyelocytic HL60 cells. HP100-1 cells had an almost 10-fold higher activity of catalase than HL60 cells without differences in levels of glutathione peroxidase, manganese superoxide dismutase (MnSOD), and copper-zinc SOD (CuZnSOD). HP100-1 cells had higher proliferative activity than HL60 cells. Treatment with catalase or the introduction of catalase cDNA into HL60 cells stimulated cell growth. Exposure of HP100-1 cells to a catalase inhibitor resulted in suppression of cell growth with concomitant increased levels of intracellular H(2)O(2). Moreover, exogenously added H(2)O(2) or depletion of glutathione suppressed cell growth in HL60 cells. Extracellular signal regulated kinase 1/2 (ERK1/2) was constitutively phosphorylated in HP100-1 cells but not in HL60 cells. Inhibition of the ERK1/2 pathway suppressed the growth of HP100-1 cells, but inhibition of p38 mitogen-activated protein kinase (p38MAPK) did not affect growth. Moreover, inhibition of catalase blocked the phosphorylation of ERK1/2 but not of p38MAPK in HP100-1 cells. Thus our results suggest that catalase activates the growth of HL60 cells through dismutation of H(2)O(2), leading to activation of the ERK1/2 pathway; H(2)O(2) is an important regulator of growth in HL60 cells.

  20. Purification and cultivation of human pituitary growth hormone secreting cells

    Science.gov (United States)

    Hymer, W. C.

    1984-01-01

    A multiphase study was conducted to examine the properties of growth hormone cells. Topics investigated included: (1) to determine if growth hormone (GH) cells contained within the rat pituitary gland can be separated from the other hormone producing cell types by continuous flow electrophoresis (CFE); (2) to determine what role, if any, gravity plays in the electrophoretic separation of GH cells; (3) to compare in vitro GH release from rat pituitary cells previously exposed to microgravity conditions vs release from cells not exposed to microgravity; (4) to determine if the frequency of different hormone producing pituitary cell types contained in cell suspensions can be quantitated by flow cytometry; and (5) to determine if GH contained within the human post mortem pituitary gland can be purified by CFE. Specific experimental procedures and results are included.